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1 /*
2  * Copyright (C) 2008, 2009, 2010 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 CodeBlock_h
31 #define CodeBlock_h
32 
33 #include "EvalCodeCache.h"
34 #include "Instruction.h"
35 #include "JITCode.h"
36 #include "JSGlobalObject.h"
37 #include "JumpTable.h"
38 #include "Nodes.h"
39 #include "RegExp.h"
40 #include "UString.h"
41 #include <wtf/FastAllocBase.h>
42 #include <wtf/PassOwnPtr.h>
43 #include <wtf/RefPtr.h>
44 #include <wtf/Vector.h>
45 
46 #if ENABLE(JIT)
47 #include "StructureStubInfo.h"
48 #endif
49 
50 // Register numbers used in bytecode operations have different meaning according to their ranges:
51 //      0x80000000-0xFFFFFFFF  Negative indices from the CallFrame pointer are entries in the call frame, see RegisterFile.h.
52 //      0x00000000-0x3FFFFFFF  Forwards indices from the CallFrame pointer are local vars and temporaries with the function's callframe.
53 //      0x40000000-0x7FFFFFFF  Positive indices from 0x40000000 specify entries in the constant pool on the CodeBlock.
54 static const int FirstConstantRegisterIndex = 0x40000000;
55 
56 namespace JSC {
57 
58     enum HasSeenShouldRepatch {
59         hasSeenShouldRepatch
60     };
61 
62     class ExecState;
63 
64     enum CodeType { GlobalCode, EvalCode, FunctionCode };
65 
unmodifiedArgumentsRegister(int argumentsRegister)66     inline int unmodifiedArgumentsRegister(int argumentsRegister) { return argumentsRegister - 1; }
67 
missingThisObjectMarker()68     static ALWAYS_INLINE int missingThisObjectMarker() { return std::numeric_limits<int>::max(); }
69 
70     struct HandlerInfo {
71         uint32_t start;
72         uint32_t end;
73         uint32_t target;
74         uint32_t scopeDepth;
75 #if ENABLE(JIT)
76         CodeLocationLabel nativeCode;
77 #endif
78     };
79 
80     struct ExpressionRangeInfo {
81         enum {
82             MaxOffset = (1 << 7) - 1,
83             MaxDivot = (1 << 25) - 1
84         };
85         uint32_t instructionOffset : 25;
86         uint32_t divotPoint : 25;
87         uint32_t startOffset : 7;
88         uint32_t endOffset : 7;
89     };
90 
91     struct LineInfo {
92         uint32_t instructionOffset;
93         int32_t lineNumber;
94     };
95 
96 #if ENABLE(JIT)
97     struct CallLinkInfo {
CallLinkInfoCallLinkInfo98         CallLinkInfo()
99             : hasSeenShouldRepatch(false)
100         {
101         }
102 
103         CodeLocationNearCall callReturnLocation;
104         CodeLocationDataLabelPtr hotPathBegin;
105         CodeLocationNearCall hotPathOther;
106         WriteBarrier<JSFunction> callee;
107         bool hasSeenShouldRepatch;
108 
setUnlinkedCallLinkInfo109         void setUnlinked() { callee.clear(); }
isLinkedCallLinkInfo110         bool isLinked() { return callee; }
111 
seenOnceCallLinkInfo112         bool seenOnce()
113         {
114             return hasSeenShouldRepatch;
115         }
116 
setSeenCallLinkInfo117         void setSeen()
118         {
119             hasSeenShouldRepatch = true;
120         }
121     };
122 
123     struct MethodCallLinkInfo {
MethodCallLinkInfoMethodCallLinkInfo124         MethodCallLinkInfo()
125         {
126         }
127 
seenOnceMethodCallLinkInfo128         bool seenOnce()
129         {
130             ASSERT(!cachedStructure);
131             return cachedPrototypeStructure;
132         }
133 
setSeenMethodCallLinkInfo134         void setSeen()
135         {
136             ASSERT(!cachedStructure && !cachedPrototypeStructure);
137             // We use the values of cachedStructure & cachedPrototypeStructure to indicate the
138             // current state.
139             //     - In the initial state, both are null.
140             //     - Once this transition has been taken once, cachedStructure is
141             //       null and cachedPrototypeStructure is set to a nun-null value.
142             //     - Once the call is linked both structures are set to non-null values.
143             cachedPrototypeStructure.setWithoutWriteBarrier((Structure*)1);
144         }
145 
146         CodeLocationCall callReturnLocation;
147         CodeLocationDataLabelPtr structureLabel;
148         WriteBarrier<Structure> cachedStructure;
149         WriteBarrier<Structure> cachedPrototypeStructure;
150     };
151 
152     struct GlobalResolveInfo {
GlobalResolveInfoGlobalResolveInfo153         GlobalResolveInfo(unsigned bytecodeOffset)
154             : offset(0)
155             , bytecodeOffset(bytecodeOffset)
156         {
157         }
158 
159         WriteBarrier<Structure> structure;
160         unsigned offset;
161         unsigned bytecodeOffset;
162     };
163 
164     // This structure is used to map from a call return location
165     // (given as an offset in bytes into the JIT code) back to
166     // the bytecode index of the corresponding bytecode operation.
167     // This is then used to look up the corresponding handler.
168     struct CallReturnOffsetToBytecodeOffset {
CallReturnOffsetToBytecodeOffsetCallReturnOffsetToBytecodeOffset169         CallReturnOffsetToBytecodeOffset(unsigned callReturnOffset, unsigned bytecodeOffset)
170             : callReturnOffset(callReturnOffset)
171             , bytecodeOffset(bytecodeOffset)
172         {
173         }
174 
175         unsigned callReturnOffset;
176         unsigned bytecodeOffset;
177     };
178 
179     // valueAtPosition helpers for the binarySearch algorithm.
180 
getStructureStubInfoReturnLocation(StructureStubInfo * structureStubInfo)181     inline void* getStructureStubInfoReturnLocation(StructureStubInfo* structureStubInfo)
182     {
183         return structureStubInfo->callReturnLocation.executableAddress();
184     }
185 
getCallLinkInfoReturnLocation(CallLinkInfo * callLinkInfo)186     inline void* getCallLinkInfoReturnLocation(CallLinkInfo* callLinkInfo)
187     {
188         return callLinkInfo->callReturnLocation.executableAddress();
189     }
190 
getMethodCallLinkInfoReturnLocation(MethodCallLinkInfo * methodCallLinkInfo)191     inline void* getMethodCallLinkInfoReturnLocation(MethodCallLinkInfo* methodCallLinkInfo)
192     {
193         return methodCallLinkInfo->callReturnLocation.executableAddress();
194     }
195 
getCallReturnOffset(CallReturnOffsetToBytecodeOffset * pc)196     inline unsigned getCallReturnOffset(CallReturnOffsetToBytecodeOffset* pc)
197     {
198         return pc->callReturnOffset;
199     }
200 #endif
201 
202     class CodeBlock {
203         WTF_MAKE_FAST_ALLOCATED;
204         friend class JIT;
205     protected:
206         CodeBlock(ScriptExecutable* ownerExecutable, CodeType, JSGlobalObject*, PassRefPtr<SourceProvider>, unsigned sourceOffset, SymbolTable* symbolTable, bool isConstructor);
207 
208         WriteBarrier<JSGlobalObject> m_globalObject;
209         Heap* m_heap;
210 
211     public:
212         virtual ~CodeBlock();
213 
214         void markAggregate(MarkStack&);
215 
216         static void dumpStatistics();
217 
218 #if !defined(NDEBUG) || ENABLE_OPCODE_SAMPLING
219         void dump(ExecState*) const;
220         void printStructures(const Instruction*) const;
221         void printStructure(const char* name, const Instruction*, int operand) const;
222 #endif
223 
isStrictMode()224         bool isStrictMode() const { return m_isStrictMode; }
225 
isKnownNotImmediate(int index)226         inline bool isKnownNotImmediate(int index)
227         {
228             if (index == m_thisRegister && !m_isStrictMode)
229                 return true;
230 
231             if (isConstantRegisterIndex(index))
232                 return getConstant(index).isCell();
233 
234             return false;
235         }
236 
isTemporaryRegisterIndex(int index)237         ALWAYS_INLINE bool isTemporaryRegisterIndex(int index)
238         {
239             return index >= m_numVars;
240         }
241 
242         HandlerInfo* handlerForBytecodeOffset(unsigned bytecodeOffset);
243         int lineNumberForBytecodeOffset(unsigned bytecodeOffset);
244         void expressionRangeForBytecodeOffset(unsigned bytecodeOffset, int& divot, int& startOffset, int& endOffset);
245 
246 #if ENABLE(JIT)
247 
getStubInfo(ReturnAddressPtr returnAddress)248         StructureStubInfo& getStubInfo(ReturnAddressPtr returnAddress)
249         {
250             return *(binarySearch<StructureStubInfo, void*, getStructureStubInfoReturnLocation>(m_structureStubInfos.begin(), m_structureStubInfos.size(), returnAddress.value()));
251         }
252 
getCallLinkInfo(ReturnAddressPtr returnAddress)253         CallLinkInfo& getCallLinkInfo(ReturnAddressPtr returnAddress)
254         {
255             return *(binarySearch<CallLinkInfo, void*, getCallLinkInfoReturnLocation>(m_callLinkInfos.begin(), m_callLinkInfos.size(), returnAddress.value()));
256         }
257 
getMethodCallLinkInfo(ReturnAddressPtr returnAddress)258         MethodCallLinkInfo& getMethodCallLinkInfo(ReturnAddressPtr returnAddress)
259         {
260             return *(binarySearch<MethodCallLinkInfo, void*, getMethodCallLinkInfoReturnLocation>(m_methodCallLinkInfos.begin(), m_methodCallLinkInfos.size(), returnAddress.value()));
261         }
262 
bytecodeOffset(ReturnAddressPtr returnAddress)263         unsigned bytecodeOffset(ReturnAddressPtr returnAddress)
264         {
265             if (!m_rareData)
266                 return 1;
267             Vector<CallReturnOffsetToBytecodeOffset>& callIndices = m_rareData->m_callReturnIndexVector;
268             if (!callIndices.size())
269                 return 1;
270             return binarySearch<CallReturnOffsetToBytecodeOffset, unsigned, getCallReturnOffset>(callIndices.begin(), callIndices.size(), getJITCode().offsetOf(returnAddress.value()))->bytecodeOffset;
271         }
272 #endif
273 #if ENABLE(INTERPRETER)
bytecodeOffset(Instruction * returnAddress)274         unsigned bytecodeOffset(Instruction* returnAddress)
275         {
276             return static_cast<Instruction*>(returnAddress) - instructions().begin();
277         }
278 #endif
279 
setIsNumericCompareFunction(bool isNumericCompareFunction)280         void setIsNumericCompareFunction(bool isNumericCompareFunction) { m_isNumericCompareFunction = isNumericCompareFunction; }
isNumericCompareFunction()281         bool isNumericCompareFunction() { return m_isNumericCompareFunction; }
282 
instructions()283         Vector<Instruction>& instructions() { return m_instructions; }
discardBytecode()284         void discardBytecode() { m_instructions.clear(); }
285 
286 #ifndef NDEBUG
instructionCount()287         unsigned instructionCount() { return m_instructionCount; }
setInstructionCount(unsigned instructionCount)288         void setInstructionCount(unsigned instructionCount) { m_instructionCount = instructionCount; }
289 #endif
290 
291 #if ENABLE(JIT)
getJITCode()292         JITCode& getJITCode() { return m_isConstructor ? ownerExecutable()->generatedJITCodeForConstruct() : ownerExecutable()->generatedJITCodeForCall(); }
executablePool()293         ExecutablePool* executablePool() { return getJITCode().getExecutablePool(); }
294 #endif
295 
ownerExecutable()296         ScriptExecutable* ownerExecutable() const { return m_ownerExecutable.get(); }
297 
setGlobalData(JSGlobalData * globalData)298         void setGlobalData(JSGlobalData* globalData) { m_globalData = globalData; }
299 
setThisRegister(int thisRegister)300         void setThisRegister(int thisRegister) { m_thisRegister = thisRegister; }
thisRegister()301         int thisRegister() const { return m_thisRegister; }
302 
setNeedsFullScopeChain(bool needsFullScopeChain)303         void setNeedsFullScopeChain(bool needsFullScopeChain) { m_needsFullScopeChain = needsFullScopeChain; }
needsFullScopeChain()304         bool needsFullScopeChain() const { return m_needsFullScopeChain; }
setUsesEval(bool usesEval)305         void setUsesEval(bool usesEval) { m_usesEval = usesEval; }
usesEval()306         bool usesEval() const { return m_usesEval; }
307 
setArgumentsRegister(int argumentsRegister)308         void setArgumentsRegister(int argumentsRegister)
309         {
310             ASSERT(argumentsRegister != -1);
311             m_argumentsRegister = argumentsRegister;
312             ASSERT(usesArguments());
313         }
argumentsRegister()314         int argumentsRegister()
315         {
316             ASSERT(usesArguments());
317             return m_argumentsRegister;
318         }
setActivationRegister(int activationRegister)319         void setActivationRegister(int activationRegister)
320         {
321             m_activationRegister = activationRegister;
322         }
activationRegister()323         int activationRegister()
324         {
325             ASSERT(needsFullScopeChain());
326             return m_activationRegister;
327         }
usesArguments()328         bool usesArguments() const { return m_argumentsRegister != -1; }
329 
codeType()330         CodeType codeType() const { return m_codeType; }
331 
source()332         SourceProvider* source() const { return m_source.get(); }
sourceOffset()333         unsigned sourceOffset() const { return m_sourceOffset; }
334 
numberOfJumpTargets()335         size_t numberOfJumpTargets() const { return m_jumpTargets.size(); }
addJumpTarget(unsigned jumpTarget)336         void addJumpTarget(unsigned jumpTarget) { m_jumpTargets.append(jumpTarget); }
jumpTarget(int index)337         unsigned jumpTarget(int index) const { return m_jumpTargets[index]; }
lastJumpTarget()338         unsigned lastJumpTarget() const { return m_jumpTargets.last(); }
339 
340         void createActivation(CallFrame*);
341 
342 #if ENABLE(INTERPRETER)
addPropertyAccessInstruction(unsigned propertyAccessInstruction)343         void addPropertyAccessInstruction(unsigned propertyAccessInstruction) { m_propertyAccessInstructions.append(propertyAccessInstruction); }
addGlobalResolveInstruction(unsigned globalResolveInstruction)344         void addGlobalResolveInstruction(unsigned globalResolveInstruction) { m_globalResolveInstructions.append(globalResolveInstruction); }
345         bool hasGlobalResolveInstructionAtBytecodeOffset(unsigned bytecodeOffset);
346 #endif
347 #if ENABLE(JIT)
numberOfStructureStubInfos()348         size_t numberOfStructureStubInfos() const { return m_structureStubInfos.size(); }
addStructureStubInfo(const StructureStubInfo & stubInfo)349         void addStructureStubInfo(const StructureStubInfo& stubInfo) { m_structureStubInfos.append(stubInfo); }
structureStubInfo(int index)350         StructureStubInfo& structureStubInfo(int index) { return m_structureStubInfos[index]; }
351 
addGlobalResolveInfo(unsigned globalResolveInstruction)352         void addGlobalResolveInfo(unsigned globalResolveInstruction) { m_globalResolveInfos.append(GlobalResolveInfo(globalResolveInstruction)); }
globalResolveInfo(int index)353         GlobalResolveInfo& globalResolveInfo(int index) { return m_globalResolveInfos[index]; }
354         bool hasGlobalResolveInfoAtBytecodeOffset(unsigned bytecodeOffset);
355 
numberOfCallLinkInfos()356         size_t numberOfCallLinkInfos() const { return m_callLinkInfos.size(); }
addCallLinkInfo()357         void addCallLinkInfo() { m_callLinkInfos.append(CallLinkInfo()); }
callLinkInfo(int index)358         CallLinkInfo& callLinkInfo(int index) { return m_callLinkInfos[index]; }
359 
addMethodCallLinkInfos(unsigned n)360         void addMethodCallLinkInfos(unsigned n) { m_methodCallLinkInfos.grow(n); }
methodCallLinkInfo(int index)361         MethodCallLinkInfo& methodCallLinkInfo(int index) { return m_methodCallLinkInfos[index]; }
362 #endif
363 
364         // Exception handling support
365 
numberOfExceptionHandlers()366         size_t numberOfExceptionHandlers() const { return m_rareData ? m_rareData->m_exceptionHandlers.size() : 0; }
addExceptionHandler(const HandlerInfo & hanler)367         void addExceptionHandler(const HandlerInfo& hanler) { createRareDataIfNecessary(); return m_rareData->m_exceptionHandlers.append(hanler); }
exceptionHandler(int index)368         HandlerInfo& exceptionHandler(int index) { ASSERT(m_rareData); return m_rareData->m_exceptionHandlers[index]; }
369 
addExpressionInfo(const ExpressionRangeInfo & expressionInfo)370         void addExpressionInfo(const ExpressionRangeInfo& expressionInfo)
371         {
372             createRareDataIfNecessary();
373             m_rareData->m_expressionInfo.append(expressionInfo);
374         }
375 
addLineInfo(unsigned bytecodeOffset,int lineNo)376         void addLineInfo(unsigned bytecodeOffset, int lineNo)
377         {
378             createRareDataIfNecessary();
379             Vector<LineInfo>& lineInfo = m_rareData->m_lineInfo;
380             if (!lineInfo.size() || lineInfo.last().lineNumber != lineNo) {
381                 LineInfo info = { bytecodeOffset, lineNo };
382                 lineInfo.append(info);
383             }
384         }
385 
hasExpressionInfo()386         bool hasExpressionInfo() { return m_rareData && m_rareData->m_expressionInfo.size(); }
hasLineInfo()387         bool hasLineInfo() { return m_rareData && m_rareData->m_lineInfo.size(); }
388         //  We only generate exception handling info if the user is debugging
389         // (and may want line number info), or if the function contains exception handler.
needsCallReturnIndices()390         bool needsCallReturnIndices()
391         {
392             return m_rareData &&
393                 (m_rareData->m_expressionInfo.size() || m_rareData->m_lineInfo.size() || m_rareData->m_exceptionHandlers.size());
394         }
395 
396 #if ENABLE(JIT)
callReturnIndexVector()397         Vector<CallReturnOffsetToBytecodeOffset>& callReturnIndexVector()
398         {
399             createRareDataIfNecessary();
400             return m_rareData->m_callReturnIndexVector;
401         }
402 #endif
403 
404         // Constant Pool
405 
numberOfIdentifiers()406         size_t numberOfIdentifiers() const { return m_identifiers.size(); }
addIdentifier(const Identifier & i)407         void addIdentifier(const Identifier& i) { return m_identifiers.append(i); }
identifier(int index)408         Identifier& identifier(int index) { return m_identifiers[index]; }
409 
numberOfConstantRegisters()410         size_t numberOfConstantRegisters() const { return m_constantRegisters.size(); }
addConstant(JSValue v)411         void addConstant(JSValue v)
412         {
413             m_constantRegisters.append(WriteBarrier<Unknown>());
414             m_constantRegisters.last().set(m_globalObject->globalData(), m_ownerExecutable.get(), v);
415         }
constantRegister(int index)416         WriteBarrier<Unknown>& constantRegister(int index) { return m_constantRegisters[index - FirstConstantRegisterIndex]; }
isConstantRegisterIndex(int index)417         ALWAYS_INLINE bool isConstantRegisterIndex(int index) const { return index >= FirstConstantRegisterIndex; }
getConstant(int index)418         ALWAYS_INLINE JSValue getConstant(int index) const { return m_constantRegisters[index - FirstConstantRegisterIndex].get(); }
419 
addFunctionDecl(FunctionExecutable * n)420         unsigned addFunctionDecl(FunctionExecutable* n)
421         {
422             unsigned size = m_functionDecls.size();
423             m_functionDecls.append(WriteBarrier<FunctionExecutable>());
424             m_functionDecls.last().set(m_globalObject->globalData(), m_ownerExecutable.get(), n);
425             return size;
426         }
functionDecl(int index)427         FunctionExecutable* functionDecl(int index) { return m_functionDecls[index].get(); }
numberOfFunctionDecls()428         int numberOfFunctionDecls() { return m_functionDecls.size(); }
addFunctionExpr(FunctionExecutable * n)429         unsigned addFunctionExpr(FunctionExecutable* n)
430         {
431             unsigned size = m_functionExprs.size();
432             m_functionExprs.append(WriteBarrier<FunctionExecutable>());
433             m_functionExprs.last().set(m_globalObject->globalData(), m_ownerExecutable.get(), n);
434             return size;
435         }
functionExpr(int index)436         FunctionExecutable* functionExpr(int index) { return m_functionExprs[index].get(); }
437 
addRegExp(PassRefPtr<RegExp> r)438         unsigned addRegExp(PassRefPtr<RegExp> r) { createRareDataIfNecessary(); unsigned size = m_rareData->m_regexps.size(); m_rareData->m_regexps.append(r); return size; }
regexp(int index)439         RegExp* regexp(int index) const { ASSERT(m_rareData); return m_rareData->m_regexps[index].get(); }
440 
globalObject()441         JSGlobalObject* globalObject() { return m_globalObject.get(); }
442 
443         // Jump Tables
444 
numberOfImmediateSwitchJumpTables()445         size_t numberOfImmediateSwitchJumpTables() const { return m_rareData ? m_rareData->m_immediateSwitchJumpTables.size() : 0; }
addImmediateSwitchJumpTable()446         SimpleJumpTable& addImmediateSwitchJumpTable() { createRareDataIfNecessary(); m_rareData->m_immediateSwitchJumpTables.append(SimpleJumpTable()); return m_rareData->m_immediateSwitchJumpTables.last(); }
immediateSwitchJumpTable(int tableIndex)447         SimpleJumpTable& immediateSwitchJumpTable(int tableIndex) { ASSERT(m_rareData); return m_rareData->m_immediateSwitchJumpTables[tableIndex]; }
448 
numberOfCharacterSwitchJumpTables()449         size_t numberOfCharacterSwitchJumpTables() const { return m_rareData ? m_rareData->m_characterSwitchJumpTables.size() : 0; }
addCharacterSwitchJumpTable()450         SimpleJumpTable& addCharacterSwitchJumpTable() { createRareDataIfNecessary(); m_rareData->m_characterSwitchJumpTables.append(SimpleJumpTable()); return m_rareData->m_characterSwitchJumpTables.last(); }
characterSwitchJumpTable(int tableIndex)451         SimpleJumpTable& characterSwitchJumpTable(int tableIndex) { ASSERT(m_rareData); return m_rareData->m_characterSwitchJumpTables[tableIndex]; }
452 
numberOfStringSwitchJumpTables()453         size_t numberOfStringSwitchJumpTables() const { return m_rareData ? m_rareData->m_stringSwitchJumpTables.size() : 0; }
addStringSwitchJumpTable()454         StringJumpTable& addStringSwitchJumpTable() { createRareDataIfNecessary(); m_rareData->m_stringSwitchJumpTables.append(StringJumpTable()); return m_rareData->m_stringSwitchJumpTables.last(); }
stringSwitchJumpTable(int tableIndex)455         StringJumpTable& stringSwitchJumpTable(int tableIndex) { ASSERT(m_rareData); return m_rareData->m_stringSwitchJumpTables[tableIndex]; }
456 
457 
symbolTable()458         SymbolTable* symbolTable() { return m_symbolTable; }
sharedSymbolTable()459         SharedSymbolTable* sharedSymbolTable() { ASSERT(m_codeType == FunctionCode); return static_cast<SharedSymbolTable*>(m_symbolTable); }
460 
evalCodeCache()461         EvalCodeCache& evalCodeCache() { createRareDataIfNecessary(); return m_rareData->m_evalCodeCache; }
462 
463         void shrinkToFit();
464 
465         // FIXME: Make these remaining members private.
466 
467         int m_numCalleeRegisters;
468         int m_numVars;
469         int m_numCapturedVars;
470         int m_numParameters;
471         bool m_isConstructor;
472 
473     private:
474 #if !defined(NDEBUG) || ENABLE(OPCODE_SAMPLING)
475         void dump(ExecState*, const Vector<Instruction>::const_iterator& begin, Vector<Instruction>::const_iterator&) const;
476 
477         CString registerName(ExecState*, int r) const;
478         void printUnaryOp(ExecState*, int location, Vector<Instruction>::const_iterator&, const char* op) const;
479         void printBinaryOp(ExecState*, int location, Vector<Instruction>::const_iterator&, const char* op) const;
480         void printConditionalJump(ExecState*, const Vector<Instruction>::const_iterator&, Vector<Instruction>::const_iterator&, int location, const char* op) const;
481         void printGetByIdOp(ExecState*, int location, Vector<Instruction>::const_iterator&, const char* op) const;
482         void printPutByIdOp(ExecState*, int location, Vector<Instruction>::const_iterator&, const char* op) const;
483 #endif
484         void markStructures(MarkStack&, Instruction* vPC) const;
485 
createRareDataIfNecessary()486         void createRareDataIfNecessary()
487         {
488             if (!m_rareData)
489                 m_rareData = adoptPtr(new RareData);
490         }
491 
492         WriteBarrier<ScriptExecutable> m_ownerExecutable;
493         JSGlobalData* m_globalData;
494 
495         Vector<Instruction> m_instructions;
496 #ifndef NDEBUG
497         unsigned m_instructionCount;
498 #endif
499 
500         int m_thisRegister;
501         int m_argumentsRegister;
502         int m_activationRegister;
503 
504         bool m_needsFullScopeChain;
505         bool m_usesEval;
506         bool m_isNumericCompareFunction;
507         bool m_isStrictMode;
508 
509         CodeType m_codeType;
510 
511         RefPtr<SourceProvider> m_source;
512         unsigned m_sourceOffset;
513 
514 #if ENABLE(INTERPRETER)
515         Vector<unsigned> m_propertyAccessInstructions;
516         Vector<unsigned> m_globalResolveInstructions;
517 #endif
518 #if ENABLE(JIT)
519         Vector<StructureStubInfo> m_structureStubInfos;
520         Vector<GlobalResolveInfo> m_globalResolveInfos;
521         Vector<CallLinkInfo> m_callLinkInfos;
522         Vector<MethodCallLinkInfo> m_methodCallLinkInfos;
523 #endif
524 
525         Vector<unsigned> m_jumpTargets;
526 
527         // Constant Pool
528         Vector<Identifier> m_identifiers;
529         COMPILE_ASSERT(sizeof(Register) == sizeof(WriteBarrier<Unknown>), Register_must_be_same_size_as_WriteBarrier_Unknown);
530         Vector<WriteBarrier<Unknown> > m_constantRegisters;
531         Vector<WriteBarrier<FunctionExecutable> > m_functionDecls;
532         Vector<WriteBarrier<FunctionExecutable> > m_functionExprs;
533 
534         SymbolTable* m_symbolTable;
535 
536         struct RareData {
537            WTF_MAKE_FAST_ALLOCATED;
538         public:
539             Vector<HandlerInfo> m_exceptionHandlers;
540 
541             // Rare Constants
542             Vector<RefPtr<RegExp> > m_regexps;
543 
544             // Jump Tables
545             Vector<SimpleJumpTable> m_immediateSwitchJumpTables;
546             Vector<SimpleJumpTable> m_characterSwitchJumpTables;
547             Vector<StringJumpTable> m_stringSwitchJumpTables;
548 
549             EvalCodeCache m_evalCodeCache;
550 
551             // Expression info - present if debugging.
552             Vector<ExpressionRangeInfo> m_expressionInfo;
553             // Line info - present if profiling or debugging.
554             Vector<LineInfo> m_lineInfo;
555 #if ENABLE(JIT)
556             Vector<CallReturnOffsetToBytecodeOffset> m_callReturnIndexVector;
557 #endif
558         };
559 #if COMPILER(MSVC)
560         friend void WTF::deleteOwnedPtr<RareData>(RareData*);
561 #endif
562         OwnPtr<RareData> m_rareData;
563     };
564 
565     // Program code is not marked by any function, so we make the global object
566     // responsible for marking it.
567 
568     class GlobalCodeBlock : public CodeBlock {
569     public:
GlobalCodeBlock(ScriptExecutable * ownerExecutable,CodeType codeType,JSGlobalObject * globalObject,PassRefPtr<SourceProvider> sourceProvider,unsigned sourceOffset)570         GlobalCodeBlock(ScriptExecutable* ownerExecutable, CodeType codeType, JSGlobalObject* globalObject, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset)
571             : CodeBlock(ownerExecutable, codeType, globalObject, sourceProvider, sourceOffset, &m_unsharedSymbolTable, false)
572         {
573         }
574 
575     private:
576         SymbolTable m_unsharedSymbolTable;
577     };
578 
579     class ProgramCodeBlock : public GlobalCodeBlock {
580     public:
ProgramCodeBlock(ProgramExecutable * ownerExecutable,CodeType codeType,JSGlobalObject * globalObject,PassRefPtr<SourceProvider> sourceProvider)581         ProgramCodeBlock(ProgramExecutable* ownerExecutable, CodeType codeType, JSGlobalObject* globalObject, PassRefPtr<SourceProvider> sourceProvider)
582             : GlobalCodeBlock(ownerExecutable, codeType, globalObject, sourceProvider, 0)
583         {
584         }
585     };
586 
587     class EvalCodeBlock : public GlobalCodeBlock {
588     public:
EvalCodeBlock(EvalExecutable * ownerExecutable,JSGlobalObject * globalObject,PassRefPtr<SourceProvider> sourceProvider,int baseScopeDepth)589         EvalCodeBlock(EvalExecutable* ownerExecutable, JSGlobalObject* globalObject, PassRefPtr<SourceProvider> sourceProvider, int baseScopeDepth)
590             : GlobalCodeBlock(ownerExecutable, EvalCode, globalObject, sourceProvider, 0)
591             , m_baseScopeDepth(baseScopeDepth)
592         {
593         }
594 
baseScopeDepth()595         int baseScopeDepth() const { return m_baseScopeDepth; }
596 
variable(unsigned index)597         const Identifier& variable(unsigned index) { return m_variables[index]; }
numVariables()598         unsigned numVariables() { return m_variables.size(); }
adoptVariables(Vector<Identifier> & variables)599         void adoptVariables(Vector<Identifier>& variables)
600         {
601             ASSERT(m_variables.isEmpty());
602             m_variables.swap(variables);
603         }
604 
605     private:
606         int m_baseScopeDepth;
607         Vector<Identifier> m_variables;
608     };
609 
610     class FunctionCodeBlock : public CodeBlock {
611     public:
612         // Rather than using the usual RefCounted::create idiom for SharedSymbolTable we just use new
613         // as we need to initialise the CodeBlock before we could initialise any RefPtr to hold the shared
614         // symbol table, so we just pass as a raw pointer with a ref count of 1.  We then manually deref
615         // in the destructor.
FunctionCodeBlock(FunctionExecutable * ownerExecutable,CodeType codeType,JSGlobalObject * globalObject,PassRefPtr<SourceProvider> sourceProvider,unsigned sourceOffset,bool isConstructor)616         FunctionCodeBlock(FunctionExecutable* ownerExecutable, CodeType codeType, JSGlobalObject* globalObject, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset, bool isConstructor)
617             : CodeBlock(ownerExecutable, codeType, globalObject, sourceProvider, sourceOffset, SharedSymbolTable::create().leakRef(), isConstructor)
618         {
619         }
~FunctionCodeBlock()620         ~FunctionCodeBlock()
621         {
622             sharedSymbolTable()->deref();
623         }
624     };
625 
r(int index)626     inline Register& ExecState::r(int index)
627     {
628         CodeBlock* codeBlock = this->codeBlock();
629         if (codeBlock->isConstantRegisterIndex(index))
630             return *reinterpret_cast<Register*>(&codeBlock->constantRegister(index));
631         return this[index];
632     }
633 
uncheckedR(int index)634     inline Register& ExecState::uncheckedR(int index)
635     {
636         ASSERT(index < FirstConstantRegisterIndex);
637         return this[index];
638     }
639 
640 } // namespace JSC
641 
642 #endif // CodeBlock_h
643