xref: /netbsd-src/external/gpl3/gdb/dist/gnulib/import/m4/sys_time_h.m4 (revision 4b169a6ba595ae283ca507b26b15fdff40495b1c)
1# Configure a replacement for <sys/time.h>.
2# serial 12
3
4# Copyright (C) 2007, 2009-2022 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
11AC_DEFUN_ONCE([gl_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_SYS_TIME_H_DEFAULTS])
17  AC_REQUIRE([AC_C_RESTRICT])
18  AC_CHECK_HEADERS_ONCE([sys/time.h])
19  gl_CHECK_NEXT_HEADERS([sys/time.h])
20
21  if test $ac_cv_header_sys_time_h != yes; then
22    HAVE_SYS_TIME_H=0
23  fi
24
25  dnl On native Windows with MSVC, 'struct timeval' is defined in <winsock2.h>
26  dnl only. So include that header in the list.
27  gl_PREREQ_SYS_H_WINSOCK2
28  AC_CACHE_CHECK([for struct timeval], [gl_cv_sys_struct_timeval],
29    [AC_COMPILE_IFELSE(
30       [AC_LANG_PROGRAM(
31          [[#if HAVE_SYS_TIME_H
32             #include <sys/time.h>
33            #endif
34            #include <time.h>
35            #if HAVE_WINSOCK2_H
36            # include <winsock2.h>
37            #endif
38          ]],
39          [[static struct timeval x; x.tv_sec = x.tv_usec;]])],
40       [gl_cv_sys_struct_timeval=yes],
41       [gl_cv_sys_struct_timeval=no])
42    ])
43  if test $gl_cv_sys_struct_timeval != yes; then
44    HAVE_STRUCT_TIMEVAL=0
45  else
46    dnl On native Windows with a 64-bit 'time_t', 'struct timeval' is defined
47    dnl (in <sys/time.h> and <winsock2.h> for mingw64, in <winsock2.h> only
48    dnl for MSVC) with a tv_sec field of type 'long' (32-bit!), which is
49    dnl smaller than the 'time_t' type mandated by POSIX.
50    dnl On OpenBSD 5.1 amd64, tv_sec is 64 bits and time_t 32 bits, but
51    dnl that is good enough.
52    AC_CACHE_CHECK([for wide-enough struct timeval.tv_sec member],
53      [gl_cv_sys_struct_timeval_tv_sec],
54      [AC_COMPILE_IFELSE(
55         [AC_LANG_PROGRAM(
56            [[#if HAVE_SYS_TIME_H
57               #include <sys/time.h>
58              #endif
59              #include <time.h>
60              #if HAVE_WINSOCK2_H
61              # include <winsock2.h>
62              #endif
63            ]],
64            [[static struct timeval x;
65              typedef int verify_tv_sec_type[
66                sizeof (time_t) <= sizeof x.tv_sec ? 1 : -1
67              ];
68            ]])],
69         [gl_cv_sys_struct_timeval_tv_sec=yes],
70         [gl_cv_sys_struct_timeval_tv_sec=no])
71      ])
72    if test $gl_cv_sys_struct_timeval_tv_sec != yes; then
73      REPLACE_STRUCT_TIMEVAL=1
74    fi
75  fi
76
77  dnl Check for declarations of anything we want to poison if the
78  dnl corresponding gnulib module is not in use.
79  gl_WARN_ON_USE_PREPARE([[
80#if HAVE_SYS_TIME_H
81# include <sys/time.h>
82#endif
83#include <time.h>
84    ]], [gettimeofday])
85])
86
87# gl_SYS_TIME_MODULE_INDICATOR([modulename])
88# sets the shell variable that indicates the presence of the given module
89# to a C preprocessor expression that will evaluate to 1.
90# This macro invocation must not occur in macros that are AC_REQUIREd.
91AC_DEFUN([gl_SYS_TIME_MODULE_INDICATOR],
92[
93  dnl Ensure to expand the default settings once only.
94  gl_SYS_TIME_H_REQUIRE_DEFAULTS
95  gl_MODULE_INDICATOR_SET_VARIABLE([$1])
96  dnl Define it also as a C macro, for the benefit of the unit tests.
97  gl_MODULE_INDICATOR_FOR_TESTS([$1])
98])
99
100# Initializes the default values for AC_SUBSTed shell variables.
101# This macro must not be AC_REQUIREd.  It must only be invoked, and only
102# outside of macros or in macros that are not AC_REQUIREd.
103AC_DEFUN([gl_SYS_TIME_H_REQUIRE_DEFAULTS],
104[
105  m4_defun(GL_MODULE_INDICATOR_PREFIX[_SYS_TIME_H_MODULE_INDICATOR_DEFAULTS], [
106    gl_MODULE_INDICATOR_INIT_VARIABLE([GNULIB_GETTIMEOFDAY])
107  ])
108  m4_require(GL_MODULE_INDICATOR_PREFIX[_SYS_TIME_H_MODULE_INDICATOR_DEFAULTS])
109  AC_REQUIRE([gl_SYS_TIME_H_DEFAULTS])
110])
111
112AC_DEFUN([gl_SYS_TIME_H_DEFAULTS],
113[
114  dnl Assume POSIX behavior unless another module says otherwise.
115  HAVE_GETTIMEOFDAY=1;       AC_SUBST([HAVE_GETTIMEOFDAY])
116  HAVE_STRUCT_TIMEVAL=1;     AC_SUBST([HAVE_STRUCT_TIMEVAL])
117  HAVE_SYS_TIME_H=1;         AC_SUBST([HAVE_SYS_TIME_H])
118  REPLACE_GETTIMEOFDAY=0;    AC_SUBST([REPLACE_GETTIMEOFDAY])
119  REPLACE_STRUCT_TIMEVAL=0;  AC_SUBST([REPLACE_STRUCT_TIMEVAL])
120])
121