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| author | Paul Eggert <eggert@cs.ucla.edu> | 2011-06-19 22:33:03 -0700 |
|---|---|---|
| committer | Paul Eggert <eggert@cs.ucla.edu> | 2011-06-19 22:33:29 -0700 |
| commit | 6cd9f12520b0d6f76d3230d7565feba1ecf29497 (patch) | |
| tree | 2549e859d3226d3b448958978026bdc923c37f33 | |
| parent | b1747413a80add0271d6909aecfdc2b638456257 (diff) | |
| download | autoconf-6cd9f12520b0d6f76d3230d7565feba1ecf29497.tar.gz | |
* lib/autoconf/functions.m4 (_AC_LIBOBJ_ALLOCA): Be even smarter.
GCC was too smart for the previous patch. See
<http://lists.gnu.org/archive/html/bug-autoconf/2011-06/msg00035.html>.
| -rw-r--r-- | ChangeLog | 6 | ||||
| -rw-r--r-- | lib/autoconf/functions.m4 | 15 |
2 files changed, 15 insertions, 6 deletions
@@ -1,3 +1,9 @@ +2011-06-19 Paul Eggert <eggert@cs.ucla.edu> + + * lib/autoconf/functions.m4 (_AC_LIBOBJ_ALLOCA): Be even smarter. + GCC was too smart for the previous patch. See + <http://lists.gnu.org/archive/html/bug-autoconf/2011-06/msg00035.html>. + 2011-06-18 Paul Eggert <eggert@cs.ucla.edu> * lib/autoconf/functions.m4 (_AC_LIBOBJ_ALLOCA): Try to outsmart GCC. diff --git a/lib/autoconf/functions.m4 b/lib/autoconf/functions.m4 index 31568872..cbc34135 100644 --- a/lib/autoconf/functions.m4 +++ b/lib/autoconf/functions.m4 @@ -325,17 +325,20 @@ AC_CACHE_CHECK([stack direction for C alloca], [AC_RUN_IFELSE([AC_LANG_SOURCE( [AC_INCLUDES_DEFAULT int -find_stack_direction (char *addr) +find_stack_direction (int *addr, int depth) { - char dummy; - return (! addr ? find_stack_direction (&dummy) - : addr < &dummy ? 1 : -1); + int dir, dummy = 0; + if (! addr) + addr = &dummy; + *addr = addr < &dummy ? 1 : addr == &dummy ? 0 : -1; + dir = depth ? find_stack_direction (addr, depth - 1) : 0; + return dir + dummy; } int -main (void) +main (int argc, char **argv) { - return find_stack_direction (0) < 0; + return find_stack_direction (0, argc + !argv + 20) < 0; }])], [ac_cv_c_stack_direction=1], [ac_cv_c_stack_direction=-1], |