From f01ef40af37f7107f9a07ec2d2bf8b4b1a0bdf0b Mon Sep 17 00:00:00 2001 From: Sauyon Lee Date: Thu, 9 Jan 2020 10:54:57 -0800 Subject: [PATCH 1/2] Update golang.org/x/tools dependency --- go.mod | 2 +- go.sum | 11 +- .../x/tools/benchmark/parse/parse.go | 131 + vendor/golang.org/x/tools/blog/atom/atom.go | 61 + .../x/tools/container/intsets/popcnt_amd64.go | 20 + .../x/tools/container/intsets/popcnt_amd64.s | 30 + .../x/tools/container/intsets/popcnt_gccgo.go | 9 + .../tools/container/intsets/popcnt_gccgo_c.c | 19 + .../tools/container/intsets/popcnt_generic.go | 33 + .../x/tools/container/intsets/sparse.go | 1091 ++++++++ .../x/tools/container/intsets/util.go | 84 + .../x/tools/go/ast/astutil/enclosing.go | 627 +++++ .../x/tools/go/ast/astutil/imports.go | 481 ++++ .../x/tools/go/ast/astutil/rewrite.go | 477 ++++ .../golang.org/x/tools/go/ast/astutil/util.go | 14 + .../x/tools/go/buildutil/allpackages.go | 198 ++ .../x/tools/go/buildutil/fakecontext.go | 109 + .../x/tools/go/buildutil/overlay.go | 103 + .../golang.org/x/tools/go/buildutil/tags.go | 75 + .../golang.org/x/tools/go/buildutil/util.go | 212 ++ .../x/tools/go/callgraph/callgraph.go | 129 + .../x/tools/go/callgraph/cha/cha.go | 139 + .../x/tools/go/callgraph/rta/rta.go | 459 ++++ .../x/tools/go/callgraph/static/static.go | 35 + .../golang.org/x/tools/go/callgraph/util.go | 181 ++ .../golang.org/x/tools/go/internal/cgo/cgo.go | 220 ++ .../x/tools/go/internal/cgo/cgo_pkgconfig.go | 39 + .../tools/go/internal/packagesdriver/sizes.go | 17 +- vendor/golang.org/x/tools/go/loader/doc.go | 204 ++ vendor/golang.org/x/tools/go/loader/loader.go | 1086 ++++++++ vendor/golang.org/x/tools/go/loader/util.go | 124 + vendor/golang.org/x/tools/go/packages/doc.go | 3 +- .../x/tools/go/packages/external.go | 7 +- .../golang.org/x/tools/go/packages/golist.go | 169 +- .../x/tools/go/packages/loadmode_string.go | 57 + .../x/tools/go/packages/packages.go | 15 +- vendor/golang.org/x/tools/go/pointer/TODO | 33 + .../golang.org/x/tools/go/pointer/analysis.go | 452 ++++ vendor/golang.org/x/tools/go/pointer/api.go | 285 ++ .../x/tools/go/pointer/callgraph.go | 61 + .../x/tools/go/pointer/constraint.go | 149 ++ vendor/golang.org/x/tools/go/pointer/doc.go | 610 +++++ vendor/golang.org/x/tools/go/pointer/gen.go | 1325 +++++++++ vendor/golang.org/x/tools/go/pointer/hvn.go | 973 +++++++ .../x/tools/go/pointer/intrinsics.go | 361 +++ .../golang.org/x/tools/go/pointer/labels.go | 152 ++ vendor/golang.org/x/tools/go/pointer/opt.go | 132 + vendor/golang.org/x/tools/go/pointer/print.go | 43 + vendor/golang.org/x/tools/go/pointer/query.go | 221 ++ .../golang.org/x/tools/go/pointer/reflect.go | 1975 ++++++++++++++ vendor/golang.org/x/tools/go/pointer/solve.go | 370 +++ vendor/golang.org/x/tools/go/pointer/util.go | 313 +++ vendor/golang.org/x/tools/go/ssa/blockopt.go | 187 ++ vendor/golang.org/x/tools/go/ssa/builder.go | 2382 +++++++++++++++++ vendor/golang.org/x/tools/go/ssa/const.go | 169 ++ vendor/golang.org/x/tools/go/ssa/create.go | 270 ++ vendor/golang.org/x/tools/go/ssa/doc.go | 125 + vendor/golang.org/x/tools/go/ssa/dom.go | 341 +++ vendor/golang.org/x/tools/go/ssa/emit.go | 468 ++++ vendor/golang.org/x/tools/go/ssa/func.go | 691 +++++ vendor/golang.org/x/tools/go/ssa/identical.go | 7 + .../golang.org/x/tools/go/ssa/identical_17.go | 7 + vendor/golang.org/x/tools/go/ssa/lift.go | 653 +++++ vendor/golang.org/x/tools/go/ssa/lvalue.go | 120 + vendor/golang.org/x/tools/go/ssa/methods.go | 239 ++ vendor/golang.org/x/tools/go/ssa/mode.go | 100 + vendor/golang.org/x/tools/go/ssa/print.go | 431 +++ vendor/golang.org/x/tools/go/ssa/sanity.go | 532 ++++ vendor/golang.org/x/tools/go/ssa/source.go | 293 ++ vendor/golang.org/x/tools/go/ssa/ssa.go | 1695 ++++++++++++ .../golang.org/x/tools/go/ssa/ssautil/load.go | 175 ++ .../x/tools/go/ssa/ssautil/switch.go | 234 ++ .../x/tools/go/ssa/ssautil/visit.go | 79 + vendor/golang.org/x/tools/go/ssa/testmain.go | 273 ++ vendor/golang.org/x/tools/go/ssa/util.go | 119 + vendor/golang.org/x/tools/go/ssa/wrappers.go | 290 ++ .../x/tools/go/types/typeutil/callee.go | 46 + .../x/tools/go/types/typeutil/imports.go | 31 + .../x/tools/go/types/typeutil/map.go | 313 +++ .../tools/go/types/typeutil/methodsetcache.go | 72 + .../x/tools/go/types/typeutil/ui.go | 52 + .../x/tools/internal/gopathwalk/walk.go | 5 +- .../golang.org/x/tools/internal/span/parse.go | 100 - .../golang.org/x/tools/internal/span/span.go | 285 -- .../golang.org/x/tools/internal/span/token.go | 151 -- .../x/tools/internal/span/token111.go | 39 - .../x/tools/internal/span/token112.go | 16 - .../golang.org/x/tools/internal/span/uri.go | 152 -- .../golang.org/x/tools/internal/span/utf16.go | 94 - vendor/golang.org/x/tools/present/args.go | 228 ++ vendor/golang.org/x/tools/present/caption.go | 22 + vendor/golang.org/x/tools/present/code.go | 267 ++ vendor/golang.org/x/tools/present/doc.go | 261 ++ vendor/golang.org/x/tools/present/html.go | 31 + vendor/golang.org/x/tools/present/iframe.go | 48 + vendor/golang.org/x/tools/present/image.go | 53 + vendor/golang.org/x/tools/present/link.go | 100 + vendor/golang.org/x/tools/present/parse.go | 568 ++++ vendor/golang.org/x/tools/present/style.go | 167 ++ vendor/golang.org/x/tools/present/video.go | 54 + vendor/modules.txt | 19 +- 101 files changed, 26198 insertions(+), 982 deletions(-) create mode 100644 vendor/golang.org/x/tools/benchmark/parse/parse.go create mode 100644 vendor/golang.org/x/tools/blog/atom/atom.go create mode 100644 vendor/golang.org/x/tools/container/intsets/popcnt_amd64.go create mode 100644 vendor/golang.org/x/tools/container/intsets/popcnt_amd64.s create mode 100644 vendor/golang.org/x/tools/container/intsets/popcnt_gccgo.go create mode 100644 vendor/golang.org/x/tools/container/intsets/popcnt_gccgo_c.c create mode 100644 vendor/golang.org/x/tools/container/intsets/popcnt_generic.go create mode 100644 vendor/golang.org/x/tools/container/intsets/sparse.go create mode 100644 vendor/golang.org/x/tools/container/intsets/util.go create mode 100644 vendor/golang.org/x/tools/go/ast/astutil/enclosing.go create mode 100644 vendor/golang.org/x/tools/go/ast/astutil/imports.go create mode 100644 vendor/golang.org/x/tools/go/ast/astutil/rewrite.go create mode 100644 vendor/golang.org/x/tools/go/ast/astutil/util.go create mode 100644 vendor/golang.org/x/tools/go/buildutil/allpackages.go create mode 100644 vendor/golang.org/x/tools/go/buildutil/fakecontext.go create mode 100644 vendor/golang.org/x/tools/go/buildutil/overlay.go create mode 100644 vendor/golang.org/x/tools/go/buildutil/tags.go create mode 100644 vendor/golang.org/x/tools/go/buildutil/util.go create mode 100644 vendor/golang.org/x/tools/go/callgraph/callgraph.go create mode 100644 vendor/golang.org/x/tools/go/callgraph/cha/cha.go create mode 100644 vendor/golang.org/x/tools/go/callgraph/rta/rta.go create mode 100644 vendor/golang.org/x/tools/go/callgraph/static/static.go create mode 100644 vendor/golang.org/x/tools/go/callgraph/util.go create mode 100644 vendor/golang.org/x/tools/go/internal/cgo/cgo.go create mode 100644 vendor/golang.org/x/tools/go/internal/cgo/cgo_pkgconfig.go create mode 100644 vendor/golang.org/x/tools/go/loader/doc.go create mode 100644 vendor/golang.org/x/tools/go/loader/loader.go create mode 100644 vendor/golang.org/x/tools/go/loader/util.go create mode 100644 vendor/golang.org/x/tools/go/packages/loadmode_string.go create mode 100644 vendor/golang.org/x/tools/go/pointer/TODO create mode 100644 vendor/golang.org/x/tools/go/pointer/analysis.go create mode 100644 vendor/golang.org/x/tools/go/pointer/api.go create mode 100644 vendor/golang.org/x/tools/go/pointer/callgraph.go create mode 100644 vendor/golang.org/x/tools/go/pointer/constraint.go create mode 100644 vendor/golang.org/x/tools/go/pointer/doc.go create mode 100644 vendor/golang.org/x/tools/go/pointer/gen.go create mode 100644 vendor/golang.org/x/tools/go/pointer/hvn.go create mode 100644 vendor/golang.org/x/tools/go/pointer/intrinsics.go create mode 100644 vendor/golang.org/x/tools/go/pointer/labels.go create mode 100644 vendor/golang.org/x/tools/go/pointer/opt.go create mode 100644 vendor/golang.org/x/tools/go/pointer/print.go create mode 100644 vendor/golang.org/x/tools/go/pointer/query.go create mode 100644 vendor/golang.org/x/tools/go/pointer/reflect.go create mode 100644 vendor/golang.org/x/tools/go/pointer/solve.go create mode 100644 vendor/golang.org/x/tools/go/pointer/util.go create mode 100644 vendor/golang.org/x/tools/go/ssa/blockopt.go create mode 100644 vendor/golang.org/x/tools/go/ssa/builder.go create mode 100644 vendor/golang.org/x/tools/go/ssa/const.go create mode 100644 vendor/golang.org/x/tools/go/ssa/create.go create mode 100644 vendor/golang.org/x/tools/go/ssa/doc.go create mode 100644 vendor/golang.org/x/tools/go/ssa/dom.go create mode 100644 vendor/golang.org/x/tools/go/ssa/emit.go create mode 100644 vendor/golang.org/x/tools/go/ssa/func.go create mode 100644 vendor/golang.org/x/tools/go/ssa/identical.go create mode 100644 vendor/golang.org/x/tools/go/ssa/identical_17.go create mode 100644 vendor/golang.org/x/tools/go/ssa/lift.go create mode 100644 vendor/golang.org/x/tools/go/ssa/lvalue.go create mode 100644 vendor/golang.org/x/tools/go/ssa/methods.go create mode 100644 vendor/golang.org/x/tools/go/ssa/mode.go create mode 100644 vendor/golang.org/x/tools/go/ssa/print.go create mode 100644 vendor/golang.org/x/tools/go/ssa/sanity.go create mode 100644 vendor/golang.org/x/tools/go/ssa/source.go create mode 100644 vendor/golang.org/x/tools/go/ssa/ssa.go create mode 100644 vendor/golang.org/x/tools/go/ssa/ssautil/load.go create mode 100644 vendor/golang.org/x/tools/go/ssa/ssautil/switch.go create mode 100644 vendor/golang.org/x/tools/go/ssa/ssautil/visit.go create mode 100644 vendor/golang.org/x/tools/go/ssa/testmain.go create mode 100644 vendor/golang.org/x/tools/go/ssa/util.go create mode 100644 vendor/golang.org/x/tools/go/ssa/wrappers.go create mode 100644 vendor/golang.org/x/tools/go/types/typeutil/callee.go create mode 100644 vendor/golang.org/x/tools/go/types/typeutil/imports.go create mode 100644 vendor/golang.org/x/tools/go/types/typeutil/map.go create mode 100644 vendor/golang.org/x/tools/go/types/typeutil/methodsetcache.go create mode 100644 vendor/golang.org/x/tools/go/types/typeutil/ui.go delete mode 100644 vendor/golang.org/x/tools/internal/span/parse.go delete mode 100644 vendor/golang.org/x/tools/internal/span/span.go delete mode 100644 vendor/golang.org/x/tools/internal/span/token.go delete mode 100644 vendor/golang.org/x/tools/internal/span/token111.go delete mode 100644 vendor/golang.org/x/tools/internal/span/token112.go delete mode 100644 vendor/golang.org/x/tools/internal/span/uri.go delete mode 100644 vendor/golang.org/x/tools/internal/span/utf16.go create mode 100644 vendor/golang.org/x/tools/present/args.go create mode 100644 vendor/golang.org/x/tools/present/caption.go create mode 100644 vendor/golang.org/x/tools/present/code.go create mode 100644 vendor/golang.org/x/tools/present/doc.go create mode 100644 vendor/golang.org/x/tools/present/html.go create mode 100644 vendor/golang.org/x/tools/present/iframe.go create mode 100644 vendor/golang.org/x/tools/present/image.go create mode 100644 vendor/golang.org/x/tools/present/link.go create mode 100644 vendor/golang.org/x/tools/present/parse.go create mode 100644 vendor/golang.org/x/tools/present/style.go create mode 100644 vendor/golang.org/x/tools/present/video.go diff --git a/go.mod b/go.mod index aa3e198d972..87954f47307 100644 --- a/go.mod +++ b/go.mod @@ -2,4 +2,4 @@ module github.com/Semmle/go go 1.13 -require golang.org/x/tools v0.0.0-20191030225452-7871c2d76733 +require golang.org/x/tools v0.0.0-20200109174759-ac4f524c1612 diff --git a/go.sum b/go.sum index 46256501f5a..0759dfc8c7b 100644 --- a/go.sum +++ b/go.sum @@ -1,9 +1,12 @@ golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w= +golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI= +golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg= +golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg= golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s= golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM= golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY= +golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs= golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ= -golang.org/x/tools v0.0.0-20191030225452-7871c2d76733 h1:wtYExk7epHk5WDdLiCO92FIXY5eiMtZqV1RMSLiR/3M= -golang.org/x/tools v0.0.0-20191030225452-7871c2d76733/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo= -golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7 h1:9zdDQZ7Thm29KFXgAX/+yaf3eVbP7djjWp/dXAppNCc= -golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0= +golang.org/x/tools v0.0.0-20200109174759-ac4f524c1612 h1:wRxHHuBMuDzijfZQMAgmVpDDTra91XF84qmoVTyj+U0= +golang.org/x/tools v0.0.0-20200109174759-ac4f524c1612/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28= +golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0= diff --git a/vendor/golang.org/x/tools/benchmark/parse/parse.go b/vendor/golang.org/x/tools/benchmark/parse/parse.go new file mode 100644 index 00000000000..b37e6f0f975 --- /dev/null +++ b/vendor/golang.org/x/tools/benchmark/parse/parse.go @@ -0,0 +1,131 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package parse provides support for parsing benchmark results as +// generated by 'go test -bench'. +package parse // import "golang.org/x/tools/benchmark/parse" + +import ( + "bufio" + "bytes" + "fmt" + "io" + "strconv" + "strings" +) + +// Flags used by Benchmark.Measured to indicate +// which measurements a Benchmark contains. +const ( + NsPerOp = 1 << iota + MBPerS + AllocedBytesPerOp + AllocsPerOp +) + +// Benchmark is one run of a single benchmark. +type Benchmark struct { + Name string // benchmark name + N int // number of iterations + NsPerOp float64 // nanoseconds per iteration + AllocedBytesPerOp uint64 // bytes allocated per iteration + AllocsPerOp uint64 // allocs per iteration + MBPerS float64 // MB processed per second + Measured int // which measurements were recorded + Ord int // ordinal position within a benchmark run +} + +// ParseLine extracts a Benchmark from a single line of testing.B +// output. +func ParseLine(line string) (*Benchmark, error) { + fields := strings.Fields(line) + + // Two required, positional fields: Name and iterations. + if len(fields) < 2 { + return nil, fmt.Errorf("two fields required, have %d", len(fields)) + } + if !strings.HasPrefix(fields[0], "Benchmark") { + return nil, fmt.Errorf(`first field does not start with "Benchmark"`) + } + n, err := strconv.Atoi(fields[1]) + if err != nil { + return nil, err + } + b := &Benchmark{Name: fields[0], N: n} + + // Parse any remaining pairs of fields; we've parsed one pair already. + for i := 1; i < len(fields)/2; i++ { + b.parseMeasurement(fields[i*2], fields[i*2+1]) + } + return b, nil +} + +func (b *Benchmark) parseMeasurement(quant string, unit string) { + switch unit { + case "ns/op": + if f, err := strconv.ParseFloat(quant, 64); err == nil { + b.NsPerOp = f + b.Measured |= NsPerOp + } + case "MB/s": + if f, err := strconv.ParseFloat(quant, 64); err == nil { + b.MBPerS = f + b.Measured |= MBPerS + } + case "B/op": + if i, err := strconv.ParseUint(quant, 10, 64); err == nil { + b.AllocedBytesPerOp = i + b.Measured |= AllocedBytesPerOp + } + case "allocs/op": + if i, err := strconv.ParseUint(quant, 10, 64); err == nil { + b.AllocsPerOp = i + b.Measured |= AllocsPerOp + } + } +} + +func (b *Benchmark) String() string { + buf := new(bytes.Buffer) + fmt.Fprintf(buf, "%s %d", b.Name, b.N) + if (b.Measured & NsPerOp) != 0 { + fmt.Fprintf(buf, " %.2f ns/op", b.NsPerOp) + } + if (b.Measured & MBPerS) != 0 { + fmt.Fprintf(buf, " %.2f MB/s", b.MBPerS) + } + if (b.Measured & AllocedBytesPerOp) != 0 { + fmt.Fprintf(buf, " %d B/op", b.AllocedBytesPerOp) + } + if (b.Measured & AllocsPerOp) != 0 { + fmt.Fprintf(buf, " %d allocs/op", b.AllocsPerOp) + } + return buf.String() +} + +// Set is a collection of benchmarks from one +// testing.B run, keyed by name to facilitate comparison. +type Set map[string][]*Benchmark + +// ParseSet extracts a Set from testing.B output. +// ParseSet preserves the order of benchmarks that have identical +// names. +func ParseSet(r io.Reader) (Set, error) { + bb := make(Set) + scan := bufio.NewScanner(r) + ord := 0 + for scan.Scan() { + if b, err := ParseLine(scan.Text()); err == nil { + b.Ord = ord + ord++ + bb[b.Name] = append(bb[b.Name], b) + } + } + + if err := scan.Err(); err != nil { + return nil, err + } + + return bb, nil +} diff --git a/vendor/golang.org/x/tools/blog/atom/atom.go b/vendor/golang.org/x/tools/blog/atom/atom.go new file mode 100644 index 00000000000..542c50e6e41 --- /dev/null +++ b/vendor/golang.org/x/tools/blog/atom/atom.go @@ -0,0 +1,61 @@ +// Copyright 2009 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Adapted from encoding/xml/read_test.go. + +// Package atom defines XML data structures for an Atom feed. +package atom // import "golang.org/x/tools/blog/atom" + +import ( + "encoding/xml" + "time" +) + +type Feed struct { + XMLName xml.Name `xml:"http://www.w3.org/2005/Atom feed"` + Title string `xml:"title"` + ID string `xml:"id"` + Link []Link `xml:"link"` + Updated TimeStr `xml:"updated"` + Author *Person `xml:"author"` + Entry []*Entry `xml:"entry"` +} + +type Entry struct { + Title string `xml:"title"` + ID string `xml:"id"` + Link []Link `xml:"link"` + Published TimeStr `xml:"published"` + Updated TimeStr `xml:"updated"` + Author *Person `xml:"author"` + Summary *Text `xml:"summary"` + Content *Text `xml:"content"` +} + +type Link struct { + Rel string `xml:"rel,attr,omitempty"` + Href string `xml:"href,attr"` + Type string `xml:"type,attr,omitempty"` + HrefLang string `xml:"hreflang,attr,omitempty"` + Title string `xml:"title,attr,omitempty"` + Length uint `xml:"length,attr,omitempty"` +} + +type Person struct { + Name string `xml:"name"` + URI string `xml:"uri,omitempty"` + Email string `xml:"email,omitempty"` + InnerXML string `xml:",innerxml"` +} + +type Text struct { + Type string `xml:"type,attr"` + Body string `xml:",chardata"` +} + +type TimeStr string + +func Time(t time.Time) TimeStr { + return TimeStr(t.Format("2006-01-02T15:04:05-07:00")) +} diff --git a/vendor/golang.org/x/tools/container/intsets/popcnt_amd64.go b/vendor/golang.org/x/tools/container/intsets/popcnt_amd64.go new file mode 100644 index 00000000000..99ea813d284 --- /dev/null +++ b/vendor/golang.org/x/tools/container/intsets/popcnt_amd64.go @@ -0,0 +1,20 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build amd64,!appengine,!gccgo + +package intsets + +func popcnt(x word) int +func havePOPCNT() bool + +var hasPOPCNT = havePOPCNT() + +// popcount returns the population count (number of set bits) of x. +func popcount(x word) int { + if hasPOPCNT { + return popcnt(x) + } + return popcountTable(x) // faster than Hacker's Delight +} diff --git a/vendor/golang.org/x/tools/container/intsets/popcnt_amd64.s b/vendor/golang.org/x/tools/container/intsets/popcnt_amd64.s new file mode 100644 index 00000000000..05c3d6fb573 --- /dev/null +++ b/vendor/golang.org/x/tools/container/intsets/popcnt_amd64.s @@ -0,0 +1,30 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build amd64,!appengine,!gccgo + +#include "textflag.h" + +// func havePOPCNT() bool +TEXT ·havePOPCNT(SB),4,$0 + MOVQ $1, AX + CPUID + SHRQ $23, CX + ANDQ $1, CX + MOVB CX, ret+0(FP) + RET + +// func popcnt(word) int +TEXT ·popcnt(SB),NOSPLIT,$0-8 + XORQ AX, AX + MOVQ x+0(FP), SI + // POPCNT (SI), AX is not recognized by Go assembler, + // so we assemble it ourselves. + BYTE $0xf3 + BYTE $0x48 + BYTE $0x0f + BYTE $0xb8 + BYTE $0xc6 + MOVQ AX, ret+8(FP) + RET diff --git a/vendor/golang.org/x/tools/container/intsets/popcnt_gccgo.go b/vendor/golang.org/x/tools/container/intsets/popcnt_gccgo.go new file mode 100644 index 00000000000..82a8875c85d --- /dev/null +++ b/vendor/golang.org/x/tools/container/intsets/popcnt_gccgo.go @@ -0,0 +1,9 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build gccgo + +package intsets + +func popcount(x word) int diff --git a/vendor/golang.org/x/tools/container/intsets/popcnt_gccgo_c.c b/vendor/golang.org/x/tools/container/intsets/popcnt_gccgo_c.c new file mode 100644 index 00000000000..08abb32ec46 --- /dev/null +++ b/vendor/golang.org/x/tools/container/intsets/popcnt_gccgo_c.c @@ -0,0 +1,19 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build gccgo + +#include +#include +#include + +#define _STRINGIFY2_(x) #x +#define _STRINGIFY_(x) _STRINGIFY2_(x) +#define GOSYM_PREFIX _STRINGIFY_(__USER_LABEL_PREFIX__) + +extern intptr_t popcount(uintptr_t x) __asm__(GOSYM_PREFIX GOPKGPATH ".popcount"); + +intptr_t popcount(uintptr_t x) { + return __builtin_popcountl((unsigned long)(x)); +} diff --git a/vendor/golang.org/x/tools/container/intsets/popcnt_generic.go b/vendor/golang.org/x/tools/container/intsets/popcnt_generic.go new file mode 100644 index 00000000000..3985a1da1a2 --- /dev/null +++ b/vendor/golang.org/x/tools/container/intsets/popcnt_generic.go @@ -0,0 +1,33 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// +build !amd64 appengine +// +build !gccgo + +package intsets + +import "runtime" + +// We compared three algorithms---Hacker's Delight, table lookup, +// and AMD64's SSE4.1 hardware POPCNT---on a 2.67GHz Xeon X5550. +// +// % GOARCH=amd64 go test -run=NONE -bench=Popcount +// POPCNT 5.12 ns/op +// Table 8.53 ns/op +// HackersDelight 9.96 ns/op +// +// % GOARCH=386 go test -run=NONE -bench=Popcount +// Table 10.4 ns/op +// HackersDelight 5.23 ns/op +// +// (AMD64's ABM1 hardware supports ntz and nlz too, +// but they aren't critical.) + +// popcount returns the population count (number of set bits) of x. +func popcount(x word) int { + if runtime.GOARCH == "386" { + return popcountHD(uint32(x)) + } + return popcountTable(x) +} diff --git a/vendor/golang.org/x/tools/container/intsets/sparse.go b/vendor/golang.org/x/tools/container/intsets/sparse.go new file mode 100644 index 00000000000..5db01c1a448 --- /dev/null +++ b/vendor/golang.org/x/tools/container/intsets/sparse.go @@ -0,0 +1,1091 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package intsets provides Sparse, a compact and fast representation +// for sparse sets of int values. +// +// The time complexity of the operations Len, Insert, Remove and Has +// is in O(n) but in practice those methods are faster and more +// space-efficient than equivalent operations on sets based on the Go +// map type. The IsEmpty, Min, Max, Clear and TakeMin operations +// require constant time. +// +package intsets // import "golang.org/x/tools/container/intsets" + +// TODO(adonovan): +// - Add InsertAll(...int), RemoveAll(...int) +// - Add 'bool changed' results for {Intersection,Difference}With too. +// +// TODO(adonovan): implement Dense, a dense bit vector with a similar API. +// The space usage would be proportional to Max(), not Len(), and the +// implementation would be based upon big.Int. +// +// TODO(adonovan): opt: make UnionWith and Difference faster. +// These are the hot-spots for go/pointer. + +import ( + "bytes" + "fmt" +) + +// A Sparse is a set of int values. +// Sparse operations (even queries) are not concurrency-safe. +// +// The zero value for Sparse is a valid empty set. +// +// Sparse sets must be copied using the Copy method, not by assigning +// a Sparse value. +// +type Sparse struct { + // An uninitialized Sparse represents an empty set. + // An empty set may also be represented by + // root.next == root.prev == &root. + // + // The root is always the block with the smallest offset. + // It can be empty, but only if it is the only block; in that case, offset is + // MaxInt (which is not a valid offset). + root block +} + +type word uintptr + +const ( + _m = ^word(0) + bitsPerWord = 8 << (_m>>8&1 + _m>>16&1 + _m>>32&1) + bitsPerBlock = 256 // optimal value for go/pointer solver performance + wordsPerBlock = bitsPerBlock / bitsPerWord +) + +// Limit values of implementation-specific int type. +const ( + MaxInt = int(^uint(0) >> 1) + MinInt = -MaxInt - 1 +) + +// -- block ------------------------------------------------------------ + +// A set is represented as a circular doubly-linked list of blocks, +// each containing an offset and a bit array of fixed size +// bitsPerBlock; the blocks are ordered by increasing offset. +// +// The set contains an element x iff the block whose offset is x - (x +// mod bitsPerBlock) has the bit (x mod bitsPerBlock) set, where mod +// is the Euclidean remainder. +// +// A block may only be empty transiently. +// +type block struct { + offset int // offset mod bitsPerBlock == 0 + bits [wordsPerBlock]word // contains at least one set bit + next, prev *block // doubly-linked list of blocks +} + +// wordMask returns the word index (in block.bits) +// and single-bit mask for the block's ith bit. +func wordMask(i uint) (w uint, mask word) { + w = i / bitsPerWord + mask = 1 << (i % bitsPerWord) + return +} + +// insert sets the block b's ith bit and +// returns true if it was not already set. +// +func (b *block) insert(i uint) bool { + w, mask := wordMask(i) + if b.bits[w]&mask == 0 { + b.bits[w] |= mask + return true + } + return false +} + +// remove clears the block's ith bit and +// returns true if the bit was previously set. +// NB: may leave the block empty. +// +func (b *block) remove(i uint) bool { + w, mask := wordMask(i) + if b.bits[w]&mask != 0 { + b.bits[w] &^= mask + return true + } + return false +} + +// has reports whether the block's ith bit is set. +func (b *block) has(i uint) bool { + w, mask := wordMask(i) + return b.bits[w]&mask != 0 +} + +// empty reports whether b.len()==0, but more efficiently. +func (b *block) empty() bool { + for _, w := range b.bits { + if w != 0 { + return false + } + } + return true +} + +// len returns the number of set bits in block b. +func (b *block) len() int { + var l int + for _, w := range b.bits { + l += popcount(w) + } + return l +} + +// max returns the maximum element of the block. +// The block must not be empty. +func (b *block) max() int { + bi := b.offset + bitsPerBlock + // Decrement bi by number of high zeros in last.bits. + for i := len(b.bits) - 1; i >= 0; i-- { + if w := b.bits[i]; w != 0 { + return bi - nlz(w) - 1 + } + bi -= bitsPerWord + } + panic("BUG: empty block") +} + +// min returns the minimum element of the block, +// and also removes it if take is set. +// The block must not be initially empty. +// NB: may leave the block empty. +func (b *block) min(take bool) int { + for i, w := range b.bits { + if w != 0 { + tz := ntz(w) + if take { + b.bits[i] = w &^ (1 << uint(tz)) + } + return b.offset + int(i*bitsPerWord) + tz + } + } + panic("BUG: empty block") +} + +// lowerBound returns the smallest element of the block that is greater than or +// equal to the element corresponding to the ith bit. If there is no such +// element, the second return value is false. +func (b *block) lowerBound(i uint) (int, bool) { + w := i / bitsPerWord + bit := i % bitsPerWord + + if val := b.bits[w] >> bit; val != 0 { + return b.offset + int(i) + ntz(val), true + } + + for w++; w < wordsPerBlock; w++ { + if val := b.bits[w]; val != 0 { + return b.offset + int(w*bitsPerWord) + ntz(val), true + } + } + + return 0, false +} + +// forEach calls f for each element of block b. +// f must not mutate b's enclosing Sparse. +func (b *block) forEach(f func(int)) { + for i, w := range b.bits { + offset := b.offset + i*bitsPerWord + for bi := 0; w != 0 && bi < bitsPerWord; bi++ { + if w&1 != 0 { + f(offset) + } + offset++ + w >>= 1 + } + } +} + +// offsetAndBitIndex returns the offset of the block that would +// contain x and the bit index of x within that block. +// +func offsetAndBitIndex(x int) (int, uint) { + mod := x % bitsPerBlock + if mod < 0 { + // Euclidean (non-negative) remainder + mod += bitsPerBlock + } + return x - mod, uint(mod) +} + +// -- Sparse -------------------------------------------------------------- + +// none is a shared, empty, sentinel block that indicates the end of a block +// list. +var none block + +// Dummy type used to generate an implicit panic. This must be defined at the +// package level; if it is defined inside a function, it prevents the inlining +// of that function. +type to_copy_a_sparse_you_must_call_its_Copy_method struct{} + +// init ensures s is properly initialized. +func (s *Sparse) init() { + root := &s.root + if root.next == nil { + root.offset = MaxInt + root.next = root + root.prev = root + } else if root.next.prev != root { + // Copying a Sparse x leads to pernicious corruption: the + // new Sparse y shares the old linked list, but iteration + // on y will never encounter &y.root so it goes into a + // loop. Fail fast before this occurs. + // We don't want to call panic here because it prevents the + // inlining of this function. + _ = (interface{}(nil)).(to_copy_a_sparse_you_must_call_its_Copy_method) + } +} + +func (s *Sparse) first() *block { + s.init() + if s.root.offset == MaxInt { + return &none + } + return &s.root +} + +// next returns the next block in the list, or end if b is the last block. +func (s *Sparse) next(b *block) *block { + if b.next == &s.root { + return &none + } + return b.next +} + +// prev returns the previous block in the list, or end if b is the first block. +func (s *Sparse) prev(b *block) *block { + if b.prev == &s.root { + return &none + } + return b.prev +} + +// IsEmpty reports whether the set s is empty. +func (s *Sparse) IsEmpty() bool { + return s.root.next == nil || s.root.offset == MaxInt +} + +// Len returns the number of elements in the set s. +func (s *Sparse) Len() int { + var l int + for b := s.first(); b != &none; b = s.next(b) { + l += b.len() + } + return l +} + +// Max returns the maximum element of the set s, or MinInt if s is empty. +func (s *Sparse) Max() int { + if s.IsEmpty() { + return MinInt + } + return s.root.prev.max() +} + +// Min returns the minimum element of the set s, or MaxInt if s is empty. +func (s *Sparse) Min() int { + if s.IsEmpty() { + return MaxInt + } + return s.root.min(false) +} + +// LowerBound returns the smallest element >= x, or MaxInt if there is no such +// element. +func (s *Sparse) LowerBound(x int) int { + offset, i := offsetAndBitIndex(x) + for b := s.first(); b != &none; b = s.next(b) { + if b.offset > offset { + return b.min(false) + } + if b.offset == offset { + if y, ok := b.lowerBound(i); ok { + return y + } + } + } + return MaxInt +} + +// block returns the block that would contain offset, +// or nil if s contains no such block. +// Precondition: offset is a multiple of bitsPerBlock. +func (s *Sparse) block(offset int) *block { + for b := s.first(); b != &none && b.offset <= offset; b = s.next(b) { + if b.offset == offset { + return b + } + } + return nil +} + +// Insert adds x to the set s, and reports whether the set grew. +func (s *Sparse) Insert(x int) bool { + offset, i := offsetAndBitIndex(x) + + b := s.first() + for ; b != &none && b.offset <= offset; b = s.next(b) { + if b.offset == offset { + return b.insert(i) + } + } + + // Insert new block before b. + new := s.insertBlockBefore(b) + new.offset = offset + return new.insert(i) +} + +// removeBlock removes a block and returns the block that followed it (or end if +// it was the last block). +func (s *Sparse) removeBlock(b *block) *block { + if b != &s.root { + b.prev.next = b.next + b.next.prev = b.prev + if b.next == &s.root { + return &none + } + return b.next + } + + first := s.root.next + if first == &s.root { + // This was the only block. + s.Clear() + return &none + } + s.root.offset = first.offset + s.root.bits = first.bits + if first.next == &s.root { + // Single block remaining. + s.root.next = &s.root + s.root.prev = &s.root + } else { + s.root.next = first.next + first.next.prev = &s.root + } + return &s.root +} + +// Remove removes x from the set s, and reports whether the set shrank. +func (s *Sparse) Remove(x int) bool { + offset, i := offsetAndBitIndex(x) + if b := s.block(offset); b != nil { + if !b.remove(i) { + return false + } + if b.empty() { + s.removeBlock(b) + } + return true + } + return false +} + +// Clear removes all elements from the set s. +func (s *Sparse) Clear() { + s.root = block{ + offset: MaxInt, + next: &s.root, + prev: &s.root, + } +} + +// If set s is non-empty, TakeMin sets *p to the minimum element of +// the set s, removes that element from the set and returns true. +// Otherwise, it returns false and *p is undefined. +// +// This method may be used for iteration over a worklist like so: +// +// var x int +// for worklist.TakeMin(&x) { use(x) } +// +func (s *Sparse) TakeMin(p *int) bool { + if s.IsEmpty() { + return false + } + *p = s.root.min(true) + if s.root.empty() { + s.removeBlock(&s.root) + } + return true +} + +// Has reports whether x is an element of the set s. +func (s *Sparse) Has(x int) bool { + offset, i := offsetAndBitIndex(x) + if b := s.block(offset); b != nil { + return b.has(i) + } + return false +} + +// forEach applies function f to each element of the set s in order. +// +// f must not mutate s. Consequently, forEach is not safe to expose +// to clients. In any case, using "range s.AppendTo()" allows more +// natural control flow with continue/break/return. +// +func (s *Sparse) forEach(f func(int)) { + for b := s.first(); b != &none; b = s.next(b) { + b.forEach(f) + } +} + +// Copy sets s to the value of x. +func (s *Sparse) Copy(x *Sparse) { + if s == x { + return + } + + xb := x.first() + sb := s.first() + for xb != &none { + if sb == &none { + sb = s.insertBlockBefore(sb) + } + sb.offset = xb.offset + sb.bits = xb.bits + xb = x.next(xb) + sb = s.next(sb) + } + s.discardTail(sb) +} + +// insertBlockBefore returns a new block, inserting it before next. +// If next is the root, the root is replaced. If next is end, the block is +// inserted at the end. +func (s *Sparse) insertBlockBefore(next *block) *block { + if s.IsEmpty() { + if next != &none { + panic("BUG: passed block with empty set") + } + return &s.root + } + + if next == &s.root { + // Special case: we need to create a new block that will become the root + // block.The old root block becomes the second block. + second := s.root + s.root = block{ + next: &second, + } + if second.next == &s.root { + s.root.prev = &second + } else { + s.root.prev = second.prev + second.next.prev = &second + second.prev = &s.root + } + return &s.root + } + if next == &none { + // Insert before root. + next = &s.root + } + b := new(block) + b.next = next + b.prev = next.prev + b.prev.next = b + next.prev = b + return b +} + +// discardTail removes block b and all its successors from s. +func (s *Sparse) discardTail(b *block) { + if b != &none { + if b == &s.root { + s.Clear() + } else { + b.prev.next = &s.root + s.root.prev = b.prev + } + } +} + +// IntersectionWith sets s to the intersection s ∩ x. +func (s *Sparse) IntersectionWith(x *Sparse) { + if s == x { + return + } + + xb := x.first() + sb := s.first() + for xb != &none && sb != &none { + switch { + case xb.offset < sb.offset: + xb = x.next(xb) + + case xb.offset > sb.offset: + sb = s.removeBlock(sb) + + default: + var sum word + for i := range sb.bits { + r := xb.bits[i] & sb.bits[i] + sb.bits[i] = r + sum |= r + } + if sum != 0 { + sb = s.next(sb) + } else { + // sb will be overwritten or removed + } + + xb = x.next(xb) + } + } + + s.discardTail(sb) +} + +// Intersection sets s to the intersection x ∩ y. +func (s *Sparse) Intersection(x, y *Sparse) { + switch { + case s == x: + s.IntersectionWith(y) + return + case s == y: + s.IntersectionWith(x) + return + case x == y: + s.Copy(x) + return + } + + xb := x.first() + yb := y.first() + sb := s.first() + for xb != &none && yb != &none { + switch { + case xb.offset < yb.offset: + xb = x.next(xb) + continue + case xb.offset > yb.offset: + yb = y.next(yb) + continue + } + + if sb == &none { + sb = s.insertBlockBefore(sb) + } + sb.offset = xb.offset + + var sum word + for i := range sb.bits { + r := xb.bits[i] & yb.bits[i] + sb.bits[i] = r + sum |= r + } + if sum != 0 { + sb = s.next(sb) + } else { + // sb will be overwritten or removed + } + + xb = x.next(xb) + yb = y.next(yb) + } + + s.discardTail(sb) +} + +// Intersects reports whether s ∩ x ≠ ∅. +func (s *Sparse) Intersects(x *Sparse) bool { + sb := s.first() + xb := x.first() + for sb != &none && xb != &none { + switch { + case xb.offset < sb.offset: + xb = x.next(xb) + case xb.offset > sb.offset: + sb = s.next(sb) + default: + for i := range sb.bits { + if sb.bits[i]&xb.bits[i] != 0 { + return true + } + } + sb = s.next(sb) + xb = x.next(xb) + } + } + return false +} + +// UnionWith sets s to the union s ∪ x, and reports whether s grew. +func (s *Sparse) UnionWith(x *Sparse) bool { + if s == x { + return false + } + + var changed bool + xb := x.first() + sb := s.first() + for xb != &none { + if sb != &none && sb.offset == xb.offset { + for i := range xb.bits { + if sb.bits[i] != xb.bits[i] { + sb.bits[i] |= xb.bits[i] + changed = true + } + } + xb = x.next(xb) + } else if sb == &none || sb.offset > xb.offset { + sb = s.insertBlockBefore(sb) + sb.offset = xb.offset + sb.bits = xb.bits + changed = true + + xb = x.next(xb) + } + sb = s.next(sb) + } + return changed +} + +// Union sets s to the union x ∪ y. +func (s *Sparse) Union(x, y *Sparse) { + switch { + case x == y: + s.Copy(x) + return + case s == x: + s.UnionWith(y) + return + case s == y: + s.UnionWith(x) + return + } + + xb := x.first() + yb := y.first() + sb := s.first() + for xb != &none || yb != &none { + if sb == &none { + sb = s.insertBlockBefore(sb) + } + switch { + case yb == &none || (xb != &none && xb.offset < yb.offset): + sb.offset = xb.offset + sb.bits = xb.bits + xb = x.next(xb) + + case xb == &none || (yb != &none && yb.offset < xb.offset): + sb.offset = yb.offset + sb.bits = yb.bits + yb = y.next(yb) + + default: + sb.offset = xb.offset + for i := range xb.bits { + sb.bits[i] = xb.bits[i] | yb.bits[i] + } + xb = x.next(xb) + yb = y.next(yb) + } + sb = s.next(sb) + } + + s.discardTail(sb) +} + +// DifferenceWith sets s to the difference s ∖ x. +func (s *Sparse) DifferenceWith(x *Sparse) { + if s == x { + s.Clear() + return + } + + xb := x.first() + sb := s.first() + for xb != &none && sb != &none { + switch { + case xb.offset > sb.offset: + sb = s.next(sb) + + case xb.offset < sb.offset: + xb = x.next(xb) + + default: + var sum word + for i := range sb.bits { + r := sb.bits[i] & ^xb.bits[i] + sb.bits[i] = r + sum |= r + } + if sum == 0 { + sb = s.removeBlock(sb) + } else { + sb = s.next(sb) + } + xb = x.next(xb) + } + } +} + +// Difference sets s to the difference x ∖ y. +func (s *Sparse) Difference(x, y *Sparse) { + switch { + case x == y: + s.Clear() + return + case s == x: + s.DifferenceWith(y) + return + case s == y: + var y2 Sparse + y2.Copy(y) + s.Difference(x, &y2) + return + } + + xb := x.first() + yb := y.first() + sb := s.first() + for xb != &none && yb != &none { + if xb.offset > yb.offset { + // y has block, x has &none + yb = y.next(yb) + continue + } + + if sb == &none { + sb = s.insertBlockBefore(sb) + } + sb.offset = xb.offset + + switch { + case xb.offset < yb.offset: + // x has block, y has &none + sb.bits = xb.bits + + sb = s.next(sb) + + default: + // x and y have corresponding blocks + var sum word + for i := range sb.bits { + r := xb.bits[i] & ^yb.bits[i] + sb.bits[i] = r + sum |= r + } + if sum != 0 { + sb = s.next(sb) + } else { + // sb will be overwritten or removed + } + + yb = y.next(yb) + } + xb = x.next(xb) + } + + for xb != &none { + if sb == &none { + sb = s.insertBlockBefore(sb) + } + sb.offset = xb.offset + sb.bits = xb.bits + sb = s.next(sb) + + xb = x.next(xb) + } + + s.discardTail(sb) +} + +// SymmetricDifferenceWith sets s to the symmetric difference s ∆ x. +func (s *Sparse) SymmetricDifferenceWith(x *Sparse) { + if s == x { + s.Clear() + return + } + + sb := s.first() + xb := x.first() + for xb != &none && sb != &none { + switch { + case sb.offset < xb.offset: + sb = s.next(sb) + case xb.offset < sb.offset: + nb := s.insertBlockBefore(sb) + nb.offset = xb.offset + nb.bits = xb.bits + xb = x.next(xb) + default: + var sum word + for i := range sb.bits { + r := sb.bits[i] ^ xb.bits[i] + sb.bits[i] = r + sum |= r + } + if sum == 0 { + sb = s.removeBlock(sb) + } else { + sb = s.next(sb) + } + xb = x.next(xb) + } + } + + for xb != &none { // append the tail of x to s + sb = s.insertBlockBefore(sb) + sb.offset = xb.offset + sb.bits = xb.bits + sb = s.next(sb) + xb = x.next(xb) + } +} + +// SymmetricDifference sets s to the symmetric difference x ∆ y. +func (s *Sparse) SymmetricDifference(x, y *Sparse) { + switch { + case x == y: + s.Clear() + return + case s == x: + s.SymmetricDifferenceWith(y) + return + case s == y: + s.SymmetricDifferenceWith(x) + return + } + + sb := s.first() + xb := x.first() + yb := y.first() + for xb != &none && yb != &none { + if sb == &none { + sb = s.insertBlockBefore(sb) + } + switch { + case yb.offset < xb.offset: + sb.offset = yb.offset + sb.bits = yb.bits + sb = s.next(sb) + yb = y.next(yb) + case xb.offset < yb.offset: + sb.offset = xb.offset + sb.bits = xb.bits + sb = s.next(sb) + xb = x.next(xb) + default: + var sum word + for i := range sb.bits { + r := xb.bits[i] ^ yb.bits[i] + sb.bits[i] = r + sum |= r + } + if sum != 0 { + sb.offset = xb.offset + sb = s.next(sb) + } + xb = x.next(xb) + yb = y.next(yb) + } + } + + for xb != &none { // append the tail of x to s + if sb == &none { + sb = s.insertBlockBefore(sb) + } + sb.offset = xb.offset + sb.bits = xb.bits + sb = s.next(sb) + xb = x.next(xb) + } + + for yb != &none { // append the tail of y to s + if sb == &none { + sb = s.insertBlockBefore(sb) + } + sb.offset = yb.offset + sb.bits = yb.bits + sb = s.next(sb) + yb = y.next(yb) + } + + s.discardTail(sb) +} + +// SubsetOf reports whether s ∖ x = ∅. +func (s *Sparse) SubsetOf(x *Sparse) bool { + if s == x { + return true + } + + sb := s.first() + xb := x.first() + for sb != &none { + switch { + case xb == &none || xb.offset > sb.offset: + return false + case xb.offset < sb.offset: + xb = x.next(xb) + default: + for i := range sb.bits { + if sb.bits[i]&^xb.bits[i] != 0 { + return false + } + } + sb = s.next(sb) + xb = x.next(xb) + } + } + return true +} + +// Equals reports whether the sets s and t have the same elements. +func (s *Sparse) Equals(t *Sparse) bool { + if s == t { + return true + } + sb := s.first() + tb := t.first() + for { + switch { + case sb == &none && tb == &none: + return true + case sb == &none || tb == &none: + return false + case sb.offset != tb.offset: + return false + case sb.bits != tb.bits: + return false + } + + sb = s.next(sb) + tb = t.next(tb) + } +} + +// String returns a human-readable description of the set s. +func (s *Sparse) String() string { + var buf bytes.Buffer + buf.WriteByte('{') + s.forEach(func(x int) { + if buf.Len() > 1 { + buf.WriteByte(' ') + } + fmt.Fprintf(&buf, "%d", x) + }) + buf.WriteByte('}') + return buf.String() +} + +// BitString returns the set as a string of 1s and 0s denoting the sum +// of the i'th powers of 2, for each i in s. A radix point, always +// preceded by a digit, appears if the sum is non-integral. +// +// Examples: +// {}.BitString() = "0" +// {4,5}.BitString() = "110000" +// {-3}.BitString() = "0.001" +// {-3,0,4,5}.BitString() = "110001.001" +// +func (s *Sparse) BitString() string { + if s.IsEmpty() { + return "0" + } + + min, max := s.Min(), s.Max() + var nbytes int + if max > 0 { + nbytes = max + } + nbytes++ // zero bit + radix := nbytes + if min < 0 { + nbytes += len(".") - min + } + + b := make([]byte, nbytes) + for i := range b { + b[i] = '0' + } + if radix < nbytes { + b[radix] = '.' + } + s.forEach(func(x int) { + if x >= 0 { + x += len(".") + } + b[radix-x] = '1' + }) + return string(b) +} + +// GoString returns a string showing the internal representation of +// the set s. +// +func (s *Sparse) GoString() string { + var buf bytes.Buffer + for b := s.first(); b != &none; b = s.next(b) { + fmt.Fprintf(&buf, "block %p {offset=%d next=%p prev=%p", + b, b.offset, b.next, b.prev) + for _, w := range b.bits { + fmt.Fprintf(&buf, " 0%016x", w) + } + fmt.Fprintf(&buf, "}\n") + } + return buf.String() +} + +// AppendTo returns the result of appending the elements of s to slice +// in order. +func (s *Sparse) AppendTo(slice []int) []int { + s.forEach(func(x int) { + slice = append(slice, x) + }) + return slice +} + +// -- Testing/debugging ------------------------------------------------ + +// check returns an error if the representation invariants of s are violated. +func (s *Sparse) check() error { + s.init() + if s.root.empty() { + // An empty set must have only the root block with offset MaxInt. + if s.root.next != &s.root { + return fmt.Errorf("multiple blocks with empty root block") + } + if s.root.offset != MaxInt { + return fmt.Errorf("empty set has offset %d, should be MaxInt", s.root.offset) + } + return nil + } + for b := s.first(); ; b = s.next(b) { + if b.offset%bitsPerBlock != 0 { + return fmt.Errorf("bad offset modulo: %d", b.offset) + } + if b.empty() { + return fmt.Errorf("empty block") + } + if b.prev.next != b { + return fmt.Errorf("bad prev.next link") + } + if b.next.prev != b { + return fmt.Errorf("bad next.prev link") + } + if b.next == &s.root { + break + } + if b.offset >= b.next.offset { + return fmt.Errorf("bad offset order: b.offset=%d, b.next.offset=%d", + b.offset, b.next.offset) + } + } + return nil +} diff --git a/vendor/golang.org/x/tools/container/intsets/util.go b/vendor/golang.org/x/tools/container/intsets/util.go new file mode 100644 index 00000000000..dd1db86b1c1 --- /dev/null +++ b/vendor/golang.org/x/tools/container/intsets/util.go @@ -0,0 +1,84 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package intsets + +// From Hacker's Delight, fig 5.2. +func popcountHD(x uint32) int { + x -= (x >> 1) & 0x55555555 + x = (x & 0x33333333) + ((x >> 2) & 0x33333333) + x = (x + (x >> 4)) & 0x0f0f0f0f + x = x + (x >> 8) + x = x + (x >> 16) + return int(x & 0x0000003f) +} + +var a [1 << 8]byte + +func init() { + for i := range a { + var n byte + for x := i; x != 0; x >>= 1 { + if x&1 != 0 { + n++ + } + } + a[i] = n + } +} + +func popcountTable(x word) int { + return int(a[byte(x>>(0*8))] + + a[byte(x>>(1*8))] + + a[byte(x>>(2*8))] + + a[byte(x>>(3*8))] + + a[byte(x>>(4*8))] + + a[byte(x>>(5*8))] + + a[byte(x>>(6*8))] + + a[byte(x>>(7*8))]) +} + +// nlz returns the number of leading zeros of x. +// From Hacker's Delight, fig 5.11. +func nlz(x word) int { + x |= (x >> 1) + x |= (x >> 2) + x |= (x >> 4) + x |= (x >> 8) + x |= (x >> 16) + x |= (x >> 32) + return popcount(^x) +} + +// ntz returns the number of trailing zeros of x. +// From Hacker's Delight, fig 5.13. +func ntz(x word) int { + if x == 0 { + return bitsPerWord + } + n := 1 + if bitsPerWord == 64 { + if (x & 0xffffffff) == 0 { + n = n + 32 + x = x >> 32 + } + } + if (x & 0x0000ffff) == 0 { + n = n + 16 + x = x >> 16 + } + if (x & 0x000000ff) == 0 { + n = n + 8 + x = x >> 8 + } + if (x & 0x0000000f) == 0 { + n = n + 4 + x = x >> 4 + } + if (x & 0x00000003) == 0 { + n = n + 2 + x = x >> 2 + } + return n - int(x&1) +} diff --git a/vendor/golang.org/x/tools/go/ast/astutil/enclosing.go b/vendor/golang.org/x/tools/go/ast/astutil/enclosing.go new file mode 100644 index 00000000000..6b7052b892c --- /dev/null +++ b/vendor/golang.org/x/tools/go/ast/astutil/enclosing.go @@ -0,0 +1,627 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package astutil + +// This file defines utilities for working with source positions. + +import ( + "fmt" + "go/ast" + "go/token" + "sort" +) + +// PathEnclosingInterval returns the node that encloses the source +// interval [start, end), and all its ancestors up to the AST root. +// +// The definition of "enclosing" used by this function considers +// additional whitespace abutting a node to be enclosed by it. +// In this example: +// +// z := x + y // add them +// <-A-> +// <----B-----> +// +// the ast.BinaryExpr(+) node is considered to enclose interval B +// even though its [Pos()..End()) is actually only interval A. +// This behaviour makes user interfaces more tolerant of imperfect +// input. +// +// This function treats tokens as nodes, though they are not included +// in the result. e.g. PathEnclosingInterval("+") returns the +// enclosing ast.BinaryExpr("x + y"). +// +// If start==end, the 1-char interval following start is used instead. +// +// The 'exact' result is true if the interval contains only path[0] +// and perhaps some adjacent whitespace. It is false if the interval +// overlaps multiple children of path[0], or if it contains only +// interior whitespace of path[0]. +// In this example: +// +// z := x + y // add them +// <--C--> <---E--> +// ^ +// D +// +// intervals C, D and E are inexact. C is contained by the +// z-assignment statement, because it spans three of its children (:=, +// x, +). So too is the 1-char interval D, because it contains only +// interior whitespace of the assignment. E is considered interior +// whitespace of the BlockStmt containing the assignment. +// +// Precondition: [start, end) both lie within the same file as root. +// TODO(adonovan): return (nil, false) in this case and remove precond. +// Requires FileSet; see loader.tokenFileContainsPos. +// +// Postcondition: path is never nil; it always contains at least 'root'. +// +func PathEnclosingInterval(root *ast.File, start, end token.Pos) (path []ast.Node, exact bool) { + // fmt.Printf("EnclosingInterval %d %d\n", start, end) // debugging + + // Precondition: node.[Pos..End) and adjoining whitespace contain [start, end). + var visit func(node ast.Node) bool + visit = func(node ast.Node) bool { + path = append(path, node) + + nodePos := node.Pos() + nodeEnd := node.End() + + // fmt.Printf("visit(%T, %d, %d)\n", node, nodePos, nodeEnd) // debugging + + // Intersect [start, end) with interval of node. + if start < nodePos { + start = nodePos + } + if end > nodeEnd { + end = nodeEnd + } + + // Find sole child that contains [start, end). + children := childrenOf(node) + l := len(children) + for i, child := range children { + // [childPos, childEnd) is unaugmented interval of child. + childPos := child.Pos() + childEnd := child.End() + + // [augPos, augEnd) is whitespace-augmented interval of child. + augPos := childPos + augEnd := childEnd + if i > 0 { + augPos = children[i-1].End() // start of preceding whitespace + } + if i < l-1 { + nextChildPos := children[i+1].Pos() + // Does [start, end) lie between child and next child? + if start >= augEnd && end <= nextChildPos { + return false // inexact match + } + augEnd = nextChildPos // end of following whitespace + } + + // fmt.Printf("\tchild %d: [%d..%d)\tcontains interval [%d..%d)?\n", + // i, augPos, augEnd, start, end) // debugging + + // Does augmented child strictly contain [start, end)? + if augPos <= start && end <= augEnd { + _, isToken := child.(tokenNode) + return isToken || visit(child) + } + + // Does [start, end) overlap multiple children? + // i.e. left-augmented child contains start + // but LR-augmented child does not contain end. + if start < childEnd && end > augEnd { + break + } + } + + // No single child contained [start, end), + // so node is the result. Is it exact? + + // (It's tempting to put this condition before the + // child loop, but it gives the wrong result in the + // case where a node (e.g. ExprStmt) and its sole + // child have equal intervals.) + if start == nodePos && end == nodeEnd { + return true // exact match + } + + return false // inexact: overlaps multiple children + } + + if start > end { + start, end = end, start + } + + if start < root.End() && end > root.Pos() { + if start == end { + end = start + 1 // empty interval => interval of size 1 + } + exact = visit(root) + + // Reverse the path: + for i, l := 0, len(path); i < l/2; i++ { + path[i], path[l-1-i] = path[l-1-i], path[i] + } + } else { + // Selection lies within whitespace preceding the + // first (or following the last) declaration in the file. + // The result nonetheless always includes the ast.File. + path = append(path, root) + } + + return +} + +// tokenNode is a dummy implementation of ast.Node for a single token. +// They are used transiently by PathEnclosingInterval but never escape +// this package. +// +type tokenNode struct { + pos token.Pos + end token.Pos +} + +func (n tokenNode) Pos() token.Pos { + return n.pos +} + +func (n tokenNode) End() token.Pos { + return n.end +} + +func tok(pos token.Pos, len int) ast.Node { + return tokenNode{pos, pos + token.Pos(len)} +} + +// childrenOf returns the direct non-nil children of ast.Node n. +// It may include fake ast.Node implementations for bare tokens. +// it is not safe to call (e.g.) ast.Walk on such nodes. +// +func childrenOf(n ast.Node) []ast.Node { + var children []ast.Node + + // First add nodes for all true subtrees. + ast.Inspect(n, func(node ast.Node) bool { + if node == n { // push n + return true // recur + } + if node != nil { // push child + children = append(children, node) + } + return false // no recursion + }) + + // Then add fake Nodes for bare tokens. + switch n := n.(type) { + case *ast.ArrayType: + children = append(children, + tok(n.Lbrack, len("[")), + tok(n.Elt.End(), len("]"))) + + case *ast.AssignStmt: + children = append(children, + tok(n.TokPos, len(n.Tok.String()))) + + case *ast.BasicLit: + children = append(children, + tok(n.ValuePos, len(n.Value))) + + case *ast.BinaryExpr: + children = append(children, tok(n.OpPos, len(n.Op.String()))) + + case *ast.BlockStmt: + children = append(children, + tok(n.Lbrace, len("{")), + tok(n.Rbrace, len("}"))) + + case *ast.BranchStmt: + children = append(children, + tok(n.TokPos, len(n.Tok.String()))) + + case *ast.CallExpr: + children = append(children, + tok(n.Lparen, len("(")), + tok(n.Rparen, len(")"))) + if n.Ellipsis != 0 { + children = append(children, tok(n.Ellipsis, len("..."))) + } + + case *ast.CaseClause: + if n.List == nil { + children = append(children, + tok(n.Case, len("default"))) + } else { + children = append(children, + tok(n.Case, len("case"))) + } + children = append(children, tok(n.Colon, len(":"))) + + case *ast.ChanType: + switch n.Dir { + case ast.RECV: + children = append(children, tok(n.Begin, len("<-chan"))) + case ast.SEND: + children = append(children, tok(n.Begin, len("chan<-"))) + case ast.RECV | ast.SEND: + children = append(children, tok(n.Begin, len("chan"))) + } + + case *ast.CommClause: + if n.Comm == nil { + children = append(children, + tok(n.Case, len("default"))) + } else { + children = append(children, + tok(n.Case, len("case"))) + } + children = append(children, tok(n.Colon, len(":"))) + + case *ast.Comment: + // nop + + case *ast.CommentGroup: + // nop + + case *ast.CompositeLit: + children = append(children, + tok(n.Lbrace, len("{")), + tok(n.Rbrace, len("{"))) + + case *ast.DeclStmt: + // nop + + case *ast.DeferStmt: + children = append(children, + tok(n.Defer, len("defer"))) + + case *ast.Ellipsis: + children = append(children, + tok(n.Ellipsis, len("..."))) + + case *ast.EmptyStmt: + // nop + + case *ast.ExprStmt: + // nop + + case *ast.Field: + // TODO(adonovan): Field.{Doc,Comment,Tag}? + + case *ast.FieldList: + children = append(children, + tok(n.Opening, len("(")), + tok(n.Closing, len(")"))) + + case *ast.File: + // TODO test: Doc + children = append(children, + tok(n.Package, len("package"))) + + case *ast.ForStmt: + children = append(children, + tok(n.For, len("for"))) + + case *ast.FuncDecl: + // TODO(adonovan): FuncDecl.Comment? + + // Uniquely, FuncDecl breaks the invariant that + // preorder traversal yields tokens in lexical order: + // in fact, FuncDecl.Recv precedes FuncDecl.Type.Func. + // + // As a workaround, we inline the case for FuncType + // here and order things correctly. + // + children = nil // discard ast.Walk(FuncDecl) info subtrees + children = append(children, tok(n.Type.Func, len("func"))) + if n.Recv != nil { + children = append(children, n.Recv) + } + children = append(children, n.Name) + if n.Type.Params != nil { + children = append(children, n.Type.Params) + } + if n.Type.Results != nil { + children = append(children, n.Type.Results) + } + if n.Body != nil { + children = append(children, n.Body) + } + + case *ast.FuncLit: + // nop + + case *ast.FuncType: + if n.Func != 0 { + children = append(children, + tok(n.Func, len("func"))) + } + + case *ast.GenDecl: + children = append(children, + tok(n.TokPos, len(n.Tok.String()))) + if n.Lparen != 0 { + children = append(children, + tok(n.Lparen, len("(")), + tok(n.Rparen, len(")"))) + } + + case *ast.GoStmt: + children = append(children, + tok(n.Go, len("go"))) + + case *ast.Ident: + children = append(children, + tok(n.NamePos, len(n.Name))) + + case *ast.IfStmt: + children = append(children, + tok(n.If, len("if"))) + + case *ast.ImportSpec: + // TODO(adonovan): ImportSpec.{Doc,EndPos}? + + case *ast.IncDecStmt: + children = append(children, + tok(n.TokPos, len(n.Tok.String()))) + + case *ast.IndexExpr: + children = append(children, + tok(n.Lbrack, len("{")), + tok(n.Rbrack, len("}"))) + + case *ast.InterfaceType: + children = append(children, + tok(n.Interface, len("interface"))) + + case *ast.KeyValueExpr: + children = append(children, + tok(n.Colon, len(":"))) + + case *ast.LabeledStmt: + children = append(children, + tok(n.Colon, len(":"))) + + case *ast.MapType: + children = append(children, + tok(n.Map, len("map"))) + + case *ast.ParenExpr: + children = append(children, + tok(n.Lparen, len("(")), + tok(n.Rparen, len(")"))) + + case *ast.RangeStmt: + children = append(children, + tok(n.For, len("for")), + tok(n.TokPos, len(n.Tok.String()))) + + case *ast.ReturnStmt: + children = append(children, + tok(n.Return, len("return"))) + + case *ast.SelectStmt: + children = append(children, + tok(n.Select, len("select"))) + + case *ast.SelectorExpr: + // nop + + case *ast.SendStmt: + children = append(children, + tok(n.Arrow, len("<-"))) + + case *ast.SliceExpr: + children = append(children, + tok(n.Lbrack, len("[")), + tok(n.Rbrack, len("]"))) + + case *ast.StarExpr: + children = append(children, tok(n.Star, len("*"))) + + case *ast.StructType: + children = append(children, tok(n.Struct, len("struct"))) + + case *ast.SwitchStmt: + children = append(children, tok(n.Switch, len("switch"))) + + case *ast.TypeAssertExpr: + children = append(children, + tok(n.Lparen-1, len(".")), + tok(n.Lparen, len("(")), + tok(n.Rparen, len(")"))) + + case *ast.TypeSpec: + // TODO(adonovan): TypeSpec.{Doc,Comment}? + + case *ast.TypeSwitchStmt: + children = append(children, tok(n.Switch, len("switch"))) + + case *ast.UnaryExpr: + children = append(children, tok(n.OpPos, len(n.Op.String()))) + + case *ast.ValueSpec: + // TODO(adonovan): ValueSpec.{Doc,Comment}? + + case *ast.BadDecl, *ast.BadExpr, *ast.BadStmt: + // nop + } + + // TODO(adonovan): opt: merge the logic of ast.Inspect() into + // the switch above so we can make interleaved callbacks for + // both Nodes and Tokens in the right order and avoid the need + // to sort. + sort.Sort(byPos(children)) + + return children +} + +type byPos []ast.Node + +func (sl byPos) Len() int { + return len(sl) +} +func (sl byPos) Less(i, j int) bool { + return sl[i].Pos() < sl[j].Pos() +} +func (sl byPos) Swap(i, j int) { + sl[i], sl[j] = sl[j], sl[i] +} + +// NodeDescription returns a description of the concrete type of n suitable +// for a user interface. +// +// TODO(adonovan): in some cases (e.g. Field, FieldList, Ident, +// StarExpr) we could be much more specific given the path to the AST +// root. Perhaps we should do that. +// +func NodeDescription(n ast.Node) string { + switch n := n.(type) { + case *ast.ArrayType: + return "array type" + case *ast.AssignStmt: + return "assignment" + case *ast.BadDecl: + return "bad declaration" + case *ast.BadExpr: + return "bad expression" + case *ast.BadStmt: + return "bad statement" + case *ast.BasicLit: + return "basic literal" + case *ast.BinaryExpr: + return fmt.Sprintf("binary %s operation", n.Op) + case *ast.BlockStmt: + return "block" + case *ast.BranchStmt: + switch n.Tok { + case token.BREAK: + return "break statement" + case token.CONTINUE: + return "continue statement" + case token.GOTO: + return "goto statement" + case token.FALLTHROUGH: + return "fall-through statement" + } + case *ast.CallExpr: + if len(n.Args) == 1 && !n.Ellipsis.IsValid() { + return "function call (or conversion)" + } + return "function call" + case *ast.CaseClause: + return "case clause" + case *ast.ChanType: + return "channel type" + case *ast.CommClause: + return "communication clause" + case *ast.Comment: + return "comment" + case *ast.CommentGroup: + return "comment group" + case *ast.CompositeLit: + return "composite literal" + case *ast.DeclStmt: + return NodeDescription(n.Decl) + " statement" + case *ast.DeferStmt: + return "defer statement" + case *ast.Ellipsis: + return "ellipsis" + case *ast.EmptyStmt: + return "empty statement" + case *ast.ExprStmt: + return "expression statement" + case *ast.Field: + // Can be any of these: + // struct {x, y int} -- struct field(s) + // struct {T} -- anon struct field + // interface {I} -- interface embedding + // interface {f()} -- interface method + // func (A) func(B) C -- receiver, param(s), result(s) + return "field/method/parameter" + case *ast.FieldList: + return "field/method/parameter list" + case *ast.File: + return "source file" + case *ast.ForStmt: + return "for loop" + case *ast.FuncDecl: + return "function declaration" + case *ast.FuncLit: + return "function literal" + case *ast.FuncType: + return "function type" + case *ast.GenDecl: + switch n.Tok { + case token.IMPORT: + return "import declaration" + case token.CONST: + return "constant declaration" + case token.TYPE: + return "type declaration" + case token.VAR: + return "variable declaration" + } + case *ast.GoStmt: + return "go statement" + case *ast.Ident: + return "identifier" + case *ast.IfStmt: + return "if statement" + case *ast.ImportSpec: + return "import specification" + case *ast.IncDecStmt: + if n.Tok == token.INC { + return "increment statement" + } + return "decrement statement" + case *ast.IndexExpr: + return "index expression" + case *ast.InterfaceType: + return "interface type" + case *ast.KeyValueExpr: + return "key/value association" + case *ast.LabeledStmt: + return "statement label" + case *ast.MapType: + return "map type" + case *ast.Package: + return "package" + case *ast.ParenExpr: + return "parenthesized " + NodeDescription(n.X) + case *ast.RangeStmt: + return "range loop" + case *ast.ReturnStmt: + return "return statement" + case *ast.SelectStmt: + return "select statement" + case *ast.SelectorExpr: + return "selector" + case *ast.SendStmt: + return "channel send" + case *ast.SliceExpr: + return "slice expression" + case *ast.StarExpr: + return "*-operation" // load/store expr or pointer type + case *ast.StructType: + return "struct type" + case *ast.SwitchStmt: + return "switch statement" + case *ast.TypeAssertExpr: + return "type assertion" + case *ast.TypeSpec: + return "type specification" + case *ast.TypeSwitchStmt: + return "type switch" + case *ast.UnaryExpr: + return fmt.Sprintf("unary %s operation", n.Op) + case *ast.ValueSpec: + return "value specification" + + } + panic(fmt.Sprintf("unexpected node type: %T", n)) +} diff --git a/vendor/golang.org/x/tools/go/ast/astutil/imports.go b/vendor/golang.org/x/tools/go/ast/astutil/imports.go new file mode 100644 index 00000000000..3e4b195368b --- /dev/null +++ b/vendor/golang.org/x/tools/go/ast/astutil/imports.go @@ -0,0 +1,481 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package astutil contains common utilities for working with the Go AST. +package astutil // import "golang.org/x/tools/go/ast/astutil" + +import ( + "fmt" + "go/ast" + "go/token" + "strconv" + "strings" +) + +// AddImport adds the import path to the file f, if absent. +func AddImport(fset *token.FileSet, f *ast.File, path string) (added bool) { + return AddNamedImport(fset, f, "", path) +} + +// AddNamedImport adds the import with the given name and path to the file f, if absent. +// If name is not empty, it is used to rename the import. +// +// For example, calling +// AddNamedImport(fset, f, "pathpkg", "path") +// adds +// import pathpkg "path" +func AddNamedImport(fset *token.FileSet, f *ast.File, name, path string) (added bool) { + if imports(f, name, path) { + return false + } + + newImport := &ast.ImportSpec{ + Path: &ast.BasicLit{ + Kind: token.STRING, + Value: strconv.Quote(path), + }, + } + if name != "" { + newImport.Name = &ast.Ident{Name: name} + } + + // Find an import decl to add to. + // The goal is to find an existing import + // whose import path has the longest shared + // prefix with path. + var ( + bestMatch = -1 // length of longest shared prefix + lastImport = -1 // index in f.Decls of the file's final import decl + impDecl *ast.GenDecl // import decl containing the best match + impIndex = -1 // spec index in impDecl containing the best match + + isThirdPartyPath = isThirdParty(path) + ) + for i, decl := range f.Decls { + gen, ok := decl.(*ast.GenDecl) + if ok && gen.Tok == token.IMPORT { + lastImport = i + // Do not add to import "C", to avoid disrupting the + // association with its doc comment, breaking cgo. + if declImports(gen, "C") { + continue + } + + // Match an empty import decl if that's all that is available. + if len(gen.Specs) == 0 && bestMatch == -1 { + impDecl = gen + } + + // Compute longest shared prefix with imports in this group and find best + // matched import spec. + // 1. Always prefer import spec with longest shared prefix. + // 2. While match length is 0, + // - for stdlib package: prefer first import spec. + // - for third party package: prefer first third party import spec. + // We cannot use last import spec as best match for third party package + // because grouped imports are usually placed last by goimports -local + // flag. + // See issue #19190. + seenAnyThirdParty := false + for j, spec := range gen.Specs { + impspec := spec.(*ast.ImportSpec) + p := importPath(impspec) + n := matchLen(p, path) + if n > bestMatch || (bestMatch == 0 && !seenAnyThirdParty && isThirdPartyPath) { + bestMatch = n + impDecl = gen + impIndex = j + } + seenAnyThirdParty = seenAnyThirdParty || isThirdParty(p) + } + } + } + + // If no import decl found, add one after the last import. + if impDecl == nil { + impDecl = &ast.GenDecl{ + Tok: token.IMPORT, + } + if lastImport >= 0 { + impDecl.TokPos = f.Decls[lastImport].End() + } else { + // There are no existing imports. + // Our new import, preceded by a blank line, goes after the package declaration + // and after the comment, if any, that starts on the same line as the + // package declaration. + impDecl.TokPos = f.Package + + file := fset.File(f.Package) + pkgLine := file.Line(f.Package) + for _, c := range f.Comments { + if file.Line(c.Pos()) > pkgLine { + break + } + // +2 for a blank line + impDecl.TokPos = c.End() + 2 + } + } + f.Decls = append(f.Decls, nil) + copy(f.Decls[lastImport+2:], f.Decls[lastImport+1:]) + f.Decls[lastImport+1] = impDecl + } + + // Insert new import at insertAt. + insertAt := 0 + if impIndex >= 0 { + // insert after the found import + insertAt = impIndex + 1 + } + impDecl.Specs = append(impDecl.Specs, nil) + copy(impDecl.Specs[insertAt+1:], impDecl.Specs[insertAt:]) + impDecl.Specs[insertAt] = newImport + pos := impDecl.Pos() + if insertAt > 0 { + // If there is a comment after an existing import, preserve the comment + // position by adding the new import after the comment. + if spec, ok := impDecl.Specs[insertAt-1].(*ast.ImportSpec); ok && spec.Comment != nil { + pos = spec.Comment.End() + } else { + // Assign same position as the previous import, + // so that the sorter sees it as being in the same block. + pos = impDecl.Specs[insertAt-1].Pos() + } + } + if newImport.Name != nil { + newImport.Name.NamePos = pos + } + newImport.Path.ValuePos = pos + newImport.EndPos = pos + + // Clean up parens. impDecl contains at least one spec. + if len(impDecl.Specs) == 1 { + // Remove unneeded parens. + impDecl.Lparen = token.NoPos + } else if !impDecl.Lparen.IsValid() { + // impDecl needs parens added. + impDecl.Lparen = impDecl.Specs[0].Pos() + } + + f.Imports = append(f.Imports, newImport) + + if len(f.Decls) <= 1 { + return true + } + + // Merge all the import declarations into the first one. + var first *ast.GenDecl + for i := 0; i < len(f.Decls); i++ { + decl := f.Decls[i] + gen, ok := decl.(*ast.GenDecl) + if !ok || gen.Tok != token.IMPORT || declImports(gen, "C") { + continue + } + if first == nil { + first = gen + continue // Don't touch the first one. + } + // We now know there is more than one package in this import + // declaration. Ensure that it ends up parenthesized. + first.Lparen = first.Pos() + // Move the imports of the other import declaration to the first one. + for _, spec := range gen.Specs { + spec.(*ast.ImportSpec).Path.ValuePos = first.Pos() + first.Specs = append(first.Specs, spec) + } + f.Decls = append(f.Decls[:i], f.Decls[i+1:]...) + i-- + } + + return true +} + +func isThirdParty(importPath string) bool { + // Third party package import path usually contains "." (".com", ".org", ...) + // This logic is taken from golang.org/x/tools/imports package. + return strings.Contains(importPath, ".") +} + +// DeleteImport deletes the import path from the file f, if present. +// If there are duplicate import declarations, all matching ones are deleted. +func DeleteImport(fset *token.FileSet, f *ast.File, path string) (deleted bool) { + return DeleteNamedImport(fset, f, "", path) +} + +// DeleteNamedImport deletes the import with the given name and path from the file f, if present. +// If there are duplicate import declarations, all matching ones are deleted. +func DeleteNamedImport(fset *token.FileSet, f *ast.File, name, path string) (deleted bool) { + var delspecs []*ast.ImportSpec + var delcomments []*ast.CommentGroup + + // Find the import nodes that import path, if any. + for i := 0; i < len(f.Decls); i++ { + decl := f.Decls[i] + gen, ok := decl.(*ast.GenDecl) + if !ok || gen.Tok != token.IMPORT { + continue + } + for j := 0; j < len(gen.Specs); j++ { + spec := gen.Specs[j] + impspec := spec.(*ast.ImportSpec) + if importName(impspec) != name || importPath(impspec) != path { + continue + } + + // We found an import spec that imports path. + // Delete it. + delspecs = append(delspecs, impspec) + deleted = true + copy(gen.Specs[j:], gen.Specs[j+1:]) + gen.Specs = gen.Specs[:len(gen.Specs)-1] + + // If this was the last import spec in this decl, + // delete the decl, too. + if len(gen.Specs) == 0 { + copy(f.Decls[i:], f.Decls[i+1:]) + f.Decls = f.Decls[:len(f.Decls)-1] + i-- + break + } else if len(gen.Specs) == 1 { + if impspec.Doc != nil { + delcomments = append(delcomments, impspec.Doc) + } + if impspec.Comment != nil { + delcomments = append(delcomments, impspec.Comment) + } + for _, cg := range f.Comments { + // Found comment on the same line as the import spec. + if cg.End() < impspec.Pos() && fset.Position(cg.End()).Line == fset.Position(impspec.Pos()).Line { + delcomments = append(delcomments, cg) + break + } + } + + spec := gen.Specs[0].(*ast.ImportSpec) + + // Move the documentation right after the import decl. + if spec.Doc != nil { + for fset.Position(gen.TokPos).Line+1 < fset.Position(spec.Doc.Pos()).Line { + fset.File(gen.TokPos).MergeLine(fset.Position(gen.TokPos).Line) + } + } + for _, cg := range f.Comments { + if cg.End() < spec.Pos() && fset.Position(cg.End()).Line == fset.Position(spec.Pos()).Line { + for fset.Position(gen.TokPos).Line+1 < fset.Position(spec.Pos()).Line { + fset.File(gen.TokPos).MergeLine(fset.Position(gen.TokPos).Line) + } + break + } + } + } + if j > 0 { + lastImpspec := gen.Specs[j-1].(*ast.ImportSpec) + lastLine := fset.Position(lastImpspec.Path.ValuePos).Line + line := fset.Position(impspec.Path.ValuePos).Line + + // We deleted an entry but now there may be + // a blank line-sized hole where the import was. + if line-lastLine > 1 { + // There was a blank line immediately preceding the deleted import, + // so there's no need to close the hole. + // Do nothing. + } else if line != fset.File(gen.Rparen).LineCount() { + // There was no blank line. Close the hole. + fset.File(gen.Rparen).MergeLine(line) + } + } + j-- + } + } + + // Delete imports from f.Imports. + for i := 0; i < len(f.Imports); i++ { + imp := f.Imports[i] + for j, del := range delspecs { + if imp == del { + copy(f.Imports[i:], f.Imports[i+1:]) + f.Imports = f.Imports[:len(f.Imports)-1] + copy(delspecs[j:], delspecs[j+1:]) + delspecs = delspecs[:len(delspecs)-1] + i-- + break + } + } + } + + // Delete comments from f.Comments. + for i := 0; i < len(f.Comments); i++ { + cg := f.Comments[i] + for j, del := range delcomments { + if cg == del { + copy(f.Comments[i:], f.Comments[i+1:]) + f.Comments = f.Comments[:len(f.Comments)-1] + copy(delcomments[j:], delcomments[j+1:]) + delcomments = delcomments[:len(delcomments)-1] + i-- + break + } + } + } + + if len(delspecs) > 0 { + panic(fmt.Sprintf("deleted specs from Decls but not Imports: %v", delspecs)) + } + + return +} + +// RewriteImport rewrites any import of path oldPath to path newPath. +func RewriteImport(fset *token.FileSet, f *ast.File, oldPath, newPath string) (rewrote bool) { + for _, imp := range f.Imports { + if importPath(imp) == oldPath { + rewrote = true + // record old End, because the default is to compute + // it using the length of imp.Path.Value. + imp.EndPos = imp.End() + imp.Path.Value = strconv.Quote(newPath) + } + } + return +} + +// UsesImport reports whether a given import is used. +func UsesImport(f *ast.File, path string) (used bool) { + spec := importSpec(f, path) + if spec == nil { + return + } + + name := spec.Name.String() + switch name { + case "": + // If the package name is not explicitly specified, + // make an educated guess. This is not guaranteed to be correct. + lastSlash := strings.LastIndex(path, "/") + if lastSlash == -1 { + name = path + } else { + name = path[lastSlash+1:] + } + case "_", ".": + // Not sure if this import is used - err on the side of caution. + return true + } + + ast.Walk(visitFn(func(n ast.Node) { + sel, ok := n.(*ast.SelectorExpr) + if ok && isTopName(sel.X, name) { + used = true + } + }), f) + + return +} + +type visitFn func(node ast.Node) + +func (fn visitFn) Visit(node ast.Node) ast.Visitor { + fn(node) + return fn +} + +// imports reports whether f has an import with the specified name and path. +func imports(f *ast.File, name, path string) bool { + for _, s := range f.Imports { + if importName(s) == name && importPath(s) == path { + return true + } + } + return false +} + +// importSpec returns the import spec if f imports path, +// or nil otherwise. +func importSpec(f *ast.File, path string) *ast.ImportSpec { + for _, s := range f.Imports { + if importPath(s) == path { + return s + } + } + return nil +} + +// importName returns the name of s, +// or "" if the import is not named. +func importName(s *ast.ImportSpec) string { + if s.Name == nil { + return "" + } + return s.Name.Name +} + +// importPath returns the unquoted import path of s, +// or "" if the path is not properly quoted. +func importPath(s *ast.ImportSpec) string { + t, err := strconv.Unquote(s.Path.Value) + if err != nil { + return "" + } + return t +} + +// declImports reports whether gen contains an import of path. +func declImports(gen *ast.GenDecl, path string) bool { + if gen.Tok != token.IMPORT { + return false + } + for _, spec := range gen.Specs { + impspec := spec.(*ast.ImportSpec) + if importPath(impspec) == path { + return true + } + } + return false +} + +// matchLen returns the length of the longest path segment prefix shared by x and y. +func matchLen(x, y string) int { + n := 0 + for i := 0; i < len(x) && i < len(y) && x[i] == y[i]; i++ { + if x[i] == '/' { + n++ + } + } + return n +} + +// isTopName returns true if n is a top-level unresolved identifier with the given name. +func isTopName(n ast.Expr, name string) bool { + id, ok := n.(*ast.Ident) + return ok && id.Name == name && id.Obj == nil +} + +// Imports returns the file imports grouped by paragraph. +func Imports(fset *token.FileSet, f *ast.File) [][]*ast.ImportSpec { + var groups [][]*ast.ImportSpec + + for _, decl := range f.Decls { + genDecl, ok := decl.(*ast.GenDecl) + if !ok || genDecl.Tok != token.IMPORT { + break + } + + group := []*ast.ImportSpec{} + + var lastLine int + for _, spec := range genDecl.Specs { + importSpec := spec.(*ast.ImportSpec) + pos := importSpec.Path.ValuePos + line := fset.Position(pos).Line + if lastLine > 0 && pos > 0 && line-lastLine > 1 { + groups = append(groups, group) + group = []*ast.ImportSpec{} + } + group = append(group, importSpec) + lastLine = line + } + groups = append(groups, group) + } + + return groups +} diff --git a/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go b/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go new file mode 100644 index 00000000000..cf72ea990bd --- /dev/null +++ b/vendor/golang.org/x/tools/go/ast/astutil/rewrite.go @@ -0,0 +1,477 @@ +// Copyright 2017 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package astutil + +import ( + "fmt" + "go/ast" + "reflect" + "sort" +) + +// An ApplyFunc is invoked by Apply for each node n, even if n is nil, +// before and/or after the node's children, using a Cursor describing +// the current node and providing operations on it. +// +// The return value of ApplyFunc controls the syntax tree traversal. +// See Apply for details. +type ApplyFunc func(*Cursor) bool + +// Apply traverses a syntax tree recursively, starting with root, +// and calling pre and post for each node as described below. +// Apply returns the syntax tree, possibly modified. +// +// If pre is not nil, it is called for each node before the node's +// children are traversed (pre-order). If pre returns false, no +// children are traversed, and post is not called for that node. +// +// If post is not nil, and a prior call of pre didn't return false, +// post is called for each node after its children are traversed +// (post-order). If post returns false, traversal is terminated and +// Apply returns immediately. +// +// Only fields that refer to AST nodes are considered children; +// i.e., token.Pos, Scopes, Objects, and fields of basic types +// (strings, etc.) are ignored. +// +// Children are traversed in the order in which they appear in the +// respective node's struct definition. A package's files are +// traversed in the filenames' alphabetical order. +// +func Apply(root ast.Node, pre, post ApplyFunc) (result ast.Node) { + parent := &struct{ ast.Node }{root} + defer func() { + if r := recover(); r != nil && r != abort { + panic(r) + } + result = parent.Node + }() + a := &application{pre: pre, post: post} + a.apply(parent, "Node", nil, root) + return +} + +var abort = new(int) // singleton, to signal termination of Apply + +// A Cursor describes a node encountered during Apply. +// Information about the node and its parent is available +// from the Node, Parent, Name, and Index methods. +// +// If p is a variable of type and value of the current parent node +// c.Parent(), and f is the field identifier with name c.Name(), +// the following invariants hold: +// +// p.f == c.Node() if c.Index() < 0 +// p.f[c.Index()] == c.Node() if c.Index() >= 0 +// +// The methods Replace, Delete, InsertBefore, and InsertAfter +// can be used to change the AST without disrupting Apply. +type Cursor struct { + parent ast.Node + name string + iter *iterator // valid if non-nil + node ast.Node +} + +// Node returns the current Node. +func (c *Cursor) Node() ast.Node { return c.node } + +// Parent returns the parent of the current Node. +func (c *Cursor) Parent() ast.Node { return c.parent } + +// Name returns the name of the parent Node field that contains the current Node. +// If the parent is a *ast.Package and the current Node is a *ast.File, Name returns +// the filename for the current Node. +func (c *Cursor) Name() string { return c.name } + +// Index reports the index >= 0 of the current Node in the slice of Nodes that +// contains it, or a value < 0 if the current Node is not part of a slice. +// The index of the current node changes if InsertBefore is called while +// processing the current node. +func (c *Cursor) Index() int { + if c.iter != nil { + return c.iter.index + } + return -1 +} + +// field returns the current node's parent field value. +func (c *Cursor) field() reflect.Value { + return reflect.Indirect(reflect.ValueOf(c.parent)).FieldByName(c.name) +} + +// Replace replaces the current Node with n. +// The replacement node is not walked by Apply. +func (c *Cursor) Replace(n ast.Node) { + if _, ok := c.node.(*ast.File); ok { + file, ok := n.(*ast.File) + if !ok { + panic("attempt to replace *ast.File with non-*ast.File") + } + c.parent.(*ast.Package).Files[c.name] = file + return + } + + v := c.field() + if i := c.Index(); i >= 0 { + v = v.Index(i) + } + v.Set(reflect.ValueOf(n)) +} + +// Delete deletes the current Node from its containing slice. +// If the current Node is not part of a slice, Delete panics. +// As a special case, if the current node is a package file, +// Delete removes it from the package's Files map. +func (c *Cursor) Delete() { + if _, ok := c.node.(*ast.File); ok { + delete(c.parent.(*ast.Package).Files, c.name) + return + } + + i := c.Index() + if i < 0 { + panic("Delete node not contained in slice") + } + v := c.field() + l := v.Len() + reflect.Copy(v.Slice(i, l), v.Slice(i+1, l)) + v.Index(l - 1).Set(reflect.Zero(v.Type().Elem())) + v.SetLen(l - 1) + c.iter.step-- +} + +// InsertAfter inserts n after the current Node in its containing slice. +// If the current Node is not part of a slice, InsertAfter panics. +// Apply does not walk n. +func (c *Cursor) InsertAfter(n ast.Node) { + i := c.Index() + if i < 0 { + panic("InsertAfter node not contained in slice") + } + v := c.field() + v.Set(reflect.Append(v, reflect.Zero(v.Type().Elem()))) + l := v.Len() + reflect.Copy(v.Slice(i+2, l), v.Slice(i+1, l)) + v.Index(i + 1).Set(reflect.ValueOf(n)) + c.iter.step++ +} + +// InsertBefore inserts n before the current Node in its containing slice. +// If the current Node is not part of a slice, InsertBefore panics. +// Apply will not walk n. +func (c *Cursor) InsertBefore(n ast.Node) { + i := c.Index() + if i < 0 { + panic("InsertBefore node not contained in slice") + } + v := c.field() + v.Set(reflect.Append(v, reflect.Zero(v.Type().Elem()))) + l := v.Len() + reflect.Copy(v.Slice(i+1, l), v.Slice(i, l)) + v.Index(i).Set(reflect.ValueOf(n)) + c.iter.index++ +} + +// application carries all the shared data so we can pass it around cheaply. +type application struct { + pre, post ApplyFunc + cursor Cursor + iter iterator +} + +func (a *application) apply(parent ast.Node, name string, iter *iterator, n ast.Node) { + // convert typed nil into untyped nil + if v := reflect.ValueOf(n); v.Kind() == reflect.Ptr && v.IsNil() { + n = nil + } + + // avoid heap-allocating a new cursor for each apply call; reuse a.cursor instead + saved := a.cursor + a.cursor.parent = parent + a.cursor.name = name + a.cursor.iter = iter + a.cursor.node = n + + if a.pre != nil && !a.pre(&a.cursor) { + a.cursor = saved + return + } + + // walk children + // (the order of the cases matches the order of the corresponding node types in go/ast) + switch n := n.(type) { + case nil: + // nothing to do + + // Comments and fields + case *ast.Comment: + // nothing to do + + case *ast.CommentGroup: + if n != nil { + a.applyList(n, "List") + } + + case *ast.Field: + a.apply(n, "Doc", nil, n.Doc) + a.applyList(n, "Names") + a.apply(n, "Type", nil, n.Type) + a.apply(n, "Tag", nil, n.Tag) + a.apply(n, "Comment", nil, n.Comment) + + case *ast.FieldList: + a.applyList(n, "List") + + // Expressions + case *ast.BadExpr, *ast.Ident, *ast.BasicLit: + // nothing to do + + case *ast.Ellipsis: + a.apply(n, "Elt", nil, n.Elt) + + case *ast.FuncLit: + a.apply(n, "Type", nil, n.Type) + a.apply(n, "Body", nil, n.Body) + + case *ast.CompositeLit: + a.apply(n, "Type", nil, n.Type) + a.applyList(n, "Elts") + + case *ast.ParenExpr: + a.apply(n, "X", nil, n.X) + + case *ast.SelectorExpr: + a.apply(n, "X", nil, n.X) + a.apply(n, "Sel", nil, n.Sel) + + case *ast.IndexExpr: + a.apply(n, "X", nil, n.X) + a.apply(n, "Index", nil, n.Index) + + case *ast.SliceExpr: + a.apply(n, "X", nil, n.X) + a.apply(n, "Low", nil, n.Low) + a.apply(n, "High", nil, n.High) + a.apply(n, "Max", nil, n.Max) + + case *ast.TypeAssertExpr: + a.apply(n, "X", nil, n.X) + a.apply(n, "Type", nil, n.Type) + + case *ast.CallExpr: + a.apply(n, "Fun", nil, n.Fun) + a.applyList(n, "Args") + + case *ast.StarExpr: + a.apply(n, "X", nil, n.X) + + case *ast.UnaryExpr: + a.apply(n, "X", nil, n.X) + + case *ast.BinaryExpr: + a.apply(n, "X", nil, n.X) + a.apply(n, "Y", nil, n.Y) + + case *ast.KeyValueExpr: + a.apply(n, "Key", nil, n.Key) + a.apply(n, "Value", nil, n.Value) + + // Types + case *ast.ArrayType: + a.apply(n, "Len", nil, n.Len) + a.apply(n, "Elt", nil, n.Elt) + + case *ast.StructType: + a.apply(n, "Fields", nil, n.Fields) + + case *ast.FuncType: + a.apply(n, "Params", nil, n.Params) + a.apply(n, "Results", nil, n.Results) + + case *ast.InterfaceType: + a.apply(n, "Methods", nil, n.Methods) + + case *ast.MapType: + a.apply(n, "Key", nil, n.Key) + a.apply(n, "Value", nil, n.Value) + + case *ast.ChanType: + a.apply(n, "Value", nil, n.Value) + + // Statements + case *ast.BadStmt: + // nothing to do + + case *ast.DeclStmt: + a.apply(n, "Decl", nil, n.Decl) + + case *ast.EmptyStmt: + // nothing to do + + case *ast.LabeledStmt: + a.apply(n, "Label", nil, n.Label) + a.apply(n, "Stmt", nil, n.Stmt) + + case *ast.ExprStmt: + a.apply(n, "X", nil, n.X) + + case *ast.SendStmt: + a.apply(n, "Chan", nil, n.Chan) + a.apply(n, "Value", nil, n.Value) + + case *ast.IncDecStmt: + a.apply(n, "X", nil, n.X) + + case *ast.AssignStmt: + a.applyList(n, "Lhs") + a.applyList(n, "Rhs") + + case *ast.GoStmt: + a.apply(n, "Call", nil, n.Call) + + case *ast.DeferStmt: + a.apply(n, "Call", nil, n.Call) + + case *ast.ReturnStmt: + a.applyList(n, "Results") + + case *ast.BranchStmt: + a.apply(n, "Label", nil, n.Label) + + case *ast.BlockStmt: + a.applyList(n, "List") + + case *ast.IfStmt: + a.apply(n, "Init", nil, n.Init) + a.apply(n, "Cond", nil, n.Cond) + a.apply(n, "Body", nil, n.Body) + a.apply(n, "Else", nil, n.Else) + + case *ast.CaseClause: + a.applyList(n, "List") + a.applyList(n, "Body") + + case *ast.SwitchStmt: + a.apply(n, "Init", nil, n.Init) + a.apply(n, "Tag", nil, n.Tag) + a.apply(n, "Body", nil, n.Body) + + case *ast.TypeSwitchStmt: + a.apply(n, "Init", nil, n.Init) + a.apply(n, "Assign", nil, n.Assign) + a.apply(n, "Body", nil, n.Body) + + case *ast.CommClause: + a.apply(n, "Comm", nil, n.Comm) + a.applyList(n, "Body") + + case *ast.SelectStmt: + a.apply(n, "Body", nil, n.Body) + + case *ast.ForStmt: + a.apply(n, "Init", nil, n.Init) + a.apply(n, "Cond", nil, n.Cond) + a.apply(n, "Post", nil, n.Post) + a.apply(n, "Body", nil, n.Body) + + case *ast.RangeStmt: + a.apply(n, "Key", nil, n.Key) + a.apply(n, "Value", nil, n.Value) + a.apply(n, "X", nil, n.X) + a.apply(n, "Body", nil, n.Body) + + // Declarations + case *ast.ImportSpec: + a.apply(n, "Doc", nil, n.Doc) + a.apply(n, "Name", nil, n.Name) + a.apply(n, "Path", nil, n.Path) + a.apply(n, "Comment", nil, n.Comment) + + case *ast.ValueSpec: + a.apply(n, "Doc", nil, n.Doc) + a.applyList(n, "Names") + a.apply(n, "Type", nil, n.Type) + a.applyList(n, "Values") + a.apply(n, "Comment", nil, n.Comment) + + case *ast.TypeSpec: + a.apply(n, "Doc", nil, n.Doc) + a.apply(n, "Name", nil, n.Name) + a.apply(n, "Type", nil, n.Type) + a.apply(n, "Comment", nil, n.Comment) + + case *ast.BadDecl: + // nothing to do + + case *ast.GenDecl: + a.apply(n, "Doc", nil, n.Doc) + a.applyList(n, "Specs") + + case *ast.FuncDecl: + a.apply(n, "Doc", nil, n.Doc) + a.apply(n, "Recv", nil, n.Recv) + a.apply(n, "Name", nil, n.Name) + a.apply(n, "Type", nil, n.Type) + a.apply(n, "Body", nil, n.Body) + + // Files and packages + case *ast.File: + a.apply(n, "Doc", nil, n.Doc) + a.apply(n, "Name", nil, n.Name) + a.applyList(n, "Decls") + // Don't walk n.Comments; they have either been walked already if + // they are Doc comments, or they can be easily walked explicitly. + + case *ast.Package: + // collect and sort names for reproducible behavior + var names []string + for name := range n.Files { + names = append(names, name) + } + sort.Strings(names) + for _, name := range names { + a.apply(n, name, nil, n.Files[name]) + } + + default: + panic(fmt.Sprintf("Apply: unexpected node type %T", n)) + } + + if a.post != nil && !a.post(&a.cursor) { + panic(abort) + } + + a.cursor = saved +} + +// An iterator controls iteration over a slice of nodes. +type iterator struct { + index, step int +} + +func (a *application) applyList(parent ast.Node, name string) { + // avoid heap-allocating a new iterator for each applyList call; reuse a.iter instead + saved := a.iter + a.iter.index = 0 + for { + // must reload parent.name each time, since cursor modifications might change it + v := reflect.Indirect(reflect.ValueOf(parent)).FieldByName(name) + if a.iter.index >= v.Len() { + break + } + + // element x may be nil in a bad AST - be cautious + var x ast.Node + if e := v.Index(a.iter.index); e.IsValid() { + x = e.Interface().(ast.Node) + } + + a.iter.step = 1 + a.apply(parent, name, &a.iter, x) + a.iter.index += a.iter.step + } + a.iter = saved +} diff --git a/vendor/golang.org/x/tools/go/ast/astutil/util.go b/vendor/golang.org/x/tools/go/ast/astutil/util.go new file mode 100644 index 00000000000..7630629824a --- /dev/null +++ b/vendor/golang.org/x/tools/go/ast/astutil/util.go @@ -0,0 +1,14 @@ +package astutil + +import "go/ast" + +// Unparen returns e with any enclosing parentheses stripped. +func Unparen(e ast.Expr) ast.Expr { + for { + p, ok := e.(*ast.ParenExpr) + if !ok { + return e + } + e = p.X + } +} diff --git a/vendor/golang.org/x/tools/go/buildutil/allpackages.go b/vendor/golang.org/x/tools/go/buildutil/allpackages.go new file mode 100644 index 00000000000..c0cb03e7bee --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/allpackages.go @@ -0,0 +1,198 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package buildutil provides utilities related to the go/build +// package in the standard library. +// +// All I/O is done via the build.Context file system interface, which must +// be concurrency-safe. +package buildutil // import "golang.org/x/tools/go/buildutil" + +import ( + "go/build" + "os" + "path/filepath" + "sort" + "strings" + "sync" +) + +// AllPackages returns the package path of each Go package in any source +// directory of the specified build context (e.g. $GOROOT or an element +// of $GOPATH). Errors are ignored. The results are sorted. +// All package paths are canonical, and thus may contain "/vendor/". +// +// The result may include import paths for directories that contain no +// *.go files, such as "archive" (in $GOROOT/src). +// +// All I/O is done via the build.Context file system interface, +// which must be concurrency-safe. +// +func AllPackages(ctxt *build.Context) []string { + var list []string + ForEachPackage(ctxt, func(pkg string, _ error) { + list = append(list, pkg) + }) + sort.Strings(list) + return list +} + +// ForEachPackage calls the found function with the package path of +// each Go package it finds in any source directory of the specified +// build context (e.g. $GOROOT or an element of $GOPATH). +// All package paths are canonical, and thus may contain "/vendor/". +// +// If the package directory exists but could not be read, the second +// argument to the found function provides the error. +// +// All I/O is done via the build.Context file system interface, +// which must be concurrency-safe. +// +func ForEachPackage(ctxt *build.Context, found func(importPath string, err error)) { + ch := make(chan item) + + var wg sync.WaitGroup + for _, root := range ctxt.SrcDirs() { + root := root + wg.Add(1) + go func() { + allPackages(ctxt, root, ch) + wg.Done() + }() + } + go func() { + wg.Wait() + close(ch) + }() + + // All calls to found occur in the caller's goroutine. + for i := range ch { + found(i.importPath, i.err) + } +} + +type item struct { + importPath string + err error // (optional) +} + +// We use a process-wide counting semaphore to limit +// the number of parallel calls to ReadDir. +var ioLimit = make(chan bool, 20) + +func allPackages(ctxt *build.Context, root string, ch chan<- item) { + root = filepath.Clean(root) + string(os.PathSeparator) + + var wg sync.WaitGroup + + var walkDir func(dir string) + walkDir = func(dir string) { + // Avoid .foo, _foo, and testdata directory trees. + base := filepath.Base(dir) + if base == "" || base[0] == '.' || base[0] == '_' || base == "testdata" { + return + } + + pkg := filepath.ToSlash(strings.TrimPrefix(dir, root)) + + // Prune search if we encounter any of these import paths. + switch pkg { + case "builtin": + return + } + + ioLimit <- true + files, err := ReadDir(ctxt, dir) + <-ioLimit + if pkg != "" || err != nil { + ch <- item{pkg, err} + } + for _, fi := range files { + fi := fi + if fi.IsDir() { + wg.Add(1) + go func() { + walkDir(filepath.Join(dir, fi.Name())) + wg.Done() + }() + } + } + } + + walkDir(root) + wg.Wait() +} + +// ExpandPatterns returns the set of packages matched by patterns, +// which may have the following forms: +// +// golang.org/x/tools/cmd/guru # a single package +// golang.org/x/tools/... # all packages beneath dir +// ... # the entire workspace. +// +// Order is significant: a pattern preceded by '-' removes matching +// packages from the set. For example, these patterns match all encoding +// packages except encoding/xml: +// +// encoding/... -encoding/xml +// +// A trailing slash in a pattern is ignored. (Path components of Go +// package names are separated by slash, not the platform's path separator.) +// +func ExpandPatterns(ctxt *build.Context, patterns []string) map[string]bool { + // TODO(adonovan): support other features of 'go list': + // - "std"/"cmd"/"all" meta-packages + // - "..." not at the end of a pattern + // - relative patterns using "./" or "../" prefix + + pkgs := make(map[string]bool) + doPkg := func(pkg string, neg bool) { + if neg { + delete(pkgs, pkg) + } else { + pkgs[pkg] = true + } + } + + // Scan entire workspace if wildcards are present. + // TODO(adonovan): opt: scan only the necessary subtrees of the workspace. + var all []string + for _, arg := range patterns { + if strings.HasSuffix(arg, "...") { + all = AllPackages(ctxt) + break + } + } + + for _, arg := range patterns { + if arg == "" { + continue + } + + neg := arg[0] == '-' + if neg { + arg = arg[1:] + } + + if arg == "..." { + // ... matches all packages + for _, pkg := range all { + doPkg(pkg, neg) + } + } else if dir := strings.TrimSuffix(arg, "/..."); dir != arg { + // dir/... matches all packages beneath dir + for _, pkg := range all { + if strings.HasPrefix(pkg, dir) && + (len(pkg) == len(dir) || pkg[len(dir)] == '/') { + doPkg(pkg, neg) + } + } + } else { + // single package + doPkg(strings.TrimSuffix(arg, "/"), neg) + } + } + + return pkgs +} diff --git a/vendor/golang.org/x/tools/go/buildutil/fakecontext.go b/vendor/golang.org/x/tools/go/buildutil/fakecontext.go new file mode 100644 index 00000000000..8b7f066739f --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/fakecontext.go @@ -0,0 +1,109 @@ +package buildutil + +import ( + "fmt" + "go/build" + "io" + "io/ioutil" + "os" + "path" + "path/filepath" + "sort" + "strings" + "time" +) + +// FakeContext returns a build.Context for the fake file tree specified +// by pkgs, which maps package import paths to a mapping from file base +// names to contents. +// +// The fake Context has a GOROOT of "/go" and no GOPATH, and overrides +// the necessary file access methods to read from memory instead of the +// real file system. +// +// Unlike a real file tree, the fake one has only two levels---packages +// and files---so ReadDir("/go/src/") returns all packages under +// /go/src/ including, for instance, "math" and "math/big". +// ReadDir("/go/src/math/big") would return all the files in the +// "math/big" package. +// +func FakeContext(pkgs map[string]map[string]string) *build.Context { + clean := func(filename string) string { + f := path.Clean(filepath.ToSlash(filename)) + // Removing "/go/src" while respecting segment + // boundaries has this unfortunate corner case: + if f == "/go/src" { + return "" + } + return strings.TrimPrefix(f, "/go/src/") + } + + ctxt := build.Default // copy + ctxt.GOROOT = "/go" + ctxt.GOPATH = "" + ctxt.Compiler = "gc" + ctxt.IsDir = func(dir string) bool { + dir = clean(dir) + if dir == "" { + return true // needed by (*build.Context).SrcDirs + } + return pkgs[dir] != nil + } + ctxt.ReadDir = func(dir string) ([]os.FileInfo, error) { + dir = clean(dir) + var fis []os.FileInfo + if dir == "" { + // enumerate packages + for importPath := range pkgs { + fis = append(fis, fakeDirInfo(importPath)) + } + } else { + // enumerate files of package + for basename := range pkgs[dir] { + fis = append(fis, fakeFileInfo(basename)) + } + } + sort.Sort(byName(fis)) + return fis, nil + } + ctxt.OpenFile = func(filename string) (io.ReadCloser, error) { + filename = clean(filename) + dir, base := path.Split(filename) + content, ok := pkgs[path.Clean(dir)][base] + if !ok { + return nil, fmt.Errorf("file not found: %s", filename) + } + return ioutil.NopCloser(strings.NewReader(content)), nil + } + ctxt.IsAbsPath = func(path string) bool { + path = filepath.ToSlash(path) + // Don't rely on the default (filepath.Path) since on + // Windows, it reports virtual paths as non-absolute. + return strings.HasPrefix(path, "/") + } + return &ctxt +} + +type byName []os.FileInfo + +func (s byName) Len() int { return len(s) } +func (s byName) Swap(i, j int) { s[i], s[j] = s[j], s[i] } +func (s byName) Less(i, j int) bool { return s[i].Name() < s[j].Name() } + +type fakeFileInfo string + +func (fi fakeFileInfo) Name() string { return string(fi) } +func (fakeFileInfo) Sys() interface{} { return nil } +func (fakeFileInfo) ModTime() time.Time { return time.Time{} } +func (fakeFileInfo) IsDir() bool { return false } +func (fakeFileInfo) Size() int64 { return 0 } +func (fakeFileInfo) Mode() os.FileMode { return 0644 } + +type fakeDirInfo string + +func (fd fakeDirInfo) Name() string { return string(fd) } +func (fakeDirInfo) Sys() interface{} { return nil } +func (fakeDirInfo) ModTime() time.Time { return time.Time{} } +func (fakeDirInfo) IsDir() bool { return true } +func (fakeDirInfo) Size() int64 { return 0 } +func (fakeDirInfo) Mode() os.FileMode { return 0755 } diff --git a/vendor/golang.org/x/tools/go/buildutil/overlay.go b/vendor/golang.org/x/tools/go/buildutil/overlay.go new file mode 100644 index 00000000000..8e239086bd4 --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/overlay.go @@ -0,0 +1,103 @@ +// Copyright 2016 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package buildutil + +import ( + "bufio" + "bytes" + "fmt" + "go/build" + "io" + "io/ioutil" + "path/filepath" + "strconv" + "strings" +) + +// OverlayContext overlays a build.Context with additional files from +// a map. Files in the map take precedence over other files. +// +// In addition to plain string comparison, two file names are +// considered equal if their base names match and their directory +// components point at the same directory on the file system. That is, +// symbolic links are followed for directories, but not files. +// +// A common use case for OverlayContext is to allow editors to pass in +// a set of unsaved, modified files. +// +// Currently, only the Context.OpenFile function will respect the +// overlay. This may change in the future. +func OverlayContext(orig *build.Context, overlay map[string][]byte) *build.Context { + // TODO(dominikh): Implement IsDir, HasSubdir and ReadDir + + rc := func(data []byte) (io.ReadCloser, error) { + return ioutil.NopCloser(bytes.NewBuffer(data)), nil + } + + copy := *orig // make a copy + ctxt := © + ctxt.OpenFile = func(path string) (io.ReadCloser, error) { + // Fast path: names match exactly. + if content, ok := overlay[path]; ok { + return rc(content) + } + + // Slow path: check for same file under a different + // alias, perhaps due to a symbolic link. + for filename, content := range overlay { + if sameFile(path, filename) { + return rc(content) + } + } + + return OpenFile(orig, path) + } + return ctxt +} + +// ParseOverlayArchive parses an archive containing Go files and their +// contents. The result is intended to be used with OverlayContext. +// +// +// Archive format +// +// The archive consists of a series of files. Each file consists of a +// name, a decimal file size and the file contents, separated by +// newlines. No newline follows after the file contents. +func ParseOverlayArchive(archive io.Reader) (map[string][]byte, error) { + overlay := make(map[string][]byte) + r := bufio.NewReader(archive) + for { + // Read file name. + filename, err := r.ReadString('\n') + if err != nil { + if err == io.EOF { + break // OK + } + return nil, fmt.Errorf("reading archive file name: %v", err) + } + filename = filepath.Clean(strings.TrimSpace(filename)) + + // Read file size. + sz, err := r.ReadString('\n') + if err != nil { + return nil, fmt.Errorf("reading size of archive file %s: %v", filename, err) + } + sz = strings.TrimSpace(sz) + size, err := strconv.ParseUint(sz, 10, 32) + if err != nil { + return nil, fmt.Errorf("parsing size of archive file %s: %v", filename, err) + } + + // Read file content. + content := make([]byte, size) + if _, err := io.ReadFull(r, content); err != nil { + return nil, fmt.Errorf("reading archive file %s: %v", filename, err) + } + overlay[filename] = content + } + + return overlay, nil +} diff --git a/vendor/golang.org/x/tools/go/buildutil/tags.go b/vendor/golang.org/x/tools/go/buildutil/tags.go new file mode 100644 index 00000000000..486606f3768 --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/tags.go @@ -0,0 +1,75 @@ +package buildutil + +// This logic was copied from stringsFlag from $GOROOT/src/cmd/go/build.go. + +import "fmt" + +const TagsFlagDoc = "a list of `build tags` to consider satisfied during the build. " + + "For more information about build tags, see the description of " + + "build constraints in the documentation for the go/build package" + +// TagsFlag is an implementation of the flag.Value and flag.Getter interfaces that parses +// a flag value in the same manner as go build's -tags flag and +// populates a []string slice. +// +// See $GOROOT/src/go/build/doc.go for description of build tags. +// See $GOROOT/src/cmd/go/doc.go for description of 'go build -tags' flag. +// +// Example: +// flag.Var((*buildutil.TagsFlag)(&build.Default.BuildTags), "tags", buildutil.TagsFlagDoc) +type TagsFlag []string + +func (v *TagsFlag) Set(s string) error { + var err error + *v, err = splitQuotedFields(s) + if *v == nil { + *v = []string{} + } + return err +} + +func (v *TagsFlag) Get() interface{} { return *v } + +func splitQuotedFields(s string) ([]string, error) { + // Split fields allowing '' or "" around elements. + // Quotes further inside the string do not count. + var f []string + for len(s) > 0 { + for len(s) > 0 && isSpaceByte(s[0]) { + s = s[1:] + } + if len(s) == 0 { + break + } + // Accepted quoted string. No unescaping inside. + if s[0] == '"' || s[0] == '\'' { + quote := s[0] + s = s[1:] + i := 0 + for i < len(s) && s[i] != quote { + i++ + } + if i >= len(s) { + return nil, fmt.Errorf("unterminated %c string", quote) + } + f = append(f, s[:i]) + s = s[i+1:] + continue + } + i := 0 + for i < len(s) && !isSpaceByte(s[i]) { + i++ + } + f = append(f, s[:i]) + s = s[i:] + } + return f, nil +} + +func (v *TagsFlag) String() string { + return "" +} + +func isSpaceByte(c byte) bool { + return c == ' ' || c == '\t' || c == '\n' || c == '\r' +} diff --git a/vendor/golang.org/x/tools/go/buildutil/util.go b/vendor/golang.org/x/tools/go/buildutil/util.go new file mode 100644 index 00000000000..fc923d7a702 --- /dev/null +++ b/vendor/golang.org/x/tools/go/buildutil/util.go @@ -0,0 +1,212 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package buildutil + +import ( + "fmt" + "go/ast" + "go/build" + "go/parser" + "go/token" + "io" + "io/ioutil" + "os" + "path" + "path/filepath" + "strings" +) + +// ParseFile behaves like parser.ParseFile, +// but uses the build context's file system interface, if any. +// +// If file is not absolute (as defined by IsAbsPath), the (dir, file) +// components are joined using JoinPath; dir must be absolute. +// +// The displayPath function, if provided, is used to transform the +// filename that will be attached to the ASTs. +// +// TODO(adonovan): call this from go/loader.parseFiles when the tree thaws. +// +func ParseFile(fset *token.FileSet, ctxt *build.Context, displayPath func(string) string, dir string, file string, mode parser.Mode) (*ast.File, error) { + if !IsAbsPath(ctxt, file) { + file = JoinPath(ctxt, dir, file) + } + rd, err := OpenFile(ctxt, file) + if err != nil { + return nil, err + } + defer rd.Close() // ignore error + if displayPath != nil { + file = displayPath(file) + } + return parser.ParseFile(fset, file, rd, mode) +} + +// ContainingPackage returns the package containing filename. +// +// If filename is not absolute, it is interpreted relative to working directory dir. +// All I/O is via the build context's file system interface, if any. +// +// The '...Files []string' fields of the resulting build.Package are not +// populated (build.FindOnly mode). +// +func ContainingPackage(ctxt *build.Context, dir, filename string) (*build.Package, error) { + if !IsAbsPath(ctxt, filename) { + filename = JoinPath(ctxt, dir, filename) + } + + // We must not assume the file tree uses + // "/" always, + // `\` always, + // or os.PathSeparator (which varies by platform), + // but to make any progress, we are forced to assume that + // paths will not use `\` unless the PathSeparator + // is also `\`, thus we can rely on filepath.ToSlash for some sanity. + + dirSlash := path.Dir(filepath.ToSlash(filename)) + "/" + + // We assume that no source root (GOPATH[i] or GOROOT) contains any other. + for _, srcdir := range ctxt.SrcDirs() { + srcdirSlash := filepath.ToSlash(srcdir) + "/" + if importPath, ok := HasSubdir(ctxt, srcdirSlash, dirSlash); ok { + return ctxt.Import(importPath, dir, build.FindOnly) + } + } + + return nil, fmt.Errorf("can't find package containing %s", filename) +} + +// -- Effective methods of file system interface ------------------------- + +// (go/build.Context defines these as methods, but does not export them.) + +// hasSubdir calls ctxt.HasSubdir (if not nil) or else uses +// the local file system to answer the question. +func HasSubdir(ctxt *build.Context, root, dir string) (rel string, ok bool) { + if f := ctxt.HasSubdir; f != nil { + return f(root, dir) + } + + // Try using paths we received. + if rel, ok = hasSubdir(root, dir); ok { + return + } + + // Try expanding symlinks and comparing + // expanded against unexpanded and + // expanded against expanded. + rootSym, _ := filepath.EvalSymlinks(root) + dirSym, _ := filepath.EvalSymlinks(dir) + + if rel, ok = hasSubdir(rootSym, dir); ok { + return + } + if rel, ok = hasSubdir(root, dirSym); ok { + return + } + return hasSubdir(rootSym, dirSym) +} + +func hasSubdir(root, dir string) (rel string, ok bool) { + const sep = string(filepath.Separator) + root = filepath.Clean(root) + if !strings.HasSuffix(root, sep) { + root += sep + } + + dir = filepath.Clean(dir) + if !strings.HasPrefix(dir, root) { + return "", false + } + + return filepath.ToSlash(dir[len(root):]), true +} + +// FileExists returns true if the specified file exists, +// using the build context's file system interface. +func FileExists(ctxt *build.Context, path string) bool { + if ctxt.OpenFile != nil { + r, err := ctxt.OpenFile(path) + if err != nil { + return false + } + r.Close() // ignore error + return true + } + _, err := os.Stat(path) + return err == nil +} + +// OpenFile behaves like os.Open, +// but uses the build context's file system interface, if any. +func OpenFile(ctxt *build.Context, path string) (io.ReadCloser, error) { + if ctxt.OpenFile != nil { + return ctxt.OpenFile(path) + } + return os.Open(path) +} + +// IsAbsPath behaves like filepath.IsAbs, +// but uses the build context's file system interface, if any. +func IsAbsPath(ctxt *build.Context, path string) bool { + if ctxt.IsAbsPath != nil { + return ctxt.IsAbsPath(path) + } + return filepath.IsAbs(path) +} + +// JoinPath behaves like filepath.Join, +// but uses the build context's file system interface, if any. +func JoinPath(ctxt *build.Context, path ...string) string { + if ctxt.JoinPath != nil { + return ctxt.JoinPath(path...) + } + return filepath.Join(path...) +} + +// IsDir behaves like os.Stat plus IsDir, +// but uses the build context's file system interface, if any. +func IsDir(ctxt *build.Context, path string) bool { + if ctxt.IsDir != nil { + return ctxt.IsDir(path) + } + fi, err := os.Stat(path) + return err == nil && fi.IsDir() +} + +// ReadDir behaves like ioutil.ReadDir, +// but uses the build context's file system interface, if any. +func ReadDir(ctxt *build.Context, path string) ([]os.FileInfo, error) { + if ctxt.ReadDir != nil { + return ctxt.ReadDir(path) + } + return ioutil.ReadDir(path) +} + +// SplitPathList behaves like filepath.SplitList, +// but uses the build context's file system interface, if any. +func SplitPathList(ctxt *build.Context, s string) []string { + if ctxt.SplitPathList != nil { + return ctxt.SplitPathList(s) + } + return filepath.SplitList(s) +} + +// sameFile returns true if x and y have the same basename and denote +// the same file. +// +func sameFile(x, y string) bool { + if path.Clean(x) == path.Clean(y) { + return true + } + if filepath.Base(x) == filepath.Base(y) { // (optimisation) + if xi, err := os.Stat(x); err == nil { + if yi, err := os.Stat(y); err == nil { + return os.SameFile(xi, yi) + } + } + } + return false +} diff --git a/vendor/golang.org/x/tools/go/callgraph/callgraph.go b/vendor/golang.org/x/tools/go/callgraph/callgraph.go new file mode 100644 index 00000000000..707a31931a7 --- /dev/null +++ b/vendor/golang.org/x/tools/go/callgraph/callgraph.go @@ -0,0 +1,129 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +/* + +Package callgraph defines the call graph and various algorithms +and utilities to operate on it. + +A call graph is a labelled directed graph whose nodes represent +functions and whose edge labels represent syntactic function call +sites. The presence of a labelled edge (caller, site, callee) +indicates that caller may call callee at the specified call site. + +A call graph is a multigraph: it may contain multiple edges (caller, +*, callee) connecting the same pair of nodes, so long as the edges +differ by label; this occurs when one function calls another function +from multiple call sites. Also, it may contain multiple edges +(caller, site, *) that differ only by callee; this indicates a +polymorphic call. + +A SOUND call graph is one that overapproximates the dynamic calling +behaviors of the program in all possible executions. One call graph +is more PRECISE than another if it is a smaller overapproximation of +the dynamic behavior. + +All call graphs have a synthetic root node which is responsible for +calling main() and init(). + +Calls to built-in functions (e.g. panic, println) are not represented +in the call graph; they are treated like built-in operators of the +language. + +*/ +package callgraph // import "golang.org/x/tools/go/callgraph" + +// TODO(adonovan): add a function to eliminate wrappers from the +// callgraph, preserving topology. +// More generally, we could eliminate "uninteresting" nodes such as +// nodes from packages we don't care about. + +import ( + "fmt" + "go/token" + + "golang.org/x/tools/go/ssa" +) + +// A Graph represents a call graph. +// +// A graph may contain nodes that are not reachable from the root. +// If the call graph is sound, such nodes indicate unreachable +// functions. +// +type Graph struct { + Root *Node // the distinguished root node + Nodes map[*ssa.Function]*Node // all nodes by function +} + +// New returns a new Graph with the specified root node. +func New(root *ssa.Function) *Graph { + g := &Graph{Nodes: make(map[*ssa.Function]*Node)} + g.Root = g.CreateNode(root) + return g +} + +// CreateNode returns the Node for fn, creating it if not present. +func (g *Graph) CreateNode(fn *ssa.Function) *Node { + n, ok := g.Nodes[fn] + if !ok { + n = &Node{Func: fn, ID: len(g.Nodes)} + g.Nodes[fn] = n + } + return n +} + +// A Node represents a node in a call graph. +type Node struct { + Func *ssa.Function // the function this node represents + ID int // 0-based sequence number + In []*Edge // unordered set of incoming call edges (n.In[*].Callee == n) + Out []*Edge // unordered set of outgoing call edges (n.Out[*].Caller == n) +} + +func (n *Node) String() string { + return fmt.Sprintf("n%d:%s", n.ID, n.Func) +} + +// A Edge represents an edge in the call graph. +// +// Site is nil for edges originating in synthetic or intrinsic +// functions, e.g. reflect.Call or the root of the call graph. +type Edge struct { + Caller *Node + Site ssa.CallInstruction + Callee *Node +} + +func (e Edge) String() string { + return fmt.Sprintf("%s --> %s", e.Caller, e.Callee) +} + +func (e Edge) Description() string { + var prefix string + switch e.Site.(type) { + case nil: + return "synthetic call" + case *ssa.Go: + prefix = "concurrent " + case *ssa.Defer: + prefix = "deferred " + } + return prefix + e.Site.Common().Description() +} + +func (e Edge) Pos() token.Pos { + if e.Site == nil { + return token.NoPos + } + return e.Site.Pos() +} + +// AddEdge adds the edge (caller, site, callee) to the call graph. +// Elimination of duplicate edges is the caller's responsibility. +func AddEdge(caller *Node, site ssa.CallInstruction, callee *Node) { + e := &Edge{caller, site, callee} + callee.In = append(callee.In, e) + caller.Out = append(caller.Out, e) +} diff --git a/vendor/golang.org/x/tools/go/callgraph/cha/cha.go b/vendor/golang.org/x/tools/go/callgraph/cha/cha.go new file mode 100644 index 00000000000..215ff173d95 --- /dev/null +++ b/vendor/golang.org/x/tools/go/callgraph/cha/cha.go @@ -0,0 +1,139 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package cha computes the call graph of a Go program using the Class +// Hierarchy Analysis (CHA) algorithm. +// +// CHA was first described in "Optimization of Object-Oriented Programs +// Using Static Class Hierarchy Analysis", Jeffrey Dean, David Grove, +// and Craig Chambers, ECOOP'95. +// +// CHA is related to RTA (see go/callgraph/rta); the difference is that +// CHA conservatively computes the entire "implements" relation between +// interfaces and concrete types ahead of time, whereas RTA uses dynamic +// programming to construct it on the fly as it encounters new functions +// reachable from main. CHA may thus include spurious call edges for +// types that haven't been instantiated yet, or types that are never +// instantiated. +// +// Since CHA conservatively assumes that all functions are address-taken +// and all concrete types are put into interfaces, it is sound to run on +// partial programs, such as libraries without a main or test function. +// +package cha // import "golang.org/x/tools/go/callgraph/cha" + +import ( + "go/types" + + "golang.org/x/tools/go/callgraph" + "golang.org/x/tools/go/ssa" + "golang.org/x/tools/go/ssa/ssautil" + "golang.org/x/tools/go/types/typeutil" +) + +// CallGraph computes the call graph of the specified program using the +// Class Hierarchy Analysis algorithm. +// +func CallGraph(prog *ssa.Program) *callgraph.Graph { + cg := callgraph.New(nil) // TODO(adonovan) eliminate concept of rooted callgraph + + allFuncs := ssautil.AllFunctions(prog) + + // funcsBySig contains all functions, keyed by signature. It is + // the effective set of address-taken functions used to resolve + // a dynamic call of a particular signature. + var funcsBySig typeutil.Map // value is []*ssa.Function + + // methodsByName contains all methods, + // grouped by name for efficient lookup. + // (methodsById would be better but not every SSA method has a go/types ID.) + methodsByName := make(map[string][]*ssa.Function) + + // An imethod represents an interface method I.m. + // (There's no go/types object for it; + // a *types.Func may be shared by many interfaces due to interface embedding.) + type imethod struct { + I *types.Interface + id string + } + // methodsMemo records, for every abstract method call I.m on + // interface type I, the set of concrete methods C.m of all + // types C that satisfy interface I. + // + // Abstract methods may be shared by several interfaces, + // hence we must pass I explicitly, not guess from m. + // + // methodsMemo is just a cache, so it needn't be a typeutil.Map. + methodsMemo := make(map[imethod][]*ssa.Function) + lookupMethods := func(I *types.Interface, m *types.Func) []*ssa.Function { + id := m.Id() + methods, ok := methodsMemo[imethod{I, id}] + if !ok { + for _, f := range methodsByName[m.Name()] { + C := f.Signature.Recv().Type() // named or *named + if types.Implements(C, I) { + methods = append(methods, f) + } + } + methodsMemo[imethod{I, id}] = methods + } + return methods + } + + for f := range allFuncs { + if f.Signature.Recv() == nil { + // Package initializers can never be address-taken. + if f.Name() == "init" && f.Synthetic == "package initializer" { + continue + } + funcs, _ := funcsBySig.At(f.Signature).([]*ssa.Function) + funcs = append(funcs, f) + funcsBySig.Set(f.Signature, funcs) + } else { + methodsByName[f.Name()] = append(methodsByName[f.Name()], f) + } + } + + addEdge := func(fnode *callgraph.Node, site ssa.CallInstruction, g *ssa.Function) { + gnode := cg.CreateNode(g) + callgraph.AddEdge(fnode, site, gnode) + } + + addEdges := func(fnode *callgraph.Node, site ssa.CallInstruction, callees []*ssa.Function) { + // Because every call to a highly polymorphic and + // frequently used abstract method such as + // (io.Writer).Write is assumed to call every concrete + // Write method in the program, the call graph can + // contain a lot of duplication. + // + // TODO(adonovan): opt: consider factoring the callgraph + // API so that the Callers component of each edge is a + // slice of nodes, not a singleton. + for _, g := range callees { + addEdge(fnode, site, g) + } + } + + for f := range allFuncs { + fnode := cg.CreateNode(f) + for _, b := range f.Blocks { + for _, instr := range b.Instrs { + if site, ok := instr.(ssa.CallInstruction); ok { + call := site.Common() + if call.IsInvoke() { + tiface := call.Value.Type().Underlying().(*types.Interface) + addEdges(fnode, site, lookupMethods(tiface, call.Method)) + } else if g := call.StaticCallee(); g != nil { + addEdge(fnode, site, g) + } else if _, ok := call.Value.(*ssa.Builtin); !ok { + callees, _ := funcsBySig.At(call.Signature()).([]*ssa.Function) + addEdges(fnode, site, callees) + } + } + } + } + } + + return cg +} diff --git a/vendor/golang.org/x/tools/go/callgraph/rta/rta.go b/vendor/golang.org/x/tools/go/callgraph/rta/rta.go new file mode 100644 index 00000000000..e6b44606ae8 --- /dev/null +++ b/vendor/golang.org/x/tools/go/callgraph/rta/rta.go @@ -0,0 +1,459 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This package provides Rapid Type Analysis (RTA) for Go, a fast +// algorithm for call graph construction and discovery of reachable code +// (and hence dead code) and runtime types. The algorithm was first +// described in: +// +// David F. Bacon and Peter F. Sweeney. 1996. +// Fast static analysis of C++ virtual function calls. (OOPSLA '96) +// http://doi.acm.org/10.1145/236337.236371 +// +// The algorithm uses dynamic programming to tabulate the cross-product +// of the set of known "address taken" functions with the set of known +// dynamic calls of the same type. As each new address-taken function +// is discovered, call graph edges are added from each known callsite, +// and as each new call site is discovered, call graph edges are added +// from it to each known address-taken function. +// +// A similar approach is used for dynamic calls via interfaces: it +// tabulates the cross-product of the set of known "runtime types", +// i.e. types that may appear in an interface value, or be derived from +// one via reflection, with the set of known "invoke"-mode dynamic +// calls. As each new "runtime type" is discovered, call edges are +// added from the known call sites, and as each new call site is +// discovered, call graph edges are added to each compatible +// method. +// +// In addition, we must consider all exported methods of any runtime type +// as reachable, since they may be called via reflection. +// +// Each time a newly added call edge causes a new function to become +// reachable, the code of that function is analyzed for more call sites, +// address-taken functions, and runtime types. The process continues +// until a fixed point is achieved. +// +// The resulting call graph is less precise than one produced by pointer +// analysis, but the algorithm is much faster. For example, running the +// cmd/callgraph tool on its own source takes ~2.1s for RTA and ~5.4s +// for points-to analysis. +// +package rta // import "golang.org/x/tools/go/callgraph/rta" + +// TODO(adonovan): test it by connecting it to the interpreter and +// replacing all "unreachable" functions by a special intrinsic, and +// ensure that that intrinsic is never called. + +import ( + "fmt" + "go/types" + + "golang.org/x/tools/go/callgraph" + "golang.org/x/tools/go/ssa" + "golang.org/x/tools/go/types/typeutil" +) + +// A Result holds the results of Rapid Type Analysis, which includes the +// set of reachable functions/methods, runtime types, and the call graph. +// +type Result struct { + // CallGraph is the discovered callgraph. + // It does not include edges for calls made via reflection. + CallGraph *callgraph.Graph + + // Reachable contains the set of reachable functions and methods. + // This includes exported methods of runtime types, since + // they may be accessed via reflection. + // The value indicates whether the function is address-taken. + // + // (We wrap the bool in a struct to avoid inadvertent use of + // "if Reachable[f] {" to test for set membership.) + Reachable map[*ssa.Function]struct{ AddrTaken bool } + + // RuntimeTypes contains the set of types that are needed at + // runtime, for interfaces or reflection. + // + // The value indicates whether the type is inaccessible to reflection. + // Consider: + // type A struct{B} + // fmt.Println(new(A)) + // Types *A, A and B are accessible to reflection, but the unnamed + // type struct{B} is not. + RuntimeTypes typeutil.Map +} + +// Working state of the RTA algorithm. +type rta struct { + result *Result + + prog *ssa.Program + + worklist []*ssa.Function // list of functions to visit + + // addrTakenFuncsBySig contains all address-taken *Functions, grouped by signature. + // Keys are *types.Signature, values are map[*ssa.Function]bool sets. + addrTakenFuncsBySig typeutil.Map + + // dynCallSites contains all dynamic "call"-mode call sites, grouped by signature. + // Keys are *types.Signature, values are unordered []ssa.CallInstruction. + dynCallSites typeutil.Map + + // invokeSites contains all "invoke"-mode call sites, grouped by interface. + // Keys are *types.Interface (never *types.Named), + // Values are unordered []ssa.CallInstruction sets. + invokeSites typeutil.Map + + // The following two maps together define the subset of the + // m:n "implements" relation needed by the algorithm. + + // concreteTypes maps each concrete type to the set of interfaces that it implements. + // Keys are types.Type, values are unordered []*types.Interface. + // Only concrete types used as MakeInterface operands are included. + concreteTypes typeutil.Map + + // interfaceTypes maps each interface type to + // the set of concrete types that implement it. + // Keys are *types.Interface, values are unordered []types.Type. + // Only interfaces used in "invoke"-mode CallInstructions are included. + interfaceTypes typeutil.Map +} + +// addReachable marks a function as potentially callable at run-time, +// and ensures that it gets processed. +func (r *rta) addReachable(f *ssa.Function, addrTaken bool) { + reachable := r.result.Reachable + n := len(reachable) + v := reachable[f] + if addrTaken { + v.AddrTaken = true + } + reachable[f] = v + if len(reachable) > n { + // First time seeing f. Add it to the worklist. + r.worklist = append(r.worklist, f) + } +} + +// addEdge adds the specified call graph edge, and marks it reachable. +// addrTaken indicates whether to mark the callee as "address-taken". +func (r *rta) addEdge(site ssa.CallInstruction, callee *ssa.Function, addrTaken bool) { + r.addReachable(callee, addrTaken) + + if g := r.result.CallGraph; g != nil { + if site.Parent() == nil { + panic(site) + } + from := g.CreateNode(site.Parent()) + to := g.CreateNode(callee) + callgraph.AddEdge(from, site, to) + } +} + +// ---------- addrTakenFuncs × dynCallSites ---------- + +// visitAddrTakenFunc is called each time we encounter an address-taken function f. +func (r *rta) visitAddrTakenFunc(f *ssa.Function) { + // Create two-level map (Signature -> Function -> bool). + S := f.Signature + funcs, _ := r.addrTakenFuncsBySig.At(S).(map[*ssa.Function]bool) + if funcs == nil { + funcs = make(map[*ssa.Function]bool) + r.addrTakenFuncsBySig.Set(S, funcs) + } + if !funcs[f] { + // First time seeing f. + funcs[f] = true + + // If we've seen any dyncalls of this type, mark it reachable, + // and add call graph edges. + sites, _ := r.dynCallSites.At(S).([]ssa.CallInstruction) + for _, site := range sites { + r.addEdge(site, f, true) + } + } +} + +// visitDynCall is called each time we encounter a dynamic "call"-mode call. +func (r *rta) visitDynCall(site ssa.CallInstruction) { + S := site.Common().Signature() + + // Record the call site. + sites, _ := r.dynCallSites.At(S).([]ssa.CallInstruction) + r.dynCallSites.Set(S, append(sites, site)) + + // For each function of signature S that we know is address-taken, + // add an edge and mark it reachable. + funcs, _ := r.addrTakenFuncsBySig.At(S).(map[*ssa.Function]bool) + for g := range funcs { + r.addEdge(site, g, true) + } +} + +// ---------- concrete types × invoke sites ---------- + +// addInvokeEdge is called for each new pair (site, C) in the matrix. +func (r *rta) addInvokeEdge(site ssa.CallInstruction, C types.Type) { + // Ascertain the concrete method of C to be called. + imethod := site.Common().Method + cmethod := r.prog.MethodValue(r.prog.MethodSets.MethodSet(C).Lookup(imethod.Pkg(), imethod.Name())) + r.addEdge(site, cmethod, true) +} + +// visitInvoke is called each time the algorithm encounters an "invoke"-mode call. +func (r *rta) visitInvoke(site ssa.CallInstruction) { + I := site.Common().Value.Type().Underlying().(*types.Interface) + + // Record the invoke site. + sites, _ := r.invokeSites.At(I).([]ssa.CallInstruction) + r.invokeSites.Set(I, append(sites, site)) + + // Add callgraph edge for each existing + // address-taken concrete type implementing I. + for _, C := range r.implementations(I) { + r.addInvokeEdge(site, C) + } +} + +// ---------- main algorithm ---------- + +// visitFunc processes function f. +func (r *rta) visitFunc(f *ssa.Function) { + var space [32]*ssa.Value // preallocate space for common case + + for _, b := range f.Blocks { + for _, instr := range b.Instrs { + rands := instr.Operands(space[:0]) + + switch instr := instr.(type) { + case ssa.CallInstruction: + call := instr.Common() + if call.IsInvoke() { + r.visitInvoke(instr) + } else if g := call.StaticCallee(); g != nil { + r.addEdge(instr, g, false) + } else if _, ok := call.Value.(*ssa.Builtin); !ok { + r.visitDynCall(instr) + } + + // Ignore the call-position operand when + // looking for address-taken Functions. + // Hack: assume this is rands[0]. + rands = rands[1:] + + case *ssa.MakeInterface: + r.addRuntimeType(instr.X.Type(), false) + } + + // Process all address-taken functions. + for _, op := range rands { + if g, ok := (*op).(*ssa.Function); ok { + r.visitAddrTakenFunc(g) + } + } + } + } +} + +// Analyze performs Rapid Type Analysis, starting at the specified root +// functions. It returns nil if no roots were specified. +// +// If buildCallGraph is true, Result.CallGraph will contain a call +// graph; otherwise, only the other fields (reachable functions) are +// populated. +// +func Analyze(roots []*ssa.Function, buildCallGraph bool) *Result { + if len(roots) == 0 { + return nil + } + + r := &rta{ + result: &Result{Reachable: make(map[*ssa.Function]struct{ AddrTaken bool })}, + prog: roots[0].Prog, + } + + if buildCallGraph { + // TODO(adonovan): change callgraph API to eliminate the + // notion of a distinguished root node. Some callgraphs + // have many roots, or none. + r.result.CallGraph = callgraph.New(roots[0]) + } + + hasher := typeutil.MakeHasher() + r.result.RuntimeTypes.SetHasher(hasher) + r.addrTakenFuncsBySig.SetHasher(hasher) + r.dynCallSites.SetHasher(hasher) + r.invokeSites.SetHasher(hasher) + r.concreteTypes.SetHasher(hasher) + r.interfaceTypes.SetHasher(hasher) + + // Visit functions, processing their instructions, and adding + // new functions to the worklist, until a fixed point is + // reached. + var shadow []*ssa.Function // for efficiency, we double-buffer the worklist + r.worklist = append(r.worklist, roots...) + for len(r.worklist) > 0 { + shadow, r.worklist = r.worklist, shadow[:0] + for _, f := range shadow { + r.visitFunc(f) + } + } + return r.result +} + +// interfaces(C) returns all currently known interfaces implemented by C. +func (r *rta) interfaces(C types.Type) []*types.Interface { + // Ascertain set of interfaces C implements + // and update 'implements' relation. + var ifaces []*types.Interface + r.interfaceTypes.Iterate(func(I types.Type, concs interface{}) { + if I := I.(*types.Interface); types.Implements(C, I) { + concs, _ := concs.([]types.Type) + r.interfaceTypes.Set(I, append(concs, C)) + ifaces = append(ifaces, I) + } + }) + r.concreteTypes.Set(C, ifaces) + return ifaces +} + +// implementations(I) returns all currently known concrete types that implement I. +func (r *rta) implementations(I *types.Interface) []types.Type { + var concs []types.Type + if v := r.interfaceTypes.At(I); v != nil { + concs = v.([]types.Type) + } else { + // First time seeing this interface. + // Update the 'implements' relation. + r.concreteTypes.Iterate(func(C types.Type, ifaces interface{}) { + if types.Implements(C, I) { + ifaces, _ := ifaces.([]*types.Interface) + r.concreteTypes.Set(C, append(ifaces, I)) + concs = append(concs, C) + } + }) + r.interfaceTypes.Set(I, concs) + } + return concs +} + +// addRuntimeType is called for each concrete type that can be the +// dynamic type of some interface or reflect.Value. +// Adapted from needMethods in go/ssa/builder.go +// +func (r *rta) addRuntimeType(T types.Type, skip bool) { + if prev, ok := r.result.RuntimeTypes.At(T).(bool); ok { + if skip && !prev { + r.result.RuntimeTypes.Set(T, skip) + } + return + } + r.result.RuntimeTypes.Set(T, skip) + + mset := r.prog.MethodSets.MethodSet(T) + + if _, ok := T.Underlying().(*types.Interface); !ok { + // T is a new concrete type. + for i, n := 0, mset.Len(); i < n; i++ { + sel := mset.At(i) + m := sel.Obj() + + if m.Exported() { + // Exported methods are always potentially callable via reflection. + r.addReachable(r.prog.MethodValue(sel), true) + } + } + + // Add callgraph edge for each existing dynamic + // "invoke"-mode call via that interface. + for _, I := range r.interfaces(T) { + sites, _ := r.invokeSites.At(I).([]ssa.CallInstruction) + for _, site := range sites { + r.addInvokeEdge(site, T) + } + } + } + + // Precondition: T is not a method signature (*Signature with Recv()!=nil). + // Recursive case: skip => don't call makeMethods(T). + // Each package maintains its own set of types it has visited. + + var n *types.Named + switch T := T.(type) { + case *types.Named: + n = T + case *types.Pointer: + n, _ = T.Elem().(*types.Named) + } + if n != nil { + owner := n.Obj().Pkg() + if owner == nil { + return // built-in error type + } + } + + // Recursion over signatures of each exported method. + for i := 0; i < mset.Len(); i++ { + if mset.At(i).Obj().Exported() { + sig := mset.At(i).Type().(*types.Signature) + r.addRuntimeType(sig.Params(), true) // skip the Tuple itself + r.addRuntimeType(sig.Results(), true) // skip the Tuple itself + } + } + + switch t := T.(type) { + case *types.Basic: + // nop + + case *types.Interface: + // nop---handled by recursion over method set. + + case *types.Pointer: + r.addRuntimeType(t.Elem(), false) + + case *types.Slice: + r.addRuntimeType(t.Elem(), false) + + case *types.Chan: + r.addRuntimeType(t.Elem(), false) + + case *types.Map: + r.addRuntimeType(t.Key(), false) + r.addRuntimeType(t.Elem(), false) + + case *types.Signature: + if t.Recv() != nil { + panic(fmt.Sprintf("Signature %s has Recv %s", t, t.Recv())) + } + r.addRuntimeType(t.Params(), true) // skip the Tuple itself + r.addRuntimeType(t.Results(), true) // skip the Tuple itself + + case *types.Named: + // A pointer-to-named type can be derived from a named + // type via reflection. It may have methods too. + r.addRuntimeType(types.NewPointer(T), false) + + // Consider 'type T struct{S}' where S has methods. + // Reflection provides no way to get from T to struct{S}, + // only to S, so the method set of struct{S} is unwanted, + // so set 'skip' flag during recursion. + r.addRuntimeType(t.Underlying(), true) + + case *types.Array: + r.addRuntimeType(t.Elem(), false) + + case *types.Struct: + for i, n := 0, t.NumFields(); i < n; i++ { + r.addRuntimeType(t.Field(i).Type(), false) + } + + case *types.Tuple: + for i, n := 0, t.Len(); i < n; i++ { + r.addRuntimeType(t.At(i).Type(), false) + } + + default: + panic(T) + } +} diff --git a/vendor/golang.org/x/tools/go/callgraph/static/static.go b/vendor/golang.org/x/tools/go/callgraph/static/static.go new file mode 100644 index 00000000000..709bb7b6bd8 --- /dev/null +++ b/vendor/golang.org/x/tools/go/callgraph/static/static.go @@ -0,0 +1,35 @@ +// Package static computes the call graph of a Go program containing +// only static call edges. +package static // import "golang.org/x/tools/go/callgraph/static" + +import ( + "golang.org/x/tools/go/callgraph" + "golang.org/x/tools/go/ssa" + "golang.org/x/tools/go/ssa/ssautil" +) + +// CallGraph computes the call graph of the specified program +// considering only static calls. +// +func CallGraph(prog *ssa.Program) *callgraph.Graph { + cg := callgraph.New(nil) // TODO(adonovan) eliminate concept of rooted callgraph + + // TODO(adonovan): opt: use only a single pass over the ssa.Program. + // TODO(adonovan): opt: this is slower than RTA (perhaps because + // the lower precision means so many edges are allocated)! + for f := range ssautil.AllFunctions(prog) { + fnode := cg.CreateNode(f) + for _, b := range f.Blocks { + for _, instr := range b.Instrs { + if site, ok := instr.(ssa.CallInstruction); ok { + if g := site.Common().StaticCallee(); g != nil { + gnode := cg.CreateNode(g) + callgraph.AddEdge(fnode, site, gnode) + } + } + } + } + } + + return cg +} diff --git a/vendor/golang.org/x/tools/go/callgraph/util.go b/vendor/golang.org/x/tools/go/callgraph/util.go new file mode 100644 index 00000000000..a8f89031c05 --- /dev/null +++ b/vendor/golang.org/x/tools/go/callgraph/util.go @@ -0,0 +1,181 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package callgraph + +import "golang.org/x/tools/go/ssa" + +// This file provides various utilities over call graphs, such as +// visitation and path search. + +// CalleesOf returns a new set containing all direct callees of the +// caller node. +// +func CalleesOf(caller *Node) map[*Node]bool { + callees := make(map[*Node]bool) + for _, e := range caller.Out { + callees[e.Callee] = true + } + return callees +} + +// GraphVisitEdges visits all the edges in graph g in depth-first order. +// The edge function is called for each edge in postorder. If it +// returns non-nil, visitation stops and GraphVisitEdges returns that +// value. +// +func GraphVisitEdges(g *Graph, edge func(*Edge) error) error { + seen := make(map[*Node]bool) + var visit func(n *Node) error + visit = func(n *Node) error { + if !seen[n] { + seen[n] = true + for _, e := range n.Out { + if err := visit(e.Callee); err != nil { + return err + } + if err := edge(e); err != nil { + return err + } + } + } + return nil + } + for _, n := range g.Nodes { + if err := visit(n); err != nil { + return err + } + } + return nil +} + +// PathSearch finds an arbitrary path starting at node start and +// ending at some node for which isEnd() returns true. On success, +// PathSearch returns the path as an ordered list of edges; on +// failure, it returns nil. +// +func PathSearch(start *Node, isEnd func(*Node) bool) []*Edge { + stack := make([]*Edge, 0, 32) + seen := make(map[*Node]bool) + var search func(n *Node) []*Edge + search = func(n *Node) []*Edge { + if !seen[n] { + seen[n] = true + if isEnd(n) { + return stack + } + for _, e := range n.Out { + stack = append(stack, e) // push + if found := search(e.Callee); found != nil { + return found + } + stack = stack[:len(stack)-1] // pop + } + } + return nil + } + return search(start) +} + +// DeleteSyntheticNodes removes from call graph g all nodes for +// synthetic functions (except g.Root and package initializers), +// preserving the topology. In effect, calls to synthetic wrappers +// are "inlined". +// +func (g *Graph) DeleteSyntheticNodes() { + // Measurements on the standard library and go.tools show that + // resulting graph has ~15% fewer nodes and 4-8% fewer edges + // than the input. + // + // Inlining a wrapper of in-degree m, out-degree n adds m*n + // and removes m+n edges. Since most wrappers are monomorphic + // (n=1) this results in a slight reduction. Polymorphic + // wrappers (n>1), e.g. from embedding an interface value + // inside a struct to satisfy some interface, cause an + // increase in the graph, but they seem to be uncommon. + + // Hash all existing edges to avoid creating duplicates. + edges := make(map[Edge]bool) + for _, cgn := range g.Nodes { + for _, e := range cgn.Out { + edges[*e] = true + } + } + for fn, cgn := range g.Nodes { + if cgn == g.Root || fn.Synthetic == "" || isInit(cgn.Func) { + continue // keep + } + for _, eIn := range cgn.In { + for _, eOut := range cgn.Out { + newEdge := Edge{eIn.Caller, eIn.Site, eOut.Callee} + if edges[newEdge] { + continue // don't add duplicate + } + AddEdge(eIn.Caller, eIn.Site, eOut.Callee) + edges[newEdge] = true + } + } + g.DeleteNode(cgn) + } +} + +func isInit(fn *ssa.Function) bool { + return fn.Pkg != nil && fn.Pkg.Func("init") == fn +} + +// DeleteNode removes node n and its edges from the graph g. +// (NB: not efficient for batch deletion.) +func (g *Graph) DeleteNode(n *Node) { + n.deleteIns() + n.deleteOuts() + delete(g.Nodes, n.Func) +} + +// deleteIns deletes all incoming edges to n. +func (n *Node) deleteIns() { + for _, e := range n.In { + removeOutEdge(e) + } + n.In = nil +} + +// deleteOuts deletes all outgoing edges from n. +func (n *Node) deleteOuts() { + for _, e := range n.Out { + removeInEdge(e) + } + n.Out = nil +} + +// removeOutEdge removes edge.Caller's outgoing edge 'edge'. +func removeOutEdge(edge *Edge) { + caller := edge.Caller + n := len(caller.Out) + for i, e := range caller.Out { + if e == edge { + // Replace it with the final element and shrink the slice. + caller.Out[i] = caller.Out[n-1] + caller.Out[n-1] = nil // aid GC + caller.Out = caller.Out[:n-1] + return + } + } + panic("edge not found: " + edge.String()) +} + +// removeInEdge removes edge.Callee's incoming edge 'edge'. +func removeInEdge(edge *Edge) { + caller := edge.Callee + n := len(caller.In) + for i, e := range caller.In { + if e == edge { + // Replace it with the final element and shrink the slice. + caller.In[i] = caller.In[n-1] + caller.In[n-1] = nil // aid GC + caller.In = caller.In[:n-1] + return + } + } + panic("edge not found: " + edge.String()) +} diff --git a/vendor/golang.org/x/tools/go/internal/cgo/cgo.go b/vendor/golang.org/x/tools/go/internal/cgo/cgo.go new file mode 100644 index 00000000000..0f652ea6fb5 --- /dev/null +++ b/vendor/golang.org/x/tools/go/internal/cgo/cgo.go @@ -0,0 +1,220 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package cgo + +// This file handles cgo preprocessing of files containing `import "C"`. +// +// DESIGN +// +// The approach taken is to run the cgo processor on the package's +// CgoFiles and parse the output, faking the filenames of the +// resulting ASTs so that the synthetic file containing the C types is +// called "C" (e.g. "~/go/src/net/C") and the preprocessed files +// have their original names (e.g. "~/go/src/net/cgo_unix.go"), +// not the names of the actual temporary files. +// +// The advantage of this approach is its fidelity to 'go build'. The +// downside is that the token.Position.Offset for each AST node is +// incorrect, being an offset within the temporary file. Line numbers +// should still be correct because of the //line comments. +// +// The logic of this file is mostly plundered from the 'go build' +// tool, which also invokes the cgo preprocessor. +// +// +// REJECTED ALTERNATIVE +// +// An alternative approach that we explored is to extend go/types' +// Importer mechanism to provide the identity of the importing package +// so that each time `import "C"` appears it resolves to a different +// synthetic package containing just the objects needed in that case. +// The loader would invoke cgo but parse only the cgo_types.go file +// defining the package-level objects, discarding the other files +// resulting from preprocessing. +// +// The benefit of this approach would have been that source-level +// syntax information would correspond exactly to the original cgo +// file, with no preprocessing involved, making source tools like +// godoc, guru, and eg happy. However, the approach was rejected +// due to the additional complexity it would impose on go/types. (It +// made for a beautiful demo, though.) +// +// cgo files, despite their *.go extension, are not legal Go source +// files per the specification since they may refer to unexported +// members of package "C" such as C.int. Also, a function such as +// C.getpwent has in effect two types, one matching its C type and one +// which additionally returns (errno C.int). The cgo preprocessor +// uses name mangling to distinguish these two functions in the +// processed code, but go/types would need to duplicate this logic in +// its handling of function calls, analogous to the treatment of map +// lookups in which y=m[k] and y,ok=m[k] are both legal. + +import ( + "fmt" + "go/ast" + "go/build" + "go/parser" + "go/token" + "io/ioutil" + "log" + "os" + "os/exec" + "path/filepath" + "regexp" + "strings" +) + +// ProcessFiles invokes the cgo preprocessor on bp.CgoFiles, parses +// the output and returns the resulting ASTs. +// +func ProcessFiles(bp *build.Package, fset *token.FileSet, DisplayPath func(path string) string, mode parser.Mode) ([]*ast.File, error) { + tmpdir, err := ioutil.TempDir("", strings.Replace(bp.ImportPath, "/", "_", -1)+"_C") + if err != nil { + return nil, err + } + defer os.RemoveAll(tmpdir) + + pkgdir := bp.Dir + if DisplayPath != nil { + pkgdir = DisplayPath(pkgdir) + } + + cgoFiles, cgoDisplayFiles, err := Run(bp, pkgdir, tmpdir, false) + if err != nil { + return nil, err + } + var files []*ast.File + for i := range cgoFiles { + rd, err := os.Open(cgoFiles[i]) + if err != nil { + return nil, err + } + display := filepath.Join(bp.Dir, cgoDisplayFiles[i]) + f, err := parser.ParseFile(fset, display, rd, mode) + rd.Close() + if err != nil { + return nil, err + } + files = append(files, f) + } + return files, nil +} + +var cgoRe = regexp.MustCompile(`[/\\:]`) + +// Run invokes the cgo preprocessor on bp.CgoFiles and returns two +// lists of files: the resulting processed files (in temporary +// directory tmpdir) and the corresponding names of the unprocessed files. +// +// Run is adapted from (*builder).cgo in +// $GOROOT/src/cmd/go/build.go, but these features are unsupported: +// Objective C, CGOPKGPATH, CGO_FLAGS. +// +// If useabs is set to true, absolute paths of the bp.CgoFiles will be passed in +// to the cgo preprocessor. This in turn will set the // line comments +// referring to those files to use absolute paths. This is needed for +// go/packages using the legacy go list support so it is able to find +// the original files. +func Run(bp *build.Package, pkgdir, tmpdir string, useabs bool) (files, displayFiles []string, err error) { + cgoCPPFLAGS, _, _, _ := cflags(bp, true) + _, cgoexeCFLAGS, _, _ := cflags(bp, false) + + if len(bp.CgoPkgConfig) > 0 { + pcCFLAGS, err := pkgConfigFlags(bp) + if err != nil { + return nil, nil, err + } + cgoCPPFLAGS = append(cgoCPPFLAGS, pcCFLAGS...) + } + + // Allows including _cgo_export.h from .[ch] files in the package. + cgoCPPFLAGS = append(cgoCPPFLAGS, "-I", tmpdir) + + // _cgo_gotypes.go (displayed "C") contains the type definitions. + files = append(files, filepath.Join(tmpdir, "_cgo_gotypes.go")) + displayFiles = append(displayFiles, "C") + for _, fn := range bp.CgoFiles { + // "foo.cgo1.go" (displayed "foo.go") is the processed Go source. + f := cgoRe.ReplaceAllString(fn[:len(fn)-len("go")], "_") + files = append(files, filepath.Join(tmpdir, f+"cgo1.go")) + displayFiles = append(displayFiles, fn) + } + + var cgoflags []string + if bp.Goroot && bp.ImportPath == "runtime/cgo" { + cgoflags = append(cgoflags, "-import_runtime_cgo=false") + } + if bp.Goroot && bp.ImportPath == "runtime/race" || bp.ImportPath == "runtime/cgo" { + cgoflags = append(cgoflags, "-import_syscall=false") + } + + var cgoFiles []string = bp.CgoFiles + if useabs { + cgoFiles = make([]string, len(bp.CgoFiles)) + for i := range cgoFiles { + cgoFiles[i] = filepath.Join(pkgdir, bp.CgoFiles[i]) + } + } + + args := stringList( + "go", "tool", "cgo", "-objdir", tmpdir, cgoflags, "--", + cgoCPPFLAGS, cgoexeCFLAGS, cgoFiles, + ) + if false { + log.Printf("Running cgo for package %q: %s (dir=%s)", bp.ImportPath, args, pkgdir) + } + cmd := exec.Command(args[0], args[1:]...) + cmd.Dir = pkgdir + cmd.Stdout = os.Stderr + cmd.Stderr = os.Stderr + if err := cmd.Run(); err != nil { + return nil, nil, fmt.Errorf("cgo failed: %s: %s", args, err) + } + + return files, displayFiles, nil +} + +// -- unmodified from 'go build' --------------------------------------- + +// Return the flags to use when invoking the C or C++ compilers, or cgo. +func cflags(p *build.Package, def bool) (cppflags, cflags, cxxflags, ldflags []string) { + var defaults string + if def { + defaults = "-g -O2" + } + + cppflags = stringList(envList("CGO_CPPFLAGS", ""), p.CgoCPPFLAGS) + cflags = stringList(envList("CGO_CFLAGS", defaults), p.CgoCFLAGS) + cxxflags = stringList(envList("CGO_CXXFLAGS", defaults), p.CgoCXXFLAGS) + ldflags = stringList(envList("CGO_LDFLAGS", defaults), p.CgoLDFLAGS) + return +} + +// envList returns the value of the given environment variable broken +// into fields, using the default value when the variable is empty. +func envList(key, def string) []string { + v := os.Getenv(key) + if v == "" { + v = def + } + return strings.Fields(v) +} + +// stringList's arguments should be a sequence of string or []string values. +// stringList flattens them into a single []string. +func stringList(args ...interface{}) []string { + var x []string + for _, arg := range args { + switch arg := arg.(type) { + case []string: + x = append(x, arg...) + case string: + x = append(x, arg) + default: + panic("stringList: invalid argument") + } + } + return x +} diff --git a/vendor/golang.org/x/tools/go/internal/cgo/cgo_pkgconfig.go b/vendor/golang.org/x/tools/go/internal/cgo/cgo_pkgconfig.go new file mode 100644 index 00000000000..b5bb95a63e5 --- /dev/null +++ b/vendor/golang.org/x/tools/go/internal/cgo/cgo_pkgconfig.go @@ -0,0 +1,39 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package cgo + +import ( + "errors" + "fmt" + "go/build" + "os/exec" + "strings" +) + +// pkgConfig runs pkg-config with the specified arguments and returns the flags it prints. +func pkgConfig(mode string, pkgs []string) (flags []string, err error) { + cmd := exec.Command("pkg-config", append([]string{mode}, pkgs...)...) + out, err := cmd.CombinedOutput() + if err != nil { + s := fmt.Sprintf("%s failed: %v", strings.Join(cmd.Args, " "), err) + if len(out) > 0 { + s = fmt.Sprintf("%s: %s", s, out) + } + return nil, errors.New(s) + } + if len(out) > 0 { + flags = strings.Fields(string(out)) + } + return +} + +// pkgConfigFlags calls pkg-config if needed and returns the cflags +// needed to build the package. +func pkgConfigFlags(p *build.Package) (cflags []string, err error) { + if len(p.CgoPkgConfig) == 0 { + return nil, nil + } + return pkgConfig("--cflags", p.CgoPkgConfig) +} diff --git a/vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go b/vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go index ea15d57be1a..db0c9a7ea61 100644 --- a/vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go +++ b/vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go @@ -81,13 +81,13 @@ func GetSizesGolist(ctx context.Context, buildFlags, env []string, dir string, u args := []string{"list", "-f", "{{context.GOARCH}} {{context.Compiler}}"} args = append(args, buildFlags...) args = append(args, "--", "unsafe") - stdout, err := InvokeGo(ctx, env, dir, usesExportData, args...) + stdout, stderr, err := invokeGo(ctx, env, dir, usesExportData, args...) var goarch, compiler string if err != nil { if strings.Contains(err.Error(), "cannot find main module") { // User's running outside of a module. All bets are off. Get GOARCH and guess compiler is gc. // TODO(matloob): Is this a problem in practice? - envout, enverr := InvokeGo(ctx, env, dir, usesExportData, "env", "GOARCH") + envout, _, enverr := invokeGo(ctx, env, dir, usesExportData, "env", "GOARCH") if enverr != nil { return nil, err } @@ -99,7 +99,8 @@ func GetSizesGolist(ctx context.Context, buildFlags, env []string, dir string, u } else { fields := strings.Fields(stdout.String()) if len(fields) < 2 { - return nil, fmt.Errorf("could not determine GOARCH and Go compiler") + return nil, fmt.Errorf("could not parse GOARCH and Go compiler in format \" \" from stdout of go command:\n%s\ndir: %s\nstdout: <<%s>>\nstderr: <<%s>>", + cmdDebugStr(env, args...), dir, stdout.String(), stderr.String()) } goarch = fields[0] compiler = fields[1] @@ -107,8 +108,8 @@ func GetSizesGolist(ctx context.Context, buildFlags, env []string, dir string, u return types.SizesFor(compiler, goarch), nil } -// InvokeGo returns the stdout of a go command invocation. -func InvokeGo(ctx context.Context, env []string, dir string, usesExportData bool, args ...string) (*bytes.Buffer, error) { +// invokeGo returns the stdout and stderr of a go command invocation. +func invokeGo(ctx context.Context, env []string, dir string, usesExportData bool, args ...string) (*bytes.Buffer, *bytes.Buffer, error) { if debug { defer func(start time.Time) { log.Printf("%s for %v", time.Since(start), cmdDebugStr(env, args...)) }(time.Now()) } @@ -131,7 +132,7 @@ func InvokeGo(ctx context.Context, env []string, dir string, usesExportData bool // Catastrophic error: // - executable not found // - context cancellation - return nil, fmt.Errorf("couldn't exec 'go %v': %s %T", args, err, err) + return nil, nil, fmt.Errorf("couldn't exec 'go %v': %s %T", args, err, err) } // Export mode entails a build. @@ -139,7 +140,7 @@ func InvokeGo(ctx context.Context, env []string, dir string, usesExportData bool // (despite the -e flag) and the Export field is blank. // Do not fail in that case. if !usesExportData { - return nil, fmt.Errorf("go %v: %s: %s", args, exitErr, stderr) + return nil, nil, fmt.Errorf("go %v: %s: %s", args, exitErr, stderr) } } @@ -158,7 +159,7 @@ func InvokeGo(ctx context.Context, env []string, dir string, usesExportData bool fmt.Fprintf(os.Stderr, "%s stdout: <<%s>>\n", cmdDebugStr(env, args...), stdout) } - return stdout, nil + return stdout, stderr, nil } func cmdDebugStr(envlist []string, args ...string) string { diff --git a/vendor/golang.org/x/tools/go/loader/doc.go b/vendor/golang.org/x/tools/go/loader/doc.go new file mode 100644 index 00000000000..c5aa31c1a02 --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/doc.go @@ -0,0 +1,204 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package loader loads a complete Go program from source code, parsing +// and type-checking the initial packages plus their transitive closure +// of dependencies. The ASTs and the derived facts are retained for +// later use. +// +// Deprecated: This is an older API and does not have support +// for modules. Use golang.org/x/tools/go/packages instead. +// +// The package defines two primary types: Config, which specifies a +// set of initial packages to load and various other options; and +// Program, which is the result of successfully loading the packages +// specified by a configuration. +// +// The configuration can be set directly, but *Config provides various +// convenience methods to simplify the common cases, each of which can +// be called any number of times. Finally, these are followed by a +// call to Load() to actually load and type-check the program. +// +// var conf loader.Config +// +// // Use the command-line arguments to specify +// // a set of initial packages to load from source. +// // See FromArgsUsage for help. +// rest, err := conf.FromArgs(os.Args[1:], wantTests) +// +// // Parse the specified files and create an ad hoc package with path "foo". +// // All files must have the same 'package' declaration. +// conf.CreateFromFilenames("foo", "foo.go", "bar.go") +// +// // Create an ad hoc package with path "foo" from +// // the specified already-parsed files. +// // All ASTs must have the same 'package' declaration. +// conf.CreateFromFiles("foo", parsedFiles) +// +// // Add "runtime" to the set of packages to be loaded. +// conf.Import("runtime") +// +// // Adds "fmt" and "fmt_test" to the set of packages +// // to be loaded. "fmt" will include *_test.go files. +// conf.ImportWithTests("fmt") +// +// // Finally, load all the packages specified by the configuration. +// prog, err := conf.Load() +// +// See examples_test.go for examples of API usage. +// +// +// CONCEPTS AND TERMINOLOGY +// +// The WORKSPACE is the set of packages accessible to the loader. The +// workspace is defined by Config.Build, a *build.Context. The +// default context treats subdirectories of $GOROOT and $GOPATH as +// packages, but this behavior may be overridden. +// +// An AD HOC package is one specified as a set of source files on the +// command line. In the simplest case, it may consist of a single file +// such as $GOROOT/src/net/http/triv.go. +// +// EXTERNAL TEST packages are those comprised of a set of *_test.go +// files all with the same 'package foo_test' declaration, all in the +// same directory. (go/build.Package calls these files XTestFiles.) +// +// An IMPORTABLE package is one that can be referred to by some import +// spec. Every importable package is uniquely identified by its +// PACKAGE PATH or just PATH, a string such as "fmt", "encoding/json", +// or "cmd/vendor/golang.org/x/arch/x86/x86asm". A package path +// typically denotes a subdirectory of the workspace. +// +// An import declaration uses an IMPORT PATH to refer to a package. +// Most import declarations use the package path as the import path. +// +// Due to VENDORING (https://golang.org/s/go15vendor), the +// interpretation of an import path may depend on the directory in which +// it appears. To resolve an import path to a package path, go/build +// must search the enclosing directories for a subdirectory named +// "vendor". +// +// ad hoc packages and external test packages are NON-IMPORTABLE. The +// path of an ad hoc package is inferred from the package +// declarations of its files and is therefore not a unique package key. +// For example, Config.CreatePkgs may specify two initial ad hoc +// packages, both with path "main". +// +// An AUGMENTED package is an importable package P plus all the +// *_test.go files with same 'package foo' declaration as P. +// (go/build.Package calls these files TestFiles.) +// +// The INITIAL packages are those specified in the configuration. A +// DEPENDENCY is a package loaded to satisfy an import in an initial +// package or another dependency. +// +package loader + +// IMPLEMENTATION NOTES +// +// 'go test', in-package test files, and import cycles +// --------------------------------------------------- +// +// An external test package may depend upon members of the augmented +// package that are not in the unaugmented package, such as functions +// that expose internals. (See bufio/export_test.go for an example.) +// So, the loader must ensure that for each external test package +// it loads, it also augments the corresponding non-test package. +// +// The import graph over n unaugmented packages must be acyclic; the +// import graph over n-1 unaugmented packages plus one augmented +// package must also be acyclic. ('go test' relies on this.) But the +// import graph over n augmented packages may contain cycles. +// +// First, all the (unaugmented) non-test packages and their +// dependencies are imported in the usual way; the loader reports an +// error if it detects an import cycle. +// +// Then, each package P for which testing is desired is augmented by +// the list P' of its in-package test files, by calling +// (*types.Checker).Files. This arrangement ensures that P' may +// reference definitions within P, but P may not reference definitions +// within P'. Furthermore, P' may import any other package, including +// ones that depend upon P, without an import cycle error. +// +// Consider two packages A and B, both of which have lists of +// in-package test files we'll call A' and B', and which have the +// following import graph edges: +// B imports A +// B' imports A +// A' imports B +// This last edge would be expected to create an error were it not +// for the special type-checking discipline above. +// Cycles of size greater than two are possible. For example: +// compress/bzip2/bzip2_test.go (package bzip2) imports "io/ioutil" +// io/ioutil/tempfile_test.go (package ioutil) imports "regexp" +// regexp/exec_test.go (package regexp) imports "compress/bzip2" +// +// +// Concurrency +// ----------- +// +// Let us define the import dependency graph as follows. Each node is a +// list of files passed to (Checker).Files at once. Many of these lists +// are the production code of an importable Go package, so those nodes +// are labelled by the package's path. The remaining nodes are +// ad hoc packages and lists of in-package *_test.go files that augment +// an importable package; those nodes have no label. +// +// The edges of the graph represent import statements appearing within a +// file. An edge connects a node (a list of files) to the node it +// imports, which is importable and thus always labelled. +// +// Loading is controlled by this dependency graph. +// +// To reduce I/O latency, we start loading a package's dependencies +// asynchronously as soon as we've parsed its files and enumerated its +// imports (scanImports). This performs a preorder traversal of the +// import dependency graph. +// +// To exploit hardware parallelism, we type-check unrelated packages in +// parallel, where "unrelated" means not ordered by the partial order of +// the import dependency graph. +// +// We use a concurrency-safe non-blocking cache (importer.imported) to +// record the results of type-checking, whether success or failure. An +// entry is created in this cache by startLoad the first time the +// package is imported. The first goroutine to request an entry becomes +// responsible for completing the task and broadcasting completion to +// subsequent requestors, which block until then. +// +// Type checking occurs in (parallel) postorder: we cannot type-check a +// set of files until we have loaded and type-checked all of their +// immediate dependencies (and thus all of their transitive +// dependencies). If the input were guaranteed free of import cycles, +// this would be trivial: we could simply wait for completion of the +// dependencies and then invoke the typechecker. +// +// But as we saw in the 'go test' section above, some cycles in the +// import graph over packages are actually legal, so long as the +// cycle-forming edge originates in the in-package test files that +// augment the package. This explains why the nodes of the import +// dependency graph are not packages, but lists of files: the unlabelled +// nodes avoid the cycles. Consider packages A and B where B imports A +// and A's in-package tests AT import B. The naively constructed import +// graph over packages would contain a cycle (A+AT) --> B --> (A+AT) but +// the graph over lists of files is AT --> B --> A, where AT is an +// unlabelled node. +// +// Awaiting completion of the dependencies in a cyclic graph would +// deadlock, so we must materialize the import dependency graph (as +// importer.graph) and check whether each import edge forms a cycle. If +// x imports y, and the graph already contains a path from y to x, then +// there is an import cycle, in which case the processing of x must not +// wait for the completion of processing of y. +// +// When the type-checker makes a callback (doImport) to the loader for a +// given import edge, there are two possible cases. In the normal case, +// the dependency has already been completely type-checked; doImport +// does a cache lookup and returns it. In the cyclic case, the entry in +// the cache is still necessarily incomplete, indicating a cycle. We +// perform the cycle check again to obtain the error message, and return +// the error. +// +// The result of using concurrency is about a 2.5x speedup for stdlib_test. diff --git a/vendor/golang.org/x/tools/go/loader/loader.go b/vendor/golang.org/x/tools/go/loader/loader.go new file mode 100644 index 00000000000..bc12ca33d1a --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/loader.go @@ -0,0 +1,1086 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package loader + +// See doc.go for package documentation and implementation notes. + +import ( + "errors" + "fmt" + "go/ast" + "go/build" + "go/parser" + "go/token" + "go/types" + "os" + "path/filepath" + "sort" + "strings" + "sync" + "time" + + "golang.org/x/tools/go/ast/astutil" + "golang.org/x/tools/go/internal/cgo" +) + +var ignoreVendor build.ImportMode + +const trace = false // show timing info for type-checking + +// Config specifies the configuration for loading a whole program from +// Go source code. +// The zero value for Config is a ready-to-use default configuration. +type Config struct { + // Fset is the file set for the parser to use when loading the + // program. If nil, it may be lazily initialized by any + // method of Config. + Fset *token.FileSet + + // ParserMode specifies the mode to be used by the parser when + // loading source packages. + ParserMode parser.Mode + + // TypeChecker contains options relating to the type checker. + // + // The supplied IgnoreFuncBodies is not used; the effective + // value comes from the TypeCheckFuncBodies func below. + // The supplied Import function is not used either. + TypeChecker types.Config + + // TypeCheckFuncBodies is a predicate over package paths. + // A package for which the predicate is false will + // have its package-level declarations type checked, but not + // its function bodies; this can be used to quickly load + // dependencies from source. If nil, all func bodies are type + // checked. + TypeCheckFuncBodies func(path string) bool + + // If Build is non-nil, it is used to locate source packages. + // Otherwise &build.Default is used. + // + // By default, cgo is invoked to preprocess Go files that + // import the fake package "C". This behaviour can be + // disabled by setting CGO_ENABLED=0 in the environment prior + // to startup, or by setting Build.CgoEnabled=false. + Build *build.Context + + // The current directory, used for resolving relative package + // references such as "./go/loader". If empty, os.Getwd will be + // used instead. + Cwd string + + // If DisplayPath is non-nil, it is used to transform each + // file name obtained from Build.Import(). This can be used + // to prevent a virtualized build.Config's file names from + // leaking into the user interface. + DisplayPath func(path string) string + + // If AllowErrors is true, Load will return a Program even + // if some of the its packages contained I/O, parser or type + // errors; such errors are accessible via PackageInfo.Errors. If + // false, Load will fail if any package had an error. + AllowErrors bool + + // CreatePkgs specifies a list of non-importable initial + // packages to create. The resulting packages will appear in + // the corresponding elements of the Program.Created slice. + CreatePkgs []PkgSpec + + // ImportPkgs specifies a set of initial packages to load. + // The map keys are package paths. + // + // The map value indicates whether to load tests. If true, Load + // will add and type-check two lists of files to the package: + // non-test files followed by in-package *_test.go files. In + // addition, it will append the external test package (if any) + // to Program.Created. + ImportPkgs map[string]bool + + // FindPackage is called during Load to create the build.Package + // for a given import path from a given directory. + // If FindPackage is nil, (*build.Context).Import is used. + // A client may use this hook to adapt to a proprietary build + // system that does not follow the "go build" layout + // conventions, for example. + // + // It must be safe to call concurrently from multiple goroutines. + FindPackage func(ctxt *build.Context, importPath, fromDir string, mode build.ImportMode) (*build.Package, error) + + // AfterTypeCheck is called immediately after a list of files + // has been type-checked and appended to info.Files. + // + // This optional hook function is the earliest opportunity for + // the client to observe the output of the type checker, + // which may be useful to reduce analysis latency when loading + // a large program. + // + // The function is permitted to modify info.Info, for instance + // to clear data structures that are no longer needed, which can + // dramatically reduce peak memory consumption. + // + // The function may be called twice for the same PackageInfo: + // once for the files of the package and again for the + // in-package test files. + // + // It must be safe to call concurrently from multiple goroutines. + AfterTypeCheck func(info *PackageInfo, files []*ast.File) +} + +// A PkgSpec specifies a non-importable package to be created by Load. +// Files are processed first, but typically only one of Files and +// Filenames is provided. The path needn't be globally unique. +// +// For vendoring purposes, the package's directory is the one that +// contains the first file. +type PkgSpec struct { + Path string // package path ("" => use package declaration) + Files []*ast.File // ASTs of already-parsed files + Filenames []string // names of files to be parsed +} + +// A Program is a Go program loaded from source as specified by a Config. +type Program struct { + Fset *token.FileSet // the file set for this program + + // Created[i] contains the initial package whose ASTs or + // filenames were supplied by Config.CreatePkgs[i], followed by + // the external test package, if any, of each package in + // Config.ImportPkgs ordered by ImportPath. + // + // NOTE: these files must not import "C". Cgo preprocessing is + // only performed on imported packages, not ad hoc packages. + // + // TODO(adonovan): we need to copy and adapt the logic of + // goFilesPackage (from $GOROOT/src/cmd/go/build.go) and make + // Config.Import and Config.Create methods return the same kind + // of entity, essentially a build.Package. + // Perhaps we can even reuse that type directly. + Created []*PackageInfo + + // Imported contains the initially imported packages, + // as specified by Config.ImportPkgs. + Imported map[string]*PackageInfo + + // AllPackages contains the PackageInfo of every package + // encountered by Load: all initial packages and all + // dependencies, including incomplete ones. + AllPackages map[*types.Package]*PackageInfo + + // importMap is the canonical mapping of package paths to + // packages. It contains all Imported initial packages, but not + // Created ones, and all imported dependencies. + importMap map[string]*types.Package +} + +// PackageInfo holds the ASTs and facts derived by the type-checker +// for a single package. +// +// Not mutated once exposed via the API. +// +type PackageInfo struct { + Pkg *types.Package + Importable bool // true if 'import "Pkg.Path()"' would resolve to this + TransitivelyErrorFree bool // true if Pkg and all its dependencies are free of errors + Files []*ast.File // syntax trees for the package's files + Errors []error // non-nil if the package had errors + types.Info // type-checker deductions. + dir string // package directory + + checker *types.Checker // transient type-checker state + errorFunc func(error) +} + +func (info *PackageInfo) String() string { return info.Pkg.Path() } + +func (info *PackageInfo) appendError(err error) { + if info.errorFunc != nil { + info.errorFunc(err) + } else { + fmt.Fprintln(os.Stderr, err) + } + info.Errors = append(info.Errors, err) +} + +func (conf *Config) fset() *token.FileSet { + if conf.Fset == nil { + conf.Fset = token.NewFileSet() + } + return conf.Fset +} + +// ParseFile is a convenience function (intended for testing) that invokes +// the parser using the Config's FileSet, which is initialized if nil. +// +// src specifies the parser input as a string, []byte, or io.Reader, and +// filename is its apparent name. If src is nil, the contents of +// filename are read from the file system. +// +func (conf *Config) ParseFile(filename string, src interface{}) (*ast.File, error) { + // TODO(adonovan): use conf.build() etc like parseFiles does. + return parser.ParseFile(conf.fset(), filename, src, conf.ParserMode) +} + +// FromArgsUsage is a partial usage message that applications calling +// FromArgs may wish to include in their -help output. +const FromArgsUsage = ` + is a list of arguments denoting a set of initial packages. +It may take one of two forms: + +1. A list of *.go source files. + + All of the specified files are loaded, parsed and type-checked + as a single package. All the files must belong to the same directory. + +2. A list of import paths, each denoting a package. + + The package's directory is found relative to the $GOROOT and + $GOPATH using similar logic to 'go build', and the *.go files in + that directory are loaded, parsed and type-checked as a single + package. + + In addition, all *_test.go files in the directory are then loaded + and parsed. Those files whose package declaration equals that of + the non-*_test.go files are included in the primary package. Test + files whose package declaration ends with "_test" are type-checked + as another package, the 'external' test package, so that a single + import path may denote two packages. (Whether this behaviour is + enabled is tool-specific, and may depend on additional flags.) + +A '--' argument terminates the list of packages. +` + +// FromArgs interprets args as a set of initial packages to load from +// source and updates the configuration. It returns the list of +// unconsumed arguments. +// +// It is intended for use in command-line interfaces that require a +// set of initial packages to be specified; see FromArgsUsage message +// for details. +// +// Only superficial errors are reported at this stage; errors dependent +// on I/O are detected during Load. +// +func (conf *Config) FromArgs(args []string, xtest bool) ([]string, error) { + var rest []string + for i, arg := range args { + if arg == "--" { + rest = args[i+1:] + args = args[:i] + break // consume "--" and return the remaining args + } + } + + if len(args) > 0 && strings.HasSuffix(args[0], ".go") { + // Assume args is a list of a *.go files + // denoting a single ad hoc package. + for _, arg := range args { + if !strings.HasSuffix(arg, ".go") { + return nil, fmt.Errorf("named files must be .go files: %s", arg) + } + } + conf.CreateFromFilenames("", args...) + } else { + // Assume args are directories each denoting a + // package and (perhaps) an external test, iff xtest. + for _, arg := range args { + if xtest { + conf.ImportWithTests(arg) + } else { + conf.Import(arg) + } + } + } + + return rest, nil +} + +// CreateFromFilenames is a convenience function that adds +// a conf.CreatePkgs entry to create a package of the specified *.go +// files. +// +func (conf *Config) CreateFromFilenames(path string, filenames ...string) { + conf.CreatePkgs = append(conf.CreatePkgs, PkgSpec{Path: path, Filenames: filenames}) +} + +// CreateFromFiles is a convenience function that adds a conf.CreatePkgs +// entry to create package of the specified path and parsed files. +// +func (conf *Config) CreateFromFiles(path string, files ...*ast.File) { + conf.CreatePkgs = append(conf.CreatePkgs, PkgSpec{Path: path, Files: files}) +} + +// ImportWithTests is a convenience function that adds path to +// ImportPkgs, the set of initial source packages located relative to +// $GOPATH. The package will be augmented by any *_test.go files in +// its directory that contain a "package x" (not "package x_test") +// declaration. +// +// In addition, if any *_test.go files contain a "package x_test" +// declaration, an additional package comprising just those files will +// be added to CreatePkgs. +// +func (conf *Config) ImportWithTests(path string) { conf.addImport(path, true) } + +// Import is a convenience function that adds path to ImportPkgs, the +// set of initial packages that will be imported from source. +// +func (conf *Config) Import(path string) { conf.addImport(path, false) } + +func (conf *Config) addImport(path string, tests bool) { + if path == "C" { + return // ignore; not a real package + } + if conf.ImportPkgs == nil { + conf.ImportPkgs = make(map[string]bool) + } + conf.ImportPkgs[path] = conf.ImportPkgs[path] || tests +} + +// PathEnclosingInterval returns the PackageInfo and ast.Node that +// contain source interval [start, end), and all the node's ancestors +// up to the AST root. It searches all ast.Files of all packages in prog. +// exact is defined as for astutil.PathEnclosingInterval. +// +// The zero value is returned if not found. +// +func (prog *Program) PathEnclosingInterval(start, end token.Pos) (pkg *PackageInfo, path []ast.Node, exact bool) { + for _, info := range prog.AllPackages { + for _, f := range info.Files { + if f.Pos() == token.NoPos { + // This can happen if the parser saw + // too many errors and bailed out. + // (Use parser.AllErrors to prevent that.) + continue + } + if !tokenFileContainsPos(prog.Fset.File(f.Pos()), start) { + continue + } + if path, exact := astutil.PathEnclosingInterval(f, start, end); path != nil { + return info, path, exact + } + } + } + return nil, nil, false +} + +// InitialPackages returns a new slice containing the set of initial +// packages (Created + Imported) in unspecified order. +// +func (prog *Program) InitialPackages() []*PackageInfo { + infos := make([]*PackageInfo, 0, len(prog.Created)+len(prog.Imported)) + infos = append(infos, prog.Created...) + for _, info := range prog.Imported { + infos = append(infos, info) + } + return infos +} + +// Package returns the ASTs and results of type checking for the +// specified package. +func (prog *Program) Package(path string) *PackageInfo { + if info, ok := prog.AllPackages[prog.importMap[path]]; ok { + return info + } + for _, info := range prog.Created { + if path == info.Pkg.Path() { + return info + } + } + return nil +} + +// ---------- Implementation ---------- + +// importer holds the working state of the algorithm. +type importer struct { + conf *Config // the client configuration + start time.Time // for logging + + progMu sync.Mutex // guards prog + prog *Program // the resulting program + + // findpkg is a memoization of FindPackage. + findpkgMu sync.Mutex // guards findpkg + findpkg map[findpkgKey]*findpkgValue + + importedMu sync.Mutex // guards imported + imported map[string]*importInfo // all imported packages (incl. failures) by import path + + // import dependency graph: graph[x][y] => x imports y + // + // Since non-importable packages cannot be cyclic, we ignore + // their imports, thus we only need the subgraph over importable + // packages. Nodes are identified by their import paths. + graphMu sync.Mutex + graph map[string]map[string]bool +} + +type findpkgKey struct { + importPath string + fromDir string + mode build.ImportMode +} + +type findpkgValue struct { + ready chan struct{} // closed to broadcast readiness + bp *build.Package + err error +} + +// importInfo tracks the success or failure of a single import. +// +// Upon completion, exactly one of info and err is non-nil: +// info on successful creation of a package, err otherwise. +// A successful package may still contain type errors. +// +type importInfo struct { + path string // import path + info *PackageInfo // results of typechecking (including errors) + complete chan struct{} // closed to broadcast that info is set. +} + +// awaitCompletion blocks until ii is complete, +// i.e. the info field is safe to inspect. +func (ii *importInfo) awaitCompletion() { + <-ii.complete // wait for close +} + +// Complete marks ii as complete. +// Its info and err fields will not be subsequently updated. +func (ii *importInfo) Complete(info *PackageInfo) { + if info == nil { + panic("info == nil") + } + ii.info = info + close(ii.complete) +} + +type importError struct { + path string // import path + err error // reason for failure to create a package +} + +// Load creates the initial packages specified by conf.{Create,Import}Pkgs, +// loading their dependencies packages as needed. +// +// On success, Load returns a Program containing a PackageInfo for +// each package. On failure, it returns an error. +// +// If AllowErrors is true, Load will return a Program even if some +// packages contained I/O, parser or type errors, or if dependencies +// were missing. (Such errors are accessible via PackageInfo.Errors. If +// false, Load will fail if any package had an error. +// +// It is an error if no packages were loaded. +// +func (conf *Config) Load() (*Program, error) { + // Create a simple default error handler for parse/type errors. + if conf.TypeChecker.Error == nil { + conf.TypeChecker.Error = func(e error) { fmt.Fprintln(os.Stderr, e) } + } + + // Set default working directory for relative package references. + if conf.Cwd == "" { + var err error + conf.Cwd, err = os.Getwd() + if err != nil { + return nil, err + } + } + + // Install default FindPackage hook using go/build logic. + if conf.FindPackage == nil { + conf.FindPackage = (*build.Context).Import + } + + prog := &Program{ + Fset: conf.fset(), + Imported: make(map[string]*PackageInfo), + importMap: make(map[string]*types.Package), + AllPackages: make(map[*types.Package]*PackageInfo), + } + + imp := importer{ + conf: conf, + prog: prog, + findpkg: make(map[findpkgKey]*findpkgValue), + imported: make(map[string]*importInfo), + start: time.Now(), + graph: make(map[string]map[string]bool), + } + + // -- loading proper (concurrent phase) -------------------------------- + + var errpkgs []string // packages that contained errors + + // Load the initially imported packages and their dependencies, + // in parallel. + // No vendor check on packages imported from the command line. + infos, importErrors := imp.importAll("", conf.Cwd, conf.ImportPkgs, ignoreVendor) + for _, ie := range importErrors { + conf.TypeChecker.Error(ie.err) // failed to create package + errpkgs = append(errpkgs, ie.path) + } + for _, info := range infos { + prog.Imported[info.Pkg.Path()] = info + } + + // Augment the designated initial packages by their tests. + // Dependencies are loaded in parallel. + var xtestPkgs []*build.Package + for importPath, augment := range conf.ImportPkgs { + if !augment { + continue + } + + // No vendor check on packages imported from command line. + bp, err := imp.findPackage(importPath, conf.Cwd, ignoreVendor) + if err != nil { + // Package not found, or can't even parse package declaration. + // Already reported by previous loop; ignore it. + continue + } + + // Needs external test package? + if len(bp.XTestGoFiles) > 0 { + xtestPkgs = append(xtestPkgs, bp) + } + + // Consult the cache using the canonical package path. + path := bp.ImportPath + imp.importedMu.Lock() // (unnecessary, we're sequential here) + ii, ok := imp.imported[path] + // Paranoid checks added due to issue #11012. + if !ok { + // Unreachable. + // The previous loop called importAll and thus + // startLoad for each path in ImportPkgs, which + // populates imp.imported[path] with a non-zero value. + panic(fmt.Sprintf("imported[%q] not found", path)) + } + if ii == nil { + // Unreachable. + // The ii values in this loop are the same as in + // the previous loop, which enforced the invariant + // that at least one of ii.err and ii.info is non-nil. + panic(fmt.Sprintf("imported[%q] == nil", path)) + } + if ii.info == nil { + // Unreachable. + // awaitCompletion has the postcondition + // ii.info != nil. + panic(fmt.Sprintf("imported[%q].info = nil", path)) + } + info := ii.info + imp.importedMu.Unlock() + + // Parse the in-package test files. + files, errs := imp.conf.parsePackageFiles(bp, 't') + for _, err := range errs { + info.appendError(err) + } + + // The test files augmenting package P cannot be imported, + // but may import packages that import P, + // so we must disable the cycle check. + imp.addFiles(info, files, false) + } + + createPkg := func(path, dir string, files []*ast.File, errs []error) { + info := imp.newPackageInfo(path, dir) + for _, err := range errs { + info.appendError(err) + } + + // Ad hoc packages are non-importable, + // so no cycle check is needed. + // addFiles loads dependencies in parallel. + imp.addFiles(info, files, false) + prog.Created = append(prog.Created, info) + } + + // Create packages specified by conf.CreatePkgs. + for _, cp := range conf.CreatePkgs { + files, errs := parseFiles(conf.fset(), conf.build(), nil, conf.Cwd, cp.Filenames, conf.ParserMode) + files = append(files, cp.Files...) + + path := cp.Path + if path == "" { + if len(files) > 0 { + path = files[0].Name.Name + } else { + path = "(unnamed)" + } + } + + dir := conf.Cwd + if len(files) > 0 && files[0].Pos().IsValid() { + dir = filepath.Dir(conf.fset().File(files[0].Pos()).Name()) + } + createPkg(path, dir, files, errs) + } + + // Create external test packages. + sort.Sort(byImportPath(xtestPkgs)) + for _, bp := range xtestPkgs { + files, errs := imp.conf.parsePackageFiles(bp, 'x') + createPkg(bp.ImportPath+"_test", bp.Dir, files, errs) + } + + // -- finishing up (sequential) ---------------------------------------- + + if len(prog.Imported)+len(prog.Created) == 0 { + return nil, errors.New("no initial packages were loaded") + } + + // Create infos for indirectly imported packages. + // e.g. incomplete packages without syntax, loaded from export data. + for _, obj := range prog.importMap { + info := prog.AllPackages[obj] + if info == nil { + prog.AllPackages[obj] = &PackageInfo{Pkg: obj, Importable: true} + } else { + // finished + info.checker = nil + info.errorFunc = nil + } + } + + if !conf.AllowErrors { + // Report errors in indirectly imported packages. + for _, info := range prog.AllPackages { + if len(info.Errors) > 0 { + errpkgs = append(errpkgs, info.Pkg.Path()) + } + } + if errpkgs != nil { + var more string + if len(errpkgs) > 3 { + more = fmt.Sprintf(" and %d more", len(errpkgs)-3) + errpkgs = errpkgs[:3] + } + return nil, fmt.Errorf("couldn't load packages due to errors: %s%s", + strings.Join(errpkgs, ", "), more) + } + } + + markErrorFreePackages(prog.AllPackages) + + return prog, nil +} + +type byImportPath []*build.Package + +func (b byImportPath) Len() int { return len(b) } +func (b byImportPath) Less(i, j int) bool { return b[i].ImportPath < b[j].ImportPath } +func (b byImportPath) Swap(i, j int) { b[i], b[j] = b[j], b[i] } + +// markErrorFreePackages sets the TransitivelyErrorFree flag on all +// applicable packages. +func markErrorFreePackages(allPackages map[*types.Package]*PackageInfo) { + // Build the transpose of the import graph. + importedBy := make(map[*types.Package]map[*types.Package]bool) + for P := range allPackages { + for _, Q := range P.Imports() { + clients, ok := importedBy[Q] + if !ok { + clients = make(map[*types.Package]bool) + importedBy[Q] = clients + } + clients[P] = true + } + } + + // Find all packages reachable from some error package. + reachable := make(map[*types.Package]bool) + var visit func(*types.Package) + visit = func(p *types.Package) { + if !reachable[p] { + reachable[p] = true + for q := range importedBy[p] { + visit(q) + } + } + } + for _, info := range allPackages { + if len(info.Errors) > 0 { + visit(info.Pkg) + } + } + + // Mark the others as "transitively error-free". + for _, info := range allPackages { + if !reachable[info.Pkg] { + info.TransitivelyErrorFree = true + } + } +} + +// build returns the effective build context. +func (conf *Config) build() *build.Context { + if conf.Build != nil { + return conf.Build + } + return &build.Default +} + +// parsePackageFiles enumerates the files belonging to package path, +// then loads, parses and returns them, plus a list of I/O or parse +// errors that were encountered. +// +// 'which' indicates which files to include: +// 'g': include non-test *.go source files (GoFiles + processed CgoFiles) +// 't': include in-package *_test.go source files (TestGoFiles) +// 'x': include external *_test.go source files. (XTestGoFiles) +// +func (conf *Config) parsePackageFiles(bp *build.Package, which rune) ([]*ast.File, []error) { + if bp.ImportPath == "unsafe" { + return nil, nil + } + var filenames []string + switch which { + case 'g': + filenames = bp.GoFiles + case 't': + filenames = bp.TestGoFiles + case 'x': + filenames = bp.XTestGoFiles + default: + panic(which) + } + + files, errs := parseFiles(conf.fset(), conf.build(), conf.DisplayPath, bp.Dir, filenames, conf.ParserMode) + + // Preprocess CgoFiles and parse the outputs (sequentially). + if which == 'g' && bp.CgoFiles != nil { + cgofiles, err := cgo.ProcessFiles(bp, conf.fset(), conf.DisplayPath, conf.ParserMode) + if err != nil { + errs = append(errs, err) + } else { + files = append(files, cgofiles...) + } + } + + return files, errs +} + +// doImport imports the package denoted by path. +// It implements the types.Importer signature. +// +// It returns an error if a package could not be created +// (e.g. go/build or parse error), but type errors are reported via +// the types.Config.Error callback (the first of which is also saved +// in the package's PackageInfo). +// +// Idempotent. +// +func (imp *importer) doImport(from *PackageInfo, to string) (*types.Package, error) { + if to == "C" { + // This should be unreachable, but ad hoc packages are + // not currently subject to cgo preprocessing. + // See https://golang.org/issue/11627. + return nil, fmt.Errorf(`the loader doesn't cgo-process ad hoc packages like %q; see Go issue 11627`, + from.Pkg.Path()) + } + + bp, err := imp.findPackage(to, from.dir, 0) + if err != nil { + return nil, err + } + + // The standard unsafe package is handled specially, + // and has no PackageInfo. + if bp.ImportPath == "unsafe" { + return types.Unsafe, nil + } + + // Look for the package in the cache using its canonical path. + path := bp.ImportPath + imp.importedMu.Lock() + ii := imp.imported[path] + imp.importedMu.Unlock() + if ii == nil { + panic("internal error: unexpected import: " + path) + } + if ii.info != nil { + return ii.info.Pkg, nil + } + + // Import of incomplete package: this indicates a cycle. + fromPath := from.Pkg.Path() + if cycle := imp.findPath(path, fromPath); cycle != nil { + // Normalize cycle: start from alphabetically largest node. + pos, start := -1, "" + for i, s := range cycle { + if pos < 0 || s > start { + pos, start = i, s + } + } + cycle = append(cycle, cycle[:pos]...)[pos:] // rotate cycle to start from largest + cycle = append(cycle, cycle[0]) // add start node to end to show cycliness + return nil, fmt.Errorf("import cycle: %s", strings.Join(cycle, " -> ")) + } + + panic("internal error: import of incomplete (yet acyclic) package: " + fromPath) +} + +// findPackage locates the package denoted by the importPath in the +// specified directory. +func (imp *importer) findPackage(importPath, fromDir string, mode build.ImportMode) (*build.Package, error) { + // We use a non-blocking duplicate-suppressing cache (gopl.io §9.7) + // to avoid holding the lock around FindPackage. + key := findpkgKey{importPath, fromDir, mode} + imp.findpkgMu.Lock() + v, ok := imp.findpkg[key] + if ok { + // cache hit + imp.findpkgMu.Unlock() + + <-v.ready // wait for entry to become ready + } else { + // Cache miss: this goroutine becomes responsible for + // populating the map entry and broadcasting its readiness. + v = &findpkgValue{ready: make(chan struct{})} + imp.findpkg[key] = v + imp.findpkgMu.Unlock() + + ioLimit <- true + v.bp, v.err = imp.conf.FindPackage(imp.conf.build(), importPath, fromDir, mode) + <-ioLimit + + if _, ok := v.err.(*build.NoGoError); ok { + v.err = nil // empty directory is not an error + } + + close(v.ready) // broadcast ready condition + } + return v.bp, v.err +} + +// importAll loads, parses, and type-checks the specified packages in +// parallel and returns their completed importInfos in unspecified order. +// +// fromPath is the package path of the importing package, if it is +// importable, "" otherwise. It is used for cycle detection. +// +// fromDir is the directory containing the import declaration that +// caused these imports. +// +func (imp *importer) importAll(fromPath, fromDir string, imports map[string]bool, mode build.ImportMode) (infos []*PackageInfo, errors []importError) { + // TODO(adonovan): opt: do the loop in parallel once + // findPackage is non-blocking. + var pending []*importInfo + for importPath := range imports { + bp, err := imp.findPackage(importPath, fromDir, mode) + if err != nil { + errors = append(errors, importError{ + path: importPath, + err: err, + }) + continue + } + pending = append(pending, imp.startLoad(bp)) + } + + if fromPath != "" { + // We're loading a set of imports. + // + // We must record graph edges from the importing package + // to its dependencies, and check for cycles. + imp.graphMu.Lock() + deps, ok := imp.graph[fromPath] + if !ok { + deps = make(map[string]bool) + imp.graph[fromPath] = deps + } + for _, ii := range pending { + deps[ii.path] = true + } + imp.graphMu.Unlock() + } + + for _, ii := range pending { + if fromPath != "" { + if cycle := imp.findPath(ii.path, fromPath); cycle != nil { + // Cycle-forming import: we must not await its + // completion since it would deadlock. + // + // We don't record the error in ii since + // the error is really associated with the + // cycle-forming edge, not the package itself. + // (Also it would complicate the + // invariants of importPath completion.) + if trace { + fmt.Fprintf(os.Stderr, "import cycle: %q\n", cycle) + } + continue + } + } + ii.awaitCompletion() + infos = append(infos, ii.info) + } + + return infos, errors +} + +// findPath returns an arbitrary path from 'from' to 'to' in the import +// graph, or nil if there was none. +func (imp *importer) findPath(from, to string) []string { + imp.graphMu.Lock() + defer imp.graphMu.Unlock() + + seen := make(map[string]bool) + var search func(stack []string, importPath string) []string + search = func(stack []string, importPath string) []string { + if !seen[importPath] { + seen[importPath] = true + stack = append(stack, importPath) + if importPath == to { + return stack + } + for x := range imp.graph[importPath] { + if p := search(stack, x); p != nil { + return p + } + } + } + return nil + } + return search(make([]string, 0, 20), from) +} + +// startLoad initiates the loading, parsing and type-checking of the +// specified package and its dependencies, if it has not already begun. +// +// It returns an importInfo, not necessarily in a completed state. The +// caller must call awaitCompletion() before accessing its info field. +// +// startLoad is concurrency-safe and idempotent. +// +func (imp *importer) startLoad(bp *build.Package) *importInfo { + path := bp.ImportPath + imp.importedMu.Lock() + ii, ok := imp.imported[path] + if !ok { + ii = &importInfo{path: path, complete: make(chan struct{})} + imp.imported[path] = ii + go func() { + info := imp.load(bp) + ii.Complete(info) + }() + } + imp.importedMu.Unlock() + + return ii +} + +// load implements package loading by parsing Go source files +// located by go/build. +func (imp *importer) load(bp *build.Package) *PackageInfo { + info := imp.newPackageInfo(bp.ImportPath, bp.Dir) + info.Importable = true + files, errs := imp.conf.parsePackageFiles(bp, 'g') + for _, err := range errs { + info.appendError(err) + } + + imp.addFiles(info, files, true) + + imp.progMu.Lock() + imp.prog.importMap[bp.ImportPath] = info.Pkg + imp.progMu.Unlock() + + return info +} + +// addFiles adds and type-checks the specified files to info, loading +// their dependencies if needed. The order of files determines the +// package initialization order. It may be called multiple times on the +// same package. Errors are appended to the info.Errors field. +// +// cycleCheck determines whether the imports within files create +// dependency edges that should be checked for potential cycles. +// +func (imp *importer) addFiles(info *PackageInfo, files []*ast.File, cycleCheck bool) { + // Ensure the dependencies are loaded, in parallel. + var fromPath string + if cycleCheck { + fromPath = info.Pkg.Path() + } + // TODO(adonovan): opt: make the caller do scanImports. + // Callers with a build.Package can skip it. + imp.importAll(fromPath, info.dir, scanImports(files), 0) + + if trace { + fmt.Fprintf(os.Stderr, "%s: start %q (%d)\n", + time.Since(imp.start), info.Pkg.Path(), len(files)) + } + + // Don't call checker.Files on Unsafe, even with zero files, + // because it would mutate the package, which is a global. + if info.Pkg == types.Unsafe { + if len(files) > 0 { + panic(`"unsafe" package contains unexpected files`) + } + } else { + // Ignore the returned (first) error since we + // already collect them all in the PackageInfo. + info.checker.Files(files) + info.Files = append(info.Files, files...) + } + + if imp.conf.AfterTypeCheck != nil { + imp.conf.AfterTypeCheck(info, files) + } + + if trace { + fmt.Fprintf(os.Stderr, "%s: stop %q\n", + time.Since(imp.start), info.Pkg.Path()) + } +} + +func (imp *importer) newPackageInfo(path, dir string) *PackageInfo { + var pkg *types.Package + if path == "unsafe" { + pkg = types.Unsafe + } else { + pkg = types.NewPackage(path, "") + } + info := &PackageInfo{ + Pkg: pkg, + Info: types.Info{ + Types: make(map[ast.Expr]types.TypeAndValue), + Defs: make(map[*ast.Ident]types.Object), + Uses: make(map[*ast.Ident]types.Object), + Implicits: make(map[ast.Node]types.Object), + Scopes: make(map[ast.Node]*types.Scope), + Selections: make(map[*ast.SelectorExpr]*types.Selection), + }, + errorFunc: imp.conf.TypeChecker.Error, + dir: dir, + } + + // Copy the types.Config so we can vary it across PackageInfos. + tc := imp.conf.TypeChecker + tc.IgnoreFuncBodies = false + if f := imp.conf.TypeCheckFuncBodies; f != nil { + tc.IgnoreFuncBodies = !f(path) + } + tc.Importer = closure{imp, info} + tc.Error = info.appendError // appendError wraps the user's Error function + + info.checker = types.NewChecker(&tc, imp.conf.fset(), pkg, &info.Info) + imp.progMu.Lock() + imp.prog.AllPackages[pkg] = info + imp.progMu.Unlock() + return info +} + +type closure struct { + imp *importer + info *PackageInfo +} + +func (c closure) Import(to string) (*types.Package, error) { return c.imp.doImport(c.info, to) } diff --git a/vendor/golang.org/x/tools/go/loader/util.go b/vendor/golang.org/x/tools/go/loader/util.go new file mode 100644 index 00000000000..7f38dd74077 --- /dev/null +++ b/vendor/golang.org/x/tools/go/loader/util.go @@ -0,0 +1,124 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package loader + +import ( + "go/ast" + "go/build" + "go/parser" + "go/token" + "io" + "os" + "strconv" + "sync" + + "golang.org/x/tools/go/buildutil" +) + +// We use a counting semaphore to limit +// the number of parallel I/O calls per process. +var ioLimit = make(chan bool, 10) + +// parseFiles parses the Go source files within directory dir and +// returns the ASTs of the ones that could be at least partially parsed, +// along with a list of I/O and parse errors encountered. +// +// I/O is done via ctxt, which may specify a virtual file system. +// displayPath is used to transform the filenames attached to the ASTs. +// +func parseFiles(fset *token.FileSet, ctxt *build.Context, displayPath func(string) string, dir string, files []string, mode parser.Mode) ([]*ast.File, []error) { + if displayPath == nil { + displayPath = func(path string) string { return path } + } + var wg sync.WaitGroup + n := len(files) + parsed := make([]*ast.File, n) + errors := make([]error, n) + for i, file := range files { + if !buildutil.IsAbsPath(ctxt, file) { + file = buildutil.JoinPath(ctxt, dir, file) + } + wg.Add(1) + go func(i int, file string) { + ioLimit <- true // wait + defer func() { + wg.Done() + <-ioLimit // signal + }() + var rd io.ReadCloser + var err error + if ctxt.OpenFile != nil { + rd, err = ctxt.OpenFile(file) + } else { + rd, err = os.Open(file) + } + if err != nil { + errors[i] = err // open failed + return + } + + // ParseFile may return both an AST and an error. + parsed[i], errors[i] = parser.ParseFile(fset, displayPath(file), rd, mode) + rd.Close() + }(i, file) + } + wg.Wait() + + // Eliminate nils, preserving order. + var o int + for _, f := range parsed { + if f != nil { + parsed[o] = f + o++ + } + } + parsed = parsed[:o] + + o = 0 + for _, err := range errors { + if err != nil { + errors[o] = err + o++ + } + } + errors = errors[:o] + + return parsed, errors +} + +// scanImports returns the set of all import paths from all +// import specs in the specified files. +func scanImports(files []*ast.File) map[string]bool { + imports := make(map[string]bool) + for _, f := range files { + for _, decl := range f.Decls { + if decl, ok := decl.(*ast.GenDecl); ok && decl.Tok == token.IMPORT { + for _, spec := range decl.Specs { + spec := spec.(*ast.ImportSpec) + + // NB: do not assume the program is well-formed! + path, err := strconv.Unquote(spec.Path.Value) + if err != nil { + continue // quietly ignore the error + } + if path == "C" { + continue // skip pseudopackage + } + imports[path] = true + } + } + } + } + return imports +} + +// ---------- Internal helpers ---------- + +// TODO(adonovan): make this a method: func (*token.File) Contains(token.Pos) +func tokenFileContainsPos(f *token.File, pos token.Pos) bool { + p := int(pos) + base := f.Base() + return base <= p && p < base+f.Size() +} diff --git a/vendor/golang.org/x/tools/go/packages/doc.go b/vendor/golang.org/x/tools/go/packages/doc.go index 3799f8ed8be..4bfe28a51ff 100644 --- a/vendor/golang.org/x/tools/go/packages/doc.go +++ b/vendor/golang.org/x/tools/go/packages/doc.go @@ -60,8 +60,7 @@ causes Load to run in LoadFiles mode, collecting minimal information. See the documentation for type Config for details. As noted earlier, the Config.Mode controls the amount of detail -reported about the loaded packages, with each mode returning all the data of the -previous mode with some extra added. See the documentation for type LoadMode +reported about the loaded packages. See the documentation for type LoadMode for details. Most tools should pass their command-line arguments (after any flags) diff --git a/vendor/golang.org/x/tools/go/packages/external.go b/vendor/golang.org/x/tools/go/packages/external.go index 6ac3e4f5b57..8c8473fd0bd 100644 --- a/vendor/golang.org/x/tools/go/packages/external.go +++ b/vendor/golang.org/x/tools/go/packages/external.go @@ -84,13 +84,14 @@ func findExternalDriver(cfg *Config) driver { cmd.Stdin = bytes.NewReader(req) cmd.Stdout = buf cmd.Stderr = stderr - if len(stderr.Bytes()) != 0 && os.Getenv("GOPACKAGESPRINTDRIVERERRORS") != "" { - fmt.Fprintf(os.Stderr, "%s stderr: <<%s>>\n", cmdDebugStr(cmd, words...), stderr) - } if err := cmd.Run(); err != nil { return nil, fmt.Errorf("%v: %v: %s", tool, err, cmd.Stderr) } + if len(stderr.Bytes()) != 0 && os.Getenv("GOPACKAGESPRINTDRIVERERRORS") != "" { + fmt.Fprintf(os.Stderr, "%s stderr: <<%s>>\n", cmdDebugStr(cmd, words...), stderr) + } + var response driverResponse if err := json.Unmarshal(buf.Bytes(), &response); err != nil { return nil, err diff --git a/vendor/golang.org/x/tools/go/packages/golist.go b/vendor/golang.org/x/tools/go/packages/golist.go index c581bce976c..a9a1ba89e81 100644 --- a/vendor/golang.org/x/tools/go/packages/golist.go +++ b/vendor/golang.org/x/tools/go/packages/golist.go @@ -26,7 +26,6 @@ import ( "golang.org/x/tools/go/internal/packagesdriver" "golang.org/x/tools/internal/gopathwalk" "golang.org/x/tools/internal/semver" - "golang.org/x/tools/internal/span" ) // debug controls verbose logging. @@ -254,12 +253,7 @@ func addNeededOverlayPackages(cfg *Config, driver driver, response *responseDedu if len(pkgs) == 0 { return nil } - drivercfg := *cfg - if getGoInfo().env.modulesOn { - drivercfg.BuildFlags = append(drivercfg.BuildFlags, "-mod=readonly") - } - dr, err := driver(&drivercfg, pkgs...) - + dr, err := driver(cfg, pkgs...) if err != nil { return err } @@ -270,10 +264,7 @@ func addNeededOverlayPackages(cfg *Config, driver driver, response *responseDedu if err != nil { return err } - if err := addNeededOverlayPackages(cfg, driver, response, needPkgs, getGoInfo); err != nil { - return err - } - return nil + return addNeededOverlayPackages(cfg, driver, response, needPkgs, getGoInfo) } func runContainsQueries(cfg *Config, driver driver, response *responseDeduper, queries []string, goInfo func() *goInfo) error { @@ -287,42 +278,43 @@ func runContainsQueries(cfg *Config, driver driver, response *responseDeduper, q return fmt.Errorf("could not determine absolute path of file= query path %q: %v", query, err) } dirResponse, err := driver(cfg, pattern) - if err != nil { + if err != nil || (len(dirResponse.Packages) == 1 && len(dirResponse.Packages[0].Errors) == 1) { + // There was an error loading the package. Try to load the file as an ad-hoc package. + // Usually the error will appear in a returned package, but may not if we're in modules mode + // and the ad-hoc is located outside a module. var queryErr error - if dirResponse, queryErr = adHocPackage(cfg, driver, pattern, query); queryErr != nil { - return err // return the original error + dirResponse, queryErr = driver(cfg, query) + if queryErr != nil { + // Return the original error if the attempt to fall back failed. + return err } - } - // `go list` can report errors for files that are not listed as part of a package's GoFiles. - // In the case of an invalid Go file, we should assume that it is part of package if only - // one package is in the response. The file may have valid contents in an overlay. - if len(dirResponse.Packages) == 1 { - pkg := dirResponse.Packages[0] - for i, err := range pkg.Errors { - s := errorSpan(err) - if !s.IsValid() { - break - } - if len(pkg.CompiledGoFiles) == 0 { - break - } - dir := filepath.Dir(pkg.CompiledGoFiles[0]) - filename := filepath.Join(dir, filepath.Base(s.URI().Filename())) - if info, err := os.Stat(filename); err != nil || info.IsDir() { - break - } - if !contains(pkg.CompiledGoFiles, filename) { - pkg.CompiledGoFiles = append(pkg.CompiledGoFiles, filename) - pkg.GoFiles = append(pkg.GoFiles, filename) - pkg.Errors = append(pkg.Errors[:i], pkg.Errors[i+1:]...) - } + // If we get nothing back from `go list`, try to make this file into its own ad-hoc package. + if len(dirResponse.Packages) == 0 && queryErr == nil { + dirResponse.Packages = append(dirResponse.Packages, &Package{ + ID: "command-line-arguments", + PkgPath: query, + GoFiles: []string{query}, + CompiledGoFiles: []string{query}, + Imports: make(map[string]*Package), + }) + dirResponse.Roots = append(dirResponse.Roots, "command-line-arguments") } - } - // A final attempt to construct an ad-hoc package. - if len(dirResponse.Packages) == 1 && len(dirResponse.Packages[0].Errors) == 1 { - var queryErr error - if dirResponse, queryErr = adHocPackage(cfg, driver, pattern, query); queryErr != nil { - return err // return the original error + // Special case to handle issue #33482: + // If this is a file= query for ad-hoc packages where the file only exists on an overlay, + // and exists outside of a module, add the file in for the package. + if len(dirResponse.Packages) == 1 && (dirResponse.Packages[0].ID == "command-line-arguments" || + filepath.ToSlash(dirResponse.Packages[0].PkgPath) == filepath.ToSlash(query)) { + if len(dirResponse.Packages[0].GoFiles) == 0 { + filename := filepath.Join(pattern, filepath.Base(query)) // avoid recomputing abspath + // TODO(matloob): check if the file is outside of a root dir? + for path := range cfg.Overlay { + if path == filename { + dirResponse.Packages[0].Errors = nil + dirResponse.Packages[0].GoFiles = []string{path} + dirResponse.Packages[0].CompiledGoFiles = []string{path} + } + } + } } } isRoot := make(map[string]bool, len(dirResponse.Roots)) @@ -350,74 +342,6 @@ func runContainsQueries(cfg *Config, driver driver, response *responseDeduper, q return nil } -// adHocPackage attempts to construct an ad-hoc package given a query that failed. -func adHocPackage(cfg *Config, driver driver, pattern, query string) (*driverResponse, error) { - // There was an error loading the package. Try to load the file as an ad-hoc package. - // Usually the error will appear in a returned package, but may not if we're in modules mode - // and the ad-hoc is located outside a module. - dirResponse, err := driver(cfg, query) - if err != nil { - return nil, err - } - // If we get nothing back from `go list`, try to make this file into its own ad-hoc package. - if len(dirResponse.Packages) == 0 && err == nil { - dirResponse.Packages = append(dirResponse.Packages, &Package{ - ID: "command-line-arguments", - PkgPath: query, - GoFiles: []string{query}, - CompiledGoFiles: []string{query}, - Imports: make(map[string]*Package), - }) - dirResponse.Roots = append(dirResponse.Roots, "command-line-arguments") - } - // Special case to handle issue #33482: - // If this is a file= query for ad-hoc packages where the file only exists on an overlay, - // and exists outside of a module, add the file in for the package. - if len(dirResponse.Packages) == 1 && (dirResponse.Packages[0].ID == "command-line-arguments" || dirResponse.Packages[0].PkgPath == filepath.ToSlash(query)) { - if len(dirResponse.Packages[0].GoFiles) == 0 { - filename := filepath.Join(pattern, filepath.Base(query)) // avoid recomputing abspath - // TODO(matloob): check if the file is outside of a root dir? - for path := range cfg.Overlay { - if path == filename { - dirResponse.Packages[0].Errors = nil - dirResponse.Packages[0].GoFiles = []string{path} - dirResponse.Packages[0].CompiledGoFiles = []string{path} - } - } - } - } - return dirResponse, nil -} - -func contains(files []string, filename string) bool { - for _, f := range files { - if f == filename { - return true - } - } - return false -} - -// errorSpan attempts to parse a standard `go list` error message -// by stripping off the trailing error message. -// -// It works only on errors whose message is prefixed by colon, -// followed by a space (": "). For example: -// -// attributes.go:13:1: expected 'package', found 'type' -// -func errorSpan(err Error) span.Span { - if err.Pos == "" { - input := strings.TrimSpace(err.Msg) - msgIndex := strings.Index(input, ": ") - if msgIndex < 0 { - return span.Parse(input) - } - return span.Parse(input[:msgIndex]) - } - return span.Parse(err.Pos) -} - // modCacheRegexp splits a path in a module cache into module, module version, and package. var modCacheRegexp = regexp.MustCompile(`(.*)@([^/\\]*)(.*)`) @@ -749,7 +673,7 @@ func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driv // Run "go list" for complete // information on the specified packages. - buf, err := invokeGo(cfg, golistargs(cfg, words)...) + buf, err := invokeGo(cfg, "list", golistargs(cfg, words)...) if err != nil { return nil, err } @@ -881,9 +805,15 @@ func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driv } if p.Error != nil { + msg := strings.TrimSpace(p.Error.Err) // Trim to work around golang.org/issue/32363. + // Address golang.org/issue/35964 by appending import stack to error message. + if msg == "import cycle not allowed" && len(p.Error.ImportStack) != 0 { + msg += fmt.Sprintf(": import stack: %v", p.Error.ImportStack) + } pkg.Errors = append(pkg.Errors, Error{ - Pos: p.Error.Pos, - Msg: strings.TrimSpace(p.Error.Err), // Trim to work around golang.org/issue/32363. + Pos: p.Error.Pos, + Msg: msg, + Kind: ListError, }) } @@ -947,7 +877,7 @@ func absJoin(dir string, fileses ...[]string) (res []string) { func golistargs(cfg *Config, words []string) []string { const findFlags = NeedImports | NeedTypes | NeedSyntax | NeedTypesInfo fullargs := []string{ - "list", "-e", "-json", + "-e", "-json", fmt.Sprintf("-compiled=%t", cfg.Mode&(NeedCompiledGoFiles|NeedSyntax|NeedTypesInfo|NeedTypesSizes) != 0), fmt.Sprintf("-test=%t", cfg.Tests), fmt.Sprintf("-export=%t", usesExportData(cfg)), @@ -963,10 +893,13 @@ func golistargs(cfg *Config, words []string) []string { } // invokeGo returns the stdout of a go command invocation. -func invokeGo(cfg *Config, args ...string) (*bytes.Buffer, error) { +func invokeGo(cfg *Config, verb string, args ...string) (*bytes.Buffer, error) { stdout := new(bytes.Buffer) stderr := new(bytes.Buffer) - cmd := exec.CommandContext(cfg.Context, "go", args...) + goArgs := []string{verb} + goArgs = append(goArgs, cfg.BuildFlags...) + goArgs = append(goArgs, args...) + cmd := exec.CommandContext(cfg.Context, "go", goArgs...) // On darwin the cwd gets resolved to the real path, which breaks anything that // expects the working directory to keep the original path, including the // go command when dealing with modules. diff --git a/vendor/golang.org/x/tools/go/packages/loadmode_string.go b/vendor/golang.org/x/tools/go/packages/loadmode_string.go new file mode 100644 index 00000000000..aff94a3fe91 --- /dev/null +++ b/vendor/golang.org/x/tools/go/packages/loadmode_string.go @@ -0,0 +1,57 @@ +// Copyright 2019 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package packages + +import ( + "fmt" + "strings" +) + +var allModes = []LoadMode{ + NeedName, + NeedFiles, + NeedCompiledGoFiles, + NeedImports, + NeedDeps, + NeedExportsFile, + NeedTypes, + NeedSyntax, + NeedTypesInfo, + NeedTypesSizes, +} + +var modeStrings = []string{ + "NeedName", + "NeedFiles", + "NeedCompiledGoFiles", + "NeedImports", + "NeedDeps", + "NeedExportsFile", + "NeedTypes", + "NeedSyntax", + "NeedTypesInfo", + "NeedTypesSizes", +} + +func (mod LoadMode) String() string { + m := mod + if m == 0 { + return fmt.Sprintf("LoadMode(0)") + } + var out []string + for i, x := range allModes { + if x > m { + break + } + if (m & x) != 0 { + out = append(out, modeStrings[i]) + m = m ^ x + } + } + if m != 0 { + out = append(out, "Unknown") + } + return fmt.Sprintf("LoadMode(%s)", strings.Join(out, "|")) +} diff --git a/vendor/golang.org/x/tools/go/packages/packages.go b/vendor/golang.org/x/tools/go/packages/packages.go index b29c91369e1..f98a0bdcae4 100644 --- a/vendor/golang.org/x/tools/go/packages/packages.go +++ b/vendor/golang.org/x/tools/go/packages/packages.go @@ -160,7 +160,7 @@ type Config struct { Tests bool // Overlay provides a mapping of absolute file paths to file contents. - // If the file with the given path already exists, the parser will use the + // If the file with the given path already exists, the parser will use the // alternative file contents provided by the map. // // Overlays provide incomplete support for when a given file doesn't @@ -467,7 +467,7 @@ func newLoader(cfg *Config) *loader { ld.requestedMode = ld.Mode ld.Mode = impliedLoadMode(ld.Mode) - if ld.Mode&NeedTypes != 0 { + if ld.Mode&NeedTypes != 0 || ld.Mode&NeedSyntax != 0 { if ld.Fset == nil { ld.Fset = token.NewFileSet() } @@ -609,9 +609,9 @@ func (ld *loader) refine(roots []string, list ...*Package) ([]*Package, error) { } } } - // Load type data if needed, starting at + // Load type data and syntax if needed, starting at // the initial packages (roots of the import DAG). - if ld.Mode&NeedTypes != 0 { + if ld.Mode&NeedTypes != 0 || ld.Mode&NeedSyntax != 0 { var wg sync.WaitGroup for _, lpkg := range initial { wg.Add(1) @@ -713,7 +713,7 @@ func (ld *loader) loadPackage(lpkg *loaderPackage) { // which would then require that such created packages be explicitly // inserted back into the Import graph as a final step after export data loading. // The Diamond test exercises this case. - if !lpkg.needtypes { + if !lpkg.needtypes && !lpkg.needsrc { return } if !lpkg.needsrc { @@ -770,7 +770,7 @@ func (ld *loader) loadPackage(lpkg *loaderPackage) { lpkg.Errors = append(lpkg.Errors, errs...) } - if len(lpkg.CompiledGoFiles) == 0 && lpkg.ExportFile != "" { + if ld.Config.Mode&NeedTypes != 0 && len(lpkg.CompiledGoFiles) == 0 && lpkg.ExportFile != "" { // The config requested loading sources and types, but sources are missing. // Add an error to the package and fall back to loading from export data. appendError(Error{"-", fmt.Sprintf("sources missing for package %s", lpkg.ID), ParseError}) @@ -784,6 +784,9 @@ func (ld *loader) loadPackage(lpkg *loaderPackage) { } lpkg.Syntax = files + if ld.Config.Mode&NeedTypes == 0 { + return + } lpkg.TypesInfo = &types.Info{ Types: make(map[ast.Expr]types.TypeAndValue), diff --git a/vendor/golang.org/x/tools/go/pointer/TODO b/vendor/golang.org/x/tools/go/pointer/TODO new file mode 100644 index 00000000000..f95e70621d9 --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/TODO @@ -0,0 +1,33 @@ +-*- text -*- + +Pointer analysis to-do list +=========================== + +CONSTRAINT GENERATION: +- support reflection: + - a couple of operators are missing + - reflect.Values may contain lvalues (CanAddr) +- implement native intrinsics. These vary by platform. +- add to pts(a.panic) a label representing all runtime panics, e.g. + runtime.{TypeAssertionError,errorString,errorCString}. + +OPTIMISATIONS +- pre-solver: + pointer equivalence: extend HVN to HRU + location equivalence +- solver: HCD, LCD. +- experiment with map+slice worklist in lieu of bitset. + It may have faster insert. + +MISC: +- Test on all platforms. + Currently we assume these go/build tags: linux, amd64, !cgo. + +MAINTAINABILITY +- Think about ways to make debugging this code easier. PTA logs + routinely exceed a million lines and require training to read. + +BUGS: +- There's a crash bug in stdlib_test + reflection, rVCallConstraint. + + diff --git a/vendor/golang.org/x/tools/go/pointer/analysis.go b/vendor/golang.org/x/tools/go/pointer/analysis.go new file mode 100644 index 00000000000..0abb04dd80d --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/analysis.go @@ -0,0 +1,452 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pointer + +// This file defines the main datatypes and Analyze function of the pointer analysis. + +import ( + "fmt" + "go/token" + "go/types" + "io" + "os" + "reflect" + "runtime" + "runtime/debug" + "sort" + + "golang.org/x/tools/go/callgraph" + "golang.org/x/tools/go/ssa" + "golang.org/x/tools/go/types/typeutil" +) + +const ( + // optimization options; enable all when committing + optRenumber = true // enable renumbering optimization (makes logs hard to read) + optHVN = true // enable pointer equivalence via Hash-Value Numbering + + // debugging options; disable all when committing + debugHVN = false // enable assertions in HVN + debugHVNVerbose = false // enable extra HVN logging + debugHVNCrossCheck = false // run solver with/without HVN and compare (caveats below) + debugTimers = false // show running time of each phase +) + +// object.flags bitmask values. +const ( + otTagged = 1 << iota // type-tagged object + otIndirect // type-tagged object with indirect payload + otFunction // function object +) + +// An object represents a contiguous block of memory to which some +// (generalized) pointer may point. +// +// (Note: most variables called 'obj' are not *objects but nodeids +// such that a.nodes[obj].obj != nil.) +// +type object struct { + // flags is a bitset of the node type (ot*) flags defined above. + flags uint32 + + // Number of following nodes belonging to the same "object" + // allocation. Zero for all other nodes. + size uint32 + + // data describes this object; it has one of these types: + // + // ssa.Value for an object allocated by an SSA operation. + // types.Type for an rtype instance object or *rtype-tagged object. + // string for an instrinsic object, e.g. the array behind os.Args. + // nil for an object allocated by an instrinsic. + // (cgn provides the identity of the intrinsic.) + data interface{} + + // The call-graph node (=context) in which this object was allocated. + // May be nil for global objects: Global, Const, some Functions. + cgn *cgnode +} + +// nodeid denotes a node. +// It is an index within analysis.nodes. +// We use small integers, not *node pointers, for many reasons: +// - they are smaller on 64-bit systems. +// - sets of them can be represented compactly in bitvectors or BDDs. +// - order matters; a field offset can be computed by simple addition. +type nodeid uint32 + +// A node is an equivalence class of memory locations. +// Nodes may be pointers, pointed-to locations, neither, or both. +// +// Nodes that are pointed-to locations ("labels") have an enclosing +// object (see analysis.enclosingObject). +// +type node struct { + // If non-nil, this node is the start of an object + // (addressable memory location). + // The following obj.size nodes implicitly belong to the object; + // they locate their object by scanning back. + obj *object + + // The type of the field denoted by this node. Non-aggregate, + // unless this is an tagged.T node (i.e. the thing + // pointed to by an interface) in which case typ is that type. + typ types.Type + + // subelement indicates which directly embedded subelement of + // an object of aggregate type (struct, tuple, array) this is. + subelement *fieldInfo // e.g. ".a.b[*].c" + + // Solver state for the canonical node of this pointer- + // equivalence class. Each node is created with its own state + // but they become shared after HVN. + solve *solverState +} + +// An analysis instance holds the state of a single pointer analysis problem. +type analysis struct { + config *Config // the client's control/observer interface + prog *ssa.Program // the program being analyzed + log io.Writer // log stream; nil to disable + panicNode nodeid // sink for panic, source for recover + nodes []*node // indexed by nodeid + flattenMemo map[types.Type][]*fieldInfo // memoization of flatten() + trackTypes map[types.Type]bool // memoization of shouldTrack() + constraints []constraint // set of constraints + cgnodes []*cgnode // all cgnodes + genq []*cgnode // queue of functions to generate constraints for + intrinsics map[*ssa.Function]intrinsic // non-nil values are summaries for intrinsic fns + globalval map[ssa.Value]nodeid // node for each global ssa.Value + globalobj map[ssa.Value]nodeid // maps v to sole member of pts(v), if singleton + localval map[ssa.Value]nodeid // node for each local ssa.Value + localobj map[ssa.Value]nodeid // maps v to sole member of pts(v), if singleton + atFuncs map[*ssa.Function]bool // address-taken functions (for presolver) + mapValues []nodeid // values of makemap objects (indirect in HVN) + work nodeset // solver's worklist + result *Result // results of the analysis + track track // pointerlike types whose aliasing we track + deltaSpace []int // working space for iterating over PTS deltas + + // Reflection & intrinsics: + hasher typeutil.Hasher // cache of type hashes + reflectValueObj types.Object // type symbol for reflect.Value (if present) + reflectValueCall *ssa.Function // (reflect.Value).Call + reflectRtypeObj types.Object // *types.TypeName for reflect.rtype (if present) + reflectRtypePtr *types.Pointer // *reflect.rtype + reflectType *types.Named // reflect.Type + rtypes typeutil.Map // nodeid of canonical *rtype-tagged object for type T + reflectZeros typeutil.Map // nodeid of canonical T-tagged object for zero value + runtimeSetFinalizer *ssa.Function // runtime.SetFinalizer +} + +// enclosingObj returns the first node of the addressable memory +// object that encloses node id. Panic ensues if that node does not +// belong to any object. +func (a *analysis) enclosingObj(id nodeid) nodeid { + // Find previous node with obj != nil. + for i := id; i >= 0; i-- { + n := a.nodes[i] + if obj := n.obj; obj != nil { + if i+nodeid(obj.size) <= id { + break // out of bounds + } + return i + } + } + panic("node has no enclosing object") +} + +// labelFor returns the Label for node id. +// Panic ensues if that node is not addressable. +func (a *analysis) labelFor(id nodeid) *Label { + return &Label{ + obj: a.nodes[a.enclosingObj(id)].obj, + subelement: a.nodes[id].subelement, + } +} + +func (a *analysis) warnf(pos token.Pos, format string, args ...interface{}) { + msg := fmt.Sprintf(format, args...) + if a.log != nil { + fmt.Fprintf(a.log, "%s: warning: %s\n", a.prog.Fset.Position(pos), msg) + } + a.result.Warnings = append(a.result.Warnings, Warning{pos, msg}) +} + +// computeTrackBits sets a.track to the necessary 'track' bits for the pointer queries. +func (a *analysis) computeTrackBits() { + if len(a.config.extendedQueries) != 0 { + // TODO(dh): only track the types necessary for the query. + a.track = trackAll + return + } + var queryTypes []types.Type + for v := range a.config.Queries { + queryTypes = append(queryTypes, v.Type()) + } + for v := range a.config.IndirectQueries { + queryTypes = append(queryTypes, mustDeref(v.Type())) + } + for _, t := range queryTypes { + switch t.Underlying().(type) { + case *types.Chan: + a.track |= trackChan + case *types.Map: + a.track |= trackMap + case *types.Pointer: + a.track |= trackPtr + case *types.Slice: + a.track |= trackSlice + case *types.Interface: + a.track = trackAll + return + } + if rVObj := a.reflectValueObj; rVObj != nil && types.Identical(t, rVObj.Type()) { + a.track = trackAll + return + } + } +} + +// Analyze runs the pointer analysis with the scope and options +// specified by config, and returns the (synthetic) root of the callgraph. +// +// Pointer analysis of a transitively closed well-typed program should +// always succeed. An error can occur only due to an internal bug. +// +func Analyze(config *Config) (result *Result, err error) { + if config.Mains == nil { + return nil, fmt.Errorf("no main/test packages to analyze (check $GOROOT/$GOPATH)") + } + defer func() { + if p := recover(); p != nil { + err = fmt.Errorf("internal error in pointer analysis: %v (please report this bug)", p) + fmt.Fprintln(os.Stderr, "Internal panic in pointer analysis:") + debug.PrintStack() + } + }() + + a := &analysis{ + config: config, + log: config.Log, + prog: config.prog(), + globalval: make(map[ssa.Value]nodeid), + globalobj: make(map[ssa.Value]nodeid), + flattenMemo: make(map[types.Type][]*fieldInfo), + trackTypes: make(map[types.Type]bool), + atFuncs: make(map[*ssa.Function]bool), + hasher: typeutil.MakeHasher(), + intrinsics: make(map[*ssa.Function]intrinsic), + result: &Result{ + Queries: make(map[ssa.Value]Pointer), + IndirectQueries: make(map[ssa.Value]Pointer), + }, + deltaSpace: make([]int, 0, 100), + } + + if false { + a.log = os.Stderr // for debugging crashes; extremely verbose + } + + if a.log != nil { + fmt.Fprintln(a.log, "==== Starting analysis") + } + + // Pointer analysis requires a complete program for soundness. + // Check to prevent accidental misconfiguration. + for _, pkg := range a.prog.AllPackages() { + // (This only checks that the package scope is complete, + // not that func bodies exist, but it's a good signal.) + if !pkg.Pkg.Complete() { + return nil, fmt.Errorf(`pointer analysis requires a complete program yet package %q was incomplete`, pkg.Pkg.Path()) + } + } + + if reflect := a.prog.ImportedPackage("reflect"); reflect != nil { + rV := reflect.Pkg.Scope().Lookup("Value") + a.reflectValueObj = rV + a.reflectValueCall = a.prog.LookupMethod(rV.Type(), nil, "Call") + a.reflectType = reflect.Pkg.Scope().Lookup("Type").Type().(*types.Named) + a.reflectRtypeObj = reflect.Pkg.Scope().Lookup("rtype") + a.reflectRtypePtr = types.NewPointer(a.reflectRtypeObj.Type()) + + // Override flattening of reflect.Value, treating it like a basic type. + tReflectValue := a.reflectValueObj.Type() + a.flattenMemo[tReflectValue] = []*fieldInfo{{typ: tReflectValue}} + + // Override shouldTrack of reflect.Value and *reflect.rtype. + // Always track pointers of these types. + a.trackTypes[tReflectValue] = true + a.trackTypes[a.reflectRtypePtr] = true + + a.rtypes.SetHasher(a.hasher) + a.reflectZeros.SetHasher(a.hasher) + } + if runtime := a.prog.ImportedPackage("runtime"); runtime != nil { + a.runtimeSetFinalizer = runtime.Func("SetFinalizer") + } + a.computeTrackBits() + + a.generate() + a.showCounts() + + if optRenumber { + a.renumber() + } + + N := len(a.nodes) // excludes solver-created nodes + + if optHVN { + if debugHVNCrossCheck { + // Cross-check: run the solver once without + // optimization, once with, and compare the + // solutions. + savedConstraints := a.constraints + + a.solve() + a.dumpSolution("A.pts", N) + + // Restore. + a.constraints = savedConstraints + for _, n := range a.nodes { + n.solve = new(solverState) + } + a.nodes = a.nodes[:N] + + // rtypes is effectively part of the solver state. + a.rtypes = typeutil.Map{} + a.rtypes.SetHasher(a.hasher) + } + + a.hvn() + } + + if debugHVNCrossCheck { + runtime.GC() + runtime.GC() + } + + a.solve() + + // Compare solutions. + if optHVN && debugHVNCrossCheck { + a.dumpSolution("B.pts", N) + + if !diff("A.pts", "B.pts") { + return nil, fmt.Errorf("internal error: optimization changed solution") + } + } + + // Create callgraph.Nodes in deterministic order. + if cg := a.result.CallGraph; cg != nil { + for _, caller := range a.cgnodes { + cg.CreateNode(caller.fn) + } + } + + // Add dynamic edges to call graph. + var space [100]int + for _, caller := range a.cgnodes { + for _, site := range caller.sites { + for _, callee := range a.nodes[site.targets].solve.pts.AppendTo(space[:0]) { + a.callEdge(caller, site, nodeid(callee)) + } + } + } + + return a.result, nil +} + +// callEdge is called for each edge in the callgraph. +// calleeid is the callee's object node (has otFunction flag). +// +func (a *analysis) callEdge(caller *cgnode, site *callsite, calleeid nodeid) { + obj := a.nodes[calleeid].obj + if obj.flags&otFunction == 0 { + panic(fmt.Sprintf("callEdge %s -> n%d: not a function object", site, calleeid)) + } + callee := obj.cgn + + if cg := a.result.CallGraph; cg != nil { + // TODO(adonovan): opt: I would expect duplicate edges + // (to wrappers) to arise due to the elimination of + // context information, but I haven't observed any. + // Understand this better. + callgraph.AddEdge(cg.CreateNode(caller.fn), site.instr, cg.CreateNode(callee.fn)) + } + + if a.log != nil { + fmt.Fprintf(a.log, "\tcall edge %s -> %s\n", site, callee) + } + + // Warn about calls to non-intrinsic external functions. + // TODO(adonovan): de-dup these messages. + if fn := callee.fn; fn.Blocks == nil && a.findIntrinsic(fn) == nil { + a.warnf(site.pos(), "unsound call to unknown intrinsic: %s", fn) + a.warnf(fn.Pos(), " (declared here)") + } +} + +// dumpSolution writes the PTS solution to the specified file. +// +// It only dumps the nodes that existed before solving. The order in +// which solver-created nodes are created depends on pre-solver +// optimization, so we can't include them in the cross-check. +// +func (a *analysis) dumpSolution(filename string, N int) { + f, err := os.Create(filename) + if err != nil { + panic(err) + } + for id, n := range a.nodes[:N] { + if _, err := fmt.Fprintf(f, "pts(n%d) = {", id); err != nil { + panic(err) + } + var sep string + for _, l := range n.solve.pts.AppendTo(a.deltaSpace) { + if l >= N { + break + } + fmt.Fprintf(f, "%s%d", sep, l) + sep = " " + } + fmt.Fprintf(f, "} : %s\n", n.typ) + } + if err := f.Close(); err != nil { + panic(err) + } +} + +// showCounts logs the size of the constraint system. A typical +// optimized distribution is 65% copy, 13% load, 11% addr, 5% +// offsetAddr, 4% store, 2% others. +// +func (a *analysis) showCounts() { + if a.log != nil { + counts := make(map[reflect.Type]int) + for _, c := range a.constraints { + counts[reflect.TypeOf(c)]++ + } + fmt.Fprintf(a.log, "# constraints:\t%d\n", len(a.constraints)) + var lines []string + for t, n := range counts { + line := fmt.Sprintf("%7d (%2d%%)\t%s", n, 100*n/len(a.constraints), t) + lines = append(lines, line) + } + sort.Sort(sort.Reverse(sort.StringSlice(lines))) + for _, line := range lines { + fmt.Fprintf(a.log, "\t%s\n", line) + } + + fmt.Fprintf(a.log, "# nodes:\t%d\n", len(a.nodes)) + + // Show number of pointer equivalence classes. + m := make(map[*solverState]bool) + for _, n := range a.nodes { + m[n.solve] = true + } + fmt.Fprintf(a.log, "# ptsets:\t%d\n", len(m)) + } +} diff --git a/vendor/golang.org/x/tools/go/pointer/api.go b/vendor/golang.org/x/tools/go/pointer/api.go new file mode 100644 index 00000000000..3c5c6dce92b --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/api.go @@ -0,0 +1,285 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pointer + +import ( + "bytes" + "fmt" + "go/token" + "io" + + "golang.org/x/tools/container/intsets" + "golang.org/x/tools/go/callgraph" + "golang.org/x/tools/go/ssa" + "golang.org/x/tools/go/types/typeutil" +) + +// A Config formulates a pointer analysis problem for Analyze. It is +// only usable for a single invocation of Analyze and must not be +// reused. +type Config struct { + // Mains contains the set of 'main' packages to analyze + // Clients must provide the analysis with at least one + // package defining a main() function. + // + // Non-main packages in the ssa.Program that are not + // dependencies of any main package may still affect the + // analysis result, because they contribute runtime types and + // thus methods. + // TODO(adonovan): investigate whether this is desirable. + Mains []*ssa.Package + + // Reflection determines whether to handle reflection + // operators soundly, which is currently rather slow since it + // causes constraint to be generated during solving + // proportional to the number of constraint variables, which + // has not yet been reduced by presolver optimisation. + Reflection bool + + // BuildCallGraph determines whether to construct a callgraph. + // If enabled, the graph will be available in Result.CallGraph. + BuildCallGraph bool + + // The client populates Queries[v] or IndirectQueries[v] + // for each ssa.Value v of interest, to request that the + // points-to sets pts(v) or pts(*v) be computed. If the + // client needs both points-to sets, v may appear in both + // maps. + // + // (IndirectQueries is typically used for Values corresponding + // to source-level lvalues, e.g. an *ssa.Global.) + // + // The analysis populates the corresponding + // Result.{Indirect,}Queries map when it creates the pointer + // variable for v or *v. Upon completion the client can + // inspect that map for the results. + // + // TODO(adonovan): this API doesn't scale well for batch tools + // that want to dump the entire solution. Perhaps optionally + // populate a map[*ssa.DebugRef]Pointer in the Result, one + // entry per source expression. + // + Queries map[ssa.Value]struct{} + IndirectQueries map[ssa.Value]struct{} + extendedQueries map[ssa.Value][]*extendedQuery + + // If Log is non-nil, log messages are written to it. + // Logging is extremely verbose. + Log io.Writer +} + +type track uint32 + +const ( + trackChan track = 1 << iota // track 'chan' references + trackMap // track 'map' references + trackPtr // track regular pointers + trackSlice // track slice references + + trackAll = ^track(0) +) + +// AddQuery adds v to Config.Queries. +// Precondition: CanPoint(v.Type()). +func (c *Config) AddQuery(v ssa.Value) { + if !CanPoint(v.Type()) { + panic(fmt.Sprintf("%s is not a pointer-like value: %s", v, v.Type())) + } + if c.Queries == nil { + c.Queries = make(map[ssa.Value]struct{}) + } + c.Queries[v] = struct{}{} +} + +// AddQuery adds v to Config.IndirectQueries. +// Precondition: CanPoint(v.Type().Underlying().(*types.Pointer).Elem()). +func (c *Config) AddIndirectQuery(v ssa.Value) { + if c.IndirectQueries == nil { + c.IndirectQueries = make(map[ssa.Value]struct{}) + } + if !CanPoint(mustDeref(v.Type())) { + panic(fmt.Sprintf("%s is not the address of a pointer-like value: %s", v, v.Type())) + } + c.IndirectQueries[v] = struct{}{} +} + +// AddExtendedQuery adds an extended, AST-based query on v to the +// analysis. The query, which must be a single Go expression, allows +// destructuring the value. +// +// The query must operate on a variable named 'x', which represents +// the value, and result in a pointer-like object. Only a subset of +// Go expressions are permitted in queries, namely channel receives, +// pointer dereferences, field selectors, array/slice/map/tuple +// indexing and grouping with parentheses. The specific indices when +// indexing arrays, slices and maps have no significance. Indices used +// on tuples must be numeric and within bounds. +// +// All field selectors must be explicit, even ones usually elided +// due to promotion of embedded fields. +// +// The query 'x' is identical to using AddQuery. The query '*x' is +// identical to using AddIndirectQuery. +// +// On success, AddExtendedQuery returns a Pointer to the queried +// value. This Pointer will be initialized during analysis. Using it +// before analysis has finished has undefined behavior. +// +// Example: +// // given v, which represents a function call to 'fn() (int, []*T)', and +// // 'type T struct { F *int }', the following query will access the field F. +// c.AddExtendedQuery(v, "x[1][0].F") +func (c *Config) AddExtendedQuery(v ssa.Value, query string) (*Pointer, error) { + ops, _, err := parseExtendedQuery(v.Type(), query) + if err != nil { + return nil, fmt.Errorf("invalid query %q: %s", query, err) + } + if c.extendedQueries == nil { + c.extendedQueries = make(map[ssa.Value][]*extendedQuery) + } + + ptr := &Pointer{} + c.extendedQueries[v] = append(c.extendedQueries[v], &extendedQuery{ops: ops, ptr: ptr}) + return ptr, nil +} + +func (c *Config) prog() *ssa.Program { + for _, main := range c.Mains { + return main.Prog + } + panic("empty scope") +} + +type Warning struct { + Pos token.Pos + Message string +} + +// A Result contains the results of a pointer analysis. +// +// See Config for how to request the various Result components. +// +type Result struct { + CallGraph *callgraph.Graph // discovered call graph + Queries map[ssa.Value]Pointer // pts(v) for each v in Config.Queries. + IndirectQueries map[ssa.Value]Pointer // pts(*v) for each v in Config.IndirectQueries. + Warnings []Warning // warnings of unsoundness +} + +// A Pointer is an equivalence class of pointer-like values. +// +// A Pointer doesn't have a unique type because pointers of distinct +// types may alias the same object. +// +type Pointer struct { + a *analysis + n nodeid +} + +// A PointsToSet is a set of labels (locations or allocations). +type PointsToSet struct { + a *analysis // may be nil if pts is nil + pts *nodeset +} + +func (s PointsToSet) String() string { + var buf bytes.Buffer + buf.WriteByte('[') + if s.pts != nil { + var space [50]int + for i, l := range s.pts.AppendTo(space[:0]) { + if i > 0 { + buf.WriteString(", ") + } + buf.WriteString(s.a.labelFor(nodeid(l)).String()) + } + } + buf.WriteByte(']') + return buf.String() +} + +// PointsTo returns the set of labels that this points-to set +// contains. +func (s PointsToSet) Labels() []*Label { + var labels []*Label + if s.pts != nil { + var space [50]int + for _, l := range s.pts.AppendTo(space[:0]) { + labels = append(labels, s.a.labelFor(nodeid(l))) + } + } + return labels +} + +// If this PointsToSet came from a Pointer of interface kind +// or a reflect.Value, DynamicTypes returns the set of dynamic +// types that it may contain. (For an interface, they will +// always be concrete types.) +// +// The result is a mapping whose keys are the dynamic types to which +// it may point. For each pointer-like key type, the corresponding +// map value is the PointsToSet for pointers of that type. +// +// The result is empty unless CanHaveDynamicTypes(T). +// +func (s PointsToSet) DynamicTypes() *typeutil.Map { + var tmap typeutil.Map + tmap.SetHasher(s.a.hasher) + if s.pts != nil { + var space [50]int + for _, x := range s.pts.AppendTo(space[:0]) { + ifaceObjId := nodeid(x) + if !s.a.isTaggedObject(ifaceObjId) { + continue // !CanHaveDynamicTypes(tDyn) + } + tDyn, v, indirect := s.a.taggedValue(ifaceObjId) + if indirect { + panic("indirect tagged object") // implement later + } + pts, ok := tmap.At(tDyn).(PointsToSet) + if !ok { + pts = PointsToSet{s.a, new(nodeset)} + tmap.Set(tDyn, pts) + } + pts.pts.addAll(&s.a.nodes[v].solve.pts) + } + } + return &tmap +} + +// Intersects reports whether this points-to set and the +// argument points-to set contain common members. +func (x PointsToSet) Intersects(y PointsToSet) bool { + if x.pts == nil || y.pts == nil { + return false + } + // This takes Θ(|x|+|y|) time. + var z intsets.Sparse + z.Intersection(&x.pts.Sparse, &y.pts.Sparse) + return !z.IsEmpty() +} + +func (p Pointer) String() string { + return fmt.Sprintf("n%d", p.n) +} + +// PointsTo returns the points-to set of this pointer. +func (p Pointer) PointsTo() PointsToSet { + if p.n == 0 { + return PointsToSet{} + } + return PointsToSet{p.a, &p.a.nodes[p.n].solve.pts} +} + +// MayAlias reports whether the receiver pointer may alias +// the argument pointer. +func (p Pointer) MayAlias(q Pointer) bool { + return p.PointsTo().Intersects(q.PointsTo()) +} + +// DynamicTypes returns p.PointsTo().DynamicTypes(). +func (p Pointer) DynamicTypes() *typeutil.Map { + return p.PointsTo().DynamicTypes() +} diff --git a/vendor/golang.org/x/tools/go/pointer/callgraph.go b/vendor/golang.org/x/tools/go/pointer/callgraph.go new file mode 100644 index 00000000000..48e152e4afa --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/callgraph.go @@ -0,0 +1,61 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pointer + +// This file defines the internal (context-sensitive) call graph. + +import ( + "fmt" + "go/token" + + "golang.org/x/tools/go/ssa" +) + +type cgnode struct { + fn *ssa.Function + obj nodeid // start of this contour's object block + sites []*callsite // ordered list of callsites within this function + callersite *callsite // where called from, if known; nil for shared contours +} + +// contour returns a description of this node's contour. +func (n *cgnode) contour() string { + if n.callersite == nil { + return "shared contour" + } + if n.callersite.instr != nil { + return fmt.Sprintf("as called from %s", n.callersite.instr.Parent()) + } + return fmt.Sprintf("as called from intrinsic (targets=n%d)", n.callersite.targets) +} + +func (n *cgnode) String() string { + return fmt.Sprintf("cg%d:%s", n.obj, n.fn) +} + +// A callsite represents a single call site within a cgnode; +// it is implicitly context-sensitive. +// callsites never represent calls to built-ins; +// they are handled as intrinsics. +// +type callsite struct { + targets nodeid // pts(·) contains objects for dynamically called functions + instr ssa.CallInstruction // the call instruction; nil for synthetic/intrinsic +} + +func (c *callsite) String() string { + if c.instr != nil { + return c.instr.Common().Description() + } + return "synthetic function call" +} + +// pos returns the source position of this callsite, or token.NoPos if implicit. +func (c *callsite) pos() token.Pos { + if c.instr != nil { + return c.instr.Pos() + } + return token.NoPos +} diff --git a/vendor/golang.org/x/tools/go/pointer/constraint.go b/vendor/golang.org/x/tools/go/pointer/constraint.go new file mode 100644 index 00000000000..54b54288a0d --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/constraint.go @@ -0,0 +1,149 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pointer + +import "go/types" + +type constraint interface { + // For a complex constraint, returns the nodeid of the pointer + // to which it is attached. For addr and copy, returns dst. + ptr() nodeid + + // renumber replaces each nodeid n in the constraint by mapping[n]. + renumber(mapping []nodeid) + + // presolve is a hook for constraint-specific behaviour during + // pre-solver optimization. Typical implementations mark as + // indirect the set of nodes to which the solver will add copy + // edges or PTS labels. + presolve(h *hvn) + + // solve is called for complex constraints when the pts for + // the node to which they are attached has changed. + solve(a *analysis, delta *nodeset) + + String() string +} + +// dst = &src +// pts(dst) ⊇ {src} +// A base constraint used to initialize the solver's pt sets +type addrConstraint struct { + dst nodeid // (ptr) + src nodeid +} + +func (c *addrConstraint) ptr() nodeid { return c.dst } +func (c *addrConstraint) renumber(mapping []nodeid) { + c.dst = mapping[c.dst] + c.src = mapping[c.src] +} + +// dst = src +// A simple constraint represented directly as a copyTo graph edge. +type copyConstraint struct { + dst nodeid // (ptr) + src nodeid +} + +func (c *copyConstraint) ptr() nodeid { return c.dst } +func (c *copyConstraint) renumber(mapping []nodeid) { + c.dst = mapping[c.dst] + c.src = mapping[c.src] +} + +// dst = src[offset] +// A complex constraint attached to src (the pointer) +type loadConstraint struct { + offset uint32 + dst nodeid + src nodeid // (ptr) +} + +func (c *loadConstraint) ptr() nodeid { return c.src } +func (c *loadConstraint) renumber(mapping []nodeid) { + c.dst = mapping[c.dst] + c.src = mapping[c.src] +} + +// dst[offset] = src +// A complex constraint attached to dst (the pointer) +type storeConstraint struct { + offset uint32 + dst nodeid // (ptr) + src nodeid +} + +func (c *storeConstraint) ptr() nodeid { return c.dst } +func (c *storeConstraint) renumber(mapping []nodeid) { + c.dst = mapping[c.dst] + c.src = mapping[c.src] +} + +// dst = &src.f or dst = &src[0] +// A complex constraint attached to dst (the pointer) +type offsetAddrConstraint struct { + offset uint32 + dst nodeid + src nodeid // (ptr) +} + +func (c *offsetAddrConstraint) ptr() nodeid { return c.src } +func (c *offsetAddrConstraint) renumber(mapping []nodeid) { + c.dst = mapping[c.dst] + c.src = mapping[c.src] +} + +// dst = src.(typ) where typ is an interface +// A complex constraint attached to src (the interface). +// No representation change: pts(dst) and pts(src) contains tagged objects. +type typeFilterConstraint struct { + typ types.Type // an interface type + dst nodeid + src nodeid // (ptr) +} + +func (c *typeFilterConstraint) ptr() nodeid { return c.src } +func (c *typeFilterConstraint) renumber(mapping []nodeid) { + c.dst = mapping[c.dst] + c.src = mapping[c.src] +} + +// dst = src.(typ) where typ is a concrete type +// A complex constraint attached to src (the interface). +// +// If exact, only tagged objects identical to typ are untagged. +// If !exact, tagged objects assignable to typ are untagged too. +// The latter is needed for various reflect operators, e.g. Send. +// +// This entails a representation change: +// pts(src) contains tagged objects, +// pts(dst) contains their payloads. +type untagConstraint struct { + typ types.Type // a concrete type + dst nodeid + src nodeid // (ptr) + exact bool +} + +func (c *untagConstraint) ptr() nodeid { return c.src } +func (c *untagConstraint) renumber(mapping []nodeid) { + c.dst = mapping[c.dst] + c.src = mapping[c.src] +} + +// src.method(params...) +// A complex constraint attached to iface. +type invokeConstraint struct { + method *types.Func // the abstract method + iface nodeid // (ptr) the interface + params nodeid // the start of the identity/params/results block +} + +func (c *invokeConstraint) ptr() nodeid { return c.iface } +func (c *invokeConstraint) renumber(mapping []nodeid) { + c.iface = mapping[c.iface] + c.params = mapping[c.params] +} diff --git a/vendor/golang.org/x/tools/go/pointer/doc.go b/vendor/golang.org/x/tools/go/pointer/doc.go new file mode 100644 index 00000000000..e317cf5c397 --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/doc.go @@ -0,0 +1,610 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +/* + +Package pointer implements Andersen's analysis, an inclusion-based +pointer analysis algorithm first described in (Andersen, 1994). + +A pointer analysis relates every pointer expression in a whole program +to the set of memory locations to which it might point. This +information can be used to construct a call graph of the program that +precisely represents the destinations of dynamic function and method +calls. It can also be used to determine, for example, which pairs of +channel operations operate on the same channel. + +The package allows the client to request a set of expressions of +interest for which the points-to information will be returned once the +analysis is complete. In addition, the client may request that a +callgraph is constructed. The example program in example_test.go +demonstrates both of these features. Clients should not request more +information than they need since it may increase the cost of the +analysis significantly. + + +CLASSIFICATION + +Our algorithm is INCLUSION-BASED: the points-to sets for x and y will +be related by pts(y) ⊇ pts(x) if the program contains the statement +y = x. + +It is FLOW-INSENSITIVE: it ignores all control flow constructs and the +order of statements in a program. It is therefore a "MAY ALIAS" +analysis: its facts are of the form "P may/may not point to L", +not "P must point to L". + +It is FIELD-SENSITIVE: it builds separate points-to sets for distinct +fields, such as x and y in struct { x, y *int }. + +It is mostly CONTEXT-INSENSITIVE: most functions are analyzed once, +so values can flow in at one call to the function and return out at +another. Only some smaller functions are analyzed with consideration +of their calling context. + +It has a CONTEXT-SENSITIVE HEAP: objects are named by both allocation +site and context, so the objects returned by two distinct calls to f: + func f() *T { return new(T) } +are distinguished up to the limits of the calling context. + +It is a WHOLE PROGRAM analysis: it requires SSA-form IR for the +complete Go program and summaries for native code. + +See the (Hind, PASTE'01) survey paper for an explanation of these terms. + + +SOUNDNESS + +The analysis is fully sound when invoked on pure Go programs that do not +use reflection or unsafe.Pointer conversions. In other words, if there +is any possible execution of the program in which pointer P may point to +object O, the analysis will report that fact. + + +REFLECTION + +By default, the "reflect" library is ignored by the analysis, as if all +its functions were no-ops, but if the client enables the Reflection flag, +the analysis will make a reasonable attempt to model the effects of +calls into this library. However, this comes at a significant +performance cost, and not all features of that library are yet +implemented. In addition, some simplifying approximations must be made +to ensure that the analysis terminates; for example, reflection can be +used to construct an infinite set of types and values of those types, +but the analysis arbitrarily bounds the depth of such types. + +Most but not all reflection operations are supported. +In particular, addressable reflect.Values are not yet implemented, so +operations such as (reflect.Value).Set have no analytic effect. + + +UNSAFE POINTER CONVERSIONS + +The pointer analysis makes no attempt to understand aliasing between the +operand x and result y of an unsafe.Pointer conversion: + y = (*T)(unsafe.Pointer(x)) +It is as if the conversion allocated an entirely new object: + y = new(T) + + +NATIVE CODE + +The analysis cannot model the aliasing effects of functions written in +languages other than Go, such as runtime intrinsics in C or assembly, or +code accessed via cgo. The result is as if such functions are no-ops. +However, various important intrinsics are understood by the analysis, +along with built-ins such as append. + +The analysis currently provides no way for users to specify the aliasing +effects of native code. + +------------------------------------------------------------------------ + +IMPLEMENTATION + +The remaining documentation is intended for package maintainers and +pointer analysis specialists. Maintainers should have a solid +understanding of the referenced papers (especially those by H&L and PKH) +before making making significant changes. + +The implementation is similar to that described in (Pearce et al, +PASTE'04). Unlike many algorithms which interleave constraint +generation and solving, constructing the callgraph as they go, this +implementation for the most part observes a phase ordering (generation +before solving), with only simple (copy) constraints being generated +during solving. (The exception is reflection, which creates various +constraints during solving as new types flow to reflect.Value +operations.) This improves the traction of presolver optimisations, +but imposes certain restrictions, e.g. potential context sensitivity +is limited since all variants must be created a priori. + + +TERMINOLOGY + +A type is said to be "pointer-like" if it is a reference to an object. +Pointer-like types include pointers and also interfaces, maps, channels, +functions and slices. + +We occasionally use C's x->f notation to distinguish the case where x +is a struct pointer from x.f where is a struct value. + +Pointer analysis literature (and our comments) often uses the notation +dst=*src+offset to mean something different than what it means in Go. +It means: for each node index p in pts(src), the node index p+offset is +in pts(dst). Similarly *dst+offset=src is used for store constraints +and dst=src+offset for offset-address constraints. + + +NODES + +Nodes are the key datastructure of the analysis, and have a dual role: +they represent both constraint variables (equivalence classes of +pointers) and members of points-to sets (things that can be pointed +at, i.e. "labels"). + +Nodes are naturally numbered. The numbering enables compact +representations of sets of nodes such as bitvectors (or BDDs); and the +ordering enables a very cheap way to group related nodes together. For +example, passing n parameters consists of generating n parallel +constraints from caller+i to callee+i for 0<=i y is added. + + ChangeInterface is a simple copy because the representation of + tagged objects is independent of the interface type (in contrast + to the "method tables" approach used by the gc runtime). + + y := Invoke x.m(...) is implemented by allocating contiguous P/R + blocks for the callsite and adding a dynamic rule triggered by each + tagged object added to pts(x). The rule adds param/results copy + edges to/from each discovered concrete method. + + (Q. Why do we model an interface as a pointer to a pair of type and + value, rather than as a pair of a pointer to type and a pointer to + value? + A. Control-flow joins would merge interfaces ({T1}, {V1}) and ({T2}, + {V2}) to make ({T1,T2}, {V1,V2}), leading to the infeasible and + type-unsafe combination (T1,V2). Treating the value and its concrete + type as inseparable makes the analysis type-safe.) + +reflect.Value + A reflect.Value is modelled very similar to an interface{}, i.e. as + a pointer exclusively to tagged objects, but with two generalizations. + + 1) a reflect.Value that represents an lvalue points to an indirect + (obj.flags ⊇ {otIndirect}) tagged object, which has a similar + layout to an tagged object except that the value is a pointer to + the dynamic type. Indirect tagged objects preserve the correct + aliasing so that mutations made by (reflect.Value).Set can be + observed. + + Indirect objects only arise when an lvalue is derived from an + rvalue by indirection, e.g. the following code: + + type S struct { X T } + var s S + var i interface{} = &s // i points to a *S-tagged object (from MakeInterface) + v1 := reflect.ValueOf(i) // v1 points to same *S-tagged object as i + v2 := v1.Elem() // v2 points to an indirect S-tagged object, pointing to s + v3 := v2.FieldByName("X") // v3 points to an indirect int-tagged object, pointing to s.X + v3.Set(y) // pts(s.X) ⊇ pts(y) + + Whether indirect or not, the concrete type of the tagged object + corresponds to the user-visible dynamic type, and the existence + of a pointer is an implementation detail. + + (NB: indirect tagged objects are not yet implemented) + + 2) The dynamic type tag of a tagged object pointed to by a + reflect.Value may be an interface type; it need not be concrete. + + This arises in code such as this: + tEface := reflect.TypeOf(new(interface{}).Elem() // interface{} + eface := reflect.Zero(tEface) + pts(eface) is a singleton containing an interface{}-tagged + object. That tagged object's payload is an interface{} value, + i.e. the pts of the payload contains only concrete-tagged + objects, although in this example it's the zero interface{} value, + so its pts is empty. + +reflect.Type + Just as in the real "reflect" library, we represent a reflect.Type + as an interface whose sole implementation is the concrete type, + *reflect.rtype. (This choice is forced on us by go/types: clients + cannot fabricate types with arbitrary method sets.) + + rtype instances are canonical: there is at most one per dynamic + type. (rtypes are in fact large structs but since identity is all + that matters, we represent them by a single node.) + + The payload of each *rtype-tagged object is an *rtype pointer that + points to exactly one such canonical rtype object. We exploit this + by setting the node.typ of the payload to the dynamic type, not + '*rtype'. This saves us an indirection in each resolution rule. As + an optimisation, *rtype-tagged objects are canonicalized too. + + +Aggregate types: + +Aggregate types are treated as if all directly contained +aggregates are recursively flattened out. + +Structs + *ssa.Field y = x.f creates a simple edge to y from x's node at f's offset. + + *ssa.FieldAddr y = &x->f requires a dynamic closure rule to create + simple edges for each struct discovered in pts(x). + + The nodes of a struct consist of a special 'identity' node (whose + type is that of the struct itself), followed by the nodes for all + the struct's fields, recursively flattened out. A pointer to the + struct is a pointer to its identity node. That node allows us to + distinguish a pointer to a struct from a pointer to its first field. + + Field offsets are logical field offsets (plus one for the identity + node), so the sizes of the fields can be ignored by the analysis. + + (The identity node is non-traditional but enables the distinction + described above, which is valuable for code comprehension tools. + Typical pointer analyses for C, whose purpose is compiler + optimization, must soundly model unsafe.Pointer (void*) conversions, + and this requires fidelity to the actual memory layout using physical + field offsets.) + + *ssa.Field y = x.f creates a simple edge to y from x's node at f's offset. + + *ssa.FieldAddr y = &x->f requires a dynamic closure rule to create + simple edges for each struct discovered in pts(x). + +Arrays + We model an array by an identity node (whose type is that of the + array itself) followed by a node representing all the elements of + the array; the analysis does not distinguish elements with different + indices. Effectively, an array is treated like struct{elem T}, a + load y=x[i] like y=x.elem, and a store x[i]=y like x.elem=y; the + index i is ignored. + + A pointer to an array is pointer to its identity node. (A slice is + also a pointer to an array's identity node.) The identity node + allows us to distinguish a pointer to an array from a pointer to one + of its elements, but it is rather costly because it introduces more + offset constraints into the system. Furthermore, sound treatment of + unsafe.Pointer would require us to dispense with this node. + + Arrays may be allocated by Alloc, by make([]T), by calls to append, + and via reflection. + +Tuples (T, ...) + Tuples are treated like structs with naturally numbered fields. + *ssa.Extract is analogous to *ssa.Field. + + However, tuples have no identity field since by construction, they + cannot be address-taken. + + +FUNCTION CALLS + + There are three kinds of function call: + (1) static "call"-mode calls of functions. + (2) dynamic "call"-mode calls of functions. + (3) dynamic "invoke"-mode calls of interface methods. + Cases 1 and 2 apply equally to methods and standalone functions. + + Static calls. + A static call consists three steps: + - finding the function object of the callee; + - creating copy edges from the actual parameter value nodes to the + P-block in the function object (this includes the receiver if + the callee is a method); + - creating copy edges from the R-block in the function object to + the value nodes for the result of the call. + + A static function call is little more than two struct value copies + between the P/R blocks of caller and callee: + + callee.P = caller.P + caller.R = callee.R + + Context sensitivity + + Static calls (alone) may be treated context sensitively, + i.e. each callsite may cause a distinct re-analysis of the + callee, improving precision. Our current context-sensitivity + policy treats all intrinsics and getter/setter methods in this + manner since such functions are small and seem like an obvious + source of spurious confluences, though this has not yet been + evaluated. + + Dynamic function calls + + Dynamic calls work in a similar manner except that the creation of + copy edges occurs dynamically, in a similar fashion to a pair of + struct copies in which the callee is indirect: + + callee->P = caller.P + caller.R = callee->R + + (Recall that the function object's P- and R-blocks are contiguous.) + + Interface method invocation + + For invoke-mode calls, we create a params/results block for the + callsite and attach a dynamic closure rule to the interface. For + each new tagged object that flows to the interface, we look up + the concrete method, find its function object, and connect its P/R + blocks to the callsite's P/R blocks, adding copy edges to the graph + during solving. + + Recording call targets + + The analysis notifies its clients of each callsite it encounters, + passing a CallSite interface. Among other things, the CallSite + contains a synthetic constraint variable ("targets") whose + points-to solution includes the set of all function objects to + which the call may dispatch. + + It is via this mechanism that the callgraph is made available. + Clients may also elect to be notified of callgraph edges directly; + internally this just iterates all "targets" variables' pts(·)s. + + +PRESOLVER + +We implement Hash-Value Numbering (HVN), a pre-solver constraint +optimization described in Hardekopf & Lin, SAS'07. This is documented +in more detail in hvn.go. We intend to add its cousins HR and HU in +future. + + +SOLVER + +The solver is currently a naive Andersen-style implementation; it does +not perform online cycle detection, though we plan to add solver +optimisations such as Hybrid- and Lazy- Cycle Detection from (Hardekopf +& Lin, PLDI'07). + +It uses difference propagation (Pearce et al, SQC'04) to avoid +redundant re-triggering of closure rules for values already seen. + +Points-to sets are represented using sparse bit vectors (similar to +those used in LLVM and gcc), which are more space- and time-efficient +than sets based on Go's built-in map type or dense bit vectors. + +Nodes are permuted prior to solving so that object nodes (which may +appear in points-to sets) are lower numbered than non-object (var) +nodes. This improves the density of the set over which the PTSs +range, and thus the efficiency of the representation. + +Partly thanks to avoiding map iteration, the execution of the solver is +100% deterministic, a great help during debugging. + + +FURTHER READING + +Andersen, L. O. 1994. Program analysis and specialization for the C +programming language. Ph.D. dissertation. DIKU, University of +Copenhagen. + +David J. Pearce, Paul H. J. Kelly, and Chris Hankin. 2004. Efficient +field-sensitive pointer analysis for C. In Proceedings of the 5th ACM +SIGPLAN-SIGSOFT workshop on Program analysis for software tools and +engineering (PASTE '04). ACM, New York, NY, USA, 37-42. +http://doi.acm.org/10.1145/996821.996835 + +David J. Pearce, Paul H. J. Kelly, and Chris Hankin. 2004. Online +Cycle Detection and Difference Propagation: Applications to Pointer +Analysis. Software Quality Control 12, 4 (December 2004), 311-337. +http://dx.doi.org/10.1023/B:SQJO.0000039791.93071.a2 + +David Grove and Craig Chambers. 2001. A framework for call graph +construction algorithms. ACM Trans. Program. Lang. Syst. 23, 6 +(November 2001), 685-746. +http://doi.acm.org/10.1145/506315.506316 + +Ben Hardekopf and Calvin Lin. 2007. The ant and the grasshopper: fast +and accurate pointer analysis for millions of lines of code. In +Proceedings of the 2007 ACM SIGPLAN conference on Programming language +design and implementation (PLDI '07). ACM, New York, NY, USA, 290-299. +http://doi.acm.org/10.1145/1250734.1250767 + +Ben Hardekopf and Calvin Lin. 2007. Exploiting pointer and location +equivalence to optimize pointer analysis. In Proceedings of the 14th +international conference on Static Analysis (SAS'07), Hanne Riis +Nielson and Gilberto Filé (Eds.). Springer-Verlag, Berlin, Heidelberg, +265-280. + +Atanas Rountev and Satish Chandra. 2000. Off-line variable substitution +for scaling points-to analysis. In Proceedings of the ACM SIGPLAN 2000 +conference on Programming language design and implementation (PLDI '00). +ACM, New York, NY, USA, 47-56. DOI=10.1145/349299.349310 +http://doi.acm.org/10.1145/349299.349310 + +*/ +package pointer // import "golang.org/x/tools/go/pointer" diff --git a/vendor/golang.org/x/tools/go/pointer/gen.go b/vendor/golang.org/x/tools/go/pointer/gen.go new file mode 100644 index 00000000000..f2a51715b7e --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/gen.go @@ -0,0 +1,1325 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pointer + +// This file defines the constraint generation phase. + +// TODO(adonovan): move the constraint definitions and the store() etc +// functions which add them (and are also used by the solver) into a +// new file, constraints.go. + +import ( + "fmt" + "go/token" + "go/types" + + "golang.org/x/tools/go/callgraph" + "golang.org/x/tools/go/ssa" +) + +var ( + tEface = types.NewInterface(nil, nil).Complete() + tInvalid = types.Typ[types.Invalid] + tUnsafePtr = types.Typ[types.UnsafePointer] +) + +// ---------- Node creation ---------- + +// nextNode returns the index of the next unused node. +func (a *analysis) nextNode() nodeid { + return nodeid(len(a.nodes)) +} + +// addNodes creates nodes for all scalar elements in type typ, and +// returns the id of the first one, or zero if the type was +// analytically uninteresting. +// +// comment explains the origin of the nodes, as a debugging aid. +// +func (a *analysis) addNodes(typ types.Type, comment string) nodeid { + id := a.nextNode() + for _, fi := range a.flatten(typ) { + a.addOneNode(fi.typ, comment, fi) + } + if id == a.nextNode() { + return 0 // type contained no pointers + } + return id +} + +// addOneNode creates a single node with type typ, and returns its id. +// +// typ should generally be scalar (except for tagged.T nodes +// and struct/array identity nodes). Use addNodes for non-scalar types. +// +// comment explains the origin of the nodes, as a debugging aid. +// subelement indicates the subelement, e.g. ".a.b[*].c". +// +func (a *analysis) addOneNode(typ types.Type, comment string, subelement *fieldInfo) nodeid { + id := a.nextNode() + a.nodes = append(a.nodes, &node{typ: typ, subelement: subelement, solve: new(solverState)}) + if a.log != nil { + fmt.Fprintf(a.log, "\tcreate n%d %s for %s%s\n", + id, typ, comment, subelement.path()) + } + return id +} + +// setValueNode associates node id with the value v. +// cgn identifies the context iff v is a local variable. +// +func (a *analysis) setValueNode(v ssa.Value, id nodeid, cgn *cgnode) { + if cgn != nil { + a.localval[v] = id + } else { + a.globalval[v] = id + } + if a.log != nil { + fmt.Fprintf(a.log, "\tval[%s] = n%d (%T)\n", v.Name(), id, v) + } + + // Due to context-sensitivity, we may encounter the same Value + // in many contexts. We merge them to a canonical node, since + // that's what all clients want. + + // Record the (v, id) relation if the client has queried pts(v). + if _, ok := a.config.Queries[v]; ok { + t := v.Type() + ptr, ok := a.result.Queries[v] + if !ok { + // First time? Create the canonical query node. + ptr = Pointer{a, a.addNodes(t, "query")} + a.result.Queries[v] = ptr + } + a.result.Queries[v] = ptr + a.copy(ptr.n, id, a.sizeof(t)) + } + + // Record the (*v, id) relation if the client has queried pts(*v). + if _, ok := a.config.IndirectQueries[v]; ok { + t := v.Type() + ptr, ok := a.result.IndirectQueries[v] + if !ok { + // First time? Create the canonical indirect query node. + ptr = Pointer{a, a.addNodes(v.Type(), "query.indirect")} + a.result.IndirectQueries[v] = ptr + } + a.genLoad(cgn, ptr.n, v, 0, a.sizeof(t)) + } + + for _, query := range a.config.extendedQueries[v] { + t, nid := a.evalExtendedQuery(v.Type().Underlying(), id, query.ops) + + if query.ptr.a == nil { + query.ptr.a = a + query.ptr.n = a.addNodes(t, "query.extended") + } + a.copy(query.ptr.n, nid, a.sizeof(t)) + } +} + +// endObject marks the end of a sequence of calls to addNodes denoting +// a single object allocation. +// +// obj is the start node of the object, from a prior call to nextNode. +// Its size, flags and optional data will be updated. +// +func (a *analysis) endObject(obj nodeid, cgn *cgnode, data interface{}) *object { + // Ensure object is non-empty by padding; + // the pad will be the object node. + size := uint32(a.nextNode() - obj) + if size == 0 { + a.addOneNode(tInvalid, "padding", nil) + } + objNode := a.nodes[obj] + o := &object{ + size: size, // excludes padding + cgn: cgn, + data: data, + } + objNode.obj = o + + return o +} + +// makeFunctionObject creates and returns a new function object +// (contour) for fn, and returns the id of its first node. It also +// enqueues fn for subsequent constraint generation. +// +// For a context-sensitive contour, callersite identifies the sole +// callsite; for shared contours, caller is nil. +// +func (a *analysis) makeFunctionObject(fn *ssa.Function, callersite *callsite) nodeid { + if a.log != nil { + fmt.Fprintf(a.log, "\t---- makeFunctionObject %s\n", fn) + } + + // obj is the function object (identity, params, results). + obj := a.nextNode() + cgn := a.makeCGNode(fn, obj, callersite) + sig := fn.Signature + a.addOneNode(sig, "func.cgnode", nil) // (scalar with Signature type) + if recv := sig.Recv(); recv != nil { + a.addNodes(recv.Type(), "func.recv") + } + a.addNodes(sig.Params(), "func.params") + a.addNodes(sig.Results(), "func.results") + a.endObject(obj, cgn, fn).flags |= otFunction + + if a.log != nil { + fmt.Fprintf(a.log, "\t----\n") + } + + // Queue it up for constraint processing. + a.genq = append(a.genq, cgn) + + return obj +} + +// makeTagged creates a tagged object of type typ. +func (a *analysis) makeTagged(typ types.Type, cgn *cgnode, data interface{}) nodeid { + obj := a.addOneNode(typ, "tagged.T", nil) // NB: type may be non-scalar! + a.addNodes(typ, "tagged.v") + a.endObject(obj, cgn, data).flags |= otTagged + return obj +} + +// makeRtype returns the canonical tagged object of type *rtype whose +// payload points to the sole rtype object for T. +// +// TODO(adonovan): move to reflect.go; it's part of the solver really. +// +func (a *analysis) makeRtype(T types.Type) nodeid { + if v := a.rtypes.At(T); v != nil { + return v.(nodeid) + } + + // Create the object for the reflect.rtype itself, which is + // ordinarily a large struct but here a single node will do. + obj := a.nextNode() + a.addOneNode(T, "reflect.rtype", nil) + a.endObject(obj, nil, T) + + id := a.makeTagged(a.reflectRtypePtr, nil, T) + a.nodes[id+1].typ = T // trick (each *rtype tagged object is a singleton) + a.addressOf(a.reflectRtypePtr, id+1, obj) + + a.rtypes.Set(T, id) + return id +} + +// rtypeValue returns the type of the *reflect.rtype-tagged object obj. +func (a *analysis) rtypeTaggedValue(obj nodeid) types.Type { + tDyn, t, _ := a.taggedValue(obj) + if tDyn != a.reflectRtypePtr { + panic(fmt.Sprintf("not a *reflect.rtype-tagged object: obj=n%d tag=%v payload=n%d", obj, tDyn, t)) + } + return a.nodes[t].typ +} + +// valueNode returns the id of the value node for v, creating it (and +// the association) as needed. It may return zero for uninteresting +// values containing no pointers. +// +func (a *analysis) valueNode(v ssa.Value) nodeid { + // Value nodes for locals are created en masse by genFunc. + if id, ok := a.localval[v]; ok { + return id + } + + // Value nodes for globals are created on demand. + id, ok := a.globalval[v] + if !ok { + var comment string + if a.log != nil { + comment = v.String() + } + id = a.addNodes(v.Type(), comment) + if obj := a.objectNode(nil, v); obj != 0 { + a.addressOf(v.Type(), id, obj) + } + a.setValueNode(v, id, nil) + } + return id +} + +// valueOffsetNode ascertains the node for tuple/struct value v, +// then returns the node for its subfield #index. +// +func (a *analysis) valueOffsetNode(v ssa.Value, index int) nodeid { + id := a.valueNode(v) + if id == 0 { + panic(fmt.Sprintf("cannot offset within n0: %s = %s", v.Name(), v)) + } + return id + nodeid(a.offsetOf(v.Type(), index)) +} + +// isTaggedObject reports whether object obj is a tagged object. +func (a *analysis) isTaggedObject(obj nodeid) bool { + return a.nodes[obj].obj.flags&otTagged != 0 +} + +// taggedValue returns the dynamic type tag, the (first node of the) +// payload, and the indirect flag of the tagged object starting at id. +// Panic ensues if !isTaggedObject(id). +// +func (a *analysis) taggedValue(obj nodeid) (tDyn types.Type, v nodeid, indirect bool) { + n := a.nodes[obj] + flags := n.obj.flags + if flags&otTagged == 0 { + panic(fmt.Sprintf("not a tagged object: n%d", obj)) + } + return n.typ, obj + 1, flags&otIndirect != 0 +} + +// funcParams returns the first node of the params (P) block of the +// function whose object node (obj.flags&otFunction) is id. +// +func (a *analysis) funcParams(id nodeid) nodeid { + n := a.nodes[id] + if n.obj == nil || n.obj.flags&otFunction == 0 { + panic(fmt.Sprintf("funcParams(n%d): not a function object block", id)) + } + return id + 1 +} + +// funcResults returns the first node of the results (R) block of the +// function whose object node (obj.flags&otFunction) is id. +// +func (a *analysis) funcResults(id nodeid) nodeid { + n := a.nodes[id] + if n.obj == nil || n.obj.flags&otFunction == 0 { + panic(fmt.Sprintf("funcResults(n%d): not a function object block", id)) + } + sig := n.typ.(*types.Signature) + id += 1 + nodeid(a.sizeof(sig.Params())) + if sig.Recv() != nil { + id += nodeid(a.sizeof(sig.Recv().Type())) + } + return id +} + +// ---------- Constraint creation ---------- + +// copy creates a constraint of the form dst = src. +// sizeof is the width (in logical fields) of the copied type. +// +func (a *analysis) copy(dst, src nodeid, sizeof uint32) { + if src == dst || sizeof == 0 { + return // trivial + } + if src == 0 || dst == 0 { + panic(fmt.Sprintf("ill-typed copy dst=n%d src=n%d", dst, src)) + } + for i := uint32(0); i < sizeof; i++ { + a.addConstraint(©Constraint{dst, src}) + src++ + dst++ + } +} + +// addressOf creates a constraint of the form id = &obj. +// T is the type of the address. +func (a *analysis) addressOf(T types.Type, id, obj nodeid) { + if id == 0 { + panic("addressOf: zero id") + } + if obj == 0 { + panic("addressOf: zero obj") + } + if a.shouldTrack(T) { + a.addConstraint(&addrConstraint{id, obj}) + } +} + +// load creates a load constraint of the form dst = src[offset]. +// offset is the pointer offset in logical fields. +// sizeof is the width (in logical fields) of the loaded type. +// +func (a *analysis) load(dst, src nodeid, offset, sizeof uint32) { + if dst == 0 { + return // load of non-pointerlike value + } + if src == 0 && dst == 0 { + return // non-pointerlike operation + } + if src == 0 || dst == 0 { + panic(fmt.Sprintf("ill-typed load dst=n%d src=n%d", dst, src)) + } + for i := uint32(0); i < sizeof; i++ { + a.addConstraint(&loadConstraint{offset, dst, src}) + offset++ + dst++ + } +} + +// store creates a store constraint of the form dst[offset] = src. +// offset is the pointer offset in logical fields. +// sizeof is the width (in logical fields) of the stored type. +// +func (a *analysis) store(dst, src nodeid, offset uint32, sizeof uint32) { + if src == 0 { + return // store of non-pointerlike value + } + if src == 0 && dst == 0 { + return // non-pointerlike operation + } + if src == 0 || dst == 0 { + panic(fmt.Sprintf("ill-typed store dst=n%d src=n%d", dst, src)) + } + for i := uint32(0); i < sizeof; i++ { + a.addConstraint(&storeConstraint{offset, dst, src}) + offset++ + src++ + } +} + +// offsetAddr creates an offsetAddr constraint of the form dst = &src.#offset. +// offset is the field offset in logical fields. +// T is the type of the address. +// +func (a *analysis) offsetAddr(T types.Type, dst, src nodeid, offset uint32) { + if !a.shouldTrack(T) { + return + } + if offset == 0 { + // Simplify dst = &src->f0 + // to dst = src + // (NB: this optimisation is defeated by the identity + // field prepended to struct and array objects.) + a.copy(dst, src, 1) + } else { + a.addConstraint(&offsetAddrConstraint{offset, dst, src}) + } +} + +// typeAssert creates a typeFilter or untag constraint of the form dst = src.(T): +// typeFilter for an interface, untag for a concrete type. +// The exact flag is specified as for untagConstraint. +// +func (a *analysis) typeAssert(T types.Type, dst, src nodeid, exact bool) { + if isInterface(T) { + a.addConstraint(&typeFilterConstraint{T, dst, src}) + } else { + a.addConstraint(&untagConstraint{T, dst, src, exact}) + } +} + +// addConstraint adds c to the constraint set. +func (a *analysis) addConstraint(c constraint) { + a.constraints = append(a.constraints, c) + if a.log != nil { + fmt.Fprintf(a.log, "\t%s\n", c) + } +} + +// copyElems generates load/store constraints for *dst = *src, +// where src and dst are slices or *arrays. +// +func (a *analysis) copyElems(cgn *cgnode, typ types.Type, dst, src ssa.Value) { + tmp := a.addNodes(typ, "copy") + sz := a.sizeof(typ) + a.genLoad(cgn, tmp, src, 1, sz) + a.genStore(cgn, dst, tmp, 1, sz) +} + +// ---------- Constraint generation ---------- + +// genConv generates constraints for the conversion operation conv. +func (a *analysis) genConv(conv *ssa.Convert, cgn *cgnode) { + res := a.valueNode(conv) + if res == 0 { + return // result is non-pointerlike + } + + tSrc := conv.X.Type() + tDst := conv.Type() + + switch utSrc := tSrc.Underlying().(type) { + case *types.Slice: + // []byte/[]rune -> string? + return + + case *types.Pointer: + // *T -> unsafe.Pointer? + if tDst.Underlying() == tUnsafePtr { + return // we don't model unsafe aliasing (unsound) + } + + case *types.Basic: + switch tDst.Underlying().(type) { + case *types.Pointer: + // Treat unsafe.Pointer->*T conversions like + // new(T) and create an unaliased object. + if utSrc == tUnsafePtr { + obj := a.addNodes(mustDeref(tDst), "unsafe.Pointer conversion") + a.endObject(obj, cgn, conv) + a.addressOf(tDst, res, obj) + return + } + + case *types.Slice: + // string -> []byte/[]rune (or named aliases)? + if utSrc.Info()&types.IsString != 0 { + obj := a.addNodes(sliceToArray(tDst), "convert") + a.endObject(obj, cgn, conv) + a.addressOf(tDst, res, obj) + return + } + + case *types.Basic: + // All basic-to-basic type conversions are no-ops. + // This includes uintptr<->unsafe.Pointer conversions, + // which we (unsoundly) ignore. + return + } + } + + panic(fmt.Sprintf("illegal *ssa.Convert %s -> %s: %s", tSrc, tDst, conv.Parent())) +} + +// genAppend generates constraints for a call to append. +func (a *analysis) genAppend(instr *ssa.Call, cgn *cgnode) { + // Consider z = append(x, y). y is optional. + // This may allocate a new [1]T array; call its object w. + // We get the following constraints: + // z = x + // z = &w + // *z = *y + + x := instr.Call.Args[0] + + z := instr + a.copy(a.valueNode(z), a.valueNode(x), 1) // z = x + + if len(instr.Call.Args) == 1 { + return // no allocation for z = append(x) or _ = append(x). + } + + // TODO(adonovan): test append([]byte, ...string) []byte. + + y := instr.Call.Args[1] + tArray := sliceToArray(instr.Call.Args[0].Type()) + + var w nodeid + w = a.nextNode() + a.addNodes(tArray, "append") + a.endObject(w, cgn, instr) + + a.copyElems(cgn, tArray.Elem(), z, y) // *z = *y + a.addressOf(instr.Type(), a.valueNode(z), w) // z = &w +} + +// genBuiltinCall generates constraints for a call to a built-in. +func (a *analysis) genBuiltinCall(instr ssa.CallInstruction, cgn *cgnode) { + call := instr.Common() + switch call.Value.(*ssa.Builtin).Name() { + case "append": + // Safe cast: append cannot appear in a go or defer statement. + a.genAppend(instr.(*ssa.Call), cgn) + + case "copy": + tElem := call.Args[0].Type().Underlying().(*types.Slice).Elem() + a.copyElems(cgn, tElem, call.Args[0], call.Args[1]) + + case "panic": + a.copy(a.panicNode, a.valueNode(call.Args[0]), 1) + + case "recover": + if v := instr.Value(); v != nil { + a.copy(a.valueNode(v), a.panicNode, 1) + } + + case "print": + // In the tests, the probe might be the sole reference + // to its arg, so make sure we create nodes for it. + if len(call.Args) > 0 { + a.valueNode(call.Args[0]) + } + + case "ssa:wrapnilchk": + a.copy(a.valueNode(instr.Value()), a.valueNode(call.Args[0]), 1) + + default: + // No-ops: close len cap real imag complex print println delete. + } +} + +// shouldUseContext defines the context-sensitivity policy. It +// returns true if we should analyse all static calls to fn anew. +// +// Obviously this interface rather limits how much freedom we have to +// choose a policy. The current policy, rather arbitrarily, is true +// for intrinsics and accessor methods (actually: short, single-block, +// call-free functions). This is just a starting point. +// +func (a *analysis) shouldUseContext(fn *ssa.Function) bool { + if a.findIntrinsic(fn) != nil { + return true // treat intrinsics context-sensitively + } + if len(fn.Blocks) != 1 { + return false // too expensive + } + blk := fn.Blocks[0] + if len(blk.Instrs) > 10 { + return false // too expensive + } + if fn.Synthetic != "" && (fn.Pkg == nil || fn != fn.Pkg.Func("init")) { + return true // treat synthetic wrappers context-sensitively + } + for _, instr := range blk.Instrs { + switch instr := instr.(type) { + case ssa.CallInstruction: + // Disallow function calls (except to built-ins) + // because of the danger of unbounded recursion. + if _, ok := instr.Common().Value.(*ssa.Builtin); !ok { + return false + } + } + } + return true +} + +// genStaticCall generates constraints for a statically dispatched function call. +func (a *analysis) genStaticCall(caller *cgnode, site *callsite, call *ssa.CallCommon, result nodeid) { + fn := call.StaticCallee() + + // Special cases for inlined intrinsics. + switch fn { + case a.runtimeSetFinalizer: + // Inline SetFinalizer so the call appears direct. + site.targets = a.addOneNode(tInvalid, "SetFinalizer.targets", nil) + a.addConstraint(&runtimeSetFinalizerConstraint{ + targets: site.targets, + x: a.valueNode(call.Args[0]), + f: a.valueNode(call.Args[1]), + }) + return + + case a.reflectValueCall: + // Inline (reflect.Value).Call so the call appears direct. + dotdotdot := false + ret := reflectCallImpl(a, caller, site, a.valueNode(call.Args[0]), a.valueNode(call.Args[1]), dotdotdot) + if result != 0 { + a.addressOf(fn.Signature.Results().At(0).Type(), result, ret) + } + return + } + + // Ascertain the context (contour/cgnode) for a particular call. + var obj nodeid + if a.shouldUseContext(fn) { + obj = a.makeFunctionObject(fn, site) // new contour + } else { + obj = a.objectNode(nil, fn) // shared contour + } + a.callEdge(caller, site, obj) + + sig := call.Signature() + + // Copy receiver, if any. + params := a.funcParams(obj) + args := call.Args + if sig.Recv() != nil { + sz := a.sizeof(sig.Recv().Type()) + a.copy(params, a.valueNode(args[0]), sz) + params += nodeid(sz) + args = args[1:] + } + + // Copy actual parameters into formal params block. + // Must loop, since the actuals aren't contiguous. + for i, arg := range args { + sz := a.sizeof(sig.Params().At(i).Type()) + a.copy(params, a.valueNode(arg), sz) + params += nodeid(sz) + } + + // Copy formal results block to actual result. + if result != 0 { + a.copy(result, a.funcResults(obj), a.sizeof(sig.Results())) + } +} + +// genDynamicCall generates constraints for a dynamic function call. +func (a *analysis) genDynamicCall(caller *cgnode, site *callsite, call *ssa.CallCommon, result nodeid) { + // pts(targets) will be the set of possible call targets. + site.targets = a.valueNode(call.Value) + + // We add dynamic closure rules that store the arguments into + // the P-block and load the results from the R-block of each + // function discovered in pts(targets). + + sig := call.Signature() + var offset uint32 = 1 // P/R block starts at offset 1 + for i, arg := range call.Args { + sz := a.sizeof(sig.Params().At(i).Type()) + a.genStore(caller, call.Value, a.valueNode(arg), offset, sz) + offset += sz + } + if result != 0 { + a.genLoad(caller, result, call.Value, offset, a.sizeof(sig.Results())) + } +} + +// genInvoke generates constraints for a dynamic method invocation. +func (a *analysis) genInvoke(caller *cgnode, site *callsite, call *ssa.CallCommon, result nodeid) { + if call.Value.Type() == a.reflectType { + a.genInvokeReflectType(caller, site, call, result) + return + } + + sig := call.Signature() + + // Allocate a contiguous targets/params/results block for this call. + block := a.nextNode() + // pts(targets) will be the set of possible call targets + site.targets = a.addOneNode(sig, "invoke.targets", nil) + p := a.addNodes(sig.Params(), "invoke.params") + r := a.addNodes(sig.Results(), "invoke.results") + + // Copy the actual parameters into the call's params block. + for i, n := 0, sig.Params().Len(); i < n; i++ { + sz := a.sizeof(sig.Params().At(i).Type()) + a.copy(p, a.valueNode(call.Args[i]), sz) + p += nodeid(sz) + } + // Copy the call's results block to the actual results. + if result != 0 { + a.copy(result, r, a.sizeof(sig.Results())) + } + + // We add a dynamic invoke constraint that will connect the + // caller's and the callee's P/R blocks for each discovered + // call target. + a.addConstraint(&invokeConstraint{call.Method, a.valueNode(call.Value), block}) +} + +// genInvokeReflectType is a specialization of genInvoke where the +// receiver type is a reflect.Type, under the assumption that there +// can be at most one implementation of this interface, *reflect.rtype. +// +// (Though this may appear to be an instance of a pattern---method +// calls on interfaces known to have exactly one implementation---in +// practice it occurs rarely, so we special case for reflect.Type.) +// +// In effect we treat this: +// var rt reflect.Type = ... +// rt.F() +// as this: +// rt.(*reflect.rtype).F() +// +func (a *analysis) genInvokeReflectType(caller *cgnode, site *callsite, call *ssa.CallCommon, result nodeid) { + // Unpack receiver into rtype + rtype := a.addOneNode(a.reflectRtypePtr, "rtype.recv", nil) + recv := a.valueNode(call.Value) + a.typeAssert(a.reflectRtypePtr, rtype, recv, true) + + // Look up the concrete method. + fn := a.prog.LookupMethod(a.reflectRtypePtr, call.Method.Pkg(), call.Method.Name()) + + obj := a.makeFunctionObject(fn, site) // new contour for this call + a.callEdge(caller, site, obj) + + // From now on, it's essentially a static call, but little is + // gained by factoring together the code for both cases. + + sig := fn.Signature // concrete method + targets := a.addOneNode(sig, "call.targets", nil) + a.addressOf(sig, targets, obj) // (a singleton) + + // Copy receiver. + params := a.funcParams(obj) + a.copy(params, rtype, 1) + params++ + + // Copy actual parameters into formal P-block. + // Must loop, since the actuals aren't contiguous. + for i, arg := range call.Args { + sz := a.sizeof(sig.Params().At(i).Type()) + a.copy(params, a.valueNode(arg), sz) + params += nodeid(sz) + } + + // Copy formal R-block to actual R-block. + if result != 0 { + a.copy(result, a.funcResults(obj), a.sizeof(sig.Results())) + } +} + +// genCall generates constraints for call instruction instr. +func (a *analysis) genCall(caller *cgnode, instr ssa.CallInstruction) { + call := instr.Common() + + // Intrinsic implementations of built-in functions. + if _, ok := call.Value.(*ssa.Builtin); ok { + a.genBuiltinCall(instr, caller) + return + } + + var result nodeid + if v := instr.Value(); v != nil { + result = a.valueNode(v) + } + + site := &callsite{instr: instr} + if call.StaticCallee() != nil { + a.genStaticCall(caller, site, call, result) + } else if call.IsInvoke() { + a.genInvoke(caller, site, call, result) + } else { + a.genDynamicCall(caller, site, call, result) + } + + caller.sites = append(caller.sites, site) + + if a.log != nil { + // TODO(adonovan): debug: improve log message. + fmt.Fprintf(a.log, "\t%s to targets %s from %s\n", site, site.targets, caller) + } +} + +// objectNode returns the object to which v points, if known. +// In other words, if the points-to set of v is a singleton, it +// returns the sole label, zero otherwise. +// +// We exploit this information to make the generated constraints less +// dynamic. For example, a complex load constraint can be replaced by +// a simple copy constraint when the sole destination is known a priori. +// +// Some SSA instructions always have singletons points-to sets: +// Alloc, Function, Global, MakeChan, MakeClosure, MakeInterface, MakeMap, MakeSlice. +// Others may be singletons depending on their operands: +// FreeVar, Const, Convert, FieldAddr, IndexAddr, Slice. +// +// Idempotent. Objects are created as needed, possibly via recursion +// down the SSA value graph, e.g IndexAddr(FieldAddr(Alloc))). +// +func (a *analysis) objectNode(cgn *cgnode, v ssa.Value) nodeid { + switch v.(type) { + case *ssa.Global, *ssa.Function, *ssa.Const, *ssa.FreeVar: + // Global object. + obj, ok := a.globalobj[v] + if !ok { + switch v := v.(type) { + case *ssa.Global: + obj = a.nextNode() + a.addNodes(mustDeref(v.Type()), "global") + a.endObject(obj, nil, v) + + case *ssa.Function: + obj = a.makeFunctionObject(v, nil) + + case *ssa.Const: + // not addressable + + case *ssa.FreeVar: + // not addressable + } + + if a.log != nil { + fmt.Fprintf(a.log, "\tglobalobj[%s] = n%d\n", v, obj) + } + a.globalobj[v] = obj + } + return obj + } + + // Local object. + obj, ok := a.localobj[v] + if !ok { + switch v := v.(type) { + case *ssa.Alloc: + obj = a.nextNode() + a.addNodes(mustDeref(v.Type()), "alloc") + a.endObject(obj, cgn, v) + + case *ssa.MakeSlice: + obj = a.nextNode() + a.addNodes(sliceToArray(v.Type()), "makeslice") + a.endObject(obj, cgn, v) + + case *ssa.MakeChan: + obj = a.nextNode() + a.addNodes(v.Type().Underlying().(*types.Chan).Elem(), "makechan") + a.endObject(obj, cgn, v) + + case *ssa.MakeMap: + obj = a.nextNode() + tmap := v.Type().Underlying().(*types.Map) + a.addNodes(tmap.Key(), "makemap.key") + elem := a.addNodes(tmap.Elem(), "makemap.value") + + // To update the value field, MapUpdate + // generates store-with-offset constraints which + // the presolver can't model, so we must mark + // those nodes indirect. + for id, end := elem, elem+nodeid(a.sizeof(tmap.Elem())); id < end; id++ { + a.mapValues = append(a.mapValues, id) + } + a.endObject(obj, cgn, v) + + case *ssa.MakeInterface: + tConc := v.X.Type() + obj = a.makeTagged(tConc, cgn, v) + + // Copy the value into it, if nontrivial. + if x := a.valueNode(v.X); x != 0 { + a.copy(obj+1, x, a.sizeof(tConc)) + } + + case *ssa.FieldAddr: + if xobj := a.objectNode(cgn, v.X); xobj != 0 { + obj = xobj + nodeid(a.offsetOf(mustDeref(v.X.Type()), v.Field)) + } + + case *ssa.IndexAddr: + if xobj := a.objectNode(cgn, v.X); xobj != 0 { + obj = xobj + 1 + } + + case *ssa.Slice: + obj = a.objectNode(cgn, v.X) + + case *ssa.Convert: + // TODO(adonovan): opt: handle these cases too: + // - unsafe.Pointer->*T conversion acts like Alloc + // - string->[]byte/[]rune conversion acts like MakeSlice + } + + if a.log != nil { + fmt.Fprintf(a.log, "\tlocalobj[%s] = n%d\n", v.Name(), obj) + } + a.localobj[v] = obj + } + return obj +} + +// genLoad generates constraints for result = *(ptr + val). +func (a *analysis) genLoad(cgn *cgnode, result nodeid, ptr ssa.Value, offset, sizeof uint32) { + if obj := a.objectNode(cgn, ptr); obj != 0 { + // Pre-apply loadConstraint.solve(). + a.copy(result, obj+nodeid(offset), sizeof) + } else { + a.load(result, a.valueNode(ptr), offset, sizeof) + } +} + +// genOffsetAddr generates constraints for a 'v=ptr.field' (FieldAddr) +// or 'v=ptr[*]' (IndexAddr) instruction v. +func (a *analysis) genOffsetAddr(cgn *cgnode, v ssa.Value, ptr nodeid, offset uint32) { + dst := a.valueNode(v) + if obj := a.objectNode(cgn, v); obj != 0 { + // Pre-apply offsetAddrConstraint.solve(). + a.addressOf(v.Type(), dst, obj) + } else { + a.offsetAddr(v.Type(), dst, ptr, offset) + } +} + +// genStore generates constraints for *(ptr + offset) = val. +func (a *analysis) genStore(cgn *cgnode, ptr ssa.Value, val nodeid, offset, sizeof uint32) { + if obj := a.objectNode(cgn, ptr); obj != 0 { + // Pre-apply storeConstraint.solve(). + a.copy(obj+nodeid(offset), val, sizeof) + } else { + a.store(a.valueNode(ptr), val, offset, sizeof) + } +} + +// genInstr generates constraints for instruction instr in context cgn. +func (a *analysis) genInstr(cgn *cgnode, instr ssa.Instruction) { + if a.log != nil { + var prefix string + if val, ok := instr.(ssa.Value); ok { + prefix = val.Name() + " = " + } + fmt.Fprintf(a.log, "; %s%s\n", prefix, instr) + } + + switch instr := instr.(type) { + case *ssa.DebugRef: + // no-op. + + case *ssa.UnOp: + switch instr.Op { + case token.ARROW: // <-x + // We can ignore instr.CommaOk because the node we're + // altering is always at zero offset relative to instr + tElem := instr.X.Type().Underlying().(*types.Chan).Elem() + a.genLoad(cgn, a.valueNode(instr), instr.X, 0, a.sizeof(tElem)) + + case token.MUL: // *x + a.genLoad(cgn, a.valueNode(instr), instr.X, 0, a.sizeof(instr.Type())) + + default: + // NOT, SUB, XOR: no-op. + } + + case *ssa.BinOp: + // All no-ops. + + case ssa.CallInstruction: // *ssa.Call, *ssa.Go, *ssa.Defer + a.genCall(cgn, instr) + + case *ssa.ChangeType: + a.copy(a.valueNode(instr), a.valueNode(instr.X), 1) + + case *ssa.Convert: + a.genConv(instr, cgn) + + case *ssa.Extract: + a.copy(a.valueNode(instr), + a.valueOffsetNode(instr.Tuple, instr.Index), + a.sizeof(instr.Type())) + + case *ssa.FieldAddr: + a.genOffsetAddr(cgn, instr, a.valueNode(instr.X), + a.offsetOf(mustDeref(instr.X.Type()), instr.Field)) + + case *ssa.IndexAddr: + a.genOffsetAddr(cgn, instr, a.valueNode(instr.X), 1) + + case *ssa.Field: + a.copy(a.valueNode(instr), + a.valueOffsetNode(instr.X, instr.Field), + a.sizeof(instr.Type())) + + case *ssa.Index: + a.copy(a.valueNode(instr), 1+a.valueNode(instr.X), a.sizeof(instr.Type())) + + case *ssa.Select: + recv := a.valueOffsetNode(instr, 2) // instr : (index, recvOk, recv0, ... recv_n-1) + for _, st := range instr.States { + elemSize := a.sizeof(st.Chan.Type().Underlying().(*types.Chan).Elem()) + switch st.Dir { + case types.RecvOnly: + a.genLoad(cgn, recv, st.Chan, 0, elemSize) + recv += nodeid(elemSize) + + case types.SendOnly: + a.genStore(cgn, st.Chan, a.valueNode(st.Send), 0, elemSize) + } + } + + case *ssa.Return: + results := a.funcResults(cgn.obj) + for _, r := range instr.Results { + sz := a.sizeof(r.Type()) + a.copy(results, a.valueNode(r), sz) + results += nodeid(sz) + } + + case *ssa.Send: + a.genStore(cgn, instr.Chan, a.valueNode(instr.X), 0, a.sizeof(instr.X.Type())) + + case *ssa.Store: + a.genStore(cgn, instr.Addr, a.valueNode(instr.Val), 0, a.sizeof(instr.Val.Type())) + + case *ssa.Alloc, *ssa.MakeSlice, *ssa.MakeChan, *ssa.MakeMap, *ssa.MakeInterface: + v := instr.(ssa.Value) + a.addressOf(v.Type(), a.valueNode(v), a.objectNode(cgn, v)) + + case *ssa.ChangeInterface: + a.copy(a.valueNode(instr), a.valueNode(instr.X), 1) + + case *ssa.TypeAssert: + a.typeAssert(instr.AssertedType, a.valueNode(instr), a.valueNode(instr.X), true) + + case *ssa.Slice: + a.copy(a.valueNode(instr), a.valueNode(instr.X), 1) + + case *ssa.If, *ssa.Jump: + // no-op. + + case *ssa.Phi: + sz := a.sizeof(instr.Type()) + for _, e := range instr.Edges { + a.copy(a.valueNode(instr), a.valueNode(e), sz) + } + + case *ssa.MakeClosure: + fn := instr.Fn.(*ssa.Function) + a.copy(a.valueNode(instr), a.valueNode(fn), 1) + // Free variables are treated like global variables. + for i, b := range instr.Bindings { + a.copy(a.valueNode(fn.FreeVars[i]), a.valueNode(b), a.sizeof(b.Type())) + } + + case *ssa.RunDefers: + // The analysis is flow insensitive, so we just "call" + // defers as we encounter them. + + case *ssa.Range: + // Do nothing. Next{Iter: *ssa.Range} handles this case. + + case *ssa.Next: + if !instr.IsString { // map + // Assumes that Next is always directly applied to a Range result. + theMap := instr.Iter.(*ssa.Range).X + tMap := theMap.Type().Underlying().(*types.Map) + + ksize := a.sizeof(tMap.Key()) + vsize := a.sizeof(tMap.Elem()) + + // The k/v components of the Next tuple may each be invalid. + tTuple := instr.Type().(*types.Tuple) + + // Load from the map's (k,v) into the tuple's (ok, k, v). + osrc := uint32(0) // offset within map object + odst := uint32(1) // offset within tuple (initially just after 'ok bool') + sz := uint32(0) // amount to copy + + // Is key valid? + if tTuple.At(1).Type() != tInvalid { + sz += ksize + } else { + odst += ksize + osrc += ksize + } + + // Is value valid? + if tTuple.At(2).Type() != tInvalid { + sz += vsize + } + + a.genLoad(cgn, a.valueNode(instr)+nodeid(odst), theMap, osrc, sz) + } + + case *ssa.Lookup: + if tMap, ok := instr.X.Type().Underlying().(*types.Map); ok { + // CommaOk can be ignored: field 0 is a no-op. + ksize := a.sizeof(tMap.Key()) + vsize := a.sizeof(tMap.Elem()) + a.genLoad(cgn, a.valueNode(instr), instr.X, ksize, vsize) + } + + case *ssa.MapUpdate: + tmap := instr.Map.Type().Underlying().(*types.Map) + ksize := a.sizeof(tmap.Key()) + vsize := a.sizeof(tmap.Elem()) + a.genStore(cgn, instr.Map, a.valueNode(instr.Key), 0, ksize) + a.genStore(cgn, instr.Map, a.valueNode(instr.Value), ksize, vsize) + + case *ssa.Panic: + a.copy(a.panicNode, a.valueNode(instr.X), 1) + + default: + panic(fmt.Sprintf("unimplemented: %T", instr)) + } +} + +func (a *analysis) makeCGNode(fn *ssa.Function, obj nodeid, callersite *callsite) *cgnode { + cgn := &cgnode{fn: fn, obj: obj, callersite: callersite} + a.cgnodes = append(a.cgnodes, cgn) + return cgn +} + +// genRootCalls generates the synthetic root of the callgraph and the +// initial calls from it to the analysis scope, such as main, a test +// or a library. +// +func (a *analysis) genRootCalls() *cgnode { + r := a.prog.NewFunction("", new(types.Signature), "root of callgraph") + root := a.makeCGNode(r, 0, nil) + + // TODO(adonovan): make an ssa utility to construct an actual + // root function so we don't need to special-case site-less + // call edges. + + // For each main package, call main.init(), main.main(). + for _, mainPkg := range a.config.Mains { + main := mainPkg.Func("main") + if main == nil { + panic(fmt.Sprintf("%s has no main function", mainPkg)) + } + + targets := a.addOneNode(main.Signature, "root.targets", nil) + site := &callsite{targets: targets} + root.sites = append(root.sites, site) + for _, fn := range [2]*ssa.Function{mainPkg.Func("init"), main} { + if a.log != nil { + fmt.Fprintf(a.log, "\troot call to %s:\n", fn) + } + a.copy(targets, a.valueNode(fn), 1) + } + } + + return root +} + +// genFunc generates constraints for function fn. +func (a *analysis) genFunc(cgn *cgnode) { + fn := cgn.fn + + impl := a.findIntrinsic(fn) + + if a.log != nil { + fmt.Fprintf(a.log, "\n\n==== Generating constraints for %s, %s\n", cgn, cgn.contour()) + + // Hack: don't display body if intrinsic. + if impl != nil { + fn2 := *cgn.fn // copy + fn2.Locals = nil + fn2.Blocks = nil + fn2.WriteTo(a.log) + } else { + cgn.fn.WriteTo(a.log) + } + } + + if impl != nil { + impl(a, cgn) + return + } + + if fn.Blocks == nil { + // External function with no intrinsic treatment. + // We'll warn about calls to such functions at the end. + return + } + + if a.log != nil { + fmt.Fprintln(a.log, "; Creating nodes for local values") + } + + a.localval = make(map[ssa.Value]nodeid) + a.localobj = make(map[ssa.Value]nodeid) + + // The value nodes for the params are in the func object block. + params := a.funcParams(cgn.obj) + for _, p := range fn.Params { + a.setValueNode(p, params, cgn) + params += nodeid(a.sizeof(p.Type())) + } + + // Free variables have global cardinality: + // the outer function sets them with MakeClosure; + // the inner function accesses them with FreeVar. + // + // TODO(adonovan): treat free vars context-sensitively. + + // Create value nodes for all value instructions + // since SSA may contain forward references. + var space [10]*ssa.Value + for _, b := range fn.Blocks { + for _, instr := range b.Instrs { + switch instr := instr.(type) { + case *ssa.Range: + // do nothing: it has a funky type, + // and *ssa.Next does all the work. + + case ssa.Value: + var comment string + if a.log != nil { + comment = instr.Name() + } + id := a.addNodes(instr.Type(), comment) + a.setValueNode(instr, id, cgn) + } + + // Record all address-taken functions (for presolver). + rands := instr.Operands(space[:0]) + if call, ok := instr.(ssa.CallInstruction); ok && !call.Common().IsInvoke() { + // Skip CallCommon.Value in "call" mode. + // TODO(adonovan): fix: relies on unspecified ordering. Specify it. + rands = rands[1:] + } + for _, rand := range rands { + if atf, ok := (*rand).(*ssa.Function); ok { + a.atFuncs[atf] = true + } + } + } + } + + // Generate constraints for instructions. + for _, b := range fn.Blocks { + for _, instr := range b.Instrs { + a.genInstr(cgn, instr) + } + } + + a.localval = nil + a.localobj = nil +} + +// genMethodsOf generates nodes and constraints for all methods of type T. +func (a *analysis) genMethodsOf(T types.Type) { + itf := isInterface(T) + + // TODO(adonovan): can we skip this entirely if itf is true? + // I think so, but the answer may depend on reflection. + mset := a.prog.MethodSets.MethodSet(T) + for i, n := 0, mset.Len(); i < n; i++ { + m := a.prog.MethodValue(mset.At(i)) + a.valueNode(m) + + if !itf { + // Methods of concrete types are address-taken functions. + a.atFuncs[m] = true + } + } +} + +// generate generates offline constraints for the entire program. +func (a *analysis) generate() { + start("Constraint generation") + if a.log != nil { + fmt.Fprintln(a.log, "==== Generating constraints") + } + + // Create a dummy node since we use the nodeid 0 for + // non-pointerlike variables. + a.addNodes(tInvalid, "(zero)") + + // Create the global node for panic values. + a.panicNode = a.addNodes(tEface, "panic") + + // Create nodes and constraints for all methods of reflect.rtype. + // (Shared contours are used by dynamic calls to reflect.Type + // methods---typically just String().) + if rtype := a.reflectRtypePtr; rtype != nil { + a.genMethodsOf(rtype) + } + + root := a.genRootCalls() + + if a.config.BuildCallGraph { + a.result.CallGraph = callgraph.New(root.fn) + } + + // Create nodes and constraints for all methods of all types + // that are dynamically accessible via reflection or interfaces. + for _, T := range a.prog.RuntimeTypes() { + a.genMethodsOf(T) + } + + // Generate constraints for functions as they become reachable + // from the roots. (No constraints are generated for functions + // that are dead in this analysis scope.) + for len(a.genq) > 0 { + cgn := a.genq[0] + a.genq = a.genq[1:] + a.genFunc(cgn) + } + + // The runtime magically allocates os.Args; so should we. + if os := a.prog.ImportedPackage("os"); os != nil { + // In effect: os.Args = new([1]string)[:] + T := types.NewSlice(types.Typ[types.String]) + obj := a.addNodes(sliceToArray(T), "") + a.endObject(obj, nil, "") + a.addressOf(T, a.objectNode(nil, os.Var("Args")), obj) + } + + // Discard generation state, to avoid confusion after node renumbering. + a.panicNode = 0 + a.globalval = nil + a.localval = nil + a.localobj = nil + + stop("Constraint generation") +} diff --git a/vendor/golang.org/x/tools/go/pointer/hvn.go b/vendor/golang.org/x/tools/go/pointer/hvn.go new file mode 100644 index 00000000000..192e4050ddb --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/hvn.go @@ -0,0 +1,973 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pointer + +// This file implements Hash-Value Numbering (HVN), a pre-solver +// constraint optimization described in Hardekopf & Lin, SAS'07 (see +// doc.go) that analyses the graph topology to determine which sets of +// variables are "pointer equivalent" (PE), i.e. must have identical +// points-to sets in the solution. +// +// A separate ("offline") graph is constructed. Its nodes are those of +// the main-graph, plus an additional node *X for each pointer node X. +// With this graph we can reason about the unknown points-to set of +// dereferenced pointers. (We do not generalize this to represent +// unknown fields x->f, perhaps because such fields would be numerous, +// though it might be worth an experiment.) +// +// Nodes whose points-to relations are not entirely captured by the +// graph are marked as "indirect": the *X nodes, the parameters of +// address-taken functions (which includes all functions in method +// sets), or nodes updated by the solver rules for reflection, etc. +// +// All addr (y=&x) nodes are initially assigned a pointer-equivalence +// (PE) label equal to x's nodeid in the main graph. (These are the +// only PE labels that are less than len(a.nodes).) +// +// All offsetAddr (y=&x.f) constraints are initially assigned a PE +// label; such labels are memoized, keyed by (x, f), so that equivalent +// nodes y as assigned the same label. +// +// Then we process each strongly connected component (SCC) of the graph +// in topological order, assigning it a PE label based on the set P of +// PE labels that flow to it from its immediate dependencies. +// +// If any node in P is "indirect", the entire SCC is assigned a fresh PE +// label. Otherwise: +// +// |P|=0 if P is empty, all nodes in the SCC are non-pointers (e.g. +// uninitialized variables, or formal params of dead functions) +// and the SCC is assigned the PE label of zero. +// +// |P|=1 if P is a singleton, the SCC is assigned the same label as the +// sole element of P. +// +// |P|>1 if P contains multiple labels, a unique label representing P is +// invented and recorded in an hash table, so that other +// equivalent SCCs may also be assigned this label, akin to +// conventional hash-value numbering in a compiler. +// +// Finally, a renumbering is computed such that each node is replaced by +// the lowest-numbered node with the same PE label. All constraints are +// renumbered, and any resulting duplicates are eliminated. +// +// The only nodes that are not renumbered are the objects x in addr +// (y=&x) constraints, since the ids of these nodes (and fields derived +// from them via offsetAddr rules) are the elements of all points-to +// sets, so they must remain as they are if we want the same solution. +// +// The solverStates (node.solve) for nodes in the same equivalence class +// are linked together so that all nodes in the class have the same +// solution. This avoids the need to renumber nodeids buried in +// Queries, cgnodes, etc (like (*analysis).renumber() does) since only +// the solution is needed. +// +// The result of HVN is that the number of distinct nodes and +// constraints is reduced, but the solution is identical (almost---see +// CROSS-CHECK below). In particular, both linear and cyclic chains of +// copies are each replaced by a single node. +// +// Nodes and constraints created "online" (e.g. while solving reflection +// constraints) are not subject to this optimization. +// +// PERFORMANCE +// +// In two benchmarks (guru and godoc), HVN eliminates about two thirds +// of nodes, the majority accounted for by non-pointers: nodes of +// non-pointer type, pointers that remain nil, formal parameters of dead +// functions, nodes of untracked types, etc. It also reduces the number +// of constraints, also by about two thirds, and the solving time by +// 30--42%, although we must pay about 15% for the running time of HVN +// itself. The benefit is greater for larger applications. +// +// There are many possible optimizations to improve the performance: +// * Use fewer than 1:1 onodes to main graph nodes: many of the onodes +// we create are not needed. +// * HU (HVN with Union---see paper): coalesce "union" peLabels when +// their expanded-out sets are equal. +// * HR (HVN with deReference---see paper): this will require that we +// apply HVN until fixed point, which may need more bookkeeping of the +// correspondence of main nodes to onodes. +// * Location Equivalence (see paper): have points-to sets contain not +// locations but location-equivalence class labels, each representing +// a set of locations. +// * HVN with field-sensitive ref: model each of the fields of a +// pointer-to-struct. +// +// CROSS-CHECK +// +// To verify the soundness of the optimization, when the +// debugHVNCrossCheck option is enabled, we run the solver twice, once +// before and once after running HVN, dumping the solution to disk, and +// then we compare the results. If they are not identical, the analysis +// panics. +// +// The solution dumped to disk includes only the N*N submatrix of the +// complete solution where N is the number of nodes after generation. +// In other words, we ignore pointer variables and objects created by +// the solver itself, since their numbering depends on the solver order, +// which is affected by the optimization. In any case, that's the only +// part the client cares about. +// +// The cross-check is too strict and may fail spuriously. Although the +// H&L paper describing HVN states that the solutions obtained should be +// identical, this is not the case in practice because HVN can collapse +// cycles involving *p even when pts(p)={}. Consider this example +// distilled from testdata/hello.go: +// +// var x T +// func f(p **T) { +// t0 = *p +// ... +// t1 = φ(t0, &x) +// *p = t1 +// } +// +// If f is dead code, we get: +// unoptimized: pts(p)={} pts(t0)={} pts(t1)={&x} +// optimized: pts(p)={} pts(t0)=pts(t1)=pts(*p)={&x} +// +// It's hard to argue that this is a bug: the result is sound and the +// loss of precision is inconsequential---f is dead code, after all. +// But unfortunately it limits the usefulness of the cross-check since +// failures must be carefully analyzed. Ben Hardekopf suggests (in +// personal correspondence) some approaches to mitigating it: +// +// If there is a node with an HVN points-to set that is a superset +// of the NORM points-to set, then either it's a bug or it's a +// result of this issue. If it's a result of this issue, then in +// the offline constraint graph there should be a REF node inside +// some cycle that reaches this node, and in the NORM solution the +// pointer being dereferenced by that REF node should be the empty +// set. If that isn't true then this is a bug. If it is true, then +// you can further check that in the NORM solution the "extra" +// points-to info in the HVN solution does in fact come from that +// purported cycle (if it doesn't, then this is still a bug). If +// you're doing the further check then you'll need to do it for +// each "extra" points-to element in the HVN points-to set. +// +// There are probably ways to optimize these checks by taking +// advantage of graph properties. For example, extraneous points-to +// info will flow through the graph and end up in many +// nodes. Rather than checking every node with extra info, you +// could probably work out the "origin point" of the extra info and +// just check there. Note that the check in the first bullet is +// looking for soundness bugs, while the check in the second bullet +// is looking for precision bugs; depending on your needs, you may +// care more about one than the other. +// +// which we should evaluate. The cross-check is nonetheless invaluable +// for all but one of the programs in the pointer_test suite. + +import ( + "fmt" + "go/types" + "io" + "reflect" + + "golang.org/x/tools/container/intsets" +) + +// A peLabel is a pointer-equivalence label: two nodes with the same +// peLabel have identical points-to solutions. +// +// The numbers are allocated consecutively like so: +// 0 not a pointer +// 1..N-1 addrConstraints (equals the constraint's .src field, hence sparse) +// ... offsetAddr constraints +// ... SCCs (with indirect nodes or multiple inputs) +// +// Each PE label denotes a set of pointers containing a single addr, a +// single offsetAddr, or some set of other PE labels. +// +type peLabel int + +type hvn struct { + a *analysis + N int // len(a.nodes) immediately after constraint generation + log io.Writer // (optional) log of HVN lemmas + onodes []*onode // nodes of the offline graph + label peLabel // the next available PE label + hvnLabel map[string]peLabel // hash-value numbering (PE label) for each set of onodeids + stack []onodeid // DFS stack + index int32 // next onode.index, from Tarjan's SCC algorithm + + // For each distinct offsetAddrConstraint (src, offset) pair, + // offsetAddrLabels records a unique PE label >= N. + offsetAddrLabels map[offsetAddr]peLabel +} + +// The index of an node in the offline graph. +// (Currently the first N align with the main nodes, +// but this may change with HRU.) +type onodeid uint32 + +// An onode is a node in the offline constraint graph. +// (Where ambiguous, members of analysis.nodes are referred to as +// "main graph" nodes.) +// +// Edges in the offline constraint graph (edges and implicit) point to +// the source, i.e. against the flow of values: they are dependencies. +// Implicit edges are used for SCC computation, but not for gathering +// incoming labels. +// +type onode struct { + rep onodeid // index of representative of SCC in offline constraint graph + + edges intsets.Sparse // constraint edges X-->Y (this onode is X) + implicit intsets.Sparse // implicit edges *X-->*Y (this onode is X) + peLabels intsets.Sparse // set of peLabels are pointer-equivalent to this one + indirect bool // node has points-to relations not represented in graph + + // Tarjan's SCC algorithm + index, lowlink int32 // Tarjan numbering + scc int32 // -ve => on stack; 0 => unvisited; +ve => node is root of a found SCC +} + +type offsetAddr struct { + ptr nodeid + offset uint32 +} + +// nextLabel issues the next unused pointer-equivalence label. +func (h *hvn) nextLabel() peLabel { + h.label++ + return h.label +} + +// ref(X) returns the index of the onode for *X. +func (h *hvn) ref(id onodeid) onodeid { + return id + onodeid(len(h.a.nodes)) +} + +// hvn computes pointer-equivalence labels (peLabels) using the Hash-based +// Value Numbering (HVN) algorithm described in Hardekopf & Lin, SAS'07. +// +func (a *analysis) hvn() { + start("HVN") + + if a.log != nil { + fmt.Fprintf(a.log, "\n\n==== Pointer equivalence optimization\n\n") + } + + h := hvn{ + a: a, + N: len(a.nodes), + log: a.log, + hvnLabel: make(map[string]peLabel), + offsetAddrLabels: make(map[offsetAddr]peLabel), + } + + if h.log != nil { + fmt.Fprintf(h.log, "\nCreating offline graph nodes...\n") + } + + // Create offline nodes. The first N nodes correspond to main + // graph nodes; the next N are their corresponding ref() nodes. + h.onodes = make([]*onode, 2*h.N) + for id := range a.nodes { + id := onodeid(id) + h.onodes[id] = &onode{} + h.onodes[h.ref(id)] = &onode{indirect: true} + } + + // Each node initially represents just itself. + for id, o := range h.onodes { + o.rep = onodeid(id) + } + + h.markIndirectNodes() + + // Reserve the first N PE labels for addrConstraints. + h.label = peLabel(h.N) + + // Add offline constraint edges. + if h.log != nil { + fmt.Fprintf(h.log, "\nAdding offline graph edges...\n") + } + for _, c := range a.constraints { + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "; %s\n", c) + } + c.presolve(&h) + } + + // Find and collapse SCCs. + if h.log != nil { + fmt.Fprintf(h.log, "\nFinding SCCs...\n") + } + h.index = 1 + for id, o := range h.onodes { + if id > 0 && o.index == 0 { + // Start depth-first search at each unvisited node. + h.visit(onodeid(id)) + } + } + + // Dump the solution + // (NB: somewhat redundant with logging from simplify().) + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\nPointer equivalences:\n") + for id, o := range h.onodes { + if id == 0 { + continue + } + if id == int(h.N) { + fmt.Fprintf(h.log, "---\n") + } + fmt.Fprintf(h.log, "o%d\t", id) + if o.rep != onodeid(id) { + fmt.Fprintf(h.log, "rep=o%d", o.rep) + } else { + fmt.Fprintf(h.log, "p%d", o.peLabels.Min()) + if o.indirect { + fmt.Fprint(h.log, " indirect") + } + } + fmt.Fprintln(h.log) + } + } + + // Simplify the main constraint graph + h.simplify() + + a.showCounts() + + stop("HVN") +} + +// ---- constraint-specific rules ---- + +// dst := &src +func (c *addrConstraint) presolve(h *hvn) { + // Each object (src) is an initial PE label. + label := peLabel(c.src) // label < N + if debugHVNVerbose && h.log != nil { + // duplicate log messages are possible + fmt.Fprintf(h.log, "\tcreate p%d: {&n%d}\n", label, c.src) + } + odst := onodeid(c.dst) + osrc := onodeid(c.src) + + // Assign dst this label. + h.onodes[odst].peLabels.Insert(int(label)) + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\to%d has p%d\n", odst, label) + } + + h.addImplicitEdge(h.ref(odst), osrc) // *dst ~~> src. +} + +// dst = src +func (c *copyConstraint) presolve(h *hvn) { + odst := onodeid(c.dst) + osrc := onodeid(c.src) + h.addEdge(odst, osrc) // dst --> src + h.addImplicitEdge(h.ref(odst), h.ref(osrc)) // *dst ~~> *src +} + +// dst = *src + offset +func (c *loadConstraint) presolve(h *hvn) { + odst := onodeid(c.dst) + osrc := onodeid(c.src) + if c.offset == 0 { + h.addEdge(odst, h.ref(osrc)) // dst --> *src + } else { + // We don't interpret load-with-offset, e.g. results + // of map value lookup, R-block of dynamic call, slice + // copy/append, reflection. + h.markIndirect(odst, "load with offset") + } +} + +// *dst + offset = src +func (c *storeConstraint) presolve(h *hvn) { + odst := onodeid(c.dst) + osrc := onodeid(c.src) + if c.offset == 0 { + h.onodes[h.ref(odst)].edges.Insert(int(osrc)) // *dst --> src + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\to%d --> o%d\n", h.ref(odst), osrc) + } + } else { + // We don't interpret store-with-offset. + // See discussion of soundness at markIndirectNodes. + } +} + +// dst = &src.offset +func (c *offsetAddrConstraint) presolve(h *hvn) { + // Give each distinct (addr, offset) pair a fresh PE label. + // The cache performs CSE, effectively. + key := offsetAddr{c.src, c.offset} + label, ok := h.offsetAddrLabels[key] + if !ok { + label = h.nextLabel() + h.offsetAddrLabels[key] = label + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\tcreate p%d: {&n%d.#%d}\n", + label, c.src, c.offset) + } + } + + // Assign dst this label. + h.onodes[c.dst].peLabels.Insert(int(label)) + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\to%d has p%d\n", c.dst, label) + } +} + +// dst = src.(typ) where typ is an interface +func (c *typeFilterConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.dst), "typeFilter result") +} + +// dst = src.(typ) where typ is concrete +func (c *untagConstraint) presolve(h *hvn) { + odst := onodeid(c.dst) + for end := odst + onodeid(h.a.sizeof(c.typ)); odst < end; odst++ { + h.markIndirect(odst, "untag result") + } +} + +// dst = src.method(c.params...) +func (c *invokeConstraint) presolve(h *hvn) { + // All methods are address-taken functions, so + // their formal P-blocks were already marked indirect. + + // Mark the caller's targets node as indirect. + sig := c.method.Type().(*types.Signature) + id := c.params + h.markIndirect(onodeid(c.params), "invoke targets node") + id++ + + id += nodeid(h.a.sizeof(sig.Params())) + + // Mark the caller's R-block as indirect. + end := id + nodeid(h.a.sizeof(sig.Results())) + for id < end { + h.markIndirect(onodeid(id), "invoke R-block") + id++ + } +} + +// markIndirectNodes marks as indirect nodes whose points-to relations +// are not entirely captured by the offline graph, including: +// +// (a) All address-taken nodes (including the following nodes within +// the same object). This is described in the paper. +// +// The most subtle cause of indirect nodes is the generation of +// store-with-offset constraints since the offline graph doesn't +// represent them. A global audit of constraint generation reveals the +// following uses of store-with-offset: +// +// (b) genDynamicCall, for P-blocks of dynamically called functions, +// to which dynamic copy edges will be added to them during +// solving: from storeConstraint for standalone functions, +// and from invokeConstraint for methods. +// All such P-blocks must be marked indirect. +// (c) MakeUpdate, to update the value part of a map object. +// All MakeMap objects's value parts must be marked indirect. +// (d) copyElems, to update the destination array. +// All array elements must be marked indirect. +// +// Not all indirect marking happens here. ref() nodes are marked +// indirect at construction, and each constraint's presolve() method may +// mark additional nodes. +// +func (h *hvn) markIndirectNodes() { + // (a) all address-taken nodes, plus all nodes following them + // within the same object, since these may be indirectly + // stored or address-taken. + for _, c := range h.a.constraints { + if c, ok := c.(*addrConstraint); ok { + start := h.a.enclosingObj(c.src) + end := start + nodeid(h.a.nodes[start].obj.size) + for id := c.src; id < end; id++ { + h.markIndirect(onodeid(id), "A-T object") + } + } + } + + // (b) P-blocks of all address-taken functions. + for id := 0; id < h.N; id++ { + obj := h.a.nodes[id].obj + + // TODO(adonovan): opt: if obj.cgn.fn is a method and + // obj.cgn is not its shared contour, this is an + // "inlined" static method call. We needn't consider it + // address-taken since no invokeConstraint will affect it. + + if obj != nil && obj.flags&otFunction != 0 && h.a.atFuncs[obj.cgn.fn] { + // address-taken function + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "n%d is address-taken: %s\n", id, obj.cgn.fn) + } + h.markIndirect(onodeid(id), "A-T func identity") + id++ + sig := obj.cgn.fn.Signature + psize := h.a.sizeof(sig.Params()) + if sig.Recv() != nil { + psize += h.a.sizeof(sig.Recv().Type()) + } + for end := id + int(psize); id < end; id++ { + h.markIndirect(onodeid(id), "A-T func P-block") + } + id-- + continue + } + } + + // (c) all map objects' value fields. + for _, id := range h.a.mapValues { + h.markIndirect(onodeid(id), "makemap.value") + } + + // (d) all array element objects. + // TODO(adonovan): opt: can we do better? + for id := 0; id < h.N; id++ { + // Identity node for an object of array type? + if tArray, ok := h.a.nodes[id].typ.(*types.Array); ok { + // Mark the array element nodes indirect. + // (Skip past the identity field.) + for range h.a.flatten(tArray.Elem()) { + id++ + h.markIndirect(onodeid(id), "array elem") + } + } + } +} + +func (h *hvn) markIndirect(oid onodeid, comment string) { + h.onodes[oid].indirect = true + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\to%d is indirect: %s\n", oid, comment) + } +} + +// Adds an edge dst-->src. +// Note the unusual convention: edges are dependency (contraflow) edges. +func (h *hvn) addEdge(odst, osrc onodeid) { + h.onodes[odst].edges.Insert(int(osrc)) + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\to%d --> o%d\n", odst, osrc) + } +} + +func (h *hvn) addImplicitEdge(odst, osrc onodeid) { + h.onodes[odst].implicit.Insert(int(osrc)) + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\to%d ~~> o%d\n", odst, osrc) + } +} + +// visit implements the depth-first search of Tarjan's SCC algorithm. +// Precondition: x is canonical. +func (h *hvn) visit(x onodeid) { + h.checkCanonical(x) + xo := h.onodes[x] + xo.index = h.index + xo.lowlink = h.index + h.index++ + + h.stack = append(h.stack, x) // push + assert(xo.scc == 0, "node revisited") + xo.scc = -1 + + var deps []int + deps = xo.edges.AppendTo(deps) + deps = xo.implicit.AppendTo(deps) + + for _, y := range deps { + // Loop invariant: x is canonical. + + y := h.find(onodeid(y)) + + if x == y { + continue // nodes already coalesced + } + + xo := h.onodes[x] + yo := h.onodes[y] + + switch { + case yo.scc > 0: + // y is already a collapsed SCC + + case yo.scc < 0: + // y is on the stack, and thus in the current SCC. + if yo.index < xo.lowlink { + xo.lowlink = yo.index + } + + default: + // y is unvisited; visit it now. + h.visit(y) + // Note: x and y are now non-canonical. + + x = h.find(onodeid(x)) + + if yo.lowlink < xo.lowlink { + xo.lowlink = yo.lowlink + } + } + } + h.checkCanonical(x) + + // Is x the root of an SCC? + if xo.lowlink == xo.index { + // Coalesce all nodes in the SCC. + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "scc o%d\n", x) + } + for { + // Pop y from stack. + i := len(h.stack) - 1 + y := h.stack[i] + h.stack = h.stack[:i] + + h.checkCanonical(x) + xo := h.onodes[x] + h.checkCanonical(y) + yo := h.onodes[y] + + if xo == yo { + // SCC is complete. + xo.scc = 1 + h.labelSCC(x) + break + } + h.coalesce(x, y) + } + } +} + +// Precondition: x is canonical. +func (h *hvn) labelSCC(x onodeid) { + h.checkCanonical(x) + xo := h.onodes[x] + xpe := &xo.peLabels + + // All indirect nodes get new labels. + if xo.indirect { + label := h.nextLabel() + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\tcreate p%d: indirect SCC\n", label) + fmt.Fprintf(h.log, "\to%d has p%d\n", x, label) + } + + // Remove pre-labeling, in case a direct pre-labeled node was + // merged with an indirect one. + xpe.Clear() + xpe.Insert(int(label)) + + return + } + + // Invariant: all peLabels sets are non-empty. + // Those that are logically empty contain zero as their sole element. + // No other sets contains zero. + + // Find all labels coming in to the coalesced SCC node. + for _, y := range xo.edges.AppendTo(nil) { + y := h.find(onodeid(y)) + if y == x { + continue // already coalesced + } + ype := &h.onodes[y].peLabels + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\tedge from o%d = %s\n", y, ype) + } + + if ype.IsEmpty() { + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\tnode has no PE label\n") + } + } + assert(!ype.IsEmpty(), "incoming node has no PE label") + + if ype.Has(0) { + // {0} represents a non-pointer. + assert(ype.Len() == 1, "PE set contains {0, ...}") + } else { + xpe.UnionWith(ype) + } + } + + switch xpe.Len() { + case 0: + // SCC has no incoming non-zero PE labels: it is a non-pointer. + xpe.Insert(0) + + case 1: + // already a singleton + + default: + // SCC has multiple incoming non-zero PE labels. + // Find the canonical label representing this set. + // We use String() as a fingerprint consistent with Equals(). + key := xpe.String() + label, ok := h.hvnLabel[key] + if !ok { + label = h.nextLabel() + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\tcreate p%d: union %s\n", label, xpe.String()) + } + h.hvnLabel[key] = label + } + xpe.Clear() + xpe.Insert(int(label)) + } + + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\to%d has p%d\n", x, xpe.Min()) + } +} + +// coalesce combines two nodes in the offline constraint graph. +// Precondition: x and y are canonical. +func (h *hvn) coalesce(x, y onodeid) { + xo := h.onodes[x] + yo := h.onodes[y] + + // x becomes y's canonical representative. + yo.rep = x + + if debugHVNVerbose && h.log != nil { + fmt.Fprintf(h.log, "\tcoalesce o%d into o%d\n", y, x) + } + + // x accumulates y's edges. + xo.edges.UnionWith(&yo.edges) + yo.edges.Clear() + + // x accumulates y's implicit edges. + xo.implicit.UnionWith(&yo.implicit) + yo.implicit.Clear() + + // x accumulates y's pointer-equivalence labels. + xo.peLabels.UnionWith(&yo.peLabels) + yo.peLabels.Clear() + + // x accumulates y's indirect flag. + if yo.indirect { + xo.indirect = true + } +} + +// simplify computes a degenerate renumbering of nodeids from the PE +// labels assigned by the hvn, and uses it to simplify the main +// constraint graph, eliminating non-pointer nodes and duplicate +// constraints. +// +func (h *hvn) simplify() { + // canon maps each peLabel to its canonical main node. + canon := make([]nodeid, h.label) + for i := range canon { + canon[i] = nodeid(h.N) // indicates "unset" + } + + // mapping maps each main node index to the index of the canonical node. + mapping := make([]nodeid, len(h.a.nodes)) + + for id := range h.a.nodes { + id := nodeid(id) + if id == 0 { + canon[0] = 0 + mapping[0] = 0 + continue + } + oid := h.find(onodeid(id)) + peLabels := &h.onodes[oid].peLabels + assert(peLabels.Len() == 1, "PE class is not a singleton") + label := peLabel(peLabels.Min()) + + canonId := canon[label] + if canonId == nodeid(h.N) { + // id becomes the representative of the PE label. + canonId = id + canon[label] = canonId + + if h.a.log != nil { + fmt.Fprintf(h.a.log, "\tpts(n%d) is canonical : \t(%s)\n", + id, h.a.nodes[id].typ) + } + + } else { + // Link the solver states for the two nodes. + assert(h.a.nodes[canonId].solve != nil, "missing solver state") + h.a.nodes[id].solve = h.a.nodes[canonId].solve + + if h.a.log != nil { + // TODO(adonovan): debug: reorganize the log so it prints + // one line: + // pe y = x1, ..., xn + // for each canonical y. Requires allocation. + fmt.Fprintf(h.a.log, "\tpts(n%d) = pts(n%d) : %s\n", + id, canonId, h.a.nodes[id].typ) + } + } + + mapping[id] = canonId + } + + // Renumber the constraints, eliminate duplicates, and eliminate + // any containing non-pointers (n0). + addrs := make(map[addrConstraint]bool) + copys := make(map[copyConstraint]bool) + loads := make(map[loadConstraint]bool) + stores := make(map[storeConstraint]bool) + offsetAddrs := make(map[offsetAddrConstraint]bool) + untags := make(map[untagConstraint]bool) + typeFilters := make(map[typeFilterConstraint]bool) + invokes := make(map[invokeConstraint]bool) + + nbefore := len(h.a.constraints) + cc := h.a.constraints[:0] // in-situ compaction + for _, c := range h.a.constraints { + // Renumber. + switch c := c.(type) { + case *addrConstraint: + // Don't renumber c.src since it is the label of + // an addressable object and will appear in PT sets. + c.dst = mapping[c.dst] + default: + c.renumber(mapping) + } + + if c.ptr() == 0 { + continue // skip: constraint attached to non-pointer + } + + var dup bool + switch c := c.(type) { + case *addrConstraint: + _, dup = addrs[*c] + addrs[*c] = true + + case *copyConstraint: + if c.src == c.dst { + continue // skip degenerate copies + } + if c.src == 0 { + continue // skip copy from non-pointer + } + _, dup = copys[*c] + copys[*c] = true + + case *loadConstraint: + if c.src == 0 { + continue // skip load from non-pointer + } + _, dup = loads[*c] + loads[*c] = true + + case *storeConstraint: + if c.src == 0 { + continue // skip store from non-pointer + } + _, dup = stores[*c] + stores[*c] = true + + case *offsetAddrConstraint: + if c.src == 0 { + continue // skip offset from non-pointer + } + _, dup = offsetAddrs[*c] + offsetAddrs[*c] = true + + case *untagConstraint: + if c.src == 0 { + continue // skip untag of non-pointer + } + _, dup = untags[*c] + untags[*c] = true + + case *typeFilterConstraint: + if c.src == 0 { + continue // skip filter of non-pointer + } + _, dup = typeFilters[*c] + typeFilters[*c] = true + + case *invokeConstraint: + if c.params == 0 { + panic("non-pointer invoke.params") + } + if c.iface == 0 { + continue // skip invoke on non-pointer + } + _, dup = invokes[*c] + invokes[*c] = true + + default: + // We don't bother de-duping advanced constraints + // (e.g. reflection) since they are uncommon. + + // Eliminate constraints containing non-pointer nodeids. + // + // We use reflection to find the fields to avoid + // adding yet another method to constraint. + // + // TODO(adonovan): experiment with a constraint + // method that returns a slice of pointers to + // nodeids fields to enable uniform iteration; + // the renumber() method could be removed and + // implemented using the new one. + // + // TODO(adonovan): opt: this is unsound since + // some constraints still have an effect if one + // of the operands is zero: rVCall, rVMapIndex, + // rvSetMapIndex. Handle them specially. + rtNodeid := reflect.TypeOf(nodeid(0)) + x := reflect.ValueOf(c).Elem() + for i, nf := 0, x.NumField(); i < nf; i++ { + f := x.Field(i) + if f.Type() == rtNodeid { + if f.Uint() == 0 { + dup = true // skip it + break + } + } + } + } + if dup { + continue // skip duplicates + } + + cc = append(cc, c) + } + h.a.constraints = cc + + if h.log != nil { + fmt.Fprintf(h.log, "#constraints: was %d, now %d\n", nbefore, len(h.a.constraints)) + } +} + +// find returns the canonical onodeid for x. +// (The onodes form a disjoint set forest.) +func (h *hvn) find(x onodeid) onodeid { + // TODO(adonovan): opt: this is a CPU hotspot. Try "union by rank". + xo := h.onodes[x] + rep := xo.rep + if rep != x { + rep = h.find(rep) // simple path compression + xo.rep = rep + } + return rep +} + +func (h *hvn) checkCanonical(x onodeid) { + if debugHVN { + assert(x == h.find(x), "not canonical") + } +} + +func assert(p bool, msg string) { + if debugHVN && !p { + panic("assertion failed: " + msg) + } +} diff --git a/vendor/golang.org/x/tools/go/pointer/intrinsics.go b/vendor/golang.org/x/tools/go/pointer/intrinsics.go new file mode 100644 index 00000000000..b7e2b1403c4 --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/intrinsics.go @@ -0,0 +1,361 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pointer + +// This package defines the treatment of intrinsics, i.e. library +// functions requiring special analytical treatment. +// +// Most of these are C or assembly functions, but even some Go +// functions require may special treatment if the analysis completely +// replaces the implementation of an API such as reflection. + +// TODO(adonovan): support a means of writing analytic summaries in +// the target code, so that users can summarise the effects of their +// own C functions using a snippet of Go. + +import ( + "fmt" + "go/types" + + "golang.org/x/tools/go/ssa" +) + +// Instances of 'intrinsic' generate analysis constraints for calls to +// intrinsic functions. +// Implementations may exploit information from the calling site +// via cgn.callersite; for shared contours this is nil. +type intrinsic func(a *analysis, cgn *cgnode) + +// Initialized in explicit init() to defeat (spurious) initialization +// cycle error. +var intrinsicsByName = make(map[string]intrinsic) + +func init() { + // Key strings are from Function.String(). + // That little dot ۰ is an Arabic zero numeral (U+06F0), + // categories [Nd]. + for name, fn := range map[string]intrinsic{ + // Other packages. + "bytes.Equal": ext۰NoEffect, + "bytes.IndexByte": ext۰NoEffect, + "crypto/aes.decryptBlockAsm": ext۰NoEffect, + "crypto/aes.encryptBlockAsm": ext۰NoEffect, + "crypto/aes.expandKeyAsm": ext۰NoEffect, + "crypto/aes.hasAsm": ext۰NoEffect, + "crypto/md5.block": ext۰NoEffect, + "crypto/rc4.xorKeyStream": ext۰NoEffect, + "crypto/sha1.block": ext۰NoEffect, + "crypto/sha256.block": ext۰NoEffect, + "hash/crc32.castagnoliSSE42": ext۰NoEffect, + "hash/crc32.haveSSE42": ext۰NoEffect, + "math.Abs": ext۰NoEffect, + "math.Acos": ext۰NoEffect, + "math.Asin": ext۰NoEffect, + "math.Atan": ext۰NoEffect, + "math.Atan2": ext۰NoEffect, + "math.Ceil": ext۰NoEffect, + "math.Cos": ext۰NoEffect, + "math.Dim": ext۰NoEffect, + "math.Exp": ext۰NoEffect, + "math.Exp2": ext۰NoEffect, + "math.Expm1": ext۰NoEffect, + "math.Float32bits": ext۰NoEffect, + "math.Float32frombits": ext۰NoEffect, + "math.Float64bits": ext۰NoEffect, + "math.Float64frombits": ext۰NoEffect, + "math.Floor": ext۰NoEffect, + "math.Frexp": ext۰NoEffect, + "math.Hypot": ext۰NoEffect, + "math.Ldexp": ext۰NoEffect, + "math.Log": ext۰NoEffect, + "math.Log10": ext۰NoEffect, + "math.Log1p": ext۰NoEffect, + "math.Log2": ext۰NoEffect, + "math.Max": ext۰NoEffect, + "math.Min": ext۰NoEffect, + "math.Mod": ext۰NoEffect, + "math.Modf": ext۰NoEffect, + "math.Remainder": ext۰NoEffect, + "math.Sin": ext۰NoEffect, + "math.Sincos": ext۰NoEffect, + "math.Sqrt": ext۰NoEffect, + "math.Tan": ext۰NoEffect, + "math.Trunc": ext۰NoEffect, + "math/big.addMulVVW": ext۰NoEffect, + "math/big.addVV": ext۰NoEffect, + "math/big.addVW": ext۰NoEffect, + "math/big.bitLen": ext۰NoEffect, + "math/big.divWVW": ext۰NoEffect, + "math/big.divWW": ext۰NoEffect, + "math/big.mulAddVWW": ext۰NoEffect, + "math/big.mulWW": ext۰NoEffect, + "math/big.shlVU": ext۰NoEffect, + "math/big.shrVU": ext۰NoEffect, + "math/big.subVV": ext۰NoEffect, + "math/big.subVW": ext۰NoEffect, + "net.runtime_Semacquire": ext۰NoEffect, + "net.runtime_Semrelease": ext۰NoEffect, + "net.runtime_pollClose": ext۰NoEffect, + "net.runtime_pollOpen": ext۰NoEffect, + "net.runtime_pollReset": ext۰NoEffect, + "net.runtime_pollServerInit": ext۰NoEffect, + "net.runtime_pollSetDeadline": ext۰NoEffect, + "net.runtime_pollUnblock": ext۰NoEffect, + "net.runtime_pollWait": ext۰NoEffect, + "net.runtime_pollWaitCanceled": ext۰NoEffect, + "os.epipecheck": ext۰NoEffect, + // All other runtime functions are treated as NoEffect. + "runtime.SetFinalizer": ext۰runtime۰SetFinalizer, + "strings.IndexByte": ext۰NoEffect, + "sync.runtime_Semacquire": ext۰NoEffect, + "sync.runtime_Semrelease": ext۰NoEffect, + "sync.runtime_Syncsemacquire": ext۰NoEffect, + "sync.runtime_Syncsemcheck": ext۰NoEffect, + "sync.runtime_Syncsemrelease": ext۰NoEffect, + "sync.runtime_procPin": ext۰NoEffect, + "sync.runtime_procUnpin": ext۰NoEffect, + "sync.runtime_registerPool": ext۰NoEffect, + "sync/atomic.AddInt32": ext۰NoEffect, + "sync/atomic.AddInt64": ext۰NoEffect, + "sync/atomic.AddUint32": ext۰NoEffect, + "sync/atomic.AddUint64": ext۰NoEffect, + "sync/atomic.AddUintptr": ext۰NoEffect, + "sync/atomic.CompareAndSwapInt32": ext۰NoEffect, + "sync/atomic.CompareAndSwapUint32": ext۰NoEffect, + "sync/atomic.CompareAndSwapUint64": ext۰NoEffect, + "sync/atomic.CompareAndSwapUintptr": ext۰NoEffect, + "sync/atomic.LoadInt32": ext۰NoEffect, + "sync/atomic.LoadInt64": ext۰NoEffect, + "sync/atomic.LoadPointer": ext۰NoEffect, // ignore unsafe.Pointers + "sync/atomic.LoadUint32": ext۰NoEffect, + "sync/atomic.LoadUint64": ext۰NoEffect, + "sync/atomic.LoadUintptr": ext۰NoEffect, + "sync/atomic.StoreInt32": ext۰NoEffect, + "sync/atomic.StorePointer": ext۰NoEffect, // ignore unsafe.Pointers + "sync/atomic.StoreUint32": ext۰NoEffect, + "sync/atomic.StoreUintptr": ext۰NoEffect, + "syscall.Close": ext۰NoEffect, + "syscall.Exit": ext۰NoEffect, + "syscall.Getpid": ext۰NoEffect, + "syscall.Getwd": ext۰NoEffect, + "syscall.Kill": ext۰NoEffect, + "syscall.RawSyscall": ext۰NoEffect, + "syscall.RawSyscall6": ext۰NoEffect, + "syscall.Syscall": ext۰NoEffect, + "syscall.Syscall6": ext۰NoEffect, + "syscall.runtime_AfterFork": ext۰NoEffect, + "syscall.runtime_BeforeFork": ext۰NoEffect, + "syscall.setenv_c": ext۰NoEffect, + "time.Sleep": ext۰NoEffect, + "time.now": ext۰NoEffect, + "time.startTimer": ext۰time۰startTimer, + "time.stopTimer": ext۰NoEffect, + } { + intrinsicsByName[name] = fn + } +} + +// findIntrinsic returns the constraint generation function for an +// intrinsic function fn, or nil if the function should be handled normally. +// +func (a *analysis) findIntrinsic(fn *ssa.Function) intrinsic { + // Consult the *Function-keyed cache. + // A cached nil indicates a normal non-intrinsic function. + impl, ok := a.intrinsics[fn] + if !ok { + impl = intrinsicsByName[fn.String()] // may be nil + + if a.isReflect(fn) { + if !a.config.Reflection { + impl = ext۰NoEffect // reflection disabled + } else if impl == nil { + // Ensure all "reflect" code is treated intrinsically. + impl = ext۰NotYetImplemented + } + } else if impl == nil && fn.Pkg != nil && fn.Pkg.Pkg.Path() == "runtime" { + // Ignore "runtime" (except SetFinalizer): + // it has few interesting effects on aliasing + // and is full of unsafe code we can't analyze. + impl = ext۰NoEffect + } + + a.intrinsics[fn] = impl + } + return impl +} + +// isReflect reports whether fn belongs to the "reflect" package. +func (a *analysis) isReflect(fn *ssa.Function) bool { + if a.reflectValueObj == nil { + return false // "reflect" package not loaded + } + reflectPackage := a.reflectValueObj.Pkg() + if fn.Pkg != nil && fn.Pkg.Pkg == reflectPackage { + return true + } + // Synthetic wrappers have a nil Pkg, so they slip through the + // previous check. Check the receiver package. + // TODO(adonovan): should synthetic wrappers have a non-nil Pkg? + if recv := fn.Signature.Recv(); recv != nil { + if named, ok := deref(recv.Type()).(*types.Named); ok { + if named.Obj().Pkg() == reflectPackage { + return true // e.g. wrapper of (reflect.Value).f + } + } + } + return false +} + +// A trivial intrinsic suitable for any function that does not: +// 1) induce aliases between its arguments or any global variables; +// 2) call any functions; or +// 3) create any labels. +// +// Many intrinsics (such as CompareAndSwapInt32) have a fourth kind of +// effect: loading or storing through a pointer. Though these could +// be significant, we deliberately ignore them because they are +// generally not worth the effort. +// +// We sometimes violate condition #3 if the function creates only +// non-function labels, as the control-flow graph is still sound. +// +func ext۰NoEffect(a *analysis, cgn *cgnode) {} + +func ext۰NotYetImplemented(a *analysis, cgn *cgnode) { + fn := cgn.fn + a.warnf(fn.Pos(), "unsound: intrinsic treatment of %s not yet implemented", fn) +} + +// ---------- func runtime.SetFinalizer(x, f interface{}) ---------- + +// runtime.SetFinalizer(x, f) +type runtimeSetFinalizerConstraint struct { + targets nodeid // (indirect) + f nodeid // (ptr) + x nodeid +} + +func (c *runtimeSetFinalizerConstraint) ptr() nodeid { return c.f } +func (c *runtimeSetFinalizerConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.targets), "SetFinalizer.targets") +} +func (c *runtimeSetFinalizerConstraint) renumber(mapping []nodeid) { + c.targets = mapping[c.targets] + c.f = mapping[c.f] + c.x = mapping[c.x] +} + +func (c *runtimeSetFinalizerConstraint) String() string { + return fmt.Sprintf("runtime.SetFinalizer(n%d, n%d)", c.x, c.f) +} + +func (c *runtimeSetFinalizerConstraint) solve(a *analysis, delta *nodeset) { + for _, fObj := range delta.AppendTo(a.deltaSpace) { + tDyn, f, indirect := a.taggedValue(nodeid(fObj)) + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + tSig, ok := tDyn.Underlying().(*types.Signature) + if !ok { + continue // not a function + } + if tSig.Recv() != nil { + panic(tSig) + } + if tSig.Params().Len() != 1 { + continue // not a unary function + } + + // Extract x to tmp. + tx := tSig.Params().At(0).Type() + tmp := a.addNodes(tx, "SetFinalizer.tmp") + a.typeAssert(tx, tmp, c.x, false) + + // Call f(tmp). + a.store(f, tmp, 1, a.sizeof(tx)) + + // Add dynamic call target. + if a.onlineCopy(c.targets, f) { + a.addWork(c.targets) + } + } +} + +func ext۰runtime۰SetFinalizer(a *analysis, cgn *cgnode) { + // This is the shared contour, used for dynamic calls. + targets := a.addOneNode(tInvalid, "SetFinalizer.targets", nil) + cgn.sites = append(cgn.sites, &callsite{targets: targets}) + params := a.funcParams(cgn.obj) + a.addConstraint(&runtimeSetFinalizerConstraint{ + targets: targets, + x: params, + f: params + 1, + }) +} + +// ---------- func time.startTimer(t *runtimeTimer) ---------- + +// time.StartTimer(t) +type timeStartTimerConstraint struct { + targets nodeid // (indirect) + t nodeid // (ptr) +} + +func (c *timeStartTimerConstraint) ptr() nodeid { return c.t } +func (c *timeStartTimerConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.targets), "StartTimer.targets") +} +func (c *timeStartTimerConstraint) renumber(mapping []nodeid) { + c.targets = mapping[c.targets] + c.t = mapping[c.t] +} + +func (c *timeStartTimerConstraint) String() string { + return fmt.Sprintf("time.startTimer(n%d)", c.t) +} + +func (c *timeStartTimerConstraint) solve(a *analysis, delta *nodeset) { + for _, tObj := range delta.AppendTo(a.deltaSpace) { + t := nodeid(tObj) + + // We model startTimer as if it was defined thus: + // func startTimer(t *runtimeTimer) { t.f(t.arg) } + + // We hard-code the field offsets of time.runtimeTimer: + // type runtimeTimer struct { + // 0 __identity__ + // 1 i int32 + // 2 when int64 + // 3 period int64 + // 4 f func(int64, interface{}) + // 5 arg interface{} + // } + f := t + 4 + arg := t + 5 + + // store t.arg to t.f.params[0] + // (offset 1 => skip identity) + a.store(f, arg, 1, 1) + + // Add dynamic call target. + if a.onlineCopy(c.targets, f) { + a.addWork(c.targets) + } + } +} + +func ext۰time۰startTimer(a *analysis, cgn *cgnode) { + // This is the shared contour, used for dynamic calls. + targets := a.addOneNode(tInvalid, "startTimer.targets", nil) + cgn.sites = append(cgn.sites, &callsite{targets: targets}) + params := a.funcParams(cgn.obj) + a.addConstraint(&timeStartTimerConstraint{ + targets: targets, + t: params, + }) +} diff --git a/vendor/golang.org/x/tools/go/pointer/labels.go b/vendor/golang.org/x/tools/go/pointer/labels.go new file mode 100644 index 00000000000..7d64ef6a480 --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/labels.go @@ -0,0 +1,152 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pointer + +import ( + "fmt" + "go/token" + "go/types" + "strings" + + "golang.org/x/tools/go/ssa" +) + +// A Label is an entity that may be pointed to by a pointer, map, +// channel, 'func', slice or interface. +// +// Labels include: +// - functions +// - globals +// - tagged objects, representing interfaces and reflect.Values +// - arrays created by conversions (e.g. []byte("foo"), []byte(s)) +// - stack- and heap-allocated variables (including composite literals) +// - channels, maps and arrays created by make() +// - intrinsic or reflective operations that allocate (e.g. append, reflect.New) +// - intrinsic objects, e.g. the initial array behind os.Args. +// - and their subelements, e.g. "alloc.y[*].z" +// +// Labels are so varied that they defy good generalizations; +// some have no value, no callgraph node, or no position. +// Many objects have types that are inexpressible in Go: +// maps, channels, functions, tagged objects. +// +// At most one of Value() or ReflectType() may return non-nil. +// +type Label struct { + obj *object // the addressable memory location containing this label + subelement *fieldInfo // subelement path within obj, e.g. ".a.b[*].c" +} + +// Value returns the ssa.Value that allocated this label's object, if any. +func (l Label) Value() ssa.Value { + val, _ := l.obj.data.(ssa.Value) + return val +} + +// ReflectType returns the type represented by this label if it is an +// reflect.rtype instance object or *reflect.rtype-tagged object. +// +func (l Label) ReflectType() types.Type { + rtype, _ := l.obj.data.(types.Type) + return rtype +} + +// Path returns the path to the subelement of the object containing +// this label. For example, ".x[*].y". +// +func (l Label) Path() string { + return l.subelement.path() +} + +// Pos returns the position of this label, if known, zero otherwise. +func (l Label) Pos() token.Pos { + switch data := l.obj.data.(type) { + case ssa.Value: + return data.Pos() + case types.Type: + if nt, ok := deref(data).(*types.Named); ok { + return nt.Obj().Pos() + } + } + if cgn := l.obj.cgn; cgn != nil { + return cgn.fn.Pos() + } + return token.NoPos +} + +// String returns the printed form of this label. +// +// Examples: Object type: +// x (a variable) +// (sync.Mutex).Lock (a function) +// convert (array created by conversion) +// makemap (map allocated via make) +// makechan (channel allocated via make) +// makeinterface (tagged object allocated by makeinterface) +// (allocation in instrinsic) +// sync.Mutex (a reflect.rtype instance) +// (an intrinsic object) +// +// Labels within compound objects have subelement paths: +// x.y[*].z (a struct variable, x) +// append.y[*].z (array allocated by append) +// makeslice.y[*].z (array allocated via make) +// +// TODO(adonovan): expose func LabelString(*types.Package, Label). +// +func (l Label) String() string { + var s string + switch v := l.obj.data.(type) { + case types.Type: + return v.String() + + case string: + s = v // an intrinsic object (e.g. os.Args[*]) + + case nil: + if l.obj.cgn != nil { + // allocation by intrinsic or reflective operation + s = fmt.Sprintf("", l.obj.cgn.fn) + } else { + s = "" // should be unreachable + } + + case *ssa.Function: + s = v.String() + + case *ssa.Global: + s = v.String() + + case *ssa.Const: + s = v.Name() + + case *ssa.Alloc: + s = v.Comment + if s == "" { + s = "alloc" + } + + case *ssa.Call: + // Currently only calls to append can allocate objects. + if v.Call.Value.(*ssa.Builtin).Object().Name() != "append" { + panic("unhandled *ssa.Call label: " + v.Name()) + } + s = "append" + + case *ssa.MakeMap, *ssa.MakeChan, *ssa.MakeSlice, *ssa.Convert: + s = strings.ToLower(strings.TrimPrefix(fmt.Sprintf("%T", v), "*ssa.")) + + case *ssa.MakeInterface: + // MakeInterface is usually implicit in Go source (so + // Pos()==0), and tagged objects may be allocated + // synthetically (so no *MakeInterface data). + s = "makeinterface:" + v.X.Type().String() + + default: + panic(fmt.Sprintf("unhandled object data type: %T", v)) + } + + return s + l.subelement.path() +} diff --git a/vendor/golang.org/x/tools/go/pointer/opt.go b/vendor/golang.org/x/tools/go/pointer/opt.go new file mode 100644 index 00000000000..81f80aa4f5c --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/opt.go @@ -0,0 +1,132 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pointer + +// This file implements renumbering, a pre-solver optimization to +// improve the efficiency of the solver's points-to set representation. +// +// TODO(adonovan): rename file "renumber.go" + +import "fmt" + +// renumber permutes a.nodes so that all nodes within an addressable +// object appear before all non-addressable nodes, maintaining the +// order of nodes within the same object (as required by offsetAddr). +// +// renumber must update every nodeid in the analysis (constraints, +// Pointers, callgraph, etc) to reflect the new ordering. +// +// This is an optimisation to increase the locality and efficiency of +// sparse representations of points-to sets. (Typically only about +// 20% of nodes are within an object.) +// +// NB: nodes added during solving (e.g. for reflection, SetFinalizer) +// will be appended to the end. +// +// Renumbering makes the PTA log inscrutable. To aid debugging, later +// phases (e.g. HVN) must not rely on it having occurred. +// +func (a *analysis) renumber() { + if a.log != nil { + fmt.Fprintf(a.log, "\n\n==== Renumbering\n\n") + } + + N := nodeid(len(a.nodes)) + newNodes := make([]*node, N, N) + renumbering := make([]nodeid, N, N) // maps old to new + + var i, j nodeid + + // The zero node is special. + newNodes[j] = a.nodes[i] + renumbering[i] = j + i++ + j++ + + // Pass 1: object nodes. + for i < N { + obj := a.nodes[i].obj + if obj == nil { + i++ + continue + } + + end := i + nodeid(obj.size) + for i < end { + newNodes[j] = a.nodes[i] + renumbering[i] = j + i++ + j++ + } + } + nobj := j + + // Pass 2: non-object nodes. + for i = 1; i < N; { + obj := a.nodes[i].obj + if obj != nil { + i += nodeid(obj.size) + continue + } + + newNodes[j] = a.nodes[i] + renumbering[i] = j + i++ + j++ + } + + if j != N { + panic(fmt.Sprintf("internal error: j=%d, N=%d", j, N)) + } + + // Log the remapping table. + if a.log != nil { + fmt.Fprintf(a.log, "Renumbering nodes to improve density:\n") + fmt.Fprintf(a.log, "(%d object nodes of %d total)\n", nobj, N) + for old, new := range renumbering { + fmt.Fprintf(a.log, "\tn%d -> n%d\n", old, new) + } + } + + // Now renumber all existing nodeids to use the new node permutation. + // It is critical that all reachable nodeids are accounted for! + + // Renumber nodeids in queried Pointers. + for v, ptr := range a.result.Queries { + ptr.n = renumbering[ptr.n] + a.result.Queries[v] = ptr + } + for v, ptr := range a.result.IndirectQueries { + ptr.n = renumbering[ptr.n] + a.result.IndirectQueries[v] = ptr + } + for _, queries := range a.config.extendedQueries { + for _, query := range queries { + if query.ptr != nil { + query.ptr.n = renumbering[query.ptr.n] + } + } + } + + // Renumber nodeids in global objects. + for v, id := range a.globalobj { + a.globalobj[v] = renumbering[id] + } + + // Renumber nodeids in constraints. + for _, c := range a.constraints { + c.renumber(renumbering) + } + + // Renumber nodeids in the call graph. + for _, cgn := range a.cgnodes { + cgn.obj = renumbering[cgn.obj] + for _, site := range cgn.sites { + site.targets = renumbering[site.targets] + } + } + + a.nodes = newNodes +} diff --git a/vendor/golang.org/x/tools/go/pointer/print.go b/vendor/golang.org/x/tools/go/pointer/print.go new file mode 100644 index 00000000000..4f2f4c7ae12 --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/print.go @@ -0,0 +1,43 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pointer + +import "fmt" + +func (c *addrConstraint) String() string { + return fmt.Sprintf("addr n%d <- {&n%d}", c.dst, c.src) +} + +func (c *copyConstraint) String() string { + return fmt.Sprintf("copy n%d <- n%d", c.dst, c.src) +} + +func (c *loadConstraint) String() string { + return fmt.Sprintf("load n%d <- n%d[%d]", c.dst, c.src, c.offset) +} + +func (c *storeConstraint) String() string { + return fmt.Sprintf("store n%d[%d] <- n%d", c.dst, c.offset, c.src) +} + +func (c *offsetAddrConstraint) String() string { + return fmt.Sprintf("offsetAddr n%d <- n%d.#%d", c.dst, c.src, c.offset) +} + +func (c *typeFilterConstraint) String() string { + return fmt.Sprintf("typeFilter n%d <- n%d.(%s)", c.dst, c.src, c.typ) +} + +func (c *untagConstraint) String() string { + return fmt.Sprintf("untag n%d <- n%d.(%s)", c.dst, c.src, c.typ) +} + +func (c *invokeConstraint) String() string { + return fmt.Sprintf("invoke n%d.%s(n%d ...)", c.iface, c.method.Name(), c.params) +} + +func (n nodeid) String() string { + return fmt.Sprintf("n%d", n) +} diff --git a/vendor/golang.org/x/tools/go/pointer/query.go b/vendor/golang.org/x/tools/go/pointer/query.go new file mode 100644 index 00000000000..b52cc9f3bc6 --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/query.go @@ -0,0 +1,221 @@ +package pointer + +import ( + "errors" + "fmt" + "go/ast" + "go/parser" + "go/token" + "go/types" + "strconv" +) + +// An extendedQuery represents a sequence of destructuring operations +// applied to an ssa.Value (denoted by "x"). +type extendedQuery struct { + ops []interface{} + ptr *Pointer +} + +// indexValue returns the value of an integer literal used as an +// index. +func indexValue(expr ast.Expr) (int, error) { + lit, ok := expr.(*ast.BasicLit) + if !ok { + return 0, fmt.Errorf("non-integer index (%T)", expr) + } + if lit.Kind != token.INT { + return 0, fmt.Errorf("non-integer index %s", lit.Value) + } + return strconv.Atoi(lit.Value) +} + +// parseExtendedQuery parses and validates a destructuring Go +// expression and returns the sequence of destructuring operations. +// See parseDestructuringExpr for details. +func parseExtendedQuery(typ types.Type, query string) ([]interface{}, types.Type, error) { + expr, err := parser.ParseExpr(query) + if err != nil { + return nil, nil, err + } + ops, typ, err := destructuringOps(typ, expr) + if err != nil { + return nil, nil, err + } + if len(ops) == 0 { + return nil, nil, errors.New("invalid query: must not be empty") + } + if ops[0] != "x" { + return nil, nil, fmt.Errorf("invalid query: query operand must be named x") + } + if !CanPoint(typ) { + return nil, nil, fmt.Errorf("query does not describe a pointer-like value: %s", typ) + } + return ops, typ, nil +} + +// destructuringOps parses a Go expression consisting only of an +// identifier "x", field selections, indexing, channel receives, load +// operations and parens---for example: "<-(*x[i])[key]"--- and +// returns the sequence of destructuring operations on x. +func destructuringOps(typ types.Type, expr ast.Expr) ([]interface{}, types.Type, error) { + switch expr := expr.(type) { + case *ast.SelectorExpr: + out, typ, err := destructuringOps(typ, expr.X) + if err != nil { + return nil, nil, err + } + + var structT *types.Struct + switch typ := typ.Underlying().(type) { + case *types.Pointer: + var ok bool + structT, ok = typ.Elem().Underlying().(*types.Struct) + if !ok { + return nil, nil, fmt.Errorf("cannot access field %s of pointer to type %s", expr.Sel.Name, typ.Elem()) + } + + out = append(out, "load") + case *types.Struct: + structT = typ + default: + return nil, nil, fmt.Errorf("cannot access field %s of type %s", expr.Sel.Name, typ) + } + + for i := 0; i < structT.NumFields(); i++ { + field := structT.Field(i) + if field.Name() == expr.Sel.Name { + out = append(out, "field", i) + return out, field.Type().Underlying(), nil + } + } + // TODO(dh): supporting embedding would need something like + // types.LookupFieldOrMethod, but without taking package + // boundaries into account, because we may want to access + // unexported fields. If we were only interested in one level + // of unexported name, we could determine the appropriate + // package and run LookupFieldOrMethod with that. However, a + // single query may want to cross multiple package boundaries, + // and at this point it's not really worth the complexity. + return nil, nil, fmt.Errorf("no field %s in %s (embedded fields must be resolved manually)", expr.Sel.Name, structT) + case *ast.Ident: + return []interface{}{expr.Name}, typ, nil + case *ast.BasicLit: + return []interface{}{expr.Value}, nil, nil + case *ast.IndexExpr: + out, typ, err := destructuringOps(typ, expr.X) + if err != nil { + return nil, nil, err + } + switch typ := typ.Underlying().(type) { + case *types.Array: + out = append(out, "arrayelem") + return out, typ.Elem().Underlying(), nil + case *types.Slice: + out = append(out, "sliceelem") + return out, typ.Elem().Underlying(), nil + case *types.Map: + out = append(out, "mapelem") + return out, typ.Elem().Underlying(), nil + case *types.Tuple: + out = append(out, "index") + idx, err := indexValue(expr.Index) + if err != nil { + return nil, nil, err + } + out = append(out, idx) + if idx >= typ.Len() || idx < 0 { + return nil, nil, fmt.Errorf("tuple index %d out of bounds", idx) + } + return out, typ.At(idx).Type().Underlying(), nil + default: + return nil, nil, fmt.Errorf("cannot index type %s", typ) + } + + case *ast.UnaryExpr: + if expr.Op != token.ARROW { + return nil, nil, fmt.Errorf("unsupported unary operator %s", expr.Op) + } + out, typ, err := destructuringOps(typ, expr.X) + if err != nil { + return nil, nil, err + } + ch, ok := typ.(*types.Chan) + if !ok { + return nil, nil, fmt.Errorf("cannot receive from value of type %s", typ) + } + out = append(out, "recv") + return out, ch.Elem().Underlying(), err + case *ast.ParenExpr: + return destructuringOps(typ, expr.X) + case *ast.StarExpr: + out, typ, err := destructuringOps(typ, expr.X) + if err != nil { + return nil, nil, err + } + ptr, ok := typ.(*types.Pointer) + if !ok { + return nil, nil, fmt.Errorf("cannot dereference type %s", typ) + } + out = append(out, "load") + return out, ptr.Elem().Underlying(), err + default: + return nil, nil, fmt.Errorf("unsupported expression %T", expr) + } +} + +func (a *analysis) evalExtendedQuery(t types.Type, id nodeid, ops []interface{}) (types.Type, nodeid) { + pid := id + // TODO(dh): we're allocating intermediary nodes each time + // evalExtendedQuery is called. We should probably only generate + // them once per (v, ops) pair. + for i := 1; i < len(ops); i++ { + var nid nodeid + switch ops[i] { + case "recv": + t = t.(*types.Chan).Elem().Underlying() + nid = a.addNodes(t, "query.extended") + a.load(nid, pid, 0, a.sizeof(t)) + case "field": + i++ // fetch field index + tt := t.(*types.Struct) + idx := ops[i].(int) + offset := a.offsetOf(t, idx) + t = tt.Field(idx).Type().Underlying() + nid = a.addNodes(t, "query.extended") + a.copy(nid, pid+nodeid(offset), a.sizeof(t)) + case "arrayelem": + t = t.(*types.Array).Elem().Underlying() + nid = a.addNodes(t, "query.extended") + a.copy(nid, 1+pid, a.sizeof(t)) + case "sliceelem": + t = t.(*types.Slice).Elem().Underlying() + nid = a.addNodes(t, "query.extended") + a.load(nid, pid, 1, a.sizeof(t)) + case "mapelem": + tt := t.(*types.Map) + t = tt.Elem() + ksize := a.sizeof(tt.Key()) + vsize := a.sizeof(tt.Elem()) + nid = a.addNodes(t, "query.extended") + a.load(nid, pid, ksize, vsize) + case "index": + i++ // fetch index + tt := t.(*types.Tuple) + idx := ops[i].(int) + t = tt.At(idx).Type().Underlying() + nid = a.addNodes(t, "query.extended") + a.copy(nid, pid+nodeid(idx), a.sizeof(t)) + case "load": + t = t.(*types.Pointer).Elem().Underlying() + nid = a.addNodes(t, "query.extended") + a.load(nid, pid, 0, a.sizeof(t)) + default: + // shouldn't happen + panic(fmt.Sprintf("unknown op %q", ops[i])) + } + pid = nid + } + + return t, pid +} diff --git a/vendor/golang.org/x/tools/go/pointer/reflect.go b/vendor/golang.org/x/tools/go/pointer/reflect.go new file mode 100644 index 00000000000..7aa1a9cb880 --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/reflect.go @@ -0,0 +1,1975 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pointer + +// This file implements the generation and resolution rules for +// constraints arising from the use of reflection in the target +// program. See doc.go for explanation of the representation. +// +// For consistency, the names of all parameters match those of the +// actual functions in the "reflect" package. +// +// To avoid proliferation of equivalent labels, intrinsics should +// memoize as much as possible, like TypeOf and Zero do for their +// tagged objects. +// +// TODO(adonovan): this file is rather subtle. Explain how we derive +// the implementation of each reflect operator from its spec, +// including the subtleties of reflect.flag{Addr,RO,Indir}. +// [Hint: our implementation is as if reflect.flagIndir was always +// true, i.e. reflect.Values are pointers to tagged objects, there is +// no inline allocation optimization; and indirect tagged objects (not +// yet implemented) correspond to reflect.Values with +// reflect.flagAddr.] +// A picture would help too. +// +// TODO(adonovan): try factoring up the common parts of the majority of +// these constraints that are single input, single output. + +import ( + "fmt" + "go/constant" + "go/types" + "reflect" + + "golang.org/x/tools/go/ssa" +) + +func init() { + for name, fn := range map[string]intrinsic{ + // reflect.Value methods. + "(reflect.Value).Addr": ext۰reflect۰Value۰Addr, + "(reflect.Value).Bool": ext۰NoEffect, + "(reflect.Value).Bytes": ext۰reflect۰Value۰Bytes, + "(reflect.Value).Call": ext۰reflect۰Value۰Call, + "(reflect.Value).CallSlice": ext۰reflect۰Value۰CallSlice, + "(reflect.Value).CanAddr": ext۰NoEffect, + "(reflect.Value).CanInterface": ext۰NoEffect, + "(reflect.Value).CanSet": ext۰NoEffect, + "(reflect.Value).Cap": ext۰NoEffect, + "(reflect.Value).Close": ext۰NoEffect, + "(reflect.Value).Complex": ext۰NoEffect, + "(reflect.Value).Convert": ext۰reflect۰Value۰Convert, + "(reflect.Value).Elem": ext۰reflect۰Value۰Elem, + "(reflect.Value).Field": ext۰reflect۰Value۰Field, + "(reflect.Value).FieldByIndex": ext۰reflect۰Value۰FieldByIndex, + "(reflect.Value).FieldByName": ext۰reflect۰Value۰FieldByName, + "(reflect.Value).FieldByNameFunc": ext۰reflect۰Value۰FieldByNameFunc, + "(reflect.Value).Float": ext۰NoEffect, + "(reflect.Value).Index": ext۰reflect۰Value۰Index, + "(reflect.Value).Int": ext۰NoEffect, + "(reflect.Value).Interface": ext۰reflect۰Value۰Interface, + "(reflect.Value).InterfaceData": ext۰NoEffect, + "(reflect.Value).IsNil": ext۰NoEffect, + "(reflect.Value).IsValid": ext۰NoEffect, + "(reflect.Value).Kind": ext۰NoEffect, + "(reflect.Value).Len": ext۰NoEffect, + "(reflect.Value).MapIndex": ext۰reflect۰Value۰MapIndex, + "(reflect.Value).MapKeys": ext۰reflect۰Value۰MapKeys, + "(reflect.Value).Method": ext۰reflect۰Value۰Method, + "(reflect.Value).MethodByName": ext۰reflect۰Value۰MethodByName, + "(reflect.Value).NumField": ext۰NoEffect, + "(reflect.Value).NumMethod": ext۰NoEffect, + "(reflect.Value).OverflowComplex": ext۰NoEffect, + "(reflect.Value).OverflowFloat": ext۰NoEffect, + "(reflect.Value).OverflowInt": ext۰NoEffect, + "(reflect.Value).OverflowUint": ext۰NoEffect, + "(reflect.Value).Pointer": ext۰NoEffect, + "(reflect.Value).Recv": ext۰reflect۰Value۰Recv, + "(reflect.Value).Send": ext۰reflect۰Value۰Send, + "(reflect.Value).Set": ext۰reflect۰Value۰Set, + "(reflect.Value).SetBool": ext۰NoEffect, + "(reflect.Value).SetBytes": ext۰reflect۰Value۰SetBytes, + "(reflect.Value).SetComplex": ext۰NoEffect, + "(reflect.Value).SetFloat": ext۰NoEffect, + "(reflect.Value).SetInt": ext۰NoEffect, + "(reflect.Value).SetLen": ext۰NoEffect, + "(reflect.Value).SetMapIndex": ext۰reflect۰Value۰SetMapIndex, + "(reflect.Value).SetPointer": ext۰reflect۰Value۰SetPointer, + "(reflect.Value).SetString": ext۰NoEffect, + "(reflect.Value).SetUint": ext۰NoEffect, + "(reflect.Value).Slice": ext۰reflect۰Value۰Slice, + "(reflect.Value).String": ext۰NoEffect, + "(reflect.Value).TryRecv": ext۰reflect۰Value۰Recv, + "(reflect.Value).TrySend": ext۰reflect۰Value۰Send, + "(reflect.Value).Type": ext۰NoEffect, + "(reflect.Value).Uint": ext۰NoEffect, + "(reflect.Value).UnsafeAddr": ext۰NoEffect, + + // Standalone reflect.* functions. + "reflect.Append": ext۰reflect۰Append, + "reflect.AppendSlice": ext۰reflect۰AppendSlice, + "reflect.Copy": ext۰reflect۰Copy, + "reflect.ChanOf": ext۰reflect۰ChanOf, + "reflect.DeepEqual": ext۰NoEffect, + "reflect.Indirect": ext۰reflect۰Indirect, + "reflect.MakeChan": ext۰reflect۰MakeChan, + "reflect.MakeFunc": ext۰reflect۰MakeFunc, + "reflect.MakeMap": ext۰reflect۰MakeMap, + "reflect.MakeSlice": ext۰reflect۰MakeSlice, + "reflect.MapOf": ext۰reflect۰MapOf, + "reflect.New": ext۰reflect۰New, + "reflect.NewAt": ext۰reflect۰NewAt, + "reflect.PtrTo": ext۰reflect۰PtrTo, + "reflect.Select": ext۰reflect۰Select, + "reflect.SliceOf": ext۰reflect۰SliceOf, + "reflect.TypeOf": ext۰reflect۰TypeOf, + "reflect.ValueOf": ext۰reflect۰ValueOf, + "reflect.Zero": ext۰reflect۰Zero, + "reflect.init": ext۰NoEffect, + + // *reflect.rtype methods + "(*reflect.rtype).Align": ext۰NoEffect, + "(*reflect.rtype).AssignableTo": ext۰NoEffect, + "(*reflect.rtype).Bits": ext۰NoEffect, + "(*reflect.rtype).ChanDir": ext۰NoEffect, + "(*reflect.rtype).ConvertibleTo": ext۰NoEffect, + "(*reflect.rtype).Elem": ext۰reflect۰rtype۰Elem, + "(*reflect.rtype).Field": ext۰reflect۰rtype۰Field, + "(*reflect.rtype).FieldAlign": ext۰NoEffect, + "(*reflect.rtype).FieldByIndex": ext۰reflect۰rtype۰FieldByIndex, + "(*reflect.rtype).FieldByName": ext۰reflect۰rtype۰FieldByName, + "(*reflect.rtype).FieldByNameFunc": ext۰reflect۰rtype۰FieldByNameFunc, + "(*reflect.rtype).Implements": ext۰NoEffect, + "(*reflect.rtype).In": ext۰reflect۰rtype۰In, + "(*reflect.rtype).IsVariadic": ext۰NoEffect, + "(*reflect.rtype).Key": ext۰reflect۰rtype۰Key, + "(*reflect.rtype).Kind": ext۰NoEffect, + "(*reflect.rtype).Len": ext۰NoEffect, + "(*reflect.rtype).Method": ext۰reflect۰rtype۰Method, + "(*reflect.rtype).MethodByName": ext۰reflect۰rtype۰MethodByName, + "(*reflect.rtype).Name": ext۰NoEffect, + "(*reflect.rtype).NumField": ext۰NoEffect, + "(*reflect.rtype).NumIn": ext۰NoEffect, + "(*reflect.rtype).NumMethod": ext۰NoEffect, + "(*reflect.rtype).NumOut": ext۰NoEffect, + "(*reflect.rtype).Out": ext۰reflect۰rtype۰Out, + "(*reflect.rtype).PkgPath": ext۰NoEffect, + "(*reflect.rtype).Size": ext۰NoEffect, + "(*reflect.rtype).String": ext۰NoEffect, + } { + intrinsicsByName[name] = fn + } +} + +// -------------------- (reflect.Value) -------------------- + +func ext۰reflect۰Value۰Addr(a *analysis, cgn *cgnode) {} // TODO(adonovan) + +// ---------- func (Value).Bytes() Value ---------- + +// result = v.Bytes() +type rVBytesConstraint struct { + v nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *rVBytesConstraint) ptr() nodeid { return c.v } +func (c *rVBytesConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "rVBytes.result") +} +func (c *rVBytesConstraint) renumber(mapping []nodeid) { + c.v = mapping[c.v] + c.result = mapping[c.result] +} + +func (c *rVBytesConstraint) String() string { + return fmt.Sprintf("n%d = reflect n%d.Bytes()", c.result, c.v) +} + +func (c *rVBytesConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + vObj := nodeid(x) + tDyn, slice, indirect := a.taggedValue(vObj) + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + tSlice, ok := tDyn.Underlying().(*types.Slice) + if ok && types.Identical(tSlice.Elem(), types.Typ[types.Uint8]) { + if a.onlineCopy(c.result, slice) { + changed = true + } + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰Value۰Bytes(a *analysis, cgn *cgnode) { + a.addConstraint(&rVBytesConstraint{ + v: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// ---------- func (Value).Call(in []Value) []Value ---------- + +// result = v.Call(in) +type rVCallConstraint struct { + cgn *cgnode + targets nodeid // (indirect) + v nodeid // (ptr) + arg nodeid // = in[*] + result nodeid // (indirect) + dotdotdot bool // interpret last arg as a "..." slice +} + +func (c *rVCallConstraint) ptr() nodeid { return c.v } +func (c *rVCallConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.targets), "rVCall.targets") + h.markIndirect(onodeid(c.result), "rVCall.result") +} +func (c *rVCallConstraint) renumber(mapping []nodeid) { + c.targets = mapping[c.targets] + c.v = mapping[c.v] + c.arg = mapping[c.arg] + c.result = mapping[c.result] +} + +func (c *rVCallConstraint) String() string { + return fmt.Sprintf("n%d = reflect n%d.Call(n%d)", c.result, c.v, c.arg) +} + +func (c *rVCallConstraint) solve(a *analysis, delta *nodeset) { + if c.targets == 0 { + panic("no targets") + } + + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + vObj := nodeid(x) + tDyn, fn, indirect := a.taggedValue(vObj) + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + tSig, ok := tDyn.Underlying().(*types.Signature) + if !ok { + continue // not a function + } + if tSig.Recv() != nil { + panic(tSig) // TODO(adonovan): rethink when we implement Method() + } + + // Add dynamic call target. + if a.onlineCopy(c.targets, fn) { + a.addWork(c.targets) + // TODO(adonovan): is 'else continue' a sound optimisation here? + } + + // Allocate a P/R block. + tParams := tSig.Params() + tResults := tSig.Results() + params := a.addNodes(tParams, "rVCall.params") + results := a.addNodes(tResults, "rVCall.results") + + // Make a dynamic call to 'fn'. + a.store(fn, params, 1, a.sizeof(tParams)) + a.load(results, fn, 1+a.sizeof(tParams), a.sizeof(tResults)) + + // Populate P by type-asserting each actual arg (all merged in c.arg). + for i, n := 0, tParams.Len(); i < n; i++ { + T := tParams.At(i).Type() + a.typeAssert(T, params, c.arg, false) + params += nodeid(a.sizeof(T)) + } + + // Use R by tagging and copying each actual result to c.result. + for i, n := 0, tResults.Len(); i < n; i++ { + T := tResults.At(i).Type() + // Convert from an arbitrary type to a reflect.Value + // (like MakeInterface followed by reflect.ValueOf). + if isInterface(T) { + // (don't tag) + if a.onlineCopy(c.result, results) { + changed = true + } + } else { + obj := a.makeTagged(T, c.cgn, nil) + a.onlineCopyN(obj+1, results, a.sizeof(T)) + if a.addLabel(c.result, obj) { // (true) + changed = true + } + } + results += nodeid(a.sizeof(T)) + } + } + if changed { + a.addWork(c.result) + } +} + +// Common code for direct (inlined) and indirect calls to (reflect.Value).Call. +func reflectCallImpl(a *analysis, cgn *cgnode, site *callsite, recv, arg nodeid, dotdotdot bool) nodeid { + // Allocate []reflect.Value array for the result. + ret := a.nextNode() + a.addNodes(types.NewArray(a.reflectValueObj.Type(), 1), "rVCall.ret") + a.endObject(ret, cgn, nil) + + // pts(targets) will be the set of possible call targets. + site.targets = a.addOneNode(tInvalid, "rvCall.targets", nil) + + // All arguments are merged since they arrive in a slice. + argelts := a.addOneNode(a.reflectValueObj.Type(), "rVCall.args", nil) + a.load(argelts, arg, 1, 1) // slice elements + + a.addConstraint(&rVCallConstraint{ + cgn: cgn, + targets: site.targets, + v: recv, + arg: argelts, + result: ret + 1, // results go into elements of ret + dotdotdot: dotdotdot, + }) + return ret +} + +func reflectCall(a *analysis, cgn *cgnode, dotdotdot bool) { + // This is the shared contour implementation of (reflect.Value).Call + // and CallSlice, as used by indirect calls (rare). + // Direct calls are inlined in gen.go, eliding the + // intermediate cgnode for Call. + site := new(callsite) + cgn.sites = append(cgn.sites, site) + recv := a.funcParams(cgn.obj) + arg := recv + 1 + ret := reflectCallImpl(a, cgn, site, recv, arg, dotdotdot) + a.addressOf(cgn.fn.Signature.Results().At(0).Type(), a.funcResults(cgn.obj), ret) +} + +func ext۰reflect۰Value۰Call(a *analysis, cgn *cgnode) { + reflectCall(a, cgn, false) +} + +func ext۰reflect۰Value۰CallSlice(a *analysis, cgn *cgnode) { + // TODO(adonovan): implement. Also, inline direct calls in gen.go too. + if false { + reflectCall(a, cgn, true) + } +} + +func ext۰reflect۰Value۰Convert(a *analysis, cgn *cgnode) {} // TODO(adonovan) + +// ---------- func (Value).Elem() Value ---------- + +// result = v.Elem() +type rVElemConstraint struct { + cgn *cgnode + v nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *rVElemConstraint) ptr() nodeid { return c.v } +func (c *rVElemConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "rVElem.result") +} +func (c *rVElemConstraint) renumber(mapping []nodeid) { + c.v = mapping[c.v] + c.result = mapping[c.result] +} + +func (c *rVElemConstraint) String() string { + return fmt.Sprintf("n%d = reflect n%d.Elem()", c.result, c.v) +} + +func (c *rVElemConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + vObj := nodeid(x) + tDyn, payload, indirect := a.taggedValue(vObj) + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + switch t := tDyn.Underlying().(type) { + case *types.Interface: + if a.onlineCopy(c.result, payload) { + changed = true + } + + case *types.Pointer: + obj := a.makeTagged(t.Elem(), c.cgn, nil) + a.load(obj+1, payload, 0, a.sizeof(t.Elem())) + if a.addLabel(c.result, obj) { + changed = true + } + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰Value۰Elem(a *analysis, cgn *cgnode) { + a.addConstraint(&rVElemConstraint{ + cgn: cgn, + v: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +func ext۰reflect۰Value۰Field(a *analysis, cgn *cgnode) {} // TODO(adonovan) +func ext۰reflect۰Value۰FieldByIndex(a *analysis, cgn *cgnode) {} // TODO(adonovan) +func ext۰reflect۰Value۰FieldByName(a *analysis, cgn *cgnode) {} // TODO(adonovan) +func ext۰reflect۰Value۰FieldByNameFunc(a *analysis, cgn *cgnode) {} // TODO(adonovan) + +// ---------- func (Value).Index() Value ---------- + +// result = v.Index() +type rVIndexConstraint struct { + cgn *cgnode + v nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *rVIndexConstraint) ptr() nodeid { return c.v } +func (c *rVIndexConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "rVIndex.result") +} +func (c *rVIndexConstraint) renumber(mapping []nodeid) { + c.v = mapping[c.v] + c.result = mapping[c.result] +} + +func (c *rVIndexConstraint) String() string { + return fmt.Sprintf("n%d = reflect n%d.Index()", c.result, c.v) +} + +func (c *rVIndexConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + vObj := nodeid(x) + tDyn, payload, indirect := a.taggedValue(vObj) + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + var res nodeid + switch t := tDyn.Underlying().(type) { + case *types.Array: + res = a.makeTagged(t.Elem(), c.cgn, nil) + a.onlineCopyN(res+1, payload+1, a.sizeof(t.Elem())) + + case *types.Slice: + res = a.makeTagged(t.Elem(), c.cgn, nil) + a.load(res+1, payload, 1, a.sizeof(t.Elem())) + + case *types.Basic: + if t.Kind() == types.String { + res = a.makeTagged(types.Typ[types.Rune], c.cgn, nil) + } + } + if res != 0 && a.addLabel(c.result, res) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰Value۰Index(a *analysis, cgn *cgnode) { + a.addConstraint(&rVIndexConstraint{ + cgn: cgn, + v: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// ---------- func (Value).Interface() Value ---------- + +// result = v.Interface() +type rVInterfaceConstraint struct { + v nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *rVInterfaceConstraint) ptr() nodeid { return c.v } +func (c *rVInterfaceConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "rVInterface.result") +} +func (c *rVInterfaceConstraint) renumber(mapping []nodeid) { + c.v = mapping[c.v] + c.result = mapping[c.result] +} + +func (c *rVInterfaceConstraint) String() string { + return fmt.Sprintf("n%d = reflect n%d.Interface()", c.result, c.v) +} + +func (c *rVInterfaceConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + vObj := nodeid(x) + tDyn, payload, indirect := a.taggedValue(vObj) + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + if isInterface(tDyn) { + if a.onlineCopy(c.result, payload) { + a.addWork(c.result) + } + } else { + if a.addLabel(c.result, vObj) { + changed = true + } + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰Value۰Interface(a *analysis, cgn *cgnode) { + a.addConstraint(&rVInterfaceConstraint{ + v: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// ---------- func (Value).MapIndex(Value) Value ---------- + +// result = v.MapIndex(_) +type rVMapIndexConstraint struct { + cgn *cgnode + v nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *rVMapIndexConstraint) ptr() nodeid { return c.v } +func (c *rVMapIndexConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "rVMapIndex.result") +} +func (c *rVMapIndexConstraint) renumber(mapping []nodeid) { + c.v = mapping[c.v] + c.result = mapping[c.result] +} + +func (c *rVMapIndexConstraint) String() string { + return fmt.Sprintf("n%d = reflect n%d.MapIndex(_)", c.result, c.v) +} + +func (c *rVMapIndexConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + vObj := nodeid(x) + tDyn, m, indirect := a.taggedValue(vObj) + tMap, _ := tDyn.Underlying().(*types.Map) + if tMap == nil { + continue // not a map + } + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + obj := a.makeTagged(tMap.Elem(), c.cgn, nil) + a.load(obj+1, m, a.sizeof(tMap.Key()), a.sizeof(tMap.Elem())) + if a.addLabel(c.result, obj) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰Value۰MapIndex(a *analysis, cgn *cgnode) { + a.addConstraint(&rVMapIndexConstraint{ + cgn: cgn, + v: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// ---------- func (Value).MapKeys() []Value ---------- + +// result = v.MapKeys() +type rVMapKeysConstraint struct { + cgn *cgnode + v nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *rVMapKeysConstraint) ptr() nodeid { return c.v } +func (c *rVMapKeysConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "rVMapKeys.result") +} +func (c *rVMapKeysConstraint) renumber(mapping []nodeid) { + c.v = mapping[c.v] + c.result = mapping[c.result] +} + +func (c *rVMapKeysConstraint) String() string { + return fmt.Sprintf("n%d = reflect n%d.MapKeys()", c.result, c.v) +} + +func (c *rVMapKeysConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + vObj := nodeid(x) + tDyn, m, indirect := a.taggedValue(vObj) + tMap, _ := tDyn.Underlying().(*types.Map) + if tMap == nil { + continue // not a map + } + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + kObj := a.makeTagged(tMap.Key(), c.cgn, nil) + a.load(kObj+1, m, 0, a.sizeof(tMap.Key())) + if a.addLabel(c.result, kObj) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰Value۰MapKeys(a *analysis, cgn *cgnode) { + // Allocate an array for the result. + obj := a.nextNode() + T := types.NewSlice(a.reflectValueObj.Type()) + a.addNodes(sliceToArray(T), "reflect.MapKeys result") + a.endObject(obj, cgn, nil) + a.addressOf(T, a.funcResults(cgn.obj), obj) + + a.addConstraint(&rVMapKeysConstraint{ + cgn: cgn, + v: a.funcParams(cgn.obj), + result: obj + 1, // result is stored in array elems + }) +} + +func ext۰reflect۰Value۰Method(a *analysis, cgn *cgnode) {} // TODO(adonovan) +func ext۰reflect۰Value۰MethodByName(a *analysis, cgn *cgnode) {} // TODO(adonovan) + +// ---------- func (Value).Recv(Value) Value ---------- + +// result, _ = v.Recv() +type rVRecvConstraint struct { + cgn *cgnode + v nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *rVRecvConstraint) ptr() nodeid { return c.v } +func (c *rVRecvConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "rVRecv.result") +} +func (c *rVRecvConstraint) renumber(mapping []nodeid) { + c.v = mapping[c.v] + c.result = mapping[c.result] +} + +func (c *rVRecvConstraint) String() string { + return fmt.Sprintf("n%d = reflect n%d.Recv()", c.result, c.v) +} + +func (c *rVRecvConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + vObj := nodeid(x) + tDyn, ch, indirect := a.taggedValue(vObj) + tChan, _ := tDyn.Underlying().(*types.Chan) + if tChan == nil { + continue // not a channel + } + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + tElem := tChan.Elem() + elemObj := a.makeTagged(tElem, c.cgn, nil) + a.load(elemObj+1, ch, 0, a.sizeof(tElem)) + if a.addLabel(c.result, elemObj) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰Value۰Recv(a *analysis, cgn *cgnode) { + a.addConstraint(&rVRecvConstraint{ + cgn: cgn, + v: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// ---------- func (Value).Send(Value) ---------- + +// v.Send(x) +type rVSendConstraint struct { + cgn *cgnode + v nodeid // (ptr) + x nodeid +} + +func (c *rVSendConstraint) ptr() nodeid { return c.v } +func (c *rVSendConstraint) presolve(*hvn) {} +func (c *rVSendConstraint) renumber(mapping []nodeid) { + c.v = mapping[c.v] + c.x = mapping[c.x] +} + +func (c *rVSendConstraint) String() string { + return fmt.Sprintf("reflect n%d.Send(n%d)", c.v, c.x) +} + +func (c *rVSendConstraint) solve(a *analysis, delta *nodeset) { + for _, x := range delta.AppendTo(a.deltaSpace) { + vObj := nodeid(x) + tDyn, ch, indirect := a.taggedValue(vObj) + tChan, _ := tDyn.Underlying().(*types.Chan) + if tChan == nil { + continue // not a channel + } + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + // Extract x's payload to xtmp, then store to channel. + tElem := tChan.Elem() + xtmp := a.addNodes(tElem, "Send.xtmp") + a.typeAssert(tElem, xtmp, c.x, false) + a.store(ch, xtmp, 0, a.sizeof(tElem)) + } +} + +func ext۰reflect۰Value۰Send(a *analysis, cgn *cgnode) { + params := a.funcParams(cgn.obj) + a.addConstraint(&rVSendConstraint{ + cgn: cgn, + v: params, + x: params + 1, + }) +} + +func ext۰reflect۰Value۰Set(a *analysis, cgn *cgnode) {} // TODO(adonovan) + +// ---------- func (Value).SetBytes(x []byte) ---------- + +// v.SetBytes(x) +type rVSetBytesConstraint struct { + cgn *cgnode + v nodeid // (ptr) + x nodeid +} + +func (c *rVSetBytesConstraint) ptr() nodeid { return c.v } +func (c *rVSetBytesConstraint) presolve(*hvn) {} +func (c *rVSetBytesConstraint) renumber(mapping []nodeid) { + c.v = mapping[c.v] + c.x = mapping[c.x] +} + +func (c *rVSetBytesConstraint) String() string { + return fmt.Sprintf("reflect n%d.SetBytes(n%d)", c.v, c.x) +} + +func (c *rVSetBytesConstraint) solve(a *analysis, delta *nodeset) { + for _, x := range delta.AppendTo(a.deltaSpace) { + vObj := nodeid(x) + tDyn, slice, indirect := a.taggedValue(vObj) + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + tSlice, ok := tDyn.Underlying().(*types.Slice) + if ok && types.Identical(tSlice.Elem(), types.Typ[types.Uint8]) { + if a.onlineCopy(slice, c.x) { + a.addWork(slice) + } + } + } +} + +func ext۰reflect۰Value۰SetBytes(a *analysis, cgn *cgnode) { + params := a.funcParams(cgn.obj) + a.addConstraint(&rVSetBytesConstraint{ + cgn: cgn, + v: params, + x: params + 1, + }) +} + +// ---------- func (Value).SetMapIndex(k Value, v Value) ---------- + +// v.SetMapIndex(key, val) +type rVSetMapIndexConstraint struct { + cgn *cgnode + v nodeid // (ptr) + key nodeid + val nodeid +} + +func (c *rVSetMapIndexConstraint) ptr() nodeid { return c.v } +func (c *rVSetMapIndexConstraint) presolve(*hvn) {} +func (c *rVSetMapIndexConstraint) renumber(mapping []nodeid) { + c.v = mapping[c.v] + c.key = mapping[c.key] + c.val = mapping[c.val] +} + +func (c *rVSetMapIndexConstraint) String() string { + return fmt.Sprintf("reflect n%d.SetMapIndex(n%d, n%d)", c.v, c.key, c.val) +} + +func (c *rVSetMapIndexConstraint) solve(a *analysis, delta *nodeset) { + for _, x := range delta.AppendTo(a.deltaSpace) { + vObj := nodeid(x) + tDyn, m, indirect := a.taggedValue(vObj) + tMap, _ := tDyn.Underlying().(*types.Map) + if tMap == nil { + continue // not a map + } + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + keysize := a.sizeof(tMap.Key()) + + // Extract key's payload to keytmp, then store to map key. + keytmp := a.addNodes(tMap.Key(), "SetMapIndex.keytmp") + a.typeAssert(tMap.Key(), keytmp, c.key, false) + a.store(m, keytmp, 0, keysize) + + // Extract val's payload to vtmp, then store to map value. + valtmp := a.addNodes(tMap.Elem(), "SetMapIndex.valtmp") + a.typeAssert(tMap.Elem(), valtmp, c.val, false) + a.store(m, valtmp, keysize, a.sizeof(tMap.Elem())) + } +} + +func ext۰reflect۰Value۰SetMapIndex(a *analysis, cgn *cgnode) { + params := a.funcParams(cgn.obj) + a.addConstraint(&rVSetMapIndexConstraint{ + cgn: cgn, + v: params, + key: params + 1, + val: params + 2, + }) +} + +func ext۰reflect۰Value۰SetPointer(a *analysis, cgn *cgnode) {} // TODO(adonovan) + +// ---------- func (Value).Slice(v Value, i, j int) Value ---------- + +// result = v.Slice(_, _) +type rVSliceConstraint struct { + cgn *cgnode + v nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *rVSliceConstraint) ptr() nodeid { return c.v } +func (c *rVSliceConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "rVSlice.result") +} +func (c *rVSliceConstraint) renumber(mapping []nodeid) { + c.v = mapping[c.v] + c.result = mapping[c.result] +} + +func (c *rVSliceConstraint) String() string { + return fmt.Sprintf("n%d = reflect n%d.Slice(_, _)", c.result, c.v) +} + +func (c *rVSliceConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + vObj := nodeid(x) + tDyn, payload, indirect := a.taggedValue(vObj) + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + var res nodeid + switch t := tDyn.Underlying().(type) { + case *types.Pointer: + if tArr, ok := t.Elem().Underlying().(*types.Array); ok { + // pointer to array + res = a.makeTagged(types.NewSlice(tArr.Elem()), c.cgn, nil) + if a.onlineCopy(res+1, payload) { + a.addWork(res + 1) + } + } + + case *types.Array: + // TODO(adonovan): implement addressable + // arrays when we do indirect tagged objects. + + case *types.Slice: + res = vObj + + case *types.Basic: + if t == types.Typ[types.String] { + res = vObj + } + } + + if res != 0 && a.addLabel(c.result, res) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰Value۰Slice(a *analysis, cgn *cgnode) { + a.addConstraint(&rVSliceConstraint{ + cgn: cgn, + v: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// -------------------- Standalone reflect functions -------------------- + +func ext۰reflect۰Append(a *analysis, cgn *cgnode) {} // TODO(adonovan) +func ext۰reflect۰AppendSlice(a *analysis, cgn *cgnode) {} // TODO(adonovan) +func ext۰reflect۰Copy(a *analysis, cgn *cgnode) {} // TODO(adonovan) + +// ---------- func ChanOf(ChanDir, Type) Type ---------- + +// result = ChanOf(dir, t) +type reflectChanOfConstraint struct { + cgn *cgnode + t nodeid // (ptr) + result nodeid // (indirect) + dirs []types.ChanDir +} + +func (c *reflectChanOfConstraint) ptr() nodeid { return c.t } +func (c *reflectChanOfConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "reflectChanOf.result") +} +func (c *reflectChanOfConstraint) renumber(mapping []nodeid) { + c.t = mapping[c.t] + c.result = mapping[c.result] +} + +func (c *reflectChanOfConstraint) String() string { + return fmt.Sprintf("n%d = reflect.ChanOf(n%d)", c.result, c.t) +} + +func (c *reflectChanOfConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + tObj := nodeid(x) + T := a.rtypeTaggedValue(tObj) + + if typeTooHigh(T) { + continue + } + + for _, dir := range c.dirs { + if a.addLabel(c.result, a.makeRtype(types.NewChan(dir, T))) { + changed = true + } + } + } + if changed { + a.addWork(c.result) + } +} + +// dirMap maps reflect.ChanDir to the set of channel types generated by ChanOf. +var dirMap = [...][]types.ChanDir{ + 0: {types.SendOnly, types.RecvOnly, types.SendRecv}, // unknown + reflect.RecvDir: {types.RecvOnly}, + reflect.SendDir: {types.SendOnly}, + reflect.BothDir: {types.SendRecv}, +} + +func ext۰reflect۰ChanOf(a *analysis, cgn *cgnode) { + // If we have access to the callsite, + // and the channel argument is a constant (as is usual), + // only generate the requested direction. + var dir reflect.ChanDir // unknown + if site := cgn.callersite; site != nil { + if c, ok := site.instr.Common().Args[0].(*ssa.Const); ok { + v, _ := constant.Int64Val(c.Value) + if 0 <= v && v <= int64(reflect.BothDir) { + dir = reflect.ChanDir(v) + } + } + } + + params := a.funcParams(cgn.obj) + a.addConstraint(&reflectChanOfConstraint{ + cgn: cgn, + t: params + 1, + result: a.funcResults(cgn.obj), + dirs: dirMap[dir], + }) +} + +// ---------- func Indirect(v Value) Value ---------- + +// result = Indirect(v) +type reflectIndirectConstraint struct { + cgn *cgnode + v nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *reflectIndirectConstraint) ptr() nodeid { return c.v } +func (c *reflectIndirectConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "reflectIndirect.result") +} +func (c *reflectIndirectConstraint) renumber(mapping []nodeid) { + c.v = mapping[c.v] + c.result = mapping[c.result] +} + +func (c *reflectIndirectConstraint) String() string { + return fmt.Sprintf("n%d = reflect.Indirect(n%d)", c.result, c.v) +} + +func (c *reflectIndirectConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + vObj := nodeid(x) + tDyn, _, _ := a.taggedValue(vObj) + var res nodeid + if tPtr, ok := tDyn.Underlying().(*types.Pointer); ok { + // load the payload of the pointer's tagged object + // into a new tagged object + res = a.makeTagged(tPtr.Elem(), c.cgn, nil) + a.load(res+1, vObj+1, 0, a.sizeof(tPtr.Elem())) + } else { + res = vObj + } + + if a.addLabel(c.result, res) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰Indirect(a *analysis, cgn *cgnode) { + a.addConstraint(&reflectIndirectConstraint{ + cgn: cgn, + v: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// ---------- func MakeChan(Type) Value ---------- + +// result = MakeChan(typ) +type reflectMakeChanConstraint struct { + cgn *cgnode + typ nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *reflectMakeChanConstraint) ptr() nodeid { return c.typ } +func (c *reflectMakeChanConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "reflectMakeChan.result") +} +func (c *reflectMakeChanConstraint) renumber(mapping []nodeid) { + c.typ = mapping[c.typ] + c.result = mapping[c.result] +} + +func (c *reflectMakeChanConstraint) String() string { + return fmt.Sprintf("n%d = reflect.MakeChan(n%d)", c.result, c.typ) +} + +func (c *reflectMakeChanConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + typObj := nodeid(x) + T := a.rtypeTaggedValue(typObj) + tChan, ok := T.Underlying().(*types.Chan) + if !ok || tChan.Dir() != types.SendRecv { + continue // not a bidirectional channel type + } + + obj := a.nextNode() + a.addNodes(tChan.Elem(), "reflect.MakeChan.value") + a.endObject(obj, c.cgn, nil) + + // put its address in a new T-tagged object + id := a.makeTagged(T, c.cgn, nil) + a.addLabel(id+1, obj) + + // flow the T-tagged object to the result + if a.addLabel(c.result, id) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰MakeChan(a *analysis, cgn *cgnode) { + a.addConstraint(&reflectMakeChanConstraint{ + cgn: cgn, + typ: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +func ext۰reflect۰MakeFunc(a *analysis, cgn *cgnode) {} // TODO(adonovan) + +// ---------- func MakeMap(Type) Value ---------- + +// result = MakeMap(typ) +type reflectMakeMapConstraint struct { + cgn *cgnode + typ nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *reflectMakeMapConstraint) ptr() nodeid { return c.typ } +func (c *reflectMakeMapConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "reflectMakeMap.result") +} +func (c *reflectMakeMapConstraint) renumber(mapping []nodeid) { + c.typ = mapping[c.typ] + c.result = mapping[c.result] +} + +func (c *reflectMakeMapConstraint) String() string { + return fmt.Sprintf("n%d = reflect.MakeMap(n%d)", c.result, c.typ) +} + +func (c *reflectMakeMapConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + typObj := nodeid(x) + T := a.rtypeTaggedValue(typObj) + tMap, ok := T.Underlying().(*types.Map) + if !ok { + continue // not a map type + } + + mapObj := a.nextNode() + a.addNodes(tMap.Key(), "reflect.MakeMap.key") + a.addNodes(tMap.Elem(), "reflect.MakeMap.value") + a.endObject(mapObj, c.cgn, nil) + + // put its address in a new T-tagged object + id := a.makeTagged(T, c.cgn, nil) + a.addLabel(id+1, mapObj) + + // flow the T-tagged object to the result + if a.addLabel(c.result, id) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰MakeMap(a *analysis, cgn *cgnode) { + a.addConstraint(&reflectMakeMapConstraint{ + cgn: cgn, + typ: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// ---------- func MakeSlice(Type) Value ---------- + +// result = MakeSlice(typ) +type reflectMakeSliceConstraint struct { + cgn *cgnode + typ nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *reflectMakeSliceConstraint) ptr() nodeid { return c.typ } +func (c *reflectMakeSliceConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "reflectMakeSlice.result") +} +func (c *reflectMakeSliceConstraint) renumber(mapping []nodeid) { + c.typ = mapping[c.typ] + c.result = mapping[c.result] +} + +func (c *reflectMakeSliceConstraint) String() string { + return fmt.Sprintf("n%d = reflect.MakeSlice(n%d)", c.result, c.typ) +} + +func (c *reflectMakeSliceConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + typObj := nodeid(x) + T := a.rtypeTaggedValue(typObj) + if _, ok := T.Underlying().(*types.Slice); !ok { + continue // not a slice type + } + + obj := a.nextNode() + a.addNodes(sliceToArray(T), "reflect.MakeSlice") + a.endObject(obj, c.cgn, nil) + + // put its address in a new T-tagged object + id := a.makeTagged(T, c.cgn, nil) + a.addLabel(id+1, obj) + + // flow the T-tagged object to the result + if a.addLabel(c.result, id) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰MakeSlice(a *analysis, cgn *cgnode) { + a.addConstraint(&reflectMakeSliceConstraint{ + cgn: cgn, + typ: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +func ext۰reflect۰MapOf(a *analysis, cgn *cgnode) {} // TODO(adonovan) + +// ---------- func New(Type) Value ---------- + +// result = New(typ) +type reflectNewConstraint struct { + cgn *cgnode + typ nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *reflectNewConstraint) ptr() nodeid { return c.typ } +func (c *reflectNewConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "reflectNew.result") +} +func (c *reflectNewConstraint) renumber(mapping []nodeid) { + c.typ = mapping[c.typ] + c.result = mapping[c.result] +} + +func (c *reflectNewConstraint) String() string { + return fmt.Sprintf("n%d = reflect.New(n%d)", c.result, c.typ) +} + +func (c *reflectNewConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + typObj := nodeid(x) + T := a.rtypeTaggedValue(typObj) + + // allocate new T object + newObj := a.nextNode() + a.addNodes(T, "reflect.New") + a.endObject(newObj, c.cgn, nil) + + // put its address in a new *T-tagged object + id := a.makeTagged(types.NewPointer(T), c.cgn, nil) + a.addLabel(id+1, newObj) + + // flow the pointer to the result + if a.addLabel(c.result, id) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰New(a *analysis, cgn *cgnode) { + a.addConstraint(&reflectNewConstraint{ + cgn: cgn, + typ: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +func ext۰reflect۰NewAt(a *analysis, cgn *cgnode) { + ext۰reflect۰New(a, cgn) + + // TODO(adonovan): also report dynamic calls to unsound intrinsics. + if site := cgn.callersite; site != nil { + a.warnf(site.pos(), "unsound: %s contains a reflect.NewAt() call", site.instr.Parent()) + } +} + +// ---------- func PtrTo(Type) Type ---------- + +// result = PtrTo(t) +type reflectPtrToConstraint struct { + cgn *cgnode + t nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *reflectPtrToConstraint) ptr() nodeid { return c.t } +func (c *reflectPtrToConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "reflectPtrTo.result") +} +func (c *reflectPtrToConstraint) renumber(mapping []nodeid) { + c.t = mapping[c.t] + c.result = mapping[c.result] +} + +func (c *reflectPtrToConstraint) String() string { + return fmt.Sprintf("n%d = reflect.PtrTo(n%d)", c.result, c.t) +} + +func (c *reflectPtrToConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + tObj := nodeid(x) + T := a.rtypeTaggedValue(tObj) + + if typeTooHigh(T) { + continue + } + + if a.addLabel(c.result, a.makeRtype(types.NewPointer(T))) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰PtrTo(a *analysis, cgn *cgnode) { + a.addConstraint(&reflectPtrToConstraint{ + cgn: cgn, + t: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +func ext۰reflect۰Select(a *analysis, cgn *cgnode) {} // TODO(adonovan) + +// ---------- func SliceOf(Type) Type ---------- + +// result = SliceOf(t) +type reflectSliceOfConstraint struct { + cgn *cgnode + t nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *reflectSliceOfConstraint) ptr() nodeid { return c.t } +func (c *reflectSliceOfConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "reflectSliceOf.result") +} +func (c *reflectSliceOfConstraint) renumber(mapping []nodeid) { + c.t = mapping[c.t] + c.result = mapping[c.result] +} + +func (c *reflectSliceOfConstraint) String() string { + return fmt.Sprintf("n%d = reflect.SliceOf(n%d)", c.result, c.t) +} + +func (c *reflectSliceOfConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + tObj := nodeid(x) + T := a.rtypeTaggedValue(tObj) + + if typeTooHigh(T) { + continue + } + + if a.addLabel(c.result, a.makeRtype(types.NewSlice(T))) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰SliceOf(a *analysis, cgn *cgnode) { + a.addConstraint(&reflectSliceOfConstraint{ + cgn: cgn, + t: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// ---------- func TypeOf(v Value) Type ---------- + +// result = TypeOf(i) +type reflectTypeOfConstraint struct { + cgn *cgnode + i nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *reflectTypeOfConstraint) ptr() nodeid { return c.i } +func (c *reflectTypeOfConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "reflectTypeOf.result") +} +func (c *reflectTypeOfConstraint) renumber(mapping []nodeid) { + c.i = mapping[c.i] + c.result = mapping[c.result] +} + +func (c *reflectTypeOfConstraint) String() string { + return fmt.Sprintf("n%d = reflect.TypeOf(n%d)", c.result, c.i) +} + +func (c *reflectTypeOfConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + iObj := nodeid(x) + tDyn, _, _ := a.taggedValue(iObj) + if a.addLabel(c.result, a.makeRtype(tDyn)) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰TypeOf(a *analysis, cgn *cgnode) { + a.addConstraint(&reflectTypeOfConstraint{ + cgn: cgn, + i: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// ---------- func ValueOf(interface{}) Value ---------- + +func ext۰reflect۰ValueOf(a *analysis, cgn *cgnode) { + // TODO(adonovan): when we start creating indirect tagged + // objects, we'll need to handle them specially here since + // they must never appear in the PTS of an interface{}. + a.copy(a.funcResults(cgn.obj), a.funcParams(cgn.obj), 1) +} + +// ---------- func Zero(Type) Value ---------- + +// result = Zero(typ) +type reflectZeroConstraint struct { + cgn *cgnode + typ nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *reflectZeroConstraint) ptr() nodeid { return c.typ } +func (c *reflectZeroConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "reflectZero.result") +} +func (c *reflectZeroConstraint) renumber(mapping []nodeid) { + c.typ = mapping[c.typ] + c.result = mapping[c.result] +} + +func (c *reflectZeroConstraint) String() string { + return fmt.Sprintf("n%d = reflect.Zero(n%d)", c.result, c.typ) +} + +func (c *reflectZeroConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + typObj := nodeid(x) + T := a.rtypeTaggedValue(typObj) + + // TODO(adonovan): if T is an interface type, we need + // to create an indirect tagged object containing + // new(T). To avoid updates of such shared values, + // we'll need another flag on indirect tagged objects + // that marks whether they are addressable or + // readonly, just like the reflect package does. + + // memoize using a.reflectZeros[T] + var id nodeid + if z := a.reflectZeros.At(T); false && z != nil { + id = z.(nodeid) + } else { + id = a.makeTagged(T, c.cgn, nil) + a.reflectZeros.Set(T, id) + } + if a.addLabel(c.result, id) { + changed = true + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰Zero(a *analysis, cgn *cgnode) { + a.addConstraint(&reflectZeroConstraint{ + cgn: cgn, + typ: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// -------------------- (*reflect.rtype) methods -------------------- + +// ---------- func (*rtype) Elem() Type ---------- + +// result = Elem(t) +type rtypeElemConstraint struct { + cgn *cgnode + t nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *rtypeElemConstraint) ptr() nodeid { return c.t } +func (c *rtypeElemConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "rtypeElem.result") +} +func (c *rtypeElemConstraint) renumber(mapping []nodeid) { + c.t = mapping[c.t] + c.result = mapping[c.result] +} + +func (c *rtypeElemConstraint) String() string { + return fmt.Sprintf("n%d = (*reflect.rtype).Elem(n%d)", c.result, c.t) +} + +func (c *rtypeElemConstraint) solve(a *analysis, delta *nodeset) { + // Implemented by *types.{Map,Chan,Array,Slice,Pointer}. + type hasElem interface { + Elem() types.Type + } + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + tObj := nodeid(x) + T := a.nodes[tObj].obj.data.(types.Type) + if tHasElem, ok := T.Underlying().(hasElem); ok { + if a.addLabel(c.result, a.makeRtype(tHasElem.Elem())) { + changed = true + } + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰rtype۰Elem(a *analysis, cgn *cgnode) { + a.addConstraint(&rtypeElemConstraint{ + cgn: cgn, + t: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// ---------- func (*rtype) Field(int) StructField ---------- +// ---------- func (*rtype) FieldByName(string) (StructField, bool) ---------- + +// result = FieldByName(t, name) +// result = Field(t, _) +type rtypeFieldByNameConstraint struct { + cgn *cgnode + name string // name of field; "" for unknown + t nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *rtypeFieldByNameConstraint) ptr() nodeid { return c.t } +func (c *rtypeFieldByNameConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result+3), "rtypeFieldByName.result.Type") +} +func (c *rtypeFieldByNameConstraint) renumber(mapping []nodeid) { + c.t = mapping[c.t] + c.result = mapping[c.result] +} + +func (c *rtypeFieldByNameConstraint) String() string { + return fmt.Sprintf("n%d = (*reflect.rtype).FieldByName(n%d, %q)", c.result, c.t, c.name) +} + +func (c *rtypeFieldByNameConstraint) solve(a *analysis, delta *nodeset) { + // type StructField struct { + // 0 __identity__ + // 1 Name string + // 2 PkgPath string + // 3 Type Type + // 4 Tag StructTag + // 5 Offset uintptr + // 6 Index []int + // 7 Anonymous bool + // } + + for _, x := range delta.AppendTo(a.deltaSpace) { + tObj := nodeid(x) + T := a.nodes[tObj].obj.data.(types.Type) + tStruct, ok := T.Underlying().(*types.Struct) + if !ok { + continue // not a struct type + } + + n := tStruct.NumFields() + for i := 0; i < n; i++ { + f := tStruct.Field(i) + if c.name == "" || c.name == f.Name() { + + // a.offsetOf(Type) is 3. + if id := c.result + 3; a.addLabel(id, a.makeRtype(f.Type())) { + a.addWork(id) + } + // TODO(adonovan): StructField.Index should be non-nil. + } + } + } +} + +func ext۰reflect۰rtype۰FieldByName(a *analysis, cgn *cgnode) { + // If we have access to the callsite, + // and the argument is a string constant, + // return only that field. + var name string + if site := cgn.callersite; site != nil { + if c, ok := site.instr.Common().Args[0].(*ssa.Const); ok { + name = constant.StringVal(c.Value) + } + } + + a.addConstraint(&rtypeFieldByNameConstraint{ + cgn: cgn, + name: name, + t: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +func ext۰reflect۰rtype۰Field(a *analysis, cgn *cgnode) { + // No-one ever calls Field with a constant argument, + // so we don't specialize that case. + a.addConstraint(&rtypeFieldByNameConstraint{ + cgn: cgn, + t: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +func ext۰reflect۰rtype۰FieldByIndex(a *analysis, cgn *cgnode) {} // TODO(adonovan) +func ext۰reflect۰rtype۰FieldByNameFunc(a *analysis, cgn *cgnode) {} // TODO(adonovan) + +// ---------- func (*rtype) In/Out(i int) Type ---------- + +// result = In/Out(t, i) +type rtypeInOutConstraint struct { + cgn *cgnode + t nodeid // (ptr) + result nodeid // (indirect) + out bool + i int // -ve if not a constant +} + +func (c *rtypeInOutConstraint) ptr() nodeid { return c.t } +func (c *rtypeInOutConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "rtypeInOut.result") +} +func (c *rtypeInOutConstraint) renumber(mapping []nodeid) { + c.t = mapping[c.t] + c.result = mapping[c.result] +} + +func (c *rtypeInOutConstraint) String() string { + return fmt.Sprintf("n%d = (*reflect.rtype).InOut(n%d, %d)", c.result, c.t, c.i) +} + +func (c *rtypeInOutConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + tObj := nodeid(x) + T := a.nodes[tObj].obj.data.(types.Type) + sig, ok := T.Underlying().(*types.Signature) + if !ok { + continue // not a func type + } + + tuple := sig.Params() + if c.out { + tuple = sig.Results() + } + for i, n := 0, tuple.Len(); i < n; i++ { + if c.i < 0 || c.i == i { + if a.addLabel(c.result, a.makeRtype(tuple.At(i).Type())) { + changed = true + } + } + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰rtype۰InOut(a *analysis, cgn *cgnode, out bool) { + // If we have access to the callsite, + // and the argument is an int constant, + // return only that parameter. + index := -1 + if site := cgn.callersite; site != nil { + if c, ok := site.instr.Common().Args[0].(*ssa.Const); ok { + v, _ := constant.Int64Val(c.Value) + index = int(v) + } + } + a.addConstraint(&rtypeInOutConstraint{ + cgn: cgn, + t: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + out: out, + i: index, + }) +} + +func ext۰reflect۰rtype۰In(a *analysis, cgn *cgnode) { + ext۰reflect۰rtype۰InOut(a, cgn, false) +} + +func ext۰reflect۰rtype۰Out(a *analysis, cgn *cgnode) { + ext۰reflect۰rtype۰InOut(a, cgn, true) +} + +// ---------- func (*rtype) Key() Type ---------- + +// result = Key(t) +type rtypeKeyConstraint struct { + cgn *cgnode + t nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *rtypeKeyConstraint) ptr() nodeid { return c.t } +func (c *rtypeKeyConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result), "rtypeKey.result") +} +func (c *rtypeKeyConstraint) renumber(mapping []nodeid) { + c.t = mapping[c.t] + c.result = mapping[c.result] +} + +func (c *rtypeKeyConstraint) String() string { + return fmt.Sprintf("n%d = (*reflect.rtype).Key(n%d)", c.result, c.t) +} + +func (c *rtypeKeyConstraint) solve(a *analysis, delta *nodeset) { + changed := false + for _, x := range delta.AppendTo(a.deltaSpace) { + tObj := nodeid(x) + T := a.nodes[tObj].obj.data.(types.Type) + if tMap, ok := T.Underlying().(*types.Map); ok { + if a.addLabel(c.result, a.makeRtype(tMap.Key())) { + changed = true + } + } + } + if changed { + a.addWork(c.result) + } +} + +func ext۰reflect۰rtype۰Key(a *analysis, cgn *cgnode) { + a.addConstraint(&rtypeKeyConstraint{ + cgn: cgn, + t: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// ---------- func (*rtype) Method(int) (Method, bool) ---------- +// ---------- func (*rtype) MethodByName(string) (Method, bool) ---------- + +// result = MethodByName(t, name) +// result = Method(t, _) +type rtypeMethodByNameConstraint struct { + cgn *cgnode + name string // name of method; "" for unknown + t nodeid // (ptr) + result nodeid // (indirect) +} + +func (c *rtypeMethodByNameConstraint) ptr() nodeid { return c.t } +func (c *rtypeMethodByNameConstraint) presolve(h *hvn) { + h.markIndirect(onodeid(c.result+3), "rtypeMethodByName.result.Type") + h.markIndirect(onodeid(c.result+4), "rtypeMethodByName.result.Func") +} +func (c *rtypeMethodByNameConstraint) renumber(mapping []nodeid) { + c.t = mapping[c.t] + c.result = mapping[c.result] +} + +func (c *rtypeMethodByNameConstraint) String() string { + return fmt.Sprintf("n%d = (*reflect.rtype).MethodByName(n%d, %q)", c.result, c.t, c.name) +} + +// changeRecv returns sig with Recv prepended to Params(). +func changeRecv(sig *types.Signature) *types.Signature { + params := sig.Params() + n := params.Len() + p2 := make([]*types.Var, n+1) + p2[0] = sig.Recv() + for i := 0; i < n; i++ { + p2[i+1] = params.At(i) + } + return types.NewSignature(nil, types.NewTuple(p2...), sig.Results(), sig.Variadic()) +} + +func (c *rtypeMethodByNameConstraint) solve(a *analysis, delta *nodeset) { + for _, x := range delta.AppendTo(a.deltaSpace) { + tObj := nodeid(x) + T := a.nodes[tObj].obj.data.(types.Type) + + isIface := isInterface(T) + + // We don't use Lookup(c.name) when c.name != "" to avoid + // ambiguity: >1 unexported methods could match. + mset := a.prog.MethodSets.MethodSet(T) + for i, n := 0, mset.Len(); i < n; i++ { + sel := mset.At(i) + if c.name == "" || c.name == sel.Obj().Name() { + // type Method struct { + // 0 __identity__ + // 1 Name string + // 2 PkgPath string + // 3 Type Type + // 4 Func Value + // 5 Index int + // } + + var sig *types.Signature + var fn *ssa.Function + if isIface { + sig = sel.Type().(*types.Signature) + } else { + fn = a.prog.MethodValue(sel) + // move receiver to params[0] + sig = changeRecv(fn.Signature) + } + + // a.offsetOf(Type) is 3. + if id := c.result + 3; a.addLabel(id, a.makeRtype(sig)) { + a.addWork(id) + } + if fn != nil { + // a.offsetOf(Func) is 4. + if id := c.result + 4; a.addLabel(id, a.objectNode(nil, fn)) { + a.addWork(id) + } + } + } + } + } +} + +func ext۰reflect۰rtype۰MethodByName(a *analysis, cgn *cgnode) { + // If we have access to the callsite, + // and the argument is a string constant, + // return only that method. + var name string + if site := cgn.callersite; site != nil { + if c, ok := site.instr.Common().Args[0].(*ssa.Const); ok { + name = constant.StringVal(c.Value) + } + } + + a.addConstraint(&rtypeMethodByNameConstraint{ + cgn: cgn, + name: name, + t: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +func ext۰reflect۰rtype۰Method(a *analysis, cgn *cgnode) { + // No-one ever calls Method with a constant argument, + // so we don't specialize that case. + a.addConstraint(&rtypeMethodByNameConstraint{ + cgn: cgn, + t: a.funcParams(cgn.obj), + result: a.funcResults(cgn.obj), + }) +} + +// typeHeight returns the "height" of the type, which is roughly +// speaking the number of chan, map, pointer and slice type constructors +// at the root of T; these are the four type kinds that can be created +// via reflection. Chan and map constructors are counted as double the +// height of slice and pointer constructors since they are less often +// deeply nested. +// +// The solver rules for type constructors must somehow bound the set of +// types they create to ensure termination of the algorithm in cases +// where the output of a type constructor flows to its input, e.g. +// +// func f(t reflect.Type) { +// f(reflect.PtrTo(t)) +// } +// +// It does this by limiting the type height to k, but this still leaves +// a potentially exponential (4^k) number of of types that may be +// enumerated in pathological cases. +// +func typeHeight(T types.Type) int { + switch T := T.(type) { + case *types.Chan: + return 2 + typeHeight(T.Elem()) + case *types.Map: + k := typeHeight(T.Key()) + v := typeHeight(T.Elem()) + if v > k { + k = v // max(k, v) + } + return 2 + k + case *types.Slice: + return 1 + typeHeight(T.Elem()) + case *types.Pointer: + return 1 + typeHeight(T.Elem()) + } + return 0 +} + +func typeTooHigh(T types.Type) bool { + return typeHeight(T) > 3 +} diff --git a/vendor/golang.org/x/tools/go/pointer/solve.go b/vendor/golang.org/x/tools/go/pointer/solve.go new file mode 100644 index 00000000000..0fdd098b012 --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/solve.go @@ -0,0 +1,370 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pointer + +// This file defines a naive Andersen-style solver for the inclusion +// constraint system. + +import ( + "fmt" + "go/types" +) + +type solverState struct { + complex []constraint // complex constraints attached to this node + copyTo nodeset // simple copy constraint edges + pts nodeset // points-to set of this node + prevPTS nodeset // pts(n) in previous iteration (for difference propagation) +} + +func (a *analysis) solve() { + start("Solving") + if a.log != nil { + fmt.Fprintf(a.log, "\n\n==== Solving constraints\n\n") + } + + // Solver main loop. + var delta nodeset + for { + // Add new constraints to the graph: + // static constraints from SSA on round 1, + // dynamic constraints from reflection thereafter. + a.processNewConstraints() + + var x int + if !a.work.TakeMin(&x) { + break // empty + } + id := nodeid(x) + if a.log != nil { + fmt.Fprintf(a.log, "\tnode n%d\n", id) + } + + n := a.nodes[id] + + // Difference propagation. + delta.Difference(&n.solve.pts.Sparse, &n.solve.prevPTS.Sparse) + if delta.IsEmpty() { + continue + } + if a.log != nil { + fmt.Fprintf(a.log, "\t\tpts(n%d : %s) = %s + %s\n", + id, n.typ, &delta, &n.solve.prevPTS) + } + n.solve.prevPTS.Copy(&n.solve.pts.Sparse) + + // Apply all resolution rules attached to n. + a.solveConstraints(n, &delta) + + if a.log != nil { + fmt.Fprintf(a.log, "\t\tpts(n%d) = %s\n", id, &n.solve.pts) + } + } + + if !a.nodes[0].solve.pts.IsEmpty() { + panic(fmt.Sprintf("pts(0) is nonempty: %s", &a.nodes[0].solve.pts)) + } + + // Release working state (but keep final PTS). + for _, n := range a.nodes { + n.solve.complex = nil + n.solve.copyTo.Clear() + n.solve.prevPTS.Clear() + } + + if a.log != nil { + fmt.Fprintf(a.log, "Solver done\n") + + // Dump solution. + for i, n := range a.nodes { + if !n.solve.pts.IsEmpty() { + fmt.Fprintf(a.log, "pts(n%d) = %s : %s\n", i, &n.solve.pts, n.typ) + } + } + } + stop("Solving") +} + +// processNewConstraints takes the new constraints from a.constraints +// and adds them to the graph, ensuring +// that new constraints are applied to pre-existing labels and +// that pre-existing constraints are applied to new labels. +// +func (a *analysis) processNewConstraints() { + // Take the slice of new constraints. + // (May grow during call to solveConstraints.) + constraints := a.constraints + a.constraints = nil + + // Initialize points-to sets from addr-of (base) constraints. + for _, c := range constraints { + if c, ok := c.(*addrConstraint); ok { + dst := a.nodes[c.dst] + dst.solve.pts.add(c.src) + + // Populate the worklist with nodes that point to + // something initially (due to addrConstraints) and + // have other constraints attached. + // (A no-op in round 1.) + if !dst.solve.copyTo.IsEmpty() || len(dst.solve.complex) > 0 { + a.addWork(c.dst) + } + } + } + + // Attach simple (copy) and complex constraints to nodes. + var stale nodeset + for _, c := range constraints { + var id nodeid + switch c := c.(type) { + case *addrConstraint: + // base constraints handled in previous loop + continue + case *copyConstraint: + // simple (copy) constraint + id = c.src + a.nodes[id].solve.copyTo.add(c.dst) + default: + // complex constraint + id = c.ptr() + solve := a.nodes[id].solve + solve.complex = append(solve.complex, c) + } + + if n := a.nodes[id]; !n.solve.pts.IsEmpty() { + if !n.solve.prevPTS.IsEmpty() { + stale.add(id) + } + a.addWork(id) + } + } + // Apply new constraints to pre-existing PTS labels. + var space [50]int + for _, id := range stale.AppendTo(space[:0]) { + n := a.nodes[nodeid(id)] + a.solveConstraints(n, &n.solve.prevPTS) + } +} + +// solveConstraints applies each resolution rule attached to node n to +// the set of labels delta. It may generate new constraints in +// a.constraints. +// +func (a *analysis) solveConstraints(n *node, delta *nodeset) { + if delta.IsEmpty() { + return + } + + // Process complex constraints dependent on n. + for _, c := range n.solve.complex { + if a.log != nil { + fmt.Fprintf(a.log, "\t\tconstraint %s\n", c) + } + c.solve(a, delta) + } + + // Process copy constraints. + var copySeen nodeset + for _, x := range n.solve.copyTo.AppendTo(a.deltaSpace) { + mid := nodeid(x) + if copySeen.add(mid) { + if a.nodes[mid].solve.pts.addAll(delta) { + a.addWork(mid) + } + } + } +} + +// addLabel adds label to the points-to set of ptr and reports whether the set grew. +func (a *analysis) addLabel(ptr, label nodeid) bool { + b := a.nodes[ptr].solve.pts.add(label) + if b && a.log != nil { + fmt.Fprintf(a.log, "\t\tpts(n%d) += n%d\n", ptr, label) + } + return b +} + +func (a *analysis) addWork(id nodeid) { + a.work.Insert(int(id)) + if a.log != nil { + fmt.Fprintf(a.log, "\t\twork: n%d\n", id) + } +} + +// onlineCopy adds a copy edge. It is called online, i.e. during +// solving, so it adds edges and pts members directly rather than by +// instantiating a 'constraint'. +// +// The size of the copy is implicitly 1. +// It returns true if pts(dst) changed. +// +func (a *analysis) onlineCopy(dst, src nodeid) bool { + if dst != src { + if nsrc := a.nodes[src]; nsrc.solve.copyTo.add(dst) { + if a.log != nil { + fmt.Fprintf(a.log, "\t\t\tdynamic copy n%d <- n%d\n", dst, src) + } + // TODO(adonovan): most calls to onlineCopy + // are followed by addWork, possibly batched + // via a 'changed' flag; see if there's a + // noticeable penalty to calling addWork here. + return a.nodes[dst].solve.pts.addAll(&nsrc.solve.pts) + } + } + return false +} + +// Returns sizeof. +// Implicitly adds nodes to worklist. +// +// TODO(adonovan): now that we support a.copy() during solving, we +// could eliminate onlineCopyN, but it's much slower. Investigate. +// +func (a *analysis) onlineCopyN(dst, src nodeid, sizeof uint32) uint32 { + for i := uint32(0); i < sizeof; i++ { + if a.onlineCopy(dst, src) { + a.addWork(dst) + } + src++ + dst++ + } + return sizeof +} + +func (c *loadConstraint) solve(a *analysis, delta *nodeset) { + var changed bool + for _, x := range delta.AppendTo(a.deltaSpace) { + k := nodeid(x) + koff := k + nodeid(c.offset) + if a.onlineCopy(c.dst, koff) { + changed = true + } + } + if changed { + a.addWork(c.dst) + } +} + +func (c *storeConstraint) solve(a *analysis, delta *nodeset) { + for _, x := range delta.AppendTo(a.deltaSpace) { + k := nodeid(x) + koff := k + nodeid(c.offset) + if a.onlineCopy(koff, c.src) { + a.addWork(koff) + } + } +} + +func (c *offsetAddrConstraint) solve(a *analysis, delta *nodeset) { + dst := a.nodes[c.dst] + for _, x := range delta.AppendTo(a.deltaSpace) { + k := nodeid(x) + if dst.solve.pts.add(k + nodeid(c.offset)) { + a.addWork(c.dst) + } + } +} + +func (c *typeFilterConstraint) solve(a *analysis, delta *nodeset) { + for _, x := range delta.AppendTo(a.deltaSpace) { + ifaceObj := nodeid(x) + tDyn, _, indirect := a.taggedValue(ifaceObj) + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + if types.AssignableTo(tDyn, c.typ) { + if a.addLabel(c.dst, ifaceObj) { + a.addWork(c.dst) + } + } + } +} + +func (c *untagConstraint) solve(a *analysis, delta *nodeset) { + predicate := types.AssignableTo + if c.exact { + predicate = types.Identical + } + for _, x := range delta.AppendTo(a.deltaSpace) { + ifaceObj := nodeid(x) + tDyn, v, indirect := a.taggedValue(ifaceObj) + if indirect { + // TODO(adonovan): we'll need to implement this + // when we start creating indirect tagged objects. + panic("indirect tagged object") + } + + if predicate(tDyn, c.typ) { + // Copy payload sans tag to dst. + // + // TODO(adonovan): opt: if tDyn is + // nonpointerlike we can skip this entire + // constraint, perhaps. We only care about + // pointers among the fields. + a.onlineCopyN(c.dst, v, a.sizeof(tDyn)) + } + } +} + +func (c *invokeConstraint) solve(a *analysis, delta *nodeset) { + for _, x := range delta.AppendTo(a.deltaSpace) { + ifaceObj := nodeid(x) + tDyn, v, indirect := a.taggedValue(ifaceObj) + if indirect { + // TODO(adonovan): we may need to implement this if + // we ever apply invokeConstraints to reflect.Value PTSs, + // e.g. for (reflect.Value).Call. + panic("indirect tagged object") + } + + // Look up the concrete method. + fn := a.prog.LookupMethod(tDyn, c.method.Pkg(), c.method.Name()) + if fn == nil { + panic(fmt.Sprintf("n%d: no ssa.Function for %s", c.iface, c.method)) + } + sig := fn.Signature + + fnObj := a.globalobj[fn] // dynamic calls use shared contour + if fnObj == 0 { + // a.objectNode(fn) was not called during gen phase. + panic(fmt.Sprintf("a.globalobj[%s]==nil", fn)) + } + + // Make callsite's fn variable point to identity of + // concrete method. (There's no need to add it to + // worklist since it never has attached constraints.) + a.addLabel(c.params, fnObj) + + // Extract value and connect to method's receiver. + // Copy payload to method's receiver param (arg0). + arg0 := a.funcParams(fnObj) + recvSize := a.sizeof(sig.Recv().Type()) + a.onlineCopyN(arg0, v, recvSize) + + src := c.params + 1 // skip past identity + dst := arg0 + nodeid(recvSize) + + // Copy caller's argument block to method formal parameters. + paramsSize := a.sizeof(sig.Params()) + a.onlineCopyN(dst, src, paramsSize) + src += nodeid(paramsSize) + dst += nodeid(paramsSize) + + // Copy method results to caller's result block. + resultsSize := a.sizeof(sig.Results()) + a.onlineCopyN(src, dst, resultsSize) + } +} + +func (c *addrConstraint) solve(a *analysis, delta *nodeset) { + panic("addr is not a complex constraint") +} + +func (c *copyConstraint) solve(a *analysis, delta *nodeset) { + panic("copy is not a complex constraint") +} diff --git a/vendor/golang.org/x/tools/go/pointer/util.go b/vendor/golang.org/x/tools/go/pointer/util.go new file mode 100644 index 00000000000..683fddddcfd --- /dev/null +++ b/vendor/golang.org/x/tools/go/pointer/util.go @@ -0,0 +1,313 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package pointer + +import ( + "bytes" + "fmt" + "go/types" + "log" + "os" + "os/exec" + "runtime" + "time" + + "golang.org/x/tools/container/intsets" +) + +// CanPoint reports whether the type T is pointerlike, +// for the purposes of this analysis. +func CanPoint(T types.Type) bool { + switch T := T.(type) { + case *types.Named: + if obj := T.Obj(); obj.Name() == "Value" && obj.Pkg().Path() == "reflect" { + return true // treat reflect.Value like interface{} + } + return CanPoint(T.Underlying()) + case *types.Pointer, *types.Interface, *types.Map, *types.Chan, *types.Signature, *types.Slice: + return true + } + + return false // array struct tuple builtin basic +} + +// CanHaveDynamicTypes reports whether the type T can "hold" dynamic types, +// i.e. is an interface (incl. reflect.Type) or a reflect.Value. +// +func CanHaveDynamicTypes(T types.Type) bool { + switch T := T.(type) { + case *types.Named: + if obj := T.Obj(); obj.Name() == "Value" && obj.Pkg().Path() == "reflect" { + return true // reflect.Value + } + return CanHaveDynamicTypes(T.Underlying()) + case *types.Interface: + return true + } + return false +} + +func isInterface(T types.Type) bool { return types.IsInterface(T) } + +// mustDeref returns the element type of its argument, which must be a +// pointer; panic ensues otherwise. +func mustDeref(typ types.Type) types.Type { + return typ.Underlying().(*types.Pointer).Elem() +} + +// deref returns a pointer's element type; otherwise it returns typ. +func deref(typ types.Type) types.Type { + if p, ok := typ.Underlying().(*types.Pointer); ok { + return p.Elem() + } + return typ +} + +// A fieldInfo describes one subelement (node) of the flattening-out +// of a type T: the subelement's type and its path from the root of T. +// +// For example, for this type: +// type line struct{ points []struct{x, y int} } +// flatten() of the inner struct yields the following []fieldInfo: +// struct{ x, y int } "" +// int ".x" +// int ".y" +// and flatten(line) yields: +// struct{ points []struct{x, y int} } "" +// struct{ x, y int } ".points[*]" +// int ".points[*].x +// int ".points[*].y" +// +type fieldInfo struct { + typ types.Type + + // op and tail describe the path to the element (e.g. ".a#2.b[*].c"). + op interface{} // *Array: true; *Tuple: int; *Struct: *types.Var; *Named: nil + tail *fieldInfo +} + +// path returns a user-friendly string describing the subelement path. +// +func (fi *fieldInfo) path() string { + var buf bytes.Buffer + for p := fi; p != nil; p = p.tail { + switch op := p.op.(type) { + case bool: + fmt.Fprintf(&buf, "[*]") + case int: + fmt.Fprintf(&buf, "#%d", op) + case *types.Var: + fmt.Fprintf(&buf, ".%s", op.Name()) + } + } + return buf.String() +} + +// flatten returns a list of directly contained fields in the preorder +// traversal of the type tree of t. The resulting elements are all +// scalars (basic types or pointerlike types), except for struct/array +// "identity" nodes, whose type is that of the aggregate. +// +// reflect.Value is considered pointerlike, similar to interface{}. +// +// Callers must not mutate the result. +// +func (a *analysis) flatten(t types.Type) []*fieldInfo { + fl, ok := a.flattenMemo[t] + if !ok { + switch t := t.(type) { + case *types.Named: + u := t.Underlying() + if isInterface(u) { + // Debuggability hack: don't remove + // the named type from interfaces as + // they're very verbose. + fl = append(fl, &fieldInfo{typ: t}) + } else { + fl = a.flatten(u) + } + + case *types.Basic, + *types.Signature, + *types.Chan, + *types.Map, + *types.Interface, + *types.Slice, + *types.Pointer: + fl = append(fl, &fieldInfo{typ: t}) + + case *types.Array: + fl = append(fl, &fieldInfo{typ: t}) // identity node + for _, fi := range a.flatten(t.Elem()) { + fl = append(fl, &fieldInfo{typ: fi.typ, op: true, tail: fi}) + } + + case *types.Struct: + fl = append(fl, &fieldInfo{typ: t}) // identity node + for i, n := 0, t.NumFields(); i < n; i++ { + f := t.Field(i) + for _, fi := range a.flatten(f.Type()) { + fl = append(fl, &fieldInfo{typ: fi.typ, op: f, tail: fi}) + } + } + + case *types.Tuple: + // No identity node: tuples are never address-taken. + n := t.Len() + if n == 1 { + // Don't add a fieldInfo link for singletons, + // e.g. in params/results. + fl = append(fl, a.flatten(t.At(0).Type())...) + } else { + for i := 0; i < n; i++ { + f := t.At(i) + for _, fi := range a.flatten(f.Type()) { + fl = append(fl, &fieldInfo{typ: fi.typ, op: i, tail: fi}) + } + } + } + + default: + panic(fmt.Sprintf("cannot flatten unsupported type %T", t)) + } + + a.flattenMemo[t] = fl + } + + return fl +} + +// sizeof returns the number of pointerlike abstractions (nodes) in the type t. +func (a *analysis) sizeof(t types.Type) uint32 { + return uint32(len(a.flatten(t))) +} + +// shouldTrack reports whether object type T contains (recursively) +// any fields whose addresses should be tracked. +func (a *analysis) shouldTrack(T types.Type) bool { + if a.track == trackAll { + return true // fast path + } + track, ok := a.trackTypes[T] + if !ok { + a.trackTypes[T] = true // break cycles conservatively + // NB: reflect.Value, reflect.Type are pre-populated to true. + for _, fi := range a.flatten(T) { + switch ft := fi.typ.Underlying().(type) { + case *types.Interface, *types.Signature: + track = true // needed for callgraph + case *types.Basic: + // no-op + case *types.Chan: + track = a.track&trackChan != 0 || a.shouldTrack(ft.Elem()) + case *types.Map: + track = a.track&trackMap != 0 || a.shouldTrack(ft.Key()) || a.shouldTrack(ft.Elem()) + case *types.Slice: + track = a.track&trackSlice != 0 || a.shouldTrack(ft.Elem()) + case *types.Pointer: + track = a.track&trackPtr != 0 || a.shouldTrack(ft.Elem()) + case *types.Array, *types.Struct: + // No need to look at field types since they will follow (flattened). + default: + // Includes *types.Tuple, which are never address-taken. + panic(ft) + } + if track { + break + } + } + a.trackTypes[T] = track + if !track && a.log != nil { + fmt.Fprintf(a.log, "\ttype not tracked: %s\n", T) + } + } + return track +} + +// offsetOf returns the (abstract) offset of field index within struct +// or tuple typ. +func (a *analysis) offsetOf(typ types.Type, index int) uint32 { + var offset uint32 + switch t := typ.Underlying().(type) { + case *types.Tuple: + for i := 0; i < index; i++ { + offset += a.sizeof(t.At(i).Type()) + } + case *types.Struct: + offset++ // the node for the struct itself + for i := 0; i < index; i++ { + offset += a.sizeof(t.Field(i).Type()) + } + default: + panic(fmt.Sprintf("offsetOf(%s : %T)", typ, typ)) + } + return offset +} + +// sliceToArray returns the type representing the arrays to which +// slice type slice points. +func sliceToArray(slice types.Type) *types.Array { + return types.NewArray(slice.Underlying().(*types.Slice).Elem(), 1) +} + +// Node set ------------------------------------------------------------------- + +type nodeset struct { + intsets.Sparse +} + +func (ns *nodeset) String() string { + var buf bytes.Buffer + buf.WriteRune('{') + var space [50]int + for i, n := range ns.AppendTo(space[:0]) { + if i > 0 { + buf.WriteString(", ") + } + buf.WriteRune('n') + fmt.Fprintf(&buf, "%d", n) + } + buf.WriteRune('}') + return buf.String() +} + +func (ns *nodeset) add(n nodeid) bool { + return ns.Sparse.Insert(int(n)) +} + +func (x *nodeset) addAll(y *nodeset) bool { + return x.UnionWith(&y.Sparse) +} + +// Profiling & debugging ------------------------------------------------------- + +var timers = make(map[string]time.Time) + +func start(name string) { + if debugTimers { + timers[name] = time.Now() + log.Printf("%s...\n", name) + } +} + +func stop(name string) { + if debugTimers { + log.Printf("%s took %s\n", name, time.Since(timers[name])) + } +} + +// diff runs the command "diff a b" and reports its success. +func diff(a, b string) bool { + var cmd *exec.Cmd + switch runtime.GOOS { + case "plan9": + cmd = exec.Command("/bin/diff", "-c", a, b) + default: + cmd = exec.Command("/usr/bin/diff", "-u", a, b) + } + cmd.Stdout = os.Stderr + cmd.Stderr = os.Stderr + return cmd.Run() == nil +} diff --git a/vendor/golang.org/x/tools/go/ssa/blockopt.go b/vendor/golang.org/x/tools/go/ssa/blockopt.go new file mode 100644 index 00000000000..e79260a21a2 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/blockopt.go @@ -0,0 +1,187 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// Simple block optimizations to simplify the control flow graph. + +// TODO(adonovan): opt: instead of creating several "unreachable" blocks +// per function in the Builder, reuse a single one (e.g. at Blocks[1]) +// to reduce garbage. + +import ( + "fmt" + "os" +) + +// If true, perform sanity checking and show progress at each +// successive iteration of optimizeBlocks. Very verbose. +const debugBlockOpt = false + +// markReachable sets Index=-1 for all blocks reachable from b. +func markReachable(b *BasicBlock) { + b.Index = -1 + for _, succ := range b.Succs { + if succ.Index == 0 { + markReachable(succ) + } + } +} + +// deleteUnreachableBlocks marks all reachable blocks of f and +// eliminates (nils) all others, including possibly cyclic subgraphs. +// +func deleteUnreachableBlocks(f *Function) { + const white, black = 0, -1 + // We borrow b.Index temporarily as the mark bit. + for _, b := range f.Blocks { + b.Index = white + } + markReachable(f.Blocks[0]) + if f.Recover != nil { + markReachable(f.Recover) + } + for i, b := range f.Blocks { + if b.Index == white { + for _, c := range b.Succs { + if c.Index == black { + c.removePred(b) // delete white->black edge + } + } + if debugBlockOpt { + fmt.Fprintln(os.Stderr, "unreachable", b) + } + f.Blocks[i] = nil // delete b + } + } + f.removeNilBlocks() +} + +// jumpThreading attempts to apply simple jump-threading to block b, +// in which a->b->c become a->c if b is just a Jump. +// The result is true if the optimization was applied. +// +func jumpThreading(f *Function, b *BasicBlock) bool { + if b.Index == 0 { + return false // don't apply to entry block + } + if b.Instrs == nil { + return false + } + if _, ok := b.Instrs[0].(*Jump); !ok { + return false // not just a jump + } + c := b.Succs[0] + if c == b { + return false // don't apply to degenerate jump-to-self. + } + if c.hasPhi() { + return false // not sound without more effort + } + for j, a := range b.Preds { + a.replaceSucc(b, c) + + // If a now has two edges to c, replace its degenerate If by Jump. + if len(a.Succs) == 2 && a.Succs[0] == c && a.Succs[1] == c { + jump := new(Jump) + jump.setBlock(a) + a.Instrs[len(a.Instrs)-1] = jump + a.Succs = a.Succs[:1] + c.removePred(b) + } else { + if j == 0 { + c.replacePred(b, a) + } else { + c.Preds = append(c.Preds, a) + } + } + + if debugBlockOpt { + fmt.Fprintln(os.Stderr, "jumpThreading", a, b, c) + } + } + f.Blocks[b.Index] = nil // delete b + return true +} + +// fuseBlocks attempts to apply the block fusion optimization to block +// a, in which a->b becomes ab if len(a.Succs)==len(b.Preds)==1. +// The result is true if the optimization was applied. +// +func fuseBlocks(f *Function, a *BasicBlock) bool { + if len(a.Succs) != 1 { + return false + } + b := a.Succs[0] + if len(b.Preds) != 1 { + return false + } + + // Degenerate &&/|| ops may result in a straight-line CFG + // containing φ-nodes. (Ideally we'd replace such them with + // their sole operand but that requires Referrers, built later.) + if b.hasPhi() { + return false // not sound without further effort + } + + // Eliminate jump at end of A, then copy all of B across. + a.Instrs = append(a.Instrs[:len(a.Instrs)-1], b.Instrs...) + for _, instr := range b.Instrs { + instr.setBlock(a) + } + + // A inherits B's successors + a.Succs = append(a.succs2[:0], b.Succs...) + + // Fix up Preds links of all successors of B. + for _, c := range b.Succs { + c.replacePred(b, a) + } + + if debugBlockOpt { + fmt.Fprintln(os.Stderr, "fuseBlocks", a, b) + } + + f.Blocks[b.Index] = nil // delete b + return true +} + +// optimizeBlocks() performs some simple block optimizations on a +// completed function: dead block elimination, block fusion, jump +// threading. +// +func optimizeBlocks(f *Function) { + deleteUnreachableBlocks(f) + + // Loop until no further progress. + changed := true + for changed { + changed = false + + if debugBlockOpt { + f.WriteTo(os.Stderr) + mustSanityCheck(f, nil) + } + + for _, b := range f.Blocks { + // f.Blocks will temporarily contain nils to indicate + // deleted blocks; we remove them at the end. + if b == nil { + continue + } + + // Fuse blocks. b->c becomes bc. + if fuseBlocks(f, b) { + changed = true + } + + // a->b->c becomes a->c if b contains only a Jump. + if jumpThreading(f, b) { + changed = true + continue // (b was disconnected) + } + } + } + f.removeNilBlocks() +} diff --git a/vendor/golang.org/x/tools/go/ssa/builder.go b/vendor/golang.org/x/tools/go/ssa/builder.go new file mode 100644 index 00000000000..36aebdf8250 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/builder.go @@ -0,0 +1,2382 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file implements the BUILD phase of SSA construction. +// +// SSA construction has two phases, CREATE and BUILD. In the CREATE phase +// (create.go), all packages are constructed and type-checked and +// definitions of all package members are created, method-sets are +// computed, and wrapper methods are synthesized. +// ssa.Packages are created in arbitrary order. +// +// In the BUILD phase (builder.go), the builder traverses the AST of +// each Go source function and generates SSA instructions for the +// function body. Initializer expressions for package-level variables +// are emitted to the package's init() function in the order specified +// by go/types.Info.InitOrder, then code for each function in the +// package is generated in lexical order. +// The BUILD phases for distinct packages are independent and are +// executed in parallel. +// +// TODO(adonovan): indeed, building functions is now embarrassingly parallel. +// Audit for concurrency then benchmark using more goroutines. +// +// The builder's and Program's indices (maps) are populated and +// mutated during the CREATE phase, but during the BUILD phase they +// remain constant. The sole exception is Prog.methodSets and its +// related maps, which are protected by a dedicated mutex. + +import ( + "fmt" + "go/ast" + "go/constant" + "go/token" + "go/types" + "os" + "sync" +) + +type opaqueType struct { + types.Type + name string +} + +func (t *opaqueType) String() string { return t.name } + +var ( + varOk = newVar("ok", tBool) + varIndex = newVar("index", tInt) + + // Type constants. + tBool = types.Typ[types.Bool] + tByte = types.Typ[types.Byte] + tInt = types.Typ[types.Int] + tInvalid = types.Typ[types.Invalid] + tString = types.Typ[types.String] + tUntypedNil = types.Typ[types.UntypedNil] + tRangeIter = &opaqueType{nil, "iter"} // the type of all "range" iterators + tEface = types.NewInterface(nil, nil).Complete() + + // SSA Value constants. + vZero = intConst(0) + vOne = intConst(1) + vTrue = NewConst(constant.MakeBool(true), tBool) +) + +// builder holds state associated with the package currently being built. +// Its methods contain all the logic for AST-to-SSA conversion. +type builder struct{} + +// cond emits to fn code to evaluate boolean condition e and jump +// to t or f depending on its value, performing various simplifications. +// +// Postcondition: fn.currentBlock is nil. +// +func (b *builder) cond(fn *Function, e ast.Expr, t, f *BasicBlock) { + switch e := e.(type) { + case *ast.ParenExpr: + b.cond(fn, e.X, t, f) + return + + case *ast.BinaryExpr: + switch e.Op { + case token.LAND: + ltrue := fn.newBasicBlock("cond.true") + b.cond(fn, e.X, ltrue, f) + fn.currentBlock = ltrue + b.cond(fn, e.Y, t, f) + return + + case token.LOR: + lfalse := fn.newBasicBlock("cond.false") + b.cond(fn, e.X, t, lfalse) + fn.currentBlock = lfalse + b.cond(fn, e.Y, t, f) + return + } + + case *ast.UnaryExpr: + if e.Op == token.NOT { + b.cond(fn, e.X, f, t) + return + } + } + + // A traditional compiler would simplify "if false" (etc) here + // but we do not, for better fidelity to the source code. + // + // The value of a constant condition may be platform-specific, + // and may cause blocks that are reachable in some configuration + // to be hidden from subsequent analyses such as bug-finding tools. + emitIf(fn, b.expr(fn, e), t, f) +} + +// logicalBinop emits code to fn to evaluate e, a &&- or +// ||-expression whose reified boolean value is wanted. +// The value is returned. +// +func (b *builder) logicalBinop(fn *Function, e *ast.BinaryExpr) Value { + rhs := fn.newBasicBlock("binop.rhs") + done := fn.newBasicBlock("binop.done") + + // T(e) = T(e.X) = T(e.Y) after untyped constants have been + // eliminated. + // TODO(adonovan): not true; MyBool==MyBool yields UntypedBool. + t := fn.Pkg.typeOf(e) + + var short Value // value of the short-circuit path + switch e.Op { + case token.LAND: + b.cond(fn, e.X, rhs, done) + short = NewConst(constant.MakeBool(false), t) + + case token.LOR: + b.cond(fn, e.X, done, rhs) + short = NewConst(constant.MakeBool(true), t) + } + + // Is rhs unreachable? + if rhs.Preds == nil { + // Simplify false&&y to false, true||y to true. + fn.currentBlock = done + return short + } + + // Is done unreachable? + if done.Preds == nil { + // Simplify true&&y (or false||y) to y. + fn.currentBlock = rhs + return b.expr(fn, e.Y) + } + + // All edges from e.X to done carry the short-circuit value. + var edges []Value + for range done.Preds { + edges = append(edges, short) + } + + // The edge from e.Y to done carries the value of e.Y. + fn.currentBlock = rhs + edges = append(edges, b.expr(fn, e.Y)) + emitJump(fn, done) + fn.currentBlock = done + + phi := &Phi{Edges: edges, Comment: e.Op.String()} + phi.pos = e.OpPos + phi.typ = t + return done.emit(phi) +} + +// exprN lowers a multi-result expression e to SSA form, emitting code +// to fn and returning a single Value whose type is a *types.Tuple. +// The caller must access the components via Extract. +// +// Multi-result expressions include CallExprs in a multi-value +// assignment or return statement, and "value,ok" uses of +// TypeAssertExpr, IndexExpr (when X is a map), and UnaryExpr (when Op +// is token.ARROW). +// +func (b *builder) exprN(fn *Function, e ast.Expr) Value { + typ := fn.Pkg.typeOf(e).(*types.Tuple) + switch e := e.(type) { + case *ast.ParenExpr: + return b.exprN(fn, e.X) + + case *ast.CallExpr: + // Currently, no built-in function nor type conversion + // has multiple results, so we can avoid some of the + // cases for single-valued CallExpr. + var c Call + b.setCall(fn, e, &c.Call) + c.typ = typ + return fn.emit(&c) + + case *ast.IndexExpr: + mapt := fn.Pkg.typeOf(e.X).Underlying().(*types.Map) + lookup := &Lookup{ + X: b.expr(fn, e.X), + Index: emitConv(fn, b.expr(fn, e.Index), mapt.Key()), + CommaOk: true, + } + lookup.setType(typ) + lookup.setPos(e.Lbrack) + return fn.emit(lookup) + + case *ast.TypeAssertExpr: + return emitTypeTest(fn, b.expr(fn, e.X), typ.At(0).Type(), e.Lparen) + + case *ast.UnaryExpr: // must be receive <- + unop := &UnOp{ + Op: token.ARROW, + X: b.expr(fn, e.X), + CommaOk: true, + } + unop.setType(typ) + unop.setPos(e.OpPos) + return fn.emit(unop) + } + panic(fmt.Sprintf("exprN(%T) in %s", e, fn)) +} + +// builtin emits to fn SSA instructions to implement a call to the +// built-in function obj with the specified arguments +// and return type. It returns the value defined by the result. +// +// The result is nil if no special handling was required; in this case +// the caller should treat this like an ordinary library function +// call. +// +func (b *builder) builtin(fn *Function, obj *types.Builtin, args []ast.Expr, typ types.Type, pos token.Pos) Value { + switch obj.Name() { + case "make": + switch typ.Underlying().(type) { + case *types.Slice: + n := b.expr(fn, args[1]) + m := n + if len(args) == 3 { + m = b.expr(fn, args[2]) + } + if m, ok := m.(*Const); ok { + // treat make([]T, n, m) as new([m]T)[:n] + cap := m.Int64() + at := types.NewArray(typ.Underlying().(*types.Slice).Elem(), cap) + alloc := emitNew(fn, at, pos) + alloc.Comment = "makeslice" + v := &Slice{ + X: alloc, + High: n, + } + v.setPos(pos) + v.setType(typ) + return fn.emit(v) + } + v := &MakeSlice{ + Len: n, + Cap: m, + } + v.setPos(pos) + v.setType(typ) + return fn.emit(v) + + case *types.Map: + var res Value + if len(args) == 2 { + res = b.expr(fn, args[1]) + } + v := &MakeMap{Reserve: res} + v.setPos(pos) + v.setType(typ) + return fn.emit(v) + + case *types.Chan: + var sz Value = vZero + if len(args) == 2 { + sz = b.expr(fn, args[1]) + } + v := &MakeChan{Size: sz} + v.setPos(pos) + v.setType(typ) + return fn.emit(v) + } + + case "new": + alloc := emitNew(fn, deref(typ), pos) + alloc.Comment = "new" + return alloc + + case "len", "cap": + // Special case: len or cap of an array or *array is + // based on the type, not the value which may be nil. + // We must still evaluate the value, though. (If it + // was side-effect free, the whole call would have + // been constant-folded.) + t := deref(fn.Pkg.typeOf(args[0])).Underlying() + if at, ok := t.(*types.Array); ok { + b.expr(fn, args[0]) // for effects only + return intConst(at.Len()) + } + // Otherwise treat as normal. + + case "panic": + fn.emit(&Panic{ + X: emitConv(fn, b.expr(fn, args[0]), tEface), + pos: pos, + }) + fn.currentBlock = fn.newBasicBlock("unreachable") + return vTrue // any non-nil Value will do + } + return nil // treat all others as a regular function call +} + +// addr lowers a single-result addressable expression e to SSA form, +// emitting code to fn and returning the location (an lvalue) defined +// by the expression. +// +// If escaping is true, addr marks the base variable of the +// addressable expression e as being a potentially escaping pointer +// value. For example, in this code: +// +// a := A{ +// b: [1]B{B{c: 1}} +// } +// return &a.b[0].c +// +// the application of & causes a.b[0].c to have its address taken, +// which means that ultimately the local variable a must be +// heap-allocated. This is a simple but very conservative escape +// analysis. +// +// Operations forming potentially escaping pointers include: +// - &x, including when implicit in method call or composite literals. +// - a[:] iff a is an array (not *array) +// - references to variables in lexically enclosing functions. +// +func (b *builder) addr(fn *Function, e ast.Expr, escaping bool) lvalue { + switch e := e.(type) { + case *ast.Ident: + if isBlankIdent(e) { + return blank{} + } + obj := fn.Pkg.objectOf(e) + v := fn.Prog.packageLevelValue(obj) // var (address) + if v == nil { + v = fn.lookup(obj, escaping) + } + return &address{addr: v, pos: e.Pos(), expr: e} + + case *ast.CompositeLit: + t := deref(fn.Pkg.typeOf(e)) + var v *Alloc + if escaping { + v = emitNew(fn, t, e.Lbrace) + } else { + v = fn.addLocal(t, e.Lbrace) + } + v.Comment = "complit" + var sb storebuf + b.compLit(fn, v, e, true, &sb) + sb.emit(fn) + return &address{addr: v, pos: e.Lbrace, expr: e} + + case *ast.ParenExpr: + return b.addr(fn, e.X, escaping) + + case *ast.SelectorExpr: + sel, ok := fn.Pkg.info.Selections[e] + if !ok { + // qualified identifier + return b.addr(fn, e.Sel, escaping) + } + if sel.Kind() != types.FieldVal { + panic(sel) + } + wantAddr := true + v := b.receiver(fn, e.X, wantAddr, escaping, sel) + last := len(sel.Index()) - 1 + return &address{ + addr: emitFieldSelection(fn, v, sel.Index()[last], true, e.Sel), + pos: e.Sel.Pos(), + expr: e.Sel, + } + + case *ast.IndexExpr: + var x Value + var et types.Type + switch t := fn.Pkg.typeOf(e.X).Underlying().(type) { + case *types.Array: + x = b.addr(fn, e.X, escaping).address(fn) + et = types.NewPointer(t.Elem()) + case *types.Pointer: // *array + x = b.expr(fn, e.X) + et = types.NewPointer(t.Elem().Underlying().(*types.Array).Elem()) + case *types.Slice: + x = b.expr(fn, e.X) + et = types.NewPointer(t.Elem()) + case *types.Map: + return &element{ + m: b.expr(fn, e.X), + k: emitConv(fn, b.expr(fn, e.Index), t.Key()), + t: t.Elem(), + pos: e.Lbrack, + } + default: + panic("unexpected container type in IndexExpr: " + t.String()) + } + v := &IndexAddr{ + X: x, + Index: emitConv(fn, b.expr(fn, e.Index), tInt), + } + v.setPos(e.Lbrack) + v.setType(et) + return &address{addr: fn.emit(v), pos: e.Lbrack, expr: e} + + case *ast.StarExpr: + return &address{addr: b.expr(fn, e.X), pos: e.Star, expr: e} + } + + panic(fmt.Sprintf("unexpected address expression: %T", e)) +} + +type store struct { + lhs lvalue + rhs Value +} + +type storebuf struct{ stores []store } + +func (sb *storebuf) store(lhs lvalue, rhs Value) { + sb.stores = append(sb.stores, store{lhs, rhs}) +} + +func (sb *storebuf) emit(fn *Function) { + for _, s := range sb.stores { + s.lhs.store(fn, s.rhs) + } +} + +// assign emits to fn code to initialize the lvalue loc with the value +// of expression e. If isZero is true, assign assumes that loc holds +// the zero value for its type. +// +// This is equivalent to loc.store(fn, b.expr(fn, e)), but may generate +// better code in some cases, e.g., for composite literals in an +// addressable location. +// +// If sb is not nil, assign generates code to evaluate expression e, but +// not to update loc. Instead, the necessary stores are appended to the +// storebuf sb so that they can be executed later. This allows correct +// in-place update of existing variables when the RHS is a composite +// literal that may reference parts of the LHS. +// +func (b *builder) assign(fn *Function, loc lvalue, e ast.Expr, isZero bool, sb *storebuf) { + // Can we initialize it in place? + if e, ok := unparen(e).(*ast.CompositeLit); ok { + // A CompositeLit never evaluates to a pointer, + // so if the type of the location is a pointer, + // an &-operation is implied. + if _, ok := loc.(blank); !ok { // avoid calling blank.typ() + if isPointer(loc.typ()) { + ptr := b.addr(fn, e, true).address(fn) + // copy address + if sb != nil { + sb.store(loc, ptr) + } else { + loc.store(fn, ptr) + } + return + } + } + + if _, ok := loc.(*address); ok { + if isInterface(loc.typ()) { + // e.g. var x interface{} = T{...} + // Can't in-place initialize an interface value. + // Fall back to copying. + } else { + // x = T{...} or x := T{...} + addr := loc.address(fn) + if sb != nil { + b.compLit(fn, addr, e, isZero, sb) + } else { + var sb storebuf + b.compLit(fn, addr, e, isZero, &sb) + sb.emit(fn) + } + + // Subtle: emit debug ref for aggregate types only; + // slice and map are handled by store ops in compLit. + switch loc.typ().Underlying().(type) { + case *types.Struct, *types.Array: + emitDebugRef(fn, e, addr, true) + } + + return + } + } + } + + // simple case: just copy + rhs := b.expr(fn, e) + if sb != nil { + sb.store(loc, rhs) + } else { + loc.store(fn, rhs) + } +} + +// expr lowers a single-result expression e to SSA form, emitting code +// to fn and returning the Value defined by the expression. +// +func (b *builder) expr(fn *Function, e ast.Expr) Value { + e = unparen(e) + + tv := fn.Pkg.info.Types[e] + + // Is expression a constant? + if tv.Value != nil { + return NewConst(tv.Value, tv.Type) + } + + var v Value + if tv.Addressable() { + // Prefer pointer arithmetic ({Index,Field}Addr) followed + // by Load over subelement extraction (e.g. Index, Field), + // to avoid large copies. + v = b.addr(fn, e, false).load(fn) + } else { + v = b.expr0(fn, e, tv) + } + if fn.debugInfo() { + emitDebugRef(fn, e, v, false) + } + return v +} + +func (b *builder) expr0(fn *Function, e ast.Expr, tv types.TypeAndValue) Value { + switch e := e.(type) { + case *ast.BasicLit: + panic("non-constant BasicLit") // unreachable + + case *ast.FuncLit: + fn2 := &Function{ + name: fmt.Sprintf("%s$%d", fn.Name(), 1+len(fn.AnonFuncs)), + Signature: fn.Pkg.typeOf(e.Type).Underlying().(*types.Signature), + pos: e.Type.Func, + parent: fn, + Pkg: fn.Pkg, + Prog: fn.Prog, + syntax: e, + } + fn.AnonFuncs = append(fn.AnonFuncs, fn2) + b.buildFunction(fn2) + if fn2.FreeVars == nil { + return fn2 + } + v := &MakeClosure{Fn: fn2} + v.setType(tv.Type) + for _, fv := range fn2.FreeVars { + v.Bindings = append(v.Bindings, fv.outer) + fv.outer = nil + } + return fn.emit(v) + + case *ast.TypeAssertExpr: // single-result form only + return emitTypeAssert(fn, b.expr(fn, e.X), tv.Type, e.Lparen) + + case *ast.CallExpr: + if fn.Pkg.info.Types[e.Fun].IsType() { + // Explicit type conversion, e.g. string(x) or big.Int(x) + x := b.expr(fn, e.Args[0]) + y := emitConv(fn, x, tv.Type) + if y != x { + switch y := y.(type) { + case *Convert: + y.pos = e.Lparen + case *ChangeType: + y.pos = e.Lparen + case *MakeInterface: + y.pos = e.Lparen + } + } + return y + } + // Call to "intrinsic" built-ins, e.g. new, make, panic. + if id, ok := unparen(e.Fun).(*ast.Ident); ok { + if obj, ok := fn.Pkg.info.Uses[id].(*types.Builtin); ok { + if v := b.builtin(fn, obj, e.Args, tv.Type, e.Lparen); v != nil { + return v + } + } + } + // Regular function call. + var v Call + b.setCall(fn, e, &v.Call) + v.setType(tv.Type) + return fn.emit(&v) + + case *ast.UnaryExpr: + switch e.Op { + case token.AND: // &X --- potentially escaping. + addr := b.addr(fn, e.X, true) + if _, ok := unparen(e.X).(*ast.StarExpr); ok { + // &*p must panic if p is nil (http://golang.org/s/go12nil). + // For simplicity, we'll just (suboptimally) rely + // on the side effects of a load. + // TODO(adonovan): emit dedicated nilcheck. + addr.load(fn) + } + return addr.address(fn) + case token.ADD: + return b.expr(fn, e.X) + case token.NOT, token.ARROW, token.SUB, token.XOR: // ! <- - ^ + v := &UnOp{ + Op: e.Op, + X: b.expr(fn, e.X), + } + v.setPos(e.OpPos) + v.setType(tv.Type) + return fn.emit(v) + default: + panic(e.Op) + } + + case *ast.BinaryExpr: + switch e.Op { + case token.LAND, token.LOR: + return b.logicalBinop(fn, e) + case token.SHL, token.SHR: + fallthrough + case token.ADD, token.SUB, token.MUL, token.QUO, token.REM, token.AND, token.OR, token.XOR, token.AND_NOT: + return emitArith(fn, e.Op, b.expr(fn, e.X), b.expr(fn, e.Y), tv.Type, e.OpPos) + + case token.EQL, token.NEQ, token.GTR, token.LSS, token.LEQ, token.GEQ: + cmp := emitCompare(fn, e.Op, b.expr(fn, e.X), b.expr(fn, e.Y), e.OpPos) + // The type of x==y may be UntypedBool. + return emitConv(fn, cmp, DefaultType(tv.Type)) + default: + panic("illegal op in BinaryExpr: " + e.Op.String()) + } + + case *ast.SliceExpr: + var low, high, max Value + var x Value + switch fn.Pkg.typeOf(e.X).Underlying().(type) { + case *types.Array: + // Potentially escaping. + x = b.addr(fn, e.X, true).address(fn) + case *types.Basic, *types.Slice, *types.Pointer: // *array + x = b.expr(fn, e.X) + default: + panic("unreachable") + } + if e.High != nil { + high = b.expr(fn, e.High) + } + if e.Low != nil { + low = b.expr(fn, e.Low) + } + if e.Slice3 { + max = b.expr(fn, e.Max) + } + v := &Slice{ + X: x, + Low: low, + High: high, + Max: max, + } + v.setPos(e.Lbrack) + v.setType(tv.Type) + return fn.emit(v) + + case *ast.Ident: + obj := fn.Pkg.info.Uses[e] + // Universal built-in or nil? + switch obj := obj.(type) { + case *types.Builtin: + return &Builtin{name: obj.Name(), sig: tv.Type.(*types.Signature)} + case *types.Nil: + return nilConst(tv.Type) + } + // Package-level func or var? + if v := fn.Prog.packageLevelValue(obj); v != nil { + if _, ok := obj.(*types.Var); ok { + return emitLoad(fn, v) // var (address) + } + return v // (func) + } + // Local var. + return emitLoad(fn, fn.lookup(obj, false)) // var (address) + + case *ast.SelectorExpr: + sel, ok := fn.Pkg.info.Selections[e] + if !ok { + // qualified identifier + return b.expr(fn, e.Sel) + } + switch sel.Kind() { + case types.MethodExpr: + // (*T).f or T.f, the method f from the method-set of type T. + // The result is a "thunk". + return emitConv(fn, makeThunk(fn.Prog, sel), tv.Type) + + case types.MethodVal: + // e.f where e is an expression and f is a method. + // The result is a "bound". + obj := sel.Obj().(*types.Func) + rt := recvType(obj) + wantAddr := isPointer(rt) + escaping := true + v := b.receiver(fn, e.X, wantAddr, escaping, sel) + if isInterface(rt) { + // If v has interface type I, + // we must emit a check that v is non-nil. + // We use: typeassert v.(I). + emitTypeAssert(fn, v, rt, token.NoPos) + } + c := &MakeClosure{ + Fn: makeBound(fn.Prog, obj), + Bindings: []Value{v}, + } + c.setPos(e.Sel.Pos()) + c.setType(tv.Type) + return fn.emit(c) + + case types.FieldVal: + indices := sel.Index() + last := len(indices) - 1 + v := b.expr(fn, e.X) + v = emitImplicitSelections(fn, v, indices[:last]) + v = emitFieldSelection(fn, v, indices[last], false, e.Sel) + return v + } + + panic("unexpected expression-relative selector") + + case *ast.IndexExpr: + switch t := fn.Pkg.typeOf(e.X).Underlying().(type) { + case *types.Array: + // Non-addressable array (in a register). + v := &Index{ + X: b.expr(fn, e.X), + Index: emitConv(fn, b.expr(fn, e.Index), tInt), + } + v.setPos(e.Lbrack) + v.setType(t.Elem()) + return fn.emit(v) + + case *types.Map: + // Maps are not addressable. + mapt := fn.Pkg.typeOf(e.X).Underlying().(*types.Map) + v := &Lookup{ + X: b.expr(fn, e.X), + Index: emitConv(fn, b.expr(fn, e.Index), mapt.Key()), + } + v.setPos(e.Lbrack) + v.setType(mapt.Elem()) + return fn.emit(v) + + case *types.Basic: // => string + // Strings are not addressable. + v := &Lookup{ + X: b.expr(fn, e.X), + Index: b.expr(fn, e.Index), + } + v.setPos(e.Lbrack) + v.setType(tByte) + return fn.emit(v) + + case *types.Slice, *types.Pointer: // *array + // Addressable slice/array; use IndexAddr and Load. + return b.addr(fn, e, false).load(fn) + + default: + panic("unexpected container type in IndexExpr: " + t.String()) + } + + case *ast.CompositeLit, *ast.StarExpr: + // Addressable types (lvalues) + return b.addr(fn, e, false).load(fn) + } + + panic(fmt.Sprintf("unexpected expr: %T", e)) +} + +// stmtList emits to fn code for all statements in list. +func (b *builder) stmtList(fn *Function, list []ast.Stmt) { + for _, s := range list { + b.stmt(fn, s) + } +} + +// receiver emits to fn code for expression e in the "receiver" +// position of selection e.f (where f may be a field or a method) and +// returns the effective receiver after applying the implicit field +// selections of sel. +// +// wantAddr requests that the result is an an address. If +// !sel.Indirect(), this may require that e be built in addr() mode; it +// must thus be addressable. +// +// escaping is defined as per builder.addr(). +// +func (b *builder) receiver(fn *Function, e ast.Expr, wantAddr, escaping bool, sel *types.Selection) Value { + var v Value + if wantAddr && !sel.Indirect() && !isPointer(fn.Pkg.typeOf(e)) { + v = b.addr(fn, e, escaping).address(fn) + } else { + v = b.expr(fn, e) + } + + last := len(sel.Index()) - 1 + v = emitImplicitSelections(fn, v, sel.Index()[:last]) + if !wantAddr && isPointer(v.Type()) { + v = emitLoad(fn, v) + } + return v +} + +// setCallFunc populates the function parts of a CallCommon structure +// (Func, Method, Recv, Args[0]) based on the kind of invocation +// occurring in e. +// +func (b *builder) setCallFunc(fn *Function, e *ast.CallExpr, c *CallCommon) { + c.pos = e.Lparen + + // Is this a method call? + if selector, ok := unparen(e.Fun).(*ast.SelectorExpr); ok { + sel, ok := fn.Pkg.info.Selections[selector] + if ok && sel.Kind() == types.MethodVal { + obj := sel.Obj().(*types.Func) + recv := recvType(obj) + wantAddr := isPointer(recv) + escaping := true + v := b.receiver(fn, selector.X, wantAddr, escaping, sel) + if isInterface(recv) { + // Invoke-mode call. + c.Value = v + c.Method = obj + } else { + // "Call"-mode call. + c.Value = fn.Prog.declaredFunc(obj) + c.Args = append(c.Args, v) + } + return + } + + // sel.Kind()==MethodExpr indicates T.f() or (*T).f(): + // a statically dispatched call to the method f in the + // method-set of T or *T. T may be an interface. + // + // e.Fun would evaluate to a concrete method, interface + // wrapper function, or promotion wrapper. + // + // For now, we evaluate it in the usual way. + // + // TODO(adonovan): opt: inline expr() here, to make the + // call static and to avoid generation of wrappers. + // It's somewhat tricky as it may consume the first + // actual parameter if the call is "invoke" mode. + // + // Examples: + // type T struct{}; func (T) f() {} // "call" mode + // type T interface { f() } // "invoke" mode + // + // type S struct{ T } + // + // var s S + // S.f(s) + // (*S).f(&s) + // + // Suggested approach: + // - consume the first actual parameter expression + // and build it with b.expr(). + // - apply implicit field selections. + // - use MethodVal logic to populate fields of c. + } + + // Evaluate the function operand in the usual way. + c.Value = b.expr(fn, e.Fun) +} + +// emitCallArgs emits to f code for the actual parameters of call e to +// a (possibly built-in) function of effective type sig. +// The argument values are appended to args, which is then returned. +// +func (b *builder) emitCallArgs(fn *Function, sig *types.Signature, e *ast.CallExpr, args []Value) []Value { + // f(x, y, z...): pass slice z straight through. + if e.Ellipsis != 0 { + for i, arg := range e.Args { + v := emitConv(fn, b.expr(fn, arg), sig.Params().At(i).Type()) + args = append(args, v) + } + return args + } + + offset := len(args) // 1 if call has receiver, 0 otherwise + + // Evaluate actual parameter expressions. + // + // If this is a chained call of the form f(g()) where g has + // multiple return values (MRV), they are flattened out into + // args; a suffix of them may end up in a varargs slice. + for _, arg := range e.Args { + v := b.expr(fn, arg) + if ttuple, ok := v.Type().(*types.Tuple); ok { // MRV chain + for i, n := 0, ttuple.Len(); i < n; i++ { + args = append(args, emitExtract(fn, v, i)) + } + } else { + args = append(args, v) + } + } + + // Actual->formal assignability conversions for normal parameters. + np := sig.Params().Len() // number of normal parameters + if sig.Variadic() { + np-- + } + for i := 0; i < np; i++ { + args[offset+i] = emitConv(fn, args[offset+i], sig.Params().At(i).Type()) + } + + // Actual->formal assignability conversions for variadic parameter, + // and construction of slice. + if sig.Variadic() { + varargs := args[offset+np:] + st := sig.Params().At(np).Type().(*types.Slice) + vt := st.Elem() + if len(varargs) == 0 { + args = append(args, nilConst(st)) + } else { + // Replace a suffix of args with a slice containing it. + at := types.NewArray(vt, int64(len(varargs))) + a := emitNew(fn, at, token.NoPos) + a.setPos(e.Rparen) + a.Comment = "varargs" + for i, arg := range varargs { + iaddr := &IndexAddr{ + X: a, + Index: intConst(int64(i)), + } + iaddr.setType(types.NewPointer(vt)) + fn.emit(iaddr) + emitStore(fn, iaddr, arg, arg.Pos()) + } + s := &Slice{X: a} + s.setType(st) + args[offset+np] = fn.emit(s) + args = args[:offset+np+1] + } + } + return args +} + +// setCall emits to fn code to evaluate all the parameters of a function +// call e, and populates *c with those values. +// +func (b *builder) setCall(fn *Function, e *ast.CallExpr, c *CallCommon) { + // First deal with the f(...) part and optional receiver. + b.setCallFunc(fn, e, c) + + // Then append the other actual parameters. + sig, _ := fn.Pkg.typeOf(e.Fun).Underlying().(*types.Signature) + if sig == nil { + panic(fmt.Sprintf("no signature for call of %s", e.Fun)) + } + c.Args = b.emitCallArgs(fn, sig, e, c.Args) +} + +// assignOp emits to fn code to perform loc = val. +func (b *builder) assignOp(fn *Function, loc lvalue, val Value, op token.Token, pos token.Pos) { + oldv := loc.load(fn) + loc.store(fn, emitArith(fn, op, oldv, emitConv(fn, val, oldv.Type()), loc.typ(), pos)) +} + +// localValueSpec emits to fn code to define all of the vars in the +// function-local ValueSpec, spec. +// +func (b *builder) localValueSpec(fn *Function, spec *ast.ValueSpec) { + switch { + case len(spec.Values) == len(spec.Names): + // e.g. var x, y = 0, 1 + // 1:1 assignment + for i, id := range spec.Names { + if !isBlankIdent(id) { + fn.addLocalForIdent(id) + } + lval := b.addr(fn, id, false) // non-escaping + b.assign(fn, lval, spec.Values[i], true, nil) + } + + case len(spec.Values) == 0: + // e.g. var x, y int + // Locals are implicitly zero-initialized. + for _, id := range spec.Names { + if !isBlankIdent(id) { + lhs := fn.addLocalForIdent(id) + if fn.debugInfo() { + emitDebugRef(fn, id, lhs, true) + } + } + } + + default: + // e.g. var x, y = pos() + tuple := b.exprN(fn, spec.Values[0]) + for i, id := range spec.Names { + if !isBlankIdent(id) { + fn.addLocalForIdent(id) + lhs := b.addr(fn, id, false) // non-escaping + lhs.store(fn, emitExtract(fn, tuple, i)) + } + } + } +} + +// assignStmt emits code to fn for a parallel assignment of rhss to lhss. +// isDef is true if this is a short variable declaration (:=). +// +// Note the similarity with localValueSpec. +// +func (b *builder) assignStmt(fn *Function, lhss, rhss []ast.Expr, isDef bool) { + // Side effects of all LHSs and RHSs must occur in left-to-right order. + lvals := make([]lvalue, len(lhss)) + isZero := make([]bool, len(lhss)) + for i, lhs := range lhss { + var lval lvalue = blank{} + if !isBlankIdent(lhs) { + if isDef { + if obj := fn.Pkg.info.Defs[lhs.(*ast.Ident)]; obj != nil { + fn.addNamedLocal(obj) + isZero[i] = true + } + } + lval = b.addr(fn, lhs, false) // non-escaping + } + lvals[i] = lval + } + if len(lhss) == len(rhss) { + // Simple assignment: x = f() (!isDef) + // Parallel assignment: x, y = f(), g() (!isDef) + // or short var decl: x, y := f(), g() (isDef) + // + // In all cases, the RHSs may refer to the LHSs, + // so we need a storebuf. + var sb storebuf + for i := range rhss { + b.assign(fn, lvals[i], rhss[i], isZero[i], &sb) + } + sb.emit(fn) + } else { + // e.g. x, y = pos() + tuple := b.exprN(fn, rhss[0]) + emitDebugRef(fn, rhss[0], tuple, false) + for i, lval := range lvals { + lval.store(fn, emitExtract(fn, tuple, i)) + } + } +} + +// arrayLen returns the length of the array whose composite literal elements are elts. +func (b *builder) arrayLen(fn *Function, elts []ast.Expr) int64 { + var max int64 = -1 + var i int64 = -1 + for _, e := range elts { + if kv, ok := e.(*ast.KeyValueExpr); ok { + i = b.expr(fn, kv.Key).(*Const).Int64() + } else { + i++ + } + if i > max { + max = i + } + } + return max + 1 +} + +// compLit emits to fn code to initialize a composite literal e at +// address addr with type typ. +// +// Nested composite literals are recursively initialized in place +// where possible. If isZero is true, compLit assumes that addr +// holds the zero value for typ. +// +// Because the elements of a composite literal may refer to the +// variables being updated, as in the second line below, +// x := T{a: 1} +// x = T{a: x.a} +// all the reads must occur before all the writes. Thus all stores to +// loc are emitted to the storebuf sb for later execution. +// +// A CompositeLit may have pointer type only in the recursive (nested) +// case when the type name is implicit. e.g. in []*T{{}}, the inner +// literal has type *T behaves like &T{}. +// In that case, addr must hold a T, not a *T. +// +func (b *builder) compLit(fn *Function, addr Value, e *ast.CompositeLit, isZero bool, sb *storebuf) { + typ := deref(fn.Pkg.typeOf(e)) + switch t := typ.Underlying().(type) { + case *types.Struct: + if !isZero && len(e.Elts) != t.NumFields() { + // memclear + sb.store(&address{addr, e.Lbrace, nil}, + zeroValue(fn, deref(addr.Type()))) + isZero = true + } + for i, e := range e.Elts { + fieldIndex := i + pos := e.Pos() + if kv, ok := e.(*ast.KeyValueExpr); ok { + fname := kv.Key.(*ast.Ident).Name + for i, n := 0, t.NumFields(); i < n; i++ { + sf := t.Field(i) + if sf.Name() == fname { + fieldIndex = i + pos = kv.Colon + e = kv.Value + break + } + } + } + sf := t.Field(fieldIndex) + faddr := &FieldAddr{ + X: addr, + Field: fieldIndex, + } + faddr.setType(types.NewPointer(sf.Type())) + fn.emit(faddr) + b.assign(fn, &address{addr: faddr, pos: pos, expr: e}, e, isZero, sb) + } + + case *types.Array, *types.Slice: + var at *types.Array + var array Value + switch t := t.(type) { + case *types.Slice: + at = types.NewArray(t.Elem(), b.arrayLen(fn, e.Elts)) + alloc := emitNew(fn, at, e.Lbrace) + alloc.Comment = "slicelit" + array = alloc + case *types.Array: + at = t + array = addr + + if !isZero && int64(len(e.Elts)) != at.Len() { + // memclear + sb.store(&address{array, e.Lbrace, nil}, + zeroValue(fn, deref(array.Type()))) + } + } + + var idx *Const + for _, e := range e.Elts { + pos := e.Pos() + if kv, ok := e.(*ast.KeyValueExpr); ok { + idx = b.expr(fn, kv.Key).(*Const) + pos = kv.Colon + e = kv.Value + } else { + var idxval int64 + if idx != nil { + idxval = idx.Int64() + 1 + } + idx = intConst(idxval) + } + iaddr := &IndexAddr{ + X: array, + Index: idx, + } + iaddr.setType(types.NewPointer(at.Elem())) + fn.emit(iaddr) + if t != at { // slice + // backing array is unaliased => storebuf not needed. + b.assign(fn, &address{addr: iaddr, pos: pos, expr: e}, e, true, nil) + } else { + b.assign(fn, &address{addr: iaddr, pos: pos, expr: e}, e, true, sb) + } + } + + if t != at { // slice + s := &Slice{X: array} + s.setPos(e.Lbrace) + s.setType(typ) + sb.store(&address{addr: addr, pos: e.Lbrace, expr: e}, fn.emit(s)) + } + + case *types.Map: + m := &MakeMap{Reserve: intConst(int64(len(e.Elts)))} + m.setPos(e.Lbrace) + m.setType(typ) + fn.emit(m) + for _, e := range e.Elts { + e := e.(*ast.KeyValueExpr) + + // If a key expression in a map literal is itself a + // composite literal, the type may be omitted. + // For example: + // map[*struct{}]bool{{}: true} + // An &-operation may be implied: + // map[*struct{}]bool{&struct{}{}: true} + var key Value + if _, ok := unparen(e.Key).(*ast.CompositeLit); ok && isPointer(t.Key()) { + // A CompositeLit never evaluates to a pointer, + // so if the type of the location is a pointer, + // an &-operation is implied. + key = b.addr(fn, e.Key, true).address(fn) + } else { + key = b.expr(fn, e.Key) + } + + loc := element{ + m: m, + k: emitConv(fn, key, t.Key()), + t: t.Elem(), + pos: e.Colon, + } + + // We call assign() only because it takes care + // of any &-operation required in the recursive + // case, e.g., + // map[int]*struct{}{0: {}} implies &struct{}{}. + // In-place update is of course impossible, + // and no storebuf is needed. + b.assign(fn, &loc, e.Value, true, nil) + } + sb.store(&address{addr: addr, pos: e.Lbrace, expr: e}, m) + + default: + panic("unexpected CompositeLit type: " + t.String()) + } +} + +// switchStmt emits to fn code for the switch statement s, optionally +// labelled by label. +// +func (b *builder) switchStmt(fn *Function, s *ast.SwitchStmt, label *lblock) { + // We treat SwitchStmt like a sequential if-else chain. + // Multiway dispatch can be recovered later by ssautil.Switches() + // to those cases that are free of side effects. + if s.Init != nil { + b.stmt(fn, s.Init) + } + var tag Value = vTrue + if s.Tag != nil { + tag = b.expr(fn, s.Tag) + } + done := fn.newBasicBlock("switch.done") + if label != nil { + label._break = done + } + // We pull the default case (if present) down to the end. + // But each fallthrough label must point to the next + // body block in source order, so we preallocate a + // body block (fallthru) for the next case. + // Unfortunately this makes for a confusing block order. + var dfltBody *[]ast.Stmt + var dfltFallthrough *BasicBlock + var fallthru, dfltBlock *BasicBlock + ncases := len(s.Body.List) + for i, clause := range s.Body.List { + body := fallthru + if body == nil { + body = fn.newBasicBlock("switch.body") // first case only + } + + // Preallocate body block for the next case. + fallthru = done + if i+1 < ncases { + fallthru = fn.newBasicBlock("switch.body") + } + + cc := clause.(*ast.CaseClause) + if cc.List == nil { + // Default case. + dfltBody = &cc.Body + dfltFallthrough = fallthru + dfltBlock = body + continue + } + + var nextCond *BasicBlock + for _, cond := range cc.List { + nextCond = fn.newBasicBlock("switch.next") + // TODO(adonovan): opt: when tag==vTrue, we'd + // get better code if we use b.cond(cond) + // instead of BinOp(EQL, tag, b.expr(cond)) + // followed by If. Don't forget conversions + // though. + cond := emitCompare(fn, token.EQL, tag, b.expr(fn, cond), token.NoPos) + emitIf(fn, cond, body, nextCond) + fn.currentBlock = nextCond + } + fn.currentBlock = body + fn.targets = &targets{ + tail: fn.targets, + _break: done, + _fallthrough: fallthru, + } + b.stmtList(fn, cc.Body) + fn.targets = fn.targets.tail + emitJump(fn, done) + fn.currentBlock = nextCond + } + if dfltBlock != nil { + emitJump(fn, dfltBlock) + fn.currentBlock = dfltBlock + fn.targets = &targets{ + tail: fn.targets, + _break: done, + _fallthrough: dfltFallthrough, + } + b.stmtList(fn, *dfltBody) + fn.targets = fn.targets.tail + } + emitJump(fn, done) + fn.currentBlock = done +} + +// typeSwitchStmt emits to fn code for the type switch statement s, optionally +// labelled by label. +// +func (b *builder) typeSwitchStmt(fn *Function, s *ast.TypeSwitchStmt, label *lblock) { + // We treat TypeSwitchStmt like a sequential if-else chain. + // Multiway dispatch can be recovered later by ssautil.Switches(). + + // Typeswitch lowering: + // + // var x X + // switch y := x.(type) { + // case T1, T2: S1 // >1 (y := x) + // case nil: SN // nil (y := x) + // default: SD // 0 types (y := x) + // case T3: S3 // 1 type (y := x.(T3)) + // } + // + // ...s.Init... + // x := eval x + // .caseT1: + // t1, ok1 := typeswitch,ok x + // if ok1 then goto S1 else goto .caseT2 + // .caseT2: + // t2, ok2 := typeswitch,ok x + // if ok2 then goto S1 else goto .caseNil + // .S1: + // y := x + // ...S1... + // goto done + // .caseNil: + // if t2, ok2 := typeswitch,ok x + // if x == nil then goto SN else goto .caseT3 + // .SN: + // y := x + // ...SN... + // goto done + // .caseT3: + // t3, ok3 := typeswitch,ok x + // if ok3 then goto S3 else goto default + // .S3: + // y := t3 + // ...S3... + // goto done + // .default: + // y := x + // ...SD... + // goto done + // .done: + + if s.Init != nil { + b.stmt(fn, s.Init) + } + + var x Value + switch ass := s.Assign.(type) { + case *ast.ExprStmt: // x.(type) + x = b.expr(fn, unparen(ass.X).(*ast.TypeAssertExpr).X) + case *ast.AssignStmt: // y := x.(type) + x = b.expr(fn, unparen(ass.Rhs[0]).(*ast.TypeAssertExpr).X) + } + + done := fn.newBasicBlock("typeswitch.done") + if label != nil { + label._break = done + } + var default_ *ast.CaseClause + for _, clause := range s.Body.List { + cc := clause.(*ast.CaseClause) + if cc.List == nil { + default_ = cc + continue + } + body := fn.newBasicBlock("typeswitch.body") + var next *BasicBlock + var casetype types.Type + var ti Value // ti, ok := typeassert,ok x + for _, cond := range cc.List { + next = fn.newBasicBlock("typeswitch.next") + casetype = fn.Pkg.typeOf(cond) + var condv Value + if casetype == tUntypedNil { + condv = emitCompare(fn, token.EQL, x, nilConst(x.Type()), token.NoPos) + ti = x + } else { + yok := emitTypeTest(fn, x, casetype, cc.Case) + ti = emitExtract(fn, yok, 0) + condv = emitExtract(fn, yok, 1) + } + emitIf(fn, condv, body, next) + fn.currentBlock = next + } + if len(cc.List) != 1 { + ti = x + } + fn.currentBlock = body + b.typeCaseBody(fn, cc, ti, done) + fn.currentBlock = next + } + if default_ != nil { + b.typeCaseBody(fn, default_, x, done) + } else { + emitJump(fn, done) + } + fn.currentBlock = done +} + +func (b *builder) typeCaseBody(fn *Function, cc *ast.CaseClause, x Value, done *BasicBlock) { + if obj := fn.Pkg.info.Implicits[cc]; obj != nil { + // In a switch y := x.(type), each case clause + // implicitly declares a distinct object y. + // In a single-type case, y has that type. + // In multi-type cases, 'case nil' and default, + // y has the same type as the interface operand. + emitStore(fn, fn.addNamedLocal(obj), x, obj.Pos()) + } + fn.targets = &targets{ + tail: fn.targets, + _break: done, + } + b.stmtList(fn, cc.Body) + fn.targets = fn.targets.tail + emitJump(fn, done) +} + +// selectStmt emits to fn code for the select statement s, optionally +// labelled by label. +// +func (b *builder) selectStmt(fn *Function, s *ast.SelectStmt, label *lblock) { + // A blocking select of a single case degenerates to a + // simple send or receive. + // TODO(adonovan): opt: is this optimization worth its weight? + if len(s.Body.List) == 1 { + clause := s.Body.List[0].(*ast.CommClause) + if clause.Comm != nil { + b.stmt(fn, clause.Comm) + done := fn.newBasicBlock("select.done") + if label != nil { + label._break = done + } + fn.targets = &targets{ + tail: fn.targets, + _break: done, + } + b.stmtList(fn, clause.Body) + fn.targets = fn.targets.tail + emitJump(fn, done) + fn.currentBlock = done + return + } + } + + // First evaluate all channels in all cases, and find + // the directions of each state. + var states []*SelectState + blocking := true + debugInfo := fn.debugInfo() + for _, clause := range s.Body.List { + var st *SelectState + switch comm := clause.(*ast.CommClause).Comm.(type) { + case nil: // default case + blocking = false + continue + + case *ast.SendStmt: // ch<- i + ch := b.expr(fn, comm.Chan) + st = &SelectState{ + Dir: types.SendOnly, + Chan: ch, + Send: emitConv(fn, b.expr(fn, comm.Value), + ch.Type().Underlying().(*types.Chan).Elem()), + Pos: comm.Arrow, + } + if debugInfo { + st.DebugNode = comm + } + + case *ast.AssignStmt: // x := <-ch + recv := unparen(comm.Rhs[0]).(*ast.UnaryExpr) + st = &SelectState{ + Dir: types.RecvOnly, + Chan: b.expr(fn, recv.X), + Pos: recv.OpPos, + } + if debugInfo { + st.DebugNode = recv + } + + case *ast.ExprStmt: // <-ch + recv := unparen(comm.X).(*ast.UnaryExpr) + st = &SelectState{ + Dir: types.RecvOnly, + Chan: b.expr(fn, recv.X), + Pos: recv.OpPos, + } + if debugInfo { + st.DebugNode = recv + } + } + states = append(states, st) + } + + // We dispatch on the (fair) result of Select using a + // sequential if-else chain, in effect: + // + // idx, recvOk, r0...r_n-1 := select(...) + // if idx == 0 { // receive on channel 0 (first receive => r0) + // x, ok := r0, recvOk + // ...state0... + // } else if v == 1 { // send on channel 1 + // ...state1... + // } else { + // ...default... + // } + sel := &Select{ + States: states, + Blocking: blocking, + } + sel.setPos(s.Select) + var vars []*types.Var + vars = append(vars, varIndex, varOk) + for _, st := range states { + if st.Dir == types.RecvOnly { + tElem := st.Chan.Type().Underlying().(*types.Chan).Elem() + vars = append(vars, anonVar(tElem)) + } + } + sel.setType(types.NewTuple(vars...)) + + fn.emit(sel) + idx := emitExtract(fn, sel, 0) + + done := fn.newBasicBlock("select.done") + if label != nil { + label._break = done + } + + var defaultBody *[]ast.Stmt + state := 0 + r := 2 // index in 'sel' tuple of value; increments if st.Dir==RECV + for _, cc := range s.Body.List { + clause := cc.(*ast.CommClause) + if clause.Comm == nil { + defaultBody = &clause.Body + continue + } + body := fn.newBasicBlock("select.body") + next := fn.newBasicBlock("select.next") + emitIf(fn, emitCompare(fn, token.EQL, idx, intConst(int64(state)), token.NoPos), body, next) + fn.currentBlock = body + fn.targets = &targets{ + tail: fn.targets, + _break: done, + } + switch comm := clause.Comm.(type) { + case *ast.ExprStmt: // <-ch + if debugInfo { + v := emitExtract(fn, sel, r) + emitDebugRef(fn, states[state].DebugNode.(ast.Expr), v, false) + } + r++ + + case *ast.AssignStmt: // x := <-states[state].Chan + if comm.Tok == token.DEFINE { + fn.addLocalForIdent(comm.Lhs[0].(*ast.Ident)) + } + x := b.addr(fn, comm.Lhs[0], false) // non-escaping + v := emitExtract(fn, sel, r) + if debugInfo { + emitDebugRef(fn, states[state].DebugNode.(ast.Expr), v, false) + } + x.store(fn, v) + + if len(comm.Lhs) == 2 { // x, ok := ... + if comm.Tok == token.DEFINE { + fn.addLocalForIdent(comm.Lhs[1].(*ast.Ident)) + } + ok := b.addr(fn, comm.Lhs[1], false) // non-escaping + ok.store(fn, emitExtract(fn, sel, 1)) + } + r++ + } + b.stmtList(fn, clause.Body) + fn.targets = fn.targets.tail + emitJump(fn, done) + fn.currentBlock = next + state++ + } + if defaultBody != nil { + fn.targets = &targets{ + tail: fn.targets, + _break: done, + } + b.stmtList(fn, *defaultBody) + fn.targets = fn.targets.tail + } else { + // A blocking select must match some case. + // (This should really be a runtime.errorString, not a string.) + fn.emit(&Panic{ + X: emitConv(fn, stringConst("blocking select matched no case"), tEface), + }) + fn.currentBlock = fn.newBasicBlock("unreachable") + } + emitJump(fn, done) + fn.currentBlock = done +} + +// forStmt emits to fn code for the for statement s, optionally +// labelled by label. +// +func (b *builder) forStmt(fn *Function, s *ast.ForStmt, label *lblock) { + // ...init... + // jump loop + // loop: + // if cond goto body else done + // body: + // ...body... + // jump post + // post: (target of continue) + // ...post... + // jump loop + // done: (target of break) + if s.Init != nil { + b.stmt(fn, s.Init) + } + body := fn.newBasicBlock("for.body") + done := fn.newBasicBlock("for.done") // target of 'break' + loop := body // target of back-edge + if s.Cond != nil { + loop = fn.newBasicBlock("for.loop") + } + cont := loop // target of 'continue' + if s.Post != nil { + cont = fn.newBasicBlock("for.post") + } + if label != nil { + label._break = done + label._continue = cont + } + emitJump(fn, loop) + fn.currentBlock = loop + if loop != body { + b.cond(fn, s.Cond, body, done) + fn.currentBlock = body + } + fn.targets = &targets{ + tail: fn.targets, + _break: done, + _continue: cont, + } + b.stmt(fn, s.Body) + fn.targets = fn.targets.tail + emitJump(fn, cont) + + if s.Post != nil { + fn.currentBlock = cont + b.stmt(fn, s.Post) + emitJump(fn, loop) // back-edge + } + fn.currentBlock = done +} + +// rangeIndexed emits to fn the header for an integer-indexed loop +// over array, *array or slice value x. +// The v result is defined only if tv is non-nil. +// forPos is the position of the "for" token. +// +func (b *builder) rangeIndexed(fn *Function, x Value, tv types.Type, pos token.Pos) (k, v Value, loop, done *BasicBlock) { + // + // length = len(x) + // index = -1 + // loop: (target of continue) + // index++ + // if index < length goto body else done + // body: + // k = index + // v = x[index] + // ...body... + // jump loop + // done: (target of break) + + // Determine number of iterations. + var length Value + if arr, ok := deref(x.Type()).Underlying().(*types.Array); ok { + // For array or *array, the number of iterations is + // known statically thanks to the type. We avoid a + // data dependence upon x, permitting later dead-code + // elimination if x is pure, static unrolling, etc. + // Ranging over a nil *array may have >0 iterations. + // We still generate code for x, in case it has effects. + length = intConst(arr.Len()) + } else { + // length = len(x). + var c Call + c.Call.Value = makeLen(x.Type()) + c.Call.Args = []Value{x} + c.setType(tInt) + length = fn.emit(&c) + } + + index := fn.addLocal(tInt, token.NoPos) + emitStore(fn, index, intConst(-1), pos) + + loop = fn.newBasicBlock("rangeindex.loop") + emitJump(fn, loop) + fn.currentBlock = loop + + incr := &BinOp{ + Op: token.ADD, + X: emitLoad(fn, index), + Y: vOne, + } + incr.setType(tInt) + emitStore(fn, index, fn.emit(incr), pos) + + body := fn.newBasicBlock("rangeindex.body") + done = fn.newBasicBlock("rangeindex.done") + emitIf(fn, emitCompare(fn, token.LSS, incr, length, token.NoPos), body, done) + fn.currentBlock = body + + k = emitLoad(fn, index) + if tv != nil { + switch t := x.Type().Underlying().(type) { + case *types.Array: + instr := &Index{ + X: x, + Index: k, + } + instr.setType(t.Elem()) + instr.setPos(x.Pos()) + v = fn.emit(instr) + + case *types.Pointer: // *array + instr := &IndexAddr{ + X: x, + Index: k, + } + instr.setType(types.NewPointer(t.Elem().Underlying().(*types.Array).Elem())) + instr.setPos(x.Pos()) + v = emitLoad(fn, fn.emit(instr)) + + case *types.Slice: + instr := &IndexAddr{ + X: x, + Index: k, + } + instr.setType(types.NewPointer(t.Elem())) + instr.setPos(x.Pos()) + v = emitLoad(fn, fn.emit(instr)) + + default: + panic("rangeIndexed x:" + t.String()) + } + } + return +} + +// rangeIter emits to fn the header for a loop using +// Range/Next/Extract to iterate over map or string value x. +// tk and tv are the types of the key/value results k and v, or nil +// if the respective component is not wanted. +// +func (b *builder) rangeIter(fn *Function, x Value, tk, tv types.Type, pos token.Pos) (k, v Value, loop, done *BasicBlock) { + // + // it = range x + // loop: (target of continue) + // okv = next it (ok, key, value) + // ok = extract okv #0 + // if ok goto body else done + // body: + // k = extract okv #1 + // v = extract okv #2 + // ...body... + // jump loop + // done: (target of break) + // + + if tk == nil { + tk = tInvalid + } + if tv == nil { + tv = tInvalid + } + + rng := &Range{X: x} + rng.setPos(pos) + rng.setType(tRangeIter) + it := fn.emit(rng) + + loop = fn.newBasicBlock("rangeiter.loop") + emitJump(fn, loop) + fn.currentBlock = loop + + _, isString := x.Type().Underlying().(*types.Basic) + + okv := &Next{ + Iter: it, + IsString: isString, + } + okv.setType(types.NewTuple( + varOk, + newVar("k", tk), + newVar("v", tv), + )) + fn.emit(okv) + + body := fn.newBasicBlock("rangeiter.body") + done = fn.newBasicBlock("rangeiter.done") + emitIf(fn, emitExtract(fn, okv, 0), body, done) + fn.currentBlock = body + + if tk != tInvalid { + k = emitExtract(fn, okv, 1) + } + if tv != tInvalid { + v = emitExtract(fn, okv, 2) + } + return +} + +// rangeChan emits to fn the header for a loop that receives from +// channel x until it fails. +// tk is the channel's element type, or nil if the k result is +// not wanted +// pos is the position of the '=' or ':=' token. +// +func (b *builder) rangeChan(fn *Function, x Value, tk types.Type, pos token.Pos) (k Value, loop, done *BasicBlock) { + // + // loop: (target of continue) + // ko = <-x (key, ok) + // ok = extract ko #1 + // if ok goto body else done + // body: + // k = extract ko #0 + // ... + // goto loop + // done: (target of break) + + loop = fn.newBasicBlock("rangechan.loop") + emitJump(fn, loop) + fn.currentBlock = loop + recv := &UnOp{ + Op: token.ARROW, + X: x, + CommaOk: true, + } + recv.setPos(pos) + recv.setType(types.NewTuple( + newVar("k", x.Type().Underlying().(*types.Chan).Elem()), + varOk, + )) + ko := fn.emit(recv) + body := fn.newBasicBlock("rangechan.body") + done = fn.newBasicBlock("rangechan.done") + emitIf(fn, emitExtract(fn, ko, 1), body, done) + fn.currentBlock = body + if tk != nil { + k = emitExtract(fn, ko, 0) + } + return +} + +// rangeStmt emits to fn code for the range statement s, optionally +// labelled by label. +// +func (b *builder) rangeStmt(fn *Function, s *ast.RangeStmt, label *lblock) { + var tk, tv types.Type + if s.Key != nil && !isBlankIdent(s.Key) { + tk = fn.Pkg.typeOf(s.Key) + } + if s.Value != nil && !isBlankIdent(s.Value) { + tv = fn.Pkg.typeOf(s.Value) + } + + // If iteration variables are defined (:=), this + // occurs once outside the loop. + // + // Unlike a short variable declaration, a RangeStmt + // using := never redeclares an existing variable; it + // always creates a new one. + if s.Tok == token.DEFINE { + if tk != nil { + fn.addLocalForIdent(s.Key.(*ast.Ident)) + } + if tv != nil { + fn.addLocalForIdent(s.Value.(*ast.Ident)) + } + } + + x := b.expr(fn, s.X) + + var k, v Value + var loop, done *BasicBlock + switch rt := x.Type().Underlying().(type) { + case *types.Slice, *types.Array, *types.Pointer: // *array + k, v, loop, done = b.rangeIndexed(fn, x, tv, s.For) + + case *types.Chan: + k, loop, done = b.rangeChan(fn, x, tk, s.For) + + case *types.Map, *types.Basic: // string + k, v, loop, done = b.rangeIter(fn, x, tk, tv, s.For) + + default: + panic("Cannot range over: " + rt.String()) + } + + // Evaluate both LHS expressions before we update either. + var kl, vl lvalue + if tk != nil { + kl = b.addr(fn, s.Key, false) // non-escaping + } + if tv != nil { + vl = b.addr(fn, s.Value, false) // non-escaping + } + if tk != nil { + kl.store(fn, k) + } + if tv != nil { + vl.store(fn, v) + } + + if label != nil { + label._break = done + label._continue = loop + } + + fn.targets = &targets{ + tail: fn.targets, + _break: done, + _continue: loop, + } + b.stmt(fn, s.Body) + fn.targets = fn.targets.tail + emitJump(fn, loop) // back-edge + fn.currentBlock = done +} + +// stmt lowers statement s to SSA form, emitting code to fn. +func (b *builder) stmt(fn *Function, _s ast.Stmt) { + // The label of the current statement. If non-nil, its _goto + // target is always set; its _break and _continue are set only + // within the body of switch/typeswitch/select/for/range. + // It is effectively an additional default-nil parameter of stmt(). + var label *lblock +start: + switch s := _s.(type) { + case *ast.EmptyStmt: + // ignore. (Usually removed by gofmt.) + + case *ast.DeclStmt: // Con, Var or Typ + d := s.Decl.(*ast.GenDecl) + if d.Tok == token.VAR { + for _, spec := range d.Specs { + if vs, ok := spec.(*ast.ValueSpec); ok { + b.localValueSpec(fn, vs) + } + } + } + + case *ast.LabeledStmt: + label = fn.labelledBlock(s.Label) + emitJump(fn, label._goto) + fn.currentBlock = label._goto + _s = s.Stmt + goto start // effectively: tailcall stmt(fn, s.Stmt, label) + + case *ast.ExprStmt: + b.expr(fn, s.X) + + case *ast.SendStmt: + fn.emit(&Send{ + Chan: b.expr(fn, s.Chan), + X: emitConv(fn, b.expr(fn, s.Value), + fn.Pkg.typeOf(s.Chan).Underlying().(*types.Chan).Elem()), + pos: s.Arrow, + }) + + case *ast.IncDecStmt: + op := token.ADD + if s.Tok == token.DEC { + op = token.SUB + } + loc := b.addr(fn, s.X, false) + b.assignOp(fn, loc, NewConst(constant.MakeInt64(1), loc.typ()), op, s.Pos()) + + case *ast.AssignStmt: + switch s.Tok { + case token.ASSIGN, token.DEFINE: + b.assignStmt(fn, s.Lhs, s.Rhs, s.Tok == token.DEFINE) + + default: // +=, etc. + op := s.Tok + token.ADD - token.ADD_ASSIGN + b.assignOp(fn, b.addr(fn, s.Lhs[0], false), b.expr(fn, s.Rhs[0]), op, s.Pos()) + } + + case *ast.GoStmt: + // The "intrinsics" new/make/len/cap are forbidden here. + // panic is treated like an ordinary function call. + v := Go{pos: s.Go} + b.setCall(fn, s.Call, &v.Call) + fn.emit(&v) + + case *ast.DeferStmt: + // The "intrinsics" new/make/len/cap are forbidden here. + // panic is treated like an ordinary function call. + v := Defer{pos: s.Defer} + b.setCall(fn, s.Call, &v.Call) + fn.emit(&v) + + // A deferred call can cause recovery from panic, + // and control resumes at the Recover block. + createRecoverBlock(fn) + + case *ast.ReturnStmt: + var results []Value + if len(s.Results) == 1 && fn.Signature.Results().Len() > 1 { + // Return of one expression in a multi-valued function. + tuple := b.exprN(fn, s.Results[0]) + ttuple := tuple.Type().(*types.Tuple) + for i, n := 0, ttuple.Len(); i < n; i++ { + results = append(results, + emitConv(fn, emitExtract(fn, tuple, i), + fn.Signature.Results().At(i).Type())) + } + } else { + // 1:1 return, or no-arg return in non-void function. + for i, r := range s.Results { + v := emitConv(fn, b.expr(fn, r), fn.Signature.Results().At(i).Type()) + results = append(results, v) + } + } + if fn.namedResults != nil { + // Function has named result parameters (NRPs). + // Perform parallel assignment of return operands to NRPs. + for i, r := range results { + emitStore(fn, fn.namedResults[i], r, s.Return) + } + } + // Run function calls deferred in this + // function when explicitly returning from it. + fn.emit(new(RunDefers)) + if fn.namedResults != nil { + // Reload NRPs to form the result tuple. + results = results[:0] + for _, r := range fn.namedResults { + results = append(results, emitLoad(fn, r)) + } + } + fn.emit(&Return{Results: results, pos: s.Return}) + fn.currentBlock = fn.newBasicBlock("unreachable") + + case *ast.BranchStmt: + var block *BasicBlock + switch s.Tok { + case token.BREAK: + if s.Label != nil { + block = fn.labelledBlock(s.Label)._break + } else { + for t := fn.targets; t != nil && block == nil; t = t.tail { + block = t._break + } + } + + case token.CONTINUE: + if s.Label != nil { + block = fn.labelledBlock(s.Label)._continue + } else { + for t := fn.targets; t != nil && block == nil; t = t.tail { + block = t._continue + } + } + + case token.FALLTHROUGH: + for t := fn.targets; t != nil && block == nil; t = t.tail { + block = t._fallthrough + } + + case token.GOTO: + block = fn.labelledBlock(s.Label)._goto + } + emitJump(fn, block) + fn.currentBlock = fn.newBasicBlock("unreachable") + + case *ast.BlockStmt: + b.stmtList(fn, s.List) + + case *ast.IfStmt: + if s.Init != nil { + b.stmt(fn, s.Init) + } + then := fn.newBasicBlock("if.then") + done := fn.newBasicBlock("if.done") + els := done + if s.Else != nil { + els = fn.newBasicBlock("if.else") + } + b.cond(fn, s.Cond, then, els) + fn.currentBlock = then + b.stmt(fn, s.Body) + emitJump(fn, done) + + if s.Else != nil { + fn.currentBlock = els + b.stmt(fn, s.Else) + emitJump(fn, done) + } + + fn.currentBlock = done + + case *ast.SwitchStmt: + b.switchStmt(fn, s, label) + + case *ast.TypeSwitchStmt: + b.typeSwitchStmt(fn, s, label) + + case *ast.SelectStmt: + b.selectStmt(fn, s, label) + + case *ast.ForStmt: + b.forStmt(fn, s, label) + + case *ast.RangeStmt: + b.rangeStmt(fn, s, label) + + default: + panic(fmt.Sprintf("unexpected statement kind: %T", s)) + } +} + +// buildFunction builds SSA code for the body of function fn. Idempotent. +func (b *builder) buildFunction(fn *Function) { + if fn.Blocks != nil { + return // building already started + } + + var recvField *ast.FieldList + var body *ast.BlockStmt + var functype *ast.FuncType + switch n := fn.syntax.(type) { + case nil: + return // not a Go source function. (Synthetic, or from object file.) + case *ast.FuncDecl: + functype = n.Type + recvField = n.Recv + body = n.Body + case *ast.FuncLit: + functype = n.Type + body = n.Body + default: + panic(n) + } + + if body == nil { + // External function. + if fn.Params == nil { + // This condition ensures we add a non-empty + // params list once only, but we may attempt + // the degenerate empty case repeatedly. + // TODO(adonovan): opt: don't do that. + + // We set Function.Params even though there is no body + // code to reference them. This simplifies clients. + if recv := fn.Signature.Recv(); recv != nil { + fn.addParamObj(recv) + } + params := fn.Signature.Params() + for i, n := 0, params.Len(); i < n; i++ { + fn.addParamObj(params.At(i)) + } + } + return + } + if fn.Prog.mode&LogSource != 0 { + defer logStack("build function %s @ %s", fn, fn.Prog.Fset.Position(fn.pos))() + } + fn.startBody() + fn.createSyntacticParams(recvField, functype) + b.stmt(fn, body) + if cb := fn.currentBlock; cb != nil && (cb == fn.Blocks[0] || cb == fn.Recover || cb.Preds != nil) { + // Control fell off the end of the function's body block. + // + // Block optimizations eliminate the current block, if + // unreachable. It is a builder invariant that + // if this no-arg return is ill-typed for + // fn.Signature.Results, this block must be + // unreachable. The sanity checker checks this. + fn.emit(new(RunDefers)) + fn.emit(new(Return)) + } + fn.finishBody() +} + +// buildFuncDecl builds SSA code for the function or method declared +// by decl in package pkg. +// +func (b *builder) buildFuncDecl(pkg *Package, decl *ast.FuncDecl) { + id := decl.Name + if isBlankIdent(id) { + return // discard + } + fn := pkg.values[pkg.info.Defs[id]].(*Function) + if decl.Recv == nil && id.Name == "init" { + var v Call + v.Call.Value = fn + v.setType(types.NewTuple()) + pkg.init.emit(&v) + } + b.buildFunction(fn) +} + +// Build calls Package.Build for each package in prog. +// Building occurs in parallel unless the BuildSerially mode flag was set. +// +// Build is intended for whole-program analysis; a typical compiler +// need only build a single package. +// +// Build is idempotent and thread-safe. +// +func (prog *Program) Build() { + var wg sync.WaitGroup + for _, p := range prog.packages { + if prog.mode&BuildSerially != 0 { + p.Build() + } else { + wg.Add(1) + go func(p *Package) { + p.Build() + wg.Done() + }(p) + } + } + wg.Wait() +} + +// Build builds SSA code for all functions and vars in package p. +// +// Precondition: CreatePackage must have been called for all of p's +// direct imports (and hence its direct imports must have been +// error-free). +// +// Build is idempotent and thread-safe. +// +func (p *Package) Build() { p.buildOnce.Do(p.build) } + +func (p *Package) build() { + if p.info == nil { + return // synthetic package, e.g. "testmain" + } + + // Ensure we have runtime type info for all exported members. + // TODO(adonovan): ideally belongs in memberFromObject, but + // that would require package creation in topological order. + for name, mem := range p.Members { + if ast.IsExported(name) { + p.Prog.needMethodsOf(mem.Type()) + } + } + if p.Prog.mode&LogSource != 0 { + defer logStack("build %s", p)() + } + init := p.init + init.startBody() + + var done *BasicBlock + + if p.Prog.mode&BareInits == 0 { + // Make init() skip if package is already initialized. + initguard := p.Var("init$guard") + doinit := init.newBasicBlock("init.start") + done = init.newBasicBlock("init.done") + emitIf(init, emitLoad(init, initguard), done, doinit) + init.currentBlock = doinit + emitStore(init, initguard, vTrue, token.NoPos) + + // Call the init() function of each package we import. + for _, pkg := range p.Pkg.Imports() { + prereq := p.Prog.packages[pkg] + if prereq == nil { + panic(fmt.Sprintf("Package(%q).Build(): unsatisfied import: Program.CreatePackage(%q) was not called", p.Pkg.Path(), pkg.Path())) + } + var v Call + v.Call.Value = prereq.init + v.Call.pos = init.pos + v.setType(types.NewTuple()) + init.emit(&v) + } + } + + var b builder + + // Initialize package-level vars in correct order. + for _, varinit := range p.info.InitOrder { + if init.Prog.mode&LogSource != 0 { + fmt.Fprintf(os.Stderr, "build global initializer %v @ %s\n", + varinit.Lhs, p.Prog.Fset.Position(varinit.Rhs.Pos())) + } + if len(varinit.Lhs) == 1 { + // 1:1 initialization: var x, y = a(), b() + var lval lvalue + if v := varinit.Lhs[0]; v.Name() != "_" { + lval = &address{addr: p.values[v].(*Global), pos: v.Pos()} + } else { + lval = blank{} + } + b.assign(init, lval, varinit.Rhs, true, nil) + } else { + // n:1 initialization: var x, y := f() + tuple := b.exprN(init, varinit.Rhs) + for i, v := range varinit.Lhs { + if v.Name() == "_" { + continue + } + emitStore(init, p.values[v].(*Global), emitExtract(init, tuple, i), v.Pos()) + } + } + } + + // Build all package-level functions, init functions + // and methods, including unreachable/blank ones. + // We build them in source order, but it's not significant. + for _, file := range p.files { + for _, decl := range file.Decls { + if decl, ok := decl.(*ast.FuncDecl); ok { + b.buildFuncDecl(p, decl) + } + } + } + + // Finish up init(). + if p.Prog.mode&BareInits == 0 { + emitJump(init, done) + init.currentBlock = done + } + init.emit(new(Return)) + init.finishBody() + + p.info = nil // We no longer need ASTs or go/types deductions. + + if p.Prog.mode&SanityCheckFunctions != 0 { + sanityCheckPackage(p) + } +} + +// Like ObjectOf, but panics instead of returning nil. +// Only valid during p's create and build phases. +func (p *Package) objectOf(id *ast.Ident) types.Object { + if o := p.info.ObjectOf(id); o != nil { + return o + } + panic(fmt.Sprintf("no types.Object for ast.Ident %s @ %s", + id.Name, p.Prog.Fset.Position(id.Pos()))) +} + +// Like TypeOf, but panics instead of returning nil. +// Only valid during p's create and build phases. +func (p *Package) typeOf(e ast.Expr) types.Type { + if T := p.info.TypeOf(e); T != nil { + return T + } + panic(fmt.Sprintf("no type for %T @ %s", + e, p.Prog.Fset.Position(e.Pos()))) +} diff --git a/vendor/golang.org/x/tools/go/ssa/const.go b/vendor/golang.org/x/tools/go/ssa/const.go new file mode 100644 index 00000000000..f43792e7f37 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/const.go @@ -0,0 +1,169 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines the Const SSA value type. + +import ( + "fmt" + "go/constant" + "go/token" + "go/types" + "strconv" +) + +// NewConst returns a new constant of the specified value and type. +// val must be valid according to the specification of Const.Value. +// +func NewConst(val constant.Value, typ types.Type) *Const { + return &Const{typ, val} +} + +// intConst returns an 'int' constant that evaluates to i. +// (i is an int64 in case the host is narrower than the target.) +func intConst(i int64) *Const { + return NewConst(constant.MakeInt64(i), tInt) +} + +// nilConst returns a nil constant of the specified type, which may +// be any reference type, including interfaces. +// +func nilConst(typ types.Type) *Const { + return NewConst(nil, typ) +} + +// stringConst returns a 'string' constant that evaluates to s. +func stringConst(s string) *Const { + return NewConst(constant.MakeString(s), tString) +} + +// zeroConst returns a new "zero" constant of the specified type, +// which must not be an array or struct type: the zero values of +// aggregates are well-defined but cannot be represented by Const. +// +func zeroConst(t types.Type) *Const { + switch t := t.(type) { + case *types.Basic: + switch { + case t.Info()&types.IsBoolean != 0: + return NewConst(constant.MakeBool(false), t) + case t.Info()&types.IsNumeric != 0: + return NewConst(constant.MakeInt64(0), t) + case t.Info()&types.IsString != 0: + return NewConst(constant.MakeString(""), t) + case t.Kind() == types.UnsafePointer: + fallthrough + case t.Kind() == types.UntypedNil: + return nilConst(t) + default: + panic(fmt.Sprint("zeroConst for unexpected type:", t)) + } + case *types.Pointer, *types.Slice, *types.Interface, *types.Chan, *types.Map, *types.Signature: + return nilConst(t) + case *types.Named: + return NewConst(zeroConst(t.Underlying()).Value, t) + case *types.Array, *types.Struct, *types.Tuple: + panic(fmt.Sprint("zeroConst applied to aggregate:", t)) + } + panic(fmt.Sprint("zeroConst: unexpected ", t)) +} + +func (c *Const) RelString(from *types.Package) string { + var s string + if c.Value == nil { + s = "nil" + } else if c.Value.Kind() == constant.String { + s = constant.StringVal(c.Value) + const max = 20 + // TODO(adonovan): don't cut a rune in half. + if len(s) > max { + s = s[:max-3] + "..." // abbreviate + } + s = strconv.Quote(s) + } else { + s = c.Value.String() + } + return s + ":" + relType(c.Type(), from) +} + +func (c *Const) Name() string { + return c.RelString(nil) +} + +func (c *Const) String() string { + return c.Name() +} + +func (c *Const) Type() types.Type { + return c.typ +} + +func (c *Const) Referrers() *[]Instruction { + return nil +} + +func (c *Const) Parent() *Function { return nil } + +func (c *Const) Pos() token.Pos { + return token.NoPos +} + +// IsNil returns true if this constant represents a typed or untyped nil value. +func (c *Const) IsNil() bool { + return c.Value == nil +} + +// TODO(adonovan): move everything below into golang.org/x/tools/go/ssa/interp. + +// Int64 returns the numeric value of this constant truncated to fit +// a signed 64-bit integer. +// +func (c *Const) Int64() int64 { + switch x := constant.ToInt(c.Value); x.Kind() { + case constant.Int: + if i, ok := constant.Int64Val(x); ok { + return i + } + return 0 + case constant.Float: + f, _ := constant.Float64Val(x) + return int64(f) + } + panic(fmt.Sprintf("unexpected constant value: %T", c.Value)) +} + +// Uint64 returns the numeric value of this constant truncated to fit +// an unsigned 64-bit integer. +// +func (c *Const) Uint64() uint64 { + switch x := constant.ToInt(c.Value); x.Kind() { + case constant.Int: + if u, ok := constant.Uint64Val(x); ok { + return u + } + return 0 + case constant.Float: + f, _ := constant.Float64Val(x) + return uint64(f) + } + panic(fmt.Sprintf("unexpected constant value: %T", c.Value)) +} + +// Float64 returns the numeric value of this constant truncated to fit +// a float64. +// +func (c *Const) Float64() float64 { + f, _ := constant.Float64Val(c.Value) + return f +} + +// Complex128 returns the complex value of this constant truncated to +// fit a complex128. +// +func (c *Const) Complex128() complex128 { + re, _ := constant.Float64Val(constant.Real(c.Value)) + im, _ := constant.Float64Val(constant.Imag(c.Value)) + return complex(re, im) +} diff --git a/vendor/golang.org/x/tools/go/ssa/create.go b/vendor/golang.org/x/tools/go/ssa/create.go new file mode 100644 index 00000000000..85163a0c5a7 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/create.go @@ -0,0 +1,270 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file implements the CREATE phase of SSA construction. +// See builder.go for explanation. + +import ( + "fmt" + "go/ast" + "go/token" + "go/types" + "os" + "sync" + + "golang.org/x/tools/go/types/typeutil" +) + +// NewProgram returns a new SSA Program. +// +// mode controls diagnostics and checking during SSA construction. +// +func NewProgram(fset *token.FileSet, mode BuilderMode) *Program { + prog := &Program{ + Fset: fset, + imported: make(map[string]*Package), + packages: make(map[*types.Package]*Package), + thunks: make(map[selectionKey]*Function), + bounds: make(map[*types.Func]*Function), + mode: mode, + } + + h := typeutil.MakeHasher() // protected by methodsMu, in effect + prog.methodSets.SetHasher(h) + prog.canon.SetHasher(h) + + return prog +} + +// memberFromObject populates package pkg with a member for the +// typechecker object obj. +// +// For objects from Go source code, syntax is the associated syntax +// tree (for funcs and vars only); it will be used during the build +// phase. +// +func memberFromObject(pkg *Package, obj types.Object, syntax ast.Node) { + name := obj.Name() + switch obj := obj.(type) { + case *types.Builtin: + if pkg.Pkg != types.Unsafe { + panic("unexpected builtin object: " + obj.String()) + } + + case *types.TypeName: + pkg.Members[name] = &Type{ + object: obj, + pkg: pkg, + } + + case *types.Const: + c := &NamedConst{ + object: obj, + Value: NewConst(obj.Val(), obj.Type()), + pkg: pkg, + } + pkg.values[obj] = c.Value + pkg.Members[name] = c + + case *types.Var: + g := &Global{ + Pkg: pkg, + name: name, + object: obj, + typ: types.NewPointer(obj.Type()), // address + pos: obj.Pos(), + } + pkg.values[obj] = g + pkg.Members[name] = g + + case *types.Func: + sig := obj.Type().(*types.Signature) + if sig.Recv() == nil && name == "init" { + pkg.ninit++ + name = fmt.Sprintf("init#%d", pkg.ninit) + } + fn := &Function{ + name: name, + object: obj, + Signature: sig, + syntax: syntax, + pos: obj.Pos(), + Pkg: pkg, + Prog: pkg.Prog, + } + if syntax == nil { + fn.Synthetic = "loaded from gc object file" + } + + pkg.values[obj] = fn + if sig.Recv() == nil { + pkg.Members[name] = fn // package-level function + } + + default: // (incl. *types.Package) + panic("unexpected Object type: " + obj.String()) + } +} + +// membersFromDecl populates package pkg with members for each +// typechecker object (var, func, const or type) associated with the +// specified decl. +// +func membersFromDecl(pkg *Package, decl ast.Decl) { + switch decl := decl.(type) { + case *ast.GenDecl: // import, const, type or var + switch decl.Tok { + case token.CONST: + for _, spec := range decl.Specs { + for _, id := range spec.(*ast.ValueSpec).Names { + if !isBlankIdent(id) { + memberFromObject(pkg, pkg.info.Defs[id], nil) + } + } + } + + case token.VAR: + for _, spec := range decl.Specs { + for _, id := range spec.(*ast.ValueSpec).Names { + if !isBlankIdent(id) { + memberFromObject(pkg, pkg.info.Defs[id], spec) + } + } + } + + case token.TYPE: + for _, spec := range decl.Specs { + id := spec.(*ast.TypeSpec).Name + if !isBlankIdent(id) { + memberFromObject(pkg, pkg.info.Defs[id], nil) + } + } + } + + case *ast.FuncDecl: + id := decl.Name + if !isBlankIdent(id) { + memberFromObject(pkg, pkg.info.Defs[id], decl) + } + } +} + +// CreatePackage constructs and returns an SSA Package from the +// specified type-checked, error-free file ASTs, and populates its +// Members mapping. +// +// importable determines whether this package should be returned by a +// subsequent call to ImportedPackage(pkg.Path()). +// +// The real work of building SSA form for each function is not done +// until a subsequent call to Package.Build(). +// +func (prog *Program) CreatePackage(pkg *types.Package, files []*ast.File, info *types.Info, importable bool) *Package { + p := &Package{ + Prog: prog, + Members: make(map[string]Member), + values: make(map[types.Object]Value), + Pkg: pkg, + info: info, // transient (CREATE and BUILD phases) + files: files, // transient (CREATE and BUILD phases) + } + + // Add init() function. + p.init = &Function{ + name: "init", + Signature: new(types.Signature), + Synthetic: "package initializer", + Pkg: p, + Prog: prog, + } + p.Members[p.init.name] = p.init + + // CREATE phase. + // Allocate all package members: vars, funcs, consts and types. + if len(files) > 0 { + // Go source package. + for _, file := range files { + for _, decl := range file.Decls { + membersFromDecl(p, decl) + } + } + } else { + // GC-compiled binary package (or "unsafe") + // No code. + // No position information. + scope := p.Pkg.Scope() + for _, name := range scope.Names() { + obj := scope.Lookup(name) + memberFromObject(p, obj, nil) + if obj, ok := obj.(*types.TypeName); ok { + if named, ok := obj.Type().(*types.Named); ok { + for i, n := 0, named.NumMethods(); i < n; i++ { + memberFromObject(p, named.Method(i), nil) + } + } + } + } + } + + if prog.mode&BareInits == 0 { + // Add initializer guard variable. + initguard := &Global{ + Pkg: p, + name: "init$guard", + typ: types.NewPointer(tBool), + } + p.Members[initguard.Name()] = initguard + } + + if prog.mode&GlobalDebug != 0 { + p.SetDebugMode(true) + } + + if prog.mode&PrintPackages != 0 { + printMu.Lock() + p.WriteTo(os.Stdout) + printMu.Unlock() + } + + if importable { + prog.imported[p.Pkg.Path()] = p + } + prog.packages[p.Pkg] = p + + return p +} + +// printMu serializes printing of Packages/Functions to stdout. +var printMu sync.Mutex + +// AllPackages returns a new slice containing all packages in the +// program prog in unspecified order. +// +func (prog *Program) AllPackages() []*Package { + pkgs := make([]*Package, 0, len(prog.packages)) + for _, pkg := range prog.packages { + pkgs = append(pkgs, pkg) + } + return pkgs +} + +// ImportedPackage returns the importable Package whose PkgPath +// is path, or nil if no such Package has been created. +// +// A parameter to CreatePackage determines whether a package should be +// considered importable. For example, no import declaration can resolve +// to the ad-hoc main package created by 'go build foo.go'. +// +// TODO(adonovan): rethink this function and the "importable" concept; +// most packages are importable. This function assumes that all +// types.Package.Path values are unique within the ssa.Program, which is +// false---yet this function remains very convenient. +// Clients should use (*Program).Package instead where possible. +// SSA doesn't really need a string-keyed map of packages. +// +func (prog *Program) ImportedPackage(path string) *Package { + return prog.imported[path] +} diff --git a/vendor/golang.org/x/tools/go/ssa/doc.go b/vendor/golang.org/x/tools/go/ssa/doc.go new file mode 100644 index 00000000000..1a13640f9d5 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/doc.go @@ -0,0 +1,125 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package ssa defines a representation of the elements of Go programs +// (packages, types, functions, variables and constants) using a +// static single-assignment (SSA) form intermediate representation +// (IR) for the bodies of functions. +// +// THIS INTERFACE IS EXPERIMENTAL AND IS LIKELY TO CHANGE. +// +// For an introduction to SSA form, see +// http://en.wikipedia.org/wiki/Static_single_assignment_form. +// This page provides a broader reading list: +// http://www.dcs.gla.ac.uk/~jsinger/ssa.html. +// +// The level of abstraction of the SSA form is intentionally close to +// the source language to facilitate construction of source analysis +// tools. It is not intended for machine code generation. +// +// All looping, branching and switching constructs are replaced with +// unstructured control flow. Higher-level control flow constructs +// such as multi-way branch can be reconstructed as needed; see +// ssautil.Switches() for an example. +// +// The simplest way to create the SSA representation of a package is +// to load typed syntax trees using golang.org/x/tools/go/packages, then +// invoke the ssautil.Packages helper function. See ExampleLoadPackages +// and ExampleWholeProgram for examples. +// The resulting ssa.Program contains all the packages and their +// members, but SSA code is not created for function bodies until a +// subsequent call to (*Package).Build or (*Program).Build. +// +// The builder initially builds a naive SSA form in which all local +// variables are addresses of stack locations with explicit loads and +// stores. Registerisation of eligible locals and φ-node insertion +// using dominance and dataflow are then performed as a second pass +// called "lifting" to improve the accuracy and performance of +// subsequent analyses; this pass can be skipped by setting the +// NaiveForm builder flag. +// +// The primary interfaces of this package are: +// +// - Member: a named member of a Go package. +// - Value: an expression that yields a value. +// - Instruction: a statement that consumes values and performs computation. +// - Node: a Value or Instruction (emphasizing its membership in the SSA value graph) +// +// A computation that yields a result implements both the Value and +// Instruction interfaces. The following table shows for each +// concrete type which of these interfaces it implements. +// +// Value? Instruction? Member? +// *Alloc ✔ ✔ +// *BinOp ✔ ✔ +// *Builtin ✔ +// *Call ✔ ✔ +// *ChangeInterface ✔ ✔ +// *ChangeType ✔ ✔ +// *Const ✔ +// *Convert ✔ ✔ +// *DebugRef ✔ +// *Defer ✔ +// *Extract ✔ ✔ +// *Field ✔ ✔ +// *FieldAddr ✔ ✔ +// *FreeVar ✔ +// *Function ✔ ✔ (func) +// *Global ✔ ✔ (var) +// *Go ✔ +// *If ✔ +// *Index ✔ ✔ +// *IndexAddr ✔ ✔ +// *Jump ✔ +// *Lookup ✔ ✔ +// *MakeChan ✔ ✔ +// *MakeClosure ✔ ✔ +// *MakeInterface ✔ ✔ +// *MakeMap ✔ ✔ +// *MakeSlice ✔ ✔ +// *MapUpdate ✔ +// *NamedConst ✔ (const) +// *Next ✔ ✔ +// *Panic ✔ +// *Parameter ✔ +// *Phi ✔ ✔ +// *Range ✔ ✔ +// *Return ✔ +// *RunDefers ✔ +// *Select ✔ ✔ +// *Send ✔ +// *Slice ✔ ✔ +// *Store ✔ +// *Type ✔ (type) +// *TypeAssert ✔ ✔ +// *UnOp ✔ ✔ +// +// Other key types in this package include: Program, Package, Function +// and BasicBlock. +// +// The program representation constructed by this package is fully +// resolved internally, i.e. it does not rely on the names of Values, +// Packages, Functions, Types or BasicBlocks for the correct +// interpretation of the program. Only the identities of objects and +// the topology of the SSA and type graphs are semantically +// significant. (There is one exception: Ids, used to identify field +// and method names, contain strings.) Avoidance of name-based +// operations simplifies the implementation of subsequent passes and +// can make them very efficient. Many objects are nonetheless named +// to aid in debugging, but it is not essential that the names be +// either accurate or unambiguous. The public API exposes a number of +// name-based maps for client convenience. +// +// The ssa/ssautil package provides various utilities that depend only +// on the public API of this package. +// +// TODO(adonovan): Consider the exceptional control-flow implications +// of defer and recover(). +// +// TODO(adonovan): write a how-to document for all the various cases +// of trying to determine corresponding elements across the four +// domains of source locations, ast.Nodes, types.Objects, +// ssa.Values/Instructions. +// +package ssa // import "golang.org/x/tools/go/ssa" diff --git a/vendor/golang.org/x/tools/go/ssa/dom.go b/vendor/golang.org/x/tools/go/ssa/dom.go new file mode 100644 index 00000000000..12ef4308f3c --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/dom.go @@ -0,0 +1,341 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines algorithms related to dominance. + +// Dominator tree construction ---------------------------------------- +// +// We use the algorithm described in Lengauer & Tarjan. 1979. A fast +// algorithm for finding dominators in a flowgraph. +// http://doi.acm.org/10.1145/357062.357071 +// +// We also apply the optimizations to SLT described in Georgiadis et +// al, Finding Dominators in Practice, JGAA 2006, +// http://jgaa.info/accepted/2006/GeorgiadisTarjanWerneck2006.10.1.pdf +// to avoid the need for buckets of size > 1. + +import ( + "bytes" + "fmt" + "math/big" + "os" + "sort" +) + +// Idom returns the block that immediately dominates b: +// its parent in the dominator tree, if any. +// Neither the entry node (b.Index==0) nor recover node +// (b==b.Parent().Recover()) have a parent. +// +func (b *BasicBlock) Idom() *BasicBlock { return b.dom.idom } + +// Dominees returns the list of blocks that b immediately dominates: +// its children in the dominator tree. +// +func (b *BasicBlock) Dominees() []*BasicBlock { return b.dom.children } + +// Dominates reports whether b dominates c. +func (b *BasicBlock) Dominates(c *BasicBlock) bool { + return b.dom.pre <= c.dom.pre && c.dom.post <= b.dom.post +} + +type byDomPreorder []*BasicBlock + +func (a byDomPreorder) Len() int { return len(a) } +func (a byDomPreorder) Swap(i, j int) { a[i], a[j] = a[j], a[i] } +func (a byDomPreorder) Less(i, j int) bool { return a[i].dom.pre < a[j].dom.pre } + +// DomPreorder returns a new slice containing the blocks of f in +// dominator tree preorder. +// +func (f *Function) DomPreorder() []*BasicBlock { + n := len(f.Blocks) + order := make(byDomPreorder, n, n) + copy(order, f.Blocks) + sort.Sort(order) + return order +} + +// domInfo contains a BasicBlock's dominance information. +type domInfo struct { + idom *BasicBlock // immediate dominator (parent in domtree) + children []*BasicBlock // nodes immediately dominated by this one + pre, post int32 // pre- and post-order numbering within domtree +} + +// ltState holds the working state for Lengauer-Tarjan algorithm +// (during which domInfo.pre is repurposed for CFG DFS preorder number). +type ltState struct { + // Each slice is indexed by b.Index. + sdom []*BasicBlock // b's semidominator + parent []*BasicBlock // b's parent in DFS traversal of CFG + ancestor []*BasicBlock // b's ancestor with least sdom +} + +// dfs implements the depth-first search part of the LT algorithm. +func (lt *ltState) dfs(v *BasicBlock, i int32, preorder []*BasicBlock) int32 { + preorder[i] = v + v.dom.pre = i // For now: DFS preorder of spanning tree of CFG + i++ + lt.sdom[v.Index] = v + lt.link(nil, v) + for _, w := range v.Succs { + if lt.sdom[w.Index] == nil { + lt.parent[w.Index] = v + i = lt.dfs(w, i, preorder) + } + } + return i +} + +// eval implements the EVAL part of the LT algorithm. +func (lt *ltState) eval(v *BasicBlock) *BasicBlock { + // TODO(adonovan): opt: do path compression per simple LT. + u := v + for ; lt.ancestor[v.Index] != nil; v = lt.ancestor[v.Index] { + if lt.sdom[v.Index].dom.pre < lt.sdom[u.Index].dom.pre { + u = v + } + } + return u +} + +// link implements the LINK part of the LT algorithm. +func (lt *ltState) link(v, w *BasicBlock) { + lt.ancestor[w.Index] = v +} + +// buildDomTree computes the dominator tree of f using the LT algorithm. +// Precondition: all blocks are reachable (e.g. optimizeBlocks has been run). +// +func buildDomTree(f *Function) { + // The step numbers refer to the original LT paper; the + // reordering is due to Georgiadis. + + // Clear any previous domInfo. + for _, b := range f.Blocks { + b.dom = domInfo{} + } + + n := len(f.Blocks) + // Allocate space for 5 contiguous [n]*BasicBlock arrays: + // sdom, parent, ancestor, preorder, buckets. + space := make([]*BasicBlock, 5*n, 5*n) + lt := ltState{ + sdom: space[0:n], + parent: space[n : 2*n], + ancestor: space[2*n : 3*n], + } + + // Step 1. Number vertices by depth-first preorder. + preorder := space[3*n : 4*n] + root := f.Blocks[0] + prenum := lt.dfs(root, 0, preorder) + recover := f.Recover + if recover != nil { + lt.dfs(recover, prenum, preorder) + } + + buckets := space[4*n : 5*n] + copy(buckets, preorder) + + // In reverse preorder... + for i := int32(n) - 1; i > 0; i-- { + w := preorder[i] + + // Step 3. Implicitly define the immediate dominator of each node. + for v := buckets[i]; v != w; v = buckets[v.dom.pre] { + u := lt.eval(v) + if lt.sdom[u.Index].dom.pre < i { + v.dom.idom = u + } else { + v.dom.idom = w + } + } + + // Step 2. Compute the semidominators of all nodes. + lt.sdom[w.Index] = lt.parent[w.Index] + for _, v := range w.Preds { + u := lt.eval(v) + if lt.sdom[u.Index].dom.pre < lt.sdom[w.Index].dom.pre { + lt.sdom[w.Index] = lt.sdom[u.Index] + } + } + + lt.link(lt.parent[w.Index], w) + + if lt.parent[w.Index] == lt.sdom[w.Index] { + w.dom.idom = lt.parent[w.Index] + } else { + buckets[i] = buckets[lt.sdom[w.Index].dom.pre] + buckets[lt.sdom[w.Index].dom.pre] = w + } + } + + // The final 'Step 3' is now outside the loop. + for v := buckets[0]; v != root; v = buckets[v.dom.pre] { + v.dom.idom = root + } + + // Step 4. Explicitly define the immediate dominator of each + // node, in preorder. + for _, w := range preorder[1:] { + if w == root || w == recover { + w.dom.idom = nil + } else { + if w.dom.idom != lt.sdom[w.Index] { + w.dom.idom = w.dom.idom.dom.idom + } + // Calculate Children relation as inverse of Idom. + w.dom.idom.dom.children = append(w.dom.idom.dom.children, w) + } + } + + pre, post := numberDomTree(root, 0, 0) + if recover != nil { + numberDomTree(recover, pre, post) + } + + // printDomTreeDot(os.Stderr, f) // debugging + // printDomTreeText(os.Stderr, root, 0) // debugging + + if f.Prog.mode&SanityCheckFunctions != 0 { + sanityCheckDomTree(f) + } +} + +// numberDomTree sets the pre- and post-order numbers of a depth-first +// traversal of the dominator tree rooted at v. These are used to +// answer dominance queries in constant time. +// +func numberDomTree(v *BasicBlock, pre, post int32) (int32, int32) { + v.dom.pre = pre + pre++ + for _, child := range v.dom.children { + pre, post = numberDomTree(child, pre, post) + } + v.dom.post = post + post++ + return pre, post +} + +// Testing utilities ---------------------------------------- + +// sanityCheckDomTree checks the correctness of the dominator tree +// computed by the LT algorithm by comparing against the dominance +// relation computed by a naive Kildall-style forward dataflow +// analysis (Algorithm 10.16 from the "Dragon" book). +// +func sanityCheckDomTree(f *Function) { + n := len(f.Blocks) + + // D[i] is the set of blocks that dominate f.Blocks[i], + // represented as a bit-set of block indices. + D := make([]big.Int, n) + + one := big.NewInt(1) + + // all is the set of all blocks; constant. + var all big.Int + all.Set(one).Lsh(&all, uint(n)).Sub(&all, one) + + // Initialization. + for i, b := range f.Blocks { + if i == 0 || b == f.Recover { + // A root is dominated only by itself. + D[i].SetBit(&D[0], 0, 1) + } else { + // All other blocks are (initially) dominated + // by every block. + D[i].Set(&all) + } + } + + // Iteration until fixed point. + for changed := true; changed; { + changed = false + for i, b := range f.Blocks { + if i == 0 || b == f.Recover { + continue + } + // Compute intersection across predecessors. + var x big.Int + x.Set(&all) + for _, pred := range b.Preds { + x.And(&x, &D[pred.Index]) + } + x.SetBit(&x, i, 1) // a block always dominates itself. + if D[i].Cmp(&x) != 0 { + D[i].Set(&x) + changed = true + } + } + } + + // Check the entire relation. O(n^2). + // The Recover block (if any) must be treated specially so we skip it. + ok := true + for i := 0; i < n; i++ { + for j := 0; j < n; j++ { + b, c := f.Blocks[i], f.Blocks[j] + if c == f.Recover { + continue + } + actual := b.Dominates(c) + expected := D[j].Bit(i) == 1 + if actual != expected { + fmt.Fprintf(os.Stderr, "dominates(%s, %s)==%t, want %t\n", b, c, actual, expected) + ok = false + } + } + } + + preorder := f.DomPreorder() + for _, b := range f.Blocks { + if got := preorder[b.dom.pre]; got != b { + fmt.Fprintf(os.Stderr, "preorder[%d]==%s, want %s\n", b.dom.pre, got, b) + ok = false + } + } + + if !ok { + panic("sanityCheckDomTree failed for " + f.String()) + } + +} + +// Printing functions ---------------------------------------- + +// printDomTree prints the dominator tree as text, using indentation. +func printDomTreeText(buf *bytes.Buffer, v *BasicBlock, indent int) { + fmt.Fprintf(buf, "%*s%s\n", 4*indent, "", v) + for _, child := range v.dom.children { + printDomTreeText(buf, child, indent+1) + } +} + +// printDomTreeDot prints the dominator tree of f in AT&T GraphViz +// (.dot) format. +func printDomTreeDot(buf *bytes.Buffer, f *Function) { + fmt.Fprintln(buf, "//", f) + fmt.Fprintln(buf, "digraph domtree {") + for i, b := range f.Blocks { + v := b.dom + fmt.Fprintf(buf, "\tn%d [label=\"%s (%d, %d)\",shape=\"rectangle\"];\n", v.pre, b, v.pre, v.post) + // TODO(adonovan): improve appearance of edges + // belonging to both dominator tree and CFG. + + // Dominator tree edge. + if i != 0 { + fmt.Fprintf(buf, "\tn%d -> n%d [style=\"solid\",weight=100];\n", v.idom.dom.pre, v.pre) + } + // CFG edges. + for _, pred := range b.Preds { + fmt.Fprintf(buf, "\tn%d -> n%d [style=\"dotted\",weight=0];\n", pred.dom.pre, v.pre) + } + } + fmt.Fprintln(buf, "}") +} diff --git a/vendor/golang.org/x/tools/go/ssa/emit.go b/vendor/golang.org/x/tools/go/ssa/emit.go new file mode 100644 index 00000000000..1036988adcb --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/emit.go @@ -0,0 +1,468 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// Helpers for emitting SSA instructions. + +import ( + "fmt" + "go/ast" + "go/token" + "go/types" +) + +// emitNew emits to f a new (heap Alloc) instruction allocating an +// object of type typ. pos is the optional source location. +// +func emitNew(f *Function, typ types.Type, pos token.Pos) *Alloc { + v := &Alloc{Heap: true} + v.setType(types.NewPointer(typ)) + v.setPos(pos) + f.emit(v) + return v +} + +// emitLoad emits to f an instruction to load the address addr into a +// new temporary, and returns the value so defined. +// +func emitLoad(f *Function, addr Value) *UnOp { + v := &UnOp{Op: token.MUL, X: addr} + v.setType(deref(addr.Type())) + f.emit(v) + return v +} + +// emitDebugRef emits to f a DebugRef pseudo-instruction associating +// expression e with value v. +// +func emitDebugRef(f *Function, e ast.Expr, v Value, isAddr bool) { + if !f.debugInfo() { + return // debugging not enabled + } + if v == nil || e == nil { + panic("nil") + } + var obj types.Object + e = unparen(e) + if id, ok := e.(*ast.Ident); ok { + if isBlankIdent(id) { + return + } + obj = f.Pkg.objectOf(id) + switch obj.(type) { + case *types.Nil, *types.Const, *types.Builtin: + return + } + } + f.emit(&DebugRef{ + X: v, + Expr: e, + IsAddr: isAddr, + object: obj, + }) +} + +// emitArith emits to f code to compute the binary operation op(x, y) +// where op is an eager shift, logical or arithmetic operation. +// (Use emitCompare() for comparisons and Builder.logicalBinop() for +// non-eager operations.) +// +func emitArith(f *Function, op token.Token, x, y Value, t types.Type, pos token.Pos) Value { + switch op { + case token.SHL, token.SHR: + x = emitConv(f, x, t) + // y may be signed or an 'untyped' constant. + // TODO(adonovan): whence signed values? + if b, ok := y.Type().Underlying().(*types.Basic); ok && b.Info()&types.IsUnsigned == 0 { + y = emitConv(f, y, types.Typ[types.Uint64]) + } + + case token.ADD, token.SUB, token.MUL, token.QUO, token.REM, token.AND, token.OR, token.XOR, token.AND_NOT: + x = emitConv(f, x, t) + y = emitConv(f, y, t) + + default: + panic("illegal op in emitArith: " + op.String()) + + } + v := &BinOp{ + Op: op, + X: x, + Y: y, + } + v.setPos(pos) + v.setType(t) + return f.emit(v) +} + +// emitCompare emits to f code compute the boolean result of +// comparison comparison 'x op y'. +// +func emitCompare(f *Function, op token.Token, x, y Value, pos token.Pos) Value { + xt := x.Type().Underlying() + yt := y.Type().Underlying() + + // Special case to optimise a tagless SwitchStmt so that + // these are equivalent + // switch { case e: ...} + // switch true { case e: ... } + // if e==true { ... } + // even in the case when e's type is an interface. + // TODO(adonovan): opt: generalise to x==true, false!=y, etc. + if x == vTrue && op == token.EQL { + if yt, ok := yt.(*types.Basic); ok && yt.Info()&types.IsBoolean != 0 { + return y + } + } + + if types.Identical(xt, yt) { + // no conversion necessary + } else if _, ok := xt.(*types.Interface); ok { + y = emitConv(f, y, x.Type()) + } else if _, ok := yt.(*types.Interface); ok { + x = emitConv(f, x, y.Type()) + } else if _, ok := x.(*Const); ok { + x = emitConv(f, x, y.Type()) + } else if _, ok := y.(*Const); ok { + y = emitConv(f, y, x.Type()) + } else { + // other cases, e.g. channels. No-op. + } + + v := &BinOp{ + Op: op, + X: x, + Y: y, + } + v.setPos(pos) + v.setType(tBool) + return f.emit(v) +} + +// isValuePreserving returns true if a conversion from ut_src to +// ut_dst is value-preserving, i.e. just a change of type. +// Precondition: neither argument is a named type. +// +func isValuePreserving(ut_src, ut_dst types.Type) bool { + // Identical underlying types? + if structTypesIdentical(ut_dst, ut_src) { + return true + } + + switch ut_dst.(type) { + case *types.Chan: + // Conversion between channel types? + _, ok := ut_src.(*types.Chan) + return ok + + case *types.Pointer: + // Conversion between pointers with identical base types? + _, ok := ut_src.(*types.Pointer) + return ok + } + return false +} + +// emitConv emits to f code to convert Value val to exactly type typ, +// and returns the converted value. Implicit conversions are required +// by language assignability rules in assignments, parameter passing, +// etc. Conversions cannot fail dynamically. +// +func emitConv(f *Function, val Value, typ types.Type) Value { + t_src := val.Type() + + // Identical types? Conversion is a no-op. + if types.Identical(t_src, typ) { + return val + } + + ut_dst := typ.Underlying() + ut_src := t_src.Underlying() + + // Just a change of type, but not value or representation? + if isValuePreserving(ut_src, ut_dst) { + c := &ChangeType{X: val} + c.setType(typ) + return f.emit(c) + } + + // Conversion to, or construction of a value of, an interface type? + if _, ok := ut_dst.(*types.Interface); ok { + // Assignment from one interface type to another? + if _, ok := ut_src.(*types.Interface); ok { + c := &ChangeInterface{X: val} + c.setType(typ) + return f.emit(c) + } + + // Untyped nil constant? Return interface-typed nil constant. + if ut_src == tUntypedNil { + return nilConst(typ) + } + + // Convert (non-nil) "untyped" literals to their default type. + if t, ok := ut_src.(*types.Basic); ok && t.Info()&types.IsUntyped != 0 { + val = emitConv(f, val, DefaultType(ut_src)) + } + + f.Pkg.Prog.needMethodsOf(val.Type()) + mi := &MakeInterface{X: val} + mi.setType(typ) + return f.emit(mi) + } + + // Conversion of a compile-time constant value? + if c, ok := val.(*Const); ok { + if _, ok := ut_dst.(*types.Basic); ok || c.IsNil() { + // Conversion of a compile-time constant to + // another constant type results in a new + // constant of the destination type and + // (initially) the same abstract value. + // We don't truncate the value yet. + return NewConst(c.Value, typ) + } + + // We're converting from constant to non-constant type, + // e.g. string -> []byte/[]rune. + } + + // A representation-changing conversion? + // At least one of {ut_src,ut_dst} must be *Basic. + // (The other may be []byte or []rune.) + _, ok1 := ut_src.(*types.Basic) + _, ok2 := ut_dst.(*types.Basic) + if ok1 || ok2 { + c := &Convert{X: val} + c.setType(typ) + return f.emit(c) + } + + panic(fmt.Sprintf("in %s: cannot convert %s (%s) to %s", f, val, val.Type(), typ)) +} + +// emitStore emits to f an instruction to store value val at location +// addr, applying implicit conversions as required by assignability rules. +// +func emitStore(f *Function, addr, val Value, pos token.Pos) *Store { + s := &Store{ + Addr: addr, + Val: emitConv(f, val, deref(addr.Type())), + pos: pos, + } + f.emit(s) + return s +} + +// emitJump emits to f a jump to target, and updates the control-flow graph. +// Postcondition: f.currentBlock is nil. +// +func emitJump(f *Function, target *BasicBlock) { + b := f.currentBlock + b.emit(new(Jump)) + addEdge(b, target) + f.currentBlock = nil +} + +// emitIf emits to f a conditional jump to tblock or fblock based on +// cond, and updates the control-flow graph. +// Postcondition: f.currentBlock is nil. +// +func emitIf(f *Function, cond Value, tblock, fblock *BasicBlock) { + b := f.currentBlock + b.emit(&If{Cond: cond}) + addEdge(b, tblock) + addEdge(b, fblock) + f.currentBlock = nil +} + +// emitExtract emits to f an instruction to extract the index'th +// component of tuple. It returns the extracted value. +// +func emitExtract(f *Function, tuple Value, index int) Value { + e := &Extract{Tuple: tuple, Index: index} + e.setType(tuple.Type().(*types.Tuple).At(index).Type()) + return f.emit(e) +} + +// emitTypeAssert emits to f a type assertion value := x.(t) and +// returns the value. x.Type() must be an interface. +// +func emitTypeAssert(f *Function, x Value, t types.Type, pos token.Pos) Value { + a := &TypeAssert{X: x, AssertedType: t} + a.setPos(pos) + a.setType(t) + return f.emit(a) +} + +// emitTypeTest emits to f a type test value,ok := x.(t) and returns +// a (value, ok) tuple. x.Type() must be an interface. +// +func emitTypeTest(f *Function, x Value, t types.Type, pos token.Pos) Value { + a := &TypeAssert{ + X: x, + AssertedType: t, + CommaOk: true, + } + a.setPos(pos) + a.setType(types.NewTuple( + newVar("value", t), + varOk, + )) + return f.emit(a) +} + +// emitTailCall emits to f a function call in tail position. The +// caller is responsible for all fields of 'call' except its type. +// Intended for wrapper methods. +// Precondition: f does/will not use deferred procedure calls. +// Postcondition: f.currentBlock is nil. +// +func emitTailCall(f *Function, call *Call) { + tresults := f.Signature.Results() + nr := tresults.Len() + if nr == 1 { + call.typ = tresults.At(0).Type() + } else { + call.typ = tresults + } + tuple := f.emit(call) + var ret Return + switch nr { + case 0: + // no-op + case 1: + ret.Results = []Value{tuple} + default: + for i := 0; i < nr; i++ { + v := emitExtract(f, tuple, i) + // TODO(adonovan): in principle, this is required: + // v = emitConv(f, o.Type, f.Signature.Results[i].Type) + // but in practice emitTailCall is only used when + // the types exactly match. + ret.Results = append(ret.Results, v) + } + } + f.emit(&ret) + f.currentBlock = nil +} + +// emitImplicitSelections emits to f code to apply the sequence of +// implicit field selections specified by indices to base value v, and +// returns the selected value. +// +// If v is the address of a struct, the result will be the address of +// a field; if it is the value of a struct, the result will be the +// value of a field. +// +func emitImplicitSelections(f *Function, v Value, indices []int) Value { + for _, index := range indices { + fld := deref(v.Type()).Underlying().(*types.Struct).Field(index) + + if isPointer(v.Type()) { + instr := &FieldAddr{ + X: v, + Field: index, + } + instr.setType(types.NewPointer(fld.Type())) + v = f.emit(instr) + // Load the field's value iff indirectly embedded. + if isPointer(fld.Type()) { + v = emitLoad(f, v) + } + } else { + instr := &Field{ + X: v, + Field: index, + } + instr.setType(fld.Type()) + v = f.emit(instr) + } + } + return v +} + +// emitFieldSelection emits to f code to select the index'th field of v. +// +// If wantAddr, the input must be a pointer-to-struct and the result +// will be the field's address; otherwise the result will be the +// field's value. +// Ident id is used for position and debug info. +// +func emitFieldSelection(f *Function, v Value, index int, wantAddr bool, id *ast.Ident) Value { + fld := deref(v.Type()).Underlying().(*types.Struct).Field(index) + if isPointer(v.Type()) { + instr := &FieldAddr{ + X: v, + Field: index, + } + instr.setPos(id.Pos()) + instr.setType(types.NewPointer(fld.Type())) + v = f.emit(instr) + // Load the field's value iff we don't want its address. + if !wantAddr { + v = emitLoad(f, v) + } + } else { + instr := &Field{ + X: v, + Field: index, + } + instr.setPos(id.Pos()) + instr.setType(fld.Type()) + v = f.emit(instr) + } + emitDebugRef(f, id, v, wantAddr) + return v +} + +// zeroValue emits to f code to produce a zero value of type t, +// and returns it. +// +func zeroValue(f *Function, t types.Type) Value { + switch t.Underlying().(type) { + case *types.Struct, *types.Array: + return emitLoad(f, f.addLocal(t, token.NoPos)) + default: + return zeroConst(t) + } +} + +// createRecoverBlock emits to f a block of code to return after a +// recovered panic, and sets f.Recover to it. +// +// If f's result parameters are named, the code loads and returns +// their current values, otherwise it returns the zero values of their +// type. +// +// Idempotent. +// +func createRecoverBlock(f *Function) { + if f.Recover != nil { + return // already created + } + saved := f.currentBlock + + f.Recover = f.newBasicBlock("recover") + f.currentBlock = f.Recover + + var results []Value + if f.namedResults != nil { + // Reload NRPs to form value tuple. + for _, r := range f.namedResults { + results = append(results, emitLoad(f, r)) + } + } else { + R := f.Signature.Results() + for i, n := 0, R.Len(); i < n; i++ { + T := R.At(i).Type() + + // Return zero value of each result type. + results = append(results, zeroValue(f, T)) + } + } + f.emit(&Return{Results: results}) + + f.currentBlock = saved +} diff --git a/vendor/golang.org/x/tools/go/ssa/func.go b/vendor/golang.org/x/tools/go/ssa/func.go new file mode 100644 index 00000000000..0b99bc9ba16 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/func.go @@ -0,0 +1,691 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file implements the Function and BasicBlock types. + +import ( + "bytes" + "fmt" + "go/ast" + "go/token" + "go/types" + "io" + "os" + "strings" +) + +// addEdge adds a control-flow graph edge from from to to. +func addEdge(from, to *BasicBlock) { + from.Succs = append(from.Succs, to) + to.Preds = append(to.Preds, from) +} + +// Parent returns the function that contains block b. +func (b *BasicBlock) Parent() *Function { return b.parent } + +// String returns a human-readable label of this block. +// It is not guaranteed unique within the function. +// +func (b *BasicBlock) String() string { + return fmt.Sprintf("%d", b.Index) +} + +// emit appends an instruction to the current basic block. +// If the instruction defines a Value, it is returned. +// +func (b *BasicBlock) emit(i Instruction) Value { + i.setBlock(b) + b.Instrs = append(b.Instrs, i) + v, _ := i.(Value) + return v +} + +// predIndex returns the i such that b.Preds[i] == c or panics if +// there is none. +func (b *BasicBlock) predIndex(c *BasicBlock) int { + for i, pred := range b.Preds { + if pred == c { + return i + } + } + panic(fmt.Sprintf("no edge %s -> %s", c, b)) +} + +// hasPhi returns true if b.Instrs contains φ-nodes. +func (b *BasicBlock) hasPhi() bool { + _, ok := b.Instrs[0].(*Phi) + return ok +} + +// phis returns the prefix of b.Instrs containing all the block's φ-nodes. +func (b *BasicBlock) phis() []Instruction { + for i, instr := range b.Instrs { + if _, ok := instr.(*Phi); !ok { + return b.Instrs[:i] + } + } + return nil // unreachable in well-formed blocks +} + +// replacePred replaces all occurrences of p in b's predecessor list with q. +// Ordinarily there should be at most one. +// +func (b *BasicBlock) replacePred(p, q *BasicBlock) { + for i, pred := range b.Preds { + if pred == p { + b.Preds[i] = q + } + } +} + +// replaceSucc replaces all occurrences of p in b's successor list with q. +// Ordinarily there should be at most one. +// +func (b *BasicBlock) replaceSucc(p, q *BasicBlock) { + for i, succ := range b.Succs { + if succ == p { + b.Succs[i] = q + } + } +} + +// removePred removes all occurrences of p in b's +// predecessor list and φ-nodes. +// Ordinarily there should be at most one. +// +func (b *BasicBlock) removePred(p *BasicBlock) { + phis := b.phis() + + // We must preserve edge order for φ-nodes. + j := 0 + for i, pred := range b.Preds { + if pred != p { + b.Preds[j] = b.Preds[i] + // Strike out φ-edge too. + for _, instr := range phis { + phi := instr.(*Phi) + phi.Edges[j] = phi.Edges[i] + } + j++ + } + } + // Nil out b.Preds[j:] and φ-edges[j:] to aid GC. + for i := j; i < len(b.Preds); i++ { + b.Preds[i] = nil + for _, instr := range phis { + instr.(*Phi).Edges[i] = nil + } + } + b.Preds = b.Preds[:j] + for _, instr := range phis { + phi := instr.(*Phi) + phi.Edges = phi.Edges[:j] + } +} + +// Destinations associated with unlabelled for/switch/select stmts. +// We push/pop one of these as we enter/leave each construct and for +// each BranchStmt we scan for the innermost target of the right type. +// +type targets struct { + tail *targets // rest of stack + _break *BasicBlock + _continue *BasicBlock + _fallthrough *BasicBlock +} + +// Destinations associated with a labelled block. +// We populate these as labels are encountered in forward gotos or +// labelled statements. +// +type lblock struct { + _goto *BasicBlock + _break *BasicBlock + _continue *BasicBlock +} + +// labelledBlock returns the branch target associated with the +// specified label, creating it if needed. +// +func (f *Function) labelledBlock(label *ast.Ident) *lblock { + lb := f.lblocks[label.Obj] + if lb == nil { + lb = &lblock{_goto: f.newBasicBlock(label.Name)} + if f.lblocks == nil { + f.lblocks = make(map[*ast.Object]*lblock) + } + f.lblocks[label.Obj] = lb + } + return lb +} + +// addParam adds a (non-escaping) parameter to f.Params of the +// specified name, type and source position. +// +func (f *Function) addParam(name string, typ types.Type, pos token.Pos) *Parameter { + v := &Parameter{ + name: name, + typ: typ, + pos: pos, + parent: f, + } + f.Params = append(f.Params, v) + return v +} + +func (f *Function) addParamObj(obj types.Object) *Parameter { + name := obj.Name() + if name == "" { + name = fmt.Sprintf("arg%d", len(f.Params)) + } + param := f.addParam(name, obj.Type(), obj.Pos()) + param.object = obj + return param +} + +// addSpilledParam declares a parameter that is pre-spilled to the +// stack; the function body will load/store the spilled location. +// Subsequent lifting will eliminate spills where possible. +// +func (f *Function) addSpilledParam(obj types.Object) { + param := f.addParamObj(obj) + spill := &Alloc{Comment: obj.Name()} + spill.setType(types.NewPointer(obj.Type())) + spill.setPos(obj.Pos()) + f.objects[obj] = spill + f.Locals = append(f.Locals, spill) + f.emit(spill) + f.emit(&Store{Addr: spill, Val: param}) +} + +// startBody initializes the function prior to generating SSA code for its body. +// Precondition: f.Type() already set. +// +func (f *Function) startBody() { + f.currentBlock = f.newBasicBlock("entry") + f.objects = make(map[types.Object]Value) // needed for some synthetics, e.g. init +} + +// createSyntacticParams populates f.Params and generates code (spills +// and named result locals) for all the parameters declared in the +// syntax. In addition it populates the f.objects mapping. +// +// Preconditions: +// f.startBody() was called. +// Postcondition: +// len(f.Params) == len(f.Signature.Params) + (f.Signature.Recv() ? 1 : 0) +// +func (f *Function) createSyntacticParams(recv *ast.FieldList, functype *ast.FuncType) { + // Receiver (at most one inner iteration). + if recv != nil { + for _, field := range recv.List { + for _, n := range field.Names { + f.addSpilledParam(f.Pkg.info.Defs[n]) + } + // Anonymous receiver? No need to spill. + if field.Names == nil { + f.addParamObj(f.Signature.Recv()) + } + } + } + + // Parameters. + if functype.Params != nil { + n := len(f.Params) // 1 if has recv, 0 otherwise + for _, field := range functype.Params.List { + for _, n := range field.Names { + f.addSpilledParam(f.Pkg.info.Defs[n]) + } + // Anonymous parameter? No need to spill. + if field.Names == nil { + f.addParamObj(f.Signature.Params().At(len(f.Params) - n)) + } + } + } + + // Named results. + if functype.Results != nil { + for _, field := range functype.Results.List { + // Implicit "var" decl of locals for named results. + for _, n := range field.Names { + f.namedResults = append(f.namedResults, f.addLocalForIdent(n)) + } + } + } +} + +type setNumable interface { + setNum(int) +} + +// numberRegisters assigns numbers to all SSA registers +// (value-defining Instructions) in f, to aid debugging. +// (Non-Instruction Values are named at construction.) +// +func numberRegisters(f *Function) { + v := 0 + for _, b := range f.Blocks { + for _, instr := range b.Instrs { + switch instr.(type) { + case Value: + instr.(setNumable).setNum(v) + v++ + } + } + } +} + +// buildReferrers populates the def/use information in all non-nil +// Value.Referrers slice. +// Precondition: all such slices are initially empty. +func buildReferrers(f *Function) { + var rands []*Value + for _, b := range f.Blocks { + for _, instr := range b.Instrs { + rands = instr.Operands(rands[:0]) // recycle storage + for _, rand := range rands { + if r := *rand; r != nil { + if ref := r.Referrers(); ref != nil { + *ref = append(*ref, instr) + } + } + } + } + } +} + +// finishBody() finalizes the function after SSA code generation of its body. +func (f *Function) finishBody() { + f.objects = nil + f.currentBlock = nil + f.lblocks = nil + + // Don't pin the AST in memory (except in debug mode). + if n := f.syntax; n != nil && !f.debugInfo() { + f.syntax = extentNode{n.Pos(), n.End()} + } + + // Remove from f.Locals any Allocs that escape to the heap. + j := 0 + for _, l := range f.Locals { + if !l.Heap { + f.Locals[j] = l + j++ + } + } + // Nil out f.Locals[j:] to aid GC. + for i := j; i < len(f.Locals); i++ { + f.Locals[i] = nil + } + f.Locals = f.Locals[:j] + + optimizeBlocks(f) + + buildReferrers(f) + + buildDomTree(f) + + if f.Prog.mode&NaiveForm == 0 { + // For debugging pre-state of lifting pass: + // numberRegisters(f) + // f.WriteTo(os.Stderr) + lift(f) + } + + f.namedResults = nil // (used by lifting) + + numberRegisters(f) + + if f.Prog.mode&PrintFunctions != 0 { + printMu.Lock() + f.WriteTo(os.Stdout) + printMu.Unlock() + } + + if f.Prog.mode&SanityCheckFunctions != 0 { + mustSanityCheck(f, nil) + } +} + +// removeNilBlocks eliminates nils from f.Blocks and updates each +// BasicBlock.Index. Use this after any pass that may delete blocks. +// +func (f *Function) removeNilBlocks() { + j := 0 + for _, b := range f.Blocks { + if b != nil { + b.Index = j + f.Blocks[j] = b + j++ + } + } + // Nil out f.Blocks[j:] to aid GC. + for i := j; i < len(f.Blocks); i++ { + f.Blocks[i] = nil + } + f.Blocks = f.Blocks[:j] +} + +// SetDebugMode sets the debug mode for package pkg. If true, all its +// functions will include full debug info. This greatly increases the +// size of the instruction stream, and causes Functions to depend upon +// the ASTs, potentially keeping them live in memory for longer. +// +func (pkg *Package) SetDebugMode(debug bool) { + // TODO(adonovan): do we want ast.File granularity? + pkg.debug = debug +} + +// debugInfo reports whether debug info is wanted for this function. +func (f *Function) debugInfo() bool { + return f.Pkg != nil && f.Pkg.debug +} + +// addNamedLocal creates a local variable, adds it to function f and +// returns it. Its name and type are taken from obj. Subsequent +// calls to f.lookup(obj) will return the same local. +// +func (f *Function) addNamedLocal(obj types.Object) *Alloc { + l := f.addLocal(obj.Type(), obj.Pos()) + l.Comment = obj.Name() + f.objects[obj] = l + return l +} + +func (f *Function) addLocalForIdent(id *ast.Ident) *Alloc { + return f.addNamedLocal(f.Pkg.info.Defs[id]) +} + +// addLocal creates an anonymous local variable of type typ, adds it +// to function f and returns it. pos is the optional source location. +// +func (f *Function) addLocal(typ types.Type, pos token.Pos) *Alloc { + v := &Alloc{} + v.setType(types.NewPointer(typ)) + v.setPos(pos) + f.Locals = append(f.Locals, v) + f.emit(v) + return v +} + +// lookup returns the address of the named variable identified by obj +// that is local to function f or one of its enclosing functions. +// If escaping, the reference comes from a potentially escaping pointer +// expression and the referent must be heap-allocated. +// +func (f *Function) lookup(obj types.Object, escaping bool) Value { + if v, ok := f.objects[obj]; ok { + if alloc, ok := v.(*Alloc); ok && escaping { + alloc.Heap = true + } + return v // function-local var (address) + } + + // Definition must be in an enclosing function; + // plumb it through intervening closures. + if f.parent == nil { + panic("no ssa.Value for " + obj.String()) + } + outer := f.parent.lookup(obj, true) // escaping + v := &FreeVar{ + name: obj.Name(), + typ: outer.Type(), + pos: outer.Pos(), + outer: outer, + parent: f, + } + f.objects[obj] = v + f.FreeVars = append(f.FreeVars, v) + return v +} + +// emit emits the specified instruction to function f. +func (f *Function) emit(instr Instruction) Value { + return f.currentBlock.emit(instr) +} + +// RelString returns the full name of this function, qualified by +// package name, receiver type, etc. +// +// The specific formatting rules are not guaranteed and may change. +// +// Examples: +// "math.IsNaN" // a package-level function +// "(*bytes.Buffer).Bytes" // a declared method or a wrapper +// "(*bytes.Buffer).Bytes$thunk" // thunk (func wrapping method; receiver is param 0) +// "(*bytes.Buffer).Bytes$bound" // bound (func wrapping method; receiver supplied by closure) +// "main.main$1" // an anonymous function in main +// "main.init#1" // a declared init function +// "main.init" // the synthesized package initializer +// +// When these functions are referred to from within the same package +// (i.e. from == f.Pkg.Object), they are rendered without the package path. +// For example: "IsNaN", "(*Buffer).Bytes", etc. +// +// All non-synthetic functions have distinct package-qualified names. +// (But two methods may have the same name "(T).f" if one is a synthetic +// wrapper promoting a non-exported method "f" from another package; in +// that case, the strings are equal but the identifiers "f" are distinct.) +// +func (f *Function) RelString(from *types.Package) string { + // Anonymous? + if f.parent != nil { + // An anonymous function's Name() looks like "parentName$1", + // but its String() should include the type/package/etc. + parent := f.parent.RelString(from) + for i, anon := range f.parent.AnonFuncs { + if anon == f { + return fmt.Sprintf("%s$%d", parent, 1+i) + } + } + + return f.name // should never happen + } + + // Method (declared or wrapper)? + if recv := f.Signature.Recv(); recv != nil { + return f.relMethod(from, recv.Type()) + } + + // Thunk? + if f.method != nil { + return f.relMethod(from, f.method.Recv()) + } + + // Bound? + if len(f.FreeVars) == 1 && strings.HasSuffix(f.name, "$bound") { + return f.relMethod(from, f.FreeVars[0].Type()) + } + + // Package-level function? + // Prefix with package name for cross-package references only. + if p := f.pkg(); p != nil && p != from { + return fmt.Sprintf("%s.%s", p.Path(), f.name) + } + + // Unknown. + return f.name +} + +func (f *Function) relMethod(from *types.Package, recv types.Type) string { + return fmt.Sprintf("(%s).%s", relType(recv, from), f.name) +} + +// writeSignature writes to buf the signature sig in declaration syntax. +func writeSignature(buf *bytes.Buffer, from *types.Package, name string, sig *types.Signature, params []*Parameter) { + buf.WriteString("func ") + if recv := sig.Recv(); recv != nil { + buf.WriteString("(") + if n := params[0].Name(); n != "" { + buf.WriteString(n) + buf.WriteString(" ") + } + types.WriteType(buf, params[0].Type(), types.RelativeTo(from)) + buf.WriteString(") ") + } + buf.WriteString(name) + types.WriteSignature(buf, sig, types.RelativeTo(from)) +} + +func (f *Function) pkg() *types.Package { + if f.Pkg != nil { + return f.Pkg.Pkg + } + return nil +} + +var _ io.WriterTo = (*Function)(nil) // *Function implements io.Writer + +func (f *Function) WriteTo(w io.Writer) (int64, error) { + var buf bytes.Buffer + WriteFunction(&buf, f) + n, err := w.Write(buf.Bytes()) + return int64(n), err +} + +// WriteFunction writes to buf a human-readable "disassembly" of f. +func WriteFunction(buf *bytes.Buffer, f *Function) { + fmt.Fprintf(buf, "# Name: %s\n", f.String()) + if f.Pkg != nil { + fmt.Fprintf(buf, "# Package: %s\n", f.Pkg.Pkg.Path()) + } + if syn := f.Synthetic; syn != "" { + fmt.Fprintln(buf, "# Synthetic:", syn) + } + if pos := f.Pos(); pos.IsValid() { + fmt.Fprintf(buf, "# Location: %s\n", f.Prog.Fset.Position(pos)) + } + + if f.parent != nil { + fmt.Fprintf(buf, "# Parent: %s\n", f.parent.Name()) + } + + if f.Recover != nil { + fmt.Fprintf(buf, "# Recover: %s\n", f.Recover) + } + + from := f.pkg() + + if f.FreeVars != nil { + buf.WriteString("# Free variables:\n") + for i, fv := range f.FreeVars { + fmt.Fprintf(buf, "# % 3d:\t%s %s\n", i, fv.Name(), relType(fv.Type(), from)) + } + } + + if len(f.Locals) > 0 { + buf.WriteString("# Locals:\n") + for i, l := range f.Locals { + fmt.Fprintf(buf, "# % 3d:\t%s %s\n", i, l.Name(), relType(deref(l.Type()), from)) + } + } + writeSignature(buf, from, f.Name(), f.Signature, f.Params) + buf.WriteString(":\n") + + if f.Blocks == nil { + buf.WriteString("\t(external)\n") + } + + // NB. column calculations are confused by non-ASCII + // characters and assume 8-space tabs. + const punchcard = 80 // for old time's sake. + const tabwidth = 8 + for _, b := range f.Blocks { + if b == nil { + // Corrupt CFG. + fmt.Fprintf(buf, ".nil:\n") + continue + } + n, _ := fmt.Fprintf(buf, "%d:", b.Index) + bmsg := fmt.Sprintf("%s P:%d S:%d", b.Comment, len(b.Preds), len(b.Succs)) + fmt.Fprintf(buf, "%*s%s\n", punchcard-1-n-len(bmsg), "", bmsg) + + if false { // CFG debugging + fmt.Fprintf(buf, "\t# CFG: %s --> %s --> %s\n", b.Preds, b, b.Succs) + } + for _, instr := range b.Instrs { + buf.WriteString("\t") + switch v := instr.(type) { + case Value: + l := punchcard - tabwidth + // Left-align the instruction. + if name := v.Name(); name != "" { + n, _ := fmt.Fprintf(buf, "%s = ", name) + l -= n + } + n, _ := buf.WriteString(instr.String()) + l -= n + // Right-align the type if there's space. + if t := v.Type(); t != nil { + buf.WriteByte(' ') + ts := relType(t, from) + l -= len(ts) + len(" ") // (spaces before and after type) + if l > 0 { + fmt.Fprintf(buf, "%*s", l, "") + } + buf.WriteString(ts) + } + case nil: + // Be robust against bad transforms. + buf.WriteString("") + default: + buf.WriteString(instr.String()) + } + buf.WriteString("\n") + } + } + fmt.Fprintf(buf, "\n") +} + +// newBasicBlock adds to f a new basic block and returns it. It does +// not automatically become the current block for subsequent calls to emit. +// comment is an optional string for more readable debugging output. +// +func (f *Function) newBasicBlock(comment string) *BasicBlock { + b := &BasicBlock{ + Index: len(f.Blocks), + Comment: comment, + parent: f, + } + b.Succs = b.succs2[:0] + f.Blocks = append(f.Blocks, b) + return b +} + +// NewFunction returns a new synthetic Function instance belonging to +// prog, with its name and signature fields set as specified. +// +// The caller is responsible for initializing the remaining fields of +// the function object, e.g. Pkg, Params, Blocks. +// +// It is practically impossible for clients to construct well-formed +// SSA functions/packages/programs directly, so we assume this is the +// job of the Builder alone. NewFunction exists to provide clients a +// little flexibility. For example, analysis tools may wish to +// construct fake Functions for the root of the callgraph, a fake +// "reflect" package, etc. +// +// TODO(adonovan): think harder about the API here. +// +func (prog *Program) NewFunction(name string, sig *types.Signature, provenance string) *Function { + return &Function{Prog: prog, name: name, Signature: sig, Synthetic: provenance} +} + +type extentNode [2]token.Pos + +func (n extentNode) Pos() token.Pos { return n[0] } +func (n extentNode) End() token.Pos { return n[1] } + +// Syntax returns an ast.Node whose Pos/End methods provide the +// lexical extent of the function if it was defined by Go source code +// (f.Synthetic==""), or nil otherwise. +// +// If f was built with debug information (see Package.SetDebugRef), +// the result is the *ast.FuncDecl or *ast.FuncLit that declared the +// function. Otherwise, it is an opaque Node providing only position +// information; this avoids pinning the AST in memory. +// +func (f *Function) Syntax() ast.Node { return f.syntax } diff --git a/vendor/golang.org/x/tools/go/ssa/identical.go b/vendor/golang.org/x/tools/go/ssa/identical.go new file mode 100644 index 00000000000..53cbee107b6 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/identical.go @@ -0,0 +1,7 @@ +// +build go1.8 + +package ssa + +import "go/types" + +var structTypesIdentical = types.IdenticalIgnoreTags diff --git a/vendor/golang.org/x/tools/go/ssa/identical_17.go b/vendor/golang.org/x/tools/go/ssa/identical_17.go new file mode 100644 index 00000000000..da89d3339a5 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/identical_17.go @@ -0,0 +1,7 @@ +// +build !go1.8 + +package ssa + +import "go/types" + +var structTypesIdentical = types.Identical diff --git a/vendor/golang.org/x/tools/go/ssa/lift.go b/vendor/golang.org/x/tools/go/ssa/lift.go new file mode 100644 index 00000000000..048e9b03260 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/lift.go @@ -0,0 +1,653 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines the lifting pass which tries to "lift" Alloc +// cells (new/local variables) into SSA registers, replacing loads +// with the dominating stored value, eliminating loads and stores, and +// inserting φ-nodes as needed. + +// Cited papers and resources: +// +// Ron Cytron et al. 1991. Efficiently computing SSA form... +// http://doi.acm.org/10.1145/115372.115320 +// +// Cooper, Harvey, Kennedy. 2001. A Simple, Fast Dominance Algorithm. +// Software Practice and Experience 2001, 4:1-10. +// http://www.hipersoft.rice.edu/grads/publications/dom14.pdf +// +// Daniel Berlin, llvmdev mailing list, 2012. +// http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-January/046638.html +// (Be sure to expand the whole thread.) + +// TODO(adonovan): opt: there are many optimizations worth evaluating, and +// the conventional wisdom for SSA construction is that a simple +// algorithm well engineered often beats those of better asymptotic +// complexity on all but the most egregious inputs. +// +// Danny Berlin suggests that the Cooper et al. algorithm for +// computing the dominance frontier is superior to Cytron et al. +// Furthermore he recommends that rather than computing the DF for the +// whole function then renaming all alloc cells, it may be cheaper to +// compute the DF for each alloc cell separately and throw it away. +// +// Consider exploiting liveness information to avoid creating dead +// φ-nodes which we then immediately remove. +// +// Also see many other "TODO: opt" suggestions in the code. + +import ( + "fmt" + "go/token" + "go/types" + "math/big" + "os" +) + +// If true, show diagnostic information at each step of lifting. +// Very verbose. +const debugLifting = false + +// domFrontier maps each block to the set of blocks in its dominance +// frontier. The outer slice is conceptually a map keyed by +// Block.Index. The inner slice is conceptually a set, possibly +// containing duplicates. +// +// TODO(adonovan): opt: measure impact of dups; consider a packed bit +// representation, e.g. big.Int, and bitwise parallel operations for +// the union step in the Children loop. +// +// domFrontier's methods mutate the slice's elements but not its +// length, so their receivers needn't be pointers. +// +type domFrontier [][]*BasicBlock + +func (df domFrontier) add(u, v *BasicBlock) { + p := &df[u.Index] + *p = append(*p, v) +} + +// build builds the dominance frontier df for the dominator (sub)tree +// rooted at u, using the Cytron et al. algorithm. +// +// TODO(adonovan): opt: consider Berlin approach, computing pruned SSA +// by pruning the entire IDF computation, rather than merely pruning +// the DF -> IDF step. +func (df domFrontier) build(u *BasicBlock) { + // Encounter each node u in postorder of dom tree. + for _, child := range u.dom.children { + df.build(child) + } + for _, vb := range u.Succs { + if v := vb.dom; v.idom != u { + df.add(u, vb) + } + } + for _, w := range u.dom.children { + for _, vb := range df[w.Index] { + // TODO(adonovan): opt: use word-parallel bitwise union. + if v := vb.dom; v.idom != u { + df.add(u, vb) + } + } + } +} + +func buildDomFrontier(fn *Function) domFrontier { + df := make(domFrontier, len(fn.Blocks)) + df.build(fn.Blocks[0]) + if fn.Recover != nil { + df.build(fn.Recover) + } + return df +} + +func removeInstr(refs []Instruction, instr Instruction) []Instruction { + i := 0 + for _, ref := range refs { + if ref == instr { + continue + } + refs[i] = ref + i++ + } + for j := i; j != len(refs); j++ { + refs[j] = nil // aid GC + } + return refs[:i] +} + +// lift replaces local and new Allocs accessed only with +// load/store by SSA registers, inserting φ-nodes where necessary. +// The result is a program in classical pruned SSA form. +// +// Preconditions: +// - fn has no dead blocks (blockopt has run). +// - Def/use info (Operands and Referrers) is up-to-date. +// - The dominator tree is up-to-date. +// +func lift(fn *Function) { + // TODO(adonovan): opt: lots of little optimizations may be + // worthwhile here, especially if they cause us to avoid + // buildDomFrontier. For example: + // + // - Alloc never loaded? Eliminate. + // - Alloc never stored? Replace all loads with a zero constant. + // - Alloc stored once? Replace loads with dominating store; + // don't forget that an Alloc is itself an effective store + // of zero. + // - Alloc used only within a single block? + // Use degenerate algorithm avoiding φ-nodes. + // - Consider synergy with scalar replacement of aggregates (SRA). + // e.g. *(&x.f) where x is an Alloc. + // Perhaps we'd get better results if we generated this as x.f + // i.e. Field(x, .f) instead of Load(FieldIndex(x, .f)). + // Unclear. + // + // But we will start with the simplest correct code. + df := buildDomFrontier(fn) + + if debugLifting { + title := false + for i, blocks := range df { + if blocks != nil { + if !title { + fmt.Fprintf(os.Stderr, "Dominance frontier of %s:\n", fn) + title = true + } + fmt.Fprintf(os.Stderr, "\t%s: %s\n", fn.Blocks[i], blocks) + } + } + } + + newPhis := make(newPhiMap) + + // During this pass we will replace some BasicBlock.Instrs + // (allocs, loads and stores) with nil, keeping a count in + // BasicBlock.gaps. At the end we will reset Instrs to the + // concatenation of all non-dead newPhis and non-nil Instrs + // for the block, reusing the original array if space permits. + + // While we're here, we also eliminate 'rundefers' + // instructions in functions that contain no 'defer' + // instructions. + usesDefer := false + + // A counter used to generate ~unique ids for Phi nodes, as an + // aid to debugging. We use large numbers to make them highly + // visible. All nodes are renumbered later. + fresh := 1000 + + // Determine which allocs we can lift and number them densely. + // The renaming phase uses this numbering for compact maps. + numAllocs := 0 + for _, b := range fn.Blocks { + b.gaps = 0 + b.rundefers = 0 + for _, instr := range b.Instrs { + switch instr := instr.(type) { + case *Alloc: + index := -1 + if liftAlloc(df, instr, newPhis, &fresh) { + index = numAllocs + numAllocs++ + } + instr.index = index + case *Defer: + usesDefer = true + case *RunDefers: + b.rundefers++ + } + } + } + + // renaming maps an alloc (keyed by index) to its replacement + // value. Initially the renaming contains nil, signifying the + // zero constant of the appropriate type; we construct the + // Const lazily at most once on each path through the domtree. + // TODO(adonovan): opt: cache per-function not per subtree. + renaming := make([]Value, numAllocs) + + // Renaming. + rename(fn.Blocks[0], renaming, newPhis) + + // Eliminate dead φ-nodes. + removeDeadPhis(fn.Blocks, newPhis) + + // Prepend remaining live φ-nodes to each block. + for _, b := range fn.Blocks { + nps := newPhis[b] + j := len(nps) + + rundefersToKill := b.rundefers + if usesDefer { + rundefersToKill = 0 + } + + if j+b.gaps+rundefersToKill == 0 { + continue // fast path: no new phis or gaps + } + + // Compact nps + non-nil Instrs into a new slice. + // TODO(adonovan): opt: compact in situ (rightwards) + // if Instrs has sufficient space or slack. + dst := make([]Instruction, len(b.Instrs)+j-b.gaps-rundefersToKill) + for i, np := range nps { + dst[i] = np.phi + } + for _, instr := range b.Instrs { + if instr == nil { + continue + } + if !usesDefer { + if _, ok := instr.(*RunDefers); ok { + continue + } + } + dst[j] = instr + j++ + } + b.Instrs = dst + } + + // Remove any fn.Locals that were lifted. + j := 0 + for _, l := range fn.Locals { + if l.index < 0 { + fn.Locals[j] = l + j++ + } + } + // Nil out fn.Locals[j:] to aid GC. + for i := j; i < len(fn.Locals); i++ { + fn.Locals[i] = nil + } + fn.Locals = fn.Locals[:j] +} + +// removeDeadPhis removes φ-nodes not transitively needed by a +// non-Phi, non-DebugRef instruction. +func removeDeadPhis(blocks []*BasicBlock, newPhis newPhiMap) { + // First pass: find the set of "live" φ-nodes: those reachable + // from some non-Phi instruction. + // + // We compute reachability in reverse, starting from each φ, + // rather than forwards, starting from each live non-Phi + // instruction, because this way visits much less of the + // Value graph. + livePhis := make(map[*Phi]bool) + for _, npList := range newPhis { + for _, np := range npList { + phi := np.phi + if !livePhis[phi] && phiHasDirectReferrer(phi) { + markLivePhi(livePhis, phi) + } + } + } + + // Existing φ-nodes due to && and || operators + // are all considered live (see Go issue 19622). + for _, b := range blocks { + for _, phi := range b.phis() { + markLivePhi(livePhis, phi.(*Phi)) + } + } + + // Second pass: eliminate unused phis from newPhis. + for block, npList := range newPhis { + j := 0 + for _, np := range npList { + if livePhis[np.phi] { + npList[j] = np + j++ + } else { + // discard it, first removing it from referrers + for _, val := range np.phi.Edges { + if refs := val.Referrers(); refs != nil { + *refs = removeInstr(*refs, np.phi) + } + } + np.phi.block = nil + } + } + newPhis[block] = npList[:j] + } +} + +// markLivePhi marks phi, and all φ-nodes transitively reachable via +// its Operands, live. +func markLivePhi(livePhis map[*Phi]bool, phi *Phi) { + livePhis[phi] = true + for _, rand := range phi.Operands(nil) { + if q, ok := (*rand).(*Phi); ok { + if !livePhis[q] { + markLivePhi(livePhis, q) + } + } + } +} + +// phiHasDirectReferrer reports whether phi is directly referred to by +// a non-Phi instruction. Such instructions are the +// roots of the liveness traversal. +func phiHasDirectReferrer(phi *Phi) bool { + for _, instr := range *phi.Referrers() { + if _, ok := instr.(*Phi); !ok { + return true + } + } + return false +} + +type blockSet struct{ big.Int } // (inherit methods from Int) + +// add adds b to the set and returns true if the set changed. +func (s *blockSet) add(b *BasicBlock) bool { + i := b.Index + if s.Bit(i) != 0 { + return false + } + s.SetBit(&s.Int, i, 1) + return true +} + +// take removes an arbitrary element from a set s and +// returns its index, or returns -1 if empty. +func (s *blockSet) take() int { + l := s.BitLen() + for i := 0; i < l; i++ { + if s.Bit(i) == 1 { + s.SetBit(&s.Int, i, 0) + return i + } + } + return -1 +} + +// newPhi is a pair of a newly introduced φ-node and the lifted Alloc +// it replaces. +type newPhi struct { + phi *Phi + alloc *Alloc +} + +// newPhiMap records for each basic block, the set of newPhis that +// must be prepended to the block. +type newPhiMap map[*BasicBlock][]newPhi + +// liftAlloc determines whether alloc can be lifted into registers, +// and if so, it populates newPhis with all the φ-nodes it may require +// and returns true. +// +// fresh is a source of fresh ids for phi nodes. +// +func liftAlloc(df domFrontier, alloc *Alloc, newPhis newPhiMap, fresh *int) bool { + // Don't lift aggregates into registers, because we don't have + // a way to express their zero-constants. + switch deref(alloc.Type()).Underlying().(type) { + case *types.Array, *types.Struct: + return false + } + + // Don't lift named return values in functions that defer + // calls that may recover from panic. + if fn := alloc.Parent(); fn.Recover != nil { + for _, nr := range fn.namedResults { + if nr == alloc { + return false + } + } + } + + // Compute defblocks, the set of blocks containing a + // definition of the alloc cell. + var defblocks blockSet + for _, instr := range *alloc.Referrers() { + // Bail out if we discover the alloc is not liftable; + // the only operations permitted to use the alloc are + // loads/stores into the cell, and DebugRef. + switch instr := instr.(type) { + case *Store: + if instr.Val == alloc { + return false // address used as value + } + if instr.Addr != alloc { + panic("Alloc.Referrers is inconsistent") + } + defblocks.add(instr.Block()) + case *UnOp: + if instr.Op != token.MUL { + return false // not a load + } + if instr.X != alloc { + panic("Alloc.Referrers is inconsistent") + } + case *DebugRef: + // ok + default: + return false // some other instruction + } + } + // The Alloc itself counts as a (zero) definition of the cell. + defblocks.add(alloc.Block()) + + if debugLifting { + fmt.Fprintln(os.Stderr, "\tlifting ", alloc, alloc.Name()) + } + + fn := alloc.Parent() + + // Φ-insertion. + // + // What follows is the body of the main loop of the insert-φ + // function described by Cytron et al, but instead of using + // counter tricks, we just reset the 'hasAlready' and 'work' + // sets each iteration. These are bitmaps so it's pretty cheap. + // + // TODO(adonovan): opt: recycle slice storage for W, + // hasAlready, defBlocks across liftAlloc calls. + var hasAlready blockSet + + // Initialize W and work to defblocks. + var work blockSet = defblocks // blocks seen + var W blockSet // blocks to do + W.Set(&defblocks.Int) + + // Traverse iterated dominance frontier, inserting φ-nodes. + for i := W.take(); i != -1; i = W.take() { + u := fn.Blocks[i] + for _, v := range df[u.Index] { + if hasAlready.add(v) { + // Create φ-node. + // It will be prepended to v.Instrs later, if needed. + phi := &Phi{ + Edges: make([]Value, len(v.Preds)), + Comment: alloc.Comment, + } + // This is merely a debugging aid: + phi.setNum(*fresh) + *fresh++ + + phi.pos = alloc.Pos() + phi.setType(deref(alloc.Type())) + phi.block = v + if debugLifting { + fmt.Fprintf(os.Stderr, "\tplace %s = %s at block %s\n", phi.Name(), phi, v) + } + newPhis[v] = append(newPhis[v], newPhi{phi, alloc}) + + if work.add(v) { + W.add(v) + } + } + } + } + + return true +} + +// replaceAll replaces all intraprocedural uses of x with y, +// updating x.Referrers and y.Referrers. +// Precondition: x.Referrers() != nil, i.e. x must be local to some function. +// +func replaceAll(x, y Value) { + var rands []*Value + pxrefs := x.Referrers() + pyrefs := y.Referrers() + for _, instr := range *pxrefs { + rands = instr.Operands(rands[:0]) // recycle storage + for _, rand := range rands { + if *rand != nil { + if *rand == x { + *rand = y + } + } + } + if pyrefs != nil { + *pyrefs = append(*pyrefs, instr) // dups ok + } + } + *pxrefs = nil // x is now unreferenced +} + +// renamed returns the value to which alloc is being renamed, +// constructing it lazily if it's the implicit zero initialization. +// +func renamed(renaming []Value, alloc *Alloc) Value { + v := renaming[alloc.index] + if v == nil { + v = zeroConst(deref(alloc.Type())) + renaming[alloc.index] = v + } + return v +} + +// rename implements the (Cytron et al) SSA renaming algorithm, a +// preorder traversal of the dominator tree replacing all loads of +// Alloc cells with the value stored to that cell by the dominating +// store instruction. For lifting, we need only consider loads, +// stores and φ-nodes. +// +// renaming is a map from *Alloc (keyed by index number) to its +// dominating stored value; newPhis[x] is the set of new φ-nodes to be +// prepended to block x. +// +func rename(u *BasicBlock, renaming []Value, newPhis newPhiMap) { + // Each φ-node becomes the new name for its associated Alloc. + for _, np := range newPhis[u] { + phi := np.phi + alloc := np.alloc + renaming[alloc.index] = phi + } + + // Rename loads and stores of allocs. + for i, instr := range u.Instrs { + switch instr := instr.(type) { + case *Alloc: + if instr.index >= 0 { // store of zero to Alloc cell + // Replace dominated loads by the zero value. + renaming[instr.index] = nil + if debugLifting { + fmt.Fprintf(os.Stderr, "\tkill alloc %s\n", instr) + } + // Delete the Alloc. + u.Instrs[i] = nil + u.gaps++ + } + + case *Store: + if alloc, ok := instr.Addr.(*Alloc); ok && alloc.index >= 0 { // store to Alloc cell + // Replace dominated loads by the stored value. + renaming[alloc.index] = instr.Val + if debugLifting { + fmt.Fprintf(os.Stderr, "\tkill store %s; new value: %s\n", + instr, instr.Val.Name()) + } + // Remove the store from the referrer list of the stored value. + if refs := instr.Val.Referrers(); refs != nil { + *refs = removeInstr(*refs, instr) + } + // Delete the Store. + u.Instrs[i] = nil + u.gaps++ + } + + case *UnOp: + if instr.Op == token.MUL { + if alloc, ok := instr.X.(*Alloc); ok && alloc.index >= 0 { // load of Alloc cell + newval := renamed(renaming, alloc) + if debugLifting { + fmt.Fprintf(os.Stderr, "\tupdate load %s = %s with %s\n", + instr.Name(), instr, newval.Name()) + } + // Replace all references to + // the loaded value by the + // dominating stored value. + replaceAll(instr, newval) + // Delete the Load. + u.Instrs[i] = nil + u.gaps++ + } + } + + case *DebugRef: + if alloc, ok := instr.X.(*Alloc); ok && alloc.index >= 0 { // ref of Alloc cell + if instr.IsAddr { + instr.X = renamed(renaming, alloc) + instr.IsAddr = false + + // Add DebugRef to instr.X's referrers. + if refs := instr.X.Referrers(); refs != nil { + *refs = append(*refs, instr) + } + } else { + // A source expression denotes the address + // of an Alloc that was optimized away. + instr.X = nil + + // Delete the DebugRef. + u.Instrs[i] = nil + u.gaps++ + } + } + } + } + + // For each φ-node in a CFG successor, rename the edge. + for _, v := range u.Succs { + phis := newPhis[v] + if len(phis) == 0 { + continue + } + i := v.predIndex(u) + for _, np := range phis { + phi := np.phi + alloc := np.alloc + newval := renamed(renaming, alloc) + if debugLifting { + fmt.Fprintf(os.Stderr, "\tsetphi %s edge %s -> %s (#%d) (alloc=%s) := %s\n", + phi.Name(), u, v, i, alloc.Name(), newval.Name()) + } + phi.Edges[i] = newval + if prefs := newval.Referrers(); prefs != nil { + *prefs = append(*prefs, phi) + } + } + } + + // Continue depth-first recursion over domtree, pushing a + // fresh copy of the renaming map for each subtree. + for i, v := range u.dom.children { + r := renaming + if i < len(u.dom.children)-1 { + // On all but the final iteration, we must make + // a copy to avoid destructive update. + r = make([]Value, len(renaming)) + copy(r, renaming) + } + rename(v, r, newPhis) + } + +} diff --git a/vendor/golang.org/x/tools/go/ssa/lvalue.go b/vendor/golang.org/x/tools/go/ssa/lvalue.go new file mode 100644 index 00000000000..4d85be3ec78 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/lvalue.go @@ -0,0 +1,120 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// lvalues are the union of addressable expressions and map-index +// expressions. + +import ( + "go/ast" + "go/token" + "go/types" +) + +// An lvalue represents an assignable location that may appear on the +// left-hand side of an assignment. This is a generalization of a +// pointer to permit updates to elements of maps. +// +type lvalue interface { + store(fn *Function, v Value) // stores v into the location + load(fn *Function) Value // loads the contents of the location + address(fn *Function) Value // address of the location + typ() types.Type // returns the type of the location +} + +// An address is an lvalue represented by a true pointer. +type address struct { + addr Value + pos token.Pos // source position + expr ast.Expr // source syntax of the value (not address) [debug mode] +} + +func (a *address) load(fn *Function) Value { + load := emitLoad(fn, a.addr) + load.pos = a.pos + return load +} + +func (a *address) store(fn *Function, v Value) { + store := emitStore(fn, a.addr, v, a.pos) + if a.expr != nil { + // store.Val is v, converted for assignability. + emitDebugRef(fn, a.expr, store.Val, false) + } +} + +func (a *address) address(fn *Function) Value { + if a.expr != nil { + emitDebugRef(fn, a.expr, a.addr, true) + } + return a.addr +} + +func (a *address) typ() types.Type { + return deref(a.addr.Type()) +} + +// An element is an lvalue represented by m[k], the location of an +// element of a map or string. These locations are not addressable +// since pointers cannot be formed from them, but they do support +// load(), and in the case of maps, store(). +// +type element struct { + m, k Value // map or string + t types.Type // map element type or string byte type + pos token.Pos // source position of colon ({k:v}) or lbrack (m[k]=v) +} + +func (e *element) load(fn *Function) Value { + l := &Lookup{ + X: e.m, + Index: e.k, + } + l.setPos(e.pos) + l.setType(e.t) + return fn.emit(l) +} + +func (e *element) store(fn *Function, v Value) { + up := &MapUpdate{ + Map: e.m, + Key: e.k, + Value: emitConv(fn, v, e.t), + } + up.pos = e.pos + fn.emit(up) +} + +func (e *element) address(fn *Function) Value { + panic("map/string elements are not addressable") +} + +func (e *element) typ() types.Type { + return e.t +} + +// A blank is a dummy variable whose name is "_". +// It is not reified: loads are illegal and stores are ignored. +// +type blank struct{} + +func (bl blank) load(fn *Function) Value { + panic("blank.load is illegal") +} + +func (bl blank) store(fn *Function, v Value) { + // no-op +} + +func (bl blank) address(fn *Function) Value { + panic("blank var is not addressable") +} + +func (bl blank) typ() types.Type { + // This should be the type of the blank Ident; the typechecker + // doesn't provide this yet, but fortunately, we don't need it + // yet either. + panic("blank.typ is unimplemented") +} diff --git a/vendor/golang.org/x/tools/go/ssa/methods.go b/vendor/golang.org/x/tools/go/ssa/methods.go new file mode 100644 index 00000000000..9cf383916bb --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/methods.go @@ -0,0 +1,239 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines utilities for population of method sets. + +import ( + "fmt" + "go/types" +) + +// MethodValue returns the Function implementing method sel, building +// wrapper methods on demand. It returns nil if sel denotes an +// abstract (interface) method. +// +// Precondition: sel.Kind() == MethodVal. +// +// Thread-safe. +// +// EXCLUSIVE_LOCKS_ACQUIRED(prog.methodsMu) +// +func (prog *Program) MethodValue(sel *types.Selection) *Function { + if sel.Kind() != types.MethodVal { + panic(fmt.Sprintf("MethodValue(%s) kind != MethodVal", sel)) + } + T := sel.Recv() + if isInterface(T) { + return nil // abstract method + } + if prog.mode&LogSource != 0 { + defer logStack("MethodValue %s %v", T, sel)() + } + + prog.methodsMu.Lock() + defer prog.methodsMu.Unlock() + + return prog.addMethod(prog.createMethodSet(T), sel) +} + +// LookupMethod returns the implementation of the method of type T +// identified by (pkg, name). It returns nil if the method exists but +// is abstract, and panics if T has no such method. +// +func (prog *Program) LookupMethod(T types.Type, pkg *types.Package, name string) *Function { + sel := prog.MethodSets.MethodSet(T).Lookup(pkg, name) + if sel == nil { + panic(fmt.Sprintf("%s has no method %s", T, types.Id(pkg, name))) + } + return prog.MethodValue(sel) +} + +// methodSet contains the (concrete) methods of a non-interface type. +type methodSet struct { + mapping map[string]*Function // populated lazily + complete bool // mapping contains all methods +} + +// Precondition: !isInterface(T). +// EXCLUSIVE_LOCKS_REQUIRED(prog.methodsMu) +func (prog *Program) createMethodSet(T types.Type) *methodSet { + mset, ok := prog.methodSets.At(T).(*methodSet) + if !ok { + mset = &methodSet{mapping: make(map[string]*Function)} + prog.methodSets.Set(T, mset) + } + return mset +} + +// EXCLUSIVE_LOCKS_REQUIRED(prog.methodsMu) +func (prog *Program) addMethod(mset *methodSet, sel *types.Selection) *Function { + if sel.Kind() == types.MethodExpr { + panic(sel) + } + id := sel.Obj().Id() + fn := mset.mapping[id] + if fn == nil { + obj := sel.Obj().(*types.Func) + + needsPromotion := len(sel.Index()) > 1 + needsIndirection := !isPointer(recvType(obj)) && isPointer(sel.Recv()) + if needsPromotion || needsIndirection { + fn = makeWrapper(prog, sel) + } else { + fn = prog.declaredFunc(obj) + } + if fn.Signature.Recv() == nil { + panic(fn) // missing receiver + } + mset.mapping[id] = fn + } + return fn +} + +// RuntimeTypes returns a new unordered slice containing all +// concrete types in the program for which a complete (non-empty) +// method set is required at run-time. +// +// Thread-safe. +// +// EXCLUSIVE_LOCKS_ACQUIRED(prog.methodsMu) +// +func (prog *Program) RuntimeTypes() []types.Type { + prog.methodsMu.Lock() + defer prog.methodsMu.Unlock() + + var res []types.Type + prog.methodSets.Iterate(func(T types.Type, v interface{}) { + if v.(*methodSet).complete { + res = append(res, T) + } + }) + return res +} + +// declaredFunc returns the concrete function/method denoted by obj. +// Panic ensues if there is none. +// +func (prog *Program) declaredFunc(obj *types.Func) *Function { + if v := prog.packageLevelValue(obj); v != nil { + return v.(*Function) + } + panic("no concrete method: " + obj.String()) +} + +// needMethodsOf ensures that runtime type information (including the +// complete method set) is available for the specified type T and all +// its subcomponents. +// +// needMethodsOf must be called for at least every type that is an +// operand of some MakeInterface instruction, and for the type of +// every exported package member. +// +// Precondition: T is not a method signature (*Signature with Recv()!=nil). +// +// Thread-safe. (Called via emitConv from multiple builder goroutines.) +// +// TODO(adonovan): make this faster. It accounts for 20% of SSA build time. +// +// EXCLUSIVE_LOCKS_ACQUIRED(prog.methodsMu) +// +func (prog *Program) needMethodsOf(T types.Type) { + prog.methodsMu.Lock() + prog.needMethods(T, false) + prog.methodsMu.Unlock() +} + +// Precondition: T is not a method signature (*Signature with Recv()!=nil). +// Recursive case: skip => don't create methods for T. +// +// EXCLUSIVE_LOCKS_REQUIRED(prog.methodsMu) +// +func (prog *Program) needMethods(T types.Type, skip bool) { + // Each package maintains its own set of types it has visited. + if prevSkip, ok := prog.runtimeTypes.At(T).(bool); ok { + // needMethods(T) was previously called + if !prevSkip || skip { + return // already seen, with same or false 'skip' value + } + } + prog.runtimeTypes.Set(T, skip) + + tmset := prog.MethodSets.MethodSet(T) + + if !skip && !isInterface(T) && tmset.Len() > 0 { + // Create methods of T. + mset := prog.createMethodSet(T) + if !mset.complete { + mset.complete = true + n := tmset.Len() + for i := 0; i < n; i++ { + prog.addMethod(mset, tmset.At(i)) + } + } + } + + // Recursion over signatures of each method. + for i := 0; i < tmset.Len(); i++ { + sig := tmset.At(i).Type().(*types.Signature) + prog.needMethods(sig.Params(), false) + prog.needMethods(sig.Results(), false) + } + + switch t := T.(type) { + case *types.Basic: + // nop + + case *types.Interface: + // nop---handled by recursion over method set. + + case *types.Pointer: + prog.needMethods(t.Elem(), false) + + case *types.Slice: + prog.needMethods(t.Elem(), false) + + case *types.Chan: + prog.needMethods(t.Elem(), false) + + case *types.Map: + prog.needMethods(t.Key(), false) + prog.needMethods(t.Elem(), false) + + case *types.Signature: + if t.Recv() != nil { + panic(fmt.Sprintf("Signature %s has Recv %s", t, t.Recv())) + } + prog.needMethods(t.Params(), false) + prog.needMethods(t.Results(), false) + + case *types.Named: + // A pointer-to-named type can be derived from a named + // type via reflection. It may have methods too. + prog.needMethods(types.NewPointer(T), false) + + // Consider 'type T struct{S}' where S has methods. + // Reflection provides no way to get from T to struct{S}, + // only to S, so the method set of struct{S} is unwanted, + // so set 'skip' flag during recursion. + prog.needMethods(t.Underlying(), true) + + case *types.Array: + prog.needMethods(t.Elem(), false) + + case *types.Struct: + for i, n := 0, t.NumFields(); i < n; i++ { + prog.needMethods(t.Field(i).Type(), false) + } + + case *types.Tuple: + for i, n := 0, t.Len(); i < n; i++ { + prog.needMethods(t.At(i).Type(), false) + } + + default: + panic(T) + } +} diff --git a/vendor/golang.org/x/tools/go/ssa/mode.go b/vendor/golang.org/x/tools/go/ssa/mode.go new file mode 100644 index 00000000000..d2a269893a7 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/mode.go @@ -0,0 +1,100 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines the BuilderMode type and its command-line flag. + +import ( + "bytes" + "fmt" +) + +// BuilderMode is a bitmask of options for diagnostics and checking. +// +// *BuilderMode satisfies the flag.Value interface. Example: +// +// var mode = ssa.BuilderMode(0) +// func init() { flag.Var(&mode, "build", ssa.BuilderModeDoc) } +// +type BuilderMode uint + +const ( + PrintPackages BuilderMode = 1 << iota // Print package inventory to stdout + PrintFunctions // Print function SSA code to stdout + LogSource // Log source locations as SSA builder progresses + SanityCheckFunctions // Perform sanity checking of function bodies + NaiveForm // Build naïve SSA form: don't replace local loads/stores with registers + BuildSerially // Build packages serially, not in parallel. + GlobalDebug // Enable debug info for all packages + BareInits // Build init functions without guards or calls to dependent inits +) + +const BuilderModeDoc = `Options controlling the SSA builder. +The value is a sequence of zero or more of these letters: +C perform sanity [C]hecking of the SSA form. +D include [D]ebug info for every function. +P print [P]ackage inventory. +F print [F]unction SSA code. +S log [S]ource locations as SSA builder progresses. +L build distinct packages seria[L]ly instead of in parallel. +N build [N]aive SSA form: don't replace local loads/stores with registers. +I build bare [I]nit functions: no init guards or calls to dependent inits. +` + +func (m BuilderMode) String() string { + var buf bytes.Buffer + if m&GlobalDebug != 0 { + buf.WriteByte('D') + } + if m&PrintPackages != 0 { + buf.WriteByte('P') + } + if m&PrintFunctions != 0 { + buf.WriteByte('F') + } + if m&LogSource != 0 { + buf.WriteByte('S') + } + if m&SanityCheckFunctions != 0 { + buf.WriteByte('C') + } + if m&NaiveForm != 0 { + buf.WriteByte('N') + } + if m&BuildSerially != 0 { + buf.WriteByte('L') + } + return buf.String() +} + +// Set parses the flag characters in s and updates *m. +func (m *BuilderMode) Set(s string) error { + var mode BuilderMode + for _, c := range s { + switch c { + case 'D': + mode |= GlobalDebug + case 'P': + mode |= PrintPackages + case 'F': + mode |= PrintFunctions + case 'S': + mode |= LogSource | BuildSerially + case 'C': + mode |= SanityCheckFunctions + case 'N': + mode |= NaiveForm + case 'L': + mode |= BuildSerially + default: + return fmt.Errorf("unknown BuilderMode option: %q", c) + } + } + *m = mode + return nil +} + +// Get returns m. +func (m BuilderMode) Get() interface{} { return m } diff --git a/vendor/golang.org/x/tools/go/ssa/print.go b/vendor/golang.org/x/tools/go/ssa/print.go new file mode 100644 index 00000000000..3333ba41a00 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/print.go @@ -0,0 +1,431 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file implements the String() methods for all Value and +// Instruction types. + +import ( + "bytes" + "fmt" + "go/types" + "io" + "reflect" + "sort" + + "golang.org/x/tools/go/types/typeutil" +) + +// relName returns the name of v relative to i. +// In most cases, this is identical to v.Name(), but references to +// Functions (including methods) and Globals use RelString and +// all types are displayed with relType, so that only cross-package +// references are package-qualified. +// +func relName(v Value, i Instruction) string { + var from *types.Package + if i != nil { + from = i.Parent().pkg() + } + switch v := v.(type) { + case Member: // *Function or *Global + return v.RelString(from) + case *Const: + return v.RelString(from) + } + return v.Name() +} + +func relType(t types.Type, from *types.Package) string { + return types.TypeString(t, types.RelativeTo(from)) +} + +func relString(m Member, from *types.Package) string { + // NB: not all globals have an Object (e.g. init$guard), + // so use Package().Object not Object.Package(). + if pkg := m.Package().Pkg; pkg != nil && pkg != from { + return fmt.Sprintf("%s.%s", pkg.Path(), m.Name()) + } + return m.Name() +} + +// Value.String() +// +// This method is provided only for debugging. +// It never appears in disassembly, which uses Value.Name(). + +func (v *Parameter) String() string { + from := v.Parent().pkg() + return fmt.Sprintf("parameter %s : %s", v.Name(), relType(v.Type(), from)) +} + +func (v *FreeVar) String() string { + from := v.Parent().pkg() + return fmt.Sprintf("freevar %s : %s", v.Name(), relType(v.Type(), from)) +} + +func (v *Builtin) String() string { + return fmt.Sprintf("builtin %s", v.Name()) +} + +// Instruction.String() + +func (v *Alloc) String() string { + op := "local" + if v.Heap { + op = "new" + } + from := v.Parent().pkg() + return fmt.Sprintf("%s %s (%s)", op, relType(deref(v.Type()), from), v.Comment) +} + +func (v *Phi) String() string { + var b bytes.Buffer + b.WriteString("phi [") + for i, edge := range v.Edges { + if i > 0 { + b.WriteString(", ") + } + // Be robust against malformed CFG. + if v.block == nil { + b.WriteString("??") + continue + } + block := -1 + if i < len(v.block.Preds) { + block = v.block.Preds[i].Index + } + fmt.Fprintf(&b, "%d: ", block) + edgeVal := "" // be robust + if edge != nil { + edgeVal = relName(edge, v) + } + b.WriteString(edgeVal) + } + b.WriteString("]") + if v.Comment != "" { + b.WriteString(" #") + b.WriteString(v.Comment) + } + return b.String() +} + +func printCall(v *CallCommon, prefix string, instr Instruction) string { + var b bytes.Buffer + b.WriteString(prefix) + if !v.IsInvoke() { + b.WriteString(relName(v.Value, instr)) + } else { + fmt.Fprintf(&b, "invoke %s.%s", relName(v.Value, instr), v.Method.Name()) + } + b.WriteString("(") + for i, arg := range v.Args { + if i > 0 { + b.WriteString(", ") + } + b.WriteString(relName(arg, instr)) + } + if v.Signature().Variadic() { + b.WriteString("...") + } + b.WriteString(")") + return b.String() +} + +func (c *CallCommon) String() string { + return printCall(c, "", nil) +} + +func (v *Call) String() string { + return printCall(&v.Call, "", v) +} + +func (v *BinOp) String() string { + return fmt.Sprintf("%s %s %s", relName(v.X, v), v.Op.String(), relName(v.Y, v)) +} + +func (v *UnOp) String() string { + return fmt.Sprintf("%s%s%s", v.Op, relName(v.X, v), commaOk(v.CommaOk)) +} + +func printConv(prefix string, v, x Value) string { + from := v.Parent().pkg() + return fmt.Sprintf("%s %s <- %s (%s)", + prefix, + relType(v.Type(), from), + relType(x.Type(), from), + relName(x, v.(Instruction))) +} + +func (v *ChangeType) String() string { return printConv("changetype", v, v.X) } +func (v *Convert) String() string { return printConv("convert", v, v.X) } +func (v *ChangeInterface) String() string { return printConv("change interface", v, v.X) } +func (v *MakeInterface) String() string { return printConv("make", v, v.X) } + +func (v *MakeClosure) String() string { + var b bytes.Buffer + fmt.Fprintf(&b, "make closure %s", relName(v.Fn, v)) + if v.Bindings != nil { + b.WriteString(" [") + for i, c := range v.Bindings { + if i > 0 { + b.WriteString(", ") + } + b.WriteString(relName(c, v)) + } + b.WriteString("]") + } + return b.String() +} + +func (v *MakeSlice) String() string { + from := v.Parent().pkg() + return fmt.Sprintf("make %s %s %s", + relType(v.Type(), from), + relName(v.Len, v), + relName(v.Cap, v)) +} + +func (v *Slice) String() string { + var b bytes.Buffer + b.WriteString("slice ") + b.WriteString(relName(v.X, v)) + b.WriteString("[") + if v.Low != nil { + b.WriteString(relName(v.Low, v)) + } + b.WriteString(":") + if v.High != nil { + b.WriteString(relName(v.High, v)) + } + if v.Max != nil { + b.WriteString(":") + b.WriteString(relName(v.Max, v)) + } + b.WriteString("]") + return b.String() +} + +func (v *MakeMap) String() string { + res := "" + if v.Reserve != nil { + res = relName(v.Reserve, v) + } + from := v.Parent().pkg() + return fmt.Sprintf("make %s %s", relType(v.Type(), from), res) +} + +func (v *MakeChan) String() string { + from := v.Parent().pkg() + return fmt.Sprintf("make %s %s", relType(v.Type(), from), relName(v.Size, v)) +} + +func (v *FieldAddr) String() string { + st := deref(v.X.Type()).Underlying().(*types.Struct) + // Be robust against a bad index. + name := "?" + if 0 <= v.Field && v.Field < st.NumFields() { + name = st.Field(v.Field).Name() + } + return fmt.Sprintf("&%s.%s [#%d]", relName(v.X, v), name, v.Field) +} + +func (v *Field) String() string { + st := v.X.Type().Underlying().(*types.Struct) + // Be robust against a bad index. + name := "?" + if 0 <= v.Field && v.Field < st.NumFields() { + name = st.Field(v.Field).Name() + } + return fmt.Sprintf("%s.%s [#%d]", relName(v.X, v), name, v.Field) +} + +func (v *IndexAddr) String() string { + return fmt.Sprintf("&%s[%s]", relName(v.X, v), relName(v.Index, v)) +} + +func (v *Index) String() string { + return fmt.Sprintf("%s[%s]", relName(v.X, v), relName(v.Index, v)) +} + +func (v *Lookup) String() string { + return fmt.Sprintf("%s[%s]%s", relName(v.X, v), relName(v.Index, v), commaOk(v.CommaOk)) +} + +func (v *Range) String() string { + return "range " + relName(v.X, v) +} + +func (v *Next) String() string { + return "next " + relName(v.Iter, v) +} + +func (v *TypeAssert) String() string { + from := v.Parent().pkg() + return fmt.Sprintf("typeassert%s %s.(%s)", commaOk(v.CommaOk), relName(v.X, v), relType(v.AssertedType, from)) +} + +func (v *Extract) String() string { + return fmt.Sprintf("extract %s #%d", relName(v.Tuple, v), v.Index) +} + +func (s *Jump) String() string { + // Be robust against malformed CFG. + block := -1 + if s.block != nil && len(s.block.Succs) == 1 { + block = s.block.Succs[0].Index + } + return fmt.Sprintf("jump %d", block) +} + +func (s *If) String() string { + // Be robust against malformed CFG. + tblock, fblock := -1, -1 + if s.block != nil && len(s.block.Succs) == 2 { + tblock = s.block.Succs[0].Index + fblock = s.block.Succs[1].Index + } + return fmt.Sprintf("if %s goto %d else %d", relName(s.Cond, s), tblock, fblock) +} + +func (s *Go) String() string { + return printCall(&s.Call, "go ", s) +} + +func (s *Panic) String() string { + return "panic " + relName(s.X, s) +} + +func (s *Return) String() string { + var b bytes.Buffer + b.WriteString("return") + for i, r := range s.Results { + if i == 0 { + b.WriteString(" ") + } else { + b.WriteString(", ") + } + b.WriteString(relName(r, s)) + } + return b.String() +} + +func (*RunDefers) String() string { + return "rundefers" +} + +func (s *Send) String() string { + return fmt.Sprintf("send %s <- %s", relName(s.Chan, s), relName(s.X, s)) +} + +func (s *Defer) String() string { + return printCall(&s.Call, "defer ", s) +} + +func (s *Select) String() string { + var b bytes.Buffer + for i, st := range s.States { + if i > 0 { + b.WriteString(", ") + } + if st.Dir == types.RecvOnly { + b.WriteString("<-") + b.WriteString(relName(st.Chan, s)) + } else { + b.WriteString(relName(st.Chan, s)) + b.WriteString("<-") + b.WriteString(relName(st.Send, s)) + } + } + non := "" + if !s.Blocking { + non = "non" + } + return fmt.Sprintf("select %sblocking [%s]", non, b.String()) +} + +func (s *Store) String() string { + return fmt.Sprintf("*%s = %s", relName(s.Addr, s), relName(s.Val, s)) +} + +func (s *MapUpdate) String() string { + return fmt.Sprintf("%s[%s] = %s", relName(s.Map, s), relName(s.Key, s), relName(s.Value, s)) +} + +func (s *DebugRef) String() string { + p := s.Parent().Prog.Fset.Position(s.Pos()) + var descr interface{} + if s.object != nil { + descr = s.object // e.g. "var x int" + } else { + descr = reflect.TypeOf(s.Expr) // e.g. "*ast.CallExpr" + } + var addr string + if s.IsAddr { + addr = "address of " + } + return fmt.Sprintf("; %s%s @ %d:%d is %s", addr, descr, p.Line, p.Column, s.X.Name()) +} + +func (p *Package) String() string { + return "package " + p.Pkg.Path() +} + +var _ io.WriterTo = (*Package)(nil) // *Package implements io.Writer + +func (p *Package) WriteTo(w io.Writer) (int64, error) { + var buf bytes.Buffer + WritePackage(&buf, p) + n, err := w.Write(buf.Bytes()) + return int64(n), err +} + +// WritePackage writes to buf a human-readable summary of p. +func WritePackage(buf *bytes.Buffer, p *Package) { + fmt.Fprintf(buf, "%s:\n", p) + + var names []string + maxname := 0 + for name := range p.Members { + if l := len(name); l > maxname { + maxname = l + } + names = append(names, name) + } + + from := p.Pkg + sort.Strings(names) + for _, name := range names { + switch mem := p.Members[name].(type) { + case *NamedConst: + fmt.Fprintf(buf, " const %-*s %s = %s\n", + maxname, name, mem.Name(), mem.Value.RelString(from)) + + case *Function: + fmt.Fprintf(buf, " func %-*s %s\n", + maxname, name, relType(mem.Type(), from)) + + case *Type: + fmt.Fprintf(buf, " type %-*s %s\n", + maxname, name, relType(mem.Type().Underlying(), from)) + for _, meth := range typeutil.IntuitiveMethodSet(mem.Type(), &p.Prog.MethodSets) { + fmt.Fprintf(buf, " %s\n", types.SelectionString(meth, types.RelativeTo(from))) + } + + case *Global: + fmt.Fprintf(buf, " var %-*s %s\n", + maxname, name, relType(mem.Type().(*types.Pointer).Elem(), from)) + } + } + + fmt.Fprintf(buf, "\n") +} + +func commaOk(x bool) string { + if x { + return ",ok" + } + return "" +} diff --git a/vendor/golang.org/x/tools/go/ssa/sanity.go b/vendor/golang.org/x/tools/go/ssa/sanity.go new file mode 100644 index 00000000000..0a7abc5e98f --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/sanity.go @@ -0,0 +1,532 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// An optional pass for sanity-checking invariants of the SSA representation. +// Currently it checks CFG invariants but little at the instruction level. + +import ( + "fmt" + "go/types" + "io" + "os" + "strings" +) + +type sanity struct { + reporter io.Writer + fn *Function + block *BasicBlock + instrs map[Instruction]struct{} + insane bool +} + +// sanityCheck performs integrity checking of the SSA representation +// of the function fn and returns true if it was valid. Diagnostics +// are written to reporter if non-nil, os.Stderr otherwise. Some +// diagnostics are only warnings and do not imply a negative result. +// +// Sanity-checking is intended to facilitate the debugging of code +// transformation passes. +// +func sanityCheck(fn *Function, reporter io.Writer) bool { + if reporter == nil { + reporter = os.Stderr + } + return (&sanity{reporter: reporter}).checkFunction(fn) +} + +// mustSanityCheck is like sanityCheck but panics instead of returning +// a negative result. +// +func mustSanityCheck(fn *Function, reporter io.Writer) { + if !sanityCheck(fn, reporter) { + fn.WriteTo(os.Stderr) + panic("SanityCheck failed") + } +} + +func (s *sanity) diagnostic(prefix, format string, args ...interface{}) { + fmt.Fprintf(s.reporter, "%s: function %s", prefix, s.fn) + if s.block != nil { + fmt.Fprintf(s.reporter, ", block %s", s.block) + } + io.WriteString(s.reporter, ": ") + fmt.Fprintf(s.reporter, format, args...) + io.WriteString(s.reporter, "\n") +} + +func (s *sanity) errorf(format string, args ...interface{}) { + s.insane = true + s.diagnostic("Error", format, args...) +} + +func (s *sanity) warnf(format string, args ...interface{}) { + s.diagnostic("Warning", format, args...) +} + +// findDuplicate returns an arbitrary basic block that appeared more +// than once in blocks, or nil if all were unique. +func findDuplicate(blocks []*BasicBlock) *BasicBlock { + if len(blocks) < 2 { + return nil + } + if blocks[0] == blocks[1] { + return blocks[0] + } + // Slow path: + m := make(map[*BasicBlock]bool) + for _, b := range blocks { + if m[b] { + return b + } + m[b] = true + } + return nil +} + +func (s *sanity) checkInstr(idx int, instr Instruction) { + switch instr := instr.(type) { + case *If, *Jump, *Return, *Panic: + s.errorf("control flow instruction not at end of block") + case *Phi: + if idx == 0 { + // It suffices to apply this check to just the first phi node. + if dup := findDuplicate(s.block.Preds); dup != nil { + s.errorf("phi node in block with duplicate predecessor %s", dup) + } + } else { + prev := s.block.Instrs[idx-1] + if _, ok := prev.(*Phi); !ok { + s.errorf("Phi instruction follows a non-Phi: %T", prev) + } + } + if ne, np := len(instr.Edges), len(s.block.Preds); ne != np { + s.errorf("phi node has %d edges but %d predecessors", ne, np) + + } else { + for i, e := range instr.Edges { + if e == nil { + s.errorf("phi node '%s' has no value for edge #%d from %s", instr.Comment, i, s.block.Preds[i]) + } + } + } + + case *Alloc: + if !instr.Heap { + found := false + for _, l := range s.fn.Locals { + if l == instr { + found = true + break + } + } + if !found { + s.errorf("local alloc %s = %s does not appear in Function.Locals", instr.Name(), instr) + } + } + + case *BinOp: + case *Call: + case *ChangeInterface: + case *ChangeType: + case *Convert: + if _, ok := instr.X.Type().Underlying().(*types.Basic); !ok { + if _, ok := instr.Type().Underlying().(*types.Basic); !ok { + s.errorf("convert %s -> %s: at least one type must be basic", instr.X.Type(), instr.Type()) + } + } + + case *Defer: + case *Extract: + case *Field: + case *FieldAddr: + case *Go: + case *Index: + case *IndexAddr: + case *Lookup: + case *MakeChan: + case *MakeClosure: + numFree := len(instr.Fn.(*Function).FreeVars) + numBind := len(instr.Bindings) + if numFree != numBind { + s.errorf("MakeClosure has %d Bindings for function %s with %d free vars", + numBind, instr.Fn, numFree) + + } + if recv := instr.Type().(*types.Signature).Recv(); recv != nil { + s.errorf("MakeClosure's type includes receiver %s", recv.Type()) + } + + case *MakeInterface: + case *MakeMap: + case *MakeSlice: + case *MapUpdate: + case *Next: + case *Range: + case *RunDefers: + case *Select: + case *Send: + case *Slice: + case *Store: + case *TypeAssert: + case *UnOp: + case *DebugRef: + // TODO(adonovan): implement checks. + default: + panic(fmt.Sprintf("Unknown instruction type: %T", instr)) + } + + if call, ok := instr.(CallInstruction); ok { + if call.Common().Signature() == nil { + s.errorf("nil signature: %s", call) + } + } + + // Check that value-defining instructions have valid types + // and a valid referrer list. + if v, ok := instr.(Value); ok { + t := v.Type() + if t == nil { + s.errorf("no type: %s = %s", v.Name(), v) + } else if t == tRangeIter { + // not a proper type; ignore. + } else if b, ok := t.Underlying().(*types.Basic); ok && b.Info()&types.IsUntyped != 0 { + s.errorf("instruction has 'untyped' result: %s = %s : %s", v.Name(), v, t) + } + s.checkReferrerList(v) + } + + // Untyped constants are legal as instruction Operands(), + // for example: + // _ = "foo"[0] + // or: + // if wordsize==64 {...} + + // All other non-Instruction Values can be found via their + // enclosing Function or Package. +} + +func (s *sanity) checkFinalInstr(instr Instruction) { + switch instr := instr.(type) { + case *If: + if nsuccs := len(s.block.Succs); nsuccs != 2 { + s.errorf("If-terminated block has %d successors; expected 2", nsuccs) + return + } + if s.block.Succs[0] == s.block.Succs[1] { + s.errorf("If-instruction has same True, False target blocks: %s", s.block.Succs[0]) + return + } + + case *Jump: + if nsuccs := len(s.block.Succs); nsuccs != 1 { + s.errorf("Jump-terminated block has %d successors; expected 1", nsuccs) + return + } + + case *Return: + if nsuccs := len(s.block.Succs); nsuccs != 0 { + s.errorf("Return-terminated block has %d successors; expected none", nsuccs) + return + } + if na, nf := len(instr.Results), s.fn.Signature.Results().Len(); nf != na { + s.errorf("%d-ary return in %d-ary function", na, nf) + } + + case *Panic: + if nsuccs := len(s.block.Succs); nsuccs != 0 { + s.errorf("Panic-terminated block has %d successors; expected none", nsuccs) + return + } + + default: + s.errorf("non-control flow instruction at end of block") + } +} + +func (s *sanity) checkBlock(b *BasicBlock, index int) { + s.block = b + + if b.Index != index { + s.errorf("block has incorrect Index %d", b.Index) + } + if b.parent != s.fn { + s.errorf("block has incorrect parent %s", b.parent) + } + + // Check all blocks are reachable. + // (The entry block is always implicitly reachable, + // as is the Recover block, if any.) + if (index > 0 && b != b.parent.Recover) && len(b.Preds) == 0 { + s.warnf("unreachable block") + if b.Instrs == nil { + // Since this block is about to be pruned, + // tolerating transient problems in it + // simplifies other optimizations. + return + } + } + + // Check predecessor and successor relations are dual, + // and that all blocks in CFG belong to same function. + for _, a := range b.Preds { + found := false + for _, bb := range a.Succs { + if bb == b { + found = true + break + } + } + if !found { + s.errorf("expected successor edge in predecessor %s; found only: %s", a, a.Succs) + } + if a.parent != s.fn { + s.errorf("predecessor %s belongs to different function %s", a, a.parent) + } + } + for _, c := range b.Succs { + found := false + for _, bb := range c.Preds { + if bb == b { + found = true + break + } + } + if !found { + s.errorf("expected predecessor edge in successor %s; found only: %s", c, c.Preds) + } + if c.parent != s.fn { + s.errorf("successor %s belongs to different function %s", c, c.parent) + } + } + + // Check each instruction is sane. + n := len(b.Instrs) + if n == 0 { + s.errorf("basic block contains no instructions") + } + var rands [10]*Value // reuse storage + for j, instr := range b.Instrs { + if instr == nil { + s.errorf("nil instruction at index %d", j) + continue + } + if b2 := instr.Block(); b2 == nil { + s.errorf("nil Block() for instruction at index %d", j) + continue + } else if b2 != b { + s.errorf("wrong Block() (%s) for instruction at index %d ", b2, j) + continue + } + if j < n-1 { + s.checkInstr(j, instr) + } else { + s.checkFinalInstr(instr) + } + + // Check Instruction.Operands. + operands: + for i, op := range instr.Operands(rands[:0]) { + if op == nil { + s.errorf("nil operand pointer %d of %s", i, instr) + continue + } + val := *op + if val == nil { + continue // a nil operand is ok + } + + // Check that "untyped" types only appear on constant operands. + if _, ok := (*op).(*Const); !ok { + if basic, ok := (*op).Type().(*types.Basic); ok { + if basic.Info()&types.IsUntyped != 0 { + s.errorf("operand #%d of %s is untyped: %s", i, instr, basic) + } + } + } + + // Check that Operands that are also Instructions belong to same function. + // TODO(adonovan): also check their block dominates block b. + if val, ok := val.(Instruction); ok { + if val.Block() == nil { + s.errorf("operand %d of %s is an instruction (%s) that belongs to no block", i, instr, val) + } else if val.Parent() != s.fn { + s.errorf("operand %d of %s is an instruction (%s) from function %s", i, instr, val, val.Parent()) + } + } + + // Check that each function-local operand of + // instr refers back to instr. (NB: quadratic) + switch val := val.(type) { + case *Const, *Global, *Builtin: + continue // not local + case *Function: + if val.parent == nil { + continue // only anon functions are local + } + } + + // TODO(adonovan): check val.Parent() != nil <=> val.Referrers() is defined. + + if refs := val.Referrers(); refs != nil { + for _, ref := range *refs { + if ref == instr { + continue operands + } + } + s.errorf("operand %d of %s (%s) does not refer to us", i, instr, val) + } else { + s.errorf("operand %d of %s (%s) has no referrers", i, instr, val) + } + } + } +} + +func (s *sanity) checkReferrerList(v Value) { + refs := v.Referrers() + if refs == nil { + s.errorf("%s has missing referrer list", v.Name()) + return + } + for i, ref := range *refs { + if _, ok := s.instrs[ref]; !ok { + s.errorf("%s.Referrers()[%d] = %s is not an instruction belonging to this function", v.Name(), i, ref) + } + } +} + +func (s *sanity) checkFunction(fn *Function) bool { + // TODO(adonovan): check Function invariants: + // - check params match signature + // - check transient fields are nil + // - warn if any fn.Locals do not appear among block instructions. + s.fn = fn + if fn.Prog == nil { + s.errorf("nil Prog") + } + + _ = fn.String() // must not crash + _ = fn.RelString(fn.pkg()) // must not crash + + // All functions have a package, except delegates (which are + // shared across packages, or duplicated as weak symbols in a + // separate-compilation model), and error.Error. + if fn.Pkg == nil { + if strings.HasPrefix(fn.Synthetic, "wrapper ") || + strings.HasPrefix(fn.Synthetic, "bound ") || + strings.HasPrefix(fn.Synthetic, "thunk ") || + strings.HasSuffix(fn.name, "Error") { + // ok + } else { + s.errorf("nil Pkg") + } + } + if src, syn := fn.Synthetic == "", fn.Syntax() != nil; src != syn { + s.errorf("got fromSource=%t, hasSyntax=%t; want same values", src, syn) + } + for i, l := range fn.Locals { + if l.Parent() != fn { + s.errorf("Local %s at index %d has wrong parent", l.Name(), i) + } + if l.Heap { + s.errorf("Local %s at index %d has Heap flag set", l.Name(), i) + } + } + // Build the set of valid referrers. + s.instrs = make(map[Instruction]struct{}) + for _, b := range fn.Blocks { + for _, instr := range b.Instrs { + s.instrs[instr] = struct{}{} + } + } + for i, p := range fn.Params { + if p.Parent() != fn { + s.errorf("Param %s at index %d has wrong parent", p.Name(), i) + } + // Check common suffix of Signature and Params match type. + if sig := fn.Signature; sig != nil { + j := i - len(fn.Params) + sig.Params().Len() // index within sig.Params + if j < 0 { + continue + } + if !types.Identical(p.Type(), sig.Params().At(j).Type()) { + s.errorf("Param %s at index %d has wrong type (%s, versus %s in Signature)", p.Name(), i, p.Type(), sig.Params().At(j).Type()) + + } + } + s.checkReferrerList(p) + } + for i, fv := range fn.FreeVars { + if fv.Parent() != fn { + s.errorf("FreeVar %s at index %d has wrong parent", fv.Name(), i) + } + s.checkReferrerList(fv) + } + + if fn.Blocks != nil && len(fn.Blocks) == 0 { + // Function _had_ blocks (so it's not external) but + // they were "optimized" away, even the entry block. + s.errorf("Blocks slice is non-nil but empty") + } + for i, b := range fn.Blocks { + if b == nil { + s.warnf("nil *BasicBlock at f.Blocks[%d]", i) + continue + } + s.checkBlock(b, i) + } + if fn.Recover != nil && fn.Blocks[fn.Recover.Index] != fn.Recover { + s.errorf("Recover block is not in Blocks slice") + } + + s.block = nil + for i, anon := range fn.AnonFuncs { + if anon.Parent() != fn { + s.errorf("AnonFuncs[%d]=%s but %s.Parent()=%s", i, anon, anon, anon.Parent()) + } + } + s.fn = nil + return !s.insane +} + +// sanityCheckPackage checks invariants of packages upon creation. +// It does not require that the package is built. +// Unlike sanityCheck (for functions), it just panics at the first error. +func sanityCheckPackage(pkg *Package) { + if pkg.Pkg == nil { + panic(fmt.Sprintf("Package %s has no Object", pkg)) + } + _ = pkg.String() // must not crash + + for name, mem := range pkg.Members { + if name != mem.Name() { + panic(fmt.Sprintf("%s: %T.Name() = %s, want %s", + pkg.Pkg.Path(), mem, mem.Name(), name)) + } + obj := mem.Object() + if obj == nil { + // This check is sound because fields + // {Global,Function}.object have type + // types.Object. (If they were declared as + // *types.{Var,Func}, we'd have a non-empty + // interface containing a nil pointer.) + + continue // not all members have typechecker objects + } + if obj.Name() != name { + if obj.Name() == "init" && strings.HasPrefix(mem.Name(), "init#") { + // Ok. The name of a declared init function varies between + // its types.Func ("init") and its ssa.Function ("init#%d"). + } else { + panic(fmt.Sprintf("%s: %T.Object().Name() = %s, want %s", + pkg.Pkg.Path(), mem, obj.Name(), name)) + } + } + if obj.Pos() != mem.Pos() { + panic(fmt.Sprintf("%s Pos=%d obj.Pos=%d", mem, mem.Pos(), obj.Pos())) + } + } +} diff --git a/vendor/golang.org/x/tools/go/ssa/source.go b/vendor/golang.org/x/tools/go/ssa/source.go new file mode 100644 index 00000000000..8d9cca17039 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/source.go @@ -0,0 +1,293 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines utilities for working with source positions +// or source-level named entities ("objects"). + +// TODO(adonovan): test that {Value,Instruction}.Pos() positions match +// the originating syntax, as specified. + +import ( + "go/ast" + "go/token" + "go/types" +) + +// EnclosingFunction returns the function that contains the syntax +// node denoted by path. +// +// Syntax associated with package-level variable specifications is +// enclosed by the package's init() function. +// +// Returns nil if not found; reasons might include: +// - the node is not enclosed by any function. +// - the node is within an anonymous function (FuncLit) and +// its SSA function has not been created yet +// (pkg.Build() has not yet been called). +// +func EnclosingFunction(pkg *Package, path []ast.Node) *Function { + // Start with package-level function... + fn := findEnclosingPackageLevelFunction(pkg, path) + if fn == nil { + return nil // not in any function + } + + // ...then walk down the nested anonymous functions. + n := len(path) +outer: + for i := range path { + if lit, ok := path[n-1-i].(*ast.FuncLit); ok { + for _, anon := range fn.AnonFuncs { + if anon.Pos() == lit.Type.Func { + fn = anon + continue outer + } + } + // SSA function not found: + // - package not yet built, or maybe + // - builder skipped FuncLit in dead block + // (in principle; but currently the Builder + // generates even dead FuncLits). + return nil + } + } + return fn +} + +// HasEnclosingFunction returns true if the AST node denoted by path +// is contained within the declaration of some function or +// package-level variable. +// +// Unlike EnclosingFunction, the behaviour of this function does not +// depend on whether SSA code for pkg has been built, so it can be +// used to quickly reject check inputs that will cause +// EnclosingFunction to fail, prior to SSA building. +// +func HasEnclosingFunction(pkg *Package, path []ast.Node) bool { + return findEnclosingPackageLevelFunction(pkg, path) != nil +} + +// findEnclosingPackageLevelFunction returns the Function +// corresponding to the package-level function enclosing path. +// +func findEnclosingPackageLevelFunction(pkg *Package, path []ast.Node) *Function { + if n := len(path); n >= 2 { // [... {Gen,Func}Decl File] + switch decl := path[n-2].(type) { + case *ast.GenDecl: + if decl.Tok == token.VAR && n >= 3 { + // Package-level 'var' initializer. + return pkg.init + } + + case *ast.FuncDecl: + if decl.Recv == nil && decl.Name.Name == "init" { + // Explicit init() function. + for _, b := range pkg.init.Blocks { + for _, instr := range b.Instrs { + if instr, ok := instr.(*Call); ok { + if callee, ok := instr.Call.Value.(*Function); ok && callee.Pkg == pkg && callee.Pos() == decl.Name.NamePos { + return callee + } + } + } + } + // Hack: return non-nil when SSA is not yet + // built so that HasEnclosingFunction works. + return pkg.init + } + // Declared function/method. + return findNamedFunc(pkg, decl.Name.NamePos) + } + } + return nil // not in any function +} + +// findNamedFunc returns the named function whose FuncDecl.Ident is at +// position pos. +// +func findNamedFunc(pkg *Package, pos token.Pos) *Function { + // Look at all package members and method sets of named types. + // Not very efficient. + for _, mem := range pkg.Members { + switch mem := mem.(type) { + case *Function: + if mem.Pos() == pos { + return mem + } + case *Type: + mset := pkg.Prog.MethodSets.MethodSet(types.NewPointer(mem.Type())) + for i, n := 0, mset.Len(); i < n; i++ { + // Don't call Program.Method: avoid creating wrappers. + obj := mset.At(i).Obj().(*types.Func) + if obj.Pos() == pos { + return pkg.values[obj].(*Function) + } + } + } + } + return nil +} + +// ValueForExpr returns the SSA Value that corresponds to non-constant +// expression e. +// +// It returns nil if no value was found, e.g. +// - the expression is not lexically contained within f; +// - f was not built with debug information; or +// - e is a constant expression. (For efficiency, no debug +// information is stored for constants. Use +// go/types.Info.Types[e].Value instead.) +// - e is a reference to nil or a built-in function. +// - the value was optimised away. +// +// If e is an addressable expression used in an lvalue context, +// value is the address denoted by e, and isAddr is true. +// +// The types of e (or &e, if isAddr) and the result are equal +// (modulo "untyped" bools resulting from comparisons). +// +// (Tip: to find the ssa.Value given a source position, use +// astutil.PathEnclosingInterval to locate the ast.Node, then +// EnclosingFunction to locate the Function, then ValueForExpr to find +// the ssa.Value.) +// +func (f *Function) ValueForExpr(e ast.Expr) (value Value, isAddr bool) { + if f.debugInfo() { // (opt) + e = unparen(e) + for _, b := range f.Blocks { + for _, instr := range b.Instrs { + if ref, ok := instr.(*DebugRef); ok { + if ref.Expr == e { + return ref.X, ref.IsAddr + } + } + } + } + } + return +} + +// --- Lookup functions for source-level named entities (types.Objects) --- + +// Package returns the SSA Package corresponding to the specified +// type-checker package object. +// It returns nil if no such SSA package has been created. +// +func (prog *Program) Package(obj *types.Package) *Package { + return prog.packages[obj] +} + +// packageLevelValue returns the package-level value corresponding to +// the specified named object, which may be a package-level const +// (*Const), var (*Global) or func (*Function) of some package in +// prog. It returns nil if the object is not found. +// +func (prog *Program) packageLevelValue(obj types.Object) Value { + if pkg, ok := prog.packages[obj.Pkg()]; ok { + return pkg.values[obj] + } + return nil +} + +// FuncValue returns the concrete Function denoted by the source-level +// named function obj, or nil if obj denotes an interface method. +// +// TODO(adonovan): check the invariant that obj.Type() matches the +// result's Signature, both in the params/results and in the receiver. +// +func (prog *Program) FuncValue(obj *types.Func) *Function { + fn, _ := prog.packageLevelValue(obj).(*Function) + return fn +} + +// ConstValue returns the SSA Value denoted by the source-level named +// constant obj. +// +func (prog *Program) ConstValue(obj *types.Const) *Const { + // TODO(adonovan): opt: share (don't reallocate) + // Consts for const objects and constant ast.Exprs. + + // Universal constant? {true,false,nil} + if obj.Parent() == types.Universe { + return NewConst(obj.Val(), obj.Type()) + } + // Package-level named constant? + if v := prog.packageLevelValue(obj); v != nil { + return v.(*Const) + } + return NewConst(obj.Val(), obj.Type()) +} + +// VarValue returns the SSA Value that corresponds to a specific +// identifier denoting the source-level named variable obj. +// +// VarValue returns nil if a local variable was not found, perhaps +// because its package was not built, the debug information was not +// requested during SSA construction, or the value was optimized away. +// +// ref is the path to an ast.Ident (e.g. from PathEnclosingInterval), +// and that ident must resolve to obj. +// +// pkg is the package enclosing the reference. (A reference to a var +// always occurs within a function, so we need to know where to find it.) +// +// If the identifier is a field selector and its base expression is +// non-addressable, then VarValue returns the value of that field. +// For example: +// func f() struct {x int} +// f().x // VarValue(x) returns a *Field instruction of type int +// +// All other identifiers denote addressable locations (variables). +// For them, VarValue may return either the variable's address or its +// value, even when the expression is evaluated only for its value; the +// situation is reported by isAddr, the second component of the result. +// +// If !isAddr, the returned value is the one associated with the +// specific identifier. For example, +// var x int // VarValue(x) returns Const 0 here +// x = 1 // VarValue(x) returns Const 1 here +// +// It is not specified whether the value or the address is returned in +// any particular case, as it may depend upon optimizations performed +// during SSA code generation, such as registerization, constant +// folding, avoidance of materialization of subexpressions, etc. +// +func (prog *Program) VarValue(obj *types.Var, pkg *Package, ref []ast.Node) (value Value, isAddr bool) { + // All references to a var are local to some function, possibly init. + fn := EnclosingFunction(pkg, ref) + if fn == nil { + return // e.g. def of struct field; SSA not built? + } + + id := ref[0].(*ast.Ident) + + // Defining ident of a parameter? + if id.Pos() == obj.Pos() { + for _, param := range fn.Params { + if param.Object() == obj { + return param, false + } + } + } + + // Other ident? + for _, b := range fn.Blocks { + for _, instr := range b.Instrs { + if dr, ok := instr.(*DebugRef); ok { + if dr.Pos() == id.Pos() { + return dr.X, dr.IsAddr + } + } + } + } + + // Defining ident of package-level var? + if v := prog.packageLevelValue(obj); v != nil { + return v.(*Global), true + } + + return // e.g. debug info not requested, or var optimized away +} diff --git a/vendor/golang.org/x/tools/go/ssa/ssa.go b/vendor/golang.org/x/tools/go/ssa/ssa.go new file mode 100644 index 00000000000..78272c546a1 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/ssa.go @@ -0,0 +1,1695 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This package defines a high-level intermediate representation for +// Go programs using static single-assignment (SSA) form. + +import ( + "fmt" + "go/ast" + "go/constant" + "go/token" + "go/types" + "sync" + + "golang.org/x/tools/go/types/typeutil" +) + +// A Program is a partial or complete Go program converted to SSA form. +type Program struct { + Fset *token.FileSet // position information for the files of this Program + imported map[string]*Package // all importable Packages, keyed by import path + packages map[*types.Package]*Package // all loaded Packages, keyed by object + mode BuilderMode // set of mode bits for SSA construction + MethodSets typeutil.MethodSetCache // cache of type-checker's method-sets + + methodsMu sync.Mutex // guards the following maps: + methodSets typeutil.Map // maps type to its concrete methodSet + runtimeTypes typeutil.Map // types for which rtypes are needed + canon typeutil.Map // type canonicalization map + bounds map[*types.Func]*Function // bounds for curried x.Method closures + thunks map[selectionKey]*Function // thunks for T.Method expressions +} + +// A Package is a single analyzed Go package containing Members for +// all package-level functions, variables, constants and types it +// declares. These may be accessed directly via Members, or via the +// type-specific accessor methods Func, Type, Var and Const. +// +// Members also contains entries for "init" (the synthetic package +// initializer) and "init#%d", the nth declared init function, +// and unspecified other things too. +// +type Package struct { + Prog *Program // the owning program + Pkg *types.Package // the corresponding go/types.Package + Members map[string]Member // all package members keyed by name (incl. init and init#%d) + values map[types.Object]Value // package members (incl. types and methods), keyed by object + init *Function // Func("init"); the package's init function + debug bool // include full debug info in this package + + // The following fields are set transiently, then cleared + // after building. + buildOnce sync.Once // ensures package building occurs once + ninit int32 // number of init functions + info *types.Info // package type information + files []*ast.File // package ASTs +} + +// A Member is a member of a Go package, implemented by *NamedConst, +// *Global, *Function, or *Type; they are created by package-level +// const, var, func and type declarations respectively. +// +type Member interface { + Name() string // declared name of the package member + String() string // package-qualified name of the package member + RelString(*types.Package) string // like String, but relative refs are unqualified + Object() types.Object // typechecker's object for this member, if any + Pos() token.Pos // position of member's declaration, if known + Type() types.Type // type of the package member + Token() token.Token // token.{VAR,FUNC,CONST,TYPE} + Package() *Package // the containing package +} + +// A Type is a Member of a Package representing a package-level named type. +type Type struct { + object *types.TypeName + pkg *Package +} + +// A NamedConst is a Member of a Package representing a package-level +// named constant. +// +// Pos() returns the position of the declaring ast.ValueSpec.Names[*] +// identifier. +// +// NB: a NamedConst is not a Value; it contains a constant Value, which +// it augments with the name and position of its 'const' declaration. +// +type NamedConst struct { + object *types.Const + Value *Const + pkg *Package +} + +// A Value is an SSA value that can be referenced by an instruction. +type Value interface { + // Name returns the name of this value, and determines how + // this Value appears when used as an operand of an + // Instruction. + // + // This is the same as the source name for Parameters, + // Builtins, Functions, FreeVars, Globals. + // For constants, it is a representation of the constant's value + // and type. For all other Values this is the name of the + // virtual register defined by the instruction. + // + // The name of an SSA Value is not semantically significant, + // and may not even be unique within a function. + Name() string + + // If this value is an Instruction, String returns its + // disassembled form; otherwise it returns unspecified + // human-readable information about the Value, such as its + // kind, name and type. + String() string + + // Type returns the type of this value. Many instructions + // (e.g. IndexAddr) change their behaviour depending on the + // types of their operands. + Type() types.Type + + // Parent returns the function to which this Value belongs. + // It returns nil for named Functions, Builtin, Const and Global. + Parent() *Function + + // Referrers returns the list of instructions that have this + // value as one of their operands; it may contain duplicates + // if an instruction has a repeated operand. + // + // Referrers actually returns a pointer through which the + // caller may perform mutations to the object's state. + // + // Referrers is currently only defined if Parent()!=nil, + // i.e. for the function-local values FreeVar, Parameter, + // Functions (iff anonymous) and all value-defining instructions. + // It returns nil for named Functions, Builtin, Const and Global. + // + // Instruction.Operands contains the inverse of this relation. + Referrers() *[]Instruction + + // Pos returns the location of the AST token most closely + // associated with the operation that gave rise to this value, + // or token.NoPos if it was not explicit in the source. + // + // For each ast.Node type, a particular token is designated as + // the closest location for the expression, e.g. the Lparen + // for an *ast.CallExpr. This permits a compact but + // approximate mapping from Values to source positions for use + // in diagnostic messages, for example. + // + // (Do not use this position to determine which Value + // corresponds to an ast.Expr; use Function.ValueForExpr + // instead. NB: it requires that the function was built with + // debug information.) + Pos() token.Pos +} + +// An Instruction is an SSA instruction that computes a new Value or +// has some effect. +// +// An Instruction that defines a value (e.g. BinOp) also implements +// the Value interface; an Instruction that only has an effect (e.g. Store) +// does not. +// +type Instruction interface { + // String returns the disassembled form of this value. + // + // Examples of Instructions that are Values: + // "x + y" (BinOp) + // "len([])" (Call) + // Note that the name of the Value is not printed. + // + // Examples of Instructions that are not Values: + // "return x" (Return) + // "*y = x" (Store) + // + // (The separation Value.Name() from Value.String() is useful + // for some analyses which distinguish the operation from the + // value it defines, e.g., 'y = local int' is both an allocation + // of memory 'local int' and a definition of a pointer y.) + String() string + + // Parent returns the function to which this instruction + // belongs. + Parent() *Function + + // Block returns the basic block to which this instruction + // belongs. + Block() *BasicBlock + + // setBlock sets the basic block to which this instruction belongs. + setBlock(*BasicBlock) + + // Operands returns the operands of this instruction: the + // set of Values it references. + // + // Specifically, it appends their addresses to rands, a + // user-provided slice, and returns the resulting slice, + // permitting avoidance of memory allocation. + // + // The operands are appended in undefined order, but the order + // is consistent for a given Instruction; the addresses are + // always non-nil but may point to a nil Value. Clients may + // store through the pointers, e.g. to effect a value + // renaming. + // + // Value.Referrers is a subset of the inverse of this + // relation. (Referrers are not tracked for all types of + // Values.) + Operands(rands []*Value) []*Value + + // Pos returns the location of the AST token most closely + // associated with the operation that gave rise to this + // instruction, or token.NoPos if it was not explicit in the + // source. + // + // For each ast.Node type, a particular token is designated as + // the closest location for the expression, e.g. the Go token + // for an *ast.GoStmt. This permits a compact but approximate + // mapping from Instructions to source positions for use in + // diagnostic messages, for example. + // + // (Do not use this position to determine which Instruction + // corresponds to an ast.Expr; see the notes for Value.Pos. + // This position may be used to determine which non-Value + // Instruction corresponds to some ast.Stmts, but not all: If + // and Jump instructions have no Pos(), for example.) + Pos() token.Pos +} + +// A Node is a node in the SSA value graph. Every concrete type that +// implements Node is also either a Value, an Instruction, or both. +// +// Node contains the methods common to Value and Instruction, plus the +// Operands and Referrers methods generalized to return nil for +// non-Instructions and non-Values, respectively. +// +// Node is provided to simplify SSA graph algorithms. Clients should +// use the more specific and informative Value or Instruction +// interfaces where appropriate. +// +type Node interface { + // Common methods: + String() string + Pos() token.Pos + Parent() *Function + + // Partial methods: + Operands(rands []*Value) []*Value // nil for non-Instructions + Referrers() *[]Instruction // nil for non-Values +} + +// Function represents the parameters, results, and code of a function +// or method. +// +// If Blocks is nil, this indicates an external function for which no +// Go source code is available. In this case, FreeVars and Locals +// are nil too. Clients performing whole-program analysis must +// handle external functions specially. +// +// Blocks contains the function's control-flow graph (CFG). +// Blocks[0] is the function entry point; block order is not otherwise +// semantically significant, though it may affect the readability of +// the disassembly. +// To iterate over the blocks in dominance order, use DomPreorder(). +// +// Recover is an optional second entry point to which control resumes +// after a recovered panic. The Recover block may contain only a return +// statement, preceded by a load of the function's named return +// parameters, if any. +// +// A nested function (Parent()!=nil) that refers to one or more +// lexically enclosing local variables ("free variables") has FreeVars. +// Such functions cannot be called directly but require a +// value created by MakeClosure which, via its Bindings, supplies +// values for these parameters. +// +// If the function is a method (Signature.Recv() != nil) then the first +// element of Params is the receiver parameter. +// +// A Go package may declare many functions called "init". +// For each one, Object().Name() returns "init" but Name() returns +// "init#1", etc, in declaration order. +// +// Pos() returns the declaring ast.FuncLit.Type.Func or the position +// of the ast.FuncDecl.Name, if the function was explicit in the +// source. Synthetic wrappers, for which Synthetic != "", may share +// the same position as the function they wrap. +// Syntax.Pos() always returns the position of the declaring "func" token. +// +// Type() returns the function's Signature. +// +type Function struct { + name string + object types.Object // a declared *types.Func or one of its wrappers + method *types.Selection // info about provenance of synthetic methods + Signature *types.Signature + pos token.Pos + + Synthetic string // provenance of synthetic function; "" for true source functions + syntax ast.Node // *ast.Func{Decl,Lit}; replaced with simple ast.Node after build, unless debug mode + parent *Function // enclosing function if anon; nil if global + Pkg *Package // enclosing package; nil for shared funcs (wrappers and error.Error) + Prog *Program // enclosing program + Params []*Parameter // function parameters; for methods, includes receiver + FreeVars []*FreeVar // free variables whose values must be supplied by closure + Locals []*Alloc // local variables of this function + Blocks []*BasicBlock // basic blocks of the function; nil => external + Recover *BasicBlock // optional; control transfers here after recovered panic + AnonFuncs []*Function // anonymous functions directly beneath this one + referrers []Instruction // referring instructions (iff Parent() != nil) + + // The following fields are set transiently during building, + // then cleared. + currentBlock *BasicBlock // where to emit code + objects map[types.Object]Value // addresses of local variables + namedResults []*Alloc // tuple of named results + targets *targets // linked stack of branch targets + lblocks map[*ast.Object]*lblock // labelled blocks +} + +// BasicBlock represents an SSA basic block. +// +// The final element of Instrs is always an explicit transfer of +// control (If, Jump, Return, or Panic). +// +// A block may contain no Instructions only if it is unreachable, +// i.e., Preds is nil. Empty blocks are typically pruned. +// +// BasicBlocks and their Preds/Succs relation form a (possibly cyclic) +// graph independent of the SSA Value graph: the control-flow graph or +// CFG. It is illegal for multiple edges to exist between the same +// pair of blocks. +// +// Each BasicBlock is also a node in the dominator tree of the CFG. +// The tree may be navigated using Idom()/Dominees() and queried using +// Dominates(). +// +// The order of Preds and Succs is significant (to Phi and If +// instructions, respectively). +// +type BasicBlock struct { + Index int // index of this block within Parent().Blocks + Comment string // optional label; no semantic significance + parent *Function // parent function + Instrs []Instruction // instructions in order + Preds, Succs []*BasicBlock // predecessors and successors + succs2 [2]*BasicBlock // initial space for Succs + dom domInfo // dominator tree info + gaps int // number of nil Instrs (transient) + rundefers int // number of rundefers (transient) +} + +// Pure values ---------------------------------------- + +// A FreeVar represents a free variable of the function to which it +// belongs. +// +// FreeVars are used to implement anonymous functions, whose free +// variables are lexically captured in a closure formed by +// MakeClosure. The value of such a free var is an Alloc or another +// FreeVar and is considered a potentially escaping heap address, with +// pointer type. +// +// FreeVars are also used to implement bound method closures. Such a +// free var represents the receiver value and may be of any type that +// has concrete methods. +// +// Pos() returns the position of the value that was captured, which +// belongs to an enclosing function. +// +type FreeVar struct { + name string + typ types.Type + pos token.Pos + parent *Function + referrers []Instruction + + // Transiently needed during building. + outer Value // the Value captured from the enclosing context. +} + +// A Parameter represents an input parameter of a function. +// +type Parameter struct { + name string + object types.Object // a *types.Var; nil for non-source locals + typ types.Type + pos token.Pos + parent *Function + referrers []Instruction +} + +// A Const represents the value of a constant expression. +// +// The underlying type of a constant may be any boolean, numeric, or +// string type. In addition, a Const may represent the nil value of +// any reference type---interface, map, channel, pointer, slice, or +// function---but not "untyped nil". +// +// All source-level constant expressions are represented by a Const +// of the same type and value. +// +// Value holds the value of the constant, independent of its Type(), +// using go/constant representation, or nil for a typed nil value. +// +// Pos() returns token.NoPos. +// +// Example printed form: +// 42:int +// "hello":untyped string +// 3+4i:MyComplex +// +type Const struct { + typ types.Type + Value constant.Value +} + +// A Global is a named Value holding the address of a package-level +// variable. +// +// Pos() returns the position of the ast.ValueSpec.Names[*] +// identifier. +// +type Global struct { + name string + object types.Object // a *types.Var; may be nil for synthetics e.g. init$guard + typ types.Type + pos token.Pos + + Pkg *Package +} + +// A Builtin represents a specific use of a built-in function, e.g. len. +// +// Builtins are immutable values. Builtins do not have addresses. +// Builtins can only appear in CallCommon.Func. +// +// Name() indicates the function: one of the built-in functions from the +// Go spec (excluding "make" and "new") or one of these ssa-defined +// intrinsics: +// +// // wrapnilchk returns ptr if non-nil, panics otherwise. +// // (For use in indirection wrappers.) +// func ssa:wrapnilchk(ptr *T, recvType, methodName string) *T +// +// Object() returns a *types.Builtin for built-ins defined by the spec, +// nil for others. +// +// Type() returns a *types.Signature representing the effective +// signature of the built-in for this call. +// +type Builtin struct { + name string + sig *types.Signature +} + +// Value-defining instructions ---------------------------------------- + +// The Alloc instruction reserves space for a variable of the given type, +// zero-initializes it, and yields its address. +// +// Alloc values are always addresses, and have pointer types, so the +// type of the allocated variable is actually +// Type().Underlying().(*types.Pointer).Elem(). +// +// If Heap is false, Alloc allocates space in the function's +// activation record (frame); we refer to an Alloc(Heap=false) as a +// "local" alloc. Each local Alloc returns the same address each time +// it is executed within the same activation; the space is +// re-initialized to zero. +// +// If Heap is true, Alloc allocates space in the heap; we +// refer to an Alloc(Heap=true) as a "new" alloc. Each new Alloc +// returns a different address each time it is executed. +// +// When Alloc is applied to a channel, map or slice type, it returns +// the address of an uninitialized (nil) reference of that kind; store +// the result of MakeSlice, MakeMap or MakeChan in that location to +// instantiate these types. +// +// Pos() returns the ast.CompositeLit.Lbrace for a composite literal, +// or the ast.CallExpr.Rparen for a call to new() or for a call that +// allocates a varargs slice. +// +// Example printed form: +// t0 = local int +// t1 = new int +// +type Alloc struct { + register + Comment string + Heap bool + index int // dense numbering; for lifting +} + +// The Phi instruction represents an SSA φ-node, which combines values +// that differ across incoming control-flow edges and yields a new +// value. Within a block, all φ-nodes must appear before all non-φ +// nodes. +// +// Pos() returns the position of the && or || for short-circuit +// control-flow joins, or that of the *Alloc for φ-nodes inserted +// during SSA renaming. +// +// Example printed form: +// t2 = phi [0: t0, 1: t1] +// +type Phi struct { + register + Comment string // a hint as to its purpose + Edges []Value // Edges[i] is value for Block().Preds[i] +} + +// The Call instruction represents a function or method call. +// +// The Call instruction yields the function result if there is exactly +// one. Otherwise it returns a tuple, the components of which are +// accessed via Extract. +// +// See CallCommon for generic function call documentation. +// +// Pos() returns the ast.CallExpr.Lparen, if explicit in the source. +// +// Example printed form: +// t2 = println(t0, t1) +// t4 = t3() +// t7 = invoke t5.Println(...t6) +// +type Call struct { + register + Call CallCommon +} + +// The BinOp instruction yields the result of binary operation X Op Y. +// +// Pos() returns the ast.BinaryExpr.OpPos, if explicit in the source. +// +// Example printed form: +// t1 = t0 + 1:int +// +type BinOp struct { + register + // One of: + // ADD SUB MUL QUO REM + - * / % + // AND OR XOR SHL SHR AND_NOT & | ^ << >> &^ + // EQL NEQ LSS LEQ GTR GEQ == != < <= < >= + Op token.Token + X, Y Value +} + +// The UnOp instruction yields the result of Op X. +// ARROW is channel receive. +// MUL is pointer indirection (load). +// XOR is bitwise complement. +// SUB is negation. +// NOT is logical negation. +// +// If CommaOk and Op=ARROW, the result is a 2-tuple of the value above +// and a boolean indicating the success of the receive. The +// components of the tuple are accessed using Extract. +// +// Pos() returns the ast.UnaryExpr.OpPos, if explicit in the source. +// For receive operations (ARROW) implicit in ranging over a channel, +// Pos() returns the ast.RangeStmt.For. +// For implicit memory loads (STAR), Pos() returns the position of the +// most closely associated source-level construct; the details are not +// specified. +// +// Example printed form: +// t0 = *x +// t2 = <-t1,ok +// +type UnOp struct { + register + Op token.Token // One of: NOT SUB ARROW MUL XOR ! - <- * ^ + X Value + CommaOk bool +} + +// The ChangeType instruction applies to X a value-preserving type +// change to Type(). +// +// Type changes are permitted: +// - between a named type and its underlying type. +// - between two named types of the same underlying type. +// - between (possibly named) pointers to identical base types. +// - from a bidirectional channel to a read- or write-channel, +// optionally adding/removing a name. +// +// This operation cannot fail dynamically. +// +// Pos() returns the ast.CallExpr.Lparen, if the instruction arose +// from an explicit conversion in the source. +// +// Example printed form: +// t1 = changetype *int <- IntPtr (t0) +// +type ChangeType struct { + register + X Value +} + +// The Convert instruction yields the conversion of value X to type +// Type(). One or both of those types is basic (but possibly named). +// +// A conversion may change the value and representation of its operand. +// Conversions are permitted: +// - between real numeric types. +// - between complex numeric types. +// - between string and []byte or []rune. +// - between pointers and unsafe.Pointer. +// - between unsafe.Pointer and uintptr. +// - from (Unicode) integer to (UTF-8) string. +// A conversion may imply a type name change also. +// +// This operation cannot fail dynamically. +// +// Conversions of untyped string/number/bool constants to a specific +// representation are eliminated during SSA construction. +// +// Pos() returns the ast.CallExpr.Lparen, if the instruction arose +// from an explicit conversion in the source. +// +// Example printed form: +// t1 = convert []byte <- string (t0) +// +type Convert struct { + register + X Value +} + +// ChangeInterface constructs a value of one interface type from a +// value of another interface type known to be assignable to it. +// This operation cannot fail. +// +// Pos() returns the ast.CallExpr.Lparen if the instruction arose from +// an explicit T(e) conversion; the ast.TypeAssertExpr.Lparen if the +// instruction arose from an explicit e.(T) operation; or token.NoPos +// otherwise. +// +// Example printed form: +// t1 = change interface interface{} <- I (t0) +// +type ChangeInterface struct { + register + X Value +} + +// MakeInterface constructs an instance of an interface type from a +// value of a concrete type. +// +// Use Program.MethodSets.MethodSet(X.Type()) to find the method-set +// of X, and Program.MethodValue(m) to find the implementation of a method. +// +// To construct the zero value of an interface type T, use: +// NewConst(constant.MakeNil(), T, pos) +// +// Pos() returns the ast.CallExpr.Lparen, if the instruction arose +// from an explicit conversion in the source. +// +// Example printed form: +// t1 = make interface{} <- int (42:int) +// t2 = make Stringer <- t0 +// +type MakeInterface struct { + register + X Value +} + +// The MakeClosure instruction yields a closure value whose code is +// Fn and whose free variables' values are supplied by Bindings. +// +// Type() returns a (possibly named) *types.Signature. +// +// Pos() returns the ast.FuncLit.Type.Func for a function literal +// closure or the ast.SelectorExpr.Sel for a bound method closure. +// +// Example printed form: +// t0 = make closure anon@1.2 [x y z] +// t1 = make closure bound$(main.I).add [i] +// +type MakeClosure struct { + register + Fn Value // always a *Function + Bindings []Value // values for each free variable in Fn.FreeVars +} + +// The MakeMap instruction creates a new hash-table-based map object +// and yields a value of kind map. +// +// Type() returns a (possibly named) *types.Map. +// +// Pos() returns the ast.CallExpr.Lparen, if created by make(map), or +// the ast.CompositeLit.Lbrack if created by a literal. +// +// Example printed form: +// t1 = make map[string]int t0 +// t1 = make StringIntMap t0 +// +type MakeMap struct { + register + Reserve Value // initial space reservation; nil => default +} + +// The MakeChan instruction creates a new channel object and yields a +// value of kind chan. +// +// Type() returns a (possibly named) *types.Chan. +// +// Pos() returns the ast.CallExpr.Lparen for the make(chan) that +// created it. +// +// Example printed form: +// t0 = make chan int 0 +// t0 = make IntChan 0 +// +type MakeChan struct { + register + Size Value // int; size of buffer; zero => synchronous. +} + +// The MakeSlice instruction yields a slice of length Len backed by a +// newly allocated array of length Cap. +// +// Both Len and Cap must be non-nil Values of integer type. +// +// (Alloc(types.Array) followed by Slice will not suffice because +// Alloc can only create arrays of constant length.) +// +// Type() returns a (possibly named) *types.Slice. +// +// Pos() returns the ast.CallExpr.Lparen for the make([]T) that +// created it. +// +// Example printed form: +// t1 = make []string 1:int t0 +// t1 = make StringSlice 1:int t0 +// +type MakeSlice struct { + register + Len Value + Cap Value +} + +// The Slice instruction yields a slice of an existing string, slice +// or *array X between optional integer bounds Low and High. +// +// Dynamically, this instruction panics if X evaluates to a nil *array +// pointer. +// +// Type() returns string if the type of X was string, otherwise a +// *types.Slice with the same element type as X. +// +// Pos() returns the ast.SliceExpr.Lbrack if created by a x[:] slice +// operation, the ast.CompositeLit.Lbrace if created by a literal, or +// NoPos if not explicit in the source (e.g. a variadic argument slice). +// +// Example printed form: +// t1 = slice t0[1:] +// +type Slice struct { + register + X Value // slice, string, or *array + Low, High, Max Value // each may be nil +} + +// The FieldAddr instruction yields the address of Field of *struct X. +// +// The field is identified by its index within the field list of the +// struct type of X. +// +// Dynamically, this instruction panics if X evaluates to a nil +// pointer. +// +// Type() returns a (possibly named) *types.Pointer. +// +// Pos() returns the position of the ast.SelectorExpr.Sel for the +// field, if explicit in the source. +// +// Example printed form: +// t1 = &t0.name [#1] +// +type FieldAddr struct { + register + X Value // *struct + Field int // field is X.Type().Underlying().(*types.Pointer).Elem().Underlying().(*types.Struct).Field(Field) +} + +// The Field instruction yields the Field of struct X. +// +// The field is identified by its index within the field list of the +// struct type of X; by using numeric indices we avoid ambiguity of +// package-local identifiers and permit compact representations. +// +// Pos() returns the position of the ast.SelectorExpr.Sel for the +// field, if explicit in the source. +// +// Example printed form: +// t1 = t0.name [#1] +// +type Field struct { + register + X Value // struct + Field int // index into X.Type().(*types.Struct).Fields +} + +// The IndexAddr instruction yields the address of the element at +// index Index of collection X. Index is an integer expression. +// +// The elements of maps and strings are not addressable; use Lookup or +// MapUpdate instead. +// +// Dynamically, this instruction panics if X evaluates to a nil *array +// pointer. +// +// Type() returns a (possibly named) *types.Pointer. +// +// Pos() returns the ast.IndexExpr.Lbrack for the index operation, if +// explicit in the source. +// +// Example printed form: +// t2 = &t0[t1] +// +type IndexAddr struct { + register + X Value // slice or *array, + Index Value // numeric index +} + +// The Index instruction yields element Index of array X. +// +// Pos() returns the ast.IndexExpr.Lbrack for the index operation, if +// explicit in the source. +// +// Example printed form: +// t2 = t0[t1] +// +type Index struct { + register + X Value // array + Index Value // integer index +} + +// The Lookup instruction yields element Index of collection X, a map +// or string. Index is an integer expression if X is a string or the +// appropriate key type if X is a map. +// +// If CommaOk, the result is a 2-tuple of the value above and a +// boolean indicating the result of a map membership test for the key. +// The components of the tuple are accessed using Extract. +// +// Pos() returns the ast.IndexExpr.Lbrack, if explicit in the source. +// +// Example printed form: +// t2 = t0[t1] +// t5 = t3[t4],ok +// +type Lookup struct { + register + X Value // string or map + Index Value // numeric or key-typed index + CommaOk bool // return a value,ok pair +} + +// SelectState is a helper for Select. +// It represents one goal state and its corresponding communication. +// +type SelectState struct { + Dir types.ChanDir // direction of case (SendOnly or RecvOnly) + Chan Value // channel to use (for send or receive) + Send Value // value to send (for send) + Pos token.Pos // position of token.ARROW + DebugNode ast.Node // ast.SendStmt or ast.UnaryExpr(<-) [debug mode] +} + +// The Select instruction tests whether (or blocks until) one +// of the specified sent or received states is entered. +// +// Let n be the number of States for which Dir==RECV and T_i (0<=i string iterator; false => map iterator. +} + +// The TypeAssert instruction tests whether interface value X has type +// AssertedType. +// +// If !CommaOk, on success it returns v, the result of the conversion +// (defined below); on failure it panics. +// +// If CommaOk: on success it returns a pair (v, true) where v is the +// result of the conversion; on failure it returns (z, false) where z +// is AssertedType's zero value. The components of the pair must be +// accessed using the Extract instruction. +// +// If AssertedType is a concrete type, TypeAssert checks whether the +// dynamic type in interface X is equal to it, and if so, the result +// of the conversion is a copy of the value in the interface. +// +// If AssertedType is an interface, TypeAssert checks whether the +// dynamic type of the interface is assignable to it, and if so, the +// result of the conversion is a copy of the interface value X. +// If AssertedType is a superinterface of X.Type(), the operation will +// fail iff the operand is nil. (Contrast with ChangeInterface, which +// performs no nil-check.) +// +// Type() reflects the actual type of the result, possibly a +// 2-types.Tuple; AssertedType is the asserted type. +// +// Pos() returns the ast.CallExpr.Lparen if the instruction arose from +// an explicit T(e) conversion; the ast.TypeAssertExpr.Lparen if the +// instruction arose from an explicit e.(T) operation; or the +// ast.CaseClause.Case if the instruction arose from a case of a +// type-switch statement. +// +// Example printed form: +// t1 = typeassert t0.(int) +// t3 = typeassert,ok t2.(T) +// +type TypeAssert struct { + register + X Value + AssertedType types.Type + CommaOk bool +} + +// The Extract instruction yields component Index of Tuple. +// +// This is used to access the results of instructions with multiple +// return values, such as Call, TypeAssert, Next, UnOp(ARROW) and +// IndexExpr(Map). +// +// Example printed form: +// t1 = extract t0 #1 +// +type Extract struct { + register + Tuple Value + Index int +} + +// Instructions executed for effect. They do not yield a value. -------------------- + +// The Jump instruction transfers control to the sole successor of its +// owning block. +// +// A Jump must be the last instruction of its containing BasicBlock. +// +// Pos() returns NoPos. +// +// Example printed form: +// jump done +// +type Jump struct { + anInstruction +} + +// The If instruction transfers control to one of the two successors +// of its owning block, depending on the boolean Cond: the first if +// true, the second if false. +// +// An If instruction must be the last instruction of its containing +// BasicBlock. +// +// Pos() returns NoPos. +// +// Example printed form: +// if t0 goto done else body +// +type If struct { + anInstruction + Cond Value +} + +// The Return instruction returns values and control back to the calling +// function. +// +// len(Results) is always equal to the number of results in the +// function's signature. +// +// If len(Results) > 1, Return returns a tuple value with the specified +// components which the caller must access using Extract instructions. +// +// There is no instruction to return a ready-made tuple like those +// returned by a "value,ok"-mode TypeAssert, Lookup or UnOp(ARROW) or +// a tail-call to a function with multiple result parameters. +// +// Return must be the last instruction of its containing BasicBlock. +// Such a block has no successors. +// +// Pos() returns the ast.ReturnStmt.Return, if explicit in the source. +// +// Example printed form: +// return +// return nil:I, 2:int +// +type Return struct { + anInstruction + Results []Value + pos token.Pos +} + +// The RunDefers instruction pops and invokes the entire stack of +// procedure calls pushed by Defer instructions in this function. +// +// It is legal to encounter multiple 'rundefers' instructions in a +// single control-flow path through a function; this is useful in +// the combined init() function, for example. +// +// Pos() returns NoPos. +// +// Example printed form: +// rundefers +// +type RunDefers struct { + anInstruction +} + +// The Panic instruction initiates a panic with value X. +// +// A Panic instruction must be the last instruction of its containing +// BasicBlock, which must have no successors. +// +// NB: 'go panic(x)' and 'defer panic(x)' do not use this instruction; +// they are treated as calls to a built-in function. +// +// Pos() returns the ast.CallExpr.Lparen if this panic was explicit +// in the source. +// +// Example printed form: +// panic t0 +// +type Panic struct { + anInstruction + X Value // an interface{} + pos token.Pos +} + +// The Go instruction creates a new goroutine and calls the specified +// function within it. +// +// See CallCommon for generic function call documentation. +// +// Pos() returns the ast.GoStmt.Go. +// +// Example printed form: +// go println(t0, t1) +// go t3() +// go invoke t5.Println(...t6) +// +type Go struct { + anInstruction + Call CallCommon + pos token.Pos +} + +// The Defer instruction pushes the specified call onto a stack of +// functions to be called by a RunDefers instruction or by a panic. +// +// See CallCommon for generic function call documentation. +// +// Pos() returns the ast.DeferStmt.Defer. +// +// Example printed form: +// defer println(t0, t1) +// defer t3() +// defer invoke t5.Println(...t6) +// +type Defer struct { + anInstruction + Call CallCommon + pos token.Pos +} + +// The Send instruction sends X on channel Chan. +// +// Pos() returns the ast.SendStmt.Arrow, if explicit in the source. +// +// Example printed form: +// send t0 <- t1 +// +type Send struct { + anInstruction + Chan, X Value + pos token.Pos +} + +// The Store instruction stores Val at address Addr. +// Stores can be of arbitrary types. +// +// Pos() returns the position of the source-level construct most closely +// associated with the memory store operation. +// Since implicit memory stores are numerous and varied and depend upon +// implementation choices, the details are not specified. +// +// Example printed form: +// *x = y +// +type Store struct { + anInstruction + Addr Value + Val Value + pos token.Pos +} + +// The MapUpdate instruction updates the association of Map[Key] to +// Value. +// +// Pos() returns the ast.KeyValueExpr.Colon or ast.IndexExpr.Lbrack, +// if explicit in the source. +// +// Example printed form: +// t0[t1] = t2 +// +type MapUpdate struct { + anInstruction + Map Value + Key Value + Value Value + pos token.Pos +} + +// A DebugRef instruction maps a source-level expression Expr to the +// SSA value X that represents the value (!IsAddr) or address (IsAddr) +// of that expression. +// +// DebugRef is a pseudo-instruction: it has no dynamic effect. +// +// Pos() returns Expr.Pos(), the start position of the source-level +// expression. This is not the same as the "designated" token as +// documented at Value.Pos(). e.g. CallExpr.Pos() does not return the +// position of the ("designated") Lparen token. +// +// If Expr is an *ast.Ident denoting a var or func, Object() returns +// the object; though this information can be obtained from the type +// checker, including it here greatly facilitates debugging. +// For non-Ident expressions, Object() returns nil. +// +// DebugRefs are generated only for functions built with debugging +// enabled; see Package.SetDebugMode() and the GlobalDebug builder +// mode flag. +// +// DebugRefs are not emitted for ast.Idents referring to constants or +// predeclared identifiers, since they are trivial and numerous. +// Nor are they emitted for ast.ParenExprs. +// +// (By representing these as instructions, rather than out-of-band, +// consistency is maintained during transformation passes by the +// ordinary SSA renaming machinery.) +// +// Example printed form: +// ; *ast.CallExpr @ 102:9 is t5 +// ; var x float64 @ 109:72 is x +// ; address of *ast.CompositeLit @ 216:10 is t0 +// +type DebugRef struct { + anInstruction + Expr ast.Expr // the referring expression (never *ast.ParenExpr) + object types.Object // the identity of the source var/func + IsAddr bool // Expr is addressable and X is the address it denotes + X Value // the value or address of Expr +} + +// Embeddable mix-ins and helpers for common parts of other structs. ----------- + +// register is a mix-in embedded by all SSA values that are also +// instructions, i.e. virtual registers, and provides a uniform +// implementation of most of the Value interface: Value.Name() is a +// numbered register (e.g. "t0"); the other methods are field accessors. +// +// Temporary names are automatically assigned to each register on +// completion of building a function in SSA form. +// +// Clients must not assume that the 'id' value (and the Name() derived +// from it) is unique within a function. As always in this API, +// semantics are determined only by identity; names exist only to +// facilitate debugging. +// +type register struct { + anInstruction + num int // "name" of virtual register, e.g. "t0". Not guaranteed unique. + typ types.Type // type of virtual register + pos token.Pos // position of source expression, or NoPos + referrers []Instruction +} + +// anInstruction is a mix-in embedded by all Instructions. +// It provides the implementations of the Block and setBlock methods. +type anInstruction struct { + block *BasicBlock // the basic block of this instruction +} + +// CallCommon is contained by Go, Defer and Call to hold the +// common parts of a function or method call. +// +// Each CallCommon exists in one of two modes, function call and +// interface method invocation, or "call" and "invoke" for short. +// +// 1. "call" mode: when Method is nil (!IsInvoke), a CallCommon +// represents an ordinary function call of the value in Value, +// which may be a *Builtin, a *Function or any other value of kind +// 'func'. +// +// Value may be one of: +// (a) a *Function, indicating a statically dispatched call +// to a package-level function, an anonymous function, or +// a method of a named type. +// (b) a *MakeClosure, indicating an immediately applied +// function literal with free variables. +// (c) a *Builtin, indicating a statically dispatched call +// to a built-in function. +// (d) any other value, indicating a dynamically dispatched +// function call. +// StaticCallee returns the identity of the callee in cases +// (a) and (b), nil otherwise. +// +// Args contains the arguments to the call. If Value is a method, +// Args[0] contains the receiver parameter. +// +// Example printed form: +// t2 = println(t0, t1) +// go t3() +// defer t5(...t6) +// +// 2. "invoke" mode: when Method is non-nil (IsInvoke), a CallCommon +// represents a dynamically dispatched call to an interface method. +// In this mode, Value is the interface value and Method is the +// interface's abstract method. Note: an abstract method may be +// shared by multiple interfaces due to embedding; Value.Type() +// provides the specific interface used for this call. +// +// Value is implicitly supplied to the concrete method implementation +// as the receiver parameter; in other words, Args[0] holds not the +// receiver but the first true argument. +// +// Example printed form: +// t1 = invoke t0.String() +// go invoke t3.Run(t2) +// defer invoke t4.Handle(...t5) +// +// For all calls to variadic functions (Signature().Variadic()), +// the last element of Args is a slice. +// +type CallCommon struct { + Value Value // receiver (invoke mode) or func value (call mode) + Method *types.Func // abstract method (invoke mode) + Args []Value // actual parameters (in static method call, includes receiver) + pos token.Pos // position of CallExpr.Lparen, iff explicit in source +} + +// IsInvoke returns true if this call has "invoke" (not "call") mode. +func (c *CallCommon) IsInvoke() bool { + return c.Method != nil +} + +func (c *CallCommon) Pos() token.Pos { return c.pos } + +// Signature returns the signature of the called function. +// +// For an "invoke"-mode call, the signature of the interface method is +// returned. +// +// In either "call" or "invoke" mode, if the callee is a method, its +// receiver is represented by sig.Recv, not sig.Params().At(0). +// +func (c *CallCommon) Signature() *types.Signature { + if c.Method != nil { + return c.Method.Type().(*types.Signature) + } + return c.Value.Type().Underlying().(*types.Signature) +} + +// StaticCallee returns the callee if this is a trivially static +// "call"-mode call to a function. +func (c *CallCommon) StaticCallee() *Function { + switch fn := c.Value.(type) { + case *Function: + return fn + case *MakeClosure: + return fn.Fn.(*Function) + } + return nil +} + +// Description returns a description of the mode of this call suitable +// for a user interface, e.g., "static method call". +func (c *CallCommon) Description() string { + switch fn := c.Value.(type) { + case *Builtin: + return "built-in function call" + case *MakeClosure: + return "static function closure call" + case *Function: + if fn.Signature.Recv() != nil { + return "static method call" + } + return "static function call" + } + if c.IsInvoke() { + return "dynamic method call" // ("invoke" mode) + } + return "dynamic function call" +} + +// The CallInstruction interface, implemented by *Go, *Defer and *Call, +// exposes the common parts of function-calling instructions, +// yet provides a way back to the Value defined by *Call alone. +// +type CallInstruction interface { + Instruction + Common() *CallCommon // returns the common parts of the call + Value() *Call // returns the result value of the call (*Call) or nil (*Go, *Defer) +} + +func (s *Call) Common() *CallCommon { return &s.Call } +func (s *Defer) Common() *CallCommon { return &s.Call } +func (s *Go) Common() *CallCommon { return &s.Call } + +func (s *Call) Value() *Call { return s } +func (s *Defer) Value() *Call { return nil } +func (s *Go) Value() *Call { return nil } + +func (v *Builtin) Type() types.Type { return v.sig } +func (v *Builtin) Name() string { return v.name } +func (*Builtin) Referrers() *[]Instruction { return nil } +func (v *Builtin) Pos() token.Pos { return token.NoPos } +func (v *Builtin) Object() types.Object { return types.Universe.Lookup(v.name) } +func (v *Builtin) Parent() *Function { return nil } + +func (v *FreeVar) Type() types.Type { return v.typ } +func (v *FreeVar) Name() string { return v.name } +func (v *FreeVar) Referrers() *[]Instruction { return &v.referrers } +func (v *FreeVar) Pos() token.Pos { return v.pos } +func (v *FreeVar) Parent() *Function { return v.parent } + +func (v *Global) Type() types.Type { return v.typ } +func (v *Global) Name() string { return v.name } +func (v *Global) Parent() *Function { return nil } +func (v *Global) Pos() token.Pos { return v.pos } +func (v *Global) Referrers() *[]Instruction { return nil } +func (v *Global) Token() token.Token { return token.VAR } +func (v *Global) Object() types.Object { return v.object } +func (v *Global) String() string { return v.RelString(nil) } +func (v *Global) Package() *Package { return v.Pkg } +func (v *Global) RelString(from *types.Package) string { return relString(v, from) } + +func (v *Function) Name() string { return v.name } +func (v *Function) Type() types.Type { return v.Signature } +func (v *Function) Pos() token.Pos { return v.pos } +func (v *Function) Token() token.Token { return token.FUNC } +func (v *Function) Object() types.Object { return v.object } +func (v *Function) String() string { return v.RelString(nil) } +func (v *Function) Package() *Package { return v.Pkg } +func (v *Function) Parent() *Function { return v.parent } +func (v *Function) Referrers() *[]Instruction { + if v.parent != nil { + return &v.referrers + } + return nil +} + +func (v *Parameter) Type() types.Type { return v.typ } +func (v *Parameter) Name() string { return v.name } +func (v *Parameter) Object() types.Object { return v.object } +func (v *Parameter) Referrers() *[]Instruction { return &v.referrers } +func (v *Parameter) Pos() token.Pos { return v.pos } +func (v *Parameter) Parent() *Function { return v.parent } + +func (v *Alloc) Type() types.Type { return v.typ } +func (v *Alloc) Referrers() *[]Instruction { return &v.referrers } +func (v *Alloc) Pos() token.Pos { return v.pos } + +func (v *register) Type() types.Type { return v.typ } +func (v *register) setType(typ types.Type) { v.typ = typ } +func (v *register) Name() string { return fmt.Sprintf("t%d", v.num) } +func (v *register) setNum(num int) { v.num = num } +func (v *register) Referrers() *[]Instruction { return &v.referrers } +func (v *register) Pos() token.Pos { return v.pos } +func (v *register) setPos(pos token.Pos) { v.pos = pos } + +func (v *anInstruction) Parent() *Function { return v.block.parent } +func (v *anInstruction) Block() *BasicBlock { return v.block } +func (v *anInstruction) setBlock(block *BasicBlock) { v.block = block } +func (v *anInstruction) Referrers() *[]Instruction { return nil } + +func (t *Type) Name() string { return t.object.Name() } +func (t *Type) Pos() token.Pos { return t.object.Pos() } +func (t *Type) Type() types.Type { return t.object.Type() } +func (t *Type) Token() token.Token { return token.TYPE } +func (t *Type) Object() types.Object { return t.object } +func (t *Type) String() string { return t.RelString(nil) } +func (t *Type) Package() *Package { return t.pkg } +func (t *Type) RelString(from *types.Package) string { return relString(t, from) } + +func (c *NamedConst) Name() string { return c.object.Name() } +func (c *NamedConst) Pos() token.Pos { return c.object.Pos() } +func (c *NamedConst) String() string { return c.RelString(nil) } +func (c *NamedConst) Type() types.Type { return c.object.Type() } +func (c *NamedConst) Token() token.Token { return token.CONST } +func (c *NamedConst) Object() types.Object { return c.object } +func (c *NamedConst) Package() *Package { return c.pkg } +func (c *NamedConst) RelString(from *types.Package) string { return relString(c, from) } + +// Func returns the package-level function of the specified name, +// or nil if not found. +// +func (p *Package) Func(name string) (f *Function) { + f, _ = p.Members[name].(*Function) + return +} + +// Var returns the package-level variable of the specified name, +// or nil if not found. +// +func (p *Package) Var(name string) (g *Global) { + g, _ = p.Members[name].(*Global) + return +} + +// Const returns the package-level constant of the specified name, +// or nil if not found. +// +func (p *Package) Const(name string) (c *NamedConst) { + c, _ = p.Members[name].(*NamedConst) + return +} + +// Type returns the package-level type of the specified name, +// or nil if not found. +// +func (p *Package) Type(name string) (t *Type) { + t, _ = p.Members[name].(*Type) + return +} + +func (v *Call) Pos() token.Pos { return v.Call.pos } +func (s *Defer) Pos() token.Pos { return s.pos } +func (s *Go) Pos() token.Pos { return s.pos } +func (s *MapUpdate) Pos() token.Pos { return s.pos } +func (s *Panic) Pos() token.Pos { return s.pos } +func (s *Return) Pos() token.Pos { return s.pos } +func (s *Send) Pos() token.Pos { return s.pos } +func (s *Store) Pos() token.Pos { return s.pos } +func (s *If) Pos() token.Pos { return token.NoPos } +func (s *Jump) Pos() token.Pos { return token.NoPos } +func (s *RunDefers) Pos() token.Pos { return token.NoPos } +func (s *DebugRef) Pos() token.Pos { return s.Expr.Pos() } + +// Operands. + +func (v *Alloc) Operands(rands []*Value) []*Value { + return rands +} + +func (v *BinOp) Operands(rands []*Value) []*Value { + return append(rands, &v.X, &v.Y) +} + +func (c *CallCommon) Operands(rands []*Value) []*Value { + rands = append(rands, &c.Value) + for i := range c.Args { + rands = append(rands, &c.Args[i]) + } + return rands +} + +func (s *Go) Operands(rands []*Value) []*Value { + return s.Call.Operands(rands) +} + +func (s *Call) Operands(rands []*Value) []*Value { + return s.Call.Operands(rands) +} + +func (s *Defer) Operands(rands []*Value) []*Value { + return s.Call.Operands(rands) +} + +func (v *ChangeInterface) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (v *ChangeType) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (v *Convert) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (s *DebugRef) Operands(rands []*Value) []*Value { + return append(rands, &s.X) +} + +func (v *Extract) Operands(rands []*Value) []*Value { + return append(rands, &v.Tuple) +} + +func (v *Field) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (v *FieldAddr) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (s *If) Operands(rands []*Value) []*Value { + return append(rands, &s.Cond) +} + +func (v *Index) Operands(rands []*Value) []*Value { + return append(rands, &v.X, &v.Index) +} + +func (v *IndexAddr) Operands(rands []*Value) []*Value { + return append(rands, &v.X, &v.Index) +} + +func (*Jump) Operands(rands []*Value) []*Value { + return rands +} + +func (v *Lookup) Operands(rands []*Value) []*Value { + return append(rands, &v.X, &v.Index) +} + +func (v *MakeChan) Operands(rands []*Value) []*Value { + return append(rands, &v.Size) +} + +func (v *MakeClosure) Operands(rands []*Value) []*Value { + rands = append(rands, &v.Fn) + for i := range v.Bindings { + rands = append(rands, &v.Bindings[i]) + } + return rands +} + +func (v *MakeInterface) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (v *MakeMap) Operands(rands []*Value) []*Value { + return append(rands, &v.Reserve) +} + +func (v *MakeSlice) Operands(rands []*Value) []*Value { + return append(rands, &v.Len, &v.Cap) +} + +func (v *MapUpdate) Operands(rands []*Value) []*Value { + return append(rands, &v.Map, &v.Key, &v.Value) +} + +func (v *Next) Operands(rands []*Value) []*Value { + return append(rands, &v.Iter) +} + +func (s *Panic) Operands(rands []*Value) []*Value { + return append(rands, &s.X) +} + +func (v *Phi) Operands(rands []*Value) []*Value { + for i := range v.Edges { + rands = append(rands, &v.Edges[i]) + } + return rands +} + +func (v *Range) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (s *Return) Operands(rands []*Value) []*Value { + for i := range s.Results { + rands = append(rands, &s.Results[i]) + } + return rands +} + +func (*RunDefers) Operands(rands []*Value) []*Value { + return rands +} + +func (v *Select) Operands(rands []*Value) []*Value { + for i := range v.States { + rands = append(rands, &v.States[i].Chan, &v.States[i].Send) + } + return rands +} + +func (s *Send) Operands(rands []*Value) []*Value { + return append(rands, &s.Chan, &s.X) +} + +func (v *Slice) Operands(rands []*Value) []*Value { + return append(rands, &v.X, &v.Low, &v.High, &v.Max) +} + +func (s *Store) Operands(rands []*Value) []*Value { + return append(rands, &s.Addr, &s.Val) +} + +func (v *TypeAssert) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +func (v *UnOp) Operands(rands []*Value) []*Value { + return append(rands, &v.X) +} + +// Non-Instruction Values: +func (v *Builtin) Operands(rands []*Value) []*Value { return rands } +func (v *FreeVar) Operands(rands []*Value) []*Value { return rands } +func (v *Const) Operands(rands []*Value) []*Value { return rands } +func (v *Function) Operands(rands []*Value) []*Value { return rands } +func (v *Global) Operands(rands []*Value) []*Value { return rands } +func (v *Parameter) Operands(rands []*Value) []*Value { return rands } diff --git a/vendor/golang.org/x/tools/go/ssa/ssautil/load.go b/vendor/golang.org/x/tools/go/ssa/ssautil/load.go new file mode 100644 index 00000000000..6d65b78ef28 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/ssautil/load.go @@ -0,0 +1,175 @@ +// Copyright 2015 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssautil + +// This file defines utility functions for constructing programs in SSA form. + +import ( + "go/ast" + "go/token" + "go/types" + + "golang.org/x/tools/go/loader" + "golang.org/x/tools/go/packages" + "golang.org/x/tools/go/ssa" +) + +// Packages creates an SSA program for a set of packages. +// +// The packages must have been loaded from source syntax using the +// golang.org/x/tools/go/packages.Load function in LoadSyntax or +// LoadAllSyntax mode. +// +// Packages creates an SSA package for each well-typed package in the +// initial list, plus all their dependencies. The resulting list of +// packages corresponds to the list of initial packages, and may contain +// a nil if SSA code could not be constructed for the corresponding initial +// package due to type errors. +// +// Code for bodies of functions is not built until Build is called on +// the resulting Program. SSA code is constructed only for the initial +// packages with well-typed syntax trees. +// +// The mode parameter controls diagnostics and checking during SSA construction. +// +func Packages(initial []*packages.Package, mode ssa.BuilderMode) (*ssa.Program, []*ssa.Package) { + return doPackages(initial, mode, false) +} + +// AllPackages creates an SSA program for a set of packages plus all +// their dependencies. +// +// The packages must have been loaded from source syntax using the +// golang.org/x/tools/go/packages.Load function in LoadAllSyntax mode. +// +// AllPackages creates an SSA package for each well-typed package in the +// initial list, plus all their dependencies. The resulting list of +// packages corresponds to the list of initial packages, and may contain +// a nil if SSA code could not be constructed for the corresponding +// initial package due to type errors. +// +// Code for bodies of functions is not built until Build is called on +// the resulting Program. SSA code is constructed for all packages with +// well-typed syntax trees. +// +// The mode parameter controls diagnostics and checking during SSA construction. +// +func AllPackages(initial []*packages.Package, mode ssa.BuilderMode) (*ssa.Program, []*ssa.Package) { + return doPackages(initial, mode, true) +} + +func doPackages(initial []*packages.Package, mode ssa.BuilderMode, deps bool) (*ssa.Program, []*ssa.Package) { + + var fset *token.FileSet + if len(initial) > 0 { + fset = initial[0].Fset + } + + prog := ssa.NewProgram(fset, mode) + + isInitial := make(map[*packages.Package]bool, len(initial)) + for _, p := range initial { + isInitial[p] = true + } + + ssamap := make(map[*packages.Package]*ssa.Package) + packages.Visit(initial, nil, func(p *packages.Package) { + if p.Types != nil && !p.IllTyped { + var files []*ast.File + if deps || isInitial[p] { + files = p.Syntax + } + ssamap[p] = prog.CreatePackage(p.Types, files, p.TypesInfo, true) + } + }) + + var ssapkgs []*ssa.Package + for _, p := range initial { + ssapkgs = append(ssapkgs, ssamap[p]) // may be nil + } + return prog, ssapkgs +} + +// CreateProgram returns a new program in SSA form, given a program +// loaded from source. An SSA package is created for each transitively +// error-free package of lprog. +// +// Code for bodies of functions is not built until Build is called +// on the result. +// +// The mode parameter controls diagnostics and checking during SSA construction. +// +// Deprecated: Use golang.org/x/tools/go/packages and the Packages +// function instead; see ssa.ExampleLoadPackages. +// +func CreateProgram(lprog *loader.Program, mode ssa.BuilderMode) *ssa.Program { + prog := ssa.NewProgram(lprog.Fset, mode) + + for _, info := range lprog.AllPackages { + if info.TransitivelyErrorFree { + prog.CreatePackage(info.Pkg, info.Files, &info.Info, info.Importable) + } + } + + return prog +} + +// BuildPackage builds an SSA program with IR for a single package. +// +// It populates pkg by type-checking the specified file ASTs. All +// dependencies are loaded using the importer specified by tc, which +// typically loads compiler export data; SSA code cannot be built for +// those packages. BuildPackage then constructs an ssa.Program with all +// dependency packages created, and builds and returns the SSA package +// corresponding to pkg. +// +// The caller must have set pkg.Path() to the import path. +// +// The operation fails if there were any type-checking or import errors. +// +// See ../ssa/example_test.go for an example. +// +func BuildPackage(tc *types.Config, fset *token.FileSet, pkg *types.Package, files []*ast.File, mode ssa.BuilderMode) (*ssa.Package, *types.Info, error) { + if fset == nil { + panic("no token.FileSet") + } + if pkg.Path() == "" { + panic("package has no import path") + } + + info := &types.Info{ + Types: make(map[ast.Expr]types.TypeAndValue), + Defs: make(map[*ast.Ident]types.Object), + Uses: make(map[*ast.Ident]types.Object), + Implicits: make(map[ast.Node]types.Object), + Scopes: make(map[ast.Node]*types.Scope), + Selections: make(map[*ast.SelectorExpr]*types.Selection), + } + if err := types.NewChecker(tc, fset, pkg, info).Files(files); err != nil { + return nil, nil, err + } + + prog := ssa.NewProgram(fset, mode) + + // Create SSA packages for all imports. + // Order is not significant. + created := make(map[*types.Package]bool) + var createAll func(pkgs []*types.Package) + createAll = func(pkgs []*types.Package) { + for _, p := range pkgs { + if !created[p] { + created[p] = true + prog.CreatePackage(p, nil, nil, true) + createAll(p.Imports()) + } + } + } + createAll(pkg.Imports()) + + // Create and build the primary package. + ssapkg := prog.CreatePackage(pkg, files, info, false) + ssapkg.Build() + return ssapkg, info, nil +} diff --git a/vendor/golang.org/x/tools/go/ssa/ssautil/switch.go b/vendor/golang.org/x/tools/go/ssa/ssautil/switch.go new file mode 100644 index 00000000000..db03bf55590 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/ssautil/switch.go @@ -0,0 +1,234 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssautil + +// This file implements discovery of switch and type-switch constructs +// from low-level control flow. +// +// Many techniques exist for compiling a high-level switch with +// constant cases to efficient machine code. The optimal choice will +// depend on the data type, the specific case values, the code in the +// body of each case, and the hardware. +// Some examples: +// - a lookup table (for a switch that maps constants to constants) +// - a computed goto +// - a binary tree +// - a perfect hash +// - a two-level switch (to partition constant strings by their first byte). + +import ( + "bytes" + "fmt" + "go/token" + "go/types" + + "golang.org/x/tools/go/ssa" +) + +// A ConstCase represents a single constant comparison. +// It is part of a Switch. +type ConstCase struct { + Block *ssa.BasicBlock // block performing the comparison + Body *ssa.BasicBlock // body of the case + Value *ssa.Const // case comparand +} + +// A TypeCase represents a single type assertion. +// It is part of a Switch. +type TypeCase struct { + Block *ssa.BasicBlock // block performing the type assert + Body *ssa.BasicBlock // body of the case + Type types.Type // case type + Binding ssa.Value // value bound by this case +} + +// A Switch is a logical high-level control flow operation +// (a multiway branch) discovered by analysis of a CFG containing +// only if/else chains. It is not part of the ssa.Instruction set. +// +// One of ConstCases and TypeCases has length >= 2; +// the other is nil. +// +// In a value switch, the list of cases may contain duplicate constants. +// A type switch may contain duplicate types, or types assignable +// to an interface type also in the list. +// TODO(adonovan): eliminate such duplicates. +// +type Switch struct { + Start *ssa.BasicBlock // block containing start of if/else chain + X ssa.Value // the switch operand + ConstCases []ConstCase // ordered list of constant comparisons + TypeCases []TypeCase // ordered list of type assertions + Default *ssa.BasicBlock // successor if all comparisons fail +} + +func (sw *Switch) String() string { + // We represent each block by the String() of its + // first Instruction, e.g. "print(42:int)". + var buf bytes.Buffer + if sw.ConstCases != nil { + fmt.Fprintf(&buf, "switch %s {\n", sw.X.Name()) + for _, c := range sw.ConstCases { + fmt.Fprintf(&buf, "case %s: %s\n", c.Value, c.Body.Instrs[0]) + } + } else { + fmt.Fprintf(&buf, "switch %s.(type) {\n", sw.X.Name()) + for _, c := range sw.TypeCases { + fmt.Fprintf(&buf, "case %s %s: %s\n", + c.Binding.Name(), c.Type, c.Body.Instrs[0]) + } + } + if sw.Default != nil { + fmt.Fprintf(&buf, "default: %s\n", sw.Default.Instrs[0]) + } + fmt.Fprintf(&buf, "}") + return buf.String() +} + +// Switches examines the control-flow graph of fn and returns the +// set of inferred value and type switches. A value switch tests an +// ssa.Value for equality against two or more compile-time constant +// values. Switches involving link-time constants (addresses) are +// ignored. A type switch type-asserts an ssa.Value against two or +// more types. +// +// The switches are returned in dominance order. +// +// The resulting switches do not necessarily correspond to uses of the +// 'switch' keyword in the source: for example, a single source-level +// switch statement with non-constant cases may result in zero, one or +// many Switches, one per plural sequence of constant cases. +// Switches may even be inferred from if/else- or goto-based control flow. +// (In general, the control flow constructs of the source program +// cannot be faithfully reproduced from the SSA representation.) +// +func Switches(fn *ssa.Function) []Switch { + // Traverse the CFG in dominance order, so we don't + // enter an if/else-chain in the middle. + var switches []Switch + seen := make(map[*ssa.BasicBlock]bool) // TODO(adonovan): opt: use ssa.blockSet + for _, b := range fn.DomPreorder() { + if x, k := isComparisonBlock(b); x != nil { + // Block b starts a switch. + sw := Switch{Start: b, X: x} + valueSwitch(&sw, k, seen) + if len(sw.ConstCases) > 1 { + switches = append(switches, sw) + } + } + + if y, x, T := isTypeAssertBlock(b); y != nil { + // Block b starts a type switch. + sw := Switch{Start: b, X: x} + typeSwitch(&sw, y, T, seen) + if len(sw.TypeCases) > 1 { + switches = append(switches, sw) + } + } + } + return switches +} + +func valueSwitch(sw *Switch, k *ssa.Const, seen map[*ssa.BasicBlock]bool) { + b := sw.Start + x := sw.X + for x == sw.X { + if seen[b] { + break + } + seen[b] = true + + sw.ConstCases = append(sw.ConstCases, ConstCase{ + Block: b, + Body: b.Succs[0], + Value: k, + }) + b = b.Succs[1] + if len(b.Instrs) > 2 { + // Block b contains not just 'if x == k', + // so it may have side effects that + // make it unsafe to elide. + break + } + if len(b.Preds) != 1 { + // Block b has multiple predecessors, + // so it cannot be treated as a case. + break + } + x, k = isComparisonBlock(b) + } + sw.Default = b +} + +func typeSwitch(sw *Switch, y ssa.Value, T types.Type, seen map[*ssa.BasicBlock]bool) { + b := sw.Start + x := sw.X + for x == sw.X { + if seen[b] { + break + } + seen[b] = true + + sw.TypeCases = append(sw.TypeCases, TypeCase{ + Block: b, + Body: b.Succs[0], + Type: T, + Binding: y, + }) + b = b.Succs[1] + if len(b.Instrs) > 4 { + // Block b contains not just + // {TypeAssert; Extract #0; Extract #1; If} + // so it may have side effects that + // make it unsafe to elide. + break + } + if len(b.Preds) != 1 { + // Block b has multiple predecessors, + // so it cannot be treated as a case. + break + } + y, x, T = isTypeAssertBlock(b) + } + sw.Default = b +} + +// isComparisonBlock returns the operands (v, k) if a block ends with +// a comparison v==k, where k is a compile-time constant. +// +func isComparisonBlock(b *ssa.BasicBlock) (v ssa.Value, k *ssa.Const) { + if n := len(b.Instrs); n >= 2 { + if i, ok := b.Instrs[n-1].(*ssa.If); ok { + if binop, ok := i.Cond.(*ssa.BinOp); ok && binop.Block() == b && binop.Op == token.EQL { + if k, ok := binop.Y.(*ssa.Const); ok { + return binop.X, k + } + if k, ok := binop.X.(*ssa.Const); ok { + return binop.Y, k + } + } + } + } + return +} + +// isTypeAssertBlock returns the operands (y, x, T) if a block ends with +// a type assertion "if y, ok := x.(T); ok {". +// +func isTypeAssertBlock(b *ssa.BasicBlock) (y, x ssa.Value, T types.Type) { + if n := len(b.Instrs); n >= 4 { + if i, ok := b.Instrs[n-1].(*ssa.If); ok { + if ext1, ok := i.Cond.(*ssa.Extract); ok && ext1.Block() == b && ext1.Index == 1 { + if ta, ok := ext1.Tuple.(*ssa.TypeAssert); ok && ta.Block() == b { + // hack: relies upon instruction ordering. + if ext0, ok := b.Instrs[n-3].(*ssa.Extract); ok { + return ext0, ta.X, ta.AssertedType + } + } + } + } + } + return +} diff --git a/vendor/golang.org/x/tools/go/ssa/ssautil/visit.go b/vendor/golang.org/x/tools/go/ssa/ssautil/visit.go new file mode 100644 index 00000000000..3424e8a3086 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/ssautil/visit.go @@ -0,0 +1,79 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssautil // import "golang.org/x/tools/go/ssa/ssautil" + +import "golang.org/x/tools/go/ssa" + +// This file defines utilities for visiting the SSA representation of +// a Program. +// +// TODO(adonovan): test coverage. + +// AllFunctions finds and returns the set of functions potentially +// needed by program prog, as determined by a simple linker-style +// reachability algorithm starting from the members and method-sets of +// each package. The result may include anonymous functions and +// synthetic wrappers. +// +// Precondition: all packages are built. +// +func AllFunctions(prog *ssa.Program) map[*ssa.Function]bool { + visit := visitor{ + prog: prog, + seen: make(map[*ssa.Function]bool), + } + visit.program() + return visit.seen +} + +type visitor struct { + prog *ssa.Program + seen map[*ssa.Function]bool +} + +func (visit *visitor) program() { + for _, pkg := range visit.prog.AllPackages() { + for _, mem := range pkg.Members { + if fn, ok := mem.(*ssa.Function); ok { + visit.function(fn) + } + } + } + for _, T := range visit.prog.RuntimeTypes() { + mset := visit.prog.MethodSets.MethodSet(T) + for i, n := 0, mset.Len(); i < n; i++ { + visit.function(visit.prog.MethodValue(mset.At(i))) + } + } +} + +func (visit *visitor) function(fn *ssa.Function) { + if !visit.seen[fn] { + visit.seen[fn] = true + var buf [10]*ssa.Value // avoid alloc in common case + for _, b := range fn.Blocks { + for _, instr := range b.Instrs { + for _, op := range instr.Operands(buf[:0]) { + if fn, ok := (*op).(*ssa.Function); ok { + visit.function(fn) + } + } + } + } + } +} + +// MainPackages returns the subset of the specified packages +// named "main" that define a main function. +// The result may include synthetic "testmain" packages. +func MainPackages(pkgs []*ssa.Package) []*ssa.Package { + var mains []*ssa.Package + for _, pkg := range pkgs { + if pkg.Pkg.Name() == "main" && pkg.Func("main") != nil { + mains = append(mains, pkg) + } + } + return mains +} diff --git a/vendor/golang.org/x/tools/go/ssa/testmain.go b/vendor/golang.org/x/tools/go/ssa/testmain.go new file mode 100644 index 00000000000..4bf8d98f3a6 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/testmain.go @@ -0,0 +1,273 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// CreateTestMainPackage synthesizes a main package that runs all the +// tests of the supplied packages. +// It is closely coupled to $GOROOT/src/cmd/go/test.go and $GOROOT/src/testing. +// +// TODO(adonovan): throws this all away now that x/tools/go/packages +// provides access to the actual synthetic test main files. + +import ( + "bytes" + "fmt" + "go/ast" + "go/parser" + "go/types" + "log" + "os" + "strings" + "text/template" +) + +// FindTests returns the Test, Benchmark, and Example functions +// (as defined by "go test") defined in the specified package, +// and its TestMain function, if any. +// +// Deprecated: Use golang.org/x/tools/go/packages to access synthetic +// testmain packages. +func FindTests(pkg *Package) (tests, benchmarks, examples []*Function, main *Function) { + prog := pkg.Prog + + // The first two of these may be nil: if the program doesn't import "testing", + // it can't contain any tests, but it may yet contain Examples. + var testSig *types.Signature // func(*testing.T) + var benchmarkSig *types.Signature // func(*testing.B) + var exampleSig = types.NewSignature(nil, nil, nil, false) // func() + + // Obtain the types from the parameters of testing.MainStart. + if testingPkg := prog.ImportedPackage("testing"); testingPkg != nil { + mainStart := testingPkg.Func("MainStart") + params := mainStart.Signature.Params() + testSig = funcField(params.At(1).Type()) + benchmarkSig = funcField(params.At(2).Type()) + + // Does the package define this function? + // func TestMain(*testing.M) + if f := pkg.Func("TestMain"); f != nil { + sig := f.Type().(*types.Signature) + starM := mainStart.Signature.Results().At(0).Type() // *testing.M + if sig.Results().Len() == 0 && + sig.Params().Len() == 1 && + types.Identical(sig.Params().At(0).Type(), starM) { + main = f + } + } + } + + // TODO(adonovan): use a stable order, e.g. lexical. + for _, mem := range pkg.Members { + if f, ok := mem.(*Function); ok && + ast.IsExported(f.Name()) && + strings.HasSuffix(prog.Fset.Position(f.Pos()).Filename, "_test.go") { + + switch { + case testSig != nil && isTestSig(f, "Test", testSig): + tests = append(tests, f) + case benchmarkSig != nil && isTestSig(f, "Benchmark", benchmarkSig): + benchmarks = append(benchmarks, f) + case isTestSig(f, "Example", exampleSig): + examples = append(examples, f) + default: + continue + } + } + } + return +} + +// Like isTest, but checks the signature too. +func isTestSig(f *Function, prefix string, sig *types.Signature) bool { + return isTest(f.Name(), prefix) && types.Identical(f.Signature, sig) +} + +// Given the type of one of the three slice parameters of testing.Main, +// returns the function type. +func funcField(slice types.Type) *types.Signature { + return slice.(*types.Slice).Elem().Underlying().(*types.Struct).Field(1).Type().(*types.Signature) +} + +// isTest tells whether name looks like a test (or benchmark, according to prefix). +// It is a Test (say) if there is a character after Test that is not a lower-case letter. +// We don't want TesticularCancer. +// Plundered from $GOROOT/src/cmd/go/test.go +func isTest(name, prefix string) bool { + if !strings.HasPrefix(name, prefix) { + return false + } + if len(name) == len(prefix) { // "Test" is ok + return true + } + return ast.IsExported(name[len(prefix):]) +} + +// CreateTestMainPackage creates and returns a synthetic "testmain" +// package for the specified package if it defines tests, benchmarks or +// executable examples, or nil otherwise. The new package is named +// "main" and provides a function named "main" that runs the tests, +// similar to the one that would be created by the 'go test' tool. +// +// Subsequent calls to prog.AllPackages include the new package. +// The package pkg must belong to the program prog. +// +// Deprecated: Use golang.org/x/tools/go/packages to access synthetic +// testmain packages. +func (prog *Program) CreateTestMainPackage(pkg *Package) *Package { + if pkg.Prog != prog { + log.Fatal("Package does not belong to Program") + } + + // Template data + var data struct { + Pkg *Package + Tests, Benchmarks, Examples []*Function + Main *Function + Go18 bool + } + data.Pkg = pkg + + // Enumerate tests. + data.Tests, data.Benchmarks, data.Examples, data.Main = FindTests(pkg) + if data.Main == nil && + data.Tests == nil && data.Benchmarks == nil && data.Examples == nil { + return nil + } + + // Synthesize source for testmain package. + path := pkg.Pkg.Path() + "$testmain" + tmpl := testmainTmpl + if testingPkg := prog.ImportedPackage("testing"); testingPkg != nil { + // In Go 1.8, testing.MainStart's first argument is an interface, not a func. + data.Go18 = types.IsInterface(testingPkg.Func("MainStart").Signature.Params().At(0).Type()) + } else { + // The program does not import "testing", but FindTests + // returned non-nil, which must mean there were Examples + // but no Test, Benchmark, or TestMain functions. + + // We'll simply call them from testmain.main; this will + // ensure they don't panic, but will not check any + // "Output:" comments. + // (We should not execute an Example that has no + // "Output:" comment, but it's impossible to tell here.) + tmpl = examplesOnlyTmpl + } + var buf bytes.Buffer + if err := tmpl.Execute(&buf, data); err != nil { + log.Fatalf("internal error expanding template for %s: %v", path, err) + } + if false { // debugging + fmt.Fprintln(os.Stderr, buf.String()) + } + + // Parse and type-check the testmain package. + f, err := parser.ParseFile(prog.Fset, path+".go", &buf, parser.Mode(0)) + if err != nil { + log.Fatalf("internal error parsing %s: %v", path, err) + } + conf := types.Config{ + DisableUnusedImportCheck: true, + Importer: importer{pkg}, + } + files := []*ast.File{f} + info := &types.Info{ + Types: make(map[ast.Expr]types.TypeAndValue), + Defs: make(map[*ast.Ident]types.Object), + Uses: make(map[*ast.Ident]types.Object), + Implicits: make(map[ast.Node]types.Object), + Scopes: make(map[ast.Node]*types.Scope), + Selections: make(map[*ast.SelectorExpr]*types.Selection), + } + testmainPkg, err := conf.Check(path, prog.Fset, files, info) + if err != nil { + log.Fatalf("internal error type-checking %s: %v", path, err) + } + + // Create and build SSA code. + testmain := prog.CreatePackage(testmainPkg, files, info, false) + testmain.SetDebugMode(false) + testmain.Build() + testmain.Func("main").Synthetic = "test main function" + testmain.Func("init").Synthetic = "package initializer" + return testmain +} + +// An implementation of types.Importer for an already loaded SSA program. +type importer struct { + pkg *Package // package under test; may be non-importable +} + +func (imp importer) Import(path string) (*types.Package, error) { + if p := imp.pkg.Prog.ImportedPackage(path); p != nil { + return p.Pkg, nil + } + if path == imp.pkg.Pkg.Path() { + return imp.pkg.Pkg, nil + } + return nil, fmt.Errorf("not found") // can't happen +} + +var testmainTmpl = template.Must(template.New("testmain").Parse(` +package main + +import "io" +import "os" +import "testing" +import p {{printf "%q" .Pkg.Pkg.Path}} + +{{if .Go18}} +type deps struct{} + +func (deps) ImportPath() string { return "" } +func (deps) MatchString(pat, str string) (bool, error) { return true, nil } +func (deps) StartCPUProfile(io.Writer) error { return nil } +func (deps) StartTestLog(io.Writer) {} +func (deps) StopCPUProfile() {} +func (deps) StopTestLog() error { return nil } +func (deps) WriteHeapProfile(io.Writer) error { return nil } +func (deps) WriteProfileTo(string, io.Writer, int) error { return nil } + +var match deps +{{else}} +func match(_, _ string) (bool, error) { return true, nil } +{{end}} + +func main() { + tests := []testing.InternalTest{ +{{range .Tests}} + { {{printf "%q" .Name}}, p.{{.Name}} }, +{{end}} + } + benchmarks := []testing.InternalBenchmark{ +{{range .Benchmarks}} + { {{printf "%q" .Name}}, p.{{.Name}} }, +{{end}} + } + examples := []testing.InternalExample{ +{{range .Examples}} + {Name: {{printf "%q" .Name}}, F: p.{{.Name}}}, +{{end}} + } + m := testing.MainStart(match, tests, benchmarks, examples) +{{with .Main}} + p.{{.Name}}(m) +{{else}} + os.Exit(m.Run()) +{{end}} +} + +`)) + +var examplesOnlyTmpl = template.Must(template.New("examples").Parse(` +package main + +import p {{printf "%q" .Pkg.Pkg.Path}} + +func main() { +{{range .Examples}} + p.{{.Name}}() +{{end}} +} +`)) diff --git a/vendor/golang.org/x/tools/go/ssa/util.go b/vendor/golang.org/x/tools/go/ssa/util.go new file mode 100644 index 00000000000..ddb11846096 --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/util.go @@ -0,0 +1,119 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines a number of miscellaneous utility functions. + +import ( + "fmt" + "go/ast" + "go/token" + "go/types" + "io" + "os" + + "golang.org/x/tools/go/ast/astutil" +) + +//// AST utilities + +func unparen(e ast.Expr) ast.Expr { return astutil.Unparen(e) } + +// isBlankIdent returns true iff e is an Ident with name "_". +// They have no associated types.Object, and thus no type. +// +func isBlankIdent(e ast.Expr) bool { + id, ok := e.(*ast.Ident) + return ok && id.Name == "_" +} + +//// Type utilities. Some of these belong in go/types. + +// isPointer returns true for types whose underlying type is a pointer. +func isPointer(typ types.Type) bool { + _, ok := typ.Underlying().(*types.Pointer) + return ok +} + +func isInterface(T types.Type) bool { return types.IsInterface(T) } + +// deref returns a pointer's element type; otherwise it returns typ. +func deref(typ types.Type) types.Type { + if p, ok := typ.Underlying().(*types.Pointer); ok { + return p.Elem() + } + return typ +} + +// recvType returns the receiver type of method obj. +func recvType(obj *types.Func) types.Type { + return obj.Type().(*types.Signature).Recv().Type() +} + +// DefaultType returns the default "typed" type for an "untyped" type; +// it returns the incoming type for all other types. The default type +// for untyped nil is untyped nil. +// +// Exported to ssa/interp. +// +// TODO(adonovan): use go/types.DefaultType after 1.8. +// +func DefaultType(typ types.Type) types.Type { + if t, ok := typ.(*types.Basic); ok { + k := t.Kind() + switch k { + case types.UntypedBool: + k = types.Bool + case types.UntypedInt: + k = types.Int + case types.UntypedRune: + k = types.Rune + case types.UntypedFloat: + k = types.Float64 + case types.UntypedComplex: + k = types.Complex128 + case types.UntypedString: + k = types.String + } + typ = types.Typ[k] + } + return typ +} + +// logStack prints the formatted "start" message to stderr and +// returns a closure that prints the corresponding "end" message. +// Call using 'defer logStack(...)()' to show builder stack on panic. +// Don't forget trailing parens! +// +func logStack(format string, args ...interface{}) func() { + msg := fmt.Sprintf(format, args...) + io.WriteString(os.Stderr, msg) + io.WriteString(os.Stderr, "\n") + return func() { + io.WriteString(os.Stderr, msg) + io.WriteString(os.Stderr, " end\n") + } +} + +// newVar creates a 'var' for use in a types.Tuple. +func newVar(name string, typ types.Type) *types.Var { + return types.NewParam(token.NoPos, nil, name, typ) +} + +// anonVar creates an anonymous 'var' for use in a types.Tuple. +func anonVar(typ types.Type) *types.Var { + return newVar("", typ) +} + +var lenResults = types.NewTuple(anonVar(tInt)) + +// makeLen returns the len builtin specialized to type func(T)int. +func makeLen(T types.Type) *Builtin { + lenParams := types.NewTuple(anonVar(T)) + return &Builtin{ + name: "len", + sig: types.NewSignature(nil, lenParams, lenResults, false), + } +} diff --git a/vendor/golang.org/x/tools/go/ssa/wrappers.go b/vendor/golang.org/x/tools/go/ssa/wrappers.go new file mode 100644 index 00000000000..a4ae71d8cfc --- /dev/null +++ b/vendor/golang.org/x/tools/go/ssa/wrappers.go @@ -0,0 +1,290 @@ +// Copyright 2013 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package ssa + +// This file defines synthesis of Functions that delegate to declared +// methods; they come in three kinds: +// +// (1) wrappers: methods that wrap declared methods, performing +// implicit pointer indirections and embedded field selections. +// +// (2) thunks: funcs that wrap declared methods. Like wrappers, +// thunks perform indirections and field selections. The thunk's +// first parameter is used as the receiver for the method call. +// +// (3) bounds: funcs that wrap declared methods. The bound's sole +// free variable, supplied by a closure, is used as the receiver +// for the method call. No indirections or field selections are +// performed since they can be done before the call. + +import ( + "fmt" + + "go/types" +) + +// -- wrappers ----------------------------------------------------------- + +// makeWrapper returns a synthetic method that delegates to the +// declared method denoted by meth.Obj(), first performing any +// necessary pointer indirections or field selections implied by meth. +// +// The resulting method's receiver type is meth.Recv(). +// +// This function is versatile but quite subtle! Consider the +// following axes of variation when making changes: +// - optional receiver indirection +// - optional implicit field selections +// - meth.Obj() may denote a concrete or an interface method +// - the result may be a thunk or a wrapper. +// +// EXCLUSIVE_LOCKS_REQUIRED(prog.methodsMu) +// +func makeWrapper(prog *Program, sel *types.Selection) *Function { + obj := sel.Obj().(*types.Func) // the declared function + sig := sel.Type().(*types.Signature) // type of this wrapper + + var recv *types.Var // wrapper's receiver or thunk's params[0] + name := obj.Name() + var description string + var start int // first regular param + if sel.Kind() == types.MethodExpr { + name += "$thunk" + description = "thunk" + recv = sig.Params().At(0) + start = 1 + } else { + description = "wrapper" + recv = sig.Recv() + } + + description = fmt.Sprintf("%s for %s", description, sel.Obj()) + if prog.mode&LogSource != 0 { + defer logStack("make %s to (%s)", description, recv.Type())() + } + fn := &Function{ + name: name, + method: sel, + object: obj, + Signature: sig, + Synthetic: description, + Prog: prog, + pos: obj.Pos(), + } + fn.startBody() + fn.addSpilledParam(recv) + createParams(fn, start) + + indices := sel.Index() + + var v Value = fn.Locals[0] // spilled receiver + if isPointer(sel.Recv()) { + v = emitLoad(fn, v) + + // For simple indirection wrappers, perform an informative nil-check: + // "value method (T).f called using nil *T pointer" + if len(indices) == 1 && !isPointer(recvType(obj)) { + var c Call + c.Call.Value = &Builtin{ + name: "ssa:wrapnilchk", + sig: types.NewSignature(nil, + types.NewTuple(anonVar(sel.Recv()), anonVar(tString), anonVar(tString)), + types.NewTuple(anonVar(sel.Recv())), false), + } + c.Call.Args = []Value{ + v, + stringConst(deref(sel.Recv()).String()), + stringConst(sel.Obj().Name()), + } + c.setType(v.Type()) + v = fn.emit(&c) + } + } + + // Invariant: v is a pointer, either + // value of *A receiver param, or + // address of A spilled receiver. + + // We use pointer arithmetic (FieldAddr possibly followed by + // Load) in preference to value extraction (Field possibly + // preceded by Load). + + v = emitImplicitSelections(fn, v, indices[:len(indices)-1]) + + // Invariant: v is a pointer, either + // value of implicit *C field, or + // address of implicit C field. + + var c Call + if r := recvType(obj); !isInterface(r) { // concrete method + if !isPointer(r) { + v = emitLoad(fn, v) + } + c.Call.Value = prog.declaredFunc(obj) + c.Call.Args = append(c.Call.Args, v) + } else { + c.Call.Method = obj + c.Call.Value = emitLoad(fn, v) + } + for _, arg := range fn.Params[1:] { + c.Call.Args = append(c.Call.Args, arg) + } + emitTailCall(fn, &c) + fn.finishBody() + return fn +} + +// createParams creates parameters for wrapper method fn based on its +// Signature.Params, which do not include the receiver. +// start is the index of the first regular parameter to use. +// +func createParams(fn *Function, start int) { + tparams := fn.Signature.Params() + for i, n := start, tparams.Len(); i < n; i++ { + fn.addParamObj(tparams.At(i)) + } +} + +// -- bounds ----------------------------------------------------------- + +// makeBound returns a bound method wrapper (or "bound"), a synthetic +// function that delegates to a concrete or interface method denoted +// by obj. The resulting function has no receiver, but has one free +// variable which will be used as the method's receiver in the +// tail-call. +// +// Use MakeClosure with such a wrapper to construct a bound method +// closure. e.g.: +// +// type T int or: type T interface { meth() } +// func (t T) meth() +// var t T +// f := t.meth +// f() // calls t.meth() +// +// f is a closure of a synthetic wrapper defined as if by: +// +// f := func() { return t.meth() } +// +// Unlike makeWrapper, makeBound need perform no indirection or field +// selections because that can be done before the closure is +// constructed. +// +// EXCLUSIVE_LOCKS_ACQUIRED(meth.Prog.methodsMu) +// +func makeBound(prog *Program, obj *types.Func) *Function { + prog.methodsMu.Lock() + defer prog.methodsMu.Unlock() + fn, ok := prog.bounds[obj] + if !ok { + description := fmt.Sprintf("bound method wrapper for %s", obj) + if prog.mode&LogSource != 0 { + defer logStack("%s", description)() + } + fn = &Function{ + name: obj.Name() + "$bound", + object: obj, + Signature: changeRecv(obj.Type().(*types.Signature), nil), // drop receiver + Synthetic: description, + Prog: prog, + pos: obj.Pos(), + } + + fv := &FreeVar{name: "recv", typ: recvType(obj), parent: fn} + fn.FreeVars = []*FreeVar{fv} + fn.startBody() + createParams(fn, 0) + var c Call + + if !isInterface(recvType(obj)) { // concrete + c.Call.Value = prog.declaredFunc(obj) + c.Call.Args = []Value{fv} + } else { + c.Call.Value = fv + c.Call.Method = obj + } + for _, arg := range fn.Params { + c.Call.Args = append(c.Call.Args, arg) + } + emitTailCall(fn, &c) + fn.finishBody() + + prog.bounds[obj] = fn + } + return fn +} + +// -- thunks ----------------------------------------------------------- + +// makeThunk returns a thunk, a synthetic function that delegates to a +// concrete or interface method denoted by sel.Obj(). The resulting +// function has no receiver, but has an additional (first) regular +// parameter. +// +// Precondition: sel.Kind() == types.MethodExpr. +// +// type T int or: type T interface { meth() } +// func (t T) meth() +// f := T.meth +// var t T +// f(t) // calls t.meth() +// +// f is a synthetic wrapper defined as if by: +// +// f := func(t T) { return t.meth() } +// +// TODO(adonovan): opt: currently the stub is created even when used +// directly in a function call: C.f(i, 0). This is less efficient +// than inlining the stub. +// +// EXCLUSIVE_LOCKS_ACQUIRED(meth.Prog.methodsMu) +// +func makeThunk(prog *Program, sel *types.Selection) *Function { + if sel.Kind() != types.MethodExpr { + panic(sel) + } + + key := selectionKey{ + kind: sel.Kind(), + recv: sel.Recv(), + obj: sel.Obj(), + index: fmt.Sprint(sel.Index()), + indirect: sel.Indirect(), + } + + prog.methodsMu.Lock() + defer prog.methodsMu.Unlock() + + // Canonicalize key.recv to avoid constructing duplicate thunks. + canonRecv, ok := prog.canon.At(key.recv).(types.Type) + if !ok { + canonRecv = key.recv + prog.canon.Set(key.recv, canonRecv) + } + key.recv = canonRecv + + fn, ok := prog.thunks[key] + if !ok { + fn = makeWrapper(prog, sel) + if fn.Signature.Recv() != nil { + panic(fn) // unexpected receiver + } + prog.thunks[key] = fn + } + return fn +} + +func changeRecv(s *types.Signature, recv *types.Var) *types.Signature { + return types.NewSignature(recv, s.Params(), s.Results(), s.Variadic()) +} + +// selectionKey is like types.Selection but a usable map key. +type selectionKey struct { + kind types.SelectionKind + recv types.Type // canonicalized via Program.canon + obj types.Object + index string + indirect bool +} diff --git a/vendor/golang.org/x/tools/go/types/typeutil/callee.go b/vendor/golang.org/x/tools/go/types/typeutil/callee.go new file mode 100644 index 00000000000..38f596daf9e --- /dev/null +++ b/vendor/golang.org/x/tools/go/types/typeutil/callee.go @@ -0,0 +1,46 @@ +// Copyright 2018 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package typeutil + +import ( + "go/ast" + "go/types" + + "golang.org/x/tools/go/ast/astutil" +) + +// Callee returns the named target of a function call, if any: +// a function, method, builtin, or variable. +func Callee(info *types.Info, call *ast.CallExpr) types.Object { + var obj types.Object + switch fun := astutil.Unparen(call.Fun).(type) { + case *ast.Ident: + obj = info.Uses[fun] // type, var, builtin, or declared func + case *ast.SelectorExpr: + if sel, ok := info.Selections[fun]; ok { + obj = sel.Obj() // method or field + } else { + obj = info.Uses[fun.Sel] // qualified identifier? + } + } + if _, ok := obj.(*types.TypeName); ok { + return nil // T(x) is a conversion, not a call + } + return obj +} + +// StaticCallee returns the target (function or method) of a static +// function call, if any. It returns nil for calls to builtins. +func StaticCallee(info *types.Info, call *ast.CallExpr) *types.Func { + if f, ok := Callee(info, call).(*types.Func); ok && !interfaceMethod(f) { + return f + } + return nil +} + +func interfaceMethod(f *types.Func) bool { + recv := f.Type().(*types.Signature).Recv() + return recv != nil && types.IsInterface(recv.Type()) +} diff --git a/vendor/golang.org/x/tools/go/types/typeutil/imports.go b/vendor/golang.org/x/tools/go/types/typeutil/imports.go new file mode 100644 index 00000000000..9c441dba9c0 --- /dev/null +++ b/vendor/golang.org/x/tools/go/types/typeutil/imports.go @@ -0,0 +1,31 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package typeutil + +import "go/types" + +// Dependencies returns all dependencies of the specified packages. +// +// Dependent packages appear in topological order: if package P imports +// package Q, Q appears earlier than P in the result. +// The algorithm follows import statements in the order they +// appear in the source code, so the result is a total order. +// +func Dependencies(pkgs ...*types.Package) []*types.Package { + var result []*types.Package + seen := make(map[*types.Package]bool) + var visit func(pkgs []*types.Package) + visit = func(pkgs []*types.Package) { + for _, p := range pkgs { + if !seen[p] { + seen[p] = true + visit(p.Imports()) + result = append(result, p) + } + } + } + visit(pkgs) + return result +} diff --git a/vendor/golang.org/x/tools/go/types/typeutil/map.go b/vendor/golang.org/x/tools/go/types/typeutil/map.go new file mode 100644 index 00000000000..c7f75450064 --- /dev/null +++ b/vendor/golang.org/x/tools/go/types/typeutil/map.go @@ -0,0 +1,313 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package typeutil defines various utilities for types, such as Map, +// a mapping from types.Type to interface{} values. +package typeutil // import "golang.org/x/tools/go/types/typeutil" + +import ( + "bytes" + "fmt" + "go/types" + "reflect" +) + +// Map is a hash-table-based mapping from types (types.Type) to +// arbitrary interface{} values. The concrete types that implement +// the Type interface are pointers. Since they are not canonicalized, +// == cannot be used to check for equivalence, and thus we cannot +// simply use a Go map. +// +// Just as with map[K]V, a nil *Map is a valid empty map. +// +// Not thread-safe. +// +type Map struct { + hasher Hasher // shared by many Maps + table map[uint32][]entry // maps hash to bucket; entry.key==nil means unused + length int // number of map entries +} + +// entry is an entry (key/value association) in a hash bucket. +type entry struct { + key types.Type + value interface{} +} + +// SetHasher sets the hasher used by Map. +// +// All Hashers are functionally equivalent but contain internal state +// used to cache the results of hashing previously seen types. +// +// A single Hasher created by MakeHasher() may be shared among many +// Maps. This is recommended if the instances have many keys in +// common, as it will amortize the cost of hash computation. +// +// A Hasher may grow without bound as new types are seen. Even when a +// type is deleted from the map, the Hasher never shrinks, since other +// types in the map may reference the deleted type indirectly. +// +// Hashers are not thread-safe, and read-only operations such as +// Map.Lookup require updates to the hasher, so a full Mutex lock (not a +// read-lock) is require around all Map operations if a shared +// hasher is accessed from multiple threads. +// +// If SetHasher is not called, the Map will create a private hasher at +// the first call to Insert. +// +func (m *Map) SetHasher(hasher Hasher) { + m.hasher = hasher +} + +// Delete removes the entry with the given key, if any. +// It returns true if the entry was found. +// +func (m *Map) Delete(key types.Type) bool { + if m != nil && m.table != nil { + hash := m.hasher.Hash(key) + bucket := m.table[hash] + for i, e := range bucket { + if e.key != nil && types.Identical(key, e.key) { + // We can't compact the bucket as it + // would disturb iterators. + bucket[i] = entry{} + m.length-- + return true + } + } + } + return false +} + +// At returns the map entry for the given key. +// The result is nil if the entry is not present. +// +func (m *Map) At(key types.Type) interface{} { + if m != nil && m.table != nil { + for _, e := range m.table[m.hasher.Hash(key)] { + if e.key != nil && types.Identical(key, e.key) { + return e.value + } + } + } + return nil +} + +// Set sets the map entry for key to val, +// and returns the previous entry, if any. +func (m *Map) Set(key types.Type, value interface{}) (prev interface{}) { + if m.table != nil { + hash := m.hasher.Hash(key) + bucket := m.table[hash] + var hole *entry + for i, e := range bucket { + if e.key == nil { + hole = &bucket[i] + } else if types.Identical(key, e.key) { + prev = e.value + bucket[i].value = value + return + } + } + + if hole != nil { + *hole = entry{key, value} // overwrite deleted entry + } else { + m.table[hash] = append(bucket, entry{key, value}) + } + } else { + if m.hasher.memo == nil { + m.hasher = MakeHasher() + } + hash := m.hasher.Hash(key) + m.table = map[uint32][]entry{hash: {entry{key, value}}} + } + + m.length++ + return +} + +// Len returns the number of map entries. +func (m *Map) Len() int { + if m != nil { + return m.length + } + return 0 +} + +// Iterate calls function f on each entry in the map in unspecified order. +// +// If f should mutate the map, Iterate provides the same guarantees as +// Go maps: if f deletes a map entry that Iterate has not yet reached, +// f will not be invoked for it, but if f inserts a map entry that +// Iterate has not yet reached, whether or not f will be invoked for +// it is unspecified. +// +func (m *Map) Iterate(f func(key types.Type, value interface{})) { + if m != nil { + for _, bucket := range m.table { + for _, e := range bucket { + if e.key != nil { + f(e.key, e.value) + } + } + } + } +} + +// Keys returns a new slice containing the set of map keys. +// The order is unspecified. +func (m *Map) Keys() []types.Type { + keys := make([]types.Type, 0, m.Len()) + m.Iterate(func(key types.Type, _ interface{}) { + keys = append(keys, key) + }) + return keys +} + +func (m *Map) toString(values bool) string { + if m == nil { + return "{}" + } + var buf bytes.Buffer + fmt.Fprint(&buf, "{") + sep := "" + m.Iterate(func(key types.Type, value interface{}) { + fmt.Fprint(&buf, sep) + sep = ", " + fmt.Fprint(&buf, key) + if values { + fmt.Fprintf(&buf, ": %q", value) + } + }) + fmt.Fprint(&buf, "}") + return buf.String() +} + +// String returns a string representation of the map's entries. +// Values are printed using fmt.Sprintf("%v", v). +// Order is unspecified. +// +func (m *Map) String() string { + return m.toString(true) +} + +// KeysString returns a string representation of the map's key set. +// Order is unspecified. +// +func (m *Map) KeysString() string { + return m.toString(false) +} + +//////////////////////////////////////////////////////////////////////// +// Hasher + +// A Hasher maps each type to its hash value. +// For efficiency, a hasher uses memoization; thus its memory +// footprint grows monotonically over time. +// Hashers are not thread-safe. +// Hashers have reference semantics. +// Call MakeHasher to create a Hasher. +type Hasher struct { + memo map[types.Type]uint32 +} + +// MakeHasher returns a new Hasher instance. +func MakeHasher() Hasher { + return Hasher{make(map[types.Type]uint32)} +} + +// Hash computes a hash value for the given type t such that +// Identical(t, t') => Hash(t) == Hash(t'). +func (h Hasher) Hash(t types.Type) uint32 { + hash, ok := h.memo[t] + if !ok { + hash = h.hashFor(t) + h.memo[t] = hash + } + return hash +} + +// hashString computes the Fowler–Noll–Vo hash of s. +func hashString(s string) uint32 { + var h uint32 + for i := 0; i < len(s); i++ { + h ^= uint32(s[i]) + h *= 16777619 + } + return h +} + +// hashFor computes the hash of t. +func (h Hasher) hashFor(t types.Type) uint32 { + // See Identical for rationale. + switch t := t.(type) { + case *types.Basic: + return uint32(t.Kind()) + + case *types.Array: + return 9043 + 2*uint32(t.Len()) + 3*h.Hash(t.Elem()) + + case *types.Slice: + return 9049 + 2*h.Hash(t.Elem()) + + case *types.Struct: + var hash uint32 = 9059 + for i, n := 0, t.NumFields(); i < n; i++ { + f := t.Field(i) + if f.Anonymous() { + hash += 8861 + } + hash += hashString(t.Tag(i)) + hash += hashString(f.Name()) // (ignore f.Pkg) + hash += h.Hash(f.Type()) + } + return hash + + case *types.Pointer: + return 9067 + 2*h.Hash(t.Elem()) + + case *types.Signature: + var hash uint32 = 9091 + if t.Variadic() { + hash *= 8863 + } + return hash + 3*h.hashTuple(t.Params()) + 5*h.hashTuple(t.Results()) + + case *types.Interface: + var hash uint32 = 9103 + for i, n := 0, t.NumMethods(); i < n; i++ { + // See go/types.identicalMethods for rationale. + // Method order is not significant. + // Ignore m.Pkg(). + m := t.Method(i) + hash += 3*hashString(m.Name()) + 5*h.Hash(m.Type()) + } + return hash + + case *types.Map: + return 9109 + 2*h.Hash(t.Key()) + 3*h.Hash(t.Elem()) + + case *types.Chan: + return 9127 + 2*uint32(t.Dir()) + 3*h.Hash(t.Elem()) + + case *types.Named: + // Not safe with a copying GC; objects may move. + return uint32(reflect.ValueOf(t.Obj()).Pointer()) + + case *types.Tuple: + return h.hashTuple(t) + } + panic(t) +} + +func (h Hasher) hashTuple(tuple *types.Tuple) uint32 { + // See go/types.identicalTypes for rationale. + n := tuple.Len() + var hash uint32 = 9137 + 2*uint32(n) + for i := 0; i < n; i++ { + hash += 3 * h.Hash(tuple.At(i).Type()) + } + return hash +} diff --git a/vendor/golang.org/x/tools/go/types/typeutil/methodsetcache.go b/vendor/golang.org/x/tools/go/types/typeutil/methodsetcache.go new file mode 100644 index 00000000000..32084610f49 --- /dev/null +++ b/vendor/golang.org/x/tools/go/types/typeutil/methodsetcache.go @@ -0,0 +1,72 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// This file implements a cache of method sets. + +package typeutil + +import ( + "go/types" + "sync" +) + +// A MethodSetCache records the method set of each type T for which +// MethodSet(T) is called so that repeat queries are fast. +// The zero value is a ready-to-use cache instance. +type MethodSetCache struct { + mu sync.Mutex + named map[*types.Named]struct{ value, pointer *types.MethodSet } // method sets for named N and *N + others map[types.Type]*types.MethodSet // all other types +} + +// MethodSet returns the method set of type T. It is thread-safe. +// +// If cache is nil, this function is equivalent to types.NewMethodSet(T). +// Utility functions can thus expose an optional *MethodSetCache +// parameter to clients that care about performance. +// +func (cache *MethodSetCache) MethodSet(T types.Type) *types.MethodSet { + if cache == nil { + return types.NewMethodSet(T) + } + cache.mu.Lock() + defer cache.mu.Unlock() + + switch T := T.(type) { + case *types.Named: + return cache.lookupNamed(T).value + + case *types.Pointer: + if N, ok := T.Elem().(*types.Named); ok { + return cache.lookupNamed(N).pointer + } + } + + // all other types + // (The map uses pointer equivalence, not type identity.) + mset := cache.others[T] + if mset == nil { + mset = types.NewMethodSet(T) + if cache.others == nil { + cache.others = make(map[types.Type]*types.MethodSet) + } + cache.others[T] = mset + } + return mset +} + +func (cache *MethodSetCache) lookupNamed(named *types.Named) struct{ value, pointer *types.MethodSet } { + if cache.named == nil { + cache.named = make(map[*types.Named]struct{ value, pointer *types.MethodSet }) + } + // Avoid recomputing mset(*T) for each distinct Pointer + // instance whose underlying type is a named type. + msets, ok := cache.named[named] + if !ok { + msets.value = types.NewMethodSet(named) + msets.pointer = types.NewMethodSet(types.NewPointer(named)) + cache.named[named] = msets + } + return msets +} diff --git a/vendor/golang.org/x/tools/go/types/typeutil/ui.go b/vendor/golang.org/x/tools/go/types/typeutil/ui.go new file mode 100644 index 00000000000..9849c24cef3 --- /dev/null +++ b/vendor/golang.org/x/tools/go/types/typeutil/ui.go @@ -0,0 +1,52 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package typeutil + +// This file defines utilities for user interfaces that display types. + +import "go/types" + +// IntuitiveMethodSet returns the intuitive method set of a type T, +// which is the set of methods you can call on an addressable value of +// that type. +// +// The result always contains MethodSet(T), and is exactly MethodSet(T) +// for interface types and for pointer-to-concrete types. +// For all other concrete types T, the result additionally +// contains each method belonging to *T if there is no identically +// named method on T itself. +// +// This corresponds to user intuition about method sets; +// this function is intended only for user interfaces. +// +// The order of the result is as for types.MethodSet(T). +// +func IntuitiveMethodSet(T types.Type, msets *MethodSetCache) []*types.Selection { + isPointerToConcrete := func(T types.Type) bool { + ptr, ok := T.(*types.Pointer) + return ok && !types.IsInterface(ptr.Elem()) + } + + var result []*types.Selection + mset := msets.MethodSet(T) + if types.IsInterface(T) || isPointerToConcrete(T) { + for i, n := 0, mset.Len(); i < n; i++ { + result = append(result, mset.At(i)) + } + } else { + // T is some other concrete type. + // Report methods of T and *T, preferring those of T. + pmset := msets.MethodSet(types.NewPointer(T)) + for i, n := 0, pmset.Len(); i < n; i++ { + meth := pmset.At(i) + if m := mset.Lookup(meth.Obj().Pkg(), meth.Obj().Name()); m != nil { + meth = m + } + result = append(result, meth) + } + + } + return result +} diff --git a/vendor/golang.org/x/tools/internal/gopathwalk/walk.go b/vendor/golang.org/x/tools/internal/gopathwalk/walk.go index 9a61bdbf5dd..d0675622893 100644 --- a/vendor/golang.org/x/tools/internal/gopathwalk/walk.go +++ b/vendor/golang.org/x/tools/internal/gopathwalk/walk.go @@ -77,6 +77,7 @@ func WalkSkip(roots []Root, add func(root Root, dir string), skip func(root Root } } +// walkDir creates a walker and starts fastwalk with this walker. func walkDir(root Root, add func(Root, string), skip func(root Root, dir string) bool, opts Options) { if _, err := os.Stat(root.Path); os.IsNotExist(err) { if opts.Debug { @@ -114,7 +115,7 @@ type walker struct { ignoredDirs []os.FileInfo // The ignored directories, loaded from .goimportsignore files. } -// init initializes the walker based on its Options. +// init initializes the walker based on its Options func (w *walker) init() { var ignoredPaths []string if w.root.Type == RootModuleCache { @@ -167,6 +168,7 @@ func (w *walker) getIgnoredDirs(path string) []string { return ignoredDirs } +// shouldSkipDir reports whether the file should be skipped or not. func (w *walker) shouldSkipDir(fi os.FileInfo, dir string) bool { for _, ignoredDir := range w.ignoredDirs { if os.SameFile(fi, ignoredDir) { @@ -180,6 +182,7 @@ func (w *walker) shouldSkipDir(fi os.FileInfo, dir string) bool { return false } +// walk walks through the given path. func (w *walker) walk(path string, typ os.FileMode) error { dir := filepath.Dir(path) if typ.IsRegular() { diff --git a/vendor/golang.org/x/tools/internal/span/parse.go b/vendor/golang.org/x/tools/internal/span/parse.go deleted file mode 100644 index b3f268a38ae..00000000000 --- a/vendor/golang.org/x/tools/internal/span/parse.go +++ /dev/null @@ -1,100 +0,0 @@ -// Copyright 2019 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package span - -import ( - "strconv" - "strings" - "unicode/utf8" -) - -// Parse returns the location represented by the input. -// All inputs are valid locations, as they can always be a pure filename. -// The returned span will be normalized, and thus if printed may produce a -// different string. -func Parse(input string) Span { - // :0:0#0-0:0#0 - valid := input - var hold, offset int - hadCol := false - suf := rstripSuffix(input) - if suf.sep == "#" { - offset = suf.num - suf = rstripSuffix(suf.remains) - } - if suf.sep == ":" { - valid = suf.remains - hold = suf.num - hadCol = true - suf = rstripSuffix(suf.remains) - } - switch { - case suf.sep == ":": - return New(NewURI(suf.remains), NewPoint(suf.num, hold, offset), Point{}) - case suf.sep == "-": - // we have a span, fall out of the case to continue - default: - // separator not valid, rewind to either the : or the start - return New(NewURI(valid), NewPoint(hold, 0, offset), Point{}) - } - // only the span form can get here - // at this point we still don't know what the numbers we have mean - // if have not yet seen a : then we might have either a line or a column depending - // on whether start has a column or not - // we build an end point and will fix it later if needed - end := NewPoint(suf.num, hold, offset) - hold, offset = 0, 0 - suf = rstripSuffix(suf.remains) - if suf.sep == "#" { - offset = suf.num - suf = rstripSuffix(suf.remains) - } - if suf.sep != ":" { - // turns out we don't have a span after all, rewind - return New(NewURI(valid), end, Point{}) - } - valid = suf.remains - hold = suf.num - suf = rstripSuffix(suf.remains) - if suf.sep != ":" { - // line#offset only - return New(NewURI(valid), NewPoint(hold, 0, offset), end) - } - // we have a column, so if end only had one number, it is also the column - if !hadCol { - end = NewPoint(suf.num, end.v.Line, end.v.Offset) - } - return New(NewURI(suf.remains), NewPoint(suf.num, hold, offset), end) -} - -type suffix struct { - remains string - sep string - num int -} - -func rstripSuffix(input string) suffix { - if len(input) == 0 { - return suffix{"", "", -1} - } - remains := input - num := -1 - // first see if we have a number at the end - last := strings.LastIndexFunc(remains, func(r rune) bool { return r < '0' || r > '9' }) - if last >= 0 && last < len(remains)-1 { - number, err := strconv.ParseInt(remains[last+1:], 10, 64) - if err == nil { - num = int(number) - remains = remains[:last+1] - } - } - // now see if we have a trailing separator - r, w := utf8.DecodeLastRuneInString(remains) - if r != ':' && r != '#' && r == '#' { - return suffix{input, "", -1} - } - remains = remains[:len(remains)-w] - return suffix{remains, string(r), num} -} diff --git a/vendor/golang.org/x/tools/internal/span/span.go b/vendor/golang.org/x/tools/internal/span/span.go deleted file mode 100644 index 4d2ad098667..00000000000 --- a/vendor/golang.org/x/tools/internal/span/span.go +++ /dev/null @@ -1,285 +0,0 @@ -// Copyright 2019 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// Package span contains support for representing with positions and ranges in -// text files. -package span - -import ( - "encoding/json" - "fmt" - "path" -) - -// Span represents a source code range in standardized form. -type Span struct { - v span -} - -// Point represents a single point within a file. -// In general this should only be used as part of a Span, as on its own it -// does not carry enough information. -type Point struct { - v point -} - -type span struct { - URI URI `json:"uri"` - Start point `json:"start"` - End point `json:"end"` -} - -type point struct { - Line int `json:"line"` - Column int `json:"column"` - Offset int `json:"offset"` -} - -// Invalid is a span that reports false from IsValid -var Invalid = Span{v: span{Start: invalidPoint.v, End: invalidPoint.v}} - -var invalidPoint = Point{v: point{Line: 0, Column: 0, Offset: -1}} - -// Converter is the interface to an object that can convert between line:column -// and offset forms for a single file. -type Converter interface { - //ToPosition converts from an offset to a line:column pair. - ToPosition(offset int) (int, int, error) - //ToOffset converts from a line:column pair to an offset. - ToOffset(line, col int) (int, error) -} - -func New(uri URI, start Point, end Point) Span { - s := Span{v: span{URI: uri, Start: start.v, End: end.v}} - s.v.clean() - return s -} - -func NewPoint(line, col, offset int) Point { - p := Point{v: point{Line: line, Column: col, Offset: offset}} - p.v.clean() - return p -} - -func Compare(a, b Span) int { - if r := CompareURI(a.URI(), b.URI()); r != 0 { - return r - } - if r := comparePoint(a.v.Start, b.v.Start); r != 0 { - return r - } - return comparePoint(a.v.End, b.v.End) -} - -func ComparePoint(a, b Point) int { - return comparePoint(a.v, b.v) -} - -func comparePoint(a, b point) int { - if !a.hasPosition() { - if a.Offset < b.Offset { - return -1 - } - if a.Offset > b.Offset { - return 1 - } - return 0 - } - if a.Line < b.Line { - return -1 - } - if a.Line > b.Line { - return 1 - } - if a.Column < b.Column { - return -1 - } - if a.Column > b.Column { - return 1 - } - return 0 -} - -func (s Span) HasPosition() bool { return s.v.Start.hasPosition() } -func (s Span) HasOffset() bool { return s.v.Start.hasOffset() } -func (s Span) IsValid() bool { return s.v.Start.isValid() } -func (s Span) IsPoint() bool { return s.v.Start == s.v.End } -func (s Span) URI() URI { return s.v.URI } -func (s Span) Start() Point { return Point{s.v.Start} } -func (s Span) End() Point { return Point{s.v.End} } -func (s *Span) MarshalJSON() ([]byte, error) { return json.Marshal(&s.v) } -func (s *Span) UnmarshalJSON(b []byte) error { return json.Unmarshal(b, &s.v) } - -func (p Point) HasPosition() bool { return p.v.hasPosition() } -func (p Point) HasOffset() bool { return p.v.hasOffset() } -func (p Point) IsValid() bool { return p.v.isValid() } -func (p *Point) MarshalJSON() ([]byte, error) { return json.Marshal(&p.v) } -func (p *Point) UnmarshalJSON(b []byte) error { return json.Unmarshal(b, &p.v) } -func (p Point) Line() int { - if !p.v.hasPosition() { - panic(fmt.Errorf("position not set in %v", p.v)) - } - return p.v.Line -} -func (p Point) Column() int { - if !p.v.hasPosition() { - panic(fmt.Errorf("position not set in %v", p.v)) - } - return p.v.Column -} -func (p Point) Offset() int { - if !p.v.hasOffset() { - panic(fmt.Errorf("offset not set in %v", p.v)) - } - return p.v.Offset -} - -func (p point) hasPosition() bool { return p.Line > 0 } -func (p point) hasOffset() bool { return p.Offset >= 0 } -func (p point) isValid() bool { return p.hasPosition() || p.hasOffset() } -func (p point) isZero() bool { - return (p.Line == 1 && p.Column == 1) || (!p.hasPosition() && p.Offset == 0) -} - -func (s *span) clean() { - //this presumes the points are already clean - if !s.End.isValid() || (s.End == point{}) { - s.End = s.Start - } -} - -func (p *point) clean() { - if p.Line < 0 { - p.Line = 0 - } - if p.Column <= 0 { - if p.Line > 0 { - p.Column = 1 - } else { - p.Column = 0 - } - } - if p.Offset == 0 && (p.Line > 1 || p.Column > 1) { - p.Offset = -1 - } -} - -// Format implements fmt.Formatter to print the Location in a standard form. -// The format produced is one that can be read back in using Parse. -func (s Span) Format(f fmt.State, c rune) { - fullForm := f.Flag('+') - preferOffset := f.Flag('#') - // we should always have a uri, simplify if it is file format - //TODO: make sure the end of the uri is unambiguous - uri := string(s.v.URI) - if c == 'f' { - uri = path.Base(uri) - } else if !fullForm { - uri = s.v.URI.Filename() - } - fmt.Fprint(f, uri) - if !s.IsValid() || (!fullForm && s.v.Start.isZero() && s.v.End.isZero()) { - return - } - // see which bits of start to write - printOffset := s.HasOffset() && (fullForm || preferOffset || !s.HasPosition()) - printLine := s.HasPosition() && (fullForm || !printOffset) - printColumn := printLine && (fullForm || (s.v.Start.Column > 1 || s.v.End.Column > 1)) - fmt.Fprint(f, ":") - if printLine { - fmt.Fprintf(f, "%d", s.v.Start.Line) - } - if printColumn { - fmt.Fprintf(f, ":%d", s.v.Start.Column) - } - if printOffset { - fmt.Fprintf(f, "#%d", s.v.Start.Offset) - } - // start is written, do we need end? - if s.IsPoint() { - return - } - // we don't print the line if it did not change - printLine = fullForm || (printLine && s.v.End.Line > s.v.Start.Line) - fmt.Fprint(f, "-") - if printLine { - fmt.Fprintf(f, "%d", s.v.End.Line) - } - if printColumn { - if printLine { - fmt.Fprint(f, ":") - } - fmt.Fprintf(f, "%d", s.v.End.Column) - } - if printOffset { - fmt.Fprintf(f, "#%d", s.v.End.Offset) - } -} - -func (s Span) WithPosition(c Converter) (Span, error) { - if err := s.update(c, true, false); err != nil { - return Span{}, err - } - return s, nil -} - -func (s Span) WithOffset(c Converter) (Span, error) { - if err := s.update(c, false, true); err != nil { - return Span{}, err - } - return s, nil -} - -func (s Span) WithAll(c Converter) (Span, error) { - if err := s.update(c, true, true); err != nil { - return Span{}, err - } - return s, nil -} - -func (s *Span) update(c Converter, withPos, withOffset bool) error { - if !s.IsValid() { - return fmt.Errorf("cannot add information to an invalid span") - } - if withPos && !s.HasPosition() { - if err := s.v.Start.updatePosition(c); err != nil { - return err - } - if s.v.End.Offset == s.v.Start.Offset { - s.v.End = s.v.Start - } else if err := s.v.End.updatePosition(c); err != nil { - return err - } - } - if withOffset && (!s.HasOffset() || (s.v.End.hasPosition() && !s.v.End.hasOffset())) { - if err := s.v.Start.updateOffset(c); err != nil { - return err - } - if s.v.End.Line == s.v.Start.Line && s.v.End.Column == s.v.Start.Column { - s.v.End.Offset = s.v.Start.Offset - } else if err := s.v.End.updateOffset(c); err != nil { - return err - } - } - return nil -} - -func (p *point) updatePosition(c Converter) error { - line, col, err := c.ToPosition(p.Offset) - if err != nil { - return err - } - p.Line = line - p.Column = col - return nil -} - -func (p *point) updateOffset(c Converter) error { - offset, err := c.ToOffset(p.Line, p.Column) - if err != nil { - return err - } - p.Offset = offset - return nil -} diff --git a/vendor/golang.org/x/tools/internal/span/token.go b/vendor/golang.org/x/tools/internal/span/token.go deleted file mode 100644 index ce44541b2fc..00000000000 --- a/vendor/golang.org/x/tools/internal/span/token.go +++ /dev/null @@ -1,151 +0,0 @@ -// Copyright 2019 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package span - -import ( - "fmt" - "go/token" -) - -// Range represents a source code range in token.Pos form. -// It also carries the FileSet that produced the positions, so that it is -// self contained. -type Range struct { - FileSet *token.FileSet - Start token.Pos - End token.Pos -} - -// TokenConverter is a Converter backed by a token file set and file. -// It uses the file set methods to work out the conversions, which -// makes it fast and does not require the file contents. -type TokenConverter struct { - fset *token.FileSet - file *token.File -} - -// NewRange creates a new Range from a FileSet and two positions. -// To represent a point pass a 0 as the end pos. -func NewRange(fset *token.FileSet, start, end token.Pos) Range { - return Range{ - FileSet: fset, - Start: start, - End: end, - } -} - -// NewTokenConverter returns an implementation of Converter backed by a -// token.File. -func NewTokenConverter(fset *token.FileSet, f *token.File) *TokenConverter { - return &TokenConverter{fset: fset, file: f} -} - -// NewContentConverter returns an implementation of Converter for the -// given file content. -func NewContentConverter(filename string, content []byte) *TokenConverter { - fset := token.NewFileSet() - f := fset.AddFile(filename, -1, len(content)) - f.SetLinesForContent(content) - return &TokenConverter{fset: fset, file: f} -} - -// IsPoint returns true if the range represents a single point. -func (r Range) IsPoint() bool { - return r.Start == r.End -} - -// Span converts a Range to a Span that represents the Range. -// It will fill in all the members of the Span, calculating the line and column -// information. -func (r Range) Span() (Span, error) { - f := r.FileSet.File(r.Start) - if f == nil { - return Span{}, fmt.Errorf("file not found in FileSet") - } - s := Span{v: span{URI: FileURI(f.Name())}} - var err error - s.v.Start.Offset, err = offset(f, r.Start) - if err != nil { - return Span{}, err - } - if r.End.IsValid() { - s.v.End.Offset, err = offset(f, r.End) - if err != nil { - return Span{}, err - } - } - s.v.Start.clean() - s.v.End.clean() - s.v.clean() - converter := NewTokenConverter(r.FileSet, f) - return s.WithPosition(converter) -} - -// offset is a copy of the Offset function in go/token, but with the adjustment -// that it does not panic on invalid positions. -func offset(f *token.File, pos token.Pos) (int, error) { - if int(pos) < f.Base() || int(pos) > f.Base()+f.Size() { - return 0, fmt.Errorf("invalid pos") - } - return int(pos) - f.Base(), nil -} - -// Range converts a Span to a Range that represents the Span for the supplied -// File. -func (s Span) Range(converter *TokenConverter) (Range, error) { - s, err := s.WithOffset(converter) - if err != nil { - return Range{}, err - } - // go/token will panic if the offset is larger than the file's size, - // so check here to avoid panicking. - if s.Start().Offset() > converter.file.Size() { - return Range{}, fmt.Errorf("start offset %v is past the end of the file %v", s.Start(), converter.file.Size()) - } - if s.End().Offset() > converter.file.Size() { - return Range{}, fmt.Errorf("end offset %v is past the end of the file %v", s.End(), converter.file.Size()) - } - return Range{ - FileSet: converter.fset, - Start: converter.file.Pos(s.Start().Offset()), - End: converter.file.Pos(s.End().Offset()), - }, nil -} - -func (l *TokenConverter) ToPosition(offset int) (int, int, error) { - if offset > l.file.Size() { - return 0, 0, fmt.Errorf("offset %v is past the end of the file %v", offset, l.file.Size()) - } - pos := l.file.Pos(offset) - p := l.fset.Position(pos) - if offset == l.file.Size() { - return p.Line + 1, 1, nil - } - return p.Line, p.Column, nil -} - -func (l *TokenConverter) ToOffset(line, col int) (int, error) { - if line < 0 { - return -1, fmt.Errorf("line is not valid") - } - lineMax := l.file.LineCount() + 1 - if line > lineMax { - return -1, fmt.Errorf("line is beyond end of file %v", lineMax) - } else if line == lineMax { - if col > 1 { - return -1, fmt.Errorf("column is beyond end of file") - } - // at the end of the file, allowing for a trailing eol - return l.file.Size(), nil - } - pos := lineStart(l.file, line) - if !pos.IsValid() { - return -1, fmt.Errorf("line is not in file") - } - // we assume that column is in bytes here, and that the first byte of a - // line is at column 1 - pos += token.Pos(col - 1) - return offset(l.file, pos) -} diff --git a/vendor/golang.org/x/tools/internal/span/token111.go b/vendor/golang.org/x/tools/internal/span/token111.go deleted file mode 100644 index bf7a5406b6e..00000000000 --- a/vendor/golang.org/x/tools/internal/span/token111.go +++ /dev/null @@ -1,39 +0,0 @@ -// Copyright 2019 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// +build !go1.12 - -package span - -import ( - "go/token" -) - -// lineStart is the pre-Go 1.12 version of (*token.File).LineStart. For Go -// versions <= 1.11, we borrow logic from the analysisutil package. -// TODO(rstambler): Delete this file when we no longer support Go 1.11. -func lineStart(f *token.File, line int) token.Pos { - // Use binary search to find the start offset of this line. - - min := 0 // inclusive - max := f.Size() // exclusive - for { - offset := (min + max) / 2 - pos := f.Pos(offset) - posn := f.Position(pos) - if posn.Line == line { - return pos - (token.Pos(posn.Column) - 1) - } - - if min+1 >= max { - return token.NoPos - } - - if posn.Line < line { - min = offset - } else { - max = offset - } - } -} diff --git a/vendor/golang.org/x/tools/internal/span/token112.go b/vendor/golang.org/x/tools/internal/span/token112.go deleted file mode 100644 index 017aec9c13e..00000000000 --- a/vendor/golang.org/x/tools/internal/span/token112.go +++ /dev/null @@ -1,16 +0,0 @@ -// Copyright 2019 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// +build go1.12 - -package span - -import ( - "go/token" -) - -// TODO(rstambler): Delete this file when we no longer support Go 1.11. -func lineStart(f *token.File, line int) token.Pos { - return f.LineStart(line) -} diff --git a/vendor/golang.org/x/tools/internal/span/uri.go b/vendor/golang.org/x/tools/internal/span/uri.go deleted file mode 100644 index e05a9e6ef5d..00000000000 --- a/vendor/golang.org/x/tools/internal/span/uri.go +++ /dev/null @@ -1,152 +0,0 @@ -// Copyright 2019 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package span - -import ( - "fmt" - "net/url" - "os" - "path" - "path/filepath" - "runtime" - "strings" - "unicode" -) - -const fileScheme = "file" - -// URI represents the full URI for a file. -type URI string - -// Filename returns the file path for the given URI. -// It is an error to call this on a URI that is not a valid filename. -func (uri URI) Filename() string { - filename, err := filename(uri) - if err != nil { - panic(err) - } - return filepath.FromSlash(filename) -} - -func filename(uri URI) (string, error) { - if uri == "" { - return "", nil - } - u, err := url.ParseRequestURI(string(uri)) - if err != nil { - return "", err - } - if u.Scheme != fileScheme { - return "", fmt.Errorf("only file URIs are supported, got %q from %q", u.Scheme, uri) - } - if isWindowsDriveURI(u.Path) { - u.Path = u.Path[1:] - } - return u.Path, nil -} - -// NewURI returns a span URI for the string. -// It will attempt to detect if the string is a file path or uri. -func NewURI(s string) URI { - if u, err := url.PathUnescape(s); err == nil { - s = u - } - if strings.HasPrefix(s, fileScheme+"://") { - return URI(s) - } - return FileURI(s) -} - -func CompareURI(a, b URI) int { - if equalURI(a, b) { - return 0 - } - if a < b { - return -1 - } - return 1 -} - -func equalURI(a, b URI) bool { - if a == b { - return true - } - // If we have the same URI basename, we may still have the same file URIs. - if !strings.EqualFold(path.Base(string(a)), path.Base(string(b))) { - return false - } - fa, err := filename(a) - if err != nil { - return false - } - fb, err := filename(b) - if err != nil { - return false - } - // Stat the files to check if they are equal. - infoa, err := os.Stat(filepath.FromSlash(fa)) - if err != nil { - return false - } - infob, err := os.Stat(filepath.FromSlash(fb)) - if err != nil { - return false - } - return os.SameFile(infoa, infob) -} - -// FileURI returns a span URI for the supplied file path. -// It will always have the file scheme. -func FileURI(path string) URI { - if path == "" { - return "" - } - // Handle standard library paths that contain the literal "$GOROOT". - // TODO(rstambler): The go/packages API should allow one to determine a user's $GOROOT. - const prefix = "$GOROOT" - if len(path) >= len(prefix) && strings.EqualFold(prefix, path[:len(prefix)]) { - suffix := path[len(prefix):] - path = runtime.GOROOT() + suffix - } - if !isWindowsDrivePath(path) { - if abs, err := filepath.Abs(path); err == nil { - path = abs - } - } - // Check the file path again, in case it became absolute. - if isWindowsDrivePath(path) { - path = "/" + path - } - path = filepath.ToSlash(path) - u := url.URL{ - Scheme: fileScheme, - Path: path, - } - uri := u.String() - if unescaped, err := url.PathUnescape(uri); err == nil { - uri = unescaped - } - return URI(uri) -} - -// isWindowsDrivePath returns true if the file path is of the form used by -// Windows. We check if the path begins with a drive letter, followed by a ":". -func isWindowsDrivePath(path string) bool { - if len(path) < 4 { - return false - } - return unicode.IsLetter(rune(path[0])) && path[1] == ':' -} - -// isWindowsDriveURI returns true if the file URI is of the format used by -// Windows URIs. The url.Parse package does not specially handle Windows paths -// (see https://golang.org/issue/6027). We check if the URI path has -// a drive prefix (e.g. "/C:"). If so, we trim the leading "/". -func isWindowsDriveURI(uri string) bool { - if len(uri) < 4 { - return false - } - return uri[0] == '/' && unicode.IsLetter(rune(uri[1])) && uri[2] == ':' -} diff --git a/vendor/golang.org/x/tools/internal/span/utf16.go b/vendor/golang.org/x/tools/internal/span/utf16.go deleted file mode 100644 index 561b3fa50a8..00000000000 --- a/vendor/golang.org/x/tools/internal/span/utf16.go +++ /dev/null @@ -1,94 +0,0 @@ -// Copyright 2019 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package span - -import ( - "fmt" - "unicode/utf16" - "unicode/utf8" -) - -// ToUTF16Column calculates the utf16 column expressed by the point given the -// supplied file contents. -// This is used to convert from the native (always in bytes) column -// representation and the utf16 counts used by some editors. -func ToUTF16Column(p Point, content []byte) (int, error) { - if content == nil { - return -1, fmt.Errorf("ToUTF16Column: missing content") - } - if !p.HasPosition() { - return -1, fmt.Errorf("ToUTF16Column: point is missing position") - } - if !p.HasOffset() { - return -1, fmt.Errorf("ToUTF16Column: point is missing offset") - } - offset := p.Offset() // 0-based - colZero := p.Column() - 1 // 0-based - if colZero == 0 { - // 0-based column 0, so it must be chr 1 - return 1, nil - } else if colZero < 0 { - return -1, fmt.Errorf("ToUTF16Column: column is invalid (%v)", colZero) - } - // work out the offset at the start of the line using the column - lineOffset := offset - colZero - if lineOffset < 0 || offset > len(content) { - return -1, fmt.Errorf("ToUTF16Column: offsets %v-%v outside file contents (%v)", lineOffset, offset, len(content)) - } - // Use the offset to pick out the line start. - // This cannot panic: offset > len(content) and lineOffset < offset. - start := content[lineOffset:] - - // Now, truncate down to the supplied column. - start = start[:colZero] - - // and count the number of utf16 characters - // in theory we could do this by hand more efficiently... - return len(utf16.Encode([]rune(string(start)))) + 1, nil -} - -// FromUTF16Column advances the point by the utf16 character offset given the -// supplied line contents. -// This is used to convert from the utf16 counts used by some editors to the -// native (always in bytes) column representation. -func FromUTF16Column(p Point, chr int, content []byte) (Point, error) { - if !p.HasOffset() { - return Point{}, fmt.Errorf("FromUTF16Column: point is missing offset") - } - // if chr is 1 then no adjustment needed - if chr <= 1 { - return p, nil - } - if p.Offset() >= len(content) { - return p, fmt.Errorf("FromUTF16Column: offset (%v) greater than length of content (%v)", p.Offset(), len(content)) - } - remains := content[p.Offset():] - // scan forward the specified number of characters - for count := 1; count < chr; count++ { - if len(remains) <= 0 { - return Point{}, fmt.Errorf("FromUTF16Column: chr goes beyond the content") - } - r, w := utf8.DecodeRune(remains) - if r == '\n' { - // Per the LSP spec: - // - // > If the character value is greater than the line length it - // > defaults back to the line length. - break - } - remains = remains[w:] - if r >= 0x10000 { - // a two point rune - count++ - // if we finished in a two point rune, do not advance past the first - if count >= chr { - break - } - } - p.v.Column += w - p.v.Offset += w - } - return p, nil -} diff --git a/vendor/golang.org/x/tools/present/args.go b/vendor/golang.org/x/tools/present/args.go new file mode 100644 index 00000000000..d63196e028c --- /dev/null +++ b/vendor/golang.org/x/tools/present/args.go @@ -0,0 +1,228 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package present + +import ( + "errors" + "regexp" + "strconv" + "unicode/utf8" +) + +// This file is stolen from go/src/cmd/godoc/codewalk.go. +// It's an evaluator for the file address syntax implemented by acme and sam, +// but using Go-native regular expressions. +// To keep things reasonably close, this version uses (?m:re) for all user-provided +// regular expressions. That is the only change to the code from codewalk.go. +// See http://9p.io/sys/doc/sam/sam.html Table II for details on the syntax. + +// addrToByte evaluates the given address starting at offset start in data. +// It returns the lo and hi byte offset of the matched region within data. +func addrToByteRange(addr string, start int, data []byte) (lo, hi int, err error) { + if addr == "" { + lo, hi = start, len(data) + return + } + var ( + dir byte + prevc byte + charOffset bool + ) + lo = start + hi = start + for addr != "" && err == nil { + c := addr[0] + switch c { + default: + err = errors.New("invalid address syntax near " + string(c)) + case ',': + if len(addr) == 1 { + hi = len(data) + } else { + _, hi, err = addrToByteRange(addr[1:], hi, data) + } + return + + case '+', '-': + if prevc == '+' || prevc == '-' { + lo, hi, err = addrNumber(data, lo, hi, prevc, 1, charOffset) + } + dir = c + + case '$': + lo = len(data) + hi = len(data) + if len(addr) > 1 { + dir = '+' + } + + case '#': + charOffset = true + + case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9': + var i int + for i = 1; i < len(addr); i++ { + if addr[i] < '0' || addr[i] > '9' { + break + } + } + var n int + n, err = strconv.Atoi(addr[0:i]) + if err != nil { + break + } + lo, hi, err = addrNumber(data, lo, hi, dir, n, charOffset) + dir = 0 + charOffset = false + prevc = c + addr = addr[i:] + continue + + case '/': + var i, j int + Regexp: + for i = 1; i < len(addr); i++ { + switch addr[i] { + case '\\': + i++ + case '/': + j = i + 1 + break Regexp + } + } + if j == 0 { + j = i + } + pattern := addr[1:i] + lo, hi, err = addrRegexp(data, lo, hi, dir, pattern) + prevc = c + addr = addr[j:] + continue + } + prevc = c + addr = addr[1:] + } + + if err == nil && dir != 0 { + lo, hi, err = addrNumber(data, lo, hi, dir, 1, charOffset) + } + if err != nil { + return 0, 0, err + } + return lo, hi, nil +} + +// addrNumber applies the given dir, n, and charOffset to the address lo, hi. +// dir is '+' or '-', n is the count, and charOffset is true if the syntax +// used was #n. Applying +n (or +#n) means to advance n lines +// (or characters) after hi. Applying -n (or -#n) means to back up n lines +// (or characters) before lo. +// The return value is the new lo, hi. +func addrNumber(data []byte, lo, hi int, dir byte, n int, charOffset bool) (int, int, error) { + switch dir { + case 0: + lo = 0 + hi = 0 + fallthrough + + case '+': + if charOffset { + pos := hi + for ; n > 0 && pos < len(data); n-- { + _, size := utf8.DecodeRune(data[pos:]) + pos += size + } + if n == 0 { + return pos, pos, nil + } + break + } + // find next beginning of line + if hi > 0 { + for hi < len(data) && data[hi-1] != '\n' { + hi++ + } + } + lo = hi + if n == 0 { + return lo, hi, nil + } + for ; hi < len(data); hi++ { + if data[hi] != '\n' { + continue + } + switch n--; n { + case 1: + lo = hi + 1 + case 0: + return lo, hi + 1, nil + } + } + + case '-': + if charOffset { + // Scan backward for bytes that are not UTF-8 continuation bytes. + pos := lo + for ; pos > 0 && n > 0; pos-- { + if data[pos]&0xc0 != 0x80 { + n-- + } + } + if n == 0 { + return pos, pos, nil + } + break + } + // find earlier beginning of line + for lo > 0 && data[lo-1] != '\n' { + lo-- + } + hi = lo + if n == 0 { + return lo, hi, nil + } + for ; lo >= 0; lo-- { + if lo > 0 && data[lo-1] != '\n' { + continue + } + switch n--; n { + case 1: + hi = lo + case 0: + return lo, hi, nil + } + } + } + + return 0, 0, errors.New("address out of range") +} + +// addrRegexp searches for pattern in the given direction starting at lo, hi. +// The direction dir is '+' (search forward from hi) or '-' (search backward from lo). +// Backward searches are unimplemented. +func addrRegexp(data []byte, lo, hi int, dir byte, pattern string) (int, int, error) { + // We want ^ and $ to work as in sam/acme, so use ?m. + re, err := regexp.Compile("(?m:" + pattern + ")") + if err != nil { + return 0, 0, err + } + if dir == '-' { + // Could implement reverse search using binary search + // through file, but that seems like overkill. + return 0, 0, errors.New("reverse search not implemented") + } + m := re.FindIndex(data[hi:]) + if len(m) > 0 { + m[0] += hi + m[1] += hi + } else if hi > 0 { + // No match. Wrap to beginning of data. + m = re.FindIndex(data) + } + if len(m) == 0 { + return 0, 0, errors.New("no match for " + pattern) + } + return m[0], m[1], nil +} diff --git a/vendor/golang.org/x/tools/present/caption.go b/vendor/golang.org/x/tools/present/caption.go new file mode 100644 index 00000000000..00e0b5d0586 --- /dev/null +++ b/vendor/golang.org/x/tools/present/caption.go @@ -0,0 +1,22 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package present + +import "strings" + +func init() { + Register("caption", parseCaption) +} + +type Caption struct { + Text string +} + +func (c Caption) TemplateName() string { return "caption" } + +func parseCaption(_ *Context, _ string, _ int, text string) (Elem, error) { + text = strings.TrimSpace(strings.TrimPrefix(text, ".caption")) + return Caption{text}, nil +} diff --git a/vendor/golang.org/x/tools/present/code.go b/vendor/golang.org/x/tools/present/code.go new file mode 100644 index 00000000000..b47a72a5069 --- /dev/null +++ b/vendor/golang.org/x/tools/present/code.go @@ -0,0 +1,267 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package present + +import ( + "bufio" + "bytes" + "fmt" + "html/template" + "path/filepath" + "regexp" + "strconv" + "strings" +) + +// PlayEnabled specifies whether runnable playground snippets should be +// displayed in the present user interface. +var PlayEnabled = false + +// TODO(adg): replace the PlayEnabled flag with something less spaghetti-like. +// Instead this will probably be determined by a template execution Context +// value that contains various global metadata required when rendering +// templates. + +// NotesEnabled specifies whether presenter notes should be displayed in the +// present user interface. +var NotesEnabled = false + +func init() { + Register("code", parseCode) + Register("play", parseCode) +} + +type Code struct { + Text template.HTML + Play bool // runnable code + Edit bool // editable code + FileName string // file name + Ext string // file extension + Raw []byte // content of the file +} + +func (c Code) TemplateName() string { return "code" } + +// The input line is a .code or .play entry with a file name and an optional HLfoo marker on the end. +// Anything between the file and HL (if any) is an address expression, which we treat as a string here. +// We pick off the HL first, for easy parsing. +var ( + highlightRE = regexp.MustCompile(`\s+HL([a-zA-Z0-9_]+)?$`) + hlCommentRE = regexp.MustCompile(`(.+) // HL(.*)$`) + codeRE = regexp.MustCompile(`\.(code|play)\s+((?:(?:-edit|-numbers)\s+)*)([^\s]+)(?:\s+(.*))?$`) +) + +// parseCode parses a code present directive. Its syntax: +// .code [-numbers] [-edit] [address] [highlight] +// The directive may also be ".play" if the snippet is executable. +func parseCode(ctx *Context, sourceFile string, sourceLine int, cmd string) (Elem, error) { + cmd = strings.TrimSpace(cmd) + + // Pull off the HL, if any, from the end of the input line. + highlight := "" + if hl := highlightRE.FindStringSubmatchIndex(cmd); len(hl) == 4 { + if hl[2] < 0 || hl[3] < 0 { + return nil, fmt.Errorf("%s:%d invalid highlight syntax", sourceFile, sourceLine) + } + highlight = cmd[hl[2]:hl[3]] + cmd = cmd[:hl[2]-2] + } + + // Parse the remaining command line. + // Arguments: + // args[0]: whole match + // args[1]: .code/.play + // args[2]: flags ("-edit -numbers") + // args[3]: file name + // args[4]: optional address + args := codeRE.FindStringSubmatch(cmd) + if len(args) != 5 { + return nil, fmt.Errorf("%s:%d: syntax error for .code/.play invocation", sourceFile, sourceLine) + } + command, flags, file, addr := args[1], args[2], args[3], strings.TrimSpace(args[4]) + play := command == "play" && PlayEnabled + + // Read in code file and (optionally) match address. + filename := filepath.Join(filepath.Dir(sourceFile), file) + textBytes, err := ctx.ReadFile(filename) + if err != nil { + return nil, fmt.Errorf("%s:%d: %v", sourceFile, sourceLine, err) + } + lo, hi, err := addrToByteRange(addr, 0, textBytes) + if err != nil { + return nil, fmt.Errorf("%s:%d: %v", sourceFile, sourceLine, err) + } + if lo > hi { + // The search in addrToByteRange can wrap around so we might + // end up with the range ending before its starting point + hi, lo = lo, hi + } + + // Acme pattern matches can stop mid-line, + // so run to end of line in both directions if not at line start/end. + for lo > 0 && textBytes[lo-1] != '\n' { + lo-- + } + if hi > 0 { + for hi < len(textBytes) && textBytes[hi-1] != '\n' { + hi++ + } + } + + lines := codeLines(textBytes, lo, hi) + + data := &codeTemplateData{ + Lines: formatLines(lines, highlight), + Edit: strings.Contains(flags, "-edit"), + Numbers: strings.Contains(flags, "-numbers"), + } + + // Include before and after in a hidden span for playground code. + if play { + data.Prefix = textBytes[:lo] + data.Suffix = textBytes[hi:] + } + + var buf bytes.Buffer + if err := codeTemplate.Execute(&buf, data); err != nil { + return nil, err + } + return Code{ + Text: template.HTML(buf.String()), + Play: play, + Edit: data.Edit, + FileName: filepath.Base(filename), + Ext: filepath.Ext(filename), + Raw: rawCode(lines), + }, nil +} + +// formatLines returns a new slice of codeLine with the given lines +// replacing tabs with spaces and adding highlighting where needed. +func formatLines(lines []codeLine, highlight string) []codeLine { + formatted := make([]codeLine, len(lines)) + for i, line := range lines { + // Replace tabs with spaces, which work better in HTML. + line.L = strings.Replace(line.L, "\t", " ", -1) + + // Highlight lines that end with "// HL[highlight]" + // and strip the magic comment. + if m := hlCommentRE.FindStringSubmatch(line.L); m != nil { + line.L = m[1] + line.HL = m[2] == highlight + } + + formatted[i] = line + } + return formatted +} + +// rawCode returns the code represented by the given codeLines without any kind +// of formatting. +func rawCode(lines []codeLine) []byte { + b := new(bytes.Buffer) + for _, line := range lines { + b.WriteString(line.L) + b.WriteByte('\n') + } + return b.Bytes() +} + +type codeTemplateData struct { + Lines []codeLine + Prefix, Suffix []byte + Edit, Numbers bool +} + +var leadingSpaceRE = regexp.MustCompile(`^[ \t]*`) + +var codeTemplate = template.Must(template.New("code").Funcs(template.FuncMap{ + "trimSpace": strings.TrimSpace, + "leadingSpace": leadingSpaceRE.FindString, +}).Parse(codeTemplateHTML)) + +const codeTemplateHTML = ` +{{with .Prefix}}
{{printf "%s" .}}
{{end}} + +{{/* + */}}{{range .Lines}}{{/* + */}}{{if .HL}}{{leadingSpace .L}}{{trimSpace .L}}{{/* + */}}{{else}}{{.L}}{{end}}{{/* +*/}} +{{end}} + +{{with .Suffix}}
{{printf "%s" .}}
{{end}} +` + +// codeLine represents a line of code extracted from a source file. +type codeLine struct { + L string // The line of code. + N int // The line number from the source file. + HL bool // Whether the line should be highlighted. +} + +// codeLines takes a source file and returns the lines that +// span the byte range specified by start and end. +// It discards lines that end in "OMIT". +func codeLines(src []byte, start, end int) (lines []codeLine) { + startLine := 1 + for i, b := range src { + if i == start { + break + } + if b == '\n' { + startLine++ + } + } + s := bufio.NewScanner(bytes.NewReader(src[start:end])) + for n := startLine; s.Scan(); n++ { + l := s.Text() + if strings.HasSuffix(l, "OMIT") { + continue + } + lines = append(lines, codeLine{L: l, N: n}) + } + // Trim leading and trailing blank lines. + for len(lines) > 0 && len(lines[0].L) == 0 { + lines = lines[1:] + } + for len(lines) > 0 && len(lines[len(lines)-1].L) == 0 { + lines = lines[:len(lines)-1] + } + return +} + +func parseArgs(name string, line int, args []string) (res []interface{}, err error) { + res = make([]interface{}, len(args)) + for i, v := range args { + if len(v) == 0 { + return nil, fmt.Errorf("%s:%d bad code argument %q", name, line, v) + } + switch v[0] { + case '0', '1', '2', '3', '4', '5', '6', '7', '8', '9': + n, err := strconv.Atoi(v) + if err != nil { + return nil, fmt.Errorf("%s:%d bad code argument %q", name, line, v) + } + res[i] = n + case '/': + if len(v) < 2 || v[len(v)-1] != '/' { + return nil, fmt.Errorf("%s:%d bad code argument %q", name, line, v) + } + res[i] = v + case '$': + res[i] = "$" + case '_': + if len(v) == 1 { + // Do nothing; "_" indicates an intentionally empty parameter. + break + } + fallthrough + default: + return nil, fmt.Errorf("%s:%d bad code argument %q", name, line, v) + } + } + return +} diff --git a/vendor/golang.org/x/tools/present/doc.go b/vendor/golang.org/x/tools/present/doc.go new file mode 100644 index 00000000000..ff75d66c44c --- /dev/null +++ b/vendor/golang.org/x/tools/present/doc.go @@ -0,0 +1,261 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +/* +The present file format + +Present files have the following format. The first non-blank non-comment +line is the title, so the header looks like + + Title of document + Subtitle of document + 15:04 2 Jan 2006 + Tags: foo, bar, baz + + Author Name + Job title, Company + joe@example.com + http://url/ + @twitter_name + +The subtitle, date, and tags lines are optional. + +The date line may be written without a time: + 2 Jan 2006 +In this case, the time will be interpreted as 10am UTC on that date. + +The tags line is a comma-separated list of tags that may be used to categorize +the document. + +The author section may contain a mixture of text, twitter names, and links. +For slide presentations, only the plain text lines will be displayed on the +first slide. + +Multiple presenters may be specified, separated by a blank line. + +After that come slides/sections, each after a blank line: + + * Title of slide or section (must have asterisk) + + Some Text + + ** Subsection + + - bullets + - more bullets + - a bullet with + + *** Sub-subsection + + Some More text + + Preformatted text + is indented (however you like) + + Further Text, including invocations like: + + .code x.go /^func main/,/^}/ + .play y.go + .image image.jpg + .background image.jpg + .iframe http://foo + .link http://foo label + .html file.html + .caption _Gopher_ by [[https://www.instagram.com/reneefrench/][Renée French]] + + Again, more text + +Blank lines are OK (not mandatory) after the title and after the +text. Text, bullets, and .code etc. are all optional; title is +not. + +Lines starting with # in column 1 are commentary. + +Fonts: + +Within the input for plain text or lists, text bracketed by font +markers will be presented in italic, bold, or program font. +Marker characters are _ (italic), * (bold) and ` (program font). +An opening marker must be preceded by a space or punctuation +character or else be at start of a line; similarly, a closing +marker must be followed by a space or punctuation character or +else be at the end of a line. Unmatched markers appear as plain text. +There must be no spaces between markers. Within marked text, +a single marker character becomes a space and a doubled single +marker quotes the marker character. + + _italic_ + *bold* + `program` + Markup—_especially_italic_text_—can easily be overused. + _Why_use_scoped__ptr_? Use plain ***ptr* instead. + +Inline links: + +Links can be included in any text with the form [[url][label]], or +[[url]] to use the URL itself as the label. + +Functions: + +A number of template functions are available through invocations +in the input text. Each such invocation contains a period as the +first character on the line, followed immediately by the name of +the function, followed by any arguments. A typical invocation might +be + .play demo.go /^func show/,/^}/ +(except that the ".play" must be at the beginning of the line and +not be indented like this.) + +Here follows a description of the functions: + +code: + +Injects program source into the output by extracting code from files +and injecting them as HTML-escaped 
 blocks.  The argument is
+a file name followed by an optional address that specifies what
+section of the file to display. The address syntax is similar in
+its simplest form to that of ed, but comes from sam and is more
+general. See
+	https://plan9.io/sys/doc/sam/sam.html Table II
+for full details. The displayed block is always rounded out to a
+full line at both ends.
+
+If no pattern is present, the entire file is displayed.
+
+Any line in the program that ends with the four characters
+	OMIT
+is deleted from the source before inclusion, making it easy
+to write things like
+	.code test.go /START OMIT/,/END OMIT/
+to find snippets like this
+	tedious_code = boring_function()
+	// START OMIT
+	interesting_code = fascinating_function()
+	// END OMIT
+and see only this:
+	interesting_code = fascinating_function()
+
+Also, inside the displayed text a line that ends
+	// HL
+will be highlighted in the display. A highlighting mark may have a
+suffix word, such as
+	// HLxxx
+Such highlights are enabled only if the code invocation ends with
+"HL" followed by the word:
+	.code test.go /^type Foo/,/^}/ HLxxx
+
+The .code function may take one or more flags immediately preceding
+the filename. This command shows test.go in an editable text area:
+	.code -edit test.go
+This command shows test.go with line numbers:
+	.code -numbers test.go
+
+play:
+
+The function "play" is the same as "code" but puts a button
+on the displayed source so the program can be run from the browser.
+Although only the selected text is shown, all the source is included
+in the HTML output so it can be presented to the compiler.
+
+link:
+
+Create a hyperlink. The syntax is 1 or 2 space-separated arguments.
+The first argument is always the HTTP URL.  If there is a second
+argument, it is the text label to display for this link.
+
+	.link http://golang.org golang.org
+
+image:
+
+The template uses the function "image" to inject picture files.
+
+The syntax is simple: 1 or 3 space-separated arguments.
+The first argument is always the file name.
+If there are more arguments, they are the height and width;
+both must be present, or substituted with an underscore.
+Replacing a dimension argument with the underscore parameter
+preserves the aspect ratio of the image when scaling.
+
+	.image images/betsy.jpg 100 200
+
+	.image images/janet.jpg _ 300
+
+video:
+
+The template uses the function "video" to inject video files.
+
+The syntax is simple: 2 or 4 space-separated arguments.
+The first argument is always the file name.
+The second argument is always the file content-type.
+If there are more arguments, they are the height and width;
+both must be present, or substituted with an underscore.
+Replacing a dimension argument with the underscore parameter
+preserves the aspect ratio of the video when scaling.
+
+	.video videos/evangeline.mp4 video/mp4 400 600
+
+	.video videos/mabel.ogg video/ogg 500 _
+
+background:
+
+The template uses the function "background" to set the background image for
+a slide.  The only argument is the file name of the image.
+
+	.background images/susan.jpg
+
+caption:
+
+The template uses the function "caption" to inject figure captions.
+
+The text after ".caption" is embedded in a figcaption element after
+processing styling and links as in standard text lines.
+
+	.caption _Gopher_ by [[http://www.reneefrench.com][Renée French]]
+
+iframe:
+
+The function "iframe" injects iframes (pages inside pages).
+Its syntax is the same as that of image.
+
+html:
+
+The function html includes the contents of the specified file as
+unescaped HTML. This is useful for including custom HTML elements
+that cannot be created using only the slide format.
+It is your responsibility to make sure the included HTML is valid and safe.
+
+	.html file.html
+
+Presenter notes:
+
+Presenter notes may be enabled by appending the "-notes" flag when you run
+your "present" binary.
+
+This will allow you to open a second window by pressing 'N' from your browser
+displaying your slides. The second window is completely synced with your main
+window, except that presenter notes are only visible on the second window.
+
+Lines that begin with ": " are treated as presenter notes.
+
+	* Title of slide
+
+	Some Text
+
+	: Presenter notes (first paragraph)
+	: Presenter notes (subsequent paragraph(s))
+
+Notes may appear anywhere within the slide text. For example:
+
+	* Title of slide
+
+	: Presenter notes (first paragraph)
+
+	Some Text
+
+	: Presenter notes (subsequent paragraph(s))
+
+This has the same result as the example above.
+
+*/
+package present // import "golang.org/x/tools/present"
diff --git a/vendor/golang.org/x/tools/present/html.go b/vendor/golang.org/x/tools/present/html.go
new file mode 100644
index 00000000000..cca90ef4af1
--- /dev/null
+++ b/vendor/golang.org/x/tools/present/html.go
@@ -0,0 +1,31 @@
+package present
+
+import (
+	"errors"
+	"html/template"
+	"path/filepath"
+	"strings"
+)
+
+func init() {
+	Register("html", parseHTML)
+}
+
+func parseHTML(ctx *Context, fileName string, lineno int, text string) (Elem, error) {
+	p := strings.Fields(text)
+	if len(p) != 2 {
+		return nil, errors.New("invalid .html args")
+	}
+	name := filepath.Join(filepath.Dir(fileName), p[1])
+	b, err := ctx.ReadFile(name)
+	if err != nil {
+		return nil, err
+	}
+	return HTML{template.HTML(b)}, nil
+}
+
+type HTML struct {
+	template.HTML
+}
+
+func (s HTML) TemplateName() string { return "html" }
diff --git a/vendor/golang.org/x/tools/present/iframe.go b/vendor/golang.org/x/tools/present/iframe.go
new file mode 100644
index 00000000000..057d2295858
--- /dev/null
+++ b/vendor/golang.org/x/tools/present/iframe.go
@@ -0,0 +1,48 @@
+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package present
+
+import (
+	"fmt"
+	"strings"
+)
+
+func init() {
+	Register("iframe", parseIframe)
+}
+
+type Iframe struct {
+	URL    string
+	Width  int
+	Height int
+}
+
+func (i Iframe) TemplateName() string { return "iframe" }
+
+func parseIframe(ctx *Context, fileName string, lineno int, text string) (Elem, error) {
+	args := strings.Fields(text)
+	if len(args) < 2 {
+		return nil, fmt.Errorf("incorrect iframe invocation: %q", text)
+	}
+	i := Iframe{URL: args[1]}
+	a, err := parseArgs(fileName, lineno, args[2:])
+	if err != nil {
+		return nil, err
+	}
+	switch len(a) {
+	case 0:
+		// no size parameters
+	case 2:
+		if v, ok := a[0].(int); ok {
+			i.Height = v
+		}
+		if v, ok := a[1].(int); ok {
+			i.Width = v
+		}
+	default:
+		return nil, fmt.Errorf("incorrect iframe invocation: %q", text)
+	}
+	return i, nil
+}
diff --git a/vendor/golang.org/x/tools/present/image.go b/vendor/golang.org/x/tools/present/image.go
new file mode 100644
index 00000000000..84965cae544
--- /dev/null
+++ b/vendor/golang.org/x/tools/present/image.go
@@ -0,0 +1,53 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package present
+
+import (
+	"fmt"
+	"strings"
+)
+
+func init() {
+	Register("image", parseImage)
+}
+
+type Image struct {
+	URL    string
+	Width  int
+	Height int
+}
+
+func (i Image) TemplateName() string { return "image" }
+
+func parseImage(ctx *Context, fileName string, lineno int, text string) (Elem, error) {
+	args := strings.Fields(text)
+	if len(args) < 2 {
+		return nil, fmt.Errorf("incorrect image invocation: %q", text)
+	}
+	img := Image{URL: args[1]}
+	a, err := parseArgs(fileName, lineno, args[2:])
+	if err != nil {
+		return nil, err
+	}
+	switch len(a) {
+	case 0:
+		// no size parameters
+	case 2:
+		// If a parameter is empty (underscore) or invalid
+		// leave the field set to zero. The "image" action
+		// template will then omit that img tag attribute and
+		// the browser will calculate the value to preserve
+		// the aspect ratio.
+		if v, ok := a[0].(int); ok {
+			img.Height = v
+		}
+		if v, ok := a[1].(int); ok {
+			img.Width = v
+		}
+	default:
+		return nil, fmt.Errorf("incorrect image invocation: %q", text)
+	}
+	return img, nil
+}
diff --git a/vendor/golang.org/x/tools/present/link.go b/vendor/golang.org/x/tools/present/link.go
new file mode 100644
index 00000000000..2aead352e9c
--- /dev/null
+++ b/vendor/golang.org/x/tools/present/link.go
@@ -0,0 +1,100 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package present
+
+import (
+	"fmt"
+	"log"
+	"net/url"
+	"strings"
+)
+
+func init() {
+	Register("link", parseLink)
+}
+
+type Link struct {
+	URL   *url.URL
+	Label string
+}
+
+func (l Link) TemplateName() string { return "link" }
+
+func parseLink(ctx *Context, fileName string, lineno int, text string) (Elem, error) {
+	args := strings.Fields(text)
+	if len(args) < 2 {
+		return nil, fmt.Errorf("link element must have at least 2 arguments")
+	}
+	url, err := url.Parse(args[1])
+	if err != nil {
+		return nil, err
+	}
+	label := ""
+	if len(args) > 2 {
+		label = strings.Join(args[2:], " ")
+	} else {
+		scheme := url.Scheme + "://"
+		if url.Scheme == "mailto" {
+			scheme = "mailto:"
+		}
+		label = strings.Replace(url.String(), scheme, "", 1)
+	}
+	return Link{url, label}, nil
+}
+
+func renderLink(href, text string) string {
+	text = font(text)
+	if text == "" {
+		text = href
+	}
+	// Open links in new window only when their url is absolute.
+	target := "_blank"
+	if u, err := url.Parse(href); err != nil {
+		log.Println("renderLink parsing url:", err)
+	} else if !u.IsAbs() || u.Scheme == "javascript" {
+		target = "_self"
+	}
+
+	return fmt.Sprintf(`%s`, href, target, text)
+}
+
+// parseInlineLink parses an inline link at the start of s, and returns
+// a rendered HTML link and the total length of the raw inline link.
+// If no inline link is present, it returns all zeroes.
+func parseInlineLink(s string) (link string, length int) {
+	if !strings.HasPrefix(s, "[[") {
+		return
+	}
+	end := strings.Index(s, "]]")
+	if end == -1 {
+		return
+	}
+	urlEnd := strings.Index(s, "]")
+	rawURL := s[2:urlEnd]
+	const badURLChars = `<>"{}|\^[] ` + "`" // per RFC2396 section 2.4.3
+	if strings.ContainsAny(rawURL, badURLChars) {
+		return
+	}
+	if urlEnd == end {
+		simpleUrl := ""
+		url, err := url.Parse(rawURL)
+		if err == nil {
+			// If the URL is http://foo.com, drop the http://
+			// In other words, render [[http://golang.org]] as:
+			//   golang.org
+			if strings.HasPrefix(rawURL, url.Scheme+"://") {
+				simpleUrl = strings.TrimPrefix(rawURL, url.Scheme+"://")
+			} else if strings.HasPrefix(rawURL, url.Scheme+":") {
+				simpleUrl = strings.TrimPrefix(rawURL, url.Scheme+":")
+			}
+		}
+		return renderLink(rawURL, simpleUrl), end + 2
+	}
+	if s[urlEnd:urlEnd+2] != "][" {
+		return
+	}
+	text := s[urlEnd+2 : end]
+	return renderLink(rawURL, text), end + 2
+}
diff --git a/vendor/golang.org/x/tools/present/parse.go b/vendor/golang.org/x/tools/present/parse.go
new file mode 100644
index 00000000000..dd0f00b27ba
--- /dev/null
+++ b/vendor/golang.org/x/tools/present/parse.go
@@ -0,0 +1,568 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package present
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"html/template"
+	"io"
+	"io/ioutil"
+	"log"
+	"net/url"
+	"regexp"
+	"strings"
+	"time"
+	"unicode"
+	"unicode/utf8"
+)
+
+var (
+	parsers = make(map[string]ParseFunc)
+	funcs   = template.FuncMap{}
+)
+
+// Template returns an empty template with the action functions in its FuncMap.
+func Template() *template.Template {
+	return template.New("").Funcs(funcs)
+}
+
+// Render renders the doc to the given writer using the provided template.
+func (d *Doc) Render(w io.Writer, t *template.Template) error {
+	data := struct {
+		*Doc
+		Template     *template.Template
+		PlayEnabled  bool
+		NotesEnabled bool
+	}{d, t, PlayEnabled, NotesEnabled}
+	return t.ExecuteTemplate(w, "root", data)
+}
+
+// Render renders the section to the given writer using the provided template.
+func (s *Section) Render(w io.Writer, t *template.Template) error {
+	data := struct {
+		*Section
+		Template    *template.Template
+		PlayEnabled bool
+	}{s, t, PlayEnabled}
+	return t.ExecuteTemplate(w, "section", data)
+}
+
+type ParseFunc func(ctx *Context, fileName string, lineNumber int, inputLine string) (Elem, error)
+
+// Register binds the named action, which does not begin with a period, to the
+// specified parser to be invoked when the name, with a period, appears in the
+// present input text.
+func Register(name string, parser ParseFunc) {
+	if len(name) == 0 || name[0] == ';' {
+		panic("bad name in Register: " + name)
+	}
+	parsers["."+name] = parser
+}
+
+// Doc represents an entire document.
+type Doc struct {
+	Title      string
+	Subtitle   string
+	Time       time.Time
+	Authors    []Author
+	TitleNotes []string
+	Sections   []Section
+	Tags       []string
+}
+
+// Author represents the person who wrote and/or is presenting the document.
+type Author struct {
+	Elem []Elem
+}
+
+// TextElem returns the first text elements of the author details.
+// This is used to display the author' name, job title, and company
+// without the contact details.
+func (p *Author) TextElem() (elems []Elem) {
+	for _, el := range p.Elem {
+		if _, ok := el.(Text); !ok {
+			break
+		}
+		elems = append(elems, el)
+	}
+	return
+}
+
+// Section represents a section of a document (such as a presentation slide)
+// comprising a title and a list of elements.
+type Section struct {
+	Number  []int
+	Title   string
+	Elem    []Elem
+	Notes   []string
+	Classes []string
+	Styles  []string
+}
+
+// HTMLAttributes for the section
+func (s Section) HTMLAttributes() template.HTMLAttr {
+	if len(s.Classes) == 0 && len(s.Styles) == 0 {
+		return ""
+	}
+
+	var class string
+	if len(s.Classes) > 0 {
+		class = fmt.Sprintf(`class=%q`, strings.Join(s.Classes, " "))
+	}
+	var style string
+	if len(s.Styles) > 0 {
+		style = fmt.Sprintf(`style=%q`, strings.Join(s.Styles, " "))
+	}
+	return template.HTMLAttr(strings.Join([]string{class, style}, " "))
+}
+
+// Sections contained within the section.
+func (s Section) Sections() (sections []Section) {
+	for _, e := range s.Elem {
+		if section, ok := e.(Section); ok {
+			sections = append(sections, section)
+		}
+	}
+	return
+}
+
+// Level returns the level of the given section.
+// The document title is level 1, main section 2, etc.
+func (s Section) Level() int {
+	return len(s.Number) + 1
+}
+
+// FormattedNumber returns a string containing the concatenation of the
+// numbers identifying a Section.
+func (s Section) FormattedNumber() string {
+	b := &bytes.Buffer{}
+	for _, n := range s.Number {
+		fmt.Fprintf(b, "%v.", n)
+	}
+	return b.String()
+}
+
+func (s Section) TemplateName() string { return "section" }
+
+// Elem defines the interface for a present element. That is, something that
+// can provide the name of the template used to render the element.
+type Elem interface {
+	TemplateName() string
+}
+
+// renderElem implements the elem template function, used to render
+// sub-templates.
+func renderElem(t *template.Template, e Elem) (template.HTML, error) {
+	var data interface{} = e
+	if s, ok := e.(Section); ok {
+		data = struct {
+			Section
+			Template *template.Template
+		}{s, t}
+	}
+	return execTemplate(t, e.TemplateName(), data)
+}
+
+// pageNum derives a page number from a section.
+func pageNum(s Section, offset int) int {
+	if len(s.Number) == 0 {
+		return offset
+	}
+	return s.Number[0] + offset
+}
+
+func init() {
+	funcs["elem"] = renderElem
+	funcs["pagenum"] = pageNum
+}
+
+// execTemplate is a helper to execute a template and return the output as a
+// template.HTML value.
+func execTemplate(t *template.Template, name string, data interface{}) (template.HTML, error) {
+	b := new(bytes.Buffer)
+	err := t.ExecuteTemplate(b, name, data)
+	if err != nil {
+		return "", err
+	}
+	return template.HTML(b.String()), nil
+}
+
+// Text represents an optionally preformatted paragraph.
+type Text struct {
+	Lines []string
+	Pre   bool
+}
+
+func (t Text) TemplateName() string { return "text" }
+
+// List represents a bulleted list.
+type List struct {
+	Bullet []string
+}
+
+func (l List) TemplateName() string { return "list" }
+
+// Lines is a helper for parsing line-based input.
+type Lines struct {
+	line int // 0 indexed, so has 1-indexed number of last line returned
+	text []string
+}
+
+func readLines(r io.Reader) (*Lines, error) {
+	var lines []string
+	s := bufio.NewScanner(r)
+	for s.Scan() {
+		lines = append(lines, s.Text())
+	}
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+	return &Lines{0, lines}, nil
+}
+
+func (l *Lines) next() (text string, ok bool) {
+	for {
+		current := l.line
+		l.line++
+		if current >= len(l.text) {
+			return "", false
+		}
+		text = l.text[current]
+		// Lines starting with # are comments.
+		if len(text) == 0 || text[0] != '#' {
+			ok = true
+			break
+		}
+	}
+	return
+}
+
+func (l *Lines) back() {
+	l.line--
+}
+
+func (l *Lines) nextNonEmpty() (text string, ok bool) {
+	for {
+		text, ok = l.next()
+		if !ok {
+			return
+		}
+		if len(text) > 0 {
+			break
+		}
+	}
+	return
+}
+
+// A Context specifies the supporting context for parsing a presentation.
+type Context struct {
+	// ReadFile reads the file named by filename and returns the contents.
+	ReadFile func(filename string) ([]byte, error)
+}
+
+// ParseMode represents flags for the Parse function.
+type ParseMode int
+
+const (
+	// If set, parse only the title and subtitle.
+	TitlesOnly ParseMode = 1
+)
+
+// Parse parses a document from r.
+func (ctx *Context) Parse(r io.Reader, name string, mode ParseMode) (*Doc, error) {
+	doc := new(Doc)
+	lines, err := readLines(r)
+	if err != nil {
+		return nil, err
+	}
+
+	for i := lines.line; i < len(lines.text); i++ {
+		if strings.HasPrefix(lines.text[i], "*") {
+			break
+		}
+
+		if isSpeakerNote(lines.text[i]) {
+			doc.TitleNotes = append(doc.TitleNotes, lines.text[i][2:])
+		}
+	}
+
+	err = parseHeader(doc, lines)
+	if err != nil {
+		return nil, err
+	}
+	if mode&TitlesOnly != 0 {
+		return doc, nil
+	}
+
+	// Authors
+	if doc.Authors, err = parseAuthors(lines); err != nil {
+		return nil, err
+	}
+	// Sections
+	if doc.Sections, err = parseSections(ctx, name, lines, []int{}); err != nil {
+		return nil, err
+	}
+	return doc, nil
+}
+
+// Parse parses a document from r. Parse reads assets used by the presentation
+// from the file system using ioutil.ReadFile.
+func Parse(r io.Reader, name string, mode ParseMode) (*Doc, error) {
+	ctx := Context{ReadFile: ioutil.ReadFile}
+	return ctx.Parse(r, name, mode)
+}
+
+// isHeading matches any section heading.
+var isHeading = regexp.MustCompile(`^\*+ `)
+
+// lesserHeading returns true if text is a heading of a lesser or equal level
+// than that denoted by prefix.
+func lesserHeading(text, prefix string) bool {
+	return isHeading.MatchString(text) && !strings.HasPrefix(text, prefix+"*")
+}
+
+// parseSections parses Sections from lines for the section level indicated by
+// number (a nil number indicates the top level).
+func parseSections(ctx *Context, name string, lines *Lines, number []int) ([]Section, error) {
+	var sections []Section
+	for i := 1; ; i++ {
+		// Next non-empty line is title.
+		text, ok := lines.nextNonEmpty()
+		for ok && text == "" {
+			text, ok = lines.next()
+		}
+		if !ok {
+			break
+		}
+		prefix := strings.Repeat("*", len(number)+1)
+		if !strings.HasPrefix(text, prefix+" ") {
+			lines.back()
+			break
+		}
+		section := Section{
+			Number: append(append([]int{}, number...), i),
+			Title:  text[len(prefix)+1:],
+		}
+		text, ok = lines.nextNonEmpty()
+		for ok && !lesserHeading(text, prefix) {
+			var e Elem
+			r, _ := utf8.DecodeRuneInString(text)
+			switch {
+			case unicode.IsSpace(r):
+				i := strings.IndexFunc(text, func(r rune) bool {
+					return !unicode.IsSpace(r)
+				})
+				if i < 0 {
+					break
+				}
+				indent := text[:i]
+				var s []string
+				for ok && (strings.HasPrefix(text, indent) || text == "") {
+					if text != "" {
+						text = text[i:]
+					}
+					s = append(s, text)
+					text, ok = lines.next()
+				}
+				lines.back()
+				pre := strings.Join(s, "\n")
+				pre = strings.Replace(pre, "\t", "    ", -1) // browsers treat tabs badly
+				pre = strings.TrimRightFunc(pre, unicode.IsSpace)
+				e = Text{Lines: []string{pre}, Pre: true}
+			case strings.HasPrefix(text, "- "):
+				var b []string
+				for ok && strings.HasPrefix(text, "- ") {
+					b = append(b, text[2:])
+					text, ok = lines.next()
+				}
+				lines.back()
+				e = List{Bullet: b}
+			case isSpeakerNote(text):
+				section.Notes = append(section.Notes, text[2:])
+			case strings.HasPrefix(text, prefix+"* "):
+				lines.back()
+				subsecs, err := parseSections(ctx, name, lines, section.Number)
+				if err != nil {
+					return nil, err
+				}
+				for _, ss := range subsecs {
+					section.Elem = append(section.Elem, ss)
+				}
+			case strings.HasPrefix(text, "."):
+				args := strings.Fields(text)
+				if args[0] == ".background" {
+					section.Classes = append(section.Classes, "background")
+					section.Styles = append(section.Styles, "background-image: url('"+args[1]+"')")
+					break
+				}
+				parser := parsers[args[0]]
+				if parser == nil {
+					return nil, fmt.Errorf("%s:%d: unknown command %q\n", name, lines.line, text)
+				}
+				t, err := parser(ctx, name, lines.line, text)
+				if err != nil {
+					return nil, err
+				}
+				e = t
+			default:
+				var l []string
+				for ok && strings.TrimSpace(text) != "" {
+					if text[0] == '.' { // Command breaks text block.
+						lines.back()
+						break
+					}
+					if strings.HasPrefix(text, `\.`) { // Backslash escapes initial period.
+						text = text[1:]
+					}
+					l = append(l, text)
+					text, ok = lines.next()
+				}
+				if len(l) > 0 {
+					e = Text{Lines: l}
+				}
+			}
+			if e != nil {
+				section.Elem = append(section.Elem, e)
+			}
+			text, ok = lines.nextNonEmpty()
+		}
+		if isHeading.MatchString(text) {
+			lines.back()
+		}
+		sections = append(sections, section)
+	}
+	return sections, nil
+}
+
+func parseHeader(doc *Doc, lines *Lines) error {
+	var ok bool
+	// First non-empty line starts header.
+	doc.Title, ok = lines.nextNonEmpty()
+	if !ok {
+		return errors.New("unexpected EOF; expected title")
+	}
+	for {
+		text, ok := lines.next()
+		if !ok {
+			return errors.New("unexpected EOF")
+		}
+		if text == "" {
+			break
+		}
+		if isSpeakerNote(text) {
+			continue
+		}
+		const tagPrefix = "Tags:"
+		if strings.HasPrefix(text, tagPrefix) {
+			tags := strings.Split(text[len(tagPrefix):], ",")
+			for i := range tags {
+				tags[i] = strings.TrimSpace(tags[i])
+			}
+			doc.Tags = append(doc.Tags, tags...)
+		} else if t, ok := parseTime(text); ok {
+			doc.Time = t
+		} else if doc.Subtitle == "" {
+			doc.Subtitle = text
+		} else {
+			return fmt.Errorf("unexpected header line: %q", text)
+		}
+	}
+	return nil
+}
+
+func parseAuthors(lines *Lines) (authors []Author, err error) {
+	// This grammar demarcates authors with blanks.
+
+	// Skip blank lines.
+	if _, ok := lines.nextNonEmpty(); !ok {
+		return nil, errors.New("unexpected EOF")
+	}
+	lines.back()
+
+	var a *Author
+	for {
+		text, ok := lines.next()
+		if !ok {
+			return nil, errors.New("unexpected EOF")
+		}
+
+		// If we find a section heading, we're done.
+		if strings.HasPrefix(text, "* ") {
+			lines.back()
+			break
+		}
+
+		if isSpeakerNote(text) {
+			continue
+		}
+
+		// If we encounter a blank we're done with this author.
+		if a != nil && len(text) == 0 {
+			authors = append(authors, *a)
+			a = nil
+			continue
+		}
+		if a == nil {
+			a = new(Author)
+		}
+
+		// Parse the line. Those that
+		// - begin with @ are twitter names,
+		// - contain slashes are links, or
+		// - contain an @ symbol are an email address.
+		// The rest is just text.
+		var el Elem
+		switch {
+		case strings.HasPrefix(text, "@"):
+			el = parseURL("http://twitter.com/" + text[1:])
+		case strings.Contains(text, ":"):
+			el = parseURL(text)
+		case strings.Contains(text, "@"):
+			el = parseURL("mailto:" + text)
+		}
+		if l, ok := el.(Link); ok {
+			l.Label = text
+			el = l
+		}
+		if el == nil {
+			el = Text{Lines: []string{text}}
+		}
+		a.Elem = append(a.Elem, el)
+	}
+	if a != nil {
+		authors = append(authors, *a)
+	}
+	return authors, nil
+}
+
+func parseURL(text string) Elem {
+	u, err := url.Parse(text)
+	if err != nil {
+		log.Printf("Parse(%q): %v", text, err)
+		return nil
+	}
+	return Link{URL: u}
+}
+
+func parseTime(text string) (t time.Time, ok bool) {
+	t, err := time.Parse("15:04 2 Jan 2006", text)
+	if err == nil {
+		return t, true
+	}
+	t, err = time.Parse("2 Jan 2006", text)
+	if err == nil {
+		// at 11am UTC it is the same date everywhere
+		t = t.Add(time.Hour * 11)
+		return t, true
+	}
+	return time.Time{}, false
+}
+
+func isSpeakerNote(s string) bool {
+	return strings.HasPrefix(s, ": ")
+}
diff --git a/vendor/golang.org/x/tools/present/style.go b/vendor/golang.org/x/tools/present/style.go
new file mode 100644
index 00000000000..e2c228e55ab
--- /dev/null
+++ b/vendor/golang.org/x/tools/present/style.go
@@ -0,0 +1,167 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package present
+
+import (
+	"bytes"
+	"html"
+	"html/template"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+/*
+	Fonts are demarcated by an initial and final char bracketing a
+	space-delimited word, plus possibly some terminal punctuation.
+	The chars are
+		_ for italic
+		* for bold
+		` (back quote) for fixed width.
+	Inner appearances of the char become spaces. For instance,
+		_this_is_italic_!
+	becomes
+		this is italic!
+*/
+
+func init() {
+	funcs["style"] = Style
+}
+
+// Style returns s with HTML entities escaped and font indicators turned into
+// HTML font tags.
+func Style(s string) template.HTML {
+	return template.HTML(font(html.EscapeString(s)))
+}
+
+// font returns s with font indicators turned into HTML font tags.
+func font(s string) string {
+	if !strings.ContainsAny(s, "[`_*") {
+		return s
+	}
+	words := split(s)
+	var b bytes.Buffer
+Word:
+	for w, word := range words {
+		if len(word) < 2 {
+			continue Word
+		}
+		if link, _ := parseInlineLink(word); link != "" {
+			words[w] = link
+			continue Word
+		}
+		const marker = "_*`"
+		// Initial punctuation is OK but must be peeled off.
+		first := strings.IndexAny(word, marker)
+		if first == -1 {
+			continue Word
+		}
+		// Opening marker must be at the beginning of the token or else preceded by punctuation.
+		if first != 0 {
+			r, _ := utf8.DecodeLastRuneInString(word[:first])
+			if !unicode.IsPunct(r) {
+				continue Word
+			}
+		}
+		open, word := word[:first], word[first:]
+		char := word[0] // ASCII is OK.
+		close := ""
+		switch char {
+		default:
+			continue Word
+		case '_':
+			open += ""
+			close = ""
+		case '*':
+			open += ""
+			close = ""
+		case '`':
+			open += ""
+			close = ""
+		}
+		// Closing marker must be at the end of the token or else followed by punctuation.
+		last := strings.LastIndex(word, word[:1])
+		if last == 0 {
+			continue Word
+		}
+		if last+1 != len(word) {
+			r, _ := utf8.DecodeRuneInString(word[last+1:])
+			if !unicode.IsPunct(r) {
+				continue Word
+			}
+		}
+		head, tail := word[:last+1], word[last+1:]
+		b.Reset()
+		b.WriteString(open)
+		var wid int
+		for i := 1; i < len(head)-1; i += wid {
+			var r rune
+			r, wid = utf8.DecodeRuneInString(head[i:])
+			if r != rune(char) {
+				// Ordinary character.
+				b.WriteRune(r)
+				continue
+			}
+			if head[i+1] != char {
+				// Inner char becomes space.
+				b.WriteRune(' ')
+				continue
+			}
+			// Doubled char becomes real char.
+			// Not worth worrying about "_x__".
+			b.WriteByte(char)
+			wid++ // Consumed two chars, both ASCII.
+		}
+		b.WriteString(close) // Write closing tag.
+		b.WriteString(tail)  // Restore trailing punctuation.
+		words[w] = b.String()
+	}
+	return strings.Join(words, "")
+}
+
+// split is like strings.Fields but also returns the runs of spaces
+// and treats inline links as distinct words.
+func split(s string) []string {
+	var (
+		words = make([]string, 0, 10)
+		start = 0
+	)
+
+	// appendWord appends the string s[start:end] to the words slice.
+	// If the word contains the beginning of a link, the non-link portion
+	// of the word and the entire link are appended as separate words,
+	// and the start index is advanced to the end of the link.
+	appendWord := func(end int) {
+		if j := strings.Index(s[start:end], "[["); j > -1 {
+			if _, l := parseInlineLink(s[start+j:]); l > 0 {
+				// Append portion before link, if any.
+				if j > 0 {
+					words = append(words, s[start:start+j])
+				}
+				// Append link itself.
+				words = append(words, s[start+j:start+j+l])
+				// Advance start index to end of link.
+				start = start + j + l
+				return
+			}
+		}
+		// No link; just add the word.
+		words = append(words, s[start:end])
+		start = end
+	}
+
+	wasSpace := false
+	for i, r := range s {
+		isSpace := unicode.IsSpace(r)
+		if i > start && isSpace != wasSpace {
+			appendWord(i)
+		}
+		wasSpace = isSpace
+	}
+	for start < len(s) {
+		appendWord(len(s))
+	}
+	return words
+}
diff --git a/vendor/golang.org/x/tools/present/video.go b/vendor/golang.org/x/tools/present/video.go
new file mode 100644
index 00000000000..93d93502bf2
--- /dev/null
+++ b/vendor/golang.org/x/tools/present/video.go
@@ -0,0 +1,54 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package present
+
+import (
+	"fmt"
+	"strings"
+)
+
+func init() {
+	Register("video", parseVideo)
+}
+
+type Video struct {
+	URL        string
+	SourceType string
+	Width      int
+	Height     int
+}
+
+func (v Video) TemplateName() string { return "video" }
+
+func parseVideo(ctx *Context, fileName string, lineno int, text string) (Elem, error) {
+	args := strings.Fields(text)
+	if len(args) < 3 {
+		return nil, fmt.Errorf("incorrect video invocation: %q", text)
+	}
+	vid := Video{URL: args[1], SourceType: args[2]}
+	a, err := parseArgs(fileName, lineno, args[3:])
+	if err != nil {
+		return nil, err
+	}
+	switch len(a) {
+	case 0:
+		// no size parameters
+	case 2:
+		// If a parameter is empty (underscore) or invalid
+		// leave the field set to zero. The "video" action
+		// template will then omit that vid tag attribute and
+		// the browser will calculate the value to preserve
+		// the aspect ratio.
+		if v, ok := a[0].(int); ok {
+			vid.Height = v
+		}
+		if v, ok := a[1].(int); ok {
+			vid.Width = v
+		}
+	default:
+		return nil, fmt.Errorf("incorrect video invocation: %q", text)
+	}
+	return vid, nil
+}
diff --git a/vendor/modules.txt b/vendor/modules.txt
index 3109da215d0..41a0659c2c3 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -1,9 +1,24 @@
-# golang.org/x/tools v0.0.0-20191030225452-7871c2d76733
+# golang.org/x/tools v0.0.0-20200109174759-ac4f524c1612
+golang.org/x/tools/benchmark/parse
+golang.org/x/tools/blog/atom
+golang.org/x/tools/container/intsets
+golang.org/x/tools/go/ast/astutil
+golang.org/x/tools/go/buildutil
+golang.org/x/tools/go/callgraph
+golang.org/x/tools/go/callgraph/cha
+golang.org/x/tools/go/callgraph/rta
+golang.org/x/tools/go/callgraph/static
 golang.org/x/tools/go/gcexportdata
+golang.org/x/tools/go/internal/cgo
 golang.org/x/tools/go/internal/gcimporter
 golang.org/x/tools/go/internal/packagesdriver
+golang.org/x/tools/go/loader
 golang.org/x/tools/go/packages
+golang.org/x/tools/go/pointer
+golang.org/x/tools/go/ssa
+golang.org/x/tools/go/ssa/ssautil
+golang.org/x/tools/go/types/typeutil
 golang.org/x/tools/internal/fastwalk
 golang.org/x/tools/internal/gopathwalk
 golang.org/x/tools/internal/semver
-golang.org/x/tools/internal/span
+golang.org/x/tools/present

From 00dd464697d1bc9f0d2783f3ee23769b1105ba4b Mon Sep 17 00:00:00 2001
From: Sauyon Lee 
Date: Thu, 9 Jan 2020 11:01:39 -0800
Subject: [PATCH 2/2] Update stats

---
 ql/src/go.dbscheme.stats | 50 ++++++++++++++++++++--------------------
 1 file changed, 25 insertions(+), 25 deletions(-)

diff --git a/ql/src/go.dbscheme.stats b/ql/src/go.dbscheme.stats
index 2f0cd6fd7a4..6536faf9f69 100644
--- a/ql/src/go.dbscheme.stats
+++ b/ql/src/go.dbscheme.stats
@@ -466,7 +466,7 @@
 
 
 @declvarobject
-43442
+43443
 
 
 @declfunctionobject
@@ -9158,11 +9158,11 @@
 
 
 objects
-73625
+73626
 
 
 id
-73625
+73626
 
 
 kind
@@ -9184,7 +9184,7 @@
 
 1
 2
-73625
+73626
 
 
 
@@ -9200,7 +9200,7 @@
 
 1
 2
-73625
+73626
 
 
 
@@ -9254,8 +9254,8 @@
 1
 
 
-43442
-43443
+43443
+43444
 1
 
 
@@ -9447,11 +9447,11 @@
 
 
 objecttypes
-73623
+73624
 
 
 object
-73623
+73624
 
 
 tp
@@ -9469,7 +9469,7 @@
 
 1
 2
-73623
+73624
 
 
 
@@ -9568,11 +9568,11 @@
 
 
 fieldstructs
-9638
+9639
 
 
 field
-9638
+9639
 
 
 struct
@@ -9590,7 +9590,7 @@
 
 1
 2
-9638
+9639
 
 
 
@@ -9631,12 +9631,12 @@
 
 6
 8
-185
+184
 
 
 8
 13
-161
+162
 
 
 13
@@ -10233,7 +10233,7 @@
 
 
 component_types
-31625
+31626
 
 
 parent
@@ -10486,7 +10486,7 @@
 
 
 205
-726
+725
 6
 
 
@@ -10584,12 +10584,12 @@
 
 3
 5
-376
+375
 
 
 5
 7783
-296
+297
 
 
 
@@ -10605,22 +10605,22 @@
 
 1
 2
-3830
+3833
 
 
 2
 3
-629
+626
 
 
 3
 6
-379
+380
 
 
 6
 28
-71
+70
 
 
 
@@ -10723,12 +10723,12 @@
 
 4
 5
-314
+313
 
 
 5
 11
-293
+294
 
 
 11