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comparison m4/frexp.m4 @ 17366:9855b352e525

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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
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equal deleted inserted replaced
17365:a154fccd3b21 17366:9855b352e525
1 # frexp.m4 serial 14 1 # frexp.m4 serial 15
2 dnl Copyright (C) 2007-2013 Free Software Foundation, Inc. 2 dnl Copyright (C) 2007-2013 Free Software Foundation, Inc.
3 dnl This file is free software; the Free Software Foundation 3 dnl This file is free software; the Free Software Foundation
4 dnl gives unlimited permission to copy and/or distribute it, 4 dnl gives unlimited permission to copy and/or distribute it,
5 dnl with or without modifications, as long as this notice is preserved. 5 dnl with or without modifications, as long as this notice is preserved.
6 6
91 dnl and on negative zero (this fails e.g. on NetBSD 4.99 and mingw). 91 dnl and on negative zero (this fails e.g. on NetBSD 4.99 and mingw).
92 AC_DEFUN([gl_FUNC_FREXP_WORKS], 92 AC_DEFUN([gl_FUNC_FREXP_WORKS],
93 [ 93 [
94 AC_REQUIRE([AC_PROG_CC]) 94 AC_REQUIRE([AC_PROG_CC])
95 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles 95 AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
96 AC_CHECK_FUNCS_ONCE([alarm]) 96 AC_CHECK_DECLS_ONCE([alarm])
97 AC_CACHE_CHECK([whether frexp works], [gl_cv_func_frexp_works], 97 AC_CACHE_CHECK([whether frexp works], [gl_cv_func_frexp_works],
98 [ 98 [
99 AC_RUN_IFELSE( 99 AC_RUN_IFELSE(
100 [AC_LANG_SOURCE([[ 100 [AC_LANG_SOURCE([[
101 #include <float.h> 101 #include <float.h>
102 #include <math.h> 102 #include <math.h>
103 #include <string.h> 103 #include <string.h>
104 #if HAVE_ALARM 104 #if HAVE_DECL_ALARM
105 # include <signal.h>
105 # include <unistd.h> 106 # include <unistd.h>
106 #endif 107 #endif
107 /* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0. 108 /* HP cc on HP-UX 10.20 has a bug with the constant expression -0.0.
108 ICC 10.0 has a bug when optimizing the expression -zero. 109 ICC 10.0 has a bug when optimizing the expression -zero.
109 The expression -DBL_MIN * DBL_MIN does not work when cross-compiling 110 The expression -DBL_MIN * DBL_MIN does not work when cross-compiling
122 { 123 {
123 int result = 0; 124 int result = 0;
124 int i; 125 int i;
125 volatile double x; 126 volatile double x;
126 double zero = 0.0; 127 double zero = 0.0;
127 #if HAVE_ALARM 128 #if HAVE_DECL_ALARM
128 /* NeXTstep 3.3 frexp() runs into an endless loop when called on an infinite 129 /* NeXTstep 3.3 frexp() runs into an endless loop when called on an infinite
129 number. Let the test fail in this case. */ 130 number. Let the test fail in this case. */
131 signal (SIGALRM, SIG_DFL);
130 alarm (5); 132 alarm (5);
131 #endif 133 #endif
132 /* Test on denormalized numbers. */ 134 /* Test on denormalized numbers. */
133 for (i = 1, x = 1.0; i >= DBL_MIN_EXP; i--, x *= 0.5) 135 for (i = 1, x = 1.0; i >= DBL_MIN_EXP; i--, x *= 0.5)
134 ; 136 ;