binutils-gdb/gnulib/import/m4/free.m4
Tom Tromey dc6c21dabf Update gnulib
This updates gnulib to a relatively recent commit.  Most of this was
done by the gnulib import script; the only change I made was to
update-gnulib.sh.

Tested on x86-64 Fedora 34.  I also did a mingw cross build.
2022-04-18 10:14:04 -06:00

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1.9 KiB
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# free.m4 serial 6
# Copyright (C) 2003-2005, 2009-2022 Free Software Foundation, Inc.
# This file is free software; the Free Software Foundation
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.
# Written by Paul Eggert and Bruno Haible.
AC_DEFUN([gl_FUNC_FREE],
[
AC_REQUIRE([gl_STDLIB_H_DEFAULTS])
dnl In the next release of POSIX, free must preserve errno.
dnl https://www.austingroupbugs.net/view.php?id=385
dnl https://sourceware.org/bugzilla/show_bug.cgi?id=17924
dnl So far, we know of three platforms that do this:
dnl * glibc >= 2.33, thanks to the fix for this bug:
dnl <https://sourceware.org/bugzilla/show_bug.cgi?id=17924>
dnl * OpenBSD >= 4.5, thanks to this commit:
dnl <https://cvsweb.openbsd.org/cgi-bin/cvsweb/src/lib/libc/stdlib/malloc.c.diff?r1=1.100&r2=1.101&f=h>
dnl * Solaris, because its malloc() implementation is based on brk(),
dnl not mmap(); hence its free() implementation makes no system calls.
dnl For other platforms, you can only be sure if they state it in their
dnl documentation, or by code inspection of the free() implementation in libc.
AC_CACHE_CHECK([whether free is known to preserve errno],
[gl_cv_func_free_preserves_errno],
[AC_COMPILE_IFELSE(
[AC_LANG_PROGRAM(
[[#include <stdlib.h>
]],
[[#if 2 < __GLIBC__ + (33 <= __GLIBC_MINOR__)
#elif defined __OpenBSD__
#elif defined __sun
#else
#error "'free' is not known to preserve errno"
#endif
]])],
[gl_cv_func_free_preserves_errno=yes],
[gl_cv_func_free_preserves_errno=no])
])
case $gl_cv_func_free_preserves_errno in
*yes)
AC_DEFINE([HAVE_FREE_POSIX], [1],
[Define if the 'free' function is guaranteed to preserve errno.])
;;
*) REPLACE_FREE=1 ;;
esac
])
# Prerequisites of lib/free.c.
AC_DEFUN([gl_PREREQ_FREE], [:])