~drizzle-trunk/drizzle/development

#serial 13

dnl Copyright (C) 2002, 2003, 2005, 2006, 2007 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 From Jim Meyering.

# Redefine AC_FUNC_MKTIME, to fix a bug in Autoconf 2.61a and earlier.

# This redefinition can be removed once a new version of Autoconf is assumed.

# The redefinition is taken from

# <http://cvs.sv.gnu.org/viewcvs/*checkout*/autoconf/autoconf/lib/autoconf/functions.m4?rev=1.119>.

# AC_FUNC_MKTIME

# --------------

AC_DEFUN([AC_FUNC_MKTIME],

[AC_CHECK_HEADERS_ONCE(unistd.h)

AC_CHECK_FUNCS_ONCE(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.  */

#include <limits.h>

#include <stdlib.h>

#include <time.h>

#ifdef HAVE_UNISTD_H

# include <unistd.h>

#endif

#ifndef 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]))

/* 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 (now)

     time_t now;

{

  struct tm *lt;

  return ! (lt = localtime (&now)) || mktime (lt) == now;

}

static int

mktime_test (now)

     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 (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))))

	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 ()

{

  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 (;;)

    {

      t = (time_t_max << 1) + 1;

      if (t <= time_t_max)

	break;

      time_t_max = t;

    }

  time_t_min = - ((time_t) ~ (time_t) 0 == (time_t) -1) - 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; t += delta)

	if (! mktime_test (t))

	  return 1;

      if (! (mktime_test ((time_t) 1)

	     && mktime_test ((time_t) (60 * 60))

	     && mktime_test ((time_t) (60 * 60 * 24))))

	return 1;

      for (j = 1; ; j <<= 1)

	if (! bigtime_test (j))

	  return 1;

	else if (INT_MAX / 2 < j)

	  break;

      if (! bigtime_test (INT_MAX))

	return 1;

    }

  return ! (irix_6_4_bug () && spring_forward_gap () && year_2050_test ());

}]])],

	       [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([gl_HEADER_TIME_H_DEFAULTS])

  AC_FUNC_MKTIME

  dnl Note: AC_FUNC_MKTIME does AC_LIBOBJ([mktime]).

  if test $ac_cv_func_working_mktime = no; then

    REPLACE_MKTIME=1

    gl_PREREQ_MKTIME

  fi

])

# Prerequisites of lib/mktime.c.

AC_DEFUN([gl_PREREQ_MKTIME],

[

  AC_REQUIRE([AC_C_INLINE])

])