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      1 /*
      2 **********************************************************************
      3 *   Copyright (C) 2000-2015, International Business Machines
      4 *   Corporation and others.  All Rights Reserved.
      5 **********************************************************************
      6 *   file name:  ucnv_lmb.cpp
      7 *   encoding:   US-ASCII
      8 *   tab size:   4 (not used)
      9 *   indentation:4
     10 *
     11 *   created on: 2000feb09
     12 *   created by: Brendan Murray
     13 *   extensively hacked up by: Jim Snyder-Grant
     14 *
     15 * Modification History:
     16 *
     17 *   Date        Name             Description
     18 *
     19 *   06/20/2000  helena           OS/400 port changes; mostly typecast.
     20 *   06/27/2000  Jim Snyder-Grant Deal with partial characters and small buffers.
     21 *                                Add comments to document LMBCS format and implementation
     22 *                                restructured order & breakdown of functions
     23 *   06/28/2000  helena           Major rewrite for the callback API changes.
     24 */
     25 
     26 #include "unicode/utypes.h"
     27 
     28 #if !UCONFIG_NO_CONVERSION && !UCONFIG_NO_LEGACY_CONVERSION && !UCONFIG_ONLY_HTML_CONVERSION
     29 
     30 #include "unicode/ucnv_err.h"
     31 #include "unicode/ucnv.h"
     32 #include "unicode/uset.h"
     33 #include "cmemory.h"
     34 #include "cstring.h"
     35 #include "uassert.h"
     36 #include "ucnv_imp.h"
     37 #include "ucnv_bld.h"
     38 #include "ucnv_cnv.h"
     39 
     40 #ifdef EBCDIC_RTL
     41     #include "ascii_a.h"
     42 #endif
     43 
     44 /*
     45   LMBCS
     46 
     47   (Lotus Multi-Byte Character Set)
     48 
     49   LMBCS was invented in the late 1980's and is primarily used in Lotus Notes
     50   databases and in Lotus 1-2-3 files. Programmers who work with the APIs
     51   into these products will sometimes need to deal with strings in this format.
     52 
     53   The code in this file provides an implementation for an ICU converter of
     54   LMBCS to and from Unicode.
     55 
     56   Since the LMBCS character set is only sparsely documented in existing
     57   printed or online material, we have added  extensive annotation to this
     58   file to serve as a guide to understanding LMBCS.
     59 
     60   LMBCS was originally designed with these four sometimes-competing design goals:
     61 
     62   -Provide encodings for the characters in 12 existing national standards
     63    (plus a few other characters)
     64   -Minimal memory footprint
     65   -Maximal speed of conversion into the existing national character sets
     66   -No need to track a changing state as you interpret a string.
     67 
     68 
     69   All of the national character sets LMBCS was trying to encode are 'ANSI'
     70   based, in that the bytes from 0x20 - 0x7F are almost exactly the
     71   same common Latin unaccented characters and symbols in all character sets.
     72 
     73   So, in order to help meet the speed & memory design goals, the common ANSI
     74   bytes from 0x20-0x7F are represented by the same single-byte values in LMBCS.
     75 
     76   The general LMBCS code unit is from 1-3 bytes. We can describe the 3 bytes as
     77   follows:
     78 
     79   [G] D1 [D2]
     80 
     81   That is, a sometimes-optional 'group' byte, followed by 1 and sometimes 2
     82   data bytes. The maximum size of a LMBCS chjaracter is 3 bytes:
     83 */
     84 #define ULMBCS_CHARSIZE_MAX      3
     85 /*
     86   The single-byte values from 0x20 to 0x7F are examples of single D1 bytes.
     87   We often have to figure out if byte values are below or above this, so we
     88   use the ANSI nomenclature 'C0' and 'C1' to refer to the range of control
     89   characters just above & below the common lower-ANSI  range */
     90 #define ULMBCS_C0END           0x1F
     91 #define ULMBCS_C1START         0x80
     92 /*
     93   Since LMBCS is always dealing in byte units. we create a local type here for
     94   dealing with these units of LMBCS code units:
     95 
     96 */
     97 typedef uint8_t ulmbcs_byte_t;
     98 
     99 /*
    100    Most of the values less than 0x20 are reserved in LMBCS to announce
    101    which national  character standard is being used for the 'D' bytes.
    102    In the comments we show the common name and the IBM character-set ID
    103    for these character-set announcers:
    104 */
    105 
    106 #define ULMBCS_GRP_L1         0x01   /* Latin-1    :ibm-850  */
    107 #define ULMBCS_GRP_GR         0x02   /* Greek      :ibm-851  */
    108 #define ULMBCS_GRP_HE         0x03   /* Hebrew     :ibm-1255 */
    109 #define ULMBCS_GRP_AR         0x04   /* Arabic     :ibm-1256 */
    110 #define ULMBCS_GRP_RU         0x05   /* Cyrillic   :ibm-1251 */
    111 #define ULMBCS_GRP_L2         0x06   /* Latin-2    :ibm-852  */
    112 #define ULMBCS_GRP_TR         0x08   /* Turkish    :ibm-1254 */
    113 #define ULMBCS_GRP_TH         0x0B   /* Thai       :ibm-874  */
    114 #define ULMBCS_GRP_JA         0x10   /* Japanese   :ibm-943  */
    115 #define ULMBCS_GRP_KO         0x11   /* Korean     :ibm-1261 */
    116 #define ULMBCS_GRP_TW         0x12   /* Chinese SC :ibm-950  */
    117 #define ULMBCS_GRP_CN         0x13   /* Chinese TC :ibm-1386 */
    118 
    119 /*
    120    So, the beginning of understanding LMBCS is that IF the first byte of a LMBCS
    121    character is one of those 12 values, you can interpret the remaining bytes of
    122    that character as coming from one of those character sets. Since the lower
    123    ANSI bytes already are represented in single bytes, using one of the character
    124    set announcers is used to announce a character that starts with a byte of
    125    0x80 or greater.
    126 
    127    The character sets are  arranged so that the single byte sets all appear
    128    before the multi-byte character sets. When we need to tell whether a
    129    group byte is for a single byte char set or not we use this define: */
    130 
    131 #define ULMBCS_DOUBLEOPTGROUP_START  0x10
    132 
    133 /*
    134 However, to fully understand LMBCS, you must also understand a series of
    135 exceptions & optimizations made in service of the design goals.
    136 
    137 First, those of you who are character set mavens may have noticed that
    138 the 'double-byte' character sets are actually multi-byte character sets
    139 that can have 1 or two bytes, even in the upper-ascii range. To force
    140 each group byte to introduce a fixed-width encoding (to make it faster to
    141 count characters), we use a convention of doubling up on the group byte
    142 to introduce any single-byte character > 0x80 in an otherwise double-byte
    143 character set. So, for example, the LMBCS sequence x10 x10 xAE is the
    144 same as '0xAE' in the Japanese code page 943.
    145 
    146 Next, you will notice that the list of group bytes has some gaps.
    147 These are used in various ways.
    148 
    149 We reserve a few special single byte values for common control
    150 characters. These are in the same place as their ANSI eqivalents for speed.
    151 */
    152 
    153 #define ULMBCS_HT    0x09   /* Fixed control char - Horizontal Tab */
    154 #define ULMBCS_LF    0x0A   /* Fixed control char - Line Feed */
    155 #define ULMBCS_CR    0x0D   /* Fixed control char - Carriage Return */
    156 
    157 /* Then, 1-2-3 reserved a special single-byte character to put at the
    158 beginning of internal 'system' range names: */
    159 
    160 #define ULMBCS_123SYSTEMRANGE  0x19
    161 
    162 /* Then we needed a place to put all the other ansi control characters
    163 that must be moved to different values because LMBCS reserves those
    164 values for other purposes. To represent the control characters, we start
    165 with a first byte of 0xF & add the control chaarcter value as the
    166 second byte */
    167 #define ULMBCS_GRP_CTRL       0x0F
    168 
    169 /* For the C0 controls (less than 0x20), we add 0x20 to preserve the
    170 useful doctrine that any byte less than 0x20 in a LMBCS char must be
    171 the first byte of a character:*/
    172 #define ULMBCS_CTRLOFFSET      0x20
    173 
    174 /*
    175 Where to put the characters that aren't part of any of the 12 national
    176 character sets? The first thing that was done, in the earlier years of
    177 LMBCS, was to use up the spaces of the form
    178 
    179   [G] D1,
    180 
    181  where  'G' was one of the single-byte character groups, and
    182  D1 was less than 0x80. These sequences are gathered together
    183  into a Lotus-invented doublebyte character set to represent a
    184  lot of stray values. Internally, in this implementation, we track this
    185  as group '0', as a place to tuck this exceptions list.*/
    186 
    187 #define ULMBCS_GRP_EXCEPT     0x00
    188 /*
    189  Finally, as the durability and usefulness of UNICODE became clear,
    190  LOTUS added a new group 0x14 to hold Unicode values not otherwise
    191  represented in LMBCS: */
    192 #define ULMBCS_GRP_UNICODE    0x14
    193 /* The two bytes appearing after a 0x14 are intrepreted as UFT-16 BE
    194 (Big-Endian) characters. The exception comes when the UTF16
    195 representation would have a zero as the second byte. In that case,
    196 'F6' is used in its place, and the bytes are swapped. (This prevents
    197 LMBCS from encoding any Unicode values of the form U+F6xx, but that's OK:
    198 0xF6xx is in the middle of the Private Use Area.)*/
    199 #define ULMBCS_UNICOMPATZERO   0xF6
    200 
    201 /* It is also useful in our code to have a constant for the size of
    202 a LMBCS char that holds a literal Unicode value */
    203 #define ULMBCS_UNICODE_SIZE      3
    204 
    205 /*
    206 To squish the LMBCS representations down even further, and to make
    207 translations even faster,sometimes the optimization group byte can be dropped
    208 from a LMBCS character. This is decided on a process-by-process basis. The
    209 group byte that is dropped is called the 'optimization group'.
    210 
    211 For Notes, the optimzation group is always 0x1.*/
    212 #define ULMBCS_DEFAULTOPTGROUP 0x1
    213 /* For 1-2-3 files, the optimzation group is stored in the header of the 1-2-3
    214 file.
    215 
    216  In any case, when using ICU, you either pass in the
    217 optimization group as part of the name of the converter (LMBCS-1, LMBCS-2,
    218 etc.). Using plain 'LMBCS' as the name of the converter will give you
    219 LMBCS-1.
    220 
    221 
    222 *** Implementation strategy ***
    223 
    224 
    225 Because of the extensive use of other character sets, the LMBCS converter
    226 keeps a mapping between optimization groups and IBM character sets, so that
    227 ICU converters can be created and used as needed. */
    228 
    229 /* As you can see, even though any byte below 0x20 could be an optimization
    230 byte, only those at 0x13 or below can map to an actual converter. To limit
    231 some loops and searches, we define a value for that last group converter:*/
    232 
    233 #define ULMBCS_GRP_LAST       0x13   /* last LMBCS group that has a converter */
    234 
    235 static const char * const OptGroupByteToCPName[ULMBCS_GRP_LAST + 1] = {
    236    /* 0x0000 */ "lmb-excp", /* internal home for the LOTUS exceptions list */
    237    /* 0x0001 */ "ibm-850",
    238    /* 0x0002 */ "ibm-851",
    239    /* 0x0003 */ "windows-1255",
    240    /* 0x0004 */ "windows-1256",
    241    /* 0x0005 */ "windows-1251",
    242    /* 0x0006 */ "ibm-852",
    243    /* 0x0007 */ NULL,      /* Unused */
    244    /* 0x0008 */ "windows-1254",
    245    /* 0x0009 */ NULL,      /* Control char HT */
    246    /* 0x000A */ NULL,      /* Control char LF */
    247    /* 0x000B */ "windows-874",
    248    /* 0x000C */ NULL,      /* Unused */
    249    /* 0x000D */ NULL,      /* Control char CR */
    250    /* 0x000E */ NULL,      /* Unused */
    251    /* 0x000F */ NULL,      /* Control chars: 0x0F20 + C0/C1 character: algorithmic */
    252    /* 0x0010 */ "windows-932",
    253    /* 0x0011 */ "windows-949",
    254    /* 0x0012 */ "windows-950",
    255    /* 0x0013 */ "windows-936"
    256 
    257    /* The rest are null, including the 0x0014 Unicode compatibility region
    258    and 0x0019, the 1-2-3 system range control char */
    259 };
    260 
    261 
    262 /* That's approximately all the data that's needed for translating
    263   LMBCS to Unicode.
    264 
    265 
    266 However, to translate Unicode to LMBCS, we need some more support.
    267 
    268 That's because there are often more than one possible mappings from a Unicode
    269 code point back into LMBCS. The first thing we do is look up into a table
    270 to figure out if there are more than one possible mappings. This table,
    271 arranged by Unicode values (including ranges) either lists which group
    272 to use, or says that it could go into one or more of the SBCS sets, or
    273 into one or more of the DBCS sets.  (If the character exists in both DBCS &
    274 SBCS, the table will place it in the SBCS sets, to make the LMBCS code point
    275 length as small as possible. Here's the two special markers we use to indicate
    276 ambiguous mappings: */
    277 
    278 #define ULMBCS_AMBIGUOUS_SBCS   0x80   /* could fit in more than one
    279                                           LMBCS sbcs native encoding
    280                                           (example: most accented latin) */
    281 #define ULMBCS_AMBIGUOUS_MBCS   0x81   /* could fit in more than one
    282                                           LMBCS mbcs native encoding
    283                                           (example: Unihan) */
    284 #define ULMBCS_AMBIGUOUS_ALL   0x82
    285 /* And here's a simple way to see if a group falls in an appropriate range */
    286 #define ULMBCS_AMBIGUOUS_MATCH(agroup, xgroup) \
    287                   ((((agroup) == ULMBCS_AMBIGUOUS_SBCS) && \
    288                   (xgroup) < ULMBCS_DOUBLEOPTGROUP_START) || \
    289                   (((agroup) == ULMBCS_AMBIGUOUS_MBCS) && \
    290                   (xgroup) >= ULMBCS_DOUBLEOPTGROUP_START)) || \
    291                   ((agroup) == ULMBCS_AMBIGUOUS_ALL)
    292 
    293 
    294 /* The table & some code to use it: */
    295 
    296 
    297 static const struct _UniLMBCSGrpMap
    298 {
    299    const UChar uniStartRange;
    300    const UChar uniEndRange;
    301    const ulmbcs_byte_t  GrpType;
    302 } UniLMBCSGrpMap[]
    303 =
    304 {
    305 
    306     {0x0001, 0x001F,  ULMBCS_GRP_CTRL},
    307     {0x0080, 0x009F,  ULMBCS_GRP_CTRL},
    308     {0x00A0, 0x00A6,  ULMBCS_AMBIGUOUS_SBCS},
    309     {0x00A7, 0x00A8,  ULMBCS_AMBIGUOUS_ALL},
    310     {0x00A9, 0x00AF,  ULMBCS_AMBIGUOUS_SBCS},
    311     {0x00B0, 0x00B1,  ULMBCS_AMBIGUOUS_ALL},
    312     {0x00B2, 0x00B3,  ULMBCS_AMBIGUOUS_SBCS},
    313     {0x00B4, 0x00B4,  ULMBCS_AMBIGUOUS_ALL},
    314     {0x00B5, 0x00B5,  ULMBCS_AMBIGUOUS_SBCS},
    315     {0x00B6, 0x00B6,  ULMBCS_AMBIGUOUS_ALL},
    316     {0x00B7, 0x00D6,  ULMBCS_AMBIGUOUS_SBCS},
    317     {0x00D7, 0x00D7,  ULMBCS_AMBIGUOUS_ALL},
    318     {0x00D8, 0x00F6,  ULMBCS_AMBIGUOUS_SBCS},
    319     {0x00F7, 0x00F7,  ULMBCS_AMBIGUOUS_ALL},
    320     {0x00F8, 0x01CD,  ULMBCS_AMBIGUOUS_SBCS},
    321     {0x01CE, 0x01CE,  ULMBCS_GRP_TW },
    322     {0x01CF, 0x02B9,  ULMBCS_AMBIGUOUS_SBCS},
    323     {0x02BA, 0x02BA,  ULMBCS_GRP_CN},
    324     {0x02BC, 0x02C8,  ULMBCS_AMBIGUOUS_SBCS},
    325     {0x02C9, 0x02D0,  ULMBCS_AMBIGUOUS_MBCS},
    326     {0x02D8, 0x02DD,  ULMBCS_AMBIGUOUS_SBCS},
    327     {0x0384, 0x0390,  ULMBCS_AMBIGUOUS_SBCS},
    328     {0x0391, 0x03A9,  ULMBCS_AMBIGUOUS_ALL},
    329     {0x03AA, 0x03B0,  ULMBCS_AMBIGUOUS_SBCS},
    330     {0x03B1, 0x03C9,  ULMBCS_AMBIGUOUS_ALL},
    331     {0x03CA, 0x03CE,  ULMBCS_AMBIGUOUS_SBCS},
    332     {0x0400, 0x0400,  ULMBCS_GRP_RU},
    333     {0x0401, 0x0401,  ULMBCS_AMBIGUOUS_ALL},
    334     {0x0402, 0x040F,  ULMBCS_GRP_RU},
    335     {0x0410, 0x0431,  ULMBCS_AMBIGUOUS_ALL},
    336     {0x0432, 0x044E,  ULMBCS_GRP_RU},
    337     {0x044F, 0x044F,  ULMBCS_AMBIGUOUS_ALL},
    338     {0x0450, 0x0491,  ULMBCS_GRP_RU},
    339     {0x05B0, 0x05F2,  ULMBCS_GRP_HE},
    340     {0x060C, 0x06AF,  ULMBCS_GRP_AR},
    341     {0x0E01, 0x0E5B,  ULMBCS_GRP_TH},
    342     {0x200C, 0x200F,  ULMBCS_AMBIGUOUS_SBCS},
    343     {0x2010, 0x2010,  ULMBCS_AMBIGUOUS_MBCS},
    344     {0x2013, 0x2014,  ULMBCS_AMBIGUOUS_SBCS},
    345     {0x2015, 0x2015,  ULMBCS_AMBIGUOUS_MBCS},
    346     {0x2016, 0x2016,  ULMBCS_AMBIGUOUS_MBCS},
    347     {0x2017, 0x2017,  ULMBCS_AMBIGUOUS_SBCS},
    348     {0x2018, 0x2019,  ULMBCS_AMBIGUOUS_ALL},
    349     {0x201A, 0x201B,  ULMBCS_AMBIGUOUS_SBCS},
    350     {0x201C, 0x201D,  ULMBCS_AMBIGUOUS_ALL},
    351     {0x201E, 0x201F,  ULMBCS_AMBIGUOUS_SBCS},
    352     {0x2020, 0x2021,  ULMBCS_AMBIGUOUS_ALL},
    353     {0x2022, 0x2024,  ULMBCS_AMBIGUOUS_SBCS},
    354     {0x2025, 0x2025,  ULMBCS_AMBIGUOUS_MBCS},
    355     {0x2026, 0x2026,  ULMBCS_AMBIGUOUS_ALL},
    356     {0x2027, 0x2027,  ULMBCS_GRP_TW},
    357     {0x2030, 0x2030,  ULMBCS_AMBIGUOUS_ALL},
    358     {0x2031, 0x2031,  ULMBCS_AMBIGUOUS_SBCS},
    359     {0x2032, 0x2033,  ULMBCS_AMBIGUOUS_MBCS},
    360     {0x2035, 0x2035,  ULMBCS_AMBIGUOUS_MBCS},
    361     {0x2039, 0x203A,  ULMBCS_AMBIGUOUS_SBCS},
    362     {0x203B, 0x203B,  ULMBCS_AMBIGUOUS_MBCS},
    363     {0x203C, 0x203C,  ULMBCS_GRP_EXCEPT},
    364     {0x2074, 0x2074,  ULMBCS_GRP_KO},
    365     {0x207F, 0x207F,  ULMBCS_GRP_EXCEPT},
    366     {0x2081, 0x2084,  ULMBCS_GRP_KO},
    367     {0x20A4, 0x20AC,  ULMBCS_AMBIGUOUS_SBCS},
    368     {0x2103, 0x2109,  ULMBCS_AMBIGUOUS_MBCS},
    369     {0x2111, 0x2120,  ULMBCS_AMBIGUOUS_SBCS},
    370     /*zhujin: upgrade, for regressiont test, spr HKIA4YHTSU*/
    371     {0x2121, 0x2121,  ULMBCS_AMBIGUOUS_MBCS},
    372     {0x2122, 0x2126,  ULMBCS_AMBIGUOUS_SBCS},
    373     {0x212B, 0x212B,  ULMBCS_AMBIGUOUS_MBCS},
    374     {0x2135, 0x2135,  ULMBCS_AMBIGUOUS_SBCS},
    375     {0x2153, 0x2154,  ULMBCS_GRP_KO},
    376     {0x215B, 0x215E,  ULMBCS_GRP_EXCEPT},
    377     {0x2160, 0x2179,  ULMBCS_AMBIGUOUS_MBCS},
    378     {0x2190, 0x2193,  ULMBCS_AMBIGUOUS_ALL},
    379     {0x2194, 0x2195,  ULMBCS_GRP_EXCEPT},
    380     {0x2196, 0x2199,  ULMBCS_AMBIGUOUS_MBCS},
    381     {0x21A8, 0x21A8,  ULMBCS_GRP_EXCEPT},
    382     {0x21B8, 0x21B9,  ULMBCS_GRP_CN},
    383     {0x21D0, 0x21D1,  ULMBCS_GRP_EXCEPT},
    384     {0x21D2, 0x21D2,  ULMBCS_AMBIGUOUS_MBCS},
    385     {0x21D3, 0x21D3,  ULMBCS_GRP_EXCEPT},
    386     {0x21D4, 0x21D4,  ULMBCS_AMBIGUOUS_MBCS},
    387     {0x21D5, 0x21D5,  ULMBCS_GRP_EXCEPT},
    388     {0x21E7, 0x21E7,  ULMBCS_GRP_CN},
    389     {0x2200, 0x2200,  ULMBCS_AMBIGUOUS_MBCS},
    390     {0x2201, 0x2201,  ULMBCS_GRP_EXCEPT},
    391     {0x2202, 0x2202,  ULMBCS_AMBIGUOUS_MBCS},
    392     {0x2203, 0x2203,  ULMBCS_AMBIGUOUS_MBCS},
    393     {0x2204, 0x2206,  ULMBCS_GRP_EXCEPT},
    394     {0x2207, 0x2208,  ULMBCS_AMBIGUOUS_MBCS},
    395     {0x2209, 0x220A,  ULMBCS_GRP_EXCEPT},
    396     {0x220B, 0x220B,  ULMBCS_AMBIGUOUS_MBCS},
    397     {0x220F, 0x2215,  ULMBCS_AMBIGUOUS_MBCS},
    398     {0x2219, 0x2219,  ULMBCS_GRP_EXCEPT},
    399     {0x221A, 0x221A,  ULMBCS_AMBIGUOUS_MBCS},
    400     {0x221B, 0x221C,  ULMBCS_GRP_EXCEPT},
    401     {0x221D, 0x221E,  ULMBCS_AMBIGUOUS_MBCS},
    402     {0x221F, 0x221F,  ULMBCS_GRP_EXCEPT},
    403     {0x2220, 0x2220,  ULMBCS_AMBIGUOUS_MBCS},
    404     {0x2223, 0x222A,  ULMBCS_AMBIGUOUS_MBCS},
    405     {0x222B, 0x223D,  ULMBCS_AMBIGUOUS_MBCS},
    406     {0x2245, 0x2248,  ULMBCS_GRP_EXCEPT},
    407     {0x224C, 0x224C,  ULMBCS_GRP_TW},
    408     {0x2252, 0x2252,  ULMBCS_AMBIGUOUS_MBCS},
    409     {0x2260, 0x2261,  ULMBCS_AMBIGUOUS_MBCS},
    410     {0x2262, 0x2265,  ULMBCS_GRP_EXCEPT},
    411     {0x2266, 0x226F,  ULMBCS_AMBIGUOUS_MBCS},
    412     {0x2282, 0x2283,  ULMBCS_AMBIGUOUS_MBCS},
    413     {0x2284, 0x2285,  ULMBCS_GRP_EXCEPT},
    414     {0x2286, 0x2287,  ULMBCS_AMBIGUOUS_MBCS},
    415     {0x2288, 0x2297,  ULMBCS_GRP_EXCEPT},
    416     {0x2299, 0x22BF,  ULMBCS_AMBIGUOUS_MBCS},
    417     {0x22C0, 0x22C0,  ULMBCS_GRP_EXCEPT},
    418     {0x2310, 0x2310,  ULMBCS_GRP_EXCEPT},
    419     {0x2312, 0x2312,  ULMBCS_AMBIGUOUS_MBCS},
    420     {0x2318, 0x2321,  ULMBCS_GRP_EXCEPT},
    421     {0x2318, 0x2321,  ULMBCS_GRP_CN},
    422     {0x2460, 0x24E9,  ULMBCS_AMBIGUOUS_MBCS},
    423     {0x2500, 0x2500,  ULMBCS_AMBIGUOUS_SBCS},
    424     {0x2501, 0x2501,  ULMBCS_AMBIGUOUS_MBCS},
    425     {0x2502, 0x2502,  ULMBCS_AMBIGUOUS_ALL},
    426     {0x2503, 0x2503,  ULMBCS_AMBIGUOUS_MBCS},
    427     {0x2504, 0x2505,  ULMBCS_GRP_TW},
    428     {0x2506, 0x2665,  ULMBCS_AMBIGUOUS_ALL},
    429     {0x2666, 0x2666,  ULMBCS_GRP_EXCEPT},
    430     {0x2667, 0x2669,  ULMBCS_AMBIGUOUS_SBCS},
    431     {0x266A, 0x266A,  ULMBCS_AMBIGUOUS_ALL},
    432     {0x266B, 0x266C,  ULMBCS_AMBIGUOUS_SBCS},
    433     {0x266D, 0x266D,  ULMBCS_AMBIGUOUS_MBCS},
    434     {0x266E, 0x266E,  ULMBCS_AMBIGUOUS_SBCS},
    435     {0x266F, 0x266F,  ULMBCS_GRP_JA},
    436     {0x2670, 0x2E7F,  ULMBCS_AMBIGUOUS_SBCS},
    437     {0x2E80, 0xF861,  ULMBCS_AMBIGUOUS_MBCS},
    438     {0xF862, 0xF8FF,  ULMBCS_GRP_EXCEPT},
    439     {0xF900, 0xFA2D,  ULMBCS_AMBIGUOUS_MBCS},
    440     {0xFB00, 0xFEFF,  ULMBCS_AMBIGUOUS_SBCS},
    441     {0xFF01, 0xFFEE,  ULMBCS_AMBIGUOUS_MBCS},
    442     {0xFFFF, 0xFFFF,  ULMBCS_GRP_UNICODE}
    443 };
    444 
    445 static ulmbcs_byte_t
    446 FindLMBCSUniRange(UChar uniChar)
    447 {
    448    const struct _UniLMBCSGrpMap * pTable = UniLMBCSGrpMap;
    449 
    450    while (uniChar > pTable->uniEndRange)
    451    {
    452       pTable++;
    453    }
    454 
    455    if (uniChar >= pTable->uniStartRange)
    456    {
    457       return pTable->GrpType;
    458    }
    459    return ULMBCS_GRP_UNICODE;
    460 }
    461 
    462 /*
    463 We also ask the creator of a converter to send in a preferred locale
    464 that we can use in resolving ambiguous mappings. They send the locale
    465 in as a string, and we map it, if possible, to one of the
    466 LMBCS groups. We use this table, and the associated code, to
    467 do the lookup: */
    468 
    469 /**************************************************
    470   This table maps locale ID's to LMBCS opt groups.
    471   The default return is group 0x01. Note that for
    472   performance reasons, the table is sorted in
    473   increasing alphabetic order, with the notable
    474   exception of zhTW. This is to force the check
    475   for Traditonal Chinese before dropping back to
    476   Simplified.
    477 
    478   Note too that the Latin-1 groups have been
    479   commented out because it's the default, and
    480   this shortens the table, allowing a serial
    481   search to go quickly.
    482  *************************************************/
    483 
    484 static const struct _LocaleLMBCSGrpMap
    485 {
    486    const char    *LocaleID;
    487    const ulmbcs_byte_t OptGroup;
    488 } LocaleLMBCSGrpMap[] =
    489 {
    490     {"ar", ULMBCS_GRP_AR},
    491     {"be", ULMBCS_GRP_RU},
    492     {"bg", ULMBCS_GRP_L2},
    493    /* {"ca", ULMBCS_GRP_L1}, */
    494     {"cs", ULMBCS_GRP_L2},
    495    /* {"da", ULMBCS_GRP_L1}, */
    496    /* {"de", ULMBCS_GRP_L1}, */
    497     {"el", ULMBCS_GRP_GR},
    498    /* {"en", ULMBCS_GRP_L1}, */
    499    /* {"es", ULMBCS_GRP_L1}, */
    500    /* {"et", ULMBCS_GRP_L1}, */
    501    /* {"fi", ULMBCS_GRP_L1}, */
    502    /* {"fr", ULMBCS_GRP_L1}, */
    503     {"he", ULMBCS_GRP_HE},
    504     {"hu", ULMBCS_GRP_L2},
    505    /* {"is", ULMBCS_GRP_L1}, */
    506    /* {"it", ULMBCS_GRP_L1}, */
    507     {"iw", ULMBCS_GRP_HE},
    508     {"ja", ULMBCS_GRP_JA},
    509     {"ko", ULMBCS_GRP_KO},
    510    /* {"lt", ULMBCS_GRP_L1}, */
    511    /* {"lv", ULMBCS_GRP_L1}, */
    512     {"mk", ULMBCS_GRP_RU},
    513    /* {"nl", ULMBCS_GRP_L1}, */
    514    /* {"no", ULMBCS_GRP_L1}, */
    515     {"pl", ULMBCS_GRP_L2},
    516    /* {"pt", ULMBCS_GRP_L1}, */
    517     {"ro", ULMBCS_GRP_L2},
    518     {"ru", ULMBCS_GRP_RU},
    519     {"sh", ULMBCS_GRP_L2},
    520     {"sk", ULMBCS_GRP_L2},
    521     {"sl", ULMBCS_GRP_L2},
    522     {"sq", ULMBCS_GRP_L2},
    523     {"sr", ULMBCS_GRP_RU},
    524    /* {"sv", ULMBCS_GRP_L1}, */
    525     {"th", ULMBCS_GRP_TH},
    526     {"tr", ULMBCS_GRP_TR},
    527     {"uk", ULMBCS_GRP_RU},
    528    /* {"vi", ULMBCS_GRP_L1}, */
    529     {"zhTW", ULMBCS_GRP_TW},
    530     {"zh", ULMBCS_GRP_CN},
    531     {NULL, ULMBCS_GRP_L1}
    532 };
    533 
    534 
    535 static ulmbcs_byte_t
    536 FindLMBCSLocale(const char *LocaleID)
    537 {
    538    const struct _LocaleLMBCSGrpMap *pTable = LocaleLMBCSGrpMap;
    539 
    540    if ((!LocaleID) || (!*LocaleID))
    541    {
    542       return 0;
    543    }
    544 
    545    while (pTable->LocaleID)
    546    {
    547       if (*pTable->LocaleID == *LocaleID) /* Check only first char for speed */
    548       {
    549          /* First char matches - check whole name, for entry-length */
    550          if (uprv_strncmp(pTable->LocaleID, LocaleID, strlen(pTable->LocaleID)) == 0)
    551             return pTable->OptGroup;
    552       }
    553       else
    554       if (*pTable->LocaleID > *LocaleID) /* Sorted alphabetically - exit */
    555          break;
    556       pTable++;
    557    }
    558    return ULMBCS_GRP_L1;
    559 }
    560 
    561 
    562 /*
    563   Before we get to the main body of code, here's how we hook up to the rest
    564   of ICU. ICU converters are required to define a structure that includes
    565   some function pointers, and some common data, in the style of a C++
    566   vtable. There is also room in there for converter-specific data. LMBCS
    567   uses that converter-specific data to keep track of the 12 subconverters
    568   we use, the optimization group, and the group (if any) that matches the
    569   locale. We have one structure instantiated for each of the 12 possible
    570   optimization groups. To avoid typos & to avoid boring the reader, we
    571   put the declarations of these structures and functions into macros. To see
    572   the definitions of these structures, see unicode\ucnv_bld.h
    573 */
    574 
    575 typedef struct
    576   {
    577     UConverterSharedData *OptGrpConverter[ULMBCS_GRP_LAST+1];    /* Converter per Opt. grp. */
    578     uint8_t    OptGroup;                  /* default Opt. grp. for this LMBCS session */
    579     uint8_t    localeConverterIndex;      /* reasonable locale match for index */
    580   }
    581 UConverterDataLMBCS;
    582 
    583 static void _LMBCSClose(UConverter * _this);
    584 
    585 #define DECLARE_LMBCS_DATA(n) \
    586 static const UConverterImpl _LMBCSImpl##n={\
    587     UCNV_LMBCS_##n,\
    588     NULL,NULL,\
    589     _LMBCSOpen##n,\
    590     _LMBCSClose,\
    591     NULL,\
    592     _LMBCSToUnicodeWithOffsets,\
    593     _LMBCSToUnicodeWithOffsets,\
    594     _LMBCSFromUnicode,\
    595     _LMBCSFromUnicode,\
    596     NULL,\
    597     NULL,\
    598     NULL,\
    599     NULL,\
    600     _LMBCSSafeClone,\
    601     ucnv_getCompleteUnicodeSet\
    602 };\
    603 static const UConverterStaticData _LMBCSStaticData##n={\
    604   sizeof(UConverterStaticData),\
    605  "LMBCS-"  #n,\
    606     0, UCNV_IBM, UCNV_LMBCS_##n, 1, 3,\
    607     { 0x3f, 0, 0, 0 },1,FALSE,FALSE,0,0,{0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0} \
    608 };\
    609 const UConverterSharedData _LMBCSData##n={\
    610     sizeof(UConverterSharedData), ~((uint32_t) 0),\
    611     NULL, NULL, &_LMBCSStaticData##n, FALSE, &_LMBCSImpl##n, \
    612     0 \
    613 };
    614 
    615  /* The only function we needed to duplicate 12 times was the 'open'
    616 function, which will do basically the same thing except set a  different
    617 optimization group. So, we put the common stuff into a worker function,
    618 and set up another macro to stamp out the 12 open functions:*/
    619 #define DEFINE_LMBCS_OPEN(n) \
    620 static void \
    621    _LMBCSOpen##n(UConverter* _this, UConverterLoadArgs* pArgs, UErrorCode* err) \
    622 { _LMBCSOpenWorker(_this, pArgs, err, n); }
    623 
    624 
    625 
    626 /* Here's the open worker & the common close function */
    627 static void
    628 _LMBCSOpenWorker(UConverter*  _this,
    629                  UConverterLoadArgs *pArgs,
    630                  UErrorCode*  err,
    631                  ulmbcs_byte_t OptGroup)
    632 {
    633     UConverterDataLMBCS * extraInfo = _this->extraInfo =
    634         (UConverterDataLMBCS*)uprv_malloc (sizeof (UConverterDataLMBCS));
    635     if(extraInfo != NULL)
    636     {
    637         UConverterNamePieces stackPieces;
    638         UConverterLoadArgs stackArgs={ (int32_t)sizeof(UConverterLoadArgs) };
    639         ulmbcs_byte_t i;
    640 
    641         uprv_memset(extraInfo, 0, sizeof(UConverterDataLMBCS));
    642 
    643         stackArgs.onlyTestIsLoadable = pArgs->onlyTestIsLoadable;
    644 
    645         for (i=0; i <= ULMBCS_GRP_LAST && U_SUCCESS(*err); i++)
    646         {
    647             if(OptGroupByteToCPName[i] != NULL) {
    648                 extraInfo->OptGrpConverter[i] = ucnv_loadSharedData(OptGroupByteToCPName[i], &stackPieces, &stackArgs, err);
    649             }
    650         }
    651 
    652         if(U_FAILURE(*err) || pArgs->onlyTestIsLoadable) {
    653             _LMBCSClose(_this);
    654             return;
    655         }
    656         extraInfo->OptGroup = OptGroup;
    657         extraInfo->localeConverterIndex = FindLMBCSLocale(pArgs->locale);
    658     }
    659     else
    660     {
    661         *err = U_MEMORY_ALLOCATION_ERROR;
    662     }
    663 }
    664 
    665 static void
    666 _LMBCSClose(UConverter *   _this)
    667 {
    668     if (_this->extraInfo != NULL)
    669     {
    670         ulmbcs_byte_t Ix;
    671         UConverterDataLMBCS * extraInfo = (UConverterDataLMBCS *) _this->extraInfo;
    672 
    673         for (Ix=0; Ix <= ULMBCS_GRP_LAST; Ix++)
    674         {
    675            if (extraInfo->OptGrpConverter[Ix] != NULL)
    676               ucnv_unloadSharedDataIfReady(extraInfo->OptGrpConverter[Ix]);
    677         }
    678         if (!_this->isExtraLocal) {
    679             uprv_free (_this->extraInfo);
    680             _this->extraInfo = NULL;
    681         }
    682     }
    683 }
    684 
    685 typedef struct LMBCSClone {
    686     UConverter cnv;
    687     UConverterDataLMBCS lmbcs;
    688 } LMBCSClone;
    689 
    690 static UConverter *
    691 _LMBCSSafeClone(const UConverter *cnv,
    692                 void *stackBuffer,
    693                 int32_t *pBufferSize,
    694                 UErrorCode *status) {
    695     LMBCSClone *newLMBCS;
    696     UConverterDataLMBCS *extraInfo;
    697     int32_t i;
    698 
    699     if(*pBufferSize<=0) {
    700         *pBufferSize=(int32_t)sizeof(LMBCSClone);
    701         return NULL;
    702     }
    703 
    704     extraInfo=(UConverterDataLMBCS *)cnv->extraInfo;
    705     newLMBCS=(LMBCSClone *)stackBuffer;
    706 
    707     /* ucnv.c/ucnv_safeClone() copied the main UConverter already */
    708 
    709     uprv_memcpy(&newLMBCS->lmbcs, extraInfo, sizeof(UConverterDataLMBCS));
    710 
    711     /* share the subconverters */
    712     for(i = 0; i <= ULMBCS_GRP_LAST; ++i) {
    713         if(extraInfo->OptGrpConverter[i] != NULL) {
    714             ucnv_incrementRefCount(extraInfo->OptGrpConverter[i]);
    715         }
    716     }
    717 
    718     newLMBCS->cnv.extraInfo = &newLMBCS->lmbcs;
    719     newLMBCS->cnv.isExtraLocal = TRUE;
    720     return &newLMBCS->cnv;
    721 }
    722 
    723 /*
    724  * There used to be a _LMBCSGetUnicodeSet() function here (up to svn revision 20117)
    725  * which added all code points except for U+F6xx
    726  * because those cannot be represented in the Unicode group.
    727  * However, it turns out that windows-950 has roundtrips for all of U+F6xx
    728  * which means that LMBCS can convert all Unicode code points after all.
    729  * We now simply use ucnv_getCompleteUnicodeSet().
    730  *
    731  * This may need to be looked at again as Lotus uses _LMBCSGetUnicodeSet(). (091216)
    732  */
    733 
    734 /*
    735    Here's the basic helper function that we use when converting from
    736    Unicode to LMBCS, and we suspect that a Unicode character will fit into
    737    one of the 12 groups. The return value is the number of bytes written
    738    starting at pStartLMBCS (if any).
    739 */
    740 
    741 static size_t
    742 LMBCSConversionWorker (
    743    UConverterDataLMBCS * extraInfo,    /* subconverters, opt & locale groups */
    744    ulmbcs_byte_t group,                /* The group to try */
    745    ulmbcs_byte_t  * pStartLMBCS,              /* where to put the results */
    746    UChar * pUniChar,                   /* The input unicode character */
    747    ulmbcs_byte_t * lastConverterIndex, /* output: track last successful group used */
    748    UBool * groups_tried                /* output: track any unsuccessful groups */
    749 )
    750 {
    751    ulmbcs_byte_t  * pLMBCS = pStartLMBCS;
    752    UConverterSharedData * xcnv = extraInfo->OptGrpConverter[group];
    753 
    754    int bytesConverted;
    755    uint32_t value;
    756    ulmbcs_byte_t firstByte;
    757 
    758    U_ASSERT(xcnv);
    759    U_ASSERT(group<ULMBCS_GRP_UNICODE);
    760 
    761    bytesConverted = ucnv_MBCSFromUChar32(xcnv, *pUniChar, &value, FALSE);
    762 
    763    /* get the first result byte */
    764    if(bytesConverted > 0) {
    765       firstByte = (ulmbcs_byte_t)(value >> ((bytesConverted - 1) * 8));
    766    } else {
    767       /* most common failure mode is an unassigned character */
    768       groups_tried[group] = TRUE;
    769       return 0;
    770    }
    771 
    772    *lastConverterIndex = group;
    773 
    774    /* All initial byte values in lower ascii range should have been caught by now,
    775       except with the exception group.
    776     */
    777    U_ASSERT((firstByte <= ULMBCS_C0END) || (firstByte >= ULMBCS_C1START) || (group == ULMBCS_GRP_EXCEPT));
    778 
    779    /* use converted data: first write 0, 1 or two group bytes */
    780    if (group != ULMBCS_GRP_EXCEPT && extraInfo->OptGroup != group)
    781    {
    782       *pLMBCS++ = group;
    783       if (bytesConverted == 1 && group >= ULMBCS_DOUBLEOPTGROUP_START)
    784       {
    785          *pLMBCS++ = group;
    786       }
    787    }
    788 
    789   /* don't emit control chars */
    790    if ( bytesConverted == 1 && firstByte < 0x20 )
    791       return 0;
    792 
    793 
    794    /* then move over the converted data */
    795    switch(bytesConverted)
    796    {
    797    case 4:
    798       *pLMBCS++ = (ulmbcs_byte_t)(value >> 24);
    799    case 3: /*fall through*/
    800       *pLMBCS++ = (ulmbcs_byte_t)(value >> 16);
    801    case 2: /*fall through*/
    802       *pLMBCS++ = (ulmbcs_byte_t)(value >> 8);
    803    case 1: /*fall through*/
    804       *pLMBCS++ = (ulmbcs_byte_t)value;
    805    default:
    806       /* will never occur */
    807       break;
    808    }
    809 
    810    return (pLMBCS - pStartLMBCS);
    811 }
    812 
    813 
    814 /* This is a much simpler version of above, when we
    815 know we are writing LMBCS using the Unicode group
    816 */
    817 static size_t
    818 LMBCSConvertUni(ulmbcs_byte_t * pLMBCS, UChar uniChar)
    819 {
    820      /* encode into LMBCS Unicode range */
    821    uint8_t LowCh =   (uint8_t)(uniChar & 0x00FF);
    822    uint8_t HighCh  = (uint8_t)(uniChar >> 8);
    823 
    824    *pLMBCS++ = ULMBCS_GRP_UNICODE;
    825 
    826    if (LowCh == 0)
    827    {
    828       *pLMBCS++ = ULMBCS_UNICOMPATZERO;
    829       *pLMBCS++ = HighCh;
    830    }
    831    else
    832    {
    833       *pLMBCS++ = HighCh;
    834       *pLMBCS++ = LowCh;
    835    }
    836    return ULMBCS_UNICODE_SIZE;
    837 }
    838 
    839 
    840 
    841 /* The main Unicode to LMBCS conversion function */
    842 static void
    843 _LMBCSFromUnicode(UConverterFromUnicodeArgs*     args,
    844                   UErrorCode*     err)
    845 {
    846    ulmbcs_byte_t lastConverterIndex = 0;
    847    UChar uniChar;
    848    ulmbcs_byte_t  LMBCS[ULMBCS_CHARSIZE_MAX];
    849    ulmbcs_byte_t  * pLMBCS;
    850    int32_t bytes_written;
    851    UBool groups_tried[ULMBCS_GRP_LAST+1];
    852    UConverterDataLMBCS * extraInfo = (UConverterDataLMBCS *) args->converter->extraInfo;
    853    int sourceIndex = 0;
    854 
    855    /* Basic strategy: attempt to fill in local LMBCS 1-char buffer.(LMBCS)
    856       If that succeeds, see if it will all fit into the target & copy it over
    857       if it does.
    858 
    859       We try conversions in the following order:
    860 
    861       1. Single-byte ascii & special fixed control chars (&null)
    862       2. Look up group in table & try that (could be
    863             A) Unicode group
    864             B) control group,
    865             C) national encoding,
    866                or ambiguous SBCS or MBCS group (on to step 4...)
    867 
    868       3. If its ambiguous, try this order:
    869          A) The optimization group
    870          B) The locale group
    871          C) The last group that succeeded with this string.
    872          D) every other group that's relevent (single or double)
    873          E) If its single-byte ambiguous, try the exceptions group
    874 
    875       4. And as a grand fallback: Unicode
    876    */
    877 
    878     /*Fix for SPR#DJOE66JFN3 (Lotus)*/
    879     ulmbcs_byte_t OldConverterIndex = 0;
    880 
    881    while (args->source < args->sourceLimit && !U_FAILURE(*err))
    882    {
    883       /*Fix for SPR#DJOE66JFN3 (Lotus)*/
    884       OldConverterIndex = extraInfo->localeConverterIndex;
    885 
    886       if (args->target >= args->targetLimit)
    887       {
    888          *err = U_BUFFER_OVERFLOW_ERROR;
    889          break;
    890       }
    891       uniChar = *(args->source);
    892       bytes_written = 0;
    893       pLMBCS = LMBCS;
    894 
    895       /* check cases in rough order of how common they are, for speed */
    896 
    897       /* single byte matches: strategy 1 */
    898       /*Fix for SPR#DJOE66JFN3 (Lotus)*/
    899       if((uniChar>=0x80) && (uniChar<=0xff)
    900       /*Fix for SPR#JUYA6XAERU and TSAO7GL5NK (Lotus)*/ &&(uniChar!=0xB1) &&(uniChar!=0xD7) &&(uniChar!=0xF7)
    901         &&(uniChar!=0xB0) &&(uniChar!=0xB4) &&(uniChar!=0xB6) &&(uniChar!=0xA7) &&(uniChar!=0xA8))
    902       {
    903             extraInfo->localeConverterIndex = ULMBCS_GRP_L1;
    904       }
    905       if (((uniChar > ULMBCS_C0END) && (uniChar < ULMBCS_C1START)) ||
    906           uniChar == 0 || uniChar == ULMBCS_HT || uniChar == ULMBCS_CR ||
    907           uniChar == ULMBCS_LF || uniChar == ULMBCS_123SYSTEMRANGE
    908           )
    909       {
    910          *pLMBCS++ = (ulmbcs_byte_t ) uniChar;
    911          bytes_written = 1;
    912       }
    913 
    914 
    915       if (!bytes_written)
    916       {
    917          /* Check by UNICODE range (Strategy 2) */
    918          ulmbcs_byte_t group = FindLMBCSUniRange(uniChar);
    919 
    920          if (group == ULMBCS_GRP_UNICODE)  /* (Strategy 2A) */
    921          {
    922             pLMBCS += LMBCSConvertUni(pLMBCS,uniChar);
    923 
    924             bytes_written = (int32_t)(pLMBCS - LMBCS);
    925          }
    926          else if (group == ULMBCS_GRP_CTRL)  /* (Strategy 2B) */
    927          {
    928             /* Handle control characters here */
    929             if (uniChar <= ULMBCS_C0END)
    930             {
    931                *pLMBCS++ = ULMBCS_GRP_CTRL;
    932                *pLMBCS++ = (ulmbcs_byte_t)(ULMBCS_CTRLOFFSET + uniChar);
    933             }
    934             else if (uniChar >= ULMBCS_C1START && uniChar <= ULMBCS_C1START + ULMBCS_CTRLOFFSET)
    935             {
    936                *pLMBCS++ = ULMBCS_GRP_CTRL;
    937                *pLMBCS++ = (ulmbcs_byte_t ) (uniChar & 0x00FF);
    938             }
    939             bytes_written = (int32_t)(pLMBCS - LMBCS);
    940          }
    941          else if (group < ULMBCS_GRP_UNICODE)  /* (Strategy 2C) */
    942          {
    943             /* a specific converter has been identified - use it */
    944             bytes_written = (int32_t)LMBCSConversionWorker (
    945                               extraInfo, group, pLMBCS, &uniChar,
    946                               &lastConverterIndex, groups_tried);
    947          }
    948          if (!bytes_written)    /* the ambiguous group cases  (Strategy 3) */
    949          {
    950             uprv_memset(groups_tried, 0, sizeof(groups_tried));
    951 
    952             /* check for non-default optimization group (Strategy 3A )*/
    953             if ((extraInfo->OptGroup != 1) && (ULMBCS_AMBIGUOUS_MATCH(group, extraInfo->OptGroup)))
    954             {
    955                 /*zhujin: upgrade, merge #39299 here (Lotus) */
    956                 /*To make R5 compatible translation, look for exceptional group first for non-DBCS*/
    957 
    958                 if(extraInfo->localeConverterIndex < ULMBCS_DOUBLEOPTGROUP_START)
    959                 {
    960                   bytes_written = LMBCSConversionWorker (extraInfo,
    961                      ULMBCS_GRP_L1, pLMBCS, &uniChar,
    962                      &lastConverterIndex, groups_tried);
    963 
    964                   if(!bytes_written)
    965                   {
    966                      bytes_written = LMBCSConversionWorker (extraInfo,
    967                          ULMBCS_GRP_EXCEPT, pLMBCS, &uniChar,
    968                          &lastConverterIndex, groups_tried);
    969                   }
    970                   if(!bytes_written)
    971                   {
    972                       bytes_written = LMBCSConversionWorker (extraInfo,
    973                           extraInfo->localeConverterIndex, pLMBCS, &uniChar,
    974                           &lastConverterIndex, groups_tried);
    975                   }
    976                 }
    977                 else
    978                 {
    979                      bytes_written = LMBCSConversionWorker (extraInfo,
    980                          extraInfo->localeConverterIndex, pLMBCS, &uniChar,
    981                          &lastConverterIndex, groups_tried);
    982                 }
    983             }
    984             /* check for locale optimization group (Strategy 3B) */
    985             if (!bytes_written && (extraInfo->localeConverterIndex) && (ULMBCS_AMBIGUOUS_MATCH(group, extraInfo->localeConverterIndex)))
    986             {
    987                 bytes_written = (int32_t)LMBCSConversionWorker (extraInfo,
    988                         extraInfo->localeConverterIndex, pLMBCS, &uniChar, &lastConverterIndex, groups_tried);
    989             }
    990             /* check for last optimization group used for this string (Strategy 3C) */
    991             if (!bytes_written && (lastConverterIndex) && (ULMBCS_AMBIGUOUS_MATCH(group, lastConverterIndex)))
    992             {
    993                 bytes_written = (int32_t)LMBCSConversionWorker (extraInfo,
    994                         lastConverterIndex, pLMBCS, &uniChar, &lastConverterIndex, groups_tried);
    995             }
    996             if (!bytes_written)
    997             {
    998                /* just check every possible matching converter (Strategy 3D) */
    999                ulmbcs_byte_t grp_start;
   1000                ulmbcs_byte_t grp_end;
   1001                ulmbcs_byte_t grp_ix;
   1002                grp_start = (ulmbcs_byte_t)((group == ULMBCS_AMBIGUOUS_MBCS)
   1003                         ? ULMBCS_DOUBLEOPTGROUP_START
   1004                         :  ULMBCS_GRP_L1);
   1005                grp_end = (ulmbcs_byte_t)((group == ULMBCS_AMBIGUOUS_MBCS)
   1006                         ? ULMBCS_GRP_LAST
   1007                         :  ULMBCS_GRP_TH);
   1008                if(group == ULMBCS_AMBIGUOUS_ALL)
   1009                {
   1010                    grp_start = ULMBCS_GRP_L1;
   1011                    grp_end = ULMBCS_GRP_LAST;
   1012                }
   1013                for (grp_ix = grp_start;
   1014                    grp_ix <= grp_end && !bytes_written;
   1015                     grp_ix++)
   1016                {
   1017                   if (extraInfo->OptGrpConverter [grp_ix] && !groups_tried [grp_ix])
   1018                   {
   1019                      bytes_written = (int32_t)LMBCSConversionWorker (extraInfo,
   1020                        grp_ix, pLMBCS, &uniChar,
   1021                        &lastConverterIndex, groups_tried);
   1022                   }
   1023                }
   1024                 /* a final conversion fallback to the exceptions group if its likely
   1025                      to be single byte  (Strategy 3E) */
   1026                if (!bytes_written && grp_start == ULMBCS_GRP_L1)
   1027                {
   1028                   bytes_written = (int32_t)LMBCSConversionWorker (extraInfo,
   1029                      ULMBCS_GRP_EXCEPT, pLMBCS, &uniChar,
   1030                      &lastConverterIndex, groups_tried);
   1031                }
   1032             }
   1033             /* all of our other strategies failed. Fallback to Unicode. (Strategy 4)*/
   1034             if (!bytes_written)
   1035             {
   1036 
   1037                pLMBCS += LMBCSConvertUni(pLMBCS, uniChar);
   1038                bytes_written = (int32_t)(pLMBCS - LMBCS);
   1039             }
   1040          }
   1041       }
   1042 
   1043       /* we have a translation. increment source and write as much as posible to target */
   1044       args->source++;
   1045       pLMBCS = LMBCS;
   1046       while (args->target < args->targetLimit && bytes_written--)
   1047       {
   1048          *(args->target)++ = *pLMBCS++;
   1049          if (args->offsets)
   1050          {
   1051             *(args->offsets)++ = sourceIndex;
   1052          }
   1053       }
   1054       sourceIndex++;
   1055       if (bytes_written > 0)
   1056       {
   1057          /* write any bytes that didn't fit in target to the error buffer,
   1058             common code will move this to target if we get called back with
   1059             enough target room
   1060          */
   1061          uint8_t * pErrorBuffer = args->converter->charErrorBuffer;
   1062          *err = U_BUFFER_OVERFLOW_ERROR;
   1063          args->converter->charErrorBufferLength = (int8_t)bytes_written;
   1064          while (bytes_written--)
   1065          {
   1066             *pErrorBuffer++ = *pLMBCS++;
   1067          }
   1068       }
   1069       /*Fix for SPR#DJOE66JFN3 (Lotus)*/
   1070       extraInfo->localeConverterIndex = OldConverterIndex;
   1071    }
   1072 }
   1073 
   1074 
   1075 /* Now, the Unicode from LMBCS section */
   1076 
   1077 
   1078 /* A function to call when we are looking at the Unicode group byte in LMBCS */
   1079 static UChar
   1080 GetUniFromLMBCSUni(char const ** ppLMBCSin)  /* Called with LMBCS-style Unicode byte stream */
   1081 {
   1082    uint8_t  HighCh = *(*ppLMBCSin)++;  /* Big-endian Unicode in LMBCS compatibility group*/
   1083    uint8_t  LowCh  = *(*ppLMBCSin)++;
   1084 
   1085    if (HighCh == ULMBCS_UNICOMPATZERO )
   1086    {
   1087       HighCh = LowCh;
   1088       LowCh = 0; /* zero-byte in LSB special character */
   1089    }
   1090    return (UChar)((HighCh << 8) | LowCh);
   1091 }
   1092 
   1093 
   1094 
   1095 /* CHECK_SOURCE_LIMIT: Helper macro to verify that there are at least'index'
   1096    bytes left in source up to  sourceLimit.Errors appropriately if not.
   1097    If we reach the limit, then update the source pointer to there to consume
   1098    all input as required by ICU converter semantics.
   1099 */
   1100 
   1101 #define CHECK_SOURCE_LIMIT(index) \
   1102      if (args->source+index > args->sourceLimit){\
   1103          *err = U_TRUNCATED_CHAR_FOUND;\
   1104          args->source = args->sourceLimit;\
   1105          return 0xffff;}
   1106 
   1107 /* Return the Unicode representation for the current LMBCS character */
   1108 
   1109 static UChar32
   1110 _LMBCSGetNextUCharWorker(UConverterToUnicodeArgs*   args,
   1111                          UErrorCode*   err)
   1112 {
   1113     UChar32 uniChar = 0;    /* an output UNICODE char */
   1114     ulmbcs_byte_t   CurByte; /* A byte from the input stream */
   1115 
   1116     /* error check */
   1117     if (args->source >= args->sourceLimit)
   1118     {
   1119         *err = U_ILLEGAL_ARGUMENT_ERROR;
   1120         return 0xffff;
   1121     }
   1122     /* Grab first byte & save address for error recovery */
   1123     CurByte = *((ulmbcs_byte_t  *) (args->source++));
   1124 
   1125     /*
   1126     * at entry of each if clause:
   1127     * 1. 'CurByte' points at the first byte of a LMBCS character
   1128     * 2. '*source'points to the next byte of the source stream after 'CurByte'
   1129     *
   1130     * the job of each if clause is:
   1131     * 1. set '*source' to point at the beginning of next char (nop if LMBCS char is only 1 byte)
   1132     * 2. set 'uniChar' up with the right Unicode value, or set 'err' appropriately
   1133     */
   1134 
   1135     /* First lets check the simple fixed values. */
   1136 
   1137     if(((CurByte > ULMBCS_C0END) && (CurByte < ULMBCS_C1START)) /* ascii range */
   1138     ||  (CurByte == 0)
   1139     ||  CurByte == ULMBCS_HT || CurByte == ULMBCS_CR
   1140     ||  CurByte == ULMBCS_LF || CurByte == ULMBCS_123SYSTEMRANGE)
   1141     {
   1142         uniChar = CurByte;
   1143     }
   1144     else
   1145     {
   1146         UConverterDataLMBCS * extraInfo;
   1147         ulmbcs_byte_t group;
   1148         UConverterSharedData *cnv;
   1149 
   1150         if (CurByte == ULMBCS_GRP_CTRL)  /* Control character group - no opt group update */
   1151         {
   1152             ulmbcs_byte_t  C0C1byte;
   1153             CHECK_SOURCE_LIMIT(1);
   1154             C0C1byte = *(args->source)++;
   1155             uniChar = (C0C1byte < ULMBCS_C1START) ? C0C1byte - ULMBCS_CTRLOFFSET : C0C1byte;
   1156         }
   1157         else
   1158         if (CurByte == ULMBCS_GRP_UNICODE) /* Unicode compatibility group: BigEndian UTF16 */
   1159         {
   1160             CHECK_SOURCE_LIMIT(2);
   1161 
   1162             /* don't check for error indicators fffe/ffff below */
   1163             return GetUniFromLMBCSUni(&(args->source));
   1164         }
   1165         else if (CurByte <= ULMBCS_CTRLOFFSET)
   1166         {
   1167             group = CurByte;                   /* group byte is in the source */
   1168             extraInfo = (UConverterDataLMBCS *) args->converter->extraInfo;
   1169             if (group > ULMBCS_GRP_LAST || (cnv = extraInfo->OptGrpConverter[group]) == NULL)
   1170             {
   1171                 /* this is not a valid group byte - no converter*/
   1172                 *err = U_INVALID_CHAR_FOUND;
   1173             }
   1174             else if (group >= ULMBCS_DOUBLEOPTGROUP_START)    /* double byte conversion */
   1175             {
   1176 
   1177                 CHECK_SOURCE_LIMIT(2);
   1178 
   1179                 /* check for LMBCS doubled-group-byte case */
   1180                 if (*args->source == group) {
   1181                     /* single byte */
   1182                     ++args->source;
   1183                     uniChar = ucnv_MBCSSimpleGetNextUChar(cnv, args->source, 1, FALSE);
   1184                     ++args->source;
   1185                 } else {
   1186                     /* double byte */
   1187                     uniChar = ucnv_MBCSSimpleGetNextUChar(cnv, args->source, 2, FALSE);
   1188                     args->source += 2;
   1189                 }
   1190             }
   1191             else {                                  /* single byte conversion */
   1192                 CHECK_SOURCE_LIMIT(1);
   1193                 CurByte = *(args->source)++;
   1194 
   1195                 if (CurByte >= ULMBCS_C1START)
   1196                 {
   1197                     uniChar = _MBCS_SINGLE_SIMPLE_GET_NEXT_BMP(cnv, CurByte);
   1198                 }
   1199                 else
   1200                 {
   1201                     /* The non-optimizable oddballs where there is an explicit byte
   1202                     * AND the second byte is not in the upper ascii range
   1203                     */
   1204                     char bytes[2];
   1205 
   1206                     extraInfo = (UConverterDataLMBCS *) args->converter->extraInfo;
   1207                     cnv = extraInfo->OptGrpConverter [ULMBCS_GRP_EXCEPT];
   1208 
   1209                     /* Lookup value must include opt group */
   1210                     bytes[0] = group;
   1211                     bytes[1] = CurByte;
   1212                     uniChar = ucnv_MBCSSimpleGetNextUChar(cnv, bytes, 2, FALSE);
   1213                 }
   1214             }
   1215         }
   1216         else if (CurByte >= ULMBCS_C1START) /* group byte is implicit */
   1217         {
   1218             extraInfo = (UConverterDataLMBCS *) args->converter->extraInfo;
   1219             group = extraInfo->OptGroup;
   1220             cnv = extraInfo->OptGrpConverter[group];
   1221             if (group >= ULMBCS_DOUBLEOPTGROUP_START)    /* double byte conversion */
   1222             {
   1223                 if (!ucnv_MBCSIsLeadByte(cnv, CurByte))
   1224                 {
   1225                     CHECK_SOURCE_LIMIT(0);
   1226 
   1227                     /* let the MBCS conversion consume CurByte again */
   1228                     uniChar = ucnv_MBCSSimpleGetNextUChar(cnv, args->source - 1, 1, FALSE);
   1229                 }
   1230                 else
   1231                 {
   1232                     CHECK_SOURCE_LIMIT(1);
   1233                     /* let the MBCS conversion consume CurByte again */
   1234                     uniChar = ucnv_MBCSSimpleGetNextUChar(cnv, args->source - 1, 2, FALSE);
   1235                     ++args->source;
   1236                 }
   1237             }
   1238             else                                   /* single byte conversion */
   1239             {
   1240                 uniChar = _MBCS_SINGLE_SIMPLE_GET_NEXT_BMP(cnv, CurByte);
   1241             }
   1242         }
   1243     }
   1244     return uniChar;
   1245 }
   1246 
   1247 
   1248 /* The exported function that converts lmbcs to one or more
   1249    UChars - currently UTF-16
   1250 */
   1251 static void
   1252 _LMBCSToUnicodeWithOffsets(UConverterToUnicodeArgs*    args,
   1253                      UErrorCode*    err)
   1254 {
   1255    char LMBCS [ULMBCS_CHARSIZE_MAX];
   1256    UChar uniChar;    /* one output UNICODE char */
   1257    const char * saveSource; /* beginning of current code point */
   1258    const char * pStartLMBCS = args->source;  /* beginning of whole string */
   1259    const char * errSource = NULL; /* pointer to actual input in case an error occurs */
   1260    int8_t savebytes = 0;
   1261 
   1262    /* Process from source to limit, or until error */
   1263    while (U_SUCCESS(*err) && args->sourceLimit > args->source && args->targetLimit > args->target)
   1264    {
   1265       saveSource = args->source; /* beginning of current code point */
   1266 
   1267       if (args->converter->toULength) /* reassemble char from previous call */
   1268       {
   1269         const char *saveSourceLimit;
   1270         size_t size_old = args->converter->toULength;
   1271 
   1272          /* limit from source is either remainder of temp buffer, or user limit on source */
   1273         size_t size_new_maybe_1 = sizeof(LMBCS) - size_old;
   1274         size_t size_new_maybe_2 = args->sourceLimit - args->source;
   1275         size_t size_new = (size_new_maybe_1 < size_new_maybe_2) ? size_new_maybe_1 : size_new_maybe_2;
   1276 
   1277 
   1278         uprv_memcpy(LMBCS, args->converter->toUBytes, size_old);
   1279         uprv_memcpy(LMBCS + size_old, args->source, size_new);
   1280         saveSourceLimit = args->sourceLimit;
   1281         args->source = errSource = LMBCS;
   1282         args->sourceLimit = LMBCS+size_old+size_new;
   1283         savebytes = (int8_t)(size_old+size_new);
   1284         uniChar = (UChar) _LMBCSGetNextUCharWorker(args, err);
   1285         args->source = saveSource + ((args->source - LMBCS) - size_old);
   1286         args->sourceLimit = saveSourceLimit;
   1287 
   1288         if (*err == U_TRUNCATED_CHAR_FOUND)
   1289         {
   1290             /* evil special case: source buffers so small a char spans more than 2 buffers */
   1291             args->converter->toULength = savebytes;
   1292             uprv_memcpy(args->converter->toUBytes, LMBCS, savebytes);
   1293             args->source = args->sourceLimit;
   1294             *err = U_ZERO_ERROR;
   1295             return;
   1296          }
   1297          else
   1298          {
   1299             /* clear the partial-char marker */
   1300             args->converter->toULength = 0;
   1301          }
   1302       }
   1303       else
   1304       {
   1305          errSource = saveSource;
   1306          uniChar = (UChar) _LMBCSGetNextUCharWorker(args, err);
   1307          savebytes = (int8_t)(args->source - saveSource);
   1308       }
   1309       if (U_SUCCESS(*err))
   1310       {
   1311          if (uniChar < 0xfffe)
   1312          {
   1313             *(args->target)++ = uniChar;
   1314             if(args->offsets)
   1315             {
   1316                *(args->offsets)++ = (int32_t)(saveSource - pStartLMBCS);
   1317             }
   1318          }
   1319          else if (uniChar == 0xfffe)
   1320          {
   1321             *err = U_INVALID_CHAR_FOUND;
   1322          }
   1323          else /* if (uniChar == 0xffff) */
   1324          {
   1325             *err = U_ILLEGAL_CHAR_FOUND;
   1326          }
   1327       }
   1328    }
   1329    /* if target ran out before source, return U_BUFFER_OVERFLOW_ERROR */
   1330    if (U_SUCCESS(*err) && args->sourceLimit > args->source && args->targetLimit <= args->target)
   1331    {
   1332       *err = U_BUFFER_OVERFLOW_ERROR;
   1333    }
   1334    else if (U_FAILURE(*err))
   1335    {
   1336       /* If character incomplete or unmappable/illegal, store it in toUBytes[] */
   1337       args->converter->toULength = savebytes;
   1338       if (savebytes > 0) {
   1339          uprv_memcpy(args->converter->toUBytes, errSource, savebytes);
   1340       }
   1341       if (*err == U_TRUNCATED_CHAR_FOUND) {
   1342          *err = U_ZERO_ERROR;
   1343       }
   1344    }
   1345 }
   1346 
   1347 /* And now, the macroized declarations of data & functions: */
   1348 DEFINE_LMBCS_OPEN(1)
   1349 DEFINE_LMBCS_OPEN(2)
   1350 DEFINE_LMBCS_OPEN(3)
   1351 DEFINE_LMBCS_OPEN(4)
   1352 DEFINE_LMBCS_OPEN(5)
   1353 DEFINE_LMBCS_OPEN(6)
   1354 DEFINE_LMBCS_OPEN(8)
   1355 DEFINE_LMBCS_OPEN(11)
   1356 DEFINE_LMBCS_OPEN(16)
   1357 DEFINE_LMBCS_OPEN(17)
   1358 DEFINE_LMBCS_OPEN(18)
   1359 DEFINE_LMBCS_OPEN(19)
   1360 
   1361 
   1362 DECLARE_LMBCS_DATA(1)
   1363 DECLARE_LMBCS_DATA(2)
   1364 DECLARE_LMBCS_DATA(3)
   1365 DECLARE_LMBCS_DATA(4)
   1366 DECLARE_LMBCS_DATA(5)
   1367 DECLARE_LMBCS_DATA(6)
   1368 DECLARE_LMBCS_DATA(8)
   1369 DECLARE_LMBCS_DATA(11)
   1370 DECLARE_LMBCS_DATA(16)
   1371 DECLARE_LMBCS_DATA(17)
   1372 DECLARE_LMBCS_DATA(18)
   1373 DECLARE_LMBCS_DATA(19)
   1374 
   1375 #endif /* #if !UCONFIG_NO_LEGACY_CONVERSION */
   1376