1 /*
2  * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.
3  * Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1.  Redistributions of source code must retain the above copyright
10  *     notice, this list of conditions and the following disclaimer.
11  * 2.  Redistributions in binary form must reproduce the above copyright
12  *     notice, this list of conditions and the following disclaimer in the
13  *     documentation and/or other materials provided with the distribution.
14  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
15  *     its contributors may be used to endorse or promote products derived
16  *     from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
24  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
25  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #ifndef BytecodeGenerator_h
31 #define BytecodeGenerator_h
32 
33 #include "CodeBlock.h"
34 #include "HashTraits.h"
35 #include "Instruction.h"
36 #include "Label.h"
37 #include "LabelScope.h"
38 #include "Interpreter.h"
39 #include "RegisterID.h"
40 #include "SymbolTable.h"
41 #include "Debugger.h"
42 #include "Nodes.h"
43 #include <wtf/FastAllocBase.h>
44 #include <wtf/PassRefPtr.h>
45 #include <wtf/SegmentedVector.h>
46 #include <wtf/Vector.h>
47 
48 namespace JSC {
49 
50     class Identifier;
51     class ScopeChain;
52     class ScopeNode;
53 
54     struct FinallyContext {
55         Label* finallyAddr;
56         RegisterID* retAddrDst;
57     };
58 
59     struct ControlFlowContext {
60         bool isFinallyBlock;
61         FinallyContext finallyContext;
62     };
63 
64     struct ForInContext {
65         RefPtr<RegisterID> expectedSubscriptRegister;
66         RefPtr<RegisterID> iterRegister;
67         RefPtr<RegisterID> indexRegister;
68         RefPtr<RegisterID> propertyRegister;
69     };
70 
71     class BytecodeGenerator : public FastAllocBase {
72     public:
73         typedef DeclarationStacks::VarStack VarStack;
74         typedef DeclarationStacks::FunctionStack FunctionStack;
75 
76         static void setDumpsGeneratedCode(bool dumpsGeneratedCode);
77         static bool dumpsGeneratedCode();
78 
79         BytecodeGenerator(ProgramNode*, const Debugger*, const ScopeChain&, SymbolTable*, ProgramCodeBlock*);
80         BytecodeGenerator(FunctionBodyNode*, const Debugger*, const ScopeChain&, SymbolTable*, CodeBlock*);
81         BytecodeGenerator(EvalNode*, const Debugger*, const ScopeChain&, SymbolTable*, EvalCodeBlock*);
82 
globalData()83         JSGlobalData* globalData() const { return m_globalData; }
propertyNames()84         const CommonIdentifiers& propertyNames() const { return *m_globalData->propertyNames; }
85 
86         void generate();
87 
88         // Returns the register corresponding to a local variable, or 0 if no
89         // such register exists. Registers returned by registerFor do not
90         // require explicit reference counting.
91         RegisterID* registerFor(const Identifier&);
92 
93         bool willResolveToArguments(const Identifier&);
94         RegisterID* uncheckedRegisterForArguments();
95 
96         // Behaves as registerFor does, but ignores dynamic scope as
97         // dynamic scope should not interfere with const initialisation
98         RegisterID* constRegisterFor(const Identifier&);
99 
100         // Searches the scope chain in an attempt to  statically locate the requested
101         // property.  Returns false if for any reason the property cannot be safely
102         // optimised at all.  Otherwise it will return the index and depth of the
103         // VariableObject that defines the property.  If the property cannot be found
104         // statically, depth will contain the depth of the scope chain where dynamic
105         // lookup must begin.
106         //
107         // NB: depth does _not_ include the local scope.  eg. a depth of 0 refers
108         // to the scope containing this codeblock.
109         bool findScopedProperty(const Identifier&, int& index, size_t& depth, bool forWriting, JSObject*& globalObject);
110 
111         // Returns the register storing "this"
thisRegister()112         RegisterID* thisRegister() { return &m_thisRegister; }
113 
114         bool isLocal(const Identifier&);
115         bool isLocalConstant(const Identifier&);
116 
117         // Returns the next available temporary register. Registers returned by
118         // newTemporary require a modified form of reference counting: any
119         // register with a refcount of 0 is considered "available", meaning that
120         // the next instruction may overwrite it.
121         RegisterID* newTemporary();
122 
123         RegisterID* highestUsedRegister();
124 
125         // The same as newTemporary(), but this function returns "suggestion" if
126         // "suggestion" is a temporary. This function is helpful in situations
127         // where you've put "suggestion" in a RefPtr, but you'd like to allow
128         // the next instruction to overwrite it anyway.
newTemporaryOr(RegisterID * suggestion)129         RegisterID* newTemporaryOr(RegisterID* suggestion) { return suggestion->isTemporary() ? suggestion : newTemporary(); }
130 
131         // Functions for handling of dst register
132 
ignoredResult()133         RegisterID* ignoredResult() { return &m_ignoredResultRegister; }
134 
135         // Returns a place to write intermediate values of an operation
136         // which reuses dst if it is safe to do so.
tempDestination(RegisterID * dst)137         RegisterID* tempDestination(RegisterID* dst)
138         {
139             return (dst && dst != ignoredResult() && dst->isTemporary()) ? dst : newTemporary();
140         }
141 
142         // Returns the place to write the final output of an operation.
143         RegisterID* finalDestination(RegisterID* originalDst, RegisterID* tempDst = 0)
144         {
145             if (originalDst && originalDst != ignoredResult())
146                 return originalDst;
147             ASSERT(tempDst != ignoredResult());
148             if (tempDst && tempDst->isTemporary())
149                 return tempDst;
150             return newTemporary();
151         }
152 
destinationForAssignResult(RegisterID * dst)153         RegisterID* destinationForAssignResult(RegisterID* dst)
154         {
155             if (dst && dst != ignoredResult() && m_codeBlock->needsFullScopeChain())
156                 return dst->isTemporary() ? dst : newTemporary();
157             return 0;
158         }
159 
160         // Moves src to dst if dst is not null and is different from src, otherwise just returns src.
moveToDestinationIfNeeded(RegisterID * dst,RegisterID * src)161         RegisterID* moveToDestinationIfNeeded(RegisterID* dst, RegisterID* src)
162         {
163             return dst == ignoredResult() ? 0 : (dst && dst != src) ? emitMove(dst, src) : src;
164         }
165 
166         PassRefPtr<LabelScope> newLabelScope(LabelScope::Type, const Identifier* = 0);
167         PassRefPtr<Label> newLabel();
168 
169         // The emitNode functions are just syntactic sugar for calling
170         // Node::emitCode. These functions accept a 0 for the register,
171         // meaning that the node should allocate a register, or ignoredResult(),
172         // meaning that the node need not put the result in a register.
173         // Other emit functions do not accept 0 or ignoredResult().
emitNode(RegisterID * dst,Node * n)174         RegisterID* emitNode(RegisterID* dst, Node* n)
175         {
176             // Node::emitCode assumes that dst, if provided, is either a local or a referenced temporary.
177             ASSERT(!dst || dst == ignoredResult() || !dst->isTemporary() || dst->refCount());
178             if (!m_codeBlock->numberOfLineInfos() || m_codeBlock->lastLineInfo().lineNumber != n->lineNo()) {
179                 LineInfo info = { instructions().size(), n->lineNo() };
180                 m_codeBlock->addLineInfo(info);
181             }
182             if (m_emitNodeDepth >= s_maxEmitNodeDepth)
183                 return emitThrowExpressionTooDeepException();
184             ++m_emitNodeDepth;
185             RegisterID* r = n->emitBytecode(*this, dst);
186             --m_emitNodeDepth;
187             return r;
188         }
189 
emitNode(Node * n)190         RegisterID* emitNode(Node* n)
191         {
192             return emitNode(0, n);
193         }
194 
emitNodeInConditionContext(ExpressionNode * n,Label * trueTarget,Label * falseTarget,bool fallThroughMeansTrue)195         void emitNodeInConditionContext(ExpressionNode* n, Label* trueTarget, Label* falseTarget, bool fallThroughMeansTrue)
196         {
197             if (!m_codeBlock->numberOfLineInfos() || m_codeBlock->lastLineInfo().lineNumber != n->lineNo()) {
198                 LineInfo info = { instructions().size(), n->lineNo() };
199                 m_codeBlock->addLineInfo(info);
200             }
201             if (m_emitNodeDepth >= s_maxEmitNodeDepth)
202                 emitThrowExpressionTooDeepException();
203             ++m_emitNodeDepth;
204             n->emitBytecodeInConditionContext(*this, trueTarget, falseTarget, fallThroughMeansTrue);
205             --m_emitNodeDepth;
206         }
207 
emitExpressionInfo(unsigned divot,unsigned startOffset,unsigned endOffset)208         void emitExpressionInfo(unsigned divot, unsigned startOffset, unsigned endOffset)
209         {
210             divot -= m_codeBlock->sourceOffset();
211             if (divot > ExpressionRangeInfo::MaxDivot) {
212                 // Overflow has occurred, we can only give line number info for errors for this region
213                 divot = 0;
214                 startOffset = 0;
215                 endOffset = 0;
216             } else if (startOffset > ExpressionRangeInfo::MaxOffset) {
217                 // If the start offset is out of bounds we clear both offsets
218                 // so we only get the divot marker.  Error message will have to be reduced
219                 // to line and column number.
220                 startOffset = 0;
221                 endOffset = 0;
222             } else if (endOffset > ExpressionRangeInfo::MaxOffset) {
223                 // The end offset is only used for additional context, and is much more likely
224                 // to overflow (eg. function call arguments) so we are willing to drop it without
225                 // dropping the rest of the range.
226                 endOffset = 0;
227             }
228 
229             ExpressionRangeInfo info;
230             info.instructionOffset = instructions().size();
231             info.divotPoint = divot;
232             info.startOffset = startOffset;
233             info.endOffset = endOffset;
234             m_codeBlock->addExpressionInfo(info);
235         }
236 
emitGetByIdExceptionInfo(OpcodeID opcodeID)237         void emitGetByIdExceptionInfo(OpcodeID opcodeID)
238         {
239             // Only op_construct and op_instanceof need exception info for
240             // a preceding op_get_by_id.
241             ASSERT(opcodeID == op_construct || opcodeID == op_instanceof);
242             GetByIdExceptionInfo info;
243             info.bytecodeOffset = instructions().size();
244             info.isOpConstruct = (opcodeID == op_construct);
245             m_codeBlock->addGetByIdExceptionInfo(info);
246         }
247 
leftHandSideNeedsCopy(bool rightHasAssignments,bool rightIsPure)248         ALWAYS_INLINE bool leftHandSideNeedsCopy(bool rightHasAssignments, bool rightIsPure)
249         {
250             return (m_codeType != FunctionCode || m_codeBlock->needsFullScopeChain() || rightHasAssignments) && !rightIsPure;
251         }
252 
emitNodeForLeftHandSide(ExpressionNode * n,bool rightHasAssignments,bool rightIsPure)253         ALWAYS_INLINE PassRefPtr<RegisterID> emitNodeForLeftHandSide(ExpressionNode* n, bool rightHasAssignments, bool rightIsPure)
254         {
255             if (leftHandSideNeedsCopy(rightHasAssignments, rightIsPure)) {
256                 PassRefPtr<RegisterID> dst = newTemporary();
257                 emitNode(dst.get(), n);
258                 return dst;
259             }
260 
261             return PassRefPtr<RegisterID>(emitNode(n));
262         }
263 
264         RegisterID* emitLoad(RegisterID* dst, bool);
265         RegisterID* emitLoad(RegisterID* dst, double);
266         RegisterID* emitLoad(RegisterID* dst, const Identifier&);
267         RegisterID* emitLoad(RegisterID* dst, JSValue);
268 
269         RegisterID* emitUnaryOp(OpcodeID, RegisterID* dst, RegisterID* src);
270         RegisterID* emitBinaryOp(OpcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2, OperandTypes);
271         RegisterID* emitEqualityOp(OpcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2);
272         RegisterID* emitUnaryNoDstOp(OpcodeID, RegisterID* src);
273 
274         RegisterID* emitNewObject(RegisterID* dst);
275         RegisterID* emitNewArray(RegisterID* dst, ElementNode*); // stops at first elision
276 
277         RegisterID* emitNewFunction(RegisterID* dst, FunctionBodyNode* body);
278         RegisterID* emitNewFunctionExpression(RegisterID* dst, FuncExprNode* func);
279         RegisterID* emitNewRegExp(RegisterID* dst, RegExp* regExp);
280 
281         RegisterID* emitMove(RegisterID* dst, RegisterID* src);
282 
emitToJSNumber(RegisterID * dst,RegisterID * src)283         RegisterID* emitToJSNumber(RegisterID* dst, RegisterID* src) { return emitUnaryOp(op_to_jsnumber, dst, src); }
284         RegisterID* emitPreInc(RegisterID* srcDst);
285         RegisterID* emitPreDec(RegisterID* srcDst);
286         RegisterID* emitPostInc(RegisterID* dst, RegisterID* srcDst);
287         RegisterID* emitPostDec(RegisterID* dst, RegisterID* srcDst);
288 
289         RegisterID* emitInstanceOf(RegisterID* dst, RegisterID* value, RegisterID* base, RegisterID* basePrototype);
emitTypeOf(RegisterID * dst,RegisterID * src)290         RegisterID* emitTypeOf(RegisterID* dst, RegisterID* src) { return emitUnaryOp(op_typeof, dst, src); }
emitIn(RegisterID * dst,RegisterID * property,RegisterID * base)291         RegisterID* emitIn(RegisterID* dst, RegisterID* property, RegisterID* base) { return emitBinaryOp(op_in, dst, property, base, OperandTypes()); }
292 
293         RegisterID* emitResolve(RegisterID* dst, const Identifier& property);
294         RegisterID* emitGetScopedVar(RegisterID* dst, size_t skip, int index, JSValue globalObject);
295         RegisterID* emitPutScopedVar(size_t skip, int index, RegisterID* value, JSValue globalObject);
296 
297         RegisterID* emitResolveBase(RegisterID* dst, const Identifier& property);
298         RegisterID* emitResolveWithBase(RegisterID* baseDst, RegisterID* propDst, const Identifier& property);
299 
300         void emitMethodCheck();
301 
302         RegisterID* emitGetById(RegisterID* dst, RegisterID* base, const Identifier& property);
303         RegisterID* emitPutById(RegisterID* base, const Identifier& property, RegisterID* value);
304         RegisterID* emitDeleteById(RegisterID* dst, RegisterID* base, const Identifier&);
305         RegisterID* emitGetByVal(RegisterID* dst, RegisterID* base, RegisterID* property);
306         RegisterID* emitPutByVal(RegisterID* base, RegisterID* property, RegisterID* value);
307         RegisterID* emitDeleteByVal(RegisterID* dst, RegisterID* base, RegisterID* property);
308         RegisterID* emitPutByIndex(RegisterID* base, unsigned index, RegisterID* value);
309         RegisterID* emitPutGetter(RegisterID* base, const Identifier& property, RegisterID* value);
310         RegisterID* emitPutSetter(RegisterID* base, const Identifier& property, RegisterID* value);
311 
312         RegisterID* emitCall(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
313         RegisterID* emitCallEval(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
314         RegisterID* emitCallVarargs(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, RegisterID* argCount, unsigned divot, unsigned startOffset, unsigned endOffset);
315         RegisterID* emitLoadVarargs(RegisterID* argCountDst, RegisterID* args);
316 
317         RegisterID* emitReturn(RegisterID* src);
emitEnd(RegisterID * src)318         RegisterID* emitEnd(RegisterID* src) { return emitUnaryNoDstOp(op_end, src); }
319 
320         RegisterID* emitConstruct(RegisterID* dst, RegisterID* func, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
321         RegisterID* emitStrcat(RegisterID* dst, RegisterID* src, int count);
322         void emitToPrimitive(RegisterID* dst, RegisterID* src);
323 
324         PassRefPtr<Label> emitLabel(Label*);
325         PassRefPtr<Label> emitJump(Label* target);
326         PassRefPtr<Label> emitJumpIfTrue(RegisterID* cond, Label* target);
327         PassRefPtr<Label> emitJumpIfFalse(RegisterID* cond, Label* target);
328         PassRefPtr<Label> emitJumpIfNotFunctionCall(RegisterID* cond, Label* target);
329         PassRefPtr<Label> emitJumpIfNotFunctionApply(RegisterID* cond, Label* target);
330         PassRefPtr<Label> emitJumpScopes(Label* target, int targetScopeDepth);
331 
332         PassRefPtr<Label> emitJumpSubroutine(RegisterID* retAddrDst, Label*);
333         void emitSubroutineReturn(RegisterID* retAddrSrc);
334 
335         RegisterID* emitGetPropertyNames(RegisterID* dst, RegisterID* base, RegisterID* i, RegisterID* size, Label* breakTarget);
336         RegisterID* emitNextPropertyName(RegisterID* dst, RegisterID* base, RegisterID* i, RegisterID* size, RegisterID* iter, Label* target);
337 
338         RegisterID* emitCatch(RegisterID*, Label* start, Label* end);
emitThrow(RegisterID * exc)339         void emitThrow(RegisterID* exc) { emitUnaryNoDstOp(op_throw, exc); }
340         RegisterID* emitNewError(RegisterID* dst, ErrorType type, JSValue message);
341         void emitPushNewScope(RegisterID* dst, const Identifier& property, RegisterID* value);
342 
343         RegisterID* emitPushScope(RegisterID* scope);
344         void emitPopScope();
345 
346         void emitDebugHook(DebugHookID, int firstLine, int lastLine);
347 
scopeDepth()348         int scopeDepth() { return m_dynamicScopeDepth + m_finallyDepth; }
hasFinaliser()349         bool hasFinaliser() { return m_finallyDepth != 0; }
350 
351         void pushFinallyContext(Label* target, RegisterID* returnAddrDst);
352         void popFinallyContext();
353 
pushOptimisedForIn(RegisterID * expectedBase,RegisterID * iter,RegisterID * index,RegisterID * propertyRegister)354         void pushOptimisedForIn(RegisterID* expectedBase, RegisterID* iter, RegisterID* index, RegisterID* propertyRegister)
355         {
356             ForInContext context = { expectedBase, iter, index, propertyRegister };
357             m_forInContextStack.append(context);
358         }
359 
popOptimisedForIn()360         void popOptimisedForIn()
361         {
362             m_forInContextStack.removeLast();
363         }
364 
365         LabelScope* breakTarget(const Identifier&);
366         LabelScope* continueTarget(const Identifier&);
367 
368         void beginSwitch(RegisterID*, SwitchInfo::SwitchType);
369         void endSwitch(uint32_t clauseCount, RefPtr<Label>*, ExpressionNode**, Label* defaultLabel, int32_t min, int32_t range);
370 
codeType()371         CodeType codeType() const { return m_codeType; }
372 
setRegeneratingForExceptionInfo(CodeBlock * originalCodeBlock)373         void setRegeneratingForExceptionInfo(CodeBlock* originalCodeBlock)
374         {
375             m_regeneratingForExceptionInfo = true;
376             m_codeBlockBeingRegeneratedFrom = originalCodeBlock;
377         }
378 
379     private:
380         void emitOpcode(OpcodeID);
381         void retrieveLastBinaryOp(int& dstIndex, int& src1Index, int& src2Index);
382         void retrieveLastUnaryOp(int& dstIndex, int& srcIndex);
383         void rewindBinaryOp();
384         void rewindUnaryOp();
385 
386         PassRefPtr<Label> emitComplexJumpScopes(Label* target, ControlFlowContext* topScope, ControlFlowContext* bottomScope);
387 
388         typedef HashMap<EncodedJSValue, unsigned, EncodedJSValueHash, EncodedJSValueHashTraits> JSValueMap;
389 
390         struct IdentifierMapIndexHashTraits {
391             typedef int TraitType;
392             typedef IdentifierMapIndexHashTraits StorageTraits;
emptyValueIdentifierMapIndexHashTraits393             static int emptyValue() { return std::numeric_limits<int>::max(); }
394             static const bool emptyValueIsZero = false;
395             static const bool needsDestruction = false;
396             static const bool needsRef = false;
397         };
398 
399         typedef HashMap<RefPtr<UString::Rep>, int, IdentifierRepHash, HashTraits<RefPtr<UString::Rep> >, IdentifierMapIndexHashTraits> IdentifierMap;
400         typedef HashMap<double, JSValue> NumberMap;
401         typedef HashMap<UString::Rep*, JSString*, IdentifierRepHash> IdentifierStringMap;
402 
403         RegisterID* emitCall(OpcodeID, RegisterID* dst, RegisterID* func, RegisterID* thisRegister, ArgumentsNode*, unsigned divot, unsigned startOffset, unsigned endOffset);
404 
405         RegisterID* newRegister();
406 
407         // Returns the RegisterID corresponding to ident.
addVar(const Identifier & ident,bool isConstant)408         RegisterID* addVar(const Identifier& ident, bool isConstant)
409         {
410             RegisterID* local;
411             addVar(ident, isConstant, local);
412             return local;
413         }
414         // Returns true if a new RegisterID was added, false if a pre-existing RegisterID was re-used.
415         bool addVar(const Identifier&, bool isConstant, RegisterID*&);
416 
417         // Returns the RegisterID corresponding to ident.
addGlobalVar(const Identifier & ident,bool isConstant)418         RegisterID* addGlobalVar(const Identifier& ident, bool isConstant)
419         {
420             RegisterID* local;
421             addGlobalVar(ident, isConstant, local);
422             return local;
423         }
424         // Returns true if a new RegisterID was added, false if a pre-existing RegisterID was re-used.
425         bool addGlobalVar(const Identifier&, bool isConstant, RegisterID*&);
426 
427         RegisterID* addParameter(const Identifier&);
428 
429         void preserveLastVar();
430 
registerFor(int index)431         RegisterID& registerFor(int index)
432         {
433             if (index >= 0)
434                 return m_calleeRegisters[index];
435 
436             if (index == RegisterFile::OptionalCalleeArguments)
437                 return m_argumentsRegister;
438 
439             if (m_parameters.size()) {
440                 ASSERT(!m_globals.size());
441                 return m_parameters[index + m_parameters.size() + RegisterFile::CallFrameHeaderSize];
442             }
443 
444             return m_globals[-index - 1];
445         }
446 
447         unsigned addConstant(const Identifier&);
448         RegisterID* addConstantValue(JSValue);
449         unsigned addRegExp(RegExp*);
450 
makeFunction(ExecState * exec,FunctionBodyNode * body)451         PassRefPtr<FunctionExecutable> makeFunction(ExecState* exec, FunctionBodyNode* body)
452         {
453             return FunctionExecutable::create(exec, body->ident(), body->source(), body->usesArguments(), body->parameters(), body->lineNo(), body->lastLine());
454         }
455 
makeFunction(JSGlobalData * globalData,FunctionBodyNode * body)456         PassRefPtr<FunctionExecutable> makeFunction(JSGlobalData* globalData, FunctionBodyNode* body)
457         {
458             return FunctionExecutable::create(globalData, body->ident(), body->source(), body->usesArguments(), body->parameters(), body->lineNo(), body->lastLine());
459         }
460 
instructions()461         Vector<Instruction>& instructions() { return m_codeBlock->instructions(); }
symbolTable()462         SymbolTable& symbolTable() { return *m_symbolTable; }
463 
shouldOptimizeLocals()464         bool shouldOptimizeLocals() { return (m_codeType != EvalCode) && !m_dynamicScopeDepth; }
canOptimizeNonLocals()465         bool canOptimizeNonLocals() { return (m_codeType == FunctionCode) && !m_dynamicScopeDepth && !m_codeBlock->usesEval(); }
466 
467         RegisterID* emitThrowExpressionTooDeepException();
468 
469         void createArgumentsIfNecessary();
470 
471         bool m_shouldEmitDebugHooks;
472         bool m_shouldEmitProfileHooks;
473 
474         const ScopeChain* m_scopeChain;
475         SymbolTable* m_symbolTable;
476 
477         ScopeNode* m_scopeNode;
478         CodeBlock* m_codeBlock;
479 
480         // Some of these objects keep pointers to one another. They are arranged
481         // to ensure a sane destruction order that avoids references to freed memory.
482         HashSet<RefPtr<UString::Rep>, IdentifierRepHash> m_functions;
483         RegisterID m_ignoredResultRegister;
484         RegisterID m_thisRegister;
485         RegisterID m_argumentsRegister;
486         int m_activationRegisterIndex;
487         SegmentedVector<RegisterID, 32> m_constantPoolRegisters;
488         SegmentedVector<RegisterID, 32> m_calleeRegisters;
489         SegmentedVector<RegisterID, 32> m_parameters;
490         SegmentedVector<RegisterID, 32> m_globals;
491         SegmentedVector<Label, 32> m_labels;
492         SegmentedVector<LabelScope, 8> m_labelScopes;
493         RefPtr<RegisterID> m_lastVar;
494         int m_finallyDepth;
495         int m_dynamicScopeDepth;
496         int m_baseScopeDepth;
497         CodeType m_codeType;
498 
499         Vector<ControlFlowContext> m_scopeContextStack;
500         Vector<SwitchInfo> m_switchContextStack;
501         Vector<ForInContext> m_forInContextStack;
502 
503         int m_nextGlobalIndex;
504         int m_nextParameterIndex;
505         int m_firstConstantIndex;
506         int m_nextConstantOffset;
507         unsigned m_globalConstantIndex;
508 
509         int m_globalVarStorageOffset;
510 
511         // Constant pool
512         IdentifierMap m_identifierMap;
513         JSValueMap m_jsValueMap;
514         NumberMap m_numberMap;
515         IdentifierStringMap m_stringMap;
516 
517         JSGlobalData* m_globalData;
518 
519         OpcodeID m_lastOpcodeID;
520 
521         unsigned m_emitNodeDepth;
522 
523         bool m_regeneratingForExceptionInfo;
524         CodeBlock* m_codeBlockBeingRegeneratedFrom;
525 
526         static const unsigned s_maxEmitNodeDepth = 5000;
527     };
528 
529 }
530 
531 #endif // BytecodeGenerator_h
532