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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) 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 dirPropsSize, levelsSize, openingsSize, parasSize, runsSize, isolatesSize;
278 
279     /* allocated memory */
280     DirProp *dirPropsMemory;
281     UBiDiLevel *levelsMemory;
282     Opening *openingsMemory;
283     Para *parasMemory;
284     Run *runsMemory;
285     Isolate *isolatesMemory;
286 
287     /* indicators for whether memory may be allocated after ubidi_open() */
288     UBool mayAllocateText, mayAllocateRuns;
289 
290     /* arrays with one value per text-character */
291     DirProp *dirProps;
292     UBiDiLevel *levels;
293 
294     /* are we performing an approximation of the "inverse BiDi" algorithm? */
295     UBool isInverse;
296 
297     /* are we using the basic algorithm or its variation? */
298     UBiDiReorderingMode reorderingMode;
299 
300     /* UBIDI_REORDER_xxx values must be ordered so that all the regular
301      * logical to visual modes come first, and all inverse BiDi modes
302      * come last.
303      */
304     #define UBIDI_REORDER_LAST_LOGICAL_TO_VISUAL    UBIDI_REORDER_NUMBERS_SPECIAL
305 
306     /* bitmask for reordering options */
307     uint32_t reorderingOptions;
308 
309     /* must block separators receive level 0? */
310     UBool orderParagraphsLTR;
311 
312     /* the paragraph level */
313     UBiDiLevel paraLevel;
314     /* original paraLevel when contextual */
315     /* must be one of UBIDI_DEFAULT_xxx or 0 if not contextual */
316     UBiDiLevel defaultParaLevel;
317 
318     /* context data */
319     const UChar *prologue;
320     int32_t proLength;
321     const UChar *epilogue;
322     int32_t epiLength;
323 
324     /* the following is set in ubidi_setPara, used in processPropertySeq */
325     const struct ImpTabPair * pImpTabPair;  /* pointer to levels state table pair */
326 
327     /* the overall paragraph or line directionality - see UBiDiDirection */
328     UBiDiDirection direction;
329 
330     /* flags is a bit set for which directional properties are in the text */
331     Flags flags;
332 
333     /* lastArabicPos is index to the last AL in the text, -1 if none */
334     int32_t lastArabicPos;
335 
336     /* characters after trailingWSStart are WS and are */
337     /* implicitly at the paraLevel (rule (L1)) - levels may not reflect that */
338     int32_t trailingWSStart;
339 
340     /* fields for paragraph handling */
341     int32_t paraCount;                  /* set in getDirProps() */
342     /* filled in getDirProps() */
343     Para *paras;
344 
345     /* for relatively short text, we only need a tiny array of paras (no malloc()) */
346     Para simpleParas[SIMPLE_PARAS_COUNT];
347 
348     /* fields for line reordering */
349     int32_t runCount;     /* ==-1: runs not set up yet */
350     Run *runs;
351 
352     /* for non-mixed text, we only need a tiny array of runs (no malloc()) */
353     Run simpleRuns[1];
354 
355     /* maximum or current nesting depth of isolate sequences */
356     /* Within resolveExplicitLevels() and checkExplicitLevels(), this is the maximal
357        nesting encountered.
358        Within resolveImplicitLevels(), this is the index of the current isolates
359        stack entry. */
360     int32_t isolateCount;
361     Isolate *isolates;
362 
363     /* for simple text, have a small stack (no malloc()) */
364     Isolate simpleIsolates[SIMPLE_ISOLATES_COUNT];
365 
366     /* for inverse Bidi with insertion of directional marks */
367     InsertPoints insertPoints;
368 
369     /* for option UBIDI_OPTION_REMOVE_CONTROLS */
370     int32_t controlCount;
371 
372     /* for Bidi class callback */
373     UBiDiClassCallback *fnClassCallback;    /* action pointer */
374     const void *coClassCallback;            /* context pointer */
375 };
376 
377 #define IS_VALID_PARA(x) ((x) && ((x)->pParaBiDi==(x)))
378 #define IS_VALID_PARA_OR_LINE(x) ((x) && ((x)->pParaBiDi==(x) || (((x)->pParaBiDi) && (x)->pParaBiDi->pParaBiDi==(x)->pParaBiDi)))
379 
380 typedef union {
381     DirProp *dirPropsMemory;
382     UBiDiLevel *levelsMemory;
383     Opening *openingsMemory;
384     Para *parasMemory;
385     Run *runsMemory;
386     Isolate *isolatesMemory;
387 } BidiMemoryForAllocation;
388 
389 /* Macros for initial checks at function entry */
390 #define RETURN_IF_NULL_OR_FAILING_ERRCODE(pErrcode, retvalue)   \
391         if((pErrcode)==NULL || U_FAILURE(*pErrcode)) return retvalue
392 #define RETURN_IF_NOT_VALID_PARA(bidi, errcode, retvalue)   \
393         if(!IS_VALID_PARA(bidi)) {  \
394             errcode=U_INVALID_STATE_ERROR;  \
395             return retvalue;                \
396         }
397 #define RETURN_IF_NOT_VALID_PARA_OR_LINE(bidi, errcode, retvalue)   \
398         if(!IS_VALID_PARA_OR_LINE(bidi)) {  \
399             errcode=U_INVALID_STATE_ERROR;  \
400             return retvalue;                \
401         }
402 #define RETURN_IF_BAD_RANGE(arg, start, limit, errcode, retvalue)   \
403         if((arg)<(start) || (arg)>=(limit)) {       \
404             (errcode)=U_ILLEGAL_ARGUMENT_ERROR;     \
405             return retvalue;                        \
406         }
407 
408 #define RETURN_VOID_IF_NULL_OR_FAILING_ERRCODE(pErrcode)   \
409         if((pErrcode)==NULL || U_FAILURE(*pErrcode)) return
410 #define RETURN_VOID_IF_NOT_VALID_PARA(bidi, errcode)   \
411         if(!IS_VALID_PARA(bidi)) {  \
412             errcode=U_INVALID_STATE_ERROR;  \
413             return;                \
414         }
415 #define RETURN_VOID_IF_NOT_VALID_PARA_OR_LINE(bidi, errcode)   \
416         if(!IS_VALID_PARA_OR_LINE(bidi)) {  \
417             errcode=U_INVALID_STATE_ERROR;  \
418             return;                \
419         }
420 #define RETURN_VOID_IF_BAD_RANGE(arg, start, limit, errcode)   \
421         if((arg)<(start) || (arg)>=(limit)) {       \
422             (errcode)=U_ILLEGAL_ARGUMENT_ERROR;     \
423             return;                        \
424         }
425 
426 /* helper function to (re)allocate memory if allowed */
427 U_CFUNC UBool
428 ubidi_getMemory(BidiMemoryForAllocation *pMemory, int32_t *pSize, UBool mayAllocate, int32_t sizeNeeded);
429 
430 /* helper macros for each allocated array in UBiDi */
431 #define getDirPropsMemory(pBiDi, length) \
432         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->dirPropsMemory, &(pBiDi)->dirPropsSize, \
433                         (pBiDi)->mayAllocateText, (length))
434 
435 #define getLevelsMemory(pBiDi, length) \
436         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->levelsMemory, &(pBiDi)->levelsSize, \
437                         (pBiDi)->mayAllocateText, (length))
438 
439 #define getRunsMemory(pBiDi, length) \
440         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->runsMemory, &(pBiDi)->runsSize, \
441                         (pBiDi)->mayAllocateRuns, (length)*sizeof(Run))
442 
443 /* additional macros used by ubidi_open() - always allow allocation */
444 #define getInitialDirPropsMemory(pBiDi, length) \
445         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->dirPropsMemory, &(pBiDi)->dirPropsSize, \
446                         TRUE, (length))
447 
448 #define getInitialLevelsMemory(pBiDi, length) \
449         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->levelsMemory, &(pBiDi)->levelsSize, \
450                         TRUE, (length))
451 
452 #define getInitialOpeningsMemory(pBiDi, length) \
453         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->openingsMemory, &(pBiDi)->openingsSize, \
454                         TRUE, (length)*sizeof(Opening))
455 
456 #define getInitialParasMemory(pBiDi, length) \
457         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->parasMemory, &(pBiDi)->parasSize, \
458                         TRUE, (length)*sizeof(Para))
459 
460 #define getInitialRunsMemory(pBiDi, length) \
461         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->runsMemory, &(pBiDi)->runsSize, \
462                         TRUE, (length)*sizeof(Run))
463 
464 #define getInitialIsolatesMemory(pBiDi, length) \
465         ubidi_getMemory((BidiMemoryForAllocation *)&(pBiDi)->isolatesMemory, &(pBiDi)->isolatesSize, \
466                         TRUE, (length)*sizeof(Isolate))
467 
468 #endif
469