1 # Check for stdbool.h that conforms to C99.
3 dnl Copyright (C) 2002-2006, 2009-2017 Free Software Foundation, Inc.
4 dnl This file is free software; the Free Software Foundation
5 dnl gives unlimited permission to copy and/or distribute it,
6 dnl with or without modifications, as long as this notice is preserved.
10 # Prepare for substituting <stdbool.h> if it is not supported.
12 AC_DEFUN([AM_STDBOOL_H],
14 AC_REQUIRE([AC_CHECK_HEADER_STDBOOL])
16 # Define two additional variables used in the Makefile substitution.
18 if test "$ac_cv_header_stdbool_h" = yes; then
24 AM_CONDITIONAL([GL_GENERATE_STDBOOL_H], [test -n "$STDBOOL_H"])
26 if test "$ac_cv_type__Bool" = yes; then
31 AC_SUBST([HAVE__BOOL])
34 # AM_STDBOOL_H will be renamed to gl_STDBOOL_H in the future.
35 AC_DEFUN([gl_STDBOOL_H], [AM_STDBOOL_H])
37 # This version of the macro is needed in autoconf <= 2.68.
39 AC_DEFUN([AC_CHECK_HEADER_STDBOOL],
40 [AC_CACHE_CHECK([for stdbool.h that conforms to C99],
41 [ac_cv_header_stdbool_h],
52 "error: bool is not defined"
55 "error: false is not defined"
58 "error: false is not 0"
61 "error: true is not defined"
64 "error: true is not 1"
68 #ifndef __bool_true_false_are_defined
69 "error: __bool_true_false_are_defined is not defined"
72 struct s { Bool s: 1; Bool t; bool u: 1; bool v; } s;
74 char a[true == 1 ? 1 : -1];
75 char b[false == 0 ? 1 : -1];
76 char c[__bool_true_false_are_defined == 1 ? 1 : -1];
77 char d[(bool) 0.5 == true ? 1 : -1];
78 /* See body of main program for 'e'. */
79 char f[(Bool) 0.0 == false ? 1 : -1];
81 char h[sizeof (Bool)];
83 enum { j = false, k = true, l = false * true, m = true * 256 };
84 /* The following fails for
85 HP aC++/ANSI C B3910B A.05.55 [Dec 04 2003]. */
87 char o[sizeof n == m * sizeof n[0] ? 1 : -1];
88 char p[-1 - (Bool) 0 < 0 && -1 - (bool) 0 < 0 ? 1 : -1];
89 /* Catch a bug in an HP-UX C compiler. See
90 http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html
91 http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html
100 *qq |= q; *qq |= ! q;
101 /* Refer to every declared value, to avoid compiler optimizations. */
102 return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !!j + !k + !!l
103 + !m + !n + !o + !p + !q + !pq + !qq);
105 [ac_cv_header_stdbool_h=yes],
106 [ac_cv_header_stdbool_h=no])])
107 AC_CHECK_TYPES([_Bool])