tinc/m4/malloc.m4
2019-08-26 13:44:36 +02:00

42 lines
1.2 KiB
Text

#serial 1
dnl From Jim Meyering.
dnl Determine whether malloc accepts 0 as its argument.
dnl If it doesn't, arrange to use the replacement function.
dnl
dnl If you use this macro in a package, you should
dnl add the following two lines to acconfig.h:
dnl /* Define to rpl_malloc if the replacement function should be used. */
dnl #undef malloc
dnl
AC_DEFUN([jm_FUNC_MALLOC],
[
if test x = y; then
dnl This code is deliberately never run via ./configure.
dnl FIXME: this is a gross hack to make autoheader put an entry
dnl for this symbol in config.h.in.
AC_CHECK_FUNCS(DONE_WORKING_MALLOC_CHECK)
fi
dnl xmalloc.c requires that this symbol be defined so it doesn't
dnl mistakenly use a broken malloc -- as it might if this test were omitted.
AC_DEFINE(HAVE_DONE_WORKING_MALLOC_CHECK, 1, [Needed for xmalloc.c])
AC_CACHE_CHECK([for working malloc], jm_cv_func_working_malloc,
[AC_RUN_IFELSE([AC_LANG_SOURCE([
char *malloc ();
int
main ()
{
exit (malloc (0) ? 0 : 1);
}
])],
[jm_cv_func_working_malloc=yes],
[jm_cv_func_working_malloc=no],
[When crosscompiling])
])
if test $jm_cv_func_working_malloc = no; then
AC_LIBOBJ([malloc])
AC_DEFINE(malloc, rpl_malloc, [Replacement malloc()])
fi
])