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| author | Paul Eggert <eggert@cs.ucla.edu> | 2023-02-19 00:05:24 -0600 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2023-02-23 11:16:05 -0800 |
| commit | 7352d9fec59398c76c3bb8a2ef86ba58818f0342 (patch) | |
| tree | 34abc08d812cce346359130d0b81e90712ac50ea /m4 | |
| parent | bb3fd10e6309f017618a12b2c10d3bfb813bfc08 (diff) | |
| download | gnulib-7352d9fec59398c76c3bb8a2ef86ba58818f0342.tar.gz | |
lseek: avoid SEEK_HOLE bugs in FreeBSD, macOS
This attempts to fix <https://bugs.gnu.org/61386>, a bug in GNU cp
caused by a serious data corruption bug in FreeBSD and macOS.
* doc/posix-functions/lseek.texi: Mention the bug.
* lib/unistd.in.h (SEEK_DATA, SEEK_HOLE): Undef in macOS < 13 and
FreeBSD < 14. FreeBSD fixed the bug sometime during FreeBSD 13
<https://bugs.freebsd.org/256205>, so the "FreeBSD < 14" is
conservative. It’s unknown when Apple will fix macOS so use
macOS "9999" as a placeholder.
* m4/lseek.m4 (gl_FUNC_LSEEK): Replace lseek if on one of the
above platforms.
Diffstat (limited to 'm4')
| -rw-r--r-- | m4/lseek.m4 | 32 |
1 files changed, 26 insertions, 6 deletions
diff --git a/m4/lseek.m4 b/m4/lseek.m4 index fd4f1f27d3..6e1ab6ffaa 100644 --- a/m4/lseek.m4 +++ b/m4/lseek.m4 @@ -1,4 +1,4 @@ -# lseek.m4 serial 12 +# lseek.m4 serial 13 dnl Copyright (C) 2007, 2009-2023 Free Software Foundation, Inc. dnl This file is free software; the Free Software Foundation dnl gives unlimited permission to copy and/or distribute it, @@ -70,9 +70,29 @@ AC_DEFUN([gl_FUNC_LSEEK], REPLACE_LSEEK=1 fi - dnl macOS SEEK_DATA is incompatible with other platforms. - case $host_os in - darwin*) - REPLACE_LSEEK=1;; - esac + AS_IF([test $REPLACE_LSEEK = 0], + [AC_CACHE_CHECK([whether SEEK_DATA works but is incompatible with GNU], + [gl_cv_func_lseek_works_but_incompatible], + [AC_PREPROC_IFELSE( + [AC_LANG_SOURCE( + dnl Use macOS "9999" to stand for a future fixed macOS version. + dnl See ../lib/unistd.in.h and <https://bugs.gnu.org/61386>. + [[#include <unistd.h> + #if defined __APPLE__ && defined __MACH__ && defined SEEK_DATA + # ifdef __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ + # include <AvailabilityMacros.h> + # endif + # if 99990000 <= MAC_OS_X_VERSION_MIN_REQUIRED + # define LSEEK_WORKS_BUT_IS_INCOMPATIBLE_WITH_GNU + # endif + #endif + #ifndef LSEEK_WORKS_BUT_IS_INCOMPATIBLE_WITH_GNU + #error "No need to work around the bug" + #endif + ]])], + [gl_cv_func_lseek_works_but_incompatible=yes], + [gl_cv_func_lseek_works_but_incompatible=no])]) + if test "$gl_cv_func_lseek_works_but_incompatible" = yes; then + REPLACE_LSEEK=1 + fi]) ]) |