Is it possible to simpifying google_cloud_cpp as a static library only to use 'AsyncStreamingRecognize() in speech/v1/speech_client.h only with google api key auth?

[joonghunpark]

This is the following question from #15732.

chromium: Uses c++20 clang, protobuf 6.33.0.

• May it cause link or runtime error if google_cloud_cpp 2.xy version only support Protobuf 5.xy, not 6.xy?
• If it is the case, it would be really helpful if you can share when google_cloud_cpp 3.xy will be released.

I got an initial BUILD.gn to use AsyncStreamingRecognize() in speech/v1/speech_client.h with google gemini(claude.ai generated similar result), and I adjusted it to some extent to remove compiling errors,
but then it shows a lot of link errors like below.

I'm not familiar with cmake and bazel, so it seems that I need to learn about them while proceeding
migration google_cloud_cpp to chromium by writing BUILD.gn.

I'm only interested in using AsyncStreamingRecognize() in speech/v1/speech_client.h only with
google api key authentication(not with any other authentication method like service account, etc) to use
bidirection streaming recognition for chromium based browser,
I wonder if it would be possible to just migrate the related codes for this use case.

So I have questions below, and it would be very helpful if you could give some
answer even it is in rough form.

• Do you think it would be possible to use
  'AsyncStreamingRecognize() in speech/v1/speech_client.h only with google api key auth'
  only by listing needed files in BUILD.gn,
  or should some code modification to the related code files be needed?**

• If I could skim all other logics regarding auth except google api key auth,
  I could remove unnecessary files(which I don't need for my use case) and deps library the logic uses.
  Except googleapis github proto files, would there be more files needed as dependency for this use case?
  I'd like to avoid/or/minimize adding external dependencies as much as possible except ones already existing in chromium
  as third_party libraries, because it would require making additional BUILD.gn for themselves,
  and unlike cmake/bazel which can specify external dependency repos, chromium needs to pull
  every dependency required and write BUILD.gn for each of them direcly. So I'd like to minimize/or/avoid it as much as possible.**

• Do you have any rough idea which folder chain in google_cloud_cpp would be needed as dependency chain
  so that the above api can be invoked?**

I'm sorry to ask a lot of questions at once.
I've been trying to make BUILD.gn to call AsyncStreamingRecognize() in speech/v1
during the last week, and reached the conclusion that
AI can't handle this kind of task and large projects like google_cloud_cpp and chromium,
so I need to do it myself again.

Any rough advice or guide would be very helpful for me to handle this migration task or
it would be nice if it is feasible task for my use case in the first place. Thank you for your help.

• Below is the BUILD.gn I generated and used for chromium build.

Copyright 2025 The Chromium Authors. All rights reserved.

Use of this source code is governed by a BSD-style license that can be

found in the LICENSE file.

import("//build/config/features.gni")
import("//third_party/grpc/grpc_library.gni")
import("//third_party/protobuf/proto_library.gni")

------------------------------------------------------------------------------

1. Configuration & Generated Files

------------------------------------------------------------------------------

[CRITICAL] Generate build_info.cc

This provides the implementation for "google/cloud/internal/build_info.h".

It prevents linker errors when "user_agent_prefix.cc" is compiled.

write_file("$root_gen_dir/third_party/google_cloud_cpp/google/cloud/internal/build_info.cc",
[
"#include "google/cloud/internal/build_info.h"",
"#include "google/cloud/version.h"",
"namespace google { namespace cloud {",
"GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN",
"namespace internal {",
"std::string compiler() { return "clang"; }",
"std::string compiler_flags() { return ""; }",
"std::string build_metadata() { return "chromium-gn"; }",
"} // namespace internal",
"GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_END",
"} } // namespace google::cloud",
])

config("google_cloud_cpp_config") {
include_dirs = [
".",
"$root_gen_dir/third_party/google_cloud_cpp",
"$root_gen_dir/third_party/googleapis",
"//third_party/google_cloud_cpp",
]
defines = []
cflags_cc = [
"-include", "ratio",
"-include", "chrono",
"-include", "cerrno",
]
}

config("googleapis_config") {
include_dirs = [ "//third_party/googleapis" ]
}

------------------------------------------------------------------------------

2. Proto Dependencies

------------------------------------------------------------------------------

2a. Google RPC Protos (Status, Error Details, Code)

Use proto_library (No gRPC services defined here)

proto_library("googleapis_rpc_protos") {
proto_in_dir = "//third_party/googleapis"
sources = [
"//third_party/googleapis/google/rpc/code.proto",
"//third_party/googleapis/google/rpc/error_details.proto",
"//third_party/googleapis/google/rpc/status.proto",
]
use_protobuf_full = true
}

2b. Google API Protos (Annotations, HTTP, Client)

Use proto_library (No gRPC services defined here)

proto_library("googleapis_api_protos") {
proto_in_dir = "//third_party/googleapis"
sources = [
"//third_party/googleapis/google/api/annotations.proto",
"//third_party/googleapis/google/api/client.proto",
"//third_party/googleapis/google/api/field_behavior.proto",
"//third_party/googleapis/google/api/http.proto",
"//third_party/googleapis/google/api/label.proto",
"//third_party/googleapis/google/api/launch_stage.proto",
"//third_party/googleapis/google/api/metric.proto",
"//third_party/googleapis/google/api/resource.proto",
"//third_party/googleapis/google/api/routing.proto",
]
proto_deps = [
":googleapis_rpc_protos",
]
use_protobuf_full = true
}

2c. Google LongRunning Protos (Operations)

Use grpc_library (Defines the 'Operations' service used for polling)

grpc_library("googleapis_longrunning_protos") {
proto_in_dir = "//third_party/googleapis"
sources = [
"//third_party/googleapis/google/longrunning/operations.proto",
]
proto_deps = [
":googleapis_api_protos",
":googleapis_rpc_protos",
]
use_protobuf_full = true
}

2d. Speech V1 Protos

Use grpc_library (Defines the 'Speech' service)

grpc_library("speech_protos") {
proto_in_dir = "//third_party/googleapis"
sources = [
"//third_party/googleapis/google/cloud/speech/v1/cloud_speech.proto",
"//third_party/googleapis/google/cloud/speech/v1/resource.proto",
]
proto_deps = [
":googleapis_api_protos",
":googleapis_longrunning_protos",
":googleapis_rpc_protos",
]
use_protobuf_full = true
extra_configs = [ ":googleapis_config" ]
}

2e. Google IAM Credentials Protos

grpc_library("iam_credentials_protos") {
proto_in_dir = "//third_party/googleapis"
sources = [
"//third_party/googleapis/google/iam/credentials/v1/common.proto",
"//third_party/googleapis/google/iam/credentials/v1/iamcredentials.proto",
]
proto_deps = [
":googleapis_api_protos",
":googleapis_rpc_protos",
]
use_protobuf_full = true
}

------------------------------------------------------------------------------

3. Common C++ Library (Core functionality)

------------------------------------------------------------------------------

source_set("google_cloud_cpp_common") {
configs -= [ "//build/config/compiler:chromium_code" ]
configs += [ "//build/config/compiler:no_chromium_code" ]

public_configs = [
":googleapis_config",
":google_cloud_cpp_config"
]

sources = [
# Generated Implementation
"$root_gen_dir/third_party/google_cloud_cpp/google/cloud/internal/build_info.cc",
"google/cloud/internal/build_info.h",

# Internal Abseil Wrappers
"google/cloud/internal/absl_str_cat_quiet.h",
"google/cloud/internal/absl_str_join_quiet.h",
"google/cloud/internal/absl_str_replace_quiet.h",

# Core Source Files
"google/cloud/completion_queue.cc",
"google/cloud/completion_queue.h",
"google/cloud/internal/default_completion_queue_impl.cc",
"google/cloud/internal/default_completion_queue_impl.h",
"google/cloud/internal/completion_queue_impl.h",

# Async Streaming Implementations
"google/cloud/internal/async_read_stream_impl.h",
"google/cloud/internal/async_read_write_stream_impl.h",
"google/cloud/async_streaming_read_write_rpc.h",
"google/cloud/internal/async_streaming_read_write_rpc.h",
"google/cloud/internal/grpc_async_read_write_stream_impl.h",

# User Agent, Logging & ID Generation
"google/cloud/internal/user_agent_prefix.cc",
"google/cloud/internal/user_agent_prefix.h",
"google/cloud/internal/compiler_info.cc",
"google/cloud/internal/compiler_info.h",
"google/cloud/log.cc",
"google/cloud/log.h",
"google/cloud/internal/log_impl.cc",
"google/cloud/internal/log_impl.h",
"google/cloud/internal/invocation_id_generator.cc",
"google/cloud/internal/invocation_id_generator.h",

# System / Low-level Utils
"google/cloud/internal/error_context.cc",
"google/cloud/internal/filesystem.cc",
"google/cloud/internal/filesystem.h",
"google/cloud/internal/getenv.cc",
"google/cloud/internal/getenv.h",
"google/cloud/internal/status_payload_keys.cc",
"google/cloud/internal/service_endpoint.cc",
"google/cloud/internal/service_endpoint.h",
"google/cloud/internal/strerror.cc",
"google/cloud/internal/strerror.h",
"google/cloud/idempotency.h",
"google/cloud/internal/debug_string.cc",
"google/cloud/internal/debug_string.h",

# Core Headers & Sources
"google/cloud/internal/make_status.cc",
"google/cloud/internal/make_status.h",
"google/cloud/backoff_policy.h",
"google/cloud/common_options.h",
"google/cloud/connection_options.h",
"google/cloud/credentials.h",
"google/cloud/credentials.cc",
"google/cloud/future.h",
"google/cloud/internal/future_base.h",
"google/cloud/internal/future_then_impl.cc",
"google/cloud/internal/future_then_impl.h",
"google/cloud/internal/log_wrapper.cc",
"google/cloud/internal/log_wrapper.h",
"google/cloud/future_generic.h",
"google/cloud/future_void.h",
"google/cloud/grpc_error_delegate.cc",
"google/cloud/grpc_error_delegate.h",
"google/cloud/grpc_options.h",
"google/cloud/grpc_utils/copier.h",
"google/cloud/grpc_utils/grpc_error_delegate.h",
"google/cloud/internal/algorithm.h",
"google/cloud/internal/async_long_running_operation.h",
"google/cloud/internal/attributes.h",
"google/cloud/internal/auth_header_error_handler.h",
"google/cloud/internal/backoff_policy.cc",
"google/cloud/internal/backoff_policy.h",
"google/cloud/internal/call_context.h",
"google/cloud/internal/diagnostics_context.h",
"google/cloud/internal/error_context.h",
"google/cloud/internal/future_fwd.h",
"google/cloud/internal/future_impl.cc",
"google/cloud/internal/future_impl.h",

# Auth Strategy Implementations
# Required by unified_grpc_credentials factory to link.
"google/cloud/internal/credentials_impl.cc",
"google/cloud/internal/credentials_impl.h",
"google/cloud/internal/grpc_access_token_authentication.cc",
"google/cloud/internal/grpc_access_token_authentication.h",
"google/cloud/internal/grpc_api_key_authentication.cc",
"google/cloud/internal/grpc_api_key_authentication.h",
"google/cloud/internal/grpc_async_access_token_refresh.h",
"google/cloud/internal/grpc_auth_context.h",
"google/cloud/internal/grpc_channel_credentials_authentication.cc",
"google/cloud/internal/grpc_channel_credentials_authentication.h",
"google/cloud/internal/grpc_impersonate_service_account.cc",
"google/cloud/internal/grpc_impersonate_service_account.h",
"google/cloud/internal/grpc_metadata_view.h",
"google/cloud/internal/grpc_opentelemetry.h",
"google/cloud/internal/grpc_request_metadata.cc",
"google/cloud/internal/grpc_request_metadata.h",
"google/cloud/internal/grpc_service_account_authentication.cc",
"google/cloud/internal/grpc_service_account_authentication.h",
"google/cloud/internal/make_jwt_assertion.cc",
"google/cloud/internal/make_jwt_assertion.h",
"google/cloud/internal/minimal_iam_credentials_stub.cc",
"google/cloud/internal/minimal_iam_credentials_stub.h",
"google/cloud/internal/non_constructible.h",
"google/cloud/internal/pagination_range.h",
"google/cloud/internal/parse_rfc3339.cc",
"google/cloud/internal/parse_rfc3339.h",
"google/cloud/internal/populate_common_options.cc",
"google/cloud/internal/populate_common_options.h",
"google/cloud/internal/populate_grpc_options.cc",
"google/cloud/internal/populate_grpc_options.h",
"google/cloud/internal/port_platform.h",
"google/cloud/internal/random.cc",
"google/cloud/internal/random.h",
"google/cloud/internal/retry_loop.h",
"google/cloud/internal/retry_loop_helpers.cc",
"google/cloud/internal/retry_loop_helpers.h",
"google/cloud/internal/retry_policy_impl.cc",
"google/cloud/internal/retry_policy.h",
"google/cloud/internal/retry_policy_impl.h",
"google/cloud/internal/setup_context.h",
"google/cloud/internal/status_payload_keys.h",
"google/cloud/internal/streaming_read_rpc.h",
"google/cloud/internal/streaming_write_rpc.h",
"google/cloud/internal/subject_token.h",
"google/cloud/internal/throw_delegate.cc",
"google/cloud/internal/throw_delegate.h",
"google/cloud/internal/time_utils.cc",
"google/cloud/internal/time_utils.h",
"google/cloud/internal/tracing_options.h",
"google/cloud/internal/unified_grpc_credentials.cc",
"google/cloud/internal/unified_grpc_credentials.h",
"google/cloud/internal/version.h",
"google/cloud/options.cc",
"google/cloud/options.h",
"google/cloud/status.cc",
"google/cloud/status.h",
"google/cloud/status_or.h",
"google/cloud/terminate_handler.cc",
"google/cloud/terminate_handler.h",
"google/cloud/tracing_options.cc",
"google/cloud/tracing_options.h",
"google/cloud/version.cc",
"google/cloud/version.h",

# Crypto/Encoding
"google/cloud/internal/base64_transforms.cc",
"google/cloud/internal/base64_transforms.h",
"google/cloud/internal/sha256_hmac.cc",
"google/cloud/internal/sha256_hmac.h",
"google/cloud/internal/sha256_hash.cc",
"google/cloud/internal/sha256_hash.h",
"google/cloud/internal/openssl/sign_using_sha256.cc",
"google/cloud/internal/openssl/sign_using_sha256.h",

]

public_deps = [
"//third_party/abseil-cpp:absl",
"//third_party/grpc:grpc++",
"//third_party/protobuf:protobuf_full",
"//third_party/boringssl",
":iam_credentials_protos",
":speech_protos",
]
}

------------------------------------------------------------------------------

4. Speech V1 C++ Library

------------------------------------------------------------------------------

source_set("speech_apis_v1") {
configs -= [ "//build/config/compiler:chromium_code" ]
configs += [
"//build/config/compiler:no_chromium_code",
":google_cloud_cpp_config"
]

sources = [
"google/cloud/speech/v1/internal/speech_auth_decorator.cc",
"google/cloud/speech/v1/internal/speech_auth_decorator.h",
"google/cloud/speech/v1/internal/speech_connection_impl.cc",
"google/cloud/speech/v1/internal/speech_connection_impl.h",
"google/cloud/speech/v1/internal/speech_logging_decorator.cc",
"google/cloud/speech/v1/internal/speech_logging_decorator.h",
"google/cloud/speech/v1/internal/speech_metadata_decorator.cc",
"google/cloud/speech/v1/internal/speech_metadata_decorator.h",
"google/cloud/speech/v1/internal/speech_option_defaults.cc",
"google/cloud/speech/v1/internal/speech_option_defaults.h",
"google/cloud/speech/v1/internal/speech_stub.cc",
"google/cloud/speech/v1/internal/speech_stub.h",
"google/cloud/speech/v1/internal/speech_stub_factory.cc",
"google/cloud/speech/v1/internal/speech_stub_factory.h",
"google/cloud/speech/v1/internal/speech_tracing_connection.cc",
"google/cloud/speech/v1/internal/speech_tracing_connection.h",
"google/cloud/speech/v1/internal/speech_tracing_stub.cc",
"google/cloud/speech/v1/internal/speech_tracing_stub.h",
"google/cloud/speech/v1/speech_client.cc",
"google/cloud/speech/v1/speech_client.h",
"google/cloud/speech/v1/speech_connection.cc",
"google/cloud/speech/v1/speech_connection.h",
"google/cloud/speech/v1/speech_connection_idempotency_policy.cc",
"google/cloud/speech/v1/speech_connection_idempotency_policy.h",
"google/cloud/speech/v1/speech_options.h",
]

public_deps = [
":google_cloud_cpp_common",
":speech_protos",
"//third_party/grpc:grpc++",
"//third_party/protobuf:protobuf_full",
]
}

• Below is the link error I encountered.

FAILED: libcontent.so libcontent.so.TOC
"python3" "../../build/toolchain/gcc_solink_wrapper.py" --readelf="../../third_party/llvm-build/Release+Asserts/bin/llvm-readelf" --nm="../../third_party/llvm-build/Release+Asserts/bin/llvm-nm" --sofile="./libcontent.so" --tocfile="./libcontent.so.TOC" --output="./libcontent.so" -- ../../third_party/llvm-build/Release+Asserts/bin/clang++ -shared -Wl,-soname="libcontent.so" -Werror -fuse-ld=lld -Wl,--fatal-warnings -Wl,--build-id=fast -fPIC -Wl,-z,noexecstack -Wl,-z,relro -Wl,--icf=all -Wl,--color-diagnostics -Wl,--undefined-version -Wl,--no-call-graph-profile-sort --target=x86_64-unknown-linux-gnu -no-canonical-prefixes -Wl,--gc-sections -Wl,-z,defs -Wl,--as-needed -nostdlib++ --sysroot=../../build/linux/debian_bullseye_amd64-sysroot -Wl,-rpath=$ORIGIN -Wl,-rpath=$ORIGIN -o "./libcontent.so" @"./libcontent.so.rsp"
ld.lld: error: undefined symbol: descriptor_table_google_2fapi_2fannotations_2eproto

referenced by iamcredentials.pb.cc
iam_credentials_protos/iamcredentials.pb.o:(descriptor_table_google_2fiam_2fcredentials_2fv1_2fiamcredentials_2eproto_deps) in archive obj/third_party/google_cloud_cpp/libiam_credentials_protos.a
referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(descriptor_table_google_2fcloud_2fspeech_2fv1_2fcloud_5fspeech_2eproto_deps) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a

ld.lld: error: undefined symbol: descriptor_table_google_2fapi_2fclient_2eproto

referenced by iamcredentials.pb.cc
iam_credentials_protos/iamcredentials.pb.o:(descriptor_table_google_2fiam_2fcredentials_2fv1_2fiamcredentials_2eproto_deps) in archive obj/third_party/google_cloud_cpp/libiam_credentials_protos.a
referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(descriptor_table_google_2fcloud_2fspeech_2fv1_2fcloud_5fspeech_2eproto_deps) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a

ld.lld: error: undefined symbol: descriptor_table_google_2fapi_2fresource_2eproto

referenced by resource.pb.cc
speech_protos/resource.pb.o:(descriptor_table_google_2fcloud_2fspeech_2fv1_2fresource_2eproto_deps) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a
referenced by common.pb.cc
iam_credentials_protos/common.pb.o:(descriptor_table_google_2fiam_2fcredentials_2fv1_2fcommon_2eproto_deps) in archive obj/third_party/google_cloud_cpp/libiam_credentials_protos.a

ld.lld: error: undefined symbol: google::rpc::Status::~Status()

referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(google::cloud::speech::v1::LongRunningRecognizeResponse::SharedDtor(google::protobuf::MessageLite&)) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a
referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(google::cloud::speech::v1::StreamingRecognizeResponse::SharedDtor(google::protobuf::MessageLite&)) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a
referenced by grpc_error_delegate.cc
obj/third_party/google_cloud_cpp/google_cloud_cpp_common/grpc_error_delegate.o:(google::cloud::v2_44::MakeStatusFromRpcError(grpc::Status const&))

ld.lld: error: undefined symbol: google::rpc::Status::MergeImpl(google::protobuf::MessageLite&, google::protobuf::MessageLite const&)

referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(google::cloud::speech::v1::LongRunningRecognizeResponse::MergeImpl(google::protobuf::MessageLite&, google::protobuf::MessageLite const&)) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a
referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(google::cloud::speech::v1::StreamingRecognizeResponse::MergeImpl(google::protobuf::MessageLite&, google::protobuf::MessageLite const&)) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a

ld.lld: error: undefined symbol: google::rpc::Status::Clear()

referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(google::cloud::speech::v1::LongRunningRecognizeResponse::Clear()) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a
referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(google::cloud::speech::v1::StreamingRecognizeResponse::Clear()) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a

ld.lld: error: undefined symbol: google::rpc::Status::ByteSizeLong() const

referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(google::cloud::speech::v1::LongRunningRecognizeResponse::ByteSizeLong() const) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a
referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(google::cloud::speech::v1::StreamingRecognizeResponse::ByteSizeLong() const) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a

ld.lld: error: undefined symbol: descriptor_table_google_2fapi_2ffield_5fbehavior_2eproto

referenced by common.pb.cc
iam_credentials_protos/common.pb.o:(descriptor_table_google_2fiam_2fcredentials_2fv1_2fcommon_2eproto_deps) in archive obj/third_party/google_cloud_cpp/libiam_credentials_protos.a
referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(descriptor_table_google_2fcloud_2fspeech_2fv1_2fcloud_5fspeech_2eproto_deps) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a

ld.lld: error: undefined symbol: google::rpc::Status::Status(google::protobuf::Arena*, google::rpc::Status const&)

referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(void* google::protobuf::Arena::CopyConstructgoogle::rpc::Status(google::protobuf::Arena*, void const*)) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a

ld.lld: error: undefined symbol: descriptor_table_google_2flongrunning_2foperations_2eproto

referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(descriptor_table_google_2fcloud_2fspeech_2fv1_2fcloud_5fspeech_2eproto_deps) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a

ld.lld: error: undefined symbol: descriptor_table_google_2frpc_2fstatus_2eproto

referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(descriptor_table_google_2fcloud_2fspeech_2fv1_2fcloud_5fspeech_2eproto_deps) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a

ld.lld: error: undefined symbol: google::rpc::Status::table

referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(google::cloud::speech::v1::LongRunningRecognizeResponse::table) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a
referenced by cloud_speech.pb.cc
speech_protos/cloud_speech.pb.o:(google::cloud::speech::v1::StreamingRecognizeResponse::table) in archive obj/third_party/google_cloud_cpp/libspeech_protos.a

ld.lld: error: undefined symbol: google::cloud::v2_44::internal::HandCraftedLibClientHeader()

referenced by minimal_iam_credentials_stub.cc
obj/third_party/google_cloud_cpp/google_cloud_cpp_common/minimal_iam_credentials_stub.o:(google::cloud::v2_44::internal::DecorateMinimalIamCredentialsStub(std::__Cr::shared_ptrgoogle::cloud::v2_44::internal::MinimalIamCredentialsStub, google::cloud::v2_44::Options const&))

ld.lld: error: undefined symbol: google::cloud::v2_44::internal::UrlEncode(std::__Cr::basic_string_view<char, std::__Cr::char_traits>)

referenced by minimal_iam_credentials_stub.cc
obj/third_party/google_cloud_cpp/google_cloud_cpp_common/minimal_iam_credentials_stub.o:(google::cloud::v2_44::internal::(anonymous namespace)::AsyncAccessTokenGeneratorMetadata::AsyncGenerateAccessToken(google::cloud::v2_44::CompletionQueue&, std::__Cr::shared_ptrgrpc::ClientContext, google::iam::credentials::v1::GenerateAccessTokenRequest const&))
referenced by minimal_iam_credentials_stub.cc
obj/third_party/google_cloud_cpp/google_cloud_cpp_common/minimal_iam_credentials_stub.o:(google::cloud::v2_44::internal::(anonymous namespace)::AsyncAccessTokenGeneratorMetadata::SignBlob(grpc::ClientContext&, google::iam::credentials::v1::SignBlobRequest const&))
referenced by speech_metadata_decorator.cc
obj/third_party/google_cloud_cpp/speech_apis_v1/speech_metadata_decorator.o:(google::cloud::speech_v1_internal::v2_44::SpeechMetadata::GetOperation(grpc::ClientContext&, google::cloud::v2_44::Options const&, google::longrunning::GetOperationRequest const&))
referenced 2 more times

ld.lld: error: undefined symbol: google::cloud::v2_44::internal::GrpcAsyncAccessTokenCache::Create(google::cloud::v2_44::CompletionQueue, std::__Cr::function<google::cloud::v2_44::future<google::cloud::v2_44::StatusOrgoogle::cloud::v2_44::AccessToken> (google::cloud::v2_44::CompletionQueue&)>)

referenced by grpc_impersonate_service_account.cc
obj/third_party/google_cloud_cpp/google_cloud_cpp_common/grpc_impersonate_service_account.o:(google::cloud::v2_44::internal::GrpcImpersonateServiceAccount::GrpcImpersonateServiceAccount(google::cloud::v2_44::CompletionQueue, google::cloud::v2_44::internal::ImpersonateServiceAccountConfig const&, google::cloud::v2_44::Options const&))

ld.lld: error: undefined symbol: google::cloud::v2_44::internal::GrpcAsyncAccessTokenCache::GetAccessToken(std::__Cr::chrono::time_point<std::__Cr::chrono::system_clock, std::__Cr::chrono::duration<long long, std::__Cr::ratio<1l, 1000000l>>>)

referenced by grpc_impersonate_service_account.cc
obj/third_party/google_cloud_cpp/google_cloud_cpp_common/grpc_impersonate_service_account.o:(google::cloud::v2_44::internal::GrpcImpersonateServiceAccount::ConfigureContext(grpc::ClientContext&))

ld.lld: error: undefined symbol: google::cloud::v2_44::internal::GrpcAsyncAccessTokenCache::AsyncGetAccessToken(std::__Cr::chrono::time_point<std::__Cr::chrono::system_clock, std::__Cr::chrono::duration<long long, std::__Cr::ratio<1l, 1000000l>>>)

referenced by grpc_impersonate_service_account.cc
obj/third_party/google_cloud_cpp/google_cloud_cpp_common/grpc_impersonate_service_account.o:(google::cloud::v2_44::internal::GrpcImpersonateServiceAccount::AsyncConfigureContext(std::__Cr::shared_ptrgrpc::ClientContext))

ld.lld: error: undefined symbol: google::cloud::v2_44::internal::DebugString(google::protobuf::Message const&, google::cloud::v2_44::TracingOptions const&)

referenced by minimal_iam_credentials_stub.cc
obj/third_party/google_cloud_cpp/google_cloud_cpp_common/minimal_iam_credentials_stub.o:(google::cloud::v2_44::internal::(anonymous namespace)::AsyncAccessTokenGeneratorLogging::AsyncGenerateAccessToken(google::cloud::v2_44::CompletionQueue&, std::__Cr::shared_ptrgrpc::ClientContext, google::iam::credentials::v1::GenerateAccessTokenRequest const&))
referenced by minimal_iam_credentials_stub.cc
obj/third_party/google_cloud_cpp/google_cloud_cpp_common/minimal_iam_credentials_stub.o:(google::cloud::v2_44::internal::(anonymous namespace)::AsyncAccessTokenGeneratorLogging::SignBlob(grpc::ClientContext&, google::iam::credentials::v1::SignBlobRequest const&))
referenced by minimal_iam_credentials_stub.cc
obj/third_party/google_cloud_cpp/google_cloud_cpp_common/minimal_iam_credentials_stub.o:(google::cloud::v2_44::StatusOrgoogle::iam::credentials::v1::SignBlobResponse google::cloud::v2_44::internal::LogResponsegoogle::iam::credentials::v1::SignBlobResponse(google::cloud::v2_44::StatusOrgoogle::iam::credentials::v1::SignBlobResponse, std::__Cr::basic_string_view<char, std::__Cr::char_traits>, std::__Cr::basic_string_view<char, std::__Cr::char_traits>, google::cloud::v2_44::TracingOptions const&))
referenced 12 more times

ld.lld: error: undefined symbol: google::cloud::v2_44::internal::DebugString(google::cloud::v2_44::Status const&, google::cloud::v2_44::TracingOptions const&)

referenced by minimal_iam_credentials_stub.cc
obj/third_party/google_cloud_cpp/google_cloud_cpp_common/minimal_iam_credentials_stub.o:(google::cloud::v2_44::internal::(anonymous namespace)::AsyncAccessTokenGeneratorLogging::AsyncGenerateAccessToken(google::cloud::v2_44::CompletionQueue&, std::__Cr::shared_ptrgrpc::ClientContext, google::iam::credentials::v1::GenerateAccessTokenRequest const&)::'lambda'(google::cloud::v2_44::future<google::cloud::v2_44::StatusOrgoogle::iam::credentials::v1::GenerateAccessTokenResponse>) absl::functional_internal::InvokeObject<void google::cloud::v2_44::internal::FutureThenImpl::set_result<google::cloud::v2_44::future<google::cloud::v2_44::StatusOrgoogle::iam::credentials::v1::GenerateAccessTokenResponse>, google::cloud::v2_44::internal::(anonymous namespace)::AsyncAccessTokenGeneratorLogging::AsyncGenerateAccessToken(google::cloud::v2_44::CompletionQueue&, std::__Cr::shared_ptrgrpc::ClientContext, google::iam::credentials::v1::GenerateAccessTokenRequest const&)::'lambda'(google::cloud::v2_44::future<google::cloud::v2_44::StatusOrgoogle::iam::credentials::v1::GenerateAccessTokenResponse>), google::cloud::v2_44::StatusOrgoogle::iam::credentials::v1::GenerateAccessTokenResponse>(std::__Cr::shared_ptr<google::cloud::v2_44::internal::future_shared_state<google::cloud::v2_44::StatusOrgoogle::iam::credentials::v1::GenerateAccessTokenResponse>>, google::cloud::v2_44::internal::(anonymous namespace)::AsyncAccessTokenGeneratorLogging::AsyncGenerateAccessToken(google::cloud::v2_44::CompletionQueue&, std::__Cr::shared_ptrgrpc::ClientContext, google::iam::credentials::v1::GenerateAccessTokenRequest const&)::'lambda'(google::cloud::v2_44::future<google::cloud::v2_44::StatusOrgoogle::iam::credentials::v1::GenerateAccessTokenResponse>)&&, google::cloud::v2_44::future<google::cloud::v2_44::StatusOrgoogle::iam::credentials::v1::GenerateAccessTokenResponse>&&)::'lambda'()&, void>(absl::functional_internal::VoidPtr))
referenced by speech_logging_decorator.cc
obj/third_party/google_cloud_cpp/speech_apis_v1/speech_logging_decorator.o:(google::cloud::v2_44::internal::AsyncStreamingReadWriteRpcLogging<google::cloud::speech::v1::StreamingRecognizeRequest, google::cloud::speech::v1::StreamingRecognizeResponse>::Finish()::'lambda'(google::cloud::v2_44::futuregoogle::cloud::v2_44::Status)::operator()(google::cloud::v2_44::futuregoogle::cloud::v2_44::Status) const)
referenced by log_wrapper.cc
obj/third_party/google_cloud_cpp/google_cloud_cpp_common/log_wrapper.o:(google::cloud::v2_44::internal::LogResponse(google::cloud::v2_44::Status, std::__Cr::basic_string_view<char, std::__Cr::char_traits>, std::__Cr::basic_string_view<char, std::__Cr::char_traits>, google::cloud::v2_44::TracingOptions const&))

ld.lld: error: undefined symbol: google::rpc::Status::Status(google::protobuf::Arena*)

referenced by grpc_error_delegate.cc
obj/third_party/google_cloud_cpp/google_cloud_cpp_common/grpc_error_delegate.o:(google::cloud::v2_44::MakeStatusFromRpcError(grpc::Status const&))

ld.lld: error: too many errors emitted, stopping now (use --error-limit=0 to see all errors)

[joonghunpark]

I've succeeded to make BUILD.gn by assembling only related files to make gn build target. Thank you for your help.