/*

 * Copyright (C) 2008 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.

 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of

 *     its contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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.

 */

#ifndef Interpreter_h

#define Interpreter_h

#include "ArgList.h"

#include "FastAllocBase.h"

#include "JSCell.h"

#include "JSValue.h"

#include "JSObject.h"

#include "Opcode.h"

#include "RegisterFile.h"

#include <wtf/HashMap.h>

namespace JSC {

    class CodeBlock;

    class EvalExecutable;

    class FunctionExecutable;

    class JSFunction;

    class JSGlobalObject;

    class ProgramExecutable;

    class Register;

    class ScopeChainNode;

    class SamplingTool;

    struct CallFrameClosure;

    struct HandlerInfo;

    struct Instruction;

    enum DebugHookID {

        WillExecuteProgram,

        DidExecuteProgram,

        DidEnterCallFrame,

        DidReachBreakpoint,

        WillLeaveCallFrame,

        WillExecuteStatement

    };

    enum { MaxLargeThreadReentryDepth = 256, MaxSmallThreadReentryDepth = 32 };

    class Interpreter : public FastAllocBase {

        friend class JIT;

        friend class CachedCall;

    public:

        Interpreter();

        RegisterFile& registerFile() { return m_registerFile; }

        Opcode getOpcode(OpcodeID id)

        {

            #if ENABLE(COMPUTED_GOTO_INTERPRETER)

                return m_opcodeTable[id];

            #else

                return id;

            #endif

        }

        OpcodeID getOpcodeID(Opcode opcode)

        {

            #if ENABLE(COMPUTED_GOTO_INTERPRETER)

                ASSERT(isOpcode(opcode));

                return m_opcodeIDTable.get(opcode);

            #else

                return opcode;

            #endif

        }

        bool isOpcode(Opcode);

        JSValue execute(ProgramExecutable*, CallFrame*, ScopeChainNode*, JSObject* thisObj, JSValue* exception);

        JSValue executeCall(CallFrame*, JSObject* function, CallType, const CallData&, JSValue thisValue, const ArgList&, JSValue* exception);

        JSObject* executeConstruct(CallFrame*, JSObject* function, ConstructType, const ConstructData&, const ArgList&, JSValue* exception);

        JSValue execute(EvalExecutable* evalNode, CallFrame* exec, JSObject* thisObj, ScopeChainNode* scopeChain, JSValue* exception);

        JSValue retrieveArguments(CallFrame*, JSFunction*) const;

        JSValue retrieveCaller(CallFrame*, JSFunction*) const;

        void retrieveLastCaller(CallFrame*, int& lineNumber, intptr_t& sourceID, UString& sourceURL, JSValue& function) const;

        void getArgumentsData(CallFrame*, JSFunction*&, ptrdiff_t& firstParameterIndex, Register*& argv, int& argc);

        SamplingTool* sampler() { return m_sampler.get(); }

        NEVER_INLINE JSValue callEval(CallFrame*, RegisterFile*, Register* argv, int argc, int registerOffset, JSValue& exceptionValue);

        NEVER_INLINE HandlerInfo* throwException(CallFrame*&, JSValue&, unsigned bytecodeOffset, bool);

        NEVER_INLINE void debug(CallFrame*, DebugHookID, int firstLine, int lastLine);

        void dumpSampleData(ExecState* exec);

        void startSampling();

        void stopSampling();

    private:

        enum ExecutionFlag { Normal, InitializeAndReturn };

        CallFrameClosure prepareForRepeatCall(FunctionExecutable*, CallFrame*, JSFunction*, int argCount, ScopeChainNode*, JSValue* exception);

        void endRepeatCall(CallFrameClosure&);

        JSValue execute(CallFrameClosure&, JSValue* exception);

        JSValue execute(EvalExecutable*, CallFrame*, JSObject* thisObject, int globalRegisterOffset, ScopeChainNode*, JSValue* exception);

#if ENABLE(INTERPRETER)

        NEVER_INLINE bool resolve(CallFrame*, Instruction*, JSValue& exceptionValue);

        NEVER_INLINE bool resolveSkip(CallFrame*, Instruction*, JSValue& exceptionValue);

        NEVER_INLINE bool resolveGlobal(CallFrame*, Instruction*, JSValue& exceptionValue);

        NEVER_INLINE bool resolveGlobalDynamic(CallFrame*, Instruction*, JSValue& exceptionValue);

        NEVER_INLINE void resolveBase(CallFrame*, Instruction* vPC);

        NEVER_INLINE bool resolveBaseAndProperty(CallFrame*, Instruction*, JSValue& exceptionValue);

        NEVER_INLINE ScopeChainNode* createExceptionScope(CallFrame*, const Instruction* vPC);

        void tryCacheGetByID(CallFrame*, CodeBlock*, Instruction*, JSValue baseValue, const Identifier& propertyName, const PropertySlot&);

        void uncacheGetByID(CodeBlock*, Instruction* vPC);

        void tryCachePutByID(CallFrame*, CodeBlock*, Instruction*, JSValue baseValue, const PutPropertySlot&);

        void uncachePutByID(CodeBlock*, Instruction* vPC);        

#endif // ENABLE(INTERPRETER)

        NEVER_INLINE bool unwindCallFrame(CallFrame*&, JSValue, unsigned& bytecodeOffset, CodeBlock*&);

        static ALWAYS_INLINE CallFrame* slideRegisterWindowForCall(CodeBlock*, RegisterFile*, CallFrame*, size_t registerOffset, int argc);

        static CallFrame* findFunctionCallFrame(CallFrame*, JSFunction*);

        JSValue privateExecute(ExecutionFlag, RegisterFile*, CallFrame*, JSValue* exception);

        void dumpCallFrame(CallFrame*);

        void dumpRegisters(CallFrame*);

        bool isCallBytecode(Opcode opcode) { return opcode == getOpcode(op_call) || opcode == getOpcode(op_construct) || opcode == getOpcode(op_call_eval); }

        void enableSampler();

        int m_sampleEntryDepth;

        OwnPtr<SamplingTool> m_sampler;

        int m_reentryDepth;

        RegisterFile m_registerFile;

#if ENABLE(COMPUTED_GOTO_INTERPRETER)

        Opcode m_opcodeTable[numOpcodeIDs]; // Maps OpcodeID => Opcode for compiling

        HashMap<Opcode, OpcodeID> m_opcodeIDTable; // Maps Opcode => OpcodeID for decompiling

#endif

    };

} // namespace JSC

#endif // Interpreter_h