Add features files to the set of standard imports

Makefile

@@ -82,7 +82,7 @@ lintfix: $(BIN)/golangci-lint ## Automatically fix some lint errors
 	cd internal/benchmarks && $(BIN)/golangci-lint run --fix
 
 .PHONY: generate
-generate: $(BIN)/license-header $(BIN)/goyacc test-descriptors ## Regenerate code and licenses
+generate: $(BIN)/license-header $(BIN)/goyacc test-descriptors ext-features-descriptors ## Regenerate code and licenses
 	PATH="$(BIN)$(PATH_SEP)$(PATH)" $(GO) generate ./...
 	@# We want to operate on a list of modified and new files, excluding
 	@# deleted and ignored files. git-ls-files can't do this alone. comm -23 takes
@@ -183,3 +183,11 @@ test-descriptors: internal/testdata/options/options.protoset
 test-descriptors: internal/testdata/options/test.protoset
 test-descriptors: internal/testdata/options/test_proto3.protoset
 test-descriptors: internal/testdata/options/test_editions.protoset
+
+internal/featuresext/cpp_features.protoset: $(PROTOC)
+	cd $(@D) && $(PROTOC) --experimental_editions --descriptor_set_out=$(@F) google/protobuf/cpp_features.proto
+internal/featuresext/java_features.protoset: $(PROTOC)
+	cd $(@D) && $(PROTOC) --experimental_editions --descriptor_set_out=$(@F) google/protobuf/java_features.proto
+
+.PHONY: ext-features-descriptors
+ext-features-descriptors: internal/featuresext/cpp_features.protoset internal/featuresext/java_features.protoset

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/google/go-cmp v0.6.0
 	github.com/stretchr/testify v1.9.0
 	golang.org/x/sync v0.7.0
-	google.golang.org/protobuf v1.33.1-0.20240408130810-98873a205002
+	google.golang.org/protobuf v1.33.1-0.20240422163739-e4ad8f9dfc8b
 )
 
 require (

go.sum

@@ -10,6 +10,8 @@ golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
 golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 google.golang.org/protobuf v1.33.1-0.20240408130810-98873a205002 h1:V7Da7qt0MkY3noVANIMVBk28nOnijADeOR3i5Hcvpj4=
 google.golang.org/protobuf v1.33.1-0.20240408130810-98873a205002/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
+google.golang.org/protobuf v1.33.1-0.20240422163739-e4ad8f9dfc8b h1:LtLYFcFBR7ZbrgFuP9p4Za5dPr/velw2v5t9Z9HFPiQ=
+google.golang.org/protobuf v1.33.1-0.20240422163739-e4ad8f9dfc8b/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

internal/featuresext/cpp_features.protoset

@@ -0,0 +1,7 @@
+
+ì

+"google/protobuf/cpp_features.protopb google/protobuf/descriptor.proto"_
+CppFeaturesP
+legacy_closed_enum
 
(B"ˆ

˜
˜

¢
	trueæ¢

+falseçRlegacyClosedEnum:?
+cpp.google.protobuf.FeatureSetè 
(2.pb.CppFeaturesRcpp

internal/featuresext/featuresext.go

@@ -0,0 +1,84 @@
+// Copyright 2020-2024 Buf Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package featuresext provides file descriptors for the
+// "google/protobuf/cpp_features.proto" and "google/protobuf/java_features.proto"
+// standard import files. Unlike the other standard/well-known
+// imports, these files have no standard Go package in their
+// runtime with generated code. So in order to make them available
+// as "standard imports" to compiler users, we must embed these
+// descriptors into a Go package.
+package featuresext
+
+import (
+	_ "embed"
+	"fmt"
+	"sync"
+
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protodesc"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/reflect/protoregistry"
+	"google.golang.org/protobuf/types/descriptorpb"
+)
+
+var (
+	//go:embed cpp_features.protoset
+	cppFeatures []byte
+
+	//go:embed java_features.protoset
+	javaFeatures []byte
+
+	initOnce         sync.Once
+	initCppFeatures  protoreflect.FileDescriptor
+	initCppErr       error
+	initJavaFeatures protoreflect.FileDescriptor
+	initJavaErr      error
+)
+
+func initDescriptors() {
+	initOnce.Do(func() {
+		initCppFeatures, initCppErr = buildDescriptor("google/protobuf/cpp_features.proto", cppFeatures)
+		initJavaFeatures, initJavaErr = buildDescriptor("google/protobuf/java_features.proto", javaFeatures)
+	})
+}
+
+func CppFeaturesDescriptor() (protoreflect.FileDescriptor, error) {
+	initDescriptors()
+	return initCppFeatures, initCppErr
+}
+
+func JavaFeaturesDescriptor() (protoreflect.FileDescriptor, error) {
+	initDescriptors()
+	return initJavaFeatures, initJavaErr
+}
+
+func buildDescriptor(name string, data []byte) (protoreflect.FileDescriptor, error) {
+	var files descriptorpb.FileDescriptorSet
+	err := proto.Unmarshal(data, &files)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load descriptor for %q: %w", name, err)
+	}
+	if len(files.File) != 1 {
+		return nil, fmt.Errorf("failed to load descriptor for %q: expected embedded descriptor set to contain exactly one file but it instead has %d", name, len(files.File))
+	}
+	if files.File[0].GetName() != name {
+		return nil, fmt.Errorf("failed to load descriptor for %q: embedded descriptor contains wrong file %q", name, files.File[0].GetName())
+	}
+	descriptor, err := protodesc.NewFile(files.File[0], protoregistry.GlobalFiles)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load descriptor for %q: %w", name, err)
+	}
+	return descriptor, nil
+}

internal/featuresext/featuresext_test.go

@@ -0,0 +1,37 @@
+// Copyright 2020-2024 Buf Technologies, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package featuresext
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"google.golang.org/protobuf/reflect/protoreflect"
+)
+
+func TestFeaturesExt(t *testing.T) {
+	t.Parallel()
+
+	file, err := CppFeaturesDescriptor()
+	require.NoError(t, err)
+	assert.Equal(t, protoreflect.FullName("pb"), file.Package())
+	assert.NotNil(t, file.Extensions().ByName("cpp"))
+
+	file, err = JavaFeaturesDescriptor()
+	require.NoError(t, err)
+	assert.Equal(t, protoreflect.FullName("pb"), file.Package())
+	assert.NotNil(t, file.Extensions().ByName("java"))
+}

std_imports.go

@@ -17,7 +17,8 @@ package protocompile
 import (
 	"google.golang.org/protobuf/reflect/protoreflect"
 	"google.golang.org/protobuf/reflect/protoregistry"
-	_ "google.golang.org/protobuf/types/known/anypb" // link in packages that include the standard protos included with protoc.
+	_ "google.golang.org/protobuf/types/gofeaturespb" // link in packages that include the standard protos included with protoc.
+	_ "google.golang.org/protobuf/types/known/anypb"
 	_ "google.golang.org/protobuf/types/known/apipb"
 	_ "google.golang.org/protobuf/types/known/durationpb"
 	_ "google.golang.org/protobuf/types/known/emptypb"
@@ -28,6 +29,8 @@ import (
 	_ "google.golang.org/protobuf/types/known/typepb"
 	_ "google.golang.org/protobuf/types/known/wrapperspb"
 	_ "google.golang.org/protobuf/types/pluginpb"
+
+	"github.com/bufbuild/protocompile/internal/featuresext"
 )
 
 // All files that are included with protoc are also included with this package
@@ -44,6 +47,7 @@ func init() {
 		"google/protobuf/duration.proto",
 		"google/protobuf/empty.proto",
 		"google/protobuf/field_mask.proto",
+		"google/protobuf/go_features.proto",
 		"google/protobuf/source_context.proto",
 		"google/protobuf/struct.proto",
 		"google/protobuf/timestamp.proto",
@@ -59,4 +63,34 @@ func init() {
 		}
 		standardImports[fn] = fd
 	}
+
+	otherFeatures := []struct {
+		Name          string
+		GetDescriptor func() (protoreflect.FileDescriptor, error)
+	}{
+		{
+			Name:          "google/protobuf/cpp_features.proto",
+			GetDescriptor: featuresext.CppFeaturesDescriptor,
+		},
+		{
+			Name:          "google/protobuf/java_features.proto",
+			GetDescriptor: featuresext.JavaFeaturesDescriptor,
+		},
+	}
+	for _, feature := range otherFeatures {
+		// First see if the program has generated Go code for this
+		// file linked in:
+		fd, err := protoregistry.GlobalFiles.FindFileByPath(feature.Name)
+		if err == nil {
+			standardImports[feature.Name] = fd
+			continue
+		}
+		fd, err = feature.GetDescriptor()
+		if err != nil {
+			// For these extensions to FeatureSet, we are lenient. If
+			// we can't load them, just ignore them.
+			continue
+		}
+		standardImports[feature.Name] = fd
+	}
 }

std_imports_test.go

@@ -29,6 +29,7 @@ func TestStdImports(t *testing.T) {
 	c := Compiler{Resolver: WithStandardImports(&SourceResolver{})}
 	ctx := context.Background()
 	for name, fileProto := range standardImports {
+		t.Log(name)
 		fds, err := c.Compile(ctx, name)
 		if err != nil {
 			t.Errorf("failed to compile %q: %v", name, err)