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| author | Jonathan Wakely <jwakely@redhat.com> | 2023-07-06 17:10:41 +0100 |
|---|---|---|
| committer | Jonathan Wakely <jwakely@redhat.com> | 2023-07-12 21:04:13 +0100 |
| commit | 2f6bbc9a7d9a62423c576e13dc46323fe16ba5aa (patch) | |
| tree | db52364f1ac7727290c016d724bb0c24b60127f9 /libstdc++-v3/acinclude.m4 | |
| parent | 519b29c9e53d110d165059faa8a300c74450235a (diff) | |
| download | gcc-2f6bbc9a7d9a62423c576e13dc46323fe16ba5aa.zip gcc-2f6bbc9a7d9a62423c576e13dc46323fe16ba5aa.tar.gz gcc-2f6bbc9a7d9a62423c576e13dc46323fe16ba5aa.tar.bz2 | |
libstdc++: Fix --enable-cstdio=stdio_pure [PR110574]
When configured with --enable-cstdio=stdio_pure we need to consistently
use fseek and not mix seeks on the file descriptor with reads and writes
on the FILE stream.
There are also a number of bugs related to error handling and return
values, because fread and fwrite return 0 on error, not -1, and fseek
returns 0 on success, not the file offset.
libstdc++-v3/ChangeLog:
PR libstdc++/110574
* acinclude.m4 (GLIBCXX_CHECK_LFS): Check for fseeko and ftello
and define _GLIBCXX_USE_FSEEKO_FTELLO.
* config.h.in: Regenerate.
* configure: Regenerate.
* config/io/basic_file_stdio.cc (xwrite) [_GLIBCXX_USE_STDIO_PURE]:
Check for fwrite error correctly.
(__basic_file<char>::xsgetn) [_GLIBCXX_USE_STDIO_PURE]: Check for
fread error correctly.
(get_file_offset): New function.
(__basic_file<char>::seekoff) [_GLIBCXX_USE_STDIO_PURE]: Use
fseeko if available. Use get_file_offset instead of return value
of fseek.
(__basic_file<char>::showmanyc): Use get_file_offset.
Diffstat (limited to 'libstdc++-v3/acinclude.m4')
| -rw-r--r-- | libstdc++-v3/acinclude.m4 | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/libstdc++-v3/acinclude.m4 b/libstdc++-v3/acinclude.m4 index 823832f..b25378e 100644 --- a/libstdc++-v3/acinclude.m4 +++ b/libstdc++-v3/acinclude.m4 @@ -497,6 +497,22 @@ AC_DEFUN([GLIBCXX_CHECK_LFS], [ if test $glibcxx_cv_LFS = yes; then AC_DEFINE(_GLIBCXX_USE_LFS, 1, [Define if LFS support is available.]) fi + + AC_CACHE_CHECK([for fseeko and ftello], glibcxx_cv_posix_lfs, [ + GCC_TRY_COMPILE_OR_LINK( + [#include <stdio.h> + ], + [FILE* fp; + fseeko(fp, 0, SEEK_CUR); + ftello(fp); + ], + [glibcxx_cv_posix_lfs=yes], + [glibcxx_cv_posix_lfs=no]) + ]) + if test $glibcxx_cv_posix_lfs = yes; then + AC_DEFINE(_GLIBCXX_USE_FSEEKO_FTELLO, 1, [Define if fseeko and ftello are available.]) + fi + CXXFLAGS="$ac_save_CXXFLAGS" AC_LANG_RESTORE ]) |