1 /* -*- buffer-read-only: t -*- vi: set ro: */
2 /* DO NOT EDIT! GENERATED AUTOMATICALLY! */
3 /* Copyright (C) 2001, 2002, 2003, 2006, 2007 Free Software Foundation, Inc.
4 Written by Bruno Haible <haible@clisp.cons.org>, 2001.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3, or (at your option)
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software Foundation,
18 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
23 /* ISO C 99 <stdbool.h> for platforms that lack it. */
27 Programs that use <stdbool.h> should be aware of some limitations
28 and standards compliance issues.
32 - <stdbool.h> must be #included before 'bool', 'false', 'true'
35 - You cannot assume that sizeof (bool) == 1.
37 - Programs should not undefine the macros bool, true, and false,
38 as C99 lists that as an "obsolescent feature".
40 Limitations of this substitute, when used in a C89 environment:
42 - <stdbool.h> must be #included before the '_Bool' type can be used.
44 - You cannot assume that _Bool is a typedef; it might be a macro.
46 - Bit-fields of type 'bool' are not supported. Portable code
47 should use 'unsigned int foo : 1;' rather than 'bool foo : 1;'.
49 - In C99, casts and automatic conversions to '_Bool' or 'bool' are
50 performed in such a way that every nonzero value gets converted
51 to 'true', and zero gets converted to 'false'. This doesn't work
52 with this substitute. With this substitute, only the values 0 and 1
53 give the expected result when converted to _Bool' or 'bool'.
55 Also, it is suggested that programs use 'bool' rather than '_Bool';
56 this isn't required, but 'bool' is more common. */
59 /* 7.16. Boolean type and values */
61 /* BeOS <sys/socket.h> already #defines false 0, true 1. We use the same
62 definitions below, but temporarily we have to #undef them. */
64 # include <OS.h> /* defines bool but not _Bool */
69 /* For the sake of symbolic names in gdb, we define true and false as
70 enum constants, not only as macros.
71 It is tempting to write
72 typedef enum { false = 0, true = 1 } _Bool;
73 so that gdb prints values of type 'bool' symbolically. But if we do
74 this, values of type '_Bool' may promote to 'int' or 'unsigned int'
75 (see ISO C 99 6.7.2.2.(4)); however, '_Bool' must promote to 'int'
76 (see ISO C 99 6.3.1.1.(2)). So we add a negative value to the
77 enum; this ensures that '_Bool' promotes to 'int'. */
78 #if defined __cplusplus || defined __BEOS__
79 /* A compiler known to have 'bool'. */
80 /* If the compiler already has both 'bool' and '_Bool', we can assume they
81 are the same types. */
86 # if !defined __GNUC__
88 Some HP-UX cc and AIX IBM C compiler versions have compiler bugs when
89 the built-in _Bool type is used. See
90 http://gcc.gnu.org/ml/gcc-patches/2003-12/msg02303.html
91 http://lists.gnu.org/archive/html/bug-coreutils/2005-11/msg00161.html
92 http://lists.gnu.org/archive/html/bug-coreutils/2005-10/msg00086.html
93 Similar bugs are likely with other compilers as well; this file
94 wouldn't be used if <stdbool.h> was working.
95 So we override the _Bool type.
97 Need to define _Bool ourselves. As 'signed char' or as an enum type?
98 Use of a typedef, with SunPRO C, leads to a stupid
99 "warning: _Bool is a keyword in ISO C99".
100 Use of an enum type, with IRIX cc, leads to a stupid
101 "warning(1185): enumerated type mixed with another type".
102 Even the existence of an enum type, without a typedef,
103 "Invalid enumerator. (badenum)" with HP-UX cc on Tru64.
104 The only benefit of the enum, debuggability, is not important
105 with these compilers. So use 'signed char' and no enum. */
106 # define _Bool signed char
108 /* With this compiler, trust the _Bool type if the compiler has it. */
110 typedef enum { _Bool_must_promote_to_int = -1, false = 0, true = 1 } _Bool;
116 /* The other macros must be usable in preprocessor directives. */
119 #define __bool_true_false_are_defined 1
121 #endif /* _GL_STDBOOL_H */