xref: /freebsd/contrib/llvm-project/clang/lib/Headers/limits.h (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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 #if __SHRT_WIDTH__ < __INT_WIDTH__
56 #define USHRT_MAX (__SHRT_MAX__ * 2 + 1)
57 #else
58 #define USHRT_MAX (__SHRT_MAX__ * 2U + 1U)
59 #endif
60 #define UINT_MAX  (__INT_MAX__  *2U +1U)
61 #define ULONG_MAX (__LONG_MAX__ *2UL+1UL)
62 
63 #ifndef MB_LEN_MAX
64 #define MB_LEN_MAX 1
65 #endif
66 
67 #define CHAR_BIT  __CHAR_BIT__
68 
69 /* C2x 5.2.4.2.1 */
70 /* FIXME: This is using the placeholder dates Clang produces for these macros
71    in C2x mode; switch to the correct values once they've been published. */
72 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202000L
73 #define BOOL_WIDTH   __BOOL_WIDTH__
74 #define CHAR_WIDTH   CHAR_BIT
75 #define SCHAR_WIDTH  CHAR_BIT
76 #define UCHAR_WIDTH  CHAR_BIT
77 #define USHRT_WIDTH  __SHRT_WIDTH__
78 #define SHRT_WIDTH   __SHRT_WIDTH__
79 #define UINT_WIDTH   __INT_WIDTH__
80 #define INT_WIDTH    __INT_WIDTH__
81 #define ULONG_WIDTH  __LONG_WIDTH__
82 #define LONG_WIDTH   __LONG_WIDTH__
83 #define ULLONG_WIDTH __LLONG_WIDTH__
84 #define LLONG_WIDTH  __LLONG_WIDTH__
85 
86 #define BITINT_MAXWIDTH __BITINT_MAXWIDTH__
87 #endif
88 
89 #ifdef __CHAR_UNSIGNED__  /* -funsigned-char */
90 #define CHAR_MIN 0
91 #define CHAR_MAX UCHAR_MAX
92 #else
93 #define CHAR_MIN SCHAR_MIN
94 #define CHAR_MAX __SCHAR_MAX__
95 #endif
96 
97 /* C99 5.2.4.2.1: Added long long.
98    C++11 18.3.3.2: same contents as the Standard C Library header <limits.h>.
99  */
100 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L) ||              \
101     (defined(__cplusplus) && __cplusplus >= 201103L)
102 
103 #undef  LLONG_MIN
104 #undef  LLONG_MAX
105 #undef  ULLONG_MAX
106 
107 #define LLONG_MAX  __LONG_LONG_MAX__
108 #define LLONG_MIN  (-__LONG_LONG_MAX__-1LL)
109 #define ULLONG_MAX (__LONG_LONG_MAX__*2ULL+1ULL)
110 #endif
111 
112 /* LONG_LONG_MIN/LONG_LONG_MAX/ULONG_LONG_MAX are a GNU extension.  It's too bad
113    that we don't have something like #pragma poison that could be used to
114    deprecate a macro - the code should just use LLONG_MAX and friends.
115  */
116 #if defined(__GNU_LIBRARY__) ? defined(__USE_GNU) : !defined(__STRICT_ANSI__)
117 
118 #undef   LONG_LONG_MIN
119 #undef   LONG_LONG_MAX
120 #undef   ULONG_LONG_MAX
121 
122 #define LONG_LONG_MAX  __LONG_LONG_MAX__
123 #define LONG_LONG_MIN  (-__LONG_LONG_MAX__-1LL)
124 #define ULONG_LONG_MAX (__LONG_LONG_MAX__*2ULL+1ULL)
125 #endif
126 
127 #endif /* __CLANG_LIMITS_H */
128