diff options
Diffstat (limited to 'libiberty/aclocal.m4')
| -rw-r--r-- | libiberty/aclocal.m4 | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/libiberty/aclocal.m4 b/libiberty/aclocal.m4 new file mode 100644 index 0000000..b6a38d6 --- /dev/null +++ b/libiberty/aclocal.m4 @@ -0,0 +1,71 @@ +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 +]) |