The Tor Browser: intl/icu/source/common/ubidiwrt.c@b8a032363ba2 (annotated)

intl/icu/source/common/ubidiwrt.c@b8a032363ba2 (annotated)

intl/icu/source/common/ubidiwrt.c

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /*
 ******************************************************************************
 *
 *   Copyright (C) 2000-2011, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 *
 ******************************************************************************
 *   file name:  ubidiwrt.c
 *   encoding:   US-ASCII
 *   tab size:   8 (not used)
 *   indentation:4
 *
 *   created on: 1999aug06
 *   created by: Markus W. Scherer, updated by Matitiahu Allouche
 *
 * This file contains implementations for BiDi functions that use
 * the core algorithm and core API to write reordered text.
 */
 /* set import/export definitions */
 #ifndef U_COMMON_IMPLEMENTATION
 #   define U_COMMON_IMPLEMENTATION
 #endif
 #include "unicode/utypes.h"
 #include "unicode/ustring.h"
 #include "unicode/uchar.h"
 #include "unicode/ubidi.h"
 #include "unicode/utf16.h"
 #include "cmemory.h"
 #include "ustr_imp.h"
 #include "ubidiimp.h"
 /*
  * The function implementations in this file are designed
  * for UTF-16 and UTF-32, not for UTF-8.
  *
  * Assumptions that are not true for UTF-8:
  * - Any code point always needs the same number of code units
  *   ("minimum-length-problem" of UTF-8)
  * - The BiDi control characters need only one code unit each
  *
  * Further assumptions for all UTFs:
  * - u_charMirror(c) needs the same number of code units as c
  */
 #if UTF_SIZE==8
 # error reimplement ubidi_writeReordered() for UTF-8, see comment above
 #endif
 #define IS_COMBINING(type) ((1UL<<(type))&(1UL<<U_NON_SPACING_MARK|1UL<<U_COMBINING_SPACING_MARK|1UL<<U_ENCLOSING_MARK))
 /*
  * When we have UBIDI_OUTPUT_REVERSE set on ubidi_writeReordered(), then we
  * semantically write RTL runs in reverse and later reverse them again.
  * Instead, we actually write them in forward order to begin with.
  * However, if the RTL run was to be mirrored, we need to mirror here now
  * since the implicit second reversal must not do it.
  * It looks strange to do mirroring in LTR output, but it is only because
  * we are writing RTL output in reverse.
  */
 static int32_t
 doWriteForward(const UChar *src, int32_t srcLength,
                UChar *dest, int32_t destSize,
                uint16_t options,
                UErrorCode *pErrorCode) {
     /* optimize for several combinations of options */
     switch(options&(UBIDI_REMOVE_BIDI_CONTROLS|UBIDI_DO_MIRRORING)) {
     case 0: {
         /* simply copy the LTR run to the destination */
         int32_t length=srcLength;
         if(destSize<length) {
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             return srcLength;
         }
         do {
             *dest++=*src++;
         } while(--length>0);
         return srcLength;
     }
     case UBIDI_DO_MIRRORING: {
         /* do mirroring */
         int32_t i=0, j=0;
         UChar32 c;
         if(destSize<srcLength) {
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             return srcLength;
         }
         do {
             U16_NEXT(src, i, srcLength, c);
             c=u_charMirror(c);
             U16_APPEND_UNSAFE(dest, j, c);
         } while(i<srcLength);
         return srcLength;
     }
     case UBIDI_REMOVE_BIDI_CONTROLS: {
         /* copy the LTR run and remove any BiDi control characters */
         int32_t remaining=destSize;
         UChar c;
         do {
             c=*src++;
             if(!IS_BIDI_CONTROL_CHAR(c)) {
                 if(--remaining<0) {
                     *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                     /* preflight the length */
                     while(--srcLength>0) {
                         c=*src++;
                         if(!IS_BIDI_CONTROL_CHAR(c)) {
                             --remaining;
                         }
                     }
                     return destSize-remaining;
                 }
                 *dest++=c;
             }
         } while(--srcLength>0);
         return destSize-remaining;
     }
     default: {
         /* remove BiDi control characters and do mirroring */
         int32_t remaining=destSize;
         int32_t i, j=0;
         UChar32 c;
         do {
             i=0;
             U16_NEXT(src, i, srcLength, c);
             src+=i;
             srcLength-=i;
             if(!IS_BIDI_CONTROL_CHAR(c)) {
                 remaining-=i;
                 if(remaining<0) {
                     *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                     /* preflight the length */
                     while(srcLength>0) {
                         c=*src++;
                         if(!IS_BIDI_CONTROL_CHAR(c)) {
                             --remaining;
                         }
                         --srcLength;
                     }
                     return destSize-remaining;
                 }
                 c=u_charMirror(c);
                 U16_APPEND_UNSAFE(dest, j, c);
             }
         } while(srcLength>0);
         return j;
     }
     } /* end of switch */
 }
 static int32_t
 doWriteReverse(const UChar *src, int32_t srcLength,
                UChar *dest, int32_t destSize,
                uint16_t options,
                UErrorCode *pErrorCode) {
     /*
      * RTL run -
      *
      * RTL runs need to be copied to the destination in reverse order
      * of code points, not code units, to keep Unicode characters intact.
      *
      * The general strategy for this is to read the source text
      * in backward order, collect all code units for a code point
      * (and optionally following combining characters, see below),
      * and copy all these code units in ascending order
      * to the destination for this run.
      *
      * Several options request whether combining characters
      * should be kept after their base characters,
      * whether BiDi control characters should be removed, and
      * whether characters should be replaced by their mirror-image
      * equivalent Unicode characters.
      */
     int32_t i, j;
     UChar32 c;
     /* optimize for several combinations of options */
     switch(options&(UBIDI_REMOVE_BIDI_CONTROLS|UBIDI_DO_MIRRORING|UBIDI_KEEP_BASE_COMBINING)) {
     case 0:
         /*
          * With none of the "complicated" options set, the destination
          * run will have the same length as the source run,
          * and there is no mirroring and no keeping combining characters
          * with their base characters.
          */
         if(destSize<srcLength) {
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             return srcLength;
         }
         destSize=srcLength;
         /* preserve character integrity */
         do {
             /* i is always after the last code unit known to need to be kept in this segment */
             i=srcLength;
             /* collect code units for one base character */
             U16_BACK_1(src, 0, srcLength);
             /* copy this base character */
             j=srcLength;
             do {
                 *dest++=src[j++];
             } while(j<i);
         } while(srcLength>0);
         break;
     case UBIDI_KEEP_BASE_COMBINING:
         /*
          * Here, too, the destination
          * run will have the same length as the source run,
          * and there is no mirroring.
          * We do need to keep combining characters with their base characters.
          */
         if(destSize<srcLength) {
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             return srcLength;
         }
         destSize=srcLength;
         /* preserve character integrity */
         do {
             /* i is always after the last code unit known to need to be kept in this segment */
             i=srcLength;
             /* collect code units and modifier letters for one base character */
             do {
                 U16_PREV(src, 0, srcLength, c);
             } while(srcLength>0 && IS_COMBINING(u_charType(c)));
             /* copy this "user character" */
             j=srcLength;
             do {
                 *dest++=src[j++];
             } while(j<i);
         } while(srcLength>0);
         break;
     default:
         /*
          * With several "complicated" options set, this is the most
          * general and the slowest copying of an RTL run.
          * We will do mirroring, remove BiDi controls, and
          * keep combining characters with their base characters
          * as requested.
          */
         if(!(options&UBIDI_REMOVE_BIDI_CONTROLS)) {
             i=srcLength;
         } else {
             /* we need to find out the destination length of the run,
                which will not include the BiDi control characters */
             int32_t length=srcLength;
             UChar ch;
             i=0;
             do {
                 ch=*src++;
                 if(!IS_BIDI_CONTROL_CHAR(ch)) {
                     ++i;
                 }
             } while(--length>0);
             src-=srcLength;
         }
         if(destSize<i) {
             *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             return i;
         }
         destSize=i;
         /* preserve character integrity */
         do {
             /* i is always after the last code unit known to need to be kept in this segment */
             i=srcLength;
             /* collect code units for one base character */
             U16_PREV(src, 0, srcLength, c);
             if(options&UBIDI_KEEP_BASE_COMBINING) {
                 /* collect modifier letters for this base character */
                 while(srcLength>0 && IS_COMBINING(u_charType(c))) {
                     U16_PREV(src, 0, srcLength, c);
                 }
             }
             if(options&UBIDI_REMOVE_BIDI_CONTROLS && IS_BIDI_CONTROL_CHAR(c)) {
                 /* do not copy this BiDi control character */
                 continue;
             }
             /* copy this "user character" */
             j=srcLength;
             if(options&UBIDI_DO_MIRRORING) {
                 /* mirror only the base character */
                 int32_t k=0;
                 c=u_charMirror(c);
                 U16_APPEND_UNSAFE(dest, k, c);
                 dest+=k;
                 j+=k;
             }
             while(j<i) {
                 *dest++=src[j++];
             }
         } while(srcLength>0);
         break;
     } /* end of switch */
     return destSize;
 }
 U_CAPI int32_t U_EXPORT2
 ubidi_writeReverse(const UChar *src, int32_t srcLength,
                    UChar *dest, int32_t destSize,
                    uint16_t options,
                    UErrorCode *pErrorCode) {
     int32_t destLength;
     if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
         return 0;
     }
     /* more error checking */
     if( src==NULL || srcLength<-1 ||
         destSize<0 || (destSize>0 && dest==NULL))
     {
         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
         return 0;
     }
     /* do input and output overlap? */
     if( dest!=NULL &&
         ((src>=dest && src<dest+destSize) ||
          (dest>=src && dest<src+srcLength)))
     {
         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
         return 0;
     }
     if(srcLength==-1) {
         srcLength=u_strlen(src);
     }
     if(srcLength>0) {
         destLength=doWriteReverse(src, srcLength, dest, destSize, options, pErrorCode);
     } else {
         /* nothing to do */
         destLength=0;
     }
     return u_terminateUChars(dest, destSize, destLength, pErrorCode);
 }
 U_CAPI int32_t U_EXPORT2
 ubidi_writeReordered(UBiDi *pBiDi,
                      UChar *dest, int32_t destSize,
                      uint16_t options,
                      UErrorCode *pErrorCode) {
     const UChar *text;
     UChar *saveDest;
     int32_t length, destCapacity;
     int32_t run, runCount, logicalStart, runLength;
     if(pErrorCode==NULL || U_FAILURE(*pErrorCode)) {
         return 0;
     }
     /* more error checking */
     if( pBiDi==NULL ||
         (text=pBiDi->text)==NULL || (length=pBiDi->length)<0 ||
         destSize<0 || (destSize>0 && dest==NULL))
     {
         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
         return 0;
     }
     /* do input and output overlap? */
     if( dest!=NULL &&
         ((text>=dest && text<dest+destSize) ||
          (dest>=text && dest<text+pBiDi->originalLength)))
     {
         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
         return 0;
     }
     if(length==0) {
         /* nothing to do */
         return u_terminateUChars(dest, destSize, 0, pErrorCode);
     }
     runCount=ubidi_countRuns(pBiDi, pErrorCode);
     if(U_FAILURE(*pErrorCode)) {
         return 0;
     }
     /* destSize shrinks, later destination length=destCapacity-destSize */
     saveDest=dest;
     destCapacity=destSize;
     /*
      * Option "insert marks" implies UBIDI_INSERT_LRM_FOR_NUMERIC if the
      * reordering mode (checked below) is appropriate.
      */
     if(pBiDi->reorderingOptions & UBIDI_OPTION_INSERT_MARKS) {
         options|=UBIDI_INSERT_LRM_FOR_NUMERIC;
         options&=~UBIDI_REMOVE_BIDI_CONTROLS;
     }
     /*
      * Option "remove controls" implies UBIDI_REMOVE_BIDI_CONTROLS
      * and cancels UBIDI_INSERT_LRM_FOR_NUMERIC.
      */
     if(pBiDi->reorderingOptions & UBIDI_OPTION_REMOVE_CONTROLS) {
         options|=UBIDI_REMOVE_BIDI_CONTROLS;
         options&=~UBIDI_INSERT_LRM_FOR_NUMERIC;
     }
     /*
      * If we do not perform the "inverse BiDi" algorithm, then we
      * don't need to insert any LRMs, and don't need to test for it.
      */
     if((pBiDi->reorderingMode != UBIDI_REORDER_INVERSE_NUMBERS_AS_L) &&
        (pBiDi->reorderingMode != UBIDI_REORDER_INVERSE_LIKE_DIRECT)  &&
        (pBiDi->reorderingMode != UBIDI_REORDER_INVERSE_FOR_NUMBERS_SPECIAL) &&
        (pBiDi->reorderingMode != UBIDI_REORDER_RUNS_ONLY)) {
         options&=~UBIDI_INSERT_LRM_FOR_NUMERIC;
     }
     /*
      * Iterate through all visual runs and copy the run text segments to
      * the destination, according to the options.
      *
      * The tests for where to insert LRMs ignore the fact that there may be
      * BN codes or non-BMP code points at the beginning and end of a run;
      * they may insert LRMs unnecessarily but the tests are faster this way
      * (this would have to be improved for UTF-8).
      *
      * Note that the only errors that are set by doWriteXY() are buffer overflow
      * errors. Ignore them until the end, and continue for preflighting.
      */
     if(!(options&UBIDI_OUTPUT_REVERSE)) {
         /* forward output */
         if(!(options&UBIDI_INSERT_LRM_FOR_NUMERIC)) {
             /* do not insert BiDi controls */
             for(run=0; run<runCount; ++run) {
                 if(UBIDI_LTR==ubidi_getVisualRun(pBiDi, run, &logicalStart, &runLength)) {
                     runLength=doWriteForward(text+logicalStart, runLength,
                                              dest, destSize,
                                              (uint16_t)(options&~UBIDI_DO_MIRRORING), pErrorCode);
                 } else {
                     runLength=doWriteReverse(text+logicalStart, runLength,
                                              dest, destSize,
                                              options, pErrorCode);
                 }
                 if(dest!=NULL) {
                   dest+=runLength;
                 }
                 destSize-=runLength;
             }
         } else {
             /* insert BiDi controls for "inverse BiDi" */
             const DirProp *dirProps=pBiDi->dirProps;
             const UChar *src;
             UChar uc;
             UBiDiDirection dir;
             int32_t markFlag;
             for(run=0; run<runCount; ++run) {
                 dir=ubidi_getVisualRun(pBiDi, run, &logicalStart, &runLength);
                 src=text+logicalStart;
                 /* check if something relevant in insertPoints */
                 markFlag=pBiDi->runs[run].insertRemove;
                 if(markFlag<0) {        /* BiDi controls count */
                     markFlag=0;
                 }
                 if(UBIDI_LTR==dir) {
                     if((pBiDi->isInverse) &&
                        (/*run>0 &&*/ dirProps[logicalStart]!=L)) {
                         markFlag |= LRM_BEFORE;
                     }
                     if (markFlag & LRM_BEFORE) {
                         uc=LRM_CHAR;
                     }
                     else if (markFlag & RLM_BEFORE) {
                         uc=RLM_CHAR;
                     }
                     else  uc=0;
                     if(uc) {
                         if(destSize>0) {
                             *dest++=uc;
                         }
                         --destSize;
                     }
                     runLength=doWriteForward(src, runLength,
                                              dest, destSize,
                                              (uint16_t)(options&~UBIDI_DO_MIRRORING), pErrorCode);
                     if(dest!=NULL) {
                       dest+=runLength;
                     }
                     destSize-=runLength;
                     if((pBiDi->isInverse) &&
                        (/*run<runCount-1 &&*/ dirProps[logicalStart+runLength-1]!=L)) {
                         markFlag |= LRM_AFTER;
                     }
                     if (markFlag & LRM_AFTER) {
                         uc=LRM_CHAR;
                     }
                     else if (markFlag & RLM_AFTER) {
                         uc=RLM_CHAR;
                     }
                     else  uc=0;
                     if(uc) {
                         if(destSize>0) {
                             *dest++=uc;
                         }
                         --destSize;
                     }
                 } else {                /* RTL run */
                     if((pBiDi->isInverse) &&
                        (/*run>0 &&*/ !(MASK_R_AL&DIRPROP_FLAG(dirProps[logicalStart+runLength-1])))) {
                         markFlag |= RLM_BEFORE;
                     }
                     if (markFlag & LRM_BEFORE) {
                         uc=LRM_CHAR;
                     }
                     else if (markFlag & RLM_BEFORE) {
                         uc=RLM_CHAR;
                     }
                     else  uc=0;
                     if(uc) {
                         if(destSize>0) {
                             *dest++=uc;
                         }
                         --destSize;
                     }
                     runLength=doWriteReverse(src, runLength,
                                              dest, destSize,
                                              options, pErrorCode);
                     if(dest!=NULL) {
                       dest+=runLength;
                     }
                     destSize-=runLength;
                     if((pBiDi->isInverse) &&
                        (/*run<runCount-1 &&*/ !(MASK_R_AL&DIRPROP_FLAG(dirProps[logicalStart])))) {
                         markFlag |= RLM_AFTER;
                     }
                     if (markFlag & LRM_AFTER) {
                         uc=LRM_CHAR;
                     }
                     else if (markFlag & RLM_AFTER) {
                         uc=RLM_CHAR;
                     }
                     else  uc=0;
                     if(uc) {
                         if(destSize>0) {
                             *dest++=uc;
                         }
                         --destSize;
                     }
                 }
             }
         }
     } else {
         /* reverse output */
         if(!(options&UBIDI_INSERT_LRM_FOR_NUMERIC)) {
             /* do not insert BiDi controls */
             for(run=runCount; --run>=0;) {
                 if(UBIDI_LTR==ubidi_getVisualRun(pBiDi, run, &logicalStart, &runLength)) {
                     runLength=doWriteReverse(text+logicalStart, runLength,
                                              dest, destSize,
                                              (uint16_t)(options&~UBIDI_DO_MIRRORING), pErrorCode);
                 } else {
                     runLength=doWriteForward(text+logicalStart, runLength,
                                              dest, destSize,
                                              options, pErrorCode);
                 }
                 if(dest!=NULL) {
                   dest+=runLength;
                 }
                 destSize-=runLength;
             }
         } else {
             /* insert BiDi controls for "inverse BiDi" */
             const DirProp *dirProps=pBiDi->dirProps;
             const UChar *src;
             UBiDiDirection dir;
             for(run=runCount; --run>=0;) {
                 /* reverse output */
                 dir=ubidi_getVisualRun(pBiDi, run, &logicalStart, &runLength);
                 src=text+logicalStart;
                 if(UBIDI_LTR==dir) {
                     if(/*run<runCount-1 &&*/ dirProps[logicalStart+runLength-1]!=L) {
                         if(destSize>0) {
                             *dest++=LRM_CHAR;
                         }
                         --destSize;
                     }
                     runLength=doWriteReverse(src, runLength,
                                              dest, destSize,
                                              (uint16_t)(options&~UBIDI_DO_MIRRORING), pErrorCode);
                     if(dest!=NULL) {
                       dest+=runLength;
                     }
                     destSize-=runLength;
                     if(/*run>0 &&*/ dirProps[logicalStart]!=L) {
                         if(destSize>0) {
                             *dest++=LRM_CHAR;
                         }
                         --destSize;
                     }
                 } else {
                     if(/*run<runCount-1 &&*/ !(MASK_R_AL&DIRPROP_FLAG(dirProps[logicalStart]))) {
                         if(destSize>0) {
                             *dest++=RLM_CHAR;
                         }
                         --destSize;
                     }
                     runLength=doWriteForward(src, runLength,
                                              dest, destSize,
                                              options, pErrorCode);
                     if(dest!=NULL) {
                       dest+=runLength;
                     }
                     destSize-=runLength;
                     if(/*run>0 &&*/ !(MASK_R_AL&DIRPROP_FLAG(dirProps[logicalStart+runLength-1]))) {
                         if(destSize>0) {
                             *dest++=RLM_CHAR;
                         }
                         --destSize;
                     }
                 }
             }
         }
     }
     return u_terminateUChars(saveDest, destCapacity, destCapacity-destSize, pErrorCode);
 }

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intl/icu/source/common/ubidiwrt.c@b8a032363ba2 (annotated)

intl/icu/source/common/ubidiwrt.c