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-rw-r--r--m4/mktime.m4298
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diff --git a/m4/mktime.m4 b/m4/mktime.m4
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+# serial 35
+dnl Copyright (C) 2002-2003, 2005-2007, 2009-2020 Free Software Foundation,
+dnl Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+dnl From Jim Meyering.
+
+AC_DEFUN([gl_TIME_T_IS_SIGNED],
+[
+ AC_CACHE_CHECK([whether time_t is signed],
+ [gl_cv_time_t_is_signed],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_PROGRAM([[#include <time.h>
+ char time_t_signed[(time_t) -1 < 0 ? 1 : -1];]])],
+ [gl_cv_time_t_is_signed=yes],
+ [gl_cv_time_t_is_signed=no])])
+ if test $gl_cv_time_t_is_signed = yes; then
+ AC_DEFINE([TIME_T_IS_SIGNED], [1], [Define to 1 if time_t is signed.])
+ fi
+])
+
+dnl Test whether mktime works. Set gl_cv_func_working_mktime.
+AC_DEFUN([gl_FUNC_MKTIME_WORKS],
+[
+ AC_REQUIRE([gl_TIME_T_IS_SIGNED])
+ AC_REQUIRE([AC_CANONICAL_HOST]) dnl for cross-compiles
+
+ dnl We don't use AC_FUNC_MKTIME any more, because it is no longer maintained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_DECLS_ONCE([alarm])
+ AC_REQUIRE([gl_MULTIARCH])
+ AC_CACHE_CHECK([for working mktime], [gl_cv_func_working_mktime],
+ [if test $APPLE_UNIVERSAL_BUILD = 1; then
+ # A universal build on Apple Mac OS X platforms.
+ # The test result would be 'yes' in 32-bit mode and 'no' in 64-bit mode.
+ # But we need a configuration result that is valid in both modes.
+ gl_cv_func_working_mktime="guessing no"
+ else
+ AC_RUN_IFELSE(
+ [AC_LANG_SOURCE(
+[[/* Test program from Paul Eggert and Tony Leneis. */
+#include <limits.h>
+#include <stdlib.h>
+#include <time.h>
+
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+
+#if HAVE_DECL_ALARM
+# include <signal.h>
+#endif
+
+]GL_MDA_DEFINES[
+
+#ifndef TIME_T_IS_SIGNED
+# define TIME_T_IS_SIGNED 0
+#endif
+
+static time_t time_t_max;
+static time_t time_t_min;
+
+/* Values we'll use to set the TZ environment variable. */
+static char *tz_strings[] = {
+ (char *) 0, "TZ=GMT0", "TZ=JST-9",
+ "TZ=EST+3EDT+2,M10.1.0/00:00:00,M2.3.0/00:00:00"
+};
+#define N_STRINGS (sizeof (tz_strings) / sizeof (tz_strings[0]))
+
+/* Return 0 if mktime fails to convert a date in the spring-forward gap.
+ Based on a problem report from Andreas Jaeger. */
+static int
+spring_forward_gap ()
+{
+ /* glibc (up to about 1998-10-07) failed this test. */
+ struct tm tm;
+
+ /* Use the portable POSIX.1 specification "TZ=PST8PDT,M4.1.0,M10.5.0"
+ instead of "TZ=America/Vancouver" in order to detect the bug even
+ on systems that don't support the Olson extension, or don't have the
+ full zoneinfo tables installed. */
+ putenv ("TZ=PST8PDT,M4.1.0,M10.5.0");
+
+ tm.tm_year = 98;
+ tm.tm_mon = 3;
+ tm.tm_mday = 5;
+ tm.tm_hour = 2;
+ tm.tm_min = 0;
+ tm.tm_sec = 0;
+ tm.tm_isdst = -1;
+ return mktime (&tm) != (time_t) -1;
+}
+
+static int
+mktime_test1 (time_t now)
+{
+ struct tm *lt;
+ return ! (lt = localtime (&now)) || mktime (lt) == now;
+}
+
+static int
+mktime_test (time_t now)
+{
+ return (mktime_test1 (now)
+ && mktime_test1 ((time_t) (time_t_max - now))
+ && mktime_test1 ((time_t) (time_t_min + now)));
+}
+
+static int
+irix_6_4_bug ()
+{
+ /* Based on code from Ariel Faigon. */
+ struct tm tm;
+ tm.tm_year = 96;
+ tm.tm_mon = 3;
+ tm.tm_mday = 0;
+ tm.tm_hour = 0;
+ tm.tm_min = 0;
+ tm.tm_sec = 0;
+ tm.tm_isdst = -1;
+ mktime (&tm);
+ return tm.tm_mon == 2 && tm.tm_mday == 31;
+}
+
+static int
+bigtime_test (int j)
+{
+ struct tm tm;
+ time_t now;
+ tm.tm_year = tm.tm_mon = tm.tm_mday = tm.tm_hour = tm.tm_min = tm.tm_sec = j;
+ now = mktime (&tm);
+ if (now != (time_t) -1)
+ {
+ struct tm *lt = localtime (&now);
+ if (! (lt
+ && lt->tm_year == tm.tm_year
+ && lt->tm_mon == tm.tm_mon
+ && lt->tm_mday == tm.tm_mday
+ && lt->tm_hour == tm.tm_hour
+ && lt->tm_min == tm.tm_min
+ && lt->tm_sec == tm.tm_sec
+ && lt->tm_yday == tm.tm_yday
+ && lt->tm_wday == tm.tm_wday
+ && ((lt->tm_isdst < 0 ? -1 : 0 < lt->tm_isdst)
+ == (tm.tm_isdst < 0 ? -1 : 0 < tm.tm_isdst))))
+ return 0;
+ }
+ return 1;
+}
+
+static int
+year_2050_test ()
+{
+ /* The correct answer for 2050-02-01 00:00:00 in Pacific time,
+ ignoring leap seconds. */
+ unsigned long int answer = 2527315200UL;
+
+ struct tm tm;
+ time_t t;
+ tm.tm_year = 2050 - 1900;
+ tm.tm_mon = 2 - 1;
+ tm.tm_mday = 1;
+ tm.tm_hour = tm.tm_min = tm.tm_sec = 0;
+ tm.tm_isdst = -1;
+
+ /* Use the portable POSIX.1 specification "TZ=PST8PDT,M4.1.0,M10.5.0"
+ instead of "TZ=America/Vancouver" in order to detect the bug even
+ on systems that don't support the Olson extension, or don't have the
+ full zoneinfo tables installed. */
+ putenv ("TZ=PST8PDT,M4.1.0,M10.5.0");
+
+ t = mktime (&tm);
+
+ /* Check that the result is either a failure, or close enough
+ to the correct answer that we can assume the discrepancy is
+ due to leap seconds. */
+ return (t == (time_t) -1
+ || (0 < t && answer - 120 <= t && t <= answer + 120));
+}
+
+int
+main ()
+{
+ int result = 0;
+ time_t t, delta;
+ int i, j;
+ int time_t_signed_magnitude = (time_t) ~ (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_IS_SIGNED
+ ? (time_t) -1
+ : ((((time_t) 1 << (sizeof (time_t) * CHAR_BIT - 2)) - 1)
+ * 2 + 1));
+ time_t_min = (! TIME_T_IS_SIGNED
+ ? (time_t) 0
+ : time_t_signed_magnitude
+ ? ~ (time_t) 0
+ : ~ time_t_max);
+
+ delta = time_t_max / 997; /* a suitable prime number */
+ for (i = 0; i < N_STRINGS; i++)
+ {
+ if (tz_strings[i])
+ putenv (tz_strings[i]);
+
+ for (t = 0; t <= time_t_max - delta && (result & 1) == 0; t += delta)
+ if (! mktime_test (t))
+ result |= 1;
+ if ((result & 2) == 0
+ && ! (mktime_test ((time_t) 1)
+ && mktime_test ((time_t) (60 * 60))
+ && mktime_test ((time_t) (60 * 60 * 24))))
+ result |= 2;
+
+ for (j = 1; (result & 4) == 0; j <<= 1)
+ {
+ if (! bigtime_test (j))
+ result |= 4;
+ if (INT_MAX / 2 < j)
+ break;
+ }
+ if ((result & 8) == 0 && ! bigtime_test (INT_MAX))
+ result |= 8;
+ }
+ if (! irix_6_4_bug ())
+ result |= 16;
+ if (! spring_forward_gap ())
+ result |= 32;
+ if (! year_2050_test ())
+ result |= 64;
+ return result;
+}]])],
+ [gl_cv_func_working_mktime=yes],
+ [gl_cv_func_working_mktime=no],
+ [case "$host_os" in
+ # Guess no on native Windows.
+ mingw*) gl_cv_func_working_mktime="guessing no" ;;
+ *) gl_cv_func_working_mktime="$gl_cross_guess_normal" ;;
+ esac
+ ])
+ fi
+ ])
+])
+
+dnl Main macro of module 'mktime'.
+AC_DEFUN([gl_FUNC_MKTIME],
+[
+ AC_REQUIRE([gl_HEADER_TIME_H_DEFAULTS])
+ AC_REQUIRE([AC_CANONICAL_HOST])
+ AC_REQUIRE([gl_FUNC_MKTIME_WORKS])
+
+ REPLACE_MKTIME=0
+ if test "$gl_cv_func_working_mktime" != yes; then
+ REPLACE_MKTIME=1
+ AC_DEFINE([NEED_MKTIME_WORKING], [1],
+ [Define if the compilation of mktime.c should define 'mktime'
+ with the algorithmic workarounds.])
+ fi
+ case "$host_os" in
+ mingw*)
+ REPLACE_MKTIME=1
+ AC_DEFINE([NEED_MKTIME_WINDOWS], [1],
+ [Define if the compilation of mktime.c should define 'mktime'
+ with the native Windows TZ workaround.])
+ ;;
+ esac
+])
+
+dnl Main macro of module 'mktime-internal'.
+AC_DEFUN([gl_FUNC_MKTIME_INTERNAL], [
+ AC_REQUIRE([gl_FUNC_MKTIME_WORKS])
+
+ WANT_MKTIME_INTERNAL=0
+ dnl BeOS has __mktime_internal in libc, but other platforms don't.
+ AC_CHECK_FUNC([__mktime_internal],
+ [AC_DEFINE([mktime_internal], [__mktime_internal],
+ [Define to the real name of the mktime_internal function.])
+ ],
+ [dnl mktime works but it doesn't export __mktime_internal,
+ dnl so we need to substitute our own mktime implementation.
+ WANT_MKTIME_INTERNAL=1
+ AC_DEFINE([NEED_MKTIME_INTERNAL], [1],
+ [Define if the compilation of mktime.c should define 'mktime_internal'.])
+ ])
+])
+
+# Prerequisites of lib/mktime.c.
+AC_DEFUN([gl_PREREQ_MKTIME], [:])