icuSources/common/ubidiimp.h

   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) 1999-2016, International Business Machines
   7 *   Corporation and others.  All Rights Reserved.
   8 *
   9 ******************************************************************************
  10 *   file name:  ubidiimp.h
  11 *   encoding:   UTF-8
  12 *   tab size:   8 (not used)
  13 *   indentation:4
  14 *
  15 *   created on: 1999aug06
  16 *   created by: Markus W. Scherer, updated by Matitiahu Allouche
  17 */
  18
  19 #ifndef UBIDIIMP_H
  20 #define UBIDIIMP_H
  21
  22 #include "unicode/utypes.h"
  23 #include "unicode/ubidi.h"
  24 #include "unicode/uchar.h"
  25 #include "ubidi_props.h"
  26
  27 /* miscellaneous definitions ---------------------------------------------- */
  28
  29 typedef uint8_t DirProp;
  30 typedef uint32_t Flags;
  31
  32 /*  Comparing the description of the BiDi algorithm with this implementation
  33     is easier with the same names for the BiDi types in the code as there.
  34     See UCharDirection in uchar.h .
  35 */
  36 enum {
  37     L=  U_LEFT_TO_RIGHT,                /*  0 */
  38     R=  U_RIGHT_TO_LEFT,                /*  1 */
  39     EN= U_EUROPEAN_NUMBER,              /*  2 */
  40     ES= U_EUROPEAN_NUMBER_SEPARATOR,    /*  3 */
  41     ET= U_EUROPEAN_NUMBER_TERMINATOR,   /*  4 */
  42     AN= U_ARABIC_NUMBER,                /*  5 */
  43     CS= U_COMMON_NUMBER_SEPARATOR,      /*  6 */
  44     B=  U_BLOCK_SEPARATOR,              /*  7 */
  45     S=  U_SEGMENT_SEPARATOR,            /*  8 */
  46     WS= U_WHITE_SPACE_NEUTRAL,          /*  9 */
  47     ON= U_OTHER_NEUTRAL,                /* 10 */
  48     LRE=U_LEFT_TO_RIGHT_EMBEDDING,      /* 11 */
  49     LRO=U_LEFT_TO_RIGHT_OVERRIDE,       /* 12 */
  50     AL= U_RIGHT_TO_LEFT_ARABIC,         /* 13 */
  51     RLE=U_RIGHT_TO_LEFT_EMBEDDING,      /* 14 */
  52     RLO=U_RIGHT_TO_LEFT_OVERRIDE,       /* 15 */
  53     PDF=U_POP_DIRECTIONAL_FORMAT,       /* 16 */
  54     NSM=U_DIR_NON_SPACING_MARK,         /* 17 */
  55     BN= U_BOUNDARY_NEUTRAL,             /* 18 */
  56     FSI=U_FIRST_STRONG_ISOLATE,         /* 19 */
  57     LRI=U_LEFT_TO_RIGHT_ISOLATE,        /* 20 */
  58     RLI=U_RIGHT_TO_LEFT_ISOLATE,        /* 21 */
  59     PDI=U_POP_DIRECTIONAL_ISOLATE,      /* 22 */
  60     ENL,    /* EN after W7 */           /* 23 */
  61     ENR,    /* EN not subject to W7 */  /* 24 */
  62     dirPropCount
  63 };
  64
  65 /*  Sometimes, bit values are more appropriate
  66     to deal with directionality properties.
  67     Abbreviations in these macro names refer to names
  68     used in the BiDi algorithm.
  69 */
  70 #define DIRPROP_FLAG(dir) (1UL<<(dir))
  71 #define PURE_DIRPROP(prop)  ((prop)&~0xE0)    ?????????????????????????
  72
  73 /* special flag for multiple runs from explicit embedding codes */
  74 #define DIRPROP_FLAG_MULTI_RUNS (1UL<<31)
  75
  76 /* are there any characters that are LTR or RTL? */
  77 #define MASK_LTR (DIRPROP_FLAG(L)|DIRPROP_FLAG(EN)|DIRPROP_FLAG(ENL)|DIRPROP_FLAG(ENR)|DIRPROP_FLAG(AN)|DIRPROP_FLAG(LRE)|DIRPROP_FLAG(LRO)|DIRPROP_FLAG(LRI))
  78 #define MASK_RTL (DIRPROP_FLAG(R)|DIRPROP_FLAG(AL)|DIRPROP_FLAG(RLE)|DIRPROP_FLAG(RLO)|DIRPROP_FLAG(RLI))
  79 #define MASK_R_AL (DIRPROP_FLAG(R)|DIRPROP_FLAG(AL))
  80 #define MASK_STRONG_EN_AN (DIRPROP_FLAG(L)|DIRPROP_FLAG(R)|DIRPROP_FLAG(AL)|DIRPROP_FLAG(EN)|DIRPROP_FLAG(AN))
  81
  82 /* explicit embedding codes */
  83 #define MASK_EXPLICIT (DIRPROP_FLAG(LRE)|DIRPROP_FLAG(LRO)|DIRPROP_FLAG(RLE)|DIRPROP_FLAG(RLO)|DIRPROP_FLAG(PDF))
  84
  85 /* explicit isolate codes */
  86 #define MASK_ISO (DIRPROP_FLAG(LRI)|DIRPROP_FLAG(RLI)|DIRPROP_FLAG(FSI)|DIRPROP_FLAG(PDI))
  87
  88 #define MASK_BN_EXPLICIT (DIRPROP_FLAG(BN)|MASK_EXPLICIT)
  89
  90 /* paragraph and segment separators */
  91 #define MASK_B_S (DIRPROP_FLAG(B)|DIRPROP_FLAG(S))
  92
  93 /* all types that are counted as White Space or Neutral in some steps */
  94 #define MASK_WS (MASK_B_S|DIRPROP_FLAG(WS)|MASK_BN_EXPLICIT|MASK_ISO)
  95
  96 /* types that are neutrals or could becomes neutrals in (Wn) */
  97 #define MASK_POSSIBLE_N (DIRPROP_FLAG(ON)|DIRPROP_FLAG(CS)|DIRPROP_FLAG(ES)|DIRPROP_FLAG(ET)|MASK_WS)
  98
  99 /*
 100  *  These types may be changed to "e",
 101  *  the embedding type (L or R) of the run,
 102  *  in the BiDi algorithm (N2)
 103  */
 104 #define MASK_EMBEDDING (DIRPROP_FLAG(NSM)|MASK_POSSIBLE_N)
 105
 106 /* the dirProp's L and R are defined to 0 and 1 values in UCharDirection */
 107 #define GET_LR_FROM_LEVEL(level) ((DirProp)((level)&1))
 108
 109 #define IS_DEFAULT_LEVEL(level) ((level)>=0xfe)
 110
 111 /*
 112  *  The following bit is used for the directional isolate status.
 113  *  Stack entries corresponding to isolate sequences are greater than ISOLATE.
 114  */
 115 #define ISOLATE  0x0100
 116
 117 U_CFUNC UBiDiLevel
 118 ubidi_getParaLevelAtIndex(const UBiDi *pBiDi, int32_t index);
 119
 120 #define GET_PARALEVEL(ubidi, index) \
 121             ((UBiDiLevel)(!(ubidi)->defaultParaLevel || (index)<(ubidi)->paras[0].limit ? \
 122                          (ubidi)->paraLevel : ubidi_getParaLevelAtIndex((ubidi), (index))))
 123
 124 /* number of paras entries allocated initially without malloc */
 125 #define SIMPLE_PARAS_COUNT      10
 126 /* number of isolate entries allocated initially without malloc */
 127 #define SIMPLE_ISOLATES_COUNT   5
 128 /* number of isolate run entries for paired brackets allocated initially without malloc */
 129 #define SIMPLE_OPENINGS_COUNT   20
 130
 131 #define CR  0x000D
 132 #define LF  0x000A
 133
 134 /* Run structure for reordering --------------------------------------------- */
 135 enum {
 136     LRM_BEFORE=1,
 137     LRM_AFTER=2,
 138     RLM_BEFORE=4,
 139     RLM_AFTER=8
 140 };
 141
 142 typedef struct Para {
 143     int32_t limit;
 144     int32_t level;
 145 } Para;
 146
 147 enum {                                  /* flags for Opening.flags */
 148     FOUND_L=DIRPROP_FLAG(L),
 149     FOUND_R=DIRPROP_FLAG(R)
 150 };
 151
 152 typedef struct Opening {
 153     int32_t position;                   /* position of opening bracket */
 154     int32_t match;                      /* matching char or -position of closing bracket */
 155     int32_t contextPos;                 /* position of last strong char found before opening */
 156     uint16_t flags;                     /* bits for L or R/AL found within the pair */
 157     UBiDiDirection contextDir;          /* L or R according to last strong char before opening */
 158     uint8_t filler;                     /* to complete a nice multiple of 4 chars */
 159 } Opening;
 160
 161 typedef struct IsoRun {
 162     int32_t  contextPos;                /* position of char determining context */
 163     uint16_t start;                     /* index of first opening entry for this run */
 164     uint16_t limit;                     /* index after last opening entry for this run */
 165     UBiDiLevel level;                   /* level of this run */
 166     DirProp lastStrong;                 /* bidi class of last strong char found in this run */
 167     DirProp lastBase;                   /* bidi class of last base char found in this run */
 168     UBiDiDirection contextDir;          /* L or R to use as context for following openings */
 169 } IsoRun;
 170
 171 typedef struct BracketData {
 172     UBiDi   *pBiDi;
 173     /* array of opening entries which should be enough in most cases; no malloc() */
 174     Opening simpleOpenings[SIMPLE_OPENINGS_COUNT];
 175     Opening *openings;                  /* pointer to current array of entries */
 176     int32_t openingsCount;              /* number of allocated entries */
 177     int32_t isoRunLast;                 /* index of last used entry */
 178     /* array of nested isolated sequence entries; can never excess UBIDI_MAX_EXPLICIT_LEVEL
 179        + 1 for index 0, + 1 for before the first isolated sequence */
 180     IsoRun  isoRuns[UBIDI_MAX_EXPLICIT_LEVEL+2];
 181     UBool isNumbersSpecial;             /* reordering mode for NUMBERS_SPECIAL */
 182 } BracketData;
 183
 184 typedef struct Isolate {
 185     int32_t startON;
 186     int32_t start1;
 187     int32_t state;
 188     int16_t stateImp;
 189 } Isolate;
 190
 191 typedef struct Run {
 192     int32_t logicalStart,   /* first character of the run; b31 indicates even/odd level */
 193             visualLimit,    /* last visual position of the run +1 */
 194             insertRemove;   /* if >0, flags for inserting LRM/RLM before/after run,
 195                                if <0, count of bidi controls within run            */
 196 } Run;
 197
 198 /* in a Run, logicalStart will get this bit set if the run level is odd */
 199 #define INDEX_ODD_BIT (1UL<<31)
 200
 201 #define MAKE_INDEX_ODD_PAIR(index, level) ((index)|((int32_t)(level)<<31))
 202 #define ADD_ODD_BIT_FROM_LEVEL(x, level)  ((x)|=((int32_t)(level)<<31))
 203 #define REMOVE_ODD_BIT(x)                 ((x)&=~INDEX_ODD_BIT)
 204
 205 #define GET_INDEX(x)   ((x)&~INDEX_ODD_BIT)
 206 #define GET_ODD_BIT(x) ((uint32_t)(x)>>31)
 207 #define IS_ODD_RUN(x)  ((UBool)(((x)&INDEX_ODD_BIT)!=0))
 208 #define IS_EVEN_RUN(x) ((UBool)(((x)&INDEX_ODD_BIT)==0))
 209
 210 U_CFUNC UBool
 211 ubidi_getRuns(UBiDi *pBiDi, UErrorCode *pErrorCode);
 212
 213 /** BiDi control code points */
 214 enum {
 215     ZWNJ_CHAR=0x200c,
 216     ZWJ_CHAR,
 217     LRM_CHAR,
 218     RLM_CHAR,
 219     LRE_CHAR=0x202a,
 220     RLE_CHAR,
 221     PDF_CHAR,
 222     LRO_CHAR,
 223     RLO_CHAR,
 224     LRI_CHAR=0x2066,
 225     RLI_CHAR,
 226     FSI_CHAR,
 227     PDI_CHAR
 228 };
 229
 230 #define IS_BIDI_CONTROL_CHAR(c) (((uint32_t)(c)&0xfffffffc)==ZWNJ_CHAR || (uint32_t)((c)-LRE_CHAR)<5 || (uint32_t)((c)-LRI_CHAR)<4)
 231
 232 /* InsertPoints structure for noting where to put BiDi marks ---------------- */
 233
 234 typedef struct Point {
 235     int32_t pos;            /* position in text */
 236     int32_t flag;           /* flag for LRM/RLM, before/after */
 237 } Point;
 238
 239 typedef struct InsertPoints {
 240     int32_t capacity;       /* number of points allocated */
 241     int32_t size;           /* number of points used */
 242     int32_t confirmed;      /* number of points confirmed */
 243     UErrorCode errorCode;   /* for eventual memory shortage */
 244     Point *points;          /* pointer to array of points */
 245 } InsertPoints;
 246
 247
 248 /* UBiDi structure ----------------------------------------------------------- */
 249
 250 struct UBiDi {
 251     /* pointer to parent paragraph object (pointer to self if this object is
 252      * a paragraph object); set to NULL in a newly opened object; set to a
 253      * real value after a successful execution of ubidi_setPara or ubidi_setLine
 254      */
 255     const UBiDi * pParaBiDi;
 256
 257     /* alias pointer to the current text */
 258     const UChar *text;
 259
 260     /* length of the current text */
 261     int32_t originalLength;
 262
 263     /* if the UBIDI_OPTION_STREAMING option is set, this is the length
 264      * of text actually processed by ubidi_setPara, which may be shorter than
 265      * the original length.
 266      * Otherwise, it is identical to the original length.
 267      */
 268     int32_t length;
 269
 270     /* if the UBIDI_OPTION_REMOVE_CONTROLS option is set, and/or
 271      * marks are allowed to be inserted in one of the reordering mode, the
 272      * length of the result string may be different from the processed length.
 273      */
 274     int32_t resultLength;
 275
 276     /* memory sizes in bytes */
 277     int32_t dirInsertSize, dirPropsSize, levelsSize, openingsSize, parasSize, runsSize, isolatesSize;
 278
 279     /* allocated memory */
 280     uint16_t *dirInsertMemory;
 281     DirProp *dirPropsMemory;
 282     UBiDiLevel *levelsMemory;
 283     Opening *openingsMemory;
 284     Para *parasMemory;
 285     Run *runsMemory;
 286     Isolate *isolatesMemory;
 287
 288     /* indicators for whether memory may be allocated after ubidi_open() */
 289     UBool mayAllocateText, mayAllocateRuns;
 290
 291     /* arrays with one value per text-character */
 292     uint16_t *dirInsert;
 293     DirProp *dirProps;
 294     UBiDiLevel *levels;
 295
 296     /* are we performing an approximation of the "inverse BiDi" algorithm? */
 297     UBool isInverse;
 298
 299     /* are we using the basic algorithm or its variation? */
 300     UBiDiReorderingMode reorderingMode;
 301
 302     /* UBIDI_REORDER_xxx values must be ordered so that all the regular
 303      * logical to visual modes come first, and all inverse BiDi modes
 304      * come last.
 305      */
 306     #define UBIDI_REORDER_LAST_LOGICAL_TO_VISUAL    UBIDI_REORDER_NUMBERS_SPECIAL
 307
 308     /* bitmask for reordering options */
 309     uint32_t reorderingOptions;
 310
 311     /* must block separators receive level 0? */
 312     UBool orderParagraphsLTR;
 313
 314     /* the paragraph level */
 315     UBiDiLevel paraLevel;
 316     /* original paraLevel when contextual */
 317     /* must be one of UBIDI_DEFAULT_xxx or 0 if not contextual */
 318     UBiDiLevel defaultParaLevel;
 319
 320     /* context data */
 321     const UChar *prologue;
 322     int32_t proLength;
 323     const UChar *epilogue;
 324     int32_t epiLength;
 325
 326     /* the following is set in ubidi_setPara, used in processPropertySeq */
 327     const struct ImpTabPair * pImpTabPair;  /* pointer to levels state table pair */
 328
 329     /* the overall paragraph or line directionality - see UBiDiDirection */
 330     UBiDiDirection direction;
 331
 332     /* flags is a bit set for which directional properties are in the text */
 333     Flags flags;
 334
 335     /* lastArabicPos is index to the last AL in the text, -1 if none */
 336     int32_t lastArabicPos;
 337
 338     /* characters after trailingWSStart are WS and are */
 339     /* implicitly at the paraLevel (rule (L1)) - levels may not reflect that */
 340     int32_t trailingWSStart;
 341
 342     /* fields for paragraph handling */
 343     int32_t paraCount;                  /* set in getDirProps() */
 344     /* filled in getDirProps() */
 345     Para *paras;
 346
 347     /* for relatively short text, we only need a tiny array of paras (no malloc()) */
 348     Para simpleParas[SIMPLE_PARAS_COUNT];
 349
 350     /* fields for line reordering */
 351     int32_t runCount;     /* ==-1: runs not set up yet */
 352     Run *runs;
 353
 354     /* for non-mixed text, we only need a tiny array of runs (no malloc()) */
 355     Run simpleRuns[1];
 356
 357     /* maximum or current nesting depth of isolate sequences */
 358     /* Within resolveExplicitLevels() and checkExplicitLevels(), this is the maximal
 359        nesting encountered.
 360        Within resolveImplicitLevels(), this is the index of the current isolates
 361        stack entry. */
 362     int32_t isolateCount;
 363     Isolate *isolates;
 364
 365     /* for simple text, have a small stack (no malloc()) */
 366     Isolate simpleIsolates[SIMPLE_ISOLATES_COUNT];
 367
 368     /* for inverse Bidi with insertion of directional marks */
 369     InsertPoints insertPoints;
 370
 371     /* for option UBIDI_OPTION_REMOVE_CONTROLS */
 372     int32_t controlCount;
 373
 374     /* for Bidi class callback */
 375     UBiDiClassCallback *fnClassCallback;    /* action pointer */
 376     const void *coClassCallback;            /* context pointer */
 377 };
 378
 379 #define IS_VALID_PARA(x) ((x) && ((x)->pParaBiDi==(x)))
 380 #define IS_VALID_PARA_OR_LINE(x) ((x) && ((x)->pParaBiDi==(x) || (((x)->pParaBiDi) && (x)->pParaBiDi->pParaBiDi==(x)->pParaBiDi)))
 381
 382 typedef union {
 383     uint16_t *dirInsertMemory;
 384     DirProp *dirPropsMemory;
 385     UBiDiLevel *levelsMemory;
 386     Opening *openingsMemory;
 387     Para *parasMemory;
 388     Run *runsMemory;
 389     Isolate *isolatesMemory;
 390 } BidiMemoryForAllocation;
 391
 392 /* Macros for initial checks at function entry */
 393 #define RETURN_IF_NULL_OR_FAILING_ERRCODE(pErrcode, retvalue)   \
 394         if((pErrcode)==NULL || U_FAILURE(*pErrcode)) return retvalue
 395 #define RETURN_IF_NOT_VALID_PARA(bidi, errcode, retvalue)   \
 396         if(!IS_VALID_PARA(bidi)) {  \
 397             errcode=U_INVALID_STATE_ERROR;  \
 398             return retvalue;                \
 399         }
 400 #define RETURN_IF_NOT_VALID_PARA_OR_LINE(bidi, errcode, retvalue)   \
 401         if(!IS_VALID_PARA_OR_LINE(bidi)) {  \
 402             errcode=U_INVALID_STATE_ERROR;  \
 403             return retvalue;                \
 404         }
 405 #define RETURN_IF_BAD_RANGE(arg, start, limit, errcode, retvalue)   \
 406         if((arg)<(start) || (arg)>=(limit)) {       \
 407             (errcode)=U_ILLEGAL_ARGUMENT_ERROR;     \
 408             return retvalue;                        \
 409         }
 410
 411 #define RETURN_VOID_IF_NULL_OR_FAILING_ERRCODE(pErrcode)   \
 412         if((pErrcode)==NULL || U_FAILURE(*pErrcode)) return
 413 #define RETURN_VOID_IF_NOT_VALID_PARA(bidi, errcode)   \
 414         if(!IS_VALID_PARA(bidi)) {  \
 415             errcode=U_INVALID_STATE_ERROR;  \
 416             return;                \
 417         }
 418 #define RETURN_VOID_IF_NOT_VALID_PARA_OR_LINE(bidi, errcode)   \
 419         if(!IS_VALID_PARA_OR_LINE(bidi)) {  \
 420             errcode=U_INVALID_STATE_ERROR;  \
 421             return;                \
 422         }
 423 #define RETURN_VOID_IF_BAD_RANGE(arg, start, limit, errcode)   \
 424         if((arg)<(start) || (arg)>=(limit)) {       \
 425             (errcode)=U_ILLEGAL_ARGUMENT_ERROR;     \
 426             return;                        \
 427         }
 428
 429 /* helper function to (re)allocate memory if allowed */
 430 U_CFUNC UBool
 431 ubidi_getMemory(BidiMemoryForAllocation *pMemory, int32_t *pSize, UBool mayAllocate, int32_t sizeNeeded);
 432
 433 /* helper macros for each allocated array in UBiDi */
 434 #define getDirInsertMemory(pBiDi, length) \
 435         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->dirInsertMemory, &(pBiDi)->dirInsertSize, \
 436                         (pBiDi)->mayAllocateText, (length)*sizeof(uint16_t))
 437
 438 #define getDirPropsMemory(pBiDi, length) \
 439         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->dirPropsMemory, &(pBiDi)->dirPropsSize, \
 440                         (pBiDi)->mayAllocateText, (length))
 441
 442 #define getLevelsMemory(pBiDi, length) \
 443         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->levelsMemory, &(pBiDi)->levelsSize, \
 444                         (pBiDi)->mayAllocateText, (length))
 445
 446 #define getRunsMemory(pBiDi, length) \
 447         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->runsMemory, &(pBiDi)->runsSize, \
 448                         (pBiDi)->mayAllocateRuns, (length)*sizeof(Run))
 449
 450 /* additional macros used by ubidi_open() - always allow allocation */
 451 #define getInitialDirInsertMemory(pBiDi, length) \
 452         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->dirInsertMemory, &(pBiDi)->dirInsertSize, \
 453                         TRUE, (length))
 454
 455 #define getInitialDirPropsMemory(pBiDi, length) \
 456         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->dirPropsMemory, &(pBiDi)->dirPropsSize, \
 457                         TRUE, (length))
 458
 459 #define getInitialLevelsMemory(pBiDi, length) \
 460         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->levelsMemory, &(pBiDi)->levelsSize, \
 461                         TRUE, (length))
 462
 463 #define getInitialOpeningsMemory(pBiDi, length) \
 464         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->openingsMemory, &(pBiDi)->openingsSize, \
 465                         TRUE, (length)*sizeof(Opening))
 466
 467 #define getInitialParasMemory(pBiDi, length) \
 468         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->parasMemory, &(pBiDi)->parasSize, \
 469                         TRUE, (length)*sizeof(Para))
 470
 471 #define getInitialRunsMemory(pBiDi, length) \
 472         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->runsMemory, &(pBiDi)->runsSize, \
 473                         TRUE, (length)*sizeof(Run))
 474
 475 #define getInitialIsolatesMemory(pBiDi, length) \
 476         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->isolatesMemory, &(pBiDi)->isolatesSize, \
 477                         TRUE, (length)*sizeof(Isolate))
 478
 479 #endif