diff m4/mktime.m4 @ 17366:9855b352e525

regex: port to mingw's recent addition of undeclared alarm On mingw (at least, when cross-compiling with Fedora 18's mingw32-headers-2.0.999-0.15.trunk.20121110.fc18.noarch build), compilation of test-regex fails: test-regex.c: In function 'main': test-regex.c:42:11: error: 'SIGALRM' undeclared (first use in this function) test-regex.c:42:11: note: each undeclared identifier is reported only once for each function it appears in test-regex.c:43:3: warning: implicit declaration of function 'alarm' It turns out that recent mingw64 added an export of alarm() and SIGALRM, but guarded their declarations behind __USE_MINGW_ALARM (default off, and with alarm() only in the non-standard <io.h>); so the m4 tests were setting HAVE_ALARM to 1 based on link success but then failing to compile. * doc/posix-functions/alarm.texi (alarm): Document that alarm exists but still doesn't work in newer mingw. * m4/frexp.m4 (gl_FUNC_FREXP_WORKS): Check for alarm declaration, not existence. Ensure SIGALRM is not trapped. * m4/mktime.m4 (gl_FUNC_MKTIME): Likewise. * m4/regex.m4 (gl_REGEX): Likewise. * m4/remainderf.m4 (gl_FUNC_REMAINDERF_WORKS): Likewise. * tests/test-regex.c (main): Use correct probe for alarm. Signed-off-by: Eric Blake <eblake@redhat.com>
author Eric Blake <eblake@redhat.com>
date Mon, 11 Mar 2013 14:51:33 -0600
parents e542fd46ad6f
children a4a11de07980
line wrap: on
line diff
--- a/m4/mktime.m4
+++ b/m4/mktime.m4
@@ -1,4 +1,4 @@
-# serial 24
+# serial 25
 dnl Copyright (C) 2002-2003, 2005-2007, 2009-2013 Free Software Foundation,
 dnl Inc.
 dnl This file is free software; the Free Software Foundation
@@ -14,7 +14,7 @@
   dnl We don't use AC_FUNC_MKTIME any more, because it is no longer maintained
   dnl in Autoconf and because it invokes AC_LIBOBJ.
   AC_CHECK_HEADERS_ONCE([unistd.h])
-  AC_CHECK_FUNCS_ONCE([alarm])
+  AC_CHECK_DECLS_ONCE([alarm])
   AC_REQUIRE([gl_MULTIARCH])
   if test $APPLE_UNIVERSAL_BUILD = 1; then
     # A universal build on Apple Mac OS X platforms.
@@ -34,8 +34,8 @@
 # include <unistd.h>
 #endif
 
-#ifndef HAVE_ALARM
-# define alarm(X) /* empty */
+#ifndef HAVE_DECL_ALARM
+# include <signal.h>
 #endif
 
 /* Work around redefinition to rpl_putenv by other config tests.  */
@@ -171,10 +171,13 @@
   int time_t_signed_magnitude = (time_t) ~ (time_t) 0 < (time_t) -1;
   int time_t_signed = ! ((time_t) 0 < (time_t) -1);
 
+#if HAVE_DECL_ALARM
   /* This test makes some buggy mktime implementations loop.
      Give up after 60 seconds; a mktime slower than that
      isn't worth using anyway.  */
+  signal (SIGALRM, SIG_DFL);
   alarm (60);
+#endif
 
   time_t_max = (! time_t_signed
                 ? (time_t) -1