clang  16.0.0git
limits.h
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1 /*===---- limits.h - Standard header for integer sizes --------------------===*\
2  *
3  * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4  * See https://llvm.org/LICENSE.txt for license information.
5  * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6  *
7 \*===----------------------------------------------------------------------===*/
8 
9 #ifndef __CLANG_LIMITS_H
10 #define __CLANG_LIMITS_H
11 
12 /* The system's limits.h may, in turn, try to #include_next GCC's limits.h.
13  Avert this #include_next madness. */
14 #if defined __GNUC__ && !defined _GCC_LIMITS_H_
15 #define _GCC_LIMITS_H_
16 #endif
17 
18 /* System headers include a number of constants from POSIX in <limits.h>.
19  Include it if we're hosted. */
20 #if __STDC_HOSTED__ && __has_include_next(<limits.h>)
21 #include_next <limits.h>
22 #endif
23 
24 /* Many system headers try to "help us out" by defining these. No really, we
25  know how big each datatype is. */
26 #undef SCHAR_MIN
27 #undef SCHAR_MAX
28 #undef UCHAR_MAX
29 #undef SHRT_MIN
30 #undef SHRT_MAX
31 #undef USHRT_MAX
32 #undef INT_MIN
33 #undef INT_MAX
34 #undef UINT_MAX
35 #undef LONG_MIN
36 #undef LONG_MAX
37 #undef ULONG_MAX
38 
39 #undef CHAR_BIT
40 #undef CHAR_MIN
41 #undef CHAR_MAX
42 
43 /* C90/99 5.2.4.2.1 */
44 #define SCHAR_MAX __SCHAR_MAX__
45 #define SHRT_MAX __SHRT_MAX__
46 #define INT_MAX __INT_MAX__
47 #define LONG_MAX __LONG_MAX__
48 
49 #define SCHAR_MIN (-__SCHAR_MAX__-1)
50 #define SHRT_MIN (-__SHRT_MAX__ -1)
51 #define INT_MIN (-__INT_MAX__ -1)
52 #define LONG_MIN (-__LONG_MAX__ -1L)
53 
54 #define UCHAR_MAX (__SCHAR_MAX__*2 +1)
55 #define USHRT_MAX (__SHRT_MAX__ *2 +1)
56 #define UINT_MAX (__INT_MAX__ *2U +1U)
57 #define ULONG_MAX (__LONG_MAX__ *2UL+1UL)
58 
59 #ifndef MB_LEN_MAX
60 #define MB_LEN_MAX 1
61 #endif
62 
63 #define CHAR_BIT __CHAR_BIT__
64 
65 /* C2x 5.2.4.2.1 */
66 /* FIXME: This is using the placeholder dates Clang produces for these macros
67  in C2x mode; switch to the correct values once they've been published. */
68 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202000L
69 #define BOOL_WIDTH __BOOL_WIDTH__
70 #define CHAR_WIDTH CHAR_BIT
71 #define SCHAR_WIDTH CHAR_BIT
72 #define UCHAR_WIDTH CHAR_BIT
73 #define USHRT_WIDTH __SHRT_WIDTH__
74 #define SHRT_WIDTH __SHRT_WIDTH__
75 #define UINT_WIDTH __INT_WIDTH__
76 #define INT_WIDTH __INT_WIDTH__
77 #define ULONG_WIDTH __LONG_WIDTH__
78 #define LONG_WIDTH __LONG_WIDTH__
79 #define ULLONG_WIDTH __LLONG_WIDTH__
80 #define LLONG_WIDTH __LLONG_WIDTH__
81 
82 #define BITINT_MAXWIDTH __BITINT_MAXWIDTH__
83 #endif
84 
85 #ifdef __CHAR_UNSIGNED__ /* -funsigned-char */
86 #define CHAR_MIN 0
87 #define CHAR_MAX UCHAR_MAX
88 #else
89 #define CHAR_MIN SCHAR_MIN
90 #define CHAR_MAX __SCHAR_MAX__
91 #endif
92 
93 /* C99 5.2.4.2.1: Added long long.
94  C++11 18.3.3.2: same contents as the Standard C Library header <limits.h>.
95  */
96 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) || \
97  (defined(__cplusplus) && __cplusplus >= 201103L)
98 
99 #undef LLONG_MIN
100 #undef LLONG_MAX
101 #undef ULLONG_MAX
102 
103 #define LLONG_MAX __LONG_LONG_MAX__
104 #define LLONG_MIN (-__LONG_LONG_MAX__-1LL)
105 #define ULLONG_MAX (__LONG_LONG_MAX__*2ULL+1ULL)
106 #endif
107 
108 /* LONG_LONG_MIN/LONG_LONG_MAX/ULONG_LONG_MAX are a GNU extension. It's too bad
109  that we don't have something like #pragma poison that could be used to
110  deprecate a macro - the code should just use LLONG_MAX and friends.
111  */
112 #if defined(__GNU_LIBRARY__) ? defined(__USE_GNU) : !defined(__STRICT_ANSI__)
113 
114 #undef LONG_LONG_MIN
115 #undef LONG_LONG_MAX
116 #undef ULONG_LONG_MAX
117 
118 #define LONG_LONG_MAX __LONG_LONG_MAX__
119 #define LONG_LONG_MIN (-__LONG_LONG_MAX__-1LL)
120 #define ULONG_LONG_MAX (__LONG_LONG_MAX__*2ULL+1ULL)
121 #endif
122 
123 #endif /* __CLANG_LIMITS_H */