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      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) 2003-2012, International Business Machines
      7 *   Corporation and others.  All Rights Reserved.
      8 *
      9 *******************************************************************************
     10 *   file name:  ucmstate.c
     11 *   encoding:   UTF-8
     12 *   tab size:   8 (not used)
     13 *   indentation:4
     14 *
     15 *   created on: 2003oct09
     16 *   created by: Markus W. Scherer
     17 *
     18 *   This file handles ICU .ucm file state information as part of the ucm module.
     19 *   Most of this code used to be in makeconv.c.
     20 */
     21 
     22 #include "unicode/utypes.h"
     23 #include "cstring.h"
     24 #include "cmemory.h"
     25 #include "uarrsort.h"
     26 #include "ucnvmbcs.h"
     27 #include "ucnv_ext.h"
     28 #include "uparse.h"
     29 #include "ucm.h"
     30 #include <stdio.h>
     31 
     32 #if !UCONFIG_NO_CONVERSION
     33 
     34 /* MBCS state handling ------------------------------------------------------ */
     35 
     36 /*
     37  * state table row grammar (ebnf-style):
     38  * (whitespace is allowed between all tokens)
     39  *
     40  * row=[[firstentry ','] entry (',' entry)*]
     41  * firstentry="initial" | "surrogates"
     42  *            (initial state (default for state 0), output is all surrogate pairs)
     43  * entry=range [':' nextstate] ['.' action]
     44  * range=number ['-' number]
     45  * nextstate=number
     46  *           (0..7f)
     47  * action='u' | 's' | 'p' | 'i'
     48  *        (unassigned, state change only, surrogate pair, illegal)
     49  * number=(1- or 2-digit hexadecimal number)
     50  */
     51 static const char *
     52 parseState(const char *s, int32_t state[256], uint32_t *pFlags) {
     53     const char *t;
     54     uint32_t start, end, i;
     55     int32_t entry;
     56 
     57     /* initialize the state: all illegal with U+ffff */
     58     for(i=0; i<256; ++i) {
     59         state[i]=MBCS_ENTRY_FINAL(0, MBCS_STATE_ILLEGAL, 0xffff);
     60     }
     61 
     62     /* skip leading white space */
     63     s=u_skipWhitespace(s);
     64 
     65     /* is there an "initial" or "surrogates" directive? */
     66     if(uprv_strncmp("initial", s, 7)==0) {
     67         *pFlags=MBCS_STATE_FLAG_DIRECT;
     68         s=u_skipWhitespace(s+7);
     69         if(*s++!=',') {
     70             return s-1;
     71         }
     72     } else if(*pFlags==0 && uprv_strncmp("surrogates", s, 10)==0) {
     73         *pFlags=MBCS_STATE_FLAG_SURROGATES;
     74         s=u_skipWhitespace(s+10);
     75         if(*s++!=',') {
     76             return s-1;
     77         }
     78     } else if(*s==0) {
     79         /* empty state row: all-illegal */
     80         return NULL;
     81     }
     82 
     83     for(;;) {
     84         /* read an entry, the start of the range first */
     85         s=u_skipWhitespace(s);
     86         start=uprv_strtoul(s, (char **)&t, 16);
     87         if(s==t || 0xff<start) {
     88             return s;
     89         }
     90         s=u_skipWhitespace(t);
     91 
     92         /* read the end of the range if there is one */
     93         if(*s=='-') {
     94             s=u_skipWhitespace(s+1);
     95             end=uprv_strtoul(s, (char **)&t, 16);
     96             if(s==t || end<start || 0xff<end) {
     97                 return s;
     98             }
     99             s=u_skipWhitespace(t);
    100         } else {
    101             end=start;
    102         }
    103 
    104         /* determine the state entrys for this range */
    105         if(*s!=':' && *s!='.') {
    106             /* the default is: final state with valid entries */
    107             entry=MBCS_ENTRY_FINAL(0, MBCS_STATE_VALID_16, 0);
    108         } else {
    109             entry=MBCS_ENTRY_TRANSITION(0, 0);
    110             if(*s==':') {
    111                 /* get the next state, default to 0 */
    112                 s=u_skipWhitespace(s+1);
    113                 i=uprv_strtoul(s, (char **)&t, 16);
    114                 if(s!=t) {
    115                     if(0x7f<i) {
    116                         return s;
    117                     }
    118                     s=u_skipWhitespace(t);
    119                     entry=MBCS_ENTRY_SET_STATE(entry, i);
    120                 }
    121             }
    122 
    123             /* get the state action, default to valid */
    124             if(*s=='.') {
    125                 /* this is a final state */
    126                 entry=MBCS_ENTRY_SET_FINAL(entry);
    127 
    128                 s=u_skipWhitespace(s+1);
    129                 if(*s=='u') {
    130                     /* unassigned set U+fffe */
    131                     entry=MBCS_ENTRY_FINAL_SET_ACTION_VALUE(entry, MBCS_STATE_UNASSIGNED, 0xfffe);
    132                     s=u_skipWhitespace(s+1);
    133                 } else if(*s=='p') {
    134                     if(*pFlags!=MBCS_STATE_FLAG_DIRECT) {
    135                         entry=MBCS_ENTRY_FINAL_SET_ACTION(entry, MBCS_STATE_VALID_16_PAIR);
    136                     } else {
    137                         entry=MBCS_ENTRY_FINAL_SET_ACTION(entry, MBCS_STATE_VALID_16);
    138                     }
    139                     s=u_skipWhitespace(s+1);
    140                 } else if(*s=='s') {
    141                     entry=MBCS_ENTRY_FINAL_SET_ACTION(entry, MBCS_STATE_CHANGE_ONLY);
    142                     s=u_skipWhitespace(s+1);
    143                 } else if(*s=='i') {
    144                     /* illegal set U+ffff */
    145                     entry=MBCS_ENTRY_FINAL_SET_ACTION_VALUE(entry, MBCS_STATE_ILLEGAL, 0xffff);
    146                     s=u_skipWhitespace(s+1);
    147                 } else {
    148                     /* default to valid */
    149                     entry=MBCS_ENTRY_FINAL_SET_ACTION(entry, MBCS_STATE_VALID_16);
    150                 }
    151             } else {
    152                 /* this is an intermediate state, nothing to do */
    153             }
    154         }
    155 
    156         /* adjust "final valid" states according to the state flags */
    157         if(MBCS_ENTRY_FINAL_ACTION(entry)==MBCS_STATE_VALID_16) {
    158             switch(*pFlags) {
    159             case 0:
    160                 /* no adjustment */
    161                 break;
    162             case MBCS_STATE_FLAG_DIRECT:
    163                 /* set the valid-direct code point to "unassigned"==0xfffe */
    164                 entry=MBCS_ENTRY_FINAL_SET_ACTION_VALUE(entry, MBCS_STATE_VALID_DIRECT_16, 0xfffe);
    165                 break;
    166             case MBCS_STATE_FLAG_SURROGATES:
    167                 entry=MBCS_ENTRY_FINAL_SET_ACTION_VALUE(entry, MBCS_STATE_VALID_16_PAIR, 0);
    168                 break;
    169             default:
    170                 break;
    171             }
    172         }
    173 
    174         /* set this entry for the range */
    175         for(i=start; i<=end; ++i) {
    176             state[i]=entry;
    177         }
    178 
    179         if(*s==',') {
    180             ++s;
    181         } else {
    182             return *s==0 ? NULL : s;
    183         }
    184     }
    185 }
    186 
    187 U_CAPI void U_EXPORT2
    188 ucm_addState(UCMStates *states, const char *s) {
    189     const char *error;
    190 
    191     if(states->countStates==MBCS_MAX_STATE_COUNT) {
    192         fprintf(stderr, "ucm error: too many states (maximum %u)\n", MBCS_MAX_STATE_COUNT);
    193         exit(U_INVALID_TABLE_FORMAT);
    194     }
    195 
    196     error=parseState(s, states->stateTable[states->countStates],
    197                        &states->stateFlags[states->countStates]);
    198     if(error!=NULL) {
    199         fprintf(stderr, "ucm error: parse error in state definition at '%s'\n", error);
    200         exit(U_INVALID_TABLE_FORMAT);
    201     }
    202 
    203     ++states->countStates;
    204 }
    205 
    206 U_CAPI UBool U_EXPORT2
    207 ucm_parseHeaderLine(UCMFile *ucm,
    208                     char *line, char **pKey, char **pValue) {
    209     UCMStates *states;
    210     char *s, *end;
    211     char c;
    212 
    213     states=&ucm->states;
    214 
    215     /* remove comments and trailing CR and LF and remove whitespace from the end */
    216     for(end=line; (c=*end)!=0; ++end) {
    217         if(c=='#' || c=='\r' || c=='\n') {
    218             break;
    219         }
    220     }
    221     while(end>line && (*(end-1)==' ' || *(end-1)=='\t')) {
    222         --end;
    223     }
    224     *end=0;
    225 
    226     /* skip leading white space and ignore empty lines */
    227     s=(char *)u_skipWhitespace(line);
    228     if(*s==0) {
    229         return TRUE;
    230     }
    231 
    232     /* stop at the beginning of the mapping section */
    233     if(uprv_memcmp(s, "CHARMAP", 7)==0) {
    234         return FALSE;
    235     }
    236 
    237     /* get the key name, bracketed in <> */
    238     if(*s!='<') {
    239         fprintf(stderr, "ucm error: no header field <key> in line \"%s\"\n", line);
    240         exit(U_INVALID_TABLE_FORMAT);
    241     }
    242     *pKey=++s;
    243     while(*s!='>') {
    244         if(*s==0) {
    245             fprintf(stderr, "ucm error: incomplete header field <key> in line \"%s\"\n", line);
    246             exit(U_INVALID_TABLE_FORMAT);
    247         }
    248         ++s;
    249     }
    250     *s=0;
    251 
    252     /* get the value string, possibly quoted */
    253     s=(char *)u_skipWhitespace(s+1);
    254     if(*s!='"') {
    255         *pValue=s;
    256     } else {
    257         /* remove the quotes */
    258         *pValue=s+1;
    259         if(end>*pValue && *(end-1)=='"') {
    260             *--end=0;
    261         }
    262     }
    263 
    264     /* collect the information from the header field, ignore unknown keys */
    265     if(uprv_strcmp(*pKey, "uconv_class")==0) {
    266         if(uprv_strcmp(*pValue, "DBCS")==0) {
    267             states->conversionType=UCNV_DBCS;
    268         } else if(uprv_strcmp(*pValue, "SBCS")==0) {
    269             states->conversionType = UCNV_SBCS;
    270         } else if(uprv_strcmp(*pValue, "MBCS")==0) {
    271             states->conversionType = UCNV_MBCS;
    272         } else if(uprv_strcmp(*pValue, "EBCDIC_STATEFUL")==0) {
    273             states->conversionType = UCNV_EBCDIC_STATEFUL;
    274         } else {
    275             fprintf(stderr, "ucm error: unknown <uconv_class> %s\n", *pValue);
    276             exit(U_INVALID_TABLE_FORMAT);
    277         }
    278         return TRUE;
    279     } else if(uprv_strcmp(*pKey, "mb_cur_max")==0) {
    280         c=**pValue;
    281         if('1'<=c && c<='4' && (*pValue)[1]==0) {
    282             states->maxCharLength=(int8_t)(c-'0');
    283             states->outputType=(int8_t)(states->maxCharLength-1);
    284         } else {
    285             fprintf(stderr, "ucm error: illegal <mb_cur_max> %s\n", *pValue);
    286             exit(U_INVALID_TABLE_FORMAT);
    287         }
    288         return TRUE;
    289     } else if(uprv_strcmp(*pKey, "mb_cur_min")==0) {
    290         c=**pValue;
    291         if('1'<=c && c<='4' && (*pValue)[1]==0) {
    292             states->minCharLength=(int8_t)(c-'0');
    293         } else {
    294             fprintf(stderr, "ucm error: illegal <mb_cur_min> %s\n", *pValue);
    295             exit(U_INVALID_TABLE_FORMAT);
    296         }
    297         return TRUE;
    298     } else if(uprv_strcmp(*pKey, "icu:state")==0) {
    299         /* if an SBCS/DBCS/EBCDIC_STATEFUL converter has icu:state, then turn it into MBCS */
    300         switch(states->conversionType) {
    301         case UCNV_SBCS:
    302         case UCNV_DBCS:
    303         case UCNV_EBCDIC_STATEFUL:
    304             states->conversionType=UCNV_MBCS;
    305             break;
    306         case UCNV_MBCS:
    307             break;
    308         default:
    309             fprintf(stderr, "ucm error: <icu:state> entry for non-MBCS table or before the <uconv_class> line\n");
    310             exit(U_INVALID_TABLE_FORMAT);
    311         }
    312 
    313         if(states->maxCharLength==0) {
    314             fprintf(stderr, "ucm error: <icu:state> before the <mb_cur_max> line\n");
    315             exit(U_INVALID_TABLE_FORMAT);
    316         }
    317         ucm_addState(states, *pValue);
    318         return TRUE;
    319     } else if(uprv_strcmp(*pKey, "icu:base")==0) {
    320         if(**pValue==0) {
    321             fprintf(stderr, "ucm error: <icu:base> without a base table name\n");
    322             exit(U_INVALID_TABLE_FORMAT);
    323         }
    324         uprv_strcpy(ucm->baseName, *pValue);
    325         return TRUE;
    326     }
    327 
    328     return FALSE;
    329 }
    330 
    331 /* post-processing ---------------------------------------------------------- */
    332 
    333 static int32_t
    334 sumUpStates(UCMStates *states) {
    335     int32_t entry, sum, state, cell, count;
    336     UBool allStatesReady;
    337 
    338     /*
    339      * Sum up the offsets for all states.
    340      * In each final state (where there are only final entries),
    341      * the offsets add up directly.
    342      * In all other state table rows, for each transition entry to another state,
    343      * the offsets sum of that state needs to be added.
    344      * This is achieved in at most countStates iterations.
    345      */
    346     allStatesReady=FALSE;
    347     for(count=states->countStates; !allStatesReady && count>=0; --count) {
    348         allStatesReady=TRUE;
    349         for(state=states->countStates-1; state>=0; --state) {
    350             if(!(states->stateFlags[state]&MBCS_STATE_FLAG_READY)) {
    351                 allStatesReady=FALSE;
    352                 sum=0;
    353 
    354                 /* at first, add up only the final delta offsets to keep them <512 */
    355                 for(cell=0; cell<256; ++cell) {
    356                     entry=states->stateTable[state][cell];
    357                     if(MBCS_ENTRY_IS_FINAL(entry)) {
    358                         switch(MBCS_ENTRY_FINAL_ACTION(entry)) {
    359                         case MBCS_STATE_VALID_16:
    360                             states->stateTable[state][cell]=MBCS_ENTRY_FINAL_SET_VALUE(entry, sum);
    361                             sum+=1;
    362                             break;
    363                         case MBCS_STATE_VALID_16_PAIR:
    364                             states->stateTable[state][cell]=MBCS_ENTRY_FINAL_SET_VALUE(entry, sum);
    365                             sum+=2;
    366                             break;
    367                         default:
    368                             /* no addition */
    369                             break;
    370                         }
    371                     }
    372                 }
    373 
    374                 /* now, add up the delta offsets for the transitional entries */
    375                 for(cell=0; cell<256; ++cell) {
    376                     entry=states->stateTable[state][cell];
    377                     if(MBCS_ENTRY_IS_TRANSITION(entry)) {
    378                         if(states->stateFlags[MBCS_ENTRY_TRANSITION_STATE(entry)]&MBCS_STATE_FLAG_READY) {
    379                             states->stateTable[state][cell]=MBCS_ENTRY_TRANSITION_SET_OFFSET(entry, sum);
    380                             sum+=states->stateOffsetSum[MBCS_ENTRY_TRANSITION_STATE(entry)];
    381                         } else {
    382                             /* that next state does not have a sum yet, we cannot finish the one for this state */
    383                             sum=-1;
    384                             break;
    385                         }
    386                     }
    387                 }
    388 
    389                 if(sum!=-1) {
    390                     states->stateOffsetSum[state]=sum;
    391                     states->stateFlags[state]|=MBCS_STATE_FLAG_READY;
    392                 }
    393             }
    394         }
    395     }
    396 
    397     if(!allStatesReady) {
    398         fprintf(stderr, "ucm error: the state table contains loops\n");
    399         exit(U_INVALID_TABLE_FORMAT);
    400     }
    401 
    402     /*
    403      * For all "direct" (i.e., initial) states>0,
    404      * the offsets need to be increased by the sum of
    405      * the previous initial states.
    406      */
    407     sum=states->stateOffsetSum[0];
    408     for(state=1; state<states->countStates; ++state) {
    409         if((states->stateFlags[state]&0xf)==MBCS_STATE_FLAG_DIRECT) {
    410             int32_t sum2=sum;
    411             sum+=states->stateOffsetSum[state];
    412             for(cell=0; cell<256; ++cell) {
    413                 entry=states->stateTable[state][cell];
    414                 if(MBCS_ENTRY_IS_TRANSITION(entry)) {
    415                     states->stateTable[state][cell]=MBCS_ENTRY_TRANSITION_ADD_OFFSET(entry, sum2);
    416                 }
    417             }
    418         }
    419     }
    420 
    421     /* round up to the next even number to have the following data 32-bit-aligned */
    422     return states->countToUCodeUnits=(sum+1)&~1;
    423 }
    424 
    425 U_CAPI void U_EXPORT2
    426 ucm_processStates(UCMStates *states, UBool ignoreSISOCheck) {
    427     int32_t entry, state, cell, count;
    428 
    429     if(states->conversionType==UCNV_UNSUPPORTED_CONVERTER) {
    430         fprintf(stderr, "ucm error: missing conversion type (<uconv_class>)\n");
    431         exit(U_INVALID_TABLE_FORMAT);
    432     }
    433 
    434     if(states->countStates==0) {
    435         switch(states->conversionType) {
    436         case UCNV_SBCS:
    437             /* SBCS: use MBCS data structure with a default state table */
    438             if(states->maxCharLength!=1) {
    439                 fprintf(stderr, "error: SBCS codepage with max B/char!=1\n");
    440                 exit(U_INVALID_TABLE_FORMAT);
    441             }
    442             states->conversionType=UCNV_MBCS;
    443             ucm_addState(states, "0-ff");
    444             break;
    445         case UCNV_MBCS:
    446             fprintf(stderr, "ucm error: missing state table information (<icu:state>) for MBCS\n");
    447             exit(U_INVALID_TABLE_FORMAT);
    448             break;
    449         case UCNV_EBCDIC_STATEFUL:
    450             /* EBCDIC_STATEFUL: use MBCS data structure with a default state table */
    451             if(states->minCharLength!=1 || states->maxCharLength!=2) {
    452                 fprintf(stderr, "error: DBCS codepage with min B/char!=1 or max B/char!=2\n");
    453                 exit(U_INVALID_TABLE_FORMAT);
    454             }
    455             states->conversionType=UCNV_MBCS;
    456             ucm_addState(states, "0-ff, e:1.s, f:0.s");
    457             ucm_addState(states, "initial, 0-3f:4, e:1.s, f:0.s, 40:3, 41-fe:2, ff:4");
    458             ucm_addState(states, "0-40:1.i, 41-fe:1., ff:1.i");
    459             ucm_addState(states, "0-ff:1.i, 40:1.");
    460             ucm_addState(states, "0-ff:1.i");
    461             break;
    462         case UCNV_DBCS:
    463             /* DBCS: use MBCS data structure with a default state table */
    464             if(states->minCharLength!=2 || states->maxCharLength!=2) {
    465                 fprintf(stderr, "error: DBCS codepage with min or max B/char!=2\n");
    466                 exit(U_INVALID_TABLE_FORMAT);
    467             }
    468             states->conversionType = UCNV_MBCS;
    469             ucm_addState(states, "0-3f:3, 40:2, 41-fe:1, ff:3");
    470             ucm_addState(states, "41-fe");
    471             ucm_addState(states, "40");
    472             ucm_addState(states, "");
    473             break;
    474         default:
    475             fprintf(stderr, "ucm error: unknown charset structure\n");
    476             exit(U_INVALID_TABLE_FORMAT);
    477             break;
    478         }
    479     }
    480 
    481     /*
    482      * check that the min/max character lengths are reasonable;
    483      * to do this right, all paths through the state table would have to be
    484      * recursively walked while keeping track of the sequence lengths,
    485      * but these simple checks cover most state tables in practice
    486      */
    487     if(states->maxCharLength<states->minCharLength) {
    488         fprintf(stderr, "ucm error: max B/char < min B/char\n");
    489         exit(U_INVALID_TABLE_FORMAT);
    490     }
    491 
    492     /* count non-direct states and compare with max B/char */
    493     count=0;
    494     for(state=0; state<states->countStates; ++state) {
    495         if((states->stateFlags[state]&0xf)!=MBCS_STATE_FLAG_DIRECT) {
    496             ++count;
    497         }
    498     }
    499     if(states->maxCharLength>count+1) {
    500         fprintf(stderr, "ucm error: max B/char too large\n");
    501         exit(U_INVALID_TABLE_FORMAT);
    502     }
    503 
    504     if(states->minCharLength==1) {
    505         int32_t action;
    506 
    507         /*
    508          * if there are single-byte characters,
    509          * then the initial state must have direct result states
    510          */
    511         for(cell=0; cell<256; ++cell) {
    512             entry=states->stateTable[0][cell];
    513             if( MBCS_ENTRY_IS_FINAL(entry) &&
    514                 ((action=MBCS_ENTRY_FINAL_ACTION(entry))==MBCS_STATE_VALID_DIRECT_16 ||
    515                  action==MBCS_STATE_UNASSIGNED)
    516             ) {
    517                 break;
    518             }
    519         }
    520 
    521         if(cell==256) {
    522             fprintf(stderr, "ucm warning: min B/char too small\n");
    523         }
    524     }
    525 
    526     /*
    527      * make sure that all "next state" values are within limits
    528      * and that all next states after final ones have the "direct"
    529      * flag of initial states
    530      */
    531     for(state=states->countStates-1; state>=0; --state) {
    532         for(cell=0; cell<256; ++cell) {
    533             entry=states->stateTable[state][cell];
    534             if((uint8_t)MBCS_ENTRY_STATE(entry)>=states->countStates) {
    535                 fprintf(stderr, "ucm error: state table entry [%x][%x] has a next state of %x that is too high\n",
    536                     (int)state, (int)cell, (int)MBCS_ENTRY_STATE(entry));
    537                 exit(U_INVALID_TABLE_FORMAT);
    538             }
    539             if(MBCS_ENTRY_IS_FINAL(entry) && (states->stateFlags[MBCS_ENTRY_STATE(entry)]&0xf)!=MBCS_STATE_FLAG_DIRECT) {
    540                 fprintf(stderr, "ucm error: state table entry [%x][%x] is final but has a non-initial next state of %x\n",
    541                     (int)state, (int)cell, (int)MBCS_ENTRY_STATE(entry));
    542                 exit(U_INVALID_TABLE_FORMAT);
    543             } else if(MBCS_ENTRY_IS_TRANSITION(entry) && (states->stateFlags[MBCS_ENTRY_STATE(entry)]&0xf)==MBCS_STATE_FLAG_DIRECT) {
    544                 fprintf(stderr, "ucm error: state table entry [%x][%x] is not final but has an initial next state of %x\n",
    545                     (int)state, (int)cell, (int)MBCS_ENTRY_STATE(entry));
    546                 exit(U_INVALID_TABLE_FORMAT);
    547             }
    548         }
    549     }
    550 
    551     /* is this an SI/SO (like EBCDIC-stateful) state table? */
    552     if(states->countStates>=2 && (states->stateFlags[1]&0xf)==MBCS_STATE_FLAG_DIRECT) {
    553         if(states->maxCharLength!=2) {
    554             fprintf(stderr, "ucm error: SI/SO codepages must have max 2 bytes/char (not %x)\n", (int)states->maxCharLength);
    555             exit(U_INVALID_TABLE_FORMAT);
    556         }
    557         if(states->countStates<3) {
    558             fprintf(stderr, "ucm error: SI/SO codepages must have at least 3 states (not %x)\n", (int)states->countStates);
    559             exit(U_INVALID_TABLE_FORMAT);
    560         }
    561         /* are the SI/SO all in the right places? */
    562         if( ignoreSISOCheck ||
    563            (states->stateTable[0][0xe]==MBCS_ENTRY_FINAL(1, MBCS_STATE_CHANGE_ONLY, 0) &&
    564             states->stateTable[0][0xf]==MBCS_ENTRY_FINAL(0, MBCS_STATE_CHANGE_ONLY, 0) &&
    565             states->stateTable[1][0xe]==MBCS_ENTRY_FINAL(1, MBCS_STATE_CHANGE_ONLY, 0) &&
    566             states->stateTable[1][0xf]==MBCS_ENTRY_FINAL(0, MBCS_STATE_CHANGE_ONLY, 0))
    567         ) {
    568             states->outputType=MBCS_OUTPUT_2_SISO;
    569         } else {
    570             fprintf(stderr, "ucm error: SI/SO codepages must have in states 0 and 1 transitions e:1.s, f:0.s\n");
    571             exit(U_INVALID_TABLE_FORMAT);
    572         }
    573         state=2;
    574     } else {
    575         state=1;
    576     }
    577 
    578     /* check that no unexpected state is a "direct" one */
    579     while(state<states->countStates) {
    580         if((states->stateFlags[state]&0xf)==MBCS_STATE_FLAG_DIRECT) {
    581             fprintf(stderr, "ucm error: state %d is 'initial' - not supported except for SI/SO codepages\n", (int)state);
    582             exit(U_INVALID_TABLE_FORMAT);
    583         }
    584         ++state;
    585     }
    586 
    587     sumUpStates(states);
    588 }
    589 
    590 /* find a fallback for this offset; return the index or -1 if not found */
    591 U_CAPI int32_t U_EXPORT2
    592 ucm_findFallback(_MBCSToUFallback *toUFallbacks, int32_t countToUFallbacks,
    593                  uint32_t offset) {
    594     int32_t i;
    595 
    596     if(countToUFallbacks==0) {
    597         /* shortcut: most codepages do not have fallbacks from codepage to Unicode */
    598         return -1;
    599     }
    600 
    601     /* do a linear search for the fallback mapping (the table is not yet sorted) */
    602     for(i=0; i<countToUFallbacks; ++i) {
    603         if(offset==toUFallbacks[i].offset) {
    604             return i;
    605         }
    606     }
    607     return -1;
    608 }
    609 
    610 /*
    611  * This function tries to compact toUnicode tables for 2-byte codepages
    612  * by finding lead bytes with all-unassigned trail bytes and adding another state
    613  * for them.
    614  */
    615 static void
    616 compactToUnicode2(UCMStates *states,
    617                   uint16_t **pUnicodeCodeUnits,
    618                   _MBCSToUFallback *toUFallbacks, int32_t countToUFallbacks,
    619                   UBool verbose) {
    620     int32_t (*oldStateTable)[256];
    621     uint16_t count[256];
    622     uint16_t *oldUnicodeCodeUnits;
    623     int32_t entry, offset, oldOffset, trailOffset, oldTrailOffset, savings, sum;
    624     int32_t i, j, leadState, trailState, newState, fallback;
    625     uint16_t unit;
    626 
    627     /* find the lead state */
    628     if(states->outputType==MBCS_OUTPUT_2_SISO) {
    629         /* use the DBCS lead state for SI/SO codepages */
    630         leadState=1;
    631     } else {
    632         leadState=0;
    633     }
    634 
    635     /* find the main trail state: the most used target state */
    636     uprv_memset(count, 0, sizeof(count));
    637     for(i=0; i<256; ++i) {
    638         entry=states->stateTable[leadState][i];
    639         if(MBCS_ENTRY_IS_TRANSITION(entry)) {
    640             ++count[MBCS_ENTRY_TRANSITION_STATE(entry)];
    641         }
    642     }
    643     trailState=0;
    644     for(i=1; i<states->countStates; ++i) {
    645         if(count[i]>count[trailState]) {
    646             trailState=i;
    647         }
    648     }
    649 
    650     /* count possible savings from lead bytes with all-unassigned results in all trail bytes */
    651     uprv_memset(count, 0, sizeof(count));
    652     savings=0;
    653     /* for each lead byte */
    654     for(i=0; i<256; ++i) {
    655         entry=states->stateTable[leadState][i];
    656         if(MBCS_ENTRY_IS_TRANSITION(entry) && (MBCS_ENTRY_TRANSITION_STATE(entry))==trailState) {
    657             /* the offset is different for each lead byte */
    658             offset=MBCS_ENTRY_TRANSITION_OFFSET(entry);
    659             /* for each trail byte for this lead byte */
    660             for(j=0; j<256; ++j) {
    661                 entry=states->stateTable[trailState][j];
    662                 switch(MBCS_ENTRY_FINAL_ACTION(entry)) {
    663                 case MBCS_STATE_VALID_16:
    664                     entry=offset+MBCS_ENTRY_FINAL_VALUE_16(entry);
    665                     if((*pUnicodeCodeUnits)[entry]==0xfffe && ucm_findFallback(toUFallbacks, countToUFallbacks, entry)<0) {
    666                         ++count[i];
    667                     } else {
    668                         j=999; /* do not count for this lead byte because there are assignments */
    669                     }
    670                     break;
    671                 case MBCS_STATE_VALID_16_PAIR:
    672                     entry=offset+MBCS_ENTRY_FINAL_VALUE_16(entry);
    673                     if((*pUnicodeCodeUnits)[entry]==0xfffe) {
    674                         count[i]+=2;
    675                     } else {
    676                         j=999; /* do not count for this lead byte because there are assignments */
    677                     }
    678                     break;
    679                 default:
    680                     break;
    681                 }
    682             }
    683             if(j==256) {
    684                 /* all trail bytes for this lead byte are unassigned */
    685                 savings+=count[i];
    686             } else {
    687                 count[i]=0;
    688             }
    689         }
    690     }
    691     /* subtract from the possible savings the cost of an additional state */
    692     savings=savings*2-1024; /* count bytes, not 16-bit words */
    693     if(savings<=0) {
    694         return;
    695     }
    696     if(verbose) {
    697         printf("compacting toUnicode data saves %ld bytes\n", (long)savings);
    698     }
    699     if(states->countStates>=MBCS_MAX_STATE_COUNT) {
    700         fprintf(stderr, "cannot compact toUnicode because the maximum number of states is reached\n");
    701         return;
    702     }
    703 
    704     /* make a copy of the state table */
    705     oldStateTable=(int32_t (*)[256])uprv_malloc(states->countStates*1024);
    706     if(oldStateTable==NULL) {
    707         fprintf(stderr, "cannot compact toUnicode: out of memory\n");
    708         return;
    709     }
    710     uprv_memcpy(oldStateTable, states->stateTable, states->countStates*1024);
    711 
    712     /* add the new state */
    713     /*
    714      * this function does not catch the degenerate case where all lead bytes
    715      * have all-unassigned trail bytes and the lead state could be removed
    716      */
    717     newState=states->countStates++;
    718     states->stateFlags[newState]=0;
    719     /* copy the old trail state, turning all assigned states into unassigned ones */
    720     for(i=0; i<256; ++i) {
    721         entry=states->stateTable[trailState][i];
    722         switch(MBCS_ENTRY_FINAL_ACTION(entry)) {
    723         case MBCS_STATE_VALID_16:
    724         case MBCS_STATE_VALID_16_PAIR:
    725             states->stateTable[newState][i]=MBCS_ENTRY_FINAL_SET_ACTION_VALUE(entry, MBCS_STATE_UNASSIGNED, 0xfffe);
    726             break;
    727         default:
    728             states->stateTable[newState][i]=entry;
    729             break;
    730         }
    731     }
    732 
    733     /* in the lead state, redirect all lead bytes with all-unassigned trail bytes to the new state */
    734     for(i=0; i<256; ++i) {
    735         if(count[i]>0) {
    736             states->stateTable[leadState][i]=MBCS_ENTRY_SET_STATE(states->stateTable[leadState][i], newState);
    737         }
    738     }
    739 
    740     /* sum up the new state table */
    741     for(i=0; i<states->countStates; ++i) {
    742         states->stateFlags[i]&=~MBCS_STATE_FLAG_READY;
    743     }
    744     sum=sumUpStates(states);
    745 
    746     /* allocate a new, smaller code units array */
    747     oldUnicodeCodeUnits=*pUnicodeCodeUnits;
    748     if(sum==0) {
    749         *pUnicodeCodeUnits=NULL;
    750         if(oldUnicodeCodeUnits!=NULL) {
    751             uprv_free(oldUnicodeCodeUnits);
    752         }
    753         uprv_free(oldStateTable);
    754         return;
    755     }
    756     *pUnicodeCodeUnits=(uint16_t *)uprv_malloc(sum*sizeof(uint16_t));
    757     if(*pUnicodeCodeUnits==NULL) {
    758         fprintf(stderr, "cannot compact toUnicode: out of memory allocating %ld 16-bit code units\n",
    759             (long)sum);
    760         /* revert to the old state table */
    761         *pUnicodeCodeUnits=oldUnicodeCodeUnits;
    762         --states->countStates;
    763         uprv_memcpy(states->stateTable, oldStateTable, states->countStates*1024);
    764         uprv_free(oldStateTable);
    765         return;
    766     }
    767     for(i=0; i<sum; ++i) {
    768         (*pUnicodeCodeUnits)[i]=0xfffe;
    769     }
    770 
    771     /* copy the code units for all assigned characters */
    772     /*
    773      * The old state table has the same lead _and_ trail states for assigned characters!
    774      * The differences are in the offsets, and in the trail states for some unassigned characters.
    775      * For each character with an assigned state in the new table, it was assigned in the old one.
    776      * Only still-assigned characters are copied.
    777      * Note that fallback mappings need to get their offset values adjusted.
    778      */
    779 
    780     /* for each initial state */
    781     for(leadState=0; leadState<states->countStates; ++leadState) {
    782         if((states->stateFlags[leadState]&0xf)==MBCS_STATE_FLAG_DIRECT) {
    783             /* for each lead byte from there */
    784             for(i=0; i<256; ++i) {
    785                 entry=states->stateTable[leadState][i];
    786                 if(MBCS_ENTRY_IS_TRANSITION(entry)) {
    787                     trailState=(uint8_t)MBCS_ENTRY_TRANSITION_STATE(entry);
    788                     /* the new state does not have assigned states */
    789                     if(trailState!=newState) {
    790                         trailOffset=MBCS_ENTRY_TRANSITION_OFFSET(entry);
    791                         oldTrailOffset=MBCS_ENTRY_TRANSITION_OFFSET(oldStateTable[leadState][i]);
    792                         /* for each trail byte */
    793                         for(j=0; j<256; ++j) {
    794                             entry=states->stateTable[trailState][j];
    795                             /* copy assigned-character code units and adjust fallback offsets */
    796                             switch(MBCS_ENTRY_FINAL_ACTION(entry)) {
    797                             case MBCS_STATE_VALID_16:
    798                                 offset=trailOffset+MBCS_ENTRY_FINAL_VALUE_16(entry);
    799                                 /* find the old offset according to the old state table */
    800                                 oldOffset=oldTrailOffset+MBCS_ENTRY_FINAL_VALUE_16(oldStateTable[trailState][j]);
    801                                 unit=(*pUnicodeCodeUnits)[offset]=oldUnicodeCodeUnits[oldOffset];
    802                                 if(unit==0xfffe && (fallback=ucm_findFallback(toUFallbacks, countToUFallbacks, oldOffset))>=0) {
    803                                     toUFallbacks[fallback].offset=0x80000000|offset;
    804                                 }
    805                                 break;
    806                             case MBCS_STATE_VALID_16_PAIR:
    807                                 offset=trailOffset+MBCS_ENTRY_FINAL_VALUE_16(entry);
    808                                 /* find the old offset according to the old state table */
    809                                 oldOffset=oldTrailOffset+MBCS_ENTRY_FINAL_VALUE_16(oldStateTable[trailState][j]);
    810                                 (*pUnicodeCodeUnits)[offset++]=oldUnicodeCodeUnits[oldOffset++];
    811                                 (*pUnicodeCodeUnits)[offset]=oldUnicodeCodeUnits[oldOffset];
    812                                 break;
    813                             default:
    814                                 break;
    815                             }
    816                         }
    817                     }
    818                 }
    819             }
    820         }
    821     }
    822 
    823     /* remove temporary flags from fallback offsets that protected them from being modified twice */
    824     for(i=0; i<countToUFallbacks; ++i) {
    825         toUFallbacks[i].offset&=0x7fffffff;
    826     }
    827 
    828     /* free temporary memory */
    829     uprv_free(oldUnicodeCodeUnits);
    830     uprv_free(oldStateTable);
    831 }
    832 
    833 /*
    834  * recursive sub-function of compactToUnicodeHelper()
    835  * returns:
    836  * >0 number of bytes that are used in unicodeCodeUnits[] that could be saved,
    837  *    if all sequences from this state are unassigned, returns the
    838  * <0 there are assignments in unicodeCodeUnits[]
    839  * 0  no use of unicodeCodeUnits[]
    840  */
    841 static int32_t
    842 findUnassigned(UCMStates *states,
    843                uint16_t *unicodeCodeUnits,
    844                _MBCSToUFallback *toUFallbacks, int32_t countToUFallbacks,
    845                int32_t state, int32_t offset, uint32_t b) {
    846     int32_t i, entry, savings, localSavings, belowSavings;
    847     UBool haveAssigned;
    848 
    849     localSavings=belowSavings=0;
    850     haveAssigned=FALSE;
    851     for(i=0; i<256; ++i) {
    852         entry=states->stateTable[state][i];
    853         if(MBCS_ENTRY_IS_TRANSITION(entry)) {
    854             savings=findUnassigned(states,
    855                         unicodeCodeUnits,
    856                         toUFallbacks, countToUFallbacks,
    857                         MBCS_ENTRY_TRANSITION_STATE(entry),
    858                         offset+MBCS_ENTRY_TRANSITION_OFFSET(entry),
    859                         (b<<8)|(uint32_t)i);
    860             if(savings<0) {
    861                 haveAssigned=TRUE;
    862             } else if(savings>0) {
    863                 printf("    all-unassigned sequences from prefix 0x%02lx state %ld use %ld bytes\n",
    864                     (unsigned long)((b<<8)|i), (long)state, (long)savings);
    865                 belowSavings+=savings;
    866             }
    867         } else if(!haveAssigned) {
    868             switch(MBCS_ENTRY_FINAL_ACTION(entry)) {
    869             case MBCS_STATE_VALID_16:
    870                 entry=offset+MBCS_ENTRY_FINAL_VALUE_16(entry);
    871                 if(unicodeCodeUnits[entry]==0xfffe && ucm_findFallback(toUFallbacks, countToUFallbacks, entry)<0) {
    872                     localSavings+=2;
    873                 } else {
    874                     haveAssigned=TRUE;
    875                 }
    876                 break;
    877             case MBCS_STATE_VALID_16_PAIR:
    878                 entry=offset+MBCS_ENTRY_FINAL_VALUE_16(entry);
    879                 if(unicodeCodeUnits[entry]==0xfffe) {
    880                     localSavings+=4;
    881                 } else {
    882                     haveAssigned=TRUE;
    883                 }
    884                 break;
    885             default:
    886                 break;
    887             }
    888         }
    889     }
    890     if(haveAssigned) {
    891         return -1;
    892     } else {
    893         return localSavings+belowSavings;
    894     }
    895 }
    896 
    897 /* helper function for finding compaction opportunities */
    898 static void
    899 compactToUnicodeHelper(UCMStates *states,
    900                        uint16_t *unicodeCodeUnits,
    901                        _MBCSToUFallback *toUFallbacks, int32_t countToUFallbacks) {
    902     int32_t state, savings;
    903 
    904     /* for each initial state */
    905     for(state=0; state<states->countStates; ++state) {
    906         if((states->stateFlags[state]&0xf)==MBCS_STATE_FLAG_DIRECT) {
    907             savings=findUnassigned(states,
    908                         unicodeCodeUnits,
    909                         toUFallbacks, countToUFallbacks,
    910                         state, 0, 0);
    911             if(savings>0) {
    912                 printf("    all-unassigned sequences from initial state %ld use %ld bytes\n",
    913                     (long)state, (long)savings);
    914             }
    915         }
    916     }
    917 }
    918 
    919 U_CDECL_BEGIN
    920 static int32_t U_CALLCONV
    921 compareFallbacks(const void *context, const void *fb1, const void *fb2) {
    922     (void)context;
    923     return ((const _MBCSToUFallback *)fb1)->offset-((const _MBCSToUFallback *)fb2)->offset;
    924 }
    925 U_CDECL_END
    926 
    927 U_CAPI void U_EXPORT2
    928 ucm_optimizeStates(UCMStates *states,
    929                    uint16_t **pUnicodeCodeUnits,
    930                    _MBCSToUFallback *toUFallbacks, int32_t countToUFallbacks,
    931                    UBool verbose) {
    932     UErrorCode errorCode;
    933     int32_t state, cell, entry;
    934 
    935     /* test each state table entry */
    936     for(state=0; state<states->countStates; ++state) {
    937         for(cell=0; cell<256; ++cell) {
    938             entry=states->stateTable[state][cell];
    939             /*
    940              * if the entry is a final one with an MBCS_STATE_VALID_DIRECT_16 action code
    941              * and the code point is "unassigned" (0xfffe), then change it to
    942              * the "unassigned" action code with bits 26..23 set to zero and U+fffe.
    943              */
    944             if(MBCS_ENTRY_SET_STATE(entry, 0)==MBCS_ENTRY_FINAL(0, MBCS_STATE_VALID_DIRECT_16, 0xfffe)) {
    945                 states->stateTable[state][cell]=MBCS_ENTRY_FINAL_SET_ACTION(entry, MBCS_STATE_UNASSIGNED);
    946             }
    947         }
    948     }
    949 
    950     /* try to compact the toUnicode tables */
    951     if(states->maxCharLength==2) {
    952         compactToUnicode2(states, pUnicodeCodeUnits, toUFallbacks, countToUFallbacks, verbose);
    953     } else if(states->maxCharLength>2) {
    954         if(verbose) {
    955             compactToUnicodeHelper(states, *pUnicodeCodeUnits, toUFallbacks, countToUFallbacks);
    956         }
    957     }
    958 
    959     /* sort toUFallbacks */
    960     /*
    961      * It should be safe to sort them before compactToUnicode2() is called,
    962      * because it should not change the relative order of the offset values
    963      * that it adjusts, but they need to be sorted at some point, and
    964      * it is safest here.
    965      */
    966     if(countToUFallbacks>0) {
    967         errorCode=U_ZERO_ERROR; /* nothing bad will happen... */
    968         uprv_sortArray(toUFallbacks, countToUFallbacks,
    969                        sizeof(_MBCSToUFallback),
    970                        compareFallbacks, NULL, FALSE, &errorCode);
    971     }
    972 }
    973 
    974 /* use a complete state table ----------------------------------------------- */
    975 
    976 U_CAPI int32_t U_EXPORT2
    977 ucm_countChars(UCMStates *states,
    978                const uint8_t *bytes, int32_t length) {
    979     uint32_t offset;
    980     int32_t i, entry, count;
    981     uint8_t state;
    982 
    983     offset=0;
    984     count=0;
    985     state=0;
    986 
    987     if(states->countStates==0) {
    988         fprintf(stderr, "ucm error: there is no state information!\n");
    989         return -1;
    990     }
    991 
    992     /* for SI/SO (like EBCDIC-stateful), double-byte sequences start in state 1 */
    993     if(length==2 && states->outputType==MBCS_OUTPUT_2_SISO) {
    994         state=1;
    995     }
    996 
    997     /*
    998      * Walk down the state table like in conversion,
    999      * much like getNextUChar().
   1000      * We assume that c<=0x10ffff.
   1001      */
   1002     for(i=0; i<length; ++i) {
   1003         entry=states->stateTable[state][bytes[i]];
   1004         if(MBCS_ENTRY_IS_TRANSITION(entry)) {
   1005             state=(uint8_t)MBCS_ENTRY_TRANSITION_STATE(entry);
   1006             offset+=MBCS_ENTRY_TRANSITION_OFFSET(entry);
   1007         } else {
   1008             switch(MBCS_ENTRY_FINAL_ACTION(entry)) {
   1009             case MBCS_STATE_ILLEGAL:
   1010                 fprintf(stderr, "ucm error: byte sequence ends in illegal state\n");
   1011                 return -1;
   1012             case MBCS_STATE_CHANGE_ONLY:
   1013                 fprintf(stderr, "ucm error: byte sequence ends in state-change-only\n");
   1014                 return -1;
   1015             case MBCS_STATE_UNASSIGNED:
   1016             case MBCS_STATE_FALLBACK_DIRECT_16:
   1017             case MBCS_STATE_VALID_DIRECT_16:
   1018             case MBCS_STATE_FALLBACK_DIRECT_20:
   1019             case MBCS_STATE_VALID_DIRECT_20:
   1020             case MBCS_STATE_VALID_16:
   1021             case MBCS_STATE_VALID_16_PAIR:
   1022                 /* count a complete character and prepare for a new one */
   1023                 ++count;
   1024                 state=(uint8_t)MBCS_ENTRY_FINAL_STATE(entry);
   1025                 offset=0;
   1026                 break;
   1027             default:
   1028                 /* reserved, must never occur */
   1029                 fprintf(stderr, "ucm error: byte sequence reached reserved action code, entry: 0x%02lx\n", (unsigned long)entry);
   1030                 return -1;
   1031             }
   1032         }
   1033     }
   1034 
   1035     if(offset!=0) {
   1036         fprintf(stderr, "ucm error: byte sequence too short, ends in non-final state %u\n", state);
   1037         return -1;
   1038     }
   1039 
   1040     /*
   1041      * for SI/SO (like EBCDIC-stateful), multiple-character results
   1042      * must consist of only double-byte sequences
   1043      */
   1044     if(count>1 && states->outputType==MBCS_OUTPUT_2_SISO && length!=2*count) {
   1045         fprintf(stderr, "ucm error: SI/SO (like EBCDIC-stateful) result with %d characters does not contain all DBCS\n", (int)count);
   1046         return -1;
   1047     }
   1048 
   1049     return count;
   1050 }
   1051 #endif
   1052 
   1053