--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/JavaScriptCore/wtf/unicode/UTF8.cpp Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,304 @@
+/*
+ * Copyright (C) 2007 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "UTF8.h"
+
+namespace WTF {
+namespace Unicode {
+
+inline int inlineUTF8SequenceLengthNonASCII(char b0)
+{
+ if ((b0 & 0xC0) != 0xC0)
+ return 0;
+ if ((b0 & 0xE0) == 0xC0)
+ return 2;
+ if ((b0 & 0xF0) == 0xE0)
+ return 3;
+ if ((b0 & 0xF8) == 0xF0)
+ return 4;
+ return 0;
+}
+
+inline int inlineUTF8SequenceLength(char b0)
+{
+ return (b0 & 0x80) == 0 ? 1 : inlineUTF8SequenceLengthNonASCII(b0);
+}
+
+int UTF8SequenceLength(char b0)
+{
+ return (b0 & 0x80) == 0 ? 1 : inlineUTF8SequenceLengthNonASCII(b0);
+}
+
+int decodeUTF8Sequence(const char* sequence)
+{
+ // Handle 0-byte sequences (never valid).
+ const unsigned char b0 = sequence[0];
+ const int length = inlineUTF8SequenceLength(b0);
+ if (length == 0)
+ return -1;
+
+ // Handle 1-byte sequences (plain ASCII).
+ const unsigned char b1 = sequence[1];
+ if (length == 1) {
+ if (b1)
+ return -1;
+ return b0;
+ }
+
+ // Handle 2-byte sequences.
+ if ((b1 & 0xC0) != 0x80)
+ return -1;
+ const unsigned char b2 = sequence[2];
+ if (length == 2) {
+ if (b2)
+ return -1;
+ const int c = ((b0 & 0x1F) << 6) | (b1 & 0x3F);
+ if (c < 0x80)
+ return -1;
+ return c;
+ }
+
+ // Handle 3-byte sequences.
+ if ((b2 & 0xC0) != 0x80)
+ return -1;
+ const unsigned char b3 = sequence[3];
+ if (length == 3) {
+ if (b3)
+ return -1;
+ const int c = ((b0 & 0xF) << 12) | ((b1 & 0x3F) << 6) | (b2 & 0x3F);
+ if (c < 0x800)
+ return -1;
+ // UTF-16 surrogates should never appear in UTF-8 data.
+ if (c >= 0xD800 && c <= 0xDFFF)
+ return -1;
+ return c;
+ }
+
+ // Handle 4-byte sequences.
+ if ((b3 & 0xC0) != 0x80)
+ return -1;
+ const unsigned char b4 = sequence[4];
+ if (length == 4) {
+ if (b4)
+ return -1;
+ const int c = ((b0 & 0x7) << 18) | ((b1 & 0x3F) << 12) | ((b2 & 0x3F) << 6) | (b3 & 0x3F);
+ if (c < 0x10000 || c > 0x10FFFF)
+ return -1;
+ return c;
+ }
+
+ return -1;
+}
+
+// Once the bits are split out into bytes of UTF-8, this is a mask OR-ed
+// into the first byte, depending on how many bytes follow. There are
+// as many entries in this table as there are UTF-8 sequence types.
+// (I.e., one byte sequence, two byte... etc.). Remember that sequencs
+// for *legal* UTF-8 will be 4 or fewer bytes total.
+static const unsigned char firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC };
+
+ConversionResult convertUTF16ToUTF8(
+ const UChar** sourceStart, const UChar* sourceEnd,
+ char** targetStart, char* targetEnd, bool strict)
+{
+ ConversionResult result = conversionOK;
+ const UChar* source = *sourceStart;
+ char* target = *targetStart;
+ while (source < sourceEnd) {
+ UChar32 ch;
+ unsigned short bytesToWrite = 0;
+ const UChar32 byteMask = 0xBF;
+ const UChar32 byteMark = 0x80;
+ const UChar* oldSource = source; // In case we have to back up because of target overflow.
+ ch = static_cast<unsigned short>(*source++);
+ // If we have a surrogate pair, convert to UChar32 first.
+ if (ch >= 0xD800 && ch <= 0xDBFF) {
+ // If the 16 bits following the high surrogate are in the source buffer...
+ if (source < sourceEnd) {
+ UChar32 ch2 = static_cast<unsigned short>(*source);
+ // If it's a low surrogate, convert to UChar32.
+ if (ch2 >= 0xDC00 && ch2 <= 0xDFFF) {
+ ch = ((ch - 0xD800) << 10) + (ch2 - 0xDC00) + 0x0010000;
+ ++source;
+ } else if (strict) { // it's an unpaired high surrogate
+ --source; // return to the illegal value itself
+ result = sourceIllegal;
+ break;
+ }
+ } else { // We don't have the 16 bits following the high surrogate.
+ --source; // return to the high surrogate
+ result = sourceExhausted;
+ break;
+ }
+ } else if (strict) {
+ // UTF-16 surrogate values are illegal in UTF-32
+ if (ch >= 0xDC00 && ch <= 0xDFFF) {
+ --source; // return to the illegal value itself
+ result = sourceIllegal;
+ break;
+ }
+ }
+ // Figure out how many bytes the result will require
+ if (ch < (UChar32)0x80) {
+ bytesToWrite = 1;
+ } else if (ch < (UChar32)0x800) {
+ bytesToWrite = 2;
+ } else if (ch < (UChar32)0x10000) {
+ bytesToWrite = 3;
+ } else if (ch < (UChar32)0x110000) {
+ bytesToWrite = 4;
+ } else {
+ bytesToWrite = 3;
+ ch = 0xFFFD;
+ }
+
+ target += bytesToWrite;
+ if (target > targetEnd) {
+ source = oldSource; // Back up source pointer!
+ target -= bytesToWrite;
+ result = targetExhausted;
+ break;
+ }
+ switch (bytesToWrite) { // note: everything falls through.
+ case 4: *--target = (char)((ch | byteMark) & byteMask); ch >>= 6;
+ case 3: *--target = (char)((ch | byteMark) & byteMask); ch >>= 6;
+ case 2: *--target = (char)((ch | byteMark) & byteMask); ch >>= 6;
+ case 1: *--target = (char)(ch | firstByteMark[bytesToWrite]);
+ }
+ target += bytesToWrite;
+ }
+ *sourceStart = source;
+ *targetStart = target;
+ return result;
+}
+
+// This must be called with the length pre-determined by the first byte.
+// If presented with a length > 4, this returns false. The Unicode
+// definition of UTF-8 goes up to 4-byte sequences.
+static bool isLegalUTF8(const unsigned char* source, int length)
+{
+ unsigned char a;
+ const unsigned char* srcptr = source + length;
+ switch (length) {
+ default: return false;
+ // Everything else falls through when "true"...
+ case 4: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
+ case 3: if ((a = (*--srcptr)) < 0x80 || a > 0xBF) return false;
+ case 2: if ((a = (*--srcptr)) > 0xBF) return false;
+
+ switch (*source) {
+ // no fall-through in this inner switch
+ case 0xE0: if (a < 0xA0) return false; break;
+ case 0xED: if (a > 0x9F) return false; break;
+ case 0xF0: if (a < 0x90) return false; break;
+ case 0xF4: if (a > 0x8F) return false; break;
+ default: if (a < 0x80) return false;
+ }
+
+ case 1: if (*source >= 0x80 && *source < 0xC2) return false;
+ }
+ if (*source > 0xF4)
+ return false;
+ return true;
+}
+
+// Magic values subtracted from a buffer value during UTF8 conversion.
+// This table contains as many values as there might be trailing bytes
+// in a UTF-8 sequence.
+static const UChar32 offsetsFromUTF8[6] = { 0x00000000UL, 0x00003080UL, 0x000E2080UL,
+ 0x03C82080UL, 0xFA082080UL, 0x82082080UL };
+
+ConversionResult convertUTF8ToUTF16(
+ const char** sourceStart, const char* sourceEnd,
+ UChar** targetStart, UChar* targetEnd, bool strict)
+{
+ ConversionResult result = conversionOK;
+ const char* source = *sourceStart;
+ UChar* target = *targetStart;
+ while (source < sourceEnd) {
+ UChar32 ch = 0;
+ int extraBytesToRead = UTF8SequenceLength(*source) - 1;
+ if (source + extraBytesToRead >= sourceEnd) {
+ result = sourceExhausted;
+ break;
+ }
+ // Do this check whether lenient or strict
+ if (!isLegalUTF8(reinterpret_cast<const unsigned char*>(source), extraBytesToRead + 1)) {
+ result = sourceIllegal;
+ break;
+ }
+ // The cases all fall through.
+ switch (extraBytesToRead) {
+ case 5: ch += static_cast<unsigned char>(*source++); ch <<= 6; // remember, illegal UTF-8
+ case 4: ch += static_cast<unsigned char>(*source++); ch <<= 6; // remember, illegal UTF-8
+ case 3: ch += static_cast<unsigned char>(*source++); ch <<= 6;
+ case 2: ch += static_cast<unsigned char>(*source++); ch <<= 6;
+ case 1: ch += static_cast<unsigned char>(*source++); ch <<= 6;
+ case 0: ch += static_cast<unsigned char>(*source++);
+ }
+ ch -= offsetsFromUTF8[extraBytesToRead];
+
+ if (target >= targetEnd) {
+ source -= (extraBytesToRead + 1); // Back up source pointer!
+ result = targetExhausted; break;
+ }
+ if (ch <= 0xFFFF) {
+ // UTF-16 surrogate values are illegal in UTF-32
+ if (ch >= 0xD800 && ch <= 0xDFFF) {
+ if (strict) {
+ source -= (extraBytesToRead + 1); // return to the illegal value itself
+ result = sourceIllegal;
+ break;
+ } else
+ *target++ = 0xFFFD;
+ } else
+ *target++ = (UChar)ch; // normal case
+ } else if (ch > 0x10FFFF) {
+ if (strict) {
+ result = sourceIllegal;
+ source -= (extraBytesToRead + 1); // return to the start
+ break; // Bail out; shouldn't continue
+ } else
+ *target++ = 0xFFFD;
+ } else {
+ // target is a character in range 0xFFFF - 0x10FFFF
+ if (target + 1 >= targetEnd) {
+ source -= (extraBytesToRead + 1); // Back up source pointer!
+ result = targetExhausted;
+ break;
+ }
+ ch -= 0x0010000UL;
+ *target++ = (UChar)((ch >> 10) + 0xD800);
+ *target++ = (UChar)((ch & 0x03FF) + 0xDC00);
+ }
+ }
+ *sourceStart = source;
+ *targetStart = target;
+ return result;
+}
+
+}
+}