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]) 116
