1 /*===--- ConvertUTF.h - Universal Character Names conversions ---------------=== 2 * 3 * The LLVM Compiler Infrastructure 4 * 5 * This file is distributed under the University of Illinois Open Source 6 * License. See LICENSE.TXT for details. 7 * 8 *==------------------------------------------------------------------------==*/ 9 /* 10 * Copyright 2001-2004 Unicode, Inc. 11 * 12 * Disclaimer 13 * 14 * This source code is provided as is by Unicode, Inc. No claims are 15 * made as to fitness for any particular purpose. No warranties of any 16 * kind are expressed or implied. The recipient agrees to determine 17 * applicability of information provided. If this file has been 18 * purchased on magnetic or optical media from Unicode, Inc., the 19 * sole remedy for any claim will be exchange of defective media 20 * within 90 days of receipt. 21 * 22 * Limitations on Rights to Redistribute This Code 23 * 24 * Unicode, Inc. hereby grants the right to freely use the information 25 * supplied in this file in the creation of products supporting the 26 * Unicode Standard, and to make copies of this file in any form 27 * for internal or external distribution as long as this notice 28 * remains attached. 29 */ 30 31 /* --------------------------------------------------------------------- 32 33 Conversions between UTF32, UTF-16, and UTF-8. Header file. 34 35 Several funtions are included here, forming a complete set of 36 conversions between the three formats. UTF-7 is not included 37 here, but is handled in a separate source file. 38 39 Each of these routines takes pointers to input buffers and output 40 buffers. The input buffers are const. 41 42 Each routine converts the text between *sourceStart and sourceEnd, 43 putting the result into the buffer between *targetStart and 44 targetEnd. Note: the end pointers are *after* the last item: e.g. 45 *(sourceEnd - 1) is the last item. 46 47 The return result indicates whether the conversion was successful, 48 and if not, whether the problem was in the source or target buffers. 49 (Only the first encountered problem is indicated.) 50 51 After the conversion, *sourceStart and *targetStart are both 52 updated to point to the end of last text successfully converted in 53 the respective buffers. 54 55 Input parameters: 56 sourceStart - pointer to a pointer to the source buffer. 57 The contents of this are modified on return so that 58 it points at the next thing to be converted. 59 targetStart - similarly, pointer to pointer to the target buffer. 60 sourceEnd, targetEnd - respectively pointers to the ends of the 61 two buffers, for overflow checking only. 62 63 These conversion functions take a ConversionFlags argument. When this 64 flag is set to strict, both irregular sequences and isolated surrogates 65 will cause an error. When the flag is set to lenient, both irregular 66 sequences and isolated surrogates are converted. 67 68 Whether the flag is strict or lenient, all illegal sequences will cause 69 an error return. This includes sequences such as: <F4 90 80 80>, <C0 80>, 70 or <A0> in UTF-8, and values above 0x10FFFF in UTF-32. Conformant code 71 must check for illegal sequences. 72 73 When the flag is set to lenient, characters over 0x10FFFF are converted 74 to the replacement character; otherwise (when the flag is set to strict) 75 they constitute an error. 76 77 Output parameters: 78 The value "sourceIllegal" is returned from some routines if the input 79 sequence is malformed. When "sourceIllegal" is returned, the source 80 value will point to the illegal value that caused the problem. E.g., 81 in UTF-8 when a sequence is malformed, it points to the start of the 82 malformed sequence. 83 84 Author: Mark E. Davis, 1994. 85 Rev History: Rick McGowan, fixes & updates May 2001. 86 Fixes & updates, Sept 2001. 87 88 ------------------------------------------------------------------------ */ 89 90 #ifndef LLVM_SUPPORT_CONVERTUTF_H 91 #define LLVM_SUPPORT_CONVERTUTF_H 92 93 #include <cstddef> 94 #include <string> 95 96 // Wrap everything in namespace llvm so that programs can link with llvm and 97 // their own version of the unicode libraries. 98 99 namespace llvm { 100 101 /* --------------------------------------------------------------------- 102 The following 4 definitions are compiler-specific. 103 The C standard does not guarantee that wchar_t has at least 104 16 bits, so wchar_t is no less portable than unsigned short! 105 All should be unsigned values to avoid sign extension during 106 bit mask & shift operations. 107 ------------------------------------------------------------------------ */ 108 109 typedef unsigned int UTF32; /* at least 32 bits */ 110 typedef unsigned short UTF16; /* at least 16 bits */ 111 typedef unsigned char UTF8; /* typically 8 bits */ 112 typedef unsigned char Boolean; /* 0 or 1 */ 113 114 /* Some fundamental constants */ 115 #define UNI_REPLACEMENT_CHAR (UTF32)0x0000FFFD 116 #define UNI_MAX_BMP (UTF32)0x0000FFFF 117 #define UNI_MAX_UTF16 (UTF32)0x0010FFFF 118 #define UNI_MAX_UTF32 (UTF32)0x7FFFFFFF 119 #define UNI_MAX_LEGAL_UTF32 (UTF32)0x0010FFFF 120 121 #define UNI_MAX_UTF8_BYTES_PER_CODE_POINT 4 122 123 #define UNI_UTF16_BYTE_ORDER_MARK_NATIVE 0xFEFF 124 #define UNI_UTF16_BYTE_ORDER_MARK_SWAPPED 0xFFFE 125 126 typedef enum { 127 conversionOK, /* conversion successful */ 128 sourceExhausted, /* partial character in source, but hit end */ 129 targetExhausted, /* insuff. room in target for conversion */ 130 sourceIllegal /* source sequence is illegal/malformed */ 131 } ConversionResult; 132 133 typedef enum { 134 strictConversion = 0, 135 lenientConversion 136 } ConversionFlags; 137 138 ConversionResult ConvertUTF8toUTF16 ( 139 const UTF8** sourceStart, const UTF8* sourceEnd, 140 UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags); 141 142 /** 143 * Convert a partial UTF8 sequence to UTF32. If the sequence ends in an 144 * incomplete code unit sequence, returns \c sourceExhausted. 145 */ 146 ConversionResult ConvertUTF8toUTF32Partial( 147 const UTF8** sourceStart, const UTF8* sourceEnd, 148 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags); 149 150 /** 151 * Convert a partial UTF8 sequence to UTF32. If the sequence ends in an 152 * incomplete code unit sequence, returns \c sourceIllegal. 153 */ 154 ConversionResult ConvertUTF8toUTF32( 155 const UTF8** sourceStart, const UTF8* sourceEnd, 156 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags); 157 158 ConversionResult ConvertUTF16toUTF8 ( 159 const UTF16** sourceStart, const UTF16* sourceEnd, 160 UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags); 161 162 ConversionResult ConvertUTF32toUTF8 ( 163 const UTF32** sourceStart, const UTF32* sourceEnd, 164 UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags); 165 166 ConversionResult ConvertUTF16toUTF32 ( 167 const UTF16** sourceStart, const UTF16* sourceEnd, 168 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags); 169 170 ConversionResult ConvertUTF32toUTF16 ( 171 const UTF32** sourceStart, const UTF32* sourceEnd, 172 UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags); 173 174 Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd); 175 176 Boolean isLegalUTF8String(const UTF8 **source, const UTF8 *sourceEnd); 177 178 unsigned getNumBytesForUTF8(UTF8 firstByte); 179 180 /*************************************************************************/ 181 /* Below are LLVM-specific wrappers of the functions above. */ 182 183 template <typename T> class ArrayRef; 184 template <typename T> class SmallVectorImpl; 185 class StringRef; 186 187 /** 188 * Convert an UTF8 StringRef to UTF8, UTF16, or UTF32 depending on 189 * WideCharWidth. The converted data is written to ResultPtr, which needs to 190 * point to at least WideCharWidth * (Source.Size() + 1) bytes. On success, 191 * ResultPtr will point one after the end of the copied string. On failure, 192 * ResultPtr will not be changed, and ErrorPtr will be set to the location of 193 * the first character which could not be converted. 194 * \return true on success. 195 */ 196 bool ConvertUTF8toWide(unsigned WideCharWidth, llvm::StringRef Source, 197 char *&ResultPtr, const UTF8 *&ErrorPtr); 198 199 /** 200 * Converts a UTF-8 StringRef to a std::wstring. 201 * \return true on success. 202 */ 203 bool ConvertUTF8toWide(llvm::StringRef Source, std::wstring &Result); 204 205 /** 206 * Converts a UTF-8 C-string to a std::wstring. 207 * \return true on success. 208 */ 209 bool ConvertUTF8toWide(const char *Source, std::wstring &Result); 210 211 /** 212 * Converts a std::wstring to a UTF-8 encoded std::string. 213 * \return true on success. 214 */ 215 bool convertWideToUTF8(const std::wstring &Source, std::string &Result); 216 217 218 /** 219 * Convert an Unicode code point to UTF8 sequence. 220 * 221 * \param Source a Unicode code point. 222 * \param [in,out] ResultPtr pointer to the output buffer, needs to be at least 223 * \c UNI_MAX_UTF8_BYTES_PER_CODE_POINT bytes. On success \c ResultPtr is 224 * updated one past end of the converted sequence. 225 * 226 * \returns true on success. 227 */ 228 bool ConvertCodePointToUTF8(unsigned Source, char *&ResultPtr); 229 230 /** 231 * Convert the first UTF8 sequence in the given source buffer to a UTF32 232 * code point. 233 * 234 * \param [in,out] source A pointer to the source buffer. If the conversion 235 * succeeds, this pointer will be updated to point to the byte just past the 236 * end of the converted sequence. 237 * \param sourceEnd A pointer just past the end of the source buffer. 238 * \param [out] target The converted code 239 * \param flags Whether the conversion is strict or lenient. 240 * 241 * \returns conversionOK on success 242 * 243 * \sa ConvertUTF8toUTF32 244 */ 245 static inline ConversionResult convertUTF8Sequence(const UTF8 **source, 246 const UTF8 *sourceEnd, 247 UTF32 *target, 248 ConversionFlags flags) { 249 if (*source == sourceEnd) 250 return sourceExhausted; 251 unsigned size = getNumBytesForUTF8(**source); 252 if ((ptrdiff_t)size > sourceEnd - *source) 253 return sourceExhausted; 254 return ConvertUTF8toUTF32(source, *source + size, &target, target + 1, flags); 255 } 256 257 /** 258 * Returns true if a blob of text starts with a UTF-16 big or little endian byte 259 * order mark. 260 */ 261 bool hasUTF16ByteOrderMark(ArrayRef<char> SrcBytes); 262 263 /** 264 * Converts a stream of raw bytes assumed to be UTF16 into a UTF8 std::string. 265 * 266 * \param [in] SrcBytes A buffer of what is assumed to be UTF-16 encoded text. 267 * \param [out] Out Converted UTF-8 is stored here on success. 268 * \returns true on success 269 */ 270 bool convertUTF16ToUTF8String(ArrayRef<char> SrcBytes, std::string &Out); 271 272 /** 273 * Converts a UTF16 string into a UTF8 std::string. 274 * 275 * \param [in] Src A buffer of UTF-16 encoded text. 276 * \param [out] Out Converted UTF-8 is stored here on success. 277 * \returns true on success 278 */ 279 bool convertUTF16ToUTF8String(ArrayRef<UTF16> Src, std::string &Out); 280 281 /** 282 * Converts a UTF-8 string into a UTF-16 string with native endianness. 283 * 284 * \returns true on success 285 */ 286 bool convertUTF8ToUTF16String(StringRef SrcUTF8, 287 SmallVectorImpl<UTF16> &DstUTF16); 288 289 } /* end namespace llvm */ 290 291 #endif 292
