Files
bison/m4/realloc.m4
2002-08-12 14:25:03 +00:00

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#serial 6
dnl From Jim Meyering.
dnl Determine whether realloc works when both arguments are 0.
dnl If it doesn't, arrange to use the replacement function.
dnl
AC_DEFUN([jm_FUNC_REALLOC],
[
dnl xmalloc.c requires that this symbol be defined so it doesn't
dnl mistakenly use a broken realloc -- as it might if this test were omitted.
AC_DEFINE(HAVE_DONE_WORKING_REALLOC_CHECK, 1,
[Define if the realloc check has been performed. ])
AC_CACHE_CHECK([whether realloc(0,0) returns a non-NULL pointer],
jm_cv_func_working_realloc,
[AC_TRY_RUN([
char *realloc ();
int
main ()
{
exit (realloc (0, 0) ? 0 : 1);
}
],
jm_cv_func_working_realloc=yes,
jm_cv_func_working_realloc=no,
dnl When crosscompiling, assume realloc(0,0) returns NULL.
jm_cv_func_working_realloc=no)
])
if test $jm_cv_func_working_realloc = yes; then
AC_DEFINE([HAVE_REALLOC], 1,
[Define to 1 if your system has a working `realloc' function,
and to 0 otherwise.])
else
AC_DEFINE([HAVE_REALLOC], 0)
AC_LIBOBJ(realloc)
AC_DEFINE(realloc, rpl_realloc,
[Define to rpl_realloc if the replacement function should be used.])
fi
])