1 # Check whether free (NULL) is supposed to work.
3 # Copyright (C) 2003, 2004, 2005, 2009, 2010 Free Software Foundation, Inc.
4 # This file is free software; the Free Software Foundation
5 # gives unlimited permission to copy and/or distribute it,
6 # with or without modifications, as long as this notice is preserved.
8 # Written by Paul Eggert.
10 # We can't test for free (NULL) even at runtime, since it might
11 # happen to "work" for our test program, but not in general. So, be
12 # conservative and use feature tests for relatively modern hosts,
13 # where free (NULL) is known to work. This costs a bit of
14 # performance on some older hosts, but we can fix that later if
17 AC_DEFUN([gl_FUNC_FREE],
19 AC_CACHE_CHECK([whether free (NULL) is known to work],
23 [[@%:@include <unistd.h>]],
24 [[@%:@if _POSIX_VERSION < 199009L && \
25 (defined unix || defined _unix || defined _unix_ \
26 || defined __unix || defined __unix__)
27 @%:@error "'free (NULL)' is not known to work"
29 [gl_cv_func_free=yes],
30 [gl_cv_func_free=no])])
32 if test $gl_cv_func_free = no; then
34 AC_DEFINE([free], [rpl_free],
35 [Define to rpl_free if the replacement function should be used.])
39 # Prerequisites of lib/free.c.
40 AC_DEFUN([gl_PREREQ_FREE], [:])