mirror of
git://gcc.gnu.org/git/gcc.git
synced 2024-12-30 18:25:35 +08:00
72 lines
1.6 KiB
Plaintext
72 lines
1.6 KiB
Plaintext
|
dnl See whether strncmp reads past the end of its string parameters.
|
||
|
|
dnl On some versions of SunOS4 at least, strncmp reads a word at a time
|
||
|
|
dnl but erroneously reads past the end of strings. This can cause
|
||
|
|
dnl a SEGV in some cases.
|
||
|
|
AC_DEFUN(libiberty_AC_FUNC_STRNCMP,
|
||
|
|
[AC_REQUIRE([AC_FUNC_MMAP])
|
||
|
|
AC_CACHE_CHECK([for working strncmp], ac_cv_func_strncmp_works,
|
||
|
|
[AC_TRY_RUN([
|
||
|
|
/* Test by Jim Wilson and Kaveh Ghazi.
|
||
|
|
Check whether strncmp reads past the end of its string parameters. */
|
||
|
|
#include <sys/types.h>
|
||
|
|
|
||
|
|
#ifdef HAVE_FCNTL_H
|
||
|
|
#include <fcntl.h>
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifdef HAVE_SYS_MMAN_H
|
||
|
|
#include <sys/mman.h>
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifndef MAP_ANON
|
||
|
|
#ifdef MAP_ANONYMOUS
|
||
|
|
#define MAP_ANON MAP_ANONYMOUS
|
||
|
|
#else
|
||
|
|
#define MAP_ANON MAP_FILE
|
||
|
|
#endif
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#ifndef MAP_FILE
|
||
|
|
#define MAP_FILE 0
|
||
|
|
#endif
|
||
|
|
#ifndef O_RDONLY
|
||
|
|
#define O_RDONLY 0
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#define MAP_LEN 0x10000
|
||
|
|
|
||
|
|
main ()
|
||
|
|
{
|
||
|
|
#if defined(HAVE_MMAP) || defined(HAVE_MMAP_ANYWHERE)
|
||
|
|
char *p;
|
||
|
|
int dev_zero;
|
||
|
|
|
||
|
|
dev_zero = open ("/dev/zero", O_RDONLY);
|
||
|
|
if (dev_zero < 0)
|
||
|
|
exit (1);
|
||
|
|
|
||
|
|
p = (char *) mmap (0, MAP_LEN, PROT_READ|PROT_WRITE,
|
||
|
|
MAP_ANON|MAP_PRIVATE, dev_zero, 0);
|
||
|
|
if (p == (char *)-1)
|
||
|
|
exit (2);
|
||
|
|
else
|
||
|
|
{
|
||
|
|
char *string = "__si_type_info";
|
||
|
|
char *q = (char *) p + MAP_LEN - strlen (string) - 2;
|
||
|
|
char *r = (char *) p + 0xe;
|
||
|
|
|
||
|
|
strcpy (q, string);
|
||
|
|
strcpy (r, string);
|
||
|
|
strncmp (r, q, 14);
|
||
|
|
}
|
||
|
|
#endif /* HAVE_MMAP || HAVE_MMAP_ANYWHERE */
|
||
|
|
exit (0);
|
||
|
|
}
|
||
|
|
], ac_cv_func_strncmp_works=yes, ac_cv_func_strncmp_works=no,
|
||
|
|
ac_cv_func_strncmp_works=no)
|
||
|
|
rm -f core core.* *.core])
|
||
|
|
if test $ac_cv_func_strncmp_works = no ; then
|
||
|
|
LIBOBJS="$LIBOBJS strncmp.o"
|
||
|
|
fi
|
||
|
|
])
|