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 16Macros: 17 18 NULL 19 20namespace std 21{ 22 23Types: 24 25 size_t 26 27void* memcpy(void* restrict s1, const void* restrict s2, size_t n); 28void* memmove(void* s1, const void* s2, size_t n); 29char* strcpy (char* restrict s1, const char* restrict s2); 30char* strncpy(char* restrict s1, const char* restrict s2, size_t n); 31char* strcat (char* restrict s1, const char* restrict s2); 32char* strncat(char* restrict s1, const char* restrict s2, size_t n); 33int memcmp(const void* s1, const void* s2, size_t n); 34int strcmp (const char* s1, const char* s2); 35int strncmp(const char* s1, const char* s2, size_t n); 36int strcoll(const char* s1, const char* s2); 37size_t strxfrm(char* restrict s1, const char* restrict s2, size_t n); 38const void* memchr(const void* s, int c, size_t n); 39 void* memchr( void* s, int c, size_t n); 40const char* strchr(const char* s, int c); 41 char* strchr( char* s, int c); 42size_t strcspn(const char* s1, const char* s2); 43const char* strpbrk(const char* s1, const char* s2); 44 char* strpbrk( char* s1, const char* s2); 45const char* strrchr(const char* s, int c); 46 char* strrchr( char* s, int c); 47size_t strspn(const char* s1, const char* s2); 48const char* strstr(const char* s1, const char* s2); 49 char* strstr( char* s1, const char* s2); 50char* strtok(char* restrict s1, const char* restrict s2); 51void* memset(void* s, int c, size_t n); 52char* strerror(int errnum); 53size_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 79using ::size_t _LIBCPP_USING_IF_EXISTS; 80using ::memcpy _LIBCPP_USING_IF_EXISTS; 81using ::memmove _LIBCPP_USING_IF_EXISTS; 82using ::strcpy _LIBCPP_USING_IF_EXISTS; 83using ::strncpy _LIBCPP_USING_IF_EXISTS; 84using ::strcat _LIBCPP_USING_IF_EXISTS; 85using ::strncat _LIBCPP_USING_IF_EXISTS; 86using ::memcmp _LIBCPP_USING_IF_EXISTS; 87using ::strcmp _LIBCPP_USING_IF_EXISTS; 88using ::strncmp _LIBCPP_USING_IF_EXISTS; 89using ::strcoll _LIBCPP_USING_IF_EXISTS; 90using ::strxfrm _LIBCPP_USING_IF_EXISTS; 91using ::memchr _LIBCPP_USING_IF_EXISTS; 92using ::strchr _LIBCPP_USING_IF_EXISTS; 93using ::strcspn _LIBCPP_USING_IF_EXISTS; 94using ::strpbrk _LIBCPP_USING_IF_EXISTS; 95using ::strrchr _LIBCPP_USING_IF_EXISTS; 96using ::strspn _LIBCPP_USING_IF_EXISTS; 97using ::strstr _LIBCPP_USING_IF_EXISTS; 98using ::strtok _LIBCPP_USING_IF_EXISTS; 99using ::memset _LIBCPP_USING_IF_EXISTS; 100using ::strerror _LIBCPP_USING_IF_EXISTS; 101using ::strlen _LIBCPP_USING_IF_EXISTS; 102 103inline _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 return __builtin_strlen(__str); 115} 116 117template <class _Tp> 118_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 int 119__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 return __builtin_memcmp(__lhs, __rhs, __count); 132} 133 134inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 const char* 135__constexpr_char_memchr(const char* __str, int __char, size_t __count) { 136#if __has_builtin(__builtin_char_memchr) 137 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 153