impl(generator): handle deprecated services

generator/integration_tests/BUILD.bazel

@@ -30,6 +30,7 @@ proto_library(
         "common.proto",
         "test.proto",
         "test2.proto",
+        "test_deprecated.proto",
         "test_request_id.proto",
     ],
     deps = [

generator/integration_tests/CMakeLists.txt

@@ -31,6 +31,7 @@ google_cloud_cpp_grpcpp_library(
     ${PROJECT_SOURCE_DIR}/generator/integration_tests/test.proto
     ${PROJECT_SOURCE_DIR}/generator/integration_tests/test2.proto
     ${PROJECT_SOURCE_DIR}/generator/integration_tests/test_request_id.proto
+    ${PROJECT_SOURCE_DIR}/generator/integration_tests/test_deprecated.proto
     PROTO_PATH_DIRECTORIES
     ${PROTO_INCLUDE_DIR}
     ${PROJECT_SOURCE_DIR}

generator/integration_tests/golden/v1/deprecated_client.cc

@@ -0,0 +1,45 @@
+// Copyright 2024 Google LLC
+//
+// 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
+//
+//      https://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.
+
+// Generated by the Codegen C++ plugin.
+// If you make any local changes, they will be lost.
+// source: generator/integration_tests/test_deprecated.proto
+
+#include "google/cloud/internal/disable_deprecation_warnings.inc"
+#include "generator/integration_tests/golden/v1/deprecated_client.h"
+#include <memory>
+#include <utility>
+
+namespace google {
+namespace cloud {
+namespace golden_v1 {
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
+
+DeprecatedServiceClient::DeprecatedServiceClient(
+    std::shared_ptr<DeprecatedServiceConnection> connection, Options opts)
+    : connection_(std::move(connection)),
+      options_(internal::MergeOptions(std::move(opts),
+      connection_->options())) {}
+DeprecatedServiceClient::~DeprecatedServiceClient() = default;
+
+Status
+DeprecatedServiceClient::Noop(google::test::deprecated::v1::DeprecatedServiceRequest const& request, Options opts) {
+  internal::OptionsSpan span(internal::MergeOptions(std::move(opts), options_));
+  return connection_->Noop(request);
+}
+
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_END
+}  // namespace golden_v1
+}  // namespace cloud
+}  // namespace google

generator/integration_tests/golden/v1/deprecated_client.h

@@ -0,0 +1,127 @@
+// Copyright 2024 Google LLC
+//
+// 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
+//
+//      https://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.
+
+// Generated by the Codegen C++ plugin.
+// If you make any local changes, they will be lost.
+// source: generator/integration_tests/test_deprecated.proto
+
+#ifndef GOOGLE_CLOUD_CPP_GENERATOR_INTEGRATION_TESTS_GOLDEN_V1_DEPRECATED_CLIENT_H
+#define GOOGLE_CLOUD_CPP_GENERATOR_INTEGRATION_TESTS_GOLDEN_V1_DEPRECATED_CLIENT_H
+
+#include "google/cloud/internal/disable_deprecation_warnings.inc"
+#include "generator/integration_tests/golden/v1/deprecated_connection.h"
+#include "google/cloud/future.h"
+#include "google/cloud/options.h"
+#include "google/cloud/polling_policy.h"
+#include "google/cloud/status_or.h"
+#include "google/cloud/version.h"
+#include <memory>
+#include <string>
+
+namespace google {
+namespace cloud {
+namespace golden_v1 {
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
+
+///
+/// Service to test deprecated services.
+///
+/// @par Equality
+///
+/// Instances of this class created via copy-construction or copy-assignment
+/// always compare equal. Instances created with equal
+/// `std::shared_ptr<*Connection>` objects compare equal. Objects that compare
+/// equal share the same underlying resources.
+///
+/// @par Performance
+///
+/// Creating a new instance of this class is a relatively expensive operation,
+/// new objects establish new connections to the service. In contrast,
+/// copy-construction, move-construction, and the corresponding assignment
+/// operations are relatively efficient as the copies share all underlying
+/// resources.
+///
+/// @par Thread Safety
+///
+/// Concurrent access to different instances of this class, even if they compare
+/// equal, is guaranteed to work. Two or more threads operating on the same
+/// instance of this class is not guaranteed to work. Since copy-construction
+/// and move-construction is a relatively efficient operation, consider using
+/// such a copy when using this class from multiple threads.
+///
+class
+ GOOGLE_CLOUD_CPP_DEPRECATED(
+      "DeprecatedService has been deprecated and will be turned down in the future."
+)
+DeprecatedServiceClient {
+ public:
+  explicit DeprecatedServiceClient(std::shared_ptr<DeprecatedServiceConnection> connection, Options opts = {});
+  ~DeprecatedServiceClient();
+
+  ///@{
+  /// @name Copy and move support
+  DeprecatedServiceClient(DeprecatedServiceClient const&) = default;
+  DeprecatedServiceClient& operator=(DeprecatedServiceClient const&) = default;
+  DeprecatedServiceClient(DeprecatedServiceClient&&) = default;
+  DeprecatedServiceClient& operator=(DeprecatedServiceClient&&) = default;
+  ///@}
+
+  ///@{
+  /// @name Equality
+  friend bool operator==(DeprecatedServiceClient const& a, DeprecatedServiceClient const& b) {
+    return a.connection_ == b.connection_;
+  }
+  friend bool operator!=(DeprecatedServiceClient const& a, DeprecatedServiceClient const& b) {
+    return !(a == b);
+  }
+  ///@}
+
+  // clang-format off
+  ///
+  /// Does nothing.
+  ///
+  /// @param request Unary RPCs, such as the one wrapped by this
+  ///     function, receive a single `request` proto message which includes all
+  ///     the inputs for the RPC. In this case, the proto message is a
+  ///     [google.test.deprecated.v1.DeprecatedServiceRequest].
+  ///     Proto messages are converted to C++ classes by Protobuf, using the
+  ///     [Protobuf mapping rules].
+  /// @param opts Optional. Override the class-level options, such as retry and
+  ///     backoff policies.
+  /// @return a [`Status`] object. If the request failed, the
+  ///     status contains the details of the failure.
+  ///
+  /// [Protobuf mapping rules]: https://protobuf.dev/reference/cpp/cpp-generated/
+  /// [input iterator requirements]: https://en.cppreference.com/w/cpp/named_req/InputIterator
+  /// [`std::string`]: https://en.cppreference.com/w/cpp/string/basic_string
+  /// [`future`]: @ref google::cloud::future
+  /// [`StatusOr`]: @ref google::cloud::StatusOr
+  /// [`Status`]: @ref google::cloud::Status
+  /// [google.test.deprecated.v1.DeprecatedServiceRequest]: @googleapis_reference_link{generator/integration_tests/test_deprecated.proto#L39}
+  ///
+  // clang-format on
+  Status
+  Noop(google::test::deprecated::v1::DeprecatedServiceRequest const& request, Options opts = {});
+
+ private:
+  std::shared_ptr<DeprecatedServiceConnection> connection_;
+  Options options_;
+};
+
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_END
+}  // namespace golden_v1
+}  // namespace cloud
+}  // namespace google
+
+#endif  // GOOGLE_CLOUD_CPP_GENERATOR_INTEGRATION_TESTS_GOLDEN_V1_DEPRECATED_CLIENT_H

generator/integration_tests/golden/v1/deprecated_connection.cc

@@ -0,0 +1,66 @@
+// Copyright 2024 Google LLC
+//
+// 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
+//
+//      https://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.
+
+// Generated by the Codegen C++ plugin.
+// If you make any local changes, they will be lost.
+// source: generator/integration_tests/test_deprecated.proto
+
+#include "google/cloud/internal/disable_deprecation_warnings.inc"
+#include "generator/integration_tests/golden/v1/deprecated_connection.h"
+#include "generator/integration_tests/golden/v1/deprecated_options.h"
+#include "generator/integration_tests/golden/v1/internal/deprecated_connection_impl.h"
+#include "generator/integration_tests/golden/v1/internal/deprecated_option_defaults.h"
+#include "generator/integration_tests/golden/v1/internal/deprecated_stub_factory.h"
+#include "generator/integration_tests/golden/v1/internal/deprecated_tracing_connection.h"
+#include "google/cloud/background_threads.h"
+#include "google/cloud/common_options.h"
+#include "google/cloud/credentials.h"
+#include "google/cloud/grpc_options.h"
+#include "google/cloud/internal/unified_grpc_credentials.h"
+#include <memory>
+#include <utility>
+
+namespace google {
+namespace cloud {
+namespace golden_v1 {
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
+
+DeprecatedServiceConnection::~DeprecatedServiceConnection() = default;
+
+Status
+DeprecatedServiceConnection::Noop(
+    google::test::deprecated::v1::DeprecatedServiceRequest const&) {
+  return Status(StatusCode::kUnimplemented, "not implemented");
+}
+
+std::shared_ptr<DeprecatedServiceConnection> MakeDeprecatedServiceConnection(
+    Options options) {
+  internal::CheckExpectedOptions<CommonOptionList, GrpcOptionList,
+      UnifiedCredentialsOptionList,
+      DeprecatedServicePolicyOptionList>(options, __func__);
+  options = golden_v1_internal::DeprecatedServiceDefaultOptions(
+      std::move(options));
+  auto background = internal::MakeBackgroundThreadsFactory(options)();
+  auto auth = internal::CreateAuthenticationStrategy(background->cq(), options);
+  auto stub = golden_v1_internal::CreateDefaultDeprecatedServiceStub(
+    std::move(auth), options);
+  return golden_v1_internal::MakeDeprecatedServiceTracingConnection(
+      std::make_shared<golden_v1_internal::DeprecatedServiceConnectionImpl>(
+      std::move(background), std::move(stub), std::move(options)));
+}
+
+GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_END
+}  // namespace golden_v1
+}  // namespace cloud
+}  // namespace google