all: Release the Opaque API

For golang/protobuf#1657

Change-Id: I7b2b0c30506706015ce278e6054439c9ad9ef727
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/634815
TryBot-Bypass: Michael Stapelberg <[email protected]>
Reviewed-by: Joseph Tsai <[email protected]>
Reviewed-by: Damien Neil <[email protected]>

cmd/protoc-gen-go/descriptor_test/descriptor_test.go

@@ -0,0 +1,43 @@
+// Copyright 2024 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 descriptor_test
+
+import (
+	"testing"
+
+	testopenpb "google.golang.org/protobuf/internal/testprotos/test"
+	testhybridpb "google.golang.org/protobuf/internal/testprotos/testeditions/testeditions_hybrid"
+	testopaquepb "google.golang.org/protobuf/internal/testprotos/testeditions/testeditions_opaque"
+)
+
+func TestFileModeEnum(t *testing.T) {
+	var e any = testopenpb.ForeignEnum_FOREIGN_FOO
+	if _, ok := e.(interface{ EnumDescriptor() ([]byte, []int) }); !ok {
+		t.Errorf("Open V1 proto did not have deprecated method EnumDescriptor")
+	}
+	var oe any = testopaquepb.ForeignEnum_FOREIGN_FOO
+	if _, ok := oe.(interface{ EnumDescriptor() ([]byte, []int) }); ok {
+		t.Errorf("Opaque V0 proto did have deprecated method EnumDescriptor")
+	}
+	var he any = testhybridpb.ForeignEnum_FOREIGN_FOO
+	if _, ok := he.(interface{ EnumDescriptor() ([]byte, []int) }); ok {
+		t.Errorf("Hybrid proto did have deprecated method EnumDescriptor")
+	}
+}
+
+func TestFileModeMessage(t *testing.T) {
+	var p any = &testopenpb.TestAllTypes{}
+	if _, ok := p.(interface{ Descriptor() ([]byte, []int) }); !ok {
+		t.Errorf("Open V1 proto did not have deprecated method Descriptor")
+	}
+	var op any = &testopaquepb.TestAllTypes{}
+	if _, ok := op.(interface{ Descriptor() ([]byte, []int) }); ok {
+		t.Errorf("Opaque V0 mode proto unexpectedly has deprecated Descriptor() method")
+	}
+	var hp any = &testhybridpb.TestAllTypes{}
+	if _, ok := hp.(interface{ EnumDescriptor() ([]byte, []int) }); ok {
+		t.Errorf("Hybrid proto did have deprecated method EnumDescriptor")
+	}
+}

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

@@ -114,6 +114,7 @@ func newEnumInfo(f *fileInfo, enum *protogen.Enum) *enumInfo {
 	e := &enumInfo{Enum: enum}
 	e.genJSONMethod = true
 	e.genRawDescMethod = true
+	opaqueNewEnumInfoHook(f, e)
 	return e
 }
 
@@ -123,8 +124,9 @@ type messageInfo struct {
 	genRawDescMethod  bool
 	genExtRangeMethod bool
 
-	isTracked bool
-	hasWeak   bool
+	isTracked   bool
+	noInterface bool
+	hasWeak     bool
 }
 
 func newMessageInfo(f *fileInfo, message *protogen.Message) *messageInfo {
@@ -135,6 +137,7 @@ func newMessageInfo(f *fileInfo, message *protogen.Message) *messageInfo {
 	for _, field := range m.Fields {
 		m.hasWeak = m.hasWeak || field.Desc.IsWeak()
 	}
+	opaqueNewMessageInfoHook(f, m)
 	return m
 }
 

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

@@ -0,0 +1,33 @@
+// Copyright 2024 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 internal_gengo
+
+import "google.golang.org/protobuf/types/gofeaturespb"
+
+func (m *messageInfo) isOpen() bool {
+	return m.Message.APILevel == gofeaturespb.GoFeatures_API_OPEN
+}
+
+func (m *messageInfo) isHybrid() bool {
+	return m.Message.APILevel == gofeaturespb.GoFeatures_API_HYBRID
+}
+
+func (m *messageInfo) isOpaque() bool {
+	return m.Message.APILevel == gofeaturespb.GoFeatures_API_OPAQUE
+}
+
+func opaqueNewEnumInfoHook(f *fileInfo, e *enumInfo) {
+	if f.File.APILevel != gofeaturespb.GoFeatures_API_OPEN {
+		e.genJSONMethod = false
+		e.genRawDescMethod = false
+	}
+}
+
+func opaqueNewMessageInfoHook(f *fileInfo, m *messageInfo) {
+	if !m.isOpen() {
+		m.genRawDescMethod = false
+		m.genExtRangeMethod = false
+	}
+}

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

@@ -367,6 +367,9 @@ func genMessage(g *protogen.GeneratedFile, f *fileInfo, m *messageInfo) {
 	if m.Desc.IsMapEntry() {
 		return
 	}
+	if opaqueGenMessageHook(g, f, m) {
+		return
+	}
 
 	// Message type declaration.
 	g.AnnotateSymbol(m.GoIdent.GoName, protogen.Annotation{Location: m.Location})
@@ -657,7 +660,7 @@ func genMessageSetterMethods(g *protogen.GeneratedFile, f *fileInfo, m *messageI
 			continue
 		}
 
-		genNoInterfacePragma(g, m.isTracked)
+		genNoInterfacePragma(g, m.noInterface)
 
 		g.AnnotateSymbol(m.GoIdent.GoName+".Set"+field.GoName, protogen.Annotation{
 			Location: field.Location,