DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Header

Mercurial (31ec81b5d7bb)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603
/*
******************************************************************************
*
*   Copyright (C) 2008-2011, International Business Machines
*   Corporation and others.  All Rights Reserved.
*
******************************************************************************
*   file name:  uspoof_conf.cpp
*   encoding:   US-ASCII
*   tab size:   8 (not used)
*   indentation:4
*
*   created on: 2009Jan05  (refactoring earlier files)
*   created by: Andy Heninger
*
*   Internal classes for compililing confusable data into its binary (runtime) form.
*/

#include "unicode/utypes.h"
#include "unicode/uspoof.h"
#if !UCONFIG_NO_REGULAR_EXPRESSIONS
#if !UCONFIG_NO_NORMALIZATION

#include "unicode/unorm.h"
#include "unicode/uregex.h"
#include "unicode/ustring.h"
#include "cmemory.h"
#include "uspoof_impl.h"
#include "uhash.h"
#include "uvector.h"
#include "uassert.h"
#include "uarrsort.h"
#include "uspoof_conf.h"

U_NAMESPACE_USE


//---------------------------------------------------------------------
//
//  buildConfusableData   Compile the source confusable data, as defined by
//                        the Unicode data file confusables.txt, into the binary
//                        structures used by the confusable detector.
//
//                        The binary structures are described in uspoof_impl.h
//
//     1.  parse the data, building 4 hash tables, one each for the SL, SA, ML and MA
//         tables.  Each maps from a UChar32 to a String.
//
//     2.  Sort all of the strings encountered by length, since they will need to
//         be stored in that order in the final string table.
//
//     3.  Build a list of keys (UChar32s) from the four mapping tables.  Sort the
//         list because that will be the ordering of our runtime table.
//
//     4.  Generate the run time string table.  This is generated before the key & value
//         tables because we need the string indexes when building those tables.
//
//     5.  Build the run-time key and value tables.  These are parallel tables, and are built
//         at the same time
//

SPUString::SPUString(UnicodeString *s) {
    fStr = s;
    fStrTableIndex = 0;
}


SPUString::~SPUString() {
    delete fStr;
}


SPUStringPool::SPUStringPool(UErrorCode &status) : fVec(NULL), fHash(NULL) {
    fVec = new UVector(status);
    fHash = uhash_open(uhash_hashUnicodeString,           // key hash function
                       uhash_compareUnicodeString,        // Key Comparator
                       NULL,                              // Value Comparator
                       &status);
}


SPUStringPool::~SPUStringPool() {
    int i;
    for (i=fVec->size()-1; i>=0; i--) {
        SPUString *s = static_cast<SPUString *>(fVec->elementAt(i));
        delete s;
    }
    delete fVec;
    uhash_close(fHash);
}


int32_t SPUStringPool::size() {
    return fVec->size();
}

SPUString *SPUStringPool::getByIndex(int32_t index) {
    SPUString *retString = (SPUString *)fVec->elementAt(index);
    return retString;
}


// Comparison function for ordering strings in the string pool.
// Compare by length first, then, within a group of the same length,
// by code point order.
// Conforms to the type signature for a USortComparator in uvector.h

static int8_t U_CALLCONV SPUStringCompare(UHashTok left, UHashTok right) {
	const SPUString *sL = const_cast<const SPUString *>(
        static_cast<SPUString *>(left.pointer));
 	const SPUString *sR = const_cast<const SPUString *>(
 	    static_cast<SPUString *>(right.pointer));
    int32_t lenL = sL->fStr->length();
    int32_t lenR = sR->fStr->length();
    if (lenL < lenR) {
        return -1;
    } else if (lenL > lenR) {
        return 1;
    } else {
        return sL->fStr->compare(*(sR->fStr));
    }
}

void SPUStringPool::sort(UErrorCode &status) {
    fVec->sort(SPUStringCompare, status);
}


SPUString *SPUStringPool::addString(UnicodeString *src, UErrorCode &status) {
    SPUString *hashedString = static_cast<SPUString *>(uhash_get(fHash, src));
    if (hashedString != NULL) {
        delete src;
    } else {
        hashedString = new SPUString(src);
        uhash_put(fHash, src, hashedString, &status);
        fVec->addElement(hashedString, status);
    }
    return hashedString;
}



ConfusabledataBuilder::ConfusabledataBuilder(SpoofImpl *spImpl, UErrorCode &status) :
    fSpoofImpl(spImpl),
    fInput(NULL),
    fSLTable(NULL),
    fSATable(NULL),
    fMLTable(NULL),
    fMATable(NULL),
    fKeySet(NULL),
    fKeyVec(NULL),
    fValueVec(NULL),
    fStringTable(NULL),
    fStringLengthsTable(NULL),
    stringPool(NULL),
    fParseLine(NULL),
    fParseHexNum(NULL),
    fLineNum(0)
{
    if (U_FAILURE(status)) {
        return;
    }
    fSLTable    = uhash_open(uhash_hashLong, uhash_compareLong, NULL, &status);
    fSATable    = uhash_open(uhash_hashLong, uhash_compareLong, NULL, &status);
    fMLTable    = uhash_open(uhash_hashLong, uhash_compareLong, NULL, &status);
    fMATable    = uhash_open(uhash_hashLong, uhash_compareLong, NULL, &status);
    fKeySet     = new UnicodeSet();
    fKeyVec     = new UVector(status);
    fValueVec   = new UVector(status);
    stringPool = new SPUStringPool(status);
}


ConfusabledataBuilder::~ConfusabledataBuilder() {
    uprv_free(fInput);
    uregex_close(fParseLine);
    uregex_close(fParseHexNum);
    uhash_close(fSLTable);
    uhash_close(fSATable);
    uhash_close(fMLTable);
    uhash_close(fMATable);
    delete fKeySet;
    delete fKeyVec;
    delete fStringTable;
    delete fStringLengthsTable;
    delete fValueVec;
    delete stringPool;
}


void ConfusabledataBuilder::buildConfusableData(SpoofImpl * spImpl, const char * confusables,
    int32_t confusablesLen, int32_t *errorType, UParseError *pe, UErrorCode &status) {

    if (U_FAILURE(status)) {
        return;
    }
    ConfusabledataBuilder builder(spImpl, status);
    builder.build(confusables, confusablesLen, status);
    if (U_FAILURE(status) && errorType != NULL) {
        *errorType = USPOOF_SINGLE_SCRIPT_CONFUSABLE;
        pe->line = builder.fLineNum;
    }
}


void ConfusabledataBuilder::build(const char * confusables, int32_t confusablesLen,
               UErrorCode &status) {

    // Convert the user input data from UTF-8 to UChar (UTF-16)
    int32_t inputLen = 0;
    if (U_FAILURE(status)) {
        return;
    }
    u_strFromUTF8(NULL, 0, &inputLen, confusables, confusablesLen, &status);
    if (status != U_BUFFER_OVERFLOW_ERROR) {
        return;
    }
    status = U_ZERO_ERROR;
    fInput = static_cast<UChar *>(uprv_malloc((inputLen+1) * sizeof(UChar)));
    if (fInput == NULL) {
        status = U_MEMORY_ALLOCATION_ERROR;
        return;
    }
    u_strFromUTF8(fInput, inputLen+1, NULL, confusables, confusablesLen, &status);


    // Regular Expression to parse a line from Confusables.txt.  The expression will match
    // any line.  What was matched is determined by examining which capture groups have a match.
    //   Capture Group 1:  the source char
    //   Capture Group 2:  the replacement chars
    //   Capture Group 3-6  the table type, SL, SA, ML, or MA
    //   Capture Group 7:  A blank or comment only line.
    //   Capture Group 8:  A syntactically invalid line.  Anything that didn't match before.
    // Example Line from the confusables.txt source file:
    //   "1D702 ;	006E 0329 ;	SL	# MATHEMATICAL ITALIC SMALL ETA ... "
    UnicodeString pattern(
        "(?m)^[ \\t]*([0-9A-Fa-f]+)[ \\t]+;"      // Match the source char
        "[ \\t]*([0-9A-Fa-f]+"                    // Match the replacement char(s)
           "(?:[ \\t]+[0-9A-Fa-f]+)*)[ \\t]*;"    //     (continued)
        "\\s*(?:(SL)|(SA)|(ML)|(MA))"             // Match the table type
        "[ \\t]*(?:#.*?)?$"                       // Match any trailing #comment
        "|^([ \\t]*(?:#.*?)?)$"       // OR match empty lines or lines with only a #comment
        "|^(.*?)$", -1, US_INV);      // OR match any line, which catches illegal lines.
    // TODO: Why are we using the regex C API here? C++ would just take UnicodeString...
    fParseLine = uregex_open(pattern.getBuffer(), pattern.length(), 0, NULL, &status);

    // Regular expression for parsing a hex number out of a space-separated list of them.
    //   Capture group 1 gets the number, with spaces removed.
    pattern = UNICODE_STRING_SIMPLE("\\s*([0-9A-F]+)");
    fParseHexNum = uregex_open(pattern.getBuffer(), pattern.length(), 0, NULL, &status);

    // Zap any Byte Order Mark at the start of input.  Changing it to a space is benign
    //   given the syntax of the input.
    if (*fInput == 0xfeff) {
        *fInput = 0x20;
    }

    // Parse the input, one line per iteration of this loop.
    uregex_setText(fParseLine, fInput, inputLen, &status);
    while (uregex_findNext(fParseLine, &status)) {
        fLineNum++;
        if (uregex_start(fParseLine, 7, &status) >= 0) {
            // this was a blank or comment line.
            continue;
        }
        if (uregex_start(fParseLine, 8, &status) >= 0) {
            // input file syntax error.
            status = U_PARSE_ERROR;
            return;
        }

        // We have a good input line.  Extract the key character and mapping string, and
        //    put them into the appropriate mapping table.
        UChar32 keyChar = SpoofImpl::ScanHex(fInput, uregex_start(fParseLine, 1, &status),
                          uregex_end(fParseLine, 1, &status), status);

        int32_t mapStringStart = uregex_start(fParseLine, 2, &status);
        int32_t mapStringLength = uregex_end(fParseLine, 2, &status) - mapStringStart;
        uregex_setText(fParseHexNum, &fInput[mapStringStart], mapStringLength, &status);

        UnicodeString  *mapString = new UnicodeString();
        if (mapString == NULL) {
            status = U_MEMORY_ALLOCATION_ERROR;
            return;
        }
        while (uregex_findNext(fParseHexNum, &status)) {
            UChar32 c = SpoofImpl::ScanHex(&fInput[mapStringStart], uregex_start(fParseHexNum, 1, &status),
                                 uregex_end(fParseHexNum, 1, &status), status);
            mapString->append(c);
        }
        U_ASSERT(mapString->length() >= 1);

        // Put the map (value) string into the string pool
        // This a little like a Java intern() - any duplicates will be eliminated.
        SPUString *smapString = stringPool->addString(mapString, status);

        // Add the UChar32 -> string mapping to the appropriate table.
        UHashtable *table = uregex_start(fParseLine, 3, &status) >= 0 ? fSLTable :
                            uregex_start(fParseLine, 4, &status) >= 0 ? fSATable :
                            uregex_start(fParseLine, 5, &status) >= 0 ? fMLTable :
                            uregex_start(fParseLine, 6, &status) >= 0 ? fMATable :
                            NULL;
        U_ASSERT(table != NULL);
        uhash_iput(table, keyChar, smapString, &status);
        fKeySet->add(keyChar);
        if (U_FAILURE(status)) {
            return;
        }
    }

    // Input data is now all parsed and collected.
    // Now create the run-time binary form of the data.
    //
    // This is done in two steps.  First the data is assembled into vectors and strings,
    //   for ease of construction, then the contents of these collections are dumped
    //   into the actual raw-bytes data storage.

    // Build up the string array, and record the index of each string therein
    //  in the (build time only) string pool.
    // Strings of length one are not entered into the strings array.
    // At the same time, build up the string lengths table, which records the
    // position in the string table of the first string of each length >= 4.
    // (Strings in the table are sorted by length)
    stringPool->sort(status);
    fStringTable = new UnicodeString();
    fStringLengthsTable = new UVector(status);
    int32_t previousStringLength = 0;
    int32_t previousStringIndex  = 0;
    int32_t poolSize = stringPool->size();
    int32_t i;
    for (i=0; i<poolSize; i++) {
        SPUString *s = stringPool->getByIndex(i);
        int32_t strLen = s->fStr->length();
        int32_t strIndex = fStringTable->length();
        U_ASSERT(strLen >= previousStringLength);
        if (strLen == 1) {
            // strings of length one do not get an entry in the string table.
            // Keep the single string character itself here, which is the same
            //  convention that is used in the final run-time string table index.
            s->fStrTableIndex = s->fStr->charAt(0);
        } else {
            if ((strLen > previousStringLength) && (previousStringLength >= 4)) {
                fStringLengthsTable->addElement(previousStringIndex, status);
                fStringLengthsTable->addElement(previousStringLength, status);
            }
            s->fStrTableIndex = strIndex;
            fStringTable->append(*(s->fStr));
        }
        previousStringLength = strLen;
        previousStringIndex  = strIndex;
    }
    // Make the final entry to the string lengths table.
    //   (it holds an entry for the _last_ string of each length, so adding the
    //    final one doesn't happen in the main loop because no longer string was encountered.)
    if (previousStringLength >= 4) {
        fStringLengthsTable->addElement(previousStringIndex, status);
        fStringLengthsTable->addElement(previousStringLength, status);
    }

    // Construct the compile-time Key and Value tables
    //
    // For each key code point, check which mapping tables it applies to,
    //   and create the final data for the key & value structures.
    //
    //   The four logical mapping tables are conflated into one combined table.
    //   If multiple logical tables have the same mapping for some key, they
    //     share a single entry in the combined table.
    //   If more than one mapping exists for the same key code point, multiple
    //     entries will be created in the table

    for (int32_t range=0; range<fKeySet->getRangeCount(); range++) {
        // It is an oddity of the UnicodeSet API that simply enumerating the contained
        //   code points requires a nested loop.
        for (UChar32 keyChar=fKeySet->getRangeStart(range);
                keyChar <= fKeySet->getRangeEnd(range); keyChar++) {
            addKeyEntry(keyChar, fSLTable, USPOOF_SL_TABLE_FLAG, status);
            addKeyEntry(keyChar, fSATable, USPOOF_SA_TABLE_FLAG, status);
            addKeyEntry(keyChar, fMLTable, USPOOF_ML_TABLE_FLAG, status);
            addKeyEntry(keyChar, fMATable, USPOOF_MA_TABLE_FLAG, status);
        }
    }

    // Put the assembled data into the flat runtime array
    outputData(status);

    // All of the intermediate allocated data belongs to the ConfusabledataBuilder
    //  object  (this), and is deleted in the destructor.
    return;
}

//
// outputData     The confusable data has been compiled and stored in intermediate
//                collections and strings.  Copy it from there to the final flat
//                binary array.
//
//                Note that as each section is added to the output data, the
//                expand (reserveSpace() function will likely relocate it in memory.
//                Be careful with pointers.
//
void ConfusabledataBuilder::outputData(UErrorCode &status) {

    U_ASSERT(fSpoofImpl->fSpoofData->fDataOwned == TRUE);

    //  The Key Table
    //     While copying the keys to the runtime array,
    //       also sanity check that they are sorted.

    int32_t numKeys = fKeyVec->size();
    int32_t *keys =
        static_cast<int32_t *>(fSpoofImpl->fSpoofData->reserveSpace(numKeys*sizeof(int32_t), status));
    if (U_FAILURE(status)) {
        return;
    }
    int i;
    int32_t previousKey = 0;
    for (i=0; i<numKeys; i++) {
        int32_t key =  fKeyVec->elementAti(i);
        U_ASSERT((key & 0x00ffffff) >= (previousKey & 0x00ffffff));
        U_ASSERT((key & 0xff000000) != 0);
        keys[i] = key;
        previousKey = key;
    }
    SpoofDataHeader *rawData = fSpoofImpl->fSpoofData->fRawData;
    rawData->fCFUKeys = (int32_t)((char *)keys - (char *)rawData);
    rawData->fCFUKeysSize = numKeys;
    fSpoofImpl->fSpoofData->fCFUKeys = keys;


    // The Value Table, parallels the key table
    int32_t numValues = fValueVec->size();
    U_ASSERT(numKeys == numValues);
    uint16_t *values =
        static_cast<uint16_t *>(fSpoofImpl->fSpoofData->reserveSpace(numKeys*sizeof(uint16_t), status));
    if (U_FAILURE(status)) {
        return;
    }
    for (i=0; i<numValues; i++) {
        uint32_t value = static_cast<uint32_t>(fValueVec->elementAti(i));
        U_ASSERT(value < 0xffff);
        values[i] = static_cast<uint16_t>(value);
    }
    rawData = fSpoofImpl->fSpoofData->fRawData;
    rawData->fCFUStringIndex = (int32_t)((char *)values - (char *)rawData);
    rawData->fCFUStringIndexSize = numValues;
    fSpoofImpl->fSpoofData->fCFUValues = values;

    // The Strings Table.

    uint32_t stringsLength = fStringTable->length();
    // Reserve an extra space so the string will be nul-terminated.  This is
    // only a convenience, for when debugging; it is not needed otherwise.
    UChar *strings =
        static_cast<UChar *>(fSpoofImpl->fSpoofData->reserveSpace(stringsLength*sizeof(UChar)+2, status));
    if (U_FAILURE(status)) {
        return;
    }
    fStringTable->extract(strings, stringsLength+1, status);
    rawData = fSpoofImpl->fSpoofData->fRawData;
    U_ASSERT(rawData->fCFUStringTable == 0);
    rawData->fCFUStringTable = (int32_t)((char *)strings - (char *)rawData);
    rawData->fCFUStringTableLen = stringsLength;
    fSpoofImpl->fSpoofData->fCFUStrings = strings;

    // The String Lengths Table
    //    While copying into the runtime array do some sanity checks on the values
    //    Each complete entry contains two fields, an index and an offset.
    //    Lengths should increase with each entry.
    //    Offsets should be less than the size of the string table.
    int32_t lengthTableLength = fStringLengthsTable->size();
    uint16_t *stringLengths =
        static_cast<uint16_t *>(fSpoofImpl->fSpoofData->reserveSpace(lengthTableLength*sizeof(uint16_t), status));
    if (U_FAILURE(status)) {
        return;
    }
    int32_t destIndex = 0;
    uint32_t previousLength = 0;
    for (i=0; i<lengthTableLength; i+=2) {
        uint32_t offset = static_cast<uint32_t>(fStringLengthsTable->elementAti(i));
        uint32_t length = static_cast<uint32_t>(fStringLengthsTable->elementAti(i+1));
        U_ASSERT(offset < stringsLength);
        U_ASSERT(length < 40);
        U_ASSERT(length > previousLength);
        stringLengths[destIndex++] = static_cast<uint16_t>(offset);
        stringLengths[destIndex++] = static_cast<uint16_t>(length);
        previousLength = length;
    }
    rawData = fSpoofImpl->fSpoofData->fRawData;
    rawData->fCFUStringLengths = (int32_t)((char *)stringLengths - (char *)rawData);
    // Note: StringLengthsSize in the raw data is the number of complete entries,
    //       each consisting of a pair of 16 bit values, hence the divide by 2.
    rawData->fCFUStringLengthsSize = lengthTableLength / 2;
    fSpoofImpl->fSpoofData->fCFUStringLengths =
        reinterpret_cast<SpoofStringLengthsElement *>(stringLengths);
}



//  addKeyEntry   Construction of the confusable Key and Mapping Values tables.
//                This is an intermediate point in the building process.
//                We already have the mappings in the hash tables fSLTable, etc.
//                This function builds corresponding run-time style table entries into
//                  fKeyVec and fValueVec

void ConfusabledataBuilder::addKeyEntry(
    UChar32     keyChar,     // The key character
    UHashtable *table,       // The table, one of SATable, MATable, etc.
    int32_t     tableFlag,   // One of USPOOF_SA_TABLE_FLAG, etc.
    UErrorCode &status) {

    SPUString *targetMapping = static_cast<SPUString *>(uhash_iget(table, keyChar));
    if (targetMapping == NULL) {
        // No mapping for this key character.
        //   (This function is called for all four tables for each key char that
        //    is seen anywhere, so this no entry cases are very much expected.)
        return;
    }

    // Check whether there is already an entry with the correct mapping.
    // If so, simply set the flag in the keyTable saying that the existing entry
    // applies to the table that we're doing now.

    UBool keyHasMultipleValues = FALSE;
    int32_t i;
    for (i=fKeyVec->size()-1; i>=0 ; i--) {
        int32_t key = fKeyVec->elementAti(i);
        if ((key & 0x0ffffff) != keyChar) {
            // We have now checked all existing key entries for this key char (if any)
            //  without finding one with the same mapping.
            break;
        }
        UnicodeString mapping = getMapping(i);
        if (mapping == *(targetMapping->fStr)) {
            // The run time entry we are currently testing has the correct mapping.
            // Set the flag in it indicating that it applies to the new table also.
            key |= tableFlag;
            fKeyVec->setElementAt(key, i);
            return;
        }
        keyHasMultipleValues = TRUE;
    }

    // Need to add a new entry to the binary data being built for this mapping.
    // Includes adding entries to both the key table and the parallel values table.

    int32_t newKey = keyChar | tableFlag;
    if (keyHasMultipleValues) {
        newKey |= USPOOF_KEY_MULTIPLE_VALUES;
    }
    int32_t adjustedMappingLength = targetMapping->fStr->length() - 1;
    if (adjustedMappingLength>3) {
        adjustedMappingLength = 3;
    }
    newKey |= adjustedMappingLength << USPOOF_KEY_LENGTH_SHIFT;

    int32_t newData = targetMapping->fStrTableIndex;

    fKeyVec->addElement(newKey, status);
    fValueVec->addElement(newData, status);

    // If the preceding key entry is for the same key character (but with a different mapping)
    //   set the multiple-values flag on it.
    if (keyHasMultipleValues) {
        int32_t previousKeyIndex = fKeyVec->size() - 2;
        int32_t previousKey = fKeyVec->elementAti(previousKeyIndex);
        previousKey |= USPOOF_KEY_MULTIPLE_VALUES;
        fKeyVec->setElementAt(previousKey, previousKeyIndex);
    }
}



UnicodeString ConfusabledataBuilder::getMapping(int32_t index) {
    int32_t key = fKeyVec->elementAti(index);
    int32_t value = fValueVec->elementAti(index);
    int32_t length = USPOOF_KEY_LENGTH_FIELD(key);
    int32_t lastIndexWithLen;
    switch (length) {
      case 0:
        return UnicodeString(static_cast<UChar>(value));
      case 1:
      case 2:
        return UnicodeString(*fStringTable, value, length+1);
      case 3:
        length = 0;
        int32_t i;
        for (i=0; i<fStringLengthsTable->size(); i+=2) {
            lastIndexWithLen = fStringLengthsTable->elementAti(i);
            if (value <= lastIndexWithLen) {
                length = fStringLengthsTable->elementAti(i+1);
                break;
            }
        }
        U_ASSERT(length>=3);
        return UnicodeString(*fStringTable, value, length);
      default:
        U_ASSERT(FALSE);
    }
    return UnicodeString();
}

#endif
#endif // !UCONFIG_NO_REGULAR_EXPRESSIONS