icuSources/common/ucnv_ext.cpp

   1 /*
   2 ******************************************************************************
   3 *
   4 *   Copyright (C) 2003-2013, International Business Machines
   5 *   Corporation and others.  All Rights Reserved.
   6 *
   7 ******************************************************************************
   8 *   file name:  ucnv_ext.cpp
   9 *   encoding:   US-ASCII
  10 *   tab size:   8 (not used)
  11 *   indentation:4
  12 *
  13 *   created on: 2003jun13
  14 *   created by: Markus W. Scherer
  15 *
  16 *   Conversion extensions
  17 */
  18
  19 #include "unicode/utypes.h"
  20
  21 #if !UCONFIG_NO_CONVERSION && !UCONFIG_NO_LEGACY_CONVERSION
  22
  23 #include "unicode/uset.h"
  24 #include "ucnv_bld.h"
  25 #include "ucnv_cnv.h"
  26 #include "ucnv_ext.h"
  27 #include "cmemory.h"
  28 #include "uassert.h"
  29
  30 /* to Unicode --------------------------------------------------------------- */
  31
  32 /*
  33  * @return lookup value for the byte, if found; else 0
  34  */
  35 static inline uint32_t
  36 ucnv_extFindToU(const uint32_t *toUSection, int32_t length, uint8_t byte) {
  37     uint32_t word0, word;
  38     int32_t i, start, limit;
  39
  40     /* check the input byte against the lowest and highest section bytes */
  41     start=(int32_t)UCNV_EXT_TO_U_GET_BYTE(toUSection[0]);
  42     limit=(int32_t)UCNV_EXT_TO_U_GET_BYTE(toUSection[length-1]);
  43     if(byte<start || limit<byte) {
  44         return 0; /* the byte is out of range */
  45     }
  46
  47     if(length==((limit-start)+1)) {
  48         /* direct access on a linear array */
  49         return UCNV_EXT_TO_U_GET_VALUE(toUSection[byte-start]); /* could be 0 */
  50     }
  51
  52     /* word0 is suitable for <=toUSection[] comparison, word for <toUSection[] */
  53     word0=UCNV_EXT_TO_U_MAKE_WORD(byte, 0);
  54
  55     /*
  56      * Shift byte once instead of each section word and add 0xffffff.
  57      * We will compare the shifted/added byte (bbffffff) against
  58      * section words which have byte values in the same bit position.
  59      * If and only if byte bb < section byte ss then bbffffff<ssvvvvvv
  60      * for all v=0..f
  61      * so we need not mask off the lower 24 bits of each section word.
  62      */
  63     word=word0|UCNV_EXT_TO_U_VALUE_MASK;
  64
  65     /* binary search */
  66     start=0;
  67     limit=length;
  68     for(;;) {
  69         i=limit-start;
  70         if(i<=1) {
  71             break; /* done */
  72         }
  73         /* start<limit-1 */
  74
  75         if(i<=4) {
  76             /* linear search for the last part */
  77             if(word0<=toUSection[start]) {
  78                 break;
  79             }
  80             if(++start<limit && word0<=toUSection[start]) {
  81                 break;
  82             }
  83             if(++start<limit && word0<=toUSection[start]) {
  84                 break;
  85             }
  86             /* always break at start==limit-1 */
  87             ++start;
  88             break;
  89         }
  90
  91         i=(start+limit)/2;
  92         if(word<toUSection[i]) {
  93             limit=i;
  94         } else {
  95             start=i;
  96         }
  97     }
  98
  99     /* did we really find it? */
 100     if(start<limit && byte==UCNV_EXT_TO_U_GET_BYTE(word=toUSection[start])) {
 101         return UCNV_EXT_TO_U_GET_VALUE(word); /* never 0 */
 102     } else {
 103         return 0; /* not found */
 104     }
 105 }
 106
 107 /*
 108  * TRUE if not an SI/SO stateful converter,
 109  * or if the match length fits with the current converter state
 110  */
 111 #define UCNV_EXT_TO_U_VERIFY_SISO_MATCH(sisoState, match) \
 112     ((sisoState)<0 || ((sisoState)==0) == (match==1))
 113
 114 /*
 115  * this works like ucnv_extMatchFromU() except
 116  * - the first character is in pre
 117  * - no trie is used
 118  * - the returned matchLength is not offset by 2
 119  */
 120 static int32_t
 121 ucnv_extMatchToU(const int32_t *cx, int8_t sisoState,
 122                  const char *pre, int32_t preLength,
 123                  const char *src, int32_t srcLength,
 124                  uint32_t *pMatchValue,
 125                  UBool /*useFallback*/, UBool flush) {
 126     const uint32_t *toUTable, *toUSection;
 127
 128     uint32_t value, matchValue;
 129     int32_t i, j, idx, length, matchLength;
 130     uint8_t b;
 131
 132     if(cx==NULL || cx[UCNV_EXT_TO_U_LENGTH]<=0) {
 133         return 0; /* no extension data, no match */
 134     }
 135
 136     /* initialize */
 137     toUTable=UCNV_EXT_ARRAY(cx, UCNV_EXT_TO_U_INDEX, uint32_t);
 138     idx=0;
 139
 140     matchValue=0;
 141     i=j=matchLength=0;
 142
 143     if(sisoState==0) {
 144         /* SBCS state of an SI/SO stateful converter, look at only exactly 1 byte */
 145         if(preLength>1) {
 146             return 0; /* no match of a DBCS sequence in SBCS mode */
 147         } else if(preLength==1) {
 148             srcLength=0;
 149         } else /* preLength==0 */ {
 150             if(srcLength>1) {
 151                 srcLength=1;
 152             }
 153         }
 154         flush=TRUE;
 155     }
 156
 157     /* we must not remember fallback matches when not using fallbacks */
 158
 159     /* match input units until there is a full match or the input is consumed */
 160     for(;;) {
 161         /* go to the next section */
 162         toUSection=toUTable+idx;
 163
 164         /* read first pair of the section */
 165         value=*toUSection++;
 166         length=UCNV_EXT_TO_U_GET_BYTE(value);
 167         value=UCNV_EXT_TO_U_GET_VALUE(value);
 168         if( value!=0 &&
 169             (UCNV_EXT_TO_U_IS_ROUNDTRIP(value) ||
 170              TO_U_USE_FALLBACK(useFallback)) &&
 171             UCNV_EXT_TO_U_VERIFY_SISO_MATCH(sisoState, i+j)
 172         ) {
 173             /* remember longest match so far */
 174             matchValue=value;
 175             matchLength=i+j;
 176         }
 177
 178         /* match pre[] then src[] */
 179         if(i<preLength) {
 180             b=(uint8_t)pre[i++];
 181         } else if(j<srcLength) {
 182             b=(uint8_t)src[j++];
 183         } else {
 184             /* all input consumed, partial match */
 185             if(flush || (length=(i+j))>UCNV_EXT_MAX_BYTES) {
 186                 /*
 187                  * end of the entire input stream, stop with the longest match so far
 188                  * or: partial match must not be longer than UCNV_EXT_MAX_BYTES
 189                  * because it must fit into state buffers
 190                  */
 191                 break;
 192             } else {
 193                 /* continue with more input next time */
 194                 return -length;
 195             }
 196         }
 197
 198         /* search for the current UChar */
 199         value=ucnv_extFindToU(toUSection, length, b);
 200         if(value==0) {
 201             /* no match here, stop with the longest match so far */
 202             break;
 203         } else {
 204             if(UCNV_EXT_TO_U_IS_PARTIAL(value)) {
 205                 /* partial match, continue */
 206                 idx=(int32_t)UCNV_EXT_TO_U_GET_PARTIAL_INDEX(value);
 207             } else {
 208                 if( (UCNV_EXT_TO_U_IS_ROUNDTRIP(value) ||
 209                      TO_U_USE_FALLBACK(useFallback)) &&
 210                     UCNV_EXT_TO_U_VERIFY_SISO_MATCH(sisoState, i+j)
 211                 ) {
 212                     /* full match, stop with result */
 213                     matchValue=value;
 214                     matchLength=i+j;
 215                 } else {
 216                     /* full match on fallback not taken, stop with the longest match so far */
 217                 }
 218                 break;
 219             }
 220         }
 221     }
 222
 223     if(matchLength==0) {
 224         /* no match at all */
 225         return 0;
 226     }
 227
 228     /* return result */
 229     *pMatchValue=UCNV_EXT_TO_U_MASK_ROUNDTRIP(matchValue);
 230     return matchLength;
 231 }
 232
 233 static inline void
 234 ucnv_extWriteToU(UConverter *cnv, const int32_t *cx,
 235                  uint32_t value,
 236                  UChar **target, const UChar *targetLimit,
 237                  int32_t **offsets, int32_t srcIndex,
 238                  UErrorCode *pErrorCode) {
 239     /* output the result */
 240     if(UCNV_EXT_TO_U_IS_CODE_POINT(value)) {
 241         /* output a single code point */
 242         ucnv_toUWriteCodePoint(
 243             cnv, UCNV_EXT_TO_U_GET_CODE_POINT(value),
 244             target, targetLimit,
 245             offsets, srcIndex,
 246             pErrorCode);
 247     } else {
 248         /* output a string - with correct data we have resultLength>0 */
 249         ucnv_toUWriteUChars(
 250             cnv,
 251             UCNV_EXT_ARRAY(cx, UCNV_EXT_TO_U_UCHARS_INDEX, UChar)+
 252                 UCNV_EXT_TO_U_GET_INDEX(value),
 253             UCNV_EXT_TO_U_GET_LENGTH(value),
 254             target, targetLimit,
 255             offsets, srcIndex,
 256             pErrorCode);
 257     }
 258 }
 259
 260 /*
 261  * get the SI/SO toU state (state 0 is for SBCS, 1 for DBCS),
 262  * or 1 for DBCS-only,
 263  * or -1 if the converter is not SI/SO stateful
 264  *
 265  * Note: For SI/SO stateful converters getting here,
 266  * cnv->mode==0 is equivalent to firstLength==1.
 267  */
 268 #define UCNV_SISO_STATE(cnv) \
 269     ((cnv)->sharedData->mbcs.outputType==MBCS_OUTPUT_2_SISO ? (int8_t)(cnv)->mode : \
 270      (cnv)->sharedData->mbcs.outputType==MBCS_OUTPUT_DBCS_ONLY ? 1 : -1)
 271
 272 /*
 273  * target<targetLimit; set error code for overflow
 274  */
 275 U_CFUNC UBool
 276 ucnv_extInitialMatchToU(UConverter *cnv, const int32_t *cx,
 277                         int32_t firstLength,
 278                         const char **src, const char *srcLimit,
 279                         UChar **target, const UChar *targetLimit,
 280                         int32_t **offsets, int32_t srcIndex,
 281                         UBool flush,
 282                         UErrorCode *pErrorCode) {
 283     uint32_t value = 0;  /* initialize output-only param to 0 to silence gcc */
 284     int32_t match;
 285
 286     /* try to match */
 287     match=ucnv_extMatchToU(cx, (int8_t)UCNV_SISO_STATE(cnv),
 288                            (const char *)cnv->toUBytes, firstLength,
 289                            *src, (int32_t)(srcLimit-*src),
 290                            &value,
 291                            cnv->useFallback, flush);
 292     if(match>0) {
 293         /* advance src pointer for the consumed input */
 294         *src+=match-firstLength;
 295
 296         /* write result to target */
 297         ucnv_extWriteToU(cnv, cx,
 298                          value,
 299                          target, targetLimit,
 300                          offsets, srcIndex,
 301                          pErrorCode);
 302         return TRUE;
 303     } else if(match<0) {
 304         /* save state for partial match */
 305         const char *s;
 306         int32_t j;
 307
 308         /* copy the first code point */
 309         s=(const char *)cnv->toUBytes;
 310         cnv->preToUFirstLength=(int8_t)firstLength;
 311         for(j=0; j<firstLength; ++j) {
 312             cnv->preToU[j]=*s++;
 313         }
 314
 315         /* now copy the newly consumed input */
 316         s=*src;
 317         match=-match;
 318         for(; j<match; ++j) {
 319             cnv->preToU[j]=*s++;
 320         }
 321         *src=s; /* same as *src=srcLimit; because we reached the end of input */
 322         cnv->preToULength=(int8_t)match;
 323         return TRUE;
 324     } else /* match==0 no match */ {
 325         return FALSE;
 326     }
 327 }
 328
 329 U_CFUNC UChar32
 330 ucnv_extSimpleMatchToU(const int32_t *cx,
 331                        const char *source, int32_t length,
 332                        UBool useFallback) {
 333     uint32_t value = 0;  /* initialize output-only param to 0 to silence gcc */
 334     int32_t match;
 335
 336     if(length<=0) {
 337         return 0xffff;
 338     }
 339
 340     /* try to match */
 341     match=ucnv_extMatchToU(cx, -1,
 342                            source, length,
 343                            NULL, 0,
 344                            &value,
 345                            useFallback, TRUE);
 346     if(match==length) {
 347         /* write result for simple, single-character conversion */
 348         if(UCNV_EXT_TO_U_IS_CODE_POINT(value)) {
 349             return UCNV_EXT_TO_U_GET_CODE_POINT(value);
 350         }
 351     }
 352
 353     /*
 354      * return no match because
 355      * - match>0 && value points to string: simple conversion cannot handle multiple code points
 356      * - match>0 && match!=length: not all input consumed, forbidden for this function
 357      * - match==0: no match found in the first place
 358      * - match<0: partial match, not supported for simple conversion (and flush==TRUE)
 359      */
 360     return 0xfffe;
 361 }
 362
 363 /*
 364  * continue partial match with new input
 365  * never called for simple, single-character conversion
 366  */
 367 U_CFUNC void
 368 ucnv_extContinueMatchToU(UConverter *cnv,
 369                          UConverterToUnicodeArgs *pArgs, int32_t srcIndex,
 370                          UErrorCode *pErrorCode) {
 371     uint32_t value = 0;  /* initialize output-only param to 0 to silence gcc */
 372     int32_t match, length;
 373
 374     match=ucnv_extMatchToU(cnv->sharedData->mbcs.extIndexes, (int8_t)UCNV_SISO_STATE(cnv),
 375                            cnv->preToU, cnv->preToULength,
 376                            pArgs->source, (int32_t)(pArgs->sourceLimit-pArgs->source),
 377                            &value,
 378                            cnv->useFallback, pArgs->flush);
 379     if(match>0) {
 380         if(match>=cnv->preToULength) {
 381             /* advance src pointer for the consumed input */
 382             pArgs->source+=match-cnv->preToULength;
 383             cnv->preToULength=0;
 384         } else {
 385             /* the match did not use all of preToU[] - keep the rest for replay */
 386             length=cnv->preToULength-match;
 387             uprv_memmove(cnv->preToU, cnv->preToU+match, length);
 388             cnv->preToULength=(int8_t)-length;
 389         }
 390
 391         /* write result */
 392         ucnv_extWriteToU(cnv, cnv->sharedData->mbcs.extIndexes,
 393                          value,
 394                          &pArgs->target, pArgs->targetLimit,
 395                          &pArgs->offsets, srcIndex,
 396                          pErrorCode);
 397     } else if(match<0) {
 398         /* save state for partial match */
 399         const char *s;
 400         int32_t j;
 401
 402         /* just _append_ the newly consumed input to preToU[] */
 403         s=pArgs->source;
 404         match=-match;
 405         for(j=cnv->preToULength; j<match; ++j) {
 406             cnv->preToU[j]=*s++;
 407         }
 408         pArgs->source=s; /* same as *src=srcLimit; because we reached the end of input */
 409         cnv->preToULength=(int8_t)match;
 410     } else /* match==0 */ {
 411         /*
 412          * no match
 413          *
 414          * We need to split the previous input into two parts:
 415          *
 416          * 1. The first codepage character is unmappable - that's how we got into
 417          *    trying the extension data in the first place.
 418          *    We need to move it from the preToU buffer
 419          *    to the error buffer, set an error code,
 420          *    and prepare the rest of the previous input for 2.
 421          *
 422          * 2. The rest of the previous input must be converted once we
 423          *    come back from the callback for the first character.
 424          *    At that time, we have to try again from scratch to convert
 425          *    these input characters.
 426          *    The replay will be handled by the ucnv.c conversion code.
 427          */
 428
 429         /* move the first codepage character to the error field */
 430         uprv_memcpy(cnv->toUBytes, cnv->preToU, cnv->preToUFirstLength);
 431         cnv->toULength=cnv->preToUFirstLength;
 432
 433         /* move the rest up inside the buffer */
 434         length=cnv->preToULength-cnv->preToUFirstLength;
 435         if(length>0) {
 436             uprv_memmove(cnv->preToU, cnv->preToU+cnv->preToUFirstLength, length);
 437         }
 438
 439         /* mark preToU for replay */
 440         cnv->preToULength=(int8_t)-length;
 441
 442         /* set the error code for unassigned */
 443         *pErrorCode=U_INVALID_CHAR_FOUND;
 444     }
 445 }
 446
 447 /* from Unicode ------------------------------------------------------------- */
 448
 449 // Use roundtrips, "good one-way" mappings, and some normal fallbacks.
 450 static inline UBool
 451 extFromUUseMapping(UBool useFallback, uint32_t value, UChar32 firstCP) {
 452     return
 453         ((value&UCNV_EXT_FROM_U_STATUS_MASK)!=0 ||
 454             FROM_U_USE_FALLBACK(useFallback, firstCP)) &&
 455         (value&UCNV_EXT_FROM_U_RESERVED_MASK)==0;
 456 }
 457
 458 /*
 459  * @return index of the UChar, if found; else <0
 460  */
 461 static inline int32_t
 462 ucnv_extFindFromU(const UChar *fromUSection, int32_t length, UChar u) {
 463     int32_t i, start, limit;
 464
 465     /* binary search */
 466     start=0;
 467     limit=length;
 468     for(;;) {
 469         i=limit-start;
 470         if(i<=1) {
 471             break; /* done */
 472         }
 473         /* start<limit-1 */
 474
 475         if(i<=4) {
 476             /* linear search for the last part */
 477             if(u<=fromUSection[start]) {
 478                 break;
 479             }
 480             if(++start<limit && u<=fromUSection[start]) {
 481                 break;
 482             }
 483             if(++start<limit && u<=fromUSection[start]) {
 484                 break;
 485             }
 486             /* always break at start==limit-1 */
 487             ++start;
 488             break;
 489         }
 490
 491         i=(start+limit)/2;
 492         if(u<fromUSection[i]) {
 493             limit=i;
 494         } else {
 495             start=i;
 496         }
 497     }
 498
 499     /* did we really find it? */
 500     if(start<limit && u==fromUSection[start]) {
 501         return start;
 502     } else {
 503         return -1; /* not found */
 504     }
 505 }
 506
 507 /*
 508  * @param cx pointer to extension data; if NULL, returns 0
 509  * @param firstCP the first code point before all the other UChars
 510  * @param pre UChars that must match; !initialMatch: partial match with them
 511  * @param preLength length of pre, >=0
 512  * @param src UChars that can be used to complete a match
 513  * @param srcLength length of src, >=0
 514  * @param pMatchValue [out] output result value for the match from the data structure
 515  * @param useFallback "use fallback" flag, usually from cnv->useFallback
 516  * @param flush TRUE if the end of the input stream is reached
 517  * @return >1: matched, return value=total match length (number of input units matched)
 518  *          1: matched, no mapping but request for <subchar1>
 519  *             (only for the first code point)
 520  *          0: no match
 521  *         <0: partial match, return value=negative total match length
 522  *             (partial matches are never returned for flush==TRUE)
 523  *             (partial matches are never returned as being longer than UCNV_EXT_MAX_UCHARS)
 524  *         the matchLength is 2 if only firstCP matched, and >2 if firstCP and
 525  *         further code units matched
 526  */
 527 static int32_t
 528 ucnv_extMatchFromU(const int32_t *cx,
 529                    UChar32 firstCP,
 530                    const UChar *pre, int32_t preLength,
 531                    const UChar *src, int32_t srcLength,
 532                    uint32_t *pMatchValue,
 533                    UBool useFallback, UBool flush) {
 534     const uint16_t *stage12, *stage3;
 535     const uint32_t *stage3b;
 536
 537     const UChar *fromUTableUChars, *fromUSectionUChars;
 538     const uint32_t *fromUTableValues, *fromUSectionValues;
 539
 540     uint32_t value, matchValue;
 541     int32_t i, j, idx, length, matchLength;
 542     UChar c;
 543
 544     if(cx==NULL) {
 545         return 0; /* no extension data, no match */
 546     }
 547
 548     /* trie lookup of firstCP */
 549     idx=firstCP>>10; /* stage 1 index */
 550     if(idx>=cx[UCNV_EXT_FROM_U_STAGE_1_LENGTH]) {
 551         return 0; /* the first code point is outside the trie */
 552     }
 553
 554     stage12=UCNV_EXT_ARRAY(cx, UCNV_EXT_FROM_U_STAGE_12_INDEX, uint16_t);
 555     stage3=UCNV_EXT_ARRAY(cx, UCNV_EXT_FROM_U_STAGE_3_INDEX, uint16_t);
 556     idx=UCNV_EXT_FROM_U(stage12, stage3, idx, firstCP);
 557
 558     stage3b=UCNV_EXT_ARRAY(cx, UCNV_EXT_FROM_U_STAGE_3B_INDEX, uint32_t);
 559     value=stage3b[idx];
 560     if(value==0) {
 561         return 0;
 562     }
 563
 564     /*
 565      * Tests for (value&UCNV_EXT_FROM_U_RESERVED_MASK)==0:
 566      * Do not interpret values with reserved bits used, for forward compatibility,
 567      * and do not even remember intermediate results with reserved bits used.
 568      */
 569
 570     if(UCNV_EXT_TO_U_IS_PARTIAL(value)) {
 571         /* partial match, enter the loop below */
 572         idx=(int32_t)UCNV_EXT_FROM_U_GET_PARTIAL_INDEX(value);
 573
 574         /* initialize */
 575         fromUTableUChars=UCNV_EXT_ARRAY(cx, UCNV_EXT_FROM_U_UCHARS_INDEX, UChar);
 576         fromUTableValues=UCNV_EXT_ARRAY(cx, UCNV_EXT_FROM_U_VALUES_INDEX, uint32_t);
 577
 578         matchValue=0;
 579         i=j=matchLength=0;
 580
 581         /* we must not remember fallback matches when not using fallbacks */
 582
 583         /* match input units until there is a full match or the input is consumed */
 584         for(;;) {
 585             /* go to the next section */
 586             fromUSectionUChars=fromUTableUChars+idx;
 587             fromUSectionValues=fromUTableValues+idx;
 588
 589             /* read first pair of the section */
 590             length=*fromUSectionUChars++;
 591             value=*fromUSectionValues++;
 592             if(value!=0 && extFromUUseMapping(useFallback, value, firstCP)) {
 593                 /* remember longest match so far */
 594                 matchValue=value;
 595                 matchLength=2+i+j;
 596             }
 597
 598             /* match pre[] then src[] */
 599             if(i<preLength) {
 600                 c=pre[i++];
 601             } else if(j<srcLength) {
 602                 c=src[j++];
 603             } else {
 604                 /* all input consumed, partial match */
 605                 if(flush || (length=(i+j))>UCNV_EXT_MAX_UCHARS) {
 606                     /*
 607                      * end of the entire input stream, stop with the longest match so far
 608                      * or: partial match must not be longer than UCNV_EXT_MAX_UCHARS
 609                      * because it must fit into state buffers
 610                      */
 611                     break;
 612                 } else {
 613                     /* continue with more input next time */
 614                     return -(2+length);
 615                 }
 616             }
 617
 618             /* search for the current UChar */
 619             idx=ucnv_extFindFromU(fromUSectionUChars, length, c);
 620             if(idx<0) {
 621                 /* no match here, stop with the longest match so far */
 622                 break;
 623             } else {
 624                 value=fromUSectionValues[idx];
 625                 if(UCNV_EXT_FROM_U_IS_PARTIAL(value)) {
 626                     /* partial match, continue */
 627                     idx=(int32_t)UCNV_EXT_FROM_U_GET_PARTIAL_INDEX(value);
 628                 } else {
 629                     if(extFromUUseMapping(useFallback, value, firstCP)) {
 630                         /* full match, stop with result */
 631                         matchValue=value;
 632                         matchLength=2+i+j;
 633                     } else {
 634                         /* full match on fallback not taken, stop with the longest match so far */
 635                     }
 636                     break;
 637                 }
 638             }
 639         }
 640
 641         if(matchLength==0) {
 642             /* no match at all */
 643             return 0;
 644         }
 645     } else /* result from firstCP trie lookup */ {
 646         if(extFromUUseMapping(useFallback, value, firstCP)) {
 647             /* full match, stop with result */
 648             matchValue=value;
 649             matchLength=2;
 650         } else {
 651             /* fallback not taken */
 652             return 0;
 653         }
 654     }
 655
 656     /* return result */
 657     if(matchValue==UCNV_EXT_FROM_U_SUBCHAR1) {
 658         return 1; /* assert matchLength==2 */
 659     }
 660
 661     *pMatchValue=matchValue;
 662     return matchLength;
 663 }
 664
 665 /*
 666  * @param value fromUnicode mapping table value; ignores roundtrip and reserved bits
 667  */
 668 static inline void
 669 ucnv_extWriteFromU(UConverter *cnv, const int32_t *cx,
 670                    uint32_t value,
 671                    char **target, const char *targetLimit,
 672                    int32_t **offsets, int32_t srcIndex,
 673                    UErrorCode *pErrorCode) {
 674     uint8_t buffer[1+UCNV_EXT_MAX_BYTES];
 675     const uint8_t *result;
 676     int32_t length, prevLength;
 677
 678     length=UCNV_EXT_FROM_U_GET_LENGTH(value);
 679     value=(uint32_t)UCNV_EXT_FROM_U_GET_DATA(value);
 680
 681     /* output the result */
 682     if(length<=UCNV_EXT_FROM_U_MAX_DIRECT_LENGTH) {
 683         /*
 684          * Generate a byte array and then write it below.
 685          * This is not the fastest possible way, but it should be ok for
 686          * extension mappings, and it is much simpler.
 687          * Offset and overflow handling are only done once this way.
 688          */
 689         uint8_t *p=buffer+1; /* reserve buffer[0] for shiftByte below */
 690         switch(length) {
 691         case 3:
 692             *p++=(uint8_t)(value>>16);
 693         case 2: /*fall through*/
 694             *p++=(uint8_t)(value>>8);
 695         case 1: /*fall through*/
 696             *p++=(uint8_t)value;
 697         default:
 698             break; /* will never occur */
 699         }
 700         result=buffer+1;
 701     } else {
 702         result=UCNV_EXT_ARRAY(cx, UCNV_EXT_FROM_U_BYTES_INDEX, uint8_t)+value;
 703     }
 704
 705     /* with correct data we have length>0 */
 706
 707     if((prevLength=cnv->fromUnicodeStatus)!=0) {
 708         /* handle SI/SO stateful output */
 709         uint8_t shiftByte;
 710
 711         if(prevLength>1 && length==1) {
 712             /* change from double-byte mode to single-byte */
 713             shiftByte=(uint8_t)UCNV_SI;
 714             cnv->fromUnicodeStatus=1;
 715         } else if(prevLength==1 && length>1) {
 716             /* change from single-byte mode to double-byte */
 717             shiftByte=(uint8_t)UCNV_SO;
 718             cnv->fromUnicodeStatus=2;
 719         } else {
 720             shiftByte=0;
 721         }
 722
 723         if(shiftByte!=0) {
 724             /* prepend the shift byte to the result bytes */
 725             buffer[0]=shiftByte;
 726             if(result!=buffer+1) {
 727                 uprv_memcpy(buffer+1, result, length);
 728             }
 729             result=buffer;
 730             ++length;
 731         }
 732     }
 733
 734     ucnv_fromUWriteBytes(cnv, (const char *)result, length,
 735                          target, targetLimit,
 736                          offsets, srcIndex,
 737                          pErrorCode);
 738 }
 739
 740 /*
 741  * target<targetLimit; set error code for overflow
 742  */
 743 U_CFUNC UBool
 744 ucnv_extInitialMatchFromU(UConverter *cnv, const int32_t *cx,
 745                           UChar32 cp,
 746                           const UChar **src, const UChar *srcLimit,
 747                           char **target, const char *targetLimit,
 748                           int32_t **offsets, int32_t srcIndex,
 749                           UBool flush,
 750                           UErrorCode *pErrorCode) {
 751     uint32_t value = 0;  /* initialize output-only param to 0 to silence gcc */
 752     int32_t match;
 753
 754     /* try to match */
 755     match=ucnv_extMatchFromU(cx, cp,
 756                              NULL, 0,
 757                              *src, (int32_t)(srcLimit-*src),
 758                              &value,
 759                              cnv->useFallback, flush);
 760
 761     /* reject a match if the result is a single byte for DBCS-only */
 762     if( match>=2 &&
 763         !(UCNV_EXT_FROM_U_GET_LENGTH(value)==1 &&
 764           cnv->sharedData->mbcs.outputType==MBCS_OUTPUT_DBCS_ONLY)
 765     ) {
 766         /* advance src pointer for the consumed input */
 767         *src+=match-2; /* remove 2 for the initial code point */
 768
 769         /* write result to target */
 770         ucnv_extWriteFromU(cnv, cx,
 771                            value,
 772                            target, targetLimit,
 773                            offsets, srcIndex,
 774                            pErrorCode);
 775         return TRUE;
 776     } else if(match<0) {
 777         /* save state for partial match */
 778         const UChar *s;
 779         int32_t j;
 780
 781         /* copy the first code point */
 782         cnv->preFromUFirstCP=cp;
 783
 784         /* now copy the newly consumed input */
 785         s=*src;
 786         match=-match-2; /* remove 2 for the initial code point */
 787         for(j=0; j<match; ++j) {
 788             cnv->preFromU[j]=*s++;
 789         }
 790         *src=s; /* same as *src=srcLimit; because we reached the end of input */
 791         cnv->preFromULength=(int8_t)match;
 792         return TRUE;
 793     } else if(match==1) {
 794         /* matched, no mapping but request for <subchar1> */
 795         cnv->useSubChar1=TRUE;
 796         return FALSE;
 797     } else /* match==0 no match */ {
 798         return FALSE;
 799     }
 800 }
 801
 802 /*
 803  * Used by ISO 2022 implementation.
 804  * @return number of bytes in *pValue; negative number if fallback; 0 for no mapping
 805  */
 806 U_CFUNC int32_t
 807 ucnv_extSimpleMatchFromU(const int32_t *cx,
 808                          UChar32 cp, uint32_t *pValue,
 809                          UBool useFallback) {
 810     uint32_t value;
 811     int32_t match;
 812
 813     /* try to match */
 814     match=ucnv_extMatchFromU(cx,
 815                              cp,
 816                              NULL, 0,
 817                              NULL, 0,
 818                              &value,
 819                              useFallback, TRUE);
 820     if(match>=2) {
 821         /* write result for simple, single-character conversion */
 822         int32_t length;
 823         int isRoundtrip;
 824
 825         isRoundtrip=UCNV_EXT_FROM_U_IS_ROUNDTRIP(value);
 826         length=UCNV_EXT_FROM_U_GET_LENGTH(value);
 827         value=(uint32_t)UCNV_EXT_FROM_U_GET_DATA(value);
 828
 829         if(length<=UCNV_EXT_FROM_U_MAX_DIRECT_LENGTH) {
 830             *pValue=value;
 831             return isRoundtrip ? length : -length;
 832 #if 0 /* not currently used */
 833         } else if(length==4) {
 834             /* de-serialize a 4-byte result */
 835             const uint8_t *result=UCNV_EXT_ARRAY(cx, UCNV_EXT_FROM_U_BYTES_INDEX, uint8_t)+value;
 836             *pValue=
 837                 ((uint32_t)result[0]<<24)|
 838                 ((uint32_t)result[1]<<16)|
 839                 ((uint32_t)result[2]<<8)|
 840                 result[3];
 841             return isRoundtrip ? 4 : -4;
 842 #endif
 843         }
 844     }
 845
 846     /*
 847      * return no match because
 848      * - match>1 && resultLength>4: result too long for simple conversion
 849      * - match==1: no match found, <subchar1> preferred
 850      * - match==0: no match found in the first place
 851      * - match<0: partial match, not supported for simple conversion (and flush==TRUE)
 852      */
 853     return 0;
 854 }
 855
 856 /*
 857  * continue partial match with new input, requires cnv->preFromUFirstCP>=0
 858  * never called for simple, single-character conversion
 859  */
 860 U_CFUNC void
 861 ucnv_extContinueMatchFromU(UConverter *cnv,
 862                            UConverterFromUnicodeArgs *pArgs, int32_t srcIndex,
 863                            UErrorCode *pErrorCode) {
 864     uint32_t value = 0;  /* initialize output-only param to 0 to silence gcc */
 865     int32_t match;
 866
 867     match=ucnv_extMatchFromU(cnv->sharedData->mbcs.extIndexes,
 868                              cnv->preFromUFirstCP,
 869                              cnv->preFromU, cnv->preFromULength,
 870                              pArgs->source, (int32_t)(pArgs->sourceLimit-pArgs->source),
 871                              &value,
 872                              cnv->useFallback, pArgs->flush);
 873     if(match>=2) {
 874         match-=2; /* remove 2 for the initial code point */
 875
 876         if(match>=cnv->preFromULength) {
 877             /* advance src pointer for the consumed input */
 878             pArgs->source+=match-cnv->preFromULength;
 879             cnv->preFromULength=0;
 880         } else {
 881             /* the match did not use all of preFromU[] - keep the rest for replay */
 882             int32_t length=cnv->preFromULength-match;
 883             uprv_memmove(cnv->preFromU, cnv->preFromU+match, length*U_SIZEOF_UCHAR);
 884             cnv->preFromULength=(int8_t)-length;
 885         }
 886
 887         /* finish the partial match */
 888         cnv->preFromUFirstCP=U_SENTINEL;
 889
 890         /* write result */
 891         ucnv_extWriteFromU(cnv, cnv->sharedData->mbcs.extIndexes,
 892                            value,
 893                            &pArgs->target, pArgs->targetLimit,
 894                            &pArgs->offsets, srcIndex,
 895                            pErrorCode);
 896     } else if(match<0) {
 897         /* save state for partial match */
 898         const UChar *s;
 899         int32_t j;
 900
 901         /* just _append_ the newly consumed input to preFromU[] */
 902         s=pArgs->source;
 903         match=-match-2; /* remove 2 for the initial code point */
 904         for(j=cnv->preFromULength; j<match; ++j) {
 905             U_ASSERT(j>=0);
 906             cnv->preFromU[j]=*s++;
 907         }
 908         pArgs->source=s; /* same as *src=srcLimit; because we reached the end of input */
 909         cnv->preFromULength=(int8_t)match;
 910     } else /* match==0 or 1 */ {
 911         /*
 912          * no match
 913          *
 914          * We need to split the previous input into two parts:
 915          *
 916          * 1. The first code point is unmappable - that's how we got into
 917          *    trying the extension data in the first place.
 918          *    We need to move it from the preFromU buffer
 919          *    to the error buffer, set an error code,
 920          *    and prepare the rest of the previous input for 2.
 921          *
 922          * 2. The rest of the previous input must be converted once we
 923          *    come back from the callback for the first code point.
 924          *    At that time, we have to try again from scratch to convert
 925          *    these input characters.
 926          *    The replay will be handled by the ucnv.c conversion code.
 927          */
 928
 929         if(match==1) {
 930             /* matched, no mapping but request for <subchar1> */
 931             cnv->useSubChar1=TRUE;
 932         }
 933
 934         /* move the first code point to the error field */
 935         cnv->fromUChar32=cnv->preFromUFirstCP;
 936         cnv->preFromUFirstCP=U_SENTINEL;
 937
 938         /* mark preFromU for replay */
 939         cnv->preFromULength=-cnv->preFromULength;
 940
 941         /* set the error code for unassigned */
 942         *pErrorCode=U_INVALID_CHAR_FOUND;
 943     }
 944 }
 945
 946 static UBool
 947 extSetUseMapping(UConverterUnicodeSet which, int32_t minLength, uint32_t value) {
 948     if(which==UCNV_ROUNDTRIP_SET) {
 949         // Add only code points for which the roundtrip flag is set.
 950         // Do not add any fallbacks, even if ucnv_fromUnicode() would use them
 951         // (fallbacks from PUA). See the API docs for ucnv_getUnicodeSet().
 952         //
 953         // By analogy, also do not add "good one-way" mappings.
 954         //
 955         // Do not add entries with reserved bits set.
 956         if(((value&(UCNV_EXT_FROM_U_ROUNDTRIP_FLAG|UCNV_EXT_FROM_U_RESERVED_MASK))!=
 957                 UCNV_EXT_FROM_U_ROUNDTRIP_FLAG)) {
 958             return FALSE;
 959         }
 960     } else /* UCNV_ROUNDTRIP_AND_FALLBACK_SET */ {
 961         // Do not add entries with reserved bits set.
 962         if((value&UCNV_EXT_FROM_U_RESERVED_MASK)!=0) {
 963             return FALSE;
 964         }
 965     }
 966     // Do not add <subchar1> entries or other (future?) pseudo-entries
 967     // with an output length of 0.
 968     return UCNV_EXT_FROM_U_GET_LENGTH(value)>=minLength;
 969 }
 970
 971 static void
 972 ucnv_extGetUnicodeSetString(const UConverterSharedData *sharedData,
 973                             const int32_t *cx,
 974                             const USetAdder *sa,
 975                             UConverterUnicodeSet which,
 976                             int32_t minLength,
 977                             UChar32 firstCP,
 978                             UChar s[UCNV_EXT_MAX_UCHARS], int32_t length,
 979                             int32_t sectionIndex,
 980                             UErrorCode *pErrorCode) {
 981     const UChar *fromUSectionUChars;
 982     const uint32_t *fromUSectionValues;
 983
 984     uint32_t value;
 985     int32_t i, count;
 986
 987     fromUSectionUChars=UCNV_EXT_ARRAY(cx, UCNV_EXT_FROM_U_UCHARS_INDEX, UChar)+sectionIndex;
 988     fromUSectionValues=UCNV_EXT_ARRAY(cx, UCNV_EXT_FROM_U_VALUES_INDEX, uint32_t)+sectionIndex;
 989
 990     /* read first pair of the section */
 991     count=*fromUSectionUChars++;
 992     value=*fromUSectionValues++;
 993
 994     if(extSetUseMapping(which, minLength, value)) {
 995         if(length==U16_LENGTH(firstCP)) {
 996             /* add the initial code point */
 997             sa->add(sa->set, firstCP);
 998         } else {
 999             /* add the string so far */
1000             sa->addString(sa->set, s, length);
1001         }
1002     }
1003
1004     for(i=0; i<count; ++i) {
1005         /* append this code unit and recurse or add the string */
1006         s[length]=fromUSectionUChars[i];
1007         value=fromUSectionValues[i];
1008
1009         if(value==0) {
1010             /* no mapping, do nothing */
1011         } else if(UCNV_EXT_FROM_U_IS_PARTIAL(value)) {
1012             ucnv_extGetUnicodeSetString(
1013                 sharedData, cx, sa, which, minLength,
1014                 firstCP, s, length+1,
1015                 (int32_t)UCNV_EXT_FROM_U_GET_PARTIAL_INDEX(value),
1016                 pErrorCode);
1017         } else if(extSetUseMapping(which, minLength, value)) {
1018             sa->addString(sa->set, s, length+1);
1019         }
1020     }
1021 }
1022
1023 U_CFUNC void
1024 ucnv_extGetUnicodeSet(const UConverterSharedData *sharedData,
1025                       const USetAdder *sa,
1026                       UConverterUnicodeSet which,
1027                       UConverterSetFilter filter,
1028                       UErrorCode *pErrorCode) {
1029     const int32_t *cx;
1030     const uint16_t *stage12, *stage3, *ps2, *ps3;
1031     const uint32_t *stage3b;
1032
1033     uint32_t value;
1034     int32_t st1, stage1Length, st2, st3, minLength;
1035
1036     UChar s[UCNV_EXT_MAX_UCHARS];
1037     UChar32 c;
1038     int32_t length;
1039
1040     cx=sharedData->mbcs.extIndexes;
1041     if(cx==NULL) {
1042         return;
1043     }
1044
1045     stage12=UCNV_EXT_ARRAY(cx, UCNV_EXT_FROM_U_STAGE_12_INDEX, uint16_t);
1046     stage3=UCNV_EXT_ARRAY(cx, UCNV_EXT_FROM_U_STAGE_3_INDEX, uint16_t);
1047     stage3b=UCNV_EXT_ARRAY(cx, UCNV_EXT_FROM_U_STAGE_3B_INDEX, uint32_t);
1048
1049     stage1Length=cx[UCNV_EXT_FROM_U_STAGE_1_LENGTH];
1050
1051     /* enumerate the from-Unicode trie table */
1052     c=0; /* keep track of the current code point while enumerating */
1053
1054     if(filter==UCNV_SET_FILTER_2022_CN) {
1055         minLength=3;
1056     } else if( sharedData->mbcs.outputType==MBCS_OUTPUT_DBCS_ONLY ||
1057                filter!=UCNV_SET_FILTER_NONE
1058     ) {
1059         /* DBCS-only, ignore single-byte results */
1060         minLength=2;
1061     } else {
1062         minLength=1;
1063     }
1064
1065     /*
1066      * the trie enumeration is almost the same as
1067      * in MBCSGetUnicodeSet() for MBCS_OUTPUT_1
1068      */
1069     for(st1=0; st1<stage1Length; ++st1) {
1070         st2=stage12[st1];
1071         if(st2>stage1Length) {
1072             ps2=stage12+st2;
1073             for(st2=0; st2<64; ++st2) {
1074                 if((st3=(int32_t)ps2[st2]<<UCNV_EXT_STAGE_2_LEFT_SHIFT)!=0) {
1075                     /* read the stage 3 block */
1076                     ps3=stage3+st3;
1077
1078                     do {
1079                         value=stage3b[*ps3++];
1080                         if(value==0) {
1081                             /* no mapping, do nothing */
1082                         } else if(UCNV_EXT_FROM_U_IS_PARTIAL(value)) {
1083                             // Recurse for partial results.
1084                             length=0;
1085                             U16_APPEND_UNSAFE(s, length, c);
1086                             ucnv_extGetUnicodeSetString(
1087                                 sharedData, cx, sa, which, minLength,
1088                                 c, s, length,
1089                                 (int32_t)UCNV_EXT_FROM_U_GET_PARTIAL_INDEX(value),
1090                                 pErrorCode);
1091                         } else if(extSetUseMapping(which, minLength, value)) {
1092                             switch(filter) {
1093                             case UCNV_SET_FILTER_2022_CN:
1094                                 if(!(UCNV_EXT_FROM_U_GET_LENGTH(value)==3 && UCNV_EXT_FROM_U_GET_DATA(value)<=0x82ffff)) {
1095                                     continue;
1096                                 }
1097                                 break;
1098                             case UCNV_SET_FILTER_SJIS:
1099                                 if(!(UCNV_EXT_FROM_U_GET_LENGTH(value)==2 && (value=UCNV_EXT_FROM_U_GET_DATA(value))>=0x8140 && value<=0xeffc)) {
1100                                     continue;
1101                                 }
1102                                 break;
1103                             case UCNV_SET_FILTER_GR94DBCS:
1104                                 if(!(UCNV_EXT_FROM_U_GET_LENGTH(value)==2 &&
1105                                      (uint16_t)((value=UCNV_EXT_FROM_U_GET_DATA(value))-0xa1a1)<=(0xfefe - 0xa1a1) &&
1106                                      (uint8_t)(value-0xa1)<=(0xfe - 0xa1))) {
1107                                     continue;
1108                                 }
1109                                 break;
1110                             case UCNV_SET_FILTER_HZ:
1111                                 if(!(UCNV_EXT_FROM_U_GET_LENGTH(value)==2 &&
1112                                      (uint16_t)((value=UCNV_EXT_FROM_U_GET_DATA(value))-0xa1a1)<=(0xfdfe - 0xa1a1) &&
1113                                      (uint8_t)(value-0xa1)<=(0xfe - 0xa1))) {
1114                                     continue;
1115                                 }
1116                                 break;
1117                             default:
1118                                 /*
1119                                  * UCNV_SET_FILTER_NONE,
1120                                  * or UCNV_SET_FILTER_DBCS_ONLY which is handled via minLength
1121                                  */
1122                                 break;
1123                             }
1124                             sa->add(sa->set, c);
1125                         }
1126                     } while((++c&0xf)!=0);
1127                 } else {
1128                     c+=16; /* empty stage 3 block */
1129                 }
1130             }
1131         } else {
1132             c+=1024; /* empty stage 2 block */
1133         }
1134     }
1135 }
1136
1137 #endif /* #if !UCONFIG_NO_LEGACY_CONVERSION */