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author | Paul Eggert <eggert@cs.ucla.edu> | 2003-06-04 20:09:47 +0000 |
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committer | Paul Eggert <eggert@cs.ucla.edu> | 2003-06-04 20:09:47 +0000 |
commit | a76a349e949dfad5716eb3893052070b770e949f (patch) | |
tree | c4e4e48105ef73c3cd1c7b29109d82348b77510d /m4/mktime.m4 | |
parent | 92295bc4b2a378893386efd3cf8cf9bc31024b59 (diff) | |
download | gnulib-a76a349e949dfad5716eb3893052070b770e949f.tar.gz |
Ensure we use gnulib mktime rather than glibc's mktime, on hosts
where mktime isn't the inverse of localtime (negative time_t).
Diffstat (limited to 'm4/mktime.m4')
-rw-r--r-- | m4/mktime.m4 | 184 |
1 files changed, 182 insertions, 2 deletions
diff --git a/m4/mktime.m4 b/m4/mktime.m4 index 94468eefa6..2131cff4fb 100644 --- a/m4/mktime.m4 +++ b/m4/mktime.m4 @@ -1,5 +1,5 @@ -# mktime.m4 serial 1 -dnl Copyright (C) 2002 Free Software Foundation, Inc. +# mktime.m4 serial 2 +dnl Copyright (C) 2002, 2003 Free Software Foundation, Inc. dnl This file is free software, distributed under the terms of the GNU dnl General Public License. As a special exception to the GNU General dnl Public License, this file may be distributed as part of a program @@ -8,6 +8,186 @@ dnl the same distribution terms as the rest of that program. dnl From Jim Meyering. +# Redefine AC_FUNC_MKTIME, to fix a bug in Autoconf 2.57 and earlier. +# This redefinition can be removed once a new version of Autoconf comes out. +# The redefinition is taken from +# <http://savannah.gnu.org/cgi-bin/viewcvs/*checkout*/autoconf/autoconf/lib/autoconf/functions.m4?rev=1.78>. +# AC_FUNC_MKTIME +# -------------- +AC_DEFUN([AC_FUNC_MKTIME], +[AC_REQUIRE([AC_HEADER_TIME])dnl +AC_CHECK_HEADERS(stdlib.h sys/time.h unistd.h) +AC_CHECK_FUNCS(alarm) +AC_CACHE_CHECK([for working mktime], ac_cv_func_working_mktime, +[AC_RUN_IFELSE([AC_LANG_SOURCE( +[[/* Test program from Paul Eggert and Tony Leneis. */ +#if TIME_WITH_SYS_TIME +# include <sys/time.h> +# include <time.h> +#else +# if HAVE_SYS_TIME_H +# include <sys/time.h> +# else +# include <time.h> +# endif +#endif + +#if HAVE_STDLIB_H +# include <stdlib.h> +#endif + +#if HAVE_UNISTD_H +# include <unistd.h> +#endif + +#if !HAVE_ALARM +# define alarm(X) /* empty */ +#endif + +/* Work around redefinition to rpl_putenv by other config tests. */ +#undef putenv + +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])) + +/* Fail if mktime fails to convert a date in the spring-forward gap. + Based on a problem report from Andreas Jaeger. */ +static void +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; + if (mktime (&tm) == (time_t)-1) + exit (1); +} + +static void +mktime_test1 (now) + time_t now; +{ + struct tm *lt; + if ((lt = localtime (&now)) && mktime (lt) != now) + exit (1); +} + +static void +mktime_test (now) + time_t now; +{ + mktime_test1 (now); + mktime_test1 ((time_t) (time_t_max - now)); + mktime_test1 ((time_t) (time_t_min + now)); +} + +static void +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); + if (tm.tm_mon != 2 || tm.tm_mday != 31) + exit (1); +} + +static void +bigtime_test (j) + 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)))) + exit (1); + } +} + +int +main () +{ + time_t t, delta; + int i, j; + + /* This test makes some buggy mktime implementations loop. + Give up after 60 seconds; a mktime slower than that + isn't worth using anyway. */ + alarm (60); + + for (time_t_max = 1; 0 < time_t_max; time_t_max *= 2) + continue; + time_t_max--; + if ((time_t) -1 < 0) + for (time_t_min = -1; (time_t) (time_t_min * 2) < 0; time_t_min *= 2) + continue; + 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; t += delta) + mktime_test (t); + mktime_test ((time_t) 1); + mktime_test ((time_t) (60 * 60)); + mktime_test ((time_t) (60 * 60 * 24)); + + for (j = 1; 0 < j; j *= 2) + bigtime_test (j); + bigtime_test (j - 1); + } + irix_6_4_bug (); + spring_forward_gap (); + exit (0); +}]])], + [ac_cv_func_working_mktime=yes], + [ac_cv_func_working_mktime=no], + [ac_cv_func_working_mktime=no])]) +if test $ac_cv_func_working_mktime = no; then + AC_LIBOBJ([mktime]) +fi +])# AC_FUNC_MKTIME + AC_DEFUN([gl_FUNC_MKTIME], [ AC_REQUIRE([AC_FUNC_MKTIME]) |