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 ConversionResult ConvertUTF8toUTF32 ( 140 const UTF8** sourceStart, const UTF8* sourceEnd, 141 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags); 142 143 ConversionResult ConvertUTF16toUTF8 ( 144 const UTF16** sourceStart, const UTF16* sourceEnd, 145 UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags); 146 147 ConversionResult ConvertUTF32toUTF8 ( 148 const UTF32** sourceStart, const UTF32* sourceEnd, 149 UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags); 150 151 ConversionResult ConvertUTF16toUTF32 ( 152 const UTF16** sourceStart, const UTF16* sourceEnd, 153 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags); 154 155 ConversionResult ConvertUTF32toUTF16 ( 156 const UTF32** sourceStart, const UTF32* sourceEnd, 157 UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags); 158 159 Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd); 160 161 Boolean isLegalUTF8String(const UTF8 **source, const UTF8 *sourceEnd); 162 163 unsigned getNumBytesForUTF8(UTF8 firstByte); 164 165 #ifdef __cplusplus 166 } 167 168 /*************************************************************************/ 169 /* Below are LLVM-specific wrappers of the functions above. */ 170 171 #include "llvm/ADT/ArrayRef.h" 172 #include "llvm/ADT/StringRef.h" 173 174 namespace llvm { 175 176 /** 177 * Convert an UTF8 StringRef to UTF8, UTF16, or UTF32 depending on 178 * WideCharWidth. The converted data is written to ResultPtr, which needs to 179 * point to at least WideCharWidth * (Source.Size() + 1) bytes. On success, 180 * ResultPtr will point one after the end of the copied string. On failure, 181 * ResultPtr will not be changed, and ErrorPtr will be set to the location of 182 * the first character which could not be converted. 183 * \return true on success. 184 */ 185 bool ConvertUTF8toWide(unsigned WideCharWidth, llvm::StringRef Source, 186 char *&ResultPtr, const UTF8 *&ErrorPtr); 187 188 /** 189 * Convert an Unicode code point to UTF8 sequence. 190 * 191 * \param Source a Unicode code point. 192 * \param [in,out] ResultPtr pointer to the output buffer, needs to be at least 193 * \c UNI_MAX_UTF8_BYTES_PER_CODE_POINT bytes. On success \c ResultPtr is 194 * updated one past end of the converted sequence. 195 * 196 * \returns true on success. 197 */ 198 bool ConvertCodePointToUTF8(unsigned Source, char *&ResultPtr); 199 200 /** 201 * Convert the first UTF8 sequence in the given source buffer to a UTF32 202 * code point. 203 * 204 * \param [in,out] source A pointer to the source buffer. If the conversion 205 * succeeds, this pointer will be updated to point to the byte just past the 206 * end of the converted sequence. 207 * \param sourceEnd A pointer just past the end of the source buffer. 208 * \param [out] target The converted code 209 * \param flags Whether the conversion is strict or lenient. 210 * 211 * \returns conversionOK on success 212 * 213 * \sa ConvertUTF8toUTF32 214 */ 215 static inline ConversionResult convertUTF8Sequence(const UTF8 **source, 216 const UTF8 *sourceEnd, 217 UTF32 *target, 218 ConversionFlags flags) { 219 if (*source == sourceEnd) 220 return sourceExhausted; 221 unsigned size = getNumBytesForUTF8(**source); 222 if ((ptrdiff_t)size > sourceEnd - *source) 223 return sourceExhausted; 224 return ConvertUTF8toUTF32(source, *source + size, &target, target + 1, flags); 225 } 226 227 /** 228 * Returns true if a blob of text starts with a UTF-16 big or little endian byte 229 * order mark. 230 */ 231 bool hasUTF16ByteOrderMark(ArrayRef<char> SrcBytes); 232 233 /** 234 * Converts a stream of raw bytes assumed to be UTF16 into a UTF8 std::string. 235 * 236 * \param [in] SrcBytes A buffer of what is assumed to be UTF-16 encoded text. 237 * \param [out] Out Converted UTF-8 is stored here on success. 238 * \returns true on success 239 */ 240 bool convertUTF16ToUTF8String(ArrayRef<char> SrcBytes, std::string &Out); 241 242 } /* end namespace llvm */ 243 244 #endif 245 246 /* --------------------------------------------------------------------- */ 247 248 #endif 249
