cmd/protoc-gen-go: correlate v1 ExtensionDesc with v2 ExtensionType

Unfortunately a good amount of code uses pointer comparisons on the
v1 ExtensionDesc to determine exactly which extension field is set,
rather than checking whether the extension descriptor semantically
describes the field that they are interested in.

To preserve this behavior in v1, we need a 1:1 mapping between
a v2 ExtensionType and a specific v1 ExtensionDesc.

Change-Id: I852b3cefb4585bd656e48e5adad6cc28795d02df
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/167759
Reviewed-by: Damien Neil <dneil@google.com>

cmd/protoc-gen-go/internal_gengo/main.go

@@ -146,9 +146,7 @@ func GenerateFile(gen *protogen.Plugin, file *protogen.File) *protogen.Generated
 	for _, message := range f.allMessages {
 		genMessage(gen, g, f, message)
 	}
-	for _, extension := range f.allExtensions {
-		genExtension(gen, g, f, extension)
-	}
+	genExtensions(gen, g, f)
 
 	genInitFunction(gen, g, f)
 	genFileDescriptor(gen, g, f)
@@ -690,33 +688,58 @@ func fieldJSONTag(field *protogen.Field) string {
 	return string(field.Desc.Name()) + ",omitempty"
 }
 
-func genExtension(gen *protogen.Plugin, g *protogen.GeneratedFile, f *fileInfo, extension *protogen.Extension) {
-	// Special case for proto2 message sets: If this extension is extending
-	// proto2.bridge.MessageSet, and its final name component is "message_set_extension",
-	// then drop that last component.
-	//
-	// TODO: This should be implemented in the text formatter rather than the generator.
-	// In addition, the situation for when to apply this special case is implemented
-	// differently in other languages:
-	// https://github.com/google/protobuf/blob/aff10976/src/google/protobuf/text_format.cc#L1560
-	name := extension.Desc.FullName()
-	if n, ok := isExtensionMessageSetElement(extension); ok {
-		name = n
-	}
-
-	g.P("var ", extensionVar(f.File, extension), " = &", f.protoPackage().Ident("ExtensionDesc"), "{")
-	g.P("ExtendedType: (*", extension.ExtendedType.GoIdent, ")(nil),")
-	goType, pointer := fieldGoType(g, extension)
-	if pointer {
-		goType = "*" + goType
-	}
-	g.P("ExtensionType: (", goType, ")(nil),")
-	g.P("Field: ", extension.Desc.Number(), ",")
-	g.P("Name: ", strconv.Quote(string(name)), ",")
-	g.P("Tag: ", strconv.Quote(fieldProtobufTag(extension)), ",")
-	g.P("Filename: ", strconv.Quote(f.Desc.Path()), ",")
+func genExtensions(gen *protogen.Plugin, g *protogen.GeneratedFile, f *fileInfo) {
+	if len(f.allExtensions) == 0 {
+		return
+	}
+
+	g.P("var ", extDecsVarName(f), " = []", f.protoPackage().Ident("ExtensionDesc"), "{")
+	for _, extension := range f.allExtensions {
+		// Special case for proto2 message sets: If this extension is extending
+		// proto2.bridge.MessageSet, and its final name component is "message_set_extension",
+		// then drop that last component.
+		//
+		// TODO: This should be implemented in the text formatter rather than the generator.
+		// In addition, the situation for when to apply this special case is implemented
+		// differently in other languages:
+		// https://github.com/google/protobuf/blob/aff10976/src/google/protobuf/text_format.cc#L1560
+		name := extension.Desc.FullName()
+		if n, ok := isExtensionMessageSetElement(extension); ok {
+			name = n
+		}
+
+		g.P("{")
+		g.P("ExtendedType: (*", extension.ExtendedType.GoIdent, ")(nil),")
+		goType, pointer := fieldGoType(g, extension)
+		if pointer {
+			goType = "*" + goType
+		}
+		g.P("ExtensionType: (", goType, ")(nil),")
+		g.P("Field: ", extension.Desc.Number(), ",")
+		g.P("Name: ", strconv.Quote(string(name)), ",")
+		g.P("Tag: ", strconv.Quote(fieldProtobufTag(extension)), ",")
+		g.P("Filename: ", strconv.Quote(f.Desc.Path()), ",")
+		g.P("},")
+	}
 	g.P("}")
-	g.P()
+
+	g.P("var (")
+	for i, extension := range f.allExtensions {
+		ed := extension.Desc
+		targetName := string(ed.ExtendedType().FullName())
+		typeName := ed.Kind().String()
+		switch ed.Kind() {
+		case protoreflect.EnumKind:
+			typeName = string(ed.EnumType().FullName())
+		case protoreflect.MessageKind, protoreflect.GroupKind:
+			typeName = string(ed.MessageType().FullName())
+		}
+		fieldName := string(ed.Name())
+		g.P("// extend ", targetName, " { ", ed.Cardinality().String(), " ", typeName, " ", fieldName, " = ", ed.Number(), "; }")
+		g.P(extensionVar(f.File, extension), " = &", extDecsVarName(f), "[", i, "]")
+		g.P()
+	}
+	g.P(")")
 }
 
 // isExtensionMessageSetELement returns the adjusted name of an extension

cmd/protoc-gen-go/internal_gengo/reflect.go

@@ -167,6 +167,9 @@ func genReflectFileDescriptor(gen *protogen.Plugin, g *protogen.GeneratedFile, f
 	g.P("RawDescriptor: ", f.descriptorRawVar, ",")
 	g.P("GoTypes: ", goTypesVarName(f), ",")
 	g.P("DependencyIndexes: ", depIdxsVarName(f), ",")
+	if len(f.allExtensions) > 0 {
+		g.P("LegacyExtensions: ", extDecsVarName(f), ",")
+	}
 	if len(f.allEnums) > 0 {
 		g.P("EnumOutputTypes: ", enumTypesVarName(f), ",")
 	}
@@ -187,11 +190,6 @@ func genReflectFileDescriptor(gen *protogen.Plugin, g *protogen.GeneratedFile, f
 		g.P("}")
 	}
 
-	// Copy the local list of extension types into each global variable.
-	for i, extension := range f.allExtensions {
-		g.P(extensionVar(f.File, extension), ".Type = extensionTypes[", i, "]")
-	}
-
 	// TODO: Add v2 registration and stop v1 registration in genInitFunction.
 
 	// The descriptor proto needs to register the option types with the
@@ -241,6 +239,9 @@ func enumTypesVarName(f *fileInfo) string {
 func messageTypesVarName(f *fileInfo) string {
 	return "xxx_" + f.GoDescriptorIdent.GoName + "_messageTypes"
 }
+func extDecsVarName(f *fileInfo) string {
+	return "xxx_" + f.GoDescriptorIdent.GoName + "_extDescs"
+}
 func initFuncName(f *protogen.File) string {
 	return "xxx_" + f.GoDescriptorIdent.GoName + "_init"
 }

cmd/protoc-gen-go/testdata/extensions/ext/ext.pb.go

@@ -375,401 +375,493 @@ func (m *ExtendingMessage_ExtendingMessageSubmessage) XXX_DiscardUnknown() {
 
 var xxx_messageInfo_ExtendingMessage_ExtendingMessageSubmessage proto.InternalMessageInfo
 
-var E_ExtensionBool = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*bool)(nil),
-	Field:         101,
-	Name:          "goproto.protoc.extension.ext.extension_bool",
-	Tag:           "varint,101,opt,name=extension_bool",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionEnum = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*Enum)(nil),
-	Field:         102,
-	Name:          "goproto.protoc.extension.ext.extension_enum",
-	Tag:           "varint,102,opt,name=extension_enum,enum=goproto.protoc.extension.ext.Enum",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionInt32 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*int32)(nil),
-	Field:         103,
-	Name:          "goproto.protoc.extension.ext.extension_int32",
-	Tag:           "varint,103,opt,name=extension_int32",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionSint32 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*int32)(nil),
-	Field:         104,
-	Name:          "goproto.protoc.extension.ext.extension_sint32",
-	Tag:           "zigzag32,104,opt,name=extension_sint32",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionUint32 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*uint32)(nil),
-	Field:         105,
-	Name:          "goproto.protoc.extension.ext.extension_uint32",
-	Tag:           "varint,105,opt,name=extension_uint32",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionInt64 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*int64)(nil),
-	Field:         106,
-	Name:          "goproto.protoc.extension.ext.extension_int64",
-	Tag:           "varint,106,opt,name=extension_int64",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionSint64 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*int64)(nil),
-	Field:         107,
-	Name:          "goproto.protoc.extension.ext.extension_sint64",
-	Tag:           "zigzag64,107,opt,name=extension_sint64",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionUint64 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*uint64)(nil),
-	Field:         108,
-	Name:          "goproto.protoc.extension.ext.extension_uint64",
-	Tag:           "varint,108,opt,name=extension_uint64",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionSfixed32 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*int32)(nil),
-	Field:         109,
-	Name:          "goproto.protoc.extension.ext.extension_sfixed32",
-	Tag:           "fixed32,109,opt,name=extension_sfixed32",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionFixed32 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*uint32)(nil),
-	Field:         110,
-	Name:          "goproto.protoc.extension.ext.extension_fixed32",
-	Tag:           "fixed32,110,opt,name=extension_fixed32",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionFloat = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*float32)(nil),
-	Field:         111,
-	Name:          "goproto.protoc.extension.ext.extension_float",
-	Tag:           "fixed32,111,opt,name=extension_float",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionSfixed64 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*int64)(nil),
-	Field:         112,
-	Name:          "goproto.protoc.extension.ext.extension_sfixed64",
-	Tag:           "fixed64,112,opt,name=extension_sfixed64",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionFixed64 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*uint64)(nil),
-	Field:         113,
-	Name:          "goproto.protoc.extension.ext.extension_fixed64",
-	Tag:           "fixed64,113,opt,name=extension_fixed64",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionDouble = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*float64)(nil),
-	Field:         114,
-	Name:          "goproto.protoc.extension.ext.extension_double",
-	Tag:           "fixed64,114,opt,name=extension_double",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionString = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*string)(nil),
-	Field:         115,
-	Name:          "goproto.protoc.extension.ext.extension_string",
-	Tag:           "bytes,115,opt,name=extension_string",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtensionBytes = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]byte)(nil),
-	Field:         116,
-	Name:          "goproto.protoc.extension.ext.extension_bytes",
-	Tag:           "bytes,116,opt,name=extension_bytes",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_Extension_Message = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*Message)(nil),
-	Field:         117,
-	Name:          "goproto.protoc.extension.ext.extension_Message",
-	Tag:           "bytes,117,opt,name=extension_Message",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_Extension_MessageM = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*Message_M)(nil),
-	Field:         118,
-	Name:          "goproto.protoc.extension.ext.extension_MessageM",
-	Tag:           "bytes,118,opt,name=extension_MessageM",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_Extensiongroup = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*ExtensionGroup)(nil),
-	Field:         119,
-	Name:          "goproto.protoc.extension.ext.extensiongroup",
-	Tag:           "group,119,opt,name=ExtensionGroup",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtraMessage = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*extra.ExtraMessage)(nil),
-	Field:         9,
-	Name:          "goproto.protoc.extension.ext.extra_message",
-	Tag:           "bytes,9,opt,name=extra_message",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXBool = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]bool)(nil),
-	Field:         301,
-	Name:          "goproto.protoc.extension.ext.repeated_x_bool",
-	Tag:           "varint,301,rep,name=repeated_x_bool",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXEnum = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]Enum)(nil),
-	Field:         302,
-	Name:          "goproto.protoc.extension.ext.repeated_x_enum",
-	Tag:           "varint,302,rep,name=repeated_x_enum,enum=goproto.protoc.extension.ext.Enum",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXInt32 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]int32)(nil),
-	Field:         303,
-	Name:          "goproto.protoc.extension.ext.repeated_x_int32",
-	Tag:           "varint,303,rep,name=repeated_x_int32",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXSint32 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]int32)(nil),
-	Field:         304,
-	Name:          "goproto.protoc.extension.ext.repeated_x_sint32",
-	Tag:           "zigzag32,304,rep,name=repeated_x_sint32",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXUint32 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]uint32)(nil),
-	Field:         305,
-	Name:          "goproto.protoc.extension.ext.repeated_x_uint32",
-	Tag:           "varint,305,rep,name=repeated_x_uint32",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXInt64 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]int64)(nil),
-	Field:         306,
-	Name:          "goproto.protoc.extension.ext.repeated_x_int64",
-	Tag:           "varint,306,rep,name=repeated_x_int64",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXSint64 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]int64)(nil),
-	Field:         307,
-	Name:          "goproto.protoc.extension.ext.repeated_x_sint64",
-	Tag:           "zigzag64,307,rep,name=repeated_x_sint64",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXUint64 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]uint64)(nil),
-	Field:         308,
-	Name:          "goproto.protoc.extension.ext.repeated_x_uint64",
-	Tag:           "varint,308,rep,name=repeated_x_uint64",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXSfixed32 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]int32)(nil),
-	Field:         309,
-	Name:          "goproto.protoc.extension.ext.repeated_x_sfixed32",
-	Tag:           "fixed32,309,rep,name=repeated_x_sfixed32",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXFixed32 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]uint32)(nil),
-	Field:         310,
-	Name:          "goproto.protoc.extension.ext.repeated_x_fixed32",
-	Tag:           "fixed32,310,rep,name=repeated_x_fixed32",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXFloat = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]float32)(nil),
-	Field:         311,
-	Name:          "goproto.protoc.extension.ext.repeated_x_float",
-	Tag:           "fixed32,311,rep,name=repeated_x_float",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXSfixed64 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]int64)(nil),
-	Field:         312,
-	Name:          "goproto.protoc.extension.ext.repeated_x_sfixed64",
-	Tag:           "fixed64,312,rep,name=repeated_x_sfixed64",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXFixed64 = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]uint64)(nil),
-	Field:         313,
-	Name:          "goproto.protoc.extension.ext.repeated_x_fixed64",
-	Tag:           "fixed64,313,rep,name=repeated_x_fixed64",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXDouble = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]float64)(nil),
-	Field:         314,
-	Name:          "goproto.protoc.extension.ext.repeated_x_double",
-	Tag:           "fixed64,314,rep,name=repeated_x_double",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXString = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]string)(nil),
-	Field:         315,
-	Name:          "goproto.protoc.extension.ext.repeated_x_string",
-	Tag:           "bytes,315,rep,name=repeated_x_string",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedXBytes = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([][]byte)(nil),
-	Field:         316,
-	Name:          "goproto.protoc.extension.ext.repeated_x_bytes",
-	Tag:           "bytes,316,rep,name=repeated_x_bytes",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_RepeatedX_Message = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]*Message)(nil),
-	Field:         317,
-	Name:          "goproto.protoc.extension.ext.repeated_x_Message",
-	Tag:           "bytes,317,rep,name=repeated_x_Message",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_Repeatedgroup = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: ([]*RepeatedGroup)(nil),
-	Field:         318,
-	Name:          "goproto.protoc.extension.ext.repeatedgroup",
-	Tag:           "group,318,rep,name=RepeatedGroup",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtendableField = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*Extendable)(nil),
-	Field:         400,
-	Name:          "goproto.protoc.extension.ext.extendable_field",
-	Tag:           "bytes,400,opt,name=extendable_field",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtendableStringField = &proto.ExtensionDesc{
-	ExtendedType:  (*Extendable)(nil),
-	ExtensionType: (*string)(nil),
-	Field:         1,
-	Name:          "goproto.protoc.extension.ext.extendable_string_field",
-	Tag:           "bytes,1,opt,name=extendable_string_field",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_MessageSetExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*base.MessageSetWireFormatMessage)(nil),
-	ExtensionType: (*MessageSetWireFormatExtension)(nil),
-	Field:         101,
-	Name:          "goproto.protoc.extension.ext.",
-	Tag:           "bytes,101,opt,name=message_set_extension",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtendingMessage_ExtendingMessageString = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*string)(nil),
-	Field:         200,
-	Name:          "goproto.protoc.extension.ext.ExtendingMessage.extending_message_string",
-	Tag:           "bytes,200,opt,name=extending_message_string",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_ExtendingMessage_ExtendingMessageSubmessage = &proto.ExtensionDesc{
-	ExtendedType:  (*base.BaseMessage)(nil),
-	ExtensionType: (*ExtendingMessage_ExtendingMessageSubmessage)(nil),
-	Field:         201,
-	Name:          "goproto.protoc.extension.ext.ExtendingMessage.extending_message_submessage",
-	Tag:           "bytes,201,opt,name=extending_message_submessage",
-	Filename:      "extensions/ext/ext.proto",
-}
-
-var E_MessageSetWireFormatExtension_MessageSetExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*base.MessageSetWireFormatMessage)(nil),
-	ExtensionType: (*MessageSetWireFormatExtension)(nil),
-	Field:         100,
-	Name:          "goproto.protoc.extension.ext.MessageSetWireFormatExtension",
-	Tag:           "bytes,100,opt,name=message_set_extension",
-	Filename:      "extensions/ext/ext.proto",
-}
+var xxx_File_extensions_ext_ext_proto_extDescs = []proto.ExtensionDesc{
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*bool)(nil),
+		Field:         101,
+		Name:          "goproto.protoc.extension.ext.extension_bool",
+		Tag:           "varint,101,opt,name=extension_bool",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*Enum)(nil),
+		Field:         102,
+		Name:          "goproto.protoc.extension.ext.extension_enum",
+		Tag:           "varint,102,opt,name=extension_enum,enum=goproto.protoc.extension.ext.Enum",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*int32)(nil),
+		Field:         103,
+		Name:          "goproto.protoc.extension.ext.extension_int32",
+		Tag:           "varint,103,opt,name=extension_int32",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*int32)(nil),
+		Field:         104,
+		Name:          "goproto.protoc.extension.ext.extension_sint32",
+		Tag:           "zigzag32,104,opt,name=extension_sint32",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*uint32)(nil),
+		Field:         105,
+		Name:          "goproto.protoc.extension.ext.extension_uint32",
+		Tag:           "varint,105,opt,name=extension_uint32",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*int64)(nil),
+		Field:         106,
+		Name:          "goproto.protoc.extension.ext.extension_int64",
+		Tag:           "varint,106,opt,name=extension_int64",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*int64)(nil),
+		Field:         107,
+		Name:          "goproto.protoc.extension.ext.extension_sint64",
+		Tag:           "zigzag64,107,opt,name=extension_sint64",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*uint64)(nil),
+		Field:         108,
+		Name:          "goproto.protoc.extension.ext.extension_uint64",
+		Tag:           "varint,108,opt,name=extension_uint64",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*int32)(nil),
+		Field:         109,
+		Name:          "goproto.protoc.extension.ext.extension_sfixed32",
+		Tag:           "fixed32,109,opt,name=extension_sfixed32",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*uint32)(nil),
+		Field:         110,
+		Name:          "goproto.protoc.extension.ext.extension_fixed32",
+		Tag:           "fixed32,110,opt,name=extension_fixed32",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*float32)(nil),
+		Field:         111,
+		Name:          "goproto.protoc.extension.ext.extension_float",
+		Tag:           "fixed32,111,opt,name=extension_float",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*int64)(nil),
+		Field:         112,
+		Name:          "goproto.protoc.extension.ext.extension_sfixed64",
+		Tag:           "fixed64,112,opt,name=extension_sfixed64",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*uint64)(nil),
+		Field:         113,
+		Name:          "goproto.protoc.extension.ext.extension_fixed64",
+		Tag:           "fixed64,113,opt,name=extension_fixed64",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*float64)(nil),
+		Field:         114,
+		Name:          "goproto.protoc.extension.ext.extension_double",
+		Tag:           "fixed64,114,opt,name=extension_double",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*string)(nil),
+		Field:         115,
+		Name:          "goproto.protoc.extension.ext.extension_string",
+		Tag:           "bytes,115,opt,name=extension_string",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]byte)(nil),
+		Field:         116,
+		Name:          "goproto.protoc.extension.ext.extension_bytes",
+		Tag:           "bytes,116,opt,name=extension_bytes",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*Message)(nil),
+		Field:         117,
+		Name:          "goproto.protoc.extension.ext.extension_Message",
+		Tag:           "bytes,117,opt,name=extension_Message",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*Message_M)(nil),
+		Field:         118,
+		Name:          "goproto.protoc.extension.ext.extension_MessageM",
+		Tag:           "bytes,118,opt,name=extension_MessageM",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*ExtensionGroup)(nil),
+		Field:         119,
+		Name:          "goproto.protoc.extension.ext.extensiongroup",
+		Tag:           "group,119,opt,name=ExtensionGroup",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*extra.ExtraMessage)(nil),
+		Field:         9,
+		Name:          "goproto.protoc.extension.ext.extra_message",
+		Tag:           "bytes,9,opt,name=extra_message",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]bool)(nil),
+		Field:         301,
+		Name:          "goproto.protoc.extension.ext.repeated_x_bool",
+		Tag:           "varint,301,rep,name=repeated_x_bool",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]Enum)(nil),
+		Field:         302,
+		Name:          "goproto.protoc.extension.ext.repeated_x_enum",
+		Tag:           "varint,302,rep,name=repeated_x_enum,enum=goproto.protoc.extension.ext.Enum",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]int32)(nil),
+		Field:         303,
+		Name:          "goproto.protoc.extension.ext.repeated_x_int32",
+		Tag:           "varint,303,rep,name=repeated_x_int32",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]int32)(nil),
+		Field:         304,
+		Name:          "goproto.protoc.extension.ext.repeated_x_sint32",
+		Tag:           "zigzag32,304,rep,name=repeated_x_sint32",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]uint32)(nil),
+		Field:         305,
+		Name:          "goproto.protoc.extension.ext.repeated_x_uint32",
+		Tag:           "varint,305,rep,name=repeated_x_uint32",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]int64)(nil),
+		Field:         306,
+		Name:          "goproto.protoc.extension.ext.repeated_x_int64",
+		Tag:           "varint,306,rep,name=repeated_x_int64",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]int64)(nil),
+		Field:         307,
+		Name:          "goproto.protoc.extension.ext.repeated_x_sint64",
+		Tag:           "zigzag64,307,rep,name=repeated_x_sint64",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]uint64)(nil),
+		Field:         308,
+		Name:          "goproto.protoc.extension.ext.repeated_x_uint64",
+		Tag:           "varint,308,rep,name=repeated_x_uint64",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]int32)(nil),
+		Field:         309,
+		Name:          "goproto.protoc.extension.ext.repeated_x_sfixed32",
+		Tag:           "fixed32,309,rep,name=repeated_x_sfixed32",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]uint32)(nil),
+		Field:         310,
+		Name:          "goproto.protoc.extension.ext.repeated_x_fixed32",
+		Tag:           "fixed32,310,rep,name=repeated_x_fixed32",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]float32)(nil),
+		Field:         311,
+		Name:          "goproto.protoc.extension.ext.repeated_x_float",
+		Tag:           "fixed32,311,rep,name=repeated_x_float",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]int64)(nil),
+		Field:         312,
+		Name:          "goproto.protoc.extension.ext.repeated_x_sfixed64",
+		Tag:           "fixed64,312,rep,name=repeated_x_sfixed64",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]uint64)(nil),
+		Field:         313,
+		Name:          "goproto.protoc.extension.ext.repeated_x_fixed64",
+		Tag:           "fixed64,313,rep,name=repeated_x_fixed64",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]float64)(nil),
+		Field:         314,
+		Name:          "goproto.protoc.extension.ext.repeated_x_double",
+		Tag:           "fixed64,314,rep,name=repeated_x_double",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]string)(nil),
+		Field:         315,
+		Name:          "goproto.protoc.extension.ext.repeated_x_string",
+		Tag:           "bytes,315,rep,name=repeated_x_string",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([][]byte)(nil),
+		Field:         316,
+		Name:          "goproto.protoc.extension.ext.repeated_x_bytes",
+		Tag:           "bytes,316,rep,name=repeated_x_bytes",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]*Message)(nil),
+		Field:         317,
+		Name:          "goproto.protoc.extension.ext.repeated_x_Message",
+		Tag:           "bytes,317,rep,name=repeated_x_Message",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: ([]*RepeatedGroup)(nil),
+		Field:         318,
+		Name:          "goproto.protoc.extension.ext.repeatedgroup",
+		Tag:           "group,318,rep,name=RepeatedGroup",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*Extendable)(nil),
+		Field:         400,
+		Name:          "goproto.protoc.extension.ext.extendable_field",
+		Tag:           "bytes,400,opt,name=extendable_field",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*Extendable)(nil),
+		ExtensionType: (*string)(nil),
+		Field:         1,
+		Name:          "goproto.protoc.extension.ext.extendable_string_field",
+		Tag:           "bytes,1,opt,name=extendable_string_field",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.MessageSetWireFormatMessage)(nil),
+		ExtensionType: (*MessageSetWireFormatExtension)(nil),
+		Field:         101,
+		Name:          "goproto.protoc.extension.ext.",
+		Tag:           "bytes,101,opt,name=message_set_extension",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*string)(nil),
+		Field:         200,
+		Name:          "goproto.protoc.extension.ext.ExtendingMessage.extending_message_string",
+		Tag:           "bytes,200,opt,name=extending_message_string",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.BaseMessage)(nil),
+		ExtensionType: (*ExtendingMessage_ExtendingMessageSubmessage)(nil),
+		Field:         201,
+		Name:          "goproto.protoc.extension.ext.ExtendingMessage.extending_message_submessage",
+		Tag:           "bytes,201,opt,name=extending_message_submessage",
+		Filename:      "extensions/ext/ext.proto",
+	},
+	{
+		ExtendedType:  (*base.MessageSetWireFormatMessage)(nil),
+		ExtensionType: (*MessageSetWireFormatExtension)(nil),
+		Field:         100,
+		Name:          "goproto.protoc.extension.ext.MessageSetWireFormatExtension",
+		Tag:           "bytes,100,opt,name=message_set_extension",
+		Filename:      "extensions/ext/ext.proto",
+	},
+}
+var (
+	// extend goproto.protoc.extension.base.BaseMessage { optional bool extension_bool = 101; }
+	E_ExtensionBool = &xxx_File_extensions_ext_ext_proto_extDescs[0]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional goproto.protoc.extension.ext.Enum extension_enum = 102; }
+	E_ExtensionEnum = &xxx_File_extensions_ext_ext_proto_extDescs[1]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional int32 extension_int32 = 103; }
+	E_ExtensionInt32 = &xxx_File_extensions_ext_ext_proto_extDescs[2]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional sint32 extension_sint32 = 104; }
+	E_ExtensionSint32 = &xxx_File_extensions_ext_ext_proto_extDescs[3]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional uint32 extension_uint32 = 105; }
+	E_ExtensionUint32 = &xxx_File_extensions_ext_ext_proto_extDescs[4]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional int64 extension_int64 = 106; }
+	E_ExtensionInt64 = &xxx_File_extensions_ext_ext_proto_extDescs[5]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional sint64 extension_sint64 = 107; }
+	E_ExtensionSint64 = &xxx_File_extensions_ext_ext_proto_extDescs[6]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional uint64 extension_uint64 = 108; }
+	E_ExtensionUint64 = &xxx_File_extensions_ext_ext_proto_extDescs[7]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional sfixed32 extension_sfixed32 = 109; }
+	E_ExtensionSfixed32 = &xxx_File_extensions_ext_ext_proto_extDescs[8]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional fixed32 extension_fixed32 = 110; }
+	E_ExtensionFixed32 = &xxx_File_extensions_ext_ext_proto_extDescs[9]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional float extension_float = 111; }
+	E_ExtensionFloat = &xxx_File_extensions_ext_ext_proto_extDescs[10]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional sfixed64 extension_sfixed64 = 112; }
+	E_ExtensionSfixed64 = &xxx_File_extensions_ext_ext_proto_extDescs[11]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional fixed64 extension_fixed64 = 113; }
+	E_ExtensionFixed64 = &xxx_File_extensions_ext_ext_proto_extDescs[12]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional double extension_double = 114; }
+	E_ExtensionDouble = &xxx_File_extensions_ext_ext_proto_extDescs[13]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional string extension_string = 115; }
+	E_ExtensionString = &xxx_File_extensions_ext_ext_proto_extDescs[14]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional bytes extension_bytes = 116; }
+	E_ExtensionBytes = &xxx_File_extensions_ext_ext_proto_extDescs[15]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional goproto.protoc.extension.ext.Message extension_Message = 117; }
+	E_Extension_Message = &xxx_File_extensions_ext_ext_proto_extDescs[16]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional goproto.protoc.extension.ext.Message.M extension_MessageM = 118; }
+	E_Extension_MessageM = &xxx_File_extensions_ext_ext_proto_extDescs[17]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional goproto.protoc.extension.ext.ExtensionGroup extensiongroup = 119; }
+	E_Extensiongroup = &xxx_File_extensions_ext_ext_proto_extDescs[18]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional goproto.protoc.extension.extra.ExtraMessage extra_message = 9; }
+	E_ExtraMessage = &xxx_File_extensions_ext_ext_proto_extDescs[19]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated bool repeated_x_bool = 301; }
+	E_RepeatedXBool = &xxx_File_extensions_ext_ext_proto_extDescs[20]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated goproto.protoc.extension.ext.Enum repeated_x_enum = 302; }
+	E_RepeatedXEnum = &xxx_File_extensions_ext_ext_proto_extDescs[21]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated int32 repeated_x_int32 = 303; }
+	E_RepeatedXInt32 = &xxx_File_extensions_ext_ext_proto_extDescs[22]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated sint32 repeated_x_sint32 = 304; }
+	E_RepeatedXSint32 = &xxx_File_extensions_ext_ext_proto_extDescs[23]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated uint32 repeated_x_uint32 = 305; }
+	E_RepeatedXUint32 = &xxx_File_extensions_ext_ext_proto_extDescs[24]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated int64 repeated_x_int64 = 306; }
+	E_RepeatedXInt64 = &xxx_File_extensions_ext_ext_proto_extDescs[25]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated sint64 repeated_x_sint64 = 307; }
+	E_RepeatedXSint64 = &xxx_File_extensions_ext_ext_proto_extDescs[26]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated uint64 repeated_x_uint64 = 308; }
+	E_RepeatedXUint64 = &xxx_File_extensions_ext_ext_proto_extDescs[27]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated sfixed32 repeated_x_sfixed32 = 309; }
+	E_RepeatedXSfixed32 = &xxx_File_extensions_ext_ext_proto_extDescs[28]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated fixed32 repeated_x_fixed32 = 310; }
+	E_RepeatedXFixed32 = &xxx_File_extensions_ext_ext_proto_extDescs[29]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated float repeated_x_float = 311; }
+	E_RepeatedXFloat = &xxx_File_extensions_ext_ext_proto_extDescs[30]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated sfixed64 repeated_x_sfixed64 = 312; }
+	E_RepeatedXSfixed64 = &xxx_File_extensions_ext_ext_proto_extDescs[31]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated fixed64 repeated_x_fixed64 = 313; }
+	E_RepeatedXFixed64 = &xxx_File_extensions_ext_ext_proto_extDescs[32]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated double repeated_x_double = 314; }
+	E_RepeatedXDouble = &xxx_File_extensions_ext_ext_proto_extDescs[33]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated string repeated_x_string = 315; }
+	E_RepeatedXString = &xxx_File_extensions_ext_ext_proto_extDescs[34]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated bytes repeated_x_bytes = 316; }
+	E_RepeatedXBytes = &xxx_File_extensions_ext_ext_proto_extDescs[35]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated goproto.protoc.extension.ext.Message repeated_x_Message = 317; }
+	E_RepeatedX_Message = &xxx_File_extensions_ext_ext_proto_extDescs[36]
+
+	// extend goproto.protoc.extension.base.BaseMessage { repeated goproto.protoc.extension.ext.RepeatedGroup repeatedgroup = 318; }
+	E_Repeatedgroup = &xxx_File_extensions_ext_ext_proto_extDescs[37]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional goproto.protoc.extension.ext.Extendable extendable_field = 400; }
+	E_ExtendableField = &xxx_File_extensions_ext_ext_proto_extDescs[38]
+
+	// extend goproto.protoc.extension.ext.Extendable { optional string extendable_string_field = 1; }
+	E_ExtendableStringField = &xxx_File_extensions_ext_ext_proto_extDescs[39]
+
+	// extend goproto.protoc.extension.base.MessageSetWireFormatMessage { optional goproto.protoc.extension.ext.MessageSetWireFormatExtension message_set_extension = 101; }
+	E_MessageSetExtension = &xxx_File_extensions_ext_ext_proto_extDescs[40]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional string extending_message_string = 200; }
+	E_ExtendingMessage_ExtendingMessageString = &xxx_File_extensions_ext_ext_proto_extDescs[41]
+
+	// extend goproto.protoc.extension.base.BaseMessage { optional goproto.protoc.extension.ext.ExtendingMessage.ExtendingMessageSubmessage extending_message_submessage = 201; }
+	E_ExtendingMessage_ExtendingMessageSubmessage = &xxx_File_extensions_ext_ext_proto_extDescs[42]
+
+	// extend goproto.protoc.extension.base.MessageSetWireFormatMessage { optional goproto.protoc.extension.ext.MessageSetWireFormatExtension message_set_extension = 100; }
+	E_MessageSetWireFormatExtension_MessageSetExtension = &xxx_File_extensions_ext_ext_proto_extDescs[43]
+)
 
 func init() {
 	proto.RegisterFile("extensions/ext/ext.proto", xxx_File_extensions_ext_ext_proto_rawdesc_gzipped)
@@ -1237,6 +1329,7 @@ func xxx_File_extensions_ext_ext_proto_init() {
 		RawDescriptor:        xxx_File_extensions_ext_ext_proto_rawdesc,
 		GoTypes:              xxx_File_extensions_ext_ext_proto_goTypes,
 		DependencyIndexes:    xxx_File_extensions_ext_ext_proto_depIdxs,
+		LegacyExtensions:     xxx_File_extensions_ext_ext_proto_extDescs,
 		EnumOutputTypes:      xxx_File_extensions_ext_ext_proto_enumTypes,
 		MessageOutputTypes:   messageTypes,
 		ExtensionOutputTypes: extensionTypes,
@@ -1246,50 +1339,6 @@ func xxx_File_extensions_ext_ext_proto_init() {
 		xxx_File_extensions_ext_ext_proto_messageTypes[i].GoType = reflect.TypeOf(messageGoTypes[i])
 		xxx_File_extensions_ext_ext_proto_messageTypes[i].PBType = mt
 	}
-	E_ExtensionBool.Type = extensionTypes[0]
-	E_ExtensionEnum.Type = extensionTypes[1]
-	E_ExtensionInt32.Type = extensionTypes[2]
-	E_ExtensionSint32.Type = extensionTypes[3]
-	E_ExtensionUint32.Type = extensionTypes[4]
-	E_ExtensionInt64.Type = extensionTypes[5]
-	E_ExtensionSint64.Type = extensionTypes[6]
-	E_ExtensionUint64.Type = extensionTypes[7]
-	E_ExtensionSfixed32.Type = extensionTypes[8]
-	E_ExtensionFixed32.Type = extensionTypes[9]
-	E_ExtensionFloat.Type = extensionTypes[10]
-	E_ExtensionSfixed64.Type = extensionTypes[11]
-	E_ExtensionFixed64.Type = extensionTypes[12]
-	E_ExtensionDouble.Type = extensionTypes[13]
-	E_ExtensionString.Type = extensionTypes[14]
-	E_ExtensionBytes.Type = extensionTypes[15]
-	E_Extension_Message.Type = extensionTypes[16]
-	E_Extension_MessageM.Type = extensionTypes[17]
-	E_Extensiongroup.Type = extensionTypes[18]
-	E_ExtraMessage.Type = extensionTypes[19]
-	E_RepeatedXBool.Type = extensionTypes[20]
-	E_RepeatedXEnum.Type = extensionTypes[21]
-	E_RepeatedXInt32.Type = extensionTypes[22]
-	E_RepeatedXSint32.Type = extensionTypes[23]
-	E_RepeatedXUint32.Type = extensionTypes[24]
-	E_RepeatedXInt64.Type = extensionTypes[25]
-	E_RepeatedXSint64.Type = extensionTypes[26]
-	E_RepeatedXUint64.Type = extensionTypes[27]
-	E_RepeatedXSfixed32.Type = extensionTypes[28]
-	E_RepeatedXFixed32.Type = extensionTypes[29]
-	E_RepeatedXFloat.Type = extensionTypes[30]
-	E_RepeatedXSfixed64.Type = extensionTypes[31]
-	E_RepeatedXFixed64.Type = extensionTypes[32]
-	E_RepeatedXDouble.Type = extensionTypes[33]
-	E_RepeatedXString.Type = extensionTypes[34]
-	E_RepeatedXBytes.Type = extensionTypes[35]
-	E_RepeatedX_Message.Type = extensionTypes[36]
-	E_Repeatedgroup.Type = extensionTypes[37]
-	E_ExtendableField.Type = extensionTypes[38]
-	E_ExtendableStringField.Type = extensionTypes[39]
-	E_MessageSetExtension.Type = extensionTypes[40]
-	E_ExtendingMessage_ExtendingMessageString.Type = extensionTypes[41]
-	E_ExtendingMessage_ExtendingMessageSubmessage.Type = extensionTypes[42]
-	E_MessageSetWireFormatExtension_MessageSetExtension.Type = extensionTypes[43]
 	xxx_File_extensions_ext_ext_proto_goTypes = nil
 	xxx_File_extensions_ext_ext_proto_depIdxs = nil
 }

cmd/protoc-gen-go/testdata/extensions/proto3/ext3.pb.go

@@ -81,311 +81,383 @@ func (m *Message) XXX_DiscardUnknown() {
 
 var xxx_messageInfo_Message proto.InternalMessageInfo
 
-var E_ExtensionBool = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*bool)(nil),
-	Field:         1001,
-	Name:          "goproto.protoc.extension.proto3.extension_bool",
-	Tag:           "varint,1001,opt,name=extension_bool",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_ExtensionEnum = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*Enum)(nil),
-	Field:         1002,
-	Name:          "goproto.protoc.extension.proto3.extension_enum",
-	Tag:           "varint,1002,opt,name=extension_enum,enum=goproto.protoc.extension.proto3.Enum",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_ExtensionInt32 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*int32)(nil),
-	Field:         1003,
-	Name:          "goproto.protoc.extension.proto3.extension_int32",
-	Tag:           "varint,1003,opt,name=extension_int32",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_ExtensionSint32 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*int32)(nil),
-	Field:         1004,
-	Name:          "goproto.protoc.extension.proto3.extension_sint32",
-	Tag:           "zigzag32,1004,opt,name=extension_sint32",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_ExtensionUint32 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*uint32)(nil),
-	Field:         1005,
-	Name:          "goproto.protoc.extension.proto3.extension_uint32",
-	Tag:           "varint,1005,opt,name=extension_uint32",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_ExtensionInt64 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*int64)(nil),
-	Field:         1006,
-	Name:          "goproto.protoc.extension.proto3.extension_int64",
-	Tag:           "varint,1006,opt,name=extension_int64",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_ExtensionSint64 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*int64)(nil),
-	Field:         1007,
-	Name:          "goproto.protoc.extension.proto3.extension_sint64",
-	Tag:           "zigzag64,1007,opt,name=extension_sint64",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_ExtensionUint64 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*uint64)(nil),
-	Field:         1008,
-	Name:          "goproto.protoc.extension.proto3.extension_uint64",
-	Tag:           "varint,1008,opt,name=extension_uint64",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+var xxx_File_extensions_proto3_ext3_proto_extDescs = []proto.ExtensionDesc{
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*bool)(nil),
+		Field:         1001,
+		Name:          "goproto.protoc.extension.proto3.extension_bool",
+		Tag:           "varint,1001,opt,name=extension_bool",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*Enum)(nil),
+		Field:         1002,
+		Name:          "goproto.protoc.extension.proto3.extension_enum",
+		Tag:           "varint,1002,opt,name=extension_enum,enum=goproto.protoc.extension.proto3.Enum",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*int32)(nil),
+		Field:         1003,
+		Name:          "goproto.protoc.extension.proto3.extension_int32",
+		Tag:           "varint,1003,opt,name=extension_int32",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*int32)(nil),
+		Field:         1004,
+		Name:          "goproto.protoc.extension.proto3.extension_sint32",
+		Tag:           "zigzag32,1004,opt,name=extension_sint32",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*uint32)(nil),
+		Field:         1005,
+		Name:          "goproto.protoc.extension.proto3.extension_uint32",
+		Tag:           "varint,1005,opt,name=extension_uint32",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*int64)(nil),
+		Field:         1006,
+		Name:          "goproto.protoc.extension.proto3.extension_int64",
+		Tag:           "varint,1006,opt,name=extension_int64",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*int64)(nil),
+		Field:         1007,
+		Name:          "goproto.protoc.extension.proto3.extension_sint64",
+		Tag:           "zigzag64,1007,opt,name=extension_sint64",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*uint64)(nil),
+		Field:         1008,
+		Name:          "goproto.protoc.extension.proto3.extension_uint64",
+		Tag:           "varint,1008,opt,name=extension_uint64",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*int32)(nil),
+		Field:         1009,
+		Name:          "goproto.protoc.extension.proto3.extension_sfixed32",
+		Tag:           "fixed32,1009,opt,name=extension_sfixed32",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*uint32)(nil),
+		Field:         1010,
+		Name:          "goproto.protoc.extension.proto3.extension_fixed32",
+		Tag:           "fixed32,1010,opt,name=extension_fixed32",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*float32)(nil),
+		Field:         1011,
+		Name:          "goproto.protoc.extension.proto3.extension_float",
+		Tag:           "fixed32,1011,opt,name=extension_float",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*int64)(nil),
+		Field:         1012,
+		Name:          "goproto.protoc.extension.proto3.extension_sfixed64",
+		Tag:           "fixed64,1012,opt,name=extension_sfixed64",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*uint64)(nil),
+		Field:         1013,
+		Name:          "goproto.protoc.extension.proto3.extension_fixed64",
+		Tag:           "fixed64,1013,opt,name=extension_fixed64",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*float64)(nil),
+		Field:         1014,
+		Name:          "goproto.protoc.extension.proto3.extension_double",
+		Tag:           "fixed64,1014,opt,name=extension_double",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*string)(nil),
+		Field:         1015,
+		Name:          "goproto.protoc.extension.proto3.extension_string",
+		Tag:           "bytes,1015,opt,name=extension_string",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]byte)(nil),
+		Field:         1016,
+		Name:          "goproto.protoc.extension.proto3.extension_bytes",
+		Tag:           "bytes,1016,opt,name=extension_bytes",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: (*Message)(nil),
+		Field:         1017,
+		Name:          "goproto.protoc.extension.proto3.extension_Message",
+		Tag:           "bytes,1017,opt,name=extension_Message",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]bool)(nil),
+		Field:         2001,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_bool",
+		Tag:           "varint,2001,rep,name=repeated_extension_bool",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]Enum)(nil),
+		Field:         2002,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_enum",
+		Tag:           "varint,2002,rep,name=repeated_extension_enum,enum=goproto.protoc.extension.proto3.Enum",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]int32)(nil),
+		Field:         2003,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_int32",
+		Tag:           "varint,2003,rep,name=repeated_extension_int32",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]int32)(nil),
+		Field:         2004,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_sint32",
+		Tag:           "zigzag32,2004,rep,name=repeated_extension_sint32",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]uint32)(nil),
+		Field:         2005,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_uint32",
+		Tag:           "varint,2005,rep,name=repeated_extension_uint32",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]int64)(nil),
+		Field:         2006,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_int64",
+		Tag:           "varint,2006,rep,name=repeated_extension_int64",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]int64)(nil),
+		Field:         2007,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_sint64",
+		Tag:           "zigzag64,2007,rep,name=repeated_extension_sint64",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]uint64)(nil),
+		Field:         2008,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_uint64",
+		Tag:           "varint,2008,rep,name=repeated_extension_uint64",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]int32)(nil),
+		Field:         2009,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_sfixed32",
+		Tag:           "fixed32,2009,rep,name=repeated_extension_sfixed32",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]uint32)(nil),
+		Field:         2010,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_fixed32",
+		Tag:           "fixed32,2010,rep,name=repeated_extension_fixed32",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]float32)(nil),
+		Field:         2011,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_float",
+		Tag:           "fixed32,2011,rep,name=repeated_extension_float",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]int64)(nil),
+		Field:         2012,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_sfixed64",
+		Tag:           "fixed64,2012,rep,name=repeated_extension_sfixed64",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]uint64)(nil),
+		Field:         2013,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_fixed64",
+		Tag:           "fixed64,2013,rep,name=repeated_extension_fixed64",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]float64)(nil),
+		Field:         2014,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_double",
+		Tag:           "fixed64,2014,rep,name=repeated_extension_double",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]string)(nil),
+		Field:         2015,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_string",
+		Tag:           "bytes,2015,rep,name=repeated_extension_string",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([][]byte)(nil),
+		Field:         2016,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_bytes",
+		Tag:           "bytes,2016,rep,name=repeated_extension_bytes",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+	{
+		ExtendedType:  (*descriptor.MessageOptions)(nil),
+		ExtensionType: ([]*Message)(nil),
+		Field:         2017,
+		Name:          "goproto.protoc.extension.proto3.repeated_extension_Message",
+		Tag:           "bytes,2017,rep,name=repeated_extension_Message",
+		Filename:      "extensions/proto3/ext3.proto",
+	},
+}
+var (
+	// extend google.protobuf.MessageOptions { optional bool extension_bool = 1001; }
+	E_ExtensionBool = &xxx_File_extensions_proto3_ext3_proto_extDescs[0]
+
+	// extend google.protobuf.MessageOptions { optional goproto.protoc.extension.proto3.Enum extension_enum = 1002; }
+	E_ExtensionEnum = &xxx_File_extensions_proto3_ext3_proto_extDescs[1]
+
+	// extend google.protobuf.MessageOptions { optional int32 extension_int32 = 1003; }
+	E_ExtensionInt32 = &xxx_File_extensions_proto3_ext3_proto_extDescs[2]
+
+	// extend google.protobuf.MessageOptions { optional sint32 extension_sint32 = 1004; }
+	E_ExtensionSint32 = &xxx_File_extensions_proto3_ext3_proto_extDescs[3]
+
+	// extend google.protobuf.MessageOptions { optional uint32 extension_uint32 = 1005; }
+	E_ExtensionUint32 = &xxx_File_extensions_proto3_ext3_proto_extDescs[4]
+
+	// extend google.protobuf.MessageOptions { optional int64 extension_int64 = 1006; }
+	E_ExtensionInt64 = &xxx_File_extensions_proto3_ext3_proto_extDescs[5]
+
+	// extend google.protobuf.MessageOptions { optional sint64 extension_sint64 = 1007; }
+	E_ExtensionSint64 = &xxx_File_extensions_proto3_ext3_proto_extDescs[6]
+
+	// extend google.protobuf.MessageOptions { optional uint64 extension_uint64 = 1008; }
+	E_ExtensionUint64 = &xxx_File_extensions_proto3_ext3_proto_extDescs[7]
+
+	// extend google.protobuf.MessageOptions { optional sfixed32 extension_sfixed32 = 1009; }
+	E_ExtensionSfixed32 = &xxx_File_extensions_proto3_ext3_proto_extDescs[8]
+
+	// extend google.protobuf.MessageOptions { optional fixed32 extension_fixed32 = 1010; }
+	E_ExtensionFixed32 = &xxx_File_extensions_proto3_ext3_proto_extDescs[9]
+
+	// extend google.protobuf.MessageOptions { optional float extension_float = 1011; }
+	E_ExtensionFloat = &xxx_File_extensions_proto3_ext3_proto_extDescs[10]
+
+	// extend google.protobuf.MessageOptions { optional sfixed64 extension_sfixed64 = 1012; }
+	E_ExtensionSfixed64 = &xxx_File_extensions_proto3_ext3_proto_extDescs[11]
+
+	// extend google.protobuf.MessageOptions { optional fixed64 extension_fixed64 = 1013; }
+	E_ExtensionFixed64 = &xxx_File_extensions_proto3_ext3_proto_extDescs[12]
+
+	// extend google.protobuf.MessageOptions { optional double extension_double = 1014; }
+	E_ExtensionDouble = &xxx_File_extensions_proto3_ext3_proto_extDescs[13]
+
+	// extend google.protobuf.MessageOptions { optional string extension_string = 1015; }
+	E_ExtensionString = &xxx_File_extensions_proto3_ext3_proto_extDescs[14]
+
+	// extend google.protobuf.MessageOptions { optional bytes extension_bytes = 1016; }
+	E_ExtensionBytes = &xxx_File_extensions_proto3_ext3_proto_extDescs[15]
+
+	// extend google.protobuf.MessageOptions { optional goproto.protoc.extension.proto3.Message extension_Message = 1017; }
+	E_Extension_Message = &xxx_File_extensions_proto3_ext3_proto_extDescs[16]
+
+	// extend google.protobuf.MessageOptions { repeated bool repeated_extension_bool = 2001; }
+	E_RepeatedExtensionBool = &xxx_File_extensions_proto3_ext3_proto_extDescs[17]
+
+	// extend google.protobuf.MessageOptions { repeated goproto.protoc.extension.proto3.Enum repeated_extension_enum = 2002; }
+	E_RepeatedExtensionEnum = &xxx_File_extensions_proto3_ext3_proto_extDescs[18]
+
+	// extend google.protobuf.MessageOptions { repeated int32 repeated_extension_int32 = 2003; }
+	E_RepeatedExtensionInt32 = &xxx_File_extensions_proto3_ext3_proto_extDescs[19]
+
+	// extend google.protobuf.MessageOptions { repeated sint32 repeated_extension_sint32 = 2004; }
+	E_RepeatedExtensionSint32 = &xxx_File_extensions_proto3_ext3_proto_extDescs[20]
 
-var E_ExtensionSfixed32 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*int32)(nil),
-	Field:         1009,
-	Name:          "goproto.protoc.extension.proto3.extension_sfixed32",
-	Tag:           "fixed32,1009,opt,name=extension_sfixed32",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+	// extend google.protobuf.MessageOptions { repeated uint32 repeated_extension_uint32 = 2005; }
+	E_RepeatedExtensionUint32 = &xxx_File_extensions_proto3_ext3_proto_extDescs[21]
 
-var E_ExtensionFixed32 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*uint32)(nil),
-	Field:         1010,
-	Name:          "goproto.protoc.extension.proto3.extension_fixed32",
-	Tag:           "fixed32,1010,opt,name=extension_fixed32",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+	// extend google.protobuf.MessageOptions { repeated int64 repeated_extension_int64 = 2006; }
+	E_RepeatedExtensionInt64 = &xxx_File_extensions_proto3_ext3_proto_extDescs[22]
 
-var E_ExtensionFloat = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*float32)(nil),
-	Field:         1011,
-	Name:          "goproto.protoc.extension.proto3.extension_float",
-	Tag:           "fixed32,1011,opt,name=extension_float",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+	// extend google.protobuf.MessageOptions { repeated sint64 repeated_extension_sint64 = 2007; }
+	E_RepeatedExtensionSint64 = &xxx_File_extensions_proto3_ext3_proto_extDescs[23]
 
-var E_ExtensionSfixed64 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*int64)(nil),
-	Field:         1012,
-	Name:          "goproto.protoc.extension.proto3.extension_sfixed64",
-	Tag:           "fixed64,1012,opt,name=extension_sfixed64",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+	// extend google.protobuf.MessageOptions { repeated uint64 repeated_extension_uint64 = 2008; }
+	E_RepeatedExtensionUint64 = &xxx_File_extensions_proto3_ext3_proto_extDescs[24]
 
-var E_ExtensionFixed64 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*uint64)(nil),
-	Field:         1013,
-	Name:          "goproto.protoc.extension.proto3.extension_fixed64",
-	Tag:           "fixed64,1013,opt,name=extension_fixed64",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+	// extend google.protobuf.MessageOptions { repeated sfixed32 repeated_extension_sfixed32 = 2009; }
+	E_RepeatedExtensionSfixed32 = &xxx_File_extensions_proto3_ext3_proto_extDescs[25]
 
-var E_ExtensionDouble = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*float64)(nil),
-	Field:         1014,
-	Name:          "goproto.protoc.extension.proto3.extension_double",
-	Tag:           "fixed64,1014,opt,name=extension_double",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+	// extend google.protobuf.MessageOptions { repeated fixed32 repeated_extension_fixed32 = 2010; }
+	E_RepeatedExtensionFixed32 = &xxx_File_extensions_proto3_ext3_proto_extDescs[26]
 
-var E_ExtensionString = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*string)(nil),
-	Field:         1015,
-	Name:          "goproto.protoc.extension.proto3.extension_string",
-	Tag:           "bytes,1015,opt,name=extension_string",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+	// extend google.protobuf.MessageOptions { repeated float repeated_extension_float = 2011; }
+	E_RepeatedExtensionFloat = &xxx_File_extensions_proto3_ext3_proto_extDescs[27]
 
-var E_ExtensionBytes = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]byte)(nil),
-	Field:         1016,
-	Name:          "goproto.protoc.extension.proto3.extension_bytes",
-	Tag:           "bytes,1016,opt,name=extension_bytes",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+	// extend google.protobuf.MessageOptions { repeated sfixed64 repeated_extension_sfixed64 = 2012; }
+	E_RepeatedExtensionSfixed64 = &xxx_File_extensions_proto3_ext3_proto_extDescs[28]
 
-var E_Extension_Message = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: (*Message)(nil),
-	Field:         1017,
-	Name:          "goproto.protoc.extension.proto3.extension_Message",
-	Tag:           "bytes,1017,opt,name=extension_Message",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+	// extend google.protobuf.MessageOptions { repeated fixed64 repeated_extension_fixed64 = 2013; }
+	E_RepeatedExtensionFixed64 = &xxx_File_extensions_proto3_ext3_proto_extDescs[29]
 
-var E_RepeatedExtensionBool = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]bool)(nil),
-	Field:         2001,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_bool",
-	Tag:           "varint,2001,rep,name=repeated_extension_bool",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+	// extend google.protobuf.MessageOptions { repeated double repeated_extension_double = 2014; }
+	E_RepeatedExtensionDouble = &xxx_File_extensions_proto3_ext3_proto_extDescs[30]
 
-var E_RepeatedExtensionEnum = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]Enum)(nil),
-	Field:         2002,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_enum",
-	Tag:           "varint,2002,rep,name=repeated_extension_enum,enum=goproto.protoc.extension.proto3.Enum",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+	// extend google.protobuf.MessageOptions { repeated string repeated_extension_string = 2015; }
+	E_RepeatedExtensionString = &xxx_File_extensions_proto3_ext3_proto_extDescs[31]
 
-var E_RepeatedExtensionInt32 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]int32)(nil),
-	Field:         2003,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_int32",
-	Tag:           "varint,2003,rep,name=repeated_extension_int32",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+	// extend google.protobuf.MessageOptions { repeated bytes repeated_extension_bytes = 2016; }
+	E_RepeatedExtensionBytes = &xxx_File_extensions_proto3_ext3_proto_extDescs[32]
 
-var E_RepeatedExtensionSint32 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]int32)(nil),
-	Field:         2004,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_sint32",
-	Tag:           "zigzag32,2004,rep,name=repeated_extension_sint32",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_RepeatedExtensionUint32 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]uint32)(nil),
-	Field:         2005,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_uint32",
-	Tag:           "varint,2005,rep,name=repeated_extension_uint32",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_RepeatedExtensionInt64 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]int64)(nil),
-	Field:         2006,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_int64",
-	Tag:           "varint,2006,rep,name=repeated_extension_int64",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_RepeatedExtensionSint64 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]int64)(nil),
-	Field:         2007,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_sint64",
-	Tag:           "zigzag64,2007,rep,name=repeated_extension_sint64",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_RepeatedExtensionUint64 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]uint64)(nil),
-	Field:         2008,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_uint64",
-	Tag:           "varint,2008,rep,name=repeated_extension_uint64",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_RepeatedExtensionSfixed32 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]int32)(nil),
-	Field:         2009,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_sfixed32",
-	Tag:           "fixed32,2009,rep,name=repeated_extension_sfixed32",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_RepeatedExtensionFixed32 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]uint32)(nil),
-	Field:         2010,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_fixed32",
-	Tag:           "fixed32,2010,rep,name=repeated_extension_fixed32",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_RepeatedExtensionFloat = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]float32)(nil),
-	Field:         2011,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_float",
-	Tag:           "fixed32,2011,rep,name=repeated_extension_float",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_RepeatedExtensionSfixed64 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]int64)(nil),
-	Field:         2012,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_sfixed64",
-	Tag:           "fixed64,2012,rep,name=repeated_extension_sfixed64",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_RepeatedExtensionFixed64 = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]uint64)(nil),
-	Field:         2013,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_fixed64",
-	Tag:           "fixed64,2013,rep,name=repeated_extension_fixed64",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_RepeatedExtensionDouble = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]float64)(nil),
-	Field:         2014,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_double",
-	Tag:           "fixed64,2014,rep,name=repeated_extension_double",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_RepeatedExtensionString = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]string)(nil),
-	Field:         2015,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_string",
-	Tag:           "bytes,2015,rep,name=repeated_extension_string",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_RepeatedExtensionBytes = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([][]byte)(nil),
-	Field:         2016,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_bytes",
-	Tag:           "bytes,2016,rep,name=repeated_extension_bytes",
-	Filename:      "extensions/proto3/ext3.proto",
-}
-
-var E_RepeatedExtension_Message = &proto.ExtensionDesc{
-	ExtendedType:  (*descriptor.MessageOptions)(nil),
-	ExtensionType: ([]*Message)(nil),
-	Field:         2017,
-	Name:          "goproto.protoc.extension.proto3.repeated_extension_Message",
-	Tag:           "bytes,2017,rep,name=repeated_extension_Message",
-	Filename:      "extensions/proto3/ext3.proto",
-}
+	// extend google.protobuf.MessageOptions { repeated goproto.protoc.extension.proto3.Message repeated_extension_Message = 2017; }
+	E_RepeatedExtension_Message = &xxx_File_extensions_proto3_ext3_proto_extDescs[33]
+)
 
 func init() {
 	proto.RegisterFile("extensions/proto3/ext3.proto", xxx_File_extensions_proto3_ext3_proto_rawdesc_gzipped)
@@ -701,6 +773,7 @@ func xxx_File_extensions_proto3_ext3_proto_init() {
 		RawDescriptor:        xxx_File_extensions_proto3_ext3_proto_rawdesc,
 		GoTypes:              xxx_File_extensions_proto3_ext3_proto_goTypes,
 		DependencyIndexes:    xxx_File_extensions_proto3_ext3_proto_depIdxs,
+		LegacyExtensions:     xxx_File_extensions_proto3_ext3_proto_extDescs,
 		EnumOutputTypes:      xxx_File_extensions_proto3_ext3_proto_enumTypes,
 		MessageOutputTypes:   messageTypes,
 		ExtensionOutputTypes: extensionTypes,
@@ -710,40 +783,6 @@ func xxx_File_extensions_proto3_ext3_proto_init() {
 		xxx_File_extensions_proto3_ext3_proto_messageTypes[i].GoType = reflect.TypeOf(messageGoTypes[i])
 		xxx_File_extensions_proto3_ext3_proto_messageTypes[i].PBType = mt
 	}
-	E_ExtensionBool.Type = extensionTypes[0]
-	E_ExtensionEnum.Type = extensionTypes[1]
-	E_ExtensionInt32.Type = extensionTypes[2]
-	E_ExtensionSint32.Type = extensionTypes[3]
-	E_ExtensionUint32.Type = extensionTypes[4]
-	E_ExtensionInt64.Type = extensionTypes[5]
-	E_ExtensionSint64.Type = extensionTypes[6]
-	E_ExtensionUint64.Type = extensionTypes[7]
-	E_ExtensionSfixed32.Type = extensionTypes[8]
-	E_ExtensionFixed32.Type = extensionTypes[9]
-	E_ExtensionFloat.Type = extensionTypes[10]
-	E_ExtensionSfixed64.Type = extensionTypes[11]
-	E_ExtensionFixed64.Type = extensionTypes[12]
-	E_ExtensionDouble.Type = extensionTypes[13]
-	E_ExtensionString.Type = extensionTypes[14]
-	E_ExtensionBytes.Type = extensionTypes[15]
-	E_Extension_Message.Type = extensionTypes[16]
-	E_RepeatedExtensionBool.Type = extensionTypes[17]
-	E_RepeatedExtensionEnum.Type = extensionTypes[18]
-	E_RepeatedExtensionInt32.Type = extensionTypes[19]
-	E_RepeatedExtensionSint32.Type = extensionTypes[20]
-	E_RepeatedExtensionUint32.Type = extensionTypes[21]
-	E_RepeatedExtensionInt64.Type = extensionTypes[22]
-	E_RepeatedExtensionSint64.Type = extensionTypes[23]
-	E_RepeatedExtensionUint64.Type = extensionTypes[24]
-	E_RepeatedExtensionSfixed32.Type = extensionTypes[25]
-	E_RepeatedExtensionFixed32.Type = extensionTypes[26]
-	E_RepeatedExtensionFloat.Type = extensionTypes[27]
-	E_RepeatedExtensionSfixed64.Type = extensionTypes[28]
-	E_RepeatedExtensionFixed64.Type = extensionTypes[29]
-	E_RepeatedExtensionDouble.Type = extensionTypes[30]
-	E_RepeatedExtensionString.Type = extensionTypes[31]
-	E_RepeatedExtensionBytes.Type = extensionTypes[32]
-	E_RepeatedExtension_Message.Type = extensionTypes[33]
 	xxx_File_extensions_proto3_ext3_proto_goTypes = nil
 	xxx_File_extensions_proto3_ext3_proto_depIdxs = nil
 }

cmd/protoc-gen-go/testdata/import_public/sub/a.pb.go

@@ -368,14 +368,20 @@ func (*M_Submessage) XXX_OneofWrappers() []interface{} {
 	}
 }
 
-var E_ExtensionField = &proto.ExtensionDesc{
-	ExtendedType:  (*M)(nil),
-	ExtensionType: (*string)(nil),
-	Field:         100,
-	Name:          "goproto.protoc.import_public.sub.extension_field",
-	Tag:           "bytes,100,opt,name=extension_field",
-	Filename:      "import_public/sub/a.proto",
-}
+var xxx_File_import_public_sub_a_proto_extDescs = []proto.ExtensionDesc{
+	{
+		ExtendedType:  (*M)(nil),
+		ExtensionType: (*string)(nil),
+		Field:         100,
+		Name:          "goproto.protoc.import_public.sub.extension_field",
+		Tag:           "bytes,100,opt,name=extension_field",
+		Filename:      "import_public/sub/a.proto",
+	},
+}
+var (
+	// extend goproto.protoc.import_public.sub.M { optional string extension_field = 100; }
+	E_ExtensionField = &xxx_File_import_public_sub_a_proto_extDescs[0]
+)
 
 func init() {
 	proto.RegisterFile("import_public/sub/a.proto", xxx_File_import_public_sub_a_proto_rawdesc_gzipped)
@@ -470,6 +476,7 @@ func xxx_File_import_public_sub_a_proto_init() {
 		RawDescriptor:        xxx_File_import_public_sub_a_proto_rawdesc,
 		GoTypes:              xxx_File_import_public_sub_a_proto_goTypes,
 		DependencyIndexes:    xxx_File_import_public_sub_a_proto_depIdxs,
+		LegacyExtensions:     xxx_File_import_public_sub_a_proto_extDescs,
 		EnumOutputTypes:      xxx_File_import_public_sub_a_proto_enumTypes,
 		MessageOutputTypes:   messageTypes,
 		ExtensionOutputTypes: extensionTypes,
@@ -479,7 +486,6 @@ func xxx_File_import_public_sub_a_proto_init() {
 		xxx_File_import_public_sub_a_proto_messageTypes[i].GoType = reflect.TypeOf(messageGoTypes[i])
 		xxx_File_import_public_sub_a_proto_messageTypes[i].PBType = mt
 	}
-	E_ExtensionField.Type = extensionTypes[0]
 	xxx_File_import_public_sub_a_proto_goTypes = nil
 	xxx_File_import_public_sub_a_proto_depIdxs = nil
 }

encoding/testprotos/pb2/test.pb.go

@@ -1409,176 +1409,218 @@ func (m *Nests_OptGroup_OptNestedGroup) GetOptFixed32() uint32 {
 	return 0
 }
 
-var E_OptExtBool = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: (*bool)(nil),
-	Field:         21,
-	Name:          "pb2.opt_ext_bool",
-	Tag:           "varint,21,opt,name=opt_ext_bool",
-	Filename:      "pb2/test.proto",
-}
-
-var E_OptExtString = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: (*string)(nil),
-	Field:         22,
-	Name:          "pb2.opt_ext_string",
-	Tag:           "bytes,22,opt,name=opt_ext_string",
-	Filename:      "pb2/test.proto",
-}
-
-var E_OptExtEnum = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: (*Enum)(nil),
-	Field:         23,
-	Name:          "pb2.opt_ext_enum",
-	Tag:           "varint,23,opt,name=opt_ext_enum,enum=pb2.Enum",
-	Filename:      "pb2/test.proto",
-}
-
-var E_OptExtNested = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: (*Nested)(nil),
-	Field:         24,
-	Name:          "pb2.opt_ext_nested",
-	Tag:           "bytes,24,opt,name=opt_ext_nested",
-	Filename:      "pb2/test.proto",
-}
-
-var E_RptExtFixed32 = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: ([]uint32)(nil),
-	Field:         31,
-	Name:          "pb2.rpt_ext_fixed32",
-	Tag:           "fixed32,31,rep,name=rpt_ext_fixed32",
-	Filename:      "pb2/test.proto",
-}
-
-var E_RptExtEnum = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: ([]Enum)(nil),
-	Field:         32,
-	Name:          "pb2.rpt_ext_enum",
-	Tag:           "varint,32,rep,name=rpt_ext_enum,enum=pb2.Enum",
-	Filename:      "pb2/test.proto",
-}
-
-var E_RptExtNested = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: ([]*Nested)(nil),
-	Field:         33,
-	Name:          "pb2.rpt_ext_nested",
-	Tag:           "bytes,33,rep,name=rpt_ext_nested",
-	Filename:      "pb2/test.proto",
-}
-
-var E_MessageSetExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*MessageSet)(nil),
-	ExtensionType: (*FakeMessageSetExtension)(nil),
-	Field:         50,
-	Name:          "pb2.",
-	Tag:           "bytes,50,opt,name=message_set_extension",
-	Filename:      "pb2/test.proto",
-}
-
-var E_ExtensionsContainer_OptExtBool = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: (*bool)(nil),
-	Field:         51,
-	Name:          "pb2.ExtensionsContainer.opt_ext_bool",
-	Tag:           "varint,51,opt,name=opt_ext_bool",
-	Filename:      "pb2/test.proto",
-}
-
-var E_ExtensionsContainer_OptExtString = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: (*string)(nil),
-	Field:         52,
-	Name:          "pb2.ExtensionsContainer.opt_ext_string",
-	Tag:           "bytes,52,opt,name=opt_ext_string",
-	Filename:      "pb2/test.proto",
-}
-
-var E_ExtensionsContainer_OptExtEnum = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: (*Enum)(nil),
-	Field:         53,
-	Name:          "pb2.ExtensionsContainer.opt_ext_enum",
-	Tag:           "varint,53,opt,name=opt_ext_enum,enum=pb2.Enum",
-	Filename:      "pb2/test.proto",
-}
-
-var E_ExtensionsContainer_OptExtNested = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: (*Nested)(nil),
-	Field:         54,
-	Name:          "pb2.ExtensionsContainer.opt_ext_nested",
-	Tag:           "bytes,54,opt,name=opt_ext_nested",
-	Filename:      "pb2/test.proto",
-}
-
-var E_ExtensionsContainer_RptExtString = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: ([]string)(nil),
-	Field:         61,
-	Name:          "pb2.ExtensionsContainer.rpt_ext_string",
-	Tag:           "bytes,61,rep,name=rpt_ext_string",
-	Filename:      "pb2/test.proto",
-}
-
-var E_ExtensionsContainer_RptExtEnum = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: ([]Enum)(nil),
-	Field:         62,
-	Name:          "pb2.ExtensionsContainer.rpt_ext_enum",
-	Tag:           "varint,62,rep,name=rpt_ext_enum,enum=pb2.Enum",
-	Filename:      "pb2/test.proto",
-}
-
-var E_ExtensionsContainer_RptExtNested = &proto.ExtensionDesc{
-	ExtendedType:  (*Extensions)(nil),
-	ExtensionType: ([]*Nested)(nil),
-	Field:         63,
-	Name:          "pb2.ExtensionsContainer.rpt_ext_nested",
-	Tag:           "bytes,63,rep,name=rpt_ext_nested",
-	Filename:      "pb2/test.proto",
-}
-
-var E_MessageSetExtension_MessageSetExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*MessageSet)(nil),
-	ExtensionType: (*MessageSetExtension)(nil),
-	Field:         10,
-	Name:          "pb2.MessageSetExtension",
-	Tag:           "bytes,10,opt,name=message_set_extension",
-	Filename:      "pb2/test.proto",
-}
-
-var E_MessageSetExtension_NotMessageSetExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*MessageSet)(nil),
-	ExtensionType: (*MessageSetExtension)(nil),
-	Field:         20,
-	Name:          "pb2.MessageSetExtension.not_message_set_extension",
-	Tag:           "bytes,20,opt,name=not_message_set_extension",
-	Filename:      "pb2/test.proto",
-}
-
-var E_MessageSetExtension_ExtNested = &proto.ExtensionDesc{
-	ExtendedType:  (*MessageSet)(nil),
-	ExtensionType: (*Nested)(nil),
-	Field:         30,
-	Name:          "pb2.MessageSetExtension.ext_nested",
-	Tag:           "bytes,30,opt,name=ext_nested",
-	Filename:      "pb2/test.proto",
-}
-
-var E_FakeMessageSetExtension_MessageSetExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*FakeMessageSet)(nil),
-	ExtensionType: (*FakeMessageSetExtension)(nil),
-	Field:         10,
-	Name:          "pb2.FakeMessageSetExtension.message_set_extension",
-	Tag:           "bytes,10,opt,name=message_set_extension",
-	Filename:      "pb2/test.proto",
-}
+var xxx_File_pb2_test_proto_extDescs = []proto.ExtensionDesc{
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: (*bool)(nil),
+		Field:         21,
+		Name:          "pb2.opt_ext_bool",
+		Tag:           "varint,21,opt,name=opt_ext_bool",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: (*string)(nil),
+		Field:         22,
+		Name:          "pb2.opt_ext_string",
+		Tag:           "bytes,22,opt,name=opt_ext_string",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: (*Enum)(nil),
+		Field:         23,
+		Name:          "pb2.opt_ext_enum",
+		Tag:           "varint,23,opt,name=opt_ext_enum,enum=pb2.Enum",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: (*Nested)(nil),
+		Field:         24,
+		Name:          "pb2.opt_ext_nested",
+		Tag:           "bytes,24,opt,name=opt_ext_nested",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: ([]uint32)(nil),
+		Field:         31,
+		Name:          "pb2.rpt_ext_fixed32",
+		Tag:           "fixed32,31,rep,name=rpt_ext_fixed32",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: ([]Enum)(nil),
+		Field:         32,
+		Name:          "pb2.rpt_ext_enum",
+		Tag:           "varint,32,rep,name=rpt_ext_enum,enum=pb2.Enum",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: ([]*Nested)(nil),
+		Field:         33,
+		Name:          "pb2.rpt_ext_nested",
+		Tag:           "bytes,33,rep,name=rpt_ext_nested",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*MessageSet)(nil),
+		ExtensionType: (*FakeMessageSetExtension)(nil),
+		Field:         50,
+		Name:          "pb2.",
+		Tag:           "bytes,50,opt,name=message_set_extension",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: (*bool)(nil),
+		Field:         51,
+		Name:          "pb2.ExtensionsContainer.opt_ext_bool",
+		Tag:           "varint,51,opt,name=opt_ext_bool",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: (*string)(nil),
+		Field:         52,
+		Name:          "pb2.ExtensionsContainer.opt_ext_string",
+		Tag:           "bytes,52,opt,name=opt_ext_string",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: (*Enum)(nil),
+		Field:         53,
+		Name:          "pb2.ExtensionsContainer.opt_ext_enum",
+		Tag:           "varint,53,opt,name=opt_ext_enum,enum=pb2.Enum",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: (*Nested)(nil),
+		Field:         54,
+		Name:          "pb2.ExtensionsContainer.opt_ext_nested",
+		Tag:           "bytes,54,opt,name=opt_ext_nested",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: ([]string)(nil),
+		Field:         61,
+		Name:          "pb2.ExtensionsContainer.rpt_ext_string",
+		Tag:           "bytes,61,rep,name=rpt_ext_string",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: ([]Enum)(nil),
+		Field:         62,
+		Name:          "pb2.ExtensionsContainer.rpt_ext_enum",
+		Tag:           "varint,62,rep,name=rpt_ext_enum,enum=pb2.Enum",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*Extensions)(nil),
+		ExtensionType: ([]*Nested)(nil),
+		Field:         63,
+		Name:          "pb2.ExtensionsContainer.rpt_ext_nested",
+		Tag:           "bytes,63,rep,name=rpt_ext_nested",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*MessageSet)(nil),
+		ExtensionType: (*MessageSetExtension)(nil),
+		Field:         10,
+		Name:          "pb2.MessageSetExtension",
+		Tag:           "bytes,10,opt,name=message_set_extension",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*MessageSet)(nil),
+		ExtensionType: (*MessageSetExtension)(nil),
+		Field:         20,
+		Name:          "pb2.MessageSetExtension.not_message_set_extension",
+		Tag:           "bytes,20,opt,name=not_message_set_extension",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*MessageSet)(nil),
+		ExtensionType: (*Nested)(nil),
+		Field:         30,
+		Name:          "pb2.MessageSetExtension.ext_nested",
+		Tag:           "bytes,30,opt,name=ext_nested",
+		Filename:      "pb2/test.proto",
+	},
+	{
+		ExtendedType:  (*FakeMessageSet)(nil),
+		ExtensionType: (*FakeMessageSetExtension)(nil),
+		Field:         10,
+		Name:          "pb2.FakeMessageSetExtension.message_set_extension",
+		Tag:           "bytes,10,opt,name=message_set_extension",
+		Filename:      "pb2/test.proto",
+	},
+}
+var (
+	// extend pb2.Extensions { optional bool opt_ext_bool = 21; }
+	E_OptExtBool = &xxx_File_pb2_test_proto_extDescs[0]
+
+	// extend pb2.Extensions { optional string opt_ext_string = 22; }
+	E_OptExtString = &xxx_File_pb2_test_proto_extDescs[1]
+
+	// extend pb2.Extensions { optional pb2.Enum opt_ext_enum = 23; }
+	E_OptExtEnum = &xxx_File_pb2_test_proto_extDescs[2]
+
+	// extend pb2.Extensions { optional pb2.Nested opt_ext_nested = 24; }
+	E_OptExtNested = &xxx_File_pb2_test_proto_extDescs[3]
+
+	// extend pb2.Extensions { repeated fixed32 rpt_ext_fixed32 = 31; }
+	E_RptExtFixed32 = &xxx_File_pb2_test_proto_extDescs[4]
+
+	// extend pb2.Extensions { repeated pb2.Enum rpt_ext_enum = 32; }
+	E_RptExtEnum = &xxx_File_pb2_test_proto_extDescs[5]
+
+	// extend pb2.Extensions { repeated pb2.Nested rpt_ext_nested = 33; }
+	E_RptExtNested = &xxx_File_pb2_test_proto_extDescs[6]
+
+	// extend pb2.MessageSet { optional pb2.FakeMessageSetExtension message_set_extension = 50; }
+	E_MessageSetExtension = &xxx_File_pb2_test_proto_extDescs[7]
+
+	// extend pb2.Extensions { optional bool opt_ext_bool = 51; }
+	E_ExtensionsContainer_OptExtBool = &xxx_File_pb2_test_proto_extDescs[8]
+
+	// extend pb2.Extensions { optional string opt_ext_string = 52; }
+	E_ExtensionsContainer_OptExtString = &xxx_File_pb2_test_proto_extDescs[9]
+
+	// extend pb2.Extensions { optional pb2.Enum opt_ext_enum = 53; }
+	E_ExtensionsContainer_OptExtEnum = &xxx_File_pb2_test_proto_extDescs[10]
+
+	// extend pb2.Extensions { optional pb2.Nested opt_ext_nested = 54; }
+	E_ExtensionsContainer_OptExtNested = &xxx_File_pb2_test_proto_extDescs[11]
+
+	// extend pb2.Extensions { repeated string rpt_ext_string = 61; }
+	E_ExtensionsContainer_RptExtString = &xxx_File_pb2_test_proto_extDescs[12]
+
+	// extend pb2.Extensions { repeated pb2.Enum rpt_ext_enum = 62; }
+	E_ExtensionsContainer_RptExtEnum = &xxx_File_pb2_test_proto_extDescs[13]
+
+	// extend pb2.Extensions { repeated pb2.Nested rpt_ext_nested = 63; }
+	E_ExtensionsContainer_RptExtNested = &xxx_File_pb2_test_proto_extDescs[14]
+
+	// extend pb2.MessageSet { optional pb2.MessageSetExtension message_set_extension = 10; }
+	E_MessageSetExtension_MessageSetExtension = &xxx_File_pb2_test_proto_extDescs[15]
+
+	// extend pb2.MessageSet { optional pb2.MessageSetExtension not_message_set_extension = 20; }
+	E_MessageSetExtension_NotMessageSetExtension = &xxx_File_pb2_test_proto_extDescs[16]
+
+	// extend pb2.MessageSet { optional pb2.Nested ext_nested = 30; }
+	E_MessageSetExtension_ExtNested = &xxx_File_pb2_test_proto_extDescs[17]
+
+	// extend pb2.FakeMessageSet { optional pb2.FakeMessageSetExtension message_set_extension = 10; }
+	E_FakeMessageSetExtension_MessageSetExtension = &xxx_File_pb2_test_proto_extDescs[18]
+)
 
 func init() {
 	proto.RegisterFile("pb2/test.proto", xxx_File_pb2_test_proto_rawdesc_gzipped)
@@ -2078,6 +2120,7 @@ func xxx_File_pb2_test_proto_init() {
 		RawDescriptor:        xxx_File_pb2_test_proto_rawdesc,
 		GoTypes:              xxx_File_pb2_test_proto_goTypes,
 		DependencyIndexes:    xxx_File_pb2_test_proto_depIdxs,
+		LegacyExtensions:     xxx_File_pb2_test_proto_extDescs,
 		EnumOutputTypes:      xxx_File_pb2_test_proto_enumTypes,
 		MessageOutputTypes:   messageTypes,
 		ExtensionOutputTypes: extensionTypes,
@@ -2087,25 +2130,6 @@ func xxx_File_pb2_test_proto_init() {
 		xxx_File_pb2_test_proto_messageTypes[i].GoType = reflect.TypeOf(messageGoTypes[i])
 		xxx_File_pb2_test_proto_messageTypes[i].PBType = mt
 	}
-	E_OptExtBool.Type = extensionTypes[0]
-	E_OptExtString.Type = extensionTypes[1]
-	E_OptExtEnum.Type = extensionTypes[2]
-	E_OptExtNested.Type = extensionTypes[3]
-	E_RptExtFixed32.Type = extensionTypes[4]
-	E_RptExtEnum.Type = extensionTypes[5]
-	E_RptExtNested.Type = extensionTypes[6]
-	E_MessageSetExtension.Type = extensionTypes[7]
-	E_ExtensionsContainer_OptExtBool.Type = extensionTypes[8]
-	E_ExtensionsContainer_OptExtString.Type = extensionTypes[9]
-	E_ExtensionsContainer_OptExtEnum.Type = extensionTypes[10]
-	E_ExtensionsContainer_OptExtNested.Type = extensionTypes[11]
-	E_ExtensionsContainer_RptExtString.Type = extensionTypes[12]
-	E_ExtensionsContainer_RptExtEnum.Type = extensionTypes[13]
-	E_ExtensionsContainer_RptExtNested.Type = extensionTypes[14]
-	E_MessageSetExtension_MessageSetExtension.Type = extensionTypes[15]
-	E_MessageSetExtension_NotMessageSetExtension.Type = extensionTypes[16]
-	E_MessageSetExtension_ExtNested.Type = extensionTypes[17]
-	E_FakeMessageSetExtension_MessageSetExtension.Type = extensionTypes[18]
 	xxx_File_pb2_test_proto_goTypes = nil
 	xxx_File_pb2_test_proto_depIdxs = nil
 }

encoding/textpb/encode_test.go

@@ -17,7 +17,6 @@ import (
 	"github.com/golang/protobuf/v2/internal/encoding/pack"
 	"github.com/golang/protobuf/v2/internal/encoding/wire"
 	"github.com/golang/protobuf/v2/internal/impl"
-	"github.com/golang/protobuf/v2/internal/legacy"
 	"github.com/golang/protobuf/v2/internal/scalar"
 	"github.com/golang/protobuf/v2/proto"
 	preg "github.com/golang/protobuf/v2/reflect/protoregistry"
@@ -52,14 +51,13 @@ func pb2Enums_NestedEnum(i int32) *pb2.Enums_NestedEnum {
 }
 
 func setExtension(m proto.Message, xd *protoapi.ExtensionDesc, val interface{}) {
-	xt := legacy.Export{}.ExtensionTypeFromDesc(xd)
 	knownFields := m.ProtoReflect().KnownFields()
 	extTypes := knownFields.ExtensionTypes()
-	extTypes.Register(xt)
+	extTypes.Register(xd.Type)
 	if val == nil {
 		return
 	}
-	pval := xt.ValueOf(val)
+	pval := xd.Type.ValueOf(val)
 	knownFields.Set(wire.Number(xd.Field), pval)
 }
 

internal/fileinit/desc.go

@@ -13,6 +13,7 @@ import (
 	"reflect"
 	"sync"
 
+	papi "github.com/golang/protobuf/protoapi"
 	pragma "github.com/golang/protobuf/v2/internal/pragma"
 	ptype "github.com/golang/protobuf/v2/internal/prototype"
 	pfmt "github.com/golang/protobuf/v2/internal/typefmt"
@@ -95,6 +96,13 @@ type FileBuilder struct {
 	// TODO: Provide a list of extension types for options extensions.
 	// OptionDependencies []pref.ExtensionType
 
+	// LegacyExtensions are a list of legacy extension descriptors.
+	// If provided, the pointer to the v1 ExtensionDesc will be stored into the
+	// associated v2 ExtensionType and accessible via a pseudo-internal API.
+	// Also, the v2 ExtensionType will be stored into each v1 ExtensionDesc.
+	// If non-nil, len(LegacyExtensions) must equal len(ExtensionOutputTypes).
+	LegacyExtensions []papi.ExtensionDesc
+
 	// EnumOutputTypes is where Init stores all initialized enum types
 	// in "flattened ordering".
 	EnumOutputTypes []pref.EnumType
@@ -116,6 +124,13 @@ type FileBuilder struct {
 func (fb FileBuilder) Init() pref.FileDescriptor {
 	fd := newFileDesc(fb)
 
+	if fb.LegacyExtensions != nil {
+		for i := range fd.allExtensions {
+			fd.allExtensions[i].legacyDesc = &fb.LegacyExtensions[i]
+			fb.LegacyExtensions[i].Type = &fd.allExtensions[i]
+		}
+	}
+
 	for i := range fd.allEnums {
 		fb.EnumOutputTypes[i] = &fd.allEnums[i]
 	}
@@ -341,6 +356,8 @@ type (
 		number       pref.FieldNumber
 		extendedType pref.MessageDescriptor
 
+		legacyDesc *papi.ExtensionDesc
+
 		lazy *extensionLazy // protected by fileDesc.once
 	}
 	extensionLazy struct {
@@ -397,6 +414,10 @@ func (xd *extensionDesc) lazyInit() *extensionLazy {
 	return xd.lazy
 }
 
+// ProtoLegacyExtensionDesc is a pseudo-internal API for allowing the v1 code
+// to be able to retrieve a v1 ExtensionDesc.
+func (xd *extensionDesc) ProtoLegacyExtensionDesc() *papi.ExtensionDesc { return xd.legacyDesc }
+
 type (
 	serviceDesc struct {
 		baseDesc

internal/impl/legacy_extension.go

@@ -163,7 +163,7 @@ func (p legacyExtensionTypes) Register(t pref.ExtensionType) {
 	if x.Desc != nil {
 		panic("extension descriptor already registered")
 	}
-	x.Desc = legacyWrapper.ExtensionDescFromType(t)
+	x.Desc = extensionDescFromType(t)
 	if t.Cardinality() == pref.Repeated {
 		// If the field is repeated, initialize the entry with an empty list
 		// so that future Get operations can return a mutable and concrete list.
@@ -225,6 +225,15 @@ func (p legacyExtensionTypes) Range(f func(pref.ExtensionType) bool) {
 	})
 }
 
+func extensionDescFromType(typ pref.ExtensionType) *papi.ExtensionDesc {
+	if xt, ok := typ.(interface{ ProtoLegacyExtensionDesc() *papi.ExtensionDesc }); ok {
+		if desc := xt.ProtoLegacyExtensionDesc(); desc != nil {
+			return desc
+		}
+	}
+	return legacyWrapper.ExtensionDescFromType(typ)
+}
+
 func extensionTypeFromDesc(desc *papi.ExtensionDesc) pref.ExtensionType {
 	if desc.Type != nil {
 		return desc.Type

internal/legacy/extension.go

@@ -47,6 +47,13 @@ var (
 // extensionDescFromType converts a v2 protoreflect.ExtensionType to a
 // v1 protoapi.ExtensionDesc. The returned ExtensionDesc must not be mutated.
 func extensionDescFromType(t pref.ExtensionType) *papi.ExtensionDesc {
+	// Fast-path: check whether an extension desc is already nested within.
+	if t, ok := t.(interface{ ProtoLegacyExtensionDesc() *papi.ExtensionDesc }); ok {
+		if d := t.ProtoLegacyExtensionDesc(); d != nil {
+			return d
+		}
+	}
+
 	// Fast-path: check the cache for whether this ExtensionType has already
 	// been converted to a legacy descriptor.
 	if d, ok := extensionDescCache.Load(t); ok {

internal/testprotos/test/ext.pb.go

@@ -16,14 +16,20 @@ import (
 // proto package needs to be updated.
 const _ = proto.ProtoPackageIsVersion3 // please upgrade the proto package
 
-var E_ForeignInt32Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*int32)(nil),
-	Field:         2000,
-	Name:          "goproto.proto.test.foreign_int32_extension",
-	Tag:           "varint,2000,opt,name=foreign_int32_extension",
-	Filename:      "test/ext.proto",
+var xxx_File_test_ext_proto_extDescs = []proto.ExtensionDesc{
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*int32)(nil),
+		Field:         2000,
+		Name:          "goproto.proto.test.foreign_int32_extension",
+		Tag:           "varint,2000,opt,name=foreign_int32_extension",
+		Filename:      "test/ext.proto",
+	},
 }
+var (
+	// extend goproto.proto.test.TestAllExtensions { optional int32 foreign_int32_extension = 2000; }
+	E_ForeignInt32Extension = &xxx_File_test_ext_proto_extDescs[0]
+)
 
 func init() {
 	proto.RegisterFile("test/ext.proto", xxx_File_test_ext_proto_rawdesc_gzipped)
@@ -71,9 +77,9 @@ func xxx_File_test_ext_proto_init() {
 		RawDescriptor:        xxx_File_test_ext_proto_rawdesc,
 		GoTypes:              xxx_File_test_ext_proto_goTypes,
 		DependencyIndexes:    xxx_File_test_ext_proto_depIdxs,
+		LegacyExtensions:     xxx_File_test_ext_proto_extDescs,
 		ExtensionOutputTypes: extensionTypes,
 	}.Init()
-	E_ForeignInt32Extension.Type = extensionTypes[0]
 	xxx_File_test_ext_proto_goTypes = nil
 	xxx_File_test_ext_proto_depIdxs = nil
 }

internal/testprotos/test/test.pb.go

@@ -1567,338 +1567,416 @@ func (m *TestAllTypes_RepeatedGroup) GetA() int32 {
 	return 0
 }
 
-var E_OptionalInt32Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*int32)(nil),
-	Field:         1,
-	Name:          "goproto.proto.test.optional_int32_extension",
-	Tag:           "varint,1,opt,name=optional_int32_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalInt64Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*int64)(nil),
-	Field:         2,
-	Name:          "goproto.proto.test.optional_int64_extension",
-	Tag:           "varint,2,opt,name=optional_int64_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalUint32Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*uint32)(nil),
-	Field:         3,
-	Name:          "goproto.proto.test.optional_uint32_extension",
-	Tag:           "varint,3,opt,name=optional_uint32_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalUint64Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*uint64)(nil),
-	Field:         4,
-	Name:          "goproto.proto.test.optional_uint64_extension",
-	Tag:           "varint,4,opt,name=optional_uint64_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalSint32Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*int32)(nil),
-	Field:         5,
-	Name:          "goproto.proto.test.optional_sint32_extension",
-	Tag:           "zigzag32,5,opt,name=optional_sint32_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalSint64Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*int64)(nil),
-	Field:         6,
-	Name:          "goproto.proto.test.optional_sint64_extension",
-	Tag:           "zigzag64,6,opt,name=optional_sint64_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalFixed32Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*uint32)(nil),
-	Field:         7,
-	Name:          "goproto.proto.test.optional_fixed32_extension",
-	Tag:           "fixed32,7,opt,name=optional_fixed32_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalFixed64Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*uint64)(nil),
-	Field:         8,
-	Name:          "goproto.proto.test.optional_fixed64_extension",
-	Tag:           "fixed64,8,opt,name=optional_fixed64_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalSfixed32Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*int32)(nil),
-	Field:         9,
-	Name:          "goproto.proto.test.optional_sfixed32_extension",
-	Tag:           "fixed32,9,opt,name=optional_sfixed32_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalSfixed64Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*int64)(nil),
-	Field:         10,
-	Name:          "goproto.proto.test.optional_sfixed64_extension",
-	Tag:           "fixed64,10,opt,name=optional_sfixed64_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalFloatExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*float32)(nil),
-	Field:         11,
-	Name:          "goproto.proto.test.optional_float_extension",
-	Tag:           "fixed32,11,opt,name=optional_float_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalDoubleExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*float64)(nil),
-	Field:         12,
-	Name:          "goproto.proto.test.optional_double_extension",
-	Tag:           "fixed64,12,opt,name=optional_double_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalBoolExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*bool)(nil),
-	Field:         13,
-	Name:          "goproto.proto.test.optional_bool_extension",
-	Tag:           "varint,13,opt,name=optional_bool_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalStringExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*string)(nil),
-	Field:         14,
-	Name:          "goproto.proto.test.optional_string_extension",
-	Tag:           "bytes,14,opt,name=optional_string_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalBytesExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]byte)(nil),
-	Field:         15,
-	Name:          "goproto.proto.test.optional_bytes_extension",
-	Tag:           "bytes,15,opt,name=optional_bytes_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalgroupExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*OptionalGroupExtension)(nil),
-	Field:         16,
-	Name:          "goproto.proto.test.optionalgroup_extension",
-	Tag:           "group,16,opt,name=OptionalGroup_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalNestedMessageExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*TestAllTypes_NestedMessage)(nil),
-	Field:         18,
-	Name:          "goproto.proto.test.optional_nested_message_extension",
-	Tag:           "bytes,18,opt,name=optional_nested_message_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_OptionalNestedEnumExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*TestAllTypes_NestedEnum)(nil),
-	Field:         21,
-	Name:          "goproto.proto.test.optional_nested_enum_extension",
-	Tag:           "varint,21,opt,name=optional_nested_enum_extension,enum=goproto.proto.test.TestAllTypes_NestedEnum",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedInt32Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]int32)(nil),
-	Field:         31,
-	Name:          "goproto.proto.test.repeated_int32_extension",
-	Tag:           "varint,31,rep,name=repeated_int32_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedInt64Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]int64)(nil),
-	Field:         32,
-	Name:          "goproto.proto.test.repeated_int64_extension",
-	Tag:           "varint,32,rep,name=repeated_int64_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedUint32Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]uint32)(nil),
-	Field:         33,
-	Name:          "goproto.proto.test.repeated_uint32_extension",
-	Tag:           "varint,33,rep,name=repeated_uint32_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedUint64Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]uint64)(nil),
-	Field:         34,
-	Name:          "goproto.proto.test.repeated_uint64_extension",
-	Tag:           "varint,34,rep,name=repeated_uint64_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedSint32Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]int32)(nil),
-	Field:         35,
-	Name:          "goproto.proto.test.repeated_sint32_extension",
-	Tag:           "zigzag32,35,rep,name=repeated_sint32_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedSint64Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]int64)(nil),
-	Field:         36,
-	Name:          "goproto.proto.test.repeated_sint64_extension",
-	Tag:           "zigzag64,36,rep,name=repeated_sint64_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedFixed32Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]uint32)(nil),
-	Field:         37,
-	Name:          "goproto.proto.test.repeated_fixed32_extension",
-	Tag:           "fixed32,37,rep,name=repeated_fixed32_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedFixed64Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]uint64)(nil),
-	Field:         38,
-	Name:          "goproto.proto.test.repeated_fixed64_extension",
-	Tag:           "fixed64,38,rep,name=repeated_fixed64_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedSfixed32Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]int32)(nil),
-	Field:         39,
-	Name:          "goproto.proto.test.repeated_sfixed32_extension",
-	Tag:           "fixed32,39,rep,name=repeated_sfixed32_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedSfixed64Extension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]int64)(nil),
-	Field:         40,
-	Name:          "goproto.proto.test.repeated_sfixed64_extension",
-	Tag:           "fixed64,40,rep,name=repeated_sfixed64_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedFloatExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]float32)(nil),
-	Field:         41,
-	Name:          "goproto.proto.test.repeated_float_extension",
-	Tag:           "fixed32,41,rep,name=repeated_float_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedDoubleExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]float64)(nil),
-	Field:         42,
-	Name:          "goproto.proto.test.repeated_double_extension",
-	Tag:           "fixed64,42,rep,name=repeated_double_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedBoolExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]bool)(nil),
-	Field:         43,
-	Name:          "goproto.proto.test.repeated_bool_extension",
-	Tag:           "varint,43,rep,name=repeated_bool_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedStringExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]string)(nil),
-	Field:         44,
-	Name:          "goproto.proto.test.repeated_string_extension",
-	Tag:           "bytes,44,rep,name=repeated_string_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedBytesExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([][]byte)(nil),
-	Field:         45,
-	Name:          "goproto.proto.test.repeated_bytes_extension",
-	Tag:           "bytes,45,rep,name=repeated_bytes_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedgroupExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]*RepeatedGroupExtension)(nil),
-	Field:         46,
-	Name:          "goproto.proto.test.repeatedgroup_extension",
-	Tag:           "group,46,rep,name=RepeatedGroup_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedNestedMessageExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]*TestAllTypes_NestedMessage)(nil),
-	Field:         48,
-	Name:          "goproto.proto.test.repeated_nested_message_extension",
-	Tag:           "bytes,48,rep,name=repeated_nested_message_extension",
-	Filename:      "test/test.proto",
-}
-
-var E_RepeatedNestedEnumExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: ([]TestAllTypes_NestedEnum)(nil),
-	Field:         51,
-	Name:          "goproto.proto.test.repeated_nested_enum_extension",
-	Tag:           "varint,51,rep,name=repeated_nested_enum_extension,enum=goproto.proto.test.TestAllTypes_NestedEnum",
-	Filename:      "test/test.proto",
-}
-
-var E_TestNestedExtension_NestedStringExtension = &proto.ExtensionDesc{
-	ExtendedType:  (*TestAllExtensions)(nil),
-	ExtensionType: (*string)(nil),
-	Field:         1003,
-	Name:          "goproto.proto.test.TestNestedExtension.nested_string_extension",
-	Tag:           "bytes,1003,opt,name=nested_string_extension",
-	Filename:      "test/test.proto",
-}
+var xxx_File_test_test_proto_extDescs = []proto.ExtensionDesc{
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*int32)(nil),
+		Field:         1,
+		Name:          "goproto.proto.test.optional_int32_extension",
+		Tag:           "varint,1,opt,name=optional_int32_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*int64)(nil),
+		Field:         2,
+		Name:          "goproto.proto.test.optional_int64_extension",
+		Tag:           "varint,2,opt,name=optional_int64_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*uint32)(nil),
+		Field:         3,
+		Name:          "goproto.proto.test.optional_uint32_extension",
+		Tag:           "varint,3,opt,name=optional_uint32_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*uint64)(nil),
+		Field:         4,
+		Name:          "goproto.proto.test.optional_uint64_extension",
+		Tag:           "varint,4,opt,name=optional_uint64_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*int32)(nil),
+		Field:         5,
+		Name:          "goproto.proto.test.optional_sint32_extension",
+		Tag:           "zigzag32,5,opt,name=optional_sint32_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*int64)(nil),
+		Field:         6,
+		Name:          "goproto.proto.test.optional_sint64_extension",
+		Tag:           "zigzag64,6,opt,name=optional_sint64_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*uint32)(nil),
+		Field:         7,
+		Name:          "goproto.proto.test.optional_fixed32_extension",
+		Tag:           "fixed32,7,opt,name=optional_fixed32_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*uint64)(nil),
+		Field:         8,
+		Name:          "goproto.proto.test.optional_fixed64_extension",
+		Tag:           "fixed64,8,opt,name=optional_fixed64_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*int32)(nil),
+		Field:         9,
+		Name:          "goproto.proto.test.optional_sfixed32_extension",
+		Tag:           "fixed32,9,opt,name=optional_sfixed32_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*int64)(nil),
+		Field:         10,
+		Name:          "goproto.proto.test.optional_sfixed64_extension",
+		Tag:           "fixed64,10,opt,name=optional_sfixed64_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*float32)(nil),
+		Field:         11,
+		Name:          "goproto.proto.test.optional_float_extension",
+		Tag:           "fixed32,11,opt,name=optional_float_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*float64)(nil),
+		Field:         12,
+		Name:          "goproto.proto.test.optional_double_extension",
+		Tag:           "fixed64,12,opt,name=optional_double_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*bool)(nil),
+		Field:         13,
+		Name:          "goproto.proto.test.optional_bool_extension",
+		Tag:           "varint,13,opt,name=optional_bool_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*string)(nil),
+		Field:         14,
+		Name:          "goproto.proto.test.optional_string_extension",
+		Tag:           "bytes,14,opt,name=optional_string_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]byte)(nil),
+		Field:         15,
+		Name:          "goproto.proto.test.optional_bytes_extension",
+		Tag:           "bytes,15,opt,name=optional_bytes_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*OptionalGroupExtension)(nil),
+		Field:         16,
+		Name:          "goproto.proto.test.optionalgroup_extension",
+		Tag:           "group,16,opt,name=OptionalGroup_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*TestAllTypes_NestedMessage)(nil),
+		Field:         18,
+		Name:          "goproto.proto.test.optional_nested_message_extension",
+		Tag:           "bytes,18,opt,name=optional_nested_message_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*TestAllTypes_NestedEnum)(nil),
+		Field:         21,
+		Name:          "goproto.proto.test.optional_nested_enum_extension",
+		Tag:           "varint,21,opt,name=optional_nested_enum_extension,enum=goproto.proto.test.TestAllTypes_NestedEnum",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]int32)(nil),
+		Field:         31,
+		Name:          "goproto.proto.test.repeated_int32_extension",
+		Tag:           "varint,31,rep,name=repeated_int32_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]int64)(nil),
+		Field:         32,
+		Name:          "goproto.proto.test.repeated_int64_extension",
+		Tag:           "varint,32,rep,name=repeated_int64_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]uint32)(nil),
+		Field:         33,
+		Name:          "goproto.proto.test.repeated_uint32_extension",
+		Tag:           "varint,33,rep,name=repeated_uint32_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]uint64)(nil),
+		Field:         34,
+		Name:          "goproto.proto.test.repeated_uint64_extension",
+		Tag:           "varint,34,rep,name=repeated_uint64_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]int32)(nil),
+		Field:         35,
+		Name:          "goproto.proto.test.repeated_sint32_extension",
+		Tag:           "zigzag32,35,rep,name=repeated_sint32_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]int64)(nil),
+		Field:         36,
+		Name:          "goproto.proto.test.repeated_sint64_extension",
+		Tag:           "zigzag64,36,rep,name=repeated_sint64_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]uint32)(nil),
+		Field:         37,
+		Name:          "goproto.proto.test.repeated_fixed32_extension",
+		Tag:           "fixed32,37,rep,name=repeated_fixed32_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]uint64)(nil),
+		Field:         38,
+		Name:          "goproto.proto.test.repeated_fixed64_extension",
+		Tag:           "fixed64,38,rep,name=repeated_fixed64_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]int32)(nil),
+		Field:         39,
+		Name:          "goproto.proto.test.repeated_sfixed32_extension",
+		Tag:           "fixed32,39,rep,name=repeated_sfixed32_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]int64)(nil),
+		Field:         40,
+		Name:          "goproto.proto.test.repeated_sfixed64_extension",
+		Tag:           "fixed64,40,rep,name=repeated_sfixed64_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]float32)(nil),
+		Field:         41,
+		Name:          "goproto.proto.test.repeated_float_extension",
+		Tag:           "fixed32,41,rep,name=repeated_float_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]float64)(nil),
+		Field:         42,
+		Name:          "goproto.proto.test.repeated_double_extension",
+		Tag:           "fixed64,42,rep,name=repeated_double_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]bool)(nil),
+		Field:         43,
+		Name:          "goproto.proto.test.repeated_bool_extension",
+		Tag:           "varint,43,rep,name=repeated_bool_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]string)(nil),
+		Field:         44,
+		Name:          "goproto.proto.test.repeated_string_extension",
+		Tag:           "bytes,44,rep,name=repeated_string_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([][]byte)(nil),
+		Field:         45,
+		Name:          "goproto.proto.test.repeated_bytes_extension",
+		Tag:           "bytes,45,rep,name=repeated_bytes_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]*RepeatedGroupExtension)(nil),
+		Field:         46,
+		Name:          "goproto.proto.test.repeatedgroup_extension",
+		Tag:           "group,46,rep,name=RepeatedGroup_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]*TestAllTypes_NestedMessage)(nil),
+		Field:         48,
+		Name:          "goproto.proto.test.repeated_nested_message_extension",
+		Tag:           "bytes,48,rep,name=repeated_nested_message_extension",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: ([]TestAllTypes_NestedEnum)(nil),
+		Field:         51,
+		Name:          "goproto.proto.test.repeated_nested_enum_extension",
+		Tag:           "varint,51,rep,name=repeated_nested_enum_extension,enum=goproto.proto.test.TestAllTypes_NestedEnum",
+		Filename:      "test/test.proto",
+	},
+	{
+		ExtendedType:  (*TestAllExtensions)(nil),
+		ExtensionType: (*string)(nil),
+		Field:         1003,
+		Name:          "goproto.proto.test.TestNestedExtension.nested_string_extension",
+		Tag:           "bytes,1003,opt,name=nested_string_extension",
+		Filename:      "test/test.proto",
+	},
+}
+var (
+	// extend goproto.proto.test.TestAllExtensions { optional int32 optional_int32_extension = 1; }
+	E_OptionalInt32Extension = &xxx_File_test_test_proto_extDescs[0]
+
+	// extend goproto.proto.test.TestAllExtensions { optional int64 optional_int64_extension = 2; }
+	E_OptionalInt64Extension = &xxx_File_test_test_proto_extDescs[1]
+
+	// extend goproto.proto.test.TestAllExtensions { optional uint32 optional_uint32_extension = 3; }
+	E_OptionalUint32Extension = &xxx_File_test_test_proto_extDescs[2]
+
+	// extend goproto.proto.test.TestAllExtensions { optional uint64 optional_uint64_extension = 4; }
+	E_OptionalUint64Extension = &xxx_File_test_test_proto_extDescs[3]
+
+	// extend goproto.proto.test.TestAllExtensions { optional sint32 optional_sint32_extension = 5; }
+	E_OptionalSint32Extension = &xxx_File_test_test_proto_extDescs[4]
+
+	// extend goproto.proto.test.TestAllExtensions { optional sint64 optional_sint64_extension = 6; }
+	E_OptionalSint64Extension = &xxx_File_test_test_proto_extDescs[5]
+
+	// extend goproto.proto.test.TestAllExtensions { optional fixed32 optional_fixed32_extension = 7; }
+	E_OptionalFixed32Extension = &xxx_File_test_test_proto_extDescs[6]
+
+	// extend goproto.proto.test.TestAllExtensions { optional fixed64 optional_fixed64_extension = 8; }
+	E_OptionalFixed64Extension = &xxx_File_test_test_proto_extDescs[7]
+
+	// extend goproto.proto.test.TestAllExtensions { optional sfixed32 optional_sfixed32_extension = 9; }
+	E_OptionalSfixed32Extension = &xxx_File_test_test_proto_extDescs[8]
+
+	// extend goproto.proto.test.TestAllExtensions { optional sfixed64 optional_sfixed64_extension = 10; }
+	E_OptionalSfixed64Extension = &xxx_File_test_test_proto_extDescs[9]
+
+	// extend goproto.proto.test.TestAllExtensions { optional float optional_float_extension = 11; }
+	E_OptionalFloatExtension = &xxx_File_test_test_proto_extDescs[10]
+
+	// extend goproto.proto.test.TestAllExtensions { optional double optional_double_extension = 12; }
+	E_OptionalDoubleExtension = &xxx_File_test_test_proto_extDescs[11]
+
+	// extend goproto.proto.test.TestAllExtensions { optional bool optional_bool_extension = 13; }
+	E_OptionalBoolExtension = &xxx_File_test_test_proto_extDescs[12]
+
+	// extend goproto.proto.test.TestAllExtensions { optional string optional_string_extension = 14; }
+	E_OptionalStringExtension = &xxx_File_test_test_proto_extDescs[13]
+
+	// extend goproto.proto.test.TestAllExtensions { optional bytes optional_bytes_extension = 15; }
+	E_OptionalBytesExtension = &xxx_File_test_test_proto_extDescs[14]
+
+	// extend goproto.proto.test.TestAllExtensions { optional goproto.proto.test.OptionalGroup_extension optionalgroup_extension = 16; }
+	E_OptionalgroupExtension = &xxx_File_test_test_proto_extDescs[15]
+
+	// extend goproto.proto.test.TestAllExtensions { optional goproto.proto.test.TestAllTypes.NestedMessage optional_nested_message_extension = 18; }
+	E_OptionalNestedMessageExtension = &xxx_File_test_test_proto_extDescs[16]
+
+	// extend goproto.proto.test.TestAllExtensions { optional goproto.proto.test.TestAllTypes.NestedEnum optional_nested_enum_extension = 21; }
+	E_OptionalNestedEnumExtension = &xxx_File_test_test_proto_extDescs[17]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated int32 repeated_int32_extension = 31; }
+	E_RepeatedInt32Extension = &xxx_File_test_test_proto_extDescs[18]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated int64 repeated_int64_extension = 32; }
+	E_RepeatedInt64Extension = &xxx_File_test_test_proto_extDescs[19]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated uint32 repeated_uint32_extension = 33; }
+	E_RepeatedUint32Extension = &xxx_File_test_test_proto_extDescs[20]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated uint64 repeated_uint64_extension = 34; }
+	E_RepeatedUint64Extension = &xxx_File_test_test_proto_extDescs[21]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated sint32 repeated_sint32_extension = 35; }
+	E_RepeatedSint32Extension = &xxx_File_test_test_proto_extDescs[22]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated sint64 repeated_sint64_extension = 36; }
+	E_RepeatedSint64Extension = &xxx_File_test_test_proto_extDescs[23]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated fixed32 repeated_fixed32_extension = 37; }
+	E_RepeatedFixed32Extension = &xxx_File_test_test_proto_extDescs[24]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated fixed64 repeated_fixed64_extension = 38; }
+	E_RepeatedFixed64Extension = &xxx_File_test_test_proto_extDescs[25]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated sfixed32 repeated_sfixed32_extension = 39; }
+	E_RepeatedSfixed32Extension = &xxx_File_test_test_proto_extDescs[26]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated sfixed64 repeated_sfixed64_extension = 40; }
+	E_RepeatedSfixed64Extension = &xxx_File_test_test_proto_extDescs[27]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated float repeated_float_extension = 41; }
+	E_RepeatedFloatExtension = &xxx_File_test_test_proto_extDescs[28]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated double repeated_double_extension = 42; }
+	E_RepeatedDoubleExtension = &xxx_File_test_test_proto_extDescs[29]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated bool repeated_bool_extension = 43; }
+	E_RepeatedBoolExtension = &xxx_File_test_test_proto_extDescs[30]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated string repeated_string_extension = 44; }
+	E_RepeatedStringExtension = &xxx_File_test_test_proto_extDescs[31]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated bytes repeated_bytes_extension = 45; }
+	E_RepeatedBytesExtension = &xxx_File_test_test_proto_extDescs[32]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated goproto.proto.test.RepeatedGroup_extension repeatedgroup_extension = 46; }
+	E_RepeatedgroupExtension = &xxx_File_test_test_proto_extDescs[33]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated goproto.proto.test.TestAllTypes.NestedMessage repeated_nested_message_extension = 48; }
+	E_RepeatedNestedMessageExtension = &xxx_File_test_test_proto_extDescs[34]
+
+	// extend goproto.proto.test.TestAllExtensions { repeated goproto.proto.test.TestAllTypes.NestedEnum repeated_nested_enum_extension = 51; }
+	E_RepeatedNestedEnumExtension = &xxx_File_test_test_proto_extDescs[35]
+
+	// extend goproto.proto.test.TestAllExtensions { optional string nested_string_extension = 1003; }
+	E_TestNestedExtension_NestedStringExtension = &xxx_File_test_test_proto_extDescs[36]
+)
 
 func init() {
 	proto.RegisterFile("test/test.proto", xxx_File_test_test_proto_rawdesc_gzipped)
@@ -2884,6 +2962,7 @@ func xxx_File_test_test_proto_init() {
 		RawDescriptor:        xxx_File_test_test_proto_rawdesc,
 		GoTypes:              xxx_File_test_test_proto_goTypes,
 		DependencyIndexes:    xxx_File_test_test_proto_depIdxs,
+		LegacyExtensions:     xxx_File_test_test_proto_extDescs,
 		EnumOutputTypes:      xxx_File_test_test_proto_enumTypes,
 		MessageOutputTypes:   messageTypes,
 		ExtensionOutputTypes: extensionTypes,
@@ -2893,43 +2972,6 @@ func xxx_File_test_test_proto_init() {
 		xxx_File_test_test_proto_messageTypes[i].GoType = reflect.TypeOf(messageGoTypes[i])
 		xxx_File_test_test_proto_messageTypes[i].PBType = mt
 	}
-	E_OptionalInt32Extension.Type = extensionTypes[0]
-	E_OptionalInt64Extension.Type = extensionTypes[1]
-	E_OptionalUint32Extension.Type = extensionTypes[2]
-	E_OptionalUint64Extension.Type = extensionTypes[3]
-	E_OptionalSint32Extension.Type = extensionTypes[4]
-	E_OptionalSint64Extension.Type = extensionTypes[5]
-	E_OptionalFixed32Extension.Type = extensionTypes[6]
-	E_OptionalFixed64Extension.Type = extensionTypes[7]
-	E_OptionalSfixed32Extension.Type = extensionTypes[8]
-	E_OptionalSfixed64Extension.Type = extensionTypes[9]
-	E_OptionalFloatExtension.Type = extensionTypes[10]
-	E_OptionalDoubleExtension.Type = extensionTypes[11]
-	E_OptionalBoolExtension.Type = extensionTypes[12]
-	E_OptionalStringExtension.Type = extensionTypes[13]
-	E_OptionalBytesExtension.Type = extensionTypes[14]
-	E_OptionalgroupExtension.Type = extensionTypes[15]
-	E_OptionalNestedMessageExtension.Type = extensionTypes[16]
-	E_OptionalNestedEnumExtension.Type = extensionTypes[17]
-	E_RepeatedInt32Extension.Type = extensionTypes[18]
-	E_RepeatedInt64Extension.Type = extensionTypes[19]
-	E_RepeatedUint32Extension.Type = extensionTypes[20]
-	E_RepeatedUint64Extension.Type = extensionTypes[21]
-	E_RepeatedSint32Extension.Type = extensionTypes[22]
-	E_RepeatedSint64Extension.Type = extensionTypes[23]
-	E_RepeatedFixed32Extension.Type = extensionTypes[24]
-	E_RepeatedFixed64Extension.Type = extensionTypes[25]
-	E_RepeatedSfixed32Extension.Type = extensionTypes[26]
-	E_RepeatedSfixed64Extension.Type = extensionTypes[27]
-	E_RepeatedFloatExtension.Type = extensionTypes[28]
-	E_RepeatedDoubleExtension.Type = extensionTypes[29]
-	E_RepeatedBoolExtension.Type = extensionTypes[30]
-	E_RepeatedStringExtension.Type = extensionTypes[31]
-	E_RepeatedBytesExtension.Type = extensionTypes[32]
-	E_RepeatedgroupExtension.Type = extensionTypes[33]
-	E_RepeatedNestedMessageExtension.Type = extensionTypes[34]
-	E_RepeatedNestedEnumExtension.Type = extensionTypes[35]
-	E_TestNestedExtension_NestedStringExtension.Type = extensionTypes[36]
 	xxx_File_test_test_proto_goTypes = nil
 	xxx_File_test_test_proto_depIdxs = nil
 }

reflect/protoregistry/testprotos/test.pb.go

@@ -302,59 +302,75 @@ func (m *Message4) GetBoolField() bool {
 	return false
 }
 
-var E_StringField = &proto.ExtensionDesc{
-	ExtendedType:  (*Message1)(nil),
-	ExtensionType: (*string)(nil),
-	Field:         11,
-	Name:          "testprotos.string_field",
-	Tag:           "bytes,11,opt,name=string_field",
-	Filename:      "test.proto",
-}
-
-var E_EnumField = &proto.ExtensionDesc{
-	ExtendedType:  (*Message1)(nil),
-	ExtensionType: (*Enum1)(nil),
-	Field:         12,
-	Name:          "testprotos.enum_field",
-	Tag:           "varint,12,opt,name=enum_field,enum=testprotos.Enum1",
-	Filename:      "test.proto",
-}
-
-var E_MessageField = &proto.ExtensionDesc{
-	ExtendedType:  (*Message1)(nil),
-	ExtensionType: (*Message2)(nil),
-	Field:         13,
-	Name:          "testprotos.message_field",
-	Tag:           "bytes,13,opt,name=message_field",
-	Filename:      "test.proto",
-}
-
-var E_Message4_MessageField = &proto.ExtensionDesc{
-	ExtendedType:  (*Message1)(nil),
-	ExtensionType: (*Message2)(nil),
-	Field:         21,
-	Name:          "testprotos.Message4.message_field",
-	Tag:           "bytes,21,opt,name=message_field",
-	Filename:      "test.proto",
-}
-
-var E_Message4_EnumField = &proto.ExtensionDesc{
-	ExtendedType:  (*Message1)(nil),
-	ExtensionType: (*Enum1)(nil),
-	Field:         22,
-	Name:          "testprotos.Message4.enum_field",
-	Tag:           "varint,22,opt,name=enum_field,enum=testprotos.Enum1",
-	Filename:      "test.proto",
-}
-
-var E_Message4_StringField = &proto.ExtensionDesc{
-	ExtendedType:  (*Message1)(nil),
-	ExtensionType: (*string)(nil),
-	Field:         23,
-	Name:          "testprotos.Message4.string_field",
-	Tag:           "bytes,23,opt,name=string_field",
-	Filename:      "test.proto",
-}
+var xxx_File_test_proto_extDescs = []proto.ExtensionDesc{
+	{
+		ExtendedType:  (*Message1)(nil),
+		ExtensionType: (*string)(nil),
+		Field:         11,
+		Name:          "testprotos.string_field",
+		Tag:           "bytes,11,opt,name=string_field",
+		Filename:      "test.proto",
+	},
+	{
+		ExtendedType:  (*Message1)(nil),
+		ExtensionType: (*Enum1)(nil),
+		Field:         12,
+		Name:          "testprotos.enum_field",
+		Tag:           "varint,12,opt,name=enum_field,enum=testprotos.Enum1",
+		Filename:      "test.proto",
+	},
+	{
+		ExtendedType:  (*Message1)(nil),
+		ExtensionType: (*Message2)(nil),
+		Field:         13,
+		Name:          "testprotos.message_field",
+		Tag:           "bytes,13,opt,name=message_field",
+		Filename:      "test.proto",
+	},
+	{
+		ExtendedType:  (*Message1)(nil),
+		ExtensionType: (*Message2)(nil),
+		Field:         21,
+		Name:          "testprotos.Message4.message_field",
+		Tag:           "bytes,21,opt,name=message_field",
+		Filename:      "test.proto",
+	},
+	{
+		ExtendedType:  (*Message1)(nil),
+		ExtensionType: (*Enum1)(nil),
+		Field:         22,
+		Name:          "testprotos.Message4.enum_field",
+		Tag:           "varint,22,opt,name=enum_field,enum=testprotos.Enum1",
+		Filename:      "test.proto",
+	},
+	{
+		ExtendedType:  (*Message1)(nil),
+		ExtensionType: (*string)(nil),
+		Field:         23,
+		Name:          "testprotos.Message4.string_field",
+		Tag:           "bytes,23,opt,name=string_field",
+		Filename:      "test.proto",
+	},
+}
+var (
+	// extend testprotos.Message1 { optional string string_field = 11; }
+	E_StringField = &xxx_File_test_proto_extDescs[0]
+
+	// extend testprotos.Message1 { optional testprotos.Enum1 enum_field = 12; }
+	E_EnumField = &xxx_File_test_proto_extDescs[1]
+
+	// extend testprotos.Message1 { optional testprotos.Message2 message_field = 13; }
+	E_MessageField = &xxx_File_test_proto_extDescs[2]
+
+	// extend testprotos.Message1 { optional testprotos.Message2 message_field = 21; }
+	E_Message4_MessageField = &xxx_File_test_proto_extDescs[3]
+
+	// extend testprotos.Message1 { optional testprotos.Enum1 enum_field = 22; }
+	E_Message4_EnumField = &xxx_File_test_proto_extDescs[4]
+
+	// extend testprotos.Message1 { optional string string_field = 23; }
+	E_Message4_StringField = &xxx_File_test_proto_extDescs[5]
+)
 
 func init() {
 	proto.RegisterFile("test.proto", xxx_File_test_proto_rawdesc_gzipped)
@@ -459,6 +475,7 @@ func xxx_File_test_proto_init() {
 		RawDescriptor:        xxx_File_test_proto_rawdesc,
 		GoTypes:              xxx_File_test_proto_goTypes,
 		DependencyIndexes:    xxx_File_test_proto_depIdxs,
+		LegacyExtensions:     xxx_File_test_proto_extDescs,
 		EnumOutputTypes:      xxx_File_test_proto_enumTypes,
 		MessageOutputTypes:   messageTypes,
 		ExtensionOutputTypes: extensionTypes,
@@ -468,12 +485,6 @@ func xxx_File_test_proto_init() {
 		xxx_File_test_proto_messageTypes[i].GoType = reflect.TypeOf(messageGoTypes[i])
 		xxx_File_test_proto_messageTypes[i].PBType = mt
 	}
-	E_StringField.Type = extensionTypes[0]
-	E_EnumField.Type = extensionTypes[1]
-	E_MessageField.Type = extensionTypes[2]
-	E_Message4_MessageField.Type = extensionTypes[3]
-	E_Message4_EnumField.Type = extensionTypes[4]
-	E_Message4_StringField.Type = extensionTypes[5]
 	xxx_File_test_proto_goTypes = nil
 	xxx_File_test_proto_depIdxs = nil
 }