stddef.h (5053B) - Raw
1 /*===---- stddef.h - Basic type definitions --------------------------------=== 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 10 /* 11 * This header is designed to be included multiple times. If any of the __need_ 12 * macros are defined, then only that subset of interfaces are provided. This 13 * can be useful for POSIX headers that need to not expose all of stddef.h, but 14 * need to use some of its interfaces. Otherwise this header provides all of 15 * the expected interfaces. 16 * 17 * When clang modules are enabled, this header is a textual header to support 18 * the multiple include behavior. As such, it doesn't directly declare anything 19 * so that it doesn't add duplicate declarations to all of its includers' 20 * modules. 21 */ 22 #if defined(__MVS__) && __has_include_next(<stddef.h>) 23 #undef __need_ptrdiff_t 24 #undef __need_size_t 25 #undef __need_rsize_t 26 #undef __need_wchar_t 27 #undef __need_NULL 28 #undef __need_nullptr_t 29 #undef __need_unreachable 30 #undef __need_max_align_t 31 #undef __need_offsetof 32 #undef __need_wint_t 33 #include <__stddef_header_macro.h> 34 #include_next <stddef.h> 35 36 #else 37 38 #if !defined(__need_ptrdiff_t) && !defined(__need_size_t) && \ 39 !defined(__need_rsize_t) && !defined(__need_wchar_t) && \ 40 !defined(__need_NULL) && !defined(__need_nullptr_t) && \ 41 !defined(__need_unreachable) && !defined(__need_max_align_t) && \ 42 !defined(__need_offsetof) && !defined(__need_wint_t) 43 #define __need_ptrdiff_t 44 #define __need_size_t 45 /* ISO9899:2011 7.20 (C11 Annex K): Define rsize_t if __STDC_WANT_LIB_EXT1__ is 46 * enabled. */ 47 #if defined(__STDC_WANT_LIB_EXT1__) && __STDC_WANT_LIB_EXT1__ >= 1 48 #define __need_rsize_t 49 #endif 50 #define __need_wchar_t 51 #if !defined(__STDDEF_H) || __has_feature(modules) 52 /* 53 * __stddef_null.h is special when building without modules: if __need_NULL is 54 * set, then it will unconditionally redefine NULL. To avoid stepping on client 55 * definitions of NULL, __need_NULL should only be set the first time this 56 * header is included, that is when __STDDEF_H is not defined. However, when 57 * building with modules, this header is a textual header and needs to 58 * unconditionally include __stdef_null.h to support multiple submodules 59 * exporting _Builtin_stddef.null. Take module SM with submodules A and B, whose 60 * headers both include stddef.h When SM.A builds, __STDDEF_H will be defined. 61 * When SM.B builds, the definition from SM.A will leak when building without 62 * local submodule visibility. stddef.h wouldn't include __stddef_null.h, and 63 * SM.B wouldn't import _Builtin_stddef.null, and SM.B's `export *` wouldn't 64 * export NULL as expected. When building with modules, always include 65 * __stddef_null.h so that everything works as expected. 66 */ 67 #define __need_NULL 68 #endif 69 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L) || \ 70 defined(__cplusplus) 71 #define __need_nullptr_t 72 #endif 73 #if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 202311L 74 #define __need_unreachable 75 #endif 76 #if (defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201112L) || \ 77 (defined(__cplusplus) && __cplusplus >= 201103L) 78 #define __need_max_align_t 79 #endif 80 #define __need_offsetof 81 /* wint_t is provided by <wchar.h> and not <stddef.h>. It's here 82 * for compatibility, but must be explicitly requested. Therefore 83 * __need_wint_t is intentionally not defined here. */ 84 #include <__stddef_header_macro.h> 85 #endif 86 87 #if defined(__need_ptrdiff_t) 88 #include <__stddef_ptrdiff_t.h> 89 #undef __need_ptrdiff_t 90 #endif /* defined(__need_ptrdiff_t) */ 91 92 #if defined(__need_size_t) 93 #include <__stddef_size_t.h> 94 #undef __need_size_t 95 #endif /*defined(__need_size_t) */ 96 97 #if defined(__need_rsize_t) 98 #include <__stddef_rsize_t.h> 99 #undef __need_rsize_t 100 #endif /* defined(__need_rsize_t) */ 101 102 #if defined(__need_wchar_t) 103 #include <__stddef_wchar_t.h> 104 #undef __need_wchar_t 105 #endif /* defined(__need_wchar_t) */ 106 107 #if defined(__need_NULL) 108 #include <__stddef_null.h> 109 #undef __need_NULL 110 #endif /* defined(__need_NULL) */ 111 112 #if defined(__need_nullptr_t) 113 #include <__stddef_nullptr_t.h> 114 #undef __need_nullptr_t 115 #endif /* defined(__need_nullptr_t) */ 116 117 #if defined(__need_unreachable) 118 #include <__stddef_unreachable.h> 119 #undef __need_unreachable 120 #endif /* defined(__need_unreachable) */ 121 122 #if defined(__need_max_align_t) 123 #include <__stddef_max_align_t.h> 124 #undef __need_max_align_t 125 #endif /* defined(__need_max_align_t) */ 126 127 #if defined(__need_offsetof) 128 #include <__stddef_offsetof.h> 129 #undef __need_offsetof 130 #endif /* defined(__need_offsetof) */ 131 132 /* Some C libraries expect to see a wint_t here. Others (notably MinGW) will use 133 __WINT_TYPE__ directly; accommodate both by requiring __need_wint_t */ 134 #if defined(__need_wint_t) 135 #include <__stddef_wint_t.h> 136 #undef __need_wint_t 137 #endif /* __need_wint_t */ 138 139 #endif /* __MVS__ */