1# Check for stdbool.h that conforms to C99.
2
3dnl Copyright (C) 2002-2006, 2009-2012 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#serial 5
9
10# Prepare for substituting <stdbool.h> if it is not supported.
11
12AC_DEFUN([AM_STDBOOL_H],
13[
14  AC_REQUIRE([AC_CHECK_HEADER_STDBOOL])
15
16  # Define two additional variables used in the Makefile substitution.
17
18  if test "$ac_cv_header_stdbool_h" = yes; then
19    STDBOOL_H=''
20  else
21    STDBOOL_H='stdbool.h'
22  fi
23  AC_SUBST([STDBOOL_H])
24  AM_CONDITIONAL([GL_GENERATE_STDBOOL_H], [test -n "$STDBOOL_H"])
25
26  if test "$ac_cv_type__Bool" = yes; then
27    HAVE__BOOL=1
28  else
29    HAVE__BOOL=0
30  fi
31  AC_SUBST([HAVE__BOOL])
32])
33
34# AM_STDBOOL_H will be renamed to gl_STDBOOL_H in the future.
35AC_DEFUN([gl_STDBOOL_H], [AM_STDBOOL_H])
36
37# This version of the macro is needed in autoconf <= 2.68.
38
39AC_DEFUN([AC_CHECK_HEADER_STDBOOL],
40  [AC_CACHE_CHECK([for stdbool.h that conforms to C99],
41     [ac_cv_header_stdbool_h],
42     [AC_COMPILE_IFELSE(
43        [AC_LANG_PROGRAM(
44           [[
45             #include <stdbool.h>
46             #ifndef bool
47              "error: bool is not defined"
48             #endif
49             #ifndef false
50              "error: false is not defined"
51             #endif
52             #if false
53              "error: false is not 0"
54             #endif
55             #ifndef true
56              "error: true is not defined"
57             #endif
58             #if true != 1
59              "error: true is not 1"
60             #endif
61             #ifndef __bool_true_false_are_defined
62              "error: __bool_true_false_are_defined is not defined"
63             #endif
64
65             struct s { _Bool s: 1; _Bool t; } s;
66
67             char a[true == 1 ? 1 : -1];
68             char b[false == 0 ? 1 : -1];
69             char c[__bool_true_false_are_defined == 1 ? 1 : -1];
70             char d[(bool) 0.5 == true ? 1 : -1];
71             /* See body of main program for 'e'.  */
72             char f[(_Bool) 0.0 == false ? 1 : -1];
73             char g[true];
74             char h[sizeof (_Bool)];
75             char i[sizeof s.t];
76             enum { j = false, k = true, l = false * true, m = true * 256 };
77             /* The following fails for
78                HP aC++/ANSI C B3910B A.05.55 [Dec 04 2003]. */
79             _Bool n[m];
80             char o[sizeof n == m * sizeof n[0] ? 1 : -1];
81             char p[-1 - (_Bool) 0 < 0 && -1 - (bool) 0 < 0 ? 1 : -1];
82             /* Catch a bug in an HP-UX C compiler.  See
83                http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html
84                http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html
85              */
86             _Bool q = true;
87             _Bool *pq = &q;
88           ]],
89           [[
90             bool e = &s;
91             *pq |= q;
92             *pq |= ! q;
93             /* Refer to every declared value, to avoid compiler optimizations.  */
94             return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !!j + !k + !!l
95                     + !m + !n + !o + !p + !q + !pq);
96           ]])],
97        [ac_cv_header_stdbool_h=yes],
98        [ac_cv_header_stdbool_h=no])])
99   AC_CHECK_TYPES([_Bool])
100])
101