Undefined symbols _gpr_set_log_function

[kawanet]

commit 861ec40 fails to build on the following environments:

• M1 Mac: macOS 11.4 ARM
• Intel Mac: macOS 11.4 Intel
• Amazon Linux Intel

Linker fails with Undefined symbols or undefined reference error messages around _gpr_set_log_function.

gRPC is installed via brew or from source.
tkrzw is installed locally at $HOME/local/tkrzw.

On M1 Mac:

$ make

(snip)

g++ -g -O2 -std=c++17 -Wall -fPIC -fsigned-char -O2 -O3 -mcpu=native -dynamiclib -o libtkrzw_rpc.1.3.0.dylib \
	  -install_name /Users/xxxx/local/tkrzw/lib/libtkrzw_rpc.1.dylib \
	  -current_version 1.3.0 -compatibility_version 1 \
	  tkrzw_rpc_common.o tkrzw_dbm_remote.o tkrzw_rpc.pb.o tkrzw_rpc.grpc.pb.o -L/Users/xxxx/local/tkrzw/lib -L. -L/Users/xxxx/local/tkrzw/lib -L/Users/xxxx/lib -L/usr/local/lib -L/Users/xxxx/local/tkrzw/lib -ltkrzw -llzma -lz -lstdc++ -lpthread -lm -lc 
ld: warning: directory not found for option '-L/Users/xxxx/lib'
ar: creating archive libtkrzw_rpc.a
a - tkrzw_rpc_common.o
a - tkrzw_dbm_remote.o
a - tkrzw_rpc.pb.o
a - tkrzw_rpc.grpc.pb.o
Undefined symbols for architecture arm64:
  "grpc::ClientContext::ClientContext()", referenced from:
      tkrzw::RemoteDBMImpl::Echo(std::__1::basic_string_view<char, std::__1::char_traits<char> >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >*) in tkrzw_dbm_remote.o
      tkrzw::RemoteDBMImpl::Inspect(std::__1::vector<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > >, std::__1::allocator<std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > > >*) in tkrzw_dbm_remote.o
      tkrzw::RemoteDBMImpl::Get(std::__1::basic_string_view<char, std::__1::char_traits<char> >, std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >*) in tkrzw_dbm_remote.o
(snip)
      ...
  NOTE: a missing vtable usually means the first non-inline virtual member function has no definition.
  "_gpr_set_log_function", referenced from:
      tkrzw::SetGlobalLogger(tkrzw::Logger*) in tkrzw_rpc_common.o
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [libtkrzw_rpc.1.3.0.dylib] Error 1
make: *** Waiting for unfinished jobs....

On Intel Mac:

$ make

(snip)

g++ -g -O2 -std=c++17 -Wall -fPIC -fsigned-char -O2 -O3 -march=native -dynamiclib -o libtkrzw_rpc.1.3.0.dylib \
	  -install_name /Users/xxxx/local/tkrzw/lib/libtkrzw_rpc.1.dylib \
	  -current_version 1.3.0 -compatibility_version 1 \
	  tkrzw_rpc_common.o tkrzw_dbm_remote.o tkrzw_rpc.pb.o tkrzw_rpc.grpc.pb.o -L/Users/xxxx/local/tkrzw/lib -L. -L/Users/xxxx/local/tkrzw/lib -L/Users/xxxx/lib -L/usr/local/lib -L/Users/xxxx/local/tkrzw/lib -lgrpc++_reflection -lgrpc++ -lgrpc -lprotobuf -ltkrzw -llzma -llz4 -lzstd -lz -lstdc++ -lpthread -lm -lc 
ar: creating archive libtkrzw_rpc.a
a - tkrzw_rpc_common.o
a - tkrzw_dbm_remote.o
a - tkrzw_rpc.pb.o
a - tkrzw_rpc.grpc.pb.o
ld: warning: directory not found for option '-L/Users/xxxx/lib'
Undefined symbols for architecture x86_64:
  "_gpr_set_log_function", referenced from:
      tkrzw::SetGlobalLogger(tkrzw::Logger*) in tkrzw_rpc_common.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
make: *** [libtkrzw_rpc.1.3.0.dylib] Error 1
make: *** Waiting for unfinished jobs....

On Intel Amazon Linux

$ make

(snip)

g++ -g -O2 -std=c++17 -Wall -fPIC -fsigned-char -O2 -O3 -march=native -o tkrzw_dbm_remote_perf tkrzw_dbm_remote_perf.o -L/home/ec2-user/local/tkrzw/lib -L. -L/home/ec2-user/local/tkrzw/lib -L/home/ec2-user/lib -L/usr/local/lib -L/home/ec2-user/local/tkrzw/lib -Wl,-rpath-link,.:/usr/local/lib:/home/ec2-user/lib:/usr/local/lib::/home/ec2-user/local/tkrzw/lib -Wl,--as-needed -L. -L/home/ec2-user/local/tkrzw/lib -ltkrzw_rpc -ltkrzw -lstdc++ -lrt -lpthread -lm -lc 
./libtkrzw_rpc.so: undefined reference to `typeinfo for google::protobuf::io::ZeroCopyOutputStream'
./libtkrzw_rpc.so: undefined reference to `google::protobuf::internal::ComputeUnknownFieldsSize(google::protobuf::internal::InternalMetadata const&, unsigned long, google::protobuf::internal::CachedSize*)'
./libtkrzw_rpc.so: undefined reference to `google::protobuf::internal::AssignDescriptors(google::protobuf::internal::DescriptorTable const*, bool)'
./libtkrzw_rpc.so: undefined reference to `google::protobuf::Message::CheckTypeAndMergeFrom(google::protobuf::MessageLite const&)'
./libtkrzw_rpc.so: undefined reference to `grpc::ClientContext::~ClientContext()'
./libtkrzw_rpc.so: undefined reference to `google::protobuf::internal::VerifyUTF8(google::protobuf::StringPiece, char const*)'
./libtkrzw_rpc.so: undefined reference to `google::protobuf::internal::fixed_address_empty_string[abi:cxx11]'
./libtkrzw_rpc.so: undefined reference to `gpr_set_log_function'
./libtkrzw_rpc.so: undefined reference to `grpc::Channel::GetState(bool)'
./libtkrzw_rpc.so: undefined reference to `google::protobuf::internal::ReadSizeFallback(char const*, unsigned int)'

Steps before calling make on macOS:

brew install grpc

cd tkrzw
./configure --enable-opt-native --enable-most-features --prefix=$HOME/local/tkrzw
make all install

cd ../tkrzw-rpc
BREW=$(brew config | grep HOMEBREW_PREFIX | cut -f 2 -d ' ') # => /opt/homebrew or /usr/local

PKG_CONFIG_PATH=$HOME/local/tkrzw/lib/pkgconfig \
LDFLAGS="-L$BREW/lib -L$HOME/local/tkrzw/lib" \
CPPFLAGS="-I$BREW/include -I$HOME/local/tkrzw/include" \
./configure  --prefix=$HOME/local/tkrzw 

(snip)

checking for main in -ltkrzw... yes
checking for main in -lprotobuf... yes
checking for main in -lgrpc... yes
checking for main in -lgrpc++... yes
checking for main in -lgrpc++_reflection... yes
checking for main in -ltkrzw_rpc... no

(snip)

make

[estraier]

Hi Yusuke,
Thanks for reporting this issue.
I found the error on my M1 macbook.
As a workaround, commenting out the following line in tkrzw_rpc_common.h solves this.

void SetGlobalLogger(tkrzw::Logger* logger) {
g_logger = logger;
//gpr_set_log_function(PrintGlobalLog);
}

The reason why we call gpr_set_log_function is that gRPC's internal logger sometimes writes error logs to stderr, which is annoying for me. However, it is not a critical issue. so, commenting it out is practical.

One strange thing is that gpr_set_log_function is defined in grpc/impl/codegen/log.h .
So, somehow, the library doesn't embed the symbol of gpr_set_log_function.
I'm investigating more.

[estraier]

I found it. Adding -lgpr to LDFLAGS solves this issue. I don't know why it is not necessary on Linux though.

[estraier]

I submitted the fix so please check it.

[kawanet]

hooray!

$ make -j4 && echo 🎉
(snip)
#================================================================
# Ready to install.
#================================================================
🎉