[csharp proto plugin] Apply Obsolete attribute to deprecated services and methods in C# generated code

src/compiler/csharp_generator.cc

@@ -100,6 +100,14 @@ void GenerateGeneratedCodeAttribute(grpc::protobuf::io::Printer* printer) {
       "null)]\n");
 }
 
+void GenerateObsoleteAttribute(grpc::protobuf::io::Printer* printer,
+                               bool is_deprecated) {
+  // Mark the code deprecated using the [ObsoleteAttribute] attribute.
+  if (is_deprecated) {
+    printer->Print("[global::System.ObsoleteAttribute]\n");
+  }
+}
+
 template <typename DescriptorType>
 bool GenerateDocCommentBody(grpc::protobuf::io::Printer* printer,
                             const DescriptorType* descriptor) {
@@ -439,6 +447,7 @@ void GenerateServerClass(Printer* out, const ServiceDescriptor* service) {
       "/// <summary>Base class for server-side implementations of "
       "$servicename$</summary>\n",
       "servicename", GetServiceClassName(service));
+  GenerateObsoleteAttribute(out, service->options().deprecated());
   out->Print(
       "[grpc::BindServiceMethod(typeof($classname$), "
       "\"BindService\")]\n",
@@ -450,6 +459,7 @@ void GenerateServerClass(Printer* out, const ServiceDescriptor* service) {
   for (int i = 0; i < service->method_count(); i++) {
     const MethodDescriptor* method = service->method(i);
     GenerateDocCommentServerMethod(out, method);
+    GenerateObsoleteAttribute(out, method->options().deprecated());
     GenerateGeneratedCodeAttribute(out);
     out->Print(
         "public virtual $returntype$ "
@@ -475,6 +485,7 @@ void GenerateServerClass(Printer* out, const ServiceDescriptor* service) {
 void GenerateClientStub(Printer* out, const ServiceDescriptor* service) {
   out->Print("/// <summary>Client for $servicename$</summary>\n", "servicename",
              GetServiceClassName(service));
+  GenerateObsoleteAttribute(out, service->options().deprecated());
   out->Print("public partial class $name$ : grpc::ClientBase<$name$>\n", "name",
              GetClientClassName(service));
   out->Print("{\n");
@@ -525,9 +536,11 @@ void GenerateClientStub(Printer* out, const ServiceDescriptor* service) {
 
   for (int i = 0; i < service->method_count(); i++) {
     const MethodDescriptor* method = service->method(i);
+    const bool is_deprecated = method->options().deprecated();
     if (!method->client_streaming() && !method->server_streaming()) {
       // unary calls have an extra synchronous stub method
       GenerateDocCommentClientMethod(out, method, true, false);
+      GenerateObsoleteAttribute(out, is_deprecated);
       GenerateGeneratedCodeAttribute(out);
       out->Print(
           "public virtual $response$ $methodname$($request$ request, "
@@ -551,6 +564,7 @@ void GenerateClientStub(Printer* out, const ServiceDescriptor* service) {
 
       // overload taking CallOptions as a param
       GenerateDocCommentClientMethod(out, method, true, true);
+      GenerateObsoleteAttribute(out, is_deprecated);
       GenerateGeneratedCodeAttribute(out);
       out->Print(
           "public virtual $response$ $methodname$($request$ request, "
@@ -573,6 +587,7 @@ void GenerateClientStub(Printer* out, const ServiceDescriptor* service) {
       method_name += "Async";  // prevent name clash with synchronous method.
     }
     GenerateDocCommentClientMethod(out, method, false, false);
+    GenerateObsoleteAttribute(out, is_deprecated);
     GenerateGeneratedCodeAttribute(out);
     out->Print(
         "public virtual $returntype$ "
@@ -598,6 +613,7 @@ void GenerateClientStub(Printer* out, const ServiceDescriptor* service) {
 
     // overload taking CallOptions as a param
     GenerateDocCommentClientMethod(out, method, false, true);
+    GenerateObsoleteAttribute(out, is_deprecated);
     GenerateGeneratedCodeAttribute(out);
     out->Print(
         "public virtual $returntype$ "
@@ -739,6 +755,7 @@ void GenerateService(Printer* out, const ServiceDescriptor* service,
                      bool internal_access) {
   GenerateDocCommentBody(out, service);
 
+  GenerateObsoleteAttribute(out, service->options().deprecated());
   out->Print("$access_level$ static partial class $classname$\n",
              "access_level", GetAccessLevel(internal_access), "classname",
              GetServiceClassName(service));
@@ -801,7 +818,7 @@ std::string GetServices(const FileDescriptor* file, bool generate_client,
       out.PrintRaw(leading_comments.c_str());
     }
 
-    out.Print("#pragma warning disable 0414, 1591, 8981\n");
+    out.Print("#pragma warning disable 0414, 1591, 8981, 0612\n");
 
     out.Print("#region Designer generated code\n");
     out.Print("\n");

test/csharp/codegen/BUILD

@@ -18,6 +18,7 @@ licenses(["notice"])
 
 grpc_sh_test(
     name = "csharp_codegen_simple_test",
+    size = "small",
     srcs = ["csharp_codegen_simple_test.sh"],
     data = [
         "simple/expected/HelloworldGrpc.cs",
@@ -34,3 +35,24 @@ grpc_sh_test(
     ],
     uses_polling = False,
 )
+
+grpc_sh_test(
+    name = "csharp_codegen_deprecated_test",
+    size = "small",
+    srcs = ["csharp_codegen_deprecated_test.sh"],
+    data = [
+        "deprecated/proto/depmethod.proto",
+        "deprecated/proto/depnothing.proto",
+        "deprecated/proto/depservice.proto",
+        "//src/compiler:grpc_csharp_plugin",
+        "@com_google_protobuf//:protoc",
+    ],
+    tags = [
+        "no_windows",
+        "noasan",
+        "nomsan",
+        "notsan",
+        "noubsan",
+    ],
+    uses_polling = False,
+)

test/csharp/codegen/csharp_codegen_deprecated_test.sh

@@ -0,0 +1,115 @@
+#!/bin/bash
+# Copyright 2023 gRPC authors.
+#
+# 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.
+
+# Run this script via bazel test
+# It expects that protoc and grpc_csharp_plugin have already been built.
+
+# Simple test - compare generated output to expected files
+
+set -x
+
+TESTNAME=deprecated
+
+# protoc and grpc_csharp_plugin binaries are supplied as "data" in bazel
+PROTOC=./external/com_google_protobuf/protoc
+PLUGIN=./src/compiler/grpc_csharp_plugin
+
+# where to find the test data
+DATA_DIR=./test/csharp/codegen/${TESTNAME}
+
+# output directory for the generated files
+PROTO_OUT=./proto_out
+rm -rf ${PROTO_OUT}
+mkdir -p ${PROTO_OUT}
+
+# run protoc and the plugin
+$PROTOC \
+    --plugin=protoc-gen-grpc=$PLUGIN \
+    --csharp_out=${PROTO_OUT} \
+    --grpc_out=${PROTO_OUT} \
+    -I ${DATA_DIR}/proto \
+    ${DATA_DIR}/proto/depnothing.proto \
+    ${DATA_DIR}/proto/depservice.proto \
+    ${DATA_DIR}/proto/depmethod.proto
+
+# log the files generated
+ls -l ./proto_out
+
+# Rather than doing a diff against a known file, just using grep to
+# check for some of the code changes when "deprecated" is specified.
+# This isn't bullet proof but does avoid tests breaking when other
+# codegen changes are made.
+
+# For depnothing.proto there should zero "ObsoleteAttribute" found
+nmatches=$(grep -c ObsoleteAttribute ${PROTO_OUT}/DepnothingGrpc.cs)
+if [ "$nmatches" -ne 0 ]
+then
+    echo >&2 "Unexpected ObsoleteAttribute in DepnothingGrpc.cs"
+    exit 1
+fi
+
+# For depservice.proto need to check ObsoleteAttribute added to three classes.
+# First check ObsoleteAttribute exists in output
+nmatches=$(grep -c ObsoleteAttribute ${PROTO_OUT}/DepserviceGrpc.cs)
+if [ "$nmatches" -eq 0 ]
+then
+    echo >&2 "Missing ObsoleteAttribute in DepserviceGrpc.cs"
+    exit 1
+fi
+
+# capture context after ObsoleteAttribute for further checking
+CTX=$(grep -A 2 ObsoleteAttribute ${PROTO_OUT}/DepserviceGrpc.cs)
+
+# Check ObsoleteAttribute before class GreeterServiceLevelDep
+nmatches=$(echo "$CTX" | grep -c "class GreeterServiceLevelDep$" )
+if [ "$nmatches" -ne 1 ]
+then
+    echo >&2 "Missing ObsoleteAttribute on class GreeterServiceLevelDep"
+    exit 1
+fi
+# Check ObsoleteAttribute before class GreeterServiceLevelDepBase
+nmatches=$(echo "$CTX" | grep -c "class GreeterServiceLevelDepBase$" )
+if [ "$nmatches" -ne 1 ]
+then
+    echo >&2 "Missing ObsoleteAttribute on class GreeterServiceLevelDepBase"
+    exit 1
+fi
+# Check ObsoleteAttribute before class GreeterServiceLevelDepClient
+nmatches=$(echo "$CTX" | grep -c "class GreeterServiceLevelDepClient" )
+if [ "$nmatches" -ne 1 ]
+then
+    echo >&2 "Missing ObsoleteAttribute on class GreeterServiceLevelDepClient"
+    exit 1
+fi
+
+# For depmethod.proto need to check ObsoleteAttribute added in five places for SayHello method.
+# Check ObsoleteAttribute exists in output
+nmatches=$(grep -c ObsoleteAttribute ${PROTO_OUT}/DepmethodGrpc.cs)
+if [ "$nmatches" -eq 0 ]
+then
+    echo >&2 "Missing ObsoleteAttribute in DepmethodGrpc.cs"
+    exit 1
+fi
+# Check ObsoleteAttribute before SayHello methods
+nmatches=$(grep -A 2 ObsoleteAttribute ${PROTO_OUT}/DepmethodGrpc.cs | grep -c SayHello)
+if [ "$nmatches" -ne 5 ]
+then
+    echo >&2 "Missing ObsoleteAttribute on SayHello method"
+    exit 1
+fi
+
+# Run one extra command to clear $? before exiting the script to prevent
+# failing even when tests pass.
+echo "Plugin test: ${TESTNAME}: passed."

test/csharp/codegen/deprecated/proto/depmethod.proto

@@ -0,0 +1,38 @@
+// Copyright 2023 gRPC authors.
+//
+// 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.
+
+syntax = "proto3";
+
+package test.csharp.codegen.simple.proto.depmethod;
+
+// Service with method deprecation
+service GreeterMethodLevelDep {
+  // Sends a greeting - method is deprecated
+  rpc SayHello (HelloRequest) returns (HelloReply) {
+      option deprecated = true; // method level option
+  }
+
+  rpc SayHelloStreamReply (HelloRequest) returns (stream HelloReply) {}
+}
+
+// The request message containing the user's name.
+message HelloRequest {
+  string name = 1;
+}
+
+// The response message containing the greetings
+message HelloReply {
+  string message = 1;
+}
+

test/csharp/codegen/deprecated/proto/depnothing.proto

@@ -0,0 +1,36 @@
+// Copyright 2023 gRPC authors.
+//
+// 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.
+
+syntax = "proto3";
+
+package test.csharp.codegen.simple.proto.depnothing;
+
+// The greeting service definition - with nothing deprecated
+service Greeter {
+  // Sends a greeting
+  rpc SayHello (HelloRequest) returns (HelloReply) {}
+
+  rpc SayHelloStreamReply (HelloRequest) returns (stream HelloReply) {}
+}
+
+// The request message containing the user's name.
+message HelloRequest {
+  string name = 1;
+}
+
+// The response message containing the greetings
+message HelloReply {
+  string message = 1;
+}
+

test/csharp/codegen/deprecated/proto/depservice.proto

@@ -0,0 +1,37 @@
+// Copyright 2023 gRPC authors.
+//
+// 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.
+
+syntax = "proto3";
+
+package test.csharp.codegen.simple.proto.depservice;
+
+// Service with service-level deprecation
+service GreeterServiceLevelDep {
+  option deprecated = true; // service level option
+  // Sends a greeting
+  rpc SayHello (HelloRequest) returns (HelloReply) {}
+
+  rpc SayHelloStreamReply (HelloRequest) returns (stream HelloReply) {}
+}
+
+// The request message containing the user's name.
+message HelloRequest {
+  string name = 1;
+}
+
+// The response message containing the greetings
+message HelloReply {
+  string message = 1;
+}
+

test/csharp/codegen/simple/expected/HelloworldGrpc.cs

@@ -17,7 +17,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 //
-#pragma warning disable 0414, 1591, 8981
+#pragma warning disable 0414, 1591, 8981, 0612
 #region Designer generated code
 
 using grpc = global::Grpc.Core;