compiler: include the scope in the type code name

compiler/compiler.go

@@ -92,6 +92,7 @@ type compilerContext struct {
 	pkg              *types.Package
 	packageDir       string // directory for this package
 	runtimePkg       *types.Package
+	scopeIdx         map[*types.Scope]int
 }
 
 // newCompilerContext returns a new compiler context ready for use, most
@@ -106,6 +107,7 @@ func newCompilerContext(moduleName string, machine llvm.TargetMachine, config *C
 		targetData:    machine.CreateTargetData(),
 		functionInfos: map[*ssa.Function]functionInfo{},
 		astComments:   map[string]*ast.CommentGroup{},
+		scopeIdx:      map[*types.Scope]int{},
 	}
 
 	c.ctx = llvm.NewContext()

compiler/interface.go

@@ -158,7 +158,7 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 		}
 	}
 
-	typeCodeName, isLocal := getTypeCodeName(typ)
+	typeCodeName, isLocal := c.getTypeCodeName(typ)
 	globalName := "reflect/types.type:" + typeCodeName
 	var global llvm.Value
 	if isLocal {
@@ -511,23 +511,57 @@ var basicTypeNames = [...]string{
 	types.UnsafePointer: "unsafe.Pointer",
 }
 
+// return an integer representing this scope in a package.
+func (c *compilerContext) getScopeID(pkg *types.Scope, scope *types.Scope) string {
+	var ids []int
+
+	for scope != pkg {
+		if idx, ok := c.scopeIdx[scope]; ok {
+			ids = append(ids, idx)
+		} else {
+			// flesh out scope idx for all children of this parent
+			parent := scope.Parent()
+			for i := range parent.NumChildren() {
+				child := parent.Child(i)
+				if child == scope {
+					c.scopeIdx[scope] = i
+					break
+				}
+			}
+			ids = append(ids, c.scopeIdx[scope])
+		}
+		// move up a level
+		scope = scope.Parent()
+	}
+
+	var buf []byte
+	for _, v := range ids {
+		buf = strconv.AppendInt(buf, int64(v), 10)
+		buf = append(buf, ':')
+	}
+
+	id := string(buf)
+	return id
+}
+
 // getTypeCodeName returns a name for this type that can be used in the
 // interface lowering pass to assign type codes as expected by the reflect
 // package. See getTypeCodeNum.
-func getTypeCodeName(t types.Type) (string, bool) {
+func (c *compilerContext) getTypeCodeName(t types.Type) (string, bool) {
 	switch t := types.Unalias(t).(type) {
 	case *types.Named:
-		if t.Obj().Parent() != t.Obj().Pkg().Scope() {
-			return "named:" + t.String() + "$local", true
+		parent, pkg := t.Obj().Parent(), t.Obj().Pkg().Scope()
+		if parent != pkg {
+			return fmt.Sprintf("named:%s$local:%s", t.String(), c.getScopeID(pkg, parent)), true
 		}
 		return "named:" + t.String(), false
 	case *types.Array:
-		s, isLocal := getTypeCodeName(t.Elem())
+		s, isLocal := c.getTypeCodeName(t.Elem())
 		return "array:" + strconv.FormatInt(t.Len(), 10) + ":" + s, isLocal
 	case *types.Basic:
 		return "basic:" + basicTypeNames[t.Kind()], false
 	case *types.Chan:
-		s, isLocal := getTypeCodeName(t.Elem())
+		s, isLocal := c.getTypeCodeName(t.Elem())
 		var dir string
 		switch t.Dir() {
 		case types.SendOnly:
@@ -547,41 +581,41 @@ func getTypeCodeName(t types.Type) (string, bool) {
 			if !token.IsExported(name) {
 				name = t.Method(i).Pkg().Path() + "." + name
 			}
-			s, local := getTypeCodeName(t.Method(i).Type())
+			s, local := c.getTypeCodeName(t.Method(i).Type())
 			if local {
 				isLocal = true
 			}
 			methods[i] = name + ":" + s
 		}
 		return "interface:" + "{" + strings.Join(methods, ",") + "}", isLocal
 	case *types.Map:
-		keyType, keyLocal := getTypeCodeName(t.Key())
-		elemType, elemLocal := getTypeCodeName(t.Elem())
+		keyType, keyLocal := c.getTypeCodeName(t.Key())
+		elemType, elemLocal := c.getTypeCodeName(t.Elem())
 		return "map:" + "{" + keyType + "," + elemType + "}", keyLocal || elemLocal
 	case *types.Pointer:
-		s, isLocal := getTypeCodeName(t.Elem())
+		s, isLocal := c.getTypeCodeName(t.Elem())
 		return "pointer:" + s, isLocal
 	case *types.Signature:
 		isLocal := false
 		params := make([]string, t.Params().Len())
 		for i := 0; i < t.Params().Len(); i++ {
-			s, local := getTypeCodeName(t.Params().At(i).Type())
+			s, local := c.getTypeCodeName(t.Params().At(i).Type())
 			if local {
 				isLocal = true
 			}
 			params[i] = s
 		}
 		results := make([]string, t.Results().Len())
 		for i := 0; i < t.Results().Len(); i++ {
-			s, local := getTypeCodeName(t.Results().At(i).Type())
+			s, local := c.getTypeCodeName(t.Results().At(i).Type())
 			if local {
 				isLocal = true
 			}
 			results[i] = s
 		}
 		return "func:" + "{" + strings.Join(params, ",") + "}{" + strings.Join(results, ",") + "}", isLocal
 	case *types.Slice:
-		s, isLocal := getTypeCodeName(t.Elem())
+		s, isLocal := c.getTypeCodeName(t.Elem())
 		return "slice:" + s, isLocal
 	case *types.Struct:
 		elems := make([]string, t.NumFields())
@@ -591,7 +625,7 @@ func getTypeCodeName(t types.Type) (string, bool) {
 			if t.Field(i).Embedded() {
 				embedded = "#"
 			}
-			s, local := getTypeCodeName(t.Field(i).Type())
+			s, local := c.getTypeCodeName(t.Field(i).Type())
 			if local {
 				isLocal = true
 			}
@@ -709,7 +743,7 @@ func (b *builder) createTypeAssert(expr *ssa.TypeAssert) llvm.Value {
 			commaOk = b.CreateCall(fn.GlobalValueType(), fn, []llvm.Value{actualTypeNum}, "")
 		}
 	} else {
-		name, _ := getTypeCodeName(expr.AssertedType)
+		name, _ := b.getTypeCodeName(expr.AssertedType)
 		globalName := "reflect/types.typeid:" + name
 		assertedTypeCodeGlobal := b.mod.NamedGlobal(globalName)
 		if assertedTypeCodeGlobal.IsNil() {
@@ -786,7 +820,7 @@ func (c *compilerContext) getMethodsString(itf *types.Interface) string {
 // getInterfaceImplementsFunc returns a declared function that works as a type
 // switch. The interface lowering pass will define this function.
 func (c *compilerContext) getInterfaceImplementsFunc(assertedType types.Type) llvm.Value {
-	s, _ := getTypeCodeName(assertedType.Underlying())
+	s, _ := c.getTypeCodeName(assertedType.Underlying())
 	fnName := s + ".$typeassert"
 	llvmFn := c.mod.NamedFunction(fnName)
 	if llvmFn.IsNil() {
@@ -803,7 +837,7 @@ func (c *compilerContext) getInterfaceImplementsFunc(assertedType types.Type) ll
 // thunk is declared, not defined: it will be defined by the interface lowering
 // pass.
 func (c *compilerContext) getInvokeFunction(instr *ssa.CallCommon) llvm.Value {
-	s, _ := getTypeCodeName(instr.Value.Type().Underlying())
+	s, _ := c.getTypeCodeName(instr.Value.Type().Underlying())
 	fnName := s + "." + instr.Method.Name() + "$invoke"
 	llvmFn := c.mod.NamedFunction(fnName)
 	if llvmFn.IsNil() {

compiler/testdata/interface.go

@@ -61,3 +61,37 @@ func callFooMethod(itf fooInterface) uint8 {
 func callErrorMethod(itf error) string {
 	return itf.Error()
 }
+
+func namedFoo() {
+	type Foo struct {
+		A int
+	}
+	f1 := &Foo{}
+	fcopy := copyOf(f1)
+	f2 := fcopy.(*Foo)
+	println(f2.A)
+}
+
+func namedFoo2Nested() {
+	type Foo struct {
+		A *int
+	}
+	f1 := &Foo{}
+	fcopy := copyOf(f1)
+	f2 := fcopy.(*Foo)
+	println(f2.A == nil)
+
+	if f2.A == nil {
+		type Foo struct {
+			A *byte
+		}
+		nestedf1 := &Foo{}
+		fcopy := copyOf(nestedf1)
+		nestedf2 := fcopy.(*Foo)
+		println(nestedf2.A == nil)
+	}
+}
+
+func copyOf(src interface{}) (dst interface{}) {
+	return src
+}