X-Git-Url: https://git.saurik.com/apple/javascriptcore.git/blobdiff_plain/ba379fdc102753d6be2c4d937058fe40257329fe..ef99ff287df9046eb88937225e0554eabb00e33c:/bytecompiler/BytecodeGenerator.h

diff --git a/bytecompiler/BytecodeGenerator.h b/bytecompiler/BytecodeGenerator.h
index c273597..5e5ed61 100644
--- 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, 2013, 2014 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
@@ -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.
- * 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.
  *
@@ -31,29 +32,64 @@
 #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 "ParserError.h"
 #include "RegisterID.h"
 #include "SymbolTable.h"
 #include "Debugger.h"
 #include "Nodes.h"
-#include <wtf/FastAllocBase.h>
+#include "StaticPropertyAnalyzer.h"
+#include "UnlinkedCodeBlock.h"
+
+#include <functional>
+
 #include <wtf/PassRefPtr.h>
 #include <wtf/SegmentedVector.h>
 #include <wtf/Vector.h>
 
+
 namespace JSC {
 
     class Identifier;
-    class ScopeChain;
-    class ScopeNode;
+    class Label;
+
+    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 {
-        Label* finallyAddr;
-        RegisterID* retAddrDst;
+        StatementNode* finallyBlock;
+        unsigned scopeContextStackSize;
+        unsigned switchContextStackSize;
+        unsigned forInContextStackSize;
+        unsigned tryContextStackSize;
+        unsigned labelScopesSize;
+        int finallyDepth;
+        int dynamicScopeDepth;
     };
 
     struct ControlFlowContext {
@@ -61,60 +97,105 @@ namespace JSC {
         FinallyContext finallyContext;
     };
 
-    class BytecodeGenerator : public WTF::FastAllocBase {
+    struct ForInContext {
+        RefPtr<RegisterID> expectedSubscriptRegister;
+        RefPtr<RegisterID> iterRegister;
+        RefPtr<RegisterID> indexRegister;
+        RefPtr<RegisterID> propertyRegister;
+    };
+
+    struct TryData {
+        RefPtr<Label> target;
+        unsigned targetScopeDepth;
+    };
+
+    struct TryContext {
+        RefPtr<Label> start;
+        TryData* tryData;
+    };
+
+    enum CaptureMode {
+        NotCaptured,
+        IsCaptured
+    };
+
+    class Local {
+    public:
+        Local()
+            : m_local(0)
+            , m_attributes(0)
+        {
+        }
+
+        Local(RegisterID* local, unsigned attributes, CaptureMode captureMode)
+            : m_local(local)
+            , m_attributes(attributes)
+            , m_isCaptured(captureMode == IsCaptured)
+        {
+        }
+
+        operator bool() { return m_local; }
+
+        RegisterID* get() { return m_local; }
+
+        bool isReadOnly() { return m_attributes & ReadOnly; }
+        
+        bool isCaptured() { return m_isCaptured; }
+        CaptureMode captureMode() { return isCaptured() ? IsCaptured : NotCaptured; }
+
+    private:
+        RegisterID* m_local;
+        unsigned m_attributes;
+        bool m_isCaptured;
+    };
+
+    struct TryRange {
+        RefPtr<Label> start;
+        RefPtr<Label> end;
+        TryData* tryData;
+    };
+
+    class BytecodeGenerator {
+        WTF_MAKE_FAST_ALLOCATED;
     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&, FunctionBodyNode*, 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; }
+        const CommonIdentifiers& propertyNames() const { return *m_vm->propertyNames; }
 
-        JSGlobalData* globalData() const { return m_globalData; }
-        const CommonIdentifiers& propertyNames() const { return *m_globalData->propertyNames; }
+        bool isConstructor() { return m_codeBlock->isConstructor(); }
 
-        void generate();
+        ParserError generate();
+
+        bool isArgumentNumber(const Identifier&, int);
+
+        void setIsNumericCompareFunction(bool isNumericCompareFunction);
 
-        // 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, JSObject*& globalObject);
+        bool isCaptured(int operand);
+        CaptureMode captureMode(int operand) { return isCaptured(operand) ? IsCaptured : NotCaptured; }
+        
+        Local local(const Identifier&);
+        Local constLocal(const Identifier&);
 
         // Returns the register storing "this"
         RegisterID* thisRegister() { return &m_thisRegister; }
 
-        bool isLocal(const Identifier&);
-        bool isLocalConstant(const Identifier&);
-
         // 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();
 
-        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
@@ -156,75 +237,85 @@ namespace JSC {
             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();
 
-        // 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());
-            if (!m_codeBlock->numberOfLineInfos() || m_codeBlock->lastLineInfo().lineNumber != n->lineNo()) {
-                LineInfo info = { instructions().size(), n->lineNo() };
-                m_codeBlock->addLineInfo(info);
+            // Should never store directly into a captured variable.
+            ASSERT(!dst || dst == ignoredResult() || !isCaptured(dst->index()));
+            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());
+            // Should never store directly into a captured variable.
+            ASSERT(!dst || dst == ignoredResult() || !isCaptured(dst->index()));
+            if (!m_vm->isSafeToRecurse())
                 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);
         }
 
-        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;
+        void emitNodeInConditionContext(ExpressionNode* n, Label* trueTarget, Label* falseTarget, FallThroughMode fallThroughMode)
+        {
+            if (!m_vm->isSafeToRecurse()) {
+                emitThrowExpressionTooDeepException();
+                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;
@@ -238,252 +329,362 @@ namespace JSC {
                 return dst;
             }
 
-            return PassRefPtr<RegisterID>(emitNode(n));
+            return emitNode(n);
         }
 
         RegisterID* emitLoad(RegisterID* dst, bool);
         RegisterID* emitLoad(RegisterID* dst, double);
         RegisterID* emitLoad(RegisterID* dst, const Identifier&);
         RegisterID* emitLoad(RegisterID* dst, JSValue);
+        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);
         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, FuncDeclNode* func);
+        RegisterID* emitNewFunction(RegisterID* dst, CaptureMode, FunctionBodyNode*);
+        RegisterID* emitLazyNewFunction(RegisterID* dst, FunctionBodyNode* body);
+        RegisterID* emitNewFunctionInternal(RegisterID* dst, CaptureMode, unsigned index, bool shouldNullCheck);
         RegisterID* emitNewFunctionExpression(RegisterID* dst, FuncExprNode* func);
-        RegisterID* emitNewRegExp(RegisterID* dst, RegExp* regExp);
+        RegisterID* emitNewRegExp(RegisterID* dst, RegExp*);
 
+        RegisterID* emitMove(RegisterID* dst, CaptureMode, 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* 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* 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* emitGetArgumentsLength(RegisterID* dst, RegisterID* base);
         RegisterID* emitPutById(RegisterID* base, const Identifier& property, RegisterID* value);
+        RegisterID* emitDirectPutById(RegisterID* base, const Identifier& property, RegisterID* value);
         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);
-        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 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);
 
+        void emitEnumeration(ThrowableExpressionData* enumerationNode, ExpressionNode* subjectNode, const std::function<void(BytecodeGenerator&, RegisterID*)>& callBack);
+        
         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);
 
+        ResolveType resolveType();
+        RegisterID* emitResolveScope(RegisterID* dst, const Identifier&);
+        RegisterID* emitGetFromScope(RegisterID* dst, RegisterID* scope, const Identifier&, ResolveMode);
+        RegisterID* emitPutToScope(RegisterID* scope, const Identifier&, RegisterID* value, ResolveMode);
+
         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> emitJumpScopes(Label* target, int targetScopeDepth);
+        void emitPopScopes(int targetScopeDepth);
 
-        PassRefPtr<Label> emitJumpSubroutine(RegisterID* retAddrDst, Label*);
-        void emitSubroutineReturn(RegisterID* retAddrSrc);
+        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* emitGetPropertyNames(RegisterID* dst, RegisterID* base) { return emitUnaryOp(op_get_pnames, dst, base); }
-        RegisterID* emitNextPropertyName(RegisterID* dst, RegisterID* iter, Label* target);
+        void emitReadOnlyExceptionIfNeeded();
 
-        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, Identifier& property, RegisterID* value);
+        // Start a try block. 'start' must have been emitted.
+        TryData* pushTry(Label* start);
+        // End a try block. 'end' must have been emitted.
+        RegisterID* popTryAndEmitCatch(TryData*, RegisterID* targetRegister, Label* end);
 
-        RegisterID* emitPushScope(RegisterID* scope);
+        void emitThrow(RegisterID* exc)
+        { 
+            m_usesExceptions = true;
+            emitUnaryNoDstOp(op_throw, exc);
+        }
+
+        void emitThrowReferenceError(const String& message);
+
+        void emitPushFunctionNameScope(const Identifier& property, RegisterID* value, unsigned attributes);
+        void emitPushCatchScope(const Identifier& property, RegisterID* value, unsigned attributes);
+
+        RegisterID* emitPushWithScope(RegisterID* scope);
         void emitPopScope();
 
-        void emitDebugHook(DebugHookID, int firstLine, int lastLine);
+        void emitDebugHook(DebugHookID, unsigned line, unsigned charOffset, unsigned lineStart);
 
-        int scopeDepth() { return m_dynamicScopeDepth + m_finallyDepth; }
+        int scopeDepth() { return m_localScopeDepth + m_finallyDepth; }
         bool hasFinaliser() { return m_finallyDepth != 0; }
 
-        void pushFinallyContext(Label* target, RegisterID* returnAddrDst);
+        void pushFinallyContext(StatementNode* finallyBlock);
         void popFinallyContext();
 
-        LabelScope* breakTarget(const Identifier&);
-        LabelScope* continueTarget(const Identifier&);
+        void pushOptimisedForIn(RegisterID* expectedSubscript, RegisterID* iter, RegisterID* index, RegisterID* propertyRegister)
+        {
+            ForInContext context = { expectedSubscript, iter, index, propertyRegister };
+            m_forInContextStack.append(context);
+        }
+
+        void popOptimisedForIn()
+        {
+            m_forInContextStack.removeLast();
+        }
+
+        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 setRegeneratingForExceptionInfo(CodeBlock* originalCodeBlock)
+        bool shouldEmitProfileHooks() { return m_shouldEmitProfileHooks; }
+        bool shouldEmitDebugHooks() { return m_shouldEmitDebugHooks; }
+        
+        bool isStrictMode() const { return m_codeBlock->isStrictMode(); }
+        
+        bool isBuiltinFunction() const { return m_isBuiltinFunction; }
+        
+    private:
+        friend class Label;
+        
+        void emitOpcode(OpcodeID);
+        UnlinkedArrayAllocationProfile newArrayAllocationProfile();
+        UnlinkedObjectAllocationProfile newObjectAllocationProfile();
+        UnlinkedArrayProfile newArrayProfile();
+        UnlinkedValueProfile emitProfiledOpcode(OpcodeID);
+        int kill(RegisterID* dst)
         {
-            m_regeneratingForExceptionInfo = true;
-            m_codeBlockBeingRegeneratedFrom = originalCodeBlock;
+            int index = dst->index();
+            m_staticPropertyAnalyzer.kill(index);
+            return index;
         }
 
-    private:
-        void emitOpcode(OpcodeID);
         void retrieveLastBinaryOp(int& dstIndex, int& src1Index, int& src2Index);
         void retrieveLastUnaryOp(int& dstIndex, int& srcIndex);
-        void rewindBinaryOp();
-        void rewindUnaryOp();
-
-        PassRefPtr<Label> emitComplexJumpScopes(Label* target, ControlFlowContext* topScope, ControlFlowContext* bottomScope);
+        ALWAYS_INLINE void rewindBinaryOp();
+        ALWAYS_INLINE void rewindUnaryOp();
 
-        typedef HashMap<EncodedJSValue, unsigned, EncodedJSValueHash, EncodedJSValueHashTraits> JSValueMap;
+        void emitComplexPopScopes(ControlFlowContext* topScope, ControlFlowContext* bottomScope);
 
-        struct IdentifierMapIndexHashTraits {
-            typedef int TraitType;
-            typedef IdentifierMapIndexHashTraits StorageTraits;
-            static int emptyValue() { return std::numeric_limits<int>::max(); }
-            static const bool emptyValueIsZero = false;
-            static const bool needsDestruction = false;
-            static const bool needsRef = false;
-        };
-
-        typedef HashMap<RefPtr<UString::Rep>, int, IdentifierRepHash, HashTraits<RefPtr<UString::Rep> >, IdentifierMapIndexHashTraits> IdentifierMap;
         typedef HashMap<double, JSValue> NumberMap;
-        typedef HashMap<UString::Rep*, JSString*, IdentifierRepHash> IdentifierStringMap;
+        typedef HashMap<StringImpl*, JSString*, IdentifierRepHash> IdentifierStringMap;
         
-        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* emitCall(OpcodeID, RegisterID* dst, RegisterID* func, ExpectedFunction, CallArguments&, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd);
+
         RegisterID* newRegister();
 
-        // Returns the RegisterID corresponding to ident.
-        RegisterID* addVar(const Identifier& ident, bool isConstant)
+        // Adds a var slot and maps it to the name ident in symbolTable().
+        enum WatchMode { IsWatchable, NotWatchable };
+        RegisterID* addVar(const Identifier& ident, ConstantMode constantMode, WatchMode watchMode)
         {
             RegisterID* local;
-            addVar(ident, isConstant, local);
+            addVar(ident, constantMode, watchMode, local);
             return local;
         }
-        // Returns true if a new RegisterID was added, false if a pre-existing RegisterID was re-used.
-        bool addVar(const Identifier&, bool isConstant, RegisterID*&);
 
-        // Returns the RegisterID corresponding to ident.
-        RegisterID* addGlobalVar(const Identifier& ident, bool isConstant)
+        // Ditto. Returns true if a new RegisterID was added, false if a pre-existing RegisterID was re-used.
+        bool addVar(const Identifier&, ConstantMode, WatchMode, RegisterID*&);
+        
+        // Adds an anonymous 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;
+            return newRegister();
         }
-        // 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&);
-        
+        // Returns the index of the added var.
+        void addParameter(const Identifier&, int parameterIndex);
+        RegisterID* resolveCallee(FunctionBodyNode*);
+        void addCallee(FunctionBodyNode*, RegisterID*);
+
         void preserveLastVar();
 
         RegisterID& registerFor(int index)
         {
-            if (index >= 0)
-                return m_calleeRegisters[index];
-
-            if (index == RegisterFile::OptionalCalleeArguments)
-                return m_argumentsRegister;
+            if (operandIsLocal(index))
+                return m_calleeRegisters[VirtualRegister(index).toLocal()];
 
-            if (m_parameters.size()) {
-                ASSERT(!m_globals.size());
-                return m_parameters[index + m_parameters.size() + RegisterFile::CallFrameHeaderSize];
-            }
+            if (index == JSStack::Callee)
+                return m_calleeRegister;
 
-            return m_globals[-index - 1];
+            ASSERT(m_parameters.size());
+            return m_parameters[VirtualRegister(index).toArgument()];
         }
 
-        unsigned addConstant(FuncDeclNode*);
-        unsigned addConstant(FuncExprNode*);
         unsigned addConstant(const Identifier&);
         RegisterID* addConstantValue(JSValue);
+        RegisterID* addConstantEmptyValue();
         unsigned addRegExp(RegExp*);
 
-        Vector<Instruction>& instructions() { return m_codeBlock->instructions(); }
+        unsigned addConstantBuffer(unsigned length);
+        
+        UnlinkedFunctionExecutable* makeFunction(FunctionBodyNode* body)
+        {
+            return UnlinkedFunctionExecutable::create(m_vm, m_scopeNode->source(), body, isBuiltinFunction() ? UnlinkedBuiltinFunction : UnlinkedNormalFunction);
+        }
+
+        RegisterID* emitInitLazyRegister(RegisterID*);
+        
+        RegisterID* emitConstructVarargs(RegisterID* dst, RegisterID* func, 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&);
+
+        Vector<UnlinkedInstruction, 0, UnsafeVectorOverflow>& instructions() { return m_instructions; }
+
         SymbolTable& symbolTable() { return *m_symbolTable; }
 
-        bool shouldOptimizeLocals() { return (m_codeType != EvalCode) && !m_dynamicScopeDepth; }
-        bool canOptimizeNonLocals() { return (m_codeType == FunctionCode) && !m_dynamicScopeDepth && !m_codeBlock->usesEval(); }
+        bool shouldOptimizeLocals()
+        {
+            if (m_codeType != FunctionCode)
+                return false;
+
+            if (m_localScopeDepth)
+                return false;
+
+            return true;
+        }
+
+        bool canOptimizeNonLocals()
+        {
+            if (m_localScopeDepth)
+                return false;
+
+            if (m_codeType == EvalCode)
+                return false;
+
+            if (m_codeType == FunctionCode && m_codeBlock->usesEval())
+                return false;
+
+            return true;
+        }
+
+        bool shouldTearOffArgumentsEagerly()
+        {
+            return m_codeType == FunctionCode && isStrictMode() && m_scopeNode->modifiesParameter();
+        }
 
         RegisterID* emitThrowExpressionTooDeepException();
 
         void createArgumentsIfNecessary();
+        void createActivationIfNecessary();
+        RegisterID* createLazyRegisterIfNecessary(RegisterID*);
+        
+        unsigned watchableVariable(int operand)
+        {
+            VirtualRegister reg(operand);
+            if (!reg.isLocal())
+                return UINT_MAX;
+            if (static_cast<size_t>(reg.toLocal()) >= m_watchableVariables.size())
+                return UINT_MAX;
+            Identifier& ident = m_watchableVariables[reg.toLocal()];
+            if (ident.isNull())
+                return UINT_MAX;
+            return addConstant(ident);
+        }
+        
+        bool hasWatchableVariable(int operand)
+        {
+            return watchableVariable(operand) != UINT_MAX;
+        }
+        
+        Vector<UnlinkedInstruction, 0, UnsafeVectorOverflow> m_instructions;
 
         bool m_shouldEmitDebugHooks;
         bool m_shouldEmitProfileHooks;
 
-        const ScopeChain* m_scopeChain;
         SymbolTable* m_symbolTable;
 
         ScopeNode* m_scopeNode;
-        CodeBlock* m_codeBlock;
+        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<UString::Rep>, IdentifierRepHash> m_functions;
+        HashSet<RefPtr<StringImpl>, IdentifierRepHash> m_functions;
         RegisterID m_ignoredResultRegister;
         RegisterID m_thisRegister;
-        RegisterID m_argumentsRegister;
-        int m_activationRegisterIndex;
-        WTF::SegmentedVector<RegisterID, 32> m_constantPoolRegisters;
-        WTF::SegmentedVector<RegisterID, 32> m_calleeRegisters;
-        WTF::SegmentedVector<RegisterID, 32> m_parameters;
-        WTF::SegmentedVector<RegisterID, 32> m_globals;
-        WTF::SegmentedVector<Label, 32> m_labels;
-        WTF::SegmentedVector<LabelScope, 8> m_labelScopes;
+        RegisterID m_calleeRegister;
+        RegisterID* m_activationRegister;
+        RegisterID* m_emptyValueRegister;
+        RegisterID* m_globalObjectRegister;
+        Vector<Identifier, 16> m_watchableVariables;
+        SegmentedVector<RegisterID, 32> m_constantPoolRegisters;
+        SegmentedVector<RegisterID, 32> m_calleeRegisters;
+        SegmentedVector<RegisterID, 32> m_parameters;
+        SegmentedVector<Label, 32> m_labels;
+        LabelScopeStore m_labelScopes;
         RefPtr<RegisterID> m_lastVar;
         int m_finallyDepth;
-        int m_dynamicScopeDepth;
-        int m_baseScopeDepth;
+        int m_localScopeDepth;
         CodeType m_codeType;
 
-        Vector<ControlFlowContext> m_scopeContextStack;
+        Vector<ControlFlowContext, 0, UnsafeVectorOverflow> m_scopeContextStack;
         Vector<SwitchInfo> m_switchContextStack;
+        Vector<ForInContext> m_forInContextStack;
+        Vector<TryContext> m_tryContextStack;
+        Vector<std::pair<RefPtr<RegisterID>, const DeconstructionPatternNode*>> m_deconstructedParameters;
+        
+        Vector<TryRange> m_tryRanges;
+        SegmentedVector<TryData, 8> m_tryData;
 
-        int m_nextGlobalIndex;
-        int m_nextParameterIndex;
         int m_firstConstantIndex;
         int m_nextConstantOffset;
         unsigned m_globalConstantIndex;
 
         int m_globalVarStorageOffset;
 
+        int m_firstLazyFunction;
+        int m_lastLazyFunction;
+        HashMap<unsigned int, FunctionBodyNode*, WTF::IntHash<unsigned int>, WTF::UnsignedWithZeroKeyHashTraits<unsigned int>> m_lazyFunctions;
+        typedef HashMap<FunctionBodyNode*, unsigned> FunctionOffsetMap;
+        FunctionOffsetMap m_functionOffsets;
+        
         // Constant pool
         IdentifierMap m_identifierMap;
         JSValueMap m_jsValueMap;
         NumberMap m_numberMap;
         IdentifierStringMap m_stringMap;
 
-        JSGlobalData* m_globalData;
-
-        OpcodeID m_lastOpcodeID;
+        StaticPropertyAnalyzer m_staticPropertyAnalyzer;
 
-        unsigned m_emitNodeDepth;
+        VM* m_vm;
 
-        bool m_regeneratingForExceptionInfo;
-        CodeBlock* m_codeBlockBeingRegeneratedFrom;
+        OpcodeID m_lastOpcodeID;
+#ifndef NDEBUG
+        size_t m_lastOpcodePosition;
+#endif
 
-        static const unsigned s_maxEmitNodeDepth = 5000;
+        bool m_usesExceptions;
+        bool m_expressionTooDeep;
+        bool m_isBuiltinFunction;
     };
 
 }