intl/icu/source/common/ucnvmbcs.h

Wed, 31 Dec 2014 07:22:50 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Wed, 31 Dec 2014 07:22:50 +0100
branch
TOR_BUG_3246
changeset 4
fc2d59ddac77
permissions
-rw-r--r--

Correct previous dual key logic pending first delivery installment.

     1 /*
     2 ******************************************************************************
     3 *
     4 *   Copyright (C) 2000-2013, International Business Machines
     5 *   Corporation and others.  All Rights Reserved.
     6 *
     7 ******************************************************************************
     8 *   file name:  ucnvmbcs.h
     9 *   encoding:   US-ASCII
    10 *   tab size:   8 (not used)
    11 *   indentation:4
    12 *
    13 *   created on: 2000jul07
    14 *   created by: Markus W. Scherer
    15 */
    17 #ifndef __UCNVMBCS_H__
    18 #define __UCNVMBCS_H__
    20 #include "unicode/utypes.h"
    22 #if !UCONFIG_NO_CONVERSION
    24 #include "unicode/ucnv.h"
    25 #include "ucnv_cnv.h"
    26 #include "ucnv_ext.h"
    28 /**
    29  * ICU conversion (.cnv) data file structure, following the usual UDataInfo
    30  * header.
    31  *
    32  * Format version: 6.2
    33  *
    34  * struct UConverterStaticData -- struct containing the converter name, IBM CCSID,
    35  *                                min/max bytes per character, etc.
    36  *                                see ucnv_bld.h
    37  *
    38  * --------------------
    39  *
    40  * The static data is followed by conversionType-specific data structures.
    41  * At the moment, there are only variations of MBCS converters. They all have
    42  * the same toUnicode structures, while the fromUnicode structures for SBCS
    43  * differ from those for other MBCS-style converters.
    44  *
    45  * _MBCSHeader.version 5 is optional and not backward-compatible
    46  * (as usual for changes in the major version field).
    47  *
    48  * Versions 5.m work like versions 4.m except:
    49  * - The _MBCSHeader has variable length (and is always longer than in version 4).
    50  *   See the struct _MBCSHeader further description below.
    51  * - There is a set of flags which indicate further incompatible changes.
    52  *   (Reader code must reject the file if it does not recognize them all.)
    53  * - In particular, one of these flags indicates that most of the fromUnicode
    54  *   data is missing and must be reconstituted from the toUnicode data
    55  *   and from the utf8Friendly mbcsIndex at load time.
    56  *   (This only works with a utf8Friendly table.)
    57  *   In this case, makeconv may increase maxFastUChar automatically to U+FFFF.
    58  *
    59  * The first of these versions is 5.3, which is like 4.3 except for the differences above.
    60  *
    61  * When possible, makeconv continues to generate version 4.m files.
    62  *
    63  * _MBCSHeader.version 5.4/4.4 supports "good one-way" mappings (|4)
    64  * in the extension tables (fromUTableValues bit 30). See ucnv_ext.h for details.
    65  *
    66  * _MBCSHeader.version 4.3 optionally modifies the fromUnicode data structures
    67  * slightly and optionally adds a table for conversion to MBCS (non-SBCS)
    68  * charsets.
    69  *
    70  * The modifications are to make the data utf8Friendly. Not every 4.3 file
    71  * file contains utf8Friendly data.
    72  * It is utf8Friendly if _MBCSHeader.version[2]!=0.
    73  * In this case, the data structures are utf8Friendly up to the code point
    74  *   maxFastUChar=((_MBCSHeader.version[2]<<8)|0xff)
    75  *
    76  * A utf8Friendly file has fromUnicode stage 3 entries for code points up to
    77  * maxFastUChar allocated in blocks of 64 for indexing with the 6 bits from
    78  * a UTF-8 trail byte. ASCII is allocated linearly with 128 contiguous entries.
    79  *
    80  * In addition, a utf8Friendly MBCS file contains an additional
    81  *   uint16_t mbcsIndex[(maxFastUChar+1)>>6];
    82  * which replaces the stage 1 and 2 tables for indexing with bits from the
    83  * UTF-8 lead byte and middle trail byte. Unlike the older MBCS stage 2 table,
    84  * the mbcsIndex does not contain roundtrip flags. Therefore, all fallbacks
    85  * from code points up to maxFastUChar (and roundtrips to 0x00) are moved to
    86  * the extension data structure. This also allows for faster roundtrip
    87  * conversion from UTF-16.
    88  *
    89  * SBCS files do not contain an additional sbcsIndex[] array because the
    90  * proportional size increase would be noticeable, but the runtime
    91  * code builds one for the code point range for which the runtime conversion
    92  * code is optimized.
    93  *
    94  * For SBCS, maxFastUChar should be at least U+0FFF. The initial makeconv
    95  * implementation sets it to U+1FFF. Because the sbcsIndex is not stored in
    96  * the file, a larger maxFastUChar only affects stage 3 block allocation size
    97  * and is free in empty blocks. (Larger blocks with sparse contents cause larger
    98  * files.) U+1FFF includes almost all of the small scripts.
    99  * U+0FFF covers UTF-8 two-byte sequences and three-byte sequences starting with
   100  * 0xe0. This includes most scripts with legacy SBCS charsets.
   101  * The initial runtime implementation using 4.3 files only builds an sbcsIndex
   102  * for code points up to U+0FFF.
   103  *
   104  * For MBCS, maxFastUChar should be at least U+D7FF (=initial value).
   105  * This boundary is convenient because practically all of the commonly used
   106  * characters are below it, and because it is the boundary to surrogate
   107  * code points, above which special handling is necessary anyway.
   108  * (Surrogate pair assembly for UTF-16, validity checking for UTF-8.)
   109  *
   110  * maxFastUChar could be up to U+FFFF to cover the whole BMP, which could be
   111  * useful especially for conversion from UTF-8 when the input can be assumed
   112  * to be valid, because the surrogate range would then not have to be
   113  * checked.
   114  * (With maxFastUChar=0xffff, makeconv would have to check for mbcsIndex value
   115  * overflow because with the all-unassigned block 0 and nearly full mappings
   116  * from the BMP it is theoretically possible that an index into stage 3
   117  * exceeds 16 bits.)
   118  *
   119  * _MBCSHeader.version 4.2 adds an optional conversion extension data structure.
   120  * If it is present, then an ICU version reading header versions 4.0 or 4.1
   121  * will be able to use the base table and ignore the extension.
   122  *
   123  * The unicodeMask in the static data is part of the base table data structure.
   124  * Especially, the UCNV_HAS_SUPPLEMENTARY flag determines the length of the
   125  * fromUnicode stage 1 array.
   126  * The static data unicodeMask refers only to the base table's properties if
   127  * a base table is included.
   128  * In an extension-only file, the static data unicodeMask is 0.
   129  * The extension data indexes have a separate field with the unicodeMask flags.
   130  *
   131  * MBCS-style data structure following the static data.
   132  * Offsets are counted in bytes from the beginning of the MBCS header structure.
   133  * Details about usage in comments in ucnvmbcs.c.
   134  *
   135  * struct _MBCSHeader (see the definition in this header file below)
   136  * contains 32-bit fields as follows:
   137  * 8 values:
   138  *  0   uint8_t[4]  MBCS version in UVersionInfo format (currently 4.3.x.0)
   139  *  1   uint32_t    countStates
   140  *  2   uint32_t    countToUFallbacks
   141  *  3   uint32_t    offsetToUCodeUnits
   142  *  4   uint32_t    offsetFromUTable
   143  *  5   uint32_t    offsetFromUBytes
   144  *  6   uint32_t    flags, bits:
   145  *                      31.. 8 offsetExtension -- _MBCSHeader.version 4.2 (ICU 2.8) and higher
   146  *                                                0 for older versions and if
   147  *                                                there is not extension structure
   148  *                       7.. 0 outputType
   149  *  7   uint32_t    fromUBytesLength -- _MBCSHeader.version 4.1 (ICU 2.4) and higher
   150  *                  counts bytes in fromUBytes[]
   151  *
   152  * New and required in version 5:
   153  *  8   uint32_t    options, bits:
   154  *                      31..16 reserved for flags that can be added without breaking
   155  *                                 backward compatibility
   156  *                      15.. 6 reserved for flags whose addition will break
   157  *                                 backward compatibility
   158  *                           6 MBCS_OPT_FROM_U -- if set,
   159  *                                 then most of the fromUnicode data is omitted;
   160  *                                 fullStage2Length is present and the missing
   161  *                                 bottom part of stage 2 must be reconstituted from
   162  *                                 the toUnicode data;
   163  *                                 stage 3 is missing completely as well;
   164  *                                 not used for SBCS tables
   165  *                       5.. 0 length of the _MBCSHeader (number of uint32_t)
   166  *
   167  * New and optional in version 5:
   168  *  9   uint32_t    fullStage2Length: used if MBCS_OPT_FROM_U is set
   169  *                                 specifies the full length of stage 2
   170  *                                 including the omitted part
   171  *
   172  * if(outputType==MBCS_OUTPUT_EXT_ONLY) {
   173  *     -- base table name for extension-only table
   174  *     char baseTableName[variable]; -- with NUL plus padding for 4-alignment
   175  *
   176  *     -- all _MBCSHeader fields except for version and flags are 0
   177  * } else {
   178  *     -- normal base table with optional extension
   179  *
   180  *     int32_t stateTable[countStates][256];
   181  *    
   182  *     struct _MBCSToUFallback { (fallbacks are sorted by offset)
   183  *         uint32_t offset;
   184  *         UChar32 codePoint;
   185  *     } toUFallbacks[countToUFallbacks];
   186  *    
   187  *     uint16_t unicodeCodeUnits[(offsetFromUTable-offsetToUCodeUnits)/2];
   188  *                  (padded to an even number of units)
   189  *    
   190  *     -- stage 1 tables
   191  *     if(staticData.unicodeMask&UCNV_HAS_SUPPLEMENTARY) {
   192  *         -- stage 1 table for all of Unicode
   193  *         uint16_t fromUTable[0x440]; (32-bit-aligned)
   194  *     } else {
   195  *         -- BMP-only tables have a smaller stage 1 table
   196  *         uint16_t fromUTable[0x40]; (32-bit-aligned)
   197  *     }
   198  *
   199  *     -- stage 2 tables
   200  *        length determined by top of stage 1 and bottom of stage 3 tables
   201  *     if(outputType==MBCS_OUTPUT_1) {
   202  *         -- SBCS: pure indexes
   203  *         uint16_t stage 2 indexes[?];
   204  *     } else {
   205  *         -- DBCS, MBCS, EBCDIC_STATEFUL, ...: roundtrip flags and indexes
   206  *         uint32_t stage 2 flags and indexes[?];
   207  *         if(options&MBCS_OPT_NO_FROM_U) {
   208  *             stage 2 really has length fullStage2Length
   209  *             and the omitted lower part must be reconstituted from
   210  *             the toUnicode data
   211  *         }
   212  *     }
   213  *
   214  *     -- stage 3 tables with byte results
   215  *     if(outputType==MBCS_OUTPUT_1) {
   216  *         -- SBCS: each 16-bit result contains flags and the result byte, see ucnvmbcs.c
   217  *         uint16_t fromUBytes[fromUBytesLength/2];
   218  *     } else if(!(options&MBCS_OPT_NO_FROM_U)) {
   219  *         -- DBCS, MBCS, EBCDIC_STATEFUL, ... 2/3/4 bytes result, see ucnvmbcs.c
   220  *         uint8_t fromUBytes[fromUBytesLength]; or
   221  *         uint16_t fromUBytes[fromUBytesLength/2]; or
   222  *         uint32_t fromUBytes[fromUBytesLength/4];
   223  *     } else {
   224  *         fromUBytes[] must be reconstituted from the toUnicode data
   225  *     }
   226  *
   227  *     -- optional utf8Friendly mbcsIndex -- _MBCSHeader.version 4.3 (ICU 3.8) and higher
   228  *     if(outputType!=MBCS_OUTPUT_1 &&
   229  *        _MBCSHeader.version[1]>=3 &&
   230  *        (maxFastUChar=_MBCSHeader.version[2])!=0
   231  *     ) {
   232  *         maxFastUChar=(maxFastUChar<<8)|0xff;
   233  *         uint16_t mbcsIndex[(maxFastUChar+1)>>6];
   234  *     }
   235  * }
   236  *
   237  * -- extension table, details see ucnv_ext.h
   238  * int32_t indexes[>=32]; ...
   239  */
   241 /* MBCS converter data and state -------------------------------------------- */
   243 enum {
   244     MBCS_MAX_STATE_COUNT=128
   245 };
   247 /**
   248  * MBCS action codes for conversions to Unicode.
   249  * These values are in bits 23..20 of the state table entries.
   250  */
   251 enum {
   252     MBCS_STATE_VALID_DIRECT_16,
   253     MBCS_STATE_VALID_DIRECT_20,
   255     MBCS_STATE_FALLBACK_DIRECT_16,
   256     MBCS_STATE_FALLBACK_DIRECT_20,
   258     MBCS_STATE_VALID_16,
   259     MBCS_STATE_VALID_16_PAIR,
   261     MBCS_STATE_UNASSIGNED,
   262     MBCS_STATE_ILLEGAL,
   264     MBCS_STATE_CHANGE_ONLY
   265 };
   267 /* Macros for state table entries */
   268 #define MBCS_ENTRY_TRANSITION(state, offset) (int32_t)(((int32_t)(state)<<24L)|(offset))
   269 #define MBCS_ENTRY_TRANSITION_SET_OFFSET(entry, offset) (int32_t)(((entry)&0xff000000)|(offset))
   270 #define MBCS_ENTRY_TRANSITION_ADD_OFFSET(entry, offset) (int32_t)((entry)+(offset))
   272 #define MBCS_ENTRY_FINAL(state, action, value) (int32_t)(0x80000000|((int32_t)(state)<<24L)|((action)<<20L)|(value))
   273 #define MBCS_ENTRY_SET_FINAL(entry) (int32_t)((entry)|0x80000000)
   274 #define MBCS_ENTRY_FINAL_SET_ACTION(entry, action) (int32_t)(((entry)&0xff0fffff)|((int32_t)(action)<<20L))
   275 #define MBCS_ENTRY_FINAL_SET_VALUE(entry, value) (int32_t)(((entry)&0xfff00000)|(value))
   276 #define MBCS_ENTRY_FINAL_SET_ACTION_VALUE(entry, action, value) (int32_t)(((entry)&0xff000000)|((int32_t)(action)<<20L)|(value))
   278 #define MBCS_ENTRY_SET_STATE(entry, state) (int32_t)(((entry)&0x80ffffff)|((int32_t)(state)<<24L))
   280 #define MBCS_ENTRY_STATE(entry) ((((uint32_t)entry)>>24)&0x7f)
   282 #define MBCS_ENTRY_IS_TRANSITION(entry) ((entry)>=0)
   283 #define MBCS_ENTRY_IS_FINAL(entry) ((entry)<0)
   285 #define MBCS_ENTRY_TRANSITION_STATE(entry) (((uint32_t)entry)>>24)
   286 #define MBCS_ENTRY_TRANSITION_OFFSET(entry) ((entry)&0xffffff)
   288 #define MBCS_ENTRY_FINAL_STATE(entry) ((((uint32_t)entry)>>24)&0x7f)
   289 #define MBCS_ENTRY_FINAL_IS_VALID_DIRECT_16(entry) ((entry)<(int32_t)0x80100000)
   290 #define MBCS_ENTRY_FINAL_ACTION(entry) ((((uint32_t)entry)>>20)&0xf)
   291 #define MBCS_ENTRY_FINAL_VALUE(entry) ((entry)&0xfffff)
   292 #define MBCS_ENTRY_FINAL_VALUE_16(entry) (uint16_t)(entry)
   294 #define IS_ASCII_ROUNDTRIP(b, asciiRoundtrips) (((asciiRoundtrips) & (1<<((b)>>2)))!=0)
   296 /* single-byte fromUnicode: get the 16-bit result word */
   297 #define MBCS_SINGLE_RESULT_FROM_U(table, results, c) (results)[ (table)[ (table)[(c)>>10] +(((c)>>4)&0x3f) ] +((c)&0xf) ]
   299 /* single-byte fromUnicode using the sbcsIndex */
   300 #define SBCS_RESULT_FROM_LOW_BMP(table, results, c) (results)[ (table)[(c)>>6] +((c)&0x3f) ]
   302 /* single-byte fromUTF8 using the sbcsIndex; l and t must be masked externally; can be l=0 and t<=0x7f */
   303 #define SBCS_RESULT_FROM_UTF8(table, results, l, t) (results)[ (table)[l] +(t) ]
   305 /* multi-byte fromUnicode: get the 32-bit stage 2 entry */
   306 #define MBCS_STAGE_2_FROM_U(table, c) ((const uint32_t *)(table))[ (table)[(c)>>10] +(((c)>>4)&0x3f) ]
   307 #define MBCS_FROM_U_IS_ROUNDTRIP(stage2Entry, c) ( ((stage2Entry) & ((uint32_t)1<< (16+((c)&0xf)) )) !=0)
   309 #define MBCS_VALUE_2_FROM_STAGE_2(bytes, stage2Entry, c) ((uint16_t *)(bytes))[16*(uint32_t)(uint16_t)(stage2Entry)+((c)&0xf)]
   310 #define MBCS_VALUE_4_FROM_STAGE_2(bytes, stage2Entry, c) ((uint32_t *)(bytes))[16*(uint32_t)(uint16_t)(stage2Entry)+((c)&0xf)]
   312 #define MBCS_POINTER_3_FROM_STAGE_2(bytes, stage2Entry, c) ((bytes)+(16*(uint32_t)(uint16_t)(stage2Entry)+((c)&0xf))*3)
   314 /* double-byte fromUnicode using the mbcsIndex */
   315 #define DBCS_RESULT_FROM_MOST_BMP(table, results, c) (results)[ (table)[(c)>>6] +((c)&0x3f) ]
   317 /* double-byte fromUTF8 using the mbcsIndex; l and t1 combined into lt1; lt1 and t2 must be masked externally */
   318 #define DBCS_RESULT_FROM_UTF8(table, results, lt1, t2) (results)[ (table)[lt1] +(t2) ]
   321 /**
   322  * MBCS output types for conversions from Unicode.
   323  * These per-converter types determine the storage method in stage 3 of the lookup table,
   324  * mostly how many bytes are stored per entry.
   325  */
   326 enum {
   327     MBCS_OUTPUT_1,          /* 0 */
   328     MBCS_OUTPUT_2,          /* 1 */
   329     MBCS_OUTPUT_3,          /* 2 */
   330     MBCS_OUTPUT_4,          /* 3 */
   332     MBCS_OUTPUT_3_EUC=8,    /* 8 */
   333     MBCS_OUTPUT_4_EUC,      /* 9 */
   335     MBCS_OUTPUT_2_SISO=12,  /* c */
   336     MBCS_OUTPUT_2_HZ,       /* d */
   338     MBCS_OUTPUT_EXT_ONLY,   /* e */
   340     MBCS_OUTPUT_COUNT,
   342     MBCS_OUTPUT_DBCS_ONLY=0xdb  /* runtime-only type for DBCS-only handling of SISO tables */
   343 };
   345 /**
   346  * Fallbacks to Unicode are stored outside the normal state table and code point structures
   347  * in a vector of items of this type. They are sorted by offset.
   348  */
   349 typedef struct {
   350     uint32_t offset;
   351     UChar32 codePoint;
   352 } _MBCSToUFallback;
   354 /** Constants for fast and UTF-8-friendly conversion. */
   355 enum {
   356     SBCS_FAST_MAX=0x0fff,               /* maximum code point with UTF-8-friendly SBCS runtime code, see makeconv SBCS_UTF8_MAX */
   357     SBCS_FAST_LIMIT=SBCS_FAST_MAX+1,    /* =0x1000 */
   358     MBCS_FAST_MAX=0xd7ff,               /* maximum code point with UTF-8-friendly MBCS runtime code, see makeconv MBCS_UTF8_MAX */
   359     MBCS_FAST_LIMIT=MBCS_FAST_MAX+1     /* =0xd800 */
   360 };
   362 /**
   363  * This is the MBCS part of the UConverterTable union (a runtime data structure).
   364  * It keeps all the per-converter data and points into the loaded mapping tables.
   365  *
   366  * utf8Friendly data structures added with _MBCSHeader.version 4.3
   367  */
   368 typedef struct UConverterMBCSTable {
   369     /* toUnicode */
   370     uint8_t countStates, dbcsOnlyState, stateTableOwned;
   371     uint32_t countToUFallbacks;
   373     const int32_t (*stateTable)/*[countStates]*/[256];
   374     int32_t (*swapLFNLStateTable)/*[countStates]*/[256]; /* for swaplfnl */
   375     const uint16_t *unicodeCodeUnits/*[countUnicodeResults]*/;
   376     const _MBCSToUFallback *toUFallbacks;
   378     /* fromUnicode */
   379     const uint16_t *fromUnicodeTable;
   380     const uint16_t *mbcsIndex;              /* for fast conversion from most of BMP to MBCS (utf8Friendly data) */
   381     uint16_t sbcsIndex[SBCS_FAST_LIMIT>>6]; /* for fast conversion from low BMP to SBCS (utf8Friendly data) */
   382     const uint8_t *fromUnicodeBytes;
   383     uint8_t *swapLFNLFromUnicodeBytes;      /* for swaplfnl */
   384     uint32_t fromUBytesLength;
   385     uint8_t outputType, unicodeMask;
   386     UBool utf8Friendly;                     /* for utf8Friendly data */
   387     UChar maxFastUChar;                     /* for utf8Friendly data */
   389     /* roundtrips */
   390     uint32_t asciiRoundtrips;
   392     /* reconstituted data that was omitted from the .cnv file */
   393     uint8_t *reconstitutedData;
   395     /* converter name for swaplfnl */
   396     char *swapLFNLName;
   398     /* extension data */
   399     struct UConverterSharedData *baseSharedData;
   400     const int32_t *extIndexes;
   401 } UConverterMBCSTable;
   403 #define UCNV_MBCS_TABLE_INITIALIZER { \
   404     /* toUnicode */ \
   405     0, 0, 0, \
   406     0, \
   407      \
   408     NULL, \
   409     NULL, \
   410     NULL, \
   411     NULL, \
   412      \
   413     /* fromUnicode */ \
   414     NULL, \
   415     NULL, \
   416     { 0 }, \
   417     NULL, \
   418     NULL, \
   419     0, \
   420     0, 0, \
   421     FALSE, \
   422     0, \
   423      \
   424     /* roundtrips */ \
   425     0, \
   426      \
   427     /* reconstituted data that was omitted from the .cnv file */ \
   428     NULL, \
   429      \
   430     /* converter name for swaplfnl */ \
   431     NULL, \
   432      \
   433     /* extension data */ \
   434     NULL, \
   435     NULL \
   436 }
   438 enum {
   439     MBCS_OPT_LENGTH_MASK=0x3f,
   440     MBCS_OPT_NO_FROM_U=0x40,
   441     /*
   442      * If any of the following options bits are set,
   443      * then the file must be rejected.
   444      */
   445     MBCS_OPT_INCOMPATIBLE_MASK=0xffc0,
   446     /*
   447      * Remove bits from this mask as more options are recognized
   448      * by all implementations that use this constant.
   449      */
   450     MBCS_OPT_UNKNOWN_INCOMPATIBLE_MASK=0xff80
   451 };
   453 enum {
   454     MBCS_HEADER_V4_LENGTH=8,
   455     MBCS_HEADER_V5_MIN_LENGTH=9
   456 };
   458 /**
   459  * MBCS data header. See data format description above.
   460  */
   461 typedef struct {
   462     UVersionInfo version;
   463     uint32_t countStates,
   464              countToUFallbacks,
   465              offsetToUCodeUnits,
   466              offsetFromUTable,
   467              offsetFromUBytes,
   468              flags,
   469              fromUBytesLength;
   471     /* new and required in version 5 */
   472     uint32_t options;
   474     /* new and optional in version 5; used if options&MBCS_OPT_NO_FROM_U */
   475     uint32_t fullStage2Length;  /* number of 32-bit units */
   476 } _MBCSHeader;
   478 #define UCNV_MBCS_HEADER_INITIALIZER { { 0 },  0, 0, 0, 0, 0, 0, 0,  0,  0 }
   480 /*
   481  * This is a simple version of _MBCSGetNextUChar() that is used
   482  * by other converter implementations.
   483  * It only returns an "assigned" result if it consumes the entire input.
   484  * It does not use state from the converter, nor error codes.
   485  * It does not handle the EBCDIC swaplfnl option (set in UConverter).
   486  * It handles conversion extensions but not GB 18030.
   487  *
   488  * Return value:
   489  * U+fffe   unassigned
   490  * U+ffff   illegal
   491  * otherwise the Unicode code point
   492  */
   493 U_CFUNC UChar32
   494 ucnv_MBCSSimpleGetNextUChar(UConverterSharedData *sharedData,
   495                         const char *source, int32_t length,
   496                         UBool useFallback);
   498 /**
   499  * This version of _MBCSSimpleGetNextUChar() is optimized for single-byte, single-state codepages.
   500  * It does not handle the EBCDIC swaplfnl option (set in UConverter).
   501  * It does not handle conversion extensions (_extToU()).
   502  */
   503 U_CFUNC UChar32
   504 ucnv_MBCSSingleSimpleGetNextUChar(UConverterSharedData *sharedData,
   505                               uint8_t b, UBool useFallback);
   507 /**
   508  * This macro version of _MBCSSingleSimpleGetNextUChar() gets a code point from a byte.
   509  * It works for single-byte, single-state codepages that only map
   510  * to and from BMP code points, and it always
   511  * returns fallback values.
   512  */
   513 #define _MBCS_SINGLE_SIMPLE_GET_NEXT_BMP(sharedData, b) \
   514     (UChar)MBCS_ENTRY_FINAL_VALUE_16((sharedData)->mbcs.stateTable[0][(uint8_t)(b)])
   516 /**
   517  * This is an internal function that allows other converter implementations
   518  * to check whether a byte is a lead byte.
   519  */
   520 U_CFUNC UBool
   521 ucnv_MBCSIsLeadByte(UConverterSharedData *sharedData, char byte);
   523 /** This is a macro version of _MBCSIsLeadByte(). */
   524 #define _MBCS_IS_LEAD_BYTE(sharedData, byte) \
   525     (UBool)MBCS_ENTRY_IS_TRANSITION((sharedData)->mbcs.stateTable[0][(uint8_t)(byte)])
   527 /*
   528  * This is another simple conversion function for internal use by other
   529  * conversion implementations.
   530  * It does not use the converter state nor call callbacks.
   531  * It does not handle the EBCDIC swaplfnl option (set in UConverter).
   532  * It handles conversion extensions but not GB 18030.
   533  *
   534  * It converts one single Unicode code point into codepage bytes, encoded
   535  * as one 32-bit value. The function returns the number of bytes in *pValue:
   536  * 1..4 the number of bytes in *pValue
   537  * 0    unassigned (*pValue undefined)
   538  * -1   illegal (currently not used, *pValue undefined)
   539  *
   540  * *pValue will contain the resulting bytes with the last byte in bits 7..0,
   541  * the second to last byte in bits 15..8, etc.
   542  * Currently, the function assumes but does not check that 0<=c<=0x10ffff.
   543  */
   544 U_CFUNC int32_t
   545 ucnv_MBCSFromUChar32(UConverterSharedData *sharedData,
   546                  UChar32 c, uint32_t *pValue,
   547                  UBool useFallback);
   549 /**
   550  * This version of _MBCSFromUChar32() is optimized for single-byte codepages.
   551  * It does not handle the EBCDIC swaplfnl option (set in UConverter).
   552  *
   553  * It returns the codepage byte for the code point, or -1 if it is unassigned.
   554  */
   555 U_CFUNC int32_t
   556 ucnv_MBCSSingleFromUChar32(UConverterSharedData *sharedData,
   557                        UChar32 c,
   558                        UBool useFallback);
   560 /**
   561  * SBCS, DBCS, and EBCDIC_STATEFUL are replaced by MBCS, but
   562  * we cheat a little about the type, returning the old types if appropriate.
   563  */
   564 U_CFUNC UConverterType
   565 ucnv_MBCSGetType(const UConverter* converter);
   567 U_CFUNC void 
   568 ucnv_MBCSFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
   569                             UErrorCode *pErrorCode);
   570 U_CFUNC void 
   571 ucnv_MBCSToUnicodeWithOffsets(UConverterToUnicodeArgs *pArgs,
   572                           UErrorCode *pErrorCode);
   574 /*
   575  * Internal function returning a UnicodeSet for toUnicode() conversion.
   576  * Currently only used for ISO-2022-CN, and only handles roundtrip mappings.
   577  * In the future, if we add support for fallback sets, this function
   578  * needs to be updated.
   579  * Handles extensions.
   580  * Does not empty the set first.
   581  */
   582 U_CFUNC void
   583 ucnv_MBCSGetUnicodeSetForUnicode(const UConverterSharedData *sharedData,
   584                                  const USetAdder *sa,
   585                                  UConverterUnicodeSet which,
   586                                  UErrorCode *pErrorCode);
   588 /*
   589  * Same as ucnv_MBCSGetUnicodeSetForUnicode() but
   590  * the set can be filtered by encoding scheme.
   591  * Used by stateful converters which share regular conversion tables
   592  * but only use a subset of their mappings.
   593  */
   594 U_CFUNC void
   595 ucnv_MBCSGetFilteredUnicodeSetForUnicode(const UConverterSharedData *sharedData,
   596                                          const USetAdder *sa,
   597                                          UConverterUnicodeSet which,
   598                                          UConverterSetFilter filter,
   599                                          UErrorCode *pErrorCode);
   601 #endif
   603 #endif

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