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>
2013-03-11 Eric Blake <eblake@redhat.com>
+ regex: port to mingw's recent addition of undeclared alarm
+ * 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.
+
putenv: avoid compilation warning on mingw
* lib/putenv.c (_unsetenv): Protect variable declaration.
(putenv): Fix indentation.
Portability problems not fixed by Gnulib:
@itemize
@item
+This function has no impact if <code>SIGALRM</code> is inherited as
+ignored; programs should use <code>signal (SIGALRM, SIG_DFL)</code> if
+it is important to ensure the alarm will fire.
+@item
+Use of this function in multi-threaded applications is not advised.
+@item
This function is missing on some platforms:
-mingw, MSVC 9.
+mingw (2011), MSVC 9.
+@item
+This function is conditionally declared in the non-standard
+@code{<io.h>} header on some platforms:
+mingw (2012 or newer).
@end itemize
-# frexp.m4 serial 14
+# frexp.m4 serial 15
dnl Copyright (C) 2007-2013 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
[
AC_REQUIRE([AC_PROG_CC])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
- AC_CHECK_FUNCS_ONCE([alarm])
+ AC_CHECK_DECLS_ONCE([alarm])
AC_CACHE_CHECK([whether frexp works], [gl_cv_func_frexp_works],
[
AC_RUN_IFELSE(
#include <float.h>
#include <math.h>
#include <string.h>
-#if HAVE_ALARM
+#if HAVE_DECL_ALARM
+# include <signal.h>
# include <unistd.h>
#endif
/* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0.
int i;
volatile double x;
double zero = 0.0;
-#if HAVE_ALARM
+#if HAVE_DECL_ALARM
/* NeXTstep 3.3 frexp() runs into an endless loop when called on an infinite
number. Let the test fail in this case. */
+ signal (SIGALRM, SIG_DFL);
alarm (5);
#endif
/* Test on denormalized numbers. */
-# 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
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.
# 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. */
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
-# serial 63
+# serial 64
# Copyright (C) 1996-2001, 2003-2013 Free Software Foundation, Inc.
#
# following run test, then default to *not* using the included regex.c.
# If cross compiling, assume the test would fail and use the included
# regex.c.
- AC_CHECK_FUNCS_ONCE([alarm])
+ AC_CHECK_DECLS_ONCE([alarm])
AC_CACHE_CHECK([for working re_compile_pattern],
[gl_cv_func_re_compile_pattern_working],
[AC_RUN_IFELSE(
#include <locale.h>
#include <limits.h>
#include <string.h>
- #if HAVE_ALARM
+ #if HAVE_DECL_ALARM
# include <unistd.h>
# include <signal.h>
#endif
const char *s;
struct re_registers regs;
-#if HAVE_ALARM
+#if HAVE_DECL_ALARM
/* Some builds of glibc go into an infinite loop on this test. */
signal (SIGALRM, SIG_DFL);
alarm (2);
-# remainderf.m4 serial 7
+# remainderf.m4 serial 8
dnl Copyright (C) 2012-2013 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
[
AC_REQUIRE([AC_PROG_CC])
AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
- AC_CHECK_FUNCS_ONCE([alarm])
+ AC_CHECK_DECLS_ONCE([alarm])
AC_CACHE_CHECK([whether remainderf works], [gl_cv_func_remainderf_works],
[
AC_RUN_IFELSE(
[AC_LANG_SOURCE([[
#include <math.h>
-#if HAVE_ALARM
+#if HAVE_DECL_ALARM
+# include <signal.h>
# include <unistd.h>
#endif
extern
float z;
int main ()
{
-#if HAVE_ALARM
+#if HAVE_DECL_ALARM
+ signal (SIGALRM, SIG_DFL);
alarm (5);
#endif
/* This test fails on IRIX 6.5. */
#include <locale.h>
#include <limits.h>
#include <string.h>
-#if HAVE_ALARM
+#if HAVE_DECL_ALARM
# include <unistd.h>
# include <signal.h>
#endif
const char *s;
struct re_registers regs;
-#if HAVE_ALARM
+#if HAVE_DECL_ALARM
/* Some builds of glibc go into an infinite loop on this test. */
int alarm_value = 2;
signal (SIGALRM, SIG_DFL);