50 lines
1.8 KiB
Text
50 lines
1.8 KiB
Text
|
# free.m4 serial 5
|
||
|
|
# Copyright (C) 2003-2005, 2009-2021 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) ;;
|
||
|
|
*) REPLACE_FREE=1 ;;
|
||
|
|
esac
|
||
|
|
])
|
||
|
|
|
||
|
|
# Prerequisites of lib/free.c.
|
||
|
|
AC_DEFUN([gl_PREREQ_FREE], [:])
|