internal/impl: move filetype.EnumInfo to impl

Change-Id: I5558d9d4618df80dd08969fb8af1bc16191176b5
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/195620
Reviewed-by: Damien Neil <dneil@google.com>

internal/filetype/build.go

@@ -90,15 +90,15 @@ type Builder struct {
 	// is appended to the end in reverse order.
 	DependencyIndexes []int32
 
+	// EnumInfos is a list of enum infos in "flattened ordering".
+	EnumInfos []pimpl.EnumInfo
+
 	// MessageInfos is a list of message infos in "flattened ordering".
 	// If provided, the GoType and PBType for each element is populated.
 	//
 	// Requirement: len(MessageInfos) == len(Build.Messages)
 	MessageInfos []pimpl.MessageInfo
 
-	// EnumInfos is a list of enum infos in "flattened ordering".
-	EnumInfos []EnumInfo
-
 	// ExtensionInfos is a list of extension infos in "flattened ordering".
 	// Each element is initialized and registered with the protoregistry package.
 	//
@@ -144,9 +144,9 @@ func (tb Builder) Build() (out Out) {
 	}
 	if len(fbOut.Enums) > 0 {
 		for i := range fbOut.Enums {
-			tb.EnumInfos[i] = EnumInfo{
+			tb.EnumInfos[i] = pimpl.EnumInfo{
-				desc:   &fbOut.Enums[i],
+				GoReflectType: reflect.TypeOf(enumGoTypes[i]),
-				goType: reflect.TypeOf(enumGoTypes[i]),
+				Desc:          &fbOut.Enums[i],
 			}
 			// Register enum types.
 			if err := tb.TypeRegistry.Register(&tb.EnumInfos[i]); err != nil {
@@ -293,20 +293,3 @@ func (r *resolverByIndex) FindMessageByIndex(i, j int32, es []fdesc.Enum, ms []f
 		return pimpl.Export{}.MessageDescriptorOf(r.goTypes[depIdx])
 	}
 }
-
-type EnumInfo struct {
-	desc   pref.EnumDescriptor
-	goType reflect.Type
-}
-
-func (t *EnumInfo) New(n pref.EnumNumber) pref.Enum {
-	return reflect.ValueOf(n).Convert(t.goType).Interface().(pref.Enum)
-}
-func (t *EnumInfo) GoType() reflect.Type            { return t.goType }
-func (t *EnumInfo) Descriptor() pref.EnumDescriptor { return t.desc }
-
-func messageMaker(t reflect.Type) func() pref.Message {
-	return func() pref.Message {
-		return reflect.New(t.Elem()).Interface().(pref.ProtoMessage).ProtoReflect()
-	}
-}

internal/impl/enum.go

@@ -0,0 +1,22 @@
+// Copyright 2019 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package impl
+
+import (
+	"reflect"
+
+	pref "google.golang.org/protobuf/reflect/protoreflect"
+)
+
+type EnumInfo struct {
+	GoReflectType reflect.Type // int32 kind
+	Desc          pref.EnumDescriptor
+}
+
+func (t *EnumInfo) New(n pref.EnumNumber) pref.Enum {
+	return reflect.ValueOf(n).Convert(t.GoReflectType).Interface().(pref.Enum)
+}
+func (t *EnumInfo) GoType() reflect.Type            { return t.GoReflectType }
+func (t *EnumInfo) Descriptor() pref.EnumDescriptor { return t.Desc }

internal/impl/enum_test.go

@@ -2,14 +2,15 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package filetype_test
+package impl_test
 
 import (
 	"reflect"
 	"testing"
 
-	testpb "google.golang.org/protobuf/internal/testprotos/test"
 	pref "google.golang.org/protobuf/reflect/protoreflect"
+
+	testpb "google.golang.org/protobuf/internal/testprotos/test"
 )
 
 func TestEnum(t *testing.T) {

runtime/protoimpl/impl.go

@@ -26,7 +26,7 @@ type (
 	TypeBuilder = filetype.Builder
 
 	// Types used by generated code to implement EnumType, MessageType, and ExtensionType.
-	EnumInfo      = filetype.EnumInfo
+	EnumInfo      = impl.EnumInfo
 	MessageInfo   = impl.MessageInfo
 	ExtensionInfo = impl.ExtensionInfo