1# Check for stdbool.h that conforms to C99.
2
3dnl Copyright (C) 2002-2004 Free Software Foundation, Inc.
4dnl This file is free software; the Free Software Foundation
5dnl gives unlimited permission to copy and/or distribute it,
6dnl with or without modifications, as long as this notice is preserved.
7
8# Prepare for substituting <stdbool.h> if it is not supported.
9
10AC_DEFUN([AM_STDBOOL_H],
11[
12  AC_REQUIRE([AC_HEADER_STDBOOL])
13
14  # Define two additional variables used in the Makefile substitution.
15
16  if test "$ac_cv_header_stdbool_h" = yes; then
17    STDBOOL_H=''
18  else
19    STDBOOL_H='stdbool.h'
20  fi
21  AC_SUBST([STDBOOL_H])
22
23  if test "$ac_cv_type__Bool" = yes; then
24    HAVE__BOOL=1
25  else
26    HAVE__BOOL=0
27  fi
28  AC_SUBST([HAVE__BOOL])
29])
30
31# This macro is only needed in autoconf <= 2.59.  Newer versions of autoconf
32# have this macro built-in.
33
34AC_DEFUN([AC_HEADER_STDBOOL],
35  [AC_CACHE_CHECK([for stdbool.h that conforms to C99],
36     [ac_cv_header_stdbool_h],
37     [AC_TRY_COMPILE(
38          [
39            #include <stdbool.h>
40            #ifndef bool
41             "error: bool is not defined"
42            #endif
43            #ifndef false
44             "error: false is not defined"
45            #endif
46            #if false
47             "error: false is not 0"
48            #endif
49            #ifndef true
50             "error: true is not defined"
51            #endif
52            #if true != 1
53             "error: true is not 1"
54            #endif
55            #ifndef __bool_true_false_are_defined
56             "error: __bool_true_false_are_defined is not defined"
57            #endif
58
59            struct s { _Bool s: 1; _Bool t; } s;
60
61            char a[true == 1 ? 1 : -1];
62            char b[false == 0 ? 1 : -1];
63            char c[__bool_true_false_are_defined == 1 ? 1 : -1];
64            char d[(bool) -0.5 == true ? 1 : -1];
65            bool e = &s;
66            char f[(_Bool) -0.0 == false ? 1 : -1];
67            char g[true];
68            char h[sizeof (_Bool)];
69            char i[sizeof s.t];
70            enum { j = false, k = true, l = false * true, m = true * 256 };
71            _Bool n[m];
72            char o[sizeof n == m * sizeof n[0] ? 1 : -1];
73          ],
74          [
75            return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !j + !k + !l
76                      + !m + !n + !o);
77          ],
78          [ac_cv_header_stdbool_h=yes],
79          [ac_cv_header_stdbool_h=no])])
80   AC_CHECK_TYPES([_Bool])
81   if test $ac_cv_header_stdbool_h = yes; then
82     AC_DEFINE(HAVE_STDBOOL_H, 1, [Define to 1 if stdbool.h conforms to C99.])
83   fi])
84