b199bcdd47
`WriteUtf16Slow` should not assume that the output buffer has enough bytes to hold both words of surrogate pair. It should pass the number of remaining bytes to the `Utf8::ValueOf` instead, just as we already do in `Utf8DecoderBase::Reset`. Otherwise it will attempt to write the trail uint16_t past the buffer boundary, leading to memory corruption and possible crash. Originally reported by: Kris Reeves <kris.re@bbhmedia.com> BUG=v8:4274 R=danno R=svenpanne LOG=y Review URL: https://codereview.chromium.org/1226493003 Cr-Commit-Position: refs/heads/master@{#29485}
123 lines
3.7 KiB
C++
123 lines
3.7 KiB
C++
// Copyright 2014 the V8 project authors. All rights reserved.
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// Use of this source code is governed by a BSD-style license that can be
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// found in the LICENSE file.
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#ifndef V8_UNICODE_DECODER_H_
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#define V8_UNICODE_DECODER_H_
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#include <sys/types.h>
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#include "src/globals.h"
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namespace unibrow {
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class Utf8DecoderBase {
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public:
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// Initialization done in subclass.
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inline Utf8DecoderBase();
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inline Utf8DecoderBase(uint16_t* buffer, size_t buffer_length,
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const uint8_t* stream, size_t stream_length);
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inline size_t Utf16Length() const { return utf16_length_; }
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protected:
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// This reads all characters and sets the utf16_length_.
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// The first buffer_length utf16 chars are cached in the buffer.
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void Reset(uint16_t* buffer, size_t buffer_length, const uint8_t* stream,
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size_t stream_length);
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static void WriteUtf16Slow(const uint8_t* stream, size_t stream_length,
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uint16_t* data, size_t length);
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const uint8_t* unbuffered_start_;
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size_t unbuffered_length_;
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size_t utf16_length_;
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bool last_byte_of_buffer_unused_;
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private:
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DISALLOW_COPY_AND_ASSIGN(Utf8DecoderBase);
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};
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template <size_t kBufferSize>
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class Utf8Decoder : public Utf8DecoderBase {
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public:
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inline Utf8Decoder() {}
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inline Utf8Decoder(const char* stream, size_t length);
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inline void Reset(const char* stream, size_t length);
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inline size_t WriteUtf16(uint16_t* data, size_t length) const;
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private:
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uint16_t buffer_[kBufferSize];
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};
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Utf8DecoderBase::Utf8DecoderBase()
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: unbuffered_start_(NULL),
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unbuffered_length_(0),
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utf16_length_(0),
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last_byte_of_buffer_unused_(false) {}
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Utf8DecoderBase::Utf8DecoderBase(uint16_t* buffer, size_t buffer_length,
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const uint8_t* stream, size_t stream_length) {
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Reset(buffer, buffer_length, stream, stream_length);
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}
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template <size_t kBufferSize>
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Utf8Decoder<kBufferSize>::Utf8Decoder(const char* stream, size_t length)
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: Utf8DecoderBase(buffer_, kBufferSize,
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reinterpret_cast<const uint8_t*>(stream), length) {}
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template <size_t kBufferSize>
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void Utf8Decoder<kBufferSize>::Reset(const char* stream, size_t length) {
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Utf8DecoderBase::Reset(buffer_, kBufferSize,
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reinterpret_cast<const uint8_t*>(stream), length);
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}
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template <size_t kBufferSize>
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size_t Utf8Decoder<kBufferSize>::WriteUtf16(uint16_t* data,
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size_t length) const {
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DCHECK(length > 0);
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if (length > utf16_length_) length = utf16_length_;
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// memcpy everything in buffer.
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size_t buffer_length =
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last_byte_of_buffer_unused_ ? kBufferSize - 1 : kBufferSize;
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size_t memcpy_length = length <= buffer_length ? length : buffer_length;
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v8::internal::MemCopy(data, buffer_, memcpy_length * sizeof(uint16_t));
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if (length <= buffer_length) return length;
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DCHECK(unbuffered_start_ != NULL);
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// Copy the rest the slow way.
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WriteUtf16Slow(unbuffered_start_, unbuffered_length_, data + buffer_length,
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length - buffer_length);
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return length;
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}
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class Latin1 {
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public:
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static const unsigned kMaxChar = 0xff;
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// Returns 0 if character does not convert to single latin-1 character
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// or if the character doesn't not convert back to latin-1 via inverse
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// operation (upper to lower, etc).
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static inline uint16_t ConvertNonLatin1ToLatin1(uint16_t);
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};
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uint16_t Latin1::ConvertNonLatin1ToLatin1(uint16_t c) {
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DCHECK(c > Latin1::kMaxChar);
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switch (c) {
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// This are equivalent characters in unicode.
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case 0x39c:
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case 0x3bc:
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return 0xb5;
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// This is an uppercase of a Latin-1 character
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// outside of Latin-1.
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case 0x178:
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return 0xff;
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}
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return 0;
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}
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} // namespace unibrow
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#endif // V8_UNICODE_DECODER_H_
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