1// © 2016 and later: Unicode, Inc. and others.
2// License & terms of use: http://www.unicode.org/copyright.html
3/*
4******************************************************************************
5*
6* Copyright (C) 2000-2013, International Business Machines
7* Corporation and others. All Rights Reserved.
8*
9******************************************************************************
10* file name: ucnvmbcs.h
11* encoding: UTF-8
12* tab size: 8 (not used)
13* indentation:4
14*
15* created on: 2000jul07
16* created by: Markus W. Scherer
17*/
18
19#ifndef __UCNVMBCS_H__
20#define __UCNVMBCS_H__
21
22#include "unicode/utypes.h"
23
24#if !UCONFIG_NO_CONVERSION
25
26#include "unicode/ucnv.h"
27#include "ucnv_cnv.h"
28#include "ucnv_ext.h"
29
30/**
31 * ICU conversion (.cnv) data file structure, following the usual UDataInfo
32 * header.
33 *
34 * Format version: 6.2
35 *
36 * struct UConverterStaticData -- struct containing the converter name, IBM CCSID,
37 * min/max bytes per character, etc.
38 * see ucnv_bld.h
39 *
40 * --------------------
41 *
42 * The static data is followed by conversionType-specific data structures.
43 * At the moment, there are only variations of MBCS converters. They all have
44 * the same toUnicode structures, while the fromUnicode structures for SBCS
45 * differ from those for other MBCS-style converters.
46 *
47 * _MBCSHeader.version 5 is optional and not backward-compatible
48 * (as usual for changes in the major version field).
49 *
50 * Versions 5.m work like versions 4.m except:
51 * - The _MBCSHeader has variable length (and is always longer than in version 4).
52 * See the struct _MBCSHeader further description below.
53 * - There is a set of flags which indicate further incompatible changes.
54 * (Reader code must reject the file if it does not recognize them all.)
55 * - In particular, one of these flags indicates that most of the fromUnicode
56 * data is missing and must be reconstituted from the toUnicode data
57 * and from the utf8Friendly mbcsIndex at load time.
58 * (This only works with a utf8Friendly table.)
59 * In this case, makeconv may increase maxFastUChar automatically to U+FFFF.
60 *
61 * The first of these versions is 5.3, which is like 4.3 except for the differences above.
62 *
63 * When possible, makeconv continues to generate version 4.m files.
64 *
65 * _MBCSHeader.version 5.4/4.4 supports "good one-way" mappings (|4)
66 * in the extension tables (fromUTableValues bit 30). See ucnv_ext.h for details.
67 *
68 * _MBCSHeader.version 4.3 optionally modifies the fromUnicode data structures
69 * slightly and optionally adds a table for conversion to MBCS (non-SBCS)
70 * charsets.
71 *
72 * The modifications are to make the data utf8Friendly. Not every 4.3 file
73 * file contains utf8Friendly data.
74 * It is utf8Friendly if _MBCSHeader.version[2]!=0.
75 * In this case, the data structures are utf8Friendly up to the code point
76 * maxFastUChar=((_MBCSHeader.version[2]<<8)|0xff)
77 *
78 * A utf8Friendly file has fromUnicode stage 3 entries for code points up to
79 * maxFastUChar allocated in blocks of 64 for indexing with the 6 bits from
80 * a UTF-8 trail byte. ASCII is allocated linearly with 128 contiguous entries.
81 *
82 * In addition, a utf8Friendly MBCS file contains an additional
83 * uint16_t mbcsIndex[(maxFastUChar+1)>>6];
84 * which replaces the stage 1 and 2 tables for indexing with bits from the
85 * UTF-8 lead byte and middle trail byte. Unlike the older MBCS stage 2 table,
86 * the mbcsIndex does not contain roundtrip flags. Therefore, all fallbacks
87 * from code points up to maxFastUChar (and roundtrips to 0x00) are moved to
88 * the extension data structure. This also allows for faster roundtrip
89 * conversion from UTF-16.
90 *
91 * SBCS files do not contain an additional sbcsIndex[] array because the
92 * proportional size increase would be noticeable, but the runtime
93 * code builds one for the code point range for which the runtime conversion
94 * code is optimized.
95 *
96 * For SBCS, maxFastUChar should be at least U+0FFF. The initial makeconv
97 * implementation sets it to U+1FFF. Because the sbcsIndex is not stored in
98 * the file, a larger maxFastUChar only affects stage 3 block allocation size
99 * and is free in empty blocks. (Larger blocks with sparse contents cause larger
100 * files.) U+1FFF includes almost all of the small scripts.
101 * U+0FFF covers UTF-8 two-byte sequences and three-byte sequences starting with
102 * 0xe0. This includes most scripts with legacy SBCS charsets.
103 * The initial runtime implementation using 4.3 files only builds an sbcsIndex
104 * for code points up to U+0FFF.
105 *
106 * For MBCS, maxFastUChar should be at least U+D7FF (=initial value).
107 * This boundary is convenient because practically all of the commonly used
108 * characters are below it, and because it is the boundary to surrogate
109 * code points, above which special handling is necessary anyway.
110 * (Surrogate pair assembly for UTF-16, validity checking for UTF-8.)
111 *
112 * maxFastUChar could be up to U+FFFF to cover the whole BMP, which could be
113 * useful especially for conversion from UTF-8 when the input can be assumed
114 * to be valid, because the surrogate range would then not have to be
115 * checked.
116 * (With maxFastUChar=0xffff, makeconv would have to check for mbcsIndex value
117 * overflow because with the all-unassigned block 0 and nearly full mappings
118 * from the BMP it is theoretically possible that an index into stage 3
119 * exceeds 16 bits.)
120 *
121 * _MBCSHeader.version 4.2 adds an optional conversion extension data structure.
122 * If it is present, then an ICU version reading header versions 4.0 or 4.1
123 * will be able to use the base table and ignore the extension.
124 *
125 * The unicodeMask in the static data is part of the base table data structure.
126 * Especially, the UCNV_HAS_SUPPLEMENTARY flag determines the length of the
127 * fromUnicode stage 1 array.
128 * The static data unicodeMask refers only to the base table's properties if
129 * a base table is included.
130 * In an extension-only file, the static data unicodeMask is 0.
131 * The extension data indexes have a separate field with the unicodeMask flags.
132 *
133 * MBCS-style data structure following the static data.
134 * Offsets are counted in bytes from the beginning of the MBCS header structure.
135 * Details about usage in comments in ucnvmbcs.c.
136 *
137 * struct _MBCSHeader (see the definition in this header file below)
138 * contains 32-bit fields as follows:
139 * 8 values:
140 * 0 uint8_t[4] MBCS version in UVersionInfo format (currently 4.3.x.0)
141 * 1 uint32_t countStates
142 * 2 uint32_t countToUFallbacks
143 * 3 uint32_t offsetToUCodeUnits
144 * 4 uint32_t offsetFromUTable
145 * 5 uint32_t offsetFromUBytes
146 * 6 uint32_t flags, bits:
147 * 31.. 8 offsetExtension -- _MBCSHeader.version 4.2 (ICU 2.8) and higher
148 * 0 for older versions and if
149 * there is not extension structure
150 * 7.. 0 outputType
151 * 7 uint32_t fromUBytesLength -- _MBCSHeader.version 4.1 (ICU 2.4) and higher
152 * counts bytes in fromUBytes[]
153 *
154 * New and required in version 5:
155 * 8 uint32_t options, bits:
156 * 31..16 reserved for flags that can be added without breaking
157 * backward compatibility
158 * 15.. 6 reserved for flags whose addition will break
159 * backward compatibility
160 * 6 MBCS_OPT_FROM_U -- if set,
161 * then most of the fromUnicode data is omitted;
162 * fullStage2Length is present and the missing
163 * bottom part of stage 2 must be reconstituted from
164 * the toUnicode data;
165 * stage 3 is missing completely as well;
166 * not used for SBCS tables
167 * 5.. 0 length of the _MBCSHeader (number of uint32_t)
168 *
169 * New and optional in version 5:
170 * 9 uint32_t fullStage2Length: used if MBCS_OPT_FROM_U is set
171 * specifies the full length of stage 2
172 * including the omitted part
173 *
174 * if(outputType==MBCS_OUTPUT_EXT_ONLY) {
175 * -- base table name for extension-only table
176 * char baseTableName[variable]; -- with NUL plus padding for 4-alignment
177 *
178 * -- all _MBCSHeader fields except for version and flags are 0
179 * } else {
180 * -- normal base table with optional extension
181 *
182 * int32_t stateTable[countStates][256];
183 *
184 * struct _MBCSToUFallback { (fallbacks are sorted by offset)
185 * uint32_t offset;
186 * UChar32 codePoint;
187 * } toUFallbacks[countToUFallbacks];
188 *
189 * uint16_t unicodeCodeUnits[(offsetFromUTable-offsetToUCodeUnits)/2];
190 * (padded to an even number of units)
191 *
192 * -- stage 1 tables
193 * if(staticData.unicodeMask&UCNV_HAS_SUPPLEMENTARY) {
194 * -- stage 1 table for all of Unicode
195 * uint16_t fromUTable[0x440]; (32-bit-aligned)
196 * } else {
197 * -- BMP-only tables have a smaller stage 1 table
198 * uint16_t fromUTable[0x40]; (32-bit-aligned)
199 * }
200 *
201 * -- stage 2 tables
202 * length determined by top of stage 1 and bottom of stage 3 tables
203 * if(outputType==MBCS_OUTPUT_1) {
204 * -- SBCS: pure indexes
205 * uint16_t stage 2 indexes[?];
206 * } else {
207 * -- DBCS, MBCS, EBCDIC_STATEFUL, ...: roundtrip flags and indexes
208 * uint32_t stage 2 flags and indexes[?];
209 * if(options&MBCS_OPT_NO_FROM_U) {
210 * stage 2 really has length fullStage2Length
211 * and the omitted lower part must be reconstituted from
212 * the toUnicode data
213 * }
214 * }
215 *
216 * -- stage 3 tables with byte results
217 * if(outputType==MBCS_OUTPUT_1) {
218 * -- SBCS: each 16-bit result contains flags and the result byte, see ucnvmbcs.c
219 * uint16_t fromUBytes[fromUBytesLength/2];
220 * } else if(!(options&MBCS_OPT_NO_FROM_U)) {
221 * -- DBCS, MBCS, EBCDIC_STATEFUL, ... 2/3/4 bytes result, see ucnvmbcs.c
222 * uint8_t fromUBytes[fromUBytesLength]; or
223 * uint16_t fromUBytes[fromUBytesLength/2]; or
224 * uint32_t fromUBytes[fromUBytesLength/4];
225 * } else {
226 * fromUBytes[] must be reconstituted from the toUnicode data
227 * }
228 *
229 * -- optional utf8Friendly mbcsIndex -- _MBCSHeader.version 4.3 (ICU 3.8) and higher
230 * if(outputType!=MBCS_OUTPUT_1 &&
231 * _MBCSHeader.version[1]>=3 &&
232 * (maxFastUChar=_MBCSHeader.version[2])!=0
233 * ) {
234 * maxFastUChar=(maxFastUChar<<8)|0xff;
235 * uint16_t mbcsIndex[(maxFastUChar+1)>>6];
236 * }
237 * }
238 *
239 * -- extension table, details see ucnv_ext.h
240 * int32_t indexes[>=32]; ...
241 */
242
243/* MBCS converter data and state -------------------------------------------- */
244
245enum {
246 MBCS_MAX_STATE_COUNT=128
247};
248
249/**
250 * MBCS action codes for conversions to Unicode.
251 * These values are in bits 23..20 of the state table entries.
252 */
253enum {
254 MBCS_STATE_VALID_DIRECT_16,
255 MBCS_STATE_VALID_DIRECT_20,
256
257 MBCS_STATE_FALLBACK_DIRECT_16,
258 MBCS_STATE_FALLBACK_DIRECT_20,
259
260 MBCS_STATE_VALID_16,
261 MBCS_STATE_VALID_16_PAIR,
262
263 MBCS_STATE_UNASSIGNED,
264 MBCS_STATE_ILLEGAL,
265
266 MBCS_STATE_CHANGE_ONLY
267};
268
269/* Macros for state table entries */
270#define MBCS_ENTRY_TRANSITION(state, offset) (int32_t)(((int32_t)(state)<<24L)|(offset))
271#define MBCS_ENTRY_TRANSITION_SET_OFFSET(entry, offset) (int32_t)(((entry)&0xff000000)|(offset))
272#define MBCS_ENTRY_TRANSITION_ADD_OFFSET(entry, offset) (int32_t)((entry)+(offset))
273
274#define MBCS_ENTRY_FINAL(state, action, value) (int32_t)(0x80000000|((int32_t)(state)<<24L)|((action)<<20L)|(value))
275#define MBCS_ENTRY_SET_FINAL(entry) (int32_t)((entry)|0x80000000)
276#define MBCS_ENTRY_FINAL_SET_ACTION(entry, action) (int32_t)(((entry)&0xff0fffff)|((int32_t)(action)<<20L))
277#define MBCS_ENTRY_FINAL_SET_VALUE(entry, value) (int32_t)(((entry)&0xfff00000)|(value))
278#define MBCS_ENTRY_FINAL_SET_ACTION_VALUE(entry, action, value) (int32_t)(((entry)&0xff000000)|((int32_t)(action)<<20L)|(value))
279
280#define MBCS_ENTRY_SET_STATE(entry, state) (int32_t)(((entry)&0x80ffffff)|((int32_t)(state)<<24L))
281
282#define MBCS_ENTRY_STATE(entry) ((((uint32_t)entry)>>24)&0x7f)
283
284#define MBCS_ENTRY_IS_TRANSITION(entry) ((entry)>=0)
285#define MBCS_ENTRY_IS_FINAL(entry) ((entry)<0)
286
287#define MBCS_ENTRY_TRANSITION_STATE(entry) (((uint32_t)entry)>>24)
288#define MBCS_ENTRY_TRANSITION_OFFSET(entry) ((entry)&0xffffff)
289
290#define MBCS_ENTRY_FINAL_STATE(entry) ((((uint32_t)entry)>>24)&0x7f)
291#define MBCS_ENTRY_FINAL_IS_VALID_DIRECT_16(entry) ((entry)<(int32_t)0x80100000)
292#define MBCS_ENTRY_FINAL_ACTION(entry) ((((uint32_t)entry)>>20)&0xf)
293#define MBCS_ENTRY_FINAL_VALUE(entry) ((entry)&0xfffff)
294#define MBCS_ENTRY_FINAL_VALUE_16(entry) (uint16_t)(entry)
295
296#define IS_ASCII_ROUNDTRIP(b, asciiRoundtrips) (((asciiRoundtrips) & (1<<((b)>>2)))!=0)
297
298/* single-byte fromUnicode: get the 16-bit result word */
299#define MBCS_SINGLE_RESULT_FROM_U(table, results, c) (results)[ (table)[ (table)[(c)>>10] +(((c)>>4)&0x3f) ] +((c)&0xf) ]
300
301/* single-byte fromUnicode using the sbcsIndex */
302#define SBCS_RESULT_FROM_LOW_BMP(table, results, c) (results)[ (table)[(c)>>6] +((c)&0x3f) ]
303
304/* single-byte fromUTF8 using the sbcsIndex; l and t must be masked externally; can be l=0 and t<=0x7f */
305#define SBCS_RESULT_FROM_UTF8(table, results, l, t) (results)[ (table)[l] +(t) ]
306
307/* multi-byte fromUnicode: get the 32-bit stage 2 entry */
308#define MBCS_STAGE_2_FROM_U(table, c) ((const uint32_t *)(table))[ (table)[(c)>>10] +(((c)>>4)&0x3f) ]
309#define MBCS_FROM_U_IS_ROUNDTRIP(stage2Entry, c) ( ((stage2Entry) & ((uint32_t)1<< (16+((c)&0xf)) )) !=0)
310
311#define MBCS_VALUE_2_FROM_STAGE_2(bytes, stage2Entry, c) ((uint16_t *)(bytes))[16*(uint32_t)(uint16_t)(stage2Entry)+((c)&0xf)]
312#define MBCS_VALUE_4_FROM_STAGE_2(bytes, stage2Entry, c) ((uint32_t *)(bytes))[16*(uint32_t)(uint16_t)(stage2Entry)+((c)&0xf)]
313
314#define MBCS_POINTER_3_FROM_STAGE_2(bytes, stage2Entry, c) ((bytes)+(16*(uint32_t)(uint16_t)(stage2Entry)+((c)&0xf))*3)
315
316/* double-byte fromUnicode using the mbcsIndex */
317#define DBCS_RESULT_FROM_MOST_BMP(table, results, c) (results)[ (table)[(c)>>6] +((c)&0x3f) ]
318
319/* double-byte fromUTF8 using the mbcsIndex; l and t1 combined into lt1; lt1 and t2 must be masked externally */
320#define DBCS_RESULT_FROM_UTF8(table, results, lt1, t2) (results)[ (table)[lt1] +(t2) ]
321
322
323/**
324 * MBCS output types for conversions from Unicode.
325 * These per-converter types determine the storage method in stage 3 of the lookup table,
326 * mostly how many bytes are stored per entry.
327 */
328enum {
329 MBCS_OUTPUT_1, /* 0 */
330 MBCS_OUTPUT_2, /* 1 */
331 MBCS_OUTPUT_3, /* 2 */
332 MBCS_OUTPUT_4, /* 3 */
333
334 MBCS_OUTPUT_3_EUC=8, /* 8 */
335 MBCS_OUTPUT_4_EUC, /* 9 */
336
337 MBCS_OUTPUT_2_SISO=12, /* c */
338 MBCS_OUTPUT_2_HZ, /* d */
339
340 MBCS_OUTPUT_EXT_ONLY, /* e */
341
342 MBCS_OUTPUT_COUNT,
343
344 MBCS_OUTPUT_DBCS_ONLY=0xdb /* runtime-only type for DBCS-only handling of SISO tables */
345};
346
347/**
348 * Fallbacks to Unicode are stored outside the normal state table and code point structures
349 * in a vector of items of this type. They are sorted by offset.
350 */
351typedef struct {
352 uint32_t offset;
353 UChar32 codePoint;
354} _MBCSToUFallback;
355
356/** Constants for fast and UTF-8-friendly conversion. */
357enum {
358 SBCS_FAST_MAX=0x0fff, /* maximum code point with UTF-8-friendly SBCS runtime code, see makeconv SBCS_UTF8_MAX */
359 SBCS_FAST_LIMIT=SBCS_FAST_MAX+1, /* =0x1000 */
360 MBCS_FAST_MAX=0xd7ff, /* maximum code point with UTF-8-friendly MBCS runtime code, see makeconv MBCS_UTF8_MAX */
361 MBCS_FAST_LIMIT=MBCS_FAST_MAX+1 /* =0xd800 */
362};
363
364/**
365 * This is the MBCS part of the UConverterTable union (a runtime data structure).
366 * It keeps all the per-converter data and points into the loaded mapping tables.
367 *
368 * utf8Friendly data structures added with _MBCSHeader.version 4.3
369 */
370typedef struct UConverterMBCSTable {
371 /* toUnicode */
372 uint8_t countStates, dbcsOnlyState, stateTableOwned;
373 uint32_t countToUFallbacks;
374
375 const int32_t (*stateTable)/*[countStates]*/[256];
376 int32_t (*swapLFNLStateTable)/*[countStates]*/[256]; /* for swaplfnl */
377 const uint16_t *unicodeCodeUnits/*[countUnicodeResults]*/;
378 const _MBCSToUFallback *toUFallbacks;
379
380 /* fromUnicode */
381 const uint16_t *fromUnicodeTable;
382 const uint16_t *mbcsIndex; /* for fast conversion from most of BMP to MBCS (utf8Friendly data) */
383 uint16_t sbcsIndex[SBCS_FAST_LIMIT>>6]; /* for fast conversion from low BMP to SBCS (utf8Friendly data) */
384 const uint8_t *fromUnicodeBytes;
385 uint8_t *swapLFNLFromUnicodeBytes; /* for swaplfnl */
386 uint32_t fromUBytesLength;
387 uint8_t outputType, unicodeMask;
388 UBool utf8Friendly; /* for utf8Friendly data */
389 UChar maxFastUChar; /* for utf8Friendly data */
390
391 /* roundtrips */
392 uint32_t asciiRoundtrips;
393
394 /* reconstituted data that was omitted from the .cnv file */
395 uint8_t *reconstitutedData;
396
397 /* converter name for swaplfnl */
398 char *swapLFNLName;
399
400 /* extension data */
401 struct UConverterSharedData *baseSharedData;
402 const int32_t *extIndexes;
403} UConverterMBCSTable;
404
405#define UCNV_MBCS_TABLE_INITIALIZER { \
406 /* toUnicode */ \
407 0, 0, 0, \
408 0, \
409 \
410 NULL, \
411 NULL, \
412 NULL, \
413 NULL, \
414 \
415 /* fromUnicode */ \
416 NULL, \
417 NULL, \
418 { 0 }, \
419 NULL, \
420 NULL, \
421 0, \
422 0, 0, \
423 FALSE, \
424 0, \
425 \
426 /* roundtrips */ \
427 0, \
428 \
429 /* reconstituted data that was omitted from the .cnv file */ \
430 NULL, \
431 \
432 /* converter name for swaplfnl */ \
433 NULL, \
434 \
435 /* extension data */ \
436 NULL, \
437 NULL \
438}
439
440enum {
441 MBCS_OPT_LENGTH_MASK=0x3f,
442 MBCS_OPT_NO_FROM_U=0x40,
443 /*
444 * If any of the following options bits are set,
445 * then the file must be rejected.
446 */
447 MBCS_OPT_INCOMPATIBLE_MASK=0xffc0,
448 /*
449 * Remove bits from this mask as more options are recognized
450 * by all implementations that use this constant.
451 */
452 MBCS_OPT_UNKNOWN_INCOMPATIBLE_MASK=0xff80
453};
454
455enum {
456 MBCS_HEADER_V4_LENGTH=8,
457 MBCS_HEADER_V5_MIN_LENGTH=9
458};
459
460/**
461 * MBCS data header. See data format description above.
462 */
463typedef struct {
464 UVersionInfo version;
465 uint32_t countStates,
466 countToUFallbacks,
467 offsetToUCodeUnits,
468 offsetFromUTable,
469 offsetFromUBytes,
470 flags,
471 fromUBytesLength;
472
473 /* new and required in version 5 */
474 uint32_t options;
475
476 /* new and optional in version 5; used if options&MBCS_OPT_NO_FROM_U */
477 uint32_t fullStage2Length; /* number of 32-bit units */
478} _MBCSHeader;
479
480#define UCNV_MBCS_HEADER_INITIALIZER { { 0 }, 0, 0, 0, 0, 0, 0, 0, 0, 0 }
481
482/*
483 * This is a simple version of _MBCSGetNextUChar() that is used
484 * by other converter implementations.
485 * It only returns an "assigned" result if it consumes the entire input.
486 * It does not use state from the converter, nor error codes.
487 * It does not handle the EBCDIC swaplfnl option (set in UConverter).
488 * It handles conversion extensions but not GB 18030.
489 *
490 * Return value:
491 * U+fffe unassigned
492 * U+ffff illegal
493 * otherwise the Unicode code point
494 */
495U_CFUNC UChar32
496ucnv_MBCSSimpleGetNextUChar(UConverterSharedData *sharedData,
497 const char *source, int32_t length,
498 UBool useFallback);
499
500/**
501 * This version of _MBCSSimpleGetNextUChar() is optimized for single-byte, single-state codepages.
502 * It does not handle the EBCDIC swaplfnl option (set in UConverter).
503 * It does not handle conversion extensions (_extToU()).
504 */
505U_CFUNC UChar32
506ucnv_MBCSSingleSimpleGetNextUChar(UConverterSharedData *sharedData,
507 uint8_t b, UBool useFallback);
508
509/**
510 * This macro version of _MBCSSingleSimpleGetNextUChar() gets a code point from a byte.
511 * It works for single-byte, single-state codepages that only map
512 * to and from BMP code points, and it always
513 * returns fallback values.
514 */
515#define _MBCS_SINGLE_SIMPLE_GET_NEXT_BMP(sharedData, b) \
516 (UChar)MBCS_ENTRY_FINAL_VALUE_16((sharedData)->mbcs.stateTable[0][(uint8_t)(b)])
517
518/**
519 * This is an internal function that allows other converter implementations
520 * to check whether a byte is a lead byte.
521 */
522U_CFUNC UBool
523ucnv_MBCSIsLeadByte(UConverterSharedData *sharedData, char byte);
524
525/** This is a macro version of _MBCSIsLeadByte(). */
526#define _MBCS_IS_LEAD_BYTE(sharedData, byte) \
527 (UBool)MBCS_ENTRY_IS_TRANSITION((sharedData)->mbcs.stateTable[0][(uint8_t)(byte)])
528
529/*
530 * This is another simple conversion function for internal use by other
531 * conversion implementations.
532 * It does not use the converter state nor call callbacks.
533 * It does not handle the EBCDIC swaplfnl option (set in UConverter).
534 * It handles conversion extensions but not GB 18030.
535 *
536 * It converts one single Unicode code point into codepage bytes, encoded
537 * as one 32-bit value. The function returns the number of bytes in *pValue:
538 * 1..4 the number of bytes in *pValue
539 * 0 unassigned (*pValue undefined)
540 * -1 illegal (currently not used, *pValue undefined)
541 *
542 * *pValue will contain the resulting bytes with the last byte in bits 7..0,
543 * the second to last byte in bits 15..8, etc.
544 * Currently, the function assumes but does not check that 0<=c<=0x10ffff.
545 */
546U_CFUNC int32_t
547ucnv_MBCSFromUChar32(UConverterSharedData *sharedData,
548 UChar32 c, uint32_t *pValue,
549 UBool useFallback);
550
551/**
552 * This version of _MBCSFromUChar32() is optimized for single-byte codepages.
553 * It does not handle the EBCDIC swaplfnl option (set in UConverter).
554 *
555 * It returns the codepage byte for the code point, or -1 if it is unassigned.
556 */
557U_CFUNC int32_t
558ucnv_MBCSSingleFromUChar32(UConverterSharedData *sharedData,
559 UChar32 c,
560 UBool useFallback);
561
562/**
563 * SBCS, DBCS, and EBCDIC_STATEFUL are replaced by MBCS, but
564 * we cheat a little about the type, returning the old types if appropriate.
565 */
566U_CFUNC UConverterType
567ucnv_MBCSGetType(const UConverter* converter);
568
569U_CFUNC void
570ucnv_MBCSFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
571 UErrorCode *pErrorCode);
572U_CFUNC void
573ucnv_MBCSToUnicodeWithOffsets(UConverterToUnicodeArgs *pArgs,
574 UErrorCode *pErrorCode);
575
576/*
577 * Internal function returning a UnicodeSet for toUnicode() conversion.
578 * Currently only used for ISO-2022-CN, and only handles roundtrip mappings.
579 * In the future, if we add support for fallback sets, this function
580 * needs to be updated.
581 * Handles extensions.
582 * Does not empty the set first.
583 */
584U_CFUNC void
585ucnv_MBCSGetUnicodeSetForUnicode(const UConverterSharedData *sharedData,
586 const USetAdder *sa,
587 UConverterUnicodeSet which,
588 UErrorCode *pErrorCode);
589
590/*
591 * Same as ucnv_MBCSGetUnicodeSetForUnicode() but
592 * the set can be filtered by encoding scheme.
593 * Used by stateful converters which share regular conversion tables
594 * but only use a subset of their mappings.
595 */
596U_CFUNC void
597ucnv_MBCSGetFilteredUnicodeSetForUnicode(const UConverterSharedData *sharedData,
598 const USetAdder *sa,
599 UConverterUnicodeSet which,
600 UConverterSetFilter filter,
601 UErrorCode *pErrorCode);
602
603#endif
604
605#endif
606