1# Check for stdbool.h that conforms to C99. 2 3dnl Copyright (C) 2002-2006, 2009-2021 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 8 9 10# Prepare for substituting <stdbool.h> if it is not supported. 11 12AC_DEFUN([AM_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 "$GCC"; then 25 STDBOOL_H='stdbool.h' 26 else 27 STDBOOL_H='' 28 fi 29 ;; 30 *) 31 STDBOOL_H='' 32 ;; 33 esac 34 else 35 STDBOOL_H='stdbool.h' 36 fi 37 AC_SUBST([STDBOOL_H]) 38 AM_CONDITIONAL([GL_GENERATE_STDBOOL_H], [test -n "$STDBOOL_H"]) 39 40 if test "$ac_cv_type__Bool" = yes; then 41 HAVE__BOOL=1 42 else 43 HAVE__BOOL=0 44 fi 45 AC_SUBST([HAVE__BOOL]) 46]) 47 48# AM_STDBOOL_H will be renamed to gl_STDBOOL_H in the future. 49AC_DEFUN([gl_STDBOOL_H], [AM_STDBOOL_H]) 50 51# This version of the macro is needed in autoconf <= 2.68. 52 53AC_DEFUN([AC_CHECK_HEADER_STDBOOL], 54 [AC_CACHE_CHECK([for stdbool.h that conforms to C99], 55 [ac_cv_header_stdbool_h], 56 [AC_COMPILE_IFELSE( 57 [AC_LANG_PROGRAM( 58 [[ 59 #include <stdbool.h> 60 61 #ifdef __cplusplus 62 typedef bool Bool; 63 #else 64 typedef _Bool Bool; 65 #ifndef bool 66 "error: bool is not defined" 67 #endif 68 #ifndef false 69 "error: false is not defined" 70 #endif 71 #if false 72 "error: false is not 0" 73 #endif 74 #ifndef true 75 "error: true is not defined" 76 #endif 77 #if true != 1 78 "error: true is not 1" 79 #endif 80 #endif 81 82 #ifndef __bool_true_false_are_defined 83 "error: __bool_true_false_are_defined is not defined" 84 #endif 85 86 struct s { Bool s: 1; Bool t; bool u: 1; bool v; } s; 87 88 char a[true == 1 ? 1 : -1]; 89 char b[false == 0 ? 1 : -1]; 90 char c[__bool_true_false_are_defined == 1 ? 1 : -1]; 91 char d[(bool) 0.5 == true ? 1 : -1]; 92 /* See body of main program for 'e'. */ 93 char f[(Bool) 0.0 == false ? 1 : -1]; 94 char g[true]; 95 char h[sizeof (Bool)]; 96 char i[sizeof s.t]; 97 enum { j = false, k = true, l = false * true, m = true * 256 }; 98 /* The following fails for 99 HP aC++/ANSI C B3910B A.05.55 [Dec 04 2003]. */ 100 Bool n[m]; 101 char o[sizeof n == m * sizeof n[0] ? 1 : -1]; 102 char p[-1 - (Bool) 0 < 0 && -1 - (bool) 0 < 0 ? 1 : -1]; 103 /* Catch a bug in an HP-UX C compiler. See 104 https://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html 105 https://lists.gnu.org/r/bug-coreutils/2005-11/msg00161.html 106 */ 107 Bool q = true; 108 Bool *pq = &q; 109 bool *qq = &q; 110 ]], 111 [[ 112 bool e = &s; 113 *pq |= q; *pq |= ! q; 114 *qq |= q; *qq |= ! q; 115 /* Refer to every declared value, to avoid compiler optimizations. */ 116 return (!a + !b + !c + !d + !e + !f + !g + !h + !i + !!j + !k + !!l 117 + !m + !n + !o + !p + !q + !pq + !qq); 118 ]])], 119 [ac_cv_header_stdbool_h=yes], 120 [ac_cv_header_stdbool_h=no])]) 121 AC_CHECK_TYPES([_Bool]) 122]) 123