Added readability-redundant-string-cstr (#31707)

* Added readability-redundant-string-cstr

* Auto fix

* No need to wrap std::string

.clang-tidy

@@ -120,6 +120,7 @@ Checks: '-*,
   readability-redundant-control-flow,
   readability-redundant-function-ptr-dereference,
   readability-redundant-smartptr-get,
+  readability-redundant-string-cstr,
   readability-redundant-string-init,
   readability-simplify-boolean-expr,
   readability-static-definition-in-anonymous-namespace,

src/core/lib/json/json_writer.cc

@@ -283,7 +283,7 @@ void JsonWriter::ValueString(const std::string& string) {
 void JsonWriter::DumpObject(const Json::Object& object) {
   ContainerBegins(Json::Type::OBJECT);
   for (const auto& p : object) {
-    ObjectKey(p.first.data());
+    ObjectKey(p.first);
     DumpValue(p.second);
   }
   ContainerEnds(Json::Type::OBJECT);

src/core/lib/surface/completion_queue.cc

@@ -768,7 +768,7 @@ static void cq_end_op_for_pluck(
 
   if (GRPC_TRACE_FLAG_ENABLED(grpc_api_trace) ||
       (GRPC_TRACE_FLAG_ENABLED(grpc_trace_operation_failures) && !error.ok())) {
-    std::string errmsg = grpc_core::StatusToString(error).c_str();
+    std::string errmsg = grpc_core::StatusToString(error);
     GRPC_API_TRACE(
         "cq_end_op_for_pluck(cq=%p, tag=%p, error=%s, "
         "done=%p, done_arg=%p, storage=%p)",

src/cpp/server/external_connection_acceptor_impl.cc

@@ -92,7 +92,7 @@ void ExternalConnectionAcceptorImpl::Start() {
 }
 
 void ExternalConnectionAcceptorImpl::SetToChannelArgs(ChannelArguments* args) {
-  args->SetPointer(name_.c_str(), &handler_);
+  args->SetPointer(name_, &handler_);
 }
 
 }  // namespace internal

test/core/tsi/alts/handshaker/alts_concurrent_connectivity_test.cc

@@ -114,8 +114,7 @@ class FakeHandshakeServer {
           0 /* expected max concurrent rpcs unset */);
     }
     grpc::ServerBuilder builder;
-    builder.AddListeningPort(address_.c_str(),
-                             grpc::InsecureServerCredentials());
+    builder.AddListeningPort(address_, grpc::InsecureServerCredentials());
     builder.RegisterService(service_.get());
     // TODO(apolcyn): when removing the global concurrent handshake limiting
     // queue, set MAX_CONCURRENT_STREAMS on this server.

test/cpp/end2end/rls_end2end_test.cc

@@ -201,8 +201,8 @@ class RlsEnd2endTest : public ::testing::Test {
                                                   nullptr));
     call_creds->Unref();
     channel_creds->Unref();
-    channel_ = grpc::CreateCustomChannel(
-        absl::StrCat("fake:///", kServerName).c_str(), std::move(creds), args);
+    channel_ = grpc::CreateCustomChannel(absl::StrCat("fake:///", kServerName),
+                                         std::move(creds), args);
     stub_ = grpc::testing::EchoTestService::NewStub(channel_);
   }
 

test/cpp/end2end/xds/xds_end2end_test_lib.cc

@@ -793,7 +793,7 @@ std::shared_ptr<Channel> XdsEnd2endTest::CreateChannel(
     // same thing for the response generator to use for the xDS
     // channel and the xDS resource-does-not-exist timeout value.
     args->SetString(GRPC_ARG_TEST_ONLY_DO_NOT_USE_IN_PROD_XDS_BOOTSTRAP_CONFIG,
-                    bootstrap_.c_str());
+                    bootstrap_);
     args->SetPointerWithVtable(
         GRPC_ARG_TEST_ONLY_DO_NOT_USE_IN_PROD_XDS_CLIENT_CHANNEL_ARGS,
         &xds_channel_args_, &kChannelArgsArgVtable);

test/cpp/interop/interop_client.cc

@@ -224,7 +224,7 @@ bool InteropClient::DoComputeEngineCreds(
   gpr_log(GPR_DEBUG, "Got username %s", response.username().c_str());
   gpr_log(GPR_DEBUG, "Got oauth_scope %s", response.oauth_scope().c_str());
   GPR_ASSERT(!response.username().empty());
-  GPR_ASSERT(response.username().c_str() == default_service_account);
+  GPR_ASSERT(response.username() == default_service_account);
   GPR_ASSERT(!response.oauth_scope().empty());
   const char* oauth_scope_str = response.oauth_scope().c_str();
   GPR_ASSERT(absl::StrContains(oauth_scope, oauth_scope_str));
@@ -314,7 +314,7 @@ bool InteropClient::DoGoogleDefaultCredentials(
 
   gpr_log(GPR_DEBUG, "Got username %s", response.username().c_str());
   GPR_ASSERT(!response.username().empty());
-  GPR_ASSERT(response.username().c_str() == default_service_account);
+  GPR_ASSERT(response.username() == default_service_account);
   gpr_log(GPR_DEBUG, "Large unary rpc with GoogleDefaultCredentials done.");
   return true;
 }

test/cpp/qps/qps_json_driver.cc

@@ -256,7 +256,7 @@ static bool QpsDriver() {
     json = std::string(data, data + len);
     delete[] data;
   } else if (scjson) {
-    json = absl::GetFlag(FLAGS_scenarios_json).c_str();
+    json = absl::GetFlag(FLAGS_scenarios_json);
   } else if (absl::GetFlag(FLAGS_quit)) {
     return RunQuit(absl::GetFlag(FLAGS_credential_type),
                    per_worker_credential_types);
@@ -264,7 +264,7 @@ static bool QpsDriver() {
 
   // Parse into an array of scenarios
   Scenarios scenarios;
-  ParseJson(json.c_str(), "grpc.testing.Scenarios", &scenarios);
+  ParseJson(json, "grpc.testing.Scenarios", &scenarios);
   bool success = true;
 
   // Make sure that there is at least some valid scenario here

test/cpp/qps/qps_worker.cc

@@ -284,7 +284,7 @@ QpsWorker::QpsWorker(int driver_port, int server_port,
   if (driver_port >= 0) {
     std::string server_address = grpc_core::JoinHostPort("::", driver_port);
     builder->AddListeningPort(
-        server_address.c_str(),
+        server_address,
         GetCredentialsProvider()->GetServerCredentials(credential_type));
   }
   builder->RegisterService(impl_.get());

test/cpp/qps/server_async.cc

@@ -81,9 +81,8 @@ class AsyncQpsServerTest final : public grpc::testing::Server {
     // Negative port number means inproc server, so no listen port needed
     if (port_num >= 0) {
       std::string server_address = grpc_core::JoinHostPort("::", port_num);
-      builder->AddListeningPort(server_address.c_str(),
-                                Server::CreateServerCredentials(config),
-                                &port_num);
+      builder->AddListeningPort(
+          server_address, Server::CreateServerCredentials(config), &port_num);
     }
 
     register_service(builder.get(), &async_service_);

test/cpp/qps/server_callback.cc

@@ -103,9 +103,8 @@ class CallbackServer final : public grpc::testing::Server {
     // Negative port number means inproc server, so no listen port needed
     if (port_num >= 0) {
       std::string server_address = grpc_core::JoinHostPort("::", port_num);
-      builder->AddListeningPort(server_address.c_str(),
-                                Server::CreateServerCredentials(config),
-                                &port_num);
+      builder->AddListeningPort(
+          server_address, Server::CreateServerCredentials(config), &port_num);
     }
 
     ApplyConfigToBuilder(config, builder.get());

test/cpp/qps/server_sync.cc

@@ -161,9 +161,8 @@ class SynchronousServer final : public grpc::testing::Server {
     // Negative port number means inproc server, so no listen port needed
     if (port_num >= 0) {
       std::string server_address = grpc_core::JoinHostPort("::", port_num);
-      builder->AddListeningPort(server_address.c_str(),
-                                Server::CreateServerCredentials(config),
-                                &port_num);
+      builder->AddListeningPort(
+          server_address, Server::CreateServerCredentials(config), &port_num);
     }
 
     ApplyConfigToBuilder(config, builder.get());

test/cpp/util/grpc_tool.cc

@@ -240,7 +240,7 @@ std::shared_ptr<grpc::Channel> CreateCliChannel(
   }
   if (!absl::GetFlag(FLAGS_default_service_config).empty()) {
     args.SetString(GRPC_ARG_SERVICE_CONFIG,
-                   absl::GetFlag(FLAGS_default_service_config).c_str());
+                   absl::GetFlag(FLAGS_default_service_config));
   }
   // See |GRPC_ARG_MAX_METADATA_SIZE| in |grpc_types.h|.
   // Set to large enough size (10M) that should work for most use cases.
@@ -319,7 +319,7 @@ int GrpcToolMainLib(int argc, const char** argv, const CliCredentials& cred,
     const bool ok = cmd->function(&grpc_tool, argc, argv, cred, callback);
     return ok ? 0 : 1;
   } else {
-    Usage("Invalid command '" + std::string(command.c_str()) + "'");
+    Usage("Invalid command '" + command + "'");
   }
   return 1;
 }