1 //===----------------------------------------------------------------------===// 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 #include <cstdarg> // va_start, va_end 10 #include <cstddef> // size_t 11 #include <cstdio> // vsprintf, vsnprintf 12 #include <cstdlib> // malloc 13 #include <cstring> // strcpy, wcsncpy 14 #include <cwchar> // mbstate_t 15 16 // Like sprintf, but when return value >= 0 it returns 17 // a pointer to a malloc'd string in *sptr. 18 // If return >= 0, use free to delete *sptr. 19 int __libcpp_vasprintf(char** sptr, const char* __restrict format, va_list ap) { 20 *sptr = NULL; 21 // Query the count required. 22 va_list ap_copy; 23 va_copy(ap_copy, ap); 24 _LIBCPP_DIAGNOSTIC_PUSH 25 _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wformat-nonliteral") 26 int count = vsnprintf(NULL, 0, format, ap_copy); 27 _LIBCPP_DIAGNOSTIC_POP 28 va_end(ap_copy); 29 if (count < 0) 30 return count; 31 size_t buffer_size = static_cast<size_t>(count) + 1; 32 char* p = static_cast<char*>(malloc(buffer_size)); 33 if (!p) 34 return -1; 35 // If we haven't used exactly what was required, something is wrong. 36 // Maybe bug in vsnprintf. Report the error and return. 37 _LIBCPP_DIAGNOSTIC_PUSH 38 _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wformat-nonliteral") 39 if (vsnprintf(p, buffer_size, format, ap) != count) { 40 _LIBCPP_DIAGNOSTIC_POP 41 free(p); 42 return -1; 43 } 44 // All good. This is returning memory to the caller not freeing it. 45 *sptr = p; 46 return count; 47 } 48 49 // Returns >= 0: the number of wide characters found in the 50 // multi byte sequence src (of src_size_bytes), that fit in the buffer dst 51 // (of max_dest_chars elements size). The count returned excludes the 52 // null terminator. When dst is NULL, no characters are copied 53 // and no "out" parameters are updated. 54 // Returns (size_t) -1: an incomplete sequence encountered. 55 // Leaves *src pointing the next character to convert or NULL 56 // if a null character was converted from *src. 57 size_t mbsnrtowcs(wchar_t* __restrict dst, 58 const char** __restrict src, 59 size_t src_size_bytes, 60 size_t max_dest_chars, 61 mbstate_t* __restrict ps) { 62 const size_t terminated_sequence = static_cast<size_t>(0); 63 // const size_t invalid_sequence = static_cast<size_t>(-1); 64 const size_t incomplete_sequence = static_cast< size_t>(-2); 65 66 size_t dest_converted = 0; 67 size_t source_converted = 0; 68 size_t source_remaining = src_size_bytes; 69 size_t result = 0; 70 bool have_result = false; 71 72 // If dst is null then max_dest_chars should be ignored according to the 73 // standard. Setting max_dest_chars to a large value has this effect. 74 if (!dst) 75 max_dest_chars = static_cast<size_t>(-1); 76 77 while (source_remaining) { 78 if (dst && dest_converted >= max_dest_chars) 79 break; 80 // Converts one multi byte character. 81 // if result > 0, it's the size in bytes of that character. 82 // othewise if result is zero it indicates the null character has been found. 83 // otherwise it's an error and errno may be set. 84 size_t char_size = mbrtowc(dst ? dst + dest_converted : NULL, *src + source_converted, source_remaining, ps); 85 // Don't do anything to change errno from here on. 86 if (char_size > 0) { 87 source_remaining -= char_size; 88 source_converted += char_size; 89 ++dest_converted; 90 continue; 91 } 92 result = char_size; 93 have_result = true; 94 break; 95 } 96 if (dst) { 97 if (have_result && result == terminated_sequence) 98 *src = NULL; 99 else 100 *src += source_converted; 101 } 102 if (have_result && result != terminated_sequence && result != incomplete_sequence) 103 return static_cast<size_t>(-1); 104 105 return dest_converted; 106 } 107 108 // Converts max_source_chars from the wide character buffer pointer to by *src, 109 // into the multi byte character sequence buffer stored at dst which must be 110 // dst_size_bytes bytes in size. 111 // Returns >= 0: the number of bytes in the sequence 112 // converted from *src, excluding the null terminator. 113 // Returns size_t(-1) if an error occurs, also sets errno. 114 // If dst is NULL dst_size_bytes is ignored and no bytes are copied to dst 115 // and no "out" parameters are updated. 116 size_t wcsnrtombs(char* __restrict dst, 117 const wchar_t** __restrict src, 118 size_t max_source_chars, 119 size_t dst_size_bytes, 120 mbstate_t* __restrict ps) { 121 // const size_t invalid_sequence = static_cast<size_t>(-1); 122 123 size_t source_converted = 0; 124 size_t dest_converted = 0; 125 size_t dest_remaining = dst_size_bytes; 126 size_t char_size = 0; 127 const errno_t no_error = (errno_t)0; 128 errno_t result = (errno_t)0; 129 bool have_result = false; 130 bool terminator_found = false; 131 132 // If dst is null then dst_size_bytes should be ignored according to the 133 // standard. Setting dest_remaining to a large value has this effect. 134 if (!dst) 135 dest_remaining = static_cast<size_t>(-1); 136 137 while (source_converted != max_source_chars) { 138 if (!dest_remaining) 139 break; 140 wchar_t c = (*src)[source_converted]; 141 if (dst) 142 result = wcrtomb_s(&char_size, dst + dest_converted, dest_remaining, c, ps); 143 else 144 result = wcrtomb_s(&char_size, NULL, 0, c, ps); 145 // If result is zero there is no error and char_size contains the 146 // size of the multi-byte-sequence converted. 147 // Otherwise result indicates an errno type error. 148 if (result == no_error) { 149 if (c == L'\0') { 150 terminator_found = true; 151 break; 152 } 153 ++source_converted; 154 if (dst) 155 dest_remaining -= char_size; 156 dest_converted += char_size; 157 continue; 158 } 159 have_result = true; 160 break; 161 } 162 if (dst) { 163 if (terminator_found) 164 *src = NULL; 165 else 166 *src = *src + source_converted; 167 } 168 if (have_result && result != no_error) { 169 errno = result; 170 return static_cast<size_t>(-1); 171 } 172 173 return dest_converted; 174 } 175