Go: Remove dead extractor code

go/extractor/extractor.go

@@ -1529,12 +1529,6 @@ func extractSpec(tw *trap.Writer, spec ast.Spec, parent trap.Label, idx int) {
 	extractNodeLocation(tw, spec, lbl)
 }
 
-// Determines whether the given type is an alias.
-func isAlias(tp types.Type) bool {
-	_, ok := tp.(*types.Alias)
-	return ok
-}
-
 // extractType extracts type information for `tp` and returns its associated label;
 // types are only extracted once, so the second time `extractType` is invoked it simply returns the label
 func extractType(tw *trap.Writer, tp types.Type) trap.Label {
@@ -1644,7 +1638,6 @@ func extractType(tw *trap.Writer, tp types.Type) trap.Label {
 			dbscheme.TypeNameTable.Emit(tw, lbl, origintp.Obj().Name())
 			underlying := origintp.Underlying()
 			extractUnderlyingType(tw, lbl, underlying)
-			trackInstantiatedStructFields(tw, tp, origintp)
 
 			entitylbl, exists := tw.Labeler.LookupObjectID(origintp.Obj(), lbl)
 			if entitylbl == trap.InvalidLabel {
@@ -2035,36 +2028,6 @@ func getObjectBeingUsed(tw *trap.Writer, ident *ast.Ident) types.Object {
 	}
 }
 
-// trackInstantiatedStructFields tries to give the fields of an instantiated
-// struct type underlying `tp` the same labels as the corresponding fields of
-// the generic struct type. This is so that when we come across the
-// instantiated field in `tw.Package.TypesInfo.Uses` we will get the label for
-// the generic field instead.
-func trackInstantiatedStructFields(tw *trap.Writer, tp, origintp *types.Named) {
-	if tp == origintp {
-		return
-	}
-
-	if instantiatedStruct, ok := tp.Underlying().(*types.Struct); ok {
-		genericStruct, ok2 := origintp.Underlying().(*types.Struct)
-		if !ok2 {
-			log.Fatalf(
-				"Error: underlying type of instantiated type is a struct but underlying type of generic type is %s",
-				origintp.Underlying())
-		}
-
-		if instantiatedStruct.NumFields() != genericStruct.NumFields() {
-			log.Fatalf(
-				"Error: instantiated struct %s has different number of fields than the generic version %s (%d != %d)",
-				instantiatedStruct, genericStruct, instantiatedStruct.NumFields(), genericStruct.NumFields())
-		}
-
-		for i := 0; i < instantiatedStruct.NumFields(); i++ {
-			tw.ObjectsOverride[instantiatedStruct.Field(i)] = genericStruct.Field(i)
-		}
-	}
-}
-
 func getTypeParamParentLabel(tw *trap.Writer, tp *types.TypeParam) trap.Label {
 	parent, exists := typeParamParent[tp]
 	if !exists {

go/extractor/trap/trapwriter.go

@@ -17,16 +17,15 @@ import (
 
 // A Writer provides methods for writing data to a TRAP file
 type Writer struct {
-	zip             *gzip.Writer
-	wzip            *bufio.Writer
-	wfile           *bufio.Writer
-	file            *os.File
-	Labeler         *Labeler
-	path            string
-	trapFilePath    string
-	Package         *packages.Package
-	TypesOverride   map[ast.Expr]types.Type
-	ObjectsOverride map[types.Object]types.Object
+	zip           *gzip.Writer
+	wzip          *bufio.Writer
+	wfile         *bufio.Writer
+	file          *os.File
+	Labeler       *Labeler
+	path          string
+	trapFilePath  string
+	Package       *packages.Package
+	TypesOverride map[ast.Expr]types.Type
 }
 
 func FileFor(path string) (string, error) {
@@ -67,7 +66,6 @@ func NewWriter(path string, pkg *packages.Package) (*Writer, error) {
 		trapFilePath,
 		pkg,
 		make(map[ast.Expr]types.Type),
-		make(map[types.Object]types.Object),
 	}
 	tw.Labeler = newLabeler(tw)
 	return tw, nil