Check in the pristine copy of ICU 4.6...

icu46/source/common/ucnvmbcs.h

+/*
+******************************************************************************
+*
+*   Copyright (C) 2000-2007, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*
+******************************************************************************
+*   file name:  ucnvmbcs.h
+*   encoding:   US-ASCII
+*   tab size:   8 (not used)
+*   indentation:4
+*
+*   created on: 2000jul07
+*   created by: Markus W. Scherer
+*/
+
+#ifndef __UCNVMBCS_H__
+#define __UCNVMBCS_H__
+
+#include "unicode/utypes.h"
+
+#if !UCONFIG_NO_CONVERSION
+
+#include "unicode/ucnv.h"
+#include "ucnv_cnv.h"
+#include "ucnv_ext.h"
+
+/**
+ * ICU conversion (.cnv) data file structure, following the usual UDataInfo
+ * header.
+ *
+ * Format version: 6.2
+ *
+ * struct UConverterStaticData -- struct containing the converter name, IBM CCSID,
+ *                                min/max bytes per character, etc.
+ *                                see ucnv_bld.h
+ *
+ * --------------------
+ *
+ * The static data is followed by conversionType-specific data structures.
+ * At the moment, there are only variations of MBCS converters. They all have
+ * the same toUnicode structures, while the fromUnicode structures for SBCS
+ * differ from those for other MBCS-style converters.
+ *
+ * _MBCSHeader.version 5 is optional and not backward-compatible
+ * (as usual for changes in the major version field).
+ *
+ * Versions 5.m work like versions 4.m except:
+ * - The _MBCSHeader has variable length (and is always longer than in version 4).
+ *   See the struct _MBCSHeader further description below.
+ * - There is a set of flags which indicate further incompatible changes.
+ *   (Reader code must reject the file if it does not recognize them all.)
+ * - In particular, one of these flags indicates that most of the fromUnicode
+ *   data is missing and must be reconstituted from the toUnicode data
+ *   and from the utf8Friendly mbcsIndex at load time.
+ *   (This only works with a utf8Friendly table.)
+ *   In this case, makeconv may increase maxFastUChar automatically to U+FFFF.
+ *
+ * The first of these versions is 5.3, which is like 4.3 except for the differences above.
+ *
+ * When possible, makeconv continues to generate version 4.m files.
+ *
+ * _MBCSHeader.version 4.3 optionally modifies the fromUnicode data structures
+ * slightly and optionally adds a table for conversion to MBCS (non-SBCS)
+ * charsets.
+ *
+ * The modifications are to make the data utf8Friendly. Not every 4.3 file
+ * file contains utf8Friendly data.
+ * It is utf8Friendly if _MBCSHeader.version[2]!=0.
+ * In this case, the data structures are utf8Friendly up to the code point
+ *   maxFastUChar=((_MBCSHeader.version[2]<<8)|0xff)
+ *
+ * A utf8Friendly file has fromUnicode stage 3 entries for code points up to
+ * maxFastUChar allocated in blocks of 64 for indexing with the 6 bits from
+ * a UTF-8 trail byte. ASCII is allocated linearly with 128 contiguous entries.
+ *
+ * In addition, a utf8Friendly MBCS file contains an additional
+ *   uint16_t mbcsIndex[(maxFastUChar+1)>>6];
+ * which replaces the stage 1 and 2 tables for indexing with bits from the
+ * UTF-8 lead byte and middle trail byte. Unlike the older MBCS stage 2 table,
+ * the mbcsIndex does not contain roundtrip flags. Therefore, all fallbacks
+ * from code points up to maxFastUChar (and roundtrips to 0x00) are moved to
+ * the extension data structure. This also allows for faster roundtrip
+ * conversion from UTF-16.
+ *
+ * SBCS files do not contain an additional sbcsIndex[] array because the
+ * proportional size increase would be noticeable, but the runtime
+ * code builds one for the code point range for which the runtime conversion
+ * code is optimized.
+ *
+ * For SBCS, maxFastUChar should be at least U+0FFF. The initial makeconv
+ * implementation sets it to U+1FFF. Because the sbcsIndex is not stored in
+ * the file, a larger maxFastUChar only affects stage 3 block allocation size
+ * and is free in empty blocks. (Larger blocks with sparse contents cause larger
+ * files.) U+1FFF includes almost all of the small scripts.
+ * U+0FFF covers UTF-8 two-byte sequences and three-byte sequences starting with
+ * 0xe0. This includes most scripts with legacy SBCS charsets.
+ * The initial runtime implementation using 4.3 files only builds an sbcsIndex
+ * for code points up to U+0FFF.
+ *
+ * For MBCS, maxFastUChar should be at least U+D7FF (=initial value).
+ * This boundary is convenient because practically all of the commonly used
+ * characters are below it, and because it is the boundary to surrogate
+ * code points, above which special handling is necessary anyway.
+ * (Surrogate pair assembly for UTF-16, validity checking for UTF-8.)
+ *
+ * maxFastUChar could be up to U+FFFF to cover the whole BMP, which could be
+ * useful especially for conversion from UTF-8 when the input can be assumed
+ * to be valid, because the surrogate range would then not have to be
+ * checked.
+ * (With maxFastUChar=0xffff, makeconv would have to check for mbcsIndex value
+ * overflow because with the all-unassigned block 0 and nearly full mappings
+ * from the BMP it is theoretically possible that an index into stage 3
+ * exceeds 16 bits.)
+ *
+ * _MBCSHeader.version 4.2 adds an optional conversion extension data structure.
+ * If it is present, then an ICU version reading header versions 4.0 or 4.1
+ * will be able to use the base table and ignore the extension.
+ *
+ * The unicodeMask in the static data is part of the base table data structure.
+ * Especially, the UCNV_HAS_SUPPLEMENTARY flag determines the length of the
+ * fromUnicode stage 1 array.
+ * The static data unicodeMask refers only to the base table's properties if
+ * a base table is included.
+ * In an extension-only file, the static data unicodeMask is 0.
+ * The extension data indexes have a separate field with the unicodeMask flags.
+ *
+ * MBCS-style data structure following the static data.
+ * Offsets are counted in bytes from the beginning of the MBCS header structure.
+ * Details about usage in comments in ucnvmbcs.c.
+ *
+ * struct _MBCSHeader (see the definition in this header file below)
+ * contains 32-bit fields as follows:
+ * 8 values:
+ *  0   uint8_t[4]  MBCS version in UVersionInfo format (currently 4.3.x.0)
+ *  1   uint32_t    countStates
+ *  2   uint32_t    countToUFallbacks
+ *  3   uint32_t    offsetToUCodeUnits
+ *  4   uint32_t    offsetFromUTable
+ *  5   uint32_t    offsetFromUBytes
+ *  6   uint32_t    flags, bits:
+ *                      31.. 8 offsetExtension -- _MBCSHeader.version 4.2 (ICU 2.8) and higher
+ *                                                0 for older versions and if
+ *                                                there is not extension structure
+ *                       7.. 0 outputType
+ *  7   uint32_t    fromUBytesLength -- _MBCSHeader.version 4.1 (ICU 2.4) and higher
+ *                  counts bytes in fromUBytes[]
+ *
+ * New and required in version 5:
+ *  8   uint32_t    options, bits:
+ *                      31..16 reserved for flags that can be added without breaking
+ *                                 backward compatibility
+ *                      15.. 6 reserved for flags whose addition will break
+ *                                 backward compatibility
+ *                           6 MBCS_OPT_FROM_U -- if set,
+ *                                 then most of the fromUnicode data is omitted;
+ *                                 fullStage2Length is present and the missing
+ *                                 bottom part of stage 2 must be reconstituted from
+ *                                 the toUnicode data;
+ *                                 stage 3 is missing completely as well;
+ *                                 not used for SBCS tables
+ *                       5.. 0 length of the _MBCSHeader (number of uint32_t)
+ *
+ * New and optional in version 5:
+ *  9   uint32_t    fullStage2Length: used if MBCS_OPT_FROM_U is set
+ *                                 specifies the full length of stage 2
+ *                                 including the omitted part
+ *
+ * if(outputType==MBCS_OUTPUT_EXT_ONLY) {
+ *     -- base table name for extension-only table
+ *     char baseTableName[variable]; -- with NUL plus padding for 4-alignment
+ *
+ *     -- all _MBCSHeader fields except for version and flags are 0
+ * } else {
+ *     -- normal base table with optional extension
+ *
+ *     int32_t stateTable[countStates][256];
+ *    
+ *     struct _MBCSToUFallback { (fallbacks are sorted by offset)
+ *         uint32_t offset;
+ *         UChar32 codePoint;
+ *     } toUFallbacks[countToUFallbacks];
+ *    
+ *     uint16_t unicodeCodeUnits[(offsetFromUTable-offsetToUCodeUnits)/2];
+ *                  (padded to an even number of units)
+ *    
+ *     -- stage 1 tables
+ *     if(staticData.unicodeMask&UCNV_HAS_SUPPLEMENTARY) {
+ *         -- stage 1 table for all of Unicode
+ *         uint16_t fromUTable[0x440]; (32-bit-aligned)
+ *     } else {
+ *         -- BMP-only tables have a smaller stage 1 table
+ *         uint16_t fromUTable[0x40]; (32-bit-aligned)
+ *     }
+ *
+ *     -- stage 2 tables
+ *        length determined by top of stage 1 and bottom of stage 3 tables
+ *     if(outputType==MBCS_OUTPUT_1) {
+ *         -- SBCS: pure indexes
+ *         uint16_t stage 2 indexes[?];
+ *     } else {
+ *         -- DBCS, MBCS, EBCDIC_STATEFUL, ...: roundtrip flags and indexes
+ *         uint32_t stage 2 flags and indexes[?];
+ *         if(options&MBCS_OPT_NO_FROM_U) {
+ *             stage 2 really has length fullStage2Length
+ *             and the omitted lower part must be reconstituted from
+ *             the toUnicode data
+ *         }
+ *     }
+ *
+ *     -- stage 3 tables with byte results
+ *     if(outputType==MBCS_OUTPUT_1) {
+ *         -- SBCS: each 16-bit result contains flags and the result byte, see ucnvmbcs.c
+ *         uint16_t fromUBytes[fromUBytesLength/2];
+ *     } else if(!(options&MBCS_OPT_NO_FROM_U)) {
+ *         -- DBCS, MBCS, EBCDIC_STATEFUL, ... 2/3/4 bytes result, see ucnvmbcs.c
+ *         uint8_t fromUBytes[fromUBytesLength]; or
+ *         uint16_t fromUBytes[fromUBytesLength/2]; or
+ *         uint32_t fromUBytes[fromUBytesLength/4];
+ *     } else {
+ *         fromUBytes[] must be reconstituted from the toUnicode data
+ *     }
+ *
+ *     -- optional utf8Friendly mbcsIndex -- _MBCSHeader.version 4.3 (ICU 3.8) and higher
+ *     if(outputType!=MBCS_OUTPUT_1 &&
+ *        _MBCSHeader.version[1]>=3 &&
+ *        (maxFastUChar=_MBCSHeader.version[2])!=0
+ *     ) {
+ *         maxFastUChar=(maxFastUChar<<8)|0xff;
+ *         uint16_t mbcsIndex[(maxFastUChar+1)>>6];
+ *     }
+ * }
+ *
+ * -- extension table, details see ucnv_ext.h
+ * int32_t indexes[>=32]; ...
+ */
+
+/* MBCS converter data and state -------------------------------------------- */
+
+enum {
+    MBCS_MAX_STATE_COUNT=128
+};
+
+/**
+ * MBCS action codes for conversions to Unicode.
+ * These values are in bits 23..20 of the state table entries.
+ */
+enum {
+    MBCS_STATE_VALID_DIRECT_16,
+    MBCS_STATE_VALID_DIRECT_20,
+
+    MBCS_STATE_FALLBACK_DIRECT_16,
+    MBCS_STATE_FALLBACK_DIRECT_20,
+
+    MBCS_STATE_VALID_16,
+    MBCS_STATE_VALID_16_PAIR,
+
+    MBCS_STATE_UNASSIGNED,
+    MBCS_STATE_ILLEGAL,
+
+    MBCS_STATE_CHANGE_ONLY
+};
+
+/* Macros for state table entries */
+#define MBCS_ENTRY_TRANSITION(state, offset) (int32_t)(((int32_t)(state)<<24L)|(offset))
+#define MBCS_ENTRY_TRANSITION_SET_OFFSET(entry, offset) (int32_t)(((entry)&0xff000000)|(offset))
+#define MBCS_ENTRY_TRANSITION_ADD_OFFSET(entry, offset) (int32_t)((entry)+(offset))
+
+#define MBCS_ENTRY_FINAL(state, action, value) (int32_t)(0x80000000|((int32_t)(state)<<24L)|((action)<<20L)|(value))
+#define MBCS_ENTRY_SET_FINAL(entry) (int32_t)((entry)|0x80000000)
+#define MBCS_ENTRY_FINAL_SET_ACTION(entry, action) (int32_t)(((entry)&0xff0fffff)|((int32_t)(action)<<20L))
+#define MBCS_ENTRY_FINAL_SET_VALUE(entry, value) (int32_t)(((entry)&0xfff00000)|(value))
+#define MBCS_ENTRY_FINAL_SET_ACTION_VALUE(entry, action, value) (int32_t)(((entry)&0xff000000)|((int32_t)(action)<<20L)|(value))
+
+#define MBCS_ENTRY_SET_STATE(entry, state) (int32_t)(((entry)&0x80ffffff)|((int32_t)(state)<<24L))
+
+#define MBCS_ENTRY_STATE(entry) (((entry)>>24)&0x7f)
+
+#define MBCS_ENTRY_IS_TRANSITION(entry) ((entry)>=0)
+#define MBCS_ENTRY_IS_FINAL(entry) ((entry)<0)
+
+#define MBCS_ENTRY_TRANSITION_STATE(entry) ((entry)>>24)
+#define MBCS_ENTRY_TRANSITION_OFFSET(entry) ((entry)&0xffffff)
+
+#define MBCS_ENTRY_FINAL_STATE(entry) (((entry)>>24)&0x7f)
+#define MBCS_ENTRY_FINAL_IS_VALID_DIRECT_16(entry) ((entry)<(int32_t)0x80100000)
+#define MBCS_ENTRY_FINAL_ACTION(entry) (((entry)>>20)&0xf)
+#define MBCS_ENTRY_FINAL_VALUE(entry) ((entry)&0xfffff)
+#define MBCS_ENTRY_FINAL_VALUE_16(entry) (uint16_t)(entry)
+
+#define IS_ASCII_ROUNDTRIP(b, asciiRoundtrips) (((asciiRoundtrips) & (1<<((b)>>2)))!=0)
+
+/* single-byte fromUnicode: get the 16-bit result word */
+#define MBCS_SINGLE_RESULT_FROM_U(table, results, c) (results)[ (table)[ (table)[(c)>>10] +(((c)>>4)&0x3f) ] +((c)&0xf) ]
+
+/* single-byte fromUnicode using the sbcsIndex */
+#define SBCS_RESULT_FROM_LOW_BMP(table, results, c) (results)[ (table)[(c)>>6] +((c)&0x3f) ]
+
+/* single-byte fromUTF8 using the sbcsIndex; l and t must be masked externally; can be l=0 and t<=0x7f */
+#define SBCS_RESULT_FROM_UTF8(table, results, l, t) (results)[ (table)[l] +(t) ]
+
+/* multi-byte fromUnicode: get the 32-bit stage 2 entry */
+#define MBCS_STAGE_2_FROM_U(table, c) ((const uint32_t *)(table))[ (table)[(c)>>10] +(((c)>>4)&0x3f) ]
+#define MBCS_FROM_U_IS_ROUNDTRIP(stage2Entry, c) ( ((stage2Entry) & ((uint32_t)1<< (16+((c)&0xf)) )) !=0)
+
+#define MBCS_VALUE_2_FROM_STAGE_2(bytes, stage2Entry, c) ((uint16_t *)(bytes))[16*(uint32_t)(uint16_t)(stage2Entry)+((c)&0xf)]
+#define MBCS_VALUE_4_FROM_STAGE_2(bytes, stage2Entry, c) ((uint32_t *)(bytes))[16*(uint32_t)(uint16_t)(stage2Entry)+((c)&0xf)]
+
+#define MBCS_POINTER_3_FROM_STAGE_2(bytes, stage2Entry, c) ((bytes)+(16*(uint32_t)(uint16_t)(stage2Entry)+((c)&0xf))*3)
+
+/* double-byte fromUnicode using the mbcsIndex */
+#define DBCS_RESULT_FROM_MOST_BMP(table, results, c) (results)[ (table)[(c)>>6] +((c)&0x3f) ]
+
+/* double-byte fromUTF8 using the mbcsIndex; l and t1 combined into lt1; lt1 and t2 must be masked externally */
+#define DBCS_RESULT_FROM_UTF8(table, results, lt1, t2) (results)[ (table)[lt1] +(t2) ]
+
+
+/**
+ * MBCS output types for conversions from Unicode.
+ * These per-converter types determine the storage method in stage 3 of the lookup table,
+ * mostly how many bytes are stored per entry.
+ */
+enum {
+    MBCS_OUTPUT_1,          /* 0 */
+    MBCS_OUTPUT_2,          /* 1 */
+    MBCS_OUTPUT_3,          /* 2 */
+    MBCS_OUTPUT_4,          /* 3 */
+
+    MBCS_OUTPUT_3_EUC=8,    /* 8 */
+    MBCS_OUTPUT_4_EUC,      /* 9 */
+
+    MBCS_OUTPUT_2_SISO=12,  /* c */
+    MBCS_OUTPUT_2_HZ,       /* d */
+
+    MBCS_OUTPUT_EXT_ONLY,   /* e */
+
+    MBCS_OUTPUT_COUNT,
+
+    MBCS_OUTPUT_DBCS_ONLY=0xdb  /* runtime-only type for DBCS-only handling of SISO tables */
+};
+
+/**
+ * Fallbacks to Unicode are stored outside the normal state table and code point structures
+ * in a vector of items of this type. They are sorted by offset.
+ */
+typedef struct {
+    uint32_t offset;
+    UChar32 codePoint;
+} _MBCSToUFallback;
+
+/** Constants for fast and UTF-8-friendly conversion. */
+enum {
+    SBCS_FAST_MAX=0x0fff,               /* maximum code point with UTF-8-friendly SBCS runtime code, see makeconv SBCS_UTF8_MAX */
+    SBCS_FAST_LIMIT=SBCS_FAST_MAX+1,    /* =0x1000 */
+    MBCS_FAST_MAX=0xd7ff,               /* maximum code point with UTF-8-friendly MBCS runtime code, see makeconv MBCS_UTF8_MAX */
+    MBCS_FAST_LIMIT=MBCS_FAST_MAX+1     /* =0xd800 */
+};
+
+/**
+ * This is the MBCS part of the UConverterTable union (a runtime data structure).
+ * It keeps all the per-converter data and points into the loaded mapping tables.
+ *
+ * utf8Friendly data structures added with _MBCSHeader.version 4.3
+ */
+typedef struct UConverterMBCSTable {
+    /* toUnicode */
+    uint8_t countStates, dbcsOnlyState, stateTableOwned;
+    uint32_t countToUFallbacks;
+
+    const int32_t (*stateTable)/*[countStates]*/[256];
+    int32_t (*swapLFNLStateTable)/*[countStates]*/[256]; /* for swaplfnl */
+    const uint16_t *unicodeCodeUnits/*[countUnicodeResults]*/;
+    const _MBCSToUFallback *toUFallbacks;
+
+    /* fromUnicode */
+    const uint16_t *fromUnicodeTable;
+    const uint16_t *mbcsIndex;              /* for fast conversion from most of BMP to MBCS (utf8Friendly data) */
+    uint16_t sbcsIndex[SBCS_FAST_LIMIT>>6]; /* for fast conversion from low BMP to SBCS (utf8Friendly data) */
+    const uint8_t *fromUnicodeBytes;
+    uint8_t *swapLFNLFromUnicodeBytes;      /* for swaplfnl */
+    uint32_t fromUBytesLength;
+    uint8_t outputType, unicodeMask;
+    UBool utf8Friendly;                     /* for utf8Friendly data */
+    UChar maxFastUChar;                     /* for utf8Friendly data */
+
+    /* roundtrips */
+    uint32_t asciiRoundtrips;
+
+    /* reconstituted data that was omitted from the .cnv file */
+    uint8_t *reconstitutedData;
+
+    /* converter name for swaplfnl */
+    char *swapLFNLName;
+
+    /* extension data */
+    struct UConverterSharedData *baseSharedData;
+    const int32_t *extIndexes;
+} UConverterMBCSTable;
+
+enum {
+    MBCS_OPT_LENGTH_MASK=0x3f,
+    MBCS_OPT_NO_FROM_U=0x40,
+    /*
+     * If any of the following options bits are set,
+     * then the file must be rejected.
+     */
+    MBCS_OPT_INCOMPATIBLE_MASK=0xffc0,
+    /*
+     * Remove bits from this mask as more options are recognized
+     * by all implementations that use this constant.
+     */
+    MBCS_OPT_UNKNOWN_INCOMPATIBLE_MASK=0xff80
+};
+
+enum {
+    MBCS_HEADER_V4_LENGTH=8,
+    MBCS_HEADER_V5_MIN_LENGTH=9
+};
+
+/**
+ * MBCS data header. See data format description above.
+ */
+typedef struct {
+    UVersionInfo version;
+    uint32_t countStates,
+             countToUFallbacks,
+             offsetToUCodeUnits,
+             offsetFromUTable,
+             offsetFromUBytes,
+             flags,
+             fromUBytesLength;
+
+    /* new and required in version 5 */
+    uint32_t options;
+
+    /* new and optional in version 5; used if options&MBCS_OPT_NO_FROM_U */
+    uint32_t fullStage2Length;  /* number of 32-bit units */
+} _MBCSHeader;
+
+/*
+ * 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);
+
+/**
+ * This version of _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);
+
+/**
+ * This macro version of _MBCSSingleSimpleGetNextUChar() gets a code point from a byte.
+ * It works for single-byte, single-state codepages that only map
+ * to and from BMP code points, and it always
+ * returns fallback values.
+ */
+#define _MBCS_SINGLE_SIMPLE_GET_NEXT_BMP(sharedData, b) \
+    (UChar)MBCS_ENTRY_FINAL_VALUE_16((sharedData)->mbcs.stateTable[0][(uint8_t)(b)])
+
+/**
+ * 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);
+
+/** This is a macro version of _MBCSIsLeadByte(). */
+#define _MBCS_IS_LEAD_BYTE(sharedData, byte) \
+    (UBool)MBCS_ENTRY_IS_TRANSITION((sharedData)->mbcs.stateTable[0][(uint8_t)(byte)])
+
+/*
+ * 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);
+
+/**
+ * This version of _MBCSFromUChar32() is optimized for single-byte codepages.
+ * It does not handle the EBCDIC swaplfnl option (set in UConverter).
+ *
+ * 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);
+
+/**
+ * SBCS, DBCS, and EBCDIC_STATEFUL are replaced by MBCS, but
+ * we cheat a little about the type, returning the old types if appropriate.
+ */
+U_CFUNC UConverterType
+ucnv_MBCSGetType(const UConverter* converter);
+
+U_CFUNC void 
+ucnv_MBCSFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
+                            UErrorCode *pErrorCode);
+U_CFUNC void 
+ucnv_MBCSToUnicodeWithOffsets(UConverterToUnicodeArgs *pArgs,
+                          UErrorCode *pErrorCode);
+
+/*
+ * Internal function returning a UnicodeSet for toUnicode() conversion.
+ * Currently only used for ISO-2022-CN, and only handles roundtrip mappings.
+ * In the future, if we add support for fallback sets, this function
+ * needs to be updated.
+ * Handles extensions.
+ * Does not empty the set first.
+ */
+U_CFUNC void
+ucnv_MBCSGetUnicodeSetForUnicode(const UConverterSharedData *sharedData,
+                                 const USetAdder *sa,
+                                 UConverterUnicodeSet which,
+                                 UErrorCode *pErrorCode);
+
+/*
+ * Same as ucnv_MBCSGetUnicodeSetForUnicode() but
+ * the set can be filtered by encoding scheme.
+ * Used by stateful converters which share regular conversion tables
+ * but only use a subset of their mappings.
+ */
+U_CFUNC void
+ucnv_MBCSGetFilteredUnicodeSetForUnicode(const UConverterSharedData *sharedData,
+                                         const USetAdder *sa,
+                                         UConverterUnicodeSet which,
+                                         UConverterSetFilter filter,
+                                         UErrorCode *pErrorCode);
+
+#endif
+
+#endif