C++ linking fails when toolchain invokes gcc instead of g++ (missing libstdc++)

[abdi810103]

When using a custom GCC toolchain with Bazel (remote execution via Buildbarn), C++ linking fails with many undefined references to standard C++ symbols.

The linker is invoked as:

gcc -o ...

instead of:

g++ -o ...

This results in missing symbols like:

std::__cxx11::basic_string
operator new/delete
__gxx_personality_v0

Expected behavior:

C++ linking should use g++ or otherwise include libstdc++ automatically.

Actual behavior:

gcc is used without linking libstdc++, causing link failures.

Environment:

Bazel 8.4.2
Linux (container-based execution)
Remote execution via Buildbarn

Question:

Is this expected behavior for GCC toolchains, or should the toolchain explicitly ensure g++ (or -lstdc++) is used for C++ linking?

[f0rmiga]

It's intentional so that we are able to link against the sysroot libstdc++ as well as able to carry the libstdc++.so as a dependency of C++ targets. Take a look at https://github.com/f0rmiga/gcc-toolchain/blob/8fe3945074e704bd6afbf78e77578b0fe3fd4009/rules_cc/defs.bzl.

[f0rmiga]

Feel free to reopen if you need further assistance or want to further discuss.