https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110432
--- Comment #16 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-13 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:61bf34d17473d611bb2695329808810dbd5af478 commit r13-7591-g61bf34d17473d611bb2695329808810dbd5af478 Author: Jonathan Wakely <jwak...@redhat.com> Date: Fri Jun 30 11:07:35 2023 +0100 libstdc++: Fix iostream init for Clang on darwin [PR110432] The __has_attribute(init_priority) check in <iostream> is true for Clang on darwin, which means that user code including <iostream> thinks the library will initialize the global streams. However, when libstdc++ is built by GCC on darwin, the __has_attribute(init_priority) check is false, which means that the library thinks that user code will do the initialization when <iostream> is included. This means that the initialization is never done. Add an autoconf check so that the header and the library both make their decision based on the static properties of GCC at build time, with a consistent outcome. As a belt and braces check, also do the initialization in <iostream> if the compiler including that header doesn't support the attribute (even if the library also containers the initialization). This might result in redundant initialization done in <iostream>, but ensures the initialization happens somewhere if there's any doubt about the attribute working correctly due to missing linker support. libstdc++-v3/ChangeLog: PR libstdc++/110432 * acinclude.m4 (GLIBCXX_CHECK_INIT_PRIORITY): New. * config.h.in: Regenerate. * configure: Regenerate. * configure.ac: Use GLIBCXX_CHECK_INIT_PRIORITY. * include/std/iostream: Use new autoconf macro as well as __has_attribute. * src/c++98/ios_base_init.h: Use new autoconf macro instead of __has_attribute. Reviewed-by: Patrick Palka <ppa...@redhat.com> (cherry picked from commit fe2651affa8c15624188bfd062fb894648743431)
