Compiler errors switching from GCC to Clang

[daljit97]

So I have a Qt project in which I incorporated Firebase C++ using the wrapper here https://github.com/Larpon/QtFirebase. I decided to switch my compiler from GCC (which was working ok) to Clang as Google deprecated the former, but now I am getting these strange errors:

/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:555: error: undefined reference to 'std::string::assign(std::string const&)'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/variant.cc:242: error: undefined reference to 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/variant.cc:293: error: undefined reference to 'std::string::_Rep::_S_empty_rep_storage'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:282: error: undefined reference to 'std::_Rb_tree_increment(std::_Rb_tree_node_base const*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:282: error: undefined reference to 'std::_Rb_tree_increment(std::_Rb_tree_node_base const*)'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/variant.cc:359: error: undefined reference to 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:555: error: undefined reference to 'std::string::assign(std::string const&)'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/variant.cc:370: error: undefined reference to 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:555: error: undefined reference to 'std::string::assign(std::string const&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:555: error: undefined reference to 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/variant.cc:386: error: undefined reference to 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:282: error: undefined reference to 'std::_Rb_tree_increment(std::_Rb_tree_node_base const*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:282: error: undefined reference to 'std::_Rb_tree_increment(std::_Rb_tree_node_base const*)'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/include/firebase/app.h:93: error: undefined reference to 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >::~basic_string()'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/app_android.cc:273: error: undefined reference to 'std::string::_Rep::_S_empty_rep_storage'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:555: error: undefined reference to 'std::string::assign(std::string const&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:1149: error: undefined reference to 'std::string::assign(char const*, unsigned int)'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/include/firebase/app.h:93: error: undefined reference to 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::string const&)'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/include/firebase/app.h:93: error: undefined reference to 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::string const&)'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/include/firebase/app.h:93: error: undefined reference to 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::string const&)'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/include/firebase/app.h:93: error: undefined reference to 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(std::string const&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:1149: error: undefined reference to 'std::string::assign(char const*, unsigned int)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:1149: error: undefined reference to 'std::string::assign(char const*, unsigned int)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:1149: error: undefined reference to 'std::string::assign(char const*, unsigned int)'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/util_android.cc:843: error: undefined reference to 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&)'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/util_android.cc:840: error: undefined reference to 'std::basic_string<char, std::char_traits<char>, std::allocator<char> >::basic_string(char const*, std::allocator<char> const&)'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/util_android.cc:847: error: undefined reference to 'std::string::_Rep::_S_empty_rep_storage'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/util_android.cc:797: error: undefined reference to 'std::string::_Rep::_S_empty_rep_storage'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/vector.tcc:69: error: undefined reference to 'std::__throw_length_error(char const*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/vector.tcc:69: error: undefined reference to 'std::__throw_length_error(char const*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_list.h:1689: error: undefined reference to 'std::__detail::_List_node_base::_M_hook(std::__detail::_List_node_base*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_list.h:1697: error: undefined reference to 'std::__detail::_List_node_base::_M_unhook()'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_list.h:1697: error: undefined reference to 'std::__detail::_List_node_base::_M_unhook()'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:2442: error: undefined reference to 'std::string::append(unsigned int, char)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:2468: error: undefined reference to 'std::string::append(std::string const&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:1252: error: undefined reference to 'std::string::insert(unsigned int, std::string const&, unsigned int, unsigned int)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:950: error: undefined reference to 'std::string::append(std::string const&)'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/util_android.cc:1635: error: undefined reference to 'std::string::push_back(char)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:1426: error: undefined reference to 'std::string::erase(unsigned int, unsigned int)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_vector.h:1585: error: undefined reference to 'std::__throw_length_error(char const*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_vector.h:1585: error: undefined reference to 'std::__throw_length_error(char const*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:218: error: undefined reference to 'std::_Rb_tree_decrement(std::_Rb_tree_node_base*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:1175: error: undefined reference to 'std::_Rb_tree_insert_and_rebalance(bool, std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, std::_Rb_tree_node_base&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:218: error: undefined reference to 'std::_Rb_tree_decrement(std::_Rb_tree_node_base*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:1175: error: undefined reference to 'std::_Rb_tree_insert_and_rebalance(bool, std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, std::_Rb_tree_node_base&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:218: error: undefined reference to 'std::_Rb_tree_decrement(std::_Rb_tree_node_base*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:203: error: undefined reference to 'std::_Rb_tree_increment(std::_Rb_tree_node_base*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:1726: error: undefined reference to 'std::_Rb_tree_insert_and_rebalance(bool, std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, std::_Rb_tree_node_base&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:218: error: undefined reference to 'std::_Rb_tree_decrement(std::_Rb_tree_node_base*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:203: error: undefined reference to 'std::_Rb_tree_increment(std::_Rb_tree_node_base*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:1894: error: undefined reference to 'std::_Rb_tree_rebalance_for_erase(std::_Rb_tree_node_base*, std::_Rb_tree_node_base&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:203: error: undefined reference to 'std::_Rb_tree_increment(std::_Rb_tree_node_base*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:814: error: undefined reference to 'std::string::_M_mutate(unsigned int, unsigned int, unsigned int)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:1026: error: undefined reference to 'std::string::append(char const*, unsigned int)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:2451: error: undefined reference to 'std::string::append(std::string const&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:1026: error: undefined reference to 'std::string::append(char const*, unsigned int)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:950: error: undefined reference to 'std::string::append(std::string const&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:203: error: undefined reference to 'std::_Rb_tree_increment(std::_Rb_tree_node_base*)'
/tmpfs/src/gfile/kokoro_appandroid/firebase/app/client/cpp/src/app_common.cc:182: error: undefined reference to 'std::string::substr(unsigned int, unsigned int) const'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:592: error: undefined reference to 'std::string::swap(std::string&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:814: error: undefined reference to 'std::string::_M_mutate(unsigned int, unsigned int, unsigned int)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/basic_string.h:814: error: undefined reference to 'std::string::_M_mutate(unsigned int, unsigned int, unsigned int)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:1726: error: undefined reference to 'std::_Rb_tree_insert_and_rebalance(bool, std::_Rb_tree_node_base*, std::_Rb_tree_node_base*, std::_Rb_tree_node_base&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:1894: error: undefined reference to 'std::_Rb_tree_rebalance_for_erase(std::_Rb_tree_node_base*, std::_Rb_tree_node_base&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_list.h:1697: error: undefined reference to 'std::__detail::_List_node_base::_M_unhook()'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_list.h:1689: error: undefined reference to 'std::__detail::_List_node_base::_M_hook(std::__detail::_List_node_base*)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_list.h:1697: error: undefined reference to 'std::__detail::_List_node_base::_M_unhook()'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:1894: error: undefined reference to 'std::_Rb_tree_rebalance_for_erase(std::_Rb_tree_node_base*, std::_Rb_tree_node_base&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/bits/stl_tree.h:1894: error: undefined reference to 'std::_Rb_tree_rebalance_for_erase(std::_Rb_tree_node_base*, std::_Rb_tree_node_base&)'
/opt/android-sdk/current/ndk-bundle/sources/cxx-stl/gnu-libstdc++/4.9/include/functional:2438: error: undefined reference to 'std::__throw_bad_function_call()'
clang++: error: linker command failed with exit code 1 (use -v to see invocation)

I have tried to add this in my build.gradle but it doesn't work:

    ndk{
        toolchain = "clang"

        moduleName = "example"

        stl = "c++_static"

        cppFlags.add("-std=c++11")
        cppFlags.add("-fexceptions")
        cppFlags.add("-frtti")
        cppFlags.add("-latomic")
        ldFlags.add("-latomic")
    }

[a-maurice]

Those errors are indeed odd. It seems like there is possibly a conflict with the ndk version you have, though that is admittedly just a guess. Can you check which version of the ndk you have (you can check /opt/android-sdk/current/ndk-bundle/CHANGELOG.md, which should list it near the top).

Also, have you tried out one of the Quickstart testapps we provide at https://github.com/firebase/quickstart-cpp? They are relatively fast to set up, and recently verified, so it'd be interesting to know if you encounter a similar problem with them.

[daljit97]

@a-maurice the thing is that there is no ndk installed in /opt since that directory is completely empty! I am not even sure where /tmpfs/src/gfile/kokoro_appandroid.... is coming from. I will try that to build the quickstart example. For now I am sticking with gcc (even though that is only a temporary solution)

[larpon]

It looks like errors coming from the closed source binary lib blobs - they usually have those weird paths. I'm guessing they show the paths from the container they were compiled on.

We (QtFirebase project) haven't tried Clang yet - but it look like it's setup related indeed

[scivernet]

I came across a similar problem. It turned out that in QtFirebase in one of the .pri file it is hardcoded to use the "gnustl" versions of the firebase libraries from the firebase sdk. Changing that "gnustl" to "c++" made things work using clang.

To make things a litle bit more flexible I added an extra variable (QTFIREBASE_STL_VARIANT) so that the STL variant to be used can be specified in the app main .pro file (a bit like the QTFIREBASE_SDK_PATH variable). Also issued a pull request for this tiny change, but just wanted to mention it already here as it might be usefull

Update: putting the variable in the main .pro file does not always work, depending on the order in which the .pro files are processed. Changing in the location where the original string was does give the expected results!

[larpon]

Perfect catch!

[larpon]

I think - and hope we nailed it with a7f8247