m4/time_r.m4

   1 dnl Reentrant time functions like localtime_r.
   2
   3 dnl Copyright (C) 2003, 2006, 2007, 2008 Free Software Foundation, Inc.
   4 dnl This file is free software; the Free Software Foundation
   5 dnl gives unlimited permission to copy and/or distribute it,
   6 dnl with or without modifications, as long as this notice is preserved.
   7
   8 dnl Written by Paul Eggert.
   9
  10 AC_DEFUN([gl_TIME_R],
  11 [
  12  dnl Persuade glibc and Solaris <time.h> to declare localtime_r.
  13   AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
  14
  15   AC_REQUIRE([gl_HEADER_TIME_H_DEFAULTS])
  16   AC_REQUIRE([AC_C_RESTRICT])
  17
  18   AC_CACHE_CHECK([whether localtime_r is compatible with its POSIX signature],
  19     [gl_cv_time_r_posix],
  20     [AC_TRY_COMPILE(
  21        [#include <time.h>],
  22        [/* We don't need to append 'restrict's to the argument types,
  23            even though the POSIX signature has the 'restrict's,
  24            since C99 says they can't affect type compatibility.  */
  25         struct tm * (*ptr) (time_t const *, struct tm *) = localtime_r;
  26         if (ptr) return 0;
  27         /* Check the return type is a pointer.  On HP-UX 10 it is 'int'.  */
  28         *localtime_r (0, 0);],
  29        [gl_cv_time_r_posix=yes],
  30        [gl_cv_time_r_posix=no])])
  31   if test $gl_cv_time_r_posix = yes; then
  32     REPLACE_LOCALTIME_R=0
  33   else
  34     REPLACE_LOCALTIME_R=1
  35     AC_LIBOBJ([time_r])
  36     gl_PREREQ_TIME_R
  37   fi
  38 ])
  39
  40 # Prerequisites of lib/time_r.c.
  41 AC_DEFUN([gl_PREREQ_TIME_R], [
  42   :
  43 ])