1# gethrxtime.m4 serial 13
2dnl Copyright (C) 2005-2006, 2008-2020 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7dnl Written by Paul Eggert.
8
9AC_DEFUN([gl_GETHRXTIME],
10[
11  AC_REQUIRE([gl_ARITHMETIC_HRTIME_T])
12  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
13  AC_REQUIRE([gl_XTIME])
14  AC_CHECK_DECLS([gethrtime], [], [], [[#include <time.h>]])
15  LIB_GETHRXTIME=
16  if test $ac_cv_have_decl_gethrtime = no \
17     || test $gl_cv_arithmetic_hrtime_t = no; then
18    dnl Find libraries needed to link lib/gethrxtime.c.
19    AC_REQUIRE([gl_CLOCK_TIME])
20    AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
21    AC_CHECK_FUNCS_ONCE([microuptime nanouptime])
22    if test $ac_cv_func_nanouptime != yes \
23       && { test $ac_cv_have_decl_gethrtime = no \
24            || test $gl_cv_arithmetic_hrtime_t = no; }; then
25      AC_CACHE_CHECK([whether CLOCK_MONOTONIC or CLOCK_REALTIME is defined],
26        [gl_cv_have_clock_gettime_macro],
27        [AC_EGREP_CPP([have_clock_gettime_macro],
28          [
29#          include <time.h>
30#          if defined CLOCK_MONOTONIC || defined CLOCK_REALTIME
31            have_clock_gettime_macro
32#          endif
33          ],
34          [gl_cv_have_clock_gettime_macro=yes],
35          [gl_cv_have_clock_gettime_macro=no])])
36      if test $gl_cv_have_clock_gettime_macro = yes; then
37        LIB_GETHRXTIME=$LIB_CLOCK_GETTIME
38      fi
39    fi
40  fi
41  AC_SUBST([LIB_GETHRXTIME])
42])
43
44# Test whether hrtime_t is an arithmetic type.
45# It is not arithmetic in older Solaris c89 (which insists on
46# not having a long long int type).
47AC_DEFUN([gl_ARITHMETIC_HRTIME_T],
48[
49  AC_REQUIRE([gl_USE_SYSTEM_EXTENSIONS])
50  AC_CACHE_CHECK([for arithmetic hrtime_t], [gl_cv_arithmetic_hrtime_t],
51    [AC_COMPILE_IFELSE(
52       [AC_LANG_PROGRAM([[#include <time.h>]],
53          [[hrtime_t x = 0; return x/x;]])],
54       [gl_cv_arithmetic_hrtime_t=yes],
55       [gl_cv_arithmetic_hrtime_t=no])])
56  if test $gl_cv_arithmetic_hrtime_t = yes; then
57    AC_DEFINE([HAVE_ARITHMETIC_HRTIME_T], [1],
58      [Define if you have an arithmetic hrtime_t type.])
59  fi
60])
61
62# Prerequisites of lib/xtime.h.
63AC_DEFUN([gl_XTIME],
64[
65  :
66])
67