linker issues when building mediasoup-broadcaster-demo

mediasoup libraries
1

I’m trying to build mediasoup-broadcaster-demo and run into linker errors. I’ve a working libwebrtc m74 build.

[ 80%] Linking CXX executable broadcaster
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o: In function `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > cricket::ToStringIfSet<bool>(char const*, absl::optional<bool> const&)':
Broadcaster.cpp:(.text+0x321f): undefined reference to `rtc::ToString[abi:cxx11](bool)'
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o: In function `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > cricket::ToStringIfSet<int>(char const*, absl::optional<int> const&)':
Broadcaster.cpp:(.text+0x338f): undefined reference to `rtc::ToString[abi:cxx11](int)'
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o: In function `mediasoupclient::PeerConnection::RTCStatsCollectorCallback::OnStatsDelivered(rtc::scoped_refptr<webrtc::RTCStatsReport const> const&)':
Broadcaster.cpp:(.text._ZN15mediasoupclient14PeerConnection25RTCStatsCollectorCallback16OnStatsDeliveredERKN3rtc13scoped_refptrIKN6webrtc14RTCStatsReportEEE[_ZN15mediasoupclient14PeerConnection25RTCStatsCollectorCallback16OnStatsDeliveredERKN3rtc13scoped_refptrIKN6webrtc14RTCStatsReportEEE]+0x4a): undefined reference to `webrtc::RTCStatsReport::ToJson[abi:cxx11]() const'
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o:(.data.rel.ro._ZTVN15mediasoupclient14PeerConnection32CreateSessionDescriptionObserverE[_ZTVN15mediasoupclient14PeerConnection32CreateSessionDescriptionObserverE]+0x40): undefined reference to `webrtc::CreateSessionDescriptionObserver::OnFailure(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o:(.data.rel.ro._ZTVN15mediasoupclient14PeerConnection29SetSessionDescriptionObserverE[_ZTVN15mediasoupclient14PeerConnection29SetSessionDescriptionObserverE]+0x40): undefined reference to `webrtc::SetSessionDescriptionObserver::OnFailure(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o:(.data.rel.ro._ZTIN15mediasoupclient14PeerConnection32CreateSessionDescriptionObserverE[_ZTIN15mediasoupclient14PeerConnection32CreateSessionDescriptionObserverE]+0x10): undefined reference to `typeinfo for webrtc::CreateSessionDescriptionObserver'
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o:(.data.rel.ro._ZTIN15mediasoupclient14PeerConnection29SetSessionDescriptionObserverE[_ZTIN15mediasoupclient14PeerConnection29SetSessionDescriptionObserverE]+0x10): undefined reference to `typeinfo for webrtc::SetSessionDescriptionObserver'
CMakeFiles/broadcaster.dir/src/main.cpp.o: In function `std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > cricket::ToStringIfSet<bool>(char const*, absl::optional<bool> const&)':
...

This looks to me like a gcc/clang stdlib issue. I get this error both with a libwebrtc build with clang and gcc. Switching to clang for the mediasoup-broadcaster-demo build gives me slightly different errors

[ 80%] Linking CXX executable broadcaster
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o: In function `mediasoupclient::PeerConnection::RTCStatsCollectorCallback::OnStatsDelivered(rtc::scoped_refptr<webrtc::RTCStatsReport const> const&)':
Broadcaster.cpp:(.text._ZN15mediasoupclient14PeerConnection25RTCStatsCollectorCallback16OnStatsDeliveredERKN3rtc13scoped_refptrIKN6webrtc14RTCStatsReportEEE[_ZN15mediasoupclient14PeerConnection25RTCStatsCollectorCallback16OnStatsDeliveredERKN3rtc13scoped_refptrIKN6webrtc14RTCStatsReportEEE]+0x2f): undefined reference to `webrtc::RTCStatsReport::ToJson[abi:cxx11]() const'
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o:(.rodata._ZTVN15mediasoupclient14PeerConnection29SetSessionDescriptionObserverE[_ZTVN15mediasoupclient14PeerConnection29SetSessionDescriptionObserverE]+0x40): undefined reference to `webrtc::SetSessionDescriptionObserver::OnFailure(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o:(.rodata._ZTIN15mediasoupclient14PeerConnection29SetSessionDescriptionObserverE[_ZTIN15mediasoupclient14PeerConnection29SetSessionDescriptionObserverE]+0x10): undefined reference to `typeinfo for webrtc::SetSessionDescriptionObserver'
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o:(.rodata._ZTVN15mediasoupclient14PeerConnection32CreateSessionDescriptionObserverE[_ZTVN15mediasoupclient14PeerConnection32CreateSessionDescriptionObserverE]+0x40): undefined reference to `webrtc::CreateSessionDescriptionObserver::OnFailure(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o:(.rodata._ZTIN15mediasoupclient14PeerConnection32CreateSessionDescriptionObserverE[_ZTIN15mediasoupclient14PeerConnection32CreateSessionDescriptionObserverE]+0x10): undefined reference to `typeinfo for webrtc::CreateSessionDescriptionObserver'
CMakeFiles/broadcaster.dir/src/peerConnectionUtils.cpp.o: In function `createPeerConnectionFactory()':
peerConnectionUtils.cpp:(.text+0x430): undefined reference to `rtc::Thread::SetName(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, void const*)'
...

Any hints of how to complete this build successfully?

Thanks!
Robert

2

I missed

Build libwebrtc with the ‘use_custom_libcxx=false’ gn gen argument to force it use of the system libstdc++.

at mediasoup :: Installation

So this helped a bit but still linker errors…

[ 80%] Linking CXX executable broadcaster
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o:(.data.rel.ro._ZTIN15mediasoupclient14PeerConnection32CreateSessionDescriptionObserverE[_ZTIN15mediasoupclient14PeerConnection32CreateSessionDescriptionObserverE]+0x10): undefined reference to `typeinfo for webrtc::CreateSessionDescriptionObserver'
CMakeFiles/broadcaster.dir/src/Broadcaster.cpp.o:(.data.rel.ro._ZTIN15mediasoupclient14PeerConnection29SetSessionDescriptionObserverE[_ZTIN15mediasoupclient14PeerConnection29SetSessionDescriptionObserverE]+0x10): undefined reference to `typeinfo for webrtc::SetSessionDescriptionObserver'
CMakeFiles/broadcaster.dir/src/peerConnectionUtils.cpp.o:(.data.rel.ro._ZTI19CapturerTrackSource[_ZTI19CapturerTrackSource]+0x10): undefined reference to `typeinfo for webrtc::VideoTrackSource'
CMakeFiles/broadcaster.dir/src/peerConnectionUtils.cpp.o:(.data.rel.ro._ZTIN6webrtc25VideoTrackSourceInterfaceE[_ZTIN6webrtc25VideoTrackSourceInterfaceE]+0x18): undefined reference to `typeinfo for webrtc::MediaSourceInterface'
/path/to/webrtc-google-3/src/out/gcc/obj/libwebrtc.a(audio_device_alsa_linux.o): In function `webrtc::AudioDeviceLinuxALSA::Init()':
/path/to/webrtc-google-3/src/out/gcc/../../modules/audio_device/linux/audio_device_alsa_linux.cc:158: undefined reference to `XOpenDisplay'
/path/to/webrtc-google-3/src/out/gcc/obj/libwebrtc.a(audio_device_alsa_linux.o): In function `webrtc::AudioDeviceLinuxALSA::Terminate()':
/path/to/webrtc-google-3/src/out/gcc/../../modules/audio_device/linux/audio_device_alsa_linux.cc:202: undefined reference to `XCloseDisplay'
/path/to/webrtc-google-3/src/out/gcc/obj/libwebrtc.a(audio_device_alsa_linux.o): In function `webrtc::AudioDeviceLinuxALSA::KeyPressed() const':
/path/to/webrtc-google-3/src/out/gcc/../../modules/audio_device/linux/audio_device_alsa_linux.cc:1640: undefined reference to `XQueryKeymap'
/path/to/webrtc-google-3/src/out/gcc/obj/libwebrtc.a(audio_device_pulse_linux.o): In function `webrtc::AudioDeviceLinuxPulse::Init()':
/path/to/webrtc-google-3/src/out/gcc/../../modules/audio_device/linux/audio_device_pulse_linux.cc:154: undefined reference to `XOpenDisplay'
/path/to/webrtc-google-3/src/out/gcc/obj/libwebrtc.a(audio_device_pulse_linux.o): In function `webrtc::AudioDeviceLinuxPulse::Terminate()':
/path/to/webrtc-google-3/src/out/gcc/../../modules/audio_device/linux/audio_device_pulse_linux.cc:213: undefined reference to `XCloseDisplay'
/path/to/webrtc-google-3/src/out/gcc/obj/libwebrtc.a(audio_device_pulse_linux.o): In function `webrtc::AudioDeviceLinuxPulse::KeyPressed() const':
/path/to/webrtc-google-3/src/out/gcc/../../modules/audio_device/linux/audio_device_pulse_linux.cc:2278: undefined reference to `XQueryKeymap'
collect2: error: ld returned 1 exit status

Any ideas what that could be?

3

Alright, using gcc with $ gn gen out/mybuild-m74 --args='is_debug=false is_component_build=false is_clang=false rtc_include_tests=false rtc_use_h264=true rtc_enable_protobuf=false use_rtti=true use_custom_libcxx=false treat_warnings_as_errors=false use_ozone=true' (as mentioned in the documentation) worked. Just needed some rubber ducking.

4

Just take into account that you did not even tell which OS you are running.

BTW: is that working command the same as the one exposed in the documentation?

5

I’m using Ubuntu 18.04. And yes, the build command for libwebrtc is from the documentation.

6

So the doc is fine, right? :slight_smile:

Note however that building libwebrtc is out of the scope of libmediasoupclient, we just provide some hints but those may need to change depending on libwebrtc version or OS.

7

Yes, the docs are good and I didn’t intend to suggest otherwise. I’ve added the build command above as it is the direct answer to my question. I missed the build section when I first started out, my apologies for that. Thanks for putting it out there!

8

Thanks. If anyway you see something that can be improved in the documentation, don’t hesitate to tell it.

2 Likes
9

Looks like I have the same issues on Ubuntu 20.04.
I have built WebRTC of version branch-heads/4606 with all the arguments described above and have all these linker errors.
Should any specific linker options be added or something?