| dnl Time zone functions: tzalloc, localtime_rz, etc. |
| |
| dnl Copyright (C) 2015-2020 Free Software Foundation, 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 Written by Paul Eggert. |
| |
| AC_DEFUN([gl_TIME_RZ], |
| [ |
| AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS]) |
| AC_REQUIRE([gl_HEADER_TIME_H_DEFAULTS]) |
| AC_REQUIRE([AC_STRUCT_TIMEZONE]) |
| |
| # Mac OS X 10.6 loops forever with some time_t values. |
| # See Bug#27706, Bug#27736, and |
| # https://lists.gnu.org/r/bug-gnulib/2017-07/msg00142.html |
| AC_CACHE_CHECK([whether localtime loops forever near extrema], |
| [gl_cv_func_localtime_infloop_bug], |
| [gl_cv_func_localtime_infloop_bug=no |
| AC_RUN_IFELSE( |
| [AC_LANG_PROGRAM( |
| [[#include <stdlib.h> |
| #include <string.h> |
| #include <unistd.h> |
| #include <time.h> |
| ]], [[ |
| time_t t = -67768038400666600; |
| struct tm *tm; |
| char *tz = getenv ("TZ"); |
| if (! (tz && strcmp (tz, "QQQ0") == 0)) |
| return 0; |
| alarm (2); |
| tm = localtime (&t); |
| /* Use TM and *TM to suppress over-optimization. */ |
| return tm && tm->tm_isdst; |
| ]])], |
| [(TZ=QQQ0 ./conftest$EXEEXT) >/dev/null 2>&1 || |
| gl_cv_func_localtime_infloop_bug=yes], |
| [], |
| [gl_cv_func_localtime_infloop_bug="guessing no"])]) |
| if test "$gl_cv_func_localtime_infloop_bug" = yes; then |
| AC_DEFINE([HAVE_LOCALTIME_INFLOOP_BUG], 1, |
| [Define if localtime-like functions can loop forever on |
| extreme arguments.]) |
| fi |
| |
| AC_CHECK_TYPES([timezone_t], [], [], [[#include <time.h>]]) |
| if test "$ac_cv_type_timezone_t" = yes; then |
| HAVE_TIMEZONE_T=1 |
| fi |
| ]) |
