Add file propery to edit internal state tags

gogoproto/gogo.proto

@@ -87,6 +87,8 @@ extend google.protobuf.FileOptions {
 
 	optional bool goproto_sizecache_all = 63034;
 	optional bool goproto_unkeyed_all = 63035;
+
+	optional string internal_struct_field_tags = 63036;
 }
 
 extend google.protobuf.MessageOptions {
@@ -124,6 +126,7 @@ extend google.protobuf.MessageOptions {
 
 	optional bool goproto_sizecache = 64034;
 	optional bool goproto_unkeyed = 64035;
+
 }
 
 extend google.protobuf.FieldOptions {

gogoproto/helper.go

@@ -287,6 +287,18 @@ func GetMoreTags(field *google_protobuf.FieldDescriptorProto) *string {
 	}
 	return nil
 }
+func GetInternalStructFieldTags(file *google_protobuf.FileDescriptorProto) *string {
+	if file == nil {
+		return nil
+	}
+	if file.Options != nil {
+		v, err := proto.GetExtension(file.Options, E_InternalStructFieldTags)
+		if err == nil && v.(*string) != nil {
+			return (v.(*string))
+		}
+	}
+	return nil
+}
 
 type EnableFunc func(file *google_protobuf.FileDescriptorProto, message *google_protobuf.DescriptorProto) bool
 

protoc-gen-gogo/generator/generator.go

@@ -2494,25 +2494,32 @@ func (g *Generator) generateGet(mc *msgCtx, protoField *descriptor.FieldDescript
 
 // generateInternalStructFields just adds the XXX_<something> fields to the message struct.
 func (g *Generator) generateInternalStructFields(mc *msgCtx, topLevelFields []topLevelField) {
+	internalStructFieldTags := gogoproto.GetInternalStructFieldTags(g.file.FileDescriptorProto)
+
+	resolvedInternaltags := ""
+	if internalStructFieldTags != nil {
+		resolvedInternaltags = ", " + *internalStructFieldTags
+	}
+
 	if gogoproto.HasUnkeyed(g.file.FileDescriptorProto, mc.message.DescriptorProto) {
-		g.P("XXX_NoUnkeyedLiteral\tstruct{} `json:\"-\"`") // prevent unkeyed struct literals
+		g.P("XXX_NoUnkeyedLiteral\tstruct{} `json:\"-\"`" + resolvedInternaltags) // prevent unkeyed struct literals
 	}
 	if len(mc.message.ExtensionRange) > 0 {
 		if gogoproto.HasExtensionsMap(g.file.FileDescriptorProto, mc.message.DescriptorProto) {
 			messageset := ""
 			if opts := mc.message.Options; opts != nil && opts.GetMessageSetWireFormat() {
 				messageset = "protobuf_messageset:\"1\" "
 			}
-			g.P(g.Pkg["proto"], ".XXX_InternalExtensions `", messageset, "json:\"-\"`")
+			g.P(g.Pkg["proto"], ".XXX_InternalExtensions `", messageset, "json:\"-\"`"+resolvedInternaltags)
 		} else {
-			g.P("XXX_extensions\t\t[]byte `protobuf:\"bytes,0,opt\" json:\"-\"`")
+			g.P("XXX_extensions\t\t[]byte `protobuf:\"bytes,0,opt\" json:\"-\"`" + resolvedInternaltags)
 		}
 	}
 	if gogoproto.HasUnrecognized(g.file.FileDescriptorProto, mc.message.DescriptorProto) {
-		g.P("XXX_unrecognized\t[]byte `json:\"-\"`")
+		g.P("XXX_unrecognized\t[]byte `json:\"-\"`" + resolvedInternaltags)
 	}
 	if gogoproto.HasSizecache(g.file.FileDescriptorProto, mc.message.DescriptorProto) {
-		g.P("XXX_sizecache\tint32 `json:\"-\"`")
+		g.P("XXX_sizecache\tint32 `json:\"-\"`" + resolvedInternaltags)
 	}
 }
 

test/tags/tags.proto

@@ -33,6 +33,7 @@ package tags;
 import "github.com/gogo/protobuf/gogoproto/gogo.proto";
 
 option (gogoproto.populate_all) = true;
+option (gogoproto.internal_struct_field_tags) = "xml:\"-\"";
 
 message Outside {
 	optional Inside Inside = 1 [(gogoproto.embed) = true, (gogoproto.jsontag) = ""];

test/tags/tags_test.go

@@ -72,3 +72,17 @@ func TestTags(t *testing.T) {
 		}
 	}
 }
+
+func TestHiddenTags(t *testing.T) {
+	var tests = []string{
+		"XXX_NoUnkeyedLiteral", "XXX_unrecognized", "XXX_sizecache",
+	}
+
+	for _, tt := range tests {
+		tv := reflect.ValueOf(Inside{}).Type()
+		f, _ := tv.FieldByName(tt)
+		if xmltag := f.Tag.Get("xml"); xmltag != "-" {
+			t.Fatalf("proto %q type: xml tag %s != %s", tv.Name(), xmltag, "-")
+		}
+	}
+}