bytecode/CodeBlock.h

   1 /*
   2  * Copyright (C) 2008, 2009, 2010, 2011, 2012, 2013, 2014 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 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 "ArrayProfile.h"
  34 #include "ByValInfo.h"
  35 #include "BytecodeConventions.h"
  36 #include "BytecodeLivenessAnalysis.h"
  37 #include "CallLinkInfo.h"
  38 #include "CallReturnOffsetToBytecodeOffset.h"
  39 #include "CodeBlockHash.h"
  40 #include "CodeBlockSet.h"
  41 #include "ConcurrentJITLock.h"
  42 #include "CodeOrigin.h"
  43 #include "CodeType.h"
  44 #include "CompactJITCodeMap.h"
  45 #include "DFGCommon.h"
  46 #include "DFGCommonData.h"
  47 #include "DFGExitProfile.h"
  48 #include "DeferredCompilationCallback.h"
  49 #include "EvalCodeCache.h"
  50 #include "ExecutionCounter.h"
  51 #include "ExpressionRangeInfo.h"
  52 #include "HandlerInfo.h"
  53 #include "ObjectAllocationProfile.h"
  54 #include "Options.h"
  55 #include "PutPropertySlot.h"
  56 #include "Instruction.h"
  57 #include "JITCode.h"
  58 #include "JITWriteBarrier.h"
  59 #include "JSGlobalObject.h"
  60 #include "JumpTable.h"
  61 #include "LLIntCallLinkInfo.h"
  62 #include "LazyOperandValueProfile.h"
  63 #include "ProfilerCompilation.h"
  64 #include "ProfilerJettisonReason.h"
  65 #include "RegExpObject.h"
  66 #include "StructureStubInfo.h"
  67 #include "UnconditionalFinalizer.h"
  68 #include "ValueProfile.h"
  69 #include "VirtualRegister.h"
  70 #include "Watchpoint.h"
  71 #include <wtf/Bag.h>
  72 #include <wtf/FastMalloc.h>
  73 #include <wtf/PassOwnPtr.h>
  74 #include <wtf/RefCountedArray.h>
  75 #include <wtf/RefPtr.h>
  76 #include <wtf/SegmentedVector.h>
  77 #include <wtf/Vector.h>
  78 #include <wtf/text/WTFString.h>
  79
  80 namespace JSC {
  81
  82 class ExecState;
  83 class LLIntOffsetsExtractor;
  84 class RepatchBuffer;
  85
  86 inline VirtualRegister unmodifiedArgumentsRegister(VirtualRegister argumentsRegister) { return VirtualRegister(argumentsRegister.offset() + 1); }
  87
  88 static ALWAYS_INLINE int missingThisObjectMarker() { return std::numeric_limits<int>::max(); }
  89
  90 enum ReoptimizationMode { DontCountReoptimization, CountReoptimization };
  91
  92 class CodeBlock : public ThreadSafeRefCounted<CodeBlock>, public UnconditionalFinalizer, public WeakReferenceHarvester {
  93     WTF_MAKE_FAST_ALLOCATED;
  94     friend class BytecodeLivenessAnalysis;
  95     friend class JIT;
  96     friend class LLIntOffsetsExtractor;
  97 public:
  98     enum CopyParsedBlockTag { CopyParsedBlock };
  99 protected:
 100     CodeBlock(CopyParsedBlockTag, CodeBlock& other);
 101
 102     CodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock*, JSScope*, PassRefPtr<SourceProvider>, unsigned sourceOffset, unsigned firstLineColumnOffset);
 103
 104     WriteBarrier<JSGlobalObject> m_globalObject;
 105     Heap* m_heap;
 106
 107 public:
 108     JS_EXPORT_PRIVATE virtual ~CodeBlock();
 109
 110     UnlinkedCodeBlock* unlinkedCodeBlock() const { return m_unlinkedCode.get(); }
 111
 112     CString inferredName() const;
 113     CodeBlockHash hash() const;
 114     bool hasHash() const;
 115     bool isSafeToComputeHash() const;
 116     CString hashAsStringIfPossible() const;
 117     CString sourceCodeForTools() const; // Not quite the actual source we parsed; this will do things like prefix the source for a function with a reified signature.
 118     CString sourceCodeOnOneLine() const; // As sourceCodeForTools(), but replaces all whitespace runs with a single space.
 119     void dumpAssumingJITType(PrintStream&, JITCode::JITType) const;
 120     void dump(PrintStream&) const;
 121
 122     int numParameters() const { return m_numParameters; }
 123     void setNumParameters(int newValue);
 124
 125     int* addressOfNumParameters() { return &m_numParameters; }
 126     static ptrdiff_t offsetOfNumParameters() { return OBJECT_OFFSETOF(CodeBlock, m_numParameters); }
 127
 128     CodeBlock* alternative() { return m_alternative.get(); }
 129     PassRefPtr<CodeBlock> releaseAlternative() { return m_alternative.release(); }
 130     void setAlternative(PassRefPtr<CodeBlock> alternative) { m_alternative = alternative; }
 131
 132     template <typename Functor> void forEachRelatedCodeBlock(Functor&& functor)
 133     {
 134         Functor f(std::forward<Functor>(functor));
 135         Vector<CodeBlock*, 4> codeBlocks;
 136         codeBlocks.append(this);
 137
 138         while (!codeBlocks.isEmpty()) {
 139             CodeBlock* currentCodeBlock = codeBlocks.takeLast();
 140             f(currentCodeBlock);
 141
 142             if (CodeBlock* alternative = currentCodeBlock->alternative())
 143                 codeBlocks.append(alternative);
 144             if (CodeBlock* osrEntryBlock = currentCodeBlock->specialOSREntryBlockOrNull())
 145                 codeBlocks.append(osrEntryBlock);
 146         }
 147     }
 148
 149     CodeSpecializationKind specializationKind() const
 150     {
 151         return specializationFromIsConstruct(m_isConstructor);
 152     }
 153
 154     CodeBlock* baselineAlternative();
 155
 156     // FIXME: Get rid of this.
 157     // https://bugs.webkit.org/show_bug.cgi?id=123677
 158     CodeBlock* baselineVersion();
 159
 160     void visitAggregate(SlotVisitor&);
 161
 162     void dumpBytecode(PrintStream& = WTF::dataFile());
 163     void dumpBytecode(
 164         PrintStream&, unsigned bytecodeOffset,
 165         const StubInfoMap& = StubInfoMap(), const CallLinkInfoMap& = CallLinkInfoMap());
 166     void printStructures(PrintStream&, const Instruction*);
 167     void printStructure(PrintStream&, const char* name, const Instruction*, int operand);
 168
 169     bool isStrictMode() const { return m_isStrictMode; }
 170     ECMAMode ecmaMode() const { return isStrictMode() ? StrictMode : NotStrictMode; }
 171
 172     inline bool isKnownNotImmediate(int index)
 173     {
 174         if (index == m_thisRegister.offset() && !m_isStrictMode)
 175             return true;
 176
 177         if (isConstantRegisterIndex(index))
 178             return getConstant(index).isCell();
 179
 180         return false;
 181     }
 182
 183     ALWAYS_INLINE bool isTemporaryRegisterIndex(int index)
 184     {
 185         return index >= m_numVars;
 186     }
 187
 188     HandlerInfo* handlerForBytecodeOffset(unsigned bytecodeOffset);
 189     unsigned lineNumberForBytecodeOffset(unsigned bytecodeOffset);
 190     unsigned columnNumberForBytecodeOffset(unsigned bytecodeOffset);
 191     void expressionRangeForBytecodeOffset(unsigned bytecodeOffset, int& divot,
 192                                           int& startOffset, int& endOffset, unsigned& line, unsigned& column);
 193
 194     void getStubInfoMap(const ConcurrentJITLocker&, StubInfoMap& result);
 195     void getStubInfoMap(StubInfoMap& result);
 196
 197     void getCallLinkInfoMap(const ConcurrentJITLocker&, CallLinkInfoMap& result);
 198     void getCallLinkInfoMap(CallLinkInfoMap& result);
 199
 200 #if ENABLE(JIT)
 201     StructureStubInfo* addStubInfo();
 202     Bag<StructureStubInfo>::iterator stubInfoBegin() { return m_stubInfos.begin(); }
 203     Bag<StructureStubInfo>::iterator stubInfoEnd() { return m_stubInfos.end(); }
 204
 205     void resetStub(StructureStubInfo&);
 206
 207     ByValInfo& getByValInfo(unsigned bytecodeIndex)
 208     {
 209         return *(binarySearch<ByValInfo, unsigned>(m_byValInfos, m_byValInfos.size(), bytecodeIndex, getByValInfoBytecodeIndex));
 210     }
 211
 212     CallLinkInfo* addCallLinkInfo();
 213     Bag<CallLinkInfo>::iterator callLinkInfosBegin() { return m_callLinkInfos.begin(); }
 214     Bag<CallLinkInfo>::iterator callLinkInfosEnd() { return m_callLinkInfos.end(); }
 215
 216     // This is a slow function call used primarily for compiling OSR exits in the case
 217     // that there had been inlining. Chances are if you want to use this, you're really
 218     // looking for a CallLinkInfoMap to amortize the cost of calling this.
 219     CallLinkInfo* getCallLinkInfoForBytecodeIndex(unsigned bytecodeIndex);
 220 #endif // ENABLE(JIT)
 221
 222     void unlinkIncomingCalls();
 223
 224 #if ENABLE(JIT)
 225     void unlinkCalls();
 226
 227     void linkIncomingCall(ExecState* callerFrame, CallLinkInfo*);
 228
 229     bool isIncomingCallAlreadyLinked(CallLinkInfo* incoming)
 230     {
 231         return m_incomingCalls.isOnList(incoming);
 232     }
 233 #endif // ENABLE(JIT)
 234
 235     void linkIncomingCall(ExecState* callerFrame, LLIntCallLinkInfo*);
 236
 237     void setJITCodeMap(PassOwnPtr<CompactJITCodeMap> jitCodeMap)
 238     {
 239         m_jitCodeMap = jitCodeMap;
 240     }
 241     CompactJITCodeMap* jitCodeMap()
 242     {
 243         return m_jitCodeMap.get();
 244     }
 245
 246     unsigned bytecodeOffset(Instruction* returnAddress)
 247     {
 248         RELEASE_ASSERT(returnAddress >= instructions().begin() && returnAddress < instructions().end());
 249         return static_cast<Instruction*>(returnAddress) - instructions().begin();
 250     }
 251
 252     bool isNumericCompareFunction() { return m_unlinkedCode->isNumericCompareFunction(); }
 253
 254     unsigned numberOfInstructions() const { return m_instructions.size(); }
 255     RefCountedArray<Instruction>& instructions() { return m_instructions; }
 256     const RefCountedArray<Instruction>& instructions() const { return m_instructions; }
 257
 258     size_t predictedMachineCodeSize();
 259
 260     bool usesOpcode(OpcodeID);
 261
 262     unsigned instructionCount() const { return m_instructions.size(); }
 263
 264     int argumentIndexAfterCapture(size_t argument);
 265
 266     bool hasSlowArguments();
 267     const SlowArgument* machineSlowArguments();
 268
 269     // Exactly equivalent to codeBlock->ownerExecutable()->installCode(codeBlock);
 270     void install();
 271
 272     // Exactly equivalent to codeBlock->ownerExecutable()->newReplacementCodeBlockFor(codeBlock->specializationKind())
 273     PassRefPtr<CodeBlock> newReplacement();
 274
 275     void setJITCode(PassRefPtr<JITCode> code)
 276     {
 277         ASSERT(m_heap->isDeferred());
 278         m_heap->reportExtraMemoryCost(code->size());
 279         ConcurrentJITLocker locker(m_lock);
 280         WTF::storeStoreFence(); // This is probably not needed because the lock will also do something similar, but it's good to be paranoid.
 281         m_jitCode = code;
 282     }
 283     PassRefPtr<JITCode> jitCode() { return m_jitCode; }
 284     JITCode::JITType jitType() const
 285     {
 286         JITCode* jitCode = m_jitCode.get();
 287         WTF::loadLoadFence();
 288         JITCode::JITType result = JITCode::jitTypeFor(jitCode);
 289         WTF::loadLoadFence(); // This probably isn't needed. Oh well, paranoia is good.
 290         return result;
 291     }
 292
 293     bool hasBaselineJITProfiling() const
 294     {
 295         return jitType() == JITCode::BaselineJIT;
 296     }
 297
 298 #if ENABLE(JIT)
 299     virtual CodeBlock* replacement() = 0;
 300
 301     virtual DFG::CapabilityLevel capabilityLevelInternal() = 0;
 302     DFG::CapabilityLevel capabilityLevel();
 303     DFG::CapabilityLevel capabilityLevelState() { return m_capabilityLevelState; }
 304
 305     bool hasOptimizedReplacement(JITCode::JITType typeToReplace);
 306     bool hasOptimizedReplacement(); // the typeToReplace is my JITType
 307 #endif
 308
 309     void jettison(Profiler::JettisonReason, ReoptimizationMode = DontCountReoptimization);
 310
 311     ScriptExecutable* ownerExecutable() const { return m_ownerExecutable.get(); }
 312
 313     void setVM(VM* vm) { m_vm = vm; }
 314     VM* vm() { return m_vm; }
 315
 316     void setThisRegister(VirtualRegister thisRegister) { m_thisRegister = thisRegister; }
 317     VirtualRegister thisRegister() const { return m_thisRegister; }
 318
 319     bool usesEval() const { return m_unlinkedCode->usesEval(); }
 320
 321     void setArgumentsRegister(VirtualRegister argumentsRegister)
 322     {
 323         ASSERT(argumentsRegister.isValid());
 324         m_argumentsRegister = argumentsRegister;
 325         ASSERT(usesArguments());
 326     }
 327     VirtualRegister argumentsRegister() const
 328     {
 329         ASSERT(usesArguments());
 330         return m_argumentsRegister;
 331     }
 332     VirtualRegister uncheckedArgumentsRegister()
 333     {
 334         if (!usesArguments())
 335             return VirtualRegister();
 336         return argumentsRegister();
 337     }
 338     void setActivationRegister(VirtualRegister activationRegister)
 339     {
 340         m_activationRegister = activationRegister;
 341     }
 342
 343     VirtualRegister activationRegister() const
 344     {
 345         ASSERT(m_activationRegister.isValid());
 346         return m_activationRegister;
 347     }
 348
 349     VirtualRegister uncheckedActivationRegister()
 350     {
 351         return m_activationRegister;
 352     }
 353
 354     bool usesArguments() const { return m_argumentsRegister.isValid(); }
 355
 356     bool needsActivation() const
 357     {
 358         ASSERT(m_activationRegister.isValid() == m_needsActivation);
 359         return m_needsActivation;
 360     }
 361
 362     unsigned captureCount() const
 363     {
 364         if (!symbolTable())
 365             return 0;
 366         return symbolTable()->captureCount();
 367     }
 368
 369     int captureStart() const
 370     {
 371         if (!symbolTable())
 372             return 0;
 373         return symbolTable()->captureStart();
 374     }
 375
 376     int captureEnd() const
 377     {
 378         if (!symbolTable())
 379             return 0;
 380         return symbolTable()->captureEnd();
 381     }
 382
 383     bool isCaptured(VirtualRegister operand, InlineCallFrame* = 0) const;
 384
 385     int framePointerOffsetToGetActivationRegisters(int machineCaptureStart);
 386     int framePointerOffsetToGetActivationRegisters();
 387
 388     CodeType codeType() const { return m_unlinkedCode->codeType(); }
 389     PutPropertySlot::Context putByIdContext() const
 390     {
 391         if (codeType() == EvalCode)
 392             return PutPropertySlot::PutByIdEval;
 393         return PutPropertySlot::PutById;
 394     }
 395
 396     SourceProvider* source() const { return m_source.get(); }
 397     unsigned sourceOffset() const { return m_sourceOffset; }
 398     unsigned firstLineColumnOffset() const { return m_firstLineColumnOffset; }
 399
 400     size_t numberOfJumpTargets() const { return m_unlinkedCode->numberOfJumpTargets(); }
 401     unsigned jumpTarget(int index) const { return m_unlinkedCode->jumpTarget(index); }
 402
 403     void clearEvalCache();
 404
 405     String nameForRegister(VirtualRegister);
 406
 407 #if ENABLE(JIT)
 408     void setNumberOfByValInfos(size_t size) { m_byValInfos.resizeToFit(size); }
 409     size_t numberOfByValInfos() const { return m_byValInfos.size(); }
 410     ByValInfo& byValInfo(size_t index) { return m_byValInfos[index]; }
 411 #endif
 412
 413     unsigned numberOfArgumentValueProfiles()
 414     {
 415         ASSERT(m_numParameters >= 0);
 416         ASSERT(m_argumentValueProfiles.size() == static_cast<unsigned>(m_numParameters));
 417         return m_argumentValueProfiles.size();
 418     }
 419     ValueProfile* valueProfileForArgument(unsigned argumentIndex)
 420     {
 421         ValueProfile* result = &m_argumentValueProfiles[argumentIndex];
 422         ASSERT(result->m_bytecodeOffset == -1);
 423         return result;
 424     }
 425
 426     unsigned numberOfValueProfiles() { return m_valueProfiles.size(); }
 427     ValueProfile* valueProfile(int index) { return &m_valueProfiles[index]; }
 428     ValueProfile* valueProfileForBytecodeOffset(int bytecodeOffset)
 429     {
 430         ValueProfile* result = binarySearch<ValueProfile, int>(
 431             m_valueProfiles, m_valueProfiles.size(), bytecodeOffset,
 432             getValueProfileBytecodeOffset<ValueProfile>);
 433         ASSERT(result->m_bytecodeOffset != -1);
 434         ASSERT(instructions()[bytecodeOffset + opcodeLength(
 435             m_vm->interpreter->getOpcodeID(
 436                 instructions()[bytecodeOffset].u.opcode)) - 1].u.profile == result);
 437         return result;
 438     }
 439     SpeculatedType valueProfilePredictionForBytecodeOffset(const ConcurrentJITLocker& locker, int bytecodeOffset)
 440     {
 441         return valueProfileForBytecodeOffset(bytecodeOffset)->computeUpdatedPrediction(locker);
 442     }
 443
 444     unsigned totalNumberOfValueProfiles()
 445     {
 446         return numberOfArgumentValueProfiles() + numberOfValueProfiles();
 447     }
 448     ValueProfile* getFromAllValueProfiles(unsigned index)
 449     {
 450         if (index < numberOfArgumentValueProfiles())
 451             return valueProfileForArgument(index);
 452         return valueProfile(index - numberOfArgumentValueProfiles());
 453     }
 454
 455     RareCaseProfile* addRareCaseProfile(int bytecodeOffset)
 456     {
 457         m_rareCaseProfiles.append(RareCaseProfile(bytecodeOffset));
 458         return &m_rareCaseProfiles.last();
 459     }
 460     unsigned numberOfRareCaseProfiles() { return m_rareCaseProfiles.size(); }
 461     RareCaseProfile* rareCaseProfile(int index) { return &m_rareCaseProfiles[index]; }
 462     RareCaseProfile* rareCaseProfileForBytecodeOffset(int bytecodeOffset);
 463
 464     bool likelyToTakeSlowCase(int bytecodeOffset)
 465     {
 466         if (!hasBaselineJITProfiling())
 467             return false;
 468         unsigned value = rareCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 469         return value >= Options::likelyToTakeSlowCaseMinimumCount();
 470     }
 471
 472     bool couldTakeSlowCase(int bytecodeOffset)
 473     {
 474         if (!hasBaselineJITProfiling())
 475             return false;
 476         unsigned value = rareCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 477         return value >= Options::couldTakeSlowCaseMinimumCount();
 478     }
 479
 480     RareCaseProfile* addSpecialFastCaseProfile(int bytecodeOffset)
 481     {
 482         m_specialFastCaseProfiles.append(RareCaseProfile(bytecodeOffset));
 483         return &m_specialFastCaseProfiles.last();
 484     }
 485     unsigned numberOfSpecialFastCaseProfiles() { return m_specialFastCaseProfiles.size(); }
 486     RareCaseProfile* specialFastCaseProfile(int index) { return &m_specialFastCaseProfiles[index]; }
 487     RareCaseProfile* specialFastCaseProfileForBytecodeOffset(int bytecodeOffset)
 488     {
 489         return tryBinarySearch<RareCaseProfile, int>(
 490             m_specialFastCaseProfiles, m_specialFastCaseProfiles.size(), bytecodeOffset,
 491             getRareCaseProfileBytecodeOffset);
 492     }
 493
 494     bool likelyToTakeSpecialFastCase(int bytecodeOffset)
 495     {
 496         if (!hasBaselineJITProfiling())
 497             return false;
 498         unsigned specialFastCaseCount = specialFastCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 499         return specialFastCaseCount >= Options::likelyToTakeSlowCaseMinimumCount();
 500     }
 501
 502     bool couldTakeSpecialFastCase(int bytecodeOffset)
 503     {
 504         if (!hasBaselineJITProfiling())
 505             return false;
 506         unsigned specialFastCaseCount = specialFastCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 507         return specialFastCaseCount >= Options::couldTakeSlowCaseMinimumCount();
 508     }
 509
 510     bool likelyToTakeDeepestSlowCase(int bytecodeOffset)
 511     {
 512         if (!hasBaselineJITProfiling())
 513             return false;
 514         unsigned slowCaseCount = rareCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 515         unsigned specialFastCaseCount = specialFastCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 516         unsigned value = slowCaseCount - specialFastCaseCount;
 517         return value >= Options::likelyToTakeSlowCaseMinimumCount();
 518     }
 519
 520     bool likelyToTakeAnySlowCase(int bytecodeOffset)
 521     {
 522         if (!hasBaselineJITProfiling())
 523             return false;
 524         unsigned slowCaseCount = rareCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 525         unsigned specialFastCaseCount = specialFastCaseProfileForBytecodeOffset(bytecodeOffset)->m_counter;
 526         unsigned value = slowCaseCount + specialFastCaseCount;
 527         return value >= Options::likelyToTakeSlowCaseMinimumCount();
 528     }
 529
 530     unsigned numberOfArrayProfiles() const { return m_arrayProfiles.size(); }
 531     const ArrayProfileVector& arrayProfiles() { return m_arrayProfiles; }
 532     ArrayProfile* addArrayProfile(unsigned bytecodeOffset)
 533     {
 534         m_arrayProfiles.append(ArrayProfile(bytecodeOffset));
 535         return &m_arrayProfiles.last();
 536     }
 537     ArrayProfile* getArrayProfile(unsigned bytecodeOffset);
 538     ArrayProfile* getOrAddArrayProfile(unsigned bytecodeOffset);
 539
 540     // Exception handling support
 541
 542     size_t numberOfExceptionHandlers() const { return m_rareData ? m_rareData->m_exceptionHandlers.size() : 0; }
 543     HandlerInfo& exceptionHandler(int index) { RELEASE_ASSERT(m_rareData); return m_rareData->m_exceptionHandlers[index]; }
 544
 545     bool hasExpressionInfo() { return m_unlinkedCode->hasExpressionInfo(); }
 546
 547 #if ENABLE(DFG_JIT)
 548     Vector<CodeOrigin, 0, UnsafeVectorOverflow>& codeOrigins()
 549     {
 550         return m_jitCode->dfgCommon()->codeOrigins;
 551     }
 552
 553     // Having code origins implies that there has been some inlining.
 554     bool hasCodeOrigins()
 555     {
 556         return JITCode::isOptimizingJIT(jitType());
 557     }
 558
 559     bool canGetCodeOrigin(unsigned index)
 560     {
 561         if (!hasCodeOrigins())
 562             return false;
 563         return index < codeOrigins().size();
 564     }
 565
 566     CodeOrigin codeOrigin(unsigned index)
 567     {
 568         return codeOrigins()[index];
 569     }
 570
 571     bool addFrequentExitSite(const DFG::FrequentExitSite& site)
 572     {
 573         ASSERT(JITCode::isBaselineCode(jitType()));
 574         ConcurrentJITLocker locker(m_lock);
 575         return m_exitProfile.add(locker, site);
 576     }
 577
 578     bool hasExitSite(const ConcurrentJITLocker& locker, const DFG::FrequentExitSite& site) const
 579     {
 580         return m_exitProfile.hasExitSite(locker, site);
 581     }
 582     bool hasExitSite(const DFG::FrequentExitSite& site) const
 583     {
 584         ConcurrentJITLocker locker(m_lock);
 585         return hasExitSite(locker, site);
 586     }
 587
 588     DFG::ExitProfile& exitProfile() { return m_exitProfile; }
 589
 590     CompressedLazyOperandValueProfileHolder& lazyOperandValueProfiles()
 591     {
 592         return m_lazyOperandValueProfiles;
 593     }
 594 #endif // ENABLE(DFG_JIT)
 595
 596     // Constant Pool
 597 #if ENABLE(DFG_JIT)
 598     size_t numberOfIdentifiers() const { return m_unlinkedCode->numberOfIdentifiers() + numberOfDFGIdentifiers(); }
 599     size_t numberOfDFGIdentifiers() const
 600     {
 601         if (!JITCode::isOptimizingJIT(jitType()))
 602             return 0;
 603
 604         return m_jitCode->dfgCommon()->dfgIdentifiers.size();
 605     }
 606
 607     const Identifier& identifier(int index) const
 608     {
 609         size_t unlinkedIdentifiers = m_unlinkedCode->numberOfIdentifiers();
 610         if (static_cast<unsigned>(index) < unlinkedIdentifiers)
 611             return m_unlinkedCode->identifier(index);
 612         ASSERT(JITCode::isOptimizingJIT(jitType()));
 613         return m_jitCode->dfgCommon()->dfgIdentifiers[index - unlinkedIdentifiers];
 614     }
 615 #else
 616     size_t numberOfIdentifiers() const { return m_unlinkedCode->numberOfIdentifiers(); }
 617     const Identifier& identifier(int index) const { return m_unlinkedCode->identifier(index); }
 618 #endif
 619
 620     Vector<WriteBarrier<Unknown>>& constants() { return m_constantRegisters; }
 621     size_t numberOfConstantRegisters() const { return m_constantRegisters.size(); }
 622     unsigned addConstant(JSValue v)
 623     {
 624         unsigned result = m_constantRegisters.size();
 625         m_constantRegisters.append(WriteBarrier<Unknown>());
 626         m_constantRegisters.last().set(m_globalObject->vm(), m_ownerExecutable.get(), v);
 627         return result;
 628     }
 629
 630     unsigned addConstantLazily()
 631     {
 632         unsigned result = m_constantRegisters.size();
 633         m_constantRegisters.append(WriteBarrier<Unknown>());
 634         return result;
 635     }
 636
 637     bool findConstant(JSValue, unsigned& result);
 638     unsigned addOrFindConstant(JSValue);
 639     WriteBarrier<Unknown>& constantRegister(int index) { return m_constantRegisters[index - FirstConstantRegisterIndex]; }
 640     ALWAYS_INLINE bool isConstantRegisterIndex(int index) const { return index >= FirstConstantRegisterIndex; }
 641     ALWAYS_INLINE JSValue getConstant(int index) const { return m_constantRegisters[index - FirstConstantRegisterIndex].get(); }
 642
 643     FunctionExecutable* functionDecl(int index) { return m_functionDecls[index].get(); }
 644     int numberOfFunctionDecls() { return m_functionDecls.size(); }
 645     FunctionExecutable* functionExpr(int index) { return m_functionExprs[index].get(); }
 646
 647     RegExp* regexp(int index) const { return m_unlinkedCode->regexp(index); }
 648
 649     unsigned numberOfConstantBuffers() const
 650     {
 651         if (!m_rareData)
 652             return 0;
 653         return m_rareData->m_constantBuffers.size();
 654     }
 655     unsigned addConstantBuffer(const Vector<JSValue>& buffer)
 656     {
 657         createRareDataIfNecessary();
 658         unsigned size = m_rareData->m_constantBuffers.size();
 659         m_rareData->m_constantBuffers.append(buffer);
 660         return size;
 661     }
 662
 663     Vector<JSValue>& constantBufferAsVector(unsigned index)
 664     {
 665         ASSERT(m_rareData);
 666         return m_rareData->m_constantBuffers[index];
 667     }
 668     JSValue* constantBuffer(unsigned index)
 669     {
 670         return constantBufferAsVector(index).data();
 671     }
 672
 673     Heap* heap() const { return m_heap; }
 674     JSGlobalObject* globalObject() { return m_globalObject.get(); }
 675
 676     JSGlobalObject* globalObjectFor(CodeOrigin);
 677
 678     BytecodeLivenessAnalysis& livenessAnalysis()
 679     {
 680         {
 681             ConcurrentJITLocker locker(m_lock);
 682             if (!!m_livenessAnalysis)
 683                 return *m_livenessAnalysis;
 684         }
 685         std::unique_ptr<BytecodeLivenessAnalysis> analysis =
 686             std::make_unique<BytecodeLivenessAnalysis>(this);
 687         {
 688             ConcurrentJITLocker locker(m_lock);
 689             if (!m_livenessAnalysis)
 690                 m_livenessAnalysis = WTF::move(analysis);
 691             return *m_livenessAnalysis;
 692         }
 693     }
 694
 695     void validate();
 696
 697     // Jump Tables
 698
 699     size_t numberOfSwitchJumpTables() const { return m_rareData ? m_rareData->m_switchJumpTables.size() : 0; }
 700     SimpleJumpTable& addSwitchJumpTable() { createRareDataIfNecessary(); m_rareData->m_switchJumpTables.append(SimpleJumpTable()); return m_rareData->m_switchJumpTables.last(); }
 701     SimpleJumpTable& switchJumpTable(int tableIndex) { RELEASE_ASSERT(m_rareData); return m_rareData->m_switchJumpTables[tableIndex]; }
 702     void clearSwitchJumpTables()
 703     {
 704         if (!m_rareData)
 705             return;
 706         m_rareData->m_switchJumpTables.clear();
 707     }
 708
 709     size_t numberOfStringSwitchJumpTables() const { return m_rareData ? m_rareData->m_stringSwitchJumpTables.size() : 0; }
 710     StringJumpTable& addStringSwitchJumpTable() { createRareDataIfNecessary(); m_rareData->m_stringSwitchJumpTables.append(StringJumpTable()); return m_rareData->m_stringSwitchJumpTables.last(); }
 711     StringJumpTable& stringSwitchJumpTable(int tableIndex) { RELEASE_ASSERT(m_rareData); return m_rareData->m_stringSwitchJumpTables[tableIndex]; }
 712
 713
 714     SymbolTable* symbolTable() const { return m_symbolTable.get(); }
 715
 716     EvalCodeCache& evalCodeCache() { createRareDataIfNecessary(); return m_rareData->m_evalCodeCache; }
 717
 718     enum ShrinkMode {
 719         // Shrink prior to generating machine code that may point directly into vectors.
 720         EarlyShrink,
 721
 722         // Shrink after generating machine code, and after possibly creating new vectors
 723         // and appending to others. At this time it is not safe to shrink certain vectors
 724         // because we would have generated machine code that references them directly.
 725         LateShrink
 726     };
 727     void shrinkToFit(ShrinkMode);
 728
 729     // Functions for controlling when JITting kicks in, in a mixed mode
 730     // execution world.
 731
 732     bool checkIfJITThresholdReached()
 733     {
 734         return m_llintExecuteCounter.checkIfThresholdCrossedAndSet(this);
 735     }
 736
 737     void dontJITAnytimeSoon()
 738     {
 739         m_llintExecuteCounter.deferIndefinitely();
 740     }
 741
 742     void jitAfterWarmUp()
 743     {
 744         m_llintExecuteCounter.setNewThreshold(Options::thresholdForJITAfterWarmUp(), this);
 745     }
 746
 747     void jitSoon()
 748     {
 749         m_llintExecuteCounter.setNewThreshold(Options::thresholdForJITSoon(), this);
 750     }
 751
 752     const BaselineExecutionCounter& llintExecuteCounter() const
 753     {
 754         return m_llintExecuteCounter;
 755     }
 756
 757     // Functions for controlling when tiered compilation kicks in. This
 758     // controls both when the optimizing compiler is invoked and when OSR
 759     // entry happens. Two triggers exist: the loop trigger and the return
 760     // trigger. In either case, when an addition to m_jitExecuteCounter
 761     // causes it to become non-negative, the optimizing compiler is
 762     // invoked. This includes a fast check to see if this CodeBlock has
 763     // already been optimized (i.e. replacement() returns a CodeBlock
 764     // that was optimized with a higher tier JIT than this one). In the
 765     // case of the loop trigger, if the optimized compilation succeeds
 766     // (or has already succeeded in the past) then OSR is attempted to
 767     // redirect program flow into the optimized code.
 768
 769     // These functions are called from within the optimization triggers,
 770     // and are used as a single point at which we define the heuristics
 771     // for how much warm-up is mandated before the next optimization
 772     // trigger files. All CodeBlocks start out with optimizeAfterWarmUp(),
 773     // as this is called from the CodeBlock constructor.
 774
 775     // When we observe a lot of speculation failures, we trigger a
 776     // reoptimization. But each time, we increase the optimization trigger
 777     // to avoid thrashing.
 778     JS_EXPORT_PRIVATE unsigned reoptimizationRetryCounter() const;
 779     void countReoptimization();
 780 #if ENABLE(JIT)
 781     unsigned numberOfDFGCompiles();
 782
 783     int32_t codeTypeThresholdMultiplier() const;
 784
 785     int32_t adjustedCounterValue(int32_t desiredThreshold);
 786
 787     int32_t* addressOfJITExecuteCounter()
 788     {
 789         return &m_jitExecuteCounter.m_counter;
 790     }
 791
 792     static ptrdiff_t offsetOfJITExecuteCounter() { return OBJECT_OFFSETOF(CodeBlock, m_jitExecuteCounter) + OBJECT_OFFSETOF(BaselineExecutionCounter, m_counter); }
 793     static ptrdiff_t offsetOfJITExecutionActiveThreshold() { return OBJECT_OFFSETOF(CodeBlock, m_jitExecuteCounter) + OBJECT_OFFSETOF(BaselineExecutionCounter, m_activeThreshold); }
 794     static ptrdiff_t offsetOfJITExecutionTotalCount() { return OBJECT_OFFSETOF(CodeBlock, m_jitExecuteCounter) + OBJECT_OFFSETOF(BaselineExecutionCounter, m_totalCount); }
 795
 796     const BaselineExecutionCounter& jitExecuteCounter() const { return m_jitExecuteCounter; }
 797
 798     unsigned optimizationDelayCounter() const { return m_optimizationDelayCounter; }
 799
 800     // Check if the optimization threshold has been reached, and if not,
 801     // adjust the heuristics accordingly. Returns true if the threshold has
 802     // been reached.
 803     bool checkIfOptimizationThresholdReached();
 804
 805     // Call this to force the next optimization trigger to fire. This is
 806     // rarely wise, since optimization triggers are typically more
 807     // expensive than executing baseline code.
 808     void optimizeNextInvocation();
 809
 810     // Call this to prevent optimization from happening again. Note that
 811     // optimization will still happen after roughly 2^29 invocations,
 812     // so this is really meant to delay that as much as possible. This
 813     // is called if optimization failed, and we expect it to fail in
 814     // the future as well.
 815     void dontOptimizeAnytimeSoon();
 816
 817     // Call this to reinitialize the counter to its starting state,
 818     // forcing a warm-up to happen before the next optimization trigger
 819     // fires. This is called in the CodeBlock constructor. It also
 820     // makes sense to call this if an OSR exit occurred. Note that
 821     // OSR exit code is code generated, so the value of the execute
 822     // counter that this corresponds to is also available directly.
 823     void optimizeAfterWarmUp();
 824
 825     // Call this to force an optimization trigger to fire only after
 826     // a lot of warm-up.
 827     void optimizeAfterLongWarmUp();
 828
 829     // Call this to cause an optimization trigger to fire soon, but
 830     // not necessarily the next one. This makes sense if optimization
 831     // succeeds. Successfuly optimization means that all calls are
 832     // relinked to the optimized code, so this only affects call
 833     // frames that are still executing this CodeBlock. The value here
 834     // is tuned to strike a balance between the cost of OSR entry
 835     // (which is too high to warrant making every loop back edge to
 836     // trigger OSR immediately) and the cost of executing baseline
 837     // code (which is high enough that we don't necessarily want to
 838     // have a full warm-up). The intuition for calling this instead of
 839     // optimizeNextInvocation() is for the case of recursive functions
 840     // with loops. Consider that there may be N call frames of some
 841     // recursive function, for a reasonably large value of N. The top
 842     // one triggers optimization, and then returns, and then all of
 843     // the others return. We don't want optimization to be triggered on
 844     // each return, as that would be superfluous. It only makes sense
 845     // to trigger optimization if one of those functions becomes hot
 846     // in the baseline code.
 847     void optimizeSoon();
 848
 849     void forceOptimizationSlowPathConcurrently();
 850
 851     void setOptimizationThresholdBasedOnCompilationResult(CompilationResult);
 852
 853     uint32_t osrExitCounter() const { return m_osrExitCounter; }
 854
 855     void countOSRExit() { m_osrExitCounter++; }
 856
 857     uint32_t* addressOfOSRExitCounter() { return &m_osrExitCounter; }
 858
 859     static ptrdiff_t offsetOfOSRExitCounter() { return OBJECT_OFFSETOF(CodeBlock, m_osrExitCounter); }
 860
 861     uint32_t adjustedExitCountThreshold(uint32_t desiredThreshold);
 862     uint32_t exitCountThresholdForReoptimization();
 863     uint32_t exitCountThresholdForReoptimizationFromLoop();
 864     bool shouldReoptimizeNow();
 865     bool shouldReoptimizeFromLoopNow();
 866 #else // No JIT
 867     void optimizeAfterWarmUp() { }
 868     unsigned numberOfDFGCompiles() { return 0; }
 869 #endif
 870
 871     bool shouldOptimizeNow();
 872     void updateAllValueProfilePredictions();
 873     void updateAllArrayPredictions();
 874     void updateAllPredictions();
 875
 876     unsigned frameRegisterCount();
 877     int stackPointerOffset();
 878
 879     bool hasOpDebugForLineAndColumn(unsigned line, unsigned column);
 880
 881     bool hasDebuggerRequests() const { return m_debuggerRequests; }
 882     void* debuggerRequestsAddress() { return &m_debuggerRequests; }
 883
 884     void addBreakpoint(unsigned numBreakpoints);
 885     void removeBreakpoint(unsigned numBreakpoints)
 886     {
 887         ASSERT(m_numBreakpoints >= numBreakpoints);
 888         m_numBreakpoints -= numBreakpoints;
 889     }
 890
 891     enum SteppingMode {
 892         SteppingModeDisabled,
 893         SteppingModeEnabled
 894     };
 895     void setSteppingMode(SteppingMode);
 896
 897     void clearDebuggerRequests()
 898     {
 899         m_steppingMode = SteppingModeDisabled;
 900         m_numBreakpoints = 0;
 901     }
 902
 903     // FIXME: Make these remaining members private.
 904
 905     int m_numCalleeRegisters;
 906     int m_numVars;
 907     bool m_isConstructor : 1;
 908
 909     // This is intentionally public; it's the responsibility of anyone doing any
 910     // of the following to hold the lock:
 911     //
 912     // - Modifying any inline cache in this code block.
 913     //
 914     // - Quering any inline cache in this code block, from a thread other than
 915     //   the main thread.
 916     //
 917     // Additionally, it's only legal to modify the inline cache on the main
 918     // thread. This means that the main thread can query the inline cache without
 919     // locking. This is crucial since executing the inline cache is effectively
 920     // "querying" it.
 921     //
 922     // Another exception to the rules is that the GC can do whatever it wants
 923     // without holding any locks, because the GC is guaranteed to wait until any
 924     // concurrent compilation threads finish what they're doing.
 925     mutable ConcurrentJITLock m_lock;
 926
 927     bool m_shouldAlwaysBeInlined; // Not a bitfield because the JIT wants to store to it.
 928     bool m_allTransitionsHaveBeenMarked : 1; // Initialized and used on every GC.
 929
 930     bool m_didFailFTLCompilation : 1;
 931     bool m_hasBeenCompiledWithFTL : 1;
 932
 933     // Internal methods for use by validation code. It would be private if it wasn't
 934     // for the fact that we use it from anonymous namespaces.
 935     void beginValidationDidFail();
 936     NO_RETURN_DUE_TO_CRASH void endValidationDidFail();
 937
 938     bool isKnownToBeLiveDuringGC(); // Will only return valid results when called during GC. Assumes that you've already established that the owner executable is live.
 939
 940 protected:
 941     virtual void visitWeakReferences(SlotVisitor&) override;
 942     virtual void finalizeUnconditionally() override;
 943
 944 #if ENABLE(DFG_JIT)
 945     void tallyFrequentExitSites();
 946 #else
 947     void tallyFrequentExitSites() { }
 948 #endif
 949
 950 private:
 951     friend class CodeBlockSet;
 952
 953     CodeBlock* specialOSREntryBlockOrNull();
 954
 955     void noticeIncomingCall(ExecState* callerFrame);
 956
 957     double optimizationThresholdScalingFactor();
 958
 959 #if ENABLE(JIT)
 960     ClosureCallStubRoutine* findClosureCallForReturnPC(ReturnAddressPtr);
 961 #endif
 962
 963     void updateAllPredictionsAndCountLiveness(unsigned& numberOfLiveNonArgumentValueProfiles, unsigned& numberOfSamplesInProfiles);
 964
 965     void setConstantRegisters(const Vector<WriteBarrier<Unknown>>& constants)
 966     {
 967         size_t count = constants.size();
 968         m_constantRegisters.resize(count);
 969         for (size_t i = 0; i < count; i++)
 970             m_constantRegisters[i].set(*m_vm, ownerExecutable(), constants[i].get());
 971     }
 972
 973     void dumpBytecode(
 974         PrintStream&, ExecState*, const Instruction* begin, const Instruction*&,
 975         const StubInfoMap& = StubInfoMap(), const CallLinkInfoMap& = CallLinkInfoMap());
 976
 977     CString registerName(int r) const;
 978     void printUnaryOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op);
 979     void printBinaryOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op);
 980     void printConditionalJump(PrintStream&, ExecState*, const Instruction*, const Instruction*&, int location, const char* op);
 981     void printGetByIdOp(PrintStream&, ExecState*, int location, const Instruction*&);
 982     void printGetByIdCacheStatus(PrintStream&, ExecState*, int location, const StubInfoMap&);
 983     enum CacheDumpMode { DumpCaches, DontDumpCaches };
 984     void printCallOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op, CacheDumpMode, bool& hasPrintedProfiling, const CallLinkInfoMap&);
 985     void printPutByIdOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op);
 986     void printLocationAndOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op);
 987     void printLocationOpAndRegisterOperand(PrintStream&, ExecState*, int location, const Instruction*& it, const char* op, int operand);
 988
 989     void beginDumpProfiling(PrintStream&, bool& hasPrintedProfiling);
 990     void dumpValueProfiling(PrintStream&, const Instruction*&, bool& hasPrintedProfiling);
 991     void dumpArrayProfiling(PrintStream&, const Instruction*&, bool& hasPrintedProfiling);
 992     void dumpRareCaseProfile(PrintStream&, const char* name, RareCaseProfile*, bool& hasPrintedProfiling);
 993
 994     bool shouldImmediatelyAssumeLivenessDuringScan();
 995
 996     void propagateTransitions(SlotVisitor&);
 997     void determineLiveness(SlotVisitor&);
 998
 999     void stronglyVisitStrongReferences(SlotVisitor&);
1000     void stronglyVisitWeakReferences(SlotVisitor&);
1001
1002     void createRareDataIfNecessary()
1003     {
1004         if (!m_rareData)
1005             m_rareData = adoptPtr(new RareData);
1006     }
1007
1008 #if ENABLE(JIT)
1009     void resetStubInternal(RepatchBuffer&, StructureStubInfo&);
1010     void resetStubDuringGCInternal(RepatchBuffer&, StructureStubInfo&);
1011 #endif
1012     WriteBarrier<UnlinkedCodeBlock> m_unlinkedCode;
1013     int m_numParameters;
1014     union {
1015         unsigned m_debuggerRequests;
1016         struct {
1017             unsigned m_hasDebuggerStatement : 1;
1018             unsigned m_steppingMode : 1;
1019             unsigned m_numBreakpoints : 30;
1020         };
1021     };
1022     WriteBarrier<ScriptExecutable> m_ownerExecutable;
1023     VM* m_vm;
1024
1025     RefCountedArray<Instruction> m_instructions;
1026     WriteBarrier<SymbolTable> m_symbolTable;
1027     VirtualRegister m_thisRegister;
1028     VirtualRegister m_argumentsRegister;
1029     VirtualRegister m_activationRegister;
1030
1031     bool m_isStrictMode;
1032     bool m_needsActivation;
1033     bool m_mayBeExecuting;
1034     uint8_t m_visitAggregateHasBeenCalled;
1035
1036     RefPtr<SourceProvider> m_source;
1037     unsigned m_sourceOffset;
1038     unsigned m_firstLineColumnOffset;
1039     unsigned m_codeType;
1040
1041     Vector<LLIntCallLinkInfo> m_llintCallLinkInfos;
1042     SentinelLinkedList<LLIntCallLinkInfo, BasicRawSentinelNode<LLIntCallLinkInfo>> m_incomingLLIntCalls;
1043     RefPtr<JITCode> m_jitCode;
1044 #if ENABLE(JIT)
1045     Bag<StructureStubInfo> m_stubInfos;
1046     Vector<ByValInfo> m_byValInfos;
1047     Bag<CallLinkInfo> m_callLinkInfos;
1048     SentinelLinkedList<CallLinkInfo, BasicRawSentinelNode<CallLinkInfo>> m_incomingCalls;
1049 #endif
1050     OwnPtr<CompactJITCodeMap> m_jitCodeMap;
1051 #if ENABLE(DFG_JIT)
1052     // This is relevant to non-DFG code blocks that serve as the profiled code block
1053     // for DFG code blocks.
1054     DFG::ExitProfile m_exitProfile;
1055     CompressedLazyOperandValueProfileHolder m_lazyOperandValueProfiles;
1056 #endif
1057     Vector<ValueProfile> m_argumentValueProfiles;
1058     Vector<ValueProfile> m_valueProfiles;
1059     SegmentedVector<RareCaseProfile, 8> m_rareCaseProfiles;
1060     SegmentedVector<RareCaseProfile, 8> m_specialFastCaseProfiles;
1061     Vector<ArrayAllocationProfile> m_arrayAllocationProfiles;
1062     ArrayProfileVector m_arrayProfiles;
1063     Vector<ObjectAllocationProfile> m_objectAllocationProfiles;
1064
1065     // Constant Pool
1066     COMPILE_ASSERT(sizeof(Register) == sizeof(WriteBarrier<Unknown>), Register_must_be_same_size_as_WriteBarrier_Unknown);
1067     // TODO: This could just be a pointer to m_unlinkedCodeBlock's data, but the DFG mutates
1068     // it, so we're stuck with it for now.
1069     Vector<WriteBarrier<Unknown>> m_constantRegisters;
1070     Vector<WriteBarrier<FunctionExecutable>> m_functionDecls;
1071     Vector<WriteBarrier<FunctionExecutable>> m_functionExprs;
1072
1073     RefPtr<CodeBlock> m_alternative;
1074
1075     BaselineExecutionCounter m_llintExecuteCounter;
1076
1077     BaselineExecutionCounter m_jitExecuteCounter;
1078     int32_t m_totalJITExecutions;
1079     uint32_t m_osrExitCounter;
1080     uint16_t m_optimizationDelayCounter;
1081     uint16_t m_reoptimizationRetryCounter;
1082
1083     mutable CodeBlockHash m_hash;
1084
1085     std::unique_ptr<BytecodeLivenessAnalysis> m_livenessAnalysis;
1086
1087     struct RareData {
1088         WTF_MAKE_FAST_ALLOCATED;
1089     public:
1090         Vector<HandlerInfo> m_exceptionHandlers;
1091
1092         // Buffers used for large array literals
1093         Vector<Vector<JSValue>> m_constantBuffers;
1094
1095         // Jump Tables
1096         Vector<SimpleJumpTable> m_switchJumpTables;
1097         Vector<StringJumpTable> m_stringSwitchJumpTables;
1098
1099         EvalCodeCache m_evalCodeCache;
1100     };
1101 #if COMPILER(MSVC)
1102     friend void WTF::deleteOwnedPtr<RareData>(RareData*);
1103 #endif
1104     OwnPtr<RareData> m_rareData;
1105 #if ENABLE(JIT)
1106     DFG::CapabilityLevel m_capabilityLevelState;
1107 #endif
1108 };
1109
1110 // Program code is not marked by any function, so we make the global object
1111 // responsible for marking it.
1112
1113 class GlobalCodeBlock : public CodeBlock {
1114 protected:
1115     GlobalCodeBlock(CopyParsedBlockTag, GlobalCodeBlock& other)
1116     : CodeBlock(CopyParsedBlock, other)
1117     {
1118     }
1119
1120     GlobalCodeBlock(ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlinkedCodeBlock, JSScope* scope, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset, unsigned firstLineColumnOffset)
1121         : CodeBlock(ownerExecutable, unlinkedCodeBlock, scope, sourceProvider, sourceOffset, firstLineColumnOffset)
1122     {
1123     }
1124 };
1125
1126 class ProgramCodeBlock : public GlobalCodeBlock {
1127 public:
1128     ProgramCodeBlock(CopyParsedBlockTag, ProgramCodeBlock& other)
1129     : GlobalCodeBlock(CopyParsedBlock, other)
1130     {
1131     }
1132
1133     ProgramCodeBlock(ProgramExecutable* ownerExecutable, UnlinkedProgramCodeBlock* unlinkedCodeBlock, JSScope* scope, PassRefPtr<SourceProvider> sourceProvider, unsigned firstLineColumnOffset)
1134         : GlobalCodeBlock(ownerExecutable, unlinkedCodeBlock, scope, sourceProvider, 0, firstLineColumnOffset)
1135     {
1136     }
1137
1138 #if ENABLE(JIT)
1139 protected:
1140     virtual CodeBlock* replacement() override;
1141     virtual DFG::CapabilityLevel capabilityLevelInternal() override;
1142 #endif
1143 };
1144
1145 class EvalCodeBlock : public GlobalCodeBlock {
1146 public:
1147     EvalCodeBlock(CopyParsedBlockTag, EvalCodeBlock& other)
1148     : GlobalCodeBlock(CopyParsedBlock, other)
1149     {
1150     }
1151
1152     EvalCodeBlock(EvalExecutable* ownerExecutable, UnlinkedEvalCodeBlock* unlinkedCodeBlock, JSScope* scope, PassRefPtr<SourceProvider> sourceProvider)
1153         : GlobalCodeBlock(ownerExecutable, unlinkedCodeBlock, scope, sourceProvider, 0, 1)
1154     {
1155     }
1156
1157     const Identifier& variable(unsigned index) { return unlinkedEvalCodeBlock()->variable(index); }
1158     unsigned numVariables() { return unlinkedEvalCodeBlock()->numVariables(); }
1159
1160 #if ENABLE(JIT)
1161 protected:
1162     virtual CodeBlock* replacement() override;
1163     virtual DFG::CapabilityLevel capabilityLevelInternal() override;
1164 #endif
1165
1166 private:
1167     UnlinkedEvalCodeBlock* unlinkedEvalCodeBlock() const { return jsCast<UnlinkedEvalCodeBlock*>(unlinkedCodeBlock()); }
1168 };
1169
1170 class FunctionCodeBlock : public CodeBlock {
1171 public:
1172     FunctionCodeBlock(CopyParsedBlockTag, FunctionCodeBlock& other)
1173     : CodeBlock(CopyParsedBlock, other)
1174     {
1175     }
1176
1177     FunctionCodeBlock(FunctionExecutable* ownerExecutable, UnlinkedFunctionCodeBlock* unlinkedCodeBlock, JSScope* scope, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset, unsigned firstLineColumnOffset)
1178         : CodeBlock(ownerExecutable, unlinkedCodeBlock, scope, sourceProvider, sourceOffset, firstLineColumnOffset)
1179     {
1180     }
1181
1182 #if ENABLE(JIT)
1183 protected:
1184     virtual CodeBlock* replacement() override;
1185     virtual DFG::CapabilityLevel capabilityLevelInternal() override;
1186 #endif
1187 };
1188
1189 inline CodeBlock* baselineCodeBlockForInlineCallFrame(InlineCallFrame* inlineCallFrame)
1190 {
1191     RELEASE_ASSERT(inlineCallFrame);
1192     ExecutableBase* executable = inlineCallFrame->executable.get();
1193     RELEASE_ASSERT(executable->structure()->classInfo() == FunctionExecutable::info());
1194     return static_cast<FunctionExecutable*>(executable)->baselineCodeBlockFor(inlineCallFrame->isCall ? CodeForCall : CodeForConstruct);
1195 }
1196
1197 inline CodeBlock* baselineCodeBlockForOriginAndBaselineCodeBlock(const CodeOrigin& codeOrigin, CodeBlock* baselineCodeBlock)
1198 {
1199     if (codeOrigin.inlineCallFrame)
1200         return baselineCodeBlockForInlineCallFrame(codeOrigin.inlineCallFrame);
1201     return baselineCodeBlock;
1202 }
1203
1204 inline int CodeBlock::argumentIndexAfterCapture(size_t argument)
1205 {
1206     if (argument >= static_cast<size_t>(symbolTable()->parameterCount()))
1207         return CallFrame::argumentOffset(argument);
1208
1209     const SlowArgument* slowArguments = symbolTable()->slowArguments();
1210     if (!slowArguments || slowArguments[argument].status == SlowArgument::Normal)
1211         return CallFrame::argumentOffset(argument);
1212
1213     ASSERT(slowArguments[argument].status == SlowArgument::Captured);
1214     return slowArguments[argument].index;
1215 }
1216
1217 inline bool CodeBlock::hasSlowArguments()
1218 {
1219     return !!symbolTable()->slowArguments();
1220 }
1221
1222 inline Register& ExecState::r(int index)
1223 {
1224     CodeBlock* codeBlock = this->codeBlock();
1225     if (codeBlock->isConstantRegisterIndex(index))
1226         return *reinterpret_cast<Register*>(&codeBlock->constantRegister(index));
1227     return this[index];
1228 }
1229
1230 inline Register& ExecState::uncheckedR(int index)
1231 {
1232     RELEASE_ASSERT(index < FirstConstantRegisterIndex);
1233     return this[index];
1234 }
1235
1236 inline JSValue ExecState::argumentAfterCapture(size_t argument)
1237 {
1238     if (argument >= argumentCount())
1239         return jsUndefined();
1240
1241     if (!codeBlock())
1242         return this[argumentOffset(argument)].jsValue();
1243
1244     return this[codeBlock()->argumentIndexAfterCapture(argument)].jsValue();
1245 }
1246
1247 inline void CodeBlockSet::mark(void* candidateCodeBlock)
1248 {
1249     // We have to check for 0 and -1 because those are used by the HashMap as markers.
1250     uintptr_t value = reinterpret_cast<uintptr_t>(candidateCodeBlock);
1251
1252     // This checks for both of those nasty cases in one go.
1253     // 0 + 1 = 1
1254     // -1 + 1 = 0
1255     if (value + 1 <= 1)
1256         return;
1257
1258     CodeBlock* codeBlock = static_cast<CodeBlock*>(candidateCodeBlock);
1259     if (!m_oldCodeBlocks.contains(codeBlock) && !m_newCodeBlocks.contains(codeBlock))
1260         return;
1261
1262     mark(codeBlock);
1263 }
1264
1265 inline void CodeBlockSet::mark(CodeBlock* codeBlock)
1266 {
1267     if (!codeBlock)
1268         return;
1269
1270     if (codeBlock->m_mayBeExecuting)
1271         return;
1272
1273     codeBlock->m_mayBeExecuting = true;
1274     // We might not have cleared the marks for this CodeBlock, but we need to visit it.
1275     codeBlock->m_visitAggregateHasBeenCalled = false;
1276 #if ENABLE(GGC)
1277     m_currentlyExecuting.append(codeBlock);
1278 #endif
1279 }
1280
1281 template <typename Functor> inline void ScriptExecutable::forEachCodeBlock(Functor&& functor)
1282 {
1283     switch (type()) {
1284     case ProgramExecutableType: {
1285         if (CodeBlock* codeBlock = jsCast<ProgramExecutable*>(this)->m_programCodeBlock.get())
1286             codeBlock->forEachRelatedCodeBlock(std::forward<Functor>(functor));
1287         break;
1288     }
1289
1290     case EvalExecutableType: {
1291         if (CodeBlock* codeBlock = jsCast<EvalExecutable*>(this)->m_evalCodeBlock.get())
1292             codeBlock->forEachRelatedCodeBlock(std::forward<Functor>(functor));
1293         break;
1294     }
1295
1296     case FunctionExecutableType: {
1297         Functor f(std::forward<Functor>(functor));
1298         FunctionExecutable* executable = jsCast<FunctionExecutable*>(this);
1299         if (CodeBlock* codeBlock = executable->m_codeBlockForCall.get())
1300             codeBlock->forEachRelatedCodeBlock(f);
1301         if (CodeBlock* codeBlock = executable->m_codeBlockForConstruct.get())
1302             codeBlock->forEachRelatedCodeBlock(f);
1303         break;
1304     }
1305     default:
1306         RELEASE_ASSERT_NOT_REACHED();
1307     }
1308 }
1309
1310 } // namespace JSC
1311
1312 #endif // CodeBlock_h