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/*
* Copyright (C) 2009-2019 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 "CommonIdentifiers.h"
#include "Identifier.h"
#include "MathCommon.h"
#include <array>
#include <type_traits>
#include <wtf/SegmentedVector.h>
WTF_ALLOW_UNSAFE_BUFFER_USAGE_BEGIN
namespace JSC {
class ParserArenaDeletable;
DECLARE_ALLOCATOR_WITH_HEAP_IDENTIFIER(IdentifierArena);
class IdentifierArena {
WTF_MAKE_FAST_ALLOCATED_WITH_HEAP_IDENTIFIER(IdentifierArena);
public:
IdentifierArena()
{
clear();
}
template <typename T>
ALWAYS_INLINE const Identifier& makeIdentifier(VM&, std::span<const T> characters);
ALWAYS_INLINE const Identifier& makeEmptyIdentifier(VM&);
ALWAYS_INLINE const Identifier& makeIdentifierLCharFromUChar(VM&, std::span<const UChar> characters);
ALWAYS_INLINE const Identifier& makeIdentifier(VM&, SymbolImpl*);
const Identifier* makeBigIntDecimalIdentifier(VM&, const Identifier&, uint8_t radix);
const Identifier& makeNumericIdentifier(VM&, double number);
const Identifier& makePrivateIdentifier(VM&, ASCIILiteral, unsigned);
public:
static const int MaximumCachableCharacter = 128;
typedef SegmentedVector<Identifier, 64> IdentifierVector;
void clear()
{
m_identifiers.clear();
for (int i = 0; i < MaximumCachableCharacter; i++)
m_shortIdentifiers[i] = nullptr;
for (int i = 0; i < MaximumCachableCharacter; i++)
m_recentIdentifiers[i] = nullptr;
}
private:
IdentifierVector m_identifiers;
std::array<Identifier*, MaximumCachableCharacter> m_shortIdentifiers;
std::array<Identifier*, MaximumCachableCharacter> m_recentIdentifiers;
};
template <typename T>
ALWAYS_INLINE const Identifier& IdentifierArena::makeIdentifier(VM& vm, std::span<const T> characters)
{
if (characters.empty())
return vm.propertyNames->emptyIdentifier;
if (characters.front() >= MaximumCachableCharacter) {
m_identifiers.append(Identifier::fromString(vm, characters));
return m_identifiers.last();
}
if (characters.size() == 1) {
if (Identifier* ident = m_shortIdentifiers[characters.front()])
return *ident;
m_identifiers.append(Identifier::fromString(vm, characters));
m_shortIdentifiers[characters.front()] = &m_identifiers.last();
return m_identifiers.last();
}
Identifier* ident = m_recentIdentifiers[characters.front()];
if (ident && Identifier::equal(ident->impl(), characters))
return *ident;
m_identifiers.append(Identifier::fromString(vm, characters));
m_recentIdentifiers[characters.front()] = &m_identifiers.last();
return m_identifiers.last();
}
ALWAYS_INLINE const Identifier& IdentifierArena::makeIdentifier(VM&, SymbolImpl* symbol)
{
ASSERT(symbol);
m_identifiers.append(Identifier::fromUid(*symbol));
return m_identifiers.last();
}
ALWAYS_INLINE const Identifier& IdentifierArena::makeEmptyIdentifier(VM& vm)
{
return vm.propertyNames->emptyIdentifier;
}
ALWAYS_INLINE const Identifier& IdentifierArena::makeIdentifierLCharFromUChar(VM& vm, std::span<const UChar> characters)
{
if (characters.empty())
return vm.propertyNames->emptyIdentifier;
if (characters.front() >= MaximumCachableCharacter) {
m_identifiers.append(Identifier::createLCharFromUChar(vm, characters));
return m_identifiers.last();
}
if (characters.size() == 1) {
if (Identifier* ident = m_shortIdentifiers[characters.front()])
return *ident;
m_identifiers.append(Identifier::fromString(vm, characters));
m_shortIdentifiers[characters.front()] = &m_identifiers.last();
return m_identifiers.last();
}
Identifier* ident = m_recentIdentifiers[characters.front()];
if (ident && Identifier::equal(ident->impl(), characters))
return *ident;
m_identifiers.append(Identifier::createLCharFromUChar(vm, characters));
m_recentIdentifiers[characters.front()] = &m_identifiers.last();
return m_identifiers.last();
}
inline const Identifier& IdentifierArena::makeNumericIdentifier(VM& vm, double number)
{
Identifier token;
// This is possible that number can be -0, but it is OK since ToString(-0) is "0".
if (canBeInt32(number))
token = Identifier::from(vm, static_cast<int32_t>(number));
else
token = Identifier::from(vm, number);
m_identifiers.append(WTFMove(token));
return m_identifiers.last();
}
DECLARE_ALLOCATOR_WITH_HEAP_IDENTIFIER(ParserArena);
class ParserArena {
WTF_MAKE_NONCOPYABLE(ParserArena);
public:
ParserArena();
~ParserArena();
void swap(ParserArena& otherArena)
{
std::swap(m_freeableMemory, otherArena.m_freeableMemory);
std::swap(m_freeablePoolEnd, otherArena.m_freeablePoolEnd);
m_identifierArena.swap(otherArena.m_identifierArena);
m_freeablePools.swap(otherArena.m_freeablePools);
m_deletableObjects.swap(otherArena.m_deletableObjects);
}
void* allocateFreeable(size_t size)
{
ASSERT(size);
ASSERT(size <= freeablePoolSize);
size_t alignedSize = alignSize(size);
ASSERT(alignedSize <= freeablePoolSize);
if (UNLIKELY(static_cast<size_t>(m_freeablePoolEnd - m_freeableMemory) < alignedSize))
allocateFreeablePool();
void* block = m_freeableMemory;
m_freeableMemory += alignedSize;
return block;
}
template<typename T, typename = std::enable_if_t<std::is_base_of<ParserArenaDeletable, T>::value>>
void* allocateDeletable(size_t size)
{
// T may extend ParserArenaDeletable via multiple inheritance, but not as T's first
// base class. m_deletableObjects is expecting pointers to objects of the shape of
// ParserArenaDeletable. We ensure this by allocating T, and casting it to
// ParserArenaDeletable to get the correct pointer to append to m_deletableObjects.
T* instance = static_cast<T*>(allocateFreeable(size));
ParserArenaDeletable* deletable = static_cast<ParserArenaDeletable*>(instance);
m_deletableObjects.append(deletable);
return instance;
}
IdentifierArena& identifierArena()
{
if (UNLIKELY (!m_identifierArena))
m_identifierArena = makeUnique<IdentifierArena>();
return *m_identifierArena;
}
private:
static const size_t freeablePoolSize = 8000;
static size_t alignSize(size_t size)
{
return (size + sizeof(WTF::AllocAlignmentInteger) - 1) & ~(sizeof(WTF::AllocAlignmentInteger) - 1);
}
void* freeablePool();
void allocateFreeablePool();
void deallocateObjects();
char* m_freeableMemory;
char* m_freeablePoolEnd;
std::unique_ptr<IdentifierArena> m_identifierArena;
Vector<void*> m_freeablePools;
Vector<ParserArenaDeletable*> m_deletableObjects;
};
} // namespace JSC
WTF_ALLOW_UNSAFE_BUFFER_USAGE_END
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