m4/sys_time_h.m4

   1 # Configure a replacement for <sys/time.h>.
   2 # serial 8
   3
   4 # Copyright (C) 2007, 2009-2014 Free Software Foundation, Inc.
   5 # This file is free software; the Free Software Foundation
   6 # gives unlimited permission to copy and/or distribute it,
   7 # with or without modifications, as long as this notice is preserved.
   8
   9 # Written by Paul Eggert and Martin Lambers.
  10
  11 AC_DEFUN([gl_HEADER_SYS_TIME_H],
  12 [
  13   dnl Use AC_REQUIRE here, so that the REPLACE_GETTIMEOFDAY=0 statement
  14   dnl below is expanded once only, before all REPLACE_GETTIMEOFDAY=1
  15   dnl statements that occur in other macros.
  16   AC_REQUIRE([gl_HEADER_SYS_TIME_H_BODY])
  17 ])
  18
  19 AC_DEFUN([gl_HEADER_SYS_TIME_H_BODY],
  20 [
  21   AC_REQUIRE([AC_C_RESTRICT])
  22   AC_REQUIRE([gl_HEADER_SYS_TIME_H_DEFAULTS])
  23   AC_CHECK_HEADERS_ONCE([sys/time.h])
  24   gl_CHECK_NEXT_HEADERS([sys/time.h])
  25
  26   if test $ac_cv_header_sys_time_h != yes; then
  27     HAVE_SYS_TIME_H=0
  28   fi
  29
  30   dnl On native Windows with MSVC, 'struct timeval' is defined in <winsock2.h>
  31   dnl only. So include that header in the list.
  32   gl_PREREQ_SYS_H_WINSOCK2
  33   AC_CACHE_CHECK([for struct timeval], [gl_cv_sys_struct_timeval],
  34     [AC_COMPILE_IFELSE(
  35        [AC_LANG_PROGRAM(
  36           [[#if HAVE_SYS_TIME_H
  37              #include <sys/time.h>
  38             #endif
  39             #include <time.h>
  40             #if HAVE_WINSOCK2_H
  41             # include <winsock2.h>
  42             #endif
  43           ]],
  44           [[static struct timeval x; x.tv_sec = x.tv_usec;]])],
  45        [gl_cv_sys_struct_timeval=yes],
  46        [gl_cv_sys_struct_timeval=no])
  47     ])
  48   if test $gl_cv_sys_struct_timeval != yes; then
  49     HAVE_STRUCT_TIMEVAL=0
  50   else
  51     dnl On native Windows with a 64-bit 'time_t', 'struct timeval' is defined
  52     dnl (in <sys/time.h> and <winsock2.h> for mingw64, in <winsock2.h> only
  53     dnl for MSVC) with a tv_sec field of type 'long' (32-bit!), which is
  54     dnl smaller than the 'time_t' type mandated by POSIX.
  55     dnl On OpenBSD 5.1 amd64, tv_sec is 64 bits and time_t 32 bits, but
  56     dnl that is good enough.
  57     AC_CACHE_CHECK([for wide-enough struct timeval.tv_sec member],
  58       [gl_cv_sys_struct_timeval_tv_sec],
  59       [AC_COMPILE_IFELSE(
  60          [AC_LANG_PROGRAM(
  61             [[#if HAVE_SYS_TIME_H
  62                #include <sys/time.h>
  63               #endif
  64               #include <time.h>
  65               #if HAVE_WINSOCK2_H
  66               # include <winsock2.h>
  67               #endif
  68             ]],
  69             [[static struct timeval x;
  70               typedef int verify_tv_sec_type[
  71                 sizeof (time_t) <= sizeof x.tv_sec ? 1 : -1
  72               ];
  73             ]])],
  74          [gl_cv_sys_struct_timeval_tv_sec=yes],
  75          [gl_cv_sys_struct_timeval_tv_sec=no])
  76       ])
  77     if test $gl_cv_sys_struct_timeval_tv_sec != yes; then
  78       REPLACE_STRUCT_TIMEVAL=1
  79     fi
  80   fi
  81
  82   dnl Check for declarations of anything we want to poison if the
  83   dnl corresponding gnulib module is not in use.
  84   gl_WARN_ON_USE_PREPARE([[
  85 #if HAVE_SYS_TIME_H
  86 # include <sys/time.h>
  87 #endif
  88 #include <time.h>
  89     ]], [gettimeofday])
  90 ])
  91
  92 AC_DEFUN([gl_SYS_TIME_MODULE_INDICATOR],
  93 [
  94   dnl Use AC_REQUIRE here, so that the default settings are expanded once only.
  95   AC_REQUIRE([gl_HEADER_SYS_TIME_H_DEFAULTS])
  96   gl_MODULE_INDICATOR_SET_VARIABLE([$1])
  97   dnl Define it also as a C macro, for the benefit of the unit tests.
  98   gl_MODULE_INDICATOR_FOR_TESTS([$1])
  99 ])
 100
 101 AC_DEFUN([gl_HEADER_SYS_TIME_H_DEFAULTS],
 102 [
 103   GNULIB_GETTIMEOFDAY=0;     AC_SUBST([GNULIB_GETTIMEOFDAY])
 104   dnl Assume POSIX behavior unless another module says otherwise.
 105   HAVE_GETTIMEOFDAY=1;       AC_SUBST([HAVE_GETTIMEOFDAY])
 106   HAVE_STRUCT_TIMEVAL=1;     AC_SUBST([HAVE_STRUCT_TIMEVAL])
 107   HAVE_SYS_TIME_H=1;         AC_SUBST([HAVE_SYS_TIME_H])
 108   REPLACE_GETTIMEOFDAY=0;    AC_SUBST([REPLACE_GETTIMEOFDAY])
 109   REPLACE_STRUCT_TIMEVAL=0;  AC_SUBST([REPLACE_STRUCT_TIMEVAL])
 110 ])