Merge pull request #33 from sauyon/extract-go-mod

Add extraction for go.mod files

Makefile

@@ -87,7 +87,7 @@ ql/src/go.dbscheme: tools/$(CODEQL_PLATFORM)/go-extractor$(EXE)
 build/stats/src.stamp:
 	mkdir -p $(@D)/src
 	git clone 'https://github.com/golang/tools' $(@D)/src
-	git -C $(@D)/src checkout ac4f524c1612 -q
+	git -C $(@D)/src checkout 9b52d559c609 -q
 	touch $@
 
 ql/src/go.dbscheme.stats: ql/src/go.dbscheme build/stats/src.stamp extractor

extractor/dbscheme/tables.go

@@ -58,6 +58,9 @@ var DocumentableType = NewUnionType("@documentable", NodeType)
 // ExprParentType is the type of AST nodes that can have expressions as children
 var ExprParentType = NewUnionType("@exprparent", NodeType)
 
+// ModExprParentType is the type of go.mod nodes that can have go.mod expressions as children
+var ModExprParentType = NewUnionType("@modexprparent", NodeType)
+
 // FieldParentType is the type of AST nodes that can have fields as children
 var FieldParentType = NewUnionType("@fieldparent", NodeType)
 
@@ -71,14 +74,14 @@ var DeclParentType = NewUnionType("@declparent", NodeType)
 // declarations and function literals
 var FuncDefType = NewUnionType("@funcdef", StmtParentType, ExprParentType)
 
-// ScopeNodeType is the type of AST nodes that mapy have a scope attached to them
+// ScopeNodeType is the type of AST nodes that may have a scope attached to them
 var ScopeNodeType = NewUnionType("@scopenode", NodeType)
 
 // LocationDefaultType is the type of source locations
 var LocationDefaultType = NewPrimaryKeyType("@location_default")
 
 // FileType is the type of file AST nodes
-var FileType = NewPrimaryKeyType("@file", ContainerType, DocumentableType, ExprParentType, DeclParentType, ScopeNodeType)
+var FileType = NewPrimaryKeyType("@file", ContainerType, DocumentableType, ExprParentType, ModExprParentType, DeclParentType, ScopeNodeType)
 
 // FolderType is the type of folders
 var FolderType = NewPrimaryKeyType("@folder", ContainerType)
@@ -618,6 +621,27 @@ var NamedType = TypeKind.NewBranch("@namedtype", CompositeType)
 // PackageType is the type of packages
 var PackageType = NewPrimaryKeyType("@package")
 
+// ModExprType is the type of go.mod expression nodes
+var ModExprType = NewPrimaryKeyType("@modexpr", ModExprParentType, DocumentableType)
+
+// ModExprKind is a case type for distinguishing different kinds of go.mod expression nodes
+var ModExprKind = NewCaseType(ModExprType, "kind")
+
+// ModCommentBlockType is the type of go.mod comment block AST nodes
+var ModCommentBlockType = ModExprKind.NewBranch("@modcommentblock")
+
+// ModLineType is the type of go.mod line AST nodes
+var ModLineType = ModExprKind.NewBranch("@modline")
+
+// ModLineBlockType is the type of go.mod line block AST nodes
+var ModLineBlockType = ModExprKind.NewBranch("@modlineblock")
+
+// ModLParenType is the type of go.mod line block start AST nodes
+var ModLParenType = ModExprKind.NewBranch("@modlparen")
+
+// ModRParenType is the type of go.mod line block end AST nodes
+var ModRParenType = ModExprKind.NewBranch("@modrparen")
+
 // LocationsDefaultTable is the table defining location objects
 var LocationsDefaultTable = NewTable("locations_default",
 	EntityColumn(LocationDefaultType, "id").Key(),
@@ -684,7 +708,7 @@ var DocCommentsTable = NewTable("doc_comments",
 	EntityColumn(CommentGroupType, "comment"),
 )
 
-// ExprsTable is the table defininig expression AST nodes
+// ExprsTable is the table defining expression AST nodes
 var ExprsTable = NewTable("exprs",
 	EntityColumn(ExprType, "id").Key(),
 	IntColumn("kind"),
@@ -876,3 +900,18 @@ var PackagesTable = NewTable("packages",
 	StringColumn("path"),
 	EntityColumn(PackageScopeType, "scope"),
 )
+
+// ModExprsTable is the table defining expression AST nodes for go.mod files
+var ModExprsTable = NewTable("modexprs",
+	EntityColumn(ModExprType, "id").Key(),
+	IntColumn("kind"),
+	EntityColumn(ModExprParentType, "parent"),
+	IntColumn("idx"),
+).KeySet("parent", "idx")
+
+// ModTokensTable is the table associating go.mod tokens with their Line or LineBlock
+var ModTokensTable = NewTable("modtokens",
+	StringColumn("token"),
+	EntityColumn(ModExprType, "parent"),
+	IntColumn("idx"),
+).KeySet("parent", "idx")

extractor/extractor.go

@@ -111,6 +111,45 @@ func ExtractWithFlags(buildFlags []string, patterns []string) error {
 
 	wg.Wait()
 
+	cwd, err := os.Getwd()
+	if err != nil {
+		log.Printf("Warning: unable to get working directory: %s", err.Error())
+		log.Println("Skipping go.mod extraction")
+	}
+	rcwd, err := filepath.EvalSymlinks(cwd)
+	if err == nil {
+		cwd = rcwd
+	}
+
+	log.Printf("Walking file tree from %s to discover go.mod files...", cwd)
+
+	goModPaths := make([]string, 0, 10)
+
+	filepath.Walk(cwd, func(path string, info os.FileInfo, err error) error {
+		if filepath.Base(path) == "go.mod" && info != nil && info.Mode().IsRegular() {
+			if err != nil {
+				log.Printf("Found go.mod with path %s, but encountered error %s", path, err.Error())
+			}
+
+			goModPaths = append(goModPaths, path)
+		}
+
+		return nil
+	})
+
+	for _, path := range goModPaths {
+		log.Printf("Extracting %s", path)
+		start := time.Now()
+
+		err := extractGoMod(path)
+		if err != nil {
+			log.Printf("Failed to extract go.mod: %s", err.Error())
+		}
+
+		end := time.Since(start)
+		log.Printf("Done extracting %s (%dms)", path, end.Nanoseconds()/1000000)
+	}
+
 	return nil
 }
 

extractor/gomodextractor.go

@@ -0,0 +1,131 @@
+package extractor
+
+import (
+	"fmt"
+	"golang.org/x/mod/modfile"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+
+	"github.com/github/codeql-go/extractor/dbscheme"
+	"github.com/github/codeql-go/extractor/srcarchive"
+	"github.com/github/codeql-go/extractor/trap"
+)
+
+func extractGoMod(path string) error {
+	if normPath, err := filepath.EvalSymlinks(path); err == nil {
+		path = normPath
+	}
+
+	tw, err := trap.NewWriter(path, nil)
+	if err != nil {
+		return err
+	}
+	defer tw.Close()
+
+	err = srcarchive.Add(path)
+	if err != nil {
+		return err
+	}
+
+	extractFileInfo(tw, path)
+
+	file, err := os.Open(path)
+	if err != nil {
+		return fmt.Errorf("failed to open go.mod file %s: %s", path, err.Error())
+	}
+	data, err := ioutil.ReadAll(file)
+	if err != nil {
+		return fmt.Errorf("failed to read go.mod file %s: %s", path, err.Error())
+	}
+
+	modfile, err := modfile.Parse(path, data, nil)
+	if err != nil {
+		return fmt.Errorf("failed to parse go.mod file %s: %s", path, err.Error())
+	}
+
+	extractGoModFile(tw, modfile.Syntax)
+
+	return nil
+}
+
+func extractGoModFile(tw *trap.Writer, file *modfile.FileSyntax) {
+	for idx, stmt := range file.Stmt {
+		extractGoModExpr(tw, stmt, tw.Labeler.FileLabel(), idx)
+	}
+
+	extractGoModComments(tw, file, tw.Labeler.FileLabel())
+}
+
+func extractGoModExpr(tw *trap.Writer, expr modfile.Expr, parent trap.Label, idx int) {
+	lbl := tw.Labeler.LocalID(expr)
+
+	var kind int
+	switch expr := expr.(type) {
+	case *modfile.CommentBlock:
+		kind = dbscheme.ModCommentBlockType.Index()
+	case *modfile.LParen:
+		kind = dbscheme.ModLParenType.Index()
+	case *modfile.RParen:
+		kind = dbscheme.ModRParenType.Index()
+	case *modfile.Line:
+		kind = dbscheme.ModLineType.Index()
+		for idx, tok := range expr.Token {
+			dbscheme.ModTokensTable.Emit(tw, tok, lbl, idx)
+		}
+	case *modfile.LineBlock:
+		kind = dbscheme.ModLineBlockType.Index()
+		for idx, tok := range expr.Token {
+			dbscheme.ModTokensTable.Emit(tw, tok, lbl, idx)
+		}
+		extractGoModExpr(tw, &expr.LParen, lbl, 0)
+		for idx, line := range expr.Line {
+			extractGoModExpr(tw, line, lbl, idx+1)
+		}
+		extractGoModExpr(tw, &expr.RParen, lbl, len(expr.Line)+1)
+	default:
+		log.Fatalf("unknown go.mod expression of type %T", expr)
+	}
+
+	dbscheme.ModExprsTable.Emit(tw, lbl, kind, parent, idx)
+
+	extractGoModComments(tw, expr, lbl)
+
+	start, end := expr.Span()
+	extractLocation(tw, lbl, start.Line, start.LineRune, end.Line, end.LineRune)
+}
+
+type GoModExprCommentWrapper struct {
+	expr modfile.Expr
+}
+
+func extractGoModComments(tw *trap.Writer, expr modfile.Expr, exprlbl trap.Label) {
+	// extract a pseudo `@commentgroup` for each expr that contains their associated comments
+	grouplbl := tw.Labeler.LocalID(GoModExprCommentWrapper{expr})
+	dbscheme.CommentGroupsTable.Emit(tw, grouplbl)
+	dbscheme.DocCommentsTable.Emit(tw, exprlbl, grouplbl)
+
+	comments := expr.Comment()
+
+	idx := 0
+	for _, comment := range comments.Before {
+		extractGoModComment(tw, comment, grouplbl, idx)
+		idx++
+	}
+	for _, comment := range comments.Suffix {
+		extractGoModComment(tw, comment, grouplbl, idx)
+		idx++
+	}
+	for _, comment := range comments.After {
+		extractGoModComment(tw, comment, grouplbl, idx)
+		idx++
+	}
+}
+
+func extractGoModComment(tw *trap.Writer, comment modfile.Comment, grouplbl trap.Label, idx int) {
+	lbl := tw.Labeler.LocalID(comment)
+	dbscheme.CommentsTable.Emit(tw, lbl, dbscheme.SlashSlashComment.Index(), grouplbl, idx, comment.Token)
+
+	extractLocation(tw, lbl, comment.Start.Line, comment.Start.LineRune, comment.Start.Line, comment.Start.LineRune+len(comment.Token))
+}

extractor/trap/labels.go

@@ -2,7 +2,6 @@ package trap
 
 import (
 	"fmt"
-	"go/ast"
 	"go/types"
 )
 
@@ -25,7 +24,7 @@ type Labeler struct {
 
 	nextid       int
 	fileLabel    Label
-	nodeLabels   map[ast.Node]Label     // labels associated with AST nodes
+	nodeLabels   map[interface{}]Label  // labels associated with AST nodes
 	scopeLabels  map[*types.Scope]Label // labels associated with scopes
 	objectLabels map[types.Object]Label // labels associated with objects (that is, declared entities)
 	TypeLabels   map[types.Type]Label   // labels associated with types
@@ -37,7 +36,7 @@ func newLabeler(tw *Writer) *Labeler {
 		tw,
 		10000,
 		InvalidLabel,
-		make(map[ast.Node]Label),
+		make(map[interface{}]Label),
 		make(map[*types.Scope]Label),
 		make(map[types.Object]Label),
 		make(map[types.Type]Label),
@@ -72,7 +71,7 @@ func (l *Labeler) FileLabel() Label {
 }
 
 // LocalID associates a label with the given AST node `nd` and returns it
-func (l *Labeler) LocalID(nd ast.Node) Label {
+func (l *Labeler) LocalID(nd interface{}) Label {
 	label, exists := l.nodeLabels[nd]
 	if !exists {
 		label = l.FreshID()
@@ -162,7 +161,7 @@ func (l *Labeler) ScopedObjectID(object types.Object, typelbl Label) (Label, boo
 
 			if !isRecv {
 				scopeLbl := l.ScopeID(scope, object.Pkg())
-				label = l.GlobalID(fmt.Sprintf("{%s},%s;object", scopeLbl.String(), object.Name()))
+				label = l.GlobalID(fmt.Sprintf("{%v},%s;object", scopeLbl, object.Name()))
 			}
 		}
 		l.objectLabels[object] = label
@@ -177,7 +176,7 @@ func (l *Labeler) ReceiverObjectID(object types.Object, methlbl Label) (Label, b
 	label, exists := l.objectLabels[object]
 	if !exists {
 		// if we can't, construct a special label
-		label = l.GlobalID(fmt.Sprintf("{%s},%s;receiver", methlbl.String(), object.Name()))
+		label = l.GlobalID(fmt.Sprintf("{%v},%s;receiver", methlbl, object.Name()))
 		l.objectLabels[object] = label
 	}
 	return label, exists
@@ -197,7 +196,7 @@ func (l *Labeler) FieldID(field *types.Var, idx int, structlbl Label) (Label, bo
 		if field.Name() == "_" {
 			name = fmt.Sprintf("_%d", idx)
 		}
-		label = l.GlobalID(fmt.Sprintf("{%s},%s;field", structlbl.String(), name))
+		label = l.GlobalID(fmt.Sprintf("{%v},%s;field", structlbl, name))
 		l.objectLabels[field] = label
 	}
 	return label, exists
@@ -209,7 +208,7 @@ func (l *Labeler) FieldID(field *types.Var, idx int, structlbl Label) (Label, bo
 func (l *Labeler) MethodID(method types.Object, recvlbl Label) (Label, bool) {
 	label, exists := l.objectLabels[method]
 	if !exists {
-		label = l.GlobalID(fmt.Sprintf("{%s},%s;method", recvlbl, method.Name()))
+		label = l.GlobalID(fmt.Sprintf("{%v},%s;method", recvlbl, method.Name()))
 		l.objectLabels[method] = label
 	}
 	return label, exists

go.mod

@@ -2,4 +2,7 @@ module github.com/github/codeql-go
 
 go 1.13
 
-require golang.org/x/tools v0.0.0-20200109174759-ac4f524c1612
+require (
+	golang.org/x/mod v0.2.0
+	golang.org/x/tools v0.0.0-20200302225559-9b52d559c609
+)

go.sum

@@ -1,12 +1,17 @@
 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/mod v0.2.0 h1:KU7oHjnv3XNWfa5COkzUifxZmxp1TyI7ImMXqFxLwvQ=
+golang.org/x/mod v0.2.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 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 v0.0.0-20200109174759-ac4f524c1612 h1:wRxHHuBMuDzijfZQMAgmVpDDTra91XF84qmoVTyj+U0=
-golang.org/x/tools v0.0.0-20200109174759-ac4f524c1612/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20200302225559-9b52d559c609 h1:3/QY44rOqJoMLCsQz9bAgInYa08qsu+dH52Uk4DWH3w=
+golang.org/x/tools v0.0.0-20200302225559-9b52d559c609/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898 h1:/atklqdjdhuosWIl6AIbOeHJjicWYPqR9bpxqxYG2pA=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

ql/src/go.dbscheme

@@ -118,16 +118,25 @@ type_objects(unique int tp: @type ref, int object: @object ref);
 
 packages(unique int id: @package, string name: string ref, string path: string ref, int scope: @packagescope ref);
 
+#keyset[parent, idx]
+modexprs(unique int id: @modexpr, int kind: int ref, int parent: @modexprparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+modtokens(string token: string ref, int parent: @modexpr ref, int idx: int ref);
+
 @container = @file | @folder;
 
 @locatable = @node | @localscope;
 
-@node = @documentable | @exprparent | @fieldparent | @stmtparent | @declparent | @scopenode | @comment_group | @comment;
+@node = @documentable | @exprparent | @modexprparent | @fieldparent | @stmtparent | @declparent | @scopenode
+      | @comment_group | @comment;
 
-@documentable = @file | @field | @spec | @gendecl | @funcdecl;
+@documentable = @file | @field | @spec | @gendecl | @funcdecl | @modexpr;
 
 @exprparent = @funcdef | @file | @expr | @field | @stmt | @decl | @spec;
 
+@modexprparent = @file | @modexpr;
+
 @fieldparent = @decl | @structtypeexpr | @functypeexpr | @interfacetypeexpr;
 
 @stmtparent = @funcdef | @stmt | @decl;
@@ -402,3 +411,10 @@ case @type.kind of
 
 @chantype = @sendchantype | @recvchantype | @sendrcvchantype;
 
+case @modexpr.kind of
+  0 = @modcommentblock
+| 1 = @modline
+| 2 = @modlineblock
+| 3 = @modlparen
+| 4 = @modrparen;
+

upgrades/f1263a745347568af228ad3ddb2decb142c3a1a8/go.dbscheme

@@ -0,0 +1,420 @@
+/** Auto-generated dbscheme; do not edit. */
+
+
+/** Duplicate code **/
+
+duplicateCode(
+  unique int id : @duplication,
+  varchar(900) relativePath : string ref,
+  int equivClass : int ref);
+
+similarCode(
+  unique int id : @similarity,
+  varchar(900) relativePath : string ref,
+  int equivClass : int ref);
+
+@duplication_or_similarity = @duplication | @similarity;
+
+tokens(
+  int id : @duplication_or_similarity ref,
+  int offset : int ref,
+  int beginLine : int ref,
+  int beginColumn : int ref,
+  int endLine : int ref,
+  int endColumn : int ref);
+
+/** External data **/
+
+externalData(
+  int id : @externalDataElement,
+  varchar(900) path : string ref,
+  int column: int ref,
+  varchar(900) value : string ref
+);
+
+snapshotDate(unique date snapshotDate : date ref);
+
+sourceLocationPrefix(varchar(900) prefix : string ref);
+
+locations_default(unique int id: @location_default, int file: @file ref, int beginLine: int ref, int beginColumn: int ref,
+                  int endLine: int ref, int endColumn: int ref);
+
+numlines(int element_id: @sourceline ref, int num_lines: int ref, int num_code: int ref, int num_comment: int ref);
+
+files(unique int id: @file, string name: string ref, string simple: string ref, string ext: string ref, int fromSource: int ref);
+
+folders(unique int id: @folder, string name: string ref, string simple: string ref);
+
+containerparent(int parent: @container ref, unique int child: @container ref);
+
+has_location(unique int locatable: @locatable ref, int location: @location ref);
+
+comment_groups(unique int id: @comment_group);
+
+comments(unique int id: @comment, int kind: int ref, int parent: @comment_group ref, int idx: int ref, string text: string ref);
+
+doc_comments(unique int node: @documentable ref, int comment: @comment_group ref);
+
+#keyset[parent, idx]
+exprs(unique int id: @expr, int kind: int ref, int parent: @exprparent ref, int idx: int ref);
+
+literals(unique int expr: @expr ref, string value: string ref, string raw: string ref);
+
+constvalues(unique int expr: @expr ref, string value: string ref, string exact: string ref);
+
+fields(unique int id: @field, int parent: @fieldparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+stmts(unique int id: @stmt, int kind: int ref, int parent: @stmtparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+decls(unique int id: @decl, int kind: int ref, int parent: @declparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+specs(unique int id: @spec, int kind: int ref, int parent: @gendecl ref, int idx: int ref);
+
+scopes(unique int id: @scope, int kind: int ref);
+
+scopenesting(unique int inner: @scope ref, int outer: @scope ref);
+
+scopenodes(unique int node: @scopenode ref, int scope: @localscope ref);
+
+objects(unique int id: @object, int kind: int ref, string name: string ref);
+
+objectscopes(unique int object: @object ref, int scope: @scope ref);
+
+objecttypes(unique int object: @object ref, int tp: @type ref);
+
+methodreceivers(unique int method: @object ref, int receiver: @object ref);
+
+fieldstructs(unique int field: @object ref, int struct: @structtype ref);
+
+methodhosts(int method: @object ref, int host: @namedtype ref);
+
+defs(int ident: @ident ref, int object: @object ref);
+
+uses(int ident: @ident ref, int object: @object ref);
+
+types(unique int id: @type, int kind: int ref);
+
+type_of(unique int expr: @expr ref, int tp: @type ref);
+
+typename(unique int tp: @type ref, string name: string ref);
+
+key_type(unique int map: @maptype ref, int tp: @type ref);
+
+element_type(unique int container: @containertype ref, int tp: @type ref);
+
+base_type(unique int ptr: @pointertype ref, int tp: @type ref);
+
+underlying_type(unique int named: @namedtype ref, int tp: @type ref);
+
+#keyset[parent, index]
+component_types(int parent: @compositetype ref, int index: int ref, string name: string ref, int tp: @type ref);
+
+array_length(unique int tp: @arraytype ref, string len: string ref);
+
+type_objects(unique int tp: @type ref, int object: @object ref);
+
+packages(unique int id: @package, string name: string ref, string path: string ref, int scope: @packagescope ref);
+
+#keyset[parent, idx]
+modexprs(unique int id: @modexpr, int kind: int ref, int parent: @modexprparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+modtokens(string token: string ref, int parent: @modexpr ref, int idx: int ref);
+
+@container = @file | @folder;
+
+@locatable = @node | @localscope;
+
+@node = @documentable | @exprparent | @modexprparent | @fieldparent | @stmtparent | @declparent | @scopenode
+      | @comment_group | @comment;
+
+@documentable = @file | @field | @spec | @gendecl | @funcdecl | @modexpr;
+
+@exprparent = @funcdef | @file | @expr | @field | @stmt | @decl | @spec;
+
+@modexprparent = @file | @modexpr;
+
+@fieldparent = @decl | @structtypeexpr | @functypeexpr | @interfacetypeexpr;
+
+@stmtparent = @funcdef | @stmt | @decl;
+
+@declparent = @file | @declstmt;
+
+@funcdef = @funclit | @funcdecl;
+
+@scopenode = @file | @functypeexpr | @blockstmt | @ifstmt | @caseclause | @switchstmt | @commclause | @loopstmt;
+
+@location = @location_default;
+
+@sourceline = @locatable;
+
+case @comment.kind of
+  0 = @slashslashcomment
+| 1 = @slashstarcomment;
+
+case @expr.kind of
+  0 = @badexpr
+| 1 = @ident
+| 2 = @ellipsis
+| 3 = @intlit
+| 4 = @floatlit
+| 5 = @imaglit
+| 6 = @charlit
+| 7 = @stringlit
+| 8 = @funclit
+| 9 = @compositelit
+| 10 = @parenexpr
+| 11 = @selectorexpr
+| 12 = @indexexpr
+| 13 = @sliceexpr
+| 14 = @typeassertexpr
+| 15 = @callorconversionexpr
+| 16 = @starexpr
+| 17 = @keyvalueexpr
+| 18 = @arraytypeexpr
+| 19 = @structtypeexpr
+| 20 = @functypeexpr
+| 21 = @interfacetypeexpr
+| 22 = @maptypeexpr
+| 23 = @plusexpr
+| 24 = @minusexpr
+| 25 = @notexpr
+| 26 = @complementexpr
+| 27 = @derefexpr
+| 28 = @addressexpr
+| 29 = @arrowexpr
+| 30 = @lorexpr
+| 31 = @landexpr
+| 32 = @eqlexpr
+| 33 = @neqexpr
+| 34 = @lssexpr
+| 35 = @leqexpr
+| 36 = @gtrexpr
+| 37 = @geqexpr
+| 38 = @addexpr
+| 39 = @subexpr
+| 40 = @orexpr
+| 41 = @xorexpr
+| 42 = @mulexpr
+| 43 = @quoexpr
+| 44 = @remexpr
+| 45 = @shlexpr
+| 46 = @shrexpr
+| 47 = @andexpr
+| 48 = @andnotexpr
+| 49 = @sendchantypeexpr
+| 50 = @recvchantypeexpr
+| 51 = @sendrcvchantypeexpr;
+
+@basiclit = @intlit | @floatlit | @imaglit | @charlit | @stringlit;
+
+@operatorexpr = @logicalexpr | @arithmeticexpr | @bitwiseexpr | @unaryexpr | @binaryexpr;
+
+@logicalexpr = @logicalunaryexpr | @logicalbinaryexpr;
+
+@arithmeticexpr = @arithmeticunaryexpr | @arithmeticbinaryexpr;
+
+@bitwiseexpr = @bitwiseunaryexpr | @bitwisebinaryexpr;
+
+@unaryexpr = @logicalunaryexpr | @bitwiseunaryexpr | @arithmeticunaryexpr | @derefexpr | @addressexpr | @arrowexpr;
+
+@logicalunaryexpr = @notexpr;
+
+@bitwiseunaryexpr = @complementexpr;
+
+@arithmeticunaryexpr = @plusexpr | @minusexpr;
+
+@binaryexpr = @logicalbinaryexpr | @bitwisebinaryexpr | @arithmeticbinaryexpr | @comparison;
+
+@logicalbinaryexpr = @lorexpr | @landexpr;
+
+@bitwisebinaryexpr = @shiftexpr | @orexpr | @xorexpr | @andexpr | @andnotexpr;
+
+@arithmeticbinaryexpr = @addexpr | @subexpr | @mulexpr | @quoexpr | @remexpr;
+
+@shiftexpr = @shlexpr | @shrexpr;
+
+@comparison = @equalitytest | @relationalcomparison;
+
+@equalitytest = @eqlexpr | @neqexpr;
+
+@relationalcomparison = @lssexpr | @leqexpr | @gtrexpr | @geqexpr;
+
+@chantypeexpr = @sendchantypeexpr | @recvchantypeexpr | @sendrcvchantypeexpr;
+
+case @stmt.kind of
+  0 = @badstmt
+| 1 = @declstmt
+| 2 = @emptystmt
+| 3 = @labeledstmt
+| 4 = @exprstmt
+| 5 = @sendstmt
+| 6 = @incstmt
+| 7 = @decstmt
+| 8 = @gostmt
+| 9 = @deferstmt
+| 10 = @returnstmt
+| 11 = @breakstmt
+| 12 = @continuestmt
+| 13 = @gotostmt
+| 14 = @fallthroughstmt
+| 15 = @blockstmt
+| 16 = @ifstmt
+| 17 = @caseclause
+| 18 = @exprswitchstmt
+| 19 = @typeswitchstmt
+| 20 = @commclause
+| 21 = @selectstmt
+| 22 = @forstmt
+| 23 = @rangestmt
+| 24 = @assignstmt
+| 25 = @definestmt
+| 26 = @addassignstmt
+| 27 = @subassignstmt
+| 28 = @mulassignstmt
+| 29 = @quoassignstmt
+| 30 = @remassignstmt
+| 31 = @andassignstmt
+| 32 = @orassignstmt
+| 33 = @xorassignstmt
+| 34 = @shlassignstmt
+| 35 = @shrassignstmt
+| 36 = @andnotassignstmt;
+
+@incdecstmt = @incstmt | @decstmt;
+
+@assignment = @simpleassignstmt | @compoundassignstmt;
+
+@simpleassignstmt = @assignstmt | @definestmt;
+
+@compoundassignstmt = @addassignstmt | @subassignstmt | @mulassignstmt | @quoassignstmt | @remassignstmt
+                    | @andassignstmt | @orassignstmt | @xorassignstmt | @shlassignstmt | @shrassignstmt | @andnotassignstmt;
+
+@branchstmt = @breakstmt | @continuestmt | @gotostmt | @fallthroughstmt;
+
+@switchstmt = @exprswitchstmt | @typeswitchstmt;
+
+@loopstmt = @forstmt | @rangestmt;
+
+case @decl.kind of
+  0 = @baddecl
+| 1 = @importdecl
+| 2 = @constdecl
+| 3 = @typedecl
+| 4 = @vardecl
+| 5 = @funcdecl;
+
+@gendecl = @importdecl | @constdecl | @typedecl | @vardecl;
+
+case @spec.kind of
+  0 = @importspec
+| 1 = @valuespec
+| 2 = @typespec;
+
+case @object.kind of
+  0 = @pkgobject
+| 1 = @decltypeobject
+| 2 = @builtintypeobject
+| 3 = @declconstobject
+| 4 = @builtinconstobject
+| 5 = @declvarobject
+| 6 = @declfunctionobject
+| 7 = @builtinfunctionobject
+| 8 = @labelobject;
+
+@declobject = @decltypeobject | @declconstobject | @declvarobject | @declfunctionobject;
+
+@builtinobject = @builtintypeobject | @builtinconstobject | @builtinfunctionobject;
+
+@typeobject = @decltypeobject | @builtintypeobject;
+
+@valueobject = @constobject | @varobject | @functionobject;
+
+@constobject = @declconstobject | @builtinconstobject;
+
+@varobject = @declvarobject;
+
+@functionobject = @declfunctionobject | @builtinfunctionobject;
+
+case @scope.kind of
+  0 = @universescope
+| 1 = @packagescope
+| 2 = @localscope;
+
+case @type.kind of
+  0 = @invalidtype
+| 1 = @boolexprtype
+| 2 = @inttype
+| 3 = @int8type
+| 4 = @int16type
+| 5 = @int32type
+| 6 = @int64type
+| 7 = @uinttype
+| 8 = @uint8type
+| 9 = @uint16type
+| 10 = @uint32type
+| 11 = @uint64type
+| 12 = @uintptrtype
+| 13 = @float32type
+| 14 = @float64type
+| 15 = @complex64type
+| 16 = @complex128type
+| 17 = @stringexprtype
+| 18 = @unsafepointertype
+| 19 = @boolliteraltype
+| 20 = @intliteraltype
+| 21 = @runeliteraltype
+| 22 = @floatliteraltype
+| 23 = @complexliteraltype
+| 24 = @stringliteraltype
+| 25 = @nilliteraltype
+| 26 = @arraytype
+| 27 = @slicetype
+| 28 = @structtype
+| 29 = @pointertype
+| 30 = @interfacetype
+| 31 = @tupletype
+| 32 = @signaturetype
+| 33 = @maptype
+| 34 = @sendchantype
+| 35 = @recvchantype
+| 36 = @sendrcvchantype
+| 37 = @namedtype;
+
+@basictype = @booltype | @numerictype | @stringtype | @literaltype | @invalidtype | @uintptrtype | @unsafepointertype;
+
+@booltype = @boolexprtype | @boolliteraltype;
+
+@numerictype = @integertype | @floattype | @complextype;
+
+@integertype = @signedintegertype | @unsignedintegertype;
+
+@signedintegertype = @inttype | @int8type | @int16type | @int32type | @int64type | @intliteraltype | @runeliteraltype;
+
+@unsignedintegertype = @uinttype | @uint8type | @uint16type | @uint32type | @uint64type;
+
+@floattype = @float32type | @float64type | @floatliteraltype;
+
+@complextype = @complex64type | @complex128type | @complexliteraltype;
+
+@stringtype = @stringexprtype | @stringliteraltype;
+
+@literaltype = @boolliteraltype | @intliteraltype | @runeliteraltype | @floatliteraltype | @complexliteraltype
+             | @stringliteraltype | @nilliteraltype;
+
+@compositetype = @containertype | @structtype | @pointertype | @interfacetype | @tupletype | @signaturetype | @namedtype;
+
+@containertype = @arraytype | @slicetype | @maptype | @chantype;
+
+@chantype = @sendchantype | @recvchantype | @sendrcvchantype;
+
+case @modexpr.kind of
+  0 = @modcommentblock
+| 1 = @modline
+| 2 = @modlineblock
+| 3 = @modlparen
+| 4 = @modrparen;
+

upgrades/f1263a745347568af228ad3ddb2decb142c3a1a8/old.dbscheme

@@ -0,0 +1,404 @@
+/** Auto-generated dbscheme; do not edit. */
+
+
+/** Duplicate code **/
+
+duplicateCode(
+  unique int id : @duplication,
+  varchar(900) relativePath : string ref,
+  int equivClass : int ref);
+
+similarCode(
+  unique int id : @similarity,
+  varchar(900) relativePath : string ref,
+  int equivClass : int ref);
+
+@duplication_or_similarity = @duplication | @similarity;
+
+tokens(
+  int id : @duplication_or_similarity ref,
+  int offset : int ref,
+  int beginLine : int ref,
+  int beginColumn : int ref,
+  int endLine : int ref,
+  int endColumn : int ref);
+
+/** External data **/
+
+externalData(
+  int id : @externalDataElement,
+  varchar(900) path : string ref,
+  int column: int ref,
+  varchar(900) value : string ref
+);
+
+snapshotDate(unique date snapshotDate : date ref);
+
+sourceLocationPrefix(varchar(900) prefix : string ref);
+
+locations_default(unique int id: @location_default, int file: @file ref, int beginLine: int ref, int beginColumn: int ref,
+                  int endLine: int ref, int endColumn: int ref);
+
+numlines(int element_id: @sourceline ref, int num_lines: int ref, int num_code: int ref, int num_comment: int ref);
+
+files(unique int id: @file, string name: string ref, string simple: string ref, string ext: string ref, int fromSource: int ref);
+
+folders(unique int id: @folder, string name: string ref, string simple: string ref);
+
+containerparent(int parent: @container ref, unique int child: @container ref);
+
+has_location(unique int locatable: @locatable ref, int location: @location ref);
+
+comment_groups(unique int id: @comment_group);
+
+comments(unique int id: @comment, int kind: int ref, int parent: @comment_group ref, int idx: int ref, string text: string ref);
+
+doc_comments(unique int node: @documentable ref, int comment: @comment_group ref);
+
+#keyset[parent, idx]
+exprs(unique int id: @expr, int kind: int ref, int parent: @exprparent ref, int idx: int ref);
+
+literals(unique int expr: @expr ref, string value: string ref, string raw: string ref);
+
+constvalues(unique int expr: @expr ref, string value: string ref, string exact: string ref);
+
+fields(unique int id: @field, int parent: @fieldparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+stmts(unique int id: @stmt, int kind: int ref, int parent: @stmtparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+decls(unique int id: @decl, int kind: int ref, int parent: @declparent ref, int idx: int ref);
+
+#keyset[parent, idx]
+specs(unique int id: @spec, int kind: int ref, int parent: @gendecl ref, int idx: int ref);
+
+scopes(unique int id: @scope, int kind: int ref);
+
+scopenesting(unique int inner: @scope ref, int outer: @scope ref);
+
+scopenodes(unique int node: @scopenode ref, int scope: @localscope ref);
+
+objects(unique int id: @object, int kind: int ref, string name: string ref);
+
+objectscopes(unique int object: @object ref, int scope: @scope ref);
+
+objecttypes(unique int object: @object ref, int tp: @type ref);
+
+methodreceivers(unique int method: @object ref, int receiver: @object ref);
+
+fieldstructs(unique int field: @object ref, int struct: @structtype ref);
+
+methodhosts(int method: @object ref, int host: @namedtype ref);
+
+defs(int ident: @ident ref, int object: @object ref);
+
+uses(int ident: @ident ref, int object: @object ref);
+
+types(unique int id: @type, int kind: int ref);
+
+type_of(unique int expr: @expr ref, int tp: @type ref);
+
+typename(unique int tp: @type ref, string name: string ref);
+
+key_type(unique int map: @maptype ref, int tp: @type ref);
+
+element_type(unique int container: @containertype ref, int tp: @type ref);
+
+base_type(unique int ptr: @pointertype ref, int tp: @type ref);
+
+underlying_type(unique int named: @namedtype ref, int tp: @type ref);
+
+#keyset[parent, index]
+component_types(int parent: @compositetype ref, int index: int ref, string name: string ref, int tp: @type ref);
+
+array_length(unique int tp: @arraytype ref, string len: string ref);
+
+type_objects(unique int tp: @type ref, int object: @object ref);
+
+packages(unique int id: @package, string name: string ref, string path: string ref, int scope: @packagescope ref);
+
+@container = @file | @folder;
+
+@locatable = @node | @localscope;
+
+@node = @documentable | @exprparent | @fieldparent | @stmtparent | @declparent | @scopenode | @comment_group | @comment;
+
+@documentable = @file | @field | @spec | @gendecl | @funcdecl;
+
+@exprparent = @funcdef | @file | @expr | @field | @stmt | @decl | @spec;
+
+@fieldparent = @decl | @structtypeexpr | @functypeexpr | @interfacetypeexpr;
+
+@stmtparent = @funcdef | @stmt | @decl;
+
+@declparent = @file | @declstmt;
+
+@funcdef = @funclit | @funcdecl;
+
+@scopenode = @file | @functypeexpr | @blockstmt | @ifstmt | @caseclause | @switchstmt | @commclause | @loopstmt;
+
+@location = @location_default;
+
+@sourceline = @locatable;
+
+case @comment.kind of
+  0 = @slashslashcomment
+| 1 = @slashstarcomment;
+
+case @expr.kind of
+  0 = @badexpr
+| 1 = @ident
+| 2 = @ellipsis
+| 3 = @intlit
+| 4 = @floatlit
+| 5 = @imaglit
+| 6 = @charlit
+| 7 = @stringlit
+| 8 = @funclit
+| 9 = @compositelit
+| 10 = @parenexpr
+| 11 = @selectorexpr
+| 12 = @indexexpr
+| 13 = @sliceexpr
+| 14 = @typeassertexpr
+| 15 = @callorconversionexpr
+| 16 = @starexpr
+| 17 = @keyvalueexpr
+| 18 = @arraytypeexpr
+| 19 = @structtypeexpr
+| 20 = @functypeexpr
+| 21 = @interfacetypeexpr
+| 22 = @maptypeexpr
+| 23 = @plusexpr
+| 24 = @minusexpr
+| 25 = @notexpr
+| 26 = @complementexpr
+| 27 = @derefexpr
+| 28 = @addressexpr
+| 29 = @arrowexpr
+| 30 = @lorexpr
+| 31 = @landexpr
+| 32 = @eqlexpr
+| 33 = @neqexpr
+| 34 = @lssexpr
+| 35 = @leqexpr
+| 36 = @gtrexpr
+| 37 = @geqexpr
+| 38 = @addexpr
+| 39 = @subexpr
+| 40 = @orexpr
+| 41 = @xorexpr
+| 42 = @mulexpr
+| 43 = @quoexpr
+| 44 = @remexpr
+| 45 = @shlexpr
+| 46 = @shrexpr
+| 47 = @andexpr
+| 48 = @andnotexpr
+| 49 = @sendchantypeexpr
+| 50 = @recvchantypeexpr
+| 51 = @sendrcvchantypeexpr;
+
+@basiclit = @intlit | @floatlit | @imaglit | @charlit | @stringlit;
+
+@operatorexpr = @logicalexpr | @arithmeticexpr | @bitwiseexpr | @unaryexpr | @binaryexpr;
+
+@logicalexpr = @logicalunaryexpr | @logicalbinaryexpr;
+
+@arithmeticexpr = @arithmeticunaryexpr | @arithmeticbinaryexpr;
+
+@bitwiseexpr = @bitwiseunaryexpr | @bitwisebinaryexpr;
+
+@unaryexpr = @logicalunaryexpr | @bitwiseunaryexpr | @arithmeticunaryexpr | @derefexpr | @addressexpr | @arrowexpr;
+
+@logicalunaryexpr = @notexpr;
+
+@bitwiseunaryexpr = @complementexpr;
+
+@arithmeticunaryexpr = @plusexpr | @minusexpr;
+
+@binaryexpr = @logicalbinaryexpr | @bitwisebinaryexpr | @arithmeticbinaryexpr | @comparison;
+
+@logicalbinaryexpr = @lorexpr | @landexpr;
+
+@bitwisebinaryexpr = @shiftexpr | @orexpr | @xorexpr | @andexpr | @andnotexpr;
+
+@arithmeticbinaryexpr = @addexpr | @subexpr | @mulexpr | @quoexpr | @remexpr;
+
+@shiftexpr = @shlexpr | @shrexpr;
+
+@comparison = @equalitytest | @relationalcomparison;
+
+@equalitytest = @eqlexpr | @neqexpr;
+
+@relationalcomparison = @lssexpr | @leqexpr | @gtrexpr | @geqexpr;
+
+@chantypeexpr = @sendchantypeexpr | @recvchantypeexpr | @sendrcvchantypeexpr;
+
+case @stmt.kind of
+  0 = @badstmt
+| 1 = @declstmt
+| 2 = @emptystmt
+| 3 = @labeledstmt
+| 4 = @exprstmt
+| 5 = @sendstmt
+| 6 = @incstmt
+| 7 = @decstmt
+| 8 = @gostmt
+| 9 = @deferstmt
+| 10 = @returnstmt
+| 11 = @breakstmt
+| 12 = @continuestmt
+| 13 = @gotostmt
+| 14 = @fallthroughstmt
+| 15 = @blockstmt
+| 16 = @ifstmt
+| 17 = @caseclause
+| 18 = @exprswitchstmt
+| 19 = @typeswitchstmt
+| 20 = @commclause
+| 21 = @selectstmt
+| 22 = @forstmt
+| 23 = @rangestmt
+| 24 = @assignstmt
+| 25 = @definestmt
+| 26 = @addassignstmt
+| 27 = @subassignstmt
+| 28 = @mulassignstmt
+| 29 = @quoassignstmt
+| 30 = @remassignstmt
+| 31 = @andassignstmt
+| 32 = @orassignstmt
+| 33 = @xorassignstmt
+| 34 = @shlassignstmt
+| 35 = @shrassignstmt
+| 36 = @andnotassignstmt;
+
+@incdecstmt = @incstmt | @decstmt;
+
+@assignment = @simpleassignstmt | @compoundassignstmt;
+
+@simpleassignstmt = @assignstmt | @definestmt;
+
+@compoundassignstmt = @addassignstmt | @subassignstmt | @mulassignstmt | @quoassignstmt | @remassignstmt
+                    | @andassignstmt | @orassignstmt | @xorassignstmt | @shlassignstmt | @shrassignstmt | @andnotassignstmt;
+
+@branchstmt = @breakstmt | @continuestmt | @gotostmt | @fallthroughstmt;
+
+@switchstmt = @exprswitchstmt | @typeswitchstmt;
+
+@loopstmt = @forstmt | @rangestmt;
+
+case @decl.kind of
+  0 = @baddecl
+| 1 = @importdecl
+| 2 = @constdecl
+| 3 = @typedecl
+| 4 = @vardecl
+| 5 = @funcdecl;
+
+@gendecl = @importdecl | @constdecl | @typedecl | @vardecl;
+
+case @spec.kind of
+  0 = @importspec
+| 1 = @valuespec
+| 2 = @typespec;
+
+case @object.kind of
+  0 = @pkgobject
+| 1 = @decltypeobject
+| 2 = @builtintypeobject
+| 3 = @declconstobject
+| 4 = @builtinconstobject
+| 5 = @declvarobject
+| 6 = @declfunctionobject
+| 7 = @builtinfunctionobject
+| 8 = @labelobject;
+
+@declobject = @decltypeobject | @declconstobject | @declvarobject | @declfunctionobject;
+
+@builtinobject = @builtintypeobject | @builtinconstobject | @builtinfunctionobject;
+
+@typeobject = @decltypeobject | @builtintypeobject;
+
+@valueobject = @constobject | @varobject | @functionobject;
+
+@constobject = @declconstobject | @builtinconstobject;
+
+@varobject = @declvarobject;
+
+@functionobject = @declfunctionobject | @builtinfunctionobject;
+
+case @scope.kind of
+  0 = @universescope
+| 1 = @packagescope
+| 2 = @localscope;
+
+case @type.kind of
+  0 = @invalidtype
+| 1 = @boolexprtype
+| 2 = @inttype
+| 3 = @int8type
+| 4 = @int16type
+| 5 = @int32type
+| 6 = @int64type
+| 7 = @uinttype
+| 8 = @uint8type
+| 9 = @uint16type
+| 10 = @uint32type
+| 11 = @uint64type
+| 12 = @uintptrtype
+| 13 = @float32type
+| 14 = @float64type
+| 15 = @complex64type
+| 16 = @complex128type
+| 17 = @stringexprtype
+| 18 = @unsafepointertype
+| 19 = @boolliteraltype
+| 20 = @intliteraltype
+| 21 = @runeliteraltype
+| 22 = @floatliteraltype
+| 23 = @complexliteraltype
+| 24 = @stringliteraltype
+| 25 = @nilliteraltype
+| 26 = @arraytype
+| 27 = @slicetype
+| 28 = @structtype
+| 29 = @pointertype
+| 30 = @interfacetype
+| 31 = @tupletype
+| 32 = @signaturetype
+| 33 = @maptype
+| 34 = @sendchantype
+| 35 = @recvchantype
+| 36 = @sendrcvchantype
+| 37 = @namedtype;
+
+@basictype = @booltype | @numerictype | @stringtype | @literaltype | @invalidtype | @uintptrtype | @unsafepointertype;
+
+@booltype = @boolexprtype | @boolliteraltype;
+
+@numerictype = @integertype | @floattype | @complextype;
+
+@integertype = @signedintegertype | @unsignedintegertype;
+
+@signedintegertype = @inttype | @int8type | @int16type | @int32type | @int64type | @intliteraltype | @runeliteraltype;
+
+@unsignedintegertype = @uinttype | @uint8type | @uint16type | @uint32type | @uint64type;
+
+@floattype = @float32type | @float64type | @floatliteraltype;
+
+@complextype = @complex64type | @complex128type | @complexliteraltype;
+
+@stringtype = @stringexprtype | @stringliteraltype;
+
+@literaltype = @boolliteraltype | @intliteraltype | @runeliteraltype | @floatliteraltype | @complexliteraltype
+             | @stringliteraltype | @nilliteraltype;
+
+@compositetype = @containertype | @structtype | @pointertype | @interfacetype | @tupletype | @signaturetype | @namedtype;
+
+@containertype = @arraytype | @slicetype | @maptype | @chantype;
+
+@chantype = @sendchantype | @recvchantype | @sendrcvchantype;
+

upgrades/f1263a745347568af228ad3ddb2decb142c3a1a8/upgrade.properties

@@ -0,0 +1,2 @@
+description: Add database tables for go.mod files
+compatibility: backwards

vendor/golang.org/x/mod/LICENSE

@@ -0,0 +1,27 @@
+Copyright (c) 2009 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

vendor/golang.org/x/mod/PATENTS

@@ -0,0 +1,22 @@
+Additional IP Rights Grant (Patents)
+
+"This implementation" means the copyrightable works distributed by
+Google as part of the Go project.
+
+Google hereby grants to You a perpetual, worldwide, non-exclusive,
+no-charge, royalty-free, irrevocable (except as stated in this section)
+patent license to make, have made, use, offer to sell, sell, import,
+transfer and otherwise run, modify and propagate the contents of this
+implementation of Go, where such license applies only to those patent
+claims, both currently owned or controlled by Google and acquired in
+the future, licensable by Google that are necessarily infringed by this
+implementation of Go.  This grant does not include claims that would be
+infringed only as a consequence of further modification of this
+implementation.  If you or your agent or exclusive licensee institute or
+order or agree to the institution of patent litigation against any
+entity (including a cross-claim or counterclaim in a lawsuit) alleging
+that this implementation of Go or any code incorporated within this
+implementation of Go constitutes direct or contributory patent
+infringement, or inducement of patent infringement, then any patent
+rights granted to you under this License for this implementation of Go
+shall terminate as of the date such litigation is filed.

vendor/golang.org/x/mod/internal/lazyregexp/lazyre.go

@@ -0,0 +1,78 @@
+// 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 lazyregexp is a thin wrapper over regexp, allowing the use of global
+// regexp variables without forcing them to be compiled at init.
+package lazyregexp
+
+import (
+	"os"
+	"regexp"
+	"strings"
+	"sync"
+)
+
+// Regexp is a wrapper around regexp.Regexp, where the underlying regexp will be
+// compiled the first time it is needed.
+type Regexp struct {
+	str  string
+	once sync.Once
+	rx   *regexp.Regexp
+}
+
+func (r *Regexp) re() *regexp.Regexp {
+	r.once.Do(r.build)
+	return r.rx
+}
+
+func (r *Regexp) build() {
+	r.rx = regexp.MustCompile(r.str)
+	r.str = ""
+}
+
+func (r *Regexp) FindSubmatch(s []byte) [][]byte {
+	return r.re().FindSubmatch(s)
+}
+
+func (r *Regexp) FindStringSubmatch(s string) []string {
+	return r.re().FindStringSubmatch(s)
+}
+
+func (r *Regexp) FindStringSubmatchIndex(s string) []int {
+	return r.re().FindStringSubmatchIndex(s)
+}
+
+func (r *Regexp) ReplaceAllString(src, repl string) string {
+	return r.re().ReplaceAllString(src, repl)
+}
+
+func (r *Regexp) FindString(s string) string {
+	return r.re().FindString(s)
+}
+
+func (r *Regexp) FindAllString(s string, n int) []string {
+	return r.re().FindAllString(s, n)
+}
+
+func (r *Regexp) MatchString(s string) bool {
+	return r.re().MatchString(s)
+}
+
+func (r *Regexp) SubexpNames() []string {
+	return r.re().SubexpNames()
+}
+
+var inTest = len(os.Args) > 0 && strings.HasSuffix(strings.TrimSuffix(os.Args[0], ".exe"), ".test")
+
+// New creates a new lazy regexp, delaying the compiling work until it is first
+// needed. If the code is being run as part of tests, the regexp compiling will
+// happen immediately.
+func New(str string) *Regexp {
+	lr := &Regexp{str: str}
+	if inTest {
+		// In tests, always compile the regexps early.
+		lr.re()
+	}
+	return lr
+}

vendor/golang.org/x/mod/modfile/print.go

@@ -0,0 +1,165 @@
+// 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.
+
+// Module file printer.
+
+package modfile
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+)
+
+// Format returns a go.mod file as a byte slice, formatted in standard style.
+func Format(f *FileSyntax) []byte {
+	pr := &printer{}
+	pr.file(f)
+	return pr.Bytes()
+}
+
+// A printer collects the state during printing of a file or expression.
+type printer struct {
+	bytes.Buffer           // output buffer
+	comment      []Comment // pending end-of-line comments
+	margin       int       // left margin (indent), a number of tabs
+}
+
+// printf prints to the buffer.
+func (p *printer) printf(format string, args ...interface{}) {
+	fmt.Fprintf(p, format, args...)
+}
+
+// indent returns the position on the current line, in bytes, 0-indexed.
+func (p *printer) indent() int {
+	b := p.Bytes()
+	n := 0
+	for n < len(b) && b[len(b)-1-n] != '\n' {
+		n++
+	}
+	return n
+}
+
+// newline ends the current line, flushing end-of-line comments.
+func (p *printer) newline() {
+	if len(p.comment) > 0 {
+		p.printf(" ")
+		for i, com := range p.comment {
+			if i > 0 {
+				p.trim()
+				p.printf("\n")
+				for i := 0; i < p.margin; i++ {
+					p.printf("\t")
+				}
+			}
+			p.printf("%s", strings.TrimSpace(com.Token))
+		}
+		p.comment = p.comment[:0]
+	}
+
+	p.trim()
+	p.printf("\n")
+	for i := 0; i < p.margin; i++ {
+		p.printf("\t")
+	}
+}
+
+// trim removes trailing spaces and tabs from the current line.
+func (p *printer) trim() {
+	// Remove trailing spaces and tabs from line we're about to end.
+	b := p.Bytes()
+	n := len(b)
+	for n > 0 && (b[n-1] == '\t' || b[n-1] == ' ') {
+		n--
+	}
+	p.Truncate(n)
+}
+
+// file formats the given file into the print buffer.
+func (p *printer) file(f *FileSyntax) {
+	for _, com := range f.Before {
+		p.printf("%s", strings.TrimSpace(com.Token))
+		p.newline()
+	}
+
+	for i, stmt := range f.Stmt {
+		switch x := stmt.(type) {
+		case *CommentBlock:
+			// comments already handled
+			p.expr(x)
+
+		default:
+			p.expr(x)
+			p.newline()
+		}
+
+		for _, com := range stmt.Comment().After {
+			p.printf("%s", strings.TrimSpace(com.Token))
+			p.newline()
+		}
+
+		if i+1 < len(f.Stmt) {
+			p.newline()
+		}
+	}
+}
+
+func (p *printer) expr(x Expr) {
+	// Emit line-comments preceding this expression.
+	if before := x.Comment().Before; len(before) > 0 {
+		// Want to print a line comment.
+		// Line comments must be at the current margin.
+		p.trim()
+		if p.indent() > 0 {
+			// There's other text on the line. Start a new line.
+			p.printf("\n")
+		}
+		// Re-indent to margin.
+		for i := 0; i < p.margin; i++ {
+			p.printf("\t")
+		}
+		for _, com := range before {
+			p.printf("%s", strings.TrimSpace(com.Token))
+			p.newline()
+		}
+	}
+
+	switch x := x.(type) {
+	default:
+		panic(fmt.Errorf("printer: unexpected type %T", x))
+
+	case *CommentBlock:
+		// done
+
+	case *LParen:
+		p.printf("(")
+	case *RParen:
+		p.printf(")")
+
+	case *Line:
+		sep := ""
+		for _, tok := range x.Token {
+			p.printf("%s%s", sep, tok)
+			sep = " "
+		}
+
+	case *LineBlock:
+		for _, tok := range x.Token {
+			p.printf("%s ", tok)
+		}
+		p.expr(&x.LParen)
+		p.margin++
+		for _, l := range x.Line {
+			p.newline()
+			p.expr(l)
+		}
+		p.margin--
+		p.newline()
+		p.expr(&x.RParen)
+	}
+
+	// Queue end-of-line comments for printing when we
+	// reach the end of the line.
+	p.comment = append(p.comment, x.Comment().Suffix...)
+}

vendor/golang.org/x/mod/modfile/read.go

@@ -0,0 +1,909 @@
+// 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.
+
+// Module file parser.
+// This is a simplified copy of Google's buildifier parser.
+
+package modfile
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+)
+
+// A Position describes an arbitrary source position in a file, including the
+// file, line, column, and byte offset.
+type Position struct {
+	Line     int // line in input (starting at 1)
+	LineRune int // rune in line (starting at 1)
+	Byte     int // byte in input (starting at 0)
+}
+
+// add returns the position at the end of s, assuming it starts at p.
+func (p Position) add(s string) Position {
+	p.Byte += len(s)
+	if n := strings.Count(s, "\n"); n > 0 {
+		p.Line += n
+		s = s[strings.LastIndex(s, "\n")+1:]
+		p.LineRune = 1
+	}
+	p.LineRune += utf8.RuneCountInString(s)
+	return p
+}
+
+// An Expr represents an input element.
+type Expr interface {
+	// Span returns the start and end position of the expression,
+	// excluding leading or trailing comments.
+	Span() (start, end Position)
+
+	// Comment returns the comments attached to the expression.
+	// This method would normally be named 'Comments' but that
+	// would interfere with embedding a type of the same name.
+	Comment() *Comments
+}
+
+// A Comment represents a single // comment.
+type Comment struct {
+	Start  Position
+	Token  string // without trailing newline
+	Suffix bool   // an end of line (not whole line) comment
+}
+
+// Comments collects the comments associated with an expression.
+type Comments struct {
+	Before []Comment // whole-line comments before this expression
+	Suffix []Comment // end-of-line comments after this expression
+
+	// For top-level expressions only, After lists whole-line
+	// comments following the expression.
+	After []Comment
+}
+
+// Comment returns the receiver. This isn't useful by itself, but
+// a Comments struct is embedded into all the expression
+// implementation types, and this gives each of those a Comment
+// method to satisfy the Expr interface.
+func (c *Comments) Comment() *Comments {
+	return c
+}
+
+// A FileSyntax represents an entire go.mod file.
+type FileSyntax struct {
+	Name string // file path
+	Comments
+	Stmt []Expr
+}
+
+func (x *FileSyntax) Span() (start, end Position) {
+	if len(x.Stmt) == 0 {
+		return
+	}
+	start, _ = x.Stmt[0].Span()
+	_, end = x.Stmt[len(x.Stmt)-1].Span()
+	return start, end
+}
+
+// addLine adds a line containing the given tokens to the file.
+//
+// If the first token of the hint matches the first token of the
+// line, the new line is added at the end of the block containing hint,
+// extracting hint into a new block if it is not yet in one.
+//
+// If the hint is non-nil buts its first token does not match,
+// the new line is added after the block containing hint
+// (or hint itself, if not in a block).
+//
+// If no hint is provided, addLine appends the line to the end of
+// the last block with a matching first token,
+// or to the end of the file if no such block exists.
+func (x *FileSyntax) addLine(hint Expr, tokens ...string) *Line {
+	if hint == nil {
+		// If no hint given, add to the last statement of the given type.
+	Loop:
+		for i := len(x.Stmt) - 1; i >= 0; i-- {
+			stmt := x.Stmt[i]
+			switch stmt := stmt.(type) {
+			case *Line:
+				if stmt.Token != nil && stmt.Token[0] == tokens[0] {
+					hint = stmt
+					break Loop
+				}
+			case *LineBlock:
+				if stmt.Token[0] == tokens[0] {
+					hint = stmt
+					break Loop
+				}
+			}
+		}
+	}
+
+	newLineAfter := func(i int) *Line {
+		new := &Line{Token: tokens}
+		if i == len(x.Stmt) {
+			x.Stmt = append(x.Stmt, new)
+		} else {
+			x.Stmt = append(x.Stmt, nil)
+			copy(x.Stmt[i+2:], x.Stmt[i+1:])
+			x.Stmt[i+1] = new
+		}
+		return new
+	}
+
+	if hint != nil {
+		for i, stmt := range x.Stmt {
+			switch stmt := stmt.(type) {
+			case *Line:
+				if stmt == hint {
+					if stmt.Token == nil || stmt.Token[0] != tokens[0] {
+						return newLineAfter(i)
+					}
+
+					// Convert line to line block.
+					stmt.InBlock = true
+					block := &LineBlock{Token: stmt.Token[:1], Line: []*Line{stmt}}
+					stmt.Token = stmt.Token[1:]
+					x.Stmt[i] = block
+					new := &Line{Token: tokens[1:], InBlock: true}
+					block.Line = append(block.Line, new)
+					return new
+				}
+
+			case *LineBlock:
+				if stmt == hint {
+					if stmt.Token[0] != tokens[0] {
+						return newLineAfter(i)
+					}
+
+					new := &Line{Token: tokens[1:], InBlock: true}
+					stmt.Line = append(stmt.Line, new)
+					return new
+				}
+
+				for j, line := range stmt.Line {
+					if line == hint {
+						if stmt.Token[0] != tokens[0] {
+							return newLineAfter(i)
+						}
+
+						// Add new line after hint within the block.
+						stmt.Line = append(stmt.Line, nil)
+						copy(stmt.Line[j+2:], stmt.Line[j+1:])
+						new := &Line{Token: tokens[1:], InBlock: true}
+						stmt.Line[j+1] = new
+						return new
+					}
+				}
+			}
+		}
+	}
+
+	new := &Line{Token: tokens}
+	x.Stmt = append(x.Stmt, new)
+	return new
+}
+
+func (x *FileSyntax) updateLine(line *Line, tokens ...string) {
+	if line.InBlock {
+		tokens = tokens[1:]
+	}
+	line.Token = tokens
+}
+
+func (x *FileSyntax) removeLine(line *Line) {
+	line.Token = nil
+}
+
+// Cleanup cleans up the file syntax x after any edit operations.
+// To avoid quadratic behavior, removeLine marks the line as dead
+// by setting line.Token = nil but does not remove it from the slice
+// in which it appears. After edits have all been indicated,
+// calling Cleanup cleans out the dead lines.
+func (x *FileSyntax) Cleanup() {
+	w := 0
+	for _, stmt := range x.Stmt {
+		switch stmt := stmt.(type) {
+		case *Line:
+			if stmt.Token == nil {
+				continue
+			}
+		case *LineBlock:
+			ww := 0
+			for _, line := range stmt.Line {
+				if line.Token != nil {
+					stmt.Line[ww] = line
+					ww++
+				}
+			}
+			if ww == 0 {
+				continue
+			}
+			if ww == 1 {
+				// Collapse block into single line.
+				line := &Line{
+					Comments: Comments{
+						Before: commentsAdd(stmt.Before, stmt.Line[0].Before),
+						Suffix: commentsAdd(stmt.Line[0].Suffix, stmt.Suffix),
+						After:  commentsAdd(stmt.Line[0].After, stmt.After),
+					},
+					Token: stringsAdd(stmt.Token, stmt.Line[0].Token),
+				}
+				x.Stmt[w] = line
+				w++
+				continue
+			}
+			stmt.Line = stmt.Line[:ww]
+		}
+		x.Stmt[w] = stmt
+		w++
+	}
+	x.Stmt = x.Stmt[:w]
+}
+
+func commentsAdd(x, y []Comment) []Comment {
+	return append(x[:len(x):len(x)], y...)
+}
+
+func stringsAdd(x, y []string) []string {
+	return append(x[:len(x):len(x)], y...)
+}
+
+// A CommentBlock represents a top-level block of comments separate
+// from any rule.
+type CommentBlock struct {
+	Comments
+	Start Position
+}
+
+func (x *CommentBlock) Span() (start, end Position) {
+	return x.Start, x.Start
+}
+
+// A Line is a single line of tokens.
+type Line struct {
+	Comments
+	Start   Position
+	Token   []string
+	InBlock bool
+	End     Position
+}
+
+func (x *Line) Span() (start, end Position) {
+	return x.Start, x.End
+}
+
+// A LineBlock is a factored block of lines, like
+//
+//	require (
+//		"x"
+//		"y"
+//	)
+//
+type LineBlock struct {
+	Comments
+	Start  Position
+	LParen LParen
+	Token  []string
+	Line   []*Line
+	RParen RParen
+}
+
+func (x *LineBlock) Span() (start, end Position) {
+	return x.Start, x.RParen.Pos.add(")")
+}
+
+// An LParen represents the beginning of a parenthesized line block.
+// It is a place to store suffix comments.
+type LParen struct {
+	Comments
+	Pos Position
+}
+
+func (x *LParen) Span() (start, end Position) {
+	return x.Pos, x.Pos.add(")")
+}
+
+// An RParen represents the end of a parenthesized line block.
+// It is a place to store whole-line (before) comments.
+type RParen struct {
+	Comments
+	Pos Position
+}
+
+func (x *RParen) Span() (start, end Position) {
+	return x.Pos, x.Pos.add(")")
+}
+
+// An input represents a single input file being parsed.
+type input struct {
+	// Lexing state.
+	filename  string    // name of input file, for errors
+	complete  []byte    // entire input
+	remaining []byte    // remaining input
+	token     []byte    // token being scanned
+	lastToken string    // most recently returned token, for error messages
+	pos       Position  // current input position
+	comments  []Comment // accumulated comments
+	endRule   int       // position of end of current rule
+
+	// Parser state.
+	file       *FileSyntax // returned top-level syntax tree
+	parseError error       // error encountered during parsing
+
+	// Comment assignment state.
+	pre  []Expr // all expressions, in preorder traversal
+	post []Expr // all expressions, in postorder traversal
+}
+
+func newInput(filename string, data []byte) *input {
+	return &input{
+		filename:  filename,
+		complete:  data,
+		remaining: data,
+		pos:       Position{Line: 1, LineRune: 1, Byte: 0},
+	}
+}
+
+// parse parses the input file.
+func parse(file string, data []byte) (f *FileSyntax, err error) {
+	in := newInput(file, data)
+	// The parser panics for both routine errors like syntax errors
+	// and for programmer bugs like array index errors.
+	// Turn both into error returns. Catching bug panics is
+	// especially important when processing many files.
+	defer func() {
+		if e := recover(); e != nil {
+			if e == in.parseError {
+				err = in.parseError
+			} else {
+				err = fmt.Errorf("%s:%d:%d: internal error: %v", in.filename, in.pos.Line, in.pos.LineRune, e)
+			}
+		}
+	}()
+
+	// Invoke the parser.
+	in.parseFile()
+	if in.parseError != nil {
+		return nil, in.parseError
+	}
+	in.file.Name = in.filename
+
+	// Assign comments to nearby syntax.
+	in.assignComments()
+
+	return in.file, nil
+}
+
+// Error is called to report an error.
+// The reason s is often "syntax error".
+// Error does not return: it panics.
+func (in *input) Error(s string) {
+	if s == "syntax error" && in.lastToken != "" {
+		s += " near " + in.lastToken
+	}
+	in.parseError = fmt.Errorf("%s:%d:%d: %v", in.filename, in.pos.Line, in.pos.LineRune, s)
+	panic(in.parseError)
+}
+
+// eof reports whether the input has reached end of file.
+func (in *input) eof() bool {
+	return len(in.remaining) == 0
+}
+
+// peekRune returns the next rune in the input without consuming it.
+func (in *input) peekRune() int {
+	if len(in.remaining) == 0 {
+		return 0
+	}
+	r, _ := utf8.DecodeRune(in.remaining)
+	return int(r)
+}
+
+// peekPrefix reports whether the remaining input begins with the given prefix.
+func (in *input) peekPrefix(prefix string) bool {
+	// This is like bytes.HasPrefix(in.remaining, []byte(prefix))
+	// but without the allocation of the []byte copy of prefix.
+	for i := 0; i < len(prefix); i++ {
+		if i >= len(in.remaining) || in.remaining[i] != prefix[i] {
+			return false
+		}
+	}
+	return true
+}
+
+// readRune consumes and returns the next rune in the input.
+func (in *input) readRune() int {
+	if len(in.remaining) == 0 {
+		in.Error("internal lexer error: readRune at EOF")
+	}
+	r, size := utf8.DecodeRune(in.remaining)
+	in.remaining = in.remaining[size:]
+	if r == '\n' {
+		in.pos.Line++
+		in.pos.LineRune = 1
+	} else {
+		in.pos.LineRune++
+	}
+	in.pos.Byte += size
+	return int(r)
+}
+
+type symType struct {
+	pos    Position
+	endPos Position
+	text   string
+}
+
+// startToken marks the beginning of the next input token.
+// It must be followed by a call to endToken, once the token has
+// been consumed using readRune.
+func (in *input) startToken(sym *symType) {
+	in.token = in.remaining
+	sym.text = ""
+	sym.pos = in.pos
+}
+
+// endToken marks the end of an input token.
+// It records the actual token string in sym.text if the caller
+// has not done that already.
+func (in *input) endToken(sym *symType) {
+	if sym.text == "" {
+		tok := string(in.token[:len(in.token)-len(in.remaining)])
+		sym.text = tok
+		in.lastToken = sym.text
+	}
+	sym.endPos = in.pos
+}
+
+// lex is called from the parser to obtain the next input token.
+// It returns the token value (either a rune like '+' or a symbolic token _FOR)
+// and sets val to the data associated with the token.
+// For all our input tokens, the associated data is
+// val.Pos (the position where the token begins)
+// and val.Token (the input string corresponding to the token).
+func (in *input) lex(sym *symType) int {
+	// Skip past spaces, stopping at non-space or EOF.
+	countNL := 0 // number of newlines we've skipped past
+	for !in.eof() {
+		// Skip over spaces. Count newlines so we can give the parser
+		// information about where top-level blank lines are,
+		// for top-level comment assignment.
+		c := in.peekRune()
+		if c == ' ' || c == '\t' || c == '\r' {
+			in.readRune()
+			continue
+		}
+
+		// Comment runs to end of line.
+		if in.peekPrefix("//") {
+			in.startToken(sym)
+
+			// Is this comment the only thing on its line?
+			// Find the last \n before this // and see if it's all
+			// spaces from there to here.
+			i := bytes.LastIndex(in.complete[:in.pos.Byte], []byte("\n"))
+			suffix := len(bytes.TrimSpace(in.complete[i+1:in.pos.Byte])) > 0
+			in.readRune()
+			in.readRune()
+
+			// Consume comment.
+			for len(in.remaining) > 0 && in.readRune() != '\n' {
+			}
+			in.endToken(sym)
+
+			sym.text = strings.TrimRight(sym.text, "\n")
+			in.lastToken = "comment"
+
+			// If we are at top level (not in a statement), hand the comment to
+			// the parser as a _COMMENT token. The grammar is written
+			// to handle top-level comments itself.
+			if !suffix {
+				// Not in a statement. Tell parser about top-level comment.
+				return _COMMENT
+			}
+
+			// Otherwise, save comment for later attachment to syntax tree.
+			if countNL > 1 {
+				in.comments = append(in.comments, Comment{sym.pos, "", false})
+			}
+			in.comments = append(in.comments, Comment{sym.pos, sym.text, suffix})
+			countNL = 1
+			return _EOL
+		}
+
+		if in.peekPrefix("/*") {
+			in.Error(fmt.Sprintf("mod files must use // comments (not /* */ comments)"))
+		}
+
+		// Found non-space non-comment.
+		break
+	}
+
+	// Found the beginning of the next token.
+	in.startToken(sym)
+	defer in.endToken(sym)
+
+	// End of file.
+	if in.eof() {
+		in.lastToken = "EOF"
+		return _EOF
+	}
+
+	// Punctuation tokens.
+	switch c := in.peekRune(); c {
+	case '\n':
+		in.readRune()
+		return c
+
+	case '(':
+		in.readRune()
+		return c
+
+	case ')':
+		in.readRune()
+		return c
+
+	case '"', '`': // quoted string
+		quote := c
+		in.readRune()
+		for {
+			if in.eof() {
+				in.pos = sym.pos
+				in.Error("unexpected EOF in string")
+			}
+			if in.peekRune() == '\n' {
+				in.Error("unexpected newline in string")
+			}
+			c := in.readRune()
+			if c == quote {
+				break
+			}
+			if c == '\\' && quote != '`' {
+				if in.eof() {
+					in.pos = sym.pos
+					in.Error("unexpected EOF in string")
+				}
+				in.readRune()
+			}
+		}
+		in.endToken(sym)
+		return _STRING
+	}
+
+	// Checked all punctuation. Must be identifier token.
+	if c := in.peekRune(); !isIdent(c) {
+		in.Error(fmt.Sprintf("unexpected input character %#q", c))
+	}
+
+	// Scan over identifier.
+	for isIdent(in.peekRune()) {
+		if in.peekPrefix("//") {
+			break
+		}
+		if in.peekPrefix("/*") {
+			in.Error(fmt.Sprintf("mod files must use // comments (not /* */ comments)"))
+		}
+		in.readRune()
+	}
+	return _IDENT
+}
+
+// isIdent reports whether c is an identifier rune.
+// We treat nearly all runes as identifier runes.
+func isIdent(c int) bool {
+	return c != 0 && !unicode.IsSpace(rune(c))
+}
+
+// Comment assignment.
+// We build two lists of all subexpressions, preorder and postorder.
+// The preorder list is ordered by start location, with outer expressions first.
+// The postorder list is ordered by end location, with outer expressions last.
+// We use the preorder list to assign each whole-line comment to the syntax
+// immediately following it, and we use the postorder list to assign each
+// end-of-line comment to the syntax immediately preceding it.
+
+// order walks the expression adding it and its subexpressions to the
+// preorder and postorder lists.
+func (in *input) order(x Expr) {
+	if x != nil {
+		in.pre = append(in.pre, x)
+	}
+	switch x := x.(type) {
+	default:
+		panic(fmt.Errorf("order: unexpected type %T", x))
+	case nil:
+		// nothing
+	case *LParen, *RParen:
+		// nothing
+	case *CommentBlock:
+		// nothing
+	case *Line:
+		// nothing
+	case *FileSyntax:
+		for _, stmt := range x.Stmt {
+			in.order(stmt)
+		}
+	case *LineBlock:
+		in.order(&x.LParen)
+		for _, l := range x.Line {
+			in.order(l)
+		}
+		in.order(&x.RParen)
+	}
+	if x != nil {
+		in.post = append(in.post, x)
+	}
+}
+
+// assignComments attaches comments to nearby syntax.
+func (in *input) assignComments() {
+	const debug = false
+
+	// Generate preorder and postorder lists.
+	in.order(in.file)
+
+	// Split into whole-line comments and suffix comments.
+	var line, suffix []Comment
+	for _, com := range in.comments {
+		if com.Suffix {
+			suffix = append(suffix, com)
+		} else {
+			line = append(line, com)
+		}
+	}
+
+	if debug {
+		for _, c := range line {
+			fmt.Fprintf(os.Stderr, "LINE %q :%d:%d #%d\n", c.Token, c.Start.Line, c.Start.LineRune, c.Start.Byte)
+		}
+	}
+
+	// Assign line comments to syntax immediately following.
+	for _, x := range in.pre {
+		start, _ := x.Span()
+		if debug {
+			fmt.Printf("pre %T :%d:%d #%d\n", x, start.Line, start.LineRune, start.Byte)
+		}
+		xcom := x.Comment()
+		for len(line) > 0 && start.Byte >= line[0].Start.Byte {
+			if debug {
+				fmt.Fprintf(os.Stderr, "ASSIGN LINE %q #%d\n", line[0].Token, line[0].Start.Byte)
+			}
+			xcom.Before = append(xcom.Before, line[0])
+			line = line[1:]
+		}
+	}
+
+	// Remaining line comments go at end of file.
+	in.file.After = append(in.file.After, line...)
+
+	if debug {
+		for _, c := range suffix {
+			fmt.Fprintf(os.Stderr, "SUFFIX %q :%d:%d #%d\n", c.Token, c.Start.Line, c.Start.LineRune, c.Start.Byte)
+		}
+	}
+
+	// Assign suffix comments to syntax immediately before.
+	for i := len(in.post) - 1; i >= 0; i-- {
+		x := in.post[i]
+
+		start, end := x.Span()
+		if debug {
+			fmt.Printf("post %T :%d:%d #%d :%d:%d #%d\n", x, start.Line, start.LineRune, start.Byte, end.Line, end.LineRune, end.Byte)
+		}
+
+		// Do not assign suffix comments to end of line block or whole file.
+		// Instead assign them to the last element inside.
+		switch x.(type) {
+		case *FileSyntax:
+			continue
+		}
+
+		// Do not assign suffix comments to something that starts
+		// on an earlier line, so that in
+		//
+		//	x ( y
+		//		z ) // comment
+		//
+		// we assign the comment to z and not to x ( ... ).
+		if start.Line != end.Line {
+			continue
+		}
+		xcom := x.Comment()
+		for len(suffix) > 0 && end.Byte <= suffix[len(suffix)-1].Start.Byte {
+			if debug {
+				fmt.Fprintf(os.Stderr, "ASSIGN SUFFIX %q #%d\n", suffix[len(suffix)-1].Token, suffix[len(suffix)-1].Start.Byte)
+			}
+			xcom.Suffix = append(xcom.Suffix, suffix[len(suffix)-1])
+			suffix = suffix[:len(suffix)-1]
+		}
+	}
+
+	// We assigned suffix comments in reverse.
+	// If multiple suffix comments were appended to the same
+	// expression node, they are now in reverse. Fix that.
+	for _, x := range in.post {
+		reverseComments(x.Comment().Suffix)
+	}
+
+	// Remaining suffix comments go at beginning of file.
+	in.file.Before = append(in.file.Before, suffix...)
+}
+
+// reverseComments reverses the []Comment list.
+func reverseComments(list []Comment) {
+	for i, j := 0, len(list)-1; i < j; i, j = i+1, j-1 {
+		list[i], list[j] = list[j], list[i]
+	}
+}
+
+func (in *input) parseFile() {
+	in.file = new(FileSyntax)
+	var sym symType
+	var cb *CommentBlock
+	for {
+		tok := in.lex(&sym)
+		switch tok {
+		case '\n':
+			if cb != nil {
+				in.file.Stmt = append(in.file.Stmt, cb)
+				cb = nil
+			}
+		case _COMMENT:
+			if cb == nil {
+				cb = &CommentBlock{Start: sym.pos}
+			}
+			com := cb.Comment()
+			com.Before = append(com.Before, Comment{Start: sym.pos, Token: sym.text})
+		case _EOF:
+			if cb != nil {
+				in.file.Stmt = append(in.file.Stmt, cb)
+			}
+			return
+		default:
+			in.parseStmt(&sym)
+			if cb != nil {
+				in.file.Stmt[len(in.file.Stmt)-1].Comment().Before = cb.Before
+				cb = nil
+			}
+		}
+	}
+}
+
+func (in *input) parseStmt(sym *symType) {
+	start := sym.pos
+	end := sym.endPos
+	token := []string{sym.text}
+	for {
+		tok := in.lex(sym)
+		switch tok {
+		case '\n', _EOF, _EOL:
+			in.file.Stmt = append(in.file.Stmt, &Line{
+				Start: start,
+				Token: token,
+				End:   end,
+			})
+			return
+		case '(':
+			in.file.Stmt = append(in.file.Stmt, in.parseLineBlock(start, token, sym))
+			return
+		default:
+			token = append(token, sym.text)
+			end = sym.endPos
+		}
+	}
+}
+
+func (in *input) parseLineBlock(start Position, token []string, sym *symType) *LineBlock {
+	x := &LineBlock{
+		Start:  start,
+		Token:  token,
+		LParen: LParen{Pos: sym.pos},
+	}
+	var comments []Comment
+	for {
+		tok := in.lex(sym)
+		switch tok {
+		case _EOL:
+			// ignore
+		case '\n':
+			if len(comments) == 0 && len(x.Line) > 0 || len(comments) > 0 && comments[len(comments)-1].Token != "" {
+				comments = append(comments, Comment{})
+			}
+		case _COMMENT:
+			comments = append(comments, Comment{Start: sym.pos, Token: sym.text})
+		case _EOF:
+			in.Error(fmt.Sprintf("syntax error (unterminated block started at %s:%d:%d)", in.filename, x.Start.Line, x.Start.LineRune))
+		case ')':
+			x.RParen.Before = comments
+			x.RParen.Pos = sym.pos
+			tok = in.lex(sym)
+			if tok != '\n' && tok != _EOF && tok != _EOL {
+				in.Error("syntax error (expected newline after closing paren)")
+			}
+			return x
+		default:
+			l := in.parseLine(sym)
+			x.Line = append(x.Line, l)
+			l.Comment().Before = comments
+			comments = nil
+		}
+	}
+}
+
+func (in *input) parseLine(sym *symType) *Line {
+	start := sym.pos
+	end := sym.endPos
+	token := []string{sym.text}
+	for {
+		tok := in.lex(sym)
+		switch tok {
+		case '\n', _EOF, _EOL:
+			return &Line{
+				Start:   start,
+				Token:   token,
+				End:     end,
+				InBlock: true,
+			}
+		default:
+			token = append(token, sym.text)
+			end = sym.endPos
+		}
+	}
+}
+
+const (
+	_EOF = -(1 + iota)
+	_EOL
+	_IDENT
+	_STRING
+	_COMMENT
+)
+
+var (
+	slashSlash = []byte("//")
+	moduleStr  = []byte("module")
+)
+
+// ModulePath returns the module path from the gomod file text.
+// If it cannot find a module path, it returns an empty string.
+// It is tolerant of unrelated problems in the go.mod file.
+func ModulePath(mod []byte) string {
+	for len(mod) > 0 {
+		line := mod
+		mod = nil
+		if i := bytes.IndexByte(line, '\n'); i >= 0 {
+			line, mod = line[:i], line[i+1:]
+		}
+		if i := bytes.Index(line, slashSlash); i >= 0 {
+			line = line[:i]
+		}
+		line = bytes.TrimSpace(line)
+		if !bytes.HasPrefix(line, moduleStr) {
+			continue
+		}
+		line = line[len(moduleStr):]
+		n := len(line)
+		line = bytes.TrimSpace(line)
+		if len(line) == n || len(line) == 0 {
+			continue
+		}
+
+		if line[0] == '"' || line[0] == '`' {
+			p, err := strconv.Unquote(string(line))
+			if err != nil {
+				return "" // malformed quoted string or multiline module path
+			}
+			return p
+		}
+
+		return string(line)
+	}
+	return "" // missing module path
+}

vendor/golang.org/x/mod/modfile/rule.go

@@ -0,0 +1,776 @@
+// 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 modfile
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"strings"
+	"unicode"
+
+	"golang.org/x/mod/internal/lazyregexp"
+	"golang.org/x/mod/module"
+)
+
+// A File is the parsed, interpreted form of a go.mod file.
+type File struct {
+	Module  *Module
+	Go      *Go
+	Require []*Require
+	Exclude []*Exclude
+	Replace []*Replace
+
+	Syntax *FileSyntax
+}
+
+// A Module is the module statement.
+type Module struct {
+	Mod    module.Version
+	Syntax *Line
+}
+
+// A Go is the go statement.
+type Go struct {
+	Version string // "1.23"
+	Syntax  *Line
+}
+
+// A Require is a single require statement.
+type Require struct {
+	Mod      module.Version
+	Indirect bool // has "// indirect" comment
+	Syntax   *Line
+}
+
+// An Exclude is a single exclude statement.
+type Exclude struct {
+	Mod    module.Version
+	Syntax *Line
+}
+
+// A Replace is a single replace statement.
+type Replace struct {
+	Old    module.Version
+	New    module.Version
+	Syntax *Line
+}
+
+func (f *File) AddModuleStmt(path string) error {
+	if f.Syntax == nil {
+		f.Syntax = new(FileSyntax)
+	}
+	if f.Module == nil {
+		f.Module = &Module{
+			Mod:    module.Version{Path: path},
+			Syntax: f.Syntax.addLine(nil, "module", AutoQuote(path)),
+		}
+	} else {
+		f.Module.Mod.Path = path
+		f.Syntax.updateLine(f.Module.Syntax, "module", AutoQuote(path))
+	}
+	return nil
+}
+
+func (f *File) AddComment(text string) {
+	if f.Syntax == nil {
+		f.Syntax = new(FileSyntax)
+	}
+	f.Syntax.Stmt = append(f.Syntax.Stmt, &CommentBlock{
+		Comments: Comments{
+			Before: []Comment{
+				{
+					Token: text,
+				},
+			},
+		},
+	})
+}
+
+type VersionFixer func(path, version string) (string, error)
+
+// Parse parses the data, reported in errors as being from file,
+// into a File struct. It applies fix, if non-nil, to canonicalize all module versions found.
+func Parse(file string, data []byte, fix VersionFixer) (*File, error) {
+	return parseToFile(file, data, fix, true)
+}
+
+// ParseLax is like Parse but ignores unknown statements.
+// It is used when parsing go.mod files other than the main module,
+// under the theory that most statement types we add in the future will
+// only apply in the main module, like exclude and replace,
+// and so we get better gradual deployments if old go commands
+// simply ignore those statements when found in go.mod files
+// in dependencies.
+func ParseLax(file string, data []byte, fix VersionFixer) (*File, error) {
+	return parseToFile(file, data, fix, false)
+}
+
+func parseToFile(file string, data []byte, fix VersionFixer, strict bool) (*File, error) {
+	fs, err := parse(file, data)
+	if err != nil {
+		return nil, err
+	}
+	f := &File{
+		Syntax: fs,
+	}
+
+	var errs bytes.Buffer
+	for _, x := range fs.Stmt {
+		switch x := x.(type) {
+		case *Line:
+			f.add(&errs, x, x.Token[0], x.Token[1:], fix, strict)
+
+		case *LineBlock:
+			if len(x.Token) > 1 {
+				if strict {
+					fmt.Fprintf(&errs, "%s:%d: unknown block type: %s\n", file, x.Start.Line, strings.Join(x.Token, " "))
+				}
+				continue
+			}
+			switch x.Token[0] {
+			default:
+				if strict {
+					fmt.Fprintf(&errs, "%s:%d: unknown block type: %s\n", file, x.Start.Line, strings.Join(x.Token, " "))
+				}
+				continue
+			case "module", "require", "exclude", "replace":
+				for _, l := range x.Line {
+					f.add(&errs, l, x.Token[0], l.Token, fix, strict)
+				}
+			}
+		}
+	}
+
+	if errs.Len() > 0 {
+		return nil, errors.New(strings.TrimRight(errs.String(), "\n"))
+	}
+	return f, nil
+}
+
+var GoVersionRE = lazyregexp.New(`^([1-9][0-9]*)\.(0|[1-9][0-9]*)$`)
+
+func (f *File) add(errs *bytes.Buffer, line *Line, verb string, args []string, fix VersionFixer, strict bool) {
+	// If strict is false, this module is a dependency.
+	// We ignore all unknown directives as well as main-module-only
+	// directives like replace and exclude. It will work better for
+	// forward compatibility if we can depend on modules that have unknown
+	// statements (presumed relevant only when acting as the main module)
+	// and simply ignore those statements.
+	if !strict {
+		switch verb {
+		case "module", "require", "go":
+			// want these even for dependency go.mods
+		default:
+			return
+		}
+	}
+
+	switch verb {
+	default:
+		fmt.Fprintf(errs, "%s:%d: unknown directive: %s\n", f.Syntax.Name, line.Start.Line, verb)
+
+	case "go":
+		if f.Go != nil {
+			fmt.Fprintf(errs, "%s:%d: repeated go statement\n", f.Syntax.Name, line.Start.Line)
+			return
+		}
+		if len(args) != 1 || !GoVersionRE.MatchString(args[0]) {
+			fmt.Fprintf(errs, "%s:%d: usage: go 1.23\n", f.Syntax.Name, line.Start.Line)
+			return
+		}
+		f.Go = &Go{Syntax: line}
+		f.Go.Version = args[0]
+	case "module":
+		if f.Module != nil {
+			fmt.Fprintf(errs, "%s:%d: repeated module statement\n", f.Syntax.Name, line.Start.Line)
+			return
+		}
+		f.Module = &Module{Syntax: line}
+		if len(args) != 1 {
+
+			fmt.Fprintf(errs, "%s:%d: usage: module module/path\n", f.Syntax.Name, line.Start.Line)
+			return
+		}
+		s, err := parseString(&args[0])
+		if err != nil {
+			fmt.Fprintf(errs, "%s:%d: invalid quoted string: %v\n", f.Syntax.Name, line.Start.Line, err)
+			return
+		}
+		f.Module.Mod = module.Version{Path: s}
+	case "require", "exclude":
+		if len(args) != 2 {
+			fmt.Fprintf(errs, "%s:%d: usage: %s module/path v1.2.3\n", f.Syntax.Name, line.Start.Line, verb)
+			return
+		}
+		s, err := parseString(&args[0])
+		if err != nil {
+			fmt.Fprintf(errs, "%s:%d: invalid quoted string: %v\n", f.Syntax.Name, line.Start.Line, err)
+			return
+		}
+		v, err := parseVersion(verb, s, &args[1], fix)
+		if err != nil {
+			fmt.Fprintf(errs, "%s:%d: %v\n", f.Syntax.Name, line.Start.Line, err)
+			return
+		}
+		pathMajor, err := modulePathMajor(s)
+		if err != nil {
+			fmt.Fprintf(errs, "%s:%d: %v\n", f.Syntax.Name, line.Start.Line, err)
+			return
+		}
+		if err := module.CheckPathMajor(v, pathMajor); err != nil {
+			fmt.Fprintf(errs, "%s:%d: %v\n", f.Syntax.Name, line.Start.Line, &Error{Verb: verb, ModPath: s, Err: err})
+			return
+		}
+		if verb == "require" {
+			f.Require = append(f.Require, &Require{
+				Mod:      module.Version{Path: s, Version: v},
+				Syntax:   line,
+				Indirect: isIndirect(line),
+			})
+		} else {
+			f.Exclude = append(f.Exclude, &Exclude{
+				Mod:    module.Version{Path: s, Version: v},
+				Syntax: line,
+			})
+		}
+	case "replace":
+		arrow := 2
+		if len(args) >= 2 && args[1] == "=>" {
+			arrow = 1
+		}
+		if len(args) < arrow+2 || len(args) > arrow+3 || args[arrow] != "=>" {
+			fmt.Fprintf(errs, "%s:%d: usage: %s module/path [v1.2.3] => other/module v1.4\n\t or %s module/path [v1.2.3] => ../local/directory\n", f.Syntax.Name, line.Start.Line, verb, verb)
+			return
+		}
+		s, err := parseString(&args[0])
+		if err != nil {
+			fmt.Fprintf(errs, "%s:%d: invalid quoted string: %v\n", f.Syntax.Name, line.Start.Line, err)
+			return
+		}
+		pathMajor, err := modulePathMajor(s)
+		if err != nil {
+			fmt.Fprintf(errs, "%s:%d: %v\n", f.Syntax.Name, line.Start.Line, err)
+			return
+		}
+		var v string
+		if arrow == 2 {
+			v, err = parseVersion(verb, s, &args[1], fix)
+			if err != nil {
+				fmt.Fprintf(errs, "%s:%d: %v\n", f.Syntax.Name, line.Start.Line, err)
+				return
+			}
+			if err := module.CheckPathMajor(v, pathMajor); err != nil {
+				fmt.Fprintf(errs, "%s:%d: %v\n", f.Syntax.Name, line.Start.Line, &Error{Verb: verb, ModPath: s, Err: err})
+				return
+			}
+		}
+		ns, err := parseString(&args[arrow+1])
+		if err != nil {
+			fmt.Fprintf(errs, "%s:%d: invalid quoted string: %v\n", f.Syntax.Name, line.Start.Line, err)
+			return
+		}
+		nv := ""
+		if len(args) == arrow+2 {
+			if !IsDirectoryPath(ns) {
+				fmt.Fprintf(errs, "%s:%d: replacement module without version must be directory path (rooted or starting with ./ or ../)\n", f.Syntax.Name, line.Start.Line)
+				return
+			}
+			if filepath.Separator == '/' && strings.Contains(ns, `\`) {
+				fmt.Fprintf(errs, "%s:%d: replacement directory appears to be Windows path (on a non-windows system)\n", f.Syntax.Name, line.Start.Line)
+				return
+			}
+		}
+		if len(args) == arrow+3 {
+			nv, err = parseVersion(verb, ns, &args[arrow+2], fix)
+			if err != nil {
+				fmt.Fprintf(errs, "%s:%d: %v\n", f.Syntax.Name, line.Start.Line, err)
+				return
+			}
+			if IsDirectoryPath(ns) {
+				fmt.Fprintf(errs, "%s:%d: replacement module directory path %q cannot have version\n", f.Syntax.Name, line.Start.Line, ns)
+				return
+			}
+		}
+		f.Replace = append(f.Replace, &Replace{
+			Old:    module.Version{Path: s, Version: v},
+			New:    module.Version{Path: ns, Version: nv},
+			Syntax: line,
+		})
+	}
+}
+
+// isIndirect reports whether line has a "// indirect" comment,
+// meaning it is in go.mod only for its effect on indirect dependencies,
+// so that it can be dropped entirely once the effective version of the
+// indirect dependency reaches the given minimum version.
+func isIndirect(line *Line) bool {
+	if len(line.Suffix) == 0 {
+		return false
+	}
+	f := strings.Fields(strings.TrimPrefix(line.Suffix[0].Token, string(slashSlash)))
+	return (len(f) == 1 && f[0] == "indirect" || len(f) > 1 && f[0] == "indirect;")
+}
+
+// setIndirect sets line to have (or not have) a "// indirect" comment.
+func setIndirect(line *Line, indirect bool) {
+	if isIndirect(line) == indirect {
+		return
+	}
+	if indirect {
+		// Adding comment.
+		if len(line.Suffix) == 0 {
+			// New comment.
+			line.Suffix = []Comment{{Token: "// indirect", Suffix: true}}
+			return
+		}
+
+		com := &line.Suffix[0]
+		text := strings.TrimSpace(strings.TrimPrefix(com.Token, string(slashSlash)))
+		if text == "" {
+			// Empty comment.
+			com.Token = "// indirect"
+			return
+		}
+
+		// Insert at beginning of existing comment.
+		com.Token = "// indirect; " + text
+		return
+	}
+
+	// Removing comment.
+	f := strings.Fields(line.Suffix[0].Token)
+	if len(f) == 2 {
+		// Remove whole comment.
+		line.Suffix = nil
+		return
+	}
+
+	// Remove comment prefix.
+	com := &line.Suffix[0]
+	i := strings.Index(com.Token, "indirect;")
+	com.Token = "//" + com.Token[i+len("indirect;"):]
+}
+
+// IsDirectoryPath reports whether the given path should be interpreted
+// as a directory path. Just like on the go command line, relative paths
+// and rooted paths are directory paths; the rest are module paths.
+func IsDirectoryPath(ns string) bool {
+	// Because go.mod files can move from one system to another,
+	// we check all known path syntaxes, both Unix and Windows.
+	return strings.HasPrefix(ns, "./") || strings.HasPrefix(ns, "../") || strings.HasPrefix(ns, "/") ||
+		strings.HasPrefix(ns, `.\`) || strings.HasPrefix(ns, `..\`) || strings.HasPrefix(ns, `\`) ||
+		len(ns) >= 2 && ('A' <= ns[0] && ns[0] <= 'Z' || 'a' <= ns[0] && ns[0] <= 'z') && ns[1] == ':'
+}
+
+// MustQuote reports whether s must be quoted in order to appear as
+// a single token in a go.mod line.
+func MustQuote(s string) bool {
+	for _, r := range s {
+		if !unicode.IsPrint(r) || r == ' ' || r == '"' || r == '\'' || r == '`' {
+			return true
+		}
+	}
+	return s == "" || strings.Contains(s, "//") || strings.Contains(s, "/*")
+}
+
+// AutoQuote returns s or, if quoting is required for s to appear in a go.mod,
+// the quotation of s.
+func AutoQuote(s string) string {
+	if MustQuote(s) {
+		return strconv.Quote(s)
+	}
+	return s
+}
+
+func parseString(s *string) (string, error) {
+	t := *s
+	if strings.HasPrefix(t, `"`) {
+		var err error
+		if t, err = strconv.Unquote(t); err != nil {
+			return "", err
+		}
+	} else if strings.ContainsAny(t, "\"'`") {
+		// Other quotes are reserved both for possible future expansion
+		// and to avoid confusion. For example if someone types 'x'
+		// we want that to be a syntax error and not a literal x in literal quotation marks.
+		return "", fmt.Errorf("unquoted string cannot contain quote")
+	}
+	*s = AutoQuote(t)
+	return t, nil
+}
+
+type Error struct {
+	Verb    string
+	ModPath string
+	Err     error
+}
+
+func (e *Error) Error() string {
+	return fmt.Sprintf("%s %s: %v", e.Verb, e.ModPath, e.Err)
+}
+
+func (e *Error) Unwrap() error { return e.Err }
+
+func parseVersion(verb string, path string, s *string, fix VersionFixer) (string, error) {
+	t, err := parseString(s)
+	if err != nil {
+		return "", &Error{
+			Verb:    verb,
+			ModPath: path,
+			Err: &module.InvalidVersionError{
+				Version: *s,
+				Err:     err,
+			},
+		}
+	}
+	if fix != nil {
+		var err error
+		t, err = fix(path, t)
+		if err != nil {
+			if err, ok := err.(*module.ModuleError); ok {
+				return "", &Error{
+					Verb:    verb,
+					ModPath: path,
+					Err:     err.Err,
+				}
+			}
+			return "", err
+		}
+	}
+	if v := module.CanonicalVersion(t); v != "" {
+		*s = v
+		return *s, nil
+	}
+	return "", &Error{
+		Verb:    verb,
+		ModPath: path,
+		Err: &module.InvalidVersionError{
+			Version: t,
+			Err:     errors.New("must be of the form v1.2.3"),
+		},
+	}
+}
+
+func modulePathMajor(path string) (string, error) {
+	_, major, ok := module.SplitPathVersion(path)
+	if !ok {
+		return "", fmt.Errorf("invalid module path")
+	}
+	return major, nil
+}
+
+func (f *File) Format() ([]byte, error) {
+	return Format(f.Syntax), nil
+}
+
+// Cleanup cleans up the file f after any edit operations.
+// To avoid quadratic behavior, modifications like DropRequire
+// clear the entry but do not remove it from the slice.
+// Cleanup cleans out all the cleared entries.
+func (f *File) Cleanup() {
+	w := 0
+	for _, r := range f.Require {
+		if r.Mod.Path != "" {
+			f.Require[w] = r
+			w++
+		}
+	}
+	f.Require = f.Require[:w]
+
+	w = 0
+	for _, x := range f.Exclude {
+		if x.Mod.Path != "" {
+			f.Exclude[w] = x
+			w++
+		}
+	}
+	f.Exclude = f.Exclude[:w]
+
+	w = 0
+	for _, r := range f.Replace {
+		if r.Old.Path != "" {
+			f.Replace[w] = r
+			w++
+		}
+	}
+	f.Replace = f.Replace[:w]
+
+	f.Syntax.Cleanup()
+}
+
+func (f *File) AddGoStmt(version string) error {
+	if !GoVersionRE.MatchString(version) {
+		return fmt.Errorf("invalid language version string %q", version)
+	}
+	if f.Go == nil {
+		var hint Expr
+		if f.Module != nil && f.Module.Syntax != nil {
+			hint = f.Module.Syntax
+		}
+		f.Go = &Go{
+			Version: version,
+			Syntax:  f.Syntax.addLine(hint, "go", version),
+		}
+	} else {
+		f.Go.Version = version
+		f.Syntax.updateLine(f.Go.Syntax, "go", version)
+	}
+	return nil
+}
+
+func (f *File) AddRequire(path, vers string) error {
+	need := true
+	for _, r := range f.Require {
+		if r.Mod.Path == path {
+			if need {
+				r.Mod.Version = vers
+				f.Syntax.updateLine(r.Syntax, "require", AutoQuote(path), vers)
+				need = false
+			} else {
+				f.Syntax.removeLine(r.Syntax)
+				*r = Require{}
+			}
+		}
+	}
+
+	if need {
+		f.AddNewRequire(path, vers, false)
+	}
+	return nil
+}
+
+func (f *File) AddNewRequire(path, vers string, indirect bool) {
+	line := f.Syntax.addLine(nil, "require", AutoQuote(path), vers)
+	setIndirect(line, indirect)
+	f.Require = append(f.Require, &Require{module.Version{Path: path, Version: vers}, indirect, line})
+}
+
+func (f *File) SetRequire(req []*Require) {
+	need := make(map[string]string)
+	indirect := make(map[string]bool)
+	for _, r := range req {
+		need[r.Mod.Path] = r.Mod.Version
+		indirect[r.Mod.Path] = r.Indirect
+	}
+
+	for _, r := range f.Require {
+		if v, ok := need[r.Mod.Path]; ok {
+			r.Mod.Version = v
+			r.Indirect = indirect[r.Mod.Path]
+		} else {
+			*r = Require{}
+		}
+	}
+
+	var newStmts []Expr
+	for _, stmt := range f.Syntax.Stmt {
+		switch stmt := stmt.(type) {
+		case *LineBlock:
+			if len(stmt.Token) > 0 && stmt.Token[0] == "require" {
+				var newLines []*Line
+				for _, line := range stmt.Line {
+					if p, err := parseString(&line.Token[0]); err == nil && need[p] != "" {
+						if len(line.Comments.Before) == 1 && len(line.Comments.Before[0].Token) == 0 {
+							line.Comments.Before = line.Comments.Before[:0]
+						}
+						line.Token[1] = need[p]
+						delete(need, p)
+						setIndirect(line, indirect[p])
+						newLines = append(newLines, line)
+					}
+				}
+				if len(newLines) == 0 {
+					continue // drop stmt
+				}
+				stmt.Line = newLines
+			}
+
+		case *Line:
+			if len(stmt.Token) > 0 && stmt.Token[0] == "require" {
+				if p, err := parseString(&stmt.Token[1]); err == nil && need[p] != "" {
+					stmt.Token[2] = need[p]
+					delete(need, p)
+					setIndirect(stmt, indirect[p])
+				} else {
+					continue // drop stmt
+				}
+			}
+		}
+		newStmts = append(newStmts, stmt)
+	}
+	f.Syntax.Stmt = newStmts
+
+	for path, vers := range need {
+		f.AddNewRequire(path, vers, indirect[path])
+	}
+	f.SortBlocks()
+}
+
+func (f *File) DropRequire(path string) error {
+	for _, r := range f.Require {
+		if r.Mod.Path == path {
+			f.Syntax.removeLine(r.Syntax)
+			*r = Require{}
+		}
+	}
+	return nil
+}
+
+func (f *File) AddExclude(path, vers string) error {
+	var hint *Line
+	for _, x := range f.Exclude {
+		if x.Mod.Path == path && x.Mod.Version == vers {
+			return nil
+		}
+		if x.Mod.Path == path {
+			hint = x.Syntax
+		}
+	}
+
+	f.Exclude = append(f.Exclude, &Exclude{Mod: module.Version{Path: path, Version: vers}, Syntax: f.Syntax.addLine(hint, "exclude", AutoQuote(path), vers)})
+	return nil
+}
+
+func (f *File) DropExclude(path, vers string) error {
+	for _, x := range f.Exclude {
+		if x.Mod.Path == path && x.Mod.Version == vers {
+			f.Syntax.removeLine(x.Syntax)
+			*x = Exclude{}
+		}
+	}
+	return nil
+}
+
+func (f *File) AddReplace(oldPath, oldVers, newPath, newVers string) error {
+	need := true
+	old := module.Version{Path: oldPath, Version: oldVers}
+	new := module.Version{Path: newPath, Version: newVers}
+	tokens := []string{"replace", AutoQuote(oldPath)}
+	if oldVers != "" {
+		tokens = append(tokens, oldVers)
+	}
+	tokens = append(tokens, "=>", AutoQuote(newPath))
+	if newVers != "" {
+		tokens = append(tokens, newVers)
+	}
+
+	var hint *Line
+	for _, r := range f.Replace {
+		if r.Old.Path == oldPath && (oldVers == "" || r.Old.Version == oldVers) {
+			if need {
+				// Found replacement for old; update to use new.
+				r.New = new
+				f.Syntax.updateLine(r.Syntax, tokens...)
+				need = false
+				continue
+			}
+			// Already added; delete other replacements for same.
+			f.Syntax.removeLine(r.Syntax)
+			*r = Replace{}
+		}
+		if r.Old.Path == oldPath {
+			hint = r.Syntax
+		}
+	}
+	if need {
+		f.Replace = append(f.Replace, &Replace{Old: old, New: new, Syntax: f.Syntax.addLine(hint, tokens...)})
+	}
+	return nil
+}
+
+func (f *File) DropReplace(oldPath, oldVers string) error {
+	for _, r := range f.Replace {
+		if r.Old.Path == oldPath && r.Old.Version == oldVers {
+			f.Syntax.removeLine(r.Syntax)
+			*r = Replace{}
+		}
+	}
+	return nil
+}
+
+func (f *File) SortBlocks() {
+	f.removeDups() // otherwise sorting is unsafe
+
+	for _, stmt := range f.Syntax.Stmt {
+		block, ok := stmt.(*LineBlock)
+		if !ok {
+			continue
+		}
+		sort.Slice(block.Line, func(i, j int) bool {
+			li := block.Line[i]
+			lj := block.Line[j]
+			for k := 0; k < len(li.Token) && k < len(lj.Token); k++ {
+				if li.Token[k] != lj.Token[k] {
+					return li.Token[k] < lj.Token[k]
+				}
+			}
+			return len(li.Token) < len(lj.Token)
+		})
+	}
+}
+
+func (f *File) removeDups() {
+	have := make(map[module.Version]bool)
+	kill := make(map[*Line]bool)
+	for _, x := range f.Exclude {
+		if have[x.Mod] {
+			kill[x.Syntax] = true
+			continue
+		}
+		have[x.Mod] = true
+	}
+	var excl []*Exclude
+	for _, x := range f.Exclude {
+		if !kill[x.Syntax] {
+			excl = append(excl, x)
+		}
+	}
+	f.Exclude = excl
+
+	have = make(map[module.Version]bool)
+	// Later replacements take priority over earlier ones.
+	for i := len(f.Replace) - 1; i >= 0; i-- {
+		x := f.Replace[i]
+		if have[x.Old] {
+			kill[x.Syntax] = true
+			continue
+		}
+		have[x.Old] = true
+	}
+	var repl []*Replace
+	for _, x := range f.Replace {
+		if !kill[x.Syntax] {
+			repl = append(repl, x)
+		}
+	}
+	f.Replace = repl
+
+	var stmts []Expr
+	for _, stmt := range f.Syntax.Stmt {
+		switch stmt := stmt.(type) {
+		case *Line:
+			if kill[stmt] {
+				continue
+			}
+		case *LineBlock:
+			var lines []*Line
+			for _, line := range stmt.Line {
+				if !kill[line] {
+					lines = append(lines, line)
+				}
+			}
+			stmt.Line = lines
+			if len(lines) == 0 {
+				continue
+			}
+		}
+		stmts = append(stmts, stmt)
+	}
+	f.Syntax.Stmt = stmts
+}

vendor/golang.org/x/mod/module/module.go

@@ -0,0 +1,718 @@
+// 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 module defines the module.Version type along with support code.
+//
+// The module.Version type is a simple Path, Version pair:
+//
+//	type Version struct {
+//		Path string
+//		Version string
+//	}
+//
+// There are no restrictions imposed directly by use of this structure,
+// but additional checking functions, most notably Check, verify that
+// a particular path, version pair is valid.
+//
+// Escaped Paths
+//
+// Module paths appear as substrings of file system paths
+// (in the download cache) and of web server URLs in the proxy protocol.
+// In general we cannot rely on file systems to be case-sensitive,
+// nor can we rely on web servers, since they read from file systems.
+// That is, we cannot rely on the file system to keep rsc.io/QUOTE
+// and rsc.io/quote separate. Windows and macOS don't.
+// Instead, we must never require two different casings of a file path.
+// Because we want the download cache to match the proxy protocol,
+// and because we want the proxy protocol to be possible to serve
+// from a tree of static files (which might be stored on a case-insensitive
+// file system), the proxy protocol must never require two different casings
+// of a URL path either.
+//
+// One possibility would be to make the escaped form be the lowercase
+// hexadecimal encoding of the actual path bytes. This would avoid ever
+// needing different casings of a file path, but it would be fairly illegible
+// to most programmers when those paths appeared in the file system
+// (including in file paths in compiler errors and stack traces)
+// in web server logs, and so on. Instead, we want a safe escaped form that
+// leaves most paths unaltered.
+//
+// The safe escaped form is to replace every uppercase letter
+// with an exclamation mark followed by the letter's lowercase equivalent.
+//
+// For example,
+//
+//	github.com/Azure/azure-sdk-for-go ->  github.com/!azure/azure-sdk-for-go.
+//	github.com/GoogleCloudPlatform/cloudsql-proxy -> github.com/!google!cloud!platform/cloudsql-proxy
+//	github.com/Sirupsen/logrus -> github.com/!sirupsen/logrus.
+//
+// Import paths that avoid upper-case letters are left unchanged.
+// Note that because import paths are ASCII-only and avoid various
+// problematic punctuation (like : < and >), the escaped form is also ASCII-only
+// and avoids the same problematic punctuation.
+//
+// Import paths have never allowed exclamation marks, so there is no
+// need to define how to escape a literal !.
+//
+// Unicode Restrictions
+//
+// Today, paths are disallowed from using Unicode.
+//
+// Although paths are currently disallowed from using Unicode,
+// we would like at some point to allow Unicode letters as well, to assume that
+// file systems and URLs are Unicode-safe (storing UTF-8), and apply
+// the !-for-uppercase convention for escaping them in the file system.
+// But there are at least two subtle considerations.
+//
+// First, note that not all case-fold equivalent distinct runes
+// form an upper/lower pair.
+// For example, U+004B ('K'), U+006B ('k'), and U+212A ('K' for Kelvin)
+// are three distinct runes that case-fold to each other.
+// When we do add Unicode letters, we must not assume that upper/lower
+// are the only case-equivalent pairs.
+// Perhaps the Kelvin symbol would be disallowed entirely, for example.
+// Or perhaps it would escape as "!!k", or perhaps as "(212A)".
+//
+// Second, it would be nice to allow Unicode marks as well as letters,
+// but marks include combining marks, and then we must deal not
+// only with case folding but also normalization: both U+00E9 ('é')
+// and U+0065 U+0301 ('e' followed by combining acute accent)
+// look the same on the page and are treated by some file systems
+// as the same path. If we do allow Unicode marks in paths, there
+// must be some kind of normalization to allow only one canonical
+// encoding of any character used in an import path.
+package module
+
+// IMPORTANT NOTE
+//
+// This file essentially defines the set of valid import paths for the go command.
+// There are many subtle considerations, including Unicode ambiguity,
+// security, network, and file system representations.
+//
+// This file also defines the set of valid module path and version combinations,
+// another topic with many subtle considerations.
+//
+// Changes to the semantics in this file require approval from rsc.
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+
+	"golang.org/x/mod/semver"
+	errors "golang.org/x/xerrors"
+)
+
+// A Version (for clients, a module.Version) is defined by a module path and version pair.
+// These are stored in their plain (unescaped) form.
+type Version struct {
+	// Path is a module path, like "golang.org/x/text" or "rsc.io/quote/v2".
+	Path string
+
+	// Version is usually a semantic version in canonical form.
+	// There are three exceptions to this general rule.
+	// First, the top-level target of a build has no specific version
+	// and uses Version = "".
+	// Second, during MVS calculations the version "none" is used
+	// to represent the decision to take no version of a given module.
+	// Third, filesystem paths found in "replace" directives are
+	// represented by a path with an empty version.
+	Version string `json:",omitempty"`
+}
+
+// String returns a representation of the Version suitable for logging
+// (Path@Version, or just Path if Version is empty).
+func (m Version) String() string {
+	if m.Version == "" {
+		return m.Path
+	}
+	return m.Path + "@" + m.Version
+}
+
+// A ModuleError indicates an error specific to a module.
+type ModuleError struct {
+	Path    string
+	Version string
+	Err     error
+}
+
+// VersionError returns a ModuleError derived from a Version and error,
+// or err itself if it is already such an error.
+func VersionError(v Version, err error) error {
+	var mErr *ModuleError
+	if errors.As(err, &mErr) && mErr.Path == v.Path && mErr.Version == v.Version {
+		return err
+	}
+	return &ModuleError{
+		Path:    v.Path,
+		Version: v.Version,
+		Err:     err,
+	}
+}
+
+func (e *ModuleError) Error() string {
+	if v, ok := e.Err.(*InvalidVersionError); ok {
+		return fmt.Sprintf("%s@%s: invalid %s: %v", e.Path, v.Version, v.noun(), v.Err)
+	}
+	if e.Version != "" {
+		return fmt.Sprintf("%s@%s: %v", e.Path, e.Version, e.Err)
+	}
+	return fmt.Sprintf("module %s: %v", e.Path, e.Err)
+}
+
+func (e *ModuleError) Unwrap() error { return e.Err }
+
+// An InvalidVersionError indicates an error specific to a version, with the
+// module path unknown or specified externally.
+//
+// A ModuleError may wrap an InvalidVersionError, but an InvalidVersionError
+// must not wrap a ModuleError.
+type InvalidVersionError struct {
+	Version string
+	Pseudo  bool
+	Err     error
+}
+
+// noun returns either "version" or "pseudo-version", depending on whether
+// e.Version is a pseudo-version.
+func (e *InvalidVersionError) noun() string {
+	if e.Pseudo {
+		return "pseudo-version"
+	}
+	return "version"
+}
+
+func (e *InvalidVersionError) Error() string {
+	return fmt.Sprintf("%s %q invalid: %s", e.noun(), e.Version, e.Err)
+}
+
+func (e *InvalidVersionError) Unwrap() error { return e.Err }
+
+// Check checks that a given module path, version pair is valid.
+// In addition to the path being a valid module path
+// and the version being a valid semantic version,
+// the two must correspond.
+// For example, the path "yaml/v2" only corresponds to
+// semantic versions beginning with "v2.".
+func Check(path, version string) error {
+	if err := CheckPath(path); err != nil {
+		return err
+	}
+	if !semver.IsValid(version) {
+		return &ModuleError{
+			Path: path,
+			Err:  &InvalidVersionError{Version: version, Err: errors.New("not a semantic version")},
+		}
+	}
+	_, pathMajor, _ := SplitPathVersion(path)
+	if err := CheckPathMajor(version, pathMajor); err != nil {
+		return &ModuleError{Path: path, Err: err}
+	}
+	return nil
+}
+
+// firstPathOK reports whether r can appear in the first element of a module path.
+// The first element of the path must be an LDH domain name, at least for now.
+// To avoid case ambiguity, the domain name must be entirely lower case.
+func firstPathOK(r rune) bool {
+	return r == '-' || r == '.' ||
+		'0' <= r && r <= '9' ||
+		'a' <= r && r <= 'z'
+}
+
+// pathOK reports whether r can appear in an import path element.
+// Paths can be ASCII letters, ASCII digits, and limited ASCII punctuation: + - . _ and ~.
+// This matches what "go get" has historically recognized in import paths.
+// TODO(rsc): We would like to allow Unicode letters, but that requires additional
+// care in the safe encoding (see "escaped paths" above).
+func pathOK(r rune) bool {
+	if r < utf8.RuneSelf {
+		return r == '+' || r == '-' || r == '.' || r == '_' || r == '~' ||
+			'0' <= r && r <= '9' ||
+			'A' <= r && r <= 'Z' ||
+			'a' <= r && r <= 'z'
+	}
+	return false
+}
+
+// fileNameOK reports whether r can appear in a file name.
+// For now we allow all Unicode letters but otherwise limit to pathOK plus a few more punctuation characters.
+// If we expand the set of allowed characters here, we have to
+// work harder at detecting potential case-folding and normalization collisions.
+// See note about "escaped paths" above.
+func fileNameOK(r rune) bool {
+	if r < utf8.RuneSelf {
+		// Entire set of ASCII punctuation, from which we remove characters:
+		//     ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~
+		// We disallow some shell special characters: " ' * < > ? ` |
+		// (Note that some of those are disallowed by the Windows file system as well.)
+		// We also disallow path separators / : and \ (fileNameOK is only called on path element characters).
+		// We allow spaces (U+0020) in file names.
+		const allowed = "!#$%&()+,-.=@[]^_{}~ "
+		if '0' <= r && r <= '9' || 'A' <= r && r <= 'Z' || 'a' <= r && r <= 'z' {
+			return true
+		}
+		for i := 0; i < len(allowed); i++ {
+			if rune(allowed[i]) == r {
+				return true
+			}
+		}
+		return false
+	}
+	// It may be OK to add more ASCII punctuation here, but only carefully.
+	// For example Windows disallows < > \, and macOS disallows :, so we must not allow those.
+	return unicode.IsLetter(r)
+}
+
+// CheckPath checks that a module path is valid.
+// A valid module path is a valid import path, as checked by CheckImportPath,
+// with two additional constraints.
+// First, the leading path element (up to the first slash, if any),
+// by convention a domain name, must contain only lower-case ASCII letters,
+// ASCII digits, dots (U+002E), and dashes (U+002D);
+// it must contain at least one dot and cannot start with a dash.
+// Second, for a final path element of the form /vN, where N looks numeric
+// (ASCII digits and dots) must not begin with a leading zero, must not be /v1,
+// and must not contain any dots. For paths beginning with "gopkg.in/",
+// this second requirement is replaced by a requirement that the path
+// follow the gopkg.in server's conventions.
+func CheckPath(path string) error {
+	if err := checkPath(path, false); err != nil {
+		return fmt.Errorf("malformed module path %q: %v", path, err)
+	}
+	i := strings.Index(path, "/")
+	if i < 0 {
+		i = len(path)
+	}
+	if i == 0 {
+		return fmt.Errorf("malformed module path %q: leading slash", path)
+	}
+	if !strings.Contains(path[:i], ".") {
+		return fmt.Errorf("malformed module path %q: missing dot in first path element", path)
+	}
+	if path[0] == '-' {
+		return fmt.Errorf("malformed module path %q: leading dash in first path element", path)
+	}
+	for _, r := range path[:i] {
+		if !firstPathOK(r) {
+			return fmt.Errorf("malformed module path %q: invalid char %q in first path element", path, r)
+		}
+	}
+	if _, _, ok := SplitPathVersion(path); !ok {
+		return fmt.Errorf("malformed module path %q: invalid version", path)
+	}
+	return nil
+}
+
+// CheckImportPath checks that an import path is valid.
+//
+// A valid import path consists of one or more valid path elements
+// separated by slashes (U+002F). (It must not begin with nor end in a slash.)
+//
+// A valid path element is a non-empty string made up of
+// ASCII letters, ASCII digits, and limited ASCII punctuation: + - . _ and ~.
+// It must not begin or end with a dot (U+002E), nor contain two dots in a row.
+//
+// The element prefix up to the first dot must not be a reserved file name
+// on Windows, regardless of case (CON, com1, NuL, and so on).
+//
+// CheckImportPath may be less restrictive in the future, but see the
+// top-level package documentation for additional information about
+// subtleties of Unicode.
+func CheckImportPath(path string) error {
+	if err := checkPath(path, false); err != nil {
+		return fmt.Errorf("malformed import path %q: %v", path, err)
+	}
+	return nil
+}
+
+// checkPath checks that a general path is valid.
+// It returns an error describing why but not mentioning path.
+// Because these checks apply to both module paths and import paths,
+// the caller is expected to add the "malformed ___ path %q: " prefix.
+// fileName indicates whether the final element of the path is a file name
+// (as opposed to a directory name).
+func checkPath(path string, fileName bool) error {
+	if !utf8.ValidString(path) {
+		return fmt.Errorf("invalid UTF-8")
+	}
+	if path == "" {
+		return fmt.Errorf("empty string")
+	}
+	if path[0] == '-' {
+		return fmt.Errorf("leading dash")
+	}
+	if strings.Contains(path, "//") {
+		return fmt.Errorf("double slash")
+	}
+	if path[len(path)-1] == '/' {
+		return fmt.Errorf("trailing slash")
+	}
+	elemStart := 0
+	for i, r := range path {
+		if r == '/' {
+			if err := checkElem(path[elemStart:i], fileName); err != nil {
+				return err
+			}
+			elemStart = i + 1
+		}
+	}
+	if err := checkElem(path[elemStart:], fileName); err != nil {
+		return err
+	}
+	return nil
+}
+
+// checkElem checks whether an individual path element is valid.
+// fileName indicates whether the element is a file name (not a directory name).
+func checkElem(elem string, fileName bool) error {
+	if elem == "" {
+		return fmt.Errorf("empty path element")
+	}
+	if strings.Count(elem, ".") == len(elem) {
+		return fmt.Errorf("invalid path element %q", elem)
+	}
+	if elem[0] == '.' && !fileName {
+		return fmt.Errorf("leading dot in path element")
+	}
+	if elem[len(elem)-1] == '.' {
+		return fmt.Errorf("trailing dot in path element")
+	}
+	charOK := pathOK
+	if fileName {
+		charOK = fileNameOK
+	}
+	for _, r := range elem {
+		if !charOK(r) {
+			return fmt.Errorf("invalid char %q", r)
+		}
+	}
+
+	// Windows disallows a bunch of path elements, sadly.
+	// See https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file
+	short := elem
+	if i := strings.Index(short, "."); i >= 0 {
+		short = short[:i]
+	}
+	for _, bad := range badWindowsNames {
+		if strings.EqualFold(bad, short) {
+			return fmt.Errorf("%q disallowed as path element component on Windows", short)
+		}
+	}
+	return nil
+}
+
+// CheckFilePath checks that a slash-separated file path is valid.
+// The definition of a valid file path is the same as the definition
+// of a valid import path except that the set of allowed characters is larger:
+// all Unicode letters, ASCII digits, the ASCII space character (U+0020),
+// and the ASCII punctuation characters
+// “!#$%&()+,-.=@[]^_{}~”.
+// (The excluded punctuation characters, " * < > ? ` ' | / \ and :,
+// have special meanings in certain shells or operating systems.)
+//
+// CheckFilePath may be less restrictive in the future, but see the
+// top-level package documentation for additional information about
+// subtleties of Unicode.
+func CheckFilePath(path string) error {
+	if err := checkPath(path, true); err != nil {
+		return fmt.Errorf("malformed file path %q: %v", path, err)
+	}
+	return nil
+}
+
+// badWindowsNames are the reserved file path elements on Windows.
+// See https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file
+var badWindowsNames = []string{
+	"CON",
+	"PRN",
+	"AUX",
+	"NUL",
+	"COM1",
+	"COM2",
+	"COM3",
+	"COM4",
+	"COM5",
+	"COM6",
+	"COM7",
+	"COM8",
+	"COM9",
+	"LPT1",
+	"LPT2",
+	"LPT3",
+	"LPT4",
+	"LPT5",
+	"LPT6",
+	"LPT7",
+	"LPT8",
+	"LPT9",
+}
+
+// SplitPathVersion returns prefix and major version such that prefix+pathMajor == path
+// and version is either empty or "/vN" for N >= 2.
+// As a special case, gopkg.in paths are recognized directly;
+// they require ".vN" instead of "/vN", and for all N, not just N >= 2.
+// SplitPathVersion returns with ok = false when presented with
+// a path whose last path element does not satisfy the constraints
+// applied by CheckPath, such as "example.com/pkg/v1" or "example.com/pkg/v1.2".
+func SplitPathVersion(path string) (prefix, pathMajor string, ok bool) {
+	if strings.HasPrefix(path, "gopkg.in/") {
+		return splitGopkgIn(path)
+	}
+
+	i := len(path)
+	dot := false
+	for i > 0 && ('0' <= path[i-1] && path[i-1] <= '9' || path[i-1] == '.') {
+		if path[i-1] == '.' {
+			dot = true
+		}
+		i--
+	}
+	if i <= 1 || i == len(path) || path[i-1] != 'v' || path[i-2] != '/' {
+		return path, "", true
+	}
+	prefix, pathMajor = path[:i-2], path[i-2:]
+	if dot || len(pathMajor) <= 2 || pathMajor[2] == '0' || pathMajor == "/v1" {
+		return path, "", false
+	}
+	return prefix, pathMajor, true
+}
+
+// splitGopkgIn is like SplitPathVersion but only for gopkg.in paths.
+func splitGopkgIn(path string) (prefix, pathMajor string, ok bool) {
+	if !strings.HasPrefix(path, "gopkg.in/") {
+		return path, "", false
+	}
+	i := len(path)
+	if strings.HasSuffix(path, "-unstable") {
+		i -= len("-unstable")
+	}
+	for i > 0 && ('0' <= path[i-1] && path[i-1] <= '9') {
+		i--
+	}
+	if i <= 1 || path[i-1] != 'v' || path[i-2] != '.' {
+		// All gopkg.in paths must end in vN for some N.
+		return path, "", false
+	}
+	prefix, pathMajor = path[:i-2], path[i-2:]
+	if len(pathMajor) <= 2 || pathMajor[2] == '0' && pathMajor != ".v0" {
+		return path, "", false
+	}
+	return prefix, pathMajor, true
+}
+
+// MatchPathMajor reports whether the semantic version v
+// matches the path major version pathMajor.
+//
+// MatchPathMajor returns true if and only if CheckPathMajor returns nil.
+func MatchPathMajor(v, pathMajor string) bool {
+	return CheckPathMajor(v, pathMajor) == nil
+}
+
+// CheckPathMajor returns a non-nil error if the semantic version v
+// does not match the path major version pathMajor.
+func CheckPathMajor(v, pathMajor string) error {
+	// TODO(jayconrod): return errors or panic for invalid inputs. This function
+	// (and others) was covered by integration tests for cmd/go, and surrounding
+	// code protected against invalid inputs like non-canonical versions.
+	if strings.HasPrefix(pathMajor, ".v") && strings.HasSuffix(pathMajor, "-unstable") {
+		pathMajor = strings.TrimSuffix(pathMajor, "-unstable")
+	}
+	if strings.HasPrefix(v, "v0.0.0-") && pathMajor == ".v1" {
+		// Allow old bug in pseudo-versions that generated v0.0.0- pseudoversion for gopkg .v1.
+		// For example, gopkg.in/yaml.v2@v2.2.1's go.mod requires gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405.
+		return nil
+	}
+	m := semver.Major(v)
+	if pathMajor == "" {
+		if m == "v0" || m == "v1" || semver.Build(v) == "+incompatible" {
+			return nil
+		}
+		pathMajor = "v0 or v1"
+	} else if pathMajor[0] == '/' || pathMajor[0] == '.' {
+		if m == pathMajor[1:] {
+			return nil
+		}
+		pathMajor = pathMajor[1:]
+	}
+	return &InvalidVersionError{
+		Version: v,
+		Err:     fmt.Errorf("should be %s, not %s", pathMajor, semver.Major(v)),
+	}
+}
+
+// PathMajorPrefix returns the major-version tag prefix implied by pathMajor.
+// An empty PathMajorPrefix allows either v0 or v1.
+//
+// Note that MatchPathMajor may accept some versions that do not actually begin
+// with this prefix: namely, it accepts a 'v0.0.0-' prefix for a '.v1'
+// pathMajor, even though that pathMajor implies 'v1' tagging.
+func PathMajorPrefix(pathMajor string) string {
+	if pathMajor == "" {
+		return ""
+	}
+	if pathMajor[0] != '/' && pathMajor[0] != '.' {
+		panic("pathMajor suffix " + pathMajor + " passed to PathMajorPrefix lacks separator")
+	}
+	if strings.HasPrefix(pathMajor, ".v") && strings.HasSuffix(pathMajor, "-unstable") {
+		pathMajor = strings.TrimSuffix(pathMajor, "-unstable")
+	}
+	m := pathMajor[1:]
+	if m != semver.Major(m) {
+		panic("pathMajor suffix " + pathMajor + "passed to PathMajorPrefix is not a valid major version")
+	}
+	return m
+}
+
+// CanonicalVersion returns the canonical form of the version string v.
+// It is the same as semver.Canonical(v) except that it preserves the special build suffix "+incompatible".
+func CanonicalVersion(v string) string {
+	cv := semver.Canonical(v)
+	if semver.Build(v) == "+incompatible" {
+		cv += "+incompatible"
+	}
+	return cv
+}
+
+// Sort sorts the list by Path, breaking ties by comparing Version fields.
+// The Version fields are interpreted as semantic versions (using semver.Compare)
+// optionally followed by a tie-breaking suffix introduced by a slash character,
+// like in "v0.0.1/go.mod".
+func Sort(list []Version) {
+	sort.Slice(list, func(i, j int) bool {
+		mi := list[i]
+		mj := list[j]
+		if mi.Path != mj.Path {
+			return mi.Path < mj.Path
+		}
+		// To help go.sum formatting, allow version/file.
+		// Compare semver prefix by semver rules,
+		// file by string order.
+		vi := mi.Version
+		vj := mj.Version
+		var fi, fj string
+		if k := strings.Index(vi, "/"); k >= 0 {
+			vi, fi = vi[:k], vi[k:]
+		}
+		if k := strings.Index(vj, "/"); k >= 0 {
+			vj, fj = vj[:k], vj[k:]
+		}
+		if vi != vj {
+			return semver.Compare(vi, vj) < 0
+		}
+		return fi < fj
+	})
+}
+
+// EscapePath returns the escaped form of the given module path.
+// It fails if the module path is invalid.
+func EscapePath(path string) (escaped string, err error) {
+	if err := CheckPath(path); err != nil {
+		return "", err
+	}
+
+	return escapeString(path)
+}
+
+// EscapeVersion returns the escaped form of the given module version.
+// Versions are allowed to be in non-semver form but must be valid file names
+// and not contain exclamation marks.
+func EscapeVersion(v string) (escaped string, err error) {
+	if err := checkElem(v, true); err != nil || strings.Contains(v, "!") {
+		return "", &InvalidVersionError{
+			Version: v,
+			Err:     fmt.Errorf("disallowed version string"),
+		}
+	}
+	return escapeString(v)
+}
+
+func escapeString(s string) (escaped string, err error) {
+	haveUpper := false
+	for _, r := range s {
+		if r == '!' || r >= utf8.RuneSelf {
+			// This should be disallowed by CheckPath, but diagnose anyway.
+			// The correctness of the escaping loop below depends on it.
+			return "", fmt.Errorf("internal error: inconsistency in EscapePath")
+		}
+		if 'A' <= r && r <= 'Z' {
+			haveUpper = true
+		}
+	}
+
+	if !haveUpper {
+		return s, nil
+	}
+
+	var buf []byte
+	for _, r := range s {
+		if 'A' <= r && r <= 'Z' {
+			buf = append(buf, '!', byte(r+'a'-'A'))
+		} else {
+			buf = append(buf, byte(r))
+		}
+	}
+	return string(buf), nil
+}
+
+// UnescapePath returns the module path for the given escaped path.
+// It fails if the escaped path is invalid or describes an invalid path.
+func UnescapePath(escaped string) (path string, err error) {
+	path, ok := unescapeString(escaped)
+	if !ok {
+		return "", fmt.Errorf("invalid escaped module path %q", escaped)
+	}
+	if err := CheckPath(path); err != nil {
+		return "", fmt.Errorf("invalid escaped module path %q: %v", escaped, err)
+	}
+	return path, nil
+}
+
+// UnescapeVersion returns the version string for the given escaped version.
+// It fails if the escaped form is invalid or describes an invalid version.
+// Versions are allowed to be in non-semver form but must be valid file names
+// and not contain exclamation marks.
+func UnescapeVersion(escaped string) (v string, err error) {
+	v, ok := unescapeString(escaped)
+	if !ok {
+		return "", fmt.Errorf("invalid escaped version %q", escaped)
+	}
+	if err := checkElem(v, true); err != nil {
+		return "", fmt.Errorf("invalid escaped version %q: %v", v, err)
+	}
+	return v, nil
+}
+
+func unescapeString(escaped string) (string, bool) {
+	var buf []byte
+
+	bang := false
+	for _, r := range escaped {
+		if r >= utf8.RuneSelf {
+			return "", false
+		}
+		if bang {
+			bang = false
+			if r < 'a' || 'z' < r {
+				return "", false
+			}
+			buf = append(buf, byte(r+'A'-'a'))
+			continue
+		}
+		if r == '!' {
+			bang = true
+			continue
+		}
+		if 'A' <= r && r <= 'Z' {
+			return "", false
+		}
+		buf = append(buf, byte(r))
+	}
+	if bang {
+		return "", false
+	}
+	return string(buf), true
+}

vendor/golang.org/x/mod/semver/semver.go

@@ -107,7 +107,7 @@ func Build(v string) string {
 }
 
 // Compare returns an integer comparing two versions according to
-// according to semantic version precedence.
+// semantic version precedence.
 // The result will be 0 if v == w, -1 if v < w, or +1 if v > w.
 //
 // An invalid semantic version string is considered less than a valid one.
@@ -263,7 +263,7 @@ func parseBuild(v string) (t, rest string, ok bool) {
 	i := 1
 	start := 1
 	for i < len(v) {
-		if !isIdentChar(v[i]) {
+		if !isIdentChar(v[i]) && v[i] != '.' {
 			return
 		}
 		if v[i] == '.' {

vendor/golang.org/x/tools/benchmark/parse/parse.go

@@ -1,131 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/blog/atom/atom.go

@@ -1,61 +0,0 @@
-// 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"))
-}

vendor/golang.org/x/tools/container/intsets/popcnt_amd64.go

@@ -1,20 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/container/intsets/popcnt_amd64.s

@@ -1,30 +0,0 @@
-// 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

vendor/golang.org/x/tools/container/intsets/popcnt_gccgo.go

@@ -1,9 +0,0 @@
-// 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

vendor/golang.org/x/tools/container/intsets/popcnt_gccgo_c.c

@@ -1,19 +0,0 @@
-// 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 <errno.h>
-#include <stdint.h>
-#include <unistd.h>
-
-#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));
-}

vendor/golang.org/x/tools/container/intsets/popcnt_generic.go

@@ -1,33 +0,0 @@
-// 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)
-}

vendor/golang.org/x/tools/container/intsets/util.go

@@ -1,84 +0,0 @@
-// 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)
-}

vendor/golang.org/x/tools/go/ast/astutil/enclosing.go

@@ -1,627 +0,0 @@
-// 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))
-}

vendor/golang.org/x/tools/go/ast/astutil/imports.go

@@ -1,481 +0,0 @@
-// 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 "<nil>":
-		// 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
-}

vendor/golang.org/x/tools/go/ast/astutil/rewrite.go

@@ -1,477 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/ast/astutil/util.go

@@ -1,14 +0,0 @@
-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
-	}
-}

vendor/golang.org/x/tools/go/buildutil/allpackages.go

@@ -1,198 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/buildutil/fakecontext.go

@@ -1,109 +0,0 @@
-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 }

vendor/golang.org/x/tools/go/buildutil/overlay.go

@@ -1,103 +0,0 @@
-// 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 := &copy
-	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
-}

vendor/golang.org/x/tools/go/buildutil/tags.go

@@ -1,75 +0,0 @@
-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 "<tagsFlag>"
-}
-
-func isSpaceByte(c byte) bool {
-	return c == ' ' || c == '\t' || c == '\n' || c == '\r'
-}

vendor/golang.org/x/tools/go/buildutil/util.go

@@ -1,212 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/callgraph/callgraph.go

@@ -1,129 +0,0 @@
-// 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)
-}

vendor/golang.org/x/tools/go/callgraph/cha/cha.go

@@ -1,139 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/callgraph/rta/rta.go

@@ -1,459 +0,0 @@
-// 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)
-	}
-}

vendor/golang.org/x/tools/go/callgraph/static/static.go

@@ -1,35 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/callgraph/util.go

@@ -1,181 +0,0 @@
-// 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())
-}

vendor/golang.org/x/tools/go/internal/cgo/cgo.go

@@ -1,220 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/internal/cgo/cgo_pkgconfig.go

@@ -1,39 +0,0 @@
-// 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)
-}

vendor/golang.org/x/tools/go/internal/gcimporter/gcimporter.go

@@ -344,7 +344,7 @@ func (p *parser) expectKeyword(keyword string) {
 
 // PackageId = string_lit .
 //
-func (p *parser) parsePackageId() string {
+func (p *parser) parsePackageID() string {
 	id, err := strconv.Unquote(p.expect(scanner.String))
 	if err != nil {
 		p.error(err)
@@ -384,7 +384,7 @@ func (p *parser) parseDotIdent() string {
 //
 func (p *parser) parseQualifiedName() (id, name string) {
 	p.expect('@')
-	id = p.parsePackageId()
+	id = p.parsePackageID()
 	p.expect('.')
 	// Per rev f280b8a485fd (10/2/2013), qualified names may be used for anonymous fields.
 	if p.tok == '?' {
@@ -696,7 +696,7 @@ func (p *parser) parseInterfaceType(parent *types.Package) types.Type {
 
 	// Complete requires the type's embedded interfaces to be fully defined,
 	// but we do not define any
-	return types.NewInterface(methods, nil).Complete()
+	return newInterface(methods, nil).Complete()
 }
 
 // ChanType = ( "chan" [ "<-" ] | "<-" "chan" ) Type .
@@ -785,7 +785,7 @@ func (p *parser) parseType(parent *types.Package) types.Type {
 func (p *parser) parseImportDecl() {
 	p.expectKeyword("import")
 	name := p.parsePackageName()
-	p.getPkg(p.parsePackageId(), name)
+	p.getPkg(p.parsePackageID(), name)
 }
 
 // int_lit = [ "+" | "-" ] { "0" ... "9" } .

vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go

@@ -11,11 +11,10 @@ import (
 	"encoding/json"
 	"fmt"
 	"go/types"
-	"log"
-	"os"
 	"os/exec"
 	"strings"
-	"time"
+
+	"golang.org/x/tools/internal/gocommand"
 )
 
 var debug = false
@@ -78,97 +77,42 @@ func GetSizes(ctx context.Context, buildFlags, env []string, dir string, usesExp
 }
 
 func GetSizesGolist(ctx context.Context, buildFlags, env []string, dir string, usesExportData bool) (types.Sizes, error) {
-	args := []string{"list", "-f", "{{context.GOARCH}} {{context.Compiler}}"}
-	args = append(args, buildFlags...)
-	args = append(args, "--", "unsafe")
-	stdout, stderr, err := invokeGo(ctx, env, dir, usesExportData, args...)
+	inv := gocommand.Invocation{
+		Verb:       "list",
+		Args:       []string{"-f", "{{context.GOARCH}} {{context.Compiler}}", "--", "unsafe"},
+		Env:        env,
+		BuildFlags: buildFlags,
+		WorkingDir: dir,
+	}
+	stdout, stderr, friendlyErr, rawErr := inv.RunRaw(ctx)
 	var goarch, compiler string
-	if err != nil {
-		if strings.Contains(err.Error(), "cannot find main module") {
+	if rawErr != nil {
+		if strings.Contains(rawErr.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")
+			inv := gocommand.Invocation{
+				Verb:       "env",
+				Args:       []string{"GOARCH"},
+				Env:        env,
+				WorkingDir: dir,
+			}
+			envout, enverr := inv.Run(ctx)
 			if enverr != nil {
-				return nil, err
+				return nil, enverr
 			}
 			goarch = strings.TrimSpace(envout.String())
 			compiler = "gc"
 		} else {
-			return nil, err
+			return nil, friendlyErr
 		}
 	} else {
 		fields := strings.Fields(stdout.String())
 		if len(fields) < 2 {
-			return nil, fmt.Errorf("could not parse GOARCH and Go compiler in format \"<GOARCH> <compiler>\" from stdout of go command:\n%s\ndir: %s\nstdout: <<%s>>\nstderr: <<%s>>",
-				cmdDebugStr(env, args...), dir, stdout.String(), stderr.String())
+			return nil, fmt.Errorf("could not parse GOARCH and Go compiler in format \"<GOARCH> <compiler>\":\nstdout: <<%s>>\nstderr: <<%s>>",
+				stdout.String(), stderr.String())
 		}
 		goarch = fields[0]
 		compiler = fields[1]
 	}
 	return types.SizesFor(compiler, goarch), nil
 }
-
-// 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())
-	}
-	stdout := new(bytes.Buffer)
-	stderr := new(bytes.Buffer)
-	cmd := exec.CommandContext(ctx, "go", args...)
-	// 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.
-	// The Go stdlib has a special feature where if the cwd and the PWD are the
-	// same node then it trusts the PWD, so by setting it in the env for the child
-	// process we fix up all the paths returned by the go command.
-	cmd.Env = append(append([]string{}, env...), "PWD="+dir)
-	cmd.Dir = dir
-	cmd.Stdout = stdout
-	cmd.Stderr = stderr
-	if err := cmd.Run(); err != nil {
-		exitErr, ok := err.(*exec.ExitError)
-		if !ok {
-			// Catastrophic error:
-			// - executable not found
-			// - context cancellation
-			return nil, nil, fmt.Errorf("couldn't exec 'go %v': %s %T", args, err, err)
-		}
-
-		// Export mode entails a build.
-		// If that build fails, errors appear on stderr
-		// (despite the -e flag) and the Export field is blank.
-		// Do not fail in that case.
-		if !usesExportData {
-			return nil, nil, fmt.Errorf("go %v: %s: %s", args, exitErr, stderr)
-		}
-	}
-
-	// As of writing, go list -export prints some non-fatal compilation
-	// errors to stderr, even with -e set. We would prefer that it put
-	// them in the Package.Error JSON (see https://golang.org/issue/26319).
-	// In the meantime, there's nowhere good to put them, but they can
-	// be useful for debugging. Print them if $GOPACKAGESPRINTGOLISTERRORS
-	// is set.
-	if len(stderr.Bytes()) != 0 && os.Getenv("GOPACKAGESPRINTGOLISTERRORS") != "" {
-		fmt.Fprintf(os.Stderr, "%s stderr: <<%s>>\n", cmdDebugStr(env, args...), stderr)
-	}
-
-	// debugging
-	if false {
-		fmt.Fprintf(os.Stderr, "%s stdout: <<%s>>\n", cmdDebugStr(env, args...), stdout)
-	}
-
-	return stdout, stderr, nil
-}
-
-func cmdDebugStr(envlist []string, args ...string) string {
-	env := make(map[string]string)
-	for _, kv := range envlist {
-		split := strings.Split(kv, "=")
-		k, v := split[0], split[1]
-		env[k] = v
-	}
-
-	return fmt.Sprintf("GOROOT=%v GOPATH=%v GO111MODULE=%v PWD=%v go %v", env["GOROOT"], env["GOPATH"], env["GO111MODULE"], env["PWD"], args)
-}

vendor/golang.org/x/tools/go/loader/doc.go

@@ -1,204 +0,0 @@
-// 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.

vendor/golang.org/x/tools/go/loader/util.go

@@ -1,124 +0,0 @@
-// 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()
-}

vendor/golang.org/x/tools/go/packages/golist.go

@@ -6,26 +6,25 @@ package packages
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"fmt"
 	"go/types"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
 	"path"
 	"path/filepath"
 	"reflect"
-	"regexp"
+	"sort"
 	"strconv"
 	"strings"
 	"sync"
-	"time"
 	"unicode"
 
 	"golang.org/x/tools/go/internal/packagesdriver"
-	"golang.org/x/tools/internal/gopathwalk"
-	"golang.org/x/tools/internal/semver"
+	"golang.org/x/tools/internal/gocommand"
+	"golang.org/x/tools/internal/packagesinternal"
 )
 
 // debug controls verbose logging.
@@ -44,16 +43,21 @@ type responseDeduper struct {
 	dr           *driverResponse
 }
 
-// init fills in r with a driverResponse.
-func (r *responseDeduper) init(dr *driverResponse) {
-	r.dr = dr
-	r.seenRoots = map[string]bool{}
-	r.seenPackages = map[string]*Package{}
+func newDeduper() *responseDeduper {
+	return &responseDeduper{
+		dr:           &driverResponse{},
+		seenRoots:    map[string]bool{},
+		seenPackages: map[string]*Package{},
+	}
+}
+
+// addAll fills in r with a driverResponse.
+func (r *responseDeduper) addAll(dr *driverResponse) {
 	for _, pkg := range dr.Packages {
-		r.seenPackages[pkg.ID] = pkg
+		r.addPackage(pkg)
 	}
 	for _, root := range dr.Roots {
-		r.seenRoots[root] = true
+		r.addRoot(root)
 	}
 }
 
@@ -73,25 +77,47 @@ func (r *responseDeduper) addRoot(id string) {
 	r.dr.Roots = append(r.dr.Roots, id)
 }
 
-// goInfo contains global information from the go tool.
-type goInfo struct {
-	rootDirs map[string]string
-	env      goEnv
+type golistState struct {
+	cfg *Config
+	ctx context.Context
+
+	envOnce    sync.Once
+	goEnvError error
+	goEnv      map[string]string
+
+	rootsOnce     sync.Once
+	rootDirsError error
+	rootDirs      map[string]string
+
+	// vendorDirs caches the (non)existence of vendor directories.
+	vendorDirs map[string]bool
 }
 
-type goEnv struct {
-	modulesOn bool
+// getEnv returns Go environment variables. Only specific variables are
+// populated -- computing all of them is slow.
+func (state *golistState) getEnv() (map[string]string, error) {
+	state.envOnce.Do(func() {
+		var b *bytes.Buffer
+		b, state.goEnvError = state.invokeGo("env", "-json", "GOMOD", "GOPATH")
+		if state.goEnvError != nil {
+			return
+		}
+
+		state.goEnv = make(map[string]string)
+		decoder := json.NewDecoder(b)
+		if state.goEnvError = decoder.Decode(&state.goEnv); state.goEnvError != nil {
+			return
+		}
+	})
+	return state.goEnv, state.goEnvError
 }
 
-func determineEnv(cfg *Config) goEnv {
-	buf, err := invokeGo(cfg, "env", "GOMOD")
+// mustGetEnv is a convenience function that can be used if getEnv has already succeeded.
+func (state *golistState) mustGetEnv() map[string]string {
+	env, err := state.getEnv()
 	if err != nil {
-		return goEnv{}
+		panic(fmt.Sprintf("mustGetEnv: %v", err))
 	}
-	gomod := bytes.TrimSpace(buf.Bytes())
-
-	env := goEnv{}
-	env.modulesOn = len(gomod) > 0
 	return env
 }
 
@@ -99,47 +125,38 @@ func determineEnv(cfg *Config) goEnv {
 // the build system package structure.
 // See driver for more details.
 func goListDriver(cfg *Config, patterns ...string) (*driverResponse, error) {
-	var sizes types.Sizes
+	// Make sure that any asynchronous go commands are killed when we return.
+	parentCtx := cfg.Context
+	if parentCtx == nil {
+		parentCtx = context.Background()
+	}
+	ctx, cancel := context.WithCancel(parentCtx)
+	defer cancel()
+
+	response := newDeduper()
+
+	// Fill in response.Sizes asynchronously if necessary.
 	var sizeserr error
 	var sizeswg sync.WaitGroup
 	if cfg.Mode&NeedTypesSizes != 0 || cfg.Mode&NeedTypes != 0 {
 		sizeswg.Add(1)
 		go func() {
-			sizes, sizeserr = getSizes(cfg)
+			var sizes types.Sizes
+			sizes, sizeserr = packagesdriver.GetSizesGolist(ctx, cfg.BuildFlags, cfg.Env, cfg.Dir, usesExportData(cfg))
+			// types.SizesFor always returns nil or a *types.StdSizes.
+			response.dr.Sizes, _ = sizes.(*types.StdSizes)
 			sizeswg.Done()
 		}()
 	}
-	defer sizeswg.Wait()
 
-	// start fetching rootDirs
-	var info goInfo
-	var rootDirsReady, envReady = make(chan struct{}), make(chan struct{})
-	go func() {
-		info.rootDirs = determineRootDirs(cfg)
-		close(rootDirsReady)
-	}()
-	go func() {
-		info.env = determineEnv(cfg)
-		close(envReady)
-	}()
-	getGoInfo := func() *goInfo {
-		<-rootDirsReady
-		<-envReady
-		return &info
-	}
-
-	// Ensure that we don't leak goroutines: Load is synchronous, so callers will
-	// not expect it to access the fields of cfg after the call returns.
-	defer getGoInfo()
-
-	// always pass getGoInfo to golistDriver
-	golistDriver := func(cfg *Config, patterns ...string) (*driverResponse, error) {
-		return golistDriver(cfg, getGoInfo, patterns...)
+	state := &golistState{
+		cfg:        cfg,
+		ctx:        ctx,
+		vendorDirs: map[string]bool{},
 	}
 
 	// Determine files requested in contains patterns
 	var containFiles []string
-	var packagesNamed []string
 	restPatterns := make([]string, 0, len(patterns))
 	// Extract file= and other [querytype]= patterns. Report an error if querytype
 	// doesn't exist.
@@ -155,8 +172,6 @@ extractQueries:
 				containFiles = append(containFiles, value)
 			case "pattern":
 				restPatterns = append(restPatterns, value)
-			case "iamashamedtousethedisabledqueryname":
-				packagesNamed = append(packagesNamed, value)
 			case "": // not a reserved query
 				restPatterns = append(restPatterns, pattern)
 			default:
@@ -172,52 +187,34 @@ extractQueries:
 		}
 	}
 
-	response := &responseDeduper{}
-	var err error
-
 	// See if we have any patterns to pass through to go list. Zero initial
 	// patterns also requires a go list call, since it's the equivalent of
 	// ".".
 	if len(restPatterns) > 0 || len(patterns) == 0 {
-		dr, err := golistDriver(cfg, restPatterns...)
+		dr, err := state.createDriverResponse(restPatterns...)
 		if err != nil {
 			return nil, err
 		}
-		response.init(dr)
-	} else {
-		response.init(&driverResponse{})
+		response.addAll(dr)
 	}
 
-	sizeswg.Wait()
-	if sizeserr != nil {
-		return nil, sizeserr
-	}
-	// types.SizesFor always returns nil or a *types.StdSizes
-	response.dr.Sizes, _ = sizes.(*types.StdSizes)
-
-	var containsCandidates []string
-
 	if len(containFiles) != 0 {
-		if err := runContainsQueries(cfg, golistDriver, response, containFiles, getGoInfo); err != nil {
+		if err := state.runContainsQueries(response, containFiles); err != nil {
 			return nil, err
 		}
 	}
 
-	if len(packagesNamed) != 0 {
-		if err := runNamedQueries(cfg, golistDriver, response, packagesNamed); err != nil {
-			return nil, err
-		}
-	}
-
-	modifiedPkgs, needPkgs, err := processGolistOverlay(cfg, response, getGoInfo)
+	modifiedPkgs, needPkgs, err := state.processGolistOverlay(response)
 	if err != nil {
 		return nil, err
 	}
+
+	var containsCandidates []string
 	if len(containFiles) > 0 {
 		containsCandidates = append(containsCandidates, modifiedPkgs...)
 		containsCandidates = append(containsCandidates, needPkgs...)
 	}
-	if err := addNeededOverlayPackages(cfg, golistDriver, response, needPkgs, getGoInfo); err != nil {
+	if err := state.addNeededOverlayPackages(response, needPkgs); err != nil {
 		return nil, err
 	}
 	// Check candidate packages for containFiles.
@@ -246,28 +243,32 @@ extractQueries:
 		}
 	}
 
+	sizeswg.Wait()
+	if sizeserr != nil {
+		return nil, sizeserr
+	}
 	return response.dr, nil
 }
 
-func addNeededOverlayPackages(cfg *Config, driver driver, response *responseDeduper, pkgs []string, getGoInfo func() *goInfo) error {
+func (state *golistState) addNeededOverlayPackages(response *responseDeduper, pkgs []string) error {
 	if len(pkgs) == 0 {
 		return nil
 	}
-	dr, err := driver(cfg, pkgs...)
+	dr, err := state.createDriverResponse(pkgs...)
 	if err != nil {
 		return err
 	}
 	for _, pkg := range dr.Packages {
 		response.addPackage(pkg)
 	}
-	_, needPkgs, err := processGolistOverlay(cfg, response, getGoInfo)
+	_, needPkgs, err := state.processGolistOverlay(response)
 	if err != nil {
 		return err
 	}
-	return addNeededOverlayPackages(cfg, driver, response, needPkgs, getGoInfo)
+	return state.addNeededOverlayPackages(response, needPkgs)
 }
 
-func runContainsQueries(cfg *Config, driver driver, response *responseDeduper, queries []string, goInfo func() *goInfo) error {
+func (state *golistState) runContainsQueries(response *responseDeduper, queries []string) error {
 	for _, query := range queries {
 		// TODO(matloob): Do only one query per directory.
 		fdir := filepath.Dir(query)
@@ -277,44 +278,17 @@ func runContainsQueries(cfg *Config, driver driver, response *responseDeduper, q
 		if err != nil {
 			return fmt.Errorf("could not determine absolute path of file= query path %q: %v", query, err)
 		}
-		dirResponse, err := driver(cfg, pattern)
-		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.
+		dirResponse, err := state.createDriverResponse(pattern)
+
+		// If there was an error loading the package, or the package is returned
+		// with errors, 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 module mode and the ad-hoc is located outside a module.
+		if err != nil || len(dirResponse.Packages) == 1 && len(dirResponse.Packages[0].GoFiles) == 0 &&
+			len(dirResponse.Packages[0].Errors) == 1 {
 			var queryErr error
-			dirResponse, queryErr = driver(cfg, query)
-			if queryErr != nil {
-				// Return the original error if the attempt to fall back failed.
-				return 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 && 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")
-			}
-			// 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}
-						}
-					}
-				}
+			if dirResponse, queryErr = state.adhocPackage(pattern, query); queryErr != nil {
+				return err // return the original error
 			}
 		}
 		isRoot := make(map[string]bool, len(dirResponse.Roots))
@@ -342,276 +316,47 @@ func runContainsQueries(cfg *Config, driver driver, response *responseDeduper, q
 	return nil
 }
 
-// modCacheRegexp splits a path in a module cache into module, module version, and package.
-var modCacheRegexp = regexp.MustCompile(`(.*)@([^/\\]*)(.*)`)
-
-func runNamedQueries(cfg *Config, driver driver, response *responseDeduper, queries []string) error {
-	// calling `go env` isn't free; bail out if there's nothing to do.
-	if len(queries) == 0 {
-		return nil
-	}
-	// Determine which directories are relevant to scan.
-	roots, modRoot, err := roots(cfg)
+// adhocPackage attempts to load or construct an ad-hoc package for a given
+// query, if the original call to the driver produced inadequate results.
+func (state *golistState) adhocPackage(pattern, query string) (*driverResponse, error) {
+	response, err := state.createDriverResponse(query)
 	if err != nil {
-		return err
+		return nil, err
 	}
-
-	// Scan the selected directories. Simple matches, from GOPATH/GOROOT
-	// or the local module, can simply be "go list"ed. Matches from the
-	// module cache need special treatment.
-	var matchesMu sync.Mutex
-	var simpleMatches, modCacheMatches []string
-	add := func(root gopathwalk.Root, dir string) {
-		// Walk calls this concurrently; protect the result slices.
-		matchesMu.Lock()
-		defer matchesMu.Unlock()
-
-		path := dir
-		if dir != root.Path {
-			path = dir[len(root.Path)+1:]
-		}
-		if pathMatchesQueries(path, queries) {
-			switch root.Type {
-			case gopathwalk.RootModuleCache:
-				modCacheMatches = append(modCacheMatches, path)
-			case gopathwalk.RootCurrentModule:
-				// We'd need to read go.mod to find the full
-				// import path. Relative's easier.
-				rel, err := filepath.Rel(cfg.Dir, dir)
-				if err != nil {
-					// This ought to be impossible, since
-					// we found dir in the current module.
-					panic(err)
-				}
-				simpleMatches = append(simpleMatches, "./"+rel)
-			case gopathwalk.RootGOPATH, gopathwalk.RootGOROOT:
-				simpleMatches = append(simpleMatches, path)
-			}
-		}
-	}
-
-	startWalk := time.Now()
-	gopathwalk.Walk(roots, add, gopathwalk.Options{ModulesEnabled: modRoot != "", Debug: debug})
-	cfg.Logf("%v for walk", time.Since(startWalk))
-
-	// Weird special case: the top-level package in a module will be in
-	// whatever directory the user checked the repository out into. It's
-	// more reasonable for that to not match the package name. So, if there
-	// are any Go files in the mod root, query it just to be safe.
-	if modRoot != "" {
-		rel, err := filepath.Rel(cfg.Dir, modRoot)
-		if err != nil {
-			panic(err) // See above.
-		}
-
-		files, err := ioutil.ReadDir(modRoot)
-		if err != nil {
-			panic(err) // See above.
-		}
-
-		for _, f := range files {
-			if strings.HasSuffix(f.Name(), ".go") {
-				simpleMatches = append(simpleMatches, rel)
-				break
-			}
-		}
-	}
-
-	addResponse := func(r *driverResponse) {
-		for _, pkg := range r.Packages {
-			response.addPackage(pkg)
-			for _, name := range queries {
-				if pkg.Name == name {
-					response.addRoot(pkg.ID)
-					break
-				}
-			}
-		}
-	}
-
-	if len(simpleMatches) != 0 {
-		resp, err := driver(cfg, simpleMatches...)
-		if err != nil {
-			return err
-		}
-		addResponse(resp)
-	}
-
-	// Module cache matches are tricky. We want to avoid downloading new
-	// versions of things, so we need to use the ones present in the cache.
-	// go list doesn't accept version specifiers, so we have to write out a
-	// temporary module, and do the list in that module.
-	if len(modCacheMatches) != 0 {
-		// Collect all the matches, deduplicating by major version
-		// and preferring the newest.
-		type modInfo struct {
-			mod   string
-			major string
-		}
-		mods := make(map[modInfo]string)
-		var imports []string
-		for _, modPath := range modCacheMatches {
-			matches := modCacheRegexp.FindStringSubmatch(modPath)
-			mod, ver := filepath.ToSlash(matches[1]), matches[2]
-			importPath := filepath.ToSlash(filepath.Join(matches[1], matches[3]))
-
-			major := semver.Major(ver)
-			if prevVer, ok := mods[modInfo{mod, major}]; !ok || semver.Compare(ver, prevVer) > 0 {
-				mods[modInfo{mod, major}] = ver
-			}
-
-			imports = append(imports, importPath)
-		}
-
-		// Build the temporary module.
-		var gomod bytes.Buffer
-		gomod.WriteString("module modquery\nrequire (\n")
-		for mod, version := range mods {
-			gomod.WriteString("\t" + mod.mod + " " + version + "\n")
-		}
-		gomod.WriteString(")\n")
-
-		tmpCfg := *cfg
-
-		// We're only trying to look at stuff in the module cache, so
-		// disable the network. This should speed things up, and has
-		// prevented errors in at least one case, #28518.
-		tmpCfg.Env = append([]string{"GOPROXY=off"}, cfg.Env...)
-
-		var err error
-		tmpCfg.Dir, err = ioutil.TempDir("", "gopackages-modquery")
-		if err != nil {
-			return err
-		}
-		defer os.RemoveAll(tmpCfg.Dir)
-
-		if err := ioutil.WriteFile(filepath.Join(tmpCfg.Dir, "go.mod"), gomod.Bytes(), 0777); err != nil {
-			return fmt.Errorf("writing go.mod for module cache query: %v", err)
-		}
-
-		// Run the query, using the import paths calculated from the matches above.
-		resp, err := driver(&tmpCfg, imports...)
-		if err != nil {
-			return fmt.Errorf("querying module cache matches: %v", err)
-		}
-		addResponse(resp)
-	}
-
-	return nil
-}
-
-func getSizes(cfg *Config) (types.Sizes, error) {
-	return packagesdriver.GetSizesGolist(cfg.Context, cfg.BuildFlags, cfg.Env, cfg.Dir, usesExportData(cfg))
-}
-
-// roots selects the appropriate paths to walk based on the passed-in configuration,
-// particularly the environment and the presence of a go.mod in cfg.Dir's parents.
-func roots(cfg *Config) ([]gopathwalk.Root, string, error) {
-	stdout, err := invokeGo(cfg, "env", "GOROOT", "GOPATH", "GOMOD")
-	if err != nil {
-		return nil, "", err
-	}
-
-	fields := strings.Split(stdout.String(), "\n")
-	if len(fields) != 4 || len(fields[3]) != 0 {
-		return nil, "", fmt.Errorf("go env returned unexpected output: %q", stdout.String())
-	}
-	goroot, gopath, gomod := fields[0], filepath.SplitList(fields[1]), fields[2]
-	var modDir string
-	if gomod != "" {
-		modDir = filepath.Dir(gomod)
-	}
-
-	var roots []gopathwalk.Root
-	// Always add GOROOT.
-	roots = append(roots, gopathwalk.Root{
-		Path: filepath.Join(goroot, "/src"),
-		Type: gopathwalk.RootGOROOT,
-	})
-	// If modules are enabled, scan the module dir.
-	if modDir != "" {
-		roots = append(roots, gopathwalk.Root{
-			Path: modDir,
-			Type: gopathwalk.RootCurrentModule,
+	// If we get nothing back from `go list`,
+	// try to make this file into its own ad-hoc package.
+	// TODO(rstambler): Should this check against the original response?
+	if len(response.Packages) == 0 {
+		response.Packages = append(response.Packages, &Package{
+			ID:              "command-line-arguments",
+			PkgPath:         query,
+			GoFiles:         []string{query},
+			CompiledGoFiles: []string{query},
+			Imports:         make(map[string]*Package),
 		})
+		response.Roots = append(response.Roots, "command-line-arguments")
 	}
-	// Add either GOPATH/src or GOPATH/pkg/mod, depending on module mode.
-	for _, p := range gopath {
-		if modDir != "" {
-			roots = append(roots, gopathwalk.Root{
-				Path: filepath.Join(p, "/pkg/mod"),
-				Type: gopathwalk.RootModuleCache,
-			})
-		} else {
-			roots = append(roots, gopathwalk.Root{
-				Path: filepath.Join(p, "/src"),
-				Type: gopathwalk.RootGOPATH,
-			})
-		}
-	}
-
-	return roots, modDir, nil
-}
-
-// These functions were copied from goimports. See further documentation there.
-
-// pathMatchesQueries is adapted from pkgIsCandidate.
-// TODO: is it reasonable to do Contains here, rather than an exact match on a path component?
-func pathMatchesQueries(path string, queries []string) bool {
-	lastTwo := lastTwoComponents(path)
-	for _, query := range queries {
-		if strings.Contains(lastTwo, query) {
-			return true
-		}
-		if hasHyphenOrUpperASCII(lastTwo) && !hasHyphenOrUpperASCII(query) {
-			lastTwo = lowerASCIIAndRemoveHyphen(lastTwo)
-			if strings.Contains(lastTwo, query) {
-				return true
+	// Handle special cases.
+	if len(response.Packages) == 1 {
+		// golang/go#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 to the package and remove the errors.
+		if response.Packages[0].ID == "command-line-arguments" ||
+			filepath.ToSlash(response.Packages[0].PkgPath) == filepath.ToSlash(query) {
+			if len(response.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 state.cfg.Overlay {
+					if path == filename {
+						response.Packages[0].Errors = nil
+						response.Packages[0].GoFiles = []string{path}
+						response.Packages[0].CompiledGoFiles = []string{path}
+					}
+				}
 			}
 		}
 	}
-	return false
-}
-
-// lastTwoComponents returns at most the last two path components
-// of v, using either / or \ as the path separator.
-func lastTwoComponents(v string) string {
-	nslash := 0
-	for i := len(v) - 1; i >= 0; i-- {
-		if v[i] == '/' || v[i] == '\\' {
-			nslash++
-			if nslash == 2 {
-				return v[i:]
-			}
-		}
-	}
-	return v
-}
-
-func hasHyphenOrUpperASCII(s string) bool {
-	for i := 0; i < len(s); i++ {
-		b := s[i]
-		if b == '-' || ('A' <= b && b <= 'Z') {
-			return true
-		}
-	}
-	return false
-}
-
-func lowerASCIIAndRemoveHyphen(s string) (ret string) {
-	buf := make([]byte, 0, len(s))
-	for i := 0; i < len(s); i++ {
-		b := s[i]
-		switch {
-		case b == '-':
-			continue
-		case 'A' <= b && b <= 'Z':
-			buf = append(buf, b+('a'-'A'))
-		default:
-			buf = append(buf, b)
-		}
-	}
-	return string(buf)
+	return response, nil
 }
 
 // Fields must match go list;
@@ -636,6 +381,7 @@ type jsonPackage struct {
 	Imports         []string
 	ImportMap       map[string]string
 	Deps            []string
+	Module          *packagesinternal.Module
 	TestGoFiles     []string
 	TestImports     []string
 	XTestGoFiles    []string
@@ -656,10 +402,9 @@ func otherFiles(p *jsonPackage) [][]string {
 	return [][]string{p.CFiles, p.CXXFiles, p.MFiles, p.HFiles, p.FFiles, p.SFiles, p.SwigFiles, p.SwigCXXFiles, p.SysoFiles}
 }
 
-// golistDriver uses the "go list" command to expand the pattern
-// words and return metadata for the specified packages. dir may be
-// "" and env may be nil, as per os/exec.Command.
-func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driverResponse, error) {
+// createDriverResponse uses the "go list" command to expand the pattern
+// words and return a response for the specified packages.
+func (state *golistState) createDriverResponse(words ...string) (*driverResponse, error) {
 	// go list uses the following identifiers in ImportPath and Imports:
 	//
 	// 	"p"			-- importable package or main (command)
@@ -673,11 +418,13 @@ func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driv
 
 	// Run "go list" for complete
 	// information on the specified packages.
-	buf, err := invokeGo(cfg, "list", golistargs(cfg, words)...)
+	buf, err := state.invokeGo("list", golistargs(state.cfg, words)...)
 	if err != nil {
 		return nil, err
 	}
 	seen := make(map[string]*jsonPackage)
+	pkgs := make(map[string]*Package)
+	additionalErrors := make(map[string][]Error)
 	// Decode the JSON and convert it to Package form.
 	var response driverResponse
 	for dec := json.NewDecoder(buf); dec.More(); {
@@ -708,18 +455,72 @@ func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driv
 		// contained in a known module or GOPATH entry. This will allow the package to be
 		// properly "reclaimed" when overlays are processed.
 		if filepath.IsAbs(p.ImportPath) && p.Error != nil {
-			pkgPath, ok := getPkgPath(cfg, p.ImportPath, rootsDirs)
+			pkgPath, ok, err := state.getPkgPath(p.ImportPath)
+			if err != nil {
+				return nil, err
+			}
 			if ok {
 				p.ImportPath = pkgPath
 			}
 		}
 
 		if old, found := seen[p.ImportPath]; found {
-			if !reflect.DeepEqual(p, old) {
-				return nil, fmt.Errorf("internal error: go list gives conflicting information for package %v", p.ImportPath)
+			// If one version of the package has an error, and the other doesn't, assume
+			// that this is a case where go list is reporting a fake dependency variant
+			// of the imported package: When a package tries to invalidly import another
+			// package, go list emits a variant of the imported package (with the same
+			// import path, but with an error on it, and the package will have a
+			// DepError set on it). An example of when this can happen is for imports of
+			// main packages: main packages can not be imported, but they may be
+			// separately matched and listed by another pattern.
+			// See golang.org/issue/36188 for more details.
+
+			// The plan is that eventually, hopefully in Go 1.15, the error will be
+			// reported on the importing package rather than the duplicate "fake"
+			// version of the imported package. Once all supported versions of Go
+			// have the new behavior this logic can be deleted.
+			// TODO(matloob): delete the workaround logic once all supported versions of
+			// Go return the errors on the proper package.
+
+			// There should be exactly one version of a package that doesn't have an
+			// error.
+			if old.Error == nil && p.Error == nil {
+				if !reflect.DeepEqual(p, old) {
+					return nil, fmt.Errorf("internal error: go list gives conflicting information for package %v", p.ImportPath)
+				}
+				continue
 			}
-			// skip the duplicate
-			continue
+
+			// Determine if this package's error needs to be bubbled up.
+			// This is a hack, and we expect for go list to eventually set the error
+			// on the package.
+			if old.Error != nil {
+				var errkind string
+				if strings.Contains(old.Error.Err, "not an importable package") {
+					errkind = "not an importable package"
+				} else if strings.Contains(old.Error.Err, "use of internal package") && strings.Contains(old.Error.Err, "not allowed") {
+					errkind = "use of internal package not allowed"
+				}
+				if errkind != "" {
+					if len(old.Error.ImportStack) < 2 {
+						return nil, fmt.Errorf(`internal error: go list gave a %q error with an import stack with fewer than two elements`, errkind)
+					}
+					importingPkg := old.Error.ImportStack[len(old.Error.ImportStack)-2]
+					additionalErrors[importingPkg] = append(additionalErrors[importingPkg], Error{
+						Pos:  old.Error.Pos,
+						Msg:  old.Error.Err,
+						Kind: ListError,
+					})
+				}
+			}
+
+			// Make sure that if there's a version of the package without an error,
+			// that's the one reported to the user.
+			if old.Error == nil {
+				continue
+			}
+
+			// This package will replace the old one at the end of the loop.
 		}
 		seen[p.ImportPath] = p
 
@@ -729,6 +530,8 @@ func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driv
 			GoFiles:         absJoin(p.Dir, p.GoFiles, p.CgoFiles),
 			CompiledGoFiles: absJoin(p.Dir, p.CompiledGoFiles),
 			OtherFiles:      absJoin(p.Dir, otherFiles(p)...),
+			forTest:         p.ForTest,
+			module:          p.Module,
 		}
 
 		// Work around https://golang.org/issue/28749:
@@ -817,29 +620,37 @@ func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driv
 			})
 		}
 
+		pkgs[pkg.ID] = pkg
+	}
+
+	for id, errs := range additionalErrors {
+		if p, ok := pkgs[id]; ok {
+			p.Errors = append(p.Errors, errs...)
+		}
+	}
+	for _, pkg := range pkgs {
 		response.Packages = append(response.Packages, pkg)
 	}
+	sort.Slice(response.Packages, func(i, j int) bool { return response.Packages[i].ID < response.Packages[j].ID })
 
 	return &response, nil
 }
 
 // getPkgPath finds the package path of a directory if it's relative to a root directory.
-func getPkgPath(cfg *Config, dir string, goInfo func() *goInfo) (string, bool) {
+func (state *golistState) getPkgPath(dir string) (string, bool, error) {
 	absDir, err := filepath.Abs(dir)
 	if err != nil {
-		cfg.Logf("error getting absolute path of %s: %v", dir, err)
-		return "", false
+		return "", false, err
 	}
-	for rdir, rpath := range goInfo().rootDirs {
-		absRdir, err := filepath.Abs(rdir)
-		if err != nil {
-			cfg.Logf("error getting absolute path of %s: %v", rdir, err)
-			continue
-		}
+	roots, err := state.determineRootDirs()
+	if err != nil {
+		return "", false, err
+	}
+
+	for rdir, rpath := range roots {
 		// Make sure that the directory is in the module,
 		// to avoid creating a path relative to another module.
-		if !strings.HasPrefix(absDir, absRdir) {
-			cfg.Logf("%s does not have prefix %s", absDir, absRdir)
+		if !strings.HasPrefix(absDir, rdir) {
 			continue
 		}
 		// TODO(matloob): This doesn't properly handle symlinks.
@@ -854,11 +665,11 @@ func getPkgPath(cfg *Config, dir string, goInfo func() *goInfo) (string, bool) {
 			// Once the file is saved, gopls, or the next invocation of the tool will get the correct
 			// result straight from golist.
 			// TODO(matloob): Implement module tiebreaking?
-			return path.Join(rpath, filepath.ToSlash(r)), true
+			return path.Join(rpath, filepath.ToSlash(r)), true, nil
 		}
-		return filepath.ToSlash(r), true
+		return filepath.ToSlash(r), true, nil
 	}
-	return "", false
+	return "", false, nil
 }
 
 // absJoin absolutizes and flattens the lists of files.
@@ -878,7 +689,7 @@ func golistargs(cfg *Config, words []string) []string {
 	const findFlags = NeedImports | NeedTypes | NeedSyntax | NeedTypesInfo
 	fullargs := []string{
 		"-e", "-json",
-		fmt.Sprintf("-compiled=%t", cfg.Mode&(NeedCompiledGoFiles|NeedSyntax|NeedTypesInfo|NeedTypesSizes) != 0),
+		fmt.Sprintf("-compiled=%t", cfg.Mode&(NeedCompiledGoFiles|NeedSyntax|NeedTypes|NeedTypesInfo|NeedTypesSizes) != 0),
 		fmt.Sprintf("-test=%t", cfg.Tests),
 		fmt.Sprintf("-export=%t", usesExportData(cfg)),
 		fmt.Sprintf("-deps=%t", cfg.Mode&NeedImports != 0),
@@ -893,28 +704,20 @@ func golistargs(cfg *Config, words []string) []string {
 }
 
 // invokeGo returns the stdout of a go command invocation.
-func invokeGo(cfg *Config, verb string, args ...string) (*bytes.Buffer, error) {
-	stdout := new(bytes.Buffer)
-	stderr := new(bytes.Buffer)
-	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.
-	// The Go stdlib has a special feature where if the cwd and the PWD are the
-	// same node then it trusts the PWD, so by setting it in the env for the child
-	// process we fix up all the paths returned by the go command.
-	cmd.Env = append(append([]string{}, cfg.Env...), "PWD="+cfg.Dir)
-	cmd.Dir = cfg.Dir
-	cmd.Stdout = stdout
-	cmd.Stderr = stderr
-	defer func(start time.Time) {
-		cfg.Logf("%s for %v, stderr: <<%s>> stdout: <<%s>>\n", time.Since(start), cmdDebugStr(cmd, args...), stderr, stdout)
-	}(time.Now())
+func (state *golistState) invokeGo(verb string, args ...string) (*bytes.Buffer, error) {
+	cfg := state.cfg
 
-	if err := cmd.Run(); err != nil {
+	inv := &gocommand.Invocation{
+		Verb:       verb,
+		Args:       args,
+		BuildFlags: cfg.BuildFlags,
+		Env:        cfg.Env,
+		Logf:       cfg.Logf,
+		WorkingDir: cfg.Dir,
+	}
+
+	stdout, stderr, _, err := inv.RunRaw(cfg.Context)
+	if err != nil {
 		// Check for 'go' executable not being found.
 		if ee, ok := err.(*exec.Error); ok && ee.Err == exec.ErrNotFound {
 			return nil, fmt.Errorf("'go list' driver requires 'go', but %s", exec.ErrNotFound)
@@ -924,7 +727,7 @@ func invokeGo(cfg *Config, verb string, args ...string) (*bytes.Buffer, error) {
 		if !ok {
 			// Catastrophic error:
 			// - context cancellation
-			return nil, fmt.Errorf("couldn't exec 'go %v': %s %T", args, err, err)
+			return nil, fmt.Errorf("couldn't run 'go': %v", err)
 		}
 
 		// Old go version?
@@ -951,7 +754,12 @@ func invokeGo(cfg *Config, verb string, args ...string) (*bytes.Buffer, error) {
 				!strings.ContainsRune("!\"#$%&'()*,:;<=>?[\\]^`{|}\uFFFD", r)
 		}
 		if len(stderr.String()) > 0 && strings.HasPrefix(stderr.String(), "# ") {
-			if strings.HasPrefix(strings.TrimLeftFunc(stderr.String()[len("# "):], isPkgPathRune), "\n") {
+			msg := stderr.String()[len("# "):]
+			if strings.HasPrefix(strings.TrimLeftFunc(msg, isPkgPathRune), "\n") {
+				return stdout, nil
+			}
+			// Treat pkg-config errors as a special case (golang.org/issue/36770).
+			if strings.HasPrefix(msg, "pkg-config") {
 				return stdout, nil
 			}
 		}
@@ -1040,16 +848,6 @@ func invokeGo(cfg *Config, verb string, args ...string) (*bytes.Buffer, error) {
 			return nil, fmt.Errorf("go %v: %s: %s", args, exitErr, stderr)
 		}
 	}
-
-	// As of writing, go list -export prints some non-fatal compilation
-	// errors to stderr, even with -e set. We would prefer that it put
-	// them in the Package.Error JSON (see https://golang.org/issue/26319).
-	// In the meantime, there's nowhere good to put them, but they can
-	// be useful for debugging. Print them if $GOPACKAGESPRINTGOLISTERRORS
-	// is set.
-	if len(stderr.Bytes()) != 0 && os.Getenv("GOPACKAGESPRINTGOLISTERRORS") != "" {
-		fmt.Fprintf(os.Stderr, "%s stderr: <<%s>>\n", cmdDebugStr(cmd, args...), stderr)
-	}
 	return stdout, nil
 }
 

vendor/golang.org/x/tools/go/packages/golist_overlay.go

@@ -1,12 +1,13 @@
 package packages
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"go/parser"
 	"go/token"
+	"os"
 	"path/filepath"
+	"sort"
 	"strconv"
 	"strings"
 )
@@ -16,7 +17,7 @@ import (
 // sometimes incorrect.
 // TODO(matloob): Handle unsupported cases, including the following:
 // - determining the correct package to add given a new import path
-func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func() *goInfo) (modifiedPkgs, needPkgs []string, err error) {
+func (state *golistState) processGolistOverlay(response *responseDeduper) (modifiedPkgs, needPkgs []string, err error) {
 	havePkgs := make(map[string]string) // importPath -> non-test package ID
 	needPkgsSet := make(map[string]bool)
 	modifiedPkgsSet := make(map[string]bool)
@@ -34,7 +35,23 @@ func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func(
 	// potentially modifying the transitive set of dependencies).
 	var overlayAddsImports bool
 
-	for opath, contents := range cfg.Overlay {
+	// If both a package and its test package are created by the overlay, we
+	// need the real package first. Process all non-test files before test
+	// files, and make the whole process deterministic while we're at it.
+	var overlayFiles []string
+	for opath := range state.cfg.Overlay {
+		overlayFiles = append(overlayFiles, opath)
+	}
+	sort.Slice(overlayFiles, func(i, j int) bool {
+		iTest := strings.HasSuffix(overlayFiles[i], "_test.go")
+		jTest := strings.HasSuffix(overlayFiles[j], "_test.go")
+		if iTest != jTest {
+			return !iTest // non-tests are before tests.
+		}
+		return overlayFiles[i] < overlayFiles[j]
+	})
+	for _, opath := range overlayFiles {
+		contents := state.cfg.Overlay[opath]
 		base := filepath.Base(opath)
 		dir := filepath.Dir(opath)
 		var pkg *Package           // if opath belongs to both a package and its test variant, this will be the test variant
@@ -64,14 +81,8 @@ func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func(
 					testVariantOf = p
 					continue nextPackage
 				}
+				// We must have already seen the package of which this is a test variant.
 				if pkg != nil && p != pkg && pkg.PkgPath == p.PkgPath {
-					// If we've already seen the test variant,
-					// make sure to label which package it is a test variant of.
-					if hasTestFiles(pkg) {
-						testVariantOf = p
-						continue nextPackage
-					}
-					// If we have already seen the package of which this is a test variant.
 					if hasTestFiles(p) {
 						testVariantOf = pkg
 					}
@@ -86,7 +97,10 @@ func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func(
 		if pkg == nil {
 			// Try to find the module or gopath dir the file is contained in.
 			// Then for modules, add the module opath to the beginning.
-			pkgPath, ok := getPkgPath(cfg, dir, rootDirs)
+			pkgPath, ok, err := state.getPkgPath(dir)
+			if err != nil {
+				return nil, nil, err
+			}
 			if !ok {
 				break
 			}
@@ -114,6 +128,11 @@ func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func(
 				if isTestFile && !isXTest && testVariantOf != nil {
 					pkg.GoFiles = append(pkg.GoFiles, testVariantOf.GoFiles...)
 					pkg.CompiledGoFiles = append(pkg.CompiledGoFiles, testVariantOf.CompiledGoFiles...)
+					// Add the package under test and its imports to the test variant.
+					pkg.forTest = testVariantOf.PkgPath
+					for k, v := range testVariantOf.Imports {
+						pkg.Imports[k] = &Package{ID: v.ID}
+					}
 				}
 			}
 		}
@@ -130,42 +149,45 @@ func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func(
 			continue
 		}
 		for _, imp := range imports {
-			_, found := pkg.Imports[imp]
-			if !found {
-				overlayAddsImports = true
-				// TODO(matloob): Handle cases when the following block isn't correct.
-				// These include imports of vendored packages, etc.
-				id, ok := havePkgs[imp]
-				if !ok {
-					id = imp
-				}
-				pkg.Imports[imp] = &Package{ID: id}
-				// Add dependencies to the non-test variant version of this package as wel.
-				if testVariantOf != nil {
-					testVariantOf.Imports[imp] = &Package{ID: id}
+			if _, found := pkg.Imports[imp]; found {
+				continue
+			}
+			overlayAddsImports = true
+			id, ok := havePkgs[imp]
+			if !ok {
+				var err error
+				id, err = state.resolveImport(dir, imp)
+				if err != nil {
+					return nil, nil, err
 				}
 			}
+			pkg.Imports[imp] = &Package{ID: id}
+			// Add dependencies to the non-test variant version of this package as well.
+			if testVariantOf != nil {
+				testVariantOf.Imports[imp] = &Package{ID: id}
+			}
 		}
-		continue
 	}
 
-	// toPkgPath tries to guess the package path given the id.
-	// This isn't always correct -- it's certainly wrong for
-	// vendored packages' paths.
-	toPkgPath := func(id string) string {
-		// TODO(matloob): Handle vendor paths.
-		i := strings.IndexByte(id, ' ')
-		if i >= 0 {
-			return id[:i]
+	// toPkgPath guesses the package path given the id.
+	toPkgPath := func(sourceDir, id string) (string, error) {
+		if i := strings.IndexByte(id, ' '); i >= 0 {
+			return state.resolveImport(sourceDir, id[:i])
 		}
-		return id
+		return state.resolveImport(sourceDir, id)
 	}
 
-	// Do another pass now that new packages have been created to determine the
-	// set of missing packages.
+	// Now that new packages have been created, do another pass to determine
+	// the new set of missing packages.
 	for _, pkg := range response.dr.Packages {
 		for _, imp := range pkg.Imports {
-			pkgPath := toPkgPath(imp.ID)
+			if len(pkg.GoFiles) == 0 {
+				return nil, nil, fmt.Errorf("cannot resolve imports for package %q with no Go files", pkg.PkgPath)
+			}
+			pkgPath, err := toPkgPath(filepath.Dir(pkg.GoFiles[0]), imp.ID)
+			if err != nil {
+				return nil, nil, err
+			}
 			if _, ok := havePkgs[pkgPath]; !ok {
 				needPkgsSet[pkgPath] = true
 			}
@@ -185,6 +207,52 @@ func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func(
 	return modifiedPkgs, needPkgs, err
 }
 
+// resolveImport finds the the ID of a package given its import path.
+// In particular, it will find the right vendored copy when in GOPATH mode.
+func (state *golistState) resolveImport(sourceDir, importPath string) (string, error) {
+	env, err := state.getEnv()
+	if err != nil {
+		return "", err
+	}
+	if env["GOMOD"] != "" {
+		return importPath, nil
+	}
+
+	searchDir := sourceDir
+	for {
+		vendorDir := filepath.Join(searchDir, "vendor")
+		exists, ok := state.vendorDirs[vendorDir]
+		if !ok {
+			info, err := os.Stat(vendorDir)
+			exists = err == nil && info.IsDir()
+			state.vendorDirs[vendorDir] = exists
+		}
+
+		if exists {
+			vendoredPath := filepath.Join(vendorDir, importPath)
+			if info, err := os.Stat(vendoredPath); err == nil && info.IsDir() {
+				// We should probably check for .go files here, but shame on anyone who fools us.
+				path, ok, err := state.getPkgPath(vendoredPath)
+				if err != nil {
+					return "", err
+				}
+				if ok {
+					return path, nil
+				}
+			}
+		}
+
+		// We know we've hit the top of the filesystem when we Dir / and get /,
+		// or C:\ and get C:\, etc.
+		next := filepath.Dir(searchDir)
+		if next == searchDir {
+			break
+		}
+		searchDir = next
+	}
+	return importPath, nil
+}
+
 func hasTestFiles(p *Package) bool {
 	for _, f := range p.GoFiles {
 		if strings.HasSuffix(f, "_test.go") {
@@ -194,44 +262,59 @@ func hasTestFiles(p *Package) bool {
 	return false
 }
 
-// determineRootDirs returns a mapping from directories code can be contained in to the
-// corresponding import path prefixes of those directories.
-// Its result is used to try to determine the import path for a package containing
-// an overlay file.
-func determineRootDirs(cfg *Config) map[string]string {
-	// Assume modules first:
-	out, err := invokeGo(cfg, "list", "-m", "-json", "all")
+// determineRootDirs returns a mapping from absolute directories that could
+// contain code to their corresponding import path prefixes.
+func (state *golistState) determineRootDirs() (map[string]string, error) {
+	env, err := state.getEnv()
 	if err != nil {
-		return determineRootDirsGOPATH(cfg)
+		return nil, err
+	}
+	if env["GOMOD"] != "" {
+		state.rootsOnce.Do(func() {
+			state.rootDirs, state.rootDirsError = state.determineRootDirsModules()
+		})
+	} else {
+		state.rootsOnce.Do(func() {
+			state.rootDirs, state.rootDirsError = state.determineRootDirsGOPATH()
+		})
+	}
+	return state.rootDirs, state.rootDirsError
+}
+
+func (state *golistState) determineRootDirsModules() (map[string]string, error) {
+	out, err := state.invokeGo("list", "-m", "-json", "all")
+	if err != nil {
+		return nil, err
 	}
 	m := map[string]string{}
 	type jsonMod struct{ Path, Dir string }
 	for dec := json.NewDecoder(out); dec.More(); {
 		mod := new(jsonMod)
 		if err := dec.Decode(mod); err != nil {
-			return m // Give up and return an empty map. Package won't be found for overlay.
+			return nil, err
 		}
 		if mod.Dir != "" && mod.Path != "" {
 			// This is a valid module; add it to the map.
-			m[mod.Dir] = mod.Path
+			absDir, err := filepath.Abs(mod.Dir)
+			if err != nil {
+				return nil, err
+			}
+			m[absDir] = mod.Path
 		}
 	}
-	return m
+	return m, nil
 }
 
-func determineRootDirsGOPATH(cfg *Config) map[string]string {
+func (state *golistState) determineRootDirsGOPATH() (map[string]string, error) {
 	m := map[string]string{}
-	out, err := invokeGo(cfg, "env", "GOPATH")
-	if err != nil {
-		// Could not determine root dir mapping. Everything is best-effort, so just return an empty map.
-		// When we try to find the import path for a directory, there will be no root-dir match and
-		// we'll give up.
-		return m
+	for _, dir := range filepath.SplitList(state.mustGetEnv()["GOPATH"]) {
+		absDir, err := filepath.Abs(dir)
+		if err != nil {
+			return nil, err
+		}
+		m[filepath.Join(absDir, "src")] = ""
 	}
-	for _, p := range filepath.SplitList(string(bytes.TrimSpace(out.Bytes()))) {
-		m[filepath.Join(p, "src")] = ""
-	}
-	return m
+	return m, nil
 }
 
 func extractImports(filename string, contents []byte) ([]string, error) {

vendor/golang.org/x/tools/go/packages/packages.go

@@ -23,6 +23,7 @@ import (
 	"sync"
 
 	"golang.org/x/tools/go/gcexportdata"
+	"golang.org/x/tools/internal/packagesinternal"
 )
 
 // A LoadMode controls the amount of detail to return when loading.
@@ -34,6 +35,9 @@ import (
 // Load may return more information than requested.
 type LoadMode int
 
+// TODO(matloob): When a V2 of go/packages is released, rename NeedExportsFile to
+// NeedExportFile to make it consistent with the Package field it's adding.
+
 const (
 	// NeedName adds Name and PkgPath.
 	NeedName LoadMode = 1 << iota
@@ -51,7 +55,7 @@ const (
 	// NeedDeps adds the fields requested by the LoadMode in the packages in Imports.
 	NeedDeps
 
-	// NeedExportsFile adds ExportsFile.
+	// NeedExportsFile adds ExportFile.
 	NeedExportsFile
 
 	// NeedTypes adds Types, Fset, and IllTyped.
@@ -292,6 +296,21 @@ type Package struct {
 
 	// TypesSizes provides the effective size function for types in TypesInfo.
 	TypesSizes types.Sizes
+
+	// forTest is the package under test, if any.
+	forTest string
+
+	// module is the module information for the package if it exists.
+	module *packagesinternal.Module
+}
+
+func init() {
+	packagesinternal.GetForTest = func(p interface{}) string {
+		return p.(*Package).forTest
+	}
+	packagesinternal.GetModule = func(p interface{}) *packagesinternal.Module {
+		return p.(*Package).module
+	}
 }
 
 // An Error describes a problem with a package's metadata, syntax, or types.
@@ -500,12 +519,23 @@ func (ld *loader) refine(roots []string, list ...*Package) ([]*Package, error) {
 		if i, found := rootMap[pkg.ID]; found {
 			rootIndex = i
 		}
+
+		// Overlays can invalidate export data.
+		// TODO(matloob): make this check fine-grained based on dependencies on overlaid files
+		exportDataInvalid := len(ld.Overlay) > 0 || pkg.ExportFile == "" && pkg.PkgPath != "unsafe"
+		// This package needs type information if the caller requested types and the package is
+		// either a root, or it's a non-root and the user requested dependencies ...
+		needtypes := (ld.Mode&NeedTypes|NeedTypesInfo != 0 && (rootIndex >= 0 || ld.Mode&NeedDeps != 0))
+		// This package needs source if the call requested source (or types info, which implies source)
+		// and the package is either a root, or itas a non- root and the user requested dependencies...
+		needsrc := ((ld.Mode&(NeedSyntax|NeedTypesInfo) != 0 && (rootIndex >= 0 || ld.Mode&NeedDeps != 0)) ||
+			// ... or if we need types and the exportData is invalid. We fall back to (incompletely)
+			// typechecking packages from source if they fail to compile.
+			(ld.Mode&NeedTypes|NeedTypesInfo != 0 && exportDataInvalid)) && pkg.PkgPath != "unsafe"
 		lpkg := &loaderPackage{
 			Package:   pkg,
-			needtypes: (ld.Mode&(NeedTypes|NeedTypesInfo) != 0 && ld.Mode&NeedDeps != 0 && rootIndex < 0) || rootIndex >= 0,
-			needsrc: (ld.Mode&(NeedSyntax|NeedTypesInfo) != 0 && ld.Mode&NeedDeps != 0 && rootIndex < 0) || rootIndex >= 0 ||
-				len(ld.Overlay) > 0 || // Overlays can invalidate export data. TODO(matloob): make this check fine-grained based on dependencies on overlaid files
-				pkg.ExportFile == "" && pkg.PkgPath != "unsafe",
+			needtypes: needtypes,
+			needsrc:   needsrc,
 		}
 		ld.pkgs[lpkg.ID] = lpkg
 		if rootIndex >= 0 {

vendor/golang.org/x/tools/go/pointer/TODO

@@ -1,33 +0,0 @@
--*- 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.
-
-

vendor/golang.org/x/tools/go/pointer/analysis.go

@@ -1,452 +0,0 @@
-// 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))
-	}
-}

vendor/golang.org/x/tools/go/pointer/api.go

@@ -1,285 +0,0 @@
-// 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()
-}

vendor/golang.org/x/tools/go/pointer/callgraph.go

@@ -1,61 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/pointer/constraint.go

@@ -1,149 +0,0 @@
-// 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]
-}

vendor/golang.org/x/tools/go/pointer/doc.go

@@ -1,610 +0,0 @@
-// 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<n.
-
-The zero nodeid means "not a pointer".  For simplicity, we generate flow
-constraints even for non-pointer types such as int.  The pointer
-equivalence (PE) presolver optimization detects which variables cannot
-point to anything; this includes not only all variables of non-pointer
-types (such as int) but also variables of pointer-like types if they are
-always nil, or are parameters to a function that is never called.
-
-Each node represents a scalar part of a value or object.
-Aggregate types (structs, tuples, arrays) are recursively flattened
-out into a sequential list of scalar component types, and all the
-elements of an array are represented by a single node.  (The
-flattening of a basic type is a list containing a single node.)
-
-Nodes are connected into a graph with various kinds of labelled edges:
-simple edges (or copy constraints) represent value flow.  Complex
-edges (load, store, etc) trigger the creation of new simple edges
-during the solving phase.
-
-
-OBJECTS
-
-Conceptually, an "object" is a contiguous sequence of nodes denoting
-an addressable location: something that a pointer can point to.  The
-first node of an object has a non-nil obj field containing information
-about the allocation: its size, context, and ssa.Value.
-
-Objects include:
-   - functions and globals;
-   - variable allocations in the stack frame or heap;
-   - maps, channels and slices created by calls to make();
-   - allocations to construct an interface;
-   - allocations caused by conversions, e.g. []byte(str).
-   - arrays allocated by calls to append();
-
-Many objects have no Go types.  For example, the func, map and chan type
-kinds in Go are all varieties of pointers, but their respective objects
-are actual functions (executable code), maps (hash tables), and channels
-(synchronized queues).  Given the way we model interfaces, they too are
-pointers to "tagged" objects with no Go type.  And an *ssa.Global denotes
-the address of a global variable, but the object for a Global is the
-actual data.  So, the types of an ssa.Value that creates an object is
-"off by one indirection": a pointer to the object.
-
-The individual nodes of an object are sometimes referred to as "labels".
-
-For uniformity, all objects have a non-zero number of fields, even those
-of the empty type struct{}.  (All arrays are treated as if of length 1,
-so there are no empty arrays.  The empty tuple is never address-taken,
-so is never an object.)
-
-
-TAGGED OBJECTS
-
-An tagged object has the following layout:
-
-    T          -- obj.flags ⊇ {otTagged}
-    v
-    ...
-
-The T node's typ field is the dynamic type of the "payload": the value
-v which follows, flattened out.  The T node's obj has the otTagged
-flag.
-
-Tagged objects are needed when generalizing across types: interfaces,
-reflect.Values, reflect.Types.  Each of these three types is modelled
-as a pointer that exclusively points to tagged objects.
-
-Tagged objects may be indirect (obj.flags ⊇ {otIndirect}) meaning that
-the value v is not of type T but *T; this is used only for
-reflect.Values that represent lvalues.  (These are not implemented yet.)
-
-
-ANALYSIS ABSTRACTION OF EACH TYPE
-
-Variables of the following "scalar" types may be represented by a
-single node: basic types, pointers, channels, maps, slices, 'func'
-pointers, interfaces.
-
-Pointers
-  Nothing to say here, oddly.
-
-Basic types (bool, string, numbers, unsafe.Pointer)
-  Currently all fields in the flattening of a type, including
-  non-pointer basic types such as int, are represented in objects and
-  values.  Though non-pointer nodes within values are uninteresting,
-  non-pointer nodes in objects may be useful (if address-taken)
-  because they permit the analysis to deduce, in this example,
-
-     var s struct{ ...; x int; ... }
-     p := &s.x
-
-  that p points to s.x.  If we ignored such object fields, we could only
-  say that p points somewhere within s.
-
-  All other basic types are ignored.  Expressions of these types have
-  zero nodeid, and fields of these types within aggregate other types
-  are omitted.
-
-  unsafe.Pointers are not modelled as pointers, so a conversion of an
-  unsafe.Pointer to *T is (unsoundly) treated equivalent to new(T).
-
-Channels
-  An expression of type 'chan T' is a kind of pointer that points
-  exclusively to channel objects, i.e. objects created by MakeChan (or
-  reflection).
-
-  'chan T' is treated like *T.
-  *ssa.MakeChan is treated as equivalent to new(T).
-  *ssa.Send and receive (*ssa.UnOp(ARROW)) and are equivalent to store
-   and load.
-
-Maps
-  An expression of type 'map[K]V' is a kind of pointer that points
-  exclusively to map objects, i.e. objects created by MakeMap (or
-  reflection).
-
-  map K[V] is treated like *M where M = struct{k K; v V}.
-  *ssa.MakeMap is equivalent to new(M).
-  *ssa.MapUpdate is equivalent to *y=x where *y and x have type M.
-  *ssa.Lookup is equivalent to y=x.v where x has type *M.
-
-Slices
-  A slice []T, which dynamically resembles a struct{array *T, len, cap int},
-  is treated as if it were just a *T pointer; the len and cap fields are
-  ignored.
-
-  *ssa.MakeSlice is treated like new([1]T): an allocation of a
-   singleton array.
-  *ssa.Index on a slice is equivalent to a load.
-  *ssa.IndexAddr on a slice returns the address of the sole element of the
-  slice, i.e. the same address.
-  *ssa.Slice is treated as a simple copy.
-
-Functions
-  An expression of type 'func...' is a kind of pointer that points
-  exclusively to function objects.
-
-  A function object has the following layout:
-
-     identity         -- typ:*types.Signature; obj.flags ⊇ {otFunction}
-     params_0         -- (the receiver, if a method)
-     ...
-     params_n-1
-     results_0
-     ...
-     results_m-1
-
-  There may be multiple function objects for the same *ssa.Function
-  due to context-sensitive treatment of some functions.
-
-  The first node is the function's identity node.
-  Associated with every callsite is a special "targets" variable,
-  whose pts() contains the identity node of each function to which
-  the call may dispatch.  Identity words are not otherwise used during
-  the analysis, but we construct the call graph from the pts()
-  solution for such nodes.
-
-  The following block of contiguous nodes represents the flattened-out
-  types of the parameters ("P-block") and results ("R-block") of the
-  function object.
-
-  The treatment of free variables of closures (*ssa.FreeVar) is like
-  that of global variables; it is not context-sensitive.
-  *ssa.MakeClosure instructions create copy edges to Captures.
-
-  A Go value of type 'func' (i.e. a pointer to one or more functions)
-  is a pointer whose pts() contains function objects.  The valueNode()
-  for an *ssa.Function returns a singleton for that function.
-
-Interfaces
-  An expression of type 'interface{...}' is a kind of pointer that
-  points exclusively to tagged objects.  All tagged objects pointed to
-  by an interface are direct (the otIndirect flag is clear) and
-  concrete (the tag type T is not itself an interface type).  The
-  associated ssa.Value for an interface's tagged objects may be an
-  *ssa.MakeInterface instruction, or nil if the tagged object was
-  created by an instrinsic (e.g. reflection).
-
-  Constructing an interface value causes generation of constraints for
-  all of the concrete type's methods; we can't tell a priori which
-  ones may be called.
-
-  TypeAssert y = x.(T) is implemented by a dynamic constraint
-  triggered by each tagged object O added to pts(x): a typeFilter
-  constraint if T is an interface type, or an untag constraint if T is
-  a concrete type.  A typeFilter tests whether O.typ implements T; if
-  so, O is added to pts(y).  An untagFilter tests whether O.typ is
-  assignable to T,and if so, a copy edge O.v -> 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"

vendor/golang.org/x/tools/go/pointer/hvn.go

@@ -1,973 +0,0 @@
-// 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)
-	}
-}

vendor/golang.org/x/tools/go/pointer/intrinsics.go

@@ -1,361 +0,0 @@
-// 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,
-	})
-}

vendor/golang.org/x/tools/go/pointer/labels.go

@@ -1,152 +0,0 @@
-// 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)
-//      <alloc in reflect.Zero>                 (allocation in instrinsic)
-//      sync.Mutex                              (a reflect.rtype instance)
-//      <command-line arguments>                (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("<alloc in %s>", l.obj.cgn.fn)
-		} else {
-			s = "<unknown>" // 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()
-}

vendor/golang.org/x/tools/go/pointer/opt.go

@@ -1,132 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/pointer/print.go

@@ -1,43 +0,0 @@
-// 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)
-}

vendor/golang.org/x/tools/go/pointer/query.go

@@ -1,221 +0,0 @@
-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
-}

vendor/golang.org/x/tools/go/pointer/solve.go

@@ -1,370 +0,0 @@
-// 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")
-}

vendor/golang.org/x/tools/go/pointer/util.go

@@ -1,313 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/ssa/blockopt.go

@@ -1,187 +0,0 @@
-// 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()
-}

vendor/golang.org/x/tools/go/ssa/const.go

@@ -1,169 +0,0 @@
-// 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)
-}

vendor/golang.org/x/tools/go/ssa/create.go

@@ -1,270 +0,0 @@
-// 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]
-}

vendor/golang.org/x/tools/go/ssa/doc.go

@@ -1,125 +0,0 @@
-// 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"

vendor/golang.org/x/tools/go/ssa/dom.go

@@ -1,341 +0,0 @@
-// 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, "}")
-}

vendor/golang.org/x/tools/go/ssa/emit.go

@@ -1,468 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/ssa/func.go

@@ -1,691 +0,0 @@
-// 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("<deleted>")
-			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 }

vendor/golang.org/x/tools/go/ssa/identical.go

@@ -1,7 +0,0 @@
-// +build go1.8
-
-package ssa
-
-import "go/types"
-
-var structTypesIdentical = types.IdenticalIgnoreTags

vendor/golang.org/x/tools/go/ssa/identical_17.go

@@ -1,7 +0,0 @@
-// +build !go1.8
-
-package ssa
-
-import "go/types"
-
-var structTypesIdentical = types.Identical

vendor/golang.org/x/tools/go/ssa/lift.go

@@ -1,653 +0,0 @@
-// 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)
-	}
-
-}

vendor/golang.org/x/tools/go/ssa/lvalue.go

@@ -1,120 +0,0 @@
-// 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")
-}

vendor/golang.org/x/tools/go/ssa/methods.go

@@ -1,239 +0,0 @@
-// 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)
-	}
-}

vendor/golang.org/x/tools/go/ssa/mode.go

@@ -1,100 +0,0 @@
-// 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 }

vendor/golang.org/x/tools/go/ssa/print.go

@@ -1,431 +0,0 @@
-// 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 := "<nil>" // 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 ""
-}

vendor/golang.org/x/tools/go/ssa/sanity.go

@@ -1,532 +0,0 @@
-// 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()))
-		}
-	}
-}

vendor/golang.org/x/tools/go/ssa/source.go

@@ -1,293 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/ssa/ssautil/load.go

@@ -1,175 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/ssa/ssautil/switch.go

@@ -1,234 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/ssa/ssautil/visit.go

@@ -1,79 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/ssa/testmain.go

@@ -1,273 +0,0 @@
-// 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}}
-}
-`))

vendor/golang.org/x/tools/go/ssa/util.go

@@ -1,119 +0,0 @@
-// 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),
-	}
-}

vendor/golang.org/x/tools/go/ssa/wrappers.go

@@ -1,290 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/types/typeutil/callee.go

@@ -1,46 +0,0 @@
-// 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())
-}

vendor/golang.org/x/tools/go/types/typeutil/imports.go

@@ -1,31 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/types/typeutil/map.go

@@ -1,313 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/types/typeutil/methodsetcache.go

@@ -1,72 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/go/types/typeutil/ui.go

@@ -1,52 +0,0 @@
-// 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
-}

vendor/golang.org/x/tools/internal/fastwalk/fastwalk.go

@@ -1,196 +0,0 @@
-// 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 fastwalk provides a faster version of filepath.Walk for file system
-// scanning tools.
-package fastwalk
-
-import (
-	"errors"
-	"os"
-	"path/filepath"
-	"runtime"
-	"sync"
-)
-
-// TraverseLink is used as a return value from WalkFuncs to indicate that the
-// symlink named in the call may be traversed.
-var TraverseLink = errors.New("fastwalk: traverse symlink, assuming target is a directory")
-
-// SkipFiles is a used as a return value from WalkFuncs to indicate that the
-// callback should not be called for any other files in the current directory.
-// Child directories will still be traversed.
-var SkipFiles = errors.New("fastwalk: skip remaining files in directory")
-
-// Walk is a faster implementation of filepath.Walk.
-//
-// filepath.Walk's design necessarily calls os.Lstat on each file,
-// even if the caller needs less info.
-// Many tools need only the type of each file.
-// On some platforms, this information is provided directly by the readdir
-// system call, avoiding the need to stat each file individually.
-// fastwalk_unix.go contains a fork of the syscall routines.
-//
-// See golang.org/issue/16399
-//
-// Walk walks the file tree rooted at root, calling walkFn for
-// each file or directory in the tree, including root.
-//
-// If fastWalk returns filepath.SkipDir, the directory is skipped.
-//
-// Unlike filepath.Walk:
-//   * file stat calls must be done by the user.
-//     The only provided metadata is the file type, which does not include
-//     any permission bits.
-//   * multiple goroutines stat the filesystem concurrently. The provided
-//     walkFn must be safe for concurrent use.
-//   * fastWalk can follow symlinks if walkFn returns the TraverseLink
-//     sentinel error. It is the walkFn's responsibility to prevent
-//     fastWalk from going into symlink cycles.
-func Walk(root string, walkFn func(path string, typ os.FileMode) error) error {
-	// TODO(bradfitz): make numWorkers configurable? We used a
-	// minimum of 4 to give the kernel more info about multiple
-	// things we want, in hopes its I/O scheduling can take
-	// advantage of that. Hopefully most are in cache. Maybe 4 is
-	// even too low of a minimum. Profile more.
-	numWorkers := 4
-	if n := runtime.NumCPU(); n > numWorkers {
-		numWorkers = n
-	}
-
-	// Make sure to wait for all workers to finish, otherwise
-	// walkFn could still be called after returning. This Wait call
-	// runs after close(e.donec) below.
-	var wg sync.WaitGroup
-	defer wg.Wait()
-
-	w := &walker{
-		fn:       walkFn,
-		enqueuec: make(chan walkItem, numWorkers), // buffered for performance
-		workc:    make(chan walkItem, numWorkers), // buffered for performance
-		donec:    make(chan struct{}),
-
-		// buffered for correctness & not leaking goroutines:
-		resc: make(chan error, numWorkers),
-	}
-	defer close(w.donec)
-
-	for i := 0; i < numWorkers; i++ {
-		wg.Add(1)
-		go w.doWork(&wg)
-	}
-	todo := []walkItem{{dir: root}}
-	out := 0
-	for {
-		workc := w.workc
-		var workItem walkItem
-		if len(todo) == 0 {
-			workc = nil
-		} else {
-			workItem = todo[len(todo)-1]
-		}
-		select {
-		case workc <- workItem:
-			todo = todo[:len(todo)-1]
-			out++
-		case it := <-w.enqueuec:
-			todo = append(todo, it)
-		case err := <-w.resc:
-			out--
-			if err != nil {
-				return err
-			}
-			if out == 0 && len(todo) == 0 {
-				// It's safe to quit here, as long as the buffered
-				// enqueue channel isn't also readable, which might
-				// happen if the worker sends both another unit of
-				// work and its result before the other select was
-				// scheduled and both w.resc and w.enqueuec were
-				// readable.
-				select {
-				case it := <-w.enqueuec:
-					todo = append(todo, it)
-				default:
-					return nil
-				}
-			}
-		}
-	}
-}
-
-// doWork reads directories as instructed (via workc) and runs the
-// user's callback function.
-func (w *walker) doWork(wg *sync.WaitGroup) {
-	defer wg.Done()
-	for {
-		select {
-		case <-w.donec:
-			return
-		case it := <-w.workc:
-			select {
-			case <-w.donec:
-				return
-			case w.resc <- w.walk(it.dir, !it.callbackDone):
-			}
-		}
-	}
-}
-
-type walker struct {
-	fn func(path string, typ os.FileMode) error
-
-	donec    chan struct{} // closed on fastWalk's return
-	workc    chan walkItem // to workers
-	enqueuec chan walkItem // from workers
-	resc     chan error    // from workers
-}
-
-type walkItem struct {
-	dir          string
-	callbackDone bool // callback already called; don't do it again
-}
-
-func (w *walker) enqueue(it walkItem) {
-	select {
-	case w.enqueuec <- it:
-	case <-w.donec:
-	}
-}
-
-func (w *walker) onDirEnt(dirName, baseName string, typ os.FileMode) error {
-	joined := dirName + string(os.PathSeparator) + baseName
-	if typ == os.ModeDir {
-		w.enqueue(walkItem{dir: joined})
-		return nil
-	}
-
-	err := w.fn(joined, typ)
-	if typ == os.ModeSymlink {
-		if err == TraverseLink {
-			// Set callbackDone so we don't call it twice for both the
-			// symlink-as-symlink and the symlink-as-directory later:
-			w.enqueue(walkItem{dir: joined, callbackDone: true})
-			return nil
-		}
-		if err == filepath.SkipDir {
-			// Permit SkipDir on symlinks too.
-			return nil
-		}
-	}
-	return err
-}
-
-func (w *walker) walk(root string, runUserCallback bool) error {
-	if runUserCallback {
-		err := w.fn(root, os.ModeDir)
-		if err == filepath.SkipDir {
-			return nil
-		}
-		if err != nil {
-			return err
-		}
-	}
-
-	return readDir(root, w.onDirEnt)
-}

vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_fileno.go

@@ -1,13 +0,0 @@
-// 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.
-
-// +build freebsd openbsd netbsd
-
-package fastwalk
-
-import "syscall"
-
-func direntInode(dirent *syscall.Dirent) uint64 {
-	return uint64(dirent.Fileno)
-}