webkitgtk-2.10.2webkitgtk-2.10.2

1 files changed, 831 insertions, 0 deletions

diff --git a/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h b/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h
new file mode 100644
index 000000000..33a15c1ff
--- /dev/null
+++ b/Source/JavaScriptCore/bytecompiler/BytecodeGenerator.h
@@ -0,0 +1,831 @@
+/*
+ * Copyright (C) 2008, 2009, 2012-2015 Apple Inc. All rights reserved.
+ * 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
+ * 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 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 BytecodeGenerator_h
+#define BytecodeGenerator_h
+
+#include "CodeBlock.h"
+#include <wtf/HashTraits.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 "StaticPropertyAnalyzer.h"
+#include "TemplateRegistryKey.h"
+#include "UnlinkedCodeBlock.h"
+
+#include <functional>
+
+#include <wtf/PassRefPtr.h>
+#include <wtf/SegmentedVector.h>
+#include <wtf/Vector.h>
+
+
+namespace JSC {
+
+    class Identifier;
+    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 {
+        StatementNode* finallyBlock;
+        RegisterID* iterator;
+        ThrowableExpressionData* enumerationNode;
+        unsigned scopeContextStackSize;
+        unsigned switchContextStackSize;
+        unsigned forInContextStackSize;
+        unsigned tryContextStackSize;
+        unsigned labelScopesSize;
+        unsigned symbolTableStackSize;
+        int finallyDepth;
+        int dynamicScopeDepth;
+    };
+
+    struct ControlFlowContext {
+        bool isFinallyBlock;
+        FinallyContext finallyContext;
+    };
+
+    class ForInContext {
+        WTF_MAKE_FAST_ALLOCATED;
+    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 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;
+        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)
+            , m_symbolTableConstantIndex(0) // This is meaningless here for this kind of Variable.
+            , m_isLexicallyScoped(false)
+        {
+        }
+        
+        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.
+            , m_symbolTableConstantIndex(0) // This is meaningless here for this kind of Variable.
+            , m_isLexicallyScoped(false)
+        {
+        }
+
+        Variable(const Identifier& ident, VarOffset offset, RegisterID* local, unsigned attributes, VariableKind kind, int symbolTableConstantIndex, bool isLexicallyScoped)
+            : m_ident(ident)
+            , m_offset(offset)
+            , m_local(local)
+            , m_attributes(attributes)
+            , m_kind(kind)
+            , m_symbolTableConstantIndex(symbolTableConstantIndex)
+            , m_isLexicallyScoped(isLexicallyScoped)
+        {
+        }
+
+        // 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 a local scope, or a variable captured in the
+        // direct arguments object.
+        bool isResolved() const { return !!m_offset; }
+        int symbolTableConstantIndex() const { ASSERT(isResolved() && !isSpecial()); return m_symbolTableConstantIndex; }
+        
+        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; }
+        bool isConst() const { return isReadOnly() && m_isLexicallyScoped; }
+
+    private:
+        Identifier m_ident;
+        VarOffset m_offset;
+        RegisterID* m_local;
+        unsigned m_attributes;
+        VariableKind m_kind;
+        int m_symbolTableConstantIndex;
+        bool m_isLexicallyScoped;
+    };
+
+    struct TryRange {
+        RefPtr<Label> start;
+        RefPtr<Label> end;
+        TryData* tryData;
+    };
+
+    enum ProfileTypeBytecodeFlag {
+        ProfileTypeBytecodeClosureVar,
+        ProfileTypeBytecodeLocallyResolved,
+        ProfileTypeBytecodeDoesNotHaveGlobalID,
+        ProfileTypeBytecodeFunctionArgument,
+        ProfileTypeBytecodeFunctionReturnStatement
+    };
+
+    class BytecodeGenerator {
+        WTF_MAKE_FAST_ALLOCATED;
+        WTF_MAKE_NONCOPYABLE(BytecodeGenerator);
+    public:
+        typedef DeclarationStacks::FunctionStack FunctionStack;
+
+        BytecodeGenerator(VM&, ProgramNode*, UnlinkedProgramCodeBlock*, DebuggerMode, ProfilerMode, const VariableEnvironment*);
+        BytecodeGenerator(VM&, FunctionNode*, UnlinkedFunctionCodeBlock*, DebuggerMode, ProfilerMode, const VariableEnvironment*);
+        BytecodeGenerator(VM&, EvalNode*, UnlinkedEvalCodeBlock*, DebuggerMode, ProfilerMode, const VariableEnvironment*);
+
+        ~BytecodeGenerator();
+        
+        VM* vm() const { return m_vm; }
+        ParserArena& parserArena() const { return m_scopeNode->parserArena(); }
+        const CommonIdentifiers& propertyNames() const { return *m_vm->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
+
+        ParserError generate();
+
+        bool isArgumentNumber(const Identifier&, int);
+
+        Variable variable(const Identifier&);
+        
+        enum ExistingVariableMode { VerifyExisting, IgnoreExisting };
+        void createVariable(const Identifier&, VarKind, SymbolTable*, 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; }
+        RegisterID* argumentsRegister() { return m_argumentsRegister; }
+        RegisterID* newTarget() { return m_newTargetRegister; }
+
+        RegisterID* scopeRegister() { return m_scopeRegister; }
+
+        // Returns the next available temporary register. Registers returned by
+        // newTemporary require a modified form of reference counting: any
+        // register with a refcount of 0 is considered "available", meaning that
+        // the next instruction may overwrite it.
+        RegisterID* newTemporary();
+
+        // 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 next instruction to overwrite it anyway.
+        RegisterID* newTemporaryOr(RegisterID* suggestion) { return suggestion->isTemporary() ? suggestion : newTemporary(); }
+
+        // Functions for handling of dst register
+
+        RegisterID* ignoredResult() { return &m_ignoredResultRegister; }
+
+        // This will be allocated in the temporary region of registers, but it will
+        // not be marked as a temporary. This will ensure that finalDestination() does
+        // not overwrite a block scope variable that it mistakes as a temporary. These
+        // registers can be (and are) reclaimed when the lexical scope they belong to
+        // is no longer on the symbol table stack.
+        RegisterID* newBlockScopeVariable();
+
+        // Returns a place to write intermediate values of an operation
+        // which reuses dst if it is safe to do so.
+        RegisterID* tempDestination(RegisterID* dst)
+        {
+            return (dst && dst != ignoredResult() && dst->isTemporary()) ? dst : newTemporary();
+        }
+
+        // Returns the place to write the final output of an operation.
+        RegisterID* finalDestination(RegisterID* originalDst, RegisterID* tempDst = 0)
+        {
+            if (originalDst && originalDst != ignoredResult())
+                return originalDst;
+            ASSERT(tempDst != ignoredResult());
+            if (tempDst && tempDst->isTemporary())
+                return tempDst;
+            return newTemporary();
+        }
+
+        RegisterID* destinationForAssignResult(RegisterID* dst)
+        {
+            if (dst && dst != ignoredResult() && m_codeBlock->needsFullScopeChain())
+                return dst->isTemporary() ? dst : newTemporary();
+            return 0;
+        }
+
+        // Moves src to dst if dst is not null and is different from src, otherwise just returns src.
+        RegisterID* moveToDestinationIfNeeded(RegisterID* dst, RegisterID* src)
+        {
+            return dst == ignoredResult() ? 0 : (dst && dst != src) ? emitMove(dst, src) : src;
+        }
+
+        LabelScopePtr newLabelScope(LabelScope::Type, const Identifier* = 0);
+        PassRefPtr<Label> newLabel();
+
+        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());
+            if (!m_vm->isSafeToRecurse()) {
+                emitThrowExpressionTooDeepException();
+                return;
+            }
+            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 n->emitBytecode(*this, dst);
+        }
+
+        RegisterID* emitNode(ExpressionNode* n)
+        {
+            return emitNode(0, n);
+        }
+
+        void emitNodeInConditionContext(ExpressionNode* n, Label* trueTarget, Label* falseTarget, FallThroughMode fallThroughMode)
+        {
+            if (!m_vm->isSafeToRecurse()) {
+                emitThrowExpressionTooDeepException();
+                return;
+            }
+
+            n->emitBytecodeInConditionContext(*this, trueTarget, falseTarget, fallThroughMode);
+        }
+
+        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 PassRefPtr<RegisterID> emitNodeForLeftHandSide(ExpressionNode* n, bool rightHasAssignments, bool rightIsPure)
+        {
+            if (leftHandSideNeedsCopy(rightHasAssignments, rightIsPure)) {
+                PassRefPtr<RegisterID> dst = newTemporary();
+                emitNode(dst.get(), n);
+                return dst;
+            }
+
+            return emitNode(n);
+        }
+
+    private:
+        void emitTypeProfilerExpressionInfo(const JSTextPosition& startDivot, const JSTextPosition& endDivot);
+    public:
+
+        // This doesn't emit expression info. If using this, make sure you shouldn't be emitting text offset.
+        void emitProfileType(RegisterID* registerToProfile, ProfileTypeBytecodeFlag); 
+        // These variables are associated with variables in a program. They could be Locals, LocalClosureVar, or ClosureVar.
+        void emitProfileType(RegisterID* registerToProfile, const Variable&, const JSTextPosition& startDivot, const JSTextPosition& endDivot);
+
+        void emitProfileType(RegisterID* registerToProfile, ProfileTypeBytecodeFlag, const JSTextPosition& startDivot, const JSTextPosition& endDivot);
+        // These are not associated with variables and don't have a global id.
+        void emitProfileType(RegisterID* registerToProfile, const JSTextPosition& startDivot, const JSTextPosition& endDivot);
+
+        void emitProfileControlFlow(int);
+
+        RegisterID* emitLoad(RegisterID* dst, bool);
+        RegisterID* emitLoad(RegisterID* dst, const Identifier&);
+        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* emitCreateThis(RegisterID* dst);
+        void emitTDZCheck(RegisterID* target);
+        bool needsTDZCheck(const Variable&);
+        void emitTDZCheckIfNecessary(const Variable&, RegisterID* target, RegisterID* scope);
+        void liftTDZCheckIfPossible(const Variable&);
+        RegisterID* emitNewObject(RegisterID* dst);
+        RegisterID* emitNewArray(RegisterID* dst, ElementNode*, unsigned length); // stops at first elision
+
+        RegisterID* emitNewFunction(RegisterID* dst, FunctionMetadataNode*);
+        RegisterID* emitNewFunctionInternal(RegisterID* dst, unsigned index);
+        RegisterID* emitNewFunctionExpression(RegisterID* dst, FuncExprNode* func);
+        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* 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);
+
+        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* 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, PropertyNode::PutType);
+        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* emitDirectPutByVal(RegisterID* base, RegisterID* property, RegisterID* value);
+        RegisterID* emitDeleteByVal(RegisterID* dst, RegisterID* base, RegisterID* property);
+        RegisterID* emitPutByIndex(RegisterID* base, unsigned index, RegisterID* value);
+
+        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, VariableEnvironmentNode* = nullptr, RegisterID* forLoopSymbolTable = nullptr);
+
+#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* 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);
+
+        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*);
+        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);
+        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);
+
+        RegisterID* emitIsObject(RegisterID* dst, RegisterID* src);
+        RegisterID* emitIsUndefined(RegisterID* dst, RegisterID* src);
+
+        RegisterID* emitIteratorNext(RegisterID* dst, RegisterID* iterator, const ThrowableExpressionData* node);
+        void emitIteratorClose(RegisterID* iterator, const ThrowableExpressionData* node);
+
+        bool emitReadOnlyExceptionIfNeeded(const Variable&);
+
+        // 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 emitThrowReferenceError(const String& message);
+        void emitThrowTypeError(const String& message);
+
+        void emitPushFunctionNameScope(const Identifier& property, RegisterID* value);
+        void emitPushCatchScope(const Identifier& property, RegisterID* exceptionValue, VariableEnvironment&);
+        void emitPopCatchScope(VariableEnvironment&);
+
+        void emitGetScope();
+        RegisterID* emitPushWithScope(RegisterID* objectScope);
+        void emitPopWithScope();
+
+        void emitDebugHook(DebugHookID, unsigned line, unsigned charOffset, unsigned lineStart);
+
+        bool isInFinallyBlock() { return m_finallyDepth > 0; }
+
+        void pushFinallyContext(StatementNode* finallyBlock);
+        void popFinallyContext();
+        void pushIteratorCloseContext(RegisterID* iterator, ThrowableExpressionData* enumerationNode);
+        void popIteratorCloseContext();
+
+        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);
+
+        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; }
+
+        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:
+        enum class TDZRequirement { UnderTDZ, NotUnderTDZ };
+        enum class ScopeType { CatchScope, LetConstScope, FunctionNameScope };
+        enum class ScopeRegisterType { Var, Block };
+        void pushLexicalScopeInternal(VariableEnvironment&, bool canOptimizeTDZChecks, RegisterID** constantSymbolTableResult, TDZRequirement, ScopeType, ScopeRegisterType);
+        void popLexicalScopeInternal(VariableEnvironment&, TDZRequirement);
+        void emitPopScope(RegisterID* dst, RegisterID* scope);
+        RegisterID* emitGetParentScope(RegisterID* dst, RegisterID* scope);
+    public:
+        void pushLexicalScope(VariableEnvironmentNode*, bool canOptimizeTDZChecks, RegisterID** constantSymbolTableResult = nullptr);
+        void popLexicalScope(VariableEnvironmentNode*);
+        void prepareLexicalScopeForNextForLoopIteration(VariableEnvironmentNode*, RegisterID* loopSymbolTable);
+        int labelScopeDepth() const;
+
+    private:
+        void reclaimFreeRegisters();
+        Variable variableForLocalEntry(const Identifier&, const SymbolTableEntry&, int symbolTableConstantIndex, bool isLexicallyScoped);
+
+        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 allocateAndEmitScope();
+        void emitComplexPopScopes(RegisterID*, ControlFlowContext* topScope, ControlFlowContext* bottomScope);
+
+        typedef HashMap<double, JSValue> NumberMap;
+        typedef HashMap<UniquedStringImpl*, JSString*, IdentifierRepHash> IdentifierStringMap;
+        typedef HashMap<TemplateRegistryKey, JSTemplateRegistryKey*> TemplateRegistryKeyMap;
+        
+        // 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* emitCall(OpcodeID, RegisterID* dst, RegisterID* func, ExpectedFunction, CallArguments&, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd);
+
+        RegisterID* newRegister();
+
+        // Adds an anonymous local var slot. To give this slot a name, add it to symbolTable().
+        RegisterID* addVar()
+        {
+            ++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;
+        }
+
+        // Initializes the stack form the parameter; does nothing for the symbol table.
+        RegisterID* initializeNextParameter();
+        UniquedStringImpl* visibleNameForParameter(DestructuringPatternNode*);
+        
+        RegisterID& registerFor(VirtualRegister reg)
+        {
+            if (reg.isLocal())
+                return m_calleeRegisters[reg.toLocal()];
+
+            if (reg.offset() == JSStack::Callee)
+                return m_calleeRegister;
+
+            ASSERT(m_parameters.size());
+            return m_parameters[reg.toArgument()];
+        }
+
+        bool hasConstant(const Identifier&) const;
+        unsigned addConstant(const Identifier&);
+        RegisterID* addConstantValue(JSValue, SourceCodeRepresentation = SourceCodeRepresentation::Other);
+        RegisterID* addConstantEmptyValue();
+        unsigned addRegExp(RegExp*);
+
+        unsigned addConstantBuffer(unsigned length);
+        
+        UnlinkedFunctionExecutable* makeFunction(FunctionMetadataNode* metadata)
+        {
+            VariableEnvironment variablesUnderTDZ;
+            getVariablesUnderTDZ(variablesUnderTDZ);
+
+            SourceParseMode parseMode = metadata->parseMode();
+            ConstructAbility constructAbility = ConstructAbility::CanConstruct;
+            if (parseMode == SourceParseMode::GetterMode || parseMode == SourceParseMode::SetterMode || parseMode == SourceParseMode::ArrowFunctionMode || (parseMode == SourceParseMode::MethodMode && metadata->constructorKind() == ConstructorKind::None))
+                constructAbility = ConstructAbility::CannotConstruct;
+
+            return UnlinkedFunctionExecutable::create(m_vm, m_scopeNode->source(), metadata, isBuiltinFunction() ? UnlinkedBuiltinFunction : UnlinkedNormalFunction, constructAbility, variablesUnderTDZ);
+        }
+
+        void getVariablesUnderTDZ(VariableEnvironment&);
+
+        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);
+
+        void initializeVarLexicalEnvironment(int symbolTableConstantIndex);
+        void initializeDefaultParameterValuesAndSetupFunctionScopeStack(FunctionParameters&, FunctionNode*, SymbolTable*, int symbolTableConstantIndex, const std::function<bool (UniquedStringImpl*)>& captures);
+
+    public:
+        JSString* addStringConstant(const Identifier&);
+        JSTemplateRegistryKey* addTemplateRegistryKeyConstant(const TemplateRegistryKey&);
+
+        Vector<UnlinkedInstruction, 0, UnsafeVectorOverflow>& instructions() { return m_instructions; }
+
+        RegisterID* emitThrowExpressionTooDeepException();
+
+    private:
+        Vector<UnlinkedInstruction, 0, UnsafeVectorOverflow> m_instructions;
+
+        bool m_shouldEmitDebugHooks;
+        bool m_shouldEmitProfileHooks;
+
+        struct SymbolTableStackEntry {
+            Strong<SymbolTable> m_symbolTable;
+            RegisterID* m_scope;
+            bool m_isWithScope;
+            int m_symbolTableConstantIndex;
+        };
+        Vector<SymbolTableStackEntry> m_symbolTableStack;
+        Vector<std::pair<VariableEnvironment, bool>> m_TDZStack;
+
+        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.
+        HashSet<RefPtr<UniquedStringImpl>, IdentifierRepHash> m_functions;
+        RegisterID m_ignoredResultRegister;
+        RegisterID m_thisRegister;
+        RegisterID m_calleeRegister;
+        RegisterID* m_scopeRegister { nullptr };
+        RegisterID* m_topMostScope { 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<Label, 32> m_labels;
+        LabelScopeStore m_labelScopes;
+        int m_finallyDepth { 0 };
+        int m_localScopeDepth { 0 };
+        const CodeType m_codeType;
+
+        int localScopeDepth() const;
+        void pushScopedControlFlowContext();
+        void popScopedControlFlowContext();
+
+        Vector<ControlFlowContext, 0, UnsafeVectorOverflow> m_scopeContextStack;
+        Vector<SwitchInfo> m_switchContextStack;
+        Vector<std::unique_ptr<ForInContext>> m_forInContextStack;
+        Vector<TryContext> m_tryContextStack;
+        enum FunctionVariableType : uint8_t { NormalFunctionVariable, GlobalFunctionVariable };
+        Vector<std::pair<FunctionMetadataNode*, FunctionVariableType>> m_functionsToInitialize;
+        bool m_needToInitializeArguments { false };
+        
+        Vector<TryRange> m_tryRanges;
+        SegmentedVector<TryData, 8> m_tryData;
+
+        int m_nextConstantOffset { 0 };
+
+        typedef HashMap<FunctionMetadataNode*, unsigned> FunctionOffsetMap;
+        FunctionOffsetMap m_functionOffsets;
+        
+        // Constant pool
+        IdentifierMap m_identifierMap;
+
+        typedef HashMap<EncodedJSValueWithRepresentation, unsigned, EncodedJSValueWithRepresentationHash, EncodedJSValueWithRepresentationHashTraits> JSValueMap;
+        JSValueMap m_jsValueMap;
+        IdentifierStringMap m_stringMap;
+        TemplateRegistryKeyMap m_templateRegistryKeyMap;
+
+        StaticPropertyAnalyzer m_staticPropertyAnalyzer { &m_instructions };
+
+        VM* m_vm;
+
+        OpcodeID m_lastOpcodeID = op_end;
+#ifndef NDEBUG
+        size_t m_lastOpcodePosition { 0 };
+#endif
+
+        bool m_usesExceptions { false };
+        bool m_expressionTooDeep { false };
+        bool m_isBuiltinFunction { false };
+        bool m_usesNonStrictEval { false };
+    };
+
+}
+
+#endif // BytecodeGenerator_h