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 <cstdlib> // malloc 12#include <cstdio> // vsprintf, vsnprintf 13#include <cstring> // strcpy, wcsncpy 14#include <cwchar> // mbstate_t 15 16 17// Like sprintf, but when return value >= 0 it returns 18// a pointer to a malloc'd string in *sptr. 19// If return >= 0, use free to delete *sptr. 20int __libcpp_vasprintf( char **sptr, const char *__restrict format, va_list ap ) 21{ 22 *sptr = NULL; 23 // Query the count required. 24 va_list ap_copy; 25 va_copy(ap_copy, ap); 26 _LIBCPP_DIAGNOSTIC_PUSH 27 _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wformat-nonliteral") 28 int count = vsnprintf( NULL, 0, format, ap_copy ); 29 _LIBCPP_DIAGNOSTIC_POP 30 va_end(ap_copy); 31 if (count < 0) 32 return count; 33 size_t buffer_size = static_cast<size_t>(count) + 1; 34 char* p = static_cast<char*>(malloc(buffer_size)); 35 if ( ! p ) 36 return -1; 37 // If we haven't used exactly what was required, something is wrong. 38 // Maybe bug in vsnprintf. Report the error and return. 39 _LIBCPP_DIAGNOSTIC_PUSH 40 _LIBCPP_CLANG_DIAGNOSTIC_IGNORED("-Wformat-nonliteral") 41 if (vsnprintf(p, buffer_size, format, ap) != count) { 42 _LIBCPP_DIAGNOSTIC_POP 43 free(p); 44 return -1; 45 } 46 // All good. This is returning memory to the caller not freeing it. 47 *sptr = p; 48 return count; 49} 50 51// Returns >= 0: the number of wide characters found in the 52// multi byte sequence src (of src_size_bytes), that fit in the buffer dst 53// (of max_dest_chars elements size). The count returned excludes the 54// null terminator. When dst is NULL, no characters are copied 55// and no "out" parameters are updated. 56// Returns (size_t) -1: an incomplete sequence encountered. 57// Leaves *src pointing the next character to convert or NULL 58// if a null character was converted from *src. 59size_t mbsnrtowcs( wchar_t *__restrict dst, const char **__restrict src, 60 size_t src_size_bytes, size_t max_dest_chars, mbstate_t *__restrict ps ) 61{ 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. 116size_t wcsnrtombs( char *__restrict dst, const wchar_t **__restrict src, 117 size_t max_source_chars, size_t dst_size_bytes, mbstate_t *__restrict ps ) 118{ 119 //const size_t invalid_sequence = static_cast<size_t>(-1); 120 121 size_t source_converted = 0; 122 size_t dest_converted = 0; 123 size_t dest_remaining = dst_size_bytes; 124 size_t char_size = 0; 125 const errno_t no_error = ( errno_t) 0; 126 errno_t result = ( errno_t ) 0; 127 bool have_result = false; 128 bool terminator_found = false; 129 130 // If dst is null then dst_size_bytes should be ignored according to the 131 // standard. Setting dest_remaining to a large value has this effect. 132 if (!dst) 133 dest_remaining = static_cast<size_t>(-1); 134 135 while ( source_converted != max_source_chars ) { 136 if ( ! dest_remaining ) 137 break; 138 wchar_t c = (*src)[source_converted]; 139 if ( dst ) 140 result = wcrtomb_s( &char_size, dst + dest_converted, dest_remaining, c, ps); 141 else 142 result = wcrtomb_s( &char_size, NULL, 0, c, ps); 143 // If result is zero there is no error and char_size contains the 144 // size of the multi-byte-sequence converted. 145 // Otherwise result indicates an errno type error. 146 if ( result == no_error ) { 147 if ( c == L'\0' ) { 148 terminator_found = true; 149 break; 150 } 151 ++source_converted; 152 if ( dst ) 153 dest_remaining -= char_size; 154 dest_converted += char_size; 155 continue; 156 } 157 have_result = true; 158 break; 159 } 160 if ( dst ) { 161 if ( terminator_found ) 162 *src = NULL; 163 else 164 *src = *src + source_converted; 165 } 166 if ( have_result && result != no_error ) { 167 errno = result; 168 return static_cast<size_t>(-1); 169 } 170 171 return dest_converted; 172} 173