xref: /netbsd-src/external/gpl2/diffutils/dist/m4/malloc.m4 (revision 75f6d617e282811cb173c2ccfbf5df0dd71f7045)
1#serial 5
2
3dnl From Jim Meyering.
4dnl Determine whether malloc accepts 0 as its argument.
5dnl If it doesn't, arrange to use the replacement function.
6dnl
7
8AC_DEFUN([jm_FUNC_MALLOC],
9[
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. ])
14
15 AC_CACHE_CHECK([for working malloc], jm_cv_func_working_malloc,
16  [AC_TRY_RUN([
17    char *malloc ();
18    int
19    main ()
20    {
21      exit (malloc (0) ? 0 : 1);
22    }
23	  ],
24	 jm_cv_func_working_malloc=yes,
25	 jm_cv_func_working_malloc=no,
26	 dnl When crosscompiling, assume malloc is broken.
27	 jm_cv_func_working_malloc=no)
28  ])
29  if test $jm_cv_func_working_malloc = no; then
30    AC_LIBOBJ(malloc)
31    AC_DEFINE(malloc, rpl_malloc,
32      [Define to rpl_malloc if the replacement function should be used.])
33  fi
34])
35