bytecode/CodeBlock.h

   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 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/RefPtr.h>
  43 #include <wtf/Vector.h>
  44
  45 #if ENABLE(JIT)
  46 #include "StructureStubInfo.h"
  47 #endif
  48
  49 // Register numbers used in bytecode operations have different meaning accoring to their ranges:
  50 //      0x80000000-0xFFFFFFFF  Negative indicies from the CallFrame pointer are entries in the call frame, see RegisterFile.h.
  51 //      0x00000000-0x3FFFFFFF  Forwards indices from the CallFrame pointer are local vars and temporaries with the function's callframe.
  52 //      0x40000000-0x7FFFFFFF  Positive indices from 0x40000000 specify entries in the constant pool on the CodeBlock.
  53 static const int FirstConstantRegisterIndex = 0x40000000;
  54
  55 namespace JSC {
  56
  57     enum HasSeenShouldRepatch {
  58         hasSeenShouldRepatch
  59     };
  60
  61     class ExecState;
  62
  63     enum CodeType { GlobalCode, EvalCode, FunctionCode };
  64
  65     static ALWAYS_INLINE int missingThisObjectMarker() { return std::numeric_limits<int>::max(); }
  66
  67     struct HandlerInfo {
  68         uint32_t start;
  69         uint32_t end;
  70         uint32_t target;
  71         uint32_t scopeDepth;
  72 #if ENABLE(JIT)
  73         CodeLocationLabel nativeCode;
  74 #endif
  75     };
  76
  77     struct ExpressionRangeInfo {
  78         enum {
  79             MaxOffset = (1 << 7) - 1,
  80             MaxDivot = (1 << 25) - 1
  81         };
  82         uint32_t instructionOffset : 25;
  83         uint32_t divotPoint : 25;
  84         uint32_t startOffset : 7;
  85         uint32_t endOffset : 7;
  86     };
  87
  88     struct LineInfo {
  89         uint32_t instructionOffset;
  90         int32_t lineNumber;
  91     };
  92
  93     // Both op_construct and op_instanceof require a use of op_get_by_id to get
  94     // the prototype property from an object. The exception messages for exceptions
  95     // thrown by these instances op_get_by_id need to reflect this.
  96     struct GetByIdExceptionInfo {
  97         unsigned bytecodeOffset : 31;
  98         bool isOpConstruct : 1;
  99     };
 100
 101 #if ENABLE(JIT)
 102     struct CallLinkInfo {
 103         CallLinkInfo()
 104             : callee(0)
 105             , position(0)
 106             , hasSeenShouldRepatch(0)
 107         {
 108         }
 109
 110         unsigned bytecodeIndex;
 111         CodeLocationNearCall callReturnLocation;
 112         CodeLocationDataLabelPtr hotPathBegin;
 113         CodeLocationNearCall hotPathOther;
 114         CodeBlock* ownerCodeBlock;
 115         CodeBlock* callee;
 116         unsigned position : 31;
 117         unsigned hasSeenShouldRepatch : 1;
 118
 119         void setUnlinked() { callee = 0; }
 120         bool isLinked() { return callee; }
 121
 122         bool seenOnce()
 123         {
 124             return hasSeenShouldRepatch;
 125         }
 126
 127         void setSeen()
 128         {
 129             hasSeenShouldRepatch = true;
 130         }
 131     };
 132
 133     struct MethodCallLinkInfo {
 134         MethodCallLinkInfo()
 135             : cachedStructure(0)
 136             , cachedPrototypeStructure(0)
 137         {
 138         }
 139
 140         bool seenOnce()
 141         {
 142             ASSERT(!cachedStructure);
 143             return cachedPrototypeStructure;
 144         }
 145
 146         void setSeen()
 147         {
 148             ASSERT(!cachedStructure && !cachedPrototypeStructure);
 149             // We use the values of cachedStructure & cachedPrototypeStructure to indicate the
 150             // current state.
 151             //     - In the initial state, both are null.
 152             //     - Once this transition has been taken once, cachedStructure is
 153             //       null and cachedPrototypeStructure is set to a nun-null value.
 154             //     - Once the call is linked both structures are set to non-null values.
 155             cachedPrototypeStructure = (Structure*)1;
 156         }
 157
 158         CodeLocationCall callReturnLocation;
 159         CodeLocationDataLabelPtr structureLabel;
 160         Structure* cachedStructure;
 161         Structure* cachedPrototypeStructure;
 162     };
 163
 164     struct FunctionRegisterInfo {
 165         FunctionRegisterInfo(unsigned bytecodeOffset, int functionRegisterIndex)
 166             : bytecodeOffset(bytecodeOffset)
 167             , functionRegisterIndex(functionRegisterIndex)
 168         {
 169         }
 170
 171         unsigned bytecodeOffset;
 172         int functionRegisterIndex;
 173     };
 174
 175     struct GlobalResolveInfo {
 176         GlobalResolveInfo(unsigned bytecodeOffset)
 177             : structure(0)
 178             , offset(0)
 179             , bytecodeOffset(bytecodeOffset)
 180         {
 181         }
 182
 183         Structure* structure;
 184         unsigned offset;
 185         unsigned bytecodeOffset;
 186     };
 187
 188     // This structure is used to map from a call return location
 189     // (given as an offset in bytes into the JIT code) back to
 190     // the bytecode index of the corresponding bytecode operation.
 191     // This is then used to look up the corresponding handler.
 192     struct CallReturnOffsetToBytecodeIndex {
 193         CallReturnOffsetToBytecodeIndex(unsigned callReturnOffset, unsigned bytecodeIndex)
 194             : callReturnOffset(callReturnOffset)
 195             , bytecodeIndex(bytecodeIndex)
 196         {
 197         }
 198
 199         unsigned callReturnOffset;
 200         unsigned bytecodeIndex;
 201     };
 202
 203     // valueAtPosition helpers for the binaryChop algorithm below.
 204
 205     inline void* getStructureStubInfoReturnLocation(StructureStubInfo* structureStubInfo)
 206     {
 207         return structureStubInfo->callReturnLocation.executableAddress();
 208     }
 209
 210     inline void* getCallLinkInfoReturnLocation(CallLinkInfo* callLinkInfo)
 211     {
 212         return callLinkInfo->callReturnLocation.executableAddress();
 213     }
 214
 215     inline void* getMethodCallLinkInfoReturnLocation(MethodCallLinkInfo* methodCallLinkInfo)
 216     {
 217         return methodCallLinkInfo->callReturnLocation.executableAddress();
 218     }
 219
 220     inline unsigned getCallReturnOffset(CallReturnOffsetToBytecodeIndex* pc)
 221     {
 222         return pc->callReturnOffset;
 223     }
 224
 225     // Binary chop algorithm, calls valueAtPosition on pre-sorted elements in array,
 226     // compares result with key (KeyTypes should be comparable with '--', '<', '>').
 227     // Optimized for cases where the array contains the key, checked by assertions.
 228     template<typename ArrayType, typename KeyType, KeyType(*valueAtPosition)(ArrayType*)>
 229     inline ArrayType* binaryChop(ArrayType* array, size_t size, KeyType key)
 230     {
 231         // The array must contain at least one element (pre-condition, array does conatin key).
 232         // If the array only contains one element, no need to do the comparison.
 233         while (size > 1) {
 234             // Pick an element to check, half way through the array, and read the value.
 235             int pos = (size - 1) >> 1;
 236             KeyType val = valueAtPosition(&array[pos]);
 237
 238             // If the key matches, success!
 239             if (val == key)
 240                 return &array[pos];
 241             // The item we are looking for is smaller than the item being check; reduce the value of 'size',
 242             // chopping off the right hand half of the array.
 243             else if (key < val)
 244                 size = pos;
 245             // Discard all values in the left hand half of the array, up to and including the item at pos.
 246             else {
 247                 size -= (pos + 1);
 248                 array += (pos + 1);
 249             }
 250
 251             // 'size' should never reach zero.
 252             ASSERT(size);
 253         }
 254
 255         // If we reach this point we've chopped down to one element, no need to check it matches
 256         ASSERT(size == 1);
 257         ASSERT(key == valueAtPosition(&array[0]));
 258         return &array[0];
 259     }
 260 #endif
 261
 262     struct ExceptionInfo : FastAllocBase {
 263         Vector<ExpressionRangeInfo> m_expressionInfo;
 264         Vector<LineInfo> m_lineInfo;
 265         Vector<GetByIdExceptionInfo> m_getByIdExceptionInfo;
 266
 267 #if ENABLE(JIT)
 268         Vector<CallReturnOffsetToBytecodeIndex> m_callReturnIndexVector;
 269 #endif
 270     };
 271
 272     class CodeBlock : public FastAllocBase {
 273         friend class JIT;
 274     protected:
 275         CodeBlock(ScriptExecutable* ownerExecutable, CodeType, PassRefPtr<SourceProvider>, unsigned sourceOffset, SymbolTable* symbolTable);
 276     public:
 277         virtual ~CodeBlock();
 278
 279         void markAggregate(MarkStack&);
 280         void refStructures(Instruction* vPC) const;
 281         void derefStructures(Instruction* vPC) const;
 282 #if ENABLE(JIT_OPTIMIZE_CALL)
 283         void unlinkCallers();
 284 #endif
 285
 286         static void dumpStatistics();
 287
 288 #if !defined(NDEBUG) || ENABLE_OPCODE_SAMPLING
 289         void dump(ExecState*) const;
 290         void printStructures(const Instruction*) const;
 291         void printStructure(const char* name, const Instruction*, int operand) const;
 292 #endif
 293
 294         inline bool isKnownNotImmediate(int index)
 295         {
 296             if (index == m_thisRegister)
 297                 return true;
 298
 299             if (isConstantRegisterIndex(index))
 300                 return getConstant(index).isCell();
 301
 302             return false;
 303         }
 304
 305         ALWAYS_INLINE bool isTemporaryRegisterIndex(int index)
 306         {
 307             return index >= m_numVars;
 308         }
 309
 310         HandlerInfo* handlerForBytecodeOffset(unsigned bytecodeOffset);
 311         int lineNumberForBytecodeOffset(CallFrame*, unsigned bytecodeOffset);
 312         int expressionRangeForBytecodeOffset(CallFrame*, unsigned bytecodeOffset, int& divot, int& startOffset, int& endOffset);
 313         bool getByIdExceptionInfoForBytecodeOffset(CallFrame*, unsigned bytecodeOffset, OpcodeID&);
 314
 315 #if ENABLE(JIT)
 316         void addCaller(CallLinkInfo* caller)
 317         {
 318             caller->callee = this;
 319             caller->position = m_linkedCallerList.size();
 320             m_linkedCallerList.append(caller);
 321         }
 322
 323         void removeCaller(CallLinkInfo* caller)
 324         {
 325             unsigned pos = caller->position;
 326             unsigned lastPos = m_linkedCallerList.size() - 1;
 327
 328             if (pos != lastPos) {
 329                 m_linkedCallerList[pos] = m_linkedCallerList[lastPos];
 330                 m_linkedCallerList[pos]->position = pos;
 331             }
 332             m_linkedCallerList.shrink(lastPos);
 333         }
 334
 335         StructureStubInfo& getStubInfo(ReturnAddressPtr returnAddress)
 336         {
 337             return *(binaryChop<StructureStubInfo, void*, getStructureStubInfoReturnLocation>(m_structureStubInfos.begin(), m_structureStubInfos.size(), returnAddress.value()));
 338         }
 339
 340         CallLinkInfo& getCallLinkInfo(ReturnAddressPtr returnAddress)
 341         {
 342             return *(binaryChop<CallLinkInfo, void*, getCallLinkInfoReturnLocation>(m_callLinkInfos.begin(), m_callLinkInfos.size(), returnAddress.value()));
 343         }
 344
 345         MethodCallLinkInfo& getMethodCallLinkInfo(ReturnAddressPtr returnAddress)
 346         {
 347             return *(binaryChop<MethodCallLinkInfo, void*, getMethodCallLinkInfoReturnLocation>(m_methodCallLinkInfos.begin(), m_methodCallLinkInfos.size(), returnAddress.value()));
 348         }
 349
 350         unsigned getBytecodeIndex(CallFrame* callFrame, ReturnAddressPtr returnAddress)
 351         {
 352             reparseForExceptionInfoIfNecessary(callFrame);
 353             return binaryChop<CallReturnOffsetToBytecodeIndex, unsigned, getCallReturnOffset>(callReturnIndexVector().begin(), callReturnIndexVector().size(), ownerExecutable()->generatedJITCode().offsetOf(returnAddress.value()))->bytecodeIndex;
 354         }
 355
 356         bool functionRegisterForBytecodeOffset(unsigned bytecodeOffset, int& functionRegisterIndex);
 357 #endif
 358 #if ENABLE(INTERPRETER)
 359         unsigned bytecodeOffset(CallFrame*, Instruction* returnAddress)
 360         {
 361             return static_cast<Instruction*>(returnAddress) - instructions().begin();
 362         }
 363 #endif
 364
 365         void setIsNumericCompareFunction(bool isNumericCompareFunction) { m_isNumericCompareFunction = isNumericCompareFunction; }
 366         bool isNumericCompareFunction() { return m_isNumericCompareFunction; }
 367
 368         Vector<Instruction>& instructions() { return m_instructions; }
 369         void discardBytecode() { m_instructions.clear(); }
 370
 371 #ifndef NDEBUG
 372         unsigned instructionCount() { return m_instructionCount; }
 373         void setInstructionCount(unsigned instructionCount) { m_instructionCount = instructionCount; }
 374 #endif
 375
 376 #if ENABLE(JIT)
 377         JITCode& getJITCode() { return ownerExecutable()->generatedJITCode(); }
 378         ExecutablePool* executablePool() { return ownerExecutable()->getExecutablePool(); }
 379 #endif
 380
 381         ScriptExecutable* ownerExecutable() const { return m_ownerExecutable; }
 382
 383         void setGlobalData(JSGlobalData* globalData) { m_globalData = globalData; }
 384
 385         void setThisRegister(int thisRegister) { m_thisRegister = thisRegister; }
 386         int thisRegister() const { return m_thisRegister; }
 387
 388         void setNeedsFullScopeChain(bool needsFullScopeChain) { m_needsFullScopeChain = needsFullScopeChain; }
 389         bool needsFullScopeChain() const { return m_needsFullScopeChain; }
 390         void setUsesEval(bool usesEval) { m_usesEval = usesEval; }
 391         bool usesEval() const { return m_usesEval; }
 392         void setUsesArguments(bool usesArguments) { m_usesArguments = usesArguments; }
 393         bool usesArguments() const { return m_usesArguments; }
 394
 395         CodeType codeType() const { return m_codeType; }
 396
 397         SourceProvider* source() const { return m_source.get(); }
 398         unsigned sourceOffset() const { return m_sourceOffset; }
 399
 400         size_t numberOfJumpTargets() const { return m_jumpTargets.size(); }
 401         void addJumpTarget(unsigned jumpTarget) { m_jumpTargets.append(jumpTarget); }
 402         unsigned jumpTarget(int index) const { return m_jumpTargets[index]; }
 403         unsigned lastJumpTarget() const { return m_jumpTargets.last(); }
 404
 405 #if ENABLE(INTERPRETER)
 406         void addPropertyAccessInstruction(unsigned propertyAccessInstruction) { m_propertyAccessInstructions.append(propertyAccessInstruction); }
 407         void addGlobalResolveInstruction(unsigned globalResolveInstruction) { m_globalResolveInstructions.append(globalResolveInstruction); }
 408         bool hasGlobalResolveInstructionAtBytecodeOffset(unsigned bytecodeOffset);
 409 #endif
 410 #if ENABLE(JIT)
 411         size_t numberOfStructureStubInfos() const { return m_structureStubInfos.size(); }
 412         void addStructureStubInfo(const StructureStubInfo& stubInfo) { m_structureStubInfos.append(stubInfo); }
 413         StructureStubInfo& structureStubInfo(int index) { return m_structureStubInfos[index]; }
 414
 415         void addGlobalResolveInfo(unsigned globalResolveInstruction) { m_globalResolveInfos.append(GlobalResolveInfo(globalResolveInstruction)); }
 416         GlobalResolveInfo& globalResolveInfo(int index) { return m_globalResolveInfos[index]; }
 417         bool hasGlobalResolveInfoAtBytecodeOffset(unsigned bytecodeOffset);
 418
 419         size_t numberOfCallLinkInfos() const { return m_callLinkInfos.size(); }
 420         void addCallLinkInfo() { m_callLinkInfos.append(CallLinkInfo()); }
 421         CallLinkInfo& callLinkInfo(int index) { return m_callLinkInfos[index]; }
 422
 423         void addMethodCallLinkInfos(unsigned n) { m_methodCallLinkInfos.grow(n); }
 424         MethodCallLinkInfo& methodCallLinkInfo(int index) { return m_methodCallLinkInfos[index]; }
 425
 426         void addFunctionRegisterInfo(unsigned bytecodeOffset, int functionIndex) { createRareDataIfNecessary(); m_rareData->m_functionRegisterInfos.append(FunctionRegisterInfo(bytecodeOffset, functionIndex)); }
 427 #endif
 428
 429         // Exception handling support
 430
 431         size_t numberOfExceptionHandlers() const { return m_rareData ? m_rareData->m_exceptionHandlers.size() : 0; }
 432         void addExceptionHandler(const HandlerInfo& hanler) { createRareDataIfNecessary(); return m_rareData->m_exceptionHandlers.append(hanler); }
 433         HandlerInfo& exceptionHandler(int index) { ASSERT(m_rareData); return m_rareData->m_exceptionHandlers[index]; }
 434
 435         bool hasExceptionInfo() const { return m_exceptionInfo; }
 436         void clearExceptionInfo() { m_exceptionInfo.clear(); }
 437         ExceptionInfo* extractExceptionInfo() { ASSERT(m_exceptionInfo); return m_exceptionInfo.release(); }
 438
 439         void addExpressionInfo(const ExpressionRangeInfo& expressionInfo) { ASSERT(m_exceptionInfo); m_exceptionInfo->m_expressionInfo.append(expressionInfo); }
 440         void addGetByIdExceptionInfo(const GetByIdExceptionInfo& info) { ASSERT(m_exceptionInfo); m_exceptionInfo->m_getByIdExceptionInfo.append(info); }
 441
 442         size_t numberOfLineInfos() const { ASSERT(m_exceptionInfo); return m_exceptionInfo->m_lineInfo.size(); }
 443         void addLineInfo(const LineInfo& lineInfo) { ASSERT(m_exceptionInfo); m_exceptionInfo->m_lineInfo.append(lineInfo); }
 444         LineInfo& lastLineInfo() { ASSERT(m_exceptionInfo); return m_exceptionInfo->m_lineInfo.last(); }
 445
 446 #if ENABLE(JIT)
 447         Vector<CallReturnOffsetToBytecodeIndex>& callReturnIndexVector() { ASSERT(m_exceptionInfo); return m_exceptionInfo->m_callReturnIndexVector; }
 448 #endif
 449
 450         // Constant Pool
 451
 452         size_t numberOfIdentifiers() const { return m_identifiers.size(); }
 453         void addIdentifier(const Identifier& i) { return m_identifiers.append(i); }
 454         Identifier& identifier(int index) { return m_identifiers[index]; }
 455
 456         size_t numberOfConstantRegisters() const { return m_constantRegisters.size(); }
 457         void addConstantRegister(const Register& r) { return m_constantRegisters.append(r); }
 458         Register& constantRegister(int index) { return m_constantRegisters[index - FirstConstantRegisterIndex]; }
 459         ALWAYS_INLINE bool isConstantRegisterIndex(int index) const { return index >= FirstConstantRegisterIndex; }
 460         ALWAYS_INLINE JSValue getConstant(int index) const { return m_constantRegisters[index - FirstConstantRegisterIndex].jsValue(); }
 461
 462         unsigned addFunctionDecl(NonNullPassRefPtr<FunctionExecutable> n) { unsigned size = m_functionDecls.size(); m_functionDecls.append(n); return size; }
 463         FunctionExecutable* functionDecl(int index) { return m_functionDecls[index].get(); }
 464         int numberOfFunctionDecls() { return m_functionDecls.size(); }
 465         unsigned addFunctionExpr(NonNullPassRefPtr<FunctionExecutable> n) { unsigned size = m_functionExprs.size(); m_functionExprs.append(n); return size; }
 466         FunctionExecutable* functionExpr(int index) { return m_functionExprs[index].get(); }
 467
 468         unsigned addRegExp(RegExp* r) { createRareDataIfNecessary(); unsigned size = m_rareData->m_regexps.size(); m_rareData->m_regexps.append(r); return size; }
 469         RegExp* regexp(int index) const { ASSERT(m_rareData); return m_rareData->m_regexps[index].get(); }
 470
 471
 472         // Jump Tables
 473
 474         size_t numberOfImmediateSwitchJumpTables() const { return m_rareData ? m_rareData->m_immediateSwitchJumpTables.size() : 0; }
 475         SimpleJumpTable& addImmediateSwitchJumpTable() { createRareDataIfNecessary(); m_rareData->m_immediateSwitchJumpTables.append(SimpleJumpTable()); return m_rareData->m_immediateSwitchJumpTables.last(); }
 476         SimpleJumpTable& immediateSwitchJumpTable(int tableIndex) { ASSERT(m_rareData); return m_rareData->m_immediateSwitchJumpTables[tableIndex]; }
 477
 478         size_t numberOfCharacterSwitchJumpTables() const { return m_rareData ? m_rareData->m_characterSwitchJumpTables.size() : 0; }
 479         SimpleJumpTable& addCharacterSwitchJumpTable() { createRareDataIfNecessary(); m_rareData->m_characterSwitchJumpTables.append(SimpleJumpTable()); return m_rareData->m_characterSwitchJumpTables.last(); }
 480         SimpleJumpTable& characterSwitchJumpTable(int tableIndex) { ASSERT(m_rareData); return m_rareData->m_characterSwitchJumpTables[tableIndex]; }
 481
 482         size_t numberOfStringSwitchJumpTables() const { return m_rareData ? m_rareData->m_stringSwitchJumpTables.size() : 0; }
 483         StringJumpTable& addStringSwitchJumpTable() { createRareDataIfNecessary(); m_rareData->m_stringSwitchJumpTables.append(StringJumpTable()); return m_rareData->m_stringSwitchJumpTables.last(); }
 484         StringJumpTable& stringSwitchJumpTable(int tableIndex) { ASSERT(m_rareData); return m_rareData->m_stringSwitchJumpTables[tableIndex]; }
 485
 486
 487         SymbolTable* symbolTable() { return m_symbolTable; }
 488         SharedSymbolTable* sharedSymbolTable() { ASSERT(m_codeType == FunctionCode); return static_cast<SharedSymbolTable*>(m_symbolTable); }
 489
 490         EvalCodeCache& evalCodeCache() { createRareDataIfNecessary(); return m_rareData->m_evalCodeCache; }
 491
 492         void shrinkToFit();
 493
 494         // FIXME: Make these remaining members private.
 495
 496         int m_numCalleeRegisters;
 497         int m_numVars;
 498         int m_numParameters;
 499
 500     private:
 501 #if !defined(NDEBUG) || ENABLE(OPCODE_SAMPLING)
 502         void dump(ExecState*, const Vector<Instruction>::const_iterator& begin, Vector<Instruction>::const_iterator&) const;
 503
 504         CString registerName(ExecState*, int r) const;
 505         void printUnaryOp(ExecState*, int location, Vector<Instruction>::const_iterator&, const char* op) const;
 506         void printBinaryOp(ExecState*, int location, Vector<Instruction>::const_iterator&, const char* op) const;
 507         void printConditionalJump(ExecState*, const Vector<Instruction>::const_iterator&, Vector<Instruction>::const_iterator&, int location, const char* op) const;
 508         void printGetByIdOp(ExecState*, int location, Vector<Instruction>::const_iterator&, const char* op) const;
 509         void printPutByIdOp(ExecState*, int location, Vector<Instruction>::const_iterator&, const char* op) const;
 510 #endif
 511
 512         void reparseForExceptionInfoIfNecessary(CallFrame*);
 513
 514         void createRareDataIfNecessary()
 515         {
 516             if (!m_rareData)
 517                 m_rareData.set(new RareData);
 518         }
 519
 520         ScriptExecutable* m_ownerExecutable;
 521         JSGlobalData* m_globalData;
 522
 523         Vector<Instruction> m_instructions;
 524 #ifndef NDEBUG
 525         unsigned m_instructionCount;
 526 #endif
 527
 528         int m_thisRegister;
 529
 530         bool m_needsFullScopeChain;
 531         bool m_usesEval;
 532         bool m_usesArguments;
 533         bool m_isNumericCompareFunction;
 534
 535         CodeType m_codeType;
 536
 537         RefPtr<SourceProvider> m_source;
 538         unsigned m_sourceOffset;
 539
 540 #if ENABLE(INTERPRETER)
 541         Vector<unsigned> m_propertyAccessInstructions;
 542         Vector<unsigned> m_globalResolveInstructions;
 543 #endif
 544 #if ENABLE(JIT)
 545         Vector<StructureStubInfo> m_structureStubInfos;
 546         Vector<GlobalResolveInfo> m_globalResolveInfos;
 547         Vector<CallLinkInfo> m_callLinkInfos;
 548         Vector<MethodCallLinkInfo> m_methodCallLinkInfos;
 549         Vector<CallLinkInfo*> m_linkedCallerList;
 550 #endif
 551
 552         Vector<unsigned> m_jumpTargets;
 553
 554         // Constant Pool
 555         Vector<Identifier> m_identifiers;
 556         Vector<Register> m_constantRegisters;
 557         Vector<RefPtr<FunctionExecutable> > m_functionDecls;
 558         Vector<RefPtr<FunctionExecutable> > m_functionExprs;
 559
 560         SymbolTable* m_symbolTable;
 561
 562         OwnPtr<ExceptionInfo> m_exceptionInfo;
 563
 564         struct RareData : FastAllocBase {
 565             Vector<HandlerInfo> m_exceptionHandlers;
 566
 567             // Rare Constants
 568             Vector<RefPtr<RegExp> > m_regexps;
 569
 570             // Jump Tables
 571             Vector<SimpleJumpTable> m_immediateSwitchJumpTables;
 572             Vector<SimpleJumpTable> m_characterSwitchJumpTables;
 573             Vector<StringJumpTable> m_stringSwitchJumpTables;
 574
 575             EvalCodeCache m_evalCodeCache;
 576
 577 #if ENABLE(JIT)
 578             Vector<FunctionRegisterInfo> m_functionRegisterInfos;
 579 #endif
 580         };
 581         OwnPtr<RareData> m_rareData;
 582     };
 583
 584     // Program code is not marked by any function, so we make the global object
 585     // responsible for marking it.
 586
 587     class GlobalCodeBlock : public CodeBlock {
 588     public:
 589         GlobalCodeBlock(ScriptExecutable* ownerExecutable, CodeType codeType, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset, JSGlobalObject* globalObject)
 590             : CodeBlock(ownerExecutable, codeType, sourceProvider, sourceOffset, &m_unsharedSymbolTable)
 591             , m_globalObject(globalObject)
 592         {
 593             m_globalObject->codeBlocks().add(this);
 594         }
 595
 596         ~GlobalCodeBlock()
 597         {
 598             if (m_globalObject)
 599                 m_globalObject->codeBlocks().remove(this);
 600         }
 601
 602         void clearGlobalObject() { m_globalObject = 0; }
 603
 604     private:
 605         JSGlobalObject* m_globalObject; // For program and eval nodes, the global object that marks the constant pool.
 606         SymbolTable m_unsharedSymbolTable;
 607     };
 608
 609     class ProgramCodeBlock : public GlobalCodeBlock {
 610     public:
 611         ProgramCodeBlock(ProgramExecutable* ownerExecutable, CodeType codeType, JSGlobalObject* globalObject, PassRefPtr<SourceProvider> sourceProvider)
 612             : GlobalCodeBlock(ownerExecutable, codeType, sourceProvider, 0, globalObject)
 613         {
 614         }
 615     };
 616
 617     class EvalCodeBlock : public GlobalCodeBlock {
 618     public:
 619         EvalCodeBlock(EvalExecutable* ownerExecutable, JSGlobalObject* globalObject, PassRefPtr<SourceProvider> sourceProvider, int baseScopeDepth)
 620             : GlobalCodeBlock(ownerExecutable, EvalCode, sourceProvider, 0, globalObject)
 621             , m_baseScopeDepth(baseScopeDepth)
 622         {
 623         }
 624
 625         int baseScopeDepth() const { return m_baseScopeDepth; }
 626
 627         const Identifier& variable(unsigned index) { return m_variables[index]; }
 628         unsigned numVariables() { return m_variables.size(); }
 629         void adoptVariables(Vector<Identifier>& variables)
 630         {
 631             ASSERT(m_variables.isEmpty());
 632             m_variables.swap(variables);
 633         }
 634
 635     private:
 636         int m_baseScopeDepth;
 637         Vector<Identifier> m_variables;
 638     };
 639
 640     class FunctionCodeBlock : public CodeBlock {
 641     public:
 642         // Rather than using the usual RefCounted::create idiom for SharedSymbolTable we just use new
 643         // as we need to initialise the CodeBlock before we could initialise any RefPtr to hold the shared
 644         // symbol table, so we just pass as a raw pointer with a ref count of 1.  We then manually deref
 645         // in the destructor.
 646         FunctionCodeBlock(FunctionExecutable* ownerExecutable, CodeType codeType, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset)
 647             : CodeBlock(ownerExecutable, codeType, sourceProvider, sourceOffset, new SharedSymbolTable)
 648         {
 649         }
 650         ~FunctionCodeBlock()
 651         {
 652             sharedSymbolTable()->deref();
 653         }
 654     };
 655
 656     inline Register& ExecState::r(int index)
 657     {
 658         CodeBlock* codeBlock = this->codeBlock();
 659         if (codeBlock->isConstantRegisterIndex(index))
 660             return codeBlock->constantRegister(index);
 661         return this[index];
 662     }
 663
 664 } // namespace JSC
 665
 666 #endif // CodeBlock_h