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/*
* Copyright (C) 1999-2001 Harri Porten (porten@kde.org)
* Copyright (C) 2001 Peter Kelly (pmk@post.com)
* Copyright (C) 2003, 2007, 2008 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#ifndef CallFrame_h
#define CallFrame_h
#include "JSGlobalData.h"
#include "MacroAssemblerCodeRef.h"
#include "RegisterFile.h"
namespace JSC {
class Arguments;
class JSActivation;
class Interpreter;
class ScopeChainNode;
// Represents the current state of script execution.
// Passed as the first argument to most functions.
class ExecState : private Register {
public:
JSObject* callee() const { return this[RegisterFile::Callee].function(); }
CodeBlock* codeBlock() const { return this[RegisterFile::CodeBlock].Register::codeBlock(); }
ScopeChainNode* scopeChain() const
{
ASSERT(this[RegisterFile::ScopeChain].Register::scopeChain());
return this[RegisterFile::ScopeChain].Register::scopeChain();
}
// Global object in which execution began.
JSGlobalObject* dynamicGlobalObject();
// Global object in which the currently executing code was defined.
// Differs from dynamicGlobalObject() during function calls across web browser frames.
inline JSGlobalObject* lexicalGlobalObject() const;
// Differs from lexicalGlobalObject because this will have DOM window shell rather than
// the actual DOM window, which can't be "this" for security reasons.
inline JSObject* globalThisValue() const;
inline JSGlobalData& globalData() const;
// Convenience functions for access to global data.
// It takes a few memory references to get from a call frame to the global data
// pointer, so these are inefficient, and should be used sparingly in new code.
// But they're used in many places in legacy code, so they're not going away any time soon.
void clearException() { globalData().exception = JSValue(); }
JSValue exception() const { return globalData().exception; }
bool hadException() const { return globalData().exception; }
const CommonIdentifiers& propertyNames() const { return *globalData().propertyNames; }
const MarkedArgumentBuffer& emptyList() const { return *globalData().emptyList; }
Interpreter* interpreter() { return globalData().interpreter; }
Heap* heap() { return &globalData().heap; }
#ifndef NDEBUG
void dumpCaller();
#endif
static const HashTable* arrayTable(CallFrame* callFrame) { return callFrame->globalData().arrayTable; }
static const HashTable* dateTable(CallFrame* callFrame) { return callFrame->globalData().dateTable; }
static const HashTable* jsonTable(CallFrame* callFrame) { return callFrame->globalData().jsonTable; }
static const HashTable* mathTable(CallFrame* callFrame) { return callFrame->globalData().mathTable; }
static const HashTable* numberTable(CallFrame* callFrame) { return callFrame->globalData().numberTable; }
static const HashTable* objectConstructorTable(CallFrame* callFrame) { return callFrame->globalData().objectConstructorTable; }
static const HashTable* regExpTable(CallFrame* callFrame) { return callFrame->globalData().regExpTable; }
static const HashTable* regExpConstructorTable(CallFrame* callFrame) { return callFrame->globalData().regExpConstructorTable; }
static const HashTable* stringTable(CallFrame* callFrame) { return callFrame->globalData().stringTable; }
static CallFrame* create(Register* callFrameBase) { return static_cast<CallFrame*>(callFrameBase); }
Register* registers() { return this; }
CallFrame& operator=(const Register& r) { *static_cast<Register*>(this) = r; return *this; }
CallFrame* callerFrame() const { return this[RegisterFile::CallerFrame].callFrame(); }
#if ENABLE(JIT)
ReturnAddressPtr returnPC() const { return ReturnAddressPtr(this[RegisterFile::ReturnPC].vPC()); }
#endif
#if ENABLE(INTERPRETER)
Instruction* returnVPC() const { return this[RegisterFile::ReturnPC].vPC(); }
#endif
void setCallerFrame(CallFrame* callerFrame) { static_cast<Register*>(this)[RegisterFile::CallerFrame] = callerFrame; }
void setScopeChain(ScopeChainNode* scopeChain) { static_cast<Register*>(this)[RegisterFile::ScopeChain] = scopeChain; }
ALWAYS_INLINE void init(CodeBlock* codeBlock, Instruction* vPC, ScopeChainNode* scopeChain,
CallFrame* callerFrame, int argc, JSObject* callee)
{
ASSERT(callerFrame); // Use noCaller() rather than 0 for the outer host call frame caller.
ASSERT(callerFrame == noCaller() || callerFrame->removeHostCallFrameFlag()->registerFile()->end() >= this);
setCodeBlock(codeBlock);
setScopeChain(scopeChain);
setCallerFrame(callerFrame);
setReturnPC(vPC); // This is either an Instruction* or a pointer into JIT generated code stored as an Instruction*.
setArgumentCountIncludingThis(argc); // original argument count (for the sake of the "arguments" object)
setCallee(callee);
}
// Read a register from the codeframe (or constant from the CodeBlock).
inline Register& r(int);
// Read a register for a non-constant
inline Register& uncheckedR(int);
// Access to arguments.
int hostThisRegister() { return -RegisterFile::CallFrameHeaderSize - argumentCountIncludingThis(); }
JSValue hostThisValue() { return this[hostThisRegister()].jsValue(); }
size_t argumentCount() const { return argumentCountIncludingThis() - 1; }
size_t argumentCountIncludingThis() const { return this[RegisterFile::ArgumentCount].i(); }
JSValue argument(int argumentNumber)
{
int argumentIndex = -RegisterFile::CallFrameHeaderSize - this[RegisterFile::ArgumentCount].i() + argumentNumber + 1;
if (argumentIndex >= -RegisterFile::CallFrameHeaderSize)
return jsUndefined();
return this[argumentIndex].jsValue();
}
static CallFrame* noCaller() { return reinterpret_cast<CallFrame*>(HostCallFrameFlag); }
bool hasHostCallFrameFlag() const { return reinterpret_cast<intptr_t>(this) & HostCallFrameFlag; }
CallFrame* addHostCallFrameFlag() const { return reinterpret_cast<CallFrame*>(reinterpret_cast<intptr_t>(this) | HostCallFrameFlag); }
CallFrame* removeHostCallFrameFlag() { return reinterpret_cast<CallFrame*>(reinterpret_cast<intptr_t>(this) & ~HostCallFrameFlag); }
void setArgumentCountIncludingThis(int count) { static_cast<Register*>(this)[RegisterFile::ArgumentCount] = Register::withInt(count); }
void setCallee(JSObject* callee) { static_cast<Register*>(this)[RegisterFile::Callee] = Register::withCallee(callee); }
void setCodeBlock(CodeBlock* codeBlock) { static_cast<Register*>(this)[RegisterFile::CodeBlock] = codeBlock; }
void setReturnPC(void* value) { static_cast<Register*>(this)[RegisterFile::ReturnPC] = (Instruction*)value; }
private:
static const intptr_t HostCallFrameFlag = 1;
#ifndef NDEBUG
RegisterFile* registerFile();
#endif
ExecState();
~ExecState();
};
} // namespace JSC
#endif // CallFrame_h
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