https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81091
--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> --- The releases/gcc-8 branch has been updated by Jonathan Wakely <r...@gcc.gnu.org>: https://gcc.gnu.org/g:56b6c2ba3a45c768a33f726b130a56fc19cca650 commit r8-10084-g56b6c2ba3a45c768a33f726b130a56fc19cca650 Author: Jonathan Wakely <jwak...@redhat.com> Date: Thu Jan 9 13:38:43 2020 +0000 Build filesystem library with large file support Enable AC_SYS_LARGEFILE to set the macros needed for large file APIs to be used by default. We do not want to define those macros in the public headers that users include. The values of the macros are copied to a separate file that is only included by the filesystem sources during the build, and then the macros in <bits/c++config.h> are renamed so that they don't have any effect in user code including our headers. Also use larger type for result of filesystem::file_size to avoid truncation of large values on 32-bit systems (PR 91947). Backport from mainlne 2019-10-04 Jonathan Wakely <jwak...@redhat.com> PR libstdc++/81091 PR libstdc++/91947 * configure.ac: Use AC_SYS_LARGEFILE to enable 64-bit file APIs. * config.h.in: Regenerate: * configure: Regenerate: * include/Makefile.am (${host_builddir}/largefile-config.h): New target to generate config header for filesystem library. (${host_builddir}/c++config.h): Rename macros for large file support. * include/Makefile.in: Regenerate. * src/c++17/fs_dir.cc: Include new config header. * src/c++17/fs_ops.cc: Likewise. (filesystem::file_size): Use uintmax_t for size. * src/filesystem/dir.cc: Include new config header. * src/filesystem/ops.cc: Likewise. (experimental::filesystem::file_size): Use uintmax_t for size.