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| 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.h
tml |
| 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.ht
ml |
| 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]) |
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