1# Check for stdbool.h that conforms to C99. 2 3dnl Copyright (C) 2002-2006, 2009-2022 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 9 9 10# Prepare for substituting <stdbool.h> if it is not supported. 11 12AC_DEFUN([gl_STDBOOL_H], 13[ 14 AC_REQUIRE([AC_CHECK_HEADER_STDBOOL]) 15 AC_REQUIRE([AC_CANONICAL_HOST]) 16 17 dnl On some platforms, <stdbool.h> does not exist or does not conform to C99. 18 dnl On Solaris 10 with CC=cc CXX=CC, <stdbool.h> exists but is not usable 19 dnl in C++ mode (and no <cstdbool> exists). In this case, we use our 20 dnl replacement, also in C mode (for binary compatibility between C and C++). 21 if test "$ac_cv_header_stdbool_h" = yes; then 22 case "$host_os" in 23 solaris*) 24 if test -z "$GCC"; then 25 GL_GENERATE_STDBOOL_H=true 26 else 27 GL_GENERATE_STDBOOL_H=false 28 fi 29 ;; 30 *) 31 GL_GENERATE_STDBOOL_H=false 32 ;; 33 esac 34 else 35 GL_GENERATE_STDBOOL_H=true 36 fi 37 38 if test "$ac_cv_type__Bool" = yes; then 39 HAVE__BOOL=1 40 else 41 HAVE__BOOL=0 42 fi 43 AC_SUBST([HAVE__BOOL]) 44]) 45 46# This version of the macro is needed in autoconf <= 2.68. 47 48AC_DEFUN([AC_CHECK_HEADER_STDBOOL], 49 [AC_CACHE_CHECK([for stdbool.h that conforms to C99], 50 [ac_cv_header_stdbool_h], 51 [AC_COMPILE_IFELSE( 52 [AC_LANG_PROGRAM( 53 [[ 54 #include <stdbool.h> 55 56 #ifdef __cplusplus 57 typedef bool Bool; 58 #else 59 typedef _Bool Bool; 60 #ifndef bool 61 "error: bool is not defined" 62 #endif 63 #ifndef false 64 "error: false is not defined" 65 #endif 66 #if false 67 "error: false is not 0" 68 #endif 69 #ifndef true 70 "error: true is not defined" 71 #endif 72 #if true != 1 73 "error: true is not 1" 74 #endif 75 #endif 76 77 #ifndef __bool_true_false_are_defined 78 "error: __bool_true_false_are_defined is not defined" 79 #endif 80 81 struct s { Bool s: 1; Bool t; bool u: 1; bool v; } s; 82 83 char a[true == 1 ? 1 : -1]; 84 char b[false == 0 ? 1 : -1]; 85 char c[__bool_true_false_are_defined == 1 ? 1 : -1]; 86 char d[(bool) 0.5 == true ? 1 : -1]; 87 /* See body of main program for 'e'. */ 88 char f[(Bool) 0.0 == false ? 1 : -1]; 89 char g[true]; 90 char h[sizeof (Bool)]; 91 char i[sizeof s.t]; 92 enum { j = false, k = true, l = false * true, m = true * 256 }; 93 /* The following fails for 94 HP aC++/ANSI C B3910B A.05.55 [Dec 04 2003]. */ 95 Bool n[m]; 96 char o[sizeof n == m * sizeof n[0] ? 1 : -1]; 97 char p[-1 - (Bool) 0 < 0 && -1 - (bool) 0 < 0 ? 1 : -1]; 98 /* Catch a bug in an HP-UX C compiler. See 99 https://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html 100 https://lists.gnu.org/r/bug-coreutils/2005-11/msg00161.html 101 */ 102 Bool q = true; 103 Bool *pq = &q; 104 bool *qq = &q; 105 ]], 106 [[ 107 bool e = &s; 108 *pq |= q; *pq |= ! q; 109 *qq |= q; *qq |= ! q; 110 /* Refer to every declared value, to avoid compiler optimizations. */ 111 return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !!j + !k + !!l 112 + !m + !n + !o + !p + !q + !pq + !qq); 113 ]])], 114 [ac_cv_header_stdbool_h=yes], 115 [ac_cv_header_stdbool_h=no])]) 116 AC_CHECK_TYPES([_Bool]) 117]) 118