bind,cmd: accept ObjC wrapper types in bound packages

Accept ObjC API wrapper types as arguments and return values from
bound Go package functions and methods. Also, allow Go structs
to extend ObjC classes and implement ObjC protocols as well as override
and implement methods.

This is the third and final part of the implementation of the golang/go#17102
proposal.

Fixes golang/go#17102

Change-Id: I601d90fb6d22b8d6f8b7d5fe0130daa1a4dd4734
Reviewed-on: https://go-review.googlesource.com/29175
Reviewed-by: David Crawshaw <crawshaw@golang.org>

bind/bind_test.go

@@ -50,6 +50,7 @@ var javaTests = []string{
 
 var objcTests = []string{
 	"testdata/objc.go",
+	"testdata/objcw.go",
 }
 
 var fset = token.NewFileSet()
@@ -136,7 +137,7 @@ func TestGenObjc(t *testing.T) {
 				Pkg:     pkg,
 			},
 		}
-		g.Init()
+		g.Init(nil)
 
 		testcases := []struct {
 			suffix string
@@ -463,7 +464,7 @@ func TestCustomPrefix(t *testing.T) {
 			Pkg:     pkg,
 		},
 	}
-	og.Init()
+	og.Init(nil)
 	testCases := []struct {
 		golden string
 		gen    func(w io.Writer) error

bind/gen.go

@@ -333,7 +333,7 @@ func (g *Generator) isSigSupported(t types.Type) bool {
 
 // isSupported returns whether the generators can handle the type.
 func (g *Generator) isSupported(t types.Type) bool {
-	if isErrorType(t) || isJavaType(t) {
+	if isErrorType(t) || isWrapperType(t) {
 		return true
 	}
 	switch t := t.(type) {

bind/gengo.go

@@ -410,10 +410,11 @@ func (g *goGen) genRead(toVar, fromVar string, typ types.Type, mode varMode) {
 			if iface, ok := t.Underlying().(*types.Interface); ok {
 				hasProxy = makeIfaceSummary(iface).implementable
 			}
-			isJava := isJavaType(t)
+			pkgFirst := typePkgFirstElem(t)
+			isWrapper := pkgFirst == "Java" || pkgFirst == "ObjC"
 			o := t.Obj()
 			oPkg := o.Pkg()
-			if !isErrorType(t) && !g.validPkg(oPkg) && !isJava {
+			if !isErrorType(t) && !g.validPkg(oPkg) && !isWrapper {
 				g.errorf("type %s is defined in %s, which is not bound", t, oPkg)
 				return
 			}
@@ -424,8 +425,14 @@ func (g *goGen) genRead(toVar, fromVar string, typ types.Type, mode varMode) {
 			g.Printf("  	 %s = %s_ref.Get().(%s%s)\n", toVar, toVar, g.pkgName(oPkg), o.Name())
 			if hasProxy {
 				g.Printf("	} else { // foreign object \n")
-				if isJava {
+				if isWrapper {
-					clsName := flattenName(classNameFor(t))
+					var clsName string
+					switch pkgFirst {
+					case "Java":
+						clsName = flattenName(classNameFor(t))
+					case "ObjC":
+						clsName = t.Obj().Name()
+					}
 					g.Printf("	   %s = (*proxy_class_%s)(%s_ref)\n", toVar, clsName, toVar)
 				} else {
 					g.Printf("	   %s = (*proxy%s_%s)(%s_ref)\n", toVar, pkgPrefix(oPkg), o.Name(), toVar)
@@ -451,7 +458,7 @@ func (g *goGen) typeString(typ types.Type) string {
 			return types.TypeString(typ, types.RelativeTo(pkg))
 		}
 		oPkg := obj.Pkg()
-		if !g.validPkg(oPkg) && !isJavaType(t) {
+		if !g.validPkg(oPkg) && !isWrapperType(t) {
 			g.errorf("type %s is defined in %s, which is not bound", t, oPkg)
 			return "TODO"
 		}

bind/genjava.go

@@ -1490,6 +1490,10 @@ func classNameFor(t types.Type) string {
 	return strings.Replace(pkg.Path()[len("Java/"):], "/", ".", -1) + "." + obj.Name()
 }
 
+func isJavaType(t types.Type) bool {
+	return typePkgFirstElem(t) == "Java"
+}
+
 const (
 	javaPreamble = `// Java class %[1]s.%[2]s is a proxy for talking to a Go program.
 //   gobind %[3]s %[4]s

bind/genobjc.go

@@ -10,6 +10,8 @@ import (
 	"go/types"
 	"math"
 	"strings"
+
+	"golang.org/x/mobile/internal/importers/objc"
 )
 
 // TODO(hyangah): handle method name conflicts.
@@ -22,15 +24,64 @@ import (
 type ObjcGen struct {
 	Prefix string // prefix arg passed by flag.
 
+	*Generator
+
 	// fields set by init.
 	namePrefix string
-
+	// Map of all wrapped Objc types
-	*Generator
+	wrapMap map[string]*objc.Named
+	// Structs that embeds Objc wrapper types.
+	ostructs map[*types.TypeName]*objcClassInfo
+	modules  []string
 }
 
-func (g *ObjcGen) Init() {
+type objcClassInfo struct {
+	// The Objc class this class extends.
+	extends *objc.Named
+	// All classes and protocols this class extends and conforms to.
+	supers  []*objc.Named
+	methods map[string]*objc.Func
+}
+
+func (g *ObjcGen) Init(wrappers []*objc.Named) {
 	g.Generator.Init()
 	g.namePrefix = g.namePrefixOf(g.Pkg)
+	g.wrapMap = make(map[string]*objc.Named)
+	modMap := make(map[string]struct{})
+	for _, w := range wrappers {
+		g.wrapMap[w.GoName] = w
+		if _, exists := modMap[w.Module]; !exists {
+			g.modules = append(g.modules, w.Module)
+			modMap[w.Module] = struct{}{}
+		}
+	}
+	if _, exists := modMap["Foundation"]; !exists {
+		g.modules = append(g.modules, "Foundation")
+	}
+	g.ostructs = make(map[*types.TypeName]*objcClassInfo)
+	for _, s := range g.structs {
+		embds := embeddedObjcTypes(s.t)
+		if len(embds) == 0 {
+			continue
+		}
+		inf := &objcClassInfo{
+			methods: make(map[string]*objc.Func),
+		}
+		for _, n := range embds {
+			t := g.wrapMap[n]
+			for _, f := range t.AllMethods {
+				inf.methods[f.GoName] = f
+			}
+			inf.supers = append(inf.supers, t)
+			if !t.Protocol {
+				if inf.extends != nil {
+					g.errorf("%s embeds more than one ObjC class; only one is allowed.", s.obj)
+				}
+				inf.extends = t
+			}
+		}
+		g.ostructs[s.obj] = inf
+	}
 }
 
 func (g *ObjcGen) namePrefixOf(pkg *types.Package) string {
@@ -86,8 +137,11 @@ func (g *ObjcGen) GenH() error {
 	g.Printf("#ifndef __%s_H__\n", g.namePrefix)
 	g.Printf("#define __%s_H__\n", g.namePrefix)
 	g.Printf("\n")
-	g.Printf("#include <Foundation/Foundation.h>\n")
+	for _, m := range g.modules {
-	g.Printf("#include \"GoUniverse.h\"\n")
+		g.Printf("@import %s;\n", m)
+	}
+	g.Printf("#include \"GoUniverse.h\"\n\n")
+
 	if g.Pkg != nil {
 		for _, pkg := range g.Pkg.Imports() {
 			if g.validPkg(pkg) {
@@ -347,9 +401,11 @@ func (g *ObjcGen) genConstM(o *types.Const) {
 
 type funcSummary struct {
 	name              string
+	goname            string
 	ret               string
 	sig               *types.Signature
 	params, retParams []paramInfo
+	hasthis           bool
 }
 
 type paramInfo struct {
@@ -357,20 +413,63 @@ type paramInfo struct {
 	name string
 }
 
-func (g *ObjcGen) funcSummary(obj *types.Func) *funcSummary {
+func (g *ObjcGen) funcSummary(oinf *objcClassInfo, obj *types.Func) *funcSummary {
 	sig := obj.Type().(*types.Signature)
-	s := &funcSummary{name: obj.Name(), sig: sig}
+	s := &funcSummary{goname: obj.Name(), sig: sig}
-
+	var om *objc.Func
+	var sigElems []string
+	if oinf != nil {
+		om = oinf.methods[obj.Name()]
+	}
+	if om != nil {
+		sigElems = strings.Split(om.Sig, ":")
+		s.name = sigElems[0]
+	} else {
+		s.name = obj.Name()
+	}
 	params := sig.Params()
-	for i := 0; i < params.Len(); i++ {
+	first := 0
+	if om != nil {
+		// Check the implicit this argument and the argument count of the overridden method
+		excess := params.Len() - len(om.Params)
+		if excess < 0 {
+			g.errorf("method %s has fewer arguments than the method it overrides", obj.Name())
+		} else if excess > 1 {
+			g.errorf("overriding method %s has more arguments than the method it overrides", obj.Name())
+		} else if excess == 1 {
+			s.hasthis = true
+			first = 1
+			t := params.At(0).Type()
+			if !isObjcType(t) {
+				g.errorf("the `this` argument to method %s is not a ObjC type", obj.Name())
+				return s
+			} else {
+				ot := g.wrapMap[t.(*types.Named).Obj().Name()]
+				found := false
+				for _, sup := range oinf.supers {
+					if ot == sup {
+						found = true
+						break
+					}
+				}
+				if !found {
+					g.errorf("the type %s of the `this` argument to method %s is not a super class of the enclosing struct", ot.Name, obj.Name())
+				}
+			}
+		}
+	}
+	for i := first; i < params.Len(); i++ {
 		p := params.At(i)
 		v := paramInfo{
-			typ:  p.Type(),
+			typ: p.Type(),
-			name: g.paramName(params, i),
+		}
+		if om != nil {
+			v.name = sigElems[i-first]
+		} else {
+			v.name = g.paramName(params, i)
 		}
 		s.params = append(s.params, v)
 	}
-
 	res := sig.Results()
 	switch res.Len() {
 	case 0:
@@ -488,13 +587,13 @@ func (g *ObjcGen) genFuncH(obj *types.Func) {
 		g.Printf("// skipped function %s with unsupported parameter or return types\n\n", obj.Name())
 		return
 	}
-	if s := g.funcSummary(obj); s != nil {
+	if s := g.funcSummary(nil, obj); s != nil {
 		g.Printf("FOUNDATION_EXPORT %s;\n", s.asFunc(g))
 	}
 }
 
 func (g *ObjcGen) genFuncM(obj *types.Func) {
-	s := g.funcSummary(obj)
+	s := g.funcSummary(nil, obj)
 	if s == nil {
 		return
 	}
@@ -555,20 +654,20 @@ func (g *ObjcGen) genWrite(varName string, t types.Type, mode varMode) {
 	case *types.Named:
 		switch u := t.Underlying().(type) {
 		case *types.Interface:
-			g.genRefWrite(varName, t)
+			g.genRefWrite(varName)
 		default:
 			g.errorf("unsupported named type: %s / %T", u, u)
 		}
 	case *types.Pointer:
-		g.genRefWrite(varName, t)
+		g.genRefWrite(varName)
 	default:
 		g.Printf("%s _%s = (%s)%s;\n", g.cgoType(t), varName, g.cgoType(t), varName)
 	}
 }
 
-func (g *ObjcGen) genRefWrite(varName string, t types.Type) {
+func (g *ObjcGen) genRefWrite(varName string) {
 	g.Printf("int32_t _%s;\n", varName)
-	g.Printf("if ([(id<NSObject>)(%s) isKindOfClass:[%s class]]) {\n", varName, g.refTypeBase(t))
+	g.Printf("if ([%s conformsToProtocol:@protocol(goSeqRefInterface)]) {\n", varName)
 	g.Indent()
 	g.Printf("id<goSeqRefInterface> %[1]s_proxy = (id<goSeqRefInterface>)(%[1]s);\n", varName)
 	g.Printf("_%s = go_seq_go_to_refnum(%s_proxy._ref);\n", varName, varName)
@@ -587,7 +686,11 @@ func (g *ObjcGen) genRefRead(toName, fromName string, t types.Type) {
 	g.Printf("if (%s_ref != NULL) {\n", toName)
 	g.Printf("	%s = %s_ref.obj;\n", toName, toName)
 	g.Printf("	if (%s == nil) {\n", toName)
-	g.Printf("		%s = [[%s alloc] initWithRef:%s_ref];\n", toName, ptype, toName)
+	if isObjcType(t) {
+		g.Printf("		LOG_FATAL(@\"unexpected NULL reference\");\n")
+	} else {
+		g.Printf("		%s = [[%s alloc] initWithRef:%s_ref];\n", toName, ptype, toName)
+	}
 	g.Printf("	}\n")
 	g.Printf("}\n")
 }
@@ -637,6 +740,9 @@ func (g *ObjcGen) genRead(toName, fromName string, t types.Type, mode varMode) {
 func (g *ObjcGen) genFunc(s *funcSummary, objName string) {
 	if objName != "" {
 		g.Printf("int32_t refnum = go_seq_go_to_refnum(self._ref);\n")
+		if s.hasthis {
+			g.genRefWrite("self")
+		}
 	}
 	for _, p := range s.params {
 		g.genWrite(p.name, p.typ, modeTransient)
@@ -647,12 +753,15 @@ func (g *ObjcGen) genFunc(s *funcSummary, objName string) {
 			g.Printf("%s r0 = ", g.cgoType(s.retParams[0].typ))
 		} else {
 			resPrefix = "res."
-			g.Printf("struct proxy%s_%s_%s_return res = ", g.pkgPrefix, objName, s.name)
+			g.Printf("struct proxy%s_%s_%s_return res = ", g.pkgPrefix, objName, s.goname)
 		}
 	}
-	g.Printf("proxy%s_%s_%s(", g.pkgPrefix, objName, s.name)
+	g.Printf("proxy%s_%s_%s(", g.pkgPrefix, objName, s.goname)
 	if objName != "" {
 		g.Printf("refnum")
+		if s.hasthis {
+			g.Printf(", _self")
+		}
 	}
 	for i, p := range s.params {
 		if i > 0 || objName != "" {
@@ -700,9 +809,11 @@ func (g *ObjcGen) genInterfaceInterface(obj *types.TypeName, summary ifaceSummar
 	} else {
 		g.Printf("NSObject")
 	}
+	prots := []string{"goSeqRefInterface"}
 	if isProtocol {
-		g.Printf(" <%[1]s%[2]s>", g.namePrefix, obj.Name())
+		prots = append(prots, fmt.Sprintf("%[1]s%[2]s", g.namePrefix, obj.Name()))
 	}
+	g.Printf(" <%s>", strings.Join(prots, ", "))
 	g.Printf(" {\n}\n")
 	g.Printf("@property(strong, readonly) id _ref;\n")
 	g.Printf("\n")
@@ -712,7 +823,7 @@ func (g *ObjcGen) genInterfaceInterface(obj *types.TypeName, summary ifaceSummar
 			g.Printf("// skipped method %s.%s with unsupported parameter or return types\n\n", obj.Name(), m.Name())
 			continue
 		}
-		s := g.funcSummary(m)
+		s := g.funcSummary(nil, m)
 		g.Printf("- %s;\n", s.asMethod(g))
 	}
 	g.Printf("@end\n")
@@ -724,13 +835,13 @@ func (g *ObjcGen) genInterfaceH(obj *types.TypeName, t *types.Interface) {
 		g.genInterfaceInterface(obj, summary, false)
 		return
 	}
-	g.Printf("@protocol %s%s\n", g.namePrefix, obj.Name())
+	g.Printf("@protocol %s%s <NSObject>\n", g.namePrefix, obj.Name())
 	for _, m := range makeIfaceSummary(t).callable {
 		if !g.isSigSupported(m.Type()) {
 			g.Printf("// skipped method %s.%s with unsupported parameter or return types\n\n", obj.Name(), m.Name())
 			continue
 		}
-		s := g.funcSummary(m)
+		s := g.funcSummary(nil, m)
 		g.Printf("- %s;\n", s.asMethod(g))
 	}
 	g.Printf("@end\n")
@@ -764,7 +875,7 @@ func (g *ObjcGen) genInterfaceM(obj *types.TypeName, t *types.Interface) bool {
 			g.Printf("// skipped method %s.%s with unsupported parameter or return types\n\n", obj.Name(), m.Name())
 			continue
 		}
-		s := g.funcSummary(m)
+		s := g.funcSummary(nil, m)
 		g.Printf("- %s {\n", s.asMethod(g))
 		g.Indent()
 		g.genFunc(s, obj.Name())
@@ -779,7 +890,7 @@ func (g *ObjcGen) genInterfaceM(obj *types.TypeName, t *types.Interface) bool {
 
 func (g *ObjcGen) genInterfaceMethodProxy(obj *types.TypeName, m *types.Func) {
 	oName := obj.Name()
-	s := g.funcSummary(m)
+	s := g.funcSummary(nil, m)
 	g.genInterfaceMethodSignature(m, oName, false, g.paramName)
 	g.Indent()
 	g.Printf("@autoreleasepool {\n")
@@ -875,11 +986,31 @@ func (g *ObjcGen) genRelease(varName string, t types.Type, mode varMode) {
 }
 
 func (g *ObjcGen) genStructH(obj *types.TypeName, t *types.Struct) {
-	g.Printf("@interface %s%s : NSObject {\n", g.namePrefix, obj.Name())
+	g.Printf("@interface %s%s : ", g.namePrefix, obj.Name())
+	oinf := g.ostructs[obj]
+	if oinf != nil {
+		var prots []string
+		for _, sup := range oinf.supers {
+			if !sup.Protocol {
+				g.Printf(sup.Name)
+			} else {
+				prots = append(prots, sup.Name)
+			}
+		}
+		if len(prots) > 0 {
+			g.Printf(" <%s>", strings.Join(prots, ", "))
+		}
+	} else {
+		g.Printf("NSObject <goSeqRefInterface>")
+	}
+	g.Printf(" {\n")
 	g.Printf("}\n")
 	g.Printf("@property(strong, readonly) id _ref;\n")
 	g.Printf("\n")
 	g.Printf("- (id)initWithRef:(id)ref;\n")
+	if oinf != nil {
+		g.Printf("- (id)init;\n")
+	}
 
 	// accessors to exported fields.
 	for _, f := range exportedFields(t) {
@@ -898,7 +1029,7 @@ func (g *ObjcGen) genStructH(obj *types.TypeName, t *types.Struct) {
 			g.Printf("// skipped method %s.%s with unsupported parameter or return types\n\n", obj.Name(), m.Name())
 			continue
 		}
-		s := g.funcSummary(m)
+		s := g.funcSummary(g.ostructs[obj], m)
 		g.Printf("- %s;\n", objcNameReplacer(lowerFirst(s.asMethod(g))))
 	}
 	g.Printf("@end\n")
@@ -909,6 +1040,7 @@ func (g *ObjcGen) genStructM(obj *types.TypeName, t *types.Struct) {
 	methods := exportedMethodSet(types.NewPointer(obj.Type()))
 
 	g.Printf("\n")
+	oinf := g.ostructs[obj]
 	g.Printf("@implementation %s%s {\n", g.namePrefix, obj.Name())
 	g.Printf("}\n\n")
 	g.Printf("- (id)initWithRef:(id)ref {\n")
@@ -918,6 +1050,19 @@ func (g *ObjcGen) genStructM(obj *types.TypeName, t *types.Struct) {
 	g.Printf("return self;\n")
 	g.Outdent()
 	g.Printf("}\n\n")
+	if oinf != nil {
+		g.Printf("- (id)init {\n")
+		g.Indent()
+		g.Printf("self = [super init];\n")
+		g.Printf("if (self) {\n")
+		g.Indent()
+		g.Printf("__ref = go_seq_from_refnum(new_%s_%s());\n", g.pkgPrefix, obj.Name())
+		g.Outdent()
+		g.Printf("}\n")
+		g.Printf("return self;\n")
+		g.Outdent()
+		g.Printf("}\n\n")
+	}
 
 	for _, f := range fields {
 		if !g.isSupported(f.Type()) {
@@ -933,14 +1078,14 @@ func (g *ObjcGen) genStructM(obj *types.TypeName, t *types.Struct) {
 			g.Printf("// skipped method %s.%s with unsupported parameter or return types\n\n", obj.Name(), m.Name())
 			continue
 		}
-		s := g.funcSummary(m)
+		s := g.funcSummary(g.ostructs[obj], m)
 		g.Printf("- %s {\n", s.asMethod(g))
 		g.Indent()
 		g.genFunc(s, obj.Name())
 		g.Outdent()
 		g.Printf("}\n\n")
 	}
-	g.Printf("@end\n")
+	g.Printf("@end\n\n")
 }
 
 func (g *ObjcGen) errorf(format string, args ...interface{}) {
@@ -955,6 +1100,9 @@ func (g *ObjcGen) refTypeBase(typ types.Type) string {
 		}
 	case *types.Named:
 		n := typ.Obj()
+		if isObjcType(typ) {
+			return g.wrapMap[n.Name()].Name
+		}
 		if isErrorType(typ) || g.validPkg(n.Pkg()) {
 			switch typ.Underlying().(type) {
 			case *types.Interface, *types.Struct:
@@ -1031,6 +1179,10 @@ func (g *ObjcGen) objcType(typ types.Type) string {
 		return "TODO"
 	case *types.Named:
 		n := typ.Obj()
+		if isObjcType(typ) {
+			w := g.wrapMap[n.Name()]
+			return w.ObjcType()
+		}
 		if !isErrorType(typ) && !g.validPkg(n.Pkg()) {
 			g.errorf("type %s is in package %s, which is not bound", n.Name(), n.Pkg().Name())
 			return "TODO"
@@ -1053,6 +1205,31 @@ func (g *ObjcGen) objcType(typ types.Type) string {
 	}
 }
 
+// embeddedObjcTypes returns the possible empty list of Objc types embedded
+// in the given struct type.
+func embeddedObjcTypes(t *types.Struct) []string {
+	typeSet := make(map[string]struct{})
+	var typs []string
+	for i := 0; i < t.NumFields(); i++ {
+		f := t.Field(i)
+		if !f.Exported() {
+			continue
+		}
+		if ft := f.Type(); isObjcType(ft) {
+			name := ft.(*types.Named).Obj().Name()
+			if _, exists := typeSet[name]; !exists {
+				typeSet[name] = struct{}{}
+				typs = append(typs, name)
+			}
+		}
+	}
+	return typs
+}
+
+func isObjcType(t types.Type) bool {
+	return typePkgFirstElem(t) == "ObjC"
+}
+
 var objcNameReplacer = newNameSanitizer([]string{
 	"void", "char", "short", "int", "long", "float", "double", "signed",
 	"unsigned", "id", "const", "volatile", "in", "out", "inout", "bycopy",

bind/objc/SeqWrappers.m

@@ -35,13 +35,13 @@
 @implementation wrappers
 
 - (void)setUp {
-    [super setUp];
+	[super setUp];
-    // Put setup code here. This method is called before the invocation of each test method in the class.
+	// Put setup code here. This method is called before the invocation of each test method in the class.
 }
 
 - (void)tearDown {
-    // Put teardown code here. This method is called after the invocation of each test method in the class.
+	// Put teardown code here. This method is called after the invocation of each test method in the class.
-    [super tearDown];
+	[super tearDown];
 }
 
 - (void)testFunction {
@@ -59,4 +59,39 @@
 - (void)testError {
 	GoObjcpkgError();
 }
+
+- (void)testClass {
+	GoObjcpkgGoNSDate *d = [[GoObjcpkgGoNSDate alloc] init];
+	NSString *desc = [d description]; // Also stores this
+	XCTAssertEqual(d, [d this], "GoNSDate this not identical");
+	XCTAssertEqual(GoObjcpkgHash, [d hash], "GoNSDate this not identical");
+	XCTAssertTrue([desc isEqualToString:GoObjcpkgDescriptionStr], "GoNSDate description mismatch: %@", desc);
+	GoObjcpkgGoUIResponder *resp = [[GoObjcpkgGoUIResponder alloc] init];
+	[resp pressesBegan:nil withEvent:nil];
+	XCTAssertTrue([resp called], "GoUIResponder.pressesBegan not called");
+}
+
+- (void)testSuper {
+	GoObjcpkgGoNSObject *o = [[GoObjcpkgGoNSObject alloc] init];
+	struct objc_super _super = {
+		.receiver = o,
+		.super_class = [NSObject class],
+	};
+	NSString *superDesc = ((NSString *(*)(struct objc_super*, SEL))objc_msgSendSuper)(&_super, @selector(description));
+	XCTAssertTrue([superDesc isEqualToString:[o description]], "GoNSObject description mismatch");
+	[o setUseThis:TRUE];
+	XCTAssertTrue([GoObjcpkgDescriptionStr isEqualToString:[o description]], "GoNSObject description mismatch");
+}
+
+- (void)testIdentity {
+	NSDate *d = [[NSDate alloc] init];
+	NSDate *d2 = GoObjcpkgDupNSDate(d);
+	XCTAssertEqual(d, d2, @"GoObjcpkgDupNSDate failed to duplicate ObjC instance");
+	GoObjcpkgGoNSDate *gd = [[GoObjcpkgGoNSDate alloc] init];
+	NSDate *gd2 = GoObjcpkgDupNSDate(gd);
+	XCTAssertEqual(gd, gd2, @"GoObjcpkgDupNSDate failed to duplicate Go instance");
+	NSDate *gd3 = GoObjcpkgNewGoNSDate();
+	NSDate *gd4 = GoObjcpkgDupNSDate(gd3);
+	XCTAssertEqual(gd4, gd3, @"GoObjcpkgDupNSDate failed to duplicate instance created in Go");
+}
 @end

bind/objc/seq.h

@@ -6,6 +6,7 @@
 #define __GO_SEQ_HDR__
 
 #include <Foundation/Foundation.h>
+#include "ref.h"
 #include "GoUniverse.h"
 
 #ifdef DEBUG
@@ -24,32 +25,6 @@
                               userInfo:NULL];                                  \
   }
 
-// GoSeqRef is an object tagged with an integer for passing back and
-// forth across the language boundary. A GoSeqRef may represent either
-// an instance of a Go object, or an Objective-C object passed to Go.
-// The explicit allocation of a GoSeqRef is used to pin a Go object
-// when it is passed to Objective-C. The Go seq package maintains a
-// reference to the Go object in a map keyed by the refnum. When the
-// GoSeqRef is deallocated, the Go seq package will clear the
-// corresponding entry in the map.
-// TODO(hyangah): update the doc as golang.org/issue/10933 is fixed.
-@interface GoSeqRef : NSObject {
-}
-@property(readonly) int32_t refnum;
-@property(strong) id obj; // NULL when representing a Go object.
-
-// new GoSeqRef object to proxy a Go object. The refnum must be
-// provided from Go side.
-- (instancetype)initWithRefnum:(int32_t)refnum obj:(id)obj;
-
-- (int32_t)incNum;
-
-@end
-
-@protocol goSeqRefInterface
--(GoSeqRef*) _ref;
-@end
-
 // Platform specific types
 typedef struct nstring {
 	void *ptr;

bind/testdata/basictypes.objc.h.golden

@@ -6,9 +6,10 @@
 #ifndef __GoBasictypes_H__
 #define __GoBasictypes_H__
 
-#include <Foundation/Foundation.h>
+@import Foundation;
 #include "GoUniverse.h"
 
+
 FOUNDATION_EXPORT const BOOL GoBasictypesABool;
 FOUNDATION_EXPORT const double GoBasictypesAFloat;
 FOUNDATION_EXPORT NSString* const GoBasictypesALongString;

bind/testdata/customprefix.objc.h.golden

@@ -6,9 +6,10 @@
 #ifndef __EXCustomprefix_H__
 #define __EXCustomprefix_H__
 
-#include <Foundation/Foundation.h>
+@import Foundation;
 #include "GoUniverse.h"
 
+
 FOUNDATION_EXPORT void EXCustomprefixF();
 
 #endif

bind/testdata/ignore.objc.h.golden

@@ -6,14 +6,15 @@
 #ifndef __GoIgnore_H__
 #define __GoIgnore_H__
 
-#include <Foundation/Foundation.h>
+@import Foundation;
 #include "GoUniverse.h"
 
+
 @class GoIgnoreS;
 @protocol GoIgnoreI;
 @class GoIgnoreI;
 
-@interface GoIgnoreS : NSObject {
+@interface GoIgnoreS : NSObject <goSeqRefInterface> {
 }
 @property(strong, readonly) id _ref;
 
@@ -26,7 +27,7 @@
 
 @end
 
-@protocol GoIgnoreI
+@protocol GoIgnoreI <NSObject>
 // skipped method I.Argument with unsupported parameter or return types
 
 // skipped method I.Result with unsupported parameter or return types
@@ -51,7 +52,7 @@
 
 @class GoIgnoreI;
 
-@interface GoIgnoreI : NSObject <GoIgnoreI> {
+@interface GoIgnoreI : NSObject <goSeqRefInterface, GoIgnoreI> {
 }
 @property(strong, readonly) id _ref;
 

bind/testdata/ignore.objc.m.golden

@@ -26,6 +26,7 @@
 
 @end
 
+
 @implementation GoIgnoreI {
 }
 

bind/testdata/interfaces.objc.h.golden

@@ -6,9 +6,10 @@
 #ifndef __GoInterfaces_H__
 #define __GoInterfaces_H__
 
-#include <Foundation/Foundation.h>
+@import Foundation;
 #include "GoUniverse.h"
 
+
 @protocol GoInterfacesError;
 @class GoInterfacesError;
 @protocol GoInterfacesI;
@@ -24,15 +25,15 @@
 @protocol GoInterfacesWithParam;
 @class GoInterfacesWithParam;
 
-@protocol GoInterfacesError
+@protocol GoInterfacesError <NSObject>
 - (BOOL)err:(NSError**)error;
 @end
 
-@protocol GoInterfacesI
+@protocol GoInterfacesI <NSObject>
 - (int32_t)rand;
 @end
 
-@interface GoInterfacesI1 : NSObject {
+@interface GoInterfacesI1 : NSObject <goSeqRefInterface> {
 }
 @property(strong, readonly) id _ref;
 
@@ -40,7 +41,7 @@
 - (void)j;
 @end
 
-@interface GoInterfacesI2 : NSObject {
+@interface GoInterfacesI2 : NSObject <goSeqRefInterface> {
 }
 @property(strong, readonly) id _ref;
 
@@ -48,20 +49,20 @@
 - (void)g;
 @end
 
-@protocol GoInterfacesI3
+@protocol GoInterfacesI3 <NSObject>
 - (GoInterfacesI1*)f;
 @end
 
-@protocol GoInterfacesLargerI
+@protocol GoInterfacesLargerI <NSObject>
 - (void)anotherFunc;
 - (int32_t)rand;
 @end
 
-@protocol GoInterfacesSameI
+@protocol GoInterfacesSameI <NSObject>
 - (int32_t)rand;
 @end
 
-@protocol GoInterfacesWithParam
+@protocol GoInterfacesWithParam <NSObject>
 - (void)hasParam:(BOOL)p0;
 @end
 
@@ -83,7 +84,7 @@ FOUNDATION_EXPORT id<GoInterfacesI> GoInterfacesSeven();
 
 @class GoInterfacesWithParam;
 
-@interface GoInterfacesError : NSObject <GoInterfacesError> {
+@interface GoInterfacesError : NSObject <goSeqRefInterface, GoInterfacesError> {
 }
 @property(strong, readonly) id _ref;
 
@@ -91,7 +92,7 @@ FOUNDATION_EXPORT id<GoInterfacesI> GoInterfacesSeven();
 - (BOOL)err:(NSError**)error;
 @end
 
-@interface GoInterfacesI : NSObject <GoInterfacesI> {
+@interface GoInterfacesI : NSObject <goSeqRefInterface, GoInterfacesI> {
 }
 @property(strong, readonly) id _ref;
 
@@ -99,7 +100,7 @@ FOUNDATION_EXPORT id<GoInterfacesI> GoInterfacesSeven();
 - (int32_t)rand;
 @end
 
-@interface GoInterfacesI3 : NSObject <GoInterfacesI3> {
+@interface GoInterfacesI3 : NSObject <goSeqRefInterface, GoInterfacesI3> {
 }
 @property(strong, readonly) id _ref;
 
@@ -107,7 +108,7 @@ FOUNDATION_EXPORT id<GoInterfacesI> GoInterfacesSeven();
 - (GoInterfacesI1*)f;
 @end
 
-@interface GoInterfacesLargerI : NSObject <GoInterfacesLargerI> {
+@interface GoInterfacesLargerI : NSObject <goSeqRefInterface, GoInterfacesLargerI> {
 }
 @property(strong, readonly) id _ref;
 
@@ -116,7 +117,7 @@ FOUNDATION_EXPORT id<GoInterfacesI> GoInterfacesSeven();
 - (int32_t)rand;
 @end
 
-@interface GoInterfacesSameI : NSObject <GoInterfacesSameI> {
+@interface GoInterfacesSameI : NSObject <goSeqRefInterface, GoInterfacesSameI> {
 }
 @property(strong, readonly) id _ref;
 
@@ -124,7 +125,7 @@ FOUNDATION_EXPORT id<GoInterfacesI> GoInterfacesSeven();
 - (int32_t)rand;
 @end
 
-@interface GoInterfacesWithParam : NSObject <GoInterfacesWithParam> {
+@interface GoInterfacesWithParam : NSObject <goSeqRefInterface, GoInterfacesWithParam> {
 }
 @property(strong, readonly) id _ref;
 

bind/testdata/interfaces.objc.m.golden

@@ -180,7 +180,7 @@
 
 int32_t GoInterfacesAdd3(id<GoInterfacesI> r) {
 	int32_t _r;
-	if ([(id<NSObject>)(r) isKindOfClass:[GoInterfacesI class]]) {
+	if ([r conformsToProtocol:@protocol(goSeqRefInterface)]) {
 		id<goSeqRefInterface> r_proxy = (id<goSeqRefInterface>)(r);
 		_r = go_seq_go_to_refnum(r_proxy._ref);
 	} else {
@@ -193,7 +193,7 @@ int32_t GoInterfacesAdd3(id<GoInterfacesI> r) {
 
 BOOL GoInterfacesCallErr(id<GoInterfacesError> e, NSError** error) {
 	int32_t _e;
-	if ([(id<NSObject>)(e) isKindOfClass:[GoInterfacesError class]]) {
+	if ([e conformsToProtocol:@protocol(goSeqRefInterface)]) {
 		id<goSeqRefInterface> e_proxy = (id<goSeqRefInterface>)(e);
 		_e = go_seq_go_to_refnum(e_proxy._ref);
 	} else {
@@ -237,7 +237,7 @@ int32_t cproxyinterfaces_Error_Err(int32_t refnum) {
 			_error = error;
 		}
 		int32_t __error;
-		if ([(id<NSObject>)(_error) isKindOfClass:[GoUniverseerror class]]) {
+		if ([_error conformsToProtocol:@protocol(goSeqRefInterface)]) {
 			id<goSeqRefInterface> _error_proxy = (id<goSeqRefInterface>)(_error);
 			__error = go_seq_go_to_refnum(_error_proxy._ref);
 		} else {
@@ -275,7 +275,7 @@ int32_t cproxyinterfaces_I3_F(int32_t refnum) {
 		GoInterfacesI3* o = go_seq_objc_from_refnum(refnum);
 		GoInterfacesI1* returnVal = [o f];
 		int32_t _returnVal;
-		if ([(id<NSObject>)(returnVal) isKindOfClass:[GoInterfacesI1 class]]) {
+		if ([returnVal conformsToProtocol:@protocol(goSeqRefInterface)]) {
 			id<goSeqRefInterface> returnVal_proxy = (id<goSeqRefInterface>)(returnVal);
 			_returnVal = go_seq_go_to_refnum(returnVal_proxy._ref);
 		} else {

bind/testdata/issue10788.objc.h.golden

@@ -6,14 +6,15 @@
 #ifndef __GoIssue10788_H__
 #define __GoIssue10788_H__
 
-#include <Foundation/Foundation.h>
+@import Foundation;
 #include "GoUniverse.h"
 
+
 @class GoIssue10788TestStruct;
 @protocol GoIssue10788TestInterface;
 @class GoIssue10788TestInterface;
 
-@interface GoIssue10788TestStruct : NSObject {
+@interface GoIssue10788TestStruct : NSObject <goSeqRefInterface> {
 }
 @property(strong, readonly) id _ref;
 
@@ -22,14 +23,14 @@
 - (void)setValue:(NSString*)v;
 @end
 
-@protocol GoIssue10788TestInterface
+@protocol GoIssue10788TestInterface <NSObject>
 - (void)doSomeWork:(GoIssue10788TestStruct*)s;
 - (void)multipleUnnamedParams:(long)p0 p1:(NSString*)p1 日本:(int64_t)日本;
 @end
 
 @class GoIssue10788TestInterface;
 
-@interface GoIssue10788TestInterface : NSObject <GoIssue10788TestInterface> {
+@interface GoIssue10788TestInterface : NSObject <goSeqRefInterface, GoIssue10788TestInterface> {
 }
 @property(strong, readonly) id _ref;
 

bind/testdata/issue10788.objc.m.golden

@@ -33,6 +33,7 @@
 
 @end
 
+
 @implementation GoIssue10788TestInterface {
 }
 
@@ -45,7 +46,7 @@
 - (void)doSomeWork:(GoIssue10788TestStruct*)s {
 	int32_t refnum = go_seq_go_to_refnum(self._ref);
 	int32_t _s;
-	if ([(id<NSObject>)(s) isKindOfClass:[GoIssue10788TestStruct class]]) {
+	if ([s conformsToProtocol:@protocol(goSeqRefInterface)]) {
 		id<goSeqRefInterface> s_proxy = (id<goSeqRefInterface>)(s);
 		_s = go_seq_go_to_refnum(s_proxy._ref);
 	} else {

bind/testdata/issue12328.objc.h.golden

@@ -6,12 +6,13 @@
 #ifndef __GoIssue12328_H__
 #define __GoIssue12328_H__
 
-#include <Foundation/Foundation.h>
+@import Foundation;
 #include "GoUniverse.h"
 
+
 @class GoIssue12328T;
 
-@interface GoIssue12328T : NSObject {
+@interface GoIssue12328T : NSObject <goSeqRefInterface> {
 }
 @property(strong, readonly) id _ref;
 

bind/testdata/issue12328.objc.m.golden

@@ -35,7 +35,7 @@
 - (void)setErr:(NSError*)v {
 	int32_t refnum = go_seq_go_to_refnum(self._ref);
 	int32_t _v;
-	if ([(id<NSObject>)(v) isKindOfClass:[GoUniverseerror class]]) {
+	if ([v conformsToProtocol:@protocol(goSeqRefInterface)]) {
 		id<goSeqRefInterface> v_proxy = (id<goSeqRefInterface>)(v);
 		_v = go_seq_go_to_refnum(v_proxy._ref);
 	} else {
@@ -47,6 +47,7 @@
 @end
 
 
+
 __attribute__((constructor)) static void init() {
 	init_seq();
 }

bind/testdata/issue12403.objc.h.golden

@@ -6,20 +6,21 @@
 #ifndef __GoIssue12403_H__
 #define __GoIssue12403_H__
 
-#include <Foundation/Foundation.h>
+@import Foundation;
 #include "GoUniverse.h"
 
+
 @protocol GoIssue12403Parsable;
 @class GoIssue12403Parsable;
 
-@protocol GoIssue12403Parsable
+@protocol GoIssue12403Parsable <NSObject>
 - (NSString*)fromJSON:(NSString*)jstr;
 - (BOOL)toJSON:(NSString**)ret0_ error:(NSError**)error;
 @end
 
 @class GoIssue12403Parsable;
 
-@interface GoIssue12403Parsable : NSObject <GoIssue12403Parsable> {
+@interface GoIssue12403Parsable : NSObject <goSeqRefInterface, GoIssue12403Parsable> {
 }
 @property(strong, readonly) id _ref;
 

bind/testdata/issue12403.objc.m.golden

@@ -70,7 +70,7 @@ struct cproxyissue12403_Parsable_ToJSON_return cproxyissue12403_Parsable_ToJSON(
 			_error = error;
 		}
 		int32_t __error;
-		if ([(id<NSObject>)(_error) isKindOfClass:[GoUniverseerror class]]) {
+		if ([_error conformsToProtocol:@protocol(goSeqRefInterface)]) {
 			id<goSeqRefInterface> _error_proxy = (id<goSeqRefInterface>)(_error);
 			__error = go_seq_go_to_refnum(_error_proxy._ref);
 		} else {

bind/testdata/keywords.objc.h.golden

@@ -6,13 +6,14 @@
 #ifndef __GoKeywords_H__
 #define __GoKeywords_H__
 
-#include <Foundation/Foundation.h>
+@import Foundation;
 #include "GoUniverse.h"
 
+
 @protocol GoKeywordsKeywordCaller;
 @class GoKeywordsKeywordCaller;
 
-@protocol GoKeywordsKeywordCaller
+@protocol GoKeywordsKeywordCaller <NSObject>
 - (void)abstract;
 - (void)assert;
 - (void)boolean;
@@ -70,7 +71,7 @@
 
 @class GoKeywordsKeywordCaller;
 
-@interface GoKeywordsKeywordCaller : NSObject <GoKeywordsKeywordCaller> {
+@interface GoKeywordsKeywordCaller : NSObject <goSeqRefInterface, GoKeywordsKeywordCaller> {
 }
 @property(strong, readonly) id _ref;
 

bind/testdata/objcw.go

@@ -0,0 +1,39 @@
+// 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 objc
+
+import (
+	"ObjC/Foundation"
+	"ObjC/UIKit"
+)
+
+type GoNSDate struct {
+	Foundation.NSDate
+	this Foundation.NSDate
+}
+
+func (d *GoNSDate) Hash(this Foundation.NSDate) int {
+	return 0
+}
+
+type GoNSObject struct {
+	C Foundation.NSObjectC // The class
+	P Foundation.NSObjectP // The protocol
+}
+
+func (o *GoNSObject) Description(this Foundation.NSObjectC) string {
+	return ""
+}
+
+func DupNSDate(date Foundation.NSDate) Foundation.NSDate {
+	return date
+}
+
+type GoUIResponder struct {
+	UIKit.UIResponder
+}
+
+func (r *GoUIResponder) PressesBegan(_ Foundation.NSSet, _ UIKit.UIPressesEvent) {
+}

bind/testdata/objcw.go.golden

@@ -0,0 +1,487 @@
+//File is generated by gobind. Do not edit.
+
+package ObjC
+
+// Used to silence this package not used errors
+const Dummy = 0
+
+type Foundation_NSDate interface {
+	Hash() (uint)
+	Description() (string)
+	Super() Foundation_NSDate
+}
+
+type Foundation_NSObjectC interface {
+	Hash() (uint)
+	Description() (string)
+	Super() Foundation_NSObjectC
+}
+
+type Foundation_NSObjectP interface {
+	Hash() (uint)
+	Description() (string)
+}
+
+type Foundation_NSSet interface {
+	Hash() (uint)
+	Description() (string)
+	Super() Foundation_NSSet
+}
+
+type UIKit_UIResponder interface {
+	Hash() (uint)
+	Description() (string)
+	Super() UIKit_UIResponder
+}
+
+type UIKit_UIPressesEvent interface {
+	Hash() (uint)
+	Description() (string)
+	Super() UIKit_UIPressesEvent
+}
+
+// File is generated by gobind. Do not edit.
+
+package gomobile_bind
+
+// #cgo CFLAGS: -fobjc-arc -fmodules -fblocks
+// #include "interfaces.h"
+import "C"
+
+import "ObjC"
+import _seq "golang.org/x/mobile/bind/seq"
+
+type proxy interface { Bind_proxy_refnum__() int32 }
+
+// Suppress unused package error
+
+var _ = _seq.FromRefNum
+const _ = ObjC.Dummy
+
+func init() {
+}
+
+type proxy_class_NSDate _seq.Ref
+
+func (p *proxy_class_NSDate) Bind_proxy_refnum__() int32 { return (*_seq.Ref)(p).Bind_IncNum() }
+
+func (p *proxy_class_NSDate) Hash() (uint) {
+	res := C.cproxy_NSDate_Hash(C.int(p.Bind_proxy_refnum__()))
+	_res := uint(res)
+	return _res
+}
+
+func (p *proxy_class_NSDate) Description() (string) {
+	res := C.cproxy_NSDate_Description(C.int(p.Bind_proxy_refnum__()))
+	_res := decodeString(res)
+	return _res
+}
+
+func (p *proxy_class_NSDate) Super() ObjC.Foundation_NSDate {
+  return &super_NSDate{p}
+}
+
+type super_NSDate struct {*proxy_class_NSDate}
+
+func (p *super_NSDate) Hash() (uint) {
+	res := C.csuper_NSDate_Hash(C.int(p.Bind_proxy_refnum__()))
+	_res := uint(res)
+	return _res
+}
+
+func (p *super_NSDate) Description() (string) {
+	res := C.csuper_NSDate_Description(C.int(p.Bind_proxy_refnum__()))
+	_res := decodeString(res)
+	return _res
+}
+
+func init() {
+}
+
+type proxy_class_NSObjectC _seq.Ref
+
+func (p *proxy_class_NSObjectC) Bind_proxy_refnum__() int32 { return (*_seq.Ref)(p).Bind_IncNum() }
+
+func (p *proxy_class_NSObjectC) Hash() (uint) {
+	res := C.cproxy_NSObjectC_Hash(C.int(p.Bind_proxy_refnum__()))
+	_res := uint(res)
+	return _res
+}
+
+func (p *proxy_class_NSObjectC) Description() (string) {
+	res := C.cproxy_NSObjectC_Description(C.int(p.Bind_proxy_refnum__()))
+	_res := decodeString(res)
+	return _res
+}
+
+func (p *proxy_class_NSObjectC) Super() ObjC.Foundation_NSObjectC {
+  return &super_NSObjectC{p}
+}
+
+type super_NSObjectC struct {*proxy_class_NSObjectC}
+
+func (p *super_NSObjectC) Hash() (uint) {
+	res := C.csuper_NSObjectC_Hash(C.int(p.Bind_proxy_refnum__()))
+	_res := uint(res)
+	return _res
+}
+
+func (p *super_NSObjectC) Description() (string) {
+	res := C.csuper_NSObjectC_Description(C.int(p.Bind_proxy_refnum__()))
+	_res := decodeString(res)
+	return _res
+}
+
+func init() {
+}
+
+type proxy_class_NSObjectP _seq.Ref
+
+func (p *proxy_class_NSObjectP) Bind_proxy_refnum__() int32 { return (*_seq.Ref)(p).Bind_IncNum() }
+
+func (p *proxy_class_NSObjectP) Hash() (uint) {
+	res := C.cproxy_NSObjectP_Hash(C.int(p.Bind_proxy_refnum__()))
+	_res := uint(res)
+	return _res
+}
+
+func (p *proxy_class_NSObjectP) Description() (string) {
+	res := C.cproxy_NSObjectP_Description(C.int(p.Bind_proxy_refnum__()))
+	_res := decodeString(res)
+	return _res
+}
+
+func init() {
+}
+
+type proxy_class_NSSet _seq.Ref
+
+func (p *proxy_class_NSSet) Bind_proxy_refnum__() int32 { return (*_seq.Ref)(p).Bind_IncNum() }
+
+func (p *proxy_class_NSSet) Hash() (uint) {
+	res := C.cproxy_NSSet_Hash(C.int(p.Bind_proxy_refnum__()))
+	_res := uint(res)
+	return _res
+}
+
+func (p *proxy_class_NSSet) Description() (string) {
+	res := C.cproxy_NSSet_Description(C.int(p.Bind_proxy_refnum__()))
+	_res := decodeString(res)
+	return _res
+}
+
+func (p *proxy_class_NSSet) Super() ObjC.Foundation_NSSet {
+  return &super_NSSet{p}
+}
+
+type super_NSSet struct {*proxy_class_NSSet}
+
+func (p *super_NSSet) Hash() (uint) {
+	res := C.csuper_NSSet_Hash(C.int(p.Bind_proxy_refnum__()))
+	_res := uint(res)
+	return _res
+}
+
+func (p *super_NSSet) Description() (string) {
+	res := C.csuper_NSSet_Description(C.int(p.Bind_proxy_refnum__()))
+	_res := decodeString(res)
+	return _res
+}
+
+func init() {
+}
+
+type proxy_class_UIResponder _seq.Ref
+
+func (p *proxy_class_UIResponder) Bind_proxy_refnum__() int32 { return (*_seq.Ref)(p).Bind_IncNum() }
+
+func (p *proxy_class_UIResponder) Hash() (uint) {
+	res := C.cproxy_UIResponder_Hash(C.int(p.Bind_proxy_refnum__()))
+	_res := uint(res)
+	return _res
+}
+
+func (p *proxy_class_UIResponder) Description() (string) {
+	res := C.cproxy_UIResponder_Description(C.int(p.Bind_proxy_refnum__()))
+	_res := decodeString(res)
+	return _res
+}
+
+func (p *proxy_class_UIResponder) Super() ObjC.UIKit_UIResponder {
+  return &super_UIResponder{p}
+}
+
+type super_UIResponder struct {*proxy_class_UIResponder}
+
+func (p *super_UIResponder) Hash() (uint) {
+	res := C.csuper_UIResponder_Hash(C.int(p.Bind_proxy_refnum__()))
+	_res := uint(res)
+	return _res
+}
+
+func (p *super_UIResponder) Description() (string) {
+	res := C.csuper_UIResponder_Description(C.int(p.Bind_proxy_refnum__()))
+	_res := decodeString(res)
+	return _res
+}
+
+func init() {
+}
+
+type proxy_class_UIPressesEvent _seq.Ref
+
+func (p *proxy_class_UIPressesEvent) Bind_proxy_refnum__() int32 { return (*_seq.Ref)(p).Bind_IncNum() }
+
+func (p *proxy_class_UIPressesEvent) Hash() (uint) {
+	res := C.cproxy_UIPressesEvent_Hash(C.int(p.Bind_proxy_refnum__()))
+	_res := uint(res)
+	return _res
+}
+
+func (p *proxy_class_UIPressesEvent) Description() (string) {
+	res := C.cproxy_UIPressesEvent_Description(C.int(p.Bind_proxy_refnum__()))
+	_res := decodeString(res)
+	return _res
+}
+
+func (p *proxy_class_UIPressesEvent) Super() ObjC.UIKit_UIPressesEvent {
+  return &super_UIPressesEvent{p}
+}
+
+type super_UIPressesEvent struct {*proxy_class_UIPressesEvent}
+
+func (p *super_UIPressesEvent) Hash() (uint) {
+	res := C.csuper_UIPressesEvent_Hash(C.int(p.Bind_proxy_refnum__()))
+	_res := uint(res)
+	return _res
+}
+
+func (p *super_UIPressesEvent) Description() (string) {
+	res := C.csuper_UIPressesEvent_Description(C.int(p.Bind_proxy_refnum__()))
+	_res := decodeString(res)
+	return _res
+}
+
+// Package gomobile_bind is an autogenerated binder stub for package objc.
+//   gobind -lang=go objcw
+//
+// File is generated by gobind. Do not edit.
+package gomobile_bind
+
+/*
+#include <stdlib.h>
+#include <stdint.h>
+#include "seq.h"
+#include "objc.h"
+
+*/
+import "C"
+
+import (
+	"ObjC/Foundation"
+	"ObjC/UIKit"
+	_seq "golang.org/x/mobile/bind/seq"
+	"objcw"
+)
+
+// suppress the error if seq ends up unused
+var _ = _seq.FromRefNum
+
+//export proxyobjc_GoNSDate_NSDate_Set
+func proxyobjc_GoNSDate_NSDate_Set(refnum C.int32_t, v C.int32_t) {
+	ref := _seq.FromRefNum(int32(refnum))
+	var _v Foundation.NSDate
+	_v_ref := _seq.FromRefNum(int32(v))
+	if _v_ref != nil {
+		if v < 0 { // go object
+			_v = _v_ref.Get().(Foundation.NSDate)
+		} else { // foreign object
+			_v = (*proxy_class_NSDate)(_v_ref)
+		}
+	}
+	ref.Get().(*objc.GoNSDate).NSDate = _v
+}
+
+//export proxyobjc_GoNSDate_NSDate_Get
+func proxyobjc_GoNSDate_NSDate_Get(refnum C.int32_t) C.int32_t {
+	ref := _seq.FromRefNum(int32(refnum))
+	v := ref.Get().(*objc.GoNSDate).NSDate
+	var _v C.int32_t = _seq.NullRefNum
+	if v != nil {
+		_v = C.int32_t(_seq.ToRefNum(v))
+	}
+	return _v
+}
+
+//export proxyobjc_GoNSDate_Hash
+func proxyobjc_GoNSDate_Hash(refnum C.int32_t, param_this C.int32_t) C.nint {
+	ref := _seq.FromRefNum(int32(refnum))
+	v := ref.Get().(*objc.GoNSDate)
+	var _param_this Foundation.NSDate
+	_param_this_ref := _seq.FromRefNum(int32(param_this))
+	if _param_this_ref != nil {
+		if param_this < 0 { // go object
+			_param_this = _param_this_ref.Get().(Foundation.NSDate)
+		} else { // foreign object
+			_param_this = (*proxy_class_NSDate)(_param_this_ref)
+		}
+	}
+	res_0 := v.Hash(_param_this)
+	_res_0 := C.nint(res_0)
+	return _res_0
+}
+
+//export new_objc_GoNSDate
+func new_objc_GoNSDate() C.int32_t {
+	return C.int32_t(_seq.ToRefNum(new(objc.GoNSDate)))
+}
+
+//export proxyobjc_GoNSObject_C_Set
+func proxyobjc_GoNSObject_C_Set(refnum C.int32_t, v C.int32_t) {
+	ref := _seq.FromRefNum(int32(refnum))
+	var _v Foundation.NSObjectC
+	_v_ref := _seq.FromRefNum(int32(v))
+	if _v_ref != nil {
+		if v < 0 { // go object
+			_v = _v_ref.Get().(Foundation.NSObjectC)
+		} else { // foreign object
+			_v = (*proxy_class_NSObjectC)(_v_ref)
+		}
+	}
+	ref.Get().(*objc.GoNSObject).C = _v
+}
+
+//export proxyobjc_GoNSObject_C_Get
+func proxyobjc_GoNSObject_C_Get(refnum C.int32_t) C.int32_t {
+	ref := _seq.FromRefNum(int32(refnum))
+	v := ref.Get().(*objc.GoNSObject).C
+	var _v C.int32_t = _seq.NullRefNum
+	if v != nil {
+		_v = C.int32_t(_seq.ToRefNum(v))
+	}
+	return _v
+}
+
+//export proxyobjc_GoNSObject_P_Set
+func proxyobjc_GoNSObject_P_Set(refnum C.int32_t, v C.int32_t) {
+	ref := _seq.FromRefNum(int32(refnum))
+	var _v Foundation.NSObjectP
+	_v_ref := _seq.FromRefNum(int32(v))
+	if _v_ref != nil {
+		if v < 0 { // go object
+			_v = _v_ref.Get().(Foundation.NSObjectP)
+		} else { // foreign object
+			_v = (*proxy_class_NSObjectP)(_v_ref)
+		}
+	}
+	ref.Get().(*objc.GoNSObject).P = _v
+}
+
+//export proxyobjc_GoNSObject_P_Get
+func proxyobjc_GoNSObject_P_Get(refnum C.int32_t) C.int32_t {
+	ref := _seq.FromRefNum(int32(refnum))
+	v := ref.Get().(*objc.GoNSObject).P
+	var _v C.int32_t = _seq.NullRefNum
+	if v != nil {
+		_v = C.int32_t(_seq.ToRefNum(v))
+	}
+	return _v
+}
+
+//export proxyobjc_GoNSObject_Description
+func proxyobjc_GoNSObject_Description(refnum C.int32_t, param_this C.int32_t) C.nstring {
+	ref := _seq.FromRefNum(int32(refnum))
+	v := ref.Get().(*objc.GoNSObject)
+	var _param_this Foundation.NSObjectC
+	_param_this_ref := _seq.FromRefNum(int32(param_this))
+	if _param_this_ref != nil {
+		if param_this < 0 { // go object
+			_param_this = _param_this_ref.Get().(Foundation.NSObjectC)
+		} else { // foreign object
+			_param_this = (*proxy_class_NSObjectC)(_param_this_ref)
+		}
+	}
+	res_0 := v.Description(_param_this)
+	_res_0 := encodeString(res_0)
+	return _res_0
+}
+
+//export new_objc_GoNSObject
+func new_objc_GoNSObject() C.int32_t {
+	return C.int32_t(_seq.ToRefNum(new(objc.GoNSObject)))
+}
+
+//export proxyobjc_GoUIResponder_UIResponder_Set
+func proxyobjc_GoUIResponder_UIResponder_Set(refnum C.int32_t, v C.int32_t) {
+	ref := _seq.FromRefNum(int32(refnum))
+	var _v UIKit.UIResponder
+	_v_ref := _seq.FromRefNum(int32(v))
+	if _v_ref != nil {
+		if v < 0 { // go object
+			_v = _v_ref.Get().(UIKit.UIResponder)
+		} else { // foreign object
+			_v = (*proxy_class_UIResponder)(_v_ref)
+		}
+	}
+	ref.Get().(*objc.GoUIResponder).UIResponder = _v
+}
+
+//export proxyobjc_GoUIResponder_UIResponder_Get
+func proxyobjc_GoUIResponder_UIResponder_Get(refnum C.int32_t) C.int32_t {
+	ref := _seq.FromRefNum(int32(refnum))
+	v := ref.Get().(*objc.GoUIResponder).UIResponder
+	var _v C.int32_t = _seq.NullRefNum
+	if v != nil {
+		_v = C.int32_t(_seq.ToRefNum(v))
+	}
+	return _v
+}
+
+//export proxyobjc_GoUIResponder_PressesBegan
+func proxyobjc_GoUIResponder_PressesBegan(refnum C.int32_t, param_p0 C.int32_t, param_p1 C.int32_t) {
+	ref := _seq.FromRefNum(int32(refnum))
+	v := ref.Get().(*objc.GoUIResponder)
+	var _param_p0 Foundation.NSSet
+	_param_p0_ref := _seq.FromRefNum(int32(param_p0))
+	if _param_p0_ref != nil {
+		if param_p0 < 0 { // go object
+			_param_p0 = _param_p0_ref.Get().(Foundation.NSSet)
+		} else { // foreign object
+			_param_p0 = (*proxy_class_NSSet)(_param_p0_ref)
+		}
+	}
+	var _param_p1 UIKit.UIPressesEvent
+	_param_p1_ref := _seq.FromRefNum(int32(param_p1))
+	if _param_p1_ref != nil {
+		if param_p1 < 0 { // go object
+			_param_p1 = _param_p1_ref.Get().(UIKit.UIPressesEvent)
+		} else { // foreign object
+			_param_p1 = (*proxy_class_UIPressesEvent)(_param_p1_ref)
+		}
+	}
+	v.PressesBegan(_param_p0, _param_p1)
+}
+
+//export new_objc_GoUIResponder
+func new_objc_GoUIResponder() C.int32_t {
+	return C.int32_t(_seq.ToRefNum(new(objc.GoUIResponder)))
+}
+
+//export proxyobjc__DupNSDate
+func proxyobjc__DupNSDate(param_date C.int32_t) C.int32_t {
+	var _param_date Foundation.NSDate
+	_param_date_ref := _seq.FromRefNum(int32(param_date))
+	if _param_date_ref != nil {
+		if param_date < 0 { // go object
+			_param_date = _param_date_ref.Get().(Foundation.NSDate)
+		} else { // foreign object
+			_param_date = (*proxy_class_NSDate)(_param_date_ref)
+		}
+	}
+	res_0 := objc.DupNSDate(_param_date)
+	var _res_0 C.int32_t = _seq.NullRefNum
+	if res_0 != nil {
+		_res_0 = C.int32_t(_seq.ToRefNum(res_0))
+	}
+	return _res_0
+}

bind/testdata/structs.objc.h.golden

@@ -6,15 +6,16 @@
 #ifndef __GoStructs_H__
 #define __GoStructs_H__
 
-#include <Foundation/Foundation.h>
+@import Foundation;
 #include "GoUniverse.h"
 
+
 @class GoStructsS;
 @class GoStructsS2;
 @protocol GoStructsI;
 @class GoStructsI;
 
-@interface GoStructsS : NSObject {
+@interface GoStructsS : NSObject <goSeqRefInterface> {
 }
 @property(strong, readonly) id _ref;
 
@@ -27,7 +28,7 @@
 - (double)sum;
 @end
 
-@interface GoStructsS2 : NSObject {
+@interface GoStructsS2 : NSObject <goSeqRefInterface> {
 }
 @property(strong, readonly) id _ref;
 
@@ -36,7 +37,7 @@
 - (NSString*)string;
 @end
 
-@protocol GoStructsI
+@protocol GoStructsI <NSObject>
 - (void)m;
 @end
 
@@ -46,7 +47,7 @@ FOUNDATION_EXPORT BOOL GoStructsIdentityWithError(GoStructsS* s, GoStructsS** re
 
 @class GoStructsI;
 
-@interface GoStructsI : NSObject <GoStructsI> {
+@interface GoStructsI : NSObject <goSeqRefInterface, GoStructsI> {
 }
 @property(strong, readonly) id _ref;
 

bind/testdata/structs.objc.m.golden

@@ -80,6 +80,7 @@
 @end
 
 
+
 @implementation GoStructsS2 {
 }
 
@@ -103,6 +104,7 @@
 
 @end
 
+
 @implementation GoStructsI {
 }
 
@@ -123,7 +125,7 @@
 
 GoStructsS* GoStructsIdentity(GoStructsS* s) {
 	int32_t _s;
-	if ([(id<NSObject>)(s) isKindOfClass:[GoStructsS class]]) {
+	if ([s conformsToProtocol:@protocol(goSeqRefInterface)]) {
 		id<goSeqRefInterface> s_proxy = (id<goSeqRefInterface>)(s);
 		_s = go_seq_go_to_refnum(s_proxy._ref);
 	} else {
@@ -143,7 +145,7 @@ GoStructsS* GoStructsIdentity(GoStructsS* s) {
 
 BOOL GoStructsIdentityWithError(GoStructsS* s, GoStructsS** ret0_, NSError** error) {
 	int32_t _s;
-	if ([(id<NSObject>)(s) isKindOfClass:[GoStructsS class]]) {
+	if ([s conformsToProtocol:@protocol(goSeqRefInterface)]) {
 		id<goSeqRefInterface> s_proxy = (id<goSeqRefInterface>)(s);
 		_s = go_seq_go_to_refnum(s_proxy._ref);
 	} else {

bind/testdata/try.objc.h.golden

@@ -6,9 +6,10 @@
 #ifndef __GoTry_H__
 #define __GoTry_H__
 
-#include <Foundation/Foundation.h>
+@import Foundation;
 #include "GoUniverse.h"
 
+
 FOUNDATION_EXPORT NSString* GoTryThis();
 
 #endif

bind/testdata/vars.objc.h.golden

@@ -6,21 +6,22 @@
 #ifndef __GoVars_H__
 #define __GoVars_H__
 
-#include <Foundation/Foundation.h>
+@import Foundation;
 #include "GoUniverse.h"
 
+
 @class GoVarsS;
 @protocol GoVarsI;
 @class GoVarsI;
 
-@interface GoVarsS : NSObject {
+@interface GoVarsS : NSObject <goSeqRefInterface> {
 }
 @property(strong, readonly) id _ref;
 
 - (id)initWithRef:(id)ref;
 @end
 
-@protocol GoVarsI
+@protocol GoVarsI <NSObject>
 @end
 
 @interface GoVars : NSObject
@@ -64,7 +65,7 @@
 
 @class GoVarsI;
 
-@interface GoVarsI : NSObject <GoVarsI> {
+@interface GoVarsI : NSObject <goSeqRefInterface, GoVarsI> {
 }
 @property(strong, readonly) id _ref;
 

bind/testdata/vars.objc.m.golden

@@ -20,6 +20,7 @@
 
 @end
 
+
 @implementation GoVarsI {
 }
 
@@ -90,7 +91,7 @@
 
 + (void) setAStructPtr:(GoVarsS*)v {
 	int32_t _v;
-	if ([(id<NSObject>)(v) isKindOfClass:[GoVarsS class]]) {
+	if ([v conformsToProtocol:@protocol(goSeqRefInterface)]) {
 		id<goSeqRefInterface> v_proxy = (id<goSeqRefInterface>)(v);
 		_v = go_seq_go_to_refnum(v_proxy._ref);
 	} else {
@@ -169,7 +170,7 @@
 
 + (void) setAnInterface:(id<GoVarsI>)v {
 	int32_t _v;
-	if ([(id<NSObject>)(v) isKindOfClass:[GoVarsI class]]) {
+	if ([v conformsToProtocol:@protocol(goSeqRefInterface)]) {
 		id<goSeqRefInterface> v_proxy = (id<goSeqRefInterface>)(v);
 		_v = go_seq_go_to_refnum(v_proxy._ref);
 	} else {

bind/testpkg/objcpkg/classes.go

@@ -0,0 +1,68 @@
+// 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 objcpkg
+
+import (
+	"ObjC/Foundation"
+	"ObjC/UIKit"
+)
+
+const (
+	DescriptionStr = "Descriptrion from Go"
+	Hash           = 42
+)
+
+type GoNSDate struct {
+	Foundation.NSDate
+	this Foundation.NSDate
+}
+
+func (d *GoNSDate) Hash(this Foundation.NSDate) int {
+	return Hash
+}
+
+func (d *GoNSDate) Description(this Foundation.NSDate) string {
+	// Test this call
+	if h := this.Hash(); h != Hash {
+		panic("hash mismatch")
+	}
+	d.this = this
+	return DescriptionStr
+}
+
+func (d *GoNSDate) This() Foundation.NSDate {
+	return d.this
+}
+
+func NewGoNSDate() *GoNSDate {
+	return new(GoNSDate)
+}
+
+type GoNSObject struct {
+	C       Foundation.NSObjectC // The class
+	P       Foundation.NSObjectP // The protocol
+	UseThis bool
+}
+
+func (o *GoNSObject) Description(this Foundation.NSObjectC) string {
+	if o.UseThis {
+		return DescriptionStr
+	} else {
+		return this.Super().Description()
+	}
+}
+
+func DupNSDate(date Foundation.NSDate) Foundation.NSDate {
+	return date
+}
+
+type GoUIResponder struct {
+	UIKit.UIResponder
+	Called bool
+}
+
+func (r *GoUIResponder) PressesBegan(_ Foundation.NSSet, _ UIKit.UIPressesEvent) {
+	r.Called = true
+}

bind/types.go

@@ -76,9 +76,9 @@ func exportedMethodSet(T types.Type) []*types.Func {
 		if !obj.Exported() {
 			continue
 		}
-		// Skip methods from the embedded java classes, so that
+		// Skip methods from the embedded classes, so that
 		// only methods that are implemented in Go are included.
-		if isJavaPkg(obj.Pkg()) {
+		if pref := pkgFirstElem(obj.Pkg()); pref == "Java" || pref == "ObjC" {
 			continue
 		}
 		switch obj := obj.(type) {
@@ -142,14 +142,27 @@ func isRefType(t types.Type) bool {
 	}
 }
 
-func isJavaType(t types.Type) bool {
+func typePkgFirstElem(t types.Type) string {
 	nt, ok := t.(*types.Named)
 	if !ok {
-		return false
+		return ""
 	}
-	return isJavaPkg(nt.Obj().Pkg())
+	return pkgFirstElem(nt.Obj().Pkg())
 }
 
-func isJavaPkg(p *types.Package) bool {
+func pkgFirstElem(p *types.Package) string {
-	return p != nil && strings.HasPrefix(p.Path(), "Java/")
+	if p == nil {
+		return ""
+	}
+	path := p.Path()
+	idx := strings.Index(path, "/")
+	if idx == -1 {
+		return ""
+	}
+	return path[:idx]
+}
+
+func isWrapperType(t types.Type) bool {
+	e := typePkgFirstElem(t)
+	return e == "Java" || e == "ObjC"
 }

cmd/gobind/gen.go

@@ -119,7 +119,7 @@ func genPkg(p *types.Package, allPkg []*types.Package, classes []*java.Class) {
 			},
 			Prefix: *prefix,
 		}
-		g.Init()
+		g.Init(nil)
 
 		w, closer := writer(gohname)
 		processErr(g.GenGoH())

cmd/gomobile/bind.go

@@ -220,7 +220,7 @@ func (b *binder) GenObjc(pkg *types.Package, allPkg []*types.Package, outdir str
 		},
 		Prefix: bindPrefix,
 	}
-	g.Init()
+	g.Init(wrappers)
 
 	generate := func(w io.Writer) error {
 		if buildX {