Duncan Simpson <dps@io.stargate.co.uk>
AllPermissive
Copying and distribution of this file, with or
without modification, are permitted in any medium without royalty provided the copyright
notice and this notice are preserved. Users of this software should generally follow the
principles of the
MIT License includings its disclaimer.
cryp.to ac-archive's C Support (released)
Checks whether snprintf ignores the value of n or not and defines
HAVE_SNPRINTF_BUG if it does.
AC_DEFUN([dps_snprintf_oflow],
[AC_MSG_CHECKING(whether snprintf ignores n)
AC_CACHE_VAL(dps_cv_snprintf_bug,
[AC_TRY_RUN(
changequote(<<, >>)dnl
<<#include <stdio.h>
#ifndef HAVE_SNPRINTF
#ifdef HAVE_VSNPRINTF
#include "vsnprintf.h"
#else /* not HAVE_VSNPRINTF */
#include "vsnprintf.c"
#endif /* HAVE_VSNPRINTF */
#endif /* HAVE_SNPRINTF */
int main(void)
{
char ovbuf[7];
int i;
for (i=0; i<7; i++) ovbuf[i]='x';
snprintf(ovbuf, 4,"foo%s", "bar");
if (ovbuf[5]!='x') exit(1);
snprintf(ovbuf, 4,"foo%d", 666);
if (ovbuf[5]!='x') exit(1);
exit(0);
} >>
changequote([, ]), dps_cv_snprintf_bug=0, dps_cv_snprintf_bug=1,
dps_cv_snprintf_bug=2)])
if test $dps_cv_snprintf_bug -eq 0; then
AC_MSG_RESULT([no, snprintf is ok])
else if test $dps_cv_snprintf_bug -eq 1; then
AC_MSG_RESULT([yes, snprintf is broken])
AC_DEFINE(HAVE_SNPRINTF_BUG,1)
else
AC_MSG_RESULT([unknown, assuming yes])
AC_DEFINE(HAVE_SNPRINTF_BUG,1)
fi; fi])