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1 : // -*- C++ -*-
2 : //===----------------------------------------------------------------------===//
3 : //
4 : // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 : // See https://llvm.org/LICENSE.txt for license information.
6 : // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 : //
8 : //===----------------------------------------------------------------------===//
9 :
10 : #ifndef _LIBCPP_CSTRING
11 : #define _LIBCPP_CSTRING
12 :
13 : /*
14 : cstring synopsis
15 :
16 : Macros:
17 :
18 : NULL
19 :
20 : namespace std
21 : {
22 :
23 : Types:
24 :
25 : size_t
26 :
27 : void* memcpy(void* restrict s1, const void* restrict s2, size_t n);
28 : void* memmove(void* s1, const void* s2, size_t n);
29 : char* strcpy (char* restrict s1, const char* restrict s2);
30 : char* strncpy(char* restrict s1, const char* restrict s2, size_t n);
31 : char* strcat (char* restrict s1, const char* restrict s2);
32 : char* strncat(char* restrict s1, const char* restrict s2, size_t n);
33 : int memcmp(const void* s1, const void* s2, size_t n);
34 : int strcmp (const char* s1, const char* s2);
35 : int strncmp(const char* s1, const char* s2, size_t n);
36 : int strcoll(const char* s1, const char* s2);
37 : size_t strxfrm(char* restrict s1, const char* restrict s2, size_t n);
38 : const void* memchr(const void* s, int c, size_t n);
39 : void* memchr( void* s, int c, size_t n);
40 : const char* strchr(const char* s, int c);
41 : char* strchr( char* s, int c);
42 : size_t strcspn(const char* s1, const char* s2);
43 : const char* strpbrk(const char* s1, const char* s2);
44 : char* strpbrk( char* s1, const char* s2);
45 : const char* strrchr(const char* s, int c);
46 : char* strrchr( char* s, int c);
47 : size_t strspn(const char* s1, const char* s2);
48 : const char* strstr(const char* s1, const char* s2);
49 : char* strstr( char* s1, const char* s2);
50 : char* strtok(char* restrict s1, const char* restrict s2);
51 : void* memset(void* s, int c, size_t n);
52 : char* strerror(int errnum);
53 : size_t strlen(const char* s);
54 :
55 : } // std
56 :
57 : */
58 :
59 : #include <__assert> // all public C++ headers provide the assertion handler
60 : #include <__config>
61 : #include <__type_traits/is_constant_evaluated.h>
62 :
63 : #include <string.h>
64 :
65 : #ifndef _LIBCPP_STRING_H
66 : # error <cstring> tried including <string.h> but didn't find libc++'s <string.h> header. \
67 : This usually means that your header search paths are not configured properly. \
68 : The header search paths should contain the C++ Standard Library headers before \
69 : any C Standard Library, and you are probably using compiler flags that make that \
70 : not be the case.
71 : #endif
72 :
73 : #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
74 : # pragma GCC system_header
75 : #endif
76 :
77 : _LIBCPP_BEGIN_NAMESPACE_STD
78 :
79 : using ::size_t _LIBCPP_USING_IF_EXISTS;
80 : using ::memcpy _LIBCPP_USING_IF_EXISTS;
81 : using ::memmove _LIBCPP_USING_IF_EXISTS;
82 : using ::strcpy _LIBCPP_USING_IF_EXISTS;
83 : using ::strncpy _LIBCPP_USING_IF_EXISTS;
84 : using ::strcat _LIBCPP_USING_IF_EXISTS;
85 : using ::strncat _LIBCPP_USING_IF_EXISTS;
86 : using ::memcmp _LIBCPP_USING_IF_EXISTS;
87 : using ::strcmp _LIBCPP_USING_IF_EXISTS;
88 : using ::strncmp _LIBCPP_USING_IF_EXISTS;
89 : using ::strcoll _LIBCPP_USING_IF_EXISTS;
90 : using ::strxfrm _LIBCPP_USING_IF_EXISTS;
91 : using ::memchr _LIBCPP_USING_IF_EXISTS;
92 : using ::strchr _LIBCPP_USING_IF_EXISTS;
93 : using ::strcspn _LIBCPP_USING_IF_EXISTS;
94 : using ::strpbrk _LIBCPP_USING_IF_EXISTS;
95 : using ::strrchr _LIBCPP_USING_IF_EXISTS;
96 : using ::strspn _LIBCPP_USING_IF_EXISTS;
97 : using ::strstr _LIBCPP_USING_IF_EXISTS;
98 : using ::strtok _LIBCPP_USING_IF_EXISTS;
99 : using ::memset _LIBCPP_USING_IF_EXISTS;
100 : using ::strerror _LIBCPP_USING_IF_EXISTS;
101 : using ::strlen _LIBCPP_USING_IF_EXISTS;
102 :
103 3986675 : inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 size_t __constexpr_strlen(const char* __str) {
104 : // GCC currently doesn't support __builtin_strlen for heap-allocated memory during constant evaluation.
105 : // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70816
106 : #ifdef _LIBCPP_COMPILER_GCC
107 : if (__libcpp_is_constant_evaluated()) {
108 : size_t __i = 0;
109 : for (; __str[__i] != '\0'; ++__i)
110 : ;
111 : return __i;
112 : }
113 : #endif
114 3986675 : return __builtin_strlen(__str);
115 : }
116 :
117 : template <class _Tp>
118 : _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int
119 2424961 : __constexpr_memcmp(const _Tp* __lhs, const _Tp* __rhs, size_t __count) {
120 : #ifdef _LIBCPP_COMPILER_GCC
121 : if (__libcpp_is_constant_evaluated()) {
122 : for (; __count; --__count, ++__lhs, ++__rhs) {
123 : if (*__lhs < *__rhs)
124 : return -1;
125 : if (*__rhs < *__lhs)
126 : return 1;
127 : }
128 : return 0;
129 : }
130 : #endif
131 2424961 : return __builtin_memcmp(__lhs, __rhs, __count);
132 : }
133 :
134 : inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const char*
135 2503169 : __constexpr_char_memchr(const char* __str, int __char, size_t __count) {
136 : #if __has_builtin(__builtin_char_memchr)
137 2503169 : return __builtin_char_memchr(__str, __char, __count);
138 : #else
139 : if (!__libcpp_is_constant_evaluated())
140 : return static_cast<const char*>(std::memchr(__str, __char, __count));
141 : for (; __count; --__count) {
142 : if (*__str == __char)
143 : return __str;
144 : ++__str;
145 : }
146 : return nullptr;
147 : #endif
148 : }
149 :
150 : _LIBCPP_END_NAMESPACE_STD
151 :
152 : #endif // _LIBCPP_CSTRING
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