toolkit/crashreporter/google-breakpad/src/common/convert_UTF.c

Sat, 03 Jan 2015 20:18:00 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Sat, 03 Jan 2015 20:18:00 +0100
branch
TOR_BUG_3246
changeset 7
129ffea94266
permissions
-rw-r--r--

Conditionally enable double key logic according to:
private browsing mode or privacy.thirdparty.isolate preference and
implement in GetCookieStringCommon and FindCookie where it counts...
With some reservations of how to convince FindCookie users to test
condition and pass a nullptr when disabling double key logic.

michael@0 1 /*
michael@0 2 * Copyright 2001-2004 Unicode, Inc.
michael@0 3 *
michael@0 4 * Disclaimer
michael@0 5 *
michael@0 6 * This source code is provided as is by Unicode, Inc. No claims are
michael@0 7 * made as to fitness for any particular purpose. No warranties of any
michael@0 8 * kind are expressed or implied. The recipient agrees to determine
michael@0 9 * applicability of information provided. If this file has been
michael@0 10 * purchased on magnetic or optical media from Unicode, Inc., the
michael@0 11 * sole remedy for any claim will be exchange of defective media
michael@0 12 * within 90 days of receipt.
michael@0 13 *
michael@0 14 * Limitations on Rights to Redistribute This Code
michael@0 15 *
michael@0 16 * Unicode, Inc. hereby grants the right to freely use the information
michael@0 17 * supplied in this file in the creation of products supporting the
michael@0 18 * Unicode Standard, and to make copies of this file in any form
michael@0 19 * for internal or external distribution as long as this notice
michael@0 20 * remains attached.
michael@0 21 */
michael@0 22
michael@0 23 /* ---------------------------------------------------------------------
michael@0 24
michael@0 25 Conversions between UTF32, UTF-16, and UTF-8. Source code file.
michael@0 26 Author: Mark E. Davis, 1994.
michael@0 27 Rev History: Rick McGowan, fixes & updates May 2001.
michael@0 28 Sept 2001: fixed const & error conditions per
michael@0 29 mods suggested by S. Parent & A. Lillich.
michael@0 30 June 2002: Tim Dodd added detection and handling of incomplete
michael@0 31 source sequences, enhanced error detection, added casts
michael@0 32 to eliminate compiler warnings.
michael@0 33 July 2003: slight mods to back out aggressive FFFE detection.
michael@0 34 Jan 2004: updated switches in from-UTF8 conversions.
michael@0 35 Oct 2004: updated to use UNI_MAX_LEGAL_UTF32 in UTF-32 conversions.
michael@0 36
michael@0 37 See the header file "ConvertUTF.h" for complete documentation.
michael@0 38
michael@0 39 ------------------------------------------------------------------------ */
michael@0 40
michael@0 41
michael@0 42 #include "convert_UTF.h"
michael@0 43 #ifdef CVTUTF_DEBUG
michael@0 44 #include <stdio.h>
michael@0 45 #endif
michael@0 46
michael@0 47 static const int halfShift = 10; /* used for shifting by 10 bits */
michael@0 48
michael@0 49 static const UTF32 halfBase = 0x0010000UL;
michael@0 50 static const UTF32 halfMask = 0x3FFUL;
michael@0 51
michael@0 52 #define UNI_SUR_HIGH_START (UTF32)0xD800
michael@0 53 #define UNI_SUR_HIGH_END (UTF32)0xDBFF
michael@0 54 #define UNI_SUR_LOW_START (UTF32)0xDC00
michael@0 55 #define UNI_SUR_LOW_END (UTF32)0xDFFF
michael@0 56 #define false 0
michael@0 57 #define true 1
michael@0 58
michael@0 59 /* --------------------------------------------------------------------- */
michael@0 60
michael@0 61 ConversionResult ConvertUTF32toUTF16 (const UTF32** sourceStart, const UTF32* sourceEnd,
michael@0 62 UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags) {
michael@0 63 ConversionResult result = conversionOK;
michael@0 64 const UTF32* source = *sourceStart;
michael@0 65 UTF16* target = *targetStart;
michael@0 66 while (source < sourceEnd) {
michael@0 67 UTF32 ch;
michael@0 68 if (target >= targetEnd) {
michael@0 69 result = targetExhausted; break;
michael@0 70 }
michael@0 71 ch = *source++;
michael@0 72 if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */
michael@0 73 /* UTF-16 surrogate values are illegal in UTF-32; 0xffff or 0xfffe are both reserved values */
michael@0 74 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
michael@0 75 if (flags == strictConversion) {
michael@0 76 --source; /* return to the illegal value itself */
michael@0 77 result = sourceIllegal;
michael@0 78 break;
michael@0 79 } else {
michael@0 80 *target++ = UNI_REPLACEMENT_CHAR;
michael@0 81 }
michael@0 82 } else {
michael@0 83 *target++ = (UTF16)ch; /* normal case */
michael@0 84 }
michael@0 85 } else if (ch > UNI_MAX_LEGAL_UTF32) {
michael@0 86 if (flags == strictConversion) {
michael@0 87 result = sourceIllegal;
michael@0 88 } else {
michael@0 89 *target++ = UNI_REPLACEMENT_CHAR;
michael@0 90 }
michael@0 91 } else {
michael@0 92 /* target is a character in range 0xFFFF - 0x10FFFF. */
michael@0 93 if (target + 1 >= targetEnd) {
michael@0 94 --source; /* Back up source pointer! */
michael@0 95 result = targetExhausted; break;
michael@0 96 }
michael@0 97 ch -= halfBase;
michael@0 98 *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START);
michael@0 99 *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START);
michael@0 100 }
michael@0 101 }
michael@0 102 *sourceStart = source;
michael@0 103 *targetStart = target;
michael@0 104 return result;
michael@0 105 }
michael@0 106
michael@0 107 /* --------------------------------------------------------------------- */
michael@0 108
michael@0 109 ConversionResult ConvertUTF16toUTF32 (const UTF16** sourceStart, const UTF16* sourceEnd,
michael@0 110 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags) {
michael@0 111 ConversionResult result = conversionOK;
michael@0 112 const UTF16* source = *sourceStart;
michael@0 113 UTF32* target = *targetStart;
michael@0 114 UTF32 ch, ch2;
michael@0 115 while (source < sourceEnd) {
michael@0 116 const UTF16* oldSource = source; /* In case we have to back up because of target overflow. */
michael@0 117 ch = *source++;
michael@0 118 /* If we have a surrogate pair, convert to UTF32 first. */
michael@0 119 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) {
michael@0 120 /* If the 16 bits following the high surrogate are in the source buffer... */
michael@0 121 if (source < sourceEnd) {
michael@0 122 ch2 = *source;
michael@0 123 /* If it's a low surrogate, convert to UTF32. */
michael@0 124 if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) {
michael@0 125 ch = ((ch - UNI_SUR_HIGH_START) << halfShift)
michael@0 126 + (ch2 - UNI_SUR_LOW_START) + halfBase;
michael@0 127 ++source;
michael@0 128 } else if (flags == strictConversion) { /* it's an unpaired high surrogate */
michael@0 129 --source; /* return to the illegal value itself */
michael@0 130 result = sourceIllegal;
michael@0 131 break;
michael@0 132 }
michael@0 133 } else { /* We don't have the 16 bits following the high surrogate. */
michael@0 134 --source; /* return to the high surrogate */
michael@0 135 result = sourceExhausted;
michael@0 136 break;
michael@0 137 }
michael@0 138 } else if (flags == strictConversion) {
michael@0 139 /* UTF-16 surrogate values are illegal in UTF-32 */
michael@0 140 if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) {
michael@0 141 --source; /* return to the illegal value itself */
michael@0 142 result = sourceIllegal;
michael@0 143 break;
michael@0 144 }
michael@0 145 }
michael@0 146 if (target >= targetEnd) {
michael@0 147 source = oldSource; /* Back up source pointer! */
michael@0 148 result = targetExhausted; break;
michael@0 149 }
michael@0 150 *target++ = ch;
michael@0 151 }
michael@0 152 *sourceStart = source;
michael@0 153 *targetStart = target;
michael@0 154 #ifdef CVTUTF_DEBUG
michael@0 155 if (result == sourceIllegal) {
michael@0 156 fprintf(stderr, "ConvertUTF16toUTF32 illegal seq 0x%04x,%04x\n", ch, ch2);
michael@0 157 fflush(stderr);
michael@0 158 }
michael@0 159 #endif
michael@0 160 return result;
michael@0 161 }
michael@0 162
michael@0 163 /* --------------------------------------------------------------------- */
michael@0 164
michael@0 165 /*
michael@0 166 * Index into the table below with the first byte of a UTF-8 sequence to
michael@0 167 * get the number of trailing bytes that are supposed to follow it.
michael@0 168 * Note that *legal* UTF-8 values can't have 4 or 5-bytes. The table is
michael@0 169 * left as-is for anyone who may want to do such conversion, which was
michael@0 170 * allowed in earlier algorithms.
michael@0 171 */
michael@0 172 static const char trailingBytesForUTF8[256] = {
michael@0 173 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,
michael@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,
michael@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,
michael@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,
michael@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,
michael@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,
michael@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,
michael@0 180 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
michael@0 181 };
michael@0 182
michael@0 183 /*
michael@0 184 * Magic values subtracted from a buffer value during UTF8 conversion.
michael@0 185 * This table contains as many values as there might be trailing bytes
michael@0 186 * in a UTF-8 sequence.
michael@0 187 */
michael@0 188 static const UTF32 offsetsFromUTF8[6] = { 0x00000000UL, 0x00003080UL, 0x000E2080UL,
michael@0 189 0x03C82080UL, 0xFA082080UL, 0x82082080UL };
michael@0 190
michael@0 191 /*
michael@0 192 * Once the bits are split out into bytes of UTF-8, this is a mask OR-ed
michael@0 193 * into the first byte, depending on how many bytes follow. There are
michael@0 194 * as many entries in this table as there are UTF-8 sequence types.
michael@0 195 * (I.e., one byte sequence, two byte... etc.). Remember that sequencs
michael@0 196 * for *legal* UTF-8 will be 4 or fewer bytes total.
michael@0 197 */
michael@0 198 static const UTF8 firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };
michael@0 199
michael@0 200 /* --------------------------------------------------------------------- */
michael@0 201
michael@0 202 /* The interface converts a whole buffer to avoid function-call overhead.
michael@0 203 * Constants have been gathered. Loops & conditionals have been removed as
michael@0 204 * much as possible for efficiency, in favor of drop-through switches.
michael@0 205 * (See "Note A" at the bottom of the file for equivalent code.)
michael@0 206 * If your compiler supports it, the "isLegalUTF8" call can be turned
michael@0 207 * into an inline function.
michael@0 208 */
michael@0 209
michael@0 210 /* --------------------------------------------------------------------- */
michael@0 211
michael@0 212 ConversionResult ConvertUTF16toUTF8 (const UTF16** sourceStart, const UTF16* sourceEnd,
michael@0 213 UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) {
michael@0 214 ConversionResult result = conversionOK;
michael@0 215 const UTF16* source = *sourceStart;
michael@0 216 UTF8* target = *targetStart;
michael@0 217 while (source < sourceEnd) {
michael@0 218 UTF32 ch;
michael@0 219 unsigned short bytesToWrite = 0;
michael@0 220 const UTF32 byteMask = 0xBF;
michael@0 221 const UTF32 byteMark = 0x80;
michael@0 222 const UTF16* oldSource = source; /* In case we have to back up because of target overflow. */
michael@0 223 ch = *source++;
michael@0 224 /* If we have a surrogate pair, convert to UTF32 first. */
michael@0 225 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_HIGH_END) {
michael@0 226 /* If the 16 bits following the high surrogate are in the source buffer... */
michael@0 227 if (source < sourceEnd) {
michael@0 228 UTF32 ch2 = *source;
michael@0 229 /* If it's a low surrogate, convert to UTF32. */
michael@0 230 if (ch2 >= UNI_SUR_LOW_START && ch2 <= UNI_SUR_LOW_END) {
michael@0 231 ch = ((ch - UNI_SUR_HIGH_START) << halfShift)
michael@0 232 + (ch2 - UNI_SUR_LOW_START) + halfBase;
michael@0 233 ++source;
michael@0 234 } else if (flags == strictConversion) { /* it's an unpaired high surrogate */
michael@0 235 --source; /* return to the illegal value itself */
michael@0 236 result = sourceIllegal;
michael@0 237 break;
michael@0 238 }
michael@0 239 } else { /* We don't have the 16 bits following the high surrogate. */
michael@0 240 --source; /* return to the high surrogate */
michael@0 241 result = sourceExhausted;
michael@0 242 break;
michael@0 243 }
michael@0 244 } else if (flags == strictConversion) {
michael@0 245 /* UTF-16 surrogate values are illegal in UTF-32 */
michael@0 246 if (ch >= UNI_SUR_LOW_START && ch <= UNI_SUR_LOW_END) {
michael@0 247 --source; /* return to the illegal value itself */
michael@0 248 result = sourceIllegal;
michael@0 249 break;
michael@0 250 }
michael@0 251 }
michael@0 252 /* Figure out how many bytes the result will require */
michael@0 253 if (ch < (UTF32)0x80) { bytesToWrite = 1;
michael@0 254 } else if (ch < (UTF32)0x800) { bytesToWrite = 2;
michael@0 255 } else if (ch < (UTF32)0x10000) { bytesToWrite = 3;
michael@0 256 } else if (ch < (UTF32)0x110000) { bytesToWrite = 4;
michael@0 257 } else { bytesToWrite = 3;
michael@0 258 ch = UNI_REPLACEMENT_CHAR;
michael@0 259 }
michael@0 260
michael@0 261 target += bytesToWrite;
michael@0 262 if (target > targetEnd) {
michael@0 263 source = oldSource; /* Back up source pointer! */
michael@0 264 target -= bytesToWrite; result = targetExhausted; break;
michael@0 265 }
michael@0 266 switch (bytesToWrite) { /* note: everything falls through. */
michael@0 267 case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
michael@0 268 case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
michael@0 269 case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
michael@0 270 case 1: *--target = (UTF8)(ch | firstByteMark[bytesToWrite]);
michael@0 271 }
michael@0 272 target += bytesToWrite;
michael@0 273 }
michael@0 274 *sourceStart = source;
michael@0 275 *targetStart = target;
michael@0 276 return result;
michael@0 277 }
michael@0 278
michael@0 279 /* --------------------------------------------------------------------- */
michael@0 280
michael@0 281 /*
michael@0 282 * Utility routine to tell whether a sequence of bytes is legal UTF-8.
michael@0 283 * This must be called with the length pre-determined by the first byte.
michael@0 284 * If not calling this from ConvertUTF8to*, then the length can be set by:
michael@0 285 * length = trailingBytesForUTF8[*source]+1;
michael@0 286 * and the sequence is illegal right away if there aren't that many bytes
michael@0 287 * available.
michael@0 288 * If presented with a length > 4, this returns false. The Unicode
michael@0 289 * definition of UTF-8 goes up to 4-byte sequences.
michael@0 290 */
michael@0 291
michael@0 292 static Boolean isLegalUTF8(const UTF8 *source, int length) {
michael@0 293 UTF8 a;
michael@0 294 const UTF8 *srcptr = source+length;
michael@0 295 switch (length) {
michael@0 296 default: return false;
michael@0 297 /* Everything else falls through when "true"... */
michael@0 298 case 4: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
michael@0 299 case 3: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
michael@0 300 case 2: if ((a = (*--srcptr)) > 0xBF) return false;
michael@0 301
michael@0 302 switch (*source) {
michael@0 303 /* no fall-through in this inner switch */
michael@0 304 case 0xE0: if (a < 0xA0) return false; break;
michael@0 305 case 0xED: if (a > 0x9F) return false; break;
michael@0 306 case 0xF0: if (a < 0x90) return false; break;
michael@0 307 case 0xF4: if (a > 0x8F) return false; break;
michael@0 308 default: if (a < 0x80) return false;
michael@0 309 }
michael@0 310
michael@0 311 case 1: if (*source >= 0x80 && *source < 0xC2) return false;
michael@0 312 }
michael@0 313 if (*source > 0xF4) return false;
michael@0 314 return true;
michael@0 315 }
michael@0 316
michael@0 317 /* --------------------------------------------------------------------- */
michael@0 318
michael@0 319 /*
michael@0 320 * Exported function to return whether a UTF-8 sequence is legal or not.
michael@0 321 * This is not used here; it's just exported.
michael@0 322 */
michael@0 323 Boolean isLegalUTF8Sequence(const UTF8 *source, const UTF8 *sourceEnd) {
michael@0 324 int length = trailingBytesForUTF8[*source]+1;
michael@0 325 if (source+length > sourceEnd) {
michael@0 326 return false;
michael@0 327 }
michael@0 328 return isLegalUTF8(source, length);
michael@0 329 }
michael@0 330
michael@0 331 /* --------------------------------------------------------------------- */
michael@0 332
michael@0 333 ConversionResult ConvertUTF8toUTF16 (const UTF8** sourceStart, const UTF8* sourceEnd,
michael@0 334 UTF16** targetStart, UTF16* targetEnd, ConversionFlags flags) {
michael@0 335 ConversionResult result = conversionOK;
michael@0 336 const UTF8* source = *sourceStart;
michael@0 337 UTF16* target = *targetStart;
michael@0 338 while (source < sourceEnd) {
michael@0 339 UTF32 ch = 0;
michael@0 340 unsigned short extraBytesToRead = trailingBytesForUTF8[*source];
michael@0 341 if (source + extraBytesToRead >= sourceEnd) {
michael@0 342 result = sourceExhausted; break;
michael@0 343 }
michael@0 344 /* Do this check whether lenient or strict */
michael@0 345 if (! isLegalUTF8(source, extraBytesToRead+1)) {
michael@0 346 result = sourceIllegal;
michael@0 347 break;
michael@0 348 }
michael@0 349 /*
michael@0 350 * The cases all fall through. See "Note A" below.
michael@0 351 */
michael@0 352 switch (extraBytesToRead) {
michael@0 353 case 5: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */
michael@0 354 case 4: ch += *source++; ch <<= 6; /* remember, illegal UTF-8 */
michael@0 355 case 3: ch += *source++; ch <<= 6;
michael@0 356 case 2: ch += *source++; ch <<= 6;
michael@0 357 case 1: ch += *source++; ch <<= 6;
michael@0 358 case 0: ch += *source++;
michael@0 359 }
michael@0 360 ch -= offsetsFromUTF8[extraBytesToRead];
michael@0 361
michael@0 362 if (target >= targetEnd) {
michael@0 363 source -= (extraBytesToRead+1); /* Back up source pointer! */
michael@0 364 result = targetExhausted; break;
michael@0 365 }
michael@0 366 if (ch <= UNI_MAX_BMP) { /* Target is a character <= 0xFFFF */
michael@0 367 /* UTF-16 surrogate values are illegal in UTF-32 */
michael@0 368 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
michael@0 369 if (flags == strictConversion) {
michael@0 370 source -= (extraBytesToRead+1); /* return to the illegal value itself */
michael@0 371 result = sourceIllegal;
michael@0 372 break;
michael@0 373 } else {
michael@0 374 *target++ = UNI_REPLACEMENT_CHAR;
michael@0 375 }
michael@0 376 } else {
michael@0 377 *target++ = (UTF16)ch; /* normal case */
michael@0 378 }
michael@0 379 } else if (ch > UNI_MAX_UTF16) {
michael@0 380 if (flags == strictConversion) {
michael@0 381 result = sourceIllegal;
michael@0 382 source -= (extraBytesToRead+1); /* return to the start */
michael@0 383 break; /* Bail out; shouldn't continue */
michael@0 384 } else {
michael@0 385 *target++ = UNI_REPLACEMENT_CHAR;
michael@0 386 }
michael@0 387 } else {
michael@0 388 /* target is a character in range 0xFFFF - 0x10FFFF. */
michael@0 389 if (target + 1 >= targetEnd) {
michael@0 390 source -= (extraBytesToRead+1); /* Back up source pointer! */
michael@0 391 result = targetExhausted; break;
michael@0 392 }
michael@0 393 ch -= halfBase;
michael@0 394 *target++ = (UTF16)((ch >> halfShift) + UNI_SUR_HIGH_START);
michael@0 395 *target++ = (UTF16)((ch & halfMask) + UNI_SUR_LOW_START);
michael@0 396 }
michael@0 397 }
michael@0 398 *sourceStart = source;
michael@0 399 *targetStart = target;
michael@0 400 return result;
michael@0 401 }
michael@0 402
michael@0 403 /* --------------------------------------------------------------------- */
michael@0 404
michael@0 405 ConversionResult ConvertUTF32toUTF8 (const UTF32** sourceStart, const UTF32* sourceEnd,
michael@0 406 UTF8** targetStart, UTF8* targetEnd, ConversionFlags flags) {
michael@0 407 ConversionResult result = conversionOK;
michael@0 408 const UTF32* source = *sourceStart;
michael@0 409 UTF8* target = *targetStart;
michael@0 410 while (source < sourceEnd) {
michael@0 411 UTF32 ch;
michael@0 412 unsigned short bytesToWrite = 0;
michael@0 413 const UTF32 byteMask = 0xBF;
michael@0 414 const UTF32 byteMark = 0x80;
michael@0 415 ch = *source++;
michael@0 416 if (flags == strictConversion ) {
michael@0 417 /* UTF-16 surrogate values are illegal in UTF-32 */
michael@0 418 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
michael@0 419 --source; /* return to the illegal value itself */
michael@0 420 result = sourceIllegal;
michael@0 421 break;
michael@0 422 }
michael@0 423 }
michael@0 424 /*
michael@0 425 * Figure out how many bytes the result will require. Turn any
michael@0 426 * illegally large UTF32 things (> Plane 17) into replacement chars.
michael@0 427 */
michael@0 428 if (ch < (UTF32)0x80) { bytesToWrite = 1;
michael@0 429 } else if (ch < (UTF32)0x800) { bytesToWrite = 2;
michael@0 430 } else if (ch < (UTF32)0x10000) { bytesToWrite = 3;
michael@0 431 } else if (ch <= UNI_MAX_LEGAL_UTF32) { bytesToWrite = 4;
michael@0 432 } else { bytesToWrite = 3;
michael@0 433 ch = UNI_REPLACEMENT_CHAR;
michael@0 434 result = sourceIllegal;
michael@0 435 }
michael@0 436
michael@0 437 target += bytesToWrite;
michael@0 438 if (target > targetEnd) {
michael@0 439 --source; /* Back up source pointer! */
michael@0 440 target -= bytesToWrite; result = targetExhausted; break;
michael@0 441 }
michael@0 442 switch (bytesToWrite) { /* note: everything falls through. */
michael@0 443 case 4: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
michael@0 444 case 3: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
michael@0 445 case 2: *--target = (UTF8)((ch | byteMark) & byteMask); ch >>= 6;
michael@0 446 case 1: *--target = (UTF8) (ch | firstByteMark[bytesToWrite]);
michael@0 447 }
michael@0 448 target += bytesToWrite;
michael@0 449 }
michael@0 450 *sourceStart = source;
michael@0 451 *targetStart = target;
michael@0 452 return result;
michael@0 453 }
michael@0 454
michael@0 455 /* --------------------------------------------------------------------- */
michael@0 456
michael@0 457 ConversionResult ConvertUTF8toUTF32 (const UTF8** sourceStart, const UTF8* sourceEnd,
michael@0 458 UTF32** targetStart, UTF32* targetEnd, ConversionFlags flags) {
michael@0 459 ConversionResult result = conversionOK;
michael@0 460 const UTF8* source = *sourceStart;
michael@0 461 UTF32* target = *targetStart;
michael@0 462 while (source < sourceEnd) {
michael@0 463 UTF32 ch = 0;
michael@0 464 unsigned short extraBytesToRead = trailingBytesForUTF8[*source];
michael@0 465 if (source + extraBytesToRead >= sourceEnd) {
michael@0 466 result = sourceExhausted; break;
michael@0 467 }
michael@0 468 /* Do this check whether lenient or strict */
michael@0 469 if (! isLegalUTF8(source, extraBytesToRead+1)) {
michael@0 470 result = sourceIllegal;
michael@0 471 break;
michael@0 472 }
michael@0 473 /*
michael@0 474 * The cases all fall through. See "Note A" below.
michael@0 475 */
michael@0 476 switch (extraBytesToRead) {
michael@0 477 case 5: ch += *source++; ch <<= 6;
michael@0 478 case 4: ch += *source++; ch <<= 6;
michael@0 479 case 3: ch += *source++; ch <<= 6;
michael@0 480 case 2: ch += *source++; ch <<= 6;
michael@0 481 case 1: ch += *source++; ch <<= 6;
michael@0 482 case 0: ch += *source++;
michael@0 483 }
michael@0 484 ch -= offsetsFromUTF8[extraBytesToRead];
michael@0 485
michael@0 486 if (target >= targetEnd) {
michael@0 487 source -= (extraBytesToRead+1); /* Back up the source pointer! */
michael@0 488 result = targetExhausted; break;
michael@0 489 }
michael@0 490 if (ch <= UNI_MAX_LEGAL_UTF32) {
michael@0 491 /*
michael@0 492 * UTF-16 surrogate values are illegal in UTF-32, and anything
michael@0 493 * over Plane 17 (> 0x10FFFF) is illegal.
michael@0 494 */
michael@0 495 if (ch >= UNI_SUR_HIGH_START && ch <= UNI_SUR_LOW_END) {
michael@0 496 if (flags == strictConversion) {
michael@0 497 source -= (extraBytesToRead+1); /* return to the illegal value itself */
michael@0 498 result = sourceIllegal;
michael@0 499 break;
michael@0 500 } else {
michael@0 501 *target++ = UNI_REPLACEMENT_CHAR;
michael@0 502 }
michael@0 503 } else {
michael@0 504 *target++ = ch;
michael@0 505 }
michael@0 506 } else { /* i.e., ch > UNI_MAX_LEGAL_UTF32 */
michael@0 507 result = sourceIllegal;
michael@0 508 *target++ = UNI_REPLACEMENT_CHAR;
michael@0 509 }
michael@0 510 }
michael@0 511 *sourceStart = source;
michael@0 512 *targetStart = target;
michael@0 513 return result;
michael@0 514 }
michael@0 515
michael@0 516 /* ---------------------------------------------------------------------
michael@0 517
michael@0 518 Note A.
michael@0 519 The fall-through switches in UTF-8 reading code save a
michael@0 520 temp variable, some decrements & conditionals. The switches
michael@0 521 are equivalent to the following loop:
michael@0 522 {
michael@0 523 int tmpBytesToRead = extraBytesToRead+1;
michael@0 524 do {
michael@0 525 ch += *source++;
michael@0 526 --tmpBytesToRead;
michael@0 527 if (tmpBytesToRead) ch <<= 6;
michael@0 528 } while (tmpBytesToRead > 0);
michael@0 529 }
michael@0 530 In UTF-8 writing code, the switches on "bytesToWrite" are
michael@0 531 similarly unrolled loops.
michael@0 532
michael@0 533 --------------------------------------------------------------------- */

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