m4/stdbool.m4

   1 # Check for stdbool.h that conforms to C99.
   2
   3 # Copyright (C) 2002 Free Software Foundation, Inc.
   4
   5 # This program is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 2, or (at your option)
   8 # any later version.
   9
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program; if not, write to the Free Software
  17 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18 # 02111-1307, USA.
  19
  20 AC_DEFUN([AC_HEADER_STDBOOL],
  21   [AC_CACHE_CHECK([for stdbool.h that conforms to C99],
  22      [ac_cv_header_stdbool_h],
  23      [AC_TRY_COMPILE(
  24         [
  25           #include <stdbool.h>
  26           #ifndef bool
  27            "error: bool is not defined"
  28           #endif
  29           #ifndef false
  30            "error: false is not defined"
  31           #endif
  32           #if false
  33            "error: false is not 0"
  34           #endif
  35           #ifndef true
  36            "error: false is not defined"
  37           #endif
  38           #if true != 1
  39            "error: true is not 1"
  40           #endif
  41           #ifndef __bool_true_false_are_defined
  42            "error: __bool_true_false_are_defined is not defined"
  43           #endif
  44
  45           struct s { _Bool s: 1; _Bool t; } s;
  46
  47           char a[true == 1 ? 1 : -1];
  48           char b[false == 0 ? 1 : -1];
  49           char c[__bool_true_false_are_defined == 1 ? 1 : -1];
  50           char d[(bool) -0.5 == true ? 1 : -1];
  51           bool e = &s;
  52           char f[(_Bool) -0.0 == false ? 1 : -1];
  53           char g[true];
  54           char h[sizeof (_Bool)];
  55           char i[sizeof s.t];
  56         ],
  57         [ return !a + !b + !c + !d + !e + !f + !g + !h + !i; ],
  58         [ac_cv_header_stdbool_h=yes],
  59         [ac_cv_header_stdbool_h=no])])
  60    if test $ac_cv_header_stdbool_h = yes; then
  61      AC_DEFINE(HAVE_STDBOOL_H, 1, [Define to 1 if stdbool.h conforms to C99.])
  62    fi])