# Check whether free (NULL) is supposed to work. # Copyright (C) 2003, 2004, 2005 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. # We can't test for free (NULL) even at runtime, since it might # happen to "work" for our test program, but not in general. So, be # conservative and use feature tests for relatively modern hosts, # where free (NULL) is known to work. This costs a bit of # performance on some older hosts, but we can fix that later if # needed. AC_DEFUN([gl_FUNC_FREE], [ AC_CACHE_CHECK([whether free (NULL) is known to work], [gl_cv_func_free], [AC_COMPILE_IFELSE( [AC_LANG_PROGRAM( [[@%:@include <unistd.h>]], [[@%:@if _POSIX_VERSION < 199009L && \ (defined unix || defined _unix || defined _unix_ \ || defined __unix || defined __unix__) @%:@error "'free (NULL)' is not known to work" @%:@endif]])], [gl_cv_func_free=yes], [gl_cv_func_free=no])]) if test $gl_cv_func_free = no; then AC_LIBOBJ(free) AC_DEFINE(free, rpl_free, [Define to rpl_free if the replacement function should be used.]) fi ]) # Prerequisites of lib/free.c. AC_DEFUN([gl_PREREQ_FREE], [:])