JavaScriptCore-7601.1.46.3.tar.gz

[apple/javascriptcore.git] / bytecompiler / BytecodeGenerator.h

diff --git a/bytecompiler/BytecodeGenerator.h b/bytecompiler/BytecodeGenerator.h
index 3667198dad5466e20548747449b5fa7925cc6c8c..1a9771ef107979c49f51a3943984e63181c84de3 100644 (file)
--- a/bytecompiler/BytecodeGenerator.h
+++ b/bytecompiler/BytecodeGenerator.h
@@ -1,6 +1,7 @@
 /*
 /*

- * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
+ * Copyright (C) 2008, 2009, 2012-2015 Apple Inc. All rights reserved.

  * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
  * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>

+ * Copyright (C) 2012 Igalia, S.L.

  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions


@@ -11,7 +12,7 @@
  * 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.
  * 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
+ * 3.  Neither the name of Apple 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.
  *
  *     its contributors may be used to endorse or promote products derived
  *     from this software without specific prior written permission.
  *


@@ -31,29 +32,67 @@
 #define BytecodeGenerator_h
 
 #include "CodeBlock.h"
 #define BytecodeGenerator_h
 
 #include "CodeBlock.h"

-#include "HashTraits.h"
+#include <wtf/HashTraits.h>

 #include "Instruction.h"
 #include "Label.h"
 #include "LabelScope.h"
 #include "Interpreter.h"
 #include "Instruction.h"
 #include "Label.h"
 #include "LabelScope.h"
 #include "Interpreter.h"

+#include "ParserError.h"

 #include "RegisterID.h"
 #include "SymbolTable.h"
 #include "Debugger.h"
 #include "Nodes.h"
 #include "RegisterID.h"
 #include "SymbolTable.h"
 #include "Debugger.h"
 #include "Nodes.h"

-#include <wtf/FastAllocBase.h>
+#include "StaticPropertyAnalyzer.h"
+#include "TemplateRegistryKey.h"
+#include "UnlinkedCodeBlock.h"
+
+#include <functional>
+

 #include <wtf/PassRefPtr.h>
 #include <wtf/SegmentedVector.h>
 #include <wtf/Vector.h>
 
 #include <wtf/PassRefPtr.h>
 #include <wtf/SegmentedVector.h>
 #include <wtf/Vector.h>
 

+

 namespace JSC {
 
     class Identifier;
 namespace JSC {
 
     class Identifier;

-    class ScopeChain;
-    class ScopeNode;
+    class JSTemplateRegistryKey;
+
+    enum ExpectedFunction {
+        NoExpectedFunction,
+        ExpectObjectConstructor,
+        ExpectArrayConstructor
+    };
+
+    class CallArguments {
+    public:
+        CallArguments(BytecodeGenerator&, ArgumentsNode*, unsigned additionalArguments = 0);
+
+        RegisterID* thisRegister() { return m_argv[0].get(); }
+        RegisterID* argumentRegister(unsigned i) { return m_argv[i + 1].get(); }
+        unsigned stackOffset() { return -m_argv[0]->index() + JSStack::CallFrameHeaderSize; }
+        unsigned argumentCountIncludingThis() { return m_argv.size() - m_padding; }
+        RegisterID* profileHookRegister() { return m_profileHookRegister.get(); }
+        ArgumentsNode* argumentsNode() { return m_argumentsNode; }
+
+    private:
+        RefPtr<RegisterID> m_profileHookRegister;
+        ArgumentsNode* m_argumentsNode;
+        Vector<RefPtr<RegisterID>, 8, UnsafeVectorOverflow> m_argv;
+        unsigned m_padding;
+    };

 
     struct FinallyContext {
 
     struct FinallyContext {

-        Label* finallyAddr;
-        RegisterID* retAddrDst;
+        StatementNode* finallyBlock;
+        RegisterID* iterator;
+        ThrowableExpressionData* enumerationNode;
+        unsigned scopeContextStackSize;
+        unsigned switchContextStackSize;
+        unsigned forInContextStackSize;
+        unsigned tryContextStackSize;
+        unsigned labelScopesSize;
+        int finallyDepth;
+        int dynamicScopeDepth;

     };
 
     struct ControlFlowContext {
     };
 
     struct ControlFlowContext {


@@ -61,58 +100,199 @@ namespace JSC {
         FinallyContext finallyContext;
     };
 
         FinallyContext finallyContext;
     };
 

-    struct ForInContext {
-        RefPtr<RegisterID> expectedSubscriptRegister;
-        RefPtr<RegisterID> iterRegister;
-        RefPtr<RegisterID> indexRegister;
-        RefPtr<RegisterID> propertyRegister;
+    class ForInContext {
+    public:
+        ForInContext(RegisterID* localRegister)
+            : m_localRegister(localRegister)
+            , m_isValid(true)
+        {
+        }
+
+        virtual ~ForInContext()
+        {
+        }
+
+        bool isValid() const { return m_isValid; }
+        void invalidate() { m_isValid = false; }
+
+        enum ForInContextType {
+            StructureForInContextType,
+            IndexedForInContextType
+        };
+        virtual ForInContextType type() const = 0;
+
+        RegisterID* local() const { return m_localRegister.get(); }
+
+    private:
+        RefPtr<RegisterID> m_localRegister;
+        bool m_isValid;
+    };
+
+    class StructureForInContext : public ForInContext {
+    public:
+        StructureForInContext(RegisterID* localRegister, RegisterID* indexRegister, RegisterID* propertyRegister, RegisterID* enumeratorRegister)
+            : ForInContext(localRegister)
+            , m_indexRegister(indexRegister)
+            , m_propertyRegister(propertyRegister)
+            , m_enumeratorRegister(enumeratorRegister)
+        {
+        }
+
+        virtual ForInContextType type() const
+        {
+            return StructureForInContextType;
+        }
+
+        RegisterID* index() const { return m_indexRegister.get(); }
+        RegisterID* property() const { return m_propertyRegister.get(); }
+        RegisterID* enumerator() const { return m_enumeratorRegister.get(); }
+
+    private:
+        RefPtr<RegisterID> m_indexRegister;
+        RefPtr<RegisterID> m_propertyRegister;
+        RefPtr<RegisterID> m_enumeratorRegister;

     };
 
     };
 

-    class BytecodeGenerator : public FastAllocBase {
+    class IndexedForInContext : public ForInContext {
+    public:
+        IndexedForInContext(RegisterID* localRegister, RegisterID* indexRegister)
+            : ForInContext(localRegister)
+            , m_indexRegister(indexRegister)
+        {
+        }
+
+        virtual ForInContextType type() const
+        {
+            return IndexedForInContextType;
+        }
+
+        RegisterID* index() const { return m_indexRegister.get(); }
+
+    private:
+        RefPtr<RegisterID> m_indexRegister;
+    };
+
+    struct TryData {
+        RefPtr<Label> target;
+        unsigned targetScopeDepth;
+        HandlerType handlerType;
+    };
+
+    struct TryContext {
+        RefPtr<Label> start;
+        TryData* tryData;
+    };
+
+    class Variable {
+    public:
+        enum VariableKind { NormalVariable, SpecialVariable };
+
+        Variable()
+            : m_offset()
+            , m_local(nullptr)
+            , m_attributes(0)
+            , m_kind(NormalVariable)
+        {
+        }
+        
+        Variable(const Identifier& ident)
+            : m_ident(ident)
+            , m_local(nullptr)
+            , m_attributes(0)
+            , m_kind(NormalVariable) // This is somewhat meaningless here for this kind of Variable.
+        {
+        }
+
+        Variable(const Identifier& ident, VarOffset offset, RegisterID* local, unsigned attributes, VariableKind kind)
+            : m_ident(ident)
+            , m_offset(offset)
+            , m_local(local)
+            , m_attributes(attributes)
+            , m_kind(kind)
+        {
+        }
+
+        // If it's unset, then it is a non-locally-scoped variable. If it is set, then it could be
+        // a stack variable, a scoped variable in the local scope, or a variable captured in the
+        // direct arguments object.
+        bool isResolved() const { return !!m_offset; }
+        
+        const Identifier& ident() const { return m_ident; }
+        
+        VarOffset offset() const { return m_offset; }
+        bool isLocal() const { return m_offset.isStack(); }
+        RegisterID* local() const { return m_local; }
+
+        bool isReadOnly() const { return m_attributes & ReadOnly; }
+        bool isSpecial() const { return m_kind != NormalVariable; }
+
+    private:
+        Identifier m_ident;
+        VarOffset m_offset;
+        RegisterID* m_local;
+        unsigned m_attributes;
+        VariableKind m_kind;
+    };
+
+    struct TryRange {
+        RefPtr<Label> start;
+        RefPtr<Label> end;
+        TryData* tryData;
+    };
+
+    enum ProfileTypeBytecodeFlag {
+        ProfileTypeBytecodePutToScope,
+        ProfileTypeBytecodeGetFromScope,
+        ProfileTypeBytecodePutToLocalScope,
+        ProfileTypeBytecodeGetFromLocalScope,
+        ProfileTypeBytecodeHasGlobalID,
+        ProfileTypeBytecodeDoesNotHaveGlobalID,
+        ProfileTypeBytecodeFunctionArgument,
+        ProfileTypeBytecodeFunctionReturnStatement
+    };
+
+    class BytecodeGenerator {
+        WTF_MAKE_FAST_ALLOCATED;
+        WTF_MAKE_NONCOPYABLE(BytecodeGenerator);

     public:
         typedef DeclarationStacks::VarStack VarStack;
         typedef DeclarationStacks::FunctionStack FunctionStack;
 
     public:
         typedef DeclarationStacks::VarStack VarStack;
         typedef DeclarationStacks::FunctionStack FunctionStack;
 

-        static void setDumpsGeneratedCode(bool dumpsGeneratedCode);
-        static bool dumpsGeneratedCode();
+        BytecodeGenerator(VM&, ProgramNode*, UnlinkedProgramCodeBlock*, DebuggerMode, ProfilerMode);
+        BytecodeGenerator(VM&, FunctionNode*, UnlinkedFunctionCodeBlock*, DebuggerMode, ProfilerMode);
+        BytecodeGenerator(VM&, EvalNode*, UnlinkedEvalCodeBlock*, DebuggerMode, ProfilerMode);

 
 

-        BytecodeGenerator(ProgramNode*, const Debugger*, const ScopeChain&, SymbolTable*, ProgramCodeBlock*);
-        BytecodeGenerator(FunctionBodyNode*, const Debugger*, const ScopeChain&, SymbolTable*, CodeBlock*);
-        BytecodeGenerator(EvalNode*, const Debugger*, const ScopeChain&, SymbolTable*, EvalCodeBlock*);
+        ~BytecodeGenerator();
+        
+        VM* vm() const { return m_vm; }
+        ParserArena& parserArena() const { return m_scopeNode->parserArena(); }
+        const CommonIdentifiers& propertyNames() const { return *m_vm->propertyNames; }

 
 

-        JSGlobalData* globalData() const { return m_globalData; }
-        const CommonIdentifiers& propertyNames() const { return *m_globalData->propertyNames; }
+        bool isConstructor() const { return m_codeBlock->isConstructor(); }
+#if ENABLE(ES6_CLASS_SYNTAX)
+        ConstructorKind constructorKind() const { return m_codeBlock->constructorKind(); }
+#else
+        ConstructorKind constructorKind() const { return ConstructorKind::None; }
+#endif

 
 

-        void generate();
+        ParserError generate();

 
 

-        // Returns the register corresponding to a local variable, or 0 if no
-        // such register exists. Registers returned by registerFor do not
-        // require explicit reference counting.
-        RegisterID* registerFor(const Identifier&);
-        
-        bool willResolveToArguments(const Identifier&);
-        RegisterID* uncheckedRegisterForArguments();
-
-        // Behaves as registerFor does, but ignores dynamic scope as
-        // dynamic scope should not interfere with const initialisation
-        RegisterID* constRegisterFor(const Identifier&);
-
-        // Searches the scope chain in an attempt to  statically locate the requested
-        // property.  Returns false if for any reason the property cannot be safely
-        // optimised at all.  Otherwise it will return the index and depth of the
-        // VariableObject that defines the property.  If the property cannot be found
-        // statically, depth will contain the depth of the scope chain where dynamic
-        // lookup must begin.
-        //
-        // NB: depth does _not_ include the local scope.  eg. a depth of 0 refers
-        // to the scope containing this codeblock.
-        bool findScopedProperty(const Identifier&, int& index, size_t& depth, bool forWriting, bool& includesDynamicScopes, JSObject*& globalObject);
+        bool isArgumentNumber(const Identifier&, int);

 
 

+        Variable variable(const Identifier&);
+        
+        // Ignores the possibility of intervening scopes.
+        Variable variablePerSymbolTable(const Identifier&);
+        
+        enum ExistingVariableMode { VerifyExisting, IgnoreExisting };
+        void createVariable(const Identifier&, VarKind, ConstantMode, ExistingVariableMode = VerifyExisting); // Creates the variable, or asserts that the already-created variable is sufficiently compatible.
+        

         // Returns the register storing "this"
         RegisterID* thisRegister() { return &m_thisRegister; }
         // Returns the register storing "this"
         RegisterID* thisRegister() { return &m_thisRegister; }

+        RegisterID* argumentsRegister() { return m_argumentsRegister; }
+        RegisterID* newTarget() { return m_newTargetRegister; }

 
 

-        bool isLocal(const Identifier&);
-        bool isLocalConstant(const Identifier&);
+        RegisterID* scopeRegister() { return m_scopeRegister; }

 
         // Returns the next available temporary register. Registers returned by
         // newTemporary require a modified form of reference counting: any
 
         // Returns the next available temporary register. Registers returned by
         // newTemporary require a modified form of reference counting: any


@@ -120,8 +300,6 @@ namespace JSC {
         // the next instruction may overwrite it.
         RegisterID* newTemporary();
 
         // the next instruction may overwrite it.
         RegisterID* newTemporary();
 

-        RegisterID* highestUsedRegister();
-

         // The same as newTemporary(), but this function returns "suggestion" if
         // "suggestion" is a temporary. This function is helpful in situations
         // where you've put "suggestion" in a RefPtr, but you'd like to allow
         // The same as newTemporary(), but this function returns "suggestion" if
         // "suggestion" is a temporary. This function is helpful in situations
         // where you've put "suggestion" in a RefPtr, but you'd like to allow


@@ -163,88 +341,82 @@ namespace JSC {
             return dst == ignoredResult() ? 0 : (dst && dst != src) ? emitMove(dst, src) : src;
         }
 
             return dst == ignoredResult() ? 0 : (dst && dst != src) ? emitMove(dst, src) : src;
         }
 

-        PassRefPtr<LabelScope> newLabelScope(LabelScope::Type, const Identifier* = 0);
+        LabelScopePtr newLabelScope(LabelScope::Type, const Identifier* = 0);

         PassRefPtr<Label> newLabel();
 
         PassRefPtr<Label> newLabel();
 

-        // The emitNode functions are just syntactic sugar for calling
-        // Node::emitCode. These functions accept a 0 for the register,
-        // meaning that the node should allocate a register, or ignoredResult(),
-        // meaning that the node need not put the result in a register.
-        // Other emit functions do not accept 0 or ignoredResult().
-        RegisterID* emitNode(RegisterID* dst, Node* n)
+        void emitNode(RegisterID* dst, StatementNode* n)

         {
             // Node::emitCode assumes that dst, if provided, is either a local or a referenced temporary.
             ASSERT(!dst || dst == ignoredResult() || !dst->isTemporary() || dst->refCount());
         {
             // Node::emitCode assumes that dst, if provided, is either a local or a referenced temporary.
             ASSERT(!dst || dst == ignoredResult() || !dst->isTemporary() || dst->refCount());

-            if (!m_codeBlock->numberOfLineInfos() || m_codeBlock->lastLineInfo().lineNumber != n->lineNo()) {
-                LineInfo info = { instructions().size(), n->lineNo() };
-                m_codeBlock->addLineInfo(info);
+            if (!m_vm->isSafeToRecurse()) {
+                emitThrowExpressionTooDeepException();
+                return;

             }
             }

-            if (m_emitNodeDepth >= s_maxEmitNodeDepth)
+            n->emitBytecode(*this, dst);
+        }
+
+        void emitNode(StatementNode* n)
+        {
+            emitNode(0, n);
+        }
+
+        RegisterID* emitNode(RegisterID* dst, ExpressionNode* n)
+        {
+            // Node::emitCode assumes that dst, if provided, is either a local or a referenced temporary.
+            ASSERT(!dst || dst == ignoredResult() || !dst->isTemporary() || dst->refCount());
+            if (!m_vm->isSafeToRecurse())

                 return emitThrowExpressionTooDeepException();
                 return emitThrowExpressionTooDeepException();

-            ++m_emitNodeDepth;
-            RegisterID* r = n->emitBytecode(*this, dst);
-            --m_emitNodeDepth;
-            return r;
+            return n->emitBytecode(*this, dst);

         }
 
         }
 

-        RegisterID* emitNode(Node* n)
+        RegisterID* emitNode(ExpressionNode* n)

         {
             return emitNode(0, n);
         }
 
         {
             return emitNode(0, n);
         }
 

-        void emitNodeInConditionContext(ExpressionNode* n, Label* trueTarget, Label* falseTarget, bool fallThroughMeansTrue)
+        void emitNodeInConditionContext(ExpressionNode* n, Label* trueTarget, Label* falseTarget, FallThroughMode fallThroughMode)

         {
         {

-            if (!m_codeBlock->numberOfLineInfos() || m_codeBlock->lastLineInfo().lineNumber != n->lineNo()) {
-                LineInfo info = { instructions().size(), n->lineNo() };
-                m_codeBlock->addLineInfo(info);
-            }
-            if (m_emitNodeDepth >= s_maxEmitNodeDepth)
+            if (!m_vm->isSafeToRecurse()) {

                 emitThrowExpressionTooDeepException();
                 emitThrowExpressionTooDeepException();

-            ++m_emitNodeDepth;
-            n->emitBytecodeInConditionContext(*this, trueTarget, falseTarget, fallThroughMeansTrue);
-            --m_emitNodeDepth;
-        }
-
-        void emitExpressionInfo(unsigned divot, unsigned startOffset, unsigned endOffset)
-        { 
-            divot -= m_codeBlock->sourceOffset();
-            if (divot > ExpressionRangeInfo::MaxDivot) {
-                // Overflow has occurred, we can only give line number info for errors for this region
-                divot = 0;
-                startOffset = 0;
-                endOffset = 0;
-            } else if (startOffset > ExpressionRangeInfo::MaxOffset) {
-                // If the start offset is out of bounds we clear both offsets
-                // so we only get the divot marker.  Error message will have to be reduced
-                // to line and column number.
-                startOffset = 0;
-                endOffset = 0;
-            } else if (endOffset > ExpressionRangeInfo::MaxOffset) {
-                // The end offset is only used for additional context, and is much more likely
-                // to overflow (eg. function call arguments) so we are willing to drop it without
-                // dropping the rest of the range.
-                endOffset = 0;
+                return;

             }
             }

-            
-            ExpressionRangeInfo info;
-            info.instructionOffset = instructions().size();
-            info.divotPoint = divot;
-            info.startOffset = startOffset;
-            info.endOffset = endOffset;
-            m_codeBlock->addExpressionInfo(info);
+
+            n->emitBytecodeInConditionContext(*this, trueTarget, falseTarget, fallThroughMode);

         }
 
         }
 

-        void emitGetByIdExceptionInfo(OpcodeID opcodeID)
-        {
-            // Only op_construct and op_instanceof need exception info for
-            // a preceding op_get_by_id.
-            ASSERT(opcodeID == op_construct || opcodeID == op_instanceof);
-            GetByIdExceptionInfo info;
-            info.bytecodeOffset = instructions().size();
-            info.isOpConstruct = (opcodeID == op_construct);
-            m_codeBlock->addGetByIdExceptionInfo(info);
+        void emitExpressionInfo(const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd)
+        {            
+            ASSERT(divot.offset >= divotStart.offset);
+            ASSERT(divotEnd.offset >= divot.offset);
+
+            int sourceOffset = m_scopeNode->source().startOffset();
+            unsigned firstLine = m_scopeNode->source().firstLine();
+
+            int divotOffset = divot.offset - sourceOffset;
+            int startOffset = divot.offset - divotStart.offset;
+            int endOffset = divotEnd.offset - divot.offset;
+
+            unsigned line = divot.line;
+            ASSERT(line >= firstLine);
+            line -= firstLine;
+
+            int lineStart = divot.lineStartOffset;
+            if (lineStart > sourceOffset)
+                lineStart -= sourceOffset;
+            else
+                lineStart = 0;
+
+            if (divotOffset < lineStart)
+                return;
+
+            unsigned column = divotOffset - lineStart;
+
+            unsigned instructionOffset = instructions().size();
+            if (!m_isBuiltinFunction)
+                m_codeBlock->addExpressionInfo(instructionOffset, divotOffset, startOffset, endOffset, line, column);

         }
         }

-        
+
+

         ALWAYS_INLINE bool leftHandSideNeedsCopy(bool rightHasAssignments, bool rightIsPure)
         {
             return (m_codeType != FunctionCode || m_codeBlock->needsFullScopeChain() || rightHasAssignments) && !rightIsPure;
         ALWAYS_INLINE bool leftHandSideNeedsCopy(bool rightHasAssignments, bool rightIsPure)
         {
             return (m_codeType != FunctionCode || m_codeBlock->needsFullScopeChain() || rightHasAssignments) && !rightIsPure;


@@ -258,295 +430,367 @@ namespace JSC {
                 return dst;
             }
 
                 return dst;
             }
 

-            return PassRefPtr<RegisterID>(emitNode(n));
+            return emitNode(n);

         }
 
         }
 

+        void emitTypeProfilerExpressionInfo(const JSTextPosition& startDivot, const JSTextPosition& endDivot);
+        void emitProfileType(RegisterID* registerToProfile, ProfileTypeBytecodeFlag, const Identifier*);
+
+        void emitProfileControlFlow(int);
+

         RegisterID* emitLoad(RegisterID* dst, bool);
         RegisterID* emitLoad(RegisterID* dst, bool);

-        RegisterID* emitLoad(RegisterID* dst, double);

         RegisterID* emitLoad(RegisterID* dst, const Identifier&);
         RegisterID* emitLoad(RegisterID* dst, const Identifier&);

-        RegisterID* emitLoad(RegisterID* dst, JSValue);
+        RegisterID* emitLoad(RegisterID* dst, JSValue, SourceCodeRepresentation = SourceCodeRepresentation::Other);
+        RegisterID* emitLoadGlobalObject(RegisterID* dst);

 
         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* 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* emitCreateThis(RegisterID* dst);
+        void emitTDZCheck(RegisterID* target);

         RegisterID* emitNewObject(RegisterID* dst);
         RegisterID* emitNewObject(RegisterID* dst);

-        RegisterID* emitNewArray(RegisterID* dst, ElementNode*); // stops at first elision
+        RegisterID* emitNewArray(RegisterID* dst, ElementNode*, unsigned length); // stops at first elision

 
 

-        RegisterID* emitNewFunction(RegisterID* dst, FunctionBodyNode* body);
+        RegisterID* emitNewFunction(RegisterID* dst, FunctionBodyNode*);
+        RegisterID* emitNewFunctionInternal(RegisterID* dst, unsigned index);

         RegisterID* emitNewFunctionExpression(RegisterID* dst, FuncExprNode* func);
         RegisterID* emitNewFunctionExpression(RegisterID* dst, FuncExprNode* func);

-        RegisterID* emitNewRegExp(RegisterID* dst, RegExp* regExp);
+        RegisterID* emitNewDefaultConstructor(RegisterID* dst, ConstructorKind, const Identifier& name);
+        RegisterID* emitNewRegExp(RegisterID* dst, RegExp*);

 
 

+        RegisterID* emitMoveLinkTimeConstant(RegisterID* dst, LinkTimeConstant);
+        RegisterID* emitMoveEmptyValue(RegisterID* dst);

         RegisterID* emitMove(RegisterID* dst, RegisterID* src);
 
         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* emitToNumber(RegisterID* dst, RegisterID* src) { return emitUnaryOp(op_to_number, dst, src); }
+        RegisterID* emitToString(RegisterID* dst, RegisterID* src) { return emitUnaryOp(op_to_string, dst, src); }
+        RegisterID* emitInc(RegisterID* srcDst);
+        RegisterID* emitDec(RegisterID* srcDst);

 
 

-        RegisterID* emitInstanceOf(RegisterID* dst, RegisterID* value, RegisterID* base, RegisterID* basePrototype);
+        void emitCheckHasInstance(RegisterID* dst, RegisterID* value, RegisterID* base, Label* target);
+        RegisterID* emitInstanceOf(RegisterID* dst, RegisterID* value, 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* 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, JSValue globalObject);
-        RegisterID* emitPutScopedVar(size_t skip, int index, RegisterID* value, JSValue globalObject);
-
-        RegisterID* emitResolveBase(RegisterID* dst, const Identifier& property);
-        RegisterID* emitResolveWithBase(RegisterID* baseDst, RegisterID* propDst, const Identifier& property);
-
-        void emitMethodCheck();
+        RegisterID* emitInitGlobalConst(const Identifier&, RegisterID* value);

 
         RegisterID* emitGetById(RegisterID* dst, RegisterID* base, const Identifier& property);
         RegisterID* emitPutById(RegisterID* base, const Identifier& property, RegisterID* value);
 
         RegisterID* emitGetById(RegisterID* dst, RegisterID* base, const Identifier& property);
         RegisterID* emitPutById(RegisterID* base, const Identifier& property, RegisterID* value);

-        RegisterID* emitDirectPutById(RegisterID* base, const Identifier& property, RegisterID* value);
+        RegisterID* emitDirectPutById(RegisterID* base, const Identifier& property, RegisterID* value, PropertyNode::PutType);

         RegisterID* emitDeleteById(RegisterID* dst, RegisterID* base, const Identifier&);
         RegisterID* emitGetByVal(RegisterID* dst, RegisterID* base, RegisterID* property);
         RegisterID* emitDeleteById(RegisterID* dst, RegisterID* base, const Identifier&);
         RegisterID* emitGetByVal(RegisterID* dst, RegisterID* base, RegisterID* property);

+        RegisterID* emitGetArgumentByVal(RegisterID* dst, RegisterID* base, RegisterID* property);

         RegisterID* emitPutByVal(RegisterID* base, RegisterID* property, RegisterID* value);
         RegisterID* emitPutByVal(RegisterID* base, RegisterID* property, RegisterID* value);

+        RegisterID* emitDirectPutByVal(RegisterID* base, RegisterID* property, RegisterID* value);

         RegisterID* emitDeleteByVal(RegisterID* dst, RegisterID* base, RegisterID* property);
         RegisterID* emitPutByIndex(RegisterID* base, unsigned index, 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* emitCallVarargs(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, RegisterID* argCount, unsigned divot, unsigned startOffset, unsigned endOffset);
-        RegisterID* emitLoadVarargs(RegisterID* argCountDst, RegisterID* args);
+        void emitPutGetterById(RegisterID* base, const Identifier& property, RegisterID* getter);
+        void emitPutSetterById(RegisterID* base, const Identifier& property, RegisterID* setter);
+        void emitPutGetterSetter(RegisterID* base, const Identifier& property, RegisterID* getter, RegisterID* setter);
+        
+        ExpectedFunction expectedFunctionForIdentifier(const Identifier&);
+        RegisterID* emitCall(RegisterID* dst, RegisterID* func, ExpectedFunction, CallArguments&, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd);
+        RegisterID* emitCallEval(RegisterID* dst, RegisterID* func, CallArguments&, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd);
+        RegisterID* emitCallVarargs(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, RegisterID* arguments, RegisterID* firstFreeRegister, int32_t firstVarArgOffset, RegisterID* profileHookRegister, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd);
+
+        enum PropertyDescriptorOption {
+            PropertyConfigurable = 1,
+            PropertyWritable     = 1 << 1,
+            PropertyEnumerable   = 1 << 2,
+        };
+        void emitCallDefineProperty(RegisterID* newObj, RegisterID* propertyNameRegister,
+            RegisterID* valueRegister, RegisterID* getterRegister, RegisterID* setterRegister, unsigned options, const JSTextPosition&);
+
+        void emitEnumeration(ThrowableExpressionData* enumerationNode, ExpressionNode* subjectNode, const std::function<void(BytecodeGenerator&, RegisterID*)>& callBack);
+
+#if ENABLE(ES6_TEMPLATE_LITERAL_SYNTAX)
+        RegisterID* emitGetTemplateObject(RegisterID* dst, TaggedTemplateNode*);
+#endif

 
         RegisterID* emitReturn(RegisterID* src);
         RegisterID* emitEnd(RegisterID* src) { return emitUnaryNoDstOp(op_end, src); }
 
 
         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);
+        RegisterID* emitConstruct(RegisterID* dst, RegisterID* func, ExpectedFunction, CallArguments&, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd);

         RegisterID* emitStrcat(RegisterID* dst, RegisterID* src, int count);
         void emitToPrimitive(RegisterID* dst, RegisterID* src);
 
         RegisterID* emitStrcat(RegisterID* dst, RegisterID* src, int count);
         void emitToPrimitive(RegisterID* dst, RegisterID* src);
 

+        ResolveType resolveType();
+        RegisterID* emitResolveConstantLocal(RegisterID* dst, const Variable&);
+        RegisterID* emitResolveScope(RegisterID* dst, const Variable&);
+        RegisterID* emitGetFromScope(RegisterID* dst, RegisterID* scope, const Variable&, ResolveMode);
+        RegisterID* emitPutToScope(RegisterID* scope, const Variable&, RegisterID* value, ResolveMode);
+        RegisterID* initializeVariable(const Variable&, RegisterID* value);
+

         PassRefPtr<Label> emitLabel(Label*);
         PassRefPtr<Label> emitLabel(Label*);

+        void emitLoopHint();

         PassRefPtr<Label> emitJump(Label* target);
         PassRefPtr<Label> emitJumpIfTrue(RegisterID* cond, Label* target);
         PassRefPtr<Label> emitJumpIfFalse(RegisterID* cond, Label* target);
         PassRefPtr<Label> emitJumpIfNotFunctionCall(RegisterID* cond, Label* target);
         PassRefPtr<Label> emitJumpIfNotFunctionApply(RegisterID* cond, Label* target);
         PassRefPtr<Label> emitJump(Label* target);
         PassRefPtr<Label> emitJumpIfTrue(RegisterID* cond, Label* target);
         PassRefPtr<Label> emitJumpIfFalse(RegisterID* cond, Label* target);
         PassRefPtr<Label> emitJumpIfNotFunctionCall(RegisterID* cond, Label* target);
         PassRefPtr<Label> emitJumpIfNotFunctionApply(RegisterID* cond, Label* target);

-        PassRefPtr<Label> emitJumpScopes(Label* target, int targetScopeDepth);
+        void emitPopScopes(RegisterID* srcDst, int targetScopeDepth);
+
+        RegisterID* emitHasIndexedProperty(RegisterID* dst, RegisterID* base, RegisterID* propertyName);
+        RegisterID* emitHasStructureProperty(RegisterID* dst, RegisterID* base, RegisterID* propertyName, RegisterID* enumerator);
+        RegisterID* emitHasGenericProperty(RegisterID* dst, RegisterID* base, RegisterID* propertyName);
+        RegisterID* emitGetPropertyEnumerator(RegisterID* dst, RegisterID* base);
+        RegisterID* emitGetEnumerableLength(RegisterID* dst, RegisterID* base);
+        RegisterID* emitGetStructurePropertyEnumerator(RegisterID* dst, RegisterID* base, RegisterID* length);
+        RegisterID* emitGetGenericPropertyEnumerator(RegisterID* dst, RegisterID* base, RegisterID* length, RegisterID* structureEnumerator);
+        RegisterID* emitEnumeratorStructurePropertyName(RegisterID* dst, RegisterID* enumerator, RegisterID* index);
+        RegisterID* emitEnumeratorGenericPropertyName(RegisterID* dst, RegisterID* enumerator, RegisterID* index);
+        RegisterID* emitToIndexString(RegisterID* dst, RegisterID* index);

 
 

-        PassRefPtr<Label> emitJumpSubroutine(RegisterID* retAddrDst, Label*);
-        void emitSubroutineReturn(RegisterID* retAddrSrc);
+        RegisterID* emitIsObject(RegisterID* dst, RegisterID* src);
+        RegisterID* emitIsUndefined(RegisterID* dst, RegisterID* src);

 
 

-        RegisterID* emitGetPropertyNames(RegisterID* dst, RegisterID* base, RegisterID* i, RegisterID* size, Label* breakTarget);
-        RegisterID* emitNextPropertyName(RegisterID* dst, RegisterID* base, RegisterID* i, RegisterID* size, RegisterID* iter, Label* target);
+        RegisterID* emitIteratorNext(RegisterID* dst, RegisterID* iterator, const ThrowableExpressionData* node);
+        void emitIteratorClose(RegisterID* iterator, const ThrowableExpressionData* node);

 
 

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

 
 

-        RegisterID* emitPushScope(RegisterID* scope);
-        void emitPopScope();
+        // Start a try block. 'start' must have been emitted.
+        TryData* pushTry(Label* start);
+        // End a try block. 'end' must have been emitted.
+        void popTryAndEmitCatch(TryData*, RegisterID* exceptionRegister, RegisterID* thrownValueRegister, Label* end, HandlerType);
+
+        void emitThrow(RegisterID* exc)
+        { 
+            m_usesExceptions = true;
+            emitUnaryNoDstOp(op_throw, exc);
+        }

 
 

-        void emitDebugHook(DebugHookID, int firstLine, int lastLine);
+        void emitThrowReferenceError(const String& message);
+        void emitThrowTypeError(const String& message);

 
 

-        int scopeDepth() { return m_dynamicScopeDepth + m_finallyDepth; }
+        void emitPushFunctionNameScope(RegisterID* dst, const Identifier& property, RegisterID* value, unsigned attributes);
+        void emitPushCatchScope(RegisterID* dst, const Identifier& property, RegisterID* value, unsigned attributes);
+
+        void emitGetScope();
+        RegisterID* emitPushWithScope(RegisterID* dst, RegisterID* scope);
+        void emitPopScope(RegisterID* srcDst);
+
+        void emitDebugHook(DebugHookID, unsigned line, unsigned charOffset, unsigned lineStart);
+
+        int scopeDepth() { return m_localScopeDepth + m_finallyDepth; }

         bool hasFinaliser() { return m_finallyDepth != 0; }
 
         bool hasFinaliser() { return m_finallyDepth != 0; }
 

-        void pushFinallyContext(Label* target, RegisterID* returnAddrDst);
+        void pushFinallyContext(StatementNode* finallyBlock);

         void popFinallyContext();
         void popFinallyContext();

+        void pushIteratorCloseContext(RegisterID* iterator, ThrowableExpressionData* enumerationNode);
+        void popIteratorCloseContext();

 
 

-        void pushOptimisedForIn(RegisterID* expectedBase, RegisterID* iter, RegisterID* index, RegisterID* propertyRegister)
-        {
-            ForInContext context = { expectedBase, iter, index, propertyRegister };
-            m_forInContextStack.append(context);
-        }
-
-        void popOptimisedForIn()
-        {
-            m_forInContextStack.removeLast();
-        }
+        void pushIndexedForInScope(RegisterID* local, RegisterID* index);
+        void popIndexedForInScope(RegisterID* local);
+        void pushStructureForInScope(RegisterID* local, RegisterID* index, RegisterID* property, RegisterID* enumerator);
+        void popStructureForInScope(RegisterID* local);
+        void invalidateForInContextForLocal(RegisterID* local);

 
 

-        LabelScope* breakTarget(const Identifier&);
-        LabelScope* continueTarget(const Identifier&);
+        LabelScopePtr breakTarget(const Identifier&);
+        LabelScopePtr 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 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;
-        }
+        bool shouldEmitProfileHooks() { return m_shouldEmitProfileHooks; }
+        bool shouldEmitDebugHooks() { return m_shouldEmitDebugHooks; }
+        
+        bool isStrictMode() const { return m_codeBlock->isStrictMode(); }
+        
+        bool isBuiltinFunction() const { return m_isBuiltinFunction; }
+
+        OpcodeID lastOpcodeID() const { return m_lastOpcodeID; }

 
     private:
 
     private:

+        Variable variableForLocalEntry(const Identifier&, const SymbolTableEntry&);
+

         void emitOpcode(OpcodeID);
         void emitOpcode(OpcodeID);

+        UnlinkedArrayAllocationProfile newArrayAllocationProfile();
+        UnlinkedObjectAllocationProfile newObjectAllocationProfile();
+        UnlinkedArrayProfile newArrayProfile();
+        UnlinkedValueProfile emitProfiledOpcode(OpcodeID);
+        int kill(RegisterID* dst)
+        {
+            int index = dst->index();
+            m_staticPropertyAnalyzer.kill(index);
+            return index;
+        }
+

         void retrieveLastBinaryOp(int& dstIndex, int& src1Index, int& src2Index);
         void retrieveLastUnaryOp(int& dstIndex, int& srcIndex);
         ALWAYS_INLINE void rewindBinaryOp();
         ALWAYS_INLINE void rewindUnaryOp();
 
         void retrieveLastBinaryOp(int& dstIndex, int& src1Index, int& src2Index);
         void retrieveLastUnaryOp(int& dstIndex, int& srcIndex);
         ALWAYS_INLINE void rewindBinaryOp();
         ALWAYS_INLINE void rewindUnaryOp();
 

-        PassRefPtr<Label> emitComplexJumpScopes(Label* target, ControlFlowContext* topScope, ControlFlowContext* bottomScope);
-
-        typedef HashMap<EncodedJSValue, unsigned, EncodedJSValueHash, EncodedJSValueHashTraits> 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;
-        };
+        void allocateAndEmitScope();
+        void emitComplexPopScopes(RegisterID*, ControlFlowContext* topScope, ControlFlowContext* bottomScope);

 
 

-        typedef HashMap<RefPtr<UString::Rep>, int, IdentifierRepHash, HashTraits<RefPtr<UString::Rep> >, IdentifierMapIndexHashTraits> IdentifierMap;

         typedef HashMap<double, JSValue> NumberMap;
         typedef HashMap<double, JSValue> NumberMap;

-        typedef HashMap<UString::Rep*, JSString*, IdentifierRepHash> IdentifierStringMap;
+        typedef HashMap<UniquedStringImpl*, JSString*, IdentifierRepHash> IdentifierStringMap;
+        typedef HashMap<TemplateRegistryKey, JSTemplateRegistryKey*> TemplateRegistryKeyMap;

         
         

-        RegisterID* emitCall(OpcodeID, RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
+        // Helper for emitCall() and emitConstruct(). This works because the set of
+        // expected functions have identical behavior for both call and construct
+        // (i.e. "Object()" is identical to "new Object()").
+        ExpectedFunction emitExpectedFunctionSnippet(RegisterID* dst, RegisterID* func, ExpectedFunction, CallArguments&, Label* done);

         
         

-        RegisterID* newRegister();
+        RegisterID* emitCall(OpcodeID, RegisterID* dst, RegisterID* func, ExpectedFunction, CallArguments&, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd);

 
 

-        // 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*&);
+        RegisterID* newRegister();

 
 

-        // Returns the RegisterID corresponding to ident.
-        RegisterID* addGlobalVar(const Identifier& ident, bool isConstant)
+        // Adds an anonymous local var slot. To give this slot a name, add it to symbolTable().
+        RegisterID* addVar()

         {
         {

-            RegisterID* local;
-            addGlobalVar(ident, isConstant, local);
-            return local;
+            ++m_codeBlock->m_numVars;
+            RegisterID* result = newRegister();
+            ASSERT(VirtualRegister(result->index()).toLocal() == m_codeBlock->m_numVars - 1);
+            result->ref(); // We should never free this slot.
+            return result;

         }
         }

-        // 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&);
+        // Initializes the stack form the parameter; does nothing for the symbol table.
+        RegisterID* initializeNextParameter();
+        UniquedStringImpl* visibleNameForParameter(DestructuringPatternNode*);

         
         

-        void preserveLastVar();
-
-        RegisterID& registerFor(int index)
+        RegisterID& registerFor(VirtualRegister reg)

         {
         {

-            if (index >= 0)
-                return m_calleeRegisters[index];
+            if (reg.isLocal())
+                return m_calleeRegisters[reg.toLocal()];

 
 

-            if (index == RegisterFile::OptionalCalleeArguments)
-                return m_argumentsRegister;
-
-            if (m_parameters.size()) {
-                ASSERT(!m_globals.size());
-                return m_parameters[index + m_parameters.size() + RegisterFile::CallFrameHeaderSize];
-            }
+            if (reg.offset() == JSStack::Callee)
+                return m_calleeRegister;

 
 

-            return m_globals[-index - 1];
+            ASSERT(m_parameters.size());
+            return m_parameters[reg.toArgument()];

         }
 
         }
 

+        bool hasConstant(const Identifier&) const;

         unsigned addConstant(const Identifier&);
         unsigned addConstant(const Identifier&);

-        RegisterID* addConstantValue(JSValue);
+        RegisterID* addConstantValue(JSValue, SourceCodeRepresentation = SourceCodeRepresentation::Other);
+        RegisterID* addConstantEmptyValue();

         unsigned addRegExp(RegExp*);
 
         unsigned addRegExp(RegExp*);
 

-        PassRefPtr<FunctionExecutable> makeFunction(ExecState* exec, FunctionBodyNode* body)
+        unsigned addConstantBuffer(unsigned length);
+        
+        UnlinkedFunctionExecutable* makeFunction(FunctionBodyNode* body)

         {
         {

-            return FunctionExecutable::create(exec, body->ident(), body->source(), body->usesArguments(), body->parameters(), body->lineNo(), body->lastLine());
+            return UnlinkedFunctionExecutable::create(m_vm, m_scopeNode->source(), body, isBuiltinFunction() ? UnlinkedBuiltinFunction : UnlinkedNormalFunction);

         }
 
         }
 

-        PassRefPtr<FunctionExecutable> makeFunction(JSGlobalData* globalData, FunctionBodyNode* body)
+        RegisterID* emitConstructVarargs(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, RegisterID* arguments, RegisterID* firstFreeRegister, int32_t firstVarArgOffset, RegisterID* profileHookRegister, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd);
+        RegisterID* emitCallVarargs(OpcodeID, RegisterID* dst, RegisterID* func, RegisterID* thisRegister, RegisterID* arguments, RegisterID* firstFreeRegister, int32_t firstVarArgOffset, RegisterID* profileHookRegister, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd);
+
+    public:
+        JSString* addStringConstant(const Identifier&);
+        JSTemplateRegistryKey* addTemplateRegistryKeyConstant(const TemplateRegistryKey&);
+
+        Vector<UnlinkedInstruction, 0, UnsafeVectorOverflow>& instructions() { return m_instructions; }
+
+        SymbolTable& symbolTable() { return *m_symbolTable; }
+
+        bool shouldOptimizeLocals()

         {
         {

-            return FunctionExecutable::create(globalData, body->ident(), body->source(), body->usesArguments(), body->parameters(), body->lineNo(), body->lastLine());
+            if (m_codeType != FunctionCode)
+                return false;
+
+            if (m_localScopeDepth)
+                return false;
+
+            return true;

         }
 
         }
 

-        Vector<Instruction>& instructions() { return m_codeBlock->instructions(); }
-        SymbolTable& symbolTable() { return *m_symbolTable; }
+        bool canOptimizeNonLocals()
+        {
+            if (m_localScopeDepth)
+                return false;

 
 

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

 
         RegisterID* emitThrowExpressionTooDeepException();
 
 
         RegisterID* emitThrowExpressionTooDeepException();
 

-        void createArgumentsIfNecessary();
+    private:
+        Vector<UnlinkedInstruction, 0, UnsafeVectorOverflow> m_instructions;

 
         bool m_shouldEmitDebugHooks;
         bool m_shouldEmitProfileHooks;
 
 
         bool m_shouldEmitDebugHooks;
         bool m_shouldEmitProfileHooks;
 

-        const ScopeChain* m_scopeChain;
-        SymbolTable* m_symbolTable;
+        SymbolTable* m_symbolTable { nullptr };

 
 

-        ScopeNode* m_scopeNode;
-        CodeBlock* m_codeBlock;
+        ScopeNode* const m_scopeNode;
+        Strong<UnlinkedCodeBlock> m_codeBlock;

 
         // Some of these objects keep pointers to one another. They are arranged
         // to ensure a sane destruction order that avoids references to freed memory.
 
         // Some of these objects keep pointers to one another. They are arranged
         // to ensure a sane destruction order that avoids references to freed memory.

-        HashSet<RefPtr<UString::Rep>, IdentifierRepHash> m_functions;
+        HashSet<RefPtr<UniquedStringImpl>, IdentifierRepHash> m_functions;

         RegisterID m_ignoredResultRegister;
         RegisterID m_thisRegister;
         RegisterID m_ignoredResultRegister;
         RegisterID m_thisRegister;

-        RegisterID m_argumentsRegister;
-        int m_activationRegisterIndex;
+        RegisterID m_calleeRegister;
+        RegisterID* m_scopeRegister { nullptr };
+        RegisterID* m_argumentsRegister { nullptr };
+        RegisterID* m_lexicalEnvironmentRegister { nullptr };
+        RegisterID* m_emptyValueRegister { nullptr };
+        RegisterID* m_globalObjectRegister { nullptr };
+        RegisterID* m_newTargetRegister { nullptr };
+        RegisterID* m_linkTimeConstantRegisters[LinkTimeConstantCount];
+

         SegmentedVector<RegisterID, 32> m_constantPoolRegisters;
         SegmentedVector<RegisterID, 32> m_calleeRegisters;
         SegmentedVector<RegisterID, 32> m_parameters;
         SegmentedVector<RegisterID, 32> m_constantPoolRegisters;
         SegmentedVector<RegisterID, 32> m_calleeRegisters;
         SegmentedVector<RegisterID, 32> m_parameters;

-        SegmentedVector<RegisterID, 32> m_globals;

         SegmentedVector<Label, 32> m_labels;
         SegmentedVector<Label, 32> m_labels;

-        SegmentedVector<LabelScope, 8> m_labelScopes;
-        RefPtr<RegisterID> m_lastVar;
-        int m_finallyDepth;
-        int m_dynamicScopeDepth;
-        int m_baseScopeDepth;
-        CodeType m_codeType;
-
-        Vector<ControlFlowContext> m_scopeContextStack;
-        Vector<SwitchInfo> m_switchContextStack;
-        Vector<ForInContext> m_forInContextStack;
+        LabelScopeStore m_labelScopes;
+        int m_finallyDepth { 0 };
+        int m_localScopeDepth { 0 };
+        const CodeType m_codeType;

 
 

-        int m_nextGlobalIndex;
-        int m_nextParameterIndex;
-        int m_firstConstantIndex;
-        int m_nextConstantOffset;
-        unsigned m_globalConstantIndex;
+        Vector<ControlFlowContext, 0, UnsafeVectorOverflow> m_scopeContextStack;
+        Vector<SwitchInfo> m_switchContextStack;
+        Vector<std::unique_ptr<ForInContext>> m_forInContextStack;
+        Vector<TryContext> m_tryContextStack;
+        Vector<std::pair<RefPtr<RegisterID>, const DestructuringPatternNode*>> m_destructuringParameters;
+        enum FunctionVariableType : uint8_t { NormalFunctionVariable, GlobalFunctionVariable };
+        Vector<std::pair<FunctionBodyNode*, FunctionVariableType>> m_functionsToInitialize;
+        bool m_needToInitializeArguments { false };
+        
+        Vector<TryRange> m_tryRanges;
+        SegmentedVector<TryData, 8> m_tryData;

 
 

-        int m_globalVarStorageOffset;
+        int m_nextConstantOffset { 0 };

 
 

+        typedef HashMap<FunctionBodyNode*, unsigned> FunctionOffsetMap;
+        FunctionOffsetMap m_functionOffsets;
+        

         // Constant pool
         IdentifierMap m_identifierMap;
         // Constant pool
         IdentifierMap m_identifierMap;

+
+        typedef HashMap<EncodedJSValueWithRepresentation, unsigned, EncodedJSValueWithRepresentationHash, EncodedJSValueWithRepresentationHashTraits> JSValueMap;

         JSValueMap m_jsValueMap;
         JSValueMap m_jsValueMap;

-        NumberMap m_numberMap;

         IdentifierStringMap m_stringMap;
         IdentifierStringMap m_stringMap;

+        TemplateRegistryKeyMap m_templateRegistryKeyMap;

 
 

-        JSGlobalData* m_globalData;
-
-        OpcodeID m_lastOpcodeID;
+        StaticPropertyAnalyzer m_staticPropertyAnalyzer { &m_instructions };

 
 

-        unsigned m_emitNodeDepth;
+        VM* m_vm;

 
 

-        bool m_regeneratingForExceptionInfo;
-        CodeBlock* m_codeBlockBeingRegeneratedFrom;
+        OpcodeID m_lastOpcodeID = op_end;
+#ifndef NDEBUG
+        size_t m_lastOpcodePosition { 0 };
+#endif

 
 

-        static const unsigned s_maxEmitNodeDepth = 3000;
-
-        friend class IncreaseEmitNodeDepth;
+        bool m_usesExceptions { false };
+        bool m_expressionTooDeep { false };
+        bool m_isBuiltinFunction { false };

     };
 
     };
 

-    class IncreaseEmitNodeDepth {
-    public:
-        IncreaseEmitNodeDepth(BytecodeGenerator& generator, unsigned count = 1)
-            : m_generator(generator)
-            , m_count(count)
-        {
-            m_generator.m_emitNodeDepth += count;
-        }
-
-        ~IncreaseEmitNodeDepth()
-        {
-            m_generator.m_emitNodeDepth -= m_count;
-        }
-
-    private:
-        BytecodeGenerator& m_generator;
-        unsigned m_count;
-    };

 }
 
 #endif // BytecodeGenerator_h
 }
 
 #endif // BytecodeGenerator_h