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| author | Jim Meyering <jim@meyering.net> | 1997-09-28 02:32:26 +0000 |
|---|---|---|
| committer | Jim Meyering <jim@meyering.net> | 1997-09-28 02:32:26 +0000 |
| commit | 02ade899f9b68dbefee266c2e38d2207da943215 (patch) | |
| tree | 84d0f32894f16a3312b9a2418f9cc9cbf14d0be1 /m4 | |
| parent | 3e90df41a9271fc23fd5ffa0b59d15b81c20b6e3 (diff) | |
| download | coreutils-02ade899f9b68dbefee266c2e38d2207da943215.tar.xz | |
Integrate test to detect bug in memcmp from the
Next x86 OpenStep C library. Test program from William Lewis.
Diffstat (limited to 'm4')
| -rw-r--r-- | m4/memcmp.m4 | 48 |
1 files changed, 45 insertions, 3 deletions
diff --git a/m4/memcmp.m4 b/m4/memcmp.m4 index e76aeda87..82b4b7cc8 100644 --- a/m4/memcmp.m4 +++ b/m4/memcmp.m4 @@ -1,4 +1,46 @@ -#serial 1 +#serial 2 + +dnl A replacement for autoconf's AC_FUNC_MEMCMP that detects +dnl the losing memcmp on some x86 Next systems. +AC_DEFUN(jm_AC_FUNC_MEMCMP, +[AC_CACHE_CHECK([for working memcmp], jm_cv_func_memcmp_working, +[AC_TRY_RUN( +changequote(<<, >>)dnl +<< +main() +{ + /* Some versions of memcmp are not 8-bit clean. */ + char c0 = 0x40, c1 = 0x80, c2 = 0x81; + if (memcmp(&c0, &c2, 1) >= 0 || memcmp(&c1, &c2, 1) >= 0) + exit (1); + + /* The Next x86 OpenStep bug shows up only when comparing 16 bytes + or more and with at least one buffer not starting on a 4-byte boundary. + William Lewis provided this test program. */ + { + char foo[21]; + char bar[21]; + int i; + for (i = 0; i < 4; i++) + { + char *a = foo + i; + char *b = bar + i; + strcpy (a, "--------01111111"); + strcpy (b, "--------10000000"); + if (memcmp (a, b, 16) >= 0) + exit (1); + } + exit (0); + } +} +>>, +changequote([, ])dnl + jm_cv_func_memcmp_working=yes, + jm_cv_func_memcmp_working=no, + jm_cv_func_memcmp_working=no)]) +test $jm_cv_func_memcmp_working = no && LIBOBJS="$LIBOBJS memcmp.o" +AC_SUBST(LIBOBJS)dnl +]) dnl If you use this macro in a package, you should dnl add the following two lines to acconfig.h: @@ -6,8 +48,8 @@ dnl /* Define to rpl_memcmp if the replacement function should be used. */ dnl #undef memcmp dnl AC_DEFUN(jm_FUNC_MEMCMP, -[AC_REQUIRE([AC_FUNC_MEMCMP])dnl - if test $ac_cv_func_memcmp_clean = no; then +[AC_REQUIRE([jm_AC_FUNC_MEMCMP])dnl + if test $jm_cv_func_memcmp_working = no; then AC_DEFINE_UNQUOTED(memcmp, rpl_memcmp) fi ]) |