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extractor: Factor out method extraction

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This fixes a subtle bug where the underlying interface type was used
as the receiver when constructing method labels, causing some database
inconsistencies.
This commit is contained in:
Sauyon Lee
2020-03-10 22:01:16 -07:00
parent 0daf8c1fa3
commit ecd4c42428
1 changed files with 18 additions and 22 deletions
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40
extractor/extractor.go
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@@ -183,6 +183,20 @@ func extractObjects(tw *trap.Writer, scope *types.Scope, scopeLabel trap.Label)
}
}
// extractMethod extracts a method `meth` and emits it to the objects table, then returns its label
func extractMethod(tw *trap.Writer, meth *types.Func) trap.Label {
// get the receiver type of the method
recvtyp := meth.Type().(*types.Signature).Recv().Type()
recvlbl := extractType(tw, recvtyp) // ensure receiver type has been extracted
// if the method label does not exist, extract it
methlbl, exists := tw.Labeler.MethodID(meth, recvlbl)
if !exists {
extractObject(tw, meth, methlbl)
}
return methlbl
}
// extractObject extracts a single object and emits it to the objects table.
func extractObject(tw *trap.Writer, obj types.Object, lbl trap.Label) {
name := obj.Name()
@@ -1093,15 +1107,7 @@ func extractType(tw *trap.Writer, tp types.Type) trap.Label {
for i := 0; i < tp.NumMethods(); i++ {
meth := tp.Method(i)
// get the receiver type of component methods; for interfaces
// this can be different from the type used to get the method
recvTyp := meth.Type().(*types.Signature).Recv().Type()
recvlbl := extractType(tw, recvTyp) // ensure receiver type has a label
// ensure the method is associated with a label
methlbl, exists := tw.Labeler.MethodID(meth, recvlbl)
if !exists {
extractObject(tw, meth, methlbl)
}
extractMethod(tw, meth)
extractComponentType(tw, lbl, i, meth.Name(), meth.Type())
}
@@ -1151,24 +1157,14 @@ func extractType(tw *trap.Writer, tp types.Type) trap.Label {
// ensure all methods have labels
for i := 0; i < tp.NumMethods(); i++ {
meth := tp.Method(i)
recv := meth.Type().(*types.Signature).Recv()
typ := recv.Type()
recvTypeLbl := extractType(tw, typ) // ensure receiver type has a label
methlbl, exists := tw.Labeler.MethodID(meth, recvTypeLbl)
if !exists {
extractObject(tw, meth, methlbl)
}
extractMethod(tw, meth)
}
// associate all methods of underlying interface with this type
if underlyingInterface, ok := underlying.(*types.Interface); ok {
underlyingInterfaceLabel, _ := getTypeLabel(tw, underlyingInterface)
for i := 0; i < underlyingInterface.NumMethods(); i++ {
meth := underlyingInterface.Method(i)
methlbl, exists := tw.Labeler.MethodID(meth, underlyingInterfaceLabel)
if !exists {
extractObject(tw, meth, methlbl)
}
methlbl := extractMethod(tw, underlyingInterface.Method(i))
dbscheme.MethodHostsTable.Emit(tw, methlbl, lbl)
}
}