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| 1 /* | |
| 2 * Copyright 2001-2004 Unicode, Inc. | |
| 3 * | |
| 4 * Disclaimer | |
| 5 * | |
| 6 * This source code is provided as is by Unicode, Inc. No claims are | |
| 7 * made as to fitness for any particular purpose. No warranties of any | |
| 8 * kind are expressed or implied. The recipient agrees to determine | |
| 9 * applicability of information provided. If this file has been | |
| 10 * purchased on magnetic or optical media from Unicode, Inc., the | |
| 11 * sole remedy for any claim will be exchange of defective media | |
| 12 * within 90 days of receipt. | |
| 13 * | |
| 14 * Limitations on Rights to Redistribute This Code | |
| 15 * | |
| 16 * Unicode, Inc. hereby grants the right to freely use the information | |
| 17 * supplied in this file in the creation of products supporting the | |
| 18 * Unicode Standard, and to make copies of this file in any form | |
| 19 * for internal or external distribution as long as this notice | |
| 20 * remains attached. | |
| 21 */ | |
| 22 | |
| 23 /* --------------------------------------------------------------------- | |
| 24 | |
| 25 Conversions between UTF32, UTF-16, and UTF-8. Source code file. | |
| 26 Author: Mark E. Davis, 1994. | |
| 27 Rev History: Rick McGowan, fixes & updates May 2001. | |
| 28 Sept 2001: fixed const & error conditions per | |
| 29 mods suggested by S. Parent & A. Lillich. | |
| 30 June 2002: Tim Dodd added detection and handling of incomplete | |
| 31 source sequences, enhanced error detection, added casts | |
| 32 to eliminate compiler warnings. | |
| 33 July 2003: slight mods to back out aggressive FFFE detection. | |
| 34 Jan 2004: updated switches in from-UTF8 conversions. | |
| 35 Oct 2004: updated to use UNI_MAX_LEGAL_UTF32 in UTF-32 conversions. | |
| 36 | |
| 37 See the header file "ConvertUTF.h" for complete documentation. | |
| 38 | |
| 39 ------------------------------------------------------------------------ */ | |
| 40 | |
| 41 | |
| 42 #include "convert_UTF.h" | |
| 43 #ifdef CVTUTF_DEBUG | |
| 44 #include <stdio.h> | |
| 45 #endif | |
| 46 | |
| 47 static const int halfShift = 10; /* used for shifting by 10 bits */ | |
| 48 | |
| 49 static const UTF32 halfBase = 0x0010000UL; | |
| 50 static const UTF32 halfMask = 0x3FFUL; | |
| 51 | |
| 52 #define UNI_SUR_HIGH_START (UTF32)0xD800 | |
| 53 #define UNI_SUR_HIGH_END (UTF32)0xDBFF | |
| 54 #define UNI_SUR_LOW_START (UTF32)0xDC00 | |
| 55 #define UNI_SUR_LOW_END (UTF32)0xDFFF | |
| 56 #define false 0 | |
| 57 #define true 1 | |
| 58 | |
| 59 /* --------------------------------------------------------------------- */ | |
| 60 | |
| 61 ConversionResult ConvertUTF32toUTF16 (const UTF32** sourceStart, const UTF32* so
urceEnd, | |
| 62 UTF16** targetStart, UTF16* targetEnd, Con
versionFlags flags) { | |
| 63 ConversionResult result = conversionOK; | |
| 64 const UTF32* source = *sourceStart; | |
| 65 UTF16* target = *targetStart; | |
| 66 while (source < sourceEnd) { | |
| 67 UTF32 ch; | |
| 68 if (target >= targetEnd) { | |
| 69 result = targetExhausted; break; | |
| 70 } | |
| 71 ch = *source++; | |
| 72 if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */ | |
| 73 /* UTF-16 surrogate values are illegal in UTF-32; 0xffff or 0xfffe a
re both reserved values */ | |
| 74 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { | |
| 75 if (flags == strictConversion) { | |
| 76 --source; /* return to the illegal value itself */ | |
| 77 result = sourceIllegal; | |
| 78 break; | |
| 79 } else { | |
| 80 *target++ = UNI_REPLACEMENT_CHAR; | |
| 81 } | |
| 82 } else { | |
| 83 *target++ = (UTF16)ch; /* normal case */ | |
| 84 } | |
| 85 } else if (ch > UNI_MAX_LEGAL_UTF32) { | |
| 86 if (flags == strictConversion) { | |
| 87 result = sourceIllegal; | |
| 88 } else { | |
| 89 *target++ = UNI_REPLACEMENT_CHAR; | |
| 90 } | |
| 91 } else { | |
| 92 /* target is a character in range 0xFFFF - 0x10FFFF. */ | |
| 93 if (target + 1 >= targetEnd) { | |
| 94 --source; /* Back up source pointer! */ | |
| 95 result = targetExhausted; break; | |
| 96 } | |
| 97 ch -= halfBase; | |
| 98 *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START); | |
| 99 *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START); | |
| 100 } | |
| 101 } | |
| 102 *sourceStart = source; | |
| 103 *targetStart = target; | |
| 104 return result; | |
| 105 } | |
| 106 | |
| 107 /* --------------------------------------------------------------------- */ | |
| 108 | |
| 109 ConversionResult ConvertUTF16toUTF32 (const UTF16** sourceStart, const UTF16* so
urceEnd, | |
| 110 UTF32** targetStart, UTF32* targetEnd, Con
versionFlags flags) { | |
| 111 ConversionResult result = conversionOK; | |
| 112 const UTF16* source = *sourceStart; | |
| 113 UTF32* target = *targetStart; | |
| 114 UTF32 ch, ch2; | |
| 115 while (source < sourceEnd) { | |
| 116 const UTF16* oldSource = source; /* In case we have to back up because of t
arget overflow. */ | |
| 117 ch = *source++; | |
| 118 /* If we have a surrogate pair, convert to UTF32 first. */ | |
| 119 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) { | |
| 120 /* If the 16 bits following the high surrogate are in the source buf
fer... */ | |
| 121 if (source < sourceEnd) { | |
| 122 ch2 = *source; | |
| 123 /* If it's a low surrogate, convert to UTF32. */ | |
| 124 if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) { | |
| 125 ch = ((ch - UNI_SUR_HIGH_START) << halfShift) | |
| 126 + (ch2 - UNI_SUR_LOW_START) + halfBase; | |
| 127 ++source; | |
| 128 } else if (flags == strictConversion) { /* it's an unpaired high surroga
te */ | |
| 129 --source; /* return to the illegal value itself */ | |
| 130 result = sourceIllegal; | |
| 131 break; | |
| 132 } | |
| 133 } else { /* We don't have the 16 bits following the high surrogate.
*/ | |
| 134 --source; /* return to the high surrogate */ | |
| 135 result = sourceExhausted; | |
| 136 break; | |
| 137 } | |
| 138 } else if (flags == strictConversion) { | |
| 139 /* UTF-16 surrogate values are illegal in UTF-32 */ | |
| 140 if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) { | |
| 141 --source; /* return to the illegal value itself */ | |
| 142 result = sourceIllegal; | |
| 143 break; | |
| 144 } | |
| 145 } | |
| 146 if (target >= targetEnd) { | |
| 147 source = oldSource; /* Back up source pointer! */ | |
| 148 result = targetExhausted; break; | |
| 149 } | |
| 150 *target++ = ch; | |
| 151 } | |
| 152 *sourceStart = source; | |
| 153 *targetStart = target; | |
| 154 #ifdef CVTUTF_DEBUG | |
| 155 if (result == sourceIllegal) { | |
| 156 fprintf(stderr, "ConvertUTF16toUTF32 illegal seq 0x%04x,%04x\n", ch, ch2); | |
| 157 fflush(stderr); | |
| 158 } | |
| 159 #endif | |
| 160 return result; | |
| 161 } | |
| 162 | |
| 163 /* --------------------------------------------------------------------- */ | |
| 164 | |
| 165 /* | |
| 166 * Index into the table below with the first byte of a UTF-8 sequence to | |
| 167 * get the number of trailing bytes that are supposed to follow it. | |
| 168 * Note that *legal* UTF-8 values can't have 4 or 5-bytes. The table is | |
| 169 * left as-is for anyone who may want to do such conversion, which was | |
| 170 * allowed in earlier algorithms. | |
| 171 */ | |
| 172 static const char trailingBytesForUTF8[256] = { | |
| 173 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, | |
| 174 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, | |
| 175 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, | |
| 176 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, | |
| 177 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, | |
| 178 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, | |
| 179 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, | |
| 180 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 | |
| 181 }; | |
| 182 | |
| 183 /* | |
| 184 * Magic values subtracted from a buffer value during UTF8 conversion. | |
| 185 * This table contains as many values as there might be trailing bytes | |
| 186 * in a UTF-8 sequence. | |
| 187 */ | |
| 188 static const UTF32 offsetsFromUTF8[6] = { 0x00000000UL, 0x00003080UL, 0x000E2080
UL, | |
| 189 0x03C82080UL, 0xFA082080UL, 0x82082080UL }; | |
| 190 | |
| 191 /* | |
| 192 * Once the bits are split out into bytes of UTF-8, this is a mask OR-ed | |
| 193 * into the first byte, depending on how many bytes follow. There are | |
| 194 * as many entries in this table as there are UTF-8 sequence types. | |
| 195 * (I.e., one byte sequence, two byte... etc.). Remember that sequencs | |
| 196 * for *legal* UTF-8 will be 4 or fewer bytes total. | |
| 197 */ | |
| 198 static const UTF8 firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC
}; | |
| 199 | |
| 200 /* --------------------------------------------------------------------- */ | |
| 201 | |
| 202 /* The interface converts a whole buffer to avoid function-call overhead. | |
| 203 * Constants have been gathered. Loops & conditionals have been removed as | |
| 204 * much as possible for efficiency, in favor of drop-through switches. | |
| 205 * (See "Note A" at the bottom of the file for equivalent code.) | |
| 206 * If your compiler supports it, the "isLegalUTF8" call can be turned | |
| 207 * into an inline function. | |
| 208 */ | |
| 209 | |
| 210 /* --------------------------------------------------------------------- */ | |
| 211 | |
| 212 ConversionResult ConvertUTF16toUTF8 (const UTF16** sourceStart, const UTF16* sou
rceEnd, | |
| 213 UTF8** targetStart, UTF8* targetEnd, Conver
sionFlags flags) { | |
| 214 ConversionResult result = conversionOK; | |
| 215 const UTF16* source = *sourceStart; | |
| 216 UTF8* target = *targetStart; | |
| 217 while (source < sourceEnd) { | |
| 218 UTF32 ch; | |
| 219 unsigned short bytesToWrite = 0; | |
| 220 const UTF32 byteMask = 0xBF; | |
| 221 const UTF32 byteMark = 0x80; | |
| 222 const UTF16* oldSource = source; /* In case we have to back up because of ta
rget overflow. */ | |
| 223 ch = *source++; | |
| 224 /* If we have a surrogate pair, convert to UTF32 first. */ | |
| 225 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) { | |
| 226 /* If the 16 bits following the high surrogate are in the source buf
fer... */ | |
| 227 if (source < sourceEnd) { | |
| 228 UTF32 ch2 = *source; | |
| 229 /* If it's a low surrogate, convert to UTF32. */ | |
| 230 if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) { | |
| 231 ch = ((ch - UNI_SUR_HIGH_START) << halfShift) | |
| 232 + (ch2 - UNI_SUR_LOW_START) + halfBase; | |
| 233 ++source; | |
| 234 } else if (flags == strictConversion) { /* it's an unpaired high surroga
te */ | |
| 235 --source; /* return to the illegal value itself */ | |
| 236 result = sourceIllegal; | |
| 237 break; | |
| 238 } | |
| 239 } else { /* We don't have the 16 bits following the high surrogate.
*/ | |
| 240 --source; /* return to the high surrogate */ | |
| 241 result = sourceExhausted; | |
| 242 break; | |
| 243 } | |
| 244 } else if (flags == strictConversion) { | |
| 245 /* UTF-16 surrogate values are illegal in UTF-32 */ | |
| 246 if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) { | |
| 247 --source; /* return to the illegal value itself */ | |
| 248 result = sourceIllegal; | |
| 249 break; | |
| 250 } | |
| 251 } | |
| 252 /* Figure out how many bytes the result will require */ | |
| 253 if (ch < (UTF32)0x80) { bytesToWrite = 1; | |
| 254 } else if (ch < (UTF32)0x800) { bytesToWrite = 2; | |
| 255 } else if (ch < (UTF32)0x10000) { bytesToWrite = 3; | |
| 256 } else if (ch < (UTF32)0x110000) { bytesToWrite = 4; | |
| 257 } else { bytesToWrite = 3; | |
| 258 ch = UNI_REPLACEMENT_CHAR; | |
| 259 } | |
| 260 | |
| 261 target += bytesToWrite; | |
| 262 if (target > targetEnd) { | |
| 263 source = oldSource; /* Back up source pointer! */ | |
| 264 target -= bytesToWrite; result = targetExhausted; break; | |
| 265 } | |
| 266 switch (bytesToWrite) { /* note: everything falls through. */ | |
| 267 case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; | |
| 268 case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; | |
| 269 case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; | |
| 270 case 1: *--target = (UTF8)(ch | firstByteMark[bytesToWrite]); | |
| 271 } | |
| 272 target += bytesToWrite; | |
| 273 } | |
| 274 *sourceStart = source; | |
| 275 *targetStart = target; | |
| 276 return result; | |
| 277 } | |
| 278 | |
| 279 /* --------------------------------------------------------------------- */ | |
| 280 | |
| 281 /* | |
| 282 * Utility routine to tell whether a sequence of bytes is legal UTF-8. | |
| 283 * This must be called with the length pre-determined by the first byte. | |
| 284 * If not calling this from ConvertUTF8to*, then the length can be set by: | |
| 285 * length = trailingBytesForUTF8[*source]+1; | |
| 286 * and the sequence is illegal right away if there aren't that many bytes | |
| 287 * available. | |
| 288 * If presented with a length > 4, this returns false. The Unicode | |
| 289 * definition of UTF-8 goes up to 4-byte sequences. | |
| 290 */ | |
| 291 | |
| 292 static Boolean isLegalUTF8(const UTF8 *source, int length) { | |
| 293 UTF8 a; | |
| 294 const UTF8 *srcptr = source+length; | |
| 295 switch (length) { | |
| 296 default: return false; | |
| 297 /* Everything else falls through when "true"... */ | |
| 298 case 4: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; | |
| 299 case 3: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false; | |
| 300 case 2: if ((a = (*--srcptr)) > 0xBF) return false; | |
| 301 | |
| 302 switch (*source) { | |
| 303 /* no fall-through in this inner switch */ | |
| 304 case 0xE0: if (a < 0xA0) return false; break; | |
| 305 case 0xED: if (a > 0x9F) return false; break; | |
| 306 case 0xF0: if (a < 0x90) return false; break; | |
| 307 case 0xF4: if (a > 0x8F) return false; break; | |
| 308 default: if (a < 0x80) return false; | |
| 309 } | |
| 310 | |
| 311 case 1: if (*source >= 0x80 && *source < 0xC2) return false; | |
| 312 } | |
| 313 if (*source > 0xF4) return false; | |
| 314 return true; | |
| 315 } | |
| 316 | |
| 317 /* --------------------------------------------------------------------- */ | |
| 318 | |
| 319 /* | |
| 320 * Exported function to return whether a UTF-8 sequence is legal or not. | |
| 321 * This is not used here; it's just exported. | |
| 322 */ | |
| 323 Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd) { | |
| 324 int length = trailingBytesForUTF8[*source]+1; | |
| 325 if (source+length > sourceEnd) { | |
| 326 return false; | |
| 327 } | |
| 328 return isLegalUTF8(source, length); | |
| 329 } | |
| 330 | |
| 331 /* --------------------------------------------------------------------- */ | |
| 332 | |
| 333 ConversionResult ConvertUTF8toUTF16 (const UTF8** sourceStart, const UTF8* sourc
eEnd, | |
| 334 UTF16** targetStart, UTF16* targetEnd, Conv
ersionFlags flags) { | |
| 335 ConversionResult result = conversionOK; | |
| 336 const UTF8* source = *sourceStart; | |
| 337 UTF16* target = *targetStart; | |
| 338 while (source < sourceEnd) { | |
| 339 UTF32 ch = 0; | |
| 340 unsigned short extraBytesToRead = trailingBytesForUTF8[*source]; | |
| 341 if (source + extraBytesToRead >= sourceEnd) { | |
| 342 result = sourceExhausted; break; | |
| 343 } | |
| 344 /* Do this check whether lenient or strict */ | |
| 345 if (! isLegalUTF8(source, extraBytesToRead+1)) { | |
| 346 result = sourceIllegal; | |
| 347 break; | |
| 348 } | |
| 349 /* | |
| 350 * The cases all fall through. See "Note A" below. | |
| 351 */ | |
| 352 switch (extraBytesToRead) { | |
| 353 case 5: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */ | |
| 354 case 4: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */ | |
| 355 case 3: ch += *source++; ch <<= 6; | |
| 356 case 2: ch += *source++; ch <<= 6; | |
| 357 case 1: ch += *source++; ch <<= 6; | |
| 358 case 0: ch += *source++; | |
| 359 } | |
| 360 ch -= offsetsFromUTF8[extraBytesToRead]; | |
| 361 | |
| 362 if (target >= targetEnd) { | |
| 363 source -= (extraBytesToRead+1); /* Back up source pointer! */ | |
| 364 result = targetExhausted; break; | |
| 365 } | |
| 366 if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */ | |
| 367 /* UTF-16 surrogate values are illegal in UTF-32 */ | |
| 368 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { | |
| 369 if (flags == strictConversion) { | |
| 370 source -= (extraBytesToRead+1); /* return to the illegal value itself
*/ | |
| 371 result = sourceIllegal; | |
| 372 break; | |
| 373 } else { | |
| 374 *target++ = UNI_REPLACEMENT_CHAR; | |
| 375 } | |
| 376 } else { | |
| 377 *target++ = (UTF16)ch; /* normal case */ | |
| 378 } | |
| 379 } else if (ch > UNI_MAX_UTF16) { | |
| 380 if (flags == strictConversion) { | |
| 381 result = sourceIllegal; | |
| 382 source -= (extraBytesToRead+1); /* return to the start */ | |
| 383 break; /* Bail out; shouldn't continue */ | |
| 384 } else { | |
| 385 *target++ = UNI_REPLACEMENT_CHAR; | |
| 386 } | |
| 387 } else { | |
| 388 /* target is a character in range 0xFFFF - 0x10FFFF. */ | |
| 389 if (target + 1 >= targetEnd) { | |
| 390 source -= (extraBytesToRead+1); /* Back up source pointer! */ | |
| 391 result = targetExhausted; break; | |
| 392 } | |
| 393 ch -= halfBase; | |
| 394 *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START); | |
| 395 *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START); | |
| 396 } | |
| 397 } | |
| 398 *sourceStart = source; | |
| 399 *targetStart = target; | |
| 400 return result; | |
| 401 } | |
| 402 | |
| 403 /* --------------------------------------------------------------------- */ | |
| 404 | |
| 405 ConversionResult ConvertUTF32toUTF8 (const UTF32** sourceStart, const UTF32* sou
rceEnd, | |
| 406 UTF8** targetStart, UTF8* targetEnd, Conver
sionFlags flags) { | |
| 407 ConversionResult result = conversionOK; | |
| 408 const UTF32* source = *sourceStart; | |
| 409 UTF8* target = *targetStart; | |
| 410 while (source < sourceEnd) { | |
| 411 UTF32 ch; | |
| 412 unsigned short bytesToWrite = 0; | |
| 413 const UTF32 byteMask = 0xBF; | |
| 414 const UTF32 byteMark = 0x80; | |
| 415 ch = *source++; | |
| 416 if (flags == strictConversion ) { | |
| 417 /* UTF-16 surrogate values are illegal in UTF-32 */ | |
| 418 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { | |
| 419 --source; /* return to the illegal value itself */ | |
| 420 result = sourceIllegal; | |
| 421 break; | |
| 422 } | |
| 423 } | |
| 424 /* | |
| 425 * Figure out how many bytes the result will require. Turn any | |
| 426 * illegally large UTF32 things (> Plane 17) into replacement chars. | |
| 427 */ | |
| 428 if (ch < (UTF32)0x80) { bytesToWrite = 1; | |
| 429 } else if (ch < (UTF32)0x800) { bytesToWrite = 2; | |
| 430 } else if (ch < (UTF32)0x10000) { bytesToWrite = 3; | |
| 431 } else if (ch <= UNI_MAX_LEGAL_UTF32) { bytesToWrite = 4; | |
| 432 } else { bytesToWrite = 3; | |
| 433 ch = UNI_REPLACEMENT_CHAR; | |
| 434 result = sourceIllegal; | |
| 435 } | |
| 436 | |
| 437 target += bytesToWrite; | |
| 438 if (target > targetEnd) { | |
| 439 --source; /* Back up source pointer! */ | |
| 440 target -= bytesToWrite; result = targetExhausted; break; | |
| 441 } | |
| 442 switch (bytesToWrite) { /* note: everything falls through. */ | |
| 443 case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; | |
| 444 case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; | |
| 445 case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6; | |
| 446 case 1: *--target = (UTF8) (ch | firstByteMark[bytesToWrite]); | |
| 447 } | |
| 448 target += bytesToWrite; | |
| 449 } | |
| 450 *sourceStart = source; | |
| 451 *targetStart = target; | |
| 452 return result; | |
| 453 } | |
| 454 | |
| 455 /* --------------------------------------------------------------------- */ | |
| 456 | |
| 457 ConversionResult ConvertUTF8toUTF32 (const UTF8** sourceStart, const UTF8* sourc
eEnd, | |
| 458 UTF32** targetStart, UTF32* targetEnd, Conv
ersionFlags flags) { | |
| 459 ConversionResult result = conversionOK; | |
| 460 const UTF8* source = *sourceStart; | |
| 461 UTF32* target = *targetStart; | |
| 462 while (source < sourceEnd) { | |
| 463 UTF32 ch = 0; | |
| 464 unsigned short extraBytesToRead = trailingBytesForUTF8[*source]; | |
| 465 if (source + extraBytesToRead >= sourceEnd) { | |
| 466 result = sourceExhausted; break; | |
| 467 } | |
| 468 /* Do this check whether lenient or strict */ | |
| 469 if (! isLegalUTF8(source, extraBytesToRead+1)) { | |
| 470 result = sourceIllegal; | |
| 471 break; | |
| 472 } | |
| 473 /* | |
| 474 * The cases all fall through. See "Note A" below. | |
| 475 */ | |
| 476 switch (extraBytesToRead) { | |
| 477 case 5: ch += *source++; ch <<= 6; | |
| 478 case 4: ch += *source++; ch <<= 6; | |
| 479 case 3: ch += *source++; ch <<= 6; | |
| 480 case 2: ch += *source++; ch <<= 6; | |
| 481 case 1: ch += *source++; ch <<= 6; | |
| 482 case 0: ch += *source++; | |
| 483 } | |
| 484 ch -= offsetsFromUTF8[extraBytesToRead]; | |
| 485 | |
| 486 if (target >= targetEnd) { | |
| 487 source -= (extraBytesToRead+1); /* Back up the source pointer! */ | |
| 488 result = targetExhausted; break; | |
| 489 } | |
| 490 if (ch <= UNI_MAX_LEGAL_UTF32) { | |
| 491 /* | |
| 492 * UTF-16 surrogate values are illegal in UTF-32, and anything | |
| 493 * over Plane 17 (> 0x10FFFF) is illegal. | |
| 494 */ | |
| 495 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) { | |
| 496 if (flags == strictConversion) { | |
| 497 source -= (extraBytesToRead+1); /* return to the illegal value itself
*/ | |
| 498 result = sourceIllegal; | |
| 499 break; | |
| 500 } else { | |
| 501 *target++ = UNI_REPLACEMENT_CHAR; | |
| 502 } | |
| 503 } else { | |
| 504 *target++ = ch; | |
| 505 } | |
| 506 } else { /* i.e., ch > UNI_MAX_LEGAL_UTF32 */ | |
| 507 result = sourceIllegal; | |
| 508 *target++ = UNI_REPLACEMENT_CHAR; | |
| 509 } | |
| 510 } | |
| 511 *sourceStart = source; | |
| 512 *targetStart = target; | |
| 513 return result; | |
| 514 } | |
| 515 | |
| 516 /* --------------------------------------------------------------------- | |
| 517 | |
| 518 Note A. | |
| 519 The fall-through switches in UTF-8 reading code save a | |
| 520 temp variable, some decrements & conditionals. The switches | |
| 521 are equivalent to the following loop: | |
| 522 { | |
| 523 int tmpBytesToRead = extraBytesToRead+1; | |
| 524 do { | |
| 525 ch += *source++; | |
| 526 --tmpBytesToRead; | |
| 527 if (tmpBytesToRead) ch <<= 6; | |
| 528 } while (tmpBytesToRead > 0); | |
| 529 } | |
| 530 In UTF-8 writing code, the switches on "bytesToWrite" are | |
| 531 similarly unrolled loops. | |
| 532 | |
| 533 --------------------------------------------------------------------- */ | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 10928195:
First round of dead file removal (Closed)
Base URL: https://github.com/samclegg/nativeclient-sdk.git@master