Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 1 | /*===--- ConvertUTF.c - 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. Source code file. |
| 34 | Author: Mark E. Davis, 1994. |
| 35 | Rev History: Rick McGowan, fixes & updates May 2001. |
| 36 | Sept 2001: fixed const & error conditions per |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 37 | mods suggested by S. Parent & A. Lillich. |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 38 | June 2002: Tim Dodd added detection and handling of incomplete |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 39 | source sequences, enhanced error detection, added casts |
| 40 | to eliminate compiler warnings. |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 41 | July 2003: slight mods to back out aggressive FFFE detection. |
| 42 | Jan 2004: updated switches in from-UTF8 conversions. |
| 43 | Oct 2004: updated to use UNI_MAX_LEGAL_UTF32 in UTF-32 conversions. |
| 44 | |
| 45 | See the header file "ConvertUTF.h" for complete documentation. |
| 46 | |
| 47 | ------------------------------------------------------------------------ */ |
| 48 | |
| 49 | |
| 50 | #include "clang/Basic/ConvertUTF.h" |
| 51 | #ifdef CVTUTF_DEBUG |
| 52 | #include <stdio.h> |
| 53 | #endif |
| 54 | |
| 55 | static const int halfShift = 10; /* used for shifting by 10 bits */ |
| 56 | |
| 57 | static const UTF32 halfBase = 0x0010000UL; |
| 58 | static const UTF32 halfMask = 0x3FFUL; |
| 59 | |
| 60 | #define UNI_SUR_HIGH_START (UTF32)0xD800 |
| 61 | #define UNI_SUR_HIGH_END (UTF32)0xDBFF |
| 62 | #define UNI_SUR_LOW_START (UTF32)0xDC00 |
| 63 | #define UNI_SUR_LOW_END (UTF32)0xDFFF |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 64 | #define false 0 |
| 65 | #define true 1 |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 66 | |
| 67 | /* --------------------------------------------------------------------- */ |
| 68 | |
| 69 | /* |
| 70 | * Index into the table below with the first byte of a UTF-8 sequence to |
| 71 | * get the number of trailing bytes that are supposed to follow it. |
| 72 | * Note that *legal* UTF-8 values can't have 4 or 5-bytes. The table is |
| 73 | * left as-is for anyone who may want to do such conversion, which was |
| 74 | * allowed in earlier algorithms. |
| 75 | */ |
| 76 | static const char trailingBytesForUTF8[256] = { |
| 77 | 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 78 | 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 79 | 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 80 | 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 81 | 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 82 | 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, |
| 83 | 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, |
| 84 | 2,2,2,2,2,2,2,2,2,2,2,2,2,2,2,2, 3,3,3,3,3,3,3,3,4,4,4,4,5,5,5,5 |
| 85 | }; |
| 86 | |
| 87 | /* |
| 88 | * Magic values subtracted from a buffer value during UTF8 conversion. |
| 89 | * This table contains as many values as there might be trailing bytes |
| 90 | * in a UTF-8 sequence. |
| 91 | */ |
| 92 | static const UTF32 offsetsFromUTF8[6] = { 0x00000000UL, 0x00003080UL, 0x000E2080UL, |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 93 | 0x03C82080UL, 0xFA082080UL, 0x82082080UL }; |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 94 | |
| 95 | /* |
| 96 | * Once the bits are split out into bytes of UTF-8, this is a mask OR-ed |
| 97 | * into the first byte, depending on how many bytes follow. There are |
| 98 | * as many entries in this table as there are UTF-8 sequence types. |
| 99 | * (I.e., one byte sequence, two byte... etc.). Remember that sequencs |
| 100 | * for *legal* UTF-8 will be 4 or fewer bytes total. |
| 101 | */ |
| 102 | static const UTF8 firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC }; |
| 103 | |
| 104 | /* --------------------------------------------------------------------- */ |
| 105 | |
| 106 | /* The interface converts a whole buffer to avoid function-call overhead. |
| 107 | * Constants have been gathered. Loops & conditionals have been removed as |
| 108 | * much as possible for efficiency, in favor of drop-through switches. |
| 109 | * (See "Note A" at the bottom of the file for equivalent code.) |
| 110 | * If your compiler supports it, the "isLegalUTF8" call can be turned |
| 111 | * into an inline function. |
| 112 | */ |
| 113 | |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 114 | |
| 115 | /* --------------------------------------------------------------------- */ |
| 116 | |
| 117 | ConversionResult ConvertUTF32toUTF16 ( |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 118 | const UTF32** sourceStart, const UTF32* sourceEnd, |
| 119 | UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags) { |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 120 | ConversionResult result = conversionOK; |
| 121 | const UTF32* source = *sourceStart; |
| 122 | UTF16* target = *targetStart; |
| 123 | while (source < sourceEnd) { |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 124 | UTF32 ch; |
| 125 | if (target >= targetEnd) { |
| 126 | result = targetExhausted; break; |
| 127 | } |
| 128 | ch = *source++; |
| 129 | if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */ |
| 130 | /* UTF-16 surrogate values are illegal in UTF-32; 0xffff or 0xfffe are both reserved values */ |
| 131 | if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { |
| 132 | if (flags == strictConversion) { |
| 133 | --source; /* return to the illegal value itself */ |
| 134 | result = sourceIllegal; |
| 135 | break; |
| 136 | } else { |
| 137 | *target++ = UNI_REPLACEMENT_CHAR; |
| 138 | } |
| 139 | } else { |
| 140 | *target++ = (UTF16)ch; /* normal case */ |
| 141 | } |
| 142 | } else if (ch > UNI_MAX_LEGAL_UTF32) { |
| 143 | if (flags == strictConversion) { |
| 144 | result = sourceIllegal; |
| 145 | } else { |
| 146 | *target++ = UNI_REPLACEMENT_CHAR; |
| 147 | } |
| 148 | } else { |
| 149 | /* target is a character in range 0xFFFF - 0x10FFFF. */ |
| 150 | if (target + 1 >= targetEnd) { |
| 151 | --source; /* Back up source pointer! */ |
| 152 | result = targetExhausted; break; |
| 153 | } |
| 154 | ch -= halfBase; |
| 155 | *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START); |
| 156 | *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START); |
| 157 | } |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 158 | } |
| 159 | *sourceStart = source; |
| 160 | *targetStart = target; |
| 161 | return result; |
| 162 | } |
| 163 | |
| 164 | /* --------------------------------------------------------------------- */ |
| 165 | |
| 166 | ConversionResult ConvertUTF16toUTF32 ( |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 167 | const UTF16** sourceStart, const UTF16* sourceEnd, |
| 168 | UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags) { |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 169 | ConversionResult result = conversionOK; |
| 170 | const UTF16* source = *sourceStart; |
| 171 | UTF32* target = *targetStart; |
| 172 | UTF32 ch, ch2; |
| 173 | while (source < sourceEnd) { |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 174 | const UTF16* oldSource = source; /* In case we have to back up because of target overflow. */ |
| 175 | ch = *source++; |
| 176 | /* If we have a surrogate pair, convert to UTF32 first. */ |
| 177 | if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) { |
| 178 | /* If the 16 bits following the high surrogate are in the source buffer... */ |
| 179 | if (source < sourceEnd) { |
| 180 | ch2 = *source; |
| 181 | /* If it's a low surrogate, convert to UTF32. */ |
| 182 | if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) { |
| 183 | ch = ((ch - UNI_SUR_HIGH_START) << halfShift) |
| 184 | + (ch2 - UNI_SUR_LOW_START) + halfBase; |
| 185 | ++source; |
| 186 | } else if (flags == strictConversion) { /* it's an unpaired high surrogate */ |
| 187 | --source; /* return to the illegal value itself */ |
| 188 | result = sourceIllegal; |
| 189 | break; |
| 190 | } |
| 191 | } else { /* We don't have the 16 bits following the high surrogate. */ |
| 192 | --source; /* return to the high surrogate */ |
| 193 | result = sourceExhausted; |
| 194 | break; |
| 195 | } |
| 196 | } else if (flags == strictConversion) { |
| 197 | /* UTF-16 surrogate values are illegal in UTF-32 */ |
| 198 | if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) { |
| 199 | --source; /* return to the illegal value itself */ |
| 200 | result = sourceIllegal; |
| 201 | break; |
| 202 | } |
| 203 | } |
| 204 | if (target >= targetEnd) { |
| 205 | source = oldSource; /* Back up source pointer! */ |
| 206 | result = targetExhausted; break; |
| 207 | } |
| 208 | *target++ = ch; |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 209 | } |
| 210 | *sourceStart = source; |
| 211 | *targetStart = target; |
| 212 | #ifdef CVTUTF_DEBUG |
| 213 | if (result == sourceIllegal) { |
| 214 | fprintf(stderr, "ConvertUTF16toUTF32 illegal seq 0x%04x,%04x\n", ch, ch2); |
| 215 | fflush(stderr); |
| 216 | } |
| 217 | #endif |
| 218 | return result; |
| 219 | } |
| 220 | ConversionResult ConvertUTF16toUTF8 ( |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 221 | const UTF16** sourceStart, const UTF16* sourceEnd, |
| 222 | UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) { |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 223 | ConversionResult result = conversionOK; |
| 224 | const UTF16* source = *sourceStart; |
| 225 | UTF8* target = *targetStart; |
| 226 | while (source < sourceEnd) { |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 227 | UTF32 ch; |
| 228 | unsigned short bytesToWrite = 0; |
| 229 | const UTF32 byteMask = 0xBF; |
| 230 | const UTF32 byteMark = 0x80; |
| 231 | const UTF16* oldSource = source; /* In case we have to back up because of target overflow. */ |
| 232 | ch = *source++; |
| 233 | /* If we have a surrogate pair, convert to UTF32 first. */ |
| 234 | if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) { |
| 235 | /* If the 16 bits following the high surrogate are in the source buffer... */ |
| 236 | if (source < sourceEnd) { |
| 237 | UTF32 ch2 = *source; |
| 238 | /* If it's a low surrogate, convert to UTF32. */ |
| 239 | if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) { |
| 240 | ch = ((ch - UNI_SUR_HIGH_START) << halfShift) |
| 241 | + (ch2 - UNI_SUR_LOW_START) + halfBase; |
| 242 | ++source; |
| 243 | } else if (flags == strictConversion) { /* it's an unpaired high surrogate */ |
| 244 | --source; /* return to the illegal value itself */ |
| 245 | result = sourceIllegal; |
| 246 | break; |
| 247 | } |
| 248 | } else { /* We don't have the 16 bits following the high surrogate. */ |
| 249 | --source; /* return to the high surrogate */ |
| 250 | result = sourceExhausted; |
| 251 | break; |
| 252 | } |
| 253 | } else if (flags == strictConversion) { |
| 254 | /* UTF-16 surrogate values are illegal in UTF-32 */ |
| 255 | if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) { |
| 256 | --source; /* return to the illegal value itself */ |
| 257 | result = sourceIllegal; |
| 258 | break; |
| 259 | } |
| 260 | } |
| 261 | /* Figure out how many bytes the result will require */ |
| 262 | if (ch < (UTF32)0x80) { bytesToWrite = 1; |
| 263 | } else if (ch < (UTF32)0x800) { bytesToWrite = 2; |
| 264 | } else if (ch < (UTF32)0x10000) { bytesToWrite = 3; |
| 265 | } else if (ch < (UTF32)0x110000) { bytesToWrite = 4; |
| 266 | } else { bytesToWrite = 3; |
| 267 | ch = UNI_REPLACEMENT_CHAR; |
| 268 | } |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 269 | |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 270 | target += bytesToWrite; |
| 271 | if (target > targetEnd) { |
| 272 | source = oldSource; /* Back up source pointer! */ |
| 273 | target -= bytesToWrite; result = targetExhausted; break; |
| 274 | } |
| 275 | switch (bytesToWrite) { /* note: everything falls through. */ |
| 276 | case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; |
| 277 | case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; |
| 278 | case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; |
| 279 | case 1: *--target = (UTF8)(ch | firstByteMark[bytesToWrite]); |
| 280 | } |
| 281 | target += bytesToWrite; |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 282 | } |
| 283 | *sourceStart = source; |
| 284 | *targetStart = target; |
| 285 | return result; |
| 286 | } |
| 287 | |
| 288 | /* --------------------------------------------------------------------- */ |
| 289 | |
| 290 | ConversionResult ConvertUTF32toUTF8 ( |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 291 | const UTF32** sourceStart, const UTF32* sourceEnd, |
| 292 | UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) { |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 293 | ConversionResult result = conversionOK; |
| 294 | const UTF32* source = *sourceStart; |
| 295 | UTF8* target = *targetStart; |
| 296 | while (source < sourceEnd) { |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 297 | UTF32 ch; |
| 298 | unsigned short bytesToWrite = 0; |
| 299 | const UTF32 byteMask = 0xBF; |
| 300 | const UTF32 byteMark = 0x80; |
| 301 | ch = *source++; |
| 302 | if (flags == strictConversion ) { |
| 303 | /* UTF-16 surrogate values are illegal in UTF-32 */ |
| 304 | if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { |
| 305 | --source; /* return to the illegal value itself */ |
| 306 | result = sourceIllegal; |
| 307 | break; |
| 308 | } |
| 309 | } |
| 310 | /* |
| 311 | * Figure out how many bytes the result will require. Turn any |
| 312 | * illegally large UTF32 things (> Plane 17) into replacement chars. |
| 313 | */ |
| 314 | if (ch < (UTF32)0x80) { bytesToWrite = 1; |
| 315 | } else if (ch < (UTF32)0x800) { bytesToWrite = 2; |
| 316 | } else if (ch < (UTF32)0x10000) { bytesToWrite = 3; |
| 317 | } else if (ch <= UNI_MAX_LEGAL_UTF32) { bytesToWrite = 4; |
| 318 | } else { bytesToWrite = 3; |
| 319 | ch = UNI_REPLACEMENT_CHAR; |
| 320 | result = sourceIllegal; |
| 321 | } |
| 322 | |
| 323 | target += bytesToWrite; |
| 324 | if (target > targetEnd) { |
| 325 | --source; /* Back up source pointer! */ |
| 326 | target -= bytesToWrite; result = targetExhausted; break; |
| 327 | } |
| 328 | switch (bytesToWrite) { /* note: everything falls through. */ |
| 329 | case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; |
| 330 | case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; |
| 331 | case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; |
| 332 | case 1: *--target = (UTF8) (ch | firstByteMark[bytesToWrite]); |
| 333 | } |
| 334 | target += bytesToWrite; |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 335 | } |
| 336 | *sourceStart = source; |
| 337 | *targetStart = target; |
| 338 | return result; |
| 339 | } |
| 340 | |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 341 | /* --------------------------------------------------------------------- */ |
| 342 | |
| 343 | /* |
| 344 | * Utility routine to tell whether a sequence of bytes is legal UTF-8. |
| 345 | * This must be called with the length pre-determined by the first byte. |
| 346 | * If not calling this from ConvertUTF8to*, then the length can be set by: |
| 347 | * length = trailingBytesForUTF8[*source]+1; |
| 348 | * and the sequence is illegal right away if there aren't that many bytes |
| 349 | * available. |
| 350 | * If presented with a length > 4, this returns false. The Unicode |
| 351 | * definition of UTF-8 goes up to 4-byte sequences. |
| 352 | */ |
| 353 | |
| 354 | static Boolean isLegalUTF8(const UTF8 *source, int length) { |
| 355 | UTF8 a; |
| 356 | const UTF8 *srcptr = source+length; |
| 357 | switch (length) { |
| 358 | default: return false; |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 359 | /* Everything else falls through when "true"... */ |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 360 | case 4: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; |
| 361 | case 3: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; |
Seth Cantrell | 31ba273 | 2012-10-30 23:50:26 +0000 | [diff] [blame] | 362 | case 2: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 363 | |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 364 | switch (*source) { |
| 365 | /* no fall-through in this inner switch */ |
| 366 | case 0xE0: if (a < 0xA0) return false; break; |
| 367 | case 0xED: if (a > 0x9F) return false; break; |
| 368 | case 0xF0: if (a < 0x90) return false; break; |
| 369 | case 0xF4: if (a > 0x8F) return false; break; |
| 370 | default: if (a < 0x80) return false; |
| 371 | } |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 372 | |
| 373 | case 1: if (*source >= 0x80 && *source < 0xC2) return false; |
| 374 | } |
| 375 | if (*source > 0xF4) return false; |
| 376 | return true; |
| 377 | } |
| 378 | |
| 379 | /* --------------------------------------------------------------------- */ |
| 380 | |
| 381 | /* |
| 382 | * Exported function to return whether a UTF-8 sequence is legal or not. |
| 383 | * This is not used here; it's just exported. |
| 384 | */ |
| 385 | Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd) { |
| 386 | int length = trailingBytesForUTF8[*source]+1; |
Richard Smith | 49d5174 | 2012-03-08 21:59:28 +0000 | [diff] [blame] | 387 | if (length > sourceEnd - source) { |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 388 | return false; |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 389 | } |
| 390 | return isLegalUTF8(source, length); |
| 391 | } |
| 392 | |
| 393 | /* --------------------------------------------------------------------- */ |
| 394 | |
Richard Smith | 49d5174 | 2012-03-08 21:59:28 +0000 | [diff] [blame] | 395 | /* |
Richard Smith | e5f0588 | 2012-09-08 07:16:20 +0000 | [diff] [blame] | 396 | * Exported function to return the total number of bytes in a codepoint |
| 397 | * represented in UTF-8, given the value of the first byte. |
| 398 | */ |
| 399 | unsigned getNumBytesForUTF8(UTF8 first) { |
| 400 | return trailingBytesForUTF8[first] + 1; |
| 401 | } |
| 402 | |
| 403 | /* --------------------------------------------------------------------- */ |
| 404 | |
| 405 | /* |
Richard Smith | 49d5174 | 2012-03-08 21:59:28 +0000 | [diff] [blame] | 406 | * Exported function to return whether a UTF-8 string is legal or not. |
| 407 | * This is not used here; it's just exported. |
| 408 | */ |
Richard Smith | e5f0588 | 2012-09-08 07:16:20 +0000 | [diff] [blame] | 409 | Boolean isLegalUTF8String(const UTF8 **source, const UTF8 *sourceEnd) { |
| 410 | while (*source != sourceEnd) { |
| 411 | int length = trailingBytesForUTF8[**source] + 1; |
| 412 | if (length > sourceEnd - *source || !isLegalUTF8(*source, length)) |
Richard Smith | 49d5174 | 2012-03-08 21:59:28 +0000 | [diff] [blame] | 413 | return false; |
Richard Smith | e5f0588 | 2012-09-08 07:16:20 +0000 | [diff] [blame] | 414 | *source += length; |
Richard Smith | 49d5174 | 2012-03-08 21:59:28 +0000 | [diff] [blame] | 415 | } |
| 416 | return true; |
| 417 | } |
| 418 | |
| 419 | /* --------------------------------------------------------------------- */ |
| 420 | |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 421 | ConversionResult ConvertUTF8toUTF16 ( |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 422 | const UTF8** sourceStart, const UTF8* sourceEnd, |
| 423 | UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags) { |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 424 | ConversionResult result = conversionOK; |
| 425 | const UTF8* source = *sourceStart; |
| 426 | UTF16* target = *targetStart; |
| 427 | while (source < sourceEnd) { |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 428 | UTF32 ch = 0; |
| 429 | unsigned short extraBytesToRead = trailingBytesForUTF8[*source]; |
Richard Smith | 49d5174 | 2012-03-08 21:59:28 +0000 | [diff] [blame] | 430 | if (extraBytesToRead >= sourceEnd - source) { |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 431 | result = sourceExhausted; break; |
| 432 | } |
| 433 | /* Do this check whether lenient or strict */ |
| 434 | if (!isLegalUTF8(source, extraBytesToRead+1)) { |
| 435 | result = sourceIllegal; |
| 436 | break; |
| 437 | } |
| 438 | /* |
| 439 | * The cases all fall through. See "Note A" below. |
| 440 | */ |
| 441 | switch (extraBytesToRead) { |
| 442 | case 5: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */ |
| 443 | case 4: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */ |
| 444 | case 3: ch += *source++; ch <<= 6; |
| 445 | case 2: ch += *source++; ch <<= 6; |
| 446 | case 1: ch += *source++; ch <<= 6; |
| 447 | case 0: ch += *source++; |
| 448 | } |
| 449 | ch -= offsetsFromUTF8[extraBytesToRead]; |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 450 | |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 451 | if (target >= targetEnd) { |
| 452 | source -= (extraBytesToRead+1); /* Back up source pointer! */ |
| 453 | result = targetExhausted; break; |
| 454 | } |
| 455 | if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */ |
| 456 | /* UTF-16 surrogate values are illegal in UTF-32 */ |
| 457 | if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { |
| 458 | if (flags == strictConversion) { |
| 459 | source -= (extraBytesToRead+1); /* return to the illegal value itself */ |
| 460 | result = sourceIllegal; |
| 461 | break; |
| 462 | } else { |
| 463 | *target++ = UNI_REPLACEMENT_CHAR; |
| 464 | } |
| 465 | } else { |
| 466 | *target++ = (UTF16)ch; /* normal case */ |
| 467 | } |
| 468 | } else if (ch > UNI_MAX_UTF16) { |
| 469 | if (flags == strictConversion) { |
| 470 | result = sourceIllegal; |
| 471 | source -= (extraBytesToRead+1); /* return to the start */ |
| 472 | break; /* Bail out; shouldn't continue */ |
| 473 | } else { |
| 474 | *target++ = UNI_REPLACEMENT_CHAR; |
| 475 | } |
| 476 | } else { |
| 477 | /* target is a character in range 0xFFFF - 0x10FFFF. */ |
| 478 | if (target + 1 >= targetEnd) { |
| 479 | source -= (extraBytesToRead+1); /* Back up source pointer! */ |
| 480 | result = targetExhausted; break; |
| 481 | } |
| 482 | ch -= halfBase; |
| 483 | *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START); |
| 484 | *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START); |
| 485 | } |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 486 | } |
| 487 | *sourceStart = source; |
| 488 | *targetStart = target; |
| 489 | return result; |
| 490 | } |
| 491 | |
Eli Friedman | 436ecd9 | 2011-11-01 02:10:54 +0000 | [diff] [blame] | 492 | /* --------------------------------------------------------------------- */ |
| 493 | |
| 494 | ConversionResult ConvertUTF8toUTF32 ( |
| 495 | const UTF8** sourceStart, const UTF8* sourceEnd, |
| 496 | UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags) { |
| 497 | ConversionResult result = conversionOK; |
| 498 | const UTF8* source = *sourceStart; |
| 499 | UTF32* target = *targetStart; |
| 500 | while (source < sourceEnd) { |
| 501 | UTF32 ch = 0; |
| 502 | unsigned short extraBytesToRead = trailingBytesForUTF8[*source]; |
Richard Smith | 49d5174 | 2012-03-08 21:59:28 +0000 | [diff] [blame] | 503 | if (extraBytesToRead >= sourceEnd - source) { |
Eli Friedman | 436ecd9 | 2011-11-01 02:10:54 +0000 | [diff] [blame] | 504 | result = sourceExhausted; break; |
| 505 | } |
| 506 | /* Do this check whether lenient or strict */ |
| 507 | if (!isLegalUTF8(source, extraBytesToRead+1)) { |
| 508 | result = sourceIllegal; |
| 509 | break; |
| 510 | } |
| 511 | /* |
| 512 | * The cases all fall through. See "Note A" below. |
| 513 | */ |
| 514 | switch (extraBytesToRead) { |
| 515 | case 5: ch += *source++; ch <<= 6; |
| 516 | case 4: ch += *source++; ch <<= 6; |
| 517 | case 3: ch += *source++; ch <<= 6; |
| 518 | case 2: ch += *source++; ch <<= 6; |
| 519 | case 1: ch += *source++; ch <<= 6; |
| 520 | case 0: ch += *source++; |
| 521 | } |
| 522 | ch -= offsetsFromUTF8[extraBytesToRead]; |
| 523 | |
| 524 | if (target >= targetEnd) { |
| 525 | source -= (extraBytesToRead+1); /* Back up the source pointer! */ |
| 526 | result = targetExhausted; break; |
| 527 | } |
| 528 | if (ch <= UNI_MAX_LEGAL_UTF32) { |
| 529 | /* |
| 530 | * UTF-16 surrogate values are illegal in UTF-32, and anything |
| 531 | * over Plane 17 (> 0x10FFFF) is illegal. |
| 532 | */ |
| 533 | if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { |
| 534 | if (flags == strictConversion) { |
| 535 | source -= (extraBytesToRead+1); /* return to the illegal value itself */ |
| 536 | result = sourceIllegal; |
| 537 | break; |
| 538 | } else { |
| 539 | *target++ = UNI_REPLACEMENT_CHAR; |
| 540 | } |
| 541 | } else { |
| 542 | *target++ = ch; |
| 543 | } |
| 544 | } else { /* i.e., ch > UNI_MAX_LEGAL_UTF32 */ |
| 545 | result = sourceIllegal; |
| 546 | *target++ = UNI_REPLACEMENT_CHAR; |
| 547 | } |
| 548 | } |
| 549 | *sourceStart = source; |
| 550 | *targetStart = target; |
| 551 | return result; |
| 552 | } |
| 553 | |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 554 | /* --------------------------------------------------------------------- |
| 555 | |
| 556 | Note A. |
| 557 | The fall-through switches in UTF-8 reading code save a |
| 558 | temp variable, some decrements & conditionals. The switches |
| 559 | are equivalent to the following loop: |
Mike Stump | 1eb4433 | 2009-09-09 15:08:12 +0000 | [diff] [blame] | 560 | { |
| 561 | int tmpBytesToRead = extraBytesToRead+1; |
| 562 | do { |
| 563 | ch += *source++; |
| 564 | --tmpBytesToRead; |
| 565 | if (tmpBytesToRead) ch <<= 6; |
| 566 | } while (tmpBytesToRead > 0); |
| 567 | } |
Steve Naroff | e9b7d8a | 2009-04-01 15:50:34 +0000 | [diff] [blame] | 568 | In UTF-8 writing code, the switches on "bytesToWrite" are |
| 569 | similarly unrolled loops. |
| 570 | |
| 571 | --------------------------------------------------------------------- */ |