https://gcc.gnu.org/bugzilla/show_bug.cgi?id=125312
--- Comment #16 from GCC Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jonathan Wakely <[email protected]>: https://gcc.gnu.org/g:1b191d0a23f3b82f6543913f8c3c2e46942af859 commit r17-552-g1b191d0a23f3b82f6543913f8c3c2e46942af859 Author: Jonathan Wakely <[email protected]> Date: Fri May 15 10:41:33 2026 +0100 libstdc++: Make configure check for atomics work on Windows [PR125312] The changes in r16-427-g86627faec10da5 do not work for native mingw-w64 builds because the #include with a hardcoded unix-style path doesn't work for a native mingw-w64 compiler. This results in configure detecting that native mingw builds do not support atomic builtins for the _Atomic_word type, causing non-inline atomics to be used for __gnu_cxx::__exchange_and_add and __gnu_cxx::__atomic_add, which is an unintented ABI change (and inconsistent with mingw cross-compilers where the configure test passes and so enables the inline functions using atomic builtins). This attempts to solve the problem by copying the atomic_word.h header to the current working directory, so it can be included without using an absolute path. libstdc++-v3/ChangeLog: PR libstdc++/125312 * acinclude.m4 (GLIBCXX_ENABLE_ATOMIC_BUILTINS): Copy header into cwd instead of including it via an absolute path. * configure: Regenerate.
