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dnl Time zone functions: tzalloc, localtime_rz, etc. |
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dnl Copyright (C) 2015-2023 Free Software Foundation, Inc. |
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dnl This file is free software; the Free Software Foundation |
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dnl gives unlimited permission to copy and/or distribute it, |
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dnl with or without modifications, as long as this notice is preserved. |
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dnl Written by Paul Eggert. |
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AC_DEFUN([gl_TIME_RZ], |
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[ |
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AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) |
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AC_REQUIRE([gl_TIME_H_DEFAULTS]) |
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AC_REQUIRE([AC_STRUCT_TIMEZONE]) |
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# On Mac OS X 10.6, localtime loops forever with some time_t values. |
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# See Bug#27706, Bug#27736, and |
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# https://lists.gnu.org/r/bug-gnulib/2017-07/msg00142.html |
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AC_CACHE_CHECK([whether localtime works even near extrema], |
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[gl_cv_func_localtime_works], |
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[gl_cv_func_localtime_works=yes |
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AC_RUN_IFELSE( |
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[AC_LANG_PROGRAM( |
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[[#include <stdlib.h> |
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#include <string.h> |
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#include <unistd.h> |
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#include <time.h> |
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]], [[ |
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time_t t = -67768038400666600; |
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struct tm *tm; |
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char *tz = getenv ("TZ"); |
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if (! (tz && strcmp (tz, "QQQ0") == 0)) |
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return 0; |
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alarm (2); |
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tm = localtime (&t); |
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return tm && tm->tm_isdst; |
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]])], |
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[(TZ=QQQ0 ./conftest$EXEEXT) >/dev/null 2>&1 || |
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gl_cv_func_localtime_works=no], |
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[], |
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[gl_cv_func_localtime_works="guessing yes"])]) |
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if test "$gl_cv_func_localtime_works" = no; then |
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AC_DEFINE([HAVE_LOCALTIME_INFLOOP_BUG], 1, |
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[Define if localtime-like functions can loop forever on |
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extreme arguments.]) |
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fi |
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AC_CHECK_TYPES([timezone_t], [], [], [[#include <time.h>]]) |
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if test "$ac_cv_type_timezone_t" = yes; then |
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HAVE_TIMEZONE_T=1 |
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fi |
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]) |
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