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/*
* Copyright (C) 2018 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 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 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.
*/
#pragma once
#include "Opcode.h"
#include <wtf/Ref.h>
#include <wtf/RefCounted.h>
namespace JSC {
class VM;
DECLARE_ALLOCATOR_WITH_HEAP_IDENTIFIER(MetadataTable);
class MetadataTable;
class UnlinkedMetadataTable : public RefCounted<UnlinkedMetadataTable> {
friend class LLIntOffsetsExtractor;
friend class MetadataTable;
friend class CachedMetadataTable;
public:
static constexpr unsigned s_maxMetadataAlignment = 8;
struct LinkingData {
Ref<UnlinkedMetadataTable> unlinkedMetadata;
unsigned refCount;
};
~UnlinkedMetadataTable();
unsigned addEntry(OpcodeID);
size_t sizeInBytes();
void finalize();
RefPtr<MetadataTable> link();
static Ref<UnlinkedMetadataTable> create()
{
return adoptRef(*new UnlinkedMetadataTable);
}
private:
enum EmptyTag { Empty };
UnlinkedMetadataTable();
UnlinkedMetadataTable(bool is32Bit);
UnlinkedMetadataTable(EmptyTag);
static Ref<UnlinkedMetadataTable> create(bool is32Bit)
{
return adoptRef(*new UnlinkedMetadataTable(is32Bit));
}
static Ref<UnlinkedMetadataTable> empty()
{
return adoptRef(*new UnlinkedMetadataTable(Empty));
}
void unlink(MetadataTable&);
size_t sizeInBytes(MetadataTable&);
unsigned totalSize() const
{
ASSERT(m_isFinalized);
if (m_is32Bit)
return offsetTable32()[s_offsetTableEntries - 1];
return offsetTable16()[s_offsetTableEntries - 1];
}
unsigned offsetTableSize() const
{
ASSERT(m_isFinalized);
if (m_is32Bit)
return s_offset16TableSize + s_offset32TableSize;
return s_offset16TableSize;
}
using Offset32 = uint32_t;
using Offset16 = uint16_t;
static constexpr unsigned s_offsetTableEntries = NUMBER_OF_BYTECODE_WITH_METADATA + 1; // one extra entry for the "end" offset;
// Not to break alignment of 32bit offset table, we round up size with sizeof(Offset32).
static constexpr unsigned s_offset16TableSize = roundUpToMultipleOf<sizeof(Offset32)>(s_offsetTableEntries * sizeof(Offset16));
// Not to break alignment of the metadata calculated based on the alignment of s_offset16TableSize, s_offset32TableSize must be rounded by 8.
// Then, s_offset16TableSize and s_offset16TableSize + s_offset32TableSize offer the same alignment characteristics for subsequent Metadata.
static constexpr unsigned s_offset32TableSize = roundUpToMultipleOf<s_maxMetadataAlignment>(s_offsetTableEntries * sizeof(Offset32));
Offset32* preprocessBuffer() const { return bitwise_cast<Offset32*>(m_rawBuffer + sizeof(LinkingData)); }
void* buffer() const { return m_rawBuffer + sizeof(LinkingData); }
Offset16* offsetTable16() const
{
ASSERT(!m_is32Bit);
return bitwise_cast<Offset16*>(m_rawBuffer + sizeof(LinkingData));
}
Offset32* offsetTable32() const
{
ASSERT(m_is32Bit);
return bitwise_cast<Offset32*>(m_rawBuffer + sizeof(LinkingData) + s_offset16TableSize);
}
bool m_hasMetadata : 1;
bool m_isFinalized : 1;
bool m_isLinked : 1;
bool m_is32Bit : 1;
uint8_t* m_rawBuffer;
};
} // namespace JSC