bytecodegenerator.h

linux下开源浏览器WebKit的源码,市面上的很多商用浏览器都是移植自WebKit

        RegisterID* emitLoad(RegisterID* dst, const Identifier&);
        RegisterID* emitLoad(RegisterID* dst, JSValuePtr);
        RegisterID* emitUnexpectedLoad(RegisterID* dst, bool);
        RegisterID* emitUnexpectedLoad(RegisterID* dst, double);

        RegisterID* emitUnaryOp(OpcodeID, RegisterID* dst, RegisterID* src);
        RegisterID* emitBinaryOp(OpcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2, OperandTypes);
        RegisterID* emitEqualityOp(OpcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2);
        RegisterID* emitUnaryNoDstOp(OpcodeID, RegisterID* src);

        RegisterID* emitNewObject(RegisterID* dst);
        RegisterID* emitNewArray(RegisterID* dst, ElementNode*); // stops at first elision

        RegisterID* emitNewFunction(RegisterID* dst, FuncDeclNode* func);
        RegisterID* emitNewFunctionExpression(RegisterID* dst, FuncExprNode* func);
        RegisterID* emitNewRegExp(RegisterID* dst, RegExp* regExp);

        RegisterID* emitMove(RegisterID* dst, RegisterID* src);

        RegisterID* emitToJSNumber(RegisterID* dst, RegisterID* src) { return emitUnaryOp(op_to_jsnumber, dst, src); }
        RegisterID* emitPreInc(RegisterID* srcDst);
        RegisterID* emitPreDec(RegisterID* srcDst);
        RegisterID* emitPostInc(RegisterID* dst, RegisterID* srcDst);
        RegisterID* emitPostDec(RegisterID* dst, RegisterID* srcDst);

        RegisterID* emitInstanceOf(RegisterID* dst, RegisterID* value, RegisterID* base, RegisterID* basePrototype);
        RegisterID* emitTypeOf(RegisterID* dst, RegisterID* src) { return emitUnaryOp(op_typeof, dst, src); }
        RegisterID* emitIn(RegisterID* dst, RegisterID* property, RegisterID* base) { return emitBinaryOp(op_in, dst, property, base, OperandTypes()); }

        RegisterID* emitResolve(RegisterID* dst, const Identifier& property);
        RegisterID* emitGetScopedVar(RegisterID* dst, size_t skip, int index, JSValuePtr globalObject);
        RegisterID* emitPutScopedVar(size_t skip, int index, RegisterID* value, JSValuePtr globalObject);

        RegisterID* emitResolveBase(RegisterID* dst, const Identifier& property);
        RegisterID* emitResolveWithBase(RegisterID* baseDst, RegisterID* propDst, const Identifier& property);
        RegisterID* emitResolveFunction(RegisterID* baseDst, RegisterID* funcDst, const Identifier& property);

        RegisterID* emitGetById(RegisterID* dst, RegisterID* base, const Identifier& property);
        RegisterID* emitPutById(RegisterID* base, const Identifier& property, RegisterID* value);
        RegisterID* emitDeleteById(RegisterID* dst, RegisterID* base, const Identifier&);
        RegisterID* emitGetByVal(RegisterID* dst, RegisterID* base, RegisterID* property);
        RegisterID* emitPutByVal(RegisterID* base, RegisterID* property, RegisterID* value);
        RegisterID* emitDeleteByVal(RegisterID* dst, RegisterID* base, RegisterID* property);
        RegisterID* emitPutByIndex(RegisterID* base, unsigned index, RegisterID* value);
        RegisterID* emitPutGetter(RegisterID* base, const Identifier& property, RegisterID* value);
        RegisterID* emitPutSetter(RegisterID* base, const Identifier& property, RegisterID* value);

        RegisterID* emitCall(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
        RegisterID* emitCallEval(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);

        RegisterID* emitReturn(RegisterID* src);
        RegisterID* emitEnd(RegisterID* src) { return emitUnaryNoDstOp(op_end, src); }

        RegisterID* emitConstruct(RegisterID* dst, RegisterID* func, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);

        PassRefPtr<Label> emitLabel(Label*);
        PassRefPtr<Label> emitJump(Label* target);
        PassRefPtr<Label> emitJumpIfTrue(RegisterID* cond, Label* target);
        PassRefPtr<Label> emitJumpIfFalse(RegisterID* cond, Label* target);
        PassRefPtr<Label> emitJumpScopes(Label* target, int targetScopeDepth);

        PassRefPtr<Label> emitJumpSubroutine(RegisterID* retAddrDst, Label*);
        void emitSubroutineReturn(RegisterID* retAddrSrc);

        RegisterID* emitGetPropertyNames(RegisterID* dst, RegisterID* base) { return emitUnaryOp(op_get_pnames, dst, base); }
        RegisterID* emitNextPropertyName(RegisterID* dst, RegisterID* iter, Label* target);

        RegisterID* emitCatch(RegisterID*, Label* start, Label* end);
        void emitThrow(RegisterID* exc) { emitUnaryNoDstOp(op_throw, exc); }
        RegisterID* emitNewError(RegisterID* dst, ErrorType type, JSValuePtr message);
        void emitPushNewScope(RegisterID* dst, Identifier& property, RegisterID* value);

        RegisterID* emitPushScope(RegisterID* scope);
        void emitPopScope();

        void emitDebugHook(DebugHookID, int firstLine, int lastLine);

        int scopeDepth() { return m_dynamicScopeDepth + m_finallyDepth; }

        void pushFinallyContext(Label* target, RegisterID* returnAddrDst);
        void popFinallyContext();

        LabelScope* breakTarget(const Identifier&);
        LabelScope* continueTarget(const Identifier&);

        void beginSwitch(RegisterID*, SwitchInfo::SwitchType);
        void endSwitch(uint32_t clauseCount, RefPtr<Label>*, ExpressionNode**, Label* defaultLabel, int32_t min, int32_t range);

        CodeType codeType() const { return m_codeType; }

        void setRegeneratingForExceptionInfo(CodeBlock* originalCodeBlock)
        {
            m_regeneratingForExceptionInfo = true;
            m_codeBlockBeingRegeneratedFrom = originalCodeBlock;
        }

    private:
        void emitOpcode(OpcodeID);
        void retrieveLastBinaryOp(int& dstIndex, int& src1Index, int& src2Index);
        void retrieveLastUnaryOp(int& dstIndex, int& srcIndex);
        void rewindBinaryOp();
        void rewindUnaryOp();

        PassRefPtr<Label> emitComplexJumpScopes(Label* target, ControlFlowContext* topScope, ControlFlowContext* bottomScope);

        struct JSValueHashTraits : HashTraits<JSValueEncodedAsPointer*> {
            static void constructDeletedValue(JSValueEncodedAsPointer*& slot) { slot = JSValuePtr::encode(jsImpossibleValue()); }
            static bool isDeletedValue(JSValueEncodedAsPointer* value) { return value == JSValuePtr::encode(jsImpossibleValue()); }
        };

        typedef HashMap<JSValueEncodedAsPointer*, unsigned, PtrHash<JSValueEncodedAsPointer*>, JSValueHashTraits> JSValueMap;

        struct IdentifierMapIndexHashTraits {
            typedef int TraitType;
            typedef IdentifierMapIndexHashTraits StorageTraits;
            static int emptyValue() { return std::numeric_limits<int>::max(); }
            static const bool emptyValueIsZero = false;
            static const bool needsDestruction = false;
            static const bool needsRef = false;
        };

        typedef HashMap<RefPtr<UString::Rep>, int, IdentifierRepHash, HashTraits<RefPtr<UString::Rep> >, IdentifierMapIndexHashTraits> IdentifierMap;
        typedef HashMap<double, JSValuePtr> NumberMap;
        typedef HashMap<UString::Rep*, JSString*, IdentifierRepHash> IdentifierStringMap;

        RegisterID* emitCall(OpcodeID, RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
        
        RegisterID* newRegister();

        // Returns the RegisterID corresponding to ident.
        RegisterID* addVar(const Identifier& ident, bool isConstant)
        {
            RegisterID* local;
            addVar(ident, isConstant, local);
            return local;
        }
        // Returns true if a new RegisterID was added, false if a pre-existing RegisterID was re-used.
        bool addVar(const Identifier&, bool isConstant, RegisterID*&);

        // Returns the RegisterID corresponding to ident.
        RegisterID* addGlobalVar(const Identifier& ident, bool isConstant)
        {
            RegisterID* local;
            addGlobalVar(ident, isConstant, local);
            return local;
        }
        // Returns true if a new RegisterID was added, false if a pre-existing RegisterID was re-used.
        bool addGlobalVar(const Identifier&, bool isConstant, RegisterID*&);

        RegisterID* addParameter(const Identifier&);
        
        void allocateConstants(size_t);

        RegisterID& registerFor(int index)
        {
            if (index >= 0)
                return m_calleeRegisters[index];

            if (index == RegisterFile::OptionalCalleeArguments)
                return m_argumentsRegister;

            if (m_parameters.size()) {
                ASSERT(!m_globals.size());
                return m_parameters[index + m_parameters.size() + RegisterFile::CallFrameHeaderSize];
            }

            return m_globals[-index - 1];
        }

        unsigned addConstant(FuncDeclNode*);
        unsigned addConstant(FuncExprNode*);
        unsigned addConstant(const Identifier&);
        RegisterID* addConstant(JSValuePtr);
        unsigned addUnexpectedConstant(JSValuePtr);
        unsigned addRegExp(RegExp*);

        Vector<Instruction>& instructions() { return m_codeBlock->instructions(); }
        SymbolTable& symbolTable() { return *m_symbolTable; }

        bool shouldOptimizeLocals() { return (m_codeType != EvalCode) && !m_dynamicScopeDepth; }
        bool canOptimizeNonLocals() { return (m_codeType == FunctionCode) && !m_dynamicScopeDepth && !m_codeBlock->usesEval(); }

        RegisterID* emitThrowExpressionTooDeepException();

        bool m_shouldEmitDebugHooks;
        bool m_shouldEmitProfileHooks;

        const ScopeChain* m_scopeChain;
        SymbolTable* m_symbolTable;

        ScopeNode* m_scopeNode;
        CodeBlock* m_codeBlock;

        HashSet<RefPtr<UString::Rep>, IdentifierRepHash> m_functions;
        RegisterID m_ignoredResultRegister;
        RegisterID m_thisRegister;
        RegisterID m_argumentsRegister;
        int m_activationRegisterIndex;
        SegmentedVector<RegisterID, 512> m_calleeRegisters;
        SegmentedVector<RegisterID, 512> m_parameters;
        SegmentedVector<RegisterID, 512> m_globals;
        SegmentedVector<LabelScope, 256> m_labelScopes;
        SegmentedVector<Label, 256> m_labels;
        RefPtr<RegisterID> m_lastConstant;
        int m_finallyDepth;
        int m_dynamicScopeDepth;
        int m_baseScopeDepth;
        CodeType m_codeType;

        Vector<ControlFlowContext> m_scopeContextStack;
        Vector<SwitchInfo> m_switchContextStack;

        int m_nextGlobalIndex;
        int m_nextParameterIndex;
        int m_nextConstantIndex;

        int m_globalVarStorageOffset;

        // Constant pool
        IdentifierMap m_identifierMap;
        JSValueMap m_jsValueMap;
        NumberMap m_numberMap;
        IdentifierStringMap m_stringMap;

        JSGlobalData* m_globalData;

        OpcodeID m_lastOpcodeID;

        unsigned m_emitNodeDepth;

        bool m_regeneratingForExceptionInfo;
        CodeBlock* m_codeBlockBeingRegeneratedFrom;

        static const unsigned s_maxEmitNodeDepth = 10000;
    };

}

#endif // BytecodeGenerator_h