clang  9.0.0svn
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 #ifdef __CHAR_UNSIGNED__ /* -funsigned-char */
66 #define CHAR_MIN 0
67 #define CHAR_MAX UCHAR_MAX
68 #else
69 #define CHAR_MIN SCHAR_MIN
70 #define CHAR_MAX __SCHAR_MAX__
71 #endif
72 
73 /* C99 5.2.4.2.1: Added long long.
74  C++11 18.3.3.2: same contents as the Standard C Library header <limits.h>.
75  */
76 #if __STDC_VERSION__ >= 199901L || __cplusplus >= 201103L
77 
78 #undef LLONG_MIN
79 #undef LLONG_MAX
80 #undef ULLONG_MAX
81 
82 #define LLONG_MAX __LONG_LONG_MAX__
83 #define LLONG_MIN (-__LONG_LONG_MAX__-1LL)
84 #define ULLONG_MAX (__LONG_LONG_MAX__*2ULL+1ULL)
85 #endif
86 
87 /* LONG_LONG_MIN/LONG_LONG_MAX/ULONG_LONG_MAX are a GNU extension. It's too bad
88  that we don't have something like #pragma poison that could be used to
89  deprecate a macro - the code should just use LLONG_MAX and friends.
90  */
91 #if defined(__GNU_LIBRARY__) ? defined(__USE_GNU) : !defined(__STRICT_ANSI__)
92 
93 #undef LONG_LONG_MIN
94 #undef LONG_LONG_MAX
95 #undef ULONG_LONG_MAX
96 
97 #define LONG_LONG_MAX __LONG_LONG_MAX__
98 #define LONG_LONG_MIN (-__LONG_LONG_MAX__-1LL)
99 #define ULONG_LONG_MAX (__LONG_LONG_MAX__*2ULL+1ULL)
100 #endif
101 
102 #endif /* __CLANG_LIMITS_H */