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/*
* Copyright (C) 2013, 2014, 2016 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
#if ENABLE(DFG_JIT)
#include "DFGCommon.h"
#include "DFGFrozenValue.h"
#include "GPRInfo.h"
#include <wtf/text/StringImpl.h>
namespace JSC {
class CCallHelpers;
namespace DFG {
class Graph;
class Plan;
// Represents either a JSValue, or for JSValues that require allocation in the heap,
// it tells you everything you'd need to know in order to allocate it.
class LazyJSValue {
public:
enum LazinessKind {
KnownValue,
SingleCharacterString,
KnownStringImpl,
NewStringImpl
};
LazyJSValue(FrozenValue* value = FrozenValue::emptySingleton())
: m_kind(KnownValue)
{
u.value = value;
}
static LazyJSValue singleCharacterString(UChar character)
{
LazyJSValue result;
result.m_kind = SingleCharacterString;
result.u.character = character;
return result;
}
static LazyJSValue knownStringImpl(AtomStringImpl* string)
{
LazyJSValue result;
result.m_kind = KnownStringImpl;
result.u.stringImpl = string;
return result;
}
static LazyJSValue newString(Graph&, const String&);
LazinessKind kind() const { return m_kind; }
SpeculatedType speculatedType() const { return kind() == KnownValue ? SpecBytecodeTop : SpecString; }
FrozenValue* tryGetValue(Graph&) const
{
if (m_kind == KnownValue)
return value();
return nullptr;
}
JSValue getValue(VM&) const;
FrozenValue* value() const
{
ASSERT(m_kind == KnownValue);
return u.value;
}
UChar character() const
{
ASSERT(m_kind == SingleCharacterString);
return u.character;
}
String tryGetString(Graph&) const;
StringImpl* stringImpl() const
{
ASSERT(m_kind == KnownStringImpl || m_kind == NewStringImpl);
return u.stringImpl;
}
TriState strictEqual(const LazyJSValue& other) const;
uintptr_t switchLookupValue(SwitchKind) const;
void emit(CCallHelpers&, JSValueRegs, Plan&) const;
void dump(PrintStream&) const;
void dumpInContext(PrintStream&, DumpContext*) const;
private:
const StringImpl* tryGetStringImpl() const;
union {
FrozenValue* value;
UChar character;
StringImpl* stringImpl;
} u;
LazinessKind m_kind;
};
} } // namespace JSC::DFG
#endif // ENABLE(DFG_JIT)
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