goprotobuf: Allow groups to be treated as messages.

R=r
CC=golang-dev
https://codereview.appspot.com/9117043

proto/clone.go

@@ -88,7 +88,6 @@ func mergeStruct(out, in reflect.Value) {
 		mergeExtension(emOut.ExtensionMap(), emIn.ExtensionMap())
 	}
 
-	// Groups don't have XXX_unrecognized fields.
 	uf := in.FieldByName("XXX_unrecognized")
 	if !uf.IsValid() {
 		return

proto/equal.go

@@ -126,7 +126,6 @@ func equalStruct(v1, v2 reflect.Value) bool {
 		}
 	}
 
-	// Groups don't have XXX_unrecognized.
 	uf := v1.FieldByName("XXX_unrecognized")
 	if !uf.IsValid() {
 		return true

proto/size.go

@@ -92,7 +92,6 @@ func sizeStruct(x reflect.Value) (n int) {
 		}
 	}
 
-	// Groups don't have XXX_unrecognized fields.
 	if uf := x.FieldByName("XXX_unrecognized"); uf.IsValid() {
 		n += uf.Len()
 	}

proto/testdata/test.pb.go

@@ -871,7 +871,9 @@ type GoTest_RequiredGroup struct {
 	XXX_unrecognized []byte  `json:"-"`
 }
 
-func (m *GoTest_RequiredGroup) Reset() { *m = GoTest_RequiredGroup{} }
+func (m *GoTest_RequiredGroup) Reset()         { *m = GoTest_RequiredGroup{} }
+func (m *GoTest_RequiredGroup) String() string { return proto.CompactTextString(m) }
+func (*GoTest_RequiredGroup) ProtoMessage()    {}
 
 func (m *GoTest_RequiredGroup) GetRequiredField() string {
 	if m != nil && m.RequiredField != nil {
@@ -885,7 +887,9 @@ type GoTest_RepeatedGroup struct {
 	XXX_unrecognized []byte  `json:"-"`
 }
 
-func (m *GoTest_RepeatedGroup) Reset() { *m = GoTest_RepeatedGroup{} }
+func (m *GoTest_RepeatedGroup) Reset()         { *m = GoTest_RepeatedGroup{} }
+func (m *GoTest_RepeatedGroup) String() string { return proto.CompactTextString(m) }
+func (*GoTest_RepeatedGroup) ProtoMessage()    {}
 
 func (m *GoTest_RepeatedGroup) GetRequiredField() string {
 	if m != nil && m.RequiredField != nil {
@@ -899,7 +903,9 @@ type GoTest_OptionalGroup struct {
 	XXX_unrecognized []byte  `json:"-"`
 }
 
-func (m *GoTest_OptionalGroup) Reset() { *m = GoTest_OptionalGroup{} }
+func (m *GoTest_OptionalGroup) Reset()         { *m = GoTest_OptionalGroup{} }
+func (m *GoTest_OptionalGroup) String() string { return proto.CompactTextString(m) }
+func (*GoTest_OptionalGroup) ProtoMessage()    {}
 
 func (m *GoTest_OptionalGroup) GetRequiredField() string {
 	if m != nil && m.RequiredField != nil {
@@ -962,7 +968,9 @@ type GoSkipTest_SkipGroup struct {
 	XXX_unrecognized []byte  `json:"-"`
 }
 
-func (m *GoSkipTest_SkipGroup) Reset() { *m = GoSkipTest_SkipGroup{} }
+func (m *GoSkipTest_SkipGroup) Reset()         { *m = GoSkipTest_SkipGroup{} }
+func (m *GoSkipTest_SkipGroup) String() string { return proto.CompactTextString(m) }
+func (*GoSkipTest_SkipGroup) ProtoMessage()    {}
 
 func (m *GoSkipTest_SkipGroup) GetGroupInt32() int32 {
 	if m != nil && m.GroupInt32 != nil {
@@ -1280,7 +1288,9 @@ type MyMessage_SomeGroup struct {
 	XXX_unrecognized []byte `json:"-"`
 }
 
-func (m *MyMessage_SomeGroup) Reset() { *m = MyMessage_SomeGroup{} }
+func (m *MyMessage_SomeGroup) Reset()         { *m = MyMessage_SomeGroup{} }
+func (m *MyMessage_SomeGroup) String() string { return proto.CompactTextString(m) }
+func (*MyMessage_SomeGroup) ProtoMessage()    {}
 
 func (m *MyMessage_SomeGroup) GetGroupField() int32 {
 	if m != nil && m.GroupField != nil {
@@ -1351,7 +1361,9 @@ type MessageList_Message struct {
 	XXX_unrecognized []byte  `json:"-"`
 }
 
-func (m *MessageList_Message) Reset() { *m = MessageList_Message{} }
+func (m *MessageList_Message) Reset()         { *m = MessageList_Message{} }
+func (m *MessageList_Message) String() string { return proto.CompactTextString(m) }
+func (*MessageList_Message) ProtoMessage()    {}
 
 func (m *MessageList_Message) GetName() string {
 	if m != nil && m.Name != nil {
@@ -1646,6 +1658,78 @@ func (m *MoreRepeated) GetStrings() []string {
 	return nil
 }
 
+type GroupOld struct {
+	G                *GroupOld_G `protobuf:"group,1,opt" json:"g,omitempty"`
+	XXX_unrecognized []byte      `json:"-"`
+}
+
+func (m *GroupOld) Reset()         { *m = GroupOld{} }
+func (m *GroupOld) String() string { return proto.CompactTextString(m) }
+func (*GroupOld) ProtoMessage()    {}
+
+func (m *GroupOld) GetG() *GroupOld_G {
+	if m != nil {
+		return m.G
+	}
+	return nil
+}
+
+type GroupOld_G struct {
+	X                *int32 `protobuf:"varint,2,opt,name=x" json:"x,omitempty"`
+	XXX_unrecognized []byte `json:"-"`
+}
+
+func (m *GroupOld_G) Reset()         { *m = GroupOld_G{} }
+func (m *GroupOld_G) String() string { return proto.CompactTextString(m) }
+func (*GroupOld_G) ProtoMessage()    {}
+
+func (m *GroupOld_G) GetX() int32 {
+	if m != nil && m.X != nil {
+		return *m.X
+	}
+	return 0
+}
+
+type GroupNew struct {
+	G                *GroupNew_G `protobuf:"group,1,opt" json:"g,omitempty"`
+	XXX_unrecognized []byte      `json:"-"`
+}
+
+func (m *GroupNew) Reset()         { *m = GroupNew{} }
+func (m *GroupNew) String() string { return proto.CompactTextString(m) }
+func (*GroupNew) ProtoMessage()    {}
+
+func (m *GroupNew) GetG() *GroupNew_G {
+	if m != nil {
+		return m.G
+	}
+	return nil
+}
+
+type GroupNew_G struct {
+	X                *int32 `protobuf:"varint,2,opt,name=x" json:"x,omitempty"`
+	Y                *int32 `protobuf:"varint,3,opt,name=y" json:"y,omitempty"`
+	XXX_unrecognized []byte `json:"-"`
+}
+
+func (m *GroupNew_G) Reset()         { *m = GroupNew_G{} }
+func (m *GroupNew_G) String() string { return proto.CompactTextString(m) }
+func (*GroupNew_G) ProtoMessage()    {}
+
+func (m *GroupNew_G) GetX() int32 {
+	if m != nil && m.X != nil {
+		return *m.X
+	}
+	return 0
+}
+
+func (m *GroupNew_G) GetY() int32 {
+	if m != nil && m.Y != nil {
+		return *m.Y
+	}
+	return 0
+}
+
 var E_Greeting = &proto.ExtensionDesc{
 	ExtendedType:  (*MyMessage)(nil),
 	ExtensionType: ([]string)(nil),

protoc-gen-go/generator/generator.go

@@ -1387,10 +1387,8 @@ func (g *Generator) generateMessage(message *Descriptor) {
 
 	// Reset, String and ProtoMessage methods.
 	g.P("func (m *", ccTypeName, ") Reset() { *m = ", ccTypeName, "{} }")
-	if !message.group {
-		g.P("func (m *", ccTypeName, ") String() string { return ", g.Pkg["proto"], ".CompactTextString(m) }")
-		g.P("func (*", ccTypeName, ") ProtoMessage() {}")
-	}
+	g.P("func (m *", ccTypeName, ") String() string { return ", g.Pkg["proto"], ".CompactTextString(m) }")
+	g.P("func (*", ccTypeName, ") ProtoMessage() {}")
 
 	// Extension support methods
 	var hasExtensions, isMessageSet bool

protoc-gen-go/testdata/my_test/test.pb.go

@@ -230,7 +230,9 @@ type Request_SomeGroup struct {
 	XXX_unrecognized []byte `json:"-"`
 }
 
-func (m *Request_SomeGroup) Reset() { *m = Request_SomeGroup{} }
+func (m *Request_SomeGroup) Reset()         { *m = Request_SomeGroup{} }
+func (m *Request_SomeGroup) String() string { return proto.CompactTextString(m) }
+func (*Request_SomeGroup) ProtoMessage()    {}
 
 func (m *Request_SomeGroup) GetGroupField() int32 {
 	if m != nil && m.GroupField != nil {

protoc-gen-go/testdata/my_test/test.pb.go.golden

@@ -230,7 +230,9 @@ type Request_SomeGroup struct {
 	XXX_unrecognized []byte `json:"-"`
 }
 
-func (m *Request_SomeGroup) Reset() { *m = Request_SomeGroup{} }
+func (m *Request_SomeGroup) Reset()         { *m = Request_SomeGroup{} }
+func (m *Request_SomeGroup) String() string { return proto.CompactTextString(m) }
+func (*Request_SomeGroup) ProtoMessage()    {}
 
 func (m *Request_SomeGroup) GetGroupField() int32 {
 	if m != nil && m.GroupField != nil {