feat(cmd/gen): add flag use_separate_service_package

#8233

Author: qianlongzt

cmd/protoc-gen-go-grpc/grpc.go

@@ -136,8 +136,13 @@ func generateFile(gen *protogen.Plugin, file *protogen.File) *protogen.Generated
 	if len(file.Services) == 0 {
 		return nil
 	}
+
+	importPath := file.GoImportPath
+	if *useSeparateServicePackage {
+		importPath = file.GoImportPath + "_" + protogen.GoImportPath("grpc")
+	}
 	filename := file.GeneratedFilenamePrefix + "_grpc.pb.go"
-	g := gen.NewGeneratedFile(filename, file.GoImportPath)
+	g := gen.NewGeneratedFile(filename, importPath)
 	// Attach all comments associated with the syntax field.
 	genLeadingComments(g, file.Desc.SourceLocations().ByPath(protoreflect.SourcePath{fileDescriptorProtoSyntaxFieldNumber}))
 	g.P("// Code generated by protoc-gen-go-grpc. DO NOT EDIT.")

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

@@ -44,8 +44,11 @@ import (
 
 const version = "1.5.1"
 
-var requireUnimplemented *bool
-var useGenericStreams *bool
+var (
+	requireUnimplemented      *bool
+	useGenericStreams         *bool
+	useSeparateServicePackage *bool
+)
 
 func main() {
 	showVersion := flag.Bool("version", false, "print the version and exit")
@@ -58,6 +61,7 @@ func main() {
 	var flags flag.FlagSet
 	requireUnimplemented = flags.Bool("require_unimplemented_servers", true, "set to false to match legacy behavior")
 	useGenericStreams = flags.Bool("use_generic_streams_experimental", true, "set to true to use generic types for streaming client and server objects; this flag is EXPERIMENTAL and may be changed or removed in a future release")
+	useSeparateServicePackage = flags.Bool("use_separate_service_package", false, "set to true to use separate service package, service package will import protobuf package")
 
 	protogen.Options{
 		ParamFunc: flags.Set,

cmd/protoc-gen-go-grpc/protoc-gen-go-grpc_test.sh

@@ -47,4 +47,20 @@ if [[ -n "${DIFF}" ]]; then
     exit 1
 fi
 
+# test use separate service package
+protoc \
+    --go-grpc_out="${TEMPDIR}" \
+    --go-grpc_opt=paths=source_relative,use_separate_service_package=true \
+    "examples/route_guide/routeguide/route_guide.proto"
+
+# grep is piped to [[ $? == 1 ]] to avoid exiting on grep but exit on error
+# (like if the file was not found). See man grep for more info.
+GREP=$(grep 'routeguide "google.golang.org/grpc/examples/route_guide/routeguide"' \
+    "${TEMPDIR}/examples/route_guide/routeguide/route_guide_grpc.pb.go" || [[ $? == 1 ]])
+
+if [[ -z "${GREP}" ]]; then
+    echo -e "ERROR: Generated file not import routeguide package\n"
+    exit 1
+fi
+
 echo SUCCESS