| // Copyright 2016 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "platform/inspector_protocol/InspectorProtocol.h" |
| |
| #include <algorithm> |
| #include <cctype> |
| #include <cstdio> |
| #include <locale> |
| |
| namespace blink { |
| namespace protocol { |
| |
| const UChar replacementCharacter = 0xFFFD; |
| using UChar32 = uint32_t; |
| |
| 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 String16::isASCII(b0) ? 1 : inlineUTF8SequenceLengthNonASCII(b0); |
| } |
| |
| // 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 sequences |
| // for *legal* UTF-8 will be 4 or fewer bytes total. |
| static const unsigned char firstByteMark[7] = { 0x00, 0x00, 0xC0, 0xE0, 0xF0, 0xF8, 0xFC }; |
| |
| typedef enum { |
| conversionOK, // conversion successful |
| sourceExhausted, // partial character in source, but hit end |
| targetExhausted, // insuff. room in target for conversion |
| sourceIllegal // source sequence is illegal/malformed |
| } ConversionResult; |
| |
| 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 = replacementCharacter; |
| } |
| |
| 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; |
| } |
| |
| /** |
| * Is this code point a BMP code point (U+0000..U+ffff)? |
| * @param c 32-bit code point |
| * @return TRUE or FALSE |
| * @stable ICU 2.8 |
| */ |
| #define U_IS_BMP(c) ((uint32_t)(c) <= 0xffff) |
| |
| /** |
| * Is this code point a supplementary code point (U+10000..U+10ffff)? |
| * @param c 32-bit code point |
| * @return TRUE or FALSE |
| * @stable ICU 2.8 |
| */ |
| #define U_IS_SUPPLEMENTARY(c) ((uint32_t)((c) - 0x10000) <= 0xfffff) |
| |
| /** |
| * Is this code point a surrogate (U+d800..U+dfff)? |
| * @param c 32-bit code point |
| * @return TRUE or FALSE |
| * @stable ICU 2.4 |
| */ |
| #define U_IS_SURROGATE(c) (((c) & 0xfffff800) == 0xd800) |
| |
| /** |
| * Get the lead surrogate (0xd800..0xdbff) for a |
| * supplementary code point (0x10000..0x10ffff). |
| * @param supplementary 32-bit code point (U+10000..U+10ffff) |
| * @return lead surrogate (U+d800..U+dbff) for supplementary |
| * @stable ICU 2.4 |
| */ |
| #define U16_LEAD(supplementary) (UChar)(((supplementary) >> 10) + 0xd7c0) |
| |
| /** |
| * Get the trail surrogate (0xdc00..0xdfff) for a |
| * supplementary code point (0x10000..0x10ffff). |
| * @param supplementary 32-bit code point (U+10000..U+10ffff) |
| * @return trail surrogate (U+dc00..U+dfff) for supplementary |
| * @stable ICU 2.4 |
| */ |
| #define U16_TRAIL(supplementary) (UChar)(((supplementary) & 0x3ff) | 0xdc00) |
| |
| // 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; |
| |
| // no fall-through in this inner switch |
| switch (*source) { |
| 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, static_cast<UChar32>(0xFA082080UL), static_cast<UChar32>(0x82082080UL) }; |
| |
| static inline UChar32 readUTF8Sequence(const char*& sequence, unsigned length) |
| { |
| UChar32 character = 0; |
| |
| // The cases all fall through. |
| switch (length) { |
| case 6: |
| character += static_cast<unsigned char>(*sequence++); |
| character <<= 6; |
| case 5: |
| character += static_cast<unsigned char>(*sequence++); |
| character <<= 6; |
| case 4: |
| character += static_cast<unsigned char>(*sequence++); |
| character <<= 6; |
| case 3: |
| character += static_cast<unsigned char>(*sequence++); |
| character <<= 6; |
| case 2: |
| character += static_cast<unsigned char>(*sequence++); |
| character <<= 6; |
| case 1: |
| character += static_cast<unsigned char>(*sequence++); |
| } |
| |
| return character - offsetsFromUTF8[length - 1]; |
| } |
| |
| ConversionResult convertUTF8ToUTF16( |
| const char** sourceStart, const char* sourceEnd, |
| UChar** targetStart, UChar* targetEnd, bool* sourceAllASCII, bool strict) |
| { |
| ConversionResult result = conversionOK; |
| const char* source = *sourceStart; |
| UChar* target = *targetStart; |
| UChar orAllData = 0; |
| while (source < sourceEnd) { |
| int utf8SequenceLength = inlineUTF8SequenceLength(*source); |
| if (sourceEnd - source < utf8SequenceLength) { |
| result = sourceExhausted; |
| break; |
| } |
| // Do this check whether lenient or strict |
| if (!isLegalUTF8(reinterpret_cast<const unsigned char*>(source), utf8SequenceLength)) { |
| result = sourceIllegal; |
| break; |
| } |
| |
| UChar32 character = readUTF8Sequence(source, utf8SequenceLength); |
| |
| if (target >= targetEnd) { |
| source -= utf8SequenceLength; // Back up source pointer! |
| result = targetExhausted; |
| break; |
| } |
| |
| if (U_IS_BMP(character)) { |
| // UTF-16 surrogate values are illegal in UTF-32 |
| if (U_IS_SURROGATE(character)) { |
| if (strict) { |
| source -= utf8SequenceLength; // return to the illegal value itself |
| result = sourceIllegal; |
| break; |
| } |
| *target++ = replacementCharacter; |
| orAllData |= replacementCharacter; |
| } else { |
| *target++ = static_cast<UChar>(character); // normal case |
| orAllData |= character; |
| } |
| } else if (U_IS_SUPPLEMENTARY(character)) { |
| // target is a character in range 0xFFFF - 0x10FFFF |
| if (target + 1 >= targetEnd) { |
| source -= utf8SequenceLength; // Back up source pointer! |
| result = targetExhausted; |
| break; |
| } |
| *target++ = U16_LEAD(character); |
| *target++ = U16_TRAIL(character); |
| orAllData = 0xffff; |
| } else { |
| if (strict) { |
| source -= utf8SequenceLength; // return to the start |
| result = sourceIllegal; |
| break; // Bail out; shouldn't continue |
| } else { |
| *target++ = replacementCharacter; |
| orAllData |= replacementCharacter; |
| } |
| } |
| } |
| *sourceStart = source; |
| *targetStart = target; |
| |
| if (sourceAllASCII) |
| *sourceAllASCII = !(orAllData & ~0x7f); |
| |
| return result; |
| } |
| |
| // Helper to write a three-byte UTF-8 code point to the buffer, caller must check room is available. |
| static inline void putUTF8Triple(char*& buffer, UChar ch) |
| { |
| DCHECK_GE(ch, 0x0800); |
| *buffer++ = static_cast<char>(((ch >> 12) & 0x0F) | 0xE0); |
| *buffer++ = static_cast<char>(((ch >> 6) & 0x3F) | 0x80); |
| *buffer++ = static_cast<char>((ch & 0x3F) | 0x80); |
| } |
| |
| String16 String16::fromUTF8(const char* stringStart, size_t length) |
| { |
| if (!stringStart || !length) |
| return String16(); |
| |
| std::vector<UChar> buffer(length); |
| UChar* bufferStart = buffer.data(); |
| |
| UChar* bufferCurrent = bufferStart; |
| const char* stringCurrent = stringStart; |
| if (convertUTF8ToUTF16(&stringCurrent, stringStart + length, &bufferCurrent, bufferCurrent + buffer.size(), 0, true) != conversionOK) |
| return String16(); |
| |
| unsigned utf16Length = bufferCurrent - bufferStart; |
| return String16(bufferStart, utf16Length); |
| } |
| |
| std::string String16::utf8() const |
| { |
| unsigned length = this->length(); |
| |
| if (!length) |
| return std::string(""); |
| |
| // Allocate a buffer big enough to hold all the characters |
| // (an individual UTF-16 UChar can only expand to 3 UTF-8 bytes). |
| // Optimization ideas, if we find this function is hot: |
| // * We could speculatively create a CStringBuffer to contain 'length' |
| // characters, and resize if necessary (i.e. if the buffer contains |
| // non-ascii characters). (Alternatively, scan the buffer first for |
| // ascii characters, so we know this will be sufficient). |
| // * We could allocate a CStringBuffer with an appropriate size to |
| // have a good chance of being able to write the string into the |
| // buffer without reallocing (say, 1.5 x length). |
| if (length > std::numeric_limits<unsigned>::max() / 3) |
| return std::string(); |
| std::vector<char> bufferVector(length * 3); |
| char* buffer = bufferVector.data(); |
| const UChar* characters = m_impl.data(); |
| |
| ConversionResult result = convertUTF16ToUTF8(&characters, characters + length, &buffer, buffer + bufferVector.size(), false); |
| DCHECK(result != targetExhausted); // (length * 3) should be sufficient for any conversion |
| |
| // Only produced from strict conversion. |
| DCHECK(result != sourceIllegal); |
| |
| // Check for an unconverted high surrogate. |
| if (result == sourceExhausted) { |
| // This should be one unpaired high surrogate. Treat it the same |
| // was as an unpaired high surrogate would have been handled in |
| // the middle of a string with non-strict conversion - which is |
| // to say, simply encode it to UTF-8. |
| DCHECK((characters + 1) == (m_impl.data() + length)); |
| DCHECK((*characters >= 0xD800) && (*characters <= 0xDBFF)); |
| // There should be room left, since one UChar hasn't been |
| // converted. |
| DCHECK((buffer + 3) <= (buffer + bufferVector.size())); |
| putUTF8Triple(buffer, *characters); |
| } |
| |
| return std::string(bufferVector.data(), buffer - bufferVector.data()); |
| } |
| |
| } // namespace protocol |
| } // namespace blink |
