--- /dev/null
+/* utf8.c -- convert characters to/from UTF-8
+
+ (c) 1998-2007 (W3C) MIT, ERCIM, Keio University
+ See tidy.h for the copyright notice.
+
+ Uses public interfaces to abstract input source and output
+ sink, which may be user supplied or either FILE* or memory
+ based Tidy implementations. Encoding support is uniform
+ regardless of I/O mechanism.
+
+ Note, UTF-8 encoding, by itself, does not affect the actual
+ "codepoints" of the underlying character encoding. In the
+ cases of ASCII, Latin1, Unicode (16-bit, BMP), these all
+ refer to ISO-10646 "codepoints". For anything else, they
+ refer to some other "codepoint" set.
+
+ Put another way, UTF-8 is a variable length method to
+ represent any non-negative integer value. The glyph
+ that a integer value represents is unchanged and defined
+ externally (e.g. by ISO-10646, Big5, Win1252, MacRoman,
+ Latin2-9, and so on).
+
+ Put still another way, UTF-8 is more of a _transfer_ encoding
+ than a _character_ encoding, per se.
+*/
+
+#include "tidy.h"
+#include "forward.h"
+#include "utf8.h"
+
+/*
+UTF-8 encoding/decoding functions
+Return # of bytes in UTF-8 sequence; result < 0 if illegal sequence
+
+Also see below for UTF-16 encoding/decoding functions
+
+References :
+
+1) UCS Transformation Format 8 (UTF-8):
+ISO/IEC 10646-1:1996 Amendment 2 or ISO/IEC 10646-1:2000 Annex D
+<http://anubis.dkuug.dk/JTC1/SC2/WG2/docs/n1335>
+<http://www.cl.cam.ac.uk/~mgk25/ucs/ISO-10646-UTF-8.html>
+
+Table 4 - Mapping from UCS-4 to UTF-8
+
+2) Unicode standards:
+<http://www.unicode.org/unicode/standard/standard.html>
+
+3) Legal UTF-8 byte sequences:
+<http://www.unicode.org/unicode/uni2errata/UTF-8_Corrigendum.html>
+
+Code point 1st byte 2nd byte 3rd byte 4th byte
+---------- -------- -------- -------- --------
+U+0000..U+007F 00..7F
+U+0080..U+07FF C2..DF 80..BF
+U+0800..U+0FFF E0 A0..BF 80..BF
+U+1000..U+FFFF E1..EF 80..BF 80..BF
+U+10000..U+3FFFF F0 90..BF 80..BF 80..BF
+U+40000..U+FFFFF F1..F3 80..BF 80..BF 80..BF
+U+100000..U+10FFFF F4 80..8F 80..BF 80..BF
+
+The definition of UTF-8 in Annex D of ISO/IEC 10646-1:2000 also
+allows for the use of five- and six-byte sequences to encode
+characters that are outside the range of the Unicode character
+set; those five- and six-byte sequences are illegal for the use
+of UTF-8 as a transformation of Unicode characters. ISO/IEC 10646
+does not allow mapping of unpaired surrogates, nor U+FFFE and U+FFFF
+(but it does allow other noncharacters).
+
+4) RFC 2279: UTF-8, a transformation format of ISO 10646:
+<http://www.ietf.org/rfc/rfc2279.txt>
+
+5) UTF-8 and Unicode FAQ:
+<http://www.cl.cam.ac.uk/~mgk25/unicode.html>
+
+6) Markus Kuhn's UTF-8 decoder stress test file:
+<http://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-test.txt>
+
+7) UTF-8 Demo:
+<http://www.cl.cam.ac.uk/~mgk25/ucs/examples/UTF-8-demo.txt>
+
+8) UTF-8 Sampler:
+<http://www.columbia.edu/kermit/utf8.html>
+
+9) Transformation Format for 16 Planes of Group 00 (UTF-16):
+ISO/IEC 10646-1:1996 Amendment 1 or ISO/IEC 10646-1:2000 Annex C
+<http://anubis.dkuug.dk/JTC1/SC2/WG2/docs/n2005/n2005.pdf>
+<http://www.cl.cam.ac.uk/~mgk25/ucs/ISO-10646-UTF-16.html>
+
+10) RFC 2781: UTF-16, an encoding of ISO 10646:
+<http://www.ietf.org/rfc/rfc2781.txt>
+
+11) UTF-16 invalid surrogate pairs:
+<http://www.unicode.org/unicode/faq/utf_bom.html#16>
+
+UTF-16 UTF-8 UCS-4
+D83F DFF* F0 9F BF B* 0001FFF*
+D87F DFF* F0 AF BF B* 0002FFF*
+D8BF DFF* F0 BF BF B* 0003FFF*
+D8FF DFF* F1 8F BF B* 0004FFF*
+D93F DFF* F1 9F BF B* 0005FFF*
+D97F DFF* F1 AF BF B* 0006FFF*
+ ...
+DBBF DFF* F3 BF BF B* 000FFFF*
+DBFF DFF* F4 8F BF B* 0010FFF*
+
+* = E or F
+
+1010 A
+1011 B
+1100 C
+1101 D
+1110 E
+1111 F
+
+*/
+
+#define kNumUTF8Sequences 7
+#define kMaxUTF8Bytes 4
+
+#define kUTF8ByteSwapNotAChar 0xFFFE
+#define kUTF8NotAChar 0xFFFF
+
+#define kMaxUTF8FromUCS4 0x10FFFF
+
+#define kUTF16SurrogatesBegin 0x10000
+#define kMaxUTF16FromUCS4 0x10FFFF
+
+/* UTF-16 surrogate pair areas */
+#define kUTF16LowSurrogateBegin 0xD800
+#define kUTF16LowSurrogateEnd 0xDBFF
+#define kUTF16HighSurrogateBegin 0xDC00
+#define kUTF16HighSurrogateEnd 0xDFFF
+
+
+/* offsets into validUTF8 table below */
+static const int offsetUTF8Sequences[kMaxUTF8Bytes + 1] =
+{
+ 0, /* 1 byte */
+ 1, /* 2 bytes */
+ 2, /* 3 bytes */
+ 4, /* 4 bytes */
+ kNumUTF8Sequences /* must be last */
+};
+
+static const struct validUTF8Sequence
+{
+ uint lowChar;
+ uint highChar;
+ int numBytes;
+ byte validBytes[8];
+} validUTF8[kNumUTF8Sequences] =
+{
+/* low high #bytes byte 1 byte 2 byte 3 byte 4 */
+ {0x0000, 0x007F, 1, {0x00, 0x7F, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}},
+ {0x0080, 0x07FF, 2, {0xC2, 0xDF, 0x80, 0xBF, 0x00, 0x00, 0x00, 0x00}},
+ {0x0800, 0x0FFF, 3, {0xE0, 0xE0, 0xA0, 0xBF, 0x80, 0xBF, 0x00, 0x00}},
+ {0x1000, 0xFFFF, 3, {0xE1, 0xEF, 0x80, 0xBF, 0x80, 0xBF, 0x00, 0x00}},
+ {0x10000, 0x3FFFF, 4, {0xF0, 0xF0, 0x90, 0xBF, 0x80, 0xBF, 0x80, 0xBF}},
+ {0x40000, 0xFFFFF, 4, {0xF1, 0xF3, 0x80, 0xBF, 0x80, 0xBF, 0x80, 0xBF}},
+ {0x100000, 0x10FFFF, 4, {0xF4, 0xF4, 0x80, 0x8F, 0x80, 0xBF, 0x80, 0xBF}}
+};
+
+int TY_(DecodeUTF8BytesToChar)( uint* c, uint firstByte, ctmbstr successorBytes,
+ TidyInputSource* inp, int* count )
+{
+ byte tempbuf[10];
+ byte *buf = &tempbuf[0];
+ uint ch = 0, n = 0;
+ int i, bytes = 0;
+ Bool hasError = no;
+
+ if ( successorBytes )
+ buf = (byte*) successorBytes;
+
+ /* special check if we have been passed an EOF char */
+ if ( firstByte == EndOfStream )
+ {
+ /* at present */
+ *c = firstByte;
+ *count = 1;
+ return 0;
+ }
+
+ ch = firstByte; /* first byte is passed in separately */
+
+ if (ch <= 0x7F) /* 0XXX XXXX one byte */
+ {
+ n = ch;
+ bytes = 1;
+ }
+ else if ((ch & 0xE0) == 0xC0) /* 110X XXXX two bytes */
+ {
+ n = ch & 31;
+ bytes = 2;
+ }
+ else if ((ch & 0xF0) == 0xE0) /* 1110 XXXX three bytes */
+ {
+ n = ch & 15;
+ bytes = 3;
+ }
+ else if ((ch & 0xF8) == 0xF0) /* 1111 0XXX four bytes */
+ {
+ n = ch & 7;
+ bytes = 4;
+ }
+ else if ((ch & 0xFC) == 0xF8) /* 1111 10XX five bytes */
+ {
+ n = ch & 3;
+ bytes = 5;
+ hasError = yes;
+ }
+ else if ((ch & 0xFE) == 0xFC) /* 1111 110X six bytes */
+ {
+ n = ch & 1;
+ bytes = 6;
+ hasError = yes;
+ }
+ else
+ {
+ /* not a valid first byte of a UTF-8 sequence */
+ n = ch;
+ bytes = 1;
+ hasError = yes;
+ }
+
+ /* successor bytes should have the form 10XX XXXX */
+
+ /* If caller supplied buffer, use it. Else see if caller
+ ** supplied an input source, use that.
+ */
+ if ( successorBytes )
+ {
+ for ( i=0; i < bytes-1; ++i )
+ {
+ if ( !buf[i] || (buf[i] & 0xC0) != 0x80 )
+ {
+ hasError = yes;
+ bytes = i+1;
+ break;
+ }
+ n = (n << 6) | (buf[i] & 0x3F);
+ }
+ }
+ else if ( inp )
+ {
+ for ( i=0; i < bytes-1 && !inp->eof(inp->sourceData); ++i )
+ {
+ int b = inp->getByte( inp->sourceData );
+ buf[i] = (tmbchar) b;
+
+ /* End of data or illegal successor byte value */
+ if ( b == EOF || (buf[i] & 0xC0) != 0x80 )
+ {
+ hasError = yes;
+ bytes = i+1;
+ if ( b != EOF )
+ inp->ungetByte( inp->sourceData, buf[i] );
+ break;
+ }
+ n = (n << 6) | (buf[i] & 0x3F);
+ }
+ }
+ else if ( bytes > 1 )
+ {
+ hasError = yes;
+ bytes = 1;
+ }
+
+ if (!hasError && ((n == kUTF8ByteSwapNotAChar) || (n == kUTF8NotAChar)))
+ hasError = yes;
+
+ if (!hasError && (n > kMaxUTF8FromUCS4))
+ hasError = yes;
+
+#if 0 /* Breaks Big5 D8 - DF */
+ if (!hasError && (n >= kUTF16LowSurrogateBegin) && (n <= kUTF16HighSurrogateEnd))
+ /* unpaired surrogates not allowed */
+ hasError = yes;
+#endif
+
+ if (!hasError)
+ {
+ int lo, hi;
+
+ lo = offsetUTF8Sequences[bytes - 1];
+ hi = offsetUTF8Sequences[bytes] - 1;
+
+ /* check for overlong sequences */
+ if ((n < validUTF8[lo].lowChar) || (n > validUTF8[hi].highChar))
+ hasError = yes;
+ else
+ {
+ hasError = yes; /* assume error until proven otherwise */
+
+ for (i = lo; i <= hi; i++)
+ {
+ int tempCount;
+ byte theByte;
+
+ for (tempCount = 0; tempCount < bytes; tempCount++)
+ {
+ if (!tempCount)
+ theByte = (tmbchar) firstByte;
+ else
+ theByte = buf[tempCount - 1];
+
+ if ( theByte >= validUTF8[i].validBytes[(tempCount * 2)] &&
+ theByte <= validUTF8[i].validBytes[(tempCount * 2) + 1] )
+ hasError = no;
+ if (hasError)
+ break;
+ }
+ }
+ }
+ }
+
+#if 1 && defined(_DEBUG)
+ if ( hasError )
+ {
+ /* debug */
+ fprintf( stderr, "UTF-8 decoding error of %d bytes : ", bytes );
+ fprintf( stderr, "0x%02x ", firstByte );
+ for (i = 1; i < bytes; i++)
+ fprintf( stderr, "0x%02x ", buf[i - 1] );
+ fprintf( stderr, " = U+%04ulx\n", n );
+ }
+#endif
+
+ *count = bytes;
+ *c = n;
+ if ( hasError )
+ return -1;
+ return 0;
+}
+
+int TY_(EncodeCharToUTF8Bytes)( uint c, tmbstr encodebuf,
+ TidyOutputSink* outp, int* count )
+{
+ byte tempbuf[10] = {0};
+ byte* buf = &tempbuf[0];
+ int bytes = 0;
+ Bool hasError = no;
+
+ if ( encodebuf )
+ buf = (byte*) encodebuf;
+
+ if (c <= 0x7F) /* 0XXX XXXX one byte */
+ {
+ buf[0] = (tmbchar) c;
+ bytes = 1;
+ }
+ else if (c <= 0x7FF) /* 110X XXXX two bytes */
+ {
+ buf[0] = (tmbchar) ( 0xC0 | (c >> 6) );
+ buf[1] = (tmbchar) ( 0x80 | (c & 0x3F) );
+ bytes = 2;
+ }
+ else if (c <= 0xFFFF) /* 1110 XXXX three bytes */
+ {
+ buf[0] = (tmbchar) (0xE0 | (c >> 12));
+ buf[1] = (tmbchar) (0x80 | ((c >> 6) & 0x3F));
+ buf[2] = (tmbchar) (0x80 | (c & 0x3F));
+ bytes = 3;
+ if ( c == kUTF8ByteSwapNotAChar || c == kUTF8NotAChar )
+ hasError = yes;
+#if 0 /* Breaks Big5 D8 - DF */
+ else if ( c >= kUTF16LowSurrogateBegin && c <= kUTF16HighSurrogateEnd )
+ /* unpaired surrogates not allowed */
+ hasError = yes;
+#endif
+ }
+ else if (c <= 0x1FFFFF) /* 1111 0XXX four bytes */
+ {
+ buf[0] = (tmbchar) (0xF0 | (c >> 18));
+ buf[1] = (tmbchar) (0x80 | ((c >> 12) & 0x3F));
+ buf[2] = (tmbchar) (0x80 | ((c >> 6) & 0x3F));
+ buf[3] = (tmbchar) (0x80 | (c & 0x3F));
+ bytes = 4;
+ if (c > kMaxUTF8FromUCS4)
+ hasError = yes;
+ }
+ else if (c <= 0x3FFFFFF) /* 1111 10XX five bytes */
+ {
+ buf[0] = (tmbchar) (0xF8 | (c >> 24));
+ buf[1] = (tmbchar) (0x80 | (c >> 18));
+ buf[2] = (tmbchar) (0x80 | ((c >> 12) & 0x3F));
+ buf[3] = (tmbchar) (0x80 | ((c >> 6) & 0x3F));
+ buf[4] = (tmbchar) (0x80 | (c & 0x3F));
+ bytes = 5;
+ hasError = yes;
+ }
+ else if (c <= 0x7FFFFFFF) /* 1111 110X six bytes */
+ {
+ buf[0] = (tmbchar) (0xFC | (c >> 30));
+ buf[1] = (tmbchar) (0x80 | ((c >> 24) & 0x3F));
+ buf[2] = (tmbchar) (0x80 | ((c >> 18) & 0x3F));
+ buf[3] = (tmbchar) (0x80 | ((c >> 12) & 0x3F));
+ buf[4] = (tmbchar) (0x80 | ((c >> 6) & 0x3F));
+ buf[5] = (tmbchar) (0x80 | (c & 0x3F));
+ bytes = 6;
+ hasError = yes;
+ }
+ else
+ hasError = yes;
+
+ /* don't output invalid UTF-8 byte sequence to a stream */
+ if ( !hasError && outp != NULL )
+ {
+ int ix;
+ for ( ix=0; ix < bytes; ++ix )
+ outp->putByte( outp->sinkData, buf[ix] );
+ }
+
+#if 1 && defined(_DEBUG)
+ if ( hasError )
+ {
+ int i;
+ fprintf( stderr, "UTF-8 encoding error for U+%x : ", c );
+ for (i = 0; i < bytes; i++)
+ fprintf( stderr, "0x%02x ", buf[i] );
+ fprintf( stderr, "\n" );
+ }
+#endif
+
+ *count = bytes;
+ if (hasError)
+ return -1;
+ return 0;
+}
+
+
+/* return one less than the number of bytes used by the UTF-8 byte sequence */
+/* str points to the UTF-8 byte sequence */
+/* the Unicode char is returned in *ch */
+uint TY_(GetUTF8)( ctmbstr str, uint *ch )
+{
+ uint n;
+ int bytes;
+
+ int err;
+
+ bytes = 0;
+
+ /* first byte "str[0]" is passed in separately from the */
+ /* rest of the UTF-8 byte sequence starting at "str[1]" */
+ err = TY_(DecodeUTF8BytesToChar)( &n, str[0], str+1, NULL, &bytes );
+ if (err)
+ {
+#if 1 && defined(_DEBUG)
+ fprintf(stderr, "pprint UTF-8 decoding error for U+%x : ", n);
+#endif
+ n = 0xFFFD; /* replacement char */
+ }
+
+ *ch = n;
+ return bytes - 1;
+}
+
+/* store char c as UTF-8 encoded byte stream */
+tmbstr TY_(PutUTF8)( tmbstr buf, uint c )
+{
+ int err, count = 0;
+
+ err = TY_(EncodeCharToUTF8Bytes)( c, buf, NULL, &count );
+ if (err)
+ {
+#if 1 && defined(_DEBUG)
+ fprintf(stderr, "pprint UTF-8 encoding error for U+%x : ", c);
+#endif
+ /* replacement char 0xFFFD encoded as UTF-8 */
+ buf[0] = (byte) 0xEF;
+ buf[1] = (byte) 0xBF;
+ buf[2] = (byte) 0xBD;
+ count = 3;
+ }
+
+ buf += count;
+ return buf;
+}
+
+Bool TY_(IsValidUTF16FromUCS4)( tchar ucs4 )
+{
+ return ( ucs4 <= kMaxUTF16FromUCS4 );
+}
+
+Bool TY_(IsHighSurrogate)( tchar ch )
+{
+ return ( ch >= kUTF16HighSurrogateBegin && ch <= kUTF16HighSurrogateEnd );
+}
+Bool TY_(IsLowSurrogate)( tchar ch )
+{
+ return ( ch >= kUTF16LowSurrogateBegin && ch <= kUTF16LowSurrogateEnd );
+}
+
+tchar TY_(CombineSurrogatePair)( tchar high, tchar low )
+{
+ assert( TY_(IsHighSurrogate)(high) && TY_(IsLowSurrogate)(low) );
+ return ( ((low - kUTF16LowSurrogateBegin) * 0x400) +
+ high - kUTF16HighSurrogateBegin + 0x10000 );
+}
+
+Bool TY_(SplitSurrogatePair)( tchar utf16, tchar* low, tchar* high )
+{
+ Bool status = ( TY_(IsValidCombinedChar)( utf16 ) && high && low );
+ if ( status )
+ {
+ *low = (utf16 - kUTF16SurrogatesBegin) / 0x400 + kUTF16LowSurrogateBegin;
+ *high = (utf16 - kUTF16SurrogatesBegin) % 0x400 + kUTF16HighSurrogateBegin;
+ }
+ return status;
+}
+
+Bool TY_(IsValidCombinedChar)( tchar ch )
+{
+ return ( ch >= kUTF16SurrogatesBegin &&
+ (ch & 0x0000FFFE) != 0x0000FFFE &&
+ (ch & 0x0000FFFF) != 0x0000FFFF );
+}
+
+Bool TY_(IsCombinedChar)( tchar ch )
+{
+ return ( ch >= kUTF16SurrogatesBegin );
+}
+
+/*
+ * local variables:
+ * mode: c
+ * indent-tabs-mode: nil
+ * c-basic-offset: 4
+ * eval: (c-set-offset 'substatement-open 0)
+ * end:
+ */
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