https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93151
--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The master branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:a2c2eec183acf25c9b214fa0827718e4d2fdfc93 commit r11-6137-ga2c2eec183acf25c9b214fa0827718e4d2fdfc93 Author: Jonathan Wakely <jwak...@redhat.com> Date: Tue Dec 15 20:28:11 2020 +0000 libstdc++: Test errno macros directly, not via autoconf [PR 93151] This fixes a bug caused by a mismatch between the macros defined by <errno.h> when GCC is built and the macros defined by <errno.h> when users include <system_error>. If the user code is compiled with _XOPEN_SOURCE defined to 500 or 600, Darwin suppresses the ENOTRECOVERABLE and EOWNERDEAD macros, which are not defined by SUSv3 (aka POSIX.1-2001). Since POSIX requires the errno macros to be macros (and not variables or enumerators) we can just test for them directly using the preprocessor. That means that <system_error> will match what is actuallydefined when it's included, not what was defined when GCC was built. With that change there is no need for the GLIBCXX_CHECK_SYSTEM_ERROR configure checks and they can be removed. libstdc++-v3/ChangeLog: PR libstdc++/93151 * acinclude.m4 (GLIBCXX_CHECK_SYSTEM_ERROR): Remove. * configure.ac: Regenerate. * config/os/generic/error_constants.h: Test POSIX errno macros directly, instead of corresponding _GLIBCXX_HAVE_EXXX macros. * testsuite/19_diagnostics/headers/system_error/errc_std_c++0x.cc: Likewise. * testsuite/19_diagnostics/headers/system_error/93151.cc: New test.
