The Tor Browser: intl/icu/source/common/ucnvmbcs.c@129ffea94266 (annotated)

intl/icu/source/common/ucnvmbcs.c@129ffea94266 (annotated)

intl/icu/source/common/ucnvmbcs.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.

 /*
 ******************************************************************************
 *
 *   Copyright (C) 2000-2013, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 ******************************************************************************
 *   file name:  ucnvmbcs.c
 *   encoding:   US-ASCII
 *   tab size:   8 (not used)
 *   indentation:4
 *
 *   created on: 2000jul03
 *   created by: Markus W. Scherer
 *
 *   The current code in this file replaces the previous implementation
 *   of conversion code from multi-byte codepages to Unicode and back.
 *   This implementation supports the following:
 *   - legacy variable-length codepages with up to 4 bytes per character
 *   - all Unicode code points (up to 0x10ffff)
 *   - efficient distinction of unassigned vs. illegal byte sequences
 *   - it is possible in fromUnicode() to directly deal with simple
 *     stateful encodings (used for EBCDIC_STATEFUL)
 *   - it is possible to convert Unicode code points
 *     to a single zero byte (but not as a fallback except for SBCS)
 *
 *   Remaining limitations in fromUnicode:
 *   - byte sequences must not have leading zero bytes
 *   - except for SBCS codepages: no fallback mapping from Unicode to a zero byte
 *   - limitation to up to 4 bytes per character
 *
 *   ICU 2.8 (late 2003) adds a secondary data structure which lifts some of these
 *   limitations and adds m:n character mappings and other features.
 *   See ucnv_ext.h for details.
 *
 *   Change history:
 *
 *    5/6/2001       Ram       Moved  MBCS_SINGLE_RESULT_FROM_U,MBCS_STAGE_2_FROM_U,
 *                             MBCS_VALUE_2_FROM_STAGE_2, MBCS_VALUE_4_FROM_STAGE_2
 *                             macros to ucnvmbcs.h file
 */
 #include "unicode/utypes.h"
 #if !UCONFIG_NO_CONVERSION && !UCONFIG_NO_LEGACY_CONVERSION
 #include "unicode/ucnv.h"
 #include "unicode/ucnv_cb.h"
 #include "unicode/udata.h"
 #include "unicode/uset.h"
 #include "unicode/utf8.h"
 #include "unicode/utf16.h"
 #include "ucnv_bld.h"
 #include "ucnvmbcs.h"
 #include "ucnv_ext.h"
 #include "ucnv_cnv.h"
 #include "cmemory.h"
 #include "cstring.h"
 #include "cmutex.h"
 /* control optimizations according to the platform */
 #define MBCS_UNROLL_SINGLE_TO_BMP 1
 #define MBCS_UNROLL_SINGLE_FROM_BMP 0
 /*
  * _MBCSHeader versions 5.3 & 4.3
  * (Note that the _MBCSHeader version is in addition to the converter formatVersion.)
  *
  * This version is optional. Version 5 is used for incompatible data format changes.
  * makeconv will continue to generate version 4 files if possible.
  *
  * Changes from version 4:
  *
  * The main difference is an additional _MBCSHeader field with
  * - the length (number of uint32_t) of the _MBCSHeader
  * - flags for further incompatible data format changes
  * - flags for further, backward compatible data format changes
  *
  * The MBCS_OPT_FROM_U flag indicates that most of the fromUnicode data is omitted from
  * the file and needs to be reconstituted at load time.
  * This requires a utf8Friendly format with an additional mbcsIndex table for fast
  * (and UTF-8-friendly) fromUnicode conversion for Unicode code points up to maxFastUChar.
  * (For details about these structures see below, and see ucnvmbcs.h.)
  *
  *   utf8Friendly also implies that the fromUnicode mappings are stored in ascending order
  *   of the Unicode code points. (This requires that the .ucm file has the |0 etc.
  *   precision markers for all mappings.)
  *
  *   All fallbacks have been moved to the extension table, leaving only roundtrips in the
  *   omitted data that can be reconstituted from the toUnicode data.
  *
  *   Of the stage 2 table, the part corresponding to maxFastUChar and below is omitted.
  *   With only roundtrip mappings in the base fromUnicode data, this part is fully
  *   redundant with the mbcsIndex and will be reconstituted from that (also using the
  *   stage 1 table which contains the information about how stage 2 was compacted).
  *
  *   The rest of the stage 2 table, the part for code points above maxFastUChar,
  *   is stored in the file and will be appended to the reconstituted part.
  *
  *   The entire fromUBytes array is omitted from the file and will be reconstitued.
  *   This is done by enumerating all toUnicode roundtrip mappings, performing
  *   each mapping (using the stage 1 and reconstituted stage 2 tables) and
  *   writing instead of reading the byte values.
  *
  * _MBCSHeader version 4.3
  *
  * Change from version 4.2:
  * - Optional utf8Friendly data structures, with 64-entry stage 3 block
  *   allocation for parts of the BMP, and an additional mbcsIndex in non-SBCS
  *   files which can be used instead of stages 1 & 2.
  *   Faster lookups for roundtrips from most commonly used characters,
  *   and lookups from UTF-8 byte sequences with a natural bit distribution.
  *   See ucnvmbcs.h for more details.
  *
  * Change from version 4.1:
  * - Added an optional extension table structure at the end of the .cnv file.
  *   It is present if the upper bits of the header flags field contains a non-zero
  *   byte offset to it.
  *   Files that contain only a conversion table and no base table
  *   use the special outputType MBCS_OUTPUT_EXT_ONLY.
  *   These contain the base table name between the MBCS header and the extension
  *   data.
  *
  * Change from version 4.0:
  * - Replace header.reserved with header.fromUBytesLength so that all
  *   fields in the data have length.
  *
  * Changes from version 3 (for performance improvements):
  * - new bit distribution for state table entries
  * - reordered action codes
  * - new data structure for single-byte fromUnicode
  *   + stage 2 only contains indexes
  *   + stage 3 stores 16 bits per character with classification bits 15..8
  * - no multiplier for stage 1 entries
  * - stage 2 for non-single-byte codepages contains the index and the flags in
  *   one 32-bit value
  * - 2-byte and 4-byte fromUnicode results are stored directly as 16/32-bit integers
  *
  * For more details about old versions of the MBCS data structure, see
  * the corresponding versions of this file.
  *
  * Converting stateless codepage data ---------------------------------------***
  * (or codepage data with simple states) to Unicode.
  *
  * Data structure and algorithm for converting from complex legacy codepages
  * to Unicode. (Designed before 2000-may-22.)
  *
  * The basic idea is that the structure of legacy codepages can be described
  * with state tables.
  * When reading a byte stream, each input byte causes a state transition.
  * Some transitions result in the output of a code point, some result in
  * "unassigned" or "illegal" output.
  * This is used here for character conversion.
  *
  * The data structure begins with a state table consisting of a row
  * per state, with 256 entries (columns) per row for each possible input
  * byte value.
  * Each entry is 32 bits wide, with two formats distinguished by
  * the sign bit (bit 31):
  *
  * One format for transitional entries (bit 31 not set) for non-final bytes, and
  * one format for final entries (bit 31 set).
  * Both formats contain the number of the next state in the same bit
  * positions.
  * State 0 is the initial state.
  *
  * Most of the time, the offset values of subsequent states are added
  * up to a scalar value. This value will eventually be the index of
  * the Unicode code point in a table that follows the state table.
  * The effect is that the code points for final state table rows
  * are contiguous. The code points of final state rows follow each other
  * in the order of the references to those final states by previous
  * states, etc.
  *
  * For some terminal states, the offset is itself the output Unicode
  * code point (16 bits for a BMP code point or 20 bits for a supplementary
  * code point (stored as code point minus 0x10000 so that 20 bits are enough).
  * For others, the code point in the Unicode table is stored with either
  * one or two code units: one for BMP code points, two for a pair of
  * surrogates.
  * All code points for a final state entry take up the same number of code
  * units, regardless of whether they all actually _use_ the same number
  * of code units. This is necessary for simple array access.
  *
  * An additional feature comes in with what in ICU is called "fallback"
  * mappings:
  *
  * In addition to round-trippable, precise, 1:1 mappings, there are often
  * mappings defined between similar, though not the same, characters.
  * Typically, such mappings occur only in fromUnicode mapping tables because
  * Unicode has a superset repertoire of most other codepages. However, it
  * is possible to provide such mappings in the toUnicode tables, too.
  * In this case, the fallback mappings are partly integrated into the
  * general state tables because the structure of the encoding includes their
  * byte sequences.
  * For final entries in an initial state, fallback mappings are stored in
  * the entry itself like with roundtrip mappings.
  * For other final entries, they are stored in the code units table if
  * the entry is for a pair of code units.
  * For single-unit results in the code units table, there is no space to
  * alternatively hold a fallback mapping; in this case, the code unit
  * is stored as U+fffe (unassigned), and the fallback mapping needs to
  * be looked up by the scalar offset value in a separate table.
  *
  * "Unassigned" state entries really mean "structurally unassigned",
  * i.e., such a byte sequence will never have a mapping result.
  *
  * The interpretation of the bits in each entry is as follows:
  *
  * Bit 31 not set, not a terminal entry ("transitional"):
  * 30..24 next state
  * 23..0  offset delta, to be added up
  *
  * Bit 31 set, terminal ("final") entry:
  * 30..24 next state (regardless of action code)
  * 23..20 action code:
  *        action codes 0 and 1 result in precise-mapping Unicode code points
  *        0  valid byte sequence
  *           19..16 not used, 0
  *           15..0  16-bit Unicode BMP code point
  *                  never U+fffe or U+ffff
  *        1  valid byte sequence
  *           19..0  20-bit Unicode supplementary code point
  *                  never U+fffe or U+ffff
  *
  *        action codes 2 and 3 result in fallback (unidirectional-mapping) Unicode code points
  *        2  valid byte sequence (fallback)
  *           19..16 not used, 0
  *           15..0  16-bit Unicode BMP code point as fallback result
  *        3  valid byte sequence (fallback)
  *           19..0  20-bit Unicode supplementary code point as fallback result
  *
  *        action codes 4 and 5 may result in roundtrip/fallback/unassigned/illegal results
  *        depending on the code units they result in
  *        4  valid byte sequence
  *           19..9  not used, 0
  *            8..0  final offset delta
  *                  pointing to one 16-bit code unit which may be
  *                  fffe  unassigned -- look for a fallback for this offset
  *                  ffff  illegal
  *        5  valid byte sequence
  *           19..9  not used, 0
  *            8..0  final offset delta
  *                  pointing to two 16-bit code units
  *                  (typically UTF-16 surrogates)
  *                  the result depends on the first code unit as follows:
  *                  0000..d7ff  roundtrip BMP code point (1st alone)
  *                  d800..dbff  roundtrip surrogate pair (1st, 2nd)
  *                  dc00..dfff  fallback surrogate pair (1st-400, 2nd)
  *                  e000        roundtrip BMP code point (2nd alone)
  *                  e001        fallback BMP code point (2nd alone)
  *                  fffe        unassigned
  *                  ffff        illegal
  *           (the final offset deltas are at most 255 * 2,
  *            times 2 because of storing code unit pairs)
  *
  *        6  unassigned byte sequence
  *           19..16 not used, 0
  *           15..0  16-bit Unicode BMP code point U+fffe (new with version 2)
  *                  this does not contain a final offset delta because the main
  *                  purpose of this action code is to save scalar offset values;
  *                  therefore, fallback values cannot be assigned to byte
  *                  sequences that result in this action code
  *        7  illegal byte sequence
  *           19..16 not used, 0
  *           15..0  16-bit Unicode BMP code point U+ffff (new with version 2)
  *        8  state change only
  *           19..0  not used, 0
  *           useful for state changes in simple stateful encodings,
  *           at Shift-In/Shift-Out codes
  *
  *
  *        9..15 reserved for future use
  *           current implementations will only perform a state change
  *           and ignore bits 19..0
  *
  * An encoding with contiguous ranges of unassigned byte sequences, like
  * Shift-JIS and especially EUC-TW, can be stored efficiently by having
  * at least two states for the trail bytes:
  * One trail byte state that results in code points, and one that only
  * has "unassigned" and "illegal" terminal states.
  *
  * Note: partly by accident, this data structure supports simple stateful
  * encodings without any additional logic.
  * Currently, only simple Shift-In/Shift-Out schemes are handled with
  * appropriate state tables (especially EBCDIC_STATEFUL!).
  *
  * MBCS version 2 added:
  * unassigned and illegal action codes have U+fffe and U+ffff
  * instead of unused bits; this is useful for _MBCS_SINGLE_SIMPLE_GET_NEXT_BMP()
  *
  * Converting from Unicode to codepage bytes --------------------------------***
  *
  * The conversion data structure for fromUnicode is designed for the known
  * structure of Unicode. It maps from 21-bit code points (0..0x10ffff) to
  * a sequence of 1..4 bytes, in addition to a flag that indicates if there is
  * a roundtrip mapping.
  *
  * The lookup is done with a 3-stage trie, using 11/6/4 bits for stage 1/2/3
  * like in the character properties table.
  * The beginning of the trie is at offsetFromUTable, the beginning of stage 3
  * with the resulting bytes is at offsetFromUBytes.
  *
  * Beginning with version 4, single-byte codepages have a significantly different
  * trie compared to other codepages.
  * In all cases, the entry in stage 1 is directly the index of the block of
  * 64 entries in stage 2.
  *
  * Single-byte lookup:
  *
  * Stage 2 only contains 16-bit indexes directly to the 16-blocks in stage 3.
  * Stage 3 contains one 16-bit word per result:
  * Bits 15..8 indicate the kind of result:
  *    f  roundtrip result
  *    c  fallback result from private-use code point
  *    8  fallback result from other code points
  *    0  unassigned
  * Bits 7..0 contain the codepage byte. A zero byte is always possible.
  *
  * In version 4.3, the runtime code can build an sbcsIndex for a utf8Friendly
  * file. For 2-byte UTF-8 byte sequences and some 3-byte sequences the lookup
  * becomes a 2-stage (single-index) trie lookup with 6 bits for stage 3.
  * ASCII code points can be looked up with a linear array access into stage 3.
  * See maxFastUChar and other details in ucnvmbcs.h.
  *
  * Multi-byte lookup:
  *
  * Stage 2 contains a 32-bit word for each 16-block in stage 3:
  * Bits 31..16 contain flags for which stage 3 entries contain roundtrip results
  *             test: MBCS_FROM_U_IS_ROUNDTRIP(stage2Entry, c)
  *             If this test is false, then a non-zero result will be interpreted as
  *             a fallback mapping.
  * Bits 15..0  contain the index to stage 3, which must be multiplied by 16*(bytes per char)
  *
  * Stage 3 contains 2, 3, or 4 bytes per result.
  * 2 or 4 bytes are stored as uint16_t/uint32_t in platform endianness,
  * while 3 bytes are stored as bytes in big-endian order.
  * Leading zero bytes are ignored, and the number of bytes is counted.
  * A zero byte mapping result is possible as a roundtrip result.
  * For some output types, the actual result is processed from this;
  * see ucnv_MBCSFromUnicodeWithOffsets().
  *
  * Note that stage 1 always contains 0x440=1088 entries (0x440==0x110000>>10),
  * or (version 3 and up) for BMP-only codepages, it contains 64 entries.
  *
  * In version 4.3, a utf8Friendly file contains an mbcsIndex table.
  * For 2-byte UTF-8 byte sequences and most 3-byte sequences the lookup
  * becomes a 2-stage (single-index) trie lookup with 6 bits for stage 3.
  * ASCII code points can be looked up with a linear array access into stage 3.
  * See maxFastUChar, mbcsIndex and other details in ucnvmbcs.h.
  *
  * In version 3, stage 2 blocks may overlap by multiples of the multiplier
  * for compaction.
  * In version 4, stage 2 blocks (and for single-byte codepages, stage 3 blocks)
  * may overlap by any number of entries.
  *
  * MBCS version 2 added:
  * the converter checks for known output types, which allows
  * adding new ones without crashing an unaware converter
  */
 static const UConverterImpl _SBCSUTF8Impl;
 static const UConverterImpl _DBCSUTF8Impl;
 /* GB 18030 data ------------------------------------------------------------ */
 /* helper macros for linear values for GB 18030 four-byte sequences */
 #define LINEAR_18030(a, b, c, d) ((((a)*10+(b))*126L+(c))*10L+(d))
 #define LINEAR_18030_BASE LINEAR_18030(0x81, 0x30, 0x81, 0x30)
 #define LINEAR(x) LINEAR_18030(x>>24, (x>>16)&0xff, (x>>8)&0xff, x&0xff)
 /*
  * Some ranges of GB 18030 where both the Unicode code points and the
  * GB four-byte sequences are contiguous and are handled algorithmically by
  * the special callback functions below.
  * The values are start & end of Unicode & GB codes.
  *
  * Note that single surrogates are not mapped by GB 18030
  * as of the re-released mapping tables from 2000-nov-30.
  */
 static const uint32_t
 gb18030Ranges[14][4]={
     {0x10000, 0x10FFFF, LINEAR(0x90308130), LINEAR(0xE3329A35)},
     {0x9FA6, 0xD7FF, LINEAR(0x82358F33), LINEAR(0x8336C738)},
     {0x0452, 0x1E3E, LINEAR(0x8130D330), LINEAR(0x8135F436)},
     {0x1E40, 0x200F, LINEAR(0x8135F438), LINEAR(0x8136A531)},
     {0xE865, 0xF92B, LINEAR(0x8336D030), LINEAR(0x84308534)},
     {0x2643, 0x2E80, LINEAR(0x8137A839), LINEAR(0x8138FD38)},
     {0xFA2A, 0xFE2F, LINEAR(0x84309C38), LINEAR(0x84318537)},
     {0x3CE1, 0x4055, LINEAR(0x8231D438), LINEAR(0x8232AF32)},
     {0x361B, 0x3917, LINEAR(0x8230A633), LINEAR(0x8230F237)},
     {0x49B8, 0x4C76, LINEAR(0x8234A131), LINEAR(0x8234E733)},
     {0x4160, 0x4336, LINEAR(0x8232C937), LINEAR(0x8232F837)},
     {0x478E, 0x4946, LINEAR(0x8233E838), LINEAR(0x82349638)},
     {0x44D7, 0x464B, LINEAR(0x8233A339), LINEAR(0x8233C931)},
     {0xFFE6, 0xFFFF, LINEAR(0x8431A234), LINEAR(0x8431A439)}
 };
 /* bit flag for UConverter.options indicating GB 18030 special handling */
 #define _MBCS_OPTION_GB18030 0x8000
 /* bit flag for UConverter.options indicating KEIS,JEF,JIF special handling */
 #define _MBCS_OPTION_KEIS 0x01000
 #define _MBCS_OPTION_JEF  0x02000
 #define _MBCS_OPTION_JIPS 0x04000
 #define KEIS_SO_CHAR_1 0x0A
 #define KEIS_SO_CHAR_2 0x42
 #define KEIS_SI_CHAR_1 0x0A
 #define KEIS_SI_CHAR_2 0x41
 #define JEF_SO_CHAR 0x28
 #define JEF_SI_CHAR 0x29
 #define JIPS_SO_CHAR_1 0x1A
 #define JIPS_SO_CHAR_2 0x70
 #define JIPS_SI_CHAR_1 0x1A
 #define JIPS_SI_CHAR_2 0x71
 enum SISO_Option {
     SI,
     SO
 };
 typedef enum SISO_Option SISO_Option;
 static int32_t getSISOBytes(SISO_Option option, uint32_t cnvOption, uint8_t *value) {
     int32_t SISOLength = 0;
     switch (option) {
         case SI:
             if ((cnvOption&_MBCS_OPTION_KEIS)!=0) {
                 value[0] = KEIS_SI_CHAR_1;
                 value[1] = KEIS_SI_CHAR_2;
                 SISOLength = 2;
             } else if ((cnvOption&_MBCS_OPTION_JEF)!=0) {
                 value[0] = JEF_SI_CHAR;
                 SISOLength = 1;
             } else if ((cnvOption&_MBCS_OPTION_JIPS)!=0) {
                 value[0] = JIPS_SI_CHAR_1;
                 value[1] = JIPS_SI_CHAR_2;
                 SISOLength = 2;
             } else {
                 value[0] = UCNV_SI;
                 SISOLength = 1;
             }
             break;
         case SO:
             if ((cnvOption&_MBCS_OPTION_KEIS)!=0) {
                 value[0] = KEIS_SO_CHAR_1;
                 value[1] = KEIS_SO_CHAR_2;
                 SISOLength = 2;
             } else if ((cnvOption&_MBCS_OPTION_JEF)!=0) {
                 value[0] = JEF_SO_CHAR;
                 SISOLength = 1;
             } else if ((cnvOption&_MBCS_OPTION_JIPS)!=0) {
                 value[0] = JIPS_SO_CHAR_1;
                 value[1] = JIPS_SO_CHAR_2;
                 SISOLength = 2;
             } else {
                 value[0] = UCNV_SO;
                 SISOLength = 1;
             }
             break;
         default:
             /* Should never happen. */
             break;
     }
     return SISOLength;
 }
 /* Miscellaneous ------------------------------------------------------------ */
 /**
  * Callback from ucnv_MBCSEnumToUnicode(), takes 32 mappings from
  * consecutive sequences of bytes, starting from the one encoded in value,
  * to Unicode code points. (Multiple mappings to reduce per-function call overhead.)
  * Does not currently support m:n mappings or reverse fallbacks.
  * This function will not be called for sequences of bytes with leading zeros.
  *
  * @param context an opaque pointer, as passed into ucnv_MBCSEnumToUnicode()
  * @param value contains 1..4 bytes of the first byte sequence, right-aligned
  * @param codePoints resulting Unicode code points, or negative if a byte sequence does
  *        not map to anything
  * @return TRUE to continue enumeration, FALSE to stop
  */
 typedef UBool U_CALLCONV
 UConverterEnumToUCallback(const void *context, uint32_t value, UChar32 codePoints[32]);
 /* similar to ucnv_MBCSGetNextUChar() but recursive */
 static UBool
 enumToU(UConverterMBCSTable *mbcsTable, int8_t stateProps[],
         int32_t state, uint32_t offset,
         uint32_t value,
         UConverterEnumToUCallback *callback, const void *context,
         UErrorCode *pErrorCode) {
     UChar32 codePoints[32];
     const int32_t *row;
     const uint16_t *unicodeCodeUnits;
     UChar32 anyCodePoints;
     int32_t b, limit;
     row=mbcsTable->stateTable[state];
     unicodeCodeUnits=mbcsTable->unicodeCodeUnits;
     value<<=8;
     anyCodePoints=-1;  /* becomes non-negative if there is a mapping */
     b=(stateProps[state]&0x38)<<2;
     if(b==0 && stateProps[state]>=0x40) {
         /* skip byte sequences with leading zeros because they are not stored in the fromUnicode table */
         codePoints[0]=U_SENTINEL;
         b=1;
     }
     limit=((stateProps[state]&7)+1)<<5;
     while(b<limit) {
         int32_t entry=row[b];
         if(MBCS_ENTRY_IS_TRANSITION(entry)) {
             int32_t nextState=MBCS_ENTRY_TRANSITION_STATE(entry);
             if(stateProps[nextState]>=0) {
                 /* recurse to a state with non-ignorable actions */
                 if(!enumToU(
                         mbcsTable, stateProps, nextState,
                         offset+MBCS_ENTRY_TRANSITION_OFFSET(entry),
                         value|(uint32_t)b,
                         callback, context,
                         pErrorCode)) {
                     return FALSE;
                 }
             }
             codePoints[b&0x1f]=U_SENTINEL;
         } else {
             UChar32 c;
             int32_t action;
             /*
              * An if-else-if chain provides more reliable performance for
              * the most common cases compared to a switch.
              */
             action=MBCS_ENTRY_FINAL_ACTION(entry);
             if(action==MBCS_STATE_VALID_DIRECT_16) {
                 /* output BMP code point */
                 c=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             } else if(action==MBCS_STATE_VALID_16) {
                 int32_t finalOffset=offset+MBCS_ENTRY_FINAL_VALUE_16(entry);
                 c=unicodeCodeUnits[finalOffset];
                 if(c<0xfffe) {
                     /* output BMP code point */
                 } else {
                     c=U_SENTINEL;
                 }
             } else if(action==MBCS_STATE_VALID_16_PAIR) {
                 int32_t finalOffset=offset+MBCS_ENTRY_FINAL_VALUE_16(entry);
                 c=unicodeCodeUnits[finalOffset++];
                 if(c<0xd800) {
                     /* output BMP code point below 0xd800 */
                 } else if(c<=0xdbff) {
                     /* output roundtrip or fallback supplementary code point */
                     c=((c&0x3ff)<<10)+unicodeCodeUnits[finalOffset]+(0x10000-0xdc00);
                 } else if(c==0xe000) {
                     /* output roundtrip BMP code point above 0xd800 or fallback BMP code point */
                     c=unicodeCodeUnits[finalOffset];
                 } else {
                     c=U_SENTINEL;
                 }
             } else if(action==MBCS_STATE_VALID_DIRECT_20) {
                 /* output supplementary code point */
                 c=(UChar32)(MBCS_ENTRY_FINAL_VALUE(entry)+0x10000);
             } else {
                 c=U_SENTINEL;
             }
             codePoints[b&0x1f]=c;
             anyCodePoints&=c;
         }
         if(((++b)&0x1f)==0) {
             if(anyCodePoints>=0) {
                 if(!callback(context, value|(uint32_t)(b-0x20), codePoints)) {
                     return FALSE;
                 }
                 anyCodePoints=-1;
             }
         }
     }
     return TRUE;
 }
 /*
  * Only called if stateProps[state]==-1.
  * A recursive call may do stateProps[state]|=0x40 if this state is the target of an
  * MBCS_STATE_CHANGE_ONLY.
  */
 static int8_t
 getStateProp(const int32_t (*stateTable)[256], int8_t stateProps[], int state) {
     const int32_t *row;
     int32_t min, max, entry, nextState;
     row=stateTable[state];
     stateProps[state]=0;
     /* find first non-ignorable state */
     for(min=0;; ++min) {
         entry=row[min];
         nextState=MBCS_ENTRY_STATE(entry);
         if(stateProps[nextState]==-1) {
             getStateProp(stateTable, stateProps, nextState);
         }
         if(MBCS_ENTRY_IS_TRANSITION(entry)) {
             if(stateProps[nextState]>=0) {
                 break;
             }
         } else if(MBCS_ENTRY_FINAL_ACTION(entry)<MBCS_STATE_UNASSIGNED) {
             break;
         }
         if(min==0xff) {
             stateProps[state]=-0x40;  /* (int8_t)0xc0 */
             return stateProps[state];
         }
     }
     stateProps[state]|=(int8_t)((min>>5)<<3);
     /* find last non-ignorable state */
     for(max=0xff; min<max; --max) {
         entry=row[max];
         nextState=MBCS_ENTRY_STATE(entry);
         if(stateProps[nextState]==-1) {
             getStateProp(stateTable, stateProps, nextState);
         }
         if(MBCS_ENTRY_IS_TRANSITION(entry)) {
             if(stateProps[nextState]>=0) {
                 break;
             }
         } else if(MBCS_ENTRY_FINAL_ACTION(entry)<MBCS_STATE_UNASSIGNED) {
             break;
         }
     }
     stateProps[state]|=(int8_t)(max>>5);
     /* recurse further and collect direct-state information */
     while(min<=max) {
         entry=row[min];
         nextState=MBCS_ENTRY_STATE(entry);
         if(stateProps[nextState]==-1) {
             getStateProp(stateTable, stateProps, nextState);
         }
         if(MBCS_ENTRY_IS_FINAL(entry)) {
             stateProps[nextState]|=0x40;
             if(MBCS_ENTRY_FINAL_ACTION(entry)<=MBCS_STATE_FALLBACK_DIRECT_20) {
                 stateProps[state]|=0x40;
             }
         }
         ++min;
     }
     return stateProps[state];
 }
 /*
  * Internal function enumerating the toUnicode data of an MBCS converter.
  * Currently only used for reconstituting data for a MBCS_OPT_NO_FROM_U
  * table, but could also be used for a future ucnv_getUnicodeSet() option
  * that includes reverse fallbacks (after updating this function's implementation).
  * Currently only handles roundtrip mappings.
  * Does not currently handle extensions.
  */
 static void
 ucnv_MBCSEnumToUnicode(UConverterMBCSTable *mbcsTable,
                        UConverterEnumToUCallback *callback, const void *context,
                        UErrorCode *pErrorCode) {
     /*
      * Properties for each state, to speed up the enumeration.
      * Ignorable actions are unassigned/illegal/state-change-only:
      * They do not lead to mappings.
      *
      * Bits 7..6:
      * 1 direct/initial state (stateful converters have multiple)
      * 0 non-initial state with transitions or with non-ignorable result actions
      * -1 final state with only ignorable actions
      *
      * Bits 5..3:
      * The lowest byte value with non-ignorable actions is
      * value<<5 (rounded down).
      *
      * Bits 2..0:
      * The highest byte value with non-ignorable actions is
      * (value<<5)&0x1f (rounded up).
      */
     int8_t stateProps[MBCS_MAX_STATE_COUNT];
     int32_t state;
     uprv_memset(stateProps, -1, sizeof(stateProps));
     /* recurse from state 0 and set all stateProps */
     getStateProp(mbcsTable->stateTable, stateProps, 0);
     for(state=0; state<mbcsTable->countStates; ++state) {
         /*if(stateProps[state]==-1) {
             printf("unused/unreachable <icu:state> %d\n", state);
         }*/
         if(stateProps[state]>=0x40) {
             /* start from each direct state */
             enumToU(
                 mbcsTable, stateProps, state, 0, 0,
                 callback, context,
                 pErrorCode);
         }
     }
 }
 U_CFUNC void
 ucnv_MBCSGetFilteredUnicodeSetForUnicode(const UConverterSharedData *sharedData,
                                          const USetAdder *sa,
                                          UConverterUnicodeSet which,
                                          UConverterSetFilter filter,
                                          UErrorCode *pErrorCode) {
     const UConverterMBCSTable *mbcsTable;
     const uint16_t *table;
     uint32_t st3;
     uint16_t st1, maxStage1, st2;
     UChar32 c;
     /* enumerate the from-Unicode trie table */
     mbcsTable=&sharedData->mbcs;
     table=mbcsTable->fromUnicodeTable;
     if(mbcsTable->unicodeMask&UCNV_HAS_SUPPLEMENTARY) {
         maxStage1=0x440;
     } else {
         maxStage1=0x40;
     }
     c=0; /* keep track of the current code point while enumerating */
     if(mbcsTable->outputType==MBCS_OUTPUT_1) {
         const uint16_t *stage2, *stage3, *results;
         uint16_t minValue;
         results=(const uint16_t *)mbcsTable->fromUnicodeBytes;
         /*
          * Set a threshold variable for selecting which mappings to use.
          * See ucnv_MBCSSingleFromBMPWithOffsets() and
          * MBCS_SINGLE_RESULT_FROM_U() for details.
          */
         if(which==UCNV_ROUNDTRIP_SET) {
             /* use only roundtrips */
             minValue=0xf00;
         } else /* UCNV_ROUNDTRIP_AND_FALLBACK_SET */ {
             /* use all roundtrip and fallback results */
             minValue=0x800;
         }
         for(st1=0; st1<maxStage1; ++st1) {
             st2=table[st1];
             if(st2>maxStage1) {
                 stage2=table+st2;
                 for(st2=0; st2<64; ++st2) {
                     if((st3=stage2[st2])!=0) {
                         /* read the stage 3 block */
                         stage3=results+st3;
                         do {
                             if(*stage3++>=minValue) {
                                 sa->add(sa->set, c);
                             }
                         } while((++c&0xf)!=0);
                     } else {
                         c+=16; /* empty stage 3 block */
                     }
                 }
             } else {
                 c+=1024; /* empty stage 2 block */
             }
         }
     } else {
         const uint32_t *stage2;
         const uint8_t *stage3, *bytes;
         uint32_t st3Multiplier;
         uint32_t value;
         UBool useFallback;
         bytes=mbcsTable->fromUnicodeBytes;
         useFallback=(UBool)(which==UCNV_ROUNDTRIP_AND_FALLBACK_SET);
         switch(mbcsTable->outputType) {
         case MBCS_OUTPUT_3:
         case MBCS_OUTPUT_4_EUC:
             st3Multiplier=3;
             break;
         case MBCS_OUTPUT_4:
             st3Multiplier=4;
             break;
         default:
             st3Multiplier=2;
             break;
         }
         for(st1=0; st1<maxStage1; ++st1) {
             st2=table[st1];
             if(st2>(maxStage1>>1)) {
                 stage2=(const uint32_t *)table+st2;
                 for(st2=0; st2<64; ++st2) {
                     if((st3=stage2[st2])!=0) {
                         /* read the stage 3 block */
                         stage3=bytes+st3Multiplier*16*(uint32_t)(uint16_t)st3;
                         /* get the roundtrip flags for the stage 3 block */
                         st3>>=16;
                         /*
                          * Add code points for which the roundtrip flag is set,
                          * or which map to non-zero bytes if we use fallbacks.
                          * See ucnv_MBCSFromUnicodeWithOffsets() for details.
                          */
                         switch(filter) {
                         case UCNV_SET_FILTER_NONE:
                             do {
                                 if(st3&1) {
                                     sa->add(sa->set, c);
                                     stage3+=st3Multiplier;
                                 } else if(useFallback) {
                                     uint8_t b=0;
                                     switch(st3Multiplier) {
                                     case 4:
                                         b|=*stage3++;
                                     case 3: /*fall through*/
                                         b|=*stage3++;
                                     case 2: /*fall through*/
                                         b|=stage3[0]|stage3[1];
                                         stage3+=2;
                                     default:
                                         break;
                                     }
                                     if(b!=0) {
                                         sa->add(sa->set, c);
                                     }
                                 }
                                 st3>>=1;
                             } while((++c&0xf)!=0);
                             break;
                         case UCNV_SET_FILTER_DBCS_ONLY:
                              /* Ignore single-byte results (<0x100). */
                             do {
                                 if(((st3&1)!=0 || useFallback) && *((const uint16_t *)stage3)>=0x100) {
                                     sa->add(sa->set, c);
                                 }
                                 st3>>=1;
                                 stage3+=2;  /* +=st3Multiplier */
                             } while((++c&0xf)!=0);
                             break;
                         case UCNV_SET_FILTER_2022_CN:
                              /* Only add code points that map to CNS 11643 planes 1 & 2 for non-EXT ISO-2022-CN. */
                             do {
                                 if(((st3&1)!=0 || useFallback) && ((value=*stage3)==0x81 || value==0x82)) {
                                     sa->add(sa->set, c);
                                 }
                                 st3>>=1;
                                 stage3+=3;  /* +=st3Multiplier */
                             } while((++c&0xf)!=0);
                             break;
                         case UCNV_SET_FILTER_SJIS:
                              /* Only add code points that map to Shift-JIS codes corresponding to JIS X 0208. */
                             do {
                                 if(((st3&1)!=0 || useFallback) && (value=*((const uint16_t *)stage3))>=0x8140 && value<=0xeffc) {
                                     sa->add(sa->set, c);
                                 }
                                 st3>>=1;
                                 stage3+=2;  /* +=st3Multiplier */
                             } while((++c&0xf)!=0);
                             break;
                         case UCNV_SET_FILTER_GR94DBCS:
                             /* Only add code points that map to ISO 2022 GR 94 DBCS codes (each byte A1..FE). */
                             do {
                                 if( ((st3&1)!=0 || useFallback) &&
                                     (uint16_t)((value=*((const uint16_t *)stage3)) - 0xa1a1)<=(0xfefe - 0xa1a1) &&
                                     (uint8_t)(value-0xa1)<=(0xfe - 0xa1)
                                 ) {
                                     sa->add(sa->set, c);
                                 }
                                 st3>>=1;
                                 stage3+=2;  /* +=st3Multiplier */
                             } while((++c&0xf)!=0);
                             break;
                         case UCNV_SET_FILTER_HZ:
                             /* Only add code points that are suitable for HZ DBCS (lead byte A1..FD). */
                             do {
                                 if( ((st3&1)!=0 || useFallback) &&
                                     (uint16_t)((value=*((const uint16_t *)stage3))-0xa1a1)<=(0xfdfe - 0xa1a1) &&
                                     (uint8_t)(value-0xa1)<=(0xfe - 0xa1)
                                 ) {
                                     sa->add(sa->set, c);
                                 }
                                 st3>>=1;
                                 stage3+=2;  /* +=st3Multiplier */
                             } while((++c&0xf)!=0);
                             break;
                         default:
                             *pErrorCode=U_INTERNAL_PROGRAM_ERROR;
                             return;
                         }
                     } else {
                         c+=16; /* empty stage 3 block */
                     }
                 }
             } else {
                 c+=1024; /* empty stage 2 block */
             }
         }
     }
     ucnv_extGetUnicodeSet(sharedData, sa, which, filter, pErrorCode);
 }
 U_CFUNC void
 ucnv_MBCSGetUnicodeSetForUnicode(const UConverterSharedData *sharedData,
                                  const USetAdder *sa,
                                  UConverterUnicodeSet which,
                                  UErrorCode *pErrorCode) {
     ucnv_MBCSGetFilteredUnicodeSetForUnicode(
         sharedData, sa, which,
         sharedData->mbcs.outputType==MBCS_OUTPUT_DBCS_ONLY ?
             UCNV_SET_FILTER_DBCS_ONLY :
             UCNV_SET_FILTER_NONE,
         pErrorCode);
 }
 static void
 ucnv_MBCSGetUnicodeSet(const UConverter *cnv,
                    const USetAdder *sa,
                    UConverterUnicodeSet which,
                    UErrorCode *pErrorCode) {
     if(cnv->options&_MBCS_OPTION_GB18030) {
         sa->addRange(sa->set, 0, 0xd7ff);
         sa->addRange(sa->set, 0xe000, 0x10ffff);
     } else {
         ucnv_MBCSGetUnicodeSetForUnicode(cnv->sharedData, sa, which, pErrorCode);
     }
 }
 /* conversion extensions for input not in the main table -------------------- */
 /*
  * Hardcoded extension handling for GB 18030.
  * Definition of LINEAR macros and gb18030Ranges see near the beginning of the file.
  *
  * In the future, conversion extensions may handle m:n mappings and delta tables,
  * see http://source.icu-project.org/repos/icu/icuhtml/trunk/design/conversion/conversion_extensions.html
  *
  * If an input character cannot be mapped, then these functions set an error
  * code. The framework will then call the callback function.
  */
 /*
  * @return if(U_FAILURE) return the code point for cnv->fromUChar32
  *         else return 0 after output has been written to the target
  */
 static UChar32
 _extFromU(UConverter *cnv, const UConverterSharedData *sharedData,
           UChar32 cp,
           const UChar **source, const UChar *sourceLimit,
           uint8_t **target, const uint8_t *targetLimit,
           int32_t **offsets, int32_t sourceIndex,
           UBool flush,
           UErrorCode *pErrorCode) {
     const int32_t *cx;
     cnv->useSubChar1=FALSE;
     if( (cx=sharedData->mbcs.extIndexes)!=NULL &&
         ucnv_extInitialMatchFromU(
             cnv, cx,
             cp, source, sourceLimit,
             (char **)target, (char *)targetLimit,
             offsets, sourceIndex,
             flush,
             pErrorCode)
     ) {
         return 0; /* an extension mapping handled the input */
     }
     /* GB 18030 */
     if((cnv->options&_MBCS_OPTION_GB18030)!=0) {
         const uint32_t *range;
         int32_t i;
         range=gb18030Ranges[0];
         for(i=0; i<sizeof(gb18030Ranges)/sizeof(gb18030Ranges[0]); range+=4, ++i) {
             if(range[0]<=(uint32_t)cp && (uint32_t)cp<=range[1]) {
                 /* found the Unicode code point, output the four-byte sequence for it */
                 uint32_t linear;
                 char bytes[4];
                 /* get the linear value of the first GB 18030 code in this range */
                 linear=range[2]-LINEAR_18030_BASE;
                 /* add the offset from the beginning of the range */
                 linear+=((uint32_t)cp-range[0]);
                 /* turn this into a four-byte sequence */
                 bytes[3]=(char)(0x30+linear%10); linear/=10;
                 bytes[2]=(char)(0x81+linear%126); linear/=126;
                 bytes[1]=(char)(0x30+linear%10); linear/=10;
                 bytes[0]=(char)(0x81+linear);
                 /* output this sequence */
                 ucnv_fromUWriteBytes(cnv,
                                      bytes, 4, (char **)target, (char *)targetLimit,
                                      offsets, sourceIndex, pErrorCode);
                 return 0;
             }
         }
     }
     /* no mapping */
     *pErrorCode=U_INVALID_CHAR_FOUND;
     return cp;
 }
 /*
  * Input sequence: cnv->toUBytes[0..length[
  * @return if(U_FAILURE) return the length (toULength, byteIndex) for the input
  *         else return 0 after output has been written to the target
  */
 static int8_t
 _extToU(UConverter *cnv, const UConverterSharedData *sharedData,
         int8_t length,
         const uint8_t **source, const uint8_t *sourceLimit,
         UChar **target, const UChar *targetLimit,
         int32_t **offsets, int32_t sourceIndex,
         UBool flush,
         UErrorCode *pErrorCode) {
     const int32_t *cx;
     if( (cx=sharedData->mbcs.extIndexes)!=NULL &&
         ucnv_extInitialMatchToU(
             cnv, cx,
             length, (const char **)source, (const char *)sourceLimit,
             target, targetLimit,
             offsets, sourceIndex,
             flush,
             pErrorCode)
     ) {
         return 0; /* an extension mapping handled the input */
     }
     /* GB 18030 */
     if(length==4 && (cnv->options&_MBCS_OPTION_GB18030)!=0) {
         const uint32_t *range;
         uint32_t linear;
         int32_t i;
         linear=LINEAR_18030(cnv->toUBytes[0], cnv->toUBytes[1], cnv->toUBytes[2], cnv->toUBytes[3]);
         range=gb18030Ranges[0];
         for(i=0; i<sizeof(gb18030Ranges)/sizeof(gb18030Ranges[0]); range+=4, ++i) {
             if(range[2]<=linear && linear<=range[3]) {
                 /* found the sequence, output the Unicode code point for it */
                 *pErrorCode=U_ZERO_ERROR;
                 /* add the linear difference between the input and start sequences to the start code point */
                 linear=range[0]+(linear-range[2]);
                 /* output this code point */
                 ucnv_toUWriteCodePoint(cnv, linear, target, targetLimit, offsets, sourceIndex, pErrorCode);
                 return 0;
             }
         }
     }
     /* no mapping */
     *pErrorCode=U_INVALID_CHAR_FOUND;
     return length;
 }
 /* EBCDIC swap LF<->NL ------------------------------------------------------ */
 /*
  * This code modifies a standard EBCDIC<->Unicode mapping table for
  * OS/390 (z/OS) Unix System Services (Open Edition).
  * The difference is in the mapping of Line Feed and New Line control codes:
  * Standard EBCDIC maps
  *
  *   <U000A> \x25 |0
  *   <U0085> \x15 |0
  *
  * but OS/390 USS EBCDIC swaps the control codes for LF and NL,
  * mapping
  *
  *   <U000A> \x15 |0
  *   <U0085> \x25 |0
  *
  * This code modifies a loaded standard EBCDIC<->Unicode mapping table
  * by copying it into allocated memory and swapping the LF and NL values.
  * It allows to support the same EBCDIC charset in both versions without
  * duplicating the entire installed table.
  */
 /* standard EBCDIC codes */
 #define EBCDIC_LF 0x25
 #define EBCDIC_NL 0x15
 /* standard EBCDIC codes with roundtrip flag as stored in Unicode-to-single-byte tables */
 #define EBCDIC_RT_LF 0xf25
 #define EBCDIC_RT_NL 0xf15
 /* Unicode code points */
 #define U_LF 0x0a
 #define U_NL 0x85
 static UBool
 _EBCDICSwapLFNL(UConverterSharedData *sharedData, UErrorCode *pErrorCode) {
     UConverterMBCSTable *mbcsTable;
     const uint16_t *table, *results;
     const uint8_t *bytes;
     int32_t (*newStateTable)[256];
     uint16_t *newResults;
     uint8_t *p;
     char *name;
     uint32_t stage2Entry;
     uint32_t size, sizeofFromUBytes;
     mbcsTable=&sharedData->mbcs;
     table=mbcsTable->fromUnicodeTable;
     bytes=mbcsTable->fromUnicodeBytes;
     results=(const uint16_t *)bytes;
     /*
      * Check that this is an EBCDIC table with SBCS portion -
      * SBCS or EBCDIC_STATEFUL with standard EBCDIC LF and NL mappings.
      *
      * If not, ignore the option. Options are always ignored if they do not apply.
      */
     if(!(
          (mbcsTable->outputType==MBCS_OUTPUT_1 || mbcsTable->outputType==MBCS_OUTPUT_2_SISO) &&
          mbcsTable->stateTable[0][EBCDIC_LF]==MBCS_ENTRY_FINAL(0, MBCS_STATE_VALID_DIRECT_16, U_LF) &&
          mbcsTable->stateTable[0][EBCDIC_NL]==MBCS_ENTRY_FINAL(0, MBCS_STATE_VALID_DIRECT_16, U_NL)
     )) {
         return FALSE;
     }
     if(mbcsTable->outputType==MBCS_OUTPUT_1) {
         if(!(
              EBCDIC_RT_LF==MBCS_SINGLE_RESULT_FROM_U(table, results, U_LF) &&
              EBCDIC_RT_NL==MBCS_SINGLE_RESULT_FROM_U(table, results, U_NL)
         )) {
             return FALSE;
         }
     } else /* MBCS_OUTPUT_2_SISO */ {
         stage2Entry=MBCS_STAGE_2_FROM_U(table, U_LF);
         if(!(
              MBCS_FROM_U_IS_ROUNDTRIP(stage2Entry, U_LF)!=0 &&
              EBCDIC_LF==MBCS_VALUE_2_FROM_STAGE_2(bytes, stage2Entry, U_LF)
         )) {
             return FALSE;
         }
         stage2Entry=MBCS_STAGE_2_FROM_U(table, U_NL);
         if(!(
              MBCS_FROM_U_IS_ROUNDTRIP(stage2Entry, U_NL)!=0 &&
              EBCDIC_NL==MBCS_VALUE_2_FROM_STAGE_2(bytes, stage2Entry, U_NL)
         )) {
             return FALSE;
         }
     }
     if(mbcsTable->fromUBytesLength>0) {
         /*
          * We _know_ the number of bytes in the fromUnicodeBytes array
          * starting with header.version 4.1.
          */
         sizeofFromUBytes=mbcsTable->fromUBytesLength;
     } else {
         /*
          * Otherwise:
          * There used to be code to enumerate the fromUnicode
          * trie and find the highest entry, but it was removed in ICU 3.2
          * because it was not tested and caused a low code coverage number.
          * See Jitterbug 3674.
          * This affects only some .cnv file formats with a header.version
          * below 4.1, and only when swaplfnl is requested.
          *
          * ucnvmbcs.c revision 1.99 is the last one with the
          * ucnv_MBCSSizeofFromUBytes() function.
          */
         *pErrorCode=U_INVALID_FORMAT_ERROR;
         return FALSE;
     }
     /*
      * The table has an appropriate format.
      * Allocate and build
      * - a modified to-Unicode state table
      * - a modified from-Unicode output array
      * - a converter name string with the swap option appended
      */
     size=
         mbcsTable->countStates*1024+
         sizeofFromUBytes+
         UCNV_MAX_CONVERTER_NAME_LENGTH+20;
     p=(uint8_t *)uprv_malloc(size);
     if(p==NULL) {
         *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
         return FALSE;
     }
     /* copy and modify the to-Unicode state table */
     newStateTable=(int32_t (*)[256])p;
     uprv_memcpy(newStateTable, mbcsTable->stateTable, mbcsTable->countStates*1024);
     newStateTable[0][EBCDIC_LF]=MBCS_ENTRY_FINAL(0, MBCS_STATE_VALID_DIRECT_16, U_NL);
     newStateTable[0][EBCDIC_NL]=MBCS_ENTRY_FINAL(0, MBCS_STATE_VALID_DIRECT_16, U_LF);
     /* copy and modify the from-Unicode result table */
     newResults=(uint16_t *)newStateTable[mbcsTable->countStates];
     uprv_memcpy(newResults, bytes, sizeofFromUBytes);
     /* conveniently, the table access macros work on the left side of expressions */
     if(mbcsTable->outputType==MBCS_OUTPUT_1) {
         MBCS_SINGLE_RESULT_FROM_U(table, newResults, U_LF)=EBCDIC_RT_NL;
         MBCS_SINGLE_RESULT_FROM_U(table, newResults, U_NL)=EBCDIC_RT_LF;
     } else /* MBCS_OUTPUT_2_SISO */ {
         stage2Entry=MBCS_STAGE_2_FROM_U(table, U_LF);
         MBCS_VALUE_2_FROM_STAGE_2(newResults, stage2Entry, U_LF)=EBCDIC_NL;
         stage2Entry=MBCS_STAGE_2_FROM_U(table, U_NL);
         MBCS_VALUE_2_FROM_STAGE_2(newResults, stage2Entry, U_NL)=EBCDIC_LF;
     }
     /* set the canonical converter name */
     name=(char *)newResults+sizeofFromUBytes;
     uprv_strcpy(name, sharedData->staticData->name);
     uprv_strcat(name, UCNV_SWAP_LFNL_OPTION_STRING);
     /* set the pointers */
     umtx_lock(NULL);
     if(mbcsTable->swapLFNLStateTable==NULL) {
         mbcsTable->swapLFNLStateTable=newStateTable;
         mbcsTable->swapLFNLFromUnicodeBytes=(uint8_t *)newResults;
         mbcsTable->swapLFNLName=name;
         newStateTable=NULL;
     }
     umtx_unlock(NULL);
     /* release the allocated memory if another thread beat us to it */
     if(newStateTable!=NULL) {
         uprv_free(newStateTable);
     }
     return TRUE;
 }
 /* reconstitute omitted fromUnicode data ------------------------------------ */
 /* for details, compare with genmbcs.c MBCSAddFromUnicode() and transformEUC() */
 static UBool U_CALLCONV
 writeStage3Roundtrip(const void *context, uint32_t value, UChar32 codePoints[32]) {
     UConverterMBCSTable *mbcsTable=(UConverterMBCSTable *)context;
     const uint16_t *table;
     uint32_t *stage2;
     uint8_t *bytes, *p;
     UChar32 c;
     int32_t i, st3;
     table=mbcsTable->fromUnicodeTable;
     bytes=(uint8_t *)mbcsTable->fromUnicodeBytes;
     /* for EUC outputTypes, modify the value like genmbcs.c's transformEUC() */
     switch(mbcsTable->outputType) {
     case MBCS_OUTPUT_3_EUC:
         if(value<=0xffff) {
             /* short sequences are stored directly */
             /* code set 0 or 1 */
         } else if(value<=0x8effff) {
             /* code set 2 */
             value&=0x7fff;
         } else /* first byte is 0x8f */ {
             /* code set 3 */
             value&=0xff7f;
         }
         break;
     case MBCS_OUTPUT_4_EUC:
         if(value<=0xffffff) {
             /* short sequences are stored directly */
             /* code set 0 or 1 */
         } else if(value<=0x8effffff) {
             /* code set 2 */
             value&=0x7fffff;
         } else /* first byte is 0x8f */ {
             /* code set 3 */
             value&=0xff7fff;
         }
         break;
     default:
         break;
     }
     for(i=0; i<=0x1f; ++value, ++i) {
         c=codePoints[i];
         if(c<0) {
             continue;
         }
         /* locate the stage 2 & 3 data */
         stage2=((uint32_t *)table)+table[c>>10]+((c>>4)&0x3f);
         p=bytes;
         st3=(int32_t)(uint16_t)*stage2*16+(c&0xf);
         /* write the codepage bytes into stage 3 */
         switch(mbcsTable->outputType) {
         case MBCS_OUTPUT_3:
         case MBCS_OUTPUT_4_EUC:
             p+=st3*3;
             p[0]=(uint8_t)(value>>16);
             p[1]=(uint8_t)(value>>8);
             p[2]=(uint8_t)value;
             break;
         case MBCS_OUTPUT_4:
             ((uint32_t *)p)[st3]=value;
             break;
         default:
             /* 2 bytes per character */
             ((uint16_t *)p)[st3]=(uint16_t)value;
             break;
         }
         /* set the roundtrip flag */
         *stage2|=(1UL<<(16+(c&0xf)));
     }
     return TRUE;
  }
 static void
 reconstituteData(UConverterMBCSTable *mbcsTable,
                  uint32_t stage1Length, uint32_t stage2Length,
                  uint32_t fullStage2Length,  /* lengths are numbers of units, not bytes */
                  UErrorCode *pErrorCode) {
     uint16_t *stage1;
     uint32_t *stage2;
     uint32_t dataLength=stage1Length*2+fullStage2Length*4+mbcsTable->fromUBytesLength;
     mbcsTable->reconstitutedData=(uint8_t *)uprv_malloc(dataLength);
     if(mbcsTable->reconstitutedData==NULL) {
         *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
         return;
     }
     uprv_memset(mbcsTable->reconstitutedData, 0, dataLength);
     /* copy existing data and reroute the pointers */
     stage1=(uint16_t *)mbcsTable->reconstitutedData;
     uprv_memcpy(stage1, mbcsTable->fromUnicodeTable, stage1Length*2);
     stage2=(uint32_t *)(stage1+stage1Length);
     uprv_memcpy(stage2+(fullStage2Length-stage2Length),
                 mbcsTable->fromUnicodeTable+stage1Length,
                 stage2Length*4);
     mbcsTable->fromUnicodeTable=stage1;
     mbcsTable->fromUnicodeBytes=(uint8_t *)(stage2+fullStage2Length);
     /* indexes into stage 2 count from the bottom of the fromUnicodeTable */
     stage2=(uint32_t *)stage1;
     /* reconstitute the initial part of stage 2 from the mbcsIndex */
     {
         int32_t stageUTF8Length=((int32_t)mbcsTable->maxFastUChar+1)>>6;
         int32_t stageUTF8Index=0;
         int32_t st1, st2, st3, i;
         for(st1=0; stageUTF8Index<stageUTF8Length; ++st1) {
             st2=stage1[st1];
             if(st2!=stage1Length/2) {
                 /* each stage 2 block has 64 entries corresponding to 16 entries in the mbcsIndex */
                 for(i=0; i<16; ++i) {
                     st3=mbcsTable->mbcsIndex[stageUTF8Index++];
                     if(st3!=0) {
                         /* an stage 2 entry's index is per stage 3 16-block, not per stage 3 entry */
                         st3>>=4;
                         /*
                          * 4 stage 2 entries point to 4 consecutive stage 3 16-blocks which are
                          * allocated together as a single 64-block for access from the mbcsIndex
                          */
                         stage2[st2++]=st3++;
                         stage2[st2++]=st3++;
                         stage2[st2++]=st3++;
                         stage2[st2++]=st3;
                     } else {
                         /* no stage 3 block, skip */
                         st2+=4;
                     }
                 }
             } else {
                 /* no stage 2 block, skip */
                 stageUTF8Index+=16;
             }
         }
     }
     /* reconstitute fromUnicodeBytes with roundtrips from toUnicode data */
     ucnv_MBCSEnumToUnicode(mbcsTable, writeStage3Roundtrip, mbcsTable, pErrorCode);
 }
 /* MBCS setup functions ----------------------------------------------------- */
 static void
 ucnv_MBCSLoad(UConverterSharedData *sharedData,
           UConverterLoadArgs *pArgs,
           const uint8_t *raw,
           UErrorCode *pErrorCode) {
     UDataInfo info;
     UConverterMBCSTable *mbcsTable=&sharedData->mbcs;
     _MBCSHeader *header=(_MBCSHeader *)raw;
     uint32_t offset;
     uint32_t headerLength;
     UBool noFromU=FALSE;
     if(header->version[0]==4) {
         headerLength=MBCS_HEADER_V4_LENGTH;
     } else if(header->version[0]==5 && header->version[1]>=3 &&
               (header->options&MBCS_OPT_UNKNOWN_INCOMPATIBLE_MASK)==0) {
         headerLength=header->options&MBCS_OPT_LENGTH_MASK;
         noFromU=(UBool)((header->options&MBCS_OPT_NO_FROM_U)!=0);
     } else {
         *pErrorCode=U_INVALID_TABLE_FORMAT;
         return;
     }
     mbcsTable->outputType=(uint8_t)header->flags;
     if(noFromU && mbcsTable->outputType==MBCS_OUTPUT_1) {
         *pErrorCode=U_INVALID_TABLE_FORMAT;
         return;
     }
     /* extension data, header version 4.2 and higher */
     offset=header->flags>>8;
     if(offset!=0) {
         mbcsTable->extIndexes=(const int32_t *)(raw+offset);
     }
     if(mbcsTable->outputType==MBCS_OUTPUT_EXT_ONLY) {
         UConverterLoadArgs args={ 0 };
         UConverterSharedData *baseSharedData;
         const int32_t *extIndexes;
         const char *baseName;
         /* extension-only file, load the base table and set values appropriately */
         if((extIndexes=mbcsTable->extIndexes)==NULL) {
             /* extension-only file without extension */
             *pErrorCode=U_INVALID_TABLE_FORMAT;
             return;
         }
         if(pArgs->nestedLoads!=1) {
             /* an extension table must not be loaded as a base table */
             *pErrorCode=U_INVALID_TABLE_FILE;
             return;
         }
         /* load the base table */
         baseName=(const char *)header+headerLength*4;
         if(0==uprv_strcmp(baseName, sharedData->staticData->name)) {
             /* forbid loading this same extension-only file */
             *pErrorCode=U_INVALID_TABLE_FORMAT;
             return;
         }
         /* TODO parse package name out of the prefix of the base name in the extension .cnv file? */
         args.size=sizeof(UConverterLoadArgs);
         args.nestedLoads=2;
         args.onlyTestIsLoadable=pArgs->onlyTestIsLoadable;
         args.reserved=pArgs->reserved;
         args.options=pArgs->options;
         args.pkg=pArgs->pkg;
         args.name=baseName;
         baseSharedData=ucnv_load(&args, pErrorCode);
         if(U_FAILURE(*pErrorCode)) {
             return;
         }
         if( baseSharedData->staticData->conversionType!=UCNV_MBCS ||
             baseSharedData->mbcs.baseSharedData!=NULL
         ) {
             ucnv_unload(baseSharedData);
             *pErrorCode=U_INVALID_TABLE_FORMAT;
             return;
         }
         if(pArgs->onlyTestIsLoadable) {
             /*
              * Exit as soon as we know that we can load the converter
              * and the format is valid and supported.
              * The worst that can happen in the following code is a memory
              * allocation error.
              */
             ucnv_unload(baseSharedData);
             return;
         }
         /* copy the base table data */
         uprv_memcpy(mbcsTable, &baseSharedData->mbcs, sizeof(UConverterMBCSTable));
         /* overwrite values with relevant ones for the extension converter */
         mbcsTable->baseSharedData=baseSharedData;
         mbcsTable->extIndexes=extIndexes;
         /*
          * It would be possible to share the swapLFNL data with a base converter,
          * but the generated name would have to be different, and the memory
          * would have to be free'd only once.
          * It is easier to just create the data for the extension converter
          * separately when it is requested.
          */
         mbcsTable->swapLFNLStateTable=NULL;
         mbcsTable->swapLFNLFromUnicodeBytes=NULL;
         mbcsTable->swapLFNLName=NULL;
         /*
          * The reconstitutedData must be deleted only when the base converter
          * is unloaded.
          */
         mbcsTable->reconstitutedData=NULL;
         /*
          * Set a special, runtime-only outputType if the extension converter
          * is a DBCS version of a base converter that also maps single bytes.
          */
         if( sharedData->staticData->conversionType==UCNV_DBCS ||
                 (sharedData->staticData->conversionType==UCNV_MBCS &&
                  sharedData->staticData->minBytesPerChar>=2)
         ) {
             if(baseSharedData->mbcs.outputType==MBCS_OUTPUT_2_SISO) {
                 /* the base converter is SI/SO-stateful */
                 int32_t entry;
                 /* get the dbcs state from the state table entry for SO=0x0e */
                 entry=mbcsTable->stateTable[0][0xe];
                 if( MBCS_ENTRY_IS_FINAL(entry) &&
                     MBCS_ENTRY_FINAL_ACTION(entry)==MBCS_STATE_CHANGE_ONLY &&
                     MBCS_ENTRY_FINAL_STATE(entry)!=0
                 ) {
                     mbcsTable->dbcsOnlyState=(uint8_t)MBCS_ENTRY_FINAL_STATE(entry);
                     mbcsTable->outputType=MBCS_OUTPUT_DBCS_ONLY;
                 }
             } else if(
                 baseSharedData->staticData->conversionType==UCNV_MBCS &&
                 baseSharedData->staticData->minBytesPerChar==1 &&
                 baseSharedData->staticData->maxBytesPerChar==2 &&
                 mbcsTable->countStates<=127
             ) {
                 /* non-stateful base converter, need to modify the state table */
                 int32_t (*newStateTable)[256];
                 int32_t *state;
                 int32_t i, count;
                 /* allocate a new state table and copy the base state table contents */
                 count=mbcsTable->countStates;
                 newStateTable=(int32_t (*)[256])uprv_malloc((count+1)*1024);
                 if(newStateTable==NULL) {
                     ucnv_unload(baseSharedData);
                     *pErrorCode=U_MEMORY_ALLOCATION_ERROR;
                     return;
                 }
                 uprv_memcpy(newStateTable, mbcsTable->stateTable, count*1024);
                 /* change all final single-byte entries to go to a new all-illegal state */
                 state=newStateTable[0];
                 for(i=0; i<256; ++i) {
                     if(MBCS_ENTRY_IS_FINAL(state[i])) {
                         state[i]=MBCS_ENTRY_TRANSITION(count, 0);
                     }
                 }
                 /* build the new all-illegal state */
                 state=newStateTable[count];
                 for(i=0; i<256; ++i) {
                     state[i]=MBCS_ENTRY_FINAL(0, MBCS_STATE_ILLEGAL, 0);
                 }
                 mbcsTable->stateTable=(const int32_t (*)[256])newStateTable;
                 mbcsTable->countStates=(uint8_t)(count+1);
                 mbcsTable->stateTableOwned=TRUE;
                 mbcsTable->outputType=MBCS_OUTPUT_DBCS_ONLY;
             }
         }
         /*
          * unlike below for files with base tables, do not get the unicodeMask
          * from the sharedData; instead, use the base table's unicodeMask,
          * which we copied in the memcpy above;
          * this is necessary because the static data unicodeMask, especially
          * the UCNV_HAS_SUPPLEMENTARY flag, is part of the base table data
          */
     } else {
         /* conversion file with a base table; an additional extension table is optional */
         /* make sure that the output type is known */
         switch(mbcsTable->outputType) {
         case MBCS_OUTPUT_1:
         case MBCS_OUTPUT_2:
         case MBCS_OUTPUT_3:
         case MBCS_OUTPUT_4:
         case MBCS_OUTPUT_3_EUC:
         case MBCS_OUTPUT_4_EUC:
         case MBCS_OUTPUT_2_SISO:
             /* OK */
             break;
         default:
             *pErrorCode=U_INVALID_TABLE_FORMAT;
             return;
         }
         if(pArgs->onlyTestIsLoadable) {
             /*
              * Exit as soon as we know that we can load the converter
              * and the format is valid and supported.
              * The worst that can happen in the following code is a memory
              * allocation error.
              */
             return;
         }
         mbcsTable->countStates=(uint8_t)header->countStates;
         mbcsTable->countToUFallbacks=header->countToUFallbacks;
         mbcsTable->stateTable=(const int32_t (*)[256])(raw+headerLength*4);
         mbcsTable->toUFallbacks=(const _MBCSToUFallback *)(mbcsTable->stateTable+header->countStates);
         mbcsTable->unicodeCodeUnits=(const uint16_t *)(raw+header->offsetToUCodeUnits);
         mbcsTable->fromUnicodeTable=(const uint16_t *)(raw+header->offsetFromUTable);
         mbcsTable->fromUnicodeBytes=(const uint8_t *)(raw+header->offsetFromUBytes);
         mbcsTable->fromUBytesLength=header->fromUBytesLength;
         /*
          * converter versions 6.1 and up contain a unicodeMask that is
          * used here to select the most efficient function implementations
          */
         info.size=sizeof(UDataInfo);
         udata_getInfo((UDataMemory *)sharedData->dataMemory, &info);
         if(info.formatVersion[0]>6 || (info.formatVersion[0]==6 && info.formatVersion[1]>=1)) {
             /* mask off possible future extensions to be safe */
             mbcsTable->unicodeMask=(uint8_t)(sharedData->staticData->unicodeMask&3);
         } else {
             /* for older versions, assume worst case: contains anything possible (prevent over-optimizations) */
             mbcsTable->unicodeMask=UCNV_HAS_SUPPLEMENTARY|UCNV_HAS_SURROGATES;
         }
         /*
          * _MBCSHeader.version 4.3 adds utf8Friendly data structures.
          * Check for the header version, SBCS vs. MBCS, and for whether the
          * data structures are optimized for code points as high as what the
          * runtime code is designed for.
          * The implementation does not handle mapping tables with entries for
          * unpaired surrogates.
          */
         if( header->version[1]>=3 &&
             (mbcsTable->unicodeMask&UCNV_HAS_SURROGATES)==0 &&
             (mbcsTable->countStates==1 ?
                 (header->version[2]>=(SBCS_FAST_MAX>>8)) :
                 (header->version[2]>=(MBCS_FAST_MAX>>8))
             )
         ) {
             mbcsTable->utf8Friendly=TRUE;
             if(mbcsTable->countStates==1) {
                 /*
                  * SBCS: Stage 3 is allocated in 64-entry blocks for U+0000..SBCS_FAST_MAX or higher.
                  * Build a table with indexes to each block, to be used instead of
                  * the regular stage 1/2 table.
                  */
                 int32_t i;
                 for(i=0; i<(SBCS_FAST_LIMIT>>6); ++i) {
                     mbcsTable->sbcsIndex[i]=mbcsTable->fromUnicodeTable[mbcsTable->fromUnicodeTable[i>>4]+((i<<2)&0x3c)];
                 }
                 /* set SBCS_FAST_MAX to reflect the reach of sbcsIndex[] even if header->version[2]>(SBCS_FAST_MAX>>8) */
                 mbcsTable->maxFastUChar=SBCS_FAST_MAX;
             } else {
                 /*
                  * MBCS: Stage 3 is allocated in 64-entry blocks for U+0000..MBCS_FAST_MAX or higher.
                  * The .cnv file is prebuilt with an additional stage table with indexes
                  * to each block.
                  */
                 mbcsTable->mbcsIndex=(const uint16_t *)
                     (mbcsTable->fromUnicodeBytes+
                      (noFromU ? 0 : mbcsTable->fromUBytesLength));
                 mbcsTable->maxFastUChar=(((UChar)header->version[2])<<8)|0xff;
             }
         }
         /* calculate a bit set of 4 ASCII characters per bit that round-trip to ASCII bytes */
         {
             uint32_t asciiRoundtrips=0xffffffff;
             int32_t i;
             for(i=0; i<0x80; ++i) {
                 if(mbcsTable->stateTable[0][i]!=MBCS_ENTRY_FINAL(0, MBCS_STATE_VALID_DIRECT_16, i)) {
                     asciiRoundtrips&=~((uint32_t)1<<(i>>2));
                 }
             }
             mbcsTable->asciiRoundtrips=asciiRoundtrips;
         }
         if(noFromU) {
             uint32_t stage1Length=
                 mbcsTable->unicodeMask&UCNV_HAS_SUPPLEMENTARY ?
 x440 : 0x40;
             uint32_t stage2Length=
                 (header->offsetFromUBytes-header->offsetFromUTable)/4-
                 stage1Length/2;
             reconstituteData(mbcsTable, stage1Length, stage2Length, header->fullStage2Length, pErrorCode);
         }
     }
     /* Set the impl pointer here so that it is set for both extension-only and base tables. */
     if(mbcsTable->utf8Friendly) {
         if(mbcsTable->countStates==1) {
             sharedData->impl=&_SBCSUTF8Impl;
         } else {
             if(mbcsTable->outputType==MBCS_OUTPUT_2) {
                 sharedData->impl=&_DBCSUTF8Impl;
             }
         }
     }
     if(mbcsTable->outputType==MBCS_OUTPUT_DBCS_ONLY || mbcsTable->outputType==MBCS_OUTPUT_2_SISO) {
         /*
          * MBCS_OUTPUT_DBCS_ONLY: No SBCS mappings, therefore ASCII does not roundtrip.
          * MBCS_OUTPUT_2_SISO: Bypass the ASCII fastpath to handle prevLength correctly.
          */
         mbcsTable->asciiRoundtrips=0;
     }
 }
 static void
 ucnv_MBCSUnload(UConverterSharedData *sharedData) {
     UConverterMBCSTable *mbcsTable=&sharedData->mbcs;
     if(mbcsTable->swapLFNLStateTable!=NULL) {
         uprv_free(mbcsTable->swapLFNLStateTable);
     }
     if(mbcsTable->stateTableOwned) {
         uprv_free((void *)mbcsTable->stateTable);
     }
     if(mbcsTable->baseSharedData!=NULL) {
         ucnv_unload(mbcsTable->baseSharedData);
     }
     if(mbcsTable->reconstitutedData!=NULL) {
         uprv_free(mbcsTable->reconstitutedData);
     }
 }
 static void
 ucnv_MBCSOpen(UConverter *cnv,
               UConverterLoadArgs *pArgs,
               UErrorCode *pErrorCode) {
     UConverterMBCSTable *mbcsTable;
     const int32_t *extIndexes;
     uint8_t outputType;
     int8_t maxBytesPerUChar;
     if(pArgs->onlyTestIsLoadable) {
         return;
     }
     mbcsTable=&cnv->sharedData->mbcs;
     outputType=mbcsTable->outputType;
     if(outputType==MBCS_OUTPUT_DBCS_ONLY) {
         /* the swaplfnl option does not apply, remove it */
         cnv->options=pArgs->options&=~UCNV_OPTION_SWAP_LFNL;
     }
     if((pArgs->options&UCNV_OPTION_SWAP_LFNL)!=0) {
         /* do this because double-checked locking is broken */
         UBool isCached;
         umtx_lock(NULL);
         isCached=mbcsTable->swapLFNLStateTable!=NULL;
         umtx_unlock(NULL);
         if(!isCached) {
             if(!_EBCDICSwapLFNL(cnv->sharedData, pErrorCode)) {
                 if(U_FAILURE(*pErrorCode)) {
                     return; /* something went wrong */
                 }
                 /* the option does not apply, remove it */
                 cnv->options=pArgs->options&=~UCNV_OPTION_SWAP_LFNL;
             }
         }
     }
     if(uprv_strstr(pArgs->name, "18030")!=NULL) {
         if(uprv_strstr(pArgs->name, "gb18030")!=NULL || uprv_strstr(pArgs->name, "GB18030")!=NULL) {
             /* set a flag for GB 18030 mode, which changes the callback behavior */
             cnv->options|=_MBCS_OPTION_GB18030;
         }
     } else if((uprv_strstr(pArgs->name, "KEIS")!=NULL) || (uprv_strstr(pArgs->name, "keis")!=NULL)) {
         /* set a flag for KEIS converter, which changes the SI/SO character sequence */
         cnv->options|=_MBCS_OPTION_KEIS;
     } else if((uprv_strstr(pArgs->name, "JEF")!=NULL) || (uprv_strstr(pArgs->name, "jef")!=NULL)) {
         /* set a flag for JEF converter, which changes the SI/SO character sequence */
         cnv->options|=_MBCS_OPTION_JEF;
     } else if((uprv_strstr(pArgs->name, "JIPS")!=NULL) || (uprv_strstr(pArgs->name, "jips")!=NULL)) {
         /* set a flag for JIPS converter, which changes the SI/SO character sequence */
         cnv->options|=_MBCS_OPTION_JIPS;
     }
     /* fix maxBytesPerUChar depending on outputType and options etc. */
     if(outputType==MBCS_OUTPUT_2_SISO) {
         cnv->maxBytesPerUChar=3; /* SO+DBCS */
     }
     extIndexes=mbcsTable->extIndexes;
     if(extIndexes!=NULL) {
         maxBytesPerUChar=(int8_t)UCNV_GET_MAX_BYTES_PER_UCHAR(extIndexes);
         if(outputType==MBCS_OUTPUT_2_SISO) {
             ++maxBytesPerUChar; /* SO + multiple DBCS */
         }
         if(maxBytesPerUChar>cnv->maxBytesPerUChar) {
             cnv->maxBytesPerUChar=maxBytesPerUChar;
         }
     }
 #if 0
     /*
      * documentation of UConverter fields used for status
      * all of these fields are (re)set to 0 by ucnv_bld.c and ucnv_reset()
      */
     /* toUnicode */
     cnv->toUnicodeStatus=0;     /* offset */
     cnv->mode=0;                /* state */
     cnv->toULength=0;           /* byteIndex */
     /* fromUnicode */
     cnv->fromUChar32=0;
     cnv->fromUnicodeStatus=1;   /* prevLength */
 #endif
 }
 static const char *
 ucnv_MBCSGetName(const UConverter *cnv) {
     if((cnv->options&UCNV_OPTION_SWAP_LFNL)!=0 && cnv->sharedData->mbcs.swapLFNLName!=NULL) {
         return cnv->sharedData->mbcs.swapLFNLName;
     } else {
         return cnv->sharedData->staticData->name;
     }
 }
 /* MBCS-to-Unicode conversion functions ------------------------------------- */
 static UChar32
 ucnv_MBCSGetFallback(UConverterMBCSTable *mbcsTable, uint32_t offset) {
     const _MBCSToUFallback *toUFallbacks;
     uint32_t i, start, limit;
     limit=mbcsTable->countToUFallbacks;
     if(limit>0) {
         /* do a binary search for the fallback mapping */
         toUFallbacks=mbcsTable->toUFallbacks;
         start=0;
         while(start<limit-1) {
             i=(start+limit)/2;
             if(offset<toUFallbacks[i].offset) {
                 limit=i;
             } else {
                 start=i;
             }
         }
         /* did we really find it? */
         if(offset==toUFallbacks[start].offset) {
             return toUFallbacks[start].codePoint;
         }
     }
     return 0xfffe;
 }
 /* This version of ucnv_MBCSToUnicodeWithOffsets() is optimized for single-byte, single-state codepages. */
 static void
 ucnv_MBCSSingleToUnicodeWithOffsets(UConverterToUnicodeArgs *pArgs,
                                 UErrorCode *pErrorCode) {
     UConverter *cnv;
     const uint8_t *source, *sourceLimit;
     UChar *target;
     const UChar *targetLimit;
     int32_t *offsets;
     const int32_t (*stateTable)[256];
     int32_t sourceIndex;
     int32_t entry;
     UChar c;
     uint8_t action;
     /* set up the local pointers */
     cnv=pArgs->converter;
     source=(const uint8_t *)pArgs->source;
     sourceLimit=(const uint8_t *)pArgs->sourceLimit;
     target=pArgs->target;
     targetLimit=pArgs->targetLimit;
     offsets=pArgs->offsets;
     if((cnv->options&UCNV_OPTION_SWAP_LFNL)!=0) {
         stateTable=(const int32_t (*)[256])cnv->sharedData->mbcs.swapLFNLStateTable;
     } else {
         stateTable=cnv->sharedData->mbcs.stateTable;
     }
     /* sourceIndex=-1 if the current character began in the previous buffer */
     sourceIndex=0;
     /* conversion loop */
     while(source<sourceLimit) {
         /*
          * This following test is to see if available input would overflow the output.
          * It does not catch output of more than one code unit that
          * overflows as a result of a surrogate pair or callback output
          * from the last source byte.
          * Therefore, those situations also test for overflows and will
          * then break the loop, too.
          */
         if(target>=targetLimit) {
             /* target is full */
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             break;
         }
         entry=stateTable[0][*source++];
         /* MBCS_ENTRY_IS_FINAL(entry) */
         /* test the most common case first */
         if(MBCS_ENTRY_FINAL_IS_VALID_DIRECT_16(entry)) {
             /* output BMP code point */
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             if(offsets!=NULL) {
                 *offsets++=sourceIndex;
             }
             /* normal end of action codes: prepare for a new character */
             ++sourceIndex;
             continue;
         }
         /*
          * An if-else-if chain provides more reliable performance for
          * the most common cases compared to a switch.
          */
         action=(uint8_t)(MBCS_ENTRY_FINAL_ACTION(entry));
         if(action==MBCS_STATE_VALID_DIRECT_20 ||
            (action==MBCS_STATE_FALLBACK_DIRECT_20 && UCNV_TO_U_USE_FALLBACK(cnv))
         ) {
             entry=MBCS_ENTRY_FINAL_VALUE(entry);
             /* output surrogate pair */
             *target++=(UChar)(0xd800|(UChar)(entry>>10));
             if(offsets!=NULL) {
                 *offsets++=sourceIndex;
             }
             c=(UChar)(0xdc00|(UChar)(entry&0x3ff));
             if(target<targetLimit) {
                 *target++=c;
                 if(offsets!=NULL) {
                     *offsets++=sourceIndex;
                 }
             } else {
                 /* target overflow */
                 cnv->UCharErrorBuffer[0]=c;
                 cnv->UCharErrorBufferLength=1;
                 *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                 break;
             }
             ++sourceIndex;
             continue;
         } else if(action==MBCS_STATE_FALLBACK_DIRECT_16) {
             if(UCNV_TO_U_USE_FALLBACK(cnv)) {
                 /* output BMP code point */
                 *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
                 if(offsets!=NULL) {
                     *offsets++=sourceIndex;
                 }
                 ++sourceIndex;
                 continue;
             }
         } else if(action==MBCS_STATE_UNASSIGNED) {
             /* just fall through */
         } else if(action==MBCS_STATE_ILLEGAL) {
             /* callback(illegal) */
             *pErrorCode=U_ILLEGAL_CHAR_FOUND;
         } else {
             /* reserved, must never occur */
             ++sourceIndex;
             continue;
         }
         if(U_FAILURE(*pErrorCode)) {
             /* callback(illegal) */
             break;
         } else /* unassigned sequences indicated with byteIndex>0 */ {
             /* try an extension mapping */
             pArgs->source=(const char *)source;
             cnv->toUBytes[0]=*(source-1);
             cnv->toULength=_extToU(cnv, cnv->sharedData,
 , &source, sourceLimit,
                                     &target, targetLimit,
                                     &offsets, sourceIndex,
                                     pArgs->flush,
                                     pErrorCode);
             sourceIndex+=1+(int32_t)(source-(const uint8_t *)pArgs->source);
             if(U_FAILURE(*pErrorCode)) {
                 /* not mappable or buffer overflow */
                 break;
             }
         }
     }
     /* write back the updated pointers */
     pArgs->source=(const char *)source;
     pArgs->target=target;
     pArgs->offsets=offsets;
 }
 /*
  * This version of ucnv_MBCSSingleToUnicodeWithOffsets() is optimized for single-byte, single-state codepages
  * that only map to and from the BMP.
  * In addition to single-byte optimizations, the offset calculations
  * become much easier.
  */
 static void
 ucnv_MBCSSingleToBMPWithOffsets(UConverterToUnicodeArgs *pArgs,
                             UErrorCode *pErrorCode) {
     UConverter *cnv;
     const uint8_t *source, *sourceLimit, *lastSource;
     UChar *target;
     int32_t targetCapacity, length;
     int32_t *offsets;
     const int32_t (*stateTable)[256];
     int32_t sourceIndex;
     int32_t entry;
     uint8_t action;
     /* set up the local pointers */
     cnv=pArgs->converter;
     source=(const uint8_t *)pArgs->source;
     sourceLimit=(const uint8_t *)pArgs->sourceLimit;
     target=pArgs->target;
     targetCapacity=(int32_t)(pArgs->targetLimit-pArgs->target);
     offsets=pArgs->offsets;
     if((cnv->options&UCNV_OPTION_SWAP_LFNL)!=0) {
         stateTable=(const int32_t (*)[256])cnv->sharedData->mbcs.swapLFNLStateTable;
     } else {
         stateTable=cnv->sharedData->mbcs.stateTable;
     }
     /* sourceIndex=-1 if the current character began in the previous buffer */
     sourceIndex=0;
     lastSource=source;
     /*
      * since the conversion here is 1:1 UChar:uint8_t, we need only one counter
      * for the minimum of the sourceLength and targetCapacity
      */
     length=(int32_t)(sourceLimit-source);
     if(length<targetCapacity) {
         targetCapacity=length;
     }
 #if MBCS_UNROLL_SINGLE_TO_BMP
     /* unrolling makes it faster on Pentium III/Windows 2000 */
     /* unroll the loop with the most common case */
 unrolled:
     if(targetCapacity>=16) {
         int32_t count, loops, oredEntries;
         loops=count=targetCapacity>>4;
         do {
             oredEntries=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             oredEntries|=entry=stateTable[0][*source++];
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             /* were all 16 entries really valid? */
             if(!MBCS_ENTRY_FINAL_IS_VALID_DIRECT_16(oredEntries)) {
                 /* no, return to the first of these 16 */
                 source-=16;
                 target-=16;
                 break;
             }
         } while(--count>0);
         count=loops-count;
         targetCapacity-=16*count;
         if(offsets!=NULL) {
             lastSource+=16*count;
             while(count>0) {
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 --count;
             }
         }
     }
 #endif
     /* conversion loop */
     while(targetCapacity > 0 && source < sourceLimit) {
         entry=stateTable[0][*source++];
         /* MBCS_ENTRY_IS_FINAL(entry) */
         /* test the most common case first */
         if(MBCS_ENTRY_FINAL_IS_VALID_DIRECT_16(entry)) {
             /* output BMP code point */
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             --targetCapacity;
             continue;
         }
         /*
          * An if-else-if chain provides more reliable performance for
          * the most common cases compared to a switch.
          */
         action=(uint8_t)(MBCS_ENTRY_FINAL_ACTION(entry));
         if(action==MBCS_STATE_FALLBACK_DIRECT_16) {
             if(UCNV_TO_U_USE_FALLBACK(cnv)) {
                 /* output BMP code point */
                 *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
                 --targetCapacity;
                 continue;
             }
         } else if(action==MBCS_STATE_UNASSIGNED) {
             /* just fall through */
         } else if(action==MBCS_STATE_ILLEGAL) {
             /* callback(illegal) */
             *pErrorCode=U_ILLEGAL_CHAR_FOUND;
         } else {
             /* reserved, must never occur */
             continue;
         }
         /* set offsets since the start or the last extension */
         if(offsets!=NULL) {
             int32_t count=(int32_t)(source-lastSource);
             /* predecrement: do not set the offset for the callback-causing character */
             while(--count>0) {
                 *offsets++=sourceIndex++;
             }
             /* offset and sourceIndex are now set for the current character */
         }
         if(U_FAILURE(*pErrorCode)) {
             /* callback(illegal) */
             break;
         } else /* unassigned sequences indicated with byteIndex>0 */ {
             /* try an extension mapping */
             lastSource=source;
             cnv->toUBytes[0]=*(source-1);
             cnv->toULength=_extToU(cnv, cnv->sharedData,
 , &source, sourceLimit,
                                     &target, pArgs->targetLimit,
                                     &offsets, sourceIndex,
                                     pArgs->flush,
                                     pErrorCode);
             sourceIndex+=1+(int32_t)(source-lastSource);
             if(U_FAILURE(*pErrorCode)) {
                 /* not mappable or buffer overflow */
                 break;
             }
             /* recalculate the targetCapacity after an extension mapping */
             targetCapacity=(int32_t)(pArgs->targetLimit-target);
             length=(int32_t)(sourceLimit-source);
             if(length<targetCapacity) {
                 targetCapacity=length;
             }
         }
 #if MBCS_UNROLL_SINGLE_TO_BMP
         /* unrolling makes it faster on Pentium III/Windows 2000 */
         goto unrolled;
 #endif
     }
     if(U_SUCCESS(*pErrorCode) && source<sourceLimit && target>=pArgs->targetLimit) {
         /* target is full */
         *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
     }
     /* set offsets since the start or the last callback */
     if(offsets!=NULL) {
         size_t count=source-lastSource;
         while(count>0) {
             *offsets++=sourceIndex++;
             --count;
         }
     }
     /* write back the updated pointers */
     pArgs->source=(const char *)source;
     pArgs->target=target;
     pArgs->offsets=offsets;
 }
 static UBool
 hasValidTrailBytes(const int32_t (*stateTable)[256], uint8_t state) {
     const int32_t *row=stateTable[state];
     int32_t b, entry;
     /* First test for final entries in this state for some commonly valid byte values. */
     entry=row[0xa1];
     if( !MBCS_ENTRY_IS_TRANSITION(entry) &&
         MBCS_ENTRY_FINAL_ACTION(entry)!=MBCS_STATE_ILLEGAL
     ) {
         return TRUE;
     }
     entry=row[0x41];
     if( !MBCS_ENTRY_IS_TRANSITION(entry) &&
         MBCS_ENTRY_FINAL_ACTION(entry)!=MBCS_STATE_ILLEGAL
     ) {
         return TRUE;
     }
     /* Then test for final entries in this state. */
     for(b=0; b<=0xff; ++b) {
         entry=row[b];
         if( !MBCS_ENTRY_IS_TRANSITION(entry) &&
             MBCS_ENTRY_FINAL_ACTION(entry)!=MBCS_STATE_ILLEGAL
         ) {
             return TRUE;
         }
     }
     /* Then recurse for transition entries. */
     for(b=0; b<=0xff; ++b) {
         entry=row[b];
         if( MBCS_ENTRY_IS_TRANSITION(entry) &&
             hasValidTrailBytes(stateTable, (uint8_t)MBCS_ENTRY_TRANSITION_STATE(entry))
         ) {
             return TRUE;
         }
     }
     return FALSE;
 }
 /*
  * Is byte b a single/lead byte in this state?
  * Recurse for transition states, because here we don't want to say that
  * b is a lead byte if all byte sequences that start with b are illegal.
  */
 static UBool
 isSingleOrLead(const int32_t (*stateTable)[256], uint8_t state, UBool isDBCSOnly, uint8_t b) {
     const int32_t *row=stateTable[state];
     int32_t entry=row[b];
     if(MBCS_ENTRY_IS_TRANSITION(entry)) {   /* lead byte */
         return hasValidTrailBytes(stateTable, (uint8_t)MBCS_ENTRY_TRANSITION_STATE(entry));
     } else {
         uint8_t action=(uint8_t)(MBCS_ENTRY_FINAL_ACTION(entry));
         if(action==MBCS_STATE_CHANGE_ONLY && isDBCSOnly) {
             return FALSE;   /* SI/SO are illegal for DBCS-only conversion */
         } else {
             return action!=MBCS_STATE_ILLEGAL;
         }
     }
 }
 U_CFUNC void
 ucnv_MBCSToUnicodeWithOffsets(UConverterToUnicodeArgs *pArgs,
                           UErrorCode *pErrorCode) {
     UConverter *cnv;
     const uint8_t *source, *sourceLimit;
     UChar *target;
     const UChar *targetLimit;
     int32_t *offsets;
     const int32_t (*stateTable)[256];
     const uint16_t *unicodeCodeUnits;
     uint32_t offset;
     uint8_t state;
     int8_t byteIndex;
     uint8_t *bytes;
     int32_t sourceIndex, nextSourceIndex;
     int32_t entry;
     UChar c;
     uint8_t action;
     /* use optimized function if possible */
     cnv=pArgs->converter;
     if(cnv->preToULength>0) {
         /*
          * pass sourceIndex=-1 because we continue from an earlier buffer
          * in the future, this may change with continuous offsets
          */
         ucnv_extContinueMatchToU(cnv, pArgs, -1, pErrorCode);
         if(U_FAILURE(*pErrorCode) || cnv->preToULength<0) {
             return;
         }
     }
     if(cnv->sharedData->mbcs.countStates==1) {
         if(!(cnv->sharedData->mbcs.unicodeMask&UCNV_HAS_SUPPLEMENTARY)) {
             ucnv_MBCSSingleToBMPWithOffsets(pArgs, pErrorCode);
         } else {
             ucnv_MBCSSingleToUnicodeWithOffsets(pArgs, pErrorCode);
         }
         return;
     }
     /* set up the local pointers */
     source=(const uint8_t *)pArgs->source;
     sourceLimit=(const uint8_t *)pArgs->sourceLimit;
     target=pArgs->target;
     targetLimit=pArgs->targetLimit;
     offsets=pArgs->offsets;
     if((cnv->options&UCNV_OPTION_SWAP_LFNL)!=0) {
         stateTable=(const int32_t (*)[256])cnv->sharedData->mbcs.swapLFNLStateTable;
     } else {
         stateTable=cnv->sharedData->mbcs.stateTable;
     }
     unicodeCodeUnits=cnv->sharedData->mbcs.unicodeCodeUnits;
     /* get the converter state from UConverter */
     offset=cnv->toUnicodeStatus;
     byteIndex=cnv->toULength;
     bytes=cnv->toUBytes;
     /*
      * if we are in the SBCS state for a DBCS-only converter,
      * then load the DBCS state from the MBCS data
      * (dbcsOnlyState==0 if it is not a DBCS-only converter)
      */
     if((state=(uint8_t)(cnv->mode))==0) {
         state=cnv->sharedData->mbcs.dbcsOnlyState;
     }
     /* sourceIndex=-1 if the current character began in the previous buffer */
     sourceIndex=byteIndex==0 ? 0 : -1;
     nextSourceIndex=0;
     /* conversion loop */
     while(source<sourceLimit) {
         /*
          * This following test is to see if available input would overflow the output.
          * It does not catch output of more than one code unit that
          * overflows as a result of a surrogate pair or callback output
          * from the last source byte.
          * Therefore, those situations also test for overflows and will
          * then break the loop, too.
          */
         if(target>=targetLimit) {
             /* target is full */
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             break;
         }
         if(byteIndex==0) {
             /* optimized loop for 1/2-byte input and BMP output */
             if(offsets==NULL) {
                 do {
                     entry=stateTable[state][*source];
                     if(MBCS_ENTRY_IS_TRANSITION(entry)) {
                         state=(uint8_t)MBCS_ENTRY_TRANSITION_STATE(entry);
                         offset=MBCS_ENTRY_TRANSITION_OFFSET(entry);
                         ++source;
                         if( source<sourceLimit &&
                             MBCS_ENTRY_IS_FINAL(entry=stateTable[state][*source]) &&
                             MBCS_ENTRY_FINAL_ACTION(entry)==MBCS_STATE_VALID_16 &&
                             (c=unicodeCodeUnits[offset+MBCS_ENTRY_FINAL_VALUE_16(entry)])<0xfffe
                         ) {
                             ++source;
                             *target++=c;
                             state=(uint8_t)MBCS_ENTRY_FINAL_STATE(entry); /* typically 0 */
                             offset=0;
                         } else {
                             /* set the state and leave the optimized loop */
                             bytes[0]=*(source-1);
                             byteIndex=1;
                             break;
                         }
                     } else {
                         if(MBCS_ENTRY_FINAL_IS_VALID_DIRECT_16(entry)) {
                             /* output BMP code point */
                             ++source;
                             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
                             state=(uint8_t)MBCS_ENTRY_FINAL_STATE(entry); /* typically 0 */
                         } else {
                             /* leave the optimized loop */
                             break;
                         }
                     }
                 } while(source<sourceLimit && target<targetLimit);
             } else /* offsets!=NULL */ {
                 do {
                     entry=stateTable[state][*source];
                     if(MBCS_ENTRY_IS_TRANSITION(entry)) {
                         state=(uint8_t)MBCS_ENTRY_TRANSITION_STATE(entry);
                         offset=MBCS_ENTRY_TRANSITION_OFFSET(entry);
                         ++source;
                         if( source<sourceLimit &&
                             MBCS_ENTRY_IS_FINAL(entry=stateTable[state][*source]) &&
                             MBCS_ENTRY_FINAL_ACTION(entry)==MBCS_STATE_VALID_16 &&
                             (c=unicodeCodeUnits[offset+MBCS_ENTRY_FINAL_VALUE_16(entry)])<0xfffe
                         ) {
                             ++source;
                             *target++=c;
                             if(offsets!=NULL) {
                                 *offsets++=sourceIndex;
                                 sourceIndex=(nextSourceIndex+=2);
                             }
                             state=(uint8_t)MBCS_ENTRY_FINAL_STATE(entry); /* typically 0 */
                             offset=0;
                         } else {
                             /* set the state and leave the optimized loop */
                             ++nextSourceIndex;
                             bytes[0]=*(source-1);
                             byteIndex=1;
                             break;
                         }
                     } else {
                         if(MBCS_ENTRY_FINAL_IS_VALID_DIRECT_16(entry)) {
                             /* output BMP code point */
                             ++source;
                             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
                             if(offsets!=NULL) {
                                 *offsets++=sourceIndex;
                                 sourceIndex=++nextSourceIndex;
                             }
                             state=(uint8_t)MBCS_ENTRY_FINAL_STATE(entry); /* typically 0 */
                         } else {
                             /* leave the optimized loop */
                             break;
                         }
                     }
                 } while(source<sourceLimit && target<targetLimit);
             }
             /*
              * these tests and break statements could be put inside the loop
              * if C had "break outerLoop" like Java
              */
             if(source>=sourceLimit) {
                 break;
             }
             if(target>=targetLimit) {
                 /* target is full */
                 *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                 break;
             }
             ++nextSourceIndex;
             bytes[byteIndex++]=*source++;
         } else /* byteIndex>0 */ {
             ++nextSourceIndex;
             entry=stateTable[state][bytes[byteIndex++]=*source++];
         }
         if(MBCS_ENTRY_IS_TRANSITION(entry)) {
             state=(uint8_t)MBCS_ENTRY_TRANSITION_STATE(entry);
             offset+=MBCS_ENTRY_TRANSITION_OFFSET(entry);
             continue;
         }
         /* save the previous state for proper extension mapping with SI/SO-stateful converters */
         cnv->mode=state;
         /* set the next state early so that we can reuse the entry variable */
         state=(uint8_t)MBCS_ENTRY_FINAL_STATE(entry); /* typically 0 */
         /*
          * An if-else-if chain provides more reliable performance for
          * the most common cases compared to a switch.
          */
         action=(uint8_t)(MBCS_ENTRY_FINAL_ACTION(entry));
         if(action==MBCS_STATE_VALID_16) {
             offset+=MBCS_ENTRY_FINAL_VALUE_16(entry);
             c=unicodeCodeUnits[offset];
             if(c<0xfffe) {
                 /* output BMP code point */
                 *target++=c;
                 if(offsets!=NULL) {
                     *offsets++=sourceIndex;
                 }
                 byteIndex=0;
             } else if(c==0xfffe) {
                 if(UCNV_TO_U_USE_FALLBACK(cnv) && (entry=(int32_t)ucnv_MBCSGetFallback(&cnv->sharedData->mbcs, offset))!=0xfffe) {
                     /* output fallback BMP code point */
                     *target++=(UChar)entry;
                     if(offsets!=NULL) {
                         *offsets++=sourceIndex;
                     }
                     byteIndex=0;
                 }
             } else {
                 /* callback(illegal) */
                 *pErrorCode=U_ILLEGAL_CHAR_FOUND;
             }
         } else if(action==MBCS_STATE_VALID_DIRECT_16) {
             /* output BMP code point */
             *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             if(offsets!=NULL) {
                 *offsets++=sourceIndex;
             }
             byteIndex=0;
         } else if(action==MBCS_STATE_VALID_16_PAIR) {
             offset+=MBCS_ENTRY_FINAL_VALUE_16(entry);
             c=unicodeCodeUnits[offset++];
             if(c<0xd800) {
                 /* output BMP code point below 0xd800 */
                 *target++=c;
                 if(offsets!=NULL) {
                     *offsets++=sourceIndex;
                 }
                 byteIndex=0;
             } else if(UCNV_TO_U_USE_FALLBACK(cnv) ? c<=0xdfff : c<=0xdbff) {
                 /* output roundtrip or fallback surrogate pair */
                 *target++=(UChar)(c&0xdbff);
                 if(offsets!=NULL) {
                     *offsets++=sourceIndex;
                 }
                 byteIndex=0;
                 if(target<targetLimit) {
                     *target++=unicodeCodeUnits[offset];
                     if(offsets!=NULL) {
                         *offsets++=sourceIndex;
                     }
                 } else {
                     /* target overflow */
                     cnv->UCharErrorBuffer[0]=unicodeCodeUnits[offset];
                     cnv->UCharErrorBufferLength=1;
                     *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                     offset=0;
                     break;
                 }
             } else if(UCNV_TO_U_USE_FALLBACK(cnv) ? (c&0xfffe)==0xe000 : c==0xe000) {
                 /* output roundtrip BMP code point above 0xd800 or fallback BMP code point */
                 *target++=unicodeCodeUnits[offset];
                 if(offsets!=NULL) {
                     *offsets++=sourceIndex;
                 }
                 byteIndex=0;
             } else if(c==0xffff) {
                 /* callback(illegal) */
                 *pErrorCode=U_ILLEGAL_CHAR_FOUND;
             }
         } else if(action==MBCS_STATE_VALID_DIRECT_20 ||
                   (action==MBCS_STATE_FALLBACK_DIRECT_20 && UCNV_TO_U_USE_FALLBACK(cnv))
         ) {
             entry=MBCS_ENTRY_FINAL_VALUE(entry);
             /* output surrogate pair */
             *target++=(UChar)(0xd800|(UChar)(entry>>10));
             if(offsets!=NULL) {
                 *offsets++=sourceIndex;
             }
             byteIndex=0;
             c=(UChar)(0xdc00|(UChar)(entry&0x3ff));
             if(target<targetLimit) {
                 *target++=c;
                 if(offsets!=NULL) {
                     *offsets++=sourceIndex;
                 }
             } else {
                 /* target overflow */
                 cnv->UCharErrorBuffer[0]=c;
                 cnv->UCharErrorBufferLength=1;
                 *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                 offset=0;
                 break;
             }
         } else if(action==MBCS_STATE_CHANGE_ONLY) {
             /*
              * This serves as a state change without any output.
              * It is useful for reading simple stateful encodings,
              * for example using just Shift-In/Shift-Out codes.
              * The 21 unused bits may later be used for more sophisticated
              * state transitions.
              */
             if(cnv->sharedData->mbcs.dbcsOnlyState==0) {
                 byteIndex=0;
             } else {
                 /* SI/SO are illegal for DBCS-only conversion */
                 state=(uint8_t)(cnv->mode); /* restore the previous state */
                 /* callback(illegal) */
                 *pErrorCode=U_ILLEGAL_CHAR_FOUND;
             }
         } else if(action==MBCS_STATE_FALLBACK_DIRECT_16) {
             if(UCNV_TO_U_USE_FALLBACK(cnv)) {
                 /* output BMP code point */
                 *target++=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
                 if(offsets!=NULL) {
                     *offsets++=sourceIndex;
                 }
                 byteIndex=0;
             }
         } else if(action==MBCS_STATE_UNASSIGNED) {
             /* just fall through */
         } else if(action==MBCS_STATE_ILLEGAL) {
             /* callback(illegal) */
             *pErrorCode=U_ILLEGAL_CHAR_FOUND;
         } else {
             /* reserved, must never occur */
             byteIndex=0;
         }
         /* end of action codes: prepare for a new character */
         offset=0;
         if(byteIndex==0) {
             sourceIndex=nextSourceIndex;
         } else if(U_FAILURE(*pErrorCode)) {
             /* callback(illegal) */
             if(byteIndex>1) {
                 /*
                  * Ticket 5691: consistent illegal sequences:
                  * - We include at least the first byte in the illegal sequence.
                  * - If any of the non-initial bytes could be the start of a character,
                  *   we stop the illegal sequence before the first one of those.
                  */
                 UBool isDBCSOnly=(UBool)(cnv->sharedData->mbcs.dbcsOnlyState!=0);
                 int8_t i;
                 for(i=1;
                     i<byteIndex && !isSingleOrLead(stateTable, state, isDBCSOnly, bytes[i]);
                     ++i) {}
                 if(i<byteIndex) {
                     /* Back out some bytes. */
                     int8_t backOutDistance=byteIndex-i;
                     int32_t bytesFromThisBuffer=(int32_t)(source-(const uint8_t *)pArgs->source);
                     byteIndex=i;  /* length of reported illegal byte sequence */
                     if(backOutDistance<=bytesFromThisBuffer) {
                         source-=backOutDistance;
                     } else {
                         /* Back out bytes from the previous buffer: Need to replay them. */
                         cnv->preToULength=(int8_t)(bytesFromThisBuffer-backOutDistance);
                         /* preToULength is negative! */
                         uprv_memcpy(cnv->preToU, bytes+i, -cnv->preToULength);
                         source=(const uint8_t *)pArgs->source;
                     }
                 }
             }
             break;
         } else /* unassigned sequences indicated with byteIndex>0 */ {
             /* try an extension mapping */
             pArgs->source=(const char *)source;
             byteIndex=_extToU(cnv, cnv->sharedData,
                               byteIndex, &source, sourceLimit,
                               &target, targetLimit,
                               &offsets, sourceIndex,
                               pArgs->flush,
                               pErrorCode);
             sourceIndex=nextSourceIndex+=(int32_t)(source-(const uint8_t *)pArgs->source);
             if(U_FAILURE(*pErrorCode)) {
                 /* not mappable or buffer overflow */
                 break;
             }
         }
     }
     /* set the converter state back into UConverter */
     cnv->toUnicodeStatus=offset;
     cnv->mode=state;
     cnv->toULength=byteIndex;
     /* write back the updated pointers */
     pArgs->source=(const char *)source;
     pArgs->target=target;
     pArgs->offsets=offsets;
 }
 /*
  * This version of ucnv_MBCSGetNextUChar() is optimized for single-byte, single-state codepages.
  * We still need a conversion loop in case we find reserved action codes, which are to be ignored.
  */
 static UChar32
 ucnv_MBCSSingleGetNextUChar(UConverterToUnicodeArgs *pArgs,
                         UErrorCode *pErrorCode) {
     UConverter *cnv;
     const int32_t (*stateTable)[256];
     const uint8_t *source, *sourceLimit;
     int32_t entry;
     uint8_t action;
     /* set up the local pointers */
     cnv=pArgs->converter;
     source=(const uint8_t *)pArgs->source;
     sourceLimit=(const uint8_t *)pArgs->sourceLimit;
     if((cnv->options&UCNV_OPTION_SWAP_LFNL)!=0) {
         stateTable=(const int32_t (*)[256])cnv->sharedData->mbcs.swapLFNLStateTable;
     } else {
         stateTable=cnv->sharedData->mbcs.stateTable;
     }
     /* conversion loop */
     while(source<sourceLimit) {
         entry=stateTable[0][*source++];
         /* MBCS_ENTRY_IS_FINAL(entry) */
         /* write back the updated pointer early so that we can return directly */
         pArgs->source=(const char *)source;
         if(MBCS_ENTRY_FINAL_IS_VALID_DIRECT_16(entry)) {
             /* output BMP code point */
             return (UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
         }
         /*
          * An if-else-if chain provides more reliable performance for
          * the most common cases compared to a switch.
          */
         action=(uint8_t)(MBCS_ENTRY_FINAL_ACTION(entry));
         if( action==MBCS_STATE_VALID_DIRECT_20 ||
             (action==MBCS_STATE_FALLBACK_DIRECT_20 && UCNV_TO_U_USE_FALLBACK(cnv))
         ) {
             /* output supplementary code point */
             return (UChar32)(MBCS_ENTRY_FINAL_VALUE(entry)+0x10000);
         } else if(action==MBCS_STATE_FALLBACK_DIRECT_16) {
             if(UCNV_TO_U_USE_FALLBACK(cnv)) {
                 /* output BMP code point */
                 return (UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
             }
         } else if(action==MBCS_STATE_UNASSIGNED) {
             /* just fall through */
         } else if(action==MBCS_STATE_ILLEGAL) {
             /* callback(illegal) */
             *pErrorCode=U_ILLEGAL_CHAR_FOUND;
         } else {
             /* reserved, must never occur */
             continue;
         }
         if(U_FAILURE(*pErrorCode)) {
             /* callback(illegal) */
             break;
         } else /* unassigned sequence */ {
             /* defer to the generic implementation */
             pArgs->source=(const char *)source-1;
             return UCNV_GET_NEXT_UCHAR_USE_TO_U;
         }
     }
     /* no output because of empty input or only state changes */
     *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
     return 0xffff;
 }
 /*
  * Version of _MBCSToUnicodeWithOffsets() optimized for single-character
  * conversion without offset handling.
  *
  * When a character does not have a mapping to Unicode, then we return to the
  * generic ucnv_getNextUChar() code for extension/GB 18030 and error/callback
  * handling.
  * We also defer to the generic code in other complicated cases and have them
  * ultimately handled by _MBCSToUnicodeWithOffsets() itself.
  *
  * All normal mappings and errors are handled here.
  */
 static UChar32
 ucnv_MBCSGetNextUChar(UConverterToUnicodeArgs *pArgs,
                   UErrorCode *pErrorCode) {
     UConverter *cnv;
     const uint8_t *source, *sourceLimit, *lastSource;
     const int32_t (*stateTable)[256];
     const uint16_t *unicodeCodeUnits;
     uint32_t offset;
     uint8_t state;
     int32_t entry;
     UChar32 c;
     uint8_t action;
     /* use optimized function if possible */
     cnv=pArgs->converter;
     if(cnv->preToULength>0) {
         /* use the generic code in ucnv_getNextUChar() to continue with a partial match */
         return UCNV_GET_NEXT_UCHAR_USE_TO_U;
     }
     if(cnv->sharedData->mbcs.unicodeMask&UCNV_HAS_SURROGATES) {
         /*
          * Using the generic ucnv_getNextUChar() code lets us deal correctly
          * with the rare case of a codepage that maps single surrogates
          * without adding the complexity to this already complicated function here.
          */
         return UCNV_GET_NEXT_UCHAR_USE_TO_U;
     } else if(cnv->sharedData->mbcs.countStates==1) {
         return ucnv_MBCSSingleGetNextUChar(pArgs, pErrorCode);
     }
     /* set up the local pointers */
     source=lastSource=(const uint8_t *)pArgs->source;
     sourceLimit=(const uint8_t *)pArgs->sourceLimit;
     if((cnv->options&UCNV_OPTION_SWAP_LFNL)!=0) {
         stateTable=(const int32_t (*)[256])cnv->sharedData->mbcs.swapLFNLStateTable;
     } else {
         stateTable=cnv->sharedData->mbcs.stateTable;
     }
     unicodeCodeUnits=cnv->sharedData->mbcs.unicodeCodeUnits;
     /* get the converter state from UConverter */
     offset=cnv->toUnicodeStatus;
     /*
      * if we are in the SBCS state for a DBCS-only converter,
      * then load the DBCS state from the MBCS data
      * (dbcsOnlyState==0 if it is not a DBCS-only converter)
      */
     if((state=(uint8_t)(cnv->mode))==0) {
         state=cnv->sharedData->mbcs.dbcsOnlyState;
     }
     /* conversion loop */
     c=U_SENTINEL;
     while(source<sourceLimit) {
         entry=stateTable[state][*source++];
         if(MBCS_ENTRY_IS_TRANSITION(entry)) {
             state=(uint8_t)MBCS_ENTRY_TRANSITION_STATE(entry);
             offset+=MBCS_ENTRY_TRANSITION_OFFSET(entry);
             /* optimization for 1/2-byte input and BMP output */
             if( source<sourceLimit &&
                 MBCS_ENTRY_IS_FINAL(entry=stateTable[state][*source]) &&
                 MBCS_ENTRY_FINAL_ACTION(entry)==MBCS_STATE_VALID_16 &&
                 (c=unicodeCodeUnits[offset+MBCS_ENTRY_FINAL_VALUE_16(entry)])<0xfffe
             ) {
                 ++source;
                 state=(uint8_t)MBCS_ENTRY_FINAL_STATE(entry); /* typically 0 */
                 /* output BMP code point */
                 break;
             }
         } else {
             /* save the previous state for proper extension mapping with SI/SO-stateful converters */
             cnv->mode=state;
             /* set the next state early so that we can reuse the entry variable */
             state=(uint8_t)MBCS_ENTRY_FINAL_STATE(entry); /* typically 0 */
             /*
              * An if-else-if chain provides more reliable performance for
              * the most common cases compared to a switch.
              */
             action=(uint8_t)(MBCS_ENTRY_FINAL_ACTION(entry));
             if(action==MBCS_STATE_VALID_DIRECT_16) {
                 /* output BMP code point */
                 c=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
                 break;
             } else if(action==MBCS_STATE_VALID_16) {
                 offset+=MBCS_ENTRY_FINAL_VALUE_16(entry);
                 c=unicodeCodeUnits[offset];
                 if(c<0xfffe) {
                     /* output BMP code point */
                     break;
                 } else if(c==0xfffe) {
                     if(UCNV_TO_U_USE_FALLBACK(cnv) && (c=ucnv_MBCSGetFallback(&cnv->sharedData->mbcs, offset))!=0xfffe) {
                         break;
                     }
                 } else {
                     /* callback(illegal) */
                     *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                 }
             } else if(action==MBCS_STATE_VALID_16_PAIR) {
                 offset+=MBCS_ENTRY_FINAL_VALUE_16(entry);
                 c=unicodeCodeUnits[offset++];
                 if(c<0xd800) {
                     /* output BMP code point below 0xd800 */
                     break;
                 } else if(UCNV_TO_U_USE_FALLBACK(cnv) ? c<=0xdfff : c<=0xdbff) {
                     /* output roundtrip or fallback supplementary code point */
                     c=((c&0x3ff)<<10)+unicodeCodeUnits[offset]+(0x10000-0xdc00);
                     break;
                 } else if(UCNV_TO_U_USE_FALLBACK(cnv) ? (c&0xfffe)==0xe000 : c==0xe000) {
                     /* output roundtrip BMP code point above 0xd800 or fallback BMP code point */
                     c=unicodeCodeUnits[offset];
                     break;
                 } else if(c==0xffff) {
                     /* callback(illegal) */
                     *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                 }
             } else if(action==MBCS_STATE_VALID_DIRECT_20 ||
                       (action==MBCS_STATE_FALLBACK_DIRECT_20 && UCNV_TO_U_USE_FALLBACK(cnv))
             ) {
                 /* output supplementary code point */
                 c=(UChar32)(MBCS_ENTRY_FINAL_VALUE(entry)+0x10000);
                 break;
             } else if(action==MBCS_STATE_CHANGE_ONLY) {
                 /*
                  * This serves as a state change without any output.
                  * It is useful for reading simple stateful encodings,
                  * for example using just Shift-In/Shift-Out codes.
                  * The 21 unused bits may later be used for more sophisticated
                  * state transitions.
                  */
                 if(cnv->sharedData->mbcs.dbcsOnlyState!=0) {
                     /* SI/SO are illegal for DBCS-only conversion */
                     state=(uint8_t)(cnv->mode); /* restore the previous state */
                     /* callback(illegal) */
                     *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                 }
             } else if(action==MBCS_STATE_FALLBACK_DIRECT_16) {
                 if(UCNV_TO_U_USE_FALLBACK(cnv)) {
                     /* output BMP code point */
                     c=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
                     break;
                 }
             } else if(action==MBCS_STATE_UNASSIGNED) {
                 /* just fall through */
             } else if(action==MBCS_STATE_ILLEGAL) {
                 /* callback(illegal) */
                 *pErrorCode=U_ILLEGAL_CHAR_FOUND;
             } else {
                 /* reserved (must never occur), or only state change */
                 offset=0;
                 lastSource=source;
                 continue;
             }
             /* end of action codes: prepare for a new character */
             offset=0;
             if(U_FAILURE(*pErrorCode)) {
                 /* callback(illegal) */
                 break;
             } else /* unassigned sequence */ {
                 /* defer to the generic implementation */
                 cnv->toUnicodeStatus=0;
                 cnv->mode=state;
                 pArgs->source=(const char *)lastSource;
                 return UCNV_GET_NEXT_UCHAR_USE_TO_U;
             }
         }
     }
     if(c<0) {
         if(U_SUCCESS(*pErrorCode) && source==sourceLimit && lastSource<source) {
             /* incomplete character byte sequence */
             uint8_t *bytes=cnv->toUBytes;
             cnv->toULength=(int8_t)(source-lastSource);
             do {
                 *bytes++=*lastSource++;
             } while(lastSource<source);
             *pErrorCode=U_TRUNCATED_CHAR_FOUND;
         } else if(U_FAILURE(*pErrorCode)) {
             /* callback(illegal) */
             /*
              * Ticket 5691: consistent illegal sequences:
              * - We include at least the first byte in the illegal sequence.
              * - If any of the non-initial bytes could be the start of a character,
              *   we stop the illegal sequence before the first one of those.
              */
             UBool isDBCSOnly=(UBool)(cnv->sharedData->mbcs.dbcsOnlyState!=0);
             uint8_t *bytes=cnv->toUBytes;
             *bytes++=*lastSource++;     /* first byte */
             if(lastSource==source) {
                 cnv->toULength=1;
             } else /* lastSource<source: multi-byte character */ {
                 int8_t i;
                 for(i=1;
                     lastSource<source && !isSingleOrLead(stateTable, state, isDBCSOnly, *lastSource);
                     ++i
                 ) {
                     *bytes++=*lastSource++;
                 }
                 cnv->toULength=i;
                 source=lastSource;
             }
         } else {
             /* no output because of empty input or only state changes */
             *pErrorCode=U_INDEX_OUTOFBOUNDS_ERROR;
         }
         c=0xffff;
     }
     /* set the converter state back into UConverter, ready for a new character */
     cnv->toUnicodeStatus=0;
     cnv->mode=state;
     /* write back the updated pointer */
     pArgs->source=(const char *)source;
     return c;
 }
 #if 0
 /*
  * Code disabled 2002dec09 (ICU 2.4) because it is not currently used in ICU. markus
  * Removal improves code coverage.
  */
 /**
  * This version of ucnv_MBCSSimpleGetNextUChar() is optimized for single-byte, single-state codepages.
  * It does not handle the EBCDIC swaplfnl option (set in UConverter).
  * It does not handle conversion extensions (_extToU()).
  */
 U_CFUNC UChar32
 ucnv_MBCSSingleSimpleGetNextUChar(UConverterSharedData *sharedData,
                               uint8_t b, UBool useFallback) {
     int32_t entry;
     uint8_t action;
     entry=sharedData->mbcs.stateTable[0][b];
     /* MBCS_ENTRY_IS_FINAL(entry) */
     if(MBCS_ENTRY_FINAL_IS_VALID_DIRECT_16(entry)) {
         /* output BMP code point */
         return (UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
     }
     /*
      * An if-else-if chain provides more reliable performance for
      * the most common cases compared to a switch.
      */
     action=(uint8_t)(MBCS_ENTRY_FINAL_ACTION(entry));
     if(action==MBCS_STATE_VALID_DIRECT_20) {
         /* output supplementary code point */
         return 0x10000+MBCS_ENTRY_FINAL_VALUE(entry);
     } else if(action==MBCS_STATE_FALLBACK_DIRECT_16) {
         if(!TO_U_USE_FALLBACK(useFallback)) {
             return 0xfffe;
         }
         /* output BMP code point */
         return (UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
     } else if(action==MBCS_STATE_FALLBACK_DIRECT_20) {
         if(!TO_U_USE_FALLBACK(useFallback)) {
             return 0xfffe;
         }
         /* output supplementary code point */
         return 0x10000+MBCS_ENTRY_FINAL_VALUE(entry);
     } else if(action==MBCS_STATE_UNASSIGNED) {
         return 0xfffe;
     } else if(action==MBCS_STATE_ILLEGAL) {
         return 0xffff;
     } else {
         /* reserved, must never occur */
         return 0xffff;
     }
 }
 #endif
 /*
  * This is a simple version of _MBCSGetNextUChar() that is used
  * by other converter implementations.
  * It only returns an "assigned" result if it consumes the entire input.
  * It does not use state from the converter, nor error codes.
  * It does not handle the EBCDIC swaplfnl option (set in UConverter).
  * It handles conversion extensions but not GB 18030.
  *
  * Return value:
  * U+fffe   unassigned
  * U+ffff   illegal
  * otherwise the Unicode code point
  */
 U_CFUNC UChar32
 ucnv_MBCSSimpleGetNextUChar(UConverterSharedData *sharedData,
                         const char *source, int32_t length,
                         UBool useFallback) {
     const int32_t (*stateTable)[256];
     const uint16_t *unicodeCodeUnits;
     uint32_t offset;
     uint8_t state, action;
     UChar32 c;
     int32_t i, entry;
     if(length<=0) {
         /* no input at all: "illegal" */
         return 0xffff;
     }
 #if 0
 /*
  * Code disabled 2002dec09 (ICU 2.4) because it is not currently used in ICU. markus
  * TODO In future releases, verify that this function is never called for SBCS
  * conversions, i.e., that sharedData->mbcs.countStates==1 is still true.
  * Removal improves code coverage.
  */
     /* use optimized function if possible */
     if(sharedData->mbcs.countStates==1) {
         if(length==1) {
             return ucnv_MBCSSingleSimpleGetNextUChar(sharedData, (uint8_t)*source, useFallback);
         } else {
             return 0xffff; /* illegal: more than a single byte for an SBCS converter */
         }
     }
 #endif
     /* set up the local pointers */
     stateTable=sharedData->mbcs.stateTable;
     unicodeCodeUnits=sharedData->mbcs.unicodeCodeUnits;
     /* converter state */
     offset=0;
     state=sharedData->mbcs.dbcsOnlyState;
     /* conversion loop */
     for(i=0;;) {
         entry=stateTable[state][(uint8_t)source[i++]];
         if(MBCS_ENTRY_IS_TRANSITION(entry)) {
             state=(uint8_t)MBCS_ENTRY_TRANSITION_STATE(entry);
             offset+=MBCS_ENTRY_TRANSITION_OFFSET(entry);
             if(i==length) {
                 return 0xffff; /* truncated character */
             }
         } else {
             /*
              * An if-else-if chain provides more reliable performance for
              * the most common cases compared to a switch.
              */
             action=(uint8_t)(MBCS_ENTRY_FINAL_ACTION(entry));
             if(action==MBCS_STATE_VALID_16) {
                 offset+=MBCS_ENTRY_FINAL_VALUE_16(entry);
                 c=unicodeCodeUnits[offset];
                 if(c!=0xfffe) {
                     /* done */
                 } else if(UCNV_TO_U_USE_FALLBACK(cnv)) {
                     c=ucnv_MBCSGetFallback(&sharedData->mbcs, offset);
                 /* else done with 0xfffe */
                 }
                 break;
             } else if(action==MBCS_STATE_VALID_DIRECT_16) {
                 /* output BMP code point */
                 c=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
                 break;
             } else if(action==MBCS_STATE_VALID_16_PAIR) {
                 offset+=MBCS_ENTRY_FINAL_VALUE_16(entry);
                 c=unicodeCodeUnits[offset++];
                 if(c<0xd800) {
                     /* output BMP code point below 0xd800 */
                 } else if(UCNV_TO_U_USE_FALLBACK(cnv) ? c<=0xdfff : c<=0xdbff) {
                     /* output roundtrip or fallback supplementary code point */
                     c=(UChar32)(((c&0x3ff)<<10)+unicodeCodeUnits[offset]+(0x10000-0xdc00));
                 } else if(UCNV_TO_U_USE_FALLBACK(cnv) ? (c&0xfffe)==0xe000 : c==0xe000) {
                     /* output roundtrip BMP code point above 0xd800 or fallback BMP code point */
                     c=unicodeCodeUnits[offset];
                 } else if(c==0xffff) {
                     return 0xffff;
                 } else {
                     c=0xfffe;
                 }
                 break;
             } else if(action==MBCS_STATE_VALID_DIRECT_20) {
                 /* output supplementary code point */
                 c=0x10000+MBCS_ENTRY_FINAL_VALUE(entry);
                 break;
             } else if(action==MBCS_STATE_FALLBACK_DIRECT_16) {
                 if(!TO_U_USE_FALLBACK(useFallback)) {
                     c=0xfffe;
                     break;
                 }
                 /* output BMP code point */
                 c=(UChar)MBCS_ENTRY_FINAL_VALUE_16(entry);
                 break;
             } else if(action==MBCS_STATE_FALLBACK_DIRECT_20) {
                 if(!TO_U_USE_FALLBACK(useFallback)) {
                     c=0xfffe;
                     break;
                 }
                 /* output supplementary code point */
                 c=0x10000+MBCS_ENTRY_FINAL_VALUE(entry);
                 break;
             } else if(action==MBCS_STATE_UNASSIGNED) {
                 c=0xfffe;
                 break;
             }
             /*
              * forbid MBCS_STATE_CHANGE_ONLY for this function,
              * and MBCS_STATE_ILLEGAL and reserved action codes
              */
             return 0xffff;
         }
     }
     if(i!=length) {
         /* illegal for this function: not all input consumed */
         return 0xffff;
     }
     if(c==0xfffe) {
         /* try an extension mapping */
         const int32_t *cx=sharedData->mbcs.extIndexes;
         if(cx!=NULL) {
             return ucnv_extSimpleMatchToU(cx, source, length, useFallback);
         }
     }
     return c;
 }
 /* MBCS-from-Unicode conversion functions ----------------------------------- */
 /* This version of ucnv_MBCSFromUnicodeWithOffsets() is optimized for double-byte codepages. */
 static void
 ucnv_MBCSDoubleFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
                                   UErrorCode *pErrorCode) {
     UConverter *cnv;
     const UChar *source, *sourceLimit;
     uint8_t *target;
     int32_t targetCapacity;
     int32_t *offsets;
     const uint16_t *table;
     const uint16_t *mbcsIndex;
     const uint8_t *bytes;
     UChar32 c;
     int32_t sourceIndex, nextSourceIndex;
     uint32_t stage2Entry;
     uint32_t asciiRoundtrips;
     uint32_t value;
     uint8_t unicodeMask;
     /* use optimized function if possible */
     cnv=pArgs->converter;
     unicodeMask=cnv->sharedData->mbcs.unicodeMask;
     /* set up the local pointers */
     source=pArgs->source;
     sourceLimit=pArgs->sourceLimit;
     target=(uint8_t *)pArgs->target;
     targetCapacity=(int32_t)(pArgs->targetLimit-pArgs->target);
     offsets=pArgs->offsets;
     table=cnv->sharedData->mbcs.fromUnicodeTable;
     mbcsIndex=cnv->sharedData->mbcs.mbcsIndex;
     if((cnv->options&UCNV_OPTION_SWAP_LFNL)!=0) {
         bytes=cnv->sharedData->mbcs.swapLFNLFromUnicodeBytes;
     } else {
         bytes=cnv->sharedData->mbcs.fromUnicodeBytes;
     }
     asciiRoundtrips=cnv->sharedData->mbcs.asciiRoundtrips;
     /* get the converter state from UConverter */
     c=cnv->fromUChar32;
     /* sourceIndex=-1 if the current character began in the previous buffer */
     sourceIndex= c==0 ? 0 : -1;
     nextSourceIndex=0;
     /* conversion loop */
     if(c!=0 && targetCapacity>0) {
         goto getTrail;
     }
     while(source<sourceLimit) {
         /*
          * This following test is to see if available input would overflow the output.
          * It does not catch output of more than one byte that
          * overflows as a result of a multi-byte character or callback output
          * from the last source character.
          * Therefore, those situations also test for overflows and will
          * then break the loop, too.
          */
         if(targetCapacity>0) {
             /*
              * Get a correct Unicode code point:
              * a single UChar for a BMP code point or
              * a matched surrogate pair for a "supplementary code point".
              */
             c=*source++;
             ++nextSourceIndex;
             if(c<=0x7f && IS_ASCII_ROUNDTRIP(c, asciiRoundtrips)) {
                 *target++=(uint8_t)c;
                 if(offsets!=NULL) {
                     *offsets++=sourceIndex;
                     sourceIndex=nextSourceIndex;
                 }
                 --targetCapacity;
                 c=0;
                 continue;
             }
             /*
              * utf8Friendly table: Test for <=0xd7ff rather than <=MBCS_FAST_MAX
              * to avoid dealing with surrogates.
              * MBCS_FAST_MAX must be >=0xd7ff.
              */
             if(c<=0xd7ff) {
                 value=DBCS_RESULT_FROM_MOST_BMP(mbcsIndex, (const uint16_t *)bytes, c);
                 /* There are only roundtrips (!=0) and no-mapping (==0) entries. */
                 if(value==0) {
                     goto unassigned;
                 }
                 /* output the value */
             } else {
                 /*
                  * This also tests if the codepage maps single surrogates.
                  * If it does, then surrogates are not paired but mapped separately.
                  * Note that in this case unmatched surrogates are not detected.
                  */
                 if(U16_IS_SURROGATE(c) && !(unicodeMask&UCNV_HAS_SURROGATES)) {
                     if(U16_IS_SURROGATE_LEAD(c)) {
 getTrail:
                         if(source<sourceLimit) {
                             /* test the following code unit */
                             UChar trail=*source;
                             if(U16_IS_TRAIL(trail)) {
                                 ++source;
                                 ++nextSourceIndex;
                                 c=U16_GET_SUPPLEMENTARY(c, trail);
                                 if(!(unicodeMask&UCNV_HAS_SUPPLEMENTARY)) {
                                     /* BMP-only codepages are stored without stage 1 entries for supplementary code points */
                                     /* callback(unassigned) */
                                     goto unassigned;
                                 }
                                 /* convert this supplementary code point */
                                 /* exit this condition tree */
                             } else {
                                 /* this is an unmatched lead code unit (1st surrogate) */
                                 /* callback(illegal) */
                                 *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                                 break;
                             }
                         } else {
                             /* no more input */
                             break;
                         }
                     } else {
                         /* this is an unmatched trail code unit (2nd surrogate) */
                         /* callback(illegal) */
                         *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                         break;
                     }
                 }
                 /* convert the Unicode code point in c into codepage bytes */
                 stage2Entry=MBCS_STAGE_2_FROM_U(table, c);
                 /* get the bytes and the length for the output */
                 /* MBCS_OUTPUT_2 */
                 value=MBCS_VALUE_2_FROM_STAGE_2(bytes, stage2Entry, c);
                 /* is this code point assigned, or do we use fallbacks? */
                 if(!(MBCS_FROM_U_IS_ROUNDTRIP(stage2Entry, c) ||
                      (UCNV_FROM_U_USE_FALLBACK(cnv, c) && value!=0))
                 ) {
                     /*
                      * We allow a 0 byte output if the "assigned" bit is set for this entry.
                      * There is no way with this data structure for fallback output
                      * to be a zero byte.
                      */
 unassigned:
                     /* try an extension mapping */
                     pArgs->source=source;
                     c=_extFromU(cnv, cnv->sharedData,
                                 c, &source, sourceLimit,
                                 &target, target+targetCapacity,
                                 &offsets, sourceIndex,
                                 pArgs->flush,
                                 pErrorCode);
                     nextSourceIndex+=(int32_t)(source-pArgs->source);
                     if(U_FAILURE(*pErrorCode)) {
                         /* not mappable or buffer overflow */
                         break;
                     } else {
                         /* a mapping was written to the target, continue */
                         /* recalculate the targetCapacity after an extension mapping */
                         targetCapacity=(int32_t)(pArgs->targetLimit-(char *)target);
                         /* normal end of conversion: prepare for a new character */
                         sourceIndex=nextSourceIndex;
                         continue;
                     }
                 }
             }
             /* write the output character bytes from value and length */
             /* from the first if in the loop we know that targetCapacity>0 */
             if(value<=0xff) {
                 /* this is easy because we know that there is enough space */
                 *target++=(uint8_t)value;
                 if(offsets!=NULL) {
                     *offsets++=sourceIndex;
                 }
                 --targetCapacity;
             } else /* length==2 */ {
                 *target++=(uint8_t)(value>>8);
                 if(2<=targetCapacity) {
                     *target++=(uint8_t)value;
                     if(offsets!=NULL) {
                         *offsets++=sourceIndex;
                         *offsets++=sourceIndex;
                     }
                     targetCapacity-=2;
                 } else {
                     if(offsets!=NULL) {
                         *offsets++=sourceIndex;
                     }
                     cnv->charErrorBuffer[0]=(char)value;
                     cnv->charErrorBufferLength=1;
                     /* target overflow */
                     targetCapacity=0;
                     *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                     c=0;
                     break;
                 }
             }
             /* normal end of conversion: prepare for a new character */
             c=0;
             sourceIndex=nextSourceIndex;
             continue;
         } else {
             /* target is full */
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             break;
         }
     }
     /* set the converter state back into UConverter */
     cnv->fromUChar32=c;
     /* write back the updated pointers */
     pArgs->source=source;
     pArgs->target=(char *)target;
     pArgs->offsets=offsets;
 }
 /* This version of ucnv_MBCSFromUnicodeWithOffsets() is optimized for single-byte codepages. */
 static void
 ucnv_MBCSSingleFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
                                   UErrorCode *pErrorCode) {
     UConverter *cnv;
     const UChar *source, *sourceLimit;
     uint8_t *target;
     int32_t targetCapacity;
     int32_t *offsets;
     const uint16_t *table;
     const uint16_t *results;
     UChar32 c;
     int32_t sourceIndex, nextSourceIndex;
     uint16_t value, minValue;
     UBool hasSupplementary;
     /* set up the local pointers */
     cnv=pArgs->converter;
     source=pArgs->source;
     sourceLimit=pArgs->sourceLimit;
     target=(uint8_t *)pArgs->target;
     targetCapacity=(int32_t)(pArgs->targetLimit-pArgs->target);
     offsets=pArgs->offsets;
     table=cnv->sharedData->mbcs.fromUnicodeTable;
     if((cnv->options&UCNV_OPTION_SWAP_LFNL)!=0) {
         results=(uint16_t *)cnv->sharedData->mbcs.swapLFNLFromUnicodeBytes;
     } else {
         results=(uint16_t *)cnv->sharedData->mbcs.fromUnicodeBytes;
     }
     if(cnv->useFallback) {
         /* use all roundtrip and fallback results */
         minValue=0x800;
     } else {
         /* use only roundtrips and fallbacks from private-use characters */
         minValue=0xc00;
     }
     hasSupplementary=(UBool)(cnv->sharedData->mbcs.unicodeMask&UCNV_HAS_SUPPLEMENTARY);
     /* get the converter state from UConverter */
     c=cnv->fromUChar32;
     /* sourceIndex=-1 if the current character began in the previous buffer */
     sourceIndex= c==0 ? 0 : -1;
     nextSourceIndex=0;
     /* conversion loop */
     if(c!=0 && targetCapacity>0) {
         goto getTrail;
     }
     while(source<sourceLimit) {
         /*
          * This following test is to see if available input would overflow the output.
          * It does not catch output of more than one byte that
          * overflows as a result of a multi-byte character or callback output
          * from the last source character.
          * Therefore, those situations also test for overflows and will
          * then break the loop, too.
          */
         if(targetCapacity>0) {
             /*
              * Get a correct Unicode code point:
              * a single UChar for a BMP code point or
              * a matched surrogate pair for a "supplementary code point".
              */
             c=*source++;
             ++nextSourceIndex;
             if(U16_IS_SURROGATE(c)) {
                 if(U16_IS_SURROGATE_LEAD(c)) {
 getTrail:
                     if(source<sourceLimit) {
                         /* test the following code unit */
                         UChar trail=*source;
                         if(U16_IS_TRAIL(trail)) {
                             ++source;
                             ++nextSourceIndex;
                             c=U16_GET_SUPPLEMENTARY(c, trail);
                             if(!hasSupplementary) {
                                 /* BMP-only codepages are stored without stage 1 entries for supplementary code points */
                                 /* callback(unassigned) */
                                 goto unassigned;
                             }
                             /* convert this supplementary code point */
                             /* exit this condition tree */
                         } else {
                             /* this is an unmatched lead code unit (1st surrogate) */
                             /* callback(illegal) */
                             *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                             break;
                         }
                     } else {
                         /* no more input */
                         break;
                     }
                 } else {
                     /* this is an unmatched trail code unit (2nd surrogate) */
                     /* callback(illegal) */
                     *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                     break;
                 }
             }
             /* convert the Unicode code point in c into codepage bytes */
             value=MBCS_SINGLE_RESULT_FROM_U(table, results, c);
             /* is this code point assigned, or do we use fallbacks? */
             if(value>=minValue) {
                 /* assigned, write the output character bytes from value and length */
                 /* length==1 */
                 /* this is easy because we know that there is enough space */
                 *target++=(uint8_t)value;
                 if(offsets!=NULL) {
                     *offsets++=sourceIndex;
                 }
                 --targetCapacity;
                 /* normal end of conversion: prepare for a new character */
                 c=0;
                 sourceIndex=nextSourceIndex;
             } else { /* unassigned */
 unassigned:
                 /* try an extension mapping */
                 pArgs->source=source;
                 c=_extFromU(cnv, cnv->sharedData,
                             c, &source, sourceLimit,
                             &target, target+targetCapacity,
                             &offsets, sourceIndex,
                             pArgs->flush,
                             pErrorCode);
                 nextSourceIndex+=(int32_t)(source-pArgs->source);
                 if(U_FAILURE(*pErrorCode)) {
                     /* not mappable or buffer overflow */
                     break;
                 } else {
                     /* a mapping was written to the target, continue */
                     /* recalculate the targetCapacity after an extension mapping */
                     targetCapacity=(int32_t)(pArgs->targetLimit-(char *)target);
                     /* normal end of conversion: prepare for a new character */
                     sourceIndex=nextSourceIndex;
                 }
             }
         } else {
             /* target is full */
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             break;
         }
     }
     /* set the converter state back into UConverter */
     cnv->fromUChar32=c;
     /* write back the updated pointers */
     pArgs->source=source;
     pArgs->target=(char *)target;
     pArgs->offsets=offsets;
 }
 /*
  * This version of ucnv_MBCSFromUnicode() is optimized for single-byte codepages
  * that map only to and from the BMP.
  * In addition to single-byte/state optimizations, the offset calculations
  * become much easier.
  * It would be possible to use the sbcsIndex for UTF-8-friendly tables,
  * but measurements have shown that this diminishes performance
  * in more cases than it improves it.
  * See SVN revision 21013 (2007-feb-06) for the last version with #if switches
  * for various MBCS and SBCS optimizations.
  */
 static void
 ucnv_MBCSSingleFromBMPWithOffsets(UConverterFromUnicodeArgs *pArgs,
                               UErrorCode *pErrorCode) {
     UConverter *cnv;
     const UChar *source, *sourceLimit, *lastSource;
     uint8_t *target;
     int32_t targetCapacity, length;
     int32_t *offsets;
     const uint16_t *table;
     const uint16_t *results;
     UChar32 c;
     int32_t sourceIndex;
     uint32_t asciiRoundtrips;
     uint16_t value, minValue;
     /* set up the local pointers */
     cnv=pArgs->converter;
     source=pArgs->source;
     sourceLimit=pArgs->sourceLimit;
     target=(uint8_t *)pArgs->target;
     targetCapacity=(int32_t)(pArgs->targetLimit-pArgs->target);
     offsets=pArgs->offsets;
     table=cnv->sharedData->mbcs.fromUnicodeTable;
     if((cnv->options&UCNV_OPTION_SWAP_LFNL)!=0) {
         results=(uint16_t *)cnv->sharedData->mbcs.swapLFNLFromUnicodeBytes;
     } else {
         results=(uint16_t *)cnv->sharedData->mbcs.fromUnicodeBytes;
     }
     asciiRoundtrips=cnv->sharedData->mbcs.asciiRoundtrips;
     if(cnv->useFallback) {
         /* use all roundtrip and fallback results */
         minValue=0x800;
     } else {
         /* use only roundtrips and fallbacks from private-use characters */
         minValue=0xc00;
     }
     /* get the converter state from UConverter */
     c=cnv->fromUChar32;
     /* sourceIndex=-1 if the current character began in the previous buffer */
     sourceIndex= c==0 ? 0 : -1;
     lastSource=source;
     /*
      * since the conversion here is 1:1 UChar:uint8_t, we need only one counter
      * for the minimum of the sourceLength and targetCapacity
      */
     length=(int32_t)(sourceLimit-source);
     if(length<targetCapacity) {
         targetCapacity=length;
     }
     /* conversion loop */
     if(c!=0 && targetCapacity>0) {
         goto getTrail;
     }
 #if MBCS_UNROLL_SINGLE_FROM_BMP
     /* unrolling makes it slower on Pentium III/Windows 2000?! */
     /* unroll the loop with the most common case */
 unrolled:
     if(targetCapacity>=4) {
         int32_t count, loops;
         uint16_t andedValues;
         loops=count=targetCapacity>>2;
         do {
             c=*source++;
             andedValues=value=MBCS_SINGLE_RESULT_FROM_U(table, results, c);
             *target++=(uint8_t)value;
             c=*source++;
             andedValues&=value=MBCS_SINGLE_RESULT_FROM_U(table, results, c);
             *target++=(uint8_t)value;
             c=*source++;
             andedValues&=value=MBCS_SINGLE_RESULT_FROM_U(table, results, c);
             *target++=(uint8_t)value;
             c=*source++;
             andedValues&=value=MBCS_SINGLE_RESULT_FROM_U(table, results, c);
             *target++=(uint8_t)value;
             /* were all 4 entries really valid? */
             if(andedValues<minValue) {
                 /* no, return to the first of these 4 */
                 source-=4;
                 target-=4;
                 break;
             }
         } while(--count>0);
         count=loops-count;
         targetCapacity-=4*count;
         if(offsets!=NULL) {
             lastSource+=4*count;
             while(count>0) {
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 *offsets++=sourceIndex++;
                 --count;
             }
         }
         c=0;
     }
 #endif
     while(targetCapacity>0) {
         /*
          * Get a correct Unicode code point:
          * a single UChar for a BMP code point or
          * a matched surrogate pair for a "supplementary code point".
          */
         c=*source++;
         /*
          * Do not immediately check for single surrogates:
          * Assume that they are unassigned and check for them in that case.
          * This speeds up the conversion of assigned characters.
          */
         /* convert the Unicode code point in c into codepage bytes */
         if(c<=0x7f && IS_ASCII_ROUNDTRIP(c, asciiRoundtrips)) {
             *target++=(uint8_t)c;
             --targetCapacity;
             c=0;
             continue;
         }
         value=MBCS_SINGLE_RESULT_FROM_U(table, results, c);
         /* is this code point assigned, or do we use fallbacks? */
         if(value>=minValue) {
             /* assigned, write the output character bytes from value and length */
             /* length==1 */
             /* this is easy because we know that there is enough space */
             *target++=(uint8_t)value;
             --targetCapacity;
             /* normal end of conversion: prepare for a new character */
             c=0;
             continue;
         } else if(!U16_IS_SURROGATE(c)) {
             /* normal, unassigned BMP character */
         } else if(U16_IS_SURROGATE_LEAD(c)) {
 getTrail:
             if(source<sourceLimit) {
                 /* test the following code unit */
                 UChar trail=*source;
                 if(U16_IS_TRAIL(trail)) {
                     ++source;
                     c=U16_GET_SUPPLEMENTARY(c, trail);
                     /* this codepage does not map supplementary code points */
                     /* callback(unassigned) */
                 } else {
                     /* this is an unmatched lead code unit (1st surrogate) */
                     /* callback(illegal) */
                     *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                     break;
                 }
             } else {
                 /* no more input */
                 if (pArgs->flush) {
                     *pErrorCode=U_TRUNCATED_CHAR_FOUND;
                 }
                 break;
             }
         } else {
             /* this is an unmatched trail code unit (2nd surrogate) */
             /* callback(illegal) */
             *pErrorCode=U_ILLEGAL_CHAR_FOUND;
             break;
         }
         /* c does not have a mapping */
         /* get the number of code units for c to correctly advance sourceIndex */
         length=U16_LENGTH(c);
         /* set offsets since the start or the last extension */
         if(offsets!=NULL) {
             int32_t count=(int32_t)(source-lastSource);
             /* do not set the offset for this character */
             count-=length;
             while(count>0) {
                 *offsets++=sourceIndex++;
                 --count;
             }
             /* offsets and sourceIndex are now set for the current character */
         }
         /* try an extension mapping */
         lastSource=source;
         c=_extFromU(cnv, cnv->sharedData,
                     c, &source, sourceLimit,
                     &target, (const uint8_t *)(pArgs->targetLimit),
                     &offsets, sourceIndex,
                     pArgs->flush,
                     pErrorCode);
         sourceIndex+=length+(int32_t)(source-lastSource);
         lastSource=source;
         if(U_FAILURE(*pErrorCode)) {
             /* not mappable or buffer overflow */
             break;
         } else {
             /* a mapping was written to the target, continue */
             /* recalculate the targetCapacity after an extension mapping */
             targetCapacity=(int32_t)(pArgs->targetLimit-(char *)target);
             length=(int32_t)(sourceLimit-source);
             if(length<targetCapacity) {
                 targetCapacity=length;
             }
         }
 #if MBCS_UNROLL_SINGLE_FROM_BMP
         /* unrolling makes it slower on Pentium III/Windows 2000?! */
         goto unrolled;
 #endif
     }
     if(U_SUCCESS(*pErrorCode) && source<sourceLimit && target>=(uint8_t *)pArgs->targetLimit) {
         /* target is full */
         *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
     }
     /* set offsets since the start or the last callback */
     if(offsets!=NULL) {
         size_t count=source-lastSource;
         if (count > 0 && *pErrorCode == U_TRUNCATED_CHAR_FOUND) {
             /*
             Caller gave us a partial supplementary character,
             which this function couldn't convert in any case.
             The callback will handle the offset.
             */
             count--;
         }
         while(count>0) {
             *offsets++=sourceIndex++;
             --count;
         }
     }
     /* set the converter state back into UConverter */
     cnv->fromUChar32=c;
     /* write back the updated pointers */
     pArgs->source=source;
     pArgs->target=(char *)target;
     pArgs->offsets=offsets;
 }
 U_CFUNC void
 ucnv_MBCSFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
                             UErrorCode *pErrorCode) {
     UConverter *cnv;
     const UChar *source, *sourceLimit;
     uint8_t *target;
     int32_t targetCapacity;
     int32_t *offsets;
     const uint16_t *table;
     const uint16_t *mbcsIndex;
     const uint8_t *p, *bytes;
     uint8_t outputType;
     UChar32 c;
     int32_t prevSourceIndex, sourceIndex, nextSourceIndex;
     uint32_t stage2Entry;
     uint32_t asciiRoundtrips;
     uint32_t value;
     /* Shift-In and Shift-Out byte sequences differ by encoding scheme. */
     uint8_t siBytes[2] = {0, 0};
     uint8_t soBytes[2] = {0, 0};
     uint8_t siLength, soLength;
     int32_t length = 0, prevLength;
     uint8_t unicodeMask;
     cnv=pArgs->converter;
     if(cnv->preFromUFirstCP>=0) {
         /*
          * pass sourceIndex=-1 because we continue from an earlier buffer
          * in the future, this may change with continuous offsets
          */
         ucnv_extContinueMatchFromU(cnv, pArgs, -1, pErrorCode);
         if(U_FAILURE(*pErrorCode) || cnv->preFromULength<0) {
             return;
         }
     }
     /* use optimized function if possible */
     outputType=cnv->sharedData->mbcs.outputType;
     unicodeMask=cnv->sharedData->mbcs.unicodeMask;
     if(outputType==MBCS_OUTPUT_1 && !(unicodeMask&UCNV_HAS_SURROGATES)) {
         if(!(unicodeMask&UCNV_HAS_SUPPLEMENTARY)) {
             ucnv_MBCSSingleFromBMPWithOffsets(pArgs, pErrorCode);
         } else {
             ucnv_MBCSSingleFromUnicodeWithOffsets(pArgs, pErrorCode);
         }
         return;
     } else if(outputType==MBCS_OUTPUT_2 && cnv->sharedData->mbcs.utf8Friendly) {
         ucnv_MBCSDoubleFromUnicodeWithOffsets(pArgs, pErrorCode);
         return;
     }
     /* set up the local pointers */
     source=pArgs->source;
     sourceLimit=pArgs->sourceLimit;
     target=(uint8_t *)pArgs->target;
     targetCapacity=(int32_t)(pArgs->targetLimit-pArgs->target);
     offsets=pArgs->offsets;
     table=cnv->sharedData->mbcs.fromUnicodeTable;
     if(cnv->sharedData->mbcs.utf8Friendly) {
         mbcsIndex=cnv->sharedData->mbcs.mbcsIndex;
     } else {
         mbcsIndex=NULL;
     }
     if((cnv->options&UCNV_OPTION_SWAP_LFNL)!=0) {
         bytes=cnv->sharedData->mbcs.swapLFNLFromUnicodeBytes;
     } else {
         bytes=cnv->sharedData->mbcs.fromUnicodeBytes;
     }
     asciiRoundtrips=cnv->sharedData->mbcs.asciiRoundtrips;
     /* get the converter state from UConverter */
     c=cnv->fromUChar32;
     if(outputType==MBCS_OUTPUT_2_SISO) {
         prevLength=cnv->fromUnicodeStatus;
         if(prevLength==0) {
             /* set the real value */
             prevLength=1;
         }
     } else {
         /* prevent fromUnicodeStatus from being set to something non-0 */
         prevLength=0;
     }
     /* sourceIndex=-1 if the current character began in the previous buffer */
     prevSourceIndex=-1;
     sourceIndex= c==0 ? 0 : -1;
     nextSourceIndex=0;
     /* Get the SI/SO character for the converter */
     siLength = getSISOBytes(SI, cnv->options, siBytes);
     soLength = getSISOBytes(SO, cnv->options, soBytes);
     /* conversion loop */
     /*
      * This is another piece of ugly code:
      * A goto into the loop if the converter state contains a first surrogate
      * from the previous function call.
      * It saves me to check in each loop iteration a check of if(c==0)
      * and duplicating the trail-surrogate-handling code in the else
      * branch of that check.
      * I could not find any other way to get around this other than
      * using a function call for the conversion and callback, which would
      * be even more inefficient.
      *
      * Markus Scherer 2000-jul-19
      */
     if(c!=0 && targetCapacity>0) {
         goto getTrail;
     }
     while(source<sourceLimit) {
         /*
          * This following test is to see if available input would overflow the output.
          * It does not catch output of more than one byte that
          * overflows as a result of a multi-byte character or callback output
          * from the last source character.
          * Therefore, those situations also test for overflows and will
          * then break the loop, too.
          */
         if(targetCapacity>0) {
             /*
              * Get a correct Unicode code point:
              * a single UChar for a BMP code point or
              * a matched surrogate pair for a "supplementary code point".
              */
             c=*source++;
             ++nextSourceIndex;
             if(c<=0x7f && IS_ASCII_ROUNDTRIP(c, asciiRoundtrips)) {
                 *target++=(uint8_t)c;
                 if(offsets!=NULL) {
                     *offsets++=sourceIndex;
                     prevSourceIndex=sourceIndex;
                     sourceIndex=nextSourceIndex;
                 }
                 --targetCapacity;
                 c=0;
                 continue;
             }
             /*
              * utf8Friendly table: Test for <=0xd7ff rather than <=MBCS_FAST_MAX
              * to avoid dealing with surrogates.
              * MBCS_FAST_MAX must be >=0xd7ff.
              */
             if(c<=0xd7ff && mbcsIndex!=NULL) {
                 value=mbcsIndex[c>>6];
                 /* get the bytes and the length for the output (copied from below and adapted for utf8Friendly data) */
                 /* There are only roundtrips (!=0) and no-mapping (==0) entries. */
                 switch(outputType) {
                 case MBCS_OUTPUT_2:
                     value=((const uint16_t *)bytes)[value +(c&0x3f)];
                     if(value<=0xff) {
                         if(value==0) {
                             goto unassigned;
                         } else {
                             length=1;
                         }
                     } else {
                         length=2;
                     }
                     break;
                 case MBCS_OUTPUT_2_SISO:
                     /* 1/2-byte stateful with Shift-In/Shift-Out */
                     /*
                      * Save the old state in the converter object
                      * right here, then change the local prevLength state variable if necessary.
                      * Then, if this character turns out to be unassigned or a fallback that
                      * is not taken, the callback code must not save the new state in the converter
                      * because the new state is for a character that is not output.
                      * However, the callback must still restore the state from the converter
                      * in case the callback function changed it for its output.
                      */
                     cnv->fromUnicodeStatus=prevLength; /* save the old state */
                     value=((const uint16_t *)bytes)[value +(c&0x3f)];
                     if(value<=0xff) {
                         if(value==0) {
                             goto unassigned;
                         } else if(prevLength<=1) {
                             length=1;
                         } else {
                             /* change from double-byte mode to single-byte */
                             if (siLength == 1) {
                                 value|=(uint32_t)siBytes[0]<<8;
                                 length = 2;
                             } else if (siLength == 2) {
                                 value|=(uint32_t)siBytes[1]<<8;
                                 value|=(uint32_t)siBytes[0]<<16;
                                 length = 3;
                             }
                             prevLength=1;
                         }
                     } else {
                         if(prevLength==2) {
                             length=2;
                         } else {
                             /* change from single-byte mode to double-byte */
                             if (soLength == 1) {
                                 value|=(uint32_t)soBytes[0]<<16;
                                 length = 3;
                             } else if (soLength == 2) {
                                 value|=(uint32_t)soBytes[1]<<16;
                                 value|=(uint32_t)soBytes[0]<<24;
                                 length = 4;
                             }
                             prevLength=2;
                         }
                     }
                     break;
                 case MBCS_OUTPUT_DBCS_ONLY:
                     /* table with single-byte results, but only DBCS mappings used */
                     value=((const uint16_t *)bytes)[value +(c&0x3f)];
                     if(value<=0xff) {
                         /* no mapping or SBCS result, not taken for DBCS-only */
                         goto unassigned;
                     } else {
                         length=2;
                     }
                     break;
                 case MBCS_OUTPUT_3:
                     p=bytes+(value+(c&0x3f))*3;
                     value=((uint32_t)*p<<16)|((uint32_t)p[1]<<8)|p[2];
                     if(value<=0xff) {
                         if(value==0) {
                             goto unassigned;
                         } else {
                             length=1;
                         }
                     } else if(value<=0xffff) {
                         length=2;
                     } else {
                         length=3;
                     }
                     break;
                 case MBCS_OUTPUT_4:
                     value=((const uint32_t *)bytes)[value +(c&0x3f)];
                     if(value<=0xff) {
                         if(value==0) {
                             goto unassigned;
                         } else {
                             length=1;
                         }
                     } else if(value<=0xffff) {
                         length=2;
                     } else if(value<=0xffffff) {
                         length=3;
                     } else {
                         length=4;
                     }
                     break;
                 case MBCS_OUTPUT_3_EUC:
                     value=((const uint16_t *)bytes)[value +(c&0x3f)];
                     /* EUC 16-bit fixed-length representation */
                     if(value<=0xff) {
                         if(value==0) {
                             goto unassigned;
                         } else {
                             length=1;
                         }
                     } else if((value&0x8000)==0) {
                         value|=0x8e8000;
                         length=3;
                     } else if((value&0x80)==0) {
                         value|=0x8f0080;
                         length=3;
                     } else {
                         length=2;
                     }
                     break;
                 case MBCS_OUTPUT_4_EUC:
                     p=bytes+(value+(c&0x3f))*3;
                     value=((uint32_t)*p<<16)|((uint32_t)p[1]<<8)|p[2];
                     /* EUC 16-bit fixed-length representation applied to the first two bytes */
                     if(value<=0xff) {
                         if(value==0) {
                             goto unassigned;
                         } else {
                             length=1;
                         }
                     } else if(value<=0xffff) {
                         length=2;
                     } else if((value&0x800000)==0) {
                         value|=0x8e800000;
                         length=4;
                     } else if((value&0x8000)==0) {
                         value|=0x8f008000;
                         length=4;
                     } else {
                         length=3;
                     }
                     break;
                 default:
                     /* must not occur */
                     /*
                      * To avoid compiler warnings that value & length may be
                      * used without having been initialized, we set them here.
                      * In reality, this is unreachable code.
                      * Not having a default branch also causes warnings with
                      * some compilers.
                      */
                     value=0;
                     length=0;
                     break;
                 }
                 /* output the value */
             } else {
                 /*
                  * This also tests if the codepage maps single surrogates.
                  * If it does, then surrogates are not paired but mapped separately.
                  * Note that in this case unmatched surrogates are not detected.
                  */
                 if(U16_IS_SURROGATE(c) && !(unicodeMask&UCNV_HAS_SURROGATES)) {
                     if(U16_IS_SURROGATE_LEAD(c)) {
 getTrail:
                         if(source<sourceLimit) {
                             /* test the following code unit */
                             UChar trail=*source;
                             if(U16_IS_TRAIL(trail)) {
                                 ++source;
                                 ++nextSourceIndex;
                                 c=U16_GET_SUPPLEMENTARY(c, trail);
                                 if(!(unicodeMask&UCNV_HAS_SUPPLEMENTARY)) {
                                     /* BMP-only codepages are stored without stage 1 entries for supplementary code points */
                                     cnv->fromUnicodeStatus=prevLength; /* save the old state */
                                     /* callback(unassigned) */
                                     goto unassigned;
                                 }
                                 /* convert this supplementary code point */
                                 /* exit this condition tree */
                             } else {
                                 /* this is an unmatched lead code unit (1st surrogate) */
                                 /* callback(illegal) */
                                 *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                                 break;
                             }
                         } else {
                             /* no more input */
                             break;
                         }
                     } else {
                         /* this is an unmatched trail code unit (2nd surrogate) */
                         /* callback(illegal) */
                         *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                         break;
                     }
                 }
                 /* convert the Unicode code point in c into codepage bytes */
                 /*
                  * The basic lookup is a triple-stage compact array (trie) lookup.
                  * For details see the beginning of this file.
                  *
                  * Single-byte codepages are handled with a different data structure
                  * by _MBCSSingle... functions.
                  *
                  * The result consists of a 32-bit value from stage 2 and
                  * a pointer to as many bytes as are stored per character.
                  * The pointer points to the character's bytes in stage 3.
                  * Bits 15..0 of the stage 2 entry contain the stage 3 index
                  * for that pointer, while bits 31..16 are flags for which of
                  * the 16 characters in the block are roundtrip-assigned.
                  *
                  * For 2-byte and 4-byte codepages, the bytes are stored as uint16_t
                  * respectively as uint32_t, in the platform encoding.
                  * For 3-byte codepages, the bytes are always stored in big-endian order.
                  *
                  * For EUC encodings that use only either 0x8e or 0x8f as the first
                  * byte of their longest byte sequences, the first two bytes in
                  * this third stage indicate with their 7th bits whether these bytes
                  * are to be written directly or actually need to be preceeded by
                  * one of the two Single-Shift codes. With this, the third stage
                  * stores one byte fewer per character than the actual maximum length of
                  * EUC byte sequences.
                  *
                  * Other than that, leading zero bytes are removed and the other
                  * bytes output. A single zero byte may be output if the "assigned"
                  * bit in stage 2 was on.
                  * The data structure does not support zero byte output as a fallback,
                  * and also does not allow output of leading zeros.
                  */
                 stage2Entry=MBCS_STAGE_2_FROM_U(table, c);
                 /* get the bytes and the length for the output */
                 switch(outputType) {
                 case MBCS_OUTPUT_2:
                     value=MBCS_VALUE_2_FROM_STAGE_2(bytes, stage2Entry, c);
                     if(value<=0xff) {
                         length=1;
                     } else {
                         length=2;
                     }
                     break;
                 case MBCS_OUTPUT_2_SISO:
                     /* 1/2-byte stateful with Shift-In/Shift-Out */
                     /*
                      * Save the old state in the converter object
                      * right here, then change the local prevLength state variable if necessary.
                      * Then, if this character turns out to be unassigned or a fallback that
                      * is not taken, the callback code must not save the new state in the converter
                      * because the new state is for a character that is not output.
                      * However, the callback must still restore the state from the converter
                      * in case the callback function changed it for its output.
                      */
                     cnv->fromUnicodeStatus=prevLength; /* save the old state */
                     value=MBCS_VALUE_2_FROM_STAGE_2(bytes, stage2Entry, c);
                     if(value<=0xff) {
                         if(value==0 && MBCS_FROM_U_IS_ROUNDTRIP(stage2Entry, c)==0) {
                             /* no mapping, leave value==0 */
                             length=0;
                         } else if(prevLength<=1) {
                             length=1;
                         } else {
                             /* change from double-byte mode to single-byte */
                             if (siLength == 1) {
                                 value|=(uint32_t)siBytes[0]<<8;
                                 length = 2;
                             } else if (siLength == 2) {
                                 value|=(uint32_t)siBytes[1]<<8;
                                 value|=(uint32_t)siBytes[0]<<16;
                                 length = 3;
                             }
                             prevLength=1;
                         }
                     } else {
                         if(prevLength==2) {
                             length=2;
                         } else {
                             /* change from single-byte mode to double-byte */
                             if (soLength == 1) {
                                 value|=(uint32_t)soBytes[0]<<16;
                                 length = 3;
                             } else if (soLength == 2) {
                                 value|=(uint32_t)soBytes[1]<<16;
                                 value|=(uint32_t)soBytes[0]<<24;
                                 length = 4;
                             }
                             prevLength=2;
                         }
                     }
                     break;
                 case MBCS_OUTPUT_DBCS_ONLY:
                     /* table with single-byte results, but only DBCS mappings used */
                     value=MBCS_VALUE_2_FROM_STAGE_2(bytes, stage2Entry, c);
                     if(value<=0xff) {
                         /* no mapping or SBCS result, not taken for DBCS-only */
                         value=stage2Entry=0; /* stage2Entry=0 to reset roundtrip flags */
                         length=0;
                     } else {
                         length=2;
                     }
                     break;
                 case MBCS_OUTPUT_3:
                     p=MBCS_POINTER_3_FROM_STAGE_2(bytes, stage2Entry, c);
                     value=((uint32_t)*p<<16)|((uint32_t)p[1]<<8)|p[2];
                     if(value<=0xff) {
                         length=1;
                     } else if(value<=0xffff) {
                         length=2;
                     } else {
                         length=3;
                     }
                     break;
                 case MBCS_OUTPUT_4:
                     value=MBCS_VALUE_4_FROM_STAGE_2(bytes, stage2Entry, c);
                     if(value<=0xff) {
                         length=1;
                     } else if(value<=0xffff) {
                         length=2;
                     } else if(value<=0xffffff) {
                         length=3;
                     } else {
                         length=4;
                     }
                     break;
                 case MBCS_OUTPUT_3_EUC:
                     value=MBCS_VALUE_2_FROM_STAGE_2(bytes, stage2Entry, c);
                     /* EUC 16-bit fixed-length representation */
                     if(value<=0xff) {
                         length=1;
                     } else if((value&0x8000)==0) {
                         value|=0x8e8000;
                         length=3;
                     } else if((value&0x80)==0) {
                         value|=0x8f0080;
                         length=3;
                     } else {
                         length=2;
                     }
                     break;
                 case MBCS_OUTPUT_4_EUC:
                     p=MBCS_POINTER_3_FROM_STAGE_2(bytes, stage2Entry, c);
                     value=((uint32_t)*p<<16)|((uint32_t)p[1]<<8)|p[2];
                     /* EUC 16-bit fixed-length representation applied to the first two bytes */
                     if(value<=0xff) {
                         length=1;
                     } else if(value<=0xffff) {
                         length=2;
                     } else if((value&0x800000)==0) {
                         value|=0x8e800000;
                         length=4;
                     } else if((value&0x8000)==0) {
                         value|=0x8f008000;
                         length=4;
                     } else {
                         length=3;
                     }
                     break;
                 default:
                     /* must not occur */
                     /*
                      * To avoid compiler warnings that value & length may be
                      * used without having been initialized, we set them here.
                      * In reality, this is unreachable code.
                      * Not having a default branch also causes warnings with
                      * some compilers.
                      */
                     value=stage2Entry=0; /* stage2Entry=0 to reset roundtrip flags */
                     length=0;
                     break;
                 }
                 /* is this code point assigned, or do we use fallbacks? */
                 if(!(MBCS_FROM_U_IS_ROUNDTRIP(stage2Entry, c)!=0 ||
                      (UCNV_FROM_U_USE_FALLBACK(cnv, c) && value!=0))
                 ) {
                     /*
                      * We allow a 0 byte output if the "assigned" bit is set for this entry.
                      * There is no way with this data structure for fallback output
                      * to be a zero byte.
                      */
 unassigned:
                     /* try an extension mapping */
                     pArgs->source=source;
                     c=_extFromU(cnv, cnv->sharedData,
                                 c, &source, sourceLimit,
                                 &target, target+targetCapacity,
                                 &offsets, sourceIndex,
                                 pArgs->flush,
                                 pErrorCode);
                     nextSourceIndex+=(int32_t)(source-pArgs->source);
                     prevLength=cnv->fromUnicodeStatus; /* restore SISO state */
                     if(U_FAILURE(*pErrorCode)) {
                         /* not mappable or buffer overflow */
                         break;
                     } else {
                         /* a mapping was written to the target, continue */
                         /* recalculate the targetCapacity after an extension mapping */
                         targetCapacity=(int32_t)(pArgs->targetLimit-(char *)target);
                         /* normal end of conversion: prepare for a new character */
                         if(offsets!=NULL) {
                             prevSourceIndex=sourceIndex;
                             sourceIndex=nextSourceIndex;
                         }
                         continue;
                     }
                 }
             }
             /* write the output character bytes from value and length */
             /* from the first if in the loop we know that targetCapacity>0 */
             if(length<=targetCapacity) {
                 if(offsets==NULL) {
                     switch(length) {
                         /* each branch falls through to the next one */
                     case 4:
                         *target++=(uint8_t)(value>>24);
                     case 3: /*fall through*/
                         *target++=(uint8_t)(value>>16);
                     case 2: /*fall through*/
                         *target++=(uint8_t)(value>>8);
                     case 1: /*fall through*/
                         *target++=(uint8_t)value;
                     default:
                         /* will never occur */
                         break;
                     }
                 } else {
                     switch(length) {
                         /* each branch falls through to the next one */
                     case 4:
                         *target++=(uint8_t)(value>>24);
                         *offsets++=sourceIndex;
                     case 3: /*fall through*/
                         *target++=(uint8_t)(value>>16);
                         *offsets++=sourceIndex;
                     case 2: /*fall through*/
                         *target++=(uint8_t)(value>>8);
                         *offsets++=sourceIndex;
                     case 1: /*fall through*/
                         *target++=(uint8_t)value;
                         *offsets++=sourceIndex;
                     default:
                         /* will never occur */
                         break;
                     }
                 }
                 targetCapacity-=length;
             } else {
                 uint8_t *charErrorBuffer;
                 /*
                  * We actually do this backwards here:
                  * In order to save an intermediate variable, we output
                  * first to the overflow buffer what does not fit into the
                  * regular target.
                  */
                 /* we know that 1<=targetCapacity<length<=4 */
                 length-=targetCapacity;
                 charErrorBuffer=(uint8_t *)cnv->charErrorBuffer;
                 switch(length) {
                     /* each branch falls through to the next one */
                 case 3:
                     *charErrorBuffer++=(uint8_t)(value>>16);
                 case 2: /*fall through*/
                     *charErrorBuffer++=(uint8_t)(value>>8);
                 case 1: /*fall through*/
                     *charErrorBuffer=(uint8_t)value;
                 default:
                     /* will never occur */
                     break;
                 }
                 cnv->charErrorBufferLength=(int8_t)length;
                 /* now output what fits into the regular target */
                 value>>=8*length; /* length was reduced by targetCapacity */
                 switch(targetCapacity) {
                     /* each branch falls through to the next one */
                 case 3:
                     *target++=(uint8_t)(value>>16);
                     if(offsets!=NULL) {
                         *offsets++=sourceIndex;
                     }
                 case 2: /*fall through*/
                     *target++=(uint8_t)(value>>8);
                     if(offsets!=NULL) {
                         *offsets++=sourceIndex;
                     }
                 case 1: /*fall through*/
                     *target++=(uint8_t)value;
                     if(offsets!=NULL) {
                         *offsets++=sourceIndex;
                     }
                 default:
                     /* will never occur */
                     break;
                 }
                 /* target overflow */
                 targetCapacity=0;
                 *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                 c=0;
                 break;
             }
             /* normal end of conversion: prepare for a new character */
             c=0;
             if(offsets!=NULL) {
                 prevSourceIndex=sourceIndex;
                 sourceIndex=nextSourceIndex;
             }
             continue;
         } else {
             /* target is full */
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             break;
         }
     }
     /*
      * the end of the input stream and detection of truncated input
      * are handled by the framework, but for EBCDIC_STATEFUL conversion
      * we need to emit an SI at the very end
      *
      * conditions:
      *   successful
      *   EBCDIC_STATEFUL in DBCS mode
      *   end of input and no truncated input
      */
     if( U_SUCCESS(*pErrorCode) &&
         outputType==MBCS_OUTPUT_2_SISO && prevLength==2 &&
         pArgs->flush && source>=sourceLimit && c==0
     ) {
         /* EBCDIC_STATEFUL ending with DBCS: emit an SI to return the output stream to SBCS */
         if(targetCapacity>0) {
             *target++=(uint8_t)siBytes[0];
             if (siLength == 2) {
                 if (targetCapacity<2) {
                     cnv->charErrorBuffer[0]=(uint8_t)siBytes[1];
                     cnv->charErrorBufferLength=1;
                     *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                 } else {
                     *target++=(uint8_t)siBytes[1];
                 }
             }
             if(offsets!=NULL) {
                 /* set the last source character's index (sourceIndex points at sourceLimit now) */
                 *offsets++=prevSourceIndex;
             }
         } else {
             /* target is full */
             cnv->charErrorBuffer[0]=(uint8_t)siBytes[0];
             if (siLength == 2) {
                 cnv->charErrorBuffer[1]=(uint8_t)siBytes[1];
             }
             cnv->charErrorBufferLength=siLength;
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
         }
         prevLength=1; /* we switched into SBCS */
     }
     /* set the converter state back into UConverter */
     cnv->fromUChar32=c;
     cnv->fromUnicodeStatus=prevLength;
     /* write back the updated pointers */
     pArgs->source=source;
     pArgs->target=(char *)target;
     pArgs->offsets=offsets;
 }
 /*
  * This is another simple conversion function for internal use by other
  * conversion implementations.
  * It does not use the converter state nor call callbacks.
  * It does not handle the EBCDIC swaplfnl option (set in UConverter).
  * It handles conversion extensions but not GB 18030.
  *
  * It converts one single Unicode code point into codepage bytes, encoded
  * as one 32-bit value. The function returns the number of bytes in *pValue:
  * 1..4 the number of bytes in *pValue
  * 0    unassigned (*pValue undefined)
  * -1   illegal (currently not used, *pValue undefined)
  *
  * *pValue will contain the resulting bytes with the last byte in bits 7..0,
  * the second to last byte in bits 15..8, etc.
  * Currently, the function assumes but does not check that 0<=c<=0x10ffff.
  */
 U_CFUNC int32_t
 ucnv_MBCSFromUChar32(UConverterSharedData *sharedData,
                  UChar32 c, uint32_t *pValue,
                  UBool useFallback) {
     const int32_t *cx;
     const uint16_t *table;
 #if 0
 /* #if 0 because this is not currently used in ICU - reduce code, increase code coverage */
     const uint8_t *p;
 #endif
     uint32_t stage2Entry;
     uint32_t value;
     int32_t length;
     /* BMP-only codepages are stored without stage 1 entries for supplementary code points */
     if(c<=0xffff || (sharedData->mbcs.unicodeMask&UCNV_HAS_SUPPLEMENTARY)) {
         table=sharedData->mbcs.fromUnicodeTable;
         /* convert the Unicode code point in c into codepage bytes (same as in _MBCSFromUnicodeWithOffsets) */
         if(sharedData->mbcs.outputType==MBCS_OUTPUT_1) {
             value=MBCS_SINGLE_RESULT_FROM_U(table, (uint16_t *)sharedData->mbcs.fromUnicodeBytes, c);
             /* is this code point assigned, or do we use fallbacks? */
             if(useFallback ? value>=0x800 : value>=0xc00) {
                 *pValue=value&0xff;
                 return 1;
             }
         } else /* outputType!=MBCS_OUTPUT_1 */ {
             stage2Entry=MBCS_STAGE_2_FROM_U(table, c);
             /* get the bytes and the length for the output */
             switch(sharedData->mbcs.outputType) {
             case MBCS_OUTPUT_2:
                 value=MBCS_VALUE_2_FROM_STAGE_2(sharedData->mbcs.fromUnicodeBytes, stage2Entry, c);
                 if(value<=0xff) {
                     length=1;
                 } else {
                     length=2;
                 }
                 break;
 #if 0
 /* #if 0 because this is not currently used in ICU - reduce code, increase code coverage */
             case MBCS_OUTPUT_DBCS_ONLY:
                 /* table with single-byte results, but only DBCS mappings used */
                 value=MBCS_VALUE_2_FROM_STAGE_2(sharedData->mbcs.fromUnicodeBytes, stage2Entry, c);
                 if(value<=0xff) {
                     /* no mapping or SBCS result, not taken for DBCS-only */
                     value=stage2Entry=0; /* stage2Entry=0 to reset roundtrip flags */
                     length=0;
                 } else {
                     length=2;
                 }
                 break;
             case MBCS_OUTPUT_3:
                 p=MBCS_POINTER_3_FROM_STAGE_2(sharedData->mbcs.fromUnicodeBytes, stage2Entry, c);
                 value=((uint32_t)*p<<16)|((uint32_t)p[1]<<8)|p[2];
                 if(value<=0xff) {
                     length=1;
                 } else if(value<=0xffff) {
                     length=2;
                 } else {
                     length=3;
                 }
                 break;
             case MBCS_OUTPUT_4:
                 value=MBCS_VALUE_4_FROM_STAGE_2(sharedData->mbcs.fromUnicodeBytes, stage2Entry, c);
                 if(value<=0xff) {
                     length=1;
                 } else if(value<=0xffff) {
                     length=2;
                 } else if(value<=0xffffff) {
                     length=3;
                 } else {
                     length=4;
                 }
                 break;
             case MBCS_OUTPUT_3_EUC:
                 value=MBCS_VALUE_2_FROM_STAGE_2(sharedData->mbcs.fromUnicodeBytes, stage2Entry, c);
                 /* EUC 16-bit fixed-length representation */
                 if(value<=0xff) {
                     length=1;
                 } else if((value&0x8000)==0) {
                     value|=0x8e8000;
                     length=3;
                 } else if((value&0x80)==0) {
                     value|=0x8f0080;
                     length=3;
                 } else {
                     length=2;
                 }
                 break;
             case MBCS_OUTPUT_4_EUC:
                 p=MBCS_POINTER_3_FROM_STAGE_2(sharedData->mbcs.fromUnicodeBytes, stage2Entry, c);
                 value=((uint32_t)*p<<16)|((uint32_t)p[1]<<8)|p[2];
                 /* EUC 16-bit fixed-length representation applied to the first two bytes */
                 if(value<=0xff) {
                     length=1;
                 } else if(value<=0xffff) {
                     length=2;
                 } else if((value&0x800000)==0) {
                     value|=0x8e800000;
                     length=4;
                 } else if((value&0x8000)==0) {
                     value|=0x8f008000;
                     length=4;
                 } else {
                     length=3;
                 }
                 break;
 #endif
             default:
                 /* must not occur */
                 return -1;
             }
             /* is this code point assigned, or do we use fallbacks? */
             if( MBCS_FROM_U_IS_ROUNDTRIP(stage2Entry, c) ||
                 (FROM_U_USE_FALLBACK(useFallback, c) && value!=0)
             ) {
                 /*
                  * We allow a 0 byte output if the "assigned" bit is set for this entry.
                  * There is no way with this data structure for fallback output
                  * to be a zero byte.
                  */
                 /* assigned */
                 *pValue=value;
                 return length;
             }
         }
     }
     cx=sharedData->mbcs.extIndexes;
     if(cx!=NULL) {
         length=ucnv_extSimpleMatchFromU(cx, c, pValue, useFallback);
         return length>=0 ? length : -length;  /* return abs(length); */
     }
     /* unassigned */
     return 0;
 }
 #if 0
 /*
  * This function has been moved to ucnv2022.c for inlining.
  * This implementation is here only for documentation purposes
  */
 /**
  * This version of ucnv_MBCSFromUChar32() is optimized for single-byte codepages.
  * It does not handle the EBCDIC swaplfnl option (set in UConverter).
  * It does not handle conversion extensions (_extFromU()).
  *
  * It returns the codepage byte for the code point, or -1 if it is unassigned.
  */
 U_CFUNC int32_t
 ucnv_MBCSSingleFromUChar32(UConverterSharedData *sharedData,
                        UChar32 c,
                        UBool useFallback) {
     const uint16_t *table;
     int32_t value;
     /* BMP-only codepages are stored without stage 1 entries for supplementary code points */
     if(c>=0x10000 && !(sharedData->mbcs.unicodeMask&UCNV_HAS_SUPPLEMENTARY)) {
         return -1;
     }
     /* convert the Unicode code point in c into codepage bytes (same as in _MBCSFromUnicodeWithOffsets) */
     table=sharedData->mbcs.fromUnicodeTable;
     /* get the byte for the output */
     value=MBCS_SINGLE_RESULT_FROM_U(table, (uint16_t *)sharedData->mbcs.fromUnicodeBytes, c);
     /* is this code point assigned, or do we use fallbacks? */
     if(useFallback ? value>=0x800 : value>=0xc00) {
         return value&0xff;
     } else {
         return -1;
     }
 }
 #endif
 /* MBCS-from-UTF-8 conversion functions ------------------------------------- */
 /* minimum code point values for n-byte UTF-8 sequences, n=0..4 */
 static const UChar32
 utf8_minLegal[5]={ 0, 0, 0x80, 0x800, 0x10000 };
 /* offsets for n-byte UTF-8 sequences that were calculated with ((lead<<6)+trail)<<6+trail... */
 static const UChar32
 utf8_offsets[7]={ 0, 0, 0x3080, 0xE2080, 0x3C82080 };
 static void
 ucnv_SBCSFromUTF8(UConverterFromUnicodeArgs *pFromUArgs,
                   UConverterToUnicodeArgs *pToUArgs,
                   UErrorCode *pErrorCode) {
     UConverter *utf8, *cnv;
     const uint8_t *source, *sourceLimit;
     uint8_t *target;
     int32_t targetCapacity;
     const uint16_t *table, *sbcsIndex;
     const uint16_t *results;
     int8_t oldToULength, toULength, toULimit;
     UChar32 c;
     uint8_t b, t1, t2;
     uint32_t asciiRoundtrips;
     uint16_t value, minValue;
     UBool hasSupplementary;
     /* set up the local pointers */
     utf8=pToUArgs->converter;
     cnv=pFromUArgs->converter;
     source=(uint8_t *)pToUArgs->source;
     sourceLimit=(uint8_t *)pToUArgs->sourceLimit;
     target=(uint8_t *)pFromUArgs->target;
     targetCapacity=(int32_t)(pFromUArgs->targetLimit-pFromUArgs->target);
     table=cnv->sharedData->mbcs.fromUnicodeTable;
     sbcsIndex=cnv->sharedData->mbcs.sbcsIndex;
     if((cnv->options&UCNV_OPTION_SWAP_LFNL)!=0) {
         results=(uint16_t *)cnv->sharedData->mbcs.swapLFNLFromUnicodeBytes;
     } else {
         results=(uint16_t *)cnv->sharedData->mbcs.fromUnicodeBytes;
     }
     asciiRoundtrips=cnv->sharedData->mbcs.asciiRoundtrips;
     if(cnv->useFallback) {
         /* use all roundtrip and fallback results */
         minValue=0x800;
     } else {
         /* use only roundtrips and fallbacks from private-use characters */
         minValue=0xc00;
     }
     hasSupplementary=(UBool)(cnv->sharedData->mbcs.unicodeMask&UCNV_HAS_SUPPLEMENTARY);
     /* get the converter state from the UTF-8 UConverter */
     c=(UChar32)utf8->toUnicodeStatus;
     if(c!=0) {
         toULength=oldToULength=utf8->toULength;
         toULimit=(int8_t)utf8->mode;
     } else {
         toULength=oldToULength=toULimit=0;
     }
     /*
      * Make sure that the last byte sequence before sourceLimit is complete
      * or runs into a lead byte.
      * Do not go back into the bytes that will be read for finishing a partial
      * sequence from the previous buffer.
      * In the conversion loop compare source with sourceLimit only once
      * per multi-byte character.
      */
     {
         int32_t i, length;
         length=(int32_t)(sourceLimit-source) - (toULimit-oldToULength);
         for(i=0; i<3 && i<length;) {
             b=*(sourceLimit-i-1);
             if(U8_IS_TRAIL(b)) {
                 ++i;
             } else {
                 if(i<U8_COUNT_TRAIL_BYTES(b)) {
                     /* exit the conversion loop before the lead byte if there are not enough trail bytes for it */
                     sourceLimit-=i+1;
                 }
                 break;
             }
         }
     }
     if(c!=0 && targetCapacity>0) {
         utf8->toUnicodeStatus=0;
         utf8->toULength=0;
         goto moreBytes;
         /*
          * Note: We could avoid the goto by duplicating some of the moreBytes
          * code, but only up to the point of collecting a complete UTF-8
          * sequence; then recurse for the toUBytes[toULength]
          * and then continue with normal conversion.
          *
          * If so, move this code to just after initializing the minimum
          * set of local variables for reading the UTF-8 input
          * (utf8, source, target, limits but not cnv, table, minValue, etc.).
          *
          * Potential advantages:
          * - avoid the goto
          * - oldToULength could become a local variable in just those code blocks
          *   that deal with buffer boundaries
          * - possibly faster if the goto prevents some compiler optimizations
          *   (this would need measuring to confirm)
          * Disadvantage:
          * - code duplication
          */
     }
     /* conversion loop */
     while(source<sourceLimit) {
         if(targetCapacity>0) {
             b=*source++;
             if((int8_t)b>=0) {
                 /* convert ASCII */
                 if(IS_ASCII_ROUNDTRIP(b, asciiRoundtrips)) {
                     *target++=(uint8_t)b;
                     --targetCapacity;
                     continue;
                 } else {
                     c=b;
                     value=SBCS_RESULT_FROM_UTF8(sbcsIndex, results, 0, c);
                 }
             } else {
                 if(b<0xe0) {
                     if( /* handle U+0080..U+07FF inline */
                         b>=0xc2 &&
                         (t1=(uint8_t)(*source-0x80)) <= 0x3f
                     ) {
                         c=b&0x1f;
                         ++source;
                         value=SBCS_RESULT_FROM_UTF8(sbcsIndex, results, c, t1);
                         if(value>=minValue) {
                             *target++=(uint8_t)value;
                             --targetCapacity;
                             continue;
                         } else {
                             c=(c<<6)|t1;
                         }
                     } else {
                         c=-1;
                     }
                 } else if(b==0xe0) {
                     if( /* handle U+0800..U+0FFF inline */
                         (t1=(uint8_t)(source[0]-0x80)) <= 0x3f && t1 >= 0x20 &&
                         (t2=(uint8_t)(source[1]-0x80)) <= 0x3f
                     ) {
                         c=t1;
                         source+=2;
                         value=SBCS_RESULT_FROM_UTF8(sbcsIndex, results, c, t2);
                         if(value>=minValue) {
                             *target++=(uint8_t)value;
                             --targetCapacity;
                             continue;
                         } else {
                             c=(c<<6)|t2;
                         }
                     } else {
                         c=-1;
                     }
                 } else {
                     c=-1;
                 }
                 if(c<0) {
                     /* handle "complicated" and error cases, and continuing partial characters */
                     oldToULength=0;
                     toULength=1;
                     toULimit=U8_COUNT_TRAIL_BYTES(b)+1;
                     c=b;
 moreBytes:
                     while(toULength<toULimit) {
                         /*
                          * The sourceLimit may have been adjusted before the conversion loop
                          * to stop before a truncated sequence.
                          * Here we need to use the real limit in case we have two truncated
                          * sequences at the end.
                          * See ticket #7492.
                          */
                         if(source<(uint8_t *)pToUArgs->sourceLimit) {
                             b=*source;
                             if(U8_IS_TRAIL(b)) {
                                 ++source;
                                 ++toULength;
                                 c=(c<<6)+b;
                             } else {
                                 break; /* sequence too short, stop with toULength<toULimit */
                             }
                         } else {
                             /* store the partial UTF-8 character, compatible with the regular UTF-8 converter */
                             source-=(toULength-oldToULength);
                             while(oldToULength<toULength) {
                                 utf8->toUBytes[oldToULength++]=*source++;
                             }
                             utf8->toUnicodeStatus=c;
                             utf8->toULength=toULength;
                             utf8->mode=toULimit;
                             pToUArgs->source=(char *)source;
                             pFromUArgs->target=(char *)target;
                             return;
                         }
                     }
                     if( toULength==toULimit &&      /* consumed all trail bytes */
                         (toULength==3 || toULength==2) &&             /* BMP */
                         (c-=utf8_offsets[toULength])>=utf8_minLegal[toULength] &&
                         (c<=0xd7ff || 0xe000<=c)    /* not a surrogate */
                     ) {
                         value=MBCS_SINGLE_RESULT_FROM_U(table, results, c);
                     } else if(
                         toULength==toULimit && toULength==4 &&
                         (0x10000<=(c-=utf8_offsets[4]) && c<=0x10ffff)
                     ) {
                         /* supplementary code point */
                         if(!hasSupplementary) {
                             /* BMP-only codepages are stored without stage 1 entries for supplementary code points */
                             value=0;
                         } else {
                             value=MBCS_SINGLE_RESULT_FROM_U(table, results, c);
                         }
                     } else {
                         /* error handling: illegal UTF-8 byte sequence */
                         source-=(toULength-oldToULength);
                         while(oldToULength<toULength) {
                             utf8->toUBytes[oldToULength++]=*source++;
                         }
                         utf8->toULength=toULength;
                         pToUArgs->source=(char *)source;
                         pFromUArgs->target=(char *)target;
                         *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                         return;
                     }
                 }
             }
             if(value>=minValue) {
                 /* output the mapping for c */
                 *target++=(uint8_t)value;
                 --targetCapacity;
             } else {
                 /* value<minValue means c is unassigned (unmappable) */
                 /*
                  * Try an extension mapping.
                  * Pass in no source because we don't have UTF-16 input.
                  * If we have a partial match on c, we will return and revert
                  * to UTF-8->UTF-16->charset conversion.
                  */
                 static const UChar nul=0;
                 const UChar *noSource=&nul;
                 c=_extFromU(cnv, cnv->sharedData,
                             c, &noSource, noSource,
                             &target, target+targetCapacity,
                             NULL, -1,
                             pFromUArgs->flush,
                             pErrorCode);
                 if(U_FAILURE(*pErrorCode)) {
                     /* not mappable or buffer overflow */
                     cnv->fromUChar32=c;
                     break;
                 } else if(cnv->preFromUFirstCP>=0) {
                     /*
                      * Partial match, return and revert to pivoting.
                      * In normal from-UTF-16 conversion, we would just continue
                      * but then exit the loop because the extension match would
                      * have consumed the source.
                      */
                     *pErrorCode=U_USING_DEFAULT_WARNING;
                     break;
                 } else {
                     /* a mapping was written to the target, continue */
                     /* recalculate the targetCapacity after an extension mapping */
                     targetCapacity=(int32_t)(pFromUArgs->targetLimit-(char *)target);
                 }
             }
         } else {
             /* target is full */
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             break;
         }
     }
     /*
      * The sourceLimit may have been adjusted before the conversion loop
      * to stop before a truncated sequence.
      * If so, then collect the truncated sequence now.
      */
     if(U_SUCCESS(*pErrorCode) &&
             cnv->preFromUFirstCP<0 &&
             source<(sourceLimit=(uint8_t *)pToUArgs->sourceLimit)) {
         c=utf8->toUBytes[0]=b=*source++;
         toULength=1;
         toULimit=U8_COUNT_TRAIL_BYTES(b)+1;
         while(source<sourceLimit) {
             utf8->toUBytes[toULength++]=b=*source++;
             c=(c<<6)+b;
         }
         utf8->toUnicodeStatus=c;
         utf8->toULength=toULength;
         utf8->mode=toULimit;
     }
     /* write back the updated pointers */
     pToUArgs->source=(char *)source;
     pFromUArgs->target=(char *)target;
 }
 static void
 ucnv_DBCSFromUTF8(UConverterFromUnicodeArgs *pFromUArgs,
                   UConverterToUnicodeArgs *pToUArgs,
                   UErrorCode *pErrorCode) {
     UConverter *utf8, *cnv;
     const uint8_t *source, *sourceLimit;
     uint8_t *target;
     int32_t targetCapacity;
     const uint16_t *table, *mbcsIndex;
     const uint16_t *results;
     int8_t oldToULength, toULength, toULimit;
     UChar32 c;
     uint8_t b, t1, t2;
     uint32_t stage2Entry;
     uint32_t asciiRoundtrips;
     uint16_t value;
     UBool hasSupplementary;
     /* set up the local pointers */
     utf8=pToUArgs->converter;
     cnv=pFromUArgs->converter;
     source=(uint8_t *)pToUArgs->source;
     sourceLimit=(uint8_t *)pToUArgs->sourceLimit;
     target=(uint8_t *)pFromUArgs->target;
     targetCapacity=(int32_t)(pFromUArgs->targetLimit-pFromUArgs->target);
     table=cnv->sharedData->mbcs.fromUnicodeTable;
     mbcsIndex=cnv->sharedData->mbcs.mbcsIndex;
     if((cnv->options&UCNV_OPTION_SWAP_LFNL)!=0) {
         results=(uint16_t *)cnv->sharedData->mbcs.swapLFNLFromUnicodeBytes;
     } else {
         results=(uint16_t *)cnv->sharedData->mbcs.fromUnicodeBytes;
     }
     asciiRoundtrips=cnv->sharedData->mbcs.asciiRoundtrips;
     hasSupplementary=(UBool)(cnv->sharedData->mbcs.unicodeMask&UCNV_HAS_SUPPLEMENTARY);
     /* get the converter state from the UTF-8 UConverter */
     c=(UChar32)utf8->toUnicodeStatus;
     if(c!=0) {
         toULength=oldToULength=utf8->toULength;
         toULimit=(int8_t)utf8->mode;
     } else {
         toULength=oldToULength=toULimit=0;
     }
     /*
      * Make sure that the last byte sequence before sourceLimit is complete
      * or runs into a lead byte.
      * Do not go back into the bytes that will be read for finishing a partial
      * sequence from the previous buffer.
      * In the conversion loop compare source with sourceLimit only once
      * per multi-byte character.
      */
     {
         int32_t i, length;
         length=(int32_t)(sourceLimit-source) - (toULimit-oldToULength);
         for(i=0; i<3 && i<length;) {
             b=*(sourceLimit-i-1);
             if(U8_IS_TRAIL(b)) {
                 ++i;
             } else {
                 if(i<U8_COUNT_TRAIL_BYTES(b)) {
                     /* exit the conversion loop before the lead byte if there are not enough trail bytes for it */
                     sourceLimit-=i+1;
                 }
                 break;
             }
         }
     }
     if(c!=0 && targetCapacity>0) {
         utf8->toUnicodeStatus=0;
         utf8->toULength=0;
         goto moreBytes;
         /* See note in ucnv_SBCSFromUTF8() about this goto. */
     }
     /* conversion loop */
     while(source<sourceLimit) {
         if(targetCapacity>0) {
             b=*source++;
             if((int8_t)b>=0) {
                 /* convert ASCII */
                 if(IS_ASCII_ROUNDTRIP(b, asciiRoundtrips)) {
                     *target++=b;
                     --targetCapacity;
                     continue;
                 } else {
                     value=DBCS_RESULT_FROM_UTF8(mbcsIndex, results, 0, b);
                     if(value==0) {
                         c=b;
                         goto unassigned;
                     }
                 }
             } else {
                 if(b>0xe0) {
                     if( /* handle U+1000..U+D7FF inline */
                         (((t1=(uint8_t)(source[0]-0x80), b<0xed) && (t1 <= 0x3f)) ||
                                                         (b==0xed && (t1 <= 0x1f))) &&
                         (t2=(uint8_t)(source[1]-0x80)) <= 0x3f
                     ) {
                         c=((b&0xf)<<6)|t1;
                         source+=2;
                         value=DBCS_RESULT_FROM_UTF8(mbcsIndex, results, c, t2);
                         if(value==0) {
                             c=(c<<6)|t2;
                             goto unassigned;
                         }
                     } else {
                         c=-1;
                     }
                 } else if(b<0xe0) {
                     if( /* handle U+0080..U+07FF inline */
                         b>=0xc2 &&
                         (t1=(uint8_t)(*source-0x80)) <= 0x3f
                     ) {
                         c=b&0x1f;
                         ++source;
                         value=DBCS_RESULT_FROM_UTF8(mbcsIndex, results, c, t1);
                         if(value==0) {
                             c=(c<<6)|t1;
                             goto unassigned;
                         }
                     } else {
                         c=-1;
                     }
                 } else {
                     c=-1;
                 }
                 if(c<0) {
                     /* handle "complicated" and error cases, and continuing partial characters */
                     oldToULength=0;
                     toULength=1;
                     toULimit=U8_COUNT_TRAIL_BYTES(b)+1;
                     c=b;
 moreBytes:
                     while(toULength<toULimit) {
                         /*
                          * The sourceLimit may have been adjusted before the conversion loop
                          * to stop before a truncated sequence.
                          * Here we need to use the real limit in case we have two truncated
                          * sequences at the end.
                          * See ticket #7492.
                          */
                         if(source<(uint8_t *)pToUArgs->sourceLimit) {
                             b=*source;
                             if(U8_IS_TRAIL(b)) {
                                 ++source;
                                 ++toULength;
                                 c=(c<<6)+b;
                             } else {
                                 break; /* sequence too short, stop with toULength<toULimit */
                             }
                         } else {
                             /* store the partial UTF-8 character, compatible with the regular UTF-8 converter */
                             source-=(toULength-oldToULength);
                             while(oldToULength<toULength) {
                                 utf8->toUBytes[oldToULength++]=*source++;
                             }
                             utf8->toUnicodeStatus=c;
                             utf8->toULength=toULength;
                             utf8->mode=toULimit;
                             pToUArgs->source=(char *)source;
                             pFromUArgs->target=(char *)target;
                             return;
                         }
                     }
                     if( toULength==toULimit &&      /* consumed all trail bytes */
                         (toULength==3 || toULength==2) &&             /* BMP */
                         (c-=utf8_offsets[toULength])>=utf8_minLegal[toULength] &&
                         (c<=0xd7ff || 0xe000<=c)    /* not a surrogate */
                     ) {
                         stage2Entry=MBCS_STAGE_2_FROM_U(table, c);
                     } else if(
                         toULength==toULimit && toULength==4 &&
                         (0x10000<=(c-=utf8_offsets[4]) && c<=0x10ffff)
                     ) {
                         /* supplementary code point */
                         if(!hasSupplementary) {
                             /* BMP-only codepages are stored without stage 1 entries for supplementary code points */
                             stage2Entry=0;
                         } else {
                             stage2Entry=MBCS_STAGE_2_FROM_U(table, c);
                         }
                     } else {
                         /* error handling: illegal UTF-8 byte sequence */
                         source-=(toULength-oldToULength);
                         while(oldToULength<toULength) {
                             utf8->toUBytes[oldToULength++]=*source++;
                         }
                         utf8->toULength=toULength;
                         pToUArgs->source=(char *)source;
                         pFromUArgs->target=(char *)target;
                         *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                         return;
                     }
                     /* get the bytes and the length for the output */
                     /* MBCS_OUTPUT_2 */
                     value=MBCS_VALUE_2_FROM_STAGE_2(results, stage2Entry, c);
                     /* is this code point assigned, or do we use fallbacks? */
                     if(!(MBCS_FROM_U_IS_ROUNDTRIP(stage2Entry, c) ||
                          (UCNV_FROM_U_USE_FALLBACK(cnv, c) && value!=0))
                     ) {
                         goto unassigned;
                     }
                 }
             }
             /* write the output character bytes from value and length */
             /* from the first if in the loop we know that targetCapacity>0 */
             if(value<=0xff) {
                 /* this is easy because we know that there is enough space */
                 *target++=(uint8_t)value;
                 --targetCapacity;
             } else /* length==2 */ {
                 *target++=(uint8_t)(value>>8);
                 if(2<=targetCapacity) {
                     *target++=(uint8_t)value;
                     targetCapacity-=2;
                 } else {
                     cnv->charErrorBuffer[0]=(char)value;
                     cnv->charErrorBufferLength=1;
                     /* target overflow */
                     *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                     break;
                 }
             }
             continue;
 unassigned:
             {
                 /*
                  * Try an extension mapping.
                  * Pass in no source because we don't have UTF-16 input.
                  * If we have a partial match on c, we will return and revert
                  * to UTF-8->UTF-16->charset conversion.
                  */
                 static const UChar nul=0;
                 const UChar *noSource=&nul;
                 c=_extFromU(cnv, cnv->sharedData,
                             c, &noSource, noSource,
                             &target, target+targetCapacity,
                             NULL, -1,
                             pFromUArgs->flush,
                             pErrorCode);
                 if(U_FAILURE(*pErrorCode)) {
                     /* not mappable or buffer overflow */
                     cnv->fromUChar32=c;
                     break;
                 } else if(cnv->preFromUFirstCP>=0) {
                     /*
                      * Partial match, return and revert to pivoting.
                      * In normal from-UTF-16 conversion, we would just continue
                      * but then exit the loop because the extension match would
                      * have consumed the source.
                      */
                     *pErrorCode=U_USING_DEFAULT_WARNING;
                     break;
                 } else {
                     /* a mapping was written to the target, continue */
                     /* recalculate the targetCapacity after an extension mapping */
                     targetCapacity=(int32_t)(pFromUArgs->targetLimit-(char *)target);
                     continue;
                 }
             }
         } else {
             /* target is full */
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             break;
         }
     }
     /*
      * The sourceLimit may have been adjusted before the conversion loop
      * to stop before a truncated sequence.
      * If so, then collect the truncated sequence now.
      */
     if(U_SUCCESS(*pErrorCode) &&
             cnv->preFromUFirstCP<0 &&
             source<(sourceLimit=(uint8_t *)pToUArgs->sourceLimit)) {
         c=utf8->toUBytes[0]=b=*source++;
         toULength=1;
         toULimit=U8_COUNT_TRAIL_BYTES(b)+1;
         while(source<sourceLimit) {
             utf8->toUBytes[toULength++]=b=*source++;
             c=(c<<6)+b;
         }
         utf8->toUnicodeStatus=c;
         utf8->toULength=toULength;
         utf8->mode=toULimit;
     }
     /* write back the updated pointers */
     pToUArgs->source=(char *)source;
     pFromUArgs->target=(char *)target;
 }
 /* miscellaneous ------------------------------------------------------------ */
 static void
 ucnv_MBCSGetStarters(const UConverter* cnv,
                  UBool starters[256],
                  UErrorCode *pErrorCode) {
     const int32_t *state0;
     int i;
     state0=cnv->sharedData->mbcs.stateTable[cnv->sharedData->mbcs.dbcsOnlyState];
     for(i=0; i<256; ++i) {
         /* all bytes that cause a state transition from state 0 are lead bytes */
         starters[i]= (UBool)MBCS_ENTRY_IS_TRANSITION(state0[i]);
     }
 }
 /*
  * This is an internal function that allows other converter implementations
  * to check whether a byte is a lead byte.
  */
 U_CFUNC UBool
 ucnv_MBCSIsLeadByte(UConverterSharedData *sharedData, char byte) {
     return (UBool)MBCS_ENTRY_IS_TRANSITION(sharedData->mbcs.stateTable[0][(uint8_t)byte]);
 }
 static void
 ucnv_MBCSWriteSub(UConverterFromUnicodeArgs *pArgs,
               int32_t offsetIndex,
               UErrorCode *pErrorCode) {
     UConverter *cnv=pArgs->converter;
     char *p, *subchar;
     char buffer[4];
     int32_t length;
     /* first, select between subChar and subChar1 */
     if( cnv->subChar1!=0 &&
         (cnv->sharedData->mbcs.extIndexes!=NULL ?
             cnv->useSubChar1 :
             (cnv->invalidUCharBuffer[0]<=0xff))
     ) {
         /* select subChar1 if it is set (not 0) and the unmappable Unicode code point is up to U+00ff (IBM MBCS behavior) */
         subchar=(char *)&cnv->subChar1;
         length=1;
     } else {
         /* select subChar in all other cases */
         subchar=(char *)cnv->subChars;
         length=cnv->subCharLen;
     }
     /* reset the selector for the next code point */
     cnv->useSubChar1=FALSE;
     if (cnv->sharedData->mbcs.outputType == MBCS_OUTPUT_2_SISO) {
         p=buffer;
         /* fromUnicodeStatus contains prevLength */
         switch(length) {
         case 1:
             if(cnv->fromUnicodeStatus==2) {
                 /* DBCS mode and SBCS sub char: change to SBCS */
                 cnv->fromUnicodeStatus=1;
                 *p++=UCNV_SI;
             }
             *p++=subchar[0];
             break;
         case 2:
             if(cnv->fromUnicodeStatus<=1) {
                 /* SBCS mode and DBCS sub char: change to DBCS */
                 cnv->fromUnicodeStatus=2;
                 *p++=UCNV_SO;
             }
             *p++=subchar[0];
             *p++=subchar[1];
             break;
         default:
             *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
             return;
         }
         subchar=buffer;
         length=(int32_t)(p-buffer);
     }
     ucnv_cbFromUWriteBytes(pArgs, subchar, length, offsetIndex, pErrorCode);
 }
 U_CFUNC UConverterType
 ucnv_MBCSGetType(const UConverter* converter) {
     /* SBCS, DBCS, and EBCDIC_STATEFUL are replaced by MBCS, but here we cheat a little */
     if(converter->sharedData->mbcs.countStates==1) {
         return (UConverterType)UCNV_SBCS;
     } else if((converter->sharedData->mbcs.outputType&0xff)==MBCS_OUTPUT_2_SISO) {
         return (UConverterType)UCNV_EBCDIC_STATEFUL;
     } else if(converter->sharedData->staticData->minBytesPerChar==2 && converter->sharedData->staticData->maxBytesPerChar==2) {
         return (UConverterType)UCNV_DBCS;
     }
     return (UConverterType)UCNV_MBCS;
 }
 static const UConverterImpl _SBCSUTF8Impl={
     UCNV_MBCS,
     ucnv_MBCSLoad,
     ucnv_MBCSUnload,
     ucnv_MBCSOpen,
     NULL,
     NULL,
     ucnv_MBCSToUnicodeWithOffsets,
     ucnv_MBCSToUnicodeWithOffsets,
     ucnv_MBCSFromUnicodeWithOffsets,
     ucnv_MBCSFromUnicodeWithOffsets,
     ucnv_MBCSGetNextUChar,
     ucnv_MBCSGetStarters,
     ucnv_MBCSGetName,
     ucnv_MBCSWriteSub,
     NULL,
     ucnv_MBCSGetUnicodeSet,
     NULL,
     ucnv_SBCSFromUTF8
 };
 static const UConverterImpl _DBCSUTF8Impl={
     UCNV_MBCS,
     ucnv_MBCSLoad,
     ucnv_MBCSUnload,
     ucnv_MBCSOpen,
     NULL,
     NULL,
     ucnv_MBCSToUnicodeWithOffsets,
     ucnv_MBCSToUnicodeWithOffsets,
     ucnv_MBCSFromUnicodeWithOffsets,
     ucnv_MBCSFromUnicodeWithOffsets,
     ucnv_MBCSGetNextUChar,
     ucnv_MBCSGetStarters,
     ucnv_MBCSGetName,
     ucnv_MBCSWriteSub,
     NULL,
     ucnv_MBCSGetUnicodeSet,
     NULL,
     ucnv_DBCSFromUTF8
 };
 static const UConverterImpl _MBCSImpl={
     UCNV_MBCS,
     ucnv_MBCSLoad,
     ucnv_MBCSUnload,
     ucnv_MBCSOpen,
     NULL,
     NULL,
     ucnv_MBCSToUnicodeWithOffsets,
     ucnv_MBCSToUnicodeWithOffsets,
     ucnv_MBCSFromUnicodeWithOffsets,
     ucnv_MBCSFromUnicodeWithOffsets,
     ucnv_MBCSGetNextUChar,
     ucnv_MBCSGetStarters,
     ucnv_MBCSGetName,
     ucnv_MBCSWriteSub,
     NULL,
     ucnv_MBCSGetUnicodeSet
 };
 /* Static data is in tools/makeconv/ucnvstat.c for data-based
  * converters. Be sure to update it as well.
  */
 const UConverterSharedData _MBCSData={
     sizeof(UConverterSharedData), 1,
     NULL, NULL, NULL, FALSE, &_MBCSImpl,
 
 };
 #endif /* #if !UCONFIG_NO_LEGACY_CONVERSION */

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intl/icu/source/common/ucnvmbcs.c@129ffea94266 (annotated)

intl/icu/source/common/ucnvmbcs.c