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date Sun, 16 Aug 2009 17:16:49 +0000
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271:3b793ba7a6c6 272:d5392bb5da3c
1 # Check for stdbool.h that conforms to C99.
2
3 dnl Copyright (C) 2002-2006 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.
7
8 # Prepare for substituting <stdbool.h> if it is not supported.
9
10 AC_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 # AM_STDBOOL_H will be renamed to gl_STDBOOL_H in the future.
32 AC_DEFUN([gl_STDBOOL_H], [AM_STDBOOL_H])
33
34 # This macro is only needed in autoconf <= 2.59. Newer versions of autoconf
35 # have this macro built-in.
36
37 AC_DEFUN([AC_HEADER_STDBOOL],
38 [AC_CACHE_CHECK([for stdbool.h that conforms to C99],
39 [ac_cv_header_stdbool_h],
40 [AC_TRY_COMPILE(
41 [
42 #include <stdbool.h>
43 #ifndef bool
44 "error: bool is not defined"
45 #endif
46 #ifndef false
47 "error: false is not defined"
48 #endif
49 #if false
50 "error: false is not 0"
51 #endif
52 #ifndef true
53 "error: true is not defined"
54 #endif
55 #if true != 1
56 "error: true is not 1"
57 #endif
58 #ifndef __bool_true_false_are_defined
59 "error: __bool_true_false_are_defined is not defined"
60 #endif
61
62 struct s { _Bool s: 1; _Bool t; } s;
63
64 char a[true == 1 ? 1 : -1];
65 char b[false == 0 ? 1 : -1];
66 char c[__bool_true_false_are_defined == 1 ? 1 : -1];
67 char d[(bool) 0.5 == true ? 1 : -1];
68 bool e = &s;
69 char f[(_Bool) 0.0 == false ? 1 : -1];
70 char g[true];
71 char h[sizeof (_Bool)];
72 char i[sizeof s.t];
73 enum { j = false, k = true, l = false * true, m = true * 256 };
74 _Bool n[m];
75 char o[sizeof n == m * sizeof n[0] ? 1 : -1];
76 char p[-1 - (_Bool) 0 < 0 && -1 - (bool) 0 < 0 ? 1 : -1];
77 #if defined __xlc__ || defined __GNUC__
78 /* Catch a bug in IBM AIX xlc compiler version 6.0.0.0
79 reported by James Lemley on 2005-10-05; see
80 http://lists.gnu.org/archive/html/bug-coreutils/2005-10/msg00086.html
81 This test is not quite right, since xlc is allowed to
82 reject this program, as the initializer for xlcbug is
83 not one of the forms that C requires support for.
84 However, doing the test right would require a run-time
85 test, and that would make cross-compilation harder.
86 Let us hope that IBM fixes the xlc bug, and also adds
87 support for this kind of constant expression. In the
88 meantime, this test will reject xlc, which is OK, since
89 our stdbool.h substitute should suffice. We also test
90 this with GCC, where it should work, to detect more
91 quickly whether someone messes up the test in the
92 future. */
93 char digs[] = "0123456789";
94 int xlcbug = 1 / (&(digs + 5)[-2 + (bool) 1] == &digs[4] ? 1 : -1);
95 #endif
96 /* Catch a bug in an HP-UX C compiler. See
97 http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html
98 http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html
99 */
100 _Bool q = true;
101 _Bool *pq = &q;
102 ],
103 [
104 *pq |= q;
105 *pq |= ! q;
106 /* Refer to every declared value, to avoid compiler optimizations. */
107 return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !!j + !k + !!l
108 + !m + !n + !o + !p + !q + !pq);
109 ],
110 [ac_cv_header_stdbool_h=yes],
111 [ac_cv_header_stdbool_h=no])])
112 AC_CHECK_TYPES([_Bool])
113 if test $ac_cv_header_stdbool_h = yes; then
114 AC_DEFINE(HAVE_STDBOOL_H, 1, [Define to 1 if stdbool.h conforms to C99.])
115 fi])