xref: /btstack/src/btstack_bool.h (revision 9eadad2068cc64aed0b2e109af6a00a371bb8c11)
1 /*
2  * Copyright (C) 2019 BlueKitchen GmbH
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the copyright holders nor the names of
14  *    contributors may be used to endorse or promote products derived
15  *    from this software without specific prior written permission.
16  * 4. Any redistribution, use, or modification is done solely for
17  *    personal benefit and not for any commercial purpose or for
18  *    monetary gain.
19  *
20  * THIS SOFTWARE IS PROVIDED BY BLUEKITCHEN GMBH AND CONTRIBUTORS
21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
23  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BLUEKITCHEN
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36  */
37 
38 /*
39  * btstack_bool.h
40  *
41  * Provide bool type */
42 
43 #ifndef BTSTACK_BOOL_H
44 #define BTSTACK_BOOL_H
45 
46 #if !defined(__cplusplus)
47 
48 //
49 // Check for C99
50 // see: https://sourceforge.net/p/predef/wiki/Standards/
51 //
52 #if defined(__STDC__)
53 #   if defined(__STDC_VERSION__)
54 #     if (__STDC_VERSION__ >= 199901L)
55 #       define PREDEF_STANDARD_C_1999
56 #     endif
57 #  endif
58 #endif /* __STDC__ */
59 
60 // Detecting C99 in Visual Studio requires to disable Microsoft Extensions (/Za) which causes other issues
61 // Workaround: if MSC, assume stdbool.h exists, which is true for Visual Studio 2022
62 #ifdef _MSC_VER
63 #define PREDEF_STANDARD_C_1999
64 #endif
65 
66 // define boolean type - required for MISRA-C 2012 Essential Type System
67 #ifdef PREDEF_STANDARD_C_1999
68 
69 // use <stdbool.h> if C99 or higher
70 #   include <stdbool.h>
71 
72 #else /* PREDEF_STANDARD_C_1999 */
73 
74 // backport for pre-c99 compilers or incorrect detection
75 #ifndef bool
76 #define bool unsigned char
77 #endif
78 #ifndef false
79 #define false 0
80 #endif
81 #ifndef true
82 #define true 1
83 #endif
84 
85 #endif /* PREDEF_STANDARD_C_1999 */
86 
87 #endif /* __cplusplus */
88 
89 #endif /* BTSTACK_BOOL_H */
90