time_h.m4

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# Configure a more-standard replacement for <time.h>.

# Copyright (C) 2000, 2001, 2003, 2004, 2005, 2006, 2007 Free Software
# Foundation, Inc.

# This file is free software; the Free Software Foundation
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.

# Written by Paul Eggert and Jim Meyering.

AC_DEFUN([gl_HEADER_TIME_H],
[
  dnl Use AC_REQUIRE here, so that the default behavior below is expanded
  dnl once only, before all statements that occur in other macros.
  AC_REQUIRE([gl_HEADER_TIME_H_BODY])
])

AC_DEFUN([gl_HEADER_TIME_H_BODY],
[
  AC_REQUIRE([AC_C_RESTRICT])
  AC_REQUIRE([gl_HEADER_TIME_H_DEFAULTS])
  gl_CHECK_NEXT_HEADERS([time.h])
  AC_REQUIRE([gl_CHECK_TYPE_STRUCT_TIMESPEC])
])

AC_DEFUN([gl_HEADER_TIME_H_DEFAULTS],
[
  dnl If another module says to replace or to not replace, do that.
  dnl Otherwise, replace only if someone compiles with -DGNULIB_PORTCHECK;
  dnl this lets maintainers check for portability.
  REPLACE_LOCALTIME_R=GNULIB_PORTCHECK;  AC_SUBST([REPLACE_LOCALTIME_R])
  REPLACE_NANOSLEEP=GNULIB_PORTCHECK;    AC_SUBST([REPLACE_NANOSLEEP])
  REPLACE_STRPTIME=GNULIB_PORTCHECK;     AC_SUBST([REPLACE_STRPTIME])
  REPLACE_TIMEGM=GNULIB_PORTCHECK;       AC_SUBST([REPLACE_TIMEGM])
])

dnl Define HAVE_STRUCT_TIMESPEC if `struct timespec' is declared
dnl in time.h or sys/time.h.

AC_DEFUN([gl_CHECK_TYPE_STRUCT_TIMESPEC],
[
  AC_CHECK_HEADERS_ONCE([sys/time.h])
  AC_CACHE_CHECK([for struct timespec in <time.h>],
    [gl_cv_sys_struct_timespec_in_time_h],
    [AC_COMPILE_IFELSE(
       [AC_LANG_PROGRAM(
	  [[#include <time.h>
	  ]],
	  [[static struct timespec x; x.tv_sec = x.tv_nsec;]])],
       [gl_cv_sys_struct_timespec_in_time_h=yes],
       [gl_cv_sys_struct_timespec_in_time_h=no])])

  TIME_H_DEFINES_STRUCT_TIMESPEC=0
  SYS_TIME_H_DEFINES_STRUCT_TIMESPEC=0
  if test $gl_cv_sys_struct_timespec_in_time_h = yes; then
    TIME_H_DEFINES_STRUCT_TIMESPEC=1
  else
    AC_CACHE_CHECK([for struct timespec in <sys/time.h>],
      [gl_cv_sys_struct_timespec_in_sys_time_h],
      [AC_COMPILE_IFELSE(
	 [AC_LANG_PROGRAM(
	    [[#include <sys/time.h>
	    ]],
	    [[static struct timespec x; x.tv_sec = x.tv_nsec;]])],
	 [gl_cv_sys_struct_timespec_in_sys_time_h=yes],
	 [gl_cv_sys_struct_timespec_in_sys_time_h=no])])
    if test $gl_cv_sys_struct_timespec_in_sys_time_h = yes; then
      SYS_TIME_H_DEFINES_STRUCT_TIMESPEC=1
    fi
  fi
  AC_SUBST([TIME_H_DEFINES_STRUCT_TIMESPEC])
  AC_SUBST([SYS_TIME_H_DEFINES_STRUCT_TIMESPEC])
])