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 /* --------------------------------------------------------------------- 94 The following 4 definitions are compiler-specific. 95 The C standard does not guarantee that wchar_t has at least 96 16 bits, so wchar_t is no less portable than unsigned short! 97 All should be unsigned values to avoid sign extension during 98 bit mask & shift operations. 99 ------------------------------------------------------------------------ */ 100 101 typedef unsigned int UTF32; /* at least 32 bits */ 102 typedef unsigned short UTF16; /* at least 16 bits */ 103 typedef unsigned char UTF8; /* typically 8 bits */ 104 typedef unsigned char Boolean; /* 0 or 1 */ 105 106 /* Some fundamental constants */ 107 #define UNI_REPLACEMENT_CHAR (UTF32)0x0000FFFD 108 #define UNI_MAX_BMP (UTF32)0x0000FFFF 109 #define UNI_MAX_UTF16 (UTF32)0x0010FFFF 110 #define UNI_MAX_UTF32 (UTF32)0x7FFFFFFF 111 #define UNI_MAX_LEGAL_UTF32 (UTF32)0x0010FFFF 112 113 #define UNI_MAX_UTF8_BYTES_PER_CODE_POINT 4 114 115 #define UNI_UTF16_BYTE_ORDER_MARK_NATIVE 0xFEFF 116 #define UNI_UTF16_BYTE_ORDER_MARK_SWAPPED 0xFFFE 117 118 typedef enum { 119 conversionOK, /* conversion successful */ 120 sourceExhausted, /* partial character in source, but hit end */ 121 targetExhausted, /* insuff. room in target for conversion */ 122 sourceIllegal /* source sequence is illegal/malformed */ 123 } ConversionResult; 124 125 typedef enum { 126 strictConversion = 0, 127 lenientConversion 128 } ConversionFlags; 129 130 /* This is for C++ and does no harm in C */ 131 #ifdef __cplusplus 132 extern "C" { 133 #endif 134 135 ConversionResult ConvertUTF8toUTF16 ( 136 const UTF8** sourceStart, const UTF8* sourceEnd, 137 UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags); 138 139 /** 140 * Convert a partial UTF8 sequence to UTF32. If the sequence ends in an 141 * incomplete code unit sequence, returns \c sourceExhausted. 142 */ 143 ConversionResult ConvertUTF8toUTF32Partial( 144 const UTF8** sourceStart, const UTF8* sourceEnd, 145 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags); 146 147 /** 148 * Convert a partial UTF8 sequence to UTF32. If the sequence ends in an 149 * incomplete code unit sequence, returns \c sourceIllegal. 150 */ 151 ConversionResult ConvertUTF8toUTF32( 152 const UTF8** sourceStart, const UTF8* sourceEnd, 153 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags); 154 155 ConversionResult ConvertUTF16toUTF8 ( 156 const UTF16** sourceStart, const UTF16* sourceEnd, 157 UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags); 158 159 ConversionResult ConvertUTF32toUTF8 ( 160 const UTF32** sourceStart, const UTF32* sourceEnd, 161 UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags); 162 163 ConversionResult ConvertUTF16toUTF32 ( 164 const UTF16** sourceStart, const UTF16* sourceEnd, 165 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags); 166 167 ConversionResult ConvertUTF32toUTF16 ( 168 const UTF32** sourceStart, const UTF32* sourceEnd, 169 UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags); 170 171 Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd); 172 173 Boolean isLegalUTF8String(const UTF8 **source, const UTF8 *sourceEnd); 174 175 unsigned getNumBytesForUTF8(UTF8 firstByte); 176 177 #ifdef __cplusplus 178 } 179 180 /*************************************************************************/ 181 /* Below are LLVM-specific wrappers of the functions above. */ 182 183 #include "llvm/ADT/ArrayRef.h" 184 #include "llvm/ADT/StringRef.h" 185 186 namespace llvm { 187 188 /** 189 * Convert an UTF8 StringRef to UTF8, UTF16, or UTF32 depending on 190 * WideCharWidth. The converted data is written to ResultPtr, which needs to 191 * point to at least WideCharWidth * (Source.Size() + 1) bytes. On success, 192 * ResultPtr will point one after the end of the copied string. On failure, 193 * ResultPtr will not be changed, and ErrorPtr will be set to the location of 194 * the first character which could not be converted. 195 * \return true on success. 196 */ 197 bool ConvertUTF8toWide(unsigned WideCharWidth, llvm::StringRef Source, 198 char *&ResultPtr, const UTF8 *&ErrorPtr); 199 200 /** 201 * Convert an Unicode code point to UTF8 sequence. 202 * 203 * \param Source a Unicode code point. 204 * \param [in,out] ResultPtr pointer to the output buffer, needs to be at least 205 * \c UNI_MAX_UTF8_BYTES_PER_CODE_POINT bytes. On success \c ResultPtr is 206 * updated one past end of the converted sequence. 207 * 208 * \returns true on success. 209 */ 210 bool ConvertCodePointToUTF8(unsigned Source, char *&ResultPtr); 211 212 /** 213 * Convert the first UTF8 sequence in the given source buffer to a UTF32 214 * code point. 215 * 216 * \param [in,out] source A pointer to the source buffer. If the conversion 217 * succeeds, this pointer will be updated to point to the byte just past the 218 * end of the converted sequence. 219 * \param sourceEnd A pointer just past the end of the source buffer. 220 * \param [out] target The converted code 221 * \param flags Whether the conversion is strict or lenient. 222 * 223 * \returns conversionOK on success 224 * 225 * \sa ConvertUTF8toUTF32 226 */ 227 static inline ConversionResult convertUTF8Sequence(const UTF8 **source, 228 const UTF8 *sourceEnd, 229 UTF32 *target, 230 ConversionFlags flags) { 231 if (*source == sourceEnd) 232 return sourceExhausted; 233 unsigned size = getNumBytesForUTF8(**source); 234 if ((ptrdiff_t)size > sourceEnd - *source) 235 return sourceExhausted; 236 return ConvertUTF8toUTF32(source, *source + size, &target, target + 1, flags); 237 } 238 239 /** 240 * Returns true if a blob of text starts with a UTF-16 big or little endian byte 241 * order mark. 242 */ 243 bool hasUTF16ByteOrderMark(ArrayRef<char> SrcBytes); 244 245 /** 246 * Converts a stream of raw bytes assumed to be UTF16 into a UTF8 std::string. 247 * 248 * \param [in] SrcBytes A buffer of what is assumed to be UTF-16 encoded text. 249 * \param [out] Out Converted UTF-8 is stored here on success. 250 * \returns true on success 251 */ 252 bool convertUTF16ToUTF8String(ArrayRef<char> SrcBytes, std::string &Out); 253 254 /** 255 * Converts a UTF-8 string into a UTF-16 string with native endianness. 256 * 257 * \returns true on success 258 */ 259 bool convertUTF8ToUTF16String(StringRef SrcUTF8, 260 SmallVectorImpl<UTF16> &DstUTF16); 261 262 } /* end namespace llvm */ 263 264 #endif 265 266 /* --------------------------------------------------------------------- */ 267 268 #endif 269
