compiler,reflect: sort out pkg path vs pkg name for named types

compiler/interface.go

@@ -134,12 +134,17 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 				types.NewVar(token.NoPos, nil, "ptrTo", types.Typ[types.UnsafePointer]),
 			)
 		case *types.Named:
+			name := typ.Obj().Name()
+			var pkgname string
+			if pkg := typ.Obj().Pkg(); pkg != nil {
+				pkgname = pkg.Name()
+			}
 			typeFieldTypes = append(typeFieldTypes,
 				types.NewVar(token.NoPos, nil, "numMethods", types.Typ[types.Uint16]),
 				types.NewVar(token.NoPos, nil, "ptrTo", types.Typ[types.UnsafePointer]),
 				types.NewVar(token.NoPos, nil, "underlying", types.Typ[types.UnsafePointer]),
 				types.NewVar(token.NoPos, nil, "pkgpath", types.Typ[types.UnsafePointer]),
-				types.NewVar(token.NoPos, nil, "name", types.NewArray(types.Typ[types.Int8], 1+int64(len(typ.Obj().Name())))),
+				types.NewVar(token.NoPos, nil, "name", types.NewArray(types.Typ[types.Int8], int64(len(pkgname)+1+len(name)+1))),
 			)
 		case *types.Chan, *types.Slice:
 			typeFieldTypes = append(typeFieldTypes,
@@ -205,8 +210,10 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 		case *types.Named:
 			name := typ.Obj().Name()
 			var pkgpath string
+			var pkgname string
 			if pkg := typ.Obj().Pkg(); pkg != nil {
 				pkgpath = pkg.Path()
+				pkgname = pkg.Name()
 			}
 			pkgPathPtr := c.pkgPathPtr(pkgpath)
 			typeFields = []llvm.Value{
@@ -214,7 +221,7 @@ func (c *compilerContext) getTypeCode(typ types.Type) llvm.Value {
 				c.getTypeCode(types.NewPointer(typ)),                      // ptrTo
 				c.getTypeCode(typ.Underlying()),                           // underlying
 				pkgPathPtr,                                                // pkgpath pointer
-				c.ctx.ConstString(name+"\x00", false),                     // name
+				c.ctx.ConstString(pkgname+"."+name+"\x00", false),         // name
 			}
 			metabyte |= 1 << 5 // "named" flag
 		case *types.Chan:

compiler/testdata/interface.ll

@@ -9,7 +9,7 @@ target triple = "wasm32-unknown-wasi"
 @"reflect/types.type:basic:int" = linkonce_odr constant { i8, ptr } { i8 2, ptr @"reflect/types.type:pointer:basic:int" }, align 4
 @"reflect/types.type:pointer:basic:int" = linkonce_odr constant { i8, i16, ptr } { i8 21, i16 0, ptr @"reflect/types.type:basic:int" }, align 4
 @"reflect/types.type:pointer:named:error" = linkonce_odr constant { i8, i16, ptr } { i8 21, i16 0, ptr @"reflect/types.type:named:error" }, align 4
-@"reflect/types.type:named:error" = linkonce_odr constant { i8, i16, ptr, ptr, ptr, [6 x i8] } { i8 52, i16 1, ptr @"reflect/types.type:pointer:named:error", ptr @"reflect/types.type:interface:{Error:func:{}{basic:string}}", ptr @"reflect/types.type.pkgpath.empty", [6 x i8] c"error\00" }, align 4
+@"reflect/types.type:named:error" = linkonce_odr constant { i8, i16, ptr, ptr, ptr, [7 x i8] } { i8 52, i16 1, ptr @"reflect/types.type:pointer:named:error", ptr @"reflect/types.type:interface:{Error:func:{}{basic:string}}", ptr @"reflect/types.type.pkgpath.empty", [7 x i8] c".error\00" }, align 4
 @"reflect/types.type.pkgpath.empty" = linkonce_odr unnamed_addr constant [1 x i8] zeroinitializer, align 1
 @"reflect/types.type:interface:{Error:func:{}{basic:string}}" = linkonce_odr constant { i8, ptr } { i8 20, ptr @"reflect/types.type:pointer:interface:{Error:func:{}{basic:string}}" }, align 4
 @"reflect/types.type:pointer:interface:{Error:func:{}{basic:string}}" = linkonce_odr constant { i8, i16, ptr } { i8 21, i16 0, ptr @"reflect/types.type:interface:{Error:func:{}{basic:string}}" }, align 4

src/reflect/type.go

@@ -504,13 +504,11 @@ func pointerTo(t *rawType) *rawType {
 
 func (t *rawType) String() string {
 	if t.isNamed() {
-		path := t.PkgPath()
-		slash := len(path) - 1
-		for slash >= 0 && path[slash] != '/' {
-			slash--
+		s := t.name()
+		if s[0] == '.' {
+			return s[1:]
 		}
-		shortened := path[slash+1:]
-		return shortened + "." + t.Name()
+		return s
 	}
 
 	switch t.Kind() {
@@ -1037,10 +1035,20 @@ func readStringZ(data unsafe.Pointer) string {
 	}))
 }
 
+func (t *rawType) name() string {
+	ntype := (*namedType)(unsafe.Pointer(t))
+	return readStringZ(unsafe.Pointer(&ntype.name[0]))
+}
+
 func (t *rawType) Name() string {
 	if t.isNamed() {
-		ntype := (*namedType)(unsafe.Pointer(t))
-		return readStringZ(unsafe.Pointer(&ntype.name[0]))
+		name := t.name()
+		for i := 0; i < len(name); i++ {
+			if name[i] == '.' {
+				return name[i+1:]
+			}
+		}
+		panic("corrupt name data")
 	}
 
 	if t.Kind() <= UnsafePointer {

src/reflect/value_test.go

@@ -243,6 +243,11 @@ func TestNamedTypes(t *testing.T) {
 		t.Errorf("TypeOf.String()=%v, want %v", got, want)
 	}
 
+	errorType := TypeOf((*error)(nil)).Elem()
+	if s := errorType.String(); s != "error" {
+		t.Errorf("error type = %v, want error", s)
+	}
+
 	m := make(map[[4]uint16]string)
 
 	if got, want := TypeOf(m).String(), "map[[4]uint16]string"; got != want {