4 dnl Determine whether malloc accepts 0 as its argument.
5 dnl If it doesn't, arrange to use the replacement function.
8 AC_DEFUN([jm_FUNC_MALLOC],
10 dnl xmalloc.c requires that this symbol be defined so it doesn't
11 dnl mistakenly use a broken malloc -- as it might if this test were omitted.
12 AC_DEFINE(HAVE_DONE_WORKING_MALLOC_CHECK, 1,
13 [Define if the malloc check has been performed. ])
15 AC_CACHE_CHECK([whether malloc(0) returns a non-NULL pointer],
16 jm_cv_func_working_malloc,
22 exit (malloc (0) ? 0 : 1);
25 jm_cv_func_working_malloc=yes,
26 jm_cv_func_working_malloc=no,
27 dnl When crosscompiling, assume malloc(0) returns NULL.
28 jm_cv_func_working_malloc=no)
30 if test $jm_cv_func_working_malloc = no; then
32 AC_DEFINE(malloc, rpl_malloc,
33 [Define to rpl_malloc if the replacement function should be used.])