https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104883
--- Comment #5 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-12 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:aa18735f7aa99b40c56b3e3aacb1b28cb805bb90 commit r12-9099-gaa18735f7aa99b40c56b3e3aacb1b28cb805bb90 Author: Jonathan Wakely <jwak...@redhat.com> Date: Tue Jan 31 22:16:31 2023 +0000 libstdc++: Fix build failures for avr The abr-libc <errno.h> does not define EOVERFLOW, which means that std::errc::value_too_large is not defined, and so <charconv> cannot be compiled. Define value_too_large for avr with a value that does not clash with any that is defined in <errno.h>. This is a kluge to fix bootstrap for avr; it can be removed after PR libstdc++/104883 is resolved. The avr-libc <errno.h> fails to meet the C and POSIX requirements that each error macro has a distinct integral value, and is usable in #if directives. Add a special case for avr to system_error.cc so that only the valid errors are recognized. Also disable the errno checks in std::filesystem::remove_all that assume a meaningful value for errno. On avr-libc <unistd.h> exists but does not define the POSIX functions needed by std::filesystem, so _GLIBCXX_HAVE_UNISTD_H is not sufficient to check for basic POSIX APIs. Check !defined __AVR__ as well as _GLIBCXX_HAVE_UNISTD_H before using those functions. This is a kluge and we should really have a specific macro that says the required functions are available. libstdc++-v3/ChangeLog: * config/os/generic/error_constants.h (errc::value_too_large) [__AVR__]: Define. * src/c++11/system_error.cc (system_category::default_error_condition) [__AVR__]: Only match recognize values equal to EDOM, ERANGE, ENOSYS and EINTR. * src/c++17/fs_ops.cc (fs::current_path) [__AVR__]: Do not check for ENOENT etc. in switch. (fs::remove_all) [__AVR__]: Likewise. * src/filesystem/ops-common.h [__AVR__]: Do not use POSIX open, close etc. (cherry picked from commit 2d2e163d12f64a5e68f9e0381751ed9d5d6d3617)
