The Tor Browser: intl/icu/source/common/ucnv_u16.c@b8a032363ba2 (annotated)

intl/icu/source/common/ucnv_u16.c@b8a032363ba2 (annotated)

intl/icu/source/common/ucnv_u16.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) 2002-2010, International Business Machines
 *   Corporation and others.  All Rights Reserved.
 **********************************************************************
 *   file name:  ucnv_u16.c
 *   encoding:   US-ASCII
 *   tab size:   8 (not used)
 *   indentation:4
 *
 *   created on: 2002jul01
 *   created by: Markus W. Scherer
 *
 *   UTF-16 converter implementation. Used to be in ucnv_utf.c.
 */
 #include "unicode/utypes.h"
 #if !UCONFIG_NO_CONVERSION
 #include "unicode/ucnv.h"
 #include "ucnv_bld.h"
 #include "ucnv_cnv.h"
 #include "cmemory.h"
 enum {
     UCNV_NEED_TO_WRITE_BOM=1
 };
 /*
  * The UTF-16 toUnicode implementation is also used for the Java-specific
  * "with BOM" variants of UTF-16BE and UTF-16LE.
  */
 static void
 _UTF16ToUnicodeWithOffsets(UConverterToUnicodeArgs *pArgs,
                            UErrorCode *pErrorCode);
 /* UTF-16BE ----------------------------------------------------------------- */
 #if U_IS_BIG_ENDIAN
 #   define _UTF16PEFromUnicodeWithOffsets   _UTF16BEFromUnicodeWithOffsets
 #else
 #   define _UTF16PEFromUnicodeWithOffsets   _UTF16LEFromUnicodeWithOffsets
 #endif
 static void
 _UTF16BEFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
                                UErrorCode *pErrorCode) {
     UConverter *cnv;
     const UChar *source;
     char *target;
     int32_t *offsets;
     uint32_t targetCapacity, length, sourceIndex;
     UChar c, trail;
     char overflow[4];
     source=pArgs->source;
     length=(int32_t)(pArgs->sourceLimit-source);
     if(length<=0) {
         /* no input, nothing to do */
         return;
     }
     cnv=pArgs->converter;
     /* write the BOM if necessary */
     if(cnv->fromUnicodeStatus==UCNV_NEED_TO_WRITE_BOM) {
         static const char bom[]={ (char)0xfe, (char)0xff };
         ucnv_fromUWriteBytes(cnv,
                              bom, 2,
                              &pArgs->target, pArgs->targetLimit,
                              &pArgs->offsets, -1,
                              pErrorCode);
         cnv->fromUnicodeStatus=0;
     }
     target=pArgs->target;
     if(target >= pArgs->targetLimit) {
         *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
         return;
     }
     targetCapacity=(uint32_t)(pArgs->targetLimit-target);
     offsets=pArgs->offsets;
     sourceIndex=0;
     /* c!=0 indicates in several places outside the main loops that a surrogate was found */
     if((c=(UChar)cnv->fromUChar32)!=0 && U16_IS_TRAIL(trail=*source) && targetCapacity>=4) {
         /* the last buffer ended with a lead surrogate, output the surrogate pair */
         ++source;
         --length;
         target[0]=(uint8_t)(c>>8);
         target[1]=(uint8_t)c;
         target[2]=(uint8_t)(trail>>8);
         target[3]=(uint8_t)trail;
         target+=4;
         targetCapacity-=4;
         if(offsets!=NULL) {
             *offsets++=-1;
             *offsets++=-1;
             *offsets++=-1;
             *offsets++=-1;
         }
         sourceIndex=1;
         cnv->fromUChar32=c=0;
     }
     if(c==0) {
         /* copy an even number of bytes for complete UChars */
         uint32_t count=2*length;
         if(count>targetCapacity) {
             count=targetCapacity&~1;
         }
         /* count is even */
         targetCapacity-=count;
         count>>=1;
         length-=count;
         if(offsets==NULL) {
             while(count>0) {
                 c=*source++;
                 if(U16_IS_SINGLE(c)) {
                     target[0]=(uint8_t)(c>>8);
                     target[1]=(uint8_t)c;
                     target+=2;
                 } else if(U16_IS_SURROGATE_LEAD(c) && count>=2 && U16_IS_TRAIL(trail=*source)) {
                     ++source;
                     --count;
                     target[0]=(uint8_t)(c>>8);
                     target[1]=(uint8_t)c;
                     target[2]=(uint8_t)(trail>>8);
                     target[3]=(uint8_t)trail;
                     target+=4;
                 } else {
                     break;
                 }
                 --count;
             }
         } else {
             while(count>0) {
                 c=*source++;
                 if(U16_IS_SINGLE(c)) {
                     target[0]=(uint8_t)(c>>8);
                     target[1]=(uint8_t)c;
                     target+=2;
                     *offsets++=sourceIndex;
                     *offsets++=sourceIndex++;
                 } else if(U16_IS_SURROGATE_LEAD(c) && count>=2 && U16_IS_TRAIL(trail=*source)) {
                     ++source;
                     --count;
                     target[0]=(uint8_t)(c>>8);
                     target[1]=(uint8_t)c;
                     target[2]=(uint8_t)(trail>>8);
                     target[3]=(uint8_t)trail;
                     target+=4;
                     *offsets++=sourceIndex;
                     *offsets++=sourceIndex;
                     *offsets++=sourceIndex;
                     *offsets++=sourceIndex;
                     sourceIndex+=2;
                 } else {
                     break;
                 }
                 --count;
             }
         }
         if(count==0) {
             /* done with the loop for complete UChars */
             if(length>0 && targetCapacity>0) {
                 /*
                  * there is more input and some target capacity -
                  * it must be targetCapacity==1 because otherwise
                  * the above would have copied more;
                  * prepare for overflow output
                  */
                 if(U16_IS_SINGLE(c=*source++)) {
                     overflow[0]=(char)(c>>8);
                     overflow[1]=(char)c;
                     length=2; /* 2 bytes to output */
                     c=0;
                 /* } else { keep c for surrogate handling, length will be set there */
                 }
             } else {
                 length=0;
                 c=0;
             }
         } else {
             /* keep c for surrogate handling, length will be set there */
             targetCapacity+=2*count;
         }
     } else {
         length=0; /* from here on, length counts the bytes in overflow[] */
     }
     if(c!=0) {
         /*
          * c is a surrogate, and
          * - source or target too short
          * - or the surrogate is unmatched
          */
         length=0;
         if(U16_IS_SURROGATE_LEAD(c)) {
             if(source<pArgs->sourceLimit) {
                 if(U16_IS_TRAIL(trail=*source)) {
                     /* output the surrogate pair, will overflow (see conditions comment above) */
                     ++source;
                     overflow[0]=(char)(c>>8);
                     overflow[1]=(char)c;
                     overflow[2]=(char)(trail>>8);
                     overflow[3]=(char)trail;
                     length=4; /* 4 bytes to output */
                     c=0;
                 } else {
                     /* unmatched lead surrogate */
                     *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                 }
             } else {
                 /* see if the trail surrogate is in the next buffer */
             }
         } else {
             /* unmatched trail surrogate */
             *pErrorCode=U_ILLEGAL_CHAR_FOUND;
         }
         cnv->fromUChar32=c;
     }
     if(length>0) {
         /* output length bytes with overflow (length>targetCapacity>0) */
         ucnv_fromUWriteBytes(cnv,
                              overflow, length,
                              (char **)&target, pArgs->targetLimit,
                              &offsets, sourceIndex,
                              pErrorCode);
         targetCapacity=(uint32_t)(pArgs->targetLimit-(char *)target);
     }
     if(U_SUCCESS(*pErrorCode) && source<pArgs->sourceLimit && targetCapacity==0) {
         *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
     }
     /* write back the updated pointers */
     pArgs->source=source;
     pArgs->target=(char *)target;
     pArgs->offsets=offsets;
 }
 static void
 _UTF16BEToUnicodeWithOffsets(UConverterToUnicodeArgs *pArgs,
                              UErrorCode *pErrorCode) {
     UConverter *cnv;
     const uint8_t *source;
     UChar *target;
     int32_t *offsets;
     uint32_t targetCapacity, length, count, sourceIndex;
     UChar c, trail;
     if(pArgs->converter->mode<8) {
         _UTF16ToUnicodeWithOffsets(pArgs, pErrorCode);
         return;
     }
     cnv=pArgs->converter;
     source=(const uint8_t *)pArgs->source;
     length=(int32_t)((const uint8_t *)pArgs->sourceLimit-source);
     if(length<=0 && cnv->toUnicodeStatus==0) {
         /* no input, nothing to do */
         return;
     }
     target=pArgs->target;
     if(target >= pArgs->targetLimit) {
         *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
         return;
     }
     targetCapacity=(uint32_t)(pArgs->targetLimit-target);
     offsets=pArgs->offsets;
     sourceIndex=0;
     c=0;
     /* complete a partial UChar or pair from the last call */
     if(cnv->toUnicodeStatus!=0) {
         /*
          * special case: single byte from a previous buffer,
          * where the byte turned out not to belong to a trail surrogate
          * and the preceding, unmatched lead surrogate was put into toUBytes[]
          * for error handling
          */
         cnv->toUBytes[0]=(uint8_t)cnv->toUnicodeStatus;
         cnv->toULength=1;
         cnv->toUnicodeStatus=0;
     }
     if((count=cnv->toULength)!=0) {
         uint8_t *p=cnv->toUBytes;
         do {
             p[count++]=*source++;
             ++sourceIndex;
             --length;
             if(count==2) {
                 c=((UChar)p[0]<<8)|p[1];
                 if(U16_IS_SINGLE(c)) {
                     /* output the BMP code point */
                     *target++=c;
                     if(offsets!=NULL) {
                         *offsets++=-1;
                     }
                     --targetCapacity;
                     count=0;
                     c=0;
                     break;
                 } else if(U16_IS_SURROGATE_LEAD(c)) {
                     /* continue collecting bytes for the trail surrogate */
                     c=0; /* avoid unnecessary surrogate handling below */
                 } else {
                     /* fall through to error handling for an unmatched trail surrogate */
                     break;
                 }
             } else if(count==4) {
                 c=((UChar)p[0]<<8)|p[1];
                 trail=((UChar)p[2]<<8)|p[3];
                 if(U16_IS_TRAIL(trail)) {
                     /* output the surrogate pair */
                     *target++=c;
                     if(targetCapacity>=2) {
                         *target++=trail;
                         if(offsets!=NULL) {
                             *offsets++=-1;
                             *offsets++=-1;
                         }
                         targetCapacity-=2;
                     } else /* targetCapacity==1 */ {
                         targetCapacity=0;
                         cnv->UCharErrorBuffer[0]=trail;
                         cnv->UCharErrorBufferLength=1;
                         *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                     }
                     count=0;
                     c=0;
                     break;
                 } else {
                     /* unmatched lead surrogate, handle here for consistent toUBytes[] */
                     *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                     /* back out reading the code unit after it */
                     if(((const uint8_t *)pArgs->source-source)>=2) {
                         source-=2;
                     } else {
                         /*
                          * if the trail unit's first byte was in a previous buffer, then
                          * we need to put it into a special place because toUBytes[] will be
                          * used for the lead unit's bytes
                          */
                         cnv->toUnicodeStatus=0x100|p[2];
                         --source;
                     }
                     cnv->toULength=2;
                     /* write back the updated pointers */
                     pArgs->source=(const char *)source;
                     pArgs->target=target;
                     pArgs->offsets=offsets;
                     return;
                 }
             }
         } while(length>0);
         cnv->toULength=(int8_t)count;
     }
     /* copy an even number of bytes for complete UChars */
     count=2*targetCapacity;
     if(count>length) {
         count=length&~1;
     }
     if(c==0 && count>0) {
         length-=count;
         count>>=1;
         targetCapacity-=count;
         if(offsets==NULL) {
             do {
                 c=((UChar)source[0]<<8)|source[1];
                 source+=2;
                 if(U16_IS_SINGLE(c)) {
                     *target++=c;
                 } else if(U16_IS_SURROGATE_LEAD(c) && count>=2 &&
                           U16_IS_TRAIL(trail=((UChar)source[0]<<8)|source[1])
                 ) {
                     source+=2;
                     --count;
                     *target++=c;
                     *target++=trail;
                 } else {
                     break;
                 }
             } while(--count>0);
         } else {
             do {
                 c=((UChar)source[0]<<8)|source[1];
                 source+=2;
                 if(U16_IS_SINGLE(c)) {
                     *target++=c;
                     *offsets++=sourceIndex;
                     sourceIndex+=2;
                 } else if(U16_IS_SURROGATE_LEAD(c) && count>=2 &&
                           U16_IS_TRAIL(trail=((UChar)source[0]<<8)|source[1])
                 ) {
                     source+=2;
                     --count;
                     *target++=c;
                     *target++=trail;
                     *offsets++=sourceIndex;
                     *offsets++=sourceIndex;
                     sourceIndex+=4;
                 } else {
                     break;
                 }
             } while(--count>0);
         }
         if(count==0) {
             /* done with the loop for complete UChars */
             c=0;
         } else {
             /* keep c for surrogate handling, trail will be set there */
             length+=2*(count-1); /* one more byte pair was consumed than count decremented */
             targetCapacity+=count;
         }
     }
     if(c!=0) {
         /*
          * c is a surrogate, and
          * - source or target too short
          * - or the surrogate is unmatched
          */
         cnv->toUBytes[0]=(uint8_t)(c>>8);
         cnv->toUBytes[1]=(uint8_t)c;
         cnv->toULength=2;
         if(U16_IS_SURROGATE_LEAD(c)) {
             if(length>=2) {
                 if(U16_IS_TRAIL(trail=((UChar)source[0]<<8)|source[1])) {
                     /* output the surrogate pair, will overflow (see conditions comment above) */
                     source+=2;
                     length-=2;
                     *target++=c;
                     if(offsets!=NULL) {
                         *offsets++=sourceIndex;
                     }
                     cnv->UCharErrorBuffer[0]=trail;
                     cnv->UCharErrorBufferLength=1;
                     cnv->toULength=0;
                     *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                 } else {
                     /* unmatched lead surrogate */
                     *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                 }
             } else {
                 /* see if the trail surrogate is in the next buffer */
             }
         } else {
             /* unmatched trail surrogate */
             *pErrorCode=U_ILLEGAL_CHAR_FOUND;
         }
     }
     if(U_SUCCESS(*pErrorCode)) {
         /* check for a remaining source byte */
         if(length>0) {
             if(targetCapacity==0) {
                 *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             } else {
                 /* it must be length==1 because otherwise the above would have copied more */
                 cnv->toUBytes[cnv->toULength++]=*source++;
             }
         }
     }
     /* write back the updated pointers */
     pArgs->source=(const char *)source;
     pArgs->target=target;
     pArgs->offsets=offsets;
 }
 static UChar32
 _UTF16BEGetNextUChar(UConverterToUnicodeArgs *pArgs, UErrorCode *err) {
     const uint8_t *s, *sourceLimit;
     UChar32 c;
     if(pArgs->converter->mode<8) {
         return UCNV_GET_NEXT_UCHAR_USE_TO_U;
     }
     s=(const uint8_t *)pArgs->source;
     sourceLimit=(const uint8_t *)pArgs->sourceLimit;
     if(s>=sourceLimit) {
         /* no input */
         *err=U_INDEX_OUTOFBOUNDS_ERROR;
         return 0xffff;
     }
     if(s+2>sourceLimit) {
         /* only one byte: truncated UChar */
         pArgs->converter->toUBytes[0]=*s++;
         pArgs->converter->toULength=1;
         pArgs->source=(const char *)s;
         *err = U_TRUNCATED_CHAR_FOUND;
         return 0xffff;
     }
     /* get one UChar */
     c=((UChar32)*s<<8)|s[1];
     s+=2;
     /* check for a surrogate pair */
     if(U_IS_SURROGATE(c)) {
         if(U16_IS_SURROGATE_LEAD(c)) {
             if(s+2<=sourceLimit) {
                 UChar trail;
                 /* get a second UChar and see if it is a trail surrogate */
                 trail=((UChar)*s<<8)|s[1];
                 if(U16_IS_TRAIL(trail)) {
                     c=U16_GET_SUPPLEMENTARY(c, trail);
                     s+=2;
                 } else {
                     /* unmatched lead surrogate */
                     c=-2;
                 }
             } else {
                 /* too few (2 or 3) bytes for a surrogate pair: truncated code point */
                 uint8_t *bytes=pArgs->converter->toUBytes;
                 s-=2;
                 pArgs->converter->toULength=(int8_t)(sourceLimit-s);
                 do {
                     *bytes++=*s++;
                 } while(s<sourceLimit);
                 c=0xffff;
                 *err=U_TRUNCATED_CHAR_FOUND;
             }
         } else {
             /* unmatched trail surrogate */
             c=-2;
         }
         if(c<0) {
             /* write the unmatched surrogate */
             uint8_t *bytes=pArgs->converter->toUBytes;
             pArgs->converter->toULength=2;
             *bytes=*(s-2);
             bytes[1]=*(s-1);
             c=0xffff;
             *err=U_ILLEGAL_CHAR_FOUND;
         }
     }
     pArgs->source=(const char *)s;
     return c;
 }
 static void
 _UTF16BEReset(UConverter *cnv, UConverterResetChoice choice) {
     if(choice<=UCNV_RESET_TO_UNICODE) {
         /* reset toUnicode state */
         if(UCNV_GET_VERSION(cnv)==0) {
             cnv->mode=8; /* no BOM handling */
         } else {
             cnv->mode=0; /* Java-specific "UnicodeBig" requires BE BOM or no BOM */
         }
     }
     if(choice!=UCNV_RESET_TO_UNICODE && UCNV_GET_VERSION(cnv)==1) {
         /* reset fromUnicode for "UnicodeBig": prepare to output the UTF-16BE BOM */
         cnv->fromUnicodeStatus=UCNV_NEED_TO_WRITE_BOM;
     }
 }
 static void
 _UTF16BEOpen(UConverter *cnv,
              UConverterLoadArgs *pArgs,
              UErrorCode *pErrorCode) {
     if(UCNV_GET_VERSION(cnv)<=1) {
         _UTF16BEReset(cnv, UCNV_RESET_BOTH);
     } else {
         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
     }
 }
 static const char *
 _UTF16BEGetName(const UConverter *cnv) {
     if(UCNV_GET_VERSION(cnv)==0) {
         return "UTF-16BE";
     } else {
         return "UTF-16BE,version=1";
     }
 }
 static const UConverterImpl _UTF16BEImpl={
     UCNV_UTF16_BigEndian,
     NULL,
     NULL,
     _UTF16BEOpen,
     NULL,
     _UTF16BEReset,
     _UTF16BEToUnicodeWithOffsets,
     _UTF16BEToUnicodeWithOffsets,
     _UTF16BEFromUnicodeWithOffsets,
     _UTF16BEFromUnicodeWithOffsets,
     _UTF16BEGetNextUChar,
     NULL,
     _UTF16BEGetName,
     NULL,
     NULL,
     ucnv_getNonSurrogateUnicodeSet
 };
 static const UConverterStaticData _UTF16BEStaticData={
     sizeof(UConverterStaticData),
     "UTF-16BE",
 , UCNV_IBM, UCNV_UTF16_BigEndian, 2, 2,
     { 0xff, 0xfd, 0, 0 },2,FALSE,FALSE,
 ,
 ,
     { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } /* reserved */
 };
 const UConverterSharedData _UTF16BEData={
     sizeof(UConverterSharedData), ~((uint32_t) 0),
     NULL, NULL, &_UTF16BEStaticData, FALSE, &_UTF16BEImpl,
 
 };
 /* UTF-16LE ----------------------------------------------------------------- */
 static void
 _UTF16LEFromUnicodeWithOffsets(UConverterFromUnicodeArgs *pArgs,
                                UErrorCode *pErrorCode) {
     UConverter *cnv;
     const UChar *source;
     char *target;
     int32_t *offsets;
     uint32_t targetCapacity, length, sourceIndex;
     UChar c, trail;
     char overflow[4];
     source=pArgs->source;
     length=(int32_t)(pArgs->sourceLimit-source);
     if(length<=0) {
         /* no input, nothing to do */
         return;
     }
     cnv=pArgs->converter;
     /* write the BOM if necessary */
     if(cnv->fromUnicodeStatus==UCNV_NEED_TO_WRITE_BOM) {
         static const char bom[]={ (char)0xff, (char)0xfe };
         ucnv_fromUWriteBytes(cnv,
                              bom, 2,
                              &pArgs->target, pArgs->targetLimit,
                              &pArgs->offsets, -1,
                              pErrorCode);
         cnv->fromUnicodeStatus=0;
     }
     target=pArgs->target;
     if(target >= pArgs->targetLimit) {
         *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
         return;
     }
     targetCapacity=(uint32_t)(pArgs->targetLimit-pArgs->target);
     offsets=pArgs->offsets;
     sourceIndex=0;
     /* c!=0 indicates in several places outside the main loops that a surrogate was found */
     if((c=(UChar)cnv->fromUChar32)!=0 && U16_IS_TRAIL(trail=*source) && targetCapacity>=4) {
         /* the last buffer ended with a lead surrogate, output the surrogate pair */
         ++source;
         --length;
         target[0]=(uint8_t)c;
         target[1]=(uint8_t)(c>>8);
         target[2]=(uint8_t)trail;
         target[3]=(uint8_t)(trail>>8);
         target+=4;
         targetCapacity-=4;
         if(offsets!=NULL) {
             *offsets++=-1;
             *offsets++=-1;
             *offsets++=-1;
             *offsets++=-1;
         }
         sourceIndex=1;
         cnv->fromUChar32=c=0;
     }
     if(c==0) {
         /* copy an even number of bytes for complete UChars */
         uint32_t count=2*length;
         if(count>targetCapacity) {
             count=targetCapacity&~1;
         }
         /* count is even */
         targetCapacity-=count;
         count>>=1;
         length-=count;
         if(offsets==NULL) {
             while(count>0) {
                 c=*source++;
                 if(U16_IS_SINGLE(c)) {
                     target[0]=(uint8_t)c;
                     target[1]=(uint8_t)(c>>8);
                     target+=2;
                 } else if(U16_IS_SURROGATE_LEAD(c) && count>=2 && U16_IS_TRAIL(trail=*source)) {
                     ++source;
                     --count;
                     target[0]=(uint8_t)c;
                     target[1]=(uint8_t)(c>>8);
                     target[2]=(uint8_t)trail;
                     target[3]=(uint8_t)(trail>>8);
                     target+=4;
                 } else {
                     break;
                 }
                 --count;
             }
         } else {
             while(count>0) {
                 c=*source++;
                 if(U16_IS_SINGLE(c)) {
                     target[0]=(uint8_t)c;
                     target[1]=(uint8_t)(c>>8);
                     target+=2;
                     *offsets++=sourceIndex;
                     *offsets++=sourceIndex++;
                 } else if(U16_IS_SURROGATE_LEAD(c) && count>=2 && U16_IS_TRAIL(trail=*source)) {
                     ++source;
                     --count;
                     target[0]=(uint8_t)c;
                     target[1]=(uint8_t)(c>>8);
                     target[2]=(uint8_t)trail;
                     target[3]=(uint8_t)(trail>>8);
                     target+=4;
                     *offsets++=sourceIndex;
                     *offsets++=sourceIndex;
                     *offsets++=sourceIndex;
                     *offsets++=sourceIndex;
                     sourceIndex+=2;
                 } else {
                     break;
                 }
                 --count;
             }
         }
         if(count==0) {
             /* done with the loop for complete UChars */
             if(length>0 && targetCapacity>0) {
                 /*
                  * there is more input and some target capacity -
                  * it must be targetCapacity==1 because otherwise
                  * the above would have copied more;
                  * prepare for overflow output
                  */
                 if(U16_IS_SINGLE(c=*source++)) {
                     overflow[0]=(char)c;
                     overflow[1]=(char)(c>>8);
                     length=2; /* 2 bytes to output */
                     c=0;
                 /* } else { keep c for surrogate handling, length will be set there */
                 }
             } else {
                 length=0;
                 c=0;
             }
         } else {
             /* keep c for surrogate handling, length will be set there */
             targetCapacity+=2*count;
         }
     } else {
         length=0; /* from here on, length counts the bytes in overflow[] */
     }
     if(c!=0) {
         /*
          * c is a surrogate, and
          * - source or target too short
          * - or the surrogate is unmatched
          */
         length=0;
         if(U16_IS_SURROGATE_LEAD(c)) {
             if(source<pArgs->sourceLimit) {
                 if(U16_IS_TRAIL(trail=*source)) {
                     /* output the surrogate pair, will overflow (see conditions comment above) */
                     ++source;
                     overflow[0]=(char)c;
                     overflow[1]=(char)(c>>8);
                     overflow[2]=(char)trail;
                     overflow[3]=(char)(trail>>8);
                     length=4; /* 4 bytes to output */
                     c=0;
                 } else {
                     /* unmatched lead surrogate */
                     *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                 }
             } else {
                 /* see if the trail surrogate is in the next buffer */
             }
         } else {
             /* unmatched trail surrogate */
             *pErrorCode=U_ILLEGAL_CHAR_FOUND;
         }
         cnv->fromUChar32=c;
     }
     if(length>0) {
         /* output length bytes with overflow (length>targetCapacity>0) */
         ucnv_fromUWriteBytes(cnv,
                              overflow, length,
                              &target, pArgs->targetLimit,
                              &offsets, sourceIndex,
                              pErrorCode);
         targetCapacity=(uint32_t)(pArgs->targetLimit-(char *)target);
     }
     if(U_SUCCESS(*pErrorCode) && source<pArgs->sourceLimit && targetCapacity==0) {
         *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
     }
     /* write back the updated pointers */
     pArgs->source=source;
     pArgs->target=target;
     pArgs->offsets=offsets;
 }
 static void
 _UTF16LEToUnicodeWithOffsets(UConverterToUnicodeArgs *pArgs,
                              UErrorCode *pErrorCode) {
     UConverter *cnv;
     const uint8_t *source;
     UChar *target;
     int32_t *offsets;
     uint32_t targetCapacity, length, count, sourceIndex;
     UChar c, trail;
     if(pArgs->converter->mode<8) {
         _UTF16ToUnicodeWithOffsets(pArgs, pErrorCode);
         return;
     }
     cnv=pArgs->converter;
     source=(const uint8_t *)pArgs->source;
     length=(int32_t)((const uint8_t *)pArgs->sourceLimit-source);
     if(length<=0 && cnv->toUnicodeStatus==0) {
         /* no input, nothing to do */
         return;
     }
     target=pArgs->target;
     if(target >= pArgs->targetLimit) {
         *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
         return;
     }
     targetCapacity=(uint32_t)(pArgs->targetLimit-pArgs->target);
     offsets=pArgs->offsets;
     sourceIndex=0;
     c=0;
     /* complete a partial UChar or pair from the last call */
     if(cnv->toUnicodeStatus!=0) {
         /*
          * special case: single byte from a previous buffer,
          * where the byte turned out not to belong to a trail surrogate
          * and the preceding, unmatched lead surrogate was put into toUBytes[]
          * for error handling
          */
         cnv->toUBytes[0]=(uint8_t)cnv->toUnicodeStatus;
         cnv->toULength=1;
         cnv->toUnicodeStatus=0;
     }
     if((count=cnv->toULength)!=0) {
         uint8_t *p=cnv->toUBytes;
         do {
             p[count++]=*source++;
             ++sourceIndex;
             --length;
             if(count==2) {
                 c=((UChar)p[1]<<8)|p[0];
                 if(U16_IS_SINGLE(c)) {
                     /* output the BMP code point */
                     *target++=c;
                     if(offsets!=NULL) {
                         *offsets++=-1;
                     }
                     --targetCapacity;
                     count=0;
                     c=0;
                     break;
                 } else if(U16_IS_SURROGATE_LEAD(c)) {
                     /* continue collecting bytes for the trail surrogate */
                     c=0; /* avoid unnecessary surrogate handling below */
                 } else {
                     /* fall through to error handling for an unmatched trail surrogate */
                     break;
                 }
             } else if(count==4) {
                 c=((UChar)p[1]<<8)|p[0];
                 trail=((UChar)p[3]<<8)|p[2];
                 if(U16_IS_TRAIL(trail)) {
                     /* output the surrogate pair */
                     *target++=c;
                     if(targetCapacity>=2) {
                         *target++=trail;
                         if(offsets!=NULL) {
                             *offsets++=-1;
                             *offsets++=-1;
                         }
                         targetCapacity-=2;
                     } else /* targetCapacity==1 */ {
                         targetCapacity=0;
                         cnv->UCharErrorBuffer[0]=trail;
                         cnv->UCharErrorBufferLength=1;
                         *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                     }
                     count=0;
                     c=0;
                     break;
                 } else {
                     /* unmatched lead surrogate, handle here for consistent toUBytes[] */
                     *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                     /* back out reading the code unit after it */
                     if(((const uint8_t *)pArgs->source-source)>=2) {
                         source-=2;
                     } else {
                         /*
                          * if the trail unit's first byte was in a previous buffer, then
                          * we need to put it into a special place because toUBytes[] will be
                          * used for the lead unit's bytes
                          */
                         cnv->toUnicodeStatus=0x100|p[2];
                         --source;
                     }
                     cnv->toULength=2;
                     /* write back the updated pointers */
                     pArgs->source=(const char *)source;
                     pArgs->target=target;
                     pArgs->offsets=offsets;
                     return;
                 }
             }
         } while(length>0);
         cnv->toULength=(int8_t)count;
     }
     /* copy an even number of bytes for complete UChars */
     count=2*targetCapacity;
     if(count>length) {
         count=length&~1;
     }
     if(c==0 && count>0) {
         length-=count;
         count>>=1;
         targetCapacity-=count;
         if(offsets==NULL) {
             do {
                 c=((UChar)source[1]<<8)|source[0];
                 source+=2;
                 if(U16_IS_SINGLE(c)) {
                     *target++=c;
                 } else if(U16_IS_SURROGATE_LEAD(c) && count>=2 &&
                           U16_IS_TRAIL(trail=((UChar)source[1]<<8)|source[0])
                 ) {
                     source+=2;
                     --count;
                     *target++=c;
                     *target++=trail;
                 } else {
                     break;
                 }
             } while(--count>0);
         } else {
             do {
                 c=((UChar)source[1]<<8)|source[0];
                 source+=2;
                 if(U16_IS_SINGLE(c)) {
                     *target++=c;
                     *offsets++=sourceIndex;
                     sourceIndex+=2;
                 } else if(U16_IS_SURROGATE_LEAD(c) && count>=2 &&
                           U16_IS_TRAIL(trail=((UChar)source[1]<<8)|source[0])
                 ) {
                     source+=2;
                     --count;
                     *target++=c;
                     *target++=trail;
                     *offsets++=sourceIndex;
                     *offsets++=sourceIndex;
                     sourceIndex+=4;
                 } else {
                     break;
                 }
             } while(--count>0);
         }
         if(count==0) {
             /* done with the loop for complete UChars */
             c=0;
         } else {
             /* keep c for surrogate handling, trail will be set there */
             length+=2*(count-1); /* one more byte pair was consumed than count decremented */
             targetCapacity+=count;
         }
     }
     if(c!=0) {
         /*
          * c is a surrogate, and
          * - source or target too short
          * - or the surrogate is unmatched
          */
         cnv->toUBytes[0]=(uint8_t)c;
         cnv->toUBytes[1]=(uint8_t)(c>>8);
         cnv->toULength=2;
         if(U16_IS_SURROGATE_LEAD(c)) {
             if(length>=2) {
                 if(U16_IS_TRAIL(trail=((UChar)source[1]<<8)|source[0])) {
                     /* output the surrogate pair, will overflow (see conditions comment above) */
                     source+=2;
                     length-=2;
                     *target++=c;
                     if(offsets!=NULL) {
                         *offsets++=sourceIndex;
                     }
                     cnv->UCharErrorBuffer[0]=trail;
                     cnv->UCharErrorBufferLength=1;
                     cnv->toULength=0;
                     *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
                 } else {
                     /* unmatched lead surrogate */
                     *pErrorCode=U_ILLEGAL_CHAR_FOUND;
                 }
             } else {
                 /* see if the trail surrogate is in the next buffer */
             }
         } else {
             /* unmatched trail surrogate */
             *pErrorCode=U_ILLEGAL_CHAR_FOUND;
         }
     }
     if(U_SUCCESS(*pErrorCode)) {
         /* check for a remaining source byte */
         if(length>0) {
             if(targetCapacity==0) {
                 *pErrorCode=U_BUFFER_OVERFLOW_ERROR;
             } else {
                 /* it must be length==1 because otherwise the above would have copied more */
                 cnv->toUBytes[cnv->toULength++]=*source++;
             }
         }
     }
     /* write back the updated pointers */
     pArgs->source=(const char *)source;
     pArgs->target=target;
     pArgs->offsets=offsets;
 }
 static UChar32
 _UTF16LEGetNextUChar(UConverterToUnicodeArgs *pArgs, UErrorCode *err) {
     const uint8_t *s, *sourceLimit;
     UChar32 c;
     if(pArgs->converter->mode<8) {
         return UCNV_GET_NEXT_UCHAR_USE_TO_U;
     }
     s=(const uint8_t *)pArgs->source;
     sourceLimit=(const uint8_t *)pArgs->sourceLimit;
     if(s>=sourceLimit) {
         /* no input */
         *err=U_INDEX_OUTOFBOUNDS_ERROR;
         return 0xffff;
     }
     if(s+2>sourceLimit) {
         /* only one byte: truncated UChar */
         pArgs->converter->toUBytes[0]=*s++;
         pArgs->converter->toULength=1;
         pArgs->source=(const char *)s;
         *err = U_TRUNCATED_CHAR_FOUND;
         return 0xffff;
     }
     /* get one UChar */
     c=((UChar32)s[1]<<8)|*s;
     s+=2;
     /* check for a surrogate pair */
     if(U_IS_SURROGATE(c)) {
         if(U16_IS_SURROGATE_LEAD(c)) {
             if(s+2<=sourceLimit) {
                 UChar trail;
                 /* get a second UChar and see if it is a trail surrogate */
                 trail=((UChar)s[1]<<8)|*s;
                 if(U16_IS_TRAIL(trail)) {
                     c=U16_GET_SUPPLEMENTARY(c, trail);
                     s+=2;
                 } else {
                     /* unmatched lead surrogate */
                     c=-2;
                 }
             } else {
                 /* too few (2 or 3) bytes for a surrogate pair: truncated code point */
                 uint8_t *bytes=pArgs->converter->toUBytes;
                 s-=2;
                 pArgs->converter->toULength=(int8_t)(sourceLimit-s);
                 do {
                     *bytes++=*s++;
                 } while(s<sourceLimit);
                 c=0xffff;
                 *err=U_TRUNCATED_CHAR_FOUND;
             }
         } else {
             /* unmatched trail surrogate */
             c=-2;
         }
         if(c<0) {
             /* write the unmatched surrogate */
             uint8_t *bytes=pArgs->converter->toUBytes;
             pArgs->converter->toULength=2;
             *bytes=*(s-2);
             bytes[1]=*(s-1);
             c=0xffff;
             *err=U_ILLEGAL_CHAR_FOUND;
         }
     }
     pArgs->source=(const char *)s;
     return c;
 }
 static void
 _UTF16LEReset(UConverter *cnv, UConverterResetChoice choice) {
     if(choice<=UCNV_RESET_TO_UNICODE) {
         /* reset toUnicode state */
         if(UCNV_GET_VERSION(cnv)==0) {
             cnv->mode=8; /* no BOM handling */
         } else {
             cnv->mode=0; /* Java-specific "UnicodeLittle" requires LE BOM or no BOM */
         }
     }
     if(choice!=UCNV_RESET_TO_UNICODE && UCNV_GET_VERSION(cnv)==1) {
         /* reset fromUnicode for "UnicodeLittle": prepare to output the UTF-16LE BOM */
         cnv->fromUnicodeStatus=UCNV_NEED_TO_WRITE_BOM;
     }
 }
 static void
 _UTF16LEOpen(UConverter *cnv,
              UConverterLoadArgs *pArgs,
              UErrorCode *pErrorCode) {
     if(UCNV_GET_VERSION(cnv)<=1) {
         _UTF16LEReset(cnv, UCNV_RESET_BOTH);
     } else {
         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
     }
 }
 static const char *
 _UTF16LEGetName(const UConverter *cnv) {
     if(UCNV_GET_VERSION(cnv)==0) {
         return "UTF-16LE";
     } else {
         return "UTF-16LE,version=1";
     }
 }
 static const UConverterImpl _UTF16LEImpl={
     UCNV_UTF16_LittleEndian,
     NULL,
     NULL,
     _UTF16LEOpen,
     NULL,
     _UTF16LEReset,
     _UTF16LEToUnicodeWithOffsets,
     _UTF16LEToUnicodeWithOffsets,
     _UTF16LEFromUnicodeWithOffsets,
     _UTF16LEFromUnicodeWithOffsets,
     _UTF16LEGetNextUChar,
     NULL,
     _UTF16LEGetName,
     NULL,
     NULL,
     ucnv_getNonSurrogateUnicodeSet
 };
 static const UConverterStaticData _UTF16LEStaticData={
     sizeof(UConverterStaticData),
     "UTF-16LE",
 , UCNV_IBM, UCNV_UTF16_LittleEndian, 2, 2,
     { 0xfd, 0xff, 0, 0 },2,FALSE,FALSE,
 ,
 ,
     { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } /* reserved */
 };
 const UConverterSharedData _UTF16LEData={
     sizeof(UConverterSharedData), ~((uint32_t) 0),
     NULL, NULL, &_UTF16LEStaticData, FALSE, &_UTF16LEImpl,
 
 };
 /* UTF-16 (Detect BOM) ------------------------------------------------------ */
 /*
  * Detect a BOM at the beginning of the stream and select UTF-16BE or UTF-16LE
  * accordingly.
  * This is a simpler version of the UTF-32 converter, with
  * fewer states for shorter BOMs.
  *
  * State values:
  * 0    initial state
  * 1    saw first byte
  * 2..5 -
  * 6..7 see _UTF16ToUnicodeWithOffsets() comments in state 1
  * 8    UTF-16BE mode
  * 9    UTF-16LE mode
  *
  * During detection: state==number of initial bytes seen so far.
  *
  * On output, emit U+FEFF as the first code point.
  *
  * Variants:
  * - UTF-16,version=1 (Java "Unicode" encoding) treats a missing BOM as an error.
  * - UTF-16BE,version=1 (Java "UnicodeBig" encoding) and
  *   UTF-16LE,version=1 (Java "UnicodeLittle" encoding) treat a reverse BOM as an error.
  */
 static void
 _UTF16Reset(UConverter *cnv, UConverterResetChoice choice) {
     if(choice<=UCNV_RESET_TO_UNICODE) {
         /* reset toUnicode: state=0 */
         cnv->mode=0;
     }
     if(choice!=UCNV_RESET_TO_UNICODE) {
         /* reset fromUnicode: prepare to output the UTF-16PE BOM */
         cnv->fromUnicodeStatus=UCNV_NEED_TO_WRITE_BOM;
     }
 }
 static const UConverterSharedData _UTF16v2Data;
 static void
 _UTF16Open(UConverter *cnv,
            UConverterLoadArgs *pArgs,
            UErrorCode *pErrorCode) {
     if(UCNV_GET_VERSION(cnv)<=2) {
         if(UCNV_GET_VERSION(cnv)==2 && !pArgs->onlyTestIsLoadable) {
             /*
              * Switch implementation, and switch the staticData that's different
              * and was copied into the UConverter.
              * (See ucnv_createConverterFromSharedData() in ucnv_bld.c.)
              * UTF-16,version=2 fromUnicode() always writes a big-endian byte stream.
              */
             cnv->sharedData=(UConverterSharedData*)&_UTF16v2Data;
             uprv_memcpy(cnv->subChars, _UTF16v2Data.staticData->subChar, UCNV_MAX_SUBCHAR_LEN);
         }
         _UTF16Reset(cnv, UCNV_RESET_BOTH);
     } else {
         *pErrorCode=U_ILLEGAL_ARGUMENT_ERROR;
     }
 }
 static const char *
 _UTF16GetName(const UConverter *cnv) {
     if(UCNV_GET_VERSION(cnv)==0) {
         return "UTF-16";
     } else if(UCNV_GET_VERSION(cnv)==1) {
         return "UTF-16,version=1";
     } else {
         return "UTF-16,version=2";
     }
 }
 const UConverterSharedData _UTF16Data;
 #define IS_UTF16BE(cnv) ((cnv)->sharedData==&_UTF16BEData)
 #define IS_UTF16LE(cnv) ((cnv)->sharedData==&_UTF16LEData)
 #define IS_UTF16(cnv) ((cnv)->sharedData==&_UTF16Data || (cnv)->sharedData==&_UTF16v2Data)
 static void
 _UTF16ToUnicodeWithOffsets(UConverterToUnicodeArgs *pArgs,
                            UErrorCode *pErrorCode) {
     UConverter *cnv=pArgs->converter;
     const char *source=pArgs->source;
     const char *sourceLimit=pArgs->sourceLimit;
     int32_t *offsets=pArgs->offsets;
     int32_t state, offsetDelta;
     uint8_t b;
     state=cnv->mode;
     /*
      * If we detect a BOM in this buffer, then we must add the BOM size to the
      * offsets because the actual converter function will not see and count the BOM.
      * offsetDelta will have the number of the BOM bytes that are in the current buffer.
      */
     offsetDelta=0;
     while(source<sourceLimit && U_SUCCESS(*pErrorCode)) {
         switch(state) {
         case 0:
             cnv->toUBytes[0]=(uint8_t)*source++;
             cnv->toULength=1;
             state=1;
             break;
         case 1:
             /*
              * Only inside this switch case can the state variable
              * temporarily take two additional values:
              * 6: BOM error, continue with BE
              * 7: BOM error, continue with LE
              */
             b=*source;
             if(cnv->toUBytes[0]==0xfe && b==0xff) {
                 if(IS_UTF16LE(cnv)) {
                     state=7; /* illegal reverse BOM for Java "UnicodeLittle" */
                 } else {
                     state=8; /* detect UTF-16BE */
                 }
             } else if(cnv->toUBytes[0]==0xff && b==0xfe) {
                 if(IS_UTF16BE(cnv)) {
                     state=6; /* illegal reverse BOM for Java "UnicodeBig" */
                 } else {
                     state=9; /* detect UTF-16LE */
                 }
             } else if((IS_UTF16(cnv) && UCNV_GET_VERSION(cnv)==1)) {
                 state=6; /* illegal missing BOM for Java "Unicode" */
             }
             if(state>=8) {
                 /* BOM detected, consume it */
                 ++source;
                 cnv->toULength=0;
                 offsetDelta=(int32_t)(source-pArgs->source);
             } else if(state<6) {
                 /* ok: no BOM, and not a reverse BOM */
                 if(source!=pArgs->source) {
                     /* reset the source for a correct first offset */
                     source=pArgs->source;
                     cnv->toULength=0;
                 }
                 if(IS_UTF16LE(cnv)) {
                     /* Make Java "UnicodeLittle" default to LE. */
                     state=9;
                 } else {
                     /* Make standard UTF-16 and Java "UnicodeBig" default to BE. */
                     state=8;
                 }
             } else {
                 /*
                  * error: missing BOM, or reverse BOM
                  * UTF-16,version=1: Java-specific "Unicode" requires a BOM.
                  * UTF-16BE,version=1: Java-specific "UnicodeBig" requires a BE BOM or no BOM.
                  * UTF-16LE,version=1: Java-specific "UnicodeLittle" requires an LE BOM or no BOM.
                  */
                 /* report the non-BOM or reverse BOM as an illegal sequence */
                 cnv->toUBytes[1]=b;
                 cnv->toULength=2;
                 pArgs->source=source+1;
                 /* continue with conversion if the callback resets the error */
                 /*
                  * Make Java "Unicode" default to BE like standard UTF-16.
                  * Make Java "UnicodeBig" and "UnicodeLittle" default
                  * to their normal endiannesses.
                  */
                 cnv->mode=state+2;
                 *pErrorCode=U_ILLEGAL_ESCAPE_SEQUENCE;
                 return;
             }
             /* convert the rest of the stream */
             cnv->mode=state;
             continue;
         case 8:
             /* call UTF-16BE */
             pArgs->source=source;
             _UTF16BEToUnicodeWithOffsets(pArgs, pErrorCode);
             source=pArgs->source;
             break;
         case 9:
             /* call UTF-16LE */
             pArgs->source=source;
             _UTF16LEToUnicodeWithOffsets(pArgs, pErrorCode);
             source=pArgs->source;
             break;
         default:
             break; /* does not occur */
         }
     }
     /* add BOM size to offsets - see comment at offsetDelta declaration */
     if(offsets!=NULL && offsetDelta!=0) {
         int32_t *offsetsLimit=pArgs->offsets;
         while(offsets<offsetsLimit) {
             *offsets++ += offsetDelta;
         }
     }
     pArgs->source=source;
     if(source==sourceLimit && pArgs->flush) {
         /* handle truncated input */
         switch(state) {
         case 0:
             break; /* no input at all, nothing to do */
         case 8:
             _UTF16BEToUnicodeWithOffsets(pArgs, pErrorCode);
             break;
         case 9:
             _UTF16LEToUnicodeWithOffsets(pArgs, pErrorCode);
             break;
         default:
             /* 0<state<8: framework will report truncation, nothing to do here */
             break;
         }
     }
     cnv->mode=state;
 }
 static UChar32
 _UTF16GetNextUChar(UConverterToUnicodeArgs *pArgs,
                    UErrorCode *pErrorCode) {
     switch(pArgs->converter->mode) {
     case 8:
         return _UTF16BEGetNextUChar(pArgs, pErrorCode);
     case 9:
         return _UTF16LEGetNextUChar(pArgs, pErrorCode);
     default:
         return UCNV_GET_NEXT_UCHAR_USE_TO_U;
     }
 }
 static const UConverterImpl _UTF16Impl = {
     UCNV_UTF16,
     NULL,
     NULL,
     _UTF16Open,
     NULL,
     _UTF16Reset,
     _UTF16ToUnicodeWithOffsets,
     _UTF16ToUnicodeWithOffsets,
     _UTF16PEFromUnicodeWithOffsets,
     _UTF16PEFromUnicodeWithOffsets,
     _UTF16GetNextUChar,
     NULL, /* ### TODO implement getStarters for all Unicode encodings?! */
     _UTF16GetName,
     NULL,
     NULL,
     ucnv_getNonSurrogateUnicodeSet
 };
 static const UConverterStaticData _UTF16StaticData = {
     sizeof(UConverterStaticData),
     "UTF-16",
 , /* CCSID for BOM sensitive UTF-16 */
     UCNV_IBM, UCNV_UTF16, 2, 2,
 #if U_IS_BIG_ENDIAN
     { 0xff, 0xfd, 0, 0 }, 2,
 #else
     { 0xfd, 0xff, 0, 0 }, 2,
 #endif
     FALSE, FALSE,
 ,
 ,
     { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } /* reserved */
 };
 const UConverterSharedData _UTF16Data = {
     sizeof(UConverterSharedData), ~((uint32_t) 0),
     NULL, NULL, &_UTF16StaticData, FALSE, &_UTF16Impl,
 
 };
 static const UConverterImpl _UTF16v2Impl = {
     UCNV_UTF16,
     NULL,
     NULL,
     _UTF16Open,
     NULL,
     _UTF16Reset,
     _UTF16ToUnicodeWithOffsets,
     _UTF16ToUnicodeWithOffsets,
     _UTF16BEFromUnicodeWithOffsets,
     _UTF16BEFromUnicodeWithOffsets,
     _UTF16GetNextUChar,
     NULL, /* ### TODO implement getStarters for all Unicode encodings?! */
     _UTF16GetName,
     NULL,
     NULL,
     ucnv_getNonSurrogateUnicodeSet
 };
 static const UConverterStaticData _UTF16v2StaticData = {
     sizeof(UConverterStaticData),
     "UTF-16,version=2",
 , /* CCSID for BOM sensitive UTF-16 */
     UCNV_IBM, UCNV_UTF16, 2, 2,
     { 0xff, 0xfd, 0, 0 }, 2,
     FALSE, FALSE,
 ,
 ,
     { 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 } /* reserved */
 };
 static const UConverterSharedData _UTF16v2Data = {
     sizeof(UConverterSharedData), ~((uint32_t) 0),
     NULL, NULL, &_UTF16v2StaticData, FALSE, &_UTF16v2Impl,
 
 };
 #endif

The Tor Browser / annotate

intl/icu/source/common/ucnv_u16.c@b8a032363ba2 (annotated)

intl/icu/source/common/ucnv_u16.c