Source/JavaScriptCore/bytecode/CodeBlock.h

   1 /*
   2  * Copyright (C) 2008-2016 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 "CodeOrigin.h"
  42 #include "CodeType.h"
  43 #include "CompactJITCodeMap.h"
  44 #include "ConcurrentJITLock.h"
  45 #include "DFGCommon.h"
  46 #include "DFGExitProfile.h"
  47 #include "DeferredCompilationCallback.h"
  48 #include "EvalCodeCache.h"
  49 #include "ExecutionCounter.h"
  50 #include "ExpressionRangeInfo.h"
  51 #include "HandlerInfo.h"
  52 #include "Instruction.h"
  53 #include "JITCode.h"
  54 #include "JITWriteBarrier.h"
  55 #include "JSCell.h"
  56 #include "JSGlobalObject.h"
  57 #include "JumpTable.h"
  58 #include "LLIntCallLinkInfo.h"
  59 #include "LLIntPrototypeLoadAdaptiveStructureWatchpoint.h"
  60 #include "LazyOperandValueProfile.h"
  61 #include "ObjectAllocationProfile.h"
  62 #include "Options.h"
  63 #include "ProfilerJettisonReason.h"
  64 #include "PutPropertySlot.h"
  65 #include "RegExpObject.h"
  66 #include "UnconditionalFinalizer.h"
  67 #include "ValueProfile.h"
  68 #include "VirtualRegister.h"
  69 #include "Watchpoint.h"
  70 #include <wtf/Bag.h>
  71 #include <wtf/FastBitVector.h>
  72 #include <wtf/FastMalloc.h>
  73 #include <wtf/RefCountedArray.h>
  74 #include <wtf/RefPtr.h>
  75 #include <wtf/SegmentedVector.h>
  76 #include <wtf/Vector.h>
  77 #include <wtf/text/WTFString.h>
  78
  79 namespace JSC {
  80
  81 class ExecState;
  82 class JSModuleEnvironment;
  83 class LLIntOffsetsExtractor;
  84 class PCToCodeOriginMap;
  85 class RegisterAtOffsetList;
  86 class StructureStubInfo;
  87 class TypeLocation;
  88
  89 enum class AccessType : int8_t;
  90
  91 typedef HashMap<CodeOrigin, StructureStubInfo*, CodeOriginApproximateHash> StubInfoMap;
  92
  93 enum ReoptimizationMode { DontCountReoptimization, CountReoptimization };
  94
  95 class CodeBlock : public JSCell {
  96     typedef JSCell Base;
  97     friend class BytecodeLivenessAnalysis;
  98     friend class JIT;
  99     friend class LLIntOffsetsExtractor;
 100
 101     class UnconditionalFinalizer : public JSC::UnconditionalFinalizer {
 102         void finalizeUnconditionally() override;
 103     };
 104
 105     class WeakReferenceHarvester : public JSC::WeakReferenceHarvester {
 106         void visitWeakReferences(SlotVisitor&) override;
 107     };
 108
 109 public:
 110     enum CopyParsedBlockTag { CopyParsedBlock };
 111
 112     static const unsigned StructureFlags = Base::StructureFlags | StructureIsImmortal;
 113
 114     DECLARE_INFO;
 115
 116 protected:
 117     CodeBlock(VM*, Structure*, CopyParsedBlockTag, CodeBlock& other);
 118     CodeBlock(VM*, Structure*, ScriptExecutable* ownerExecutable, UnlinkedCodeBlock*, JSScope*, PassRefPtr<SourceProvider>, unsigned sourceOffset, unsigned firstLineColumnOffset);
 119 #if ENABLE(WEBASSEMBLY)
 120     CodeBlock(VM*, Structure*, WebAssemblyExecutable* ownerExecutable, JSGlobalObject*);
 121 #endif
 122
 123     void finishCreation(VM&, CopyParsedBlockTag, CodeBlock& other);
 124     void finishCreation(VM&, ScriptExecutable* ownerExecutable, UnlinkedCodeBlock*, JSScope*);
 125 #if ENABLE(WEBASSEMBLY)
 126     void finishCreation(VM&, WebAssemblyExecutable* ownerExecutable, JSGlobalObject*);
 127 #endif
 128
 129     WriteBarrier<JSGlobalObject> m_globalObject;
 130
 131 public:
 132     JS_EXPORT_PRIVATE ~CodeBlock();
 133
 134     UnlinkedCodeBlock* unlinkedCodeBlock() const { return m_unlinkedCode.get(); }
 135
 136     CString inferredName() const;
 137     CodeBlockHash hash() const;
 138     bool hasHash() const;
 139     bool isSafeToComputeHash() const;
 140     CString hashAsStringIfPossible() const;
 141     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.
 142     CString sourceCodeOnOneLine() const; // As sourceCodeForTools(), but replaces all whitespace runs with a single space.
 143     void dumpAssumingJITType(PrintStream&, JITCode::JITType) const;
 144     void dump(PrintStream&) const;
 145
 146     int numParameters() const { return m_numParameters; }
 147     void setNumParameters(int newValue);
 148
 149     int numCalleeLocals() const { return m_numCalleeLocals; }
 150
 151     int* addressOfNumParameters() { return &m_numParameters; }
 152     static ptrdiff_t offsetOfNumParameters() { return OBJECT_OFFSETOF(CodeBlock, m_numParameters); }
 153
 154     CodeBlock* alternative() const { return static_cast<CodeBlock*>(m_alternative.get()); }
 155     void setAlternative(VM&, CodeBlock*);
 156
 157     template <typename Functor> void forEachRelatedCodeBlock(Functor&& functor)
 158     {
 159         Functor f(std::forward<Functor>(functor));
 160         Vector<CodeBlock*, 4> codeBlocks;
 161         codeBlocks.append(this);
 162
 163         while (!codeBlocks.isEmpty()) {
 164             CodeBlock* currentCodeBlock = codeBlocks.takeLast();
 165             f(currentCodeBlock);
 166
 167             if (CodeBlock* alternative = currentCodeBlock->alternative())
 168                 codeBlocks.append(alternative);
 169             if (CodeBlock* osrEntryBlock = currentCodeBlock->specialOSREntryBlockOrNull())
 170                 codeBlocks.append(osrEntryBlock);
 171         }
 172     }
 173
 174     CodeSpecializationKind specializationKind() const
 175     {
 176         return specializationFromIsConstruct(m_isConstructor);
 177     }
 178
 179     CodeBlock* alternativeForJettison();
 180     JS_EXPORT_PRIVATE CodeBlock* baselineAlternative();
 181
 182     // FIXME: Get rid of this.
 183     // https://bugs.webkit.org/show_bug.cgi?id=123677
 184     CodeBlock* baselineVersion();
 185
 186     static size_t estimatedSize(JSCell*);
 187     static void visitChildren(JSCell*, SlotVisitor&);
 188     void visitChildren(SlotVisitor&);
 189     void visitWeakly(SlotVisitor&);
 190     void clearVisitWeaklyHasBeenCalled();
 191
 192     void dumpSource();
 193     void dumpSource(PrintStream&);
 194
 195     void dumpBytecode();
 196     void dumpBytecode(PrintStream&);
 197     void dumpBytecode(
 198         PrintStream&, unsigned bytecodeOffset,
 199         const StubInfoMap& = StubInfoMap(), const CallLinkInfoMap& = CallLinkInfoMap());
 200     void dumpExceptionHandlers(PrintStream&);
 201     void printStructures(PrintStream&, const Instruction*);
 202     void printStructure(PrintStream&, const char* name, const Instruction*, int operand);
 203
 204     bool isStrictMode() const { return m_isStrictMode; }
 205     ECMAMode ecmaMode() const { return isStrictMode() ? StrictMode : NotStrictMode; }
 206
 207     inline bool isKnownNotImmediate(int index)
 208     {
 209         if (index == m_thisRegister.offset() && !m_isStrictMode)
 210             return true;
 211
 212         if (isConstantRegisterIndex(index))
 213             return getConstant(index).isCell();
 214
 215         return false;
 216     }
 217
 218     ALWAYS_INLINE bool isTemporaryRegisterIndex(int index)
 219     {
 220         return index >= m_numVars;
 221     }
 222
 223     enum class RequiredHandler {
 224         CatchHandler,
 225         AnyHandler
 226     };
 227     HandlerInfo* handlerForBytecodeOffset(unsigned bytecodeOffset, RequiredHandler = RequiredHandler::AnyHandler);
 228     HandlerInfo* handlerForIndex(unsigned, RequiredHandler = RequiredHandler::AnyHandler);
 229     void removeExceptionHandlerForCallSite(CallSiteIndex);
 230     unsigned lineNumberForBytecodeOffset(unsigned bytecodeOffset);
 231     unsigned columnNumberForBytecodeOffset(unsigned bytecodeOffset);
 232     void expressionRangeForBytecodeOffset(unsigned bytecodeOffset, int& divot,
 233                                           int& startOffset, int& endOffset, unsigned& line, unsigned& column);
 234
 235     Optional<unsigned> bytecodeOffsetFromCallSiteIndex(CallSiteIndex);
 236
 237     void getStubInfoMap(const ConcurrentJITLocker&, StubInfoMap& result);
 238     void getStubInfoMap(StubInfoMap& result);
 239
 240     void getCallLinkInfoMap(const ConcurrentJITLocker&, CallLinkInfoMap& result);
 241     void getCallLinkInfoMap(CallLinkInfoMap& result);
 242
 243     void getByValInfoMap(const ConcurrentJITLocker&, ByValInfoMap& result);
 244     void getByValInfoMap(ByValInfoMap& result);
 245
 246 #if ENABLE(JIT)
 247     StructureStubInfo* addStubInfo(AccessType);
 248     Bag<StructureStubInfo>::iterator stubInfoBegin() { return m_stubInfos.begin(); }
 249     Bag<StructureStubInfo>::iterator stubInfoEnd() { return m_stubInfos.end(); }
 250
 251     // O(n) operation. Use getStubInfoMap() unless you really only intend to get one
 252     // stub info.
 253     StructureStubInfo* findStubInfo(CodeOrigin);
 254
 255     ByValInfo* addByValInfo();
 256
 257     CallLinkInfo* addCallLinkInfo();
 258     Bag<CallLinkInfo>::iterator callLinkInfosBegin() { return m_callLinkInfos.begin(); }
 259     Bag<CallLinkInfo>::iterator callLinkInfosEnd() { return m_callLinkInfos.end(); }
 260
 261     // This is a slow function call used primarily for compiling OSR exits in the case
 262     // that there had been inlining. Chances are if you want to use this, you're really
 263     // looking for a CallLinkInfoMap to amortize the cost of calling this.
 264     CallLinkInfo* getCallLinkInfoForBytecodeIndex(unsigned bytecodeIndex);
 265 #endif // ENABLE(JIT)
 266
 267     void unlinkIncomingCalls();
 268
 269 #if ENABLE(JIT)
 270     void linkIncomingCall(ExecState* callerFrame, CallLinkInfo*);
 271     void linkIncomingPolymorphicCall(ExecState* callerFrame, PolymorphicCallNode*);
 272 #endif // ENABLE(JIT)
 273
 274     void linkIncomingCall(ExecState* callerFrame, LLIntCallLinkInfo*);
 275
 276     void setJITCodeMap(std::unique_ptr<CompactJITCodeMap> jitCodeMap)
 277     {
 278         m_jitCodeMap = WTFMove(jitCodeMap);
 279     }
 280     CompactJITCodeMap* jitCodeMap()
 281     {
 282         return m_jitCodeMap.get();
 283     }
 284
 285     unsigned bytecodeOffset(Instruction* returnAddress)
 286     {
 287         RELEASE_ASSERT(returnAddress >= instructions().begin() && returnAddress < instructions().end());
 288         return static_cast<Instruction*>(returnAddress) - instructions().begin();
 289     }
 290
 291     unsigned numberOfInstructions() const { return m_instructions.size(); }
 292     RefCountedArray<Instruction>& instructions() { return m_instructions; }
 293     const RefCountedArray<Instruction>& instructions() const { return m_instructions; }
 294
 295     size_t predictedMachineCodeSize();
 296
 297     bool usesOpcode(OpcodeID);
 298
 299     unsigned instructionCount() const { return m_instructions.size(); }
 300
 301     // Exactly equivalent to codeBlock->ownerExecutable()->newReplacementCodeBlockFor(codeBlock->specializationKind())
 302     CodeBlock* newReplacement();
 303
 304     void setJITCode(PassRefPtr<JITCode> code)
 305     {
 306         ASSERT(heap()->isDeferred());
 307         heap()->reportExtraMemoryAllocated(code->size());
 308         ConcurrentJITLocker locker(m_lock);
 309         WTF::storeStoreFence(); // This is probably not needed because the lock will also do something similar, but it's good to be paranoid.
 310         m_jitCode = code;
 311     }
 312     PassRefPtr<JITCode> jitCode() { return m_jitCode; }
 313     static ptrdiff_t jitCodeOffset() { return OBJECT_OFFSETOF(CodeBlock, m_jitCode); }
 314     JITCode::JITType jitType() const
 315     {
 316         JITCode* jitCode = m_jitCode.get();
 317         WTF::loadLoadFence();
 318         JITCode::JITType result = JITCode::jitTypeFor(jitCode);
 319         WTF::loadLoadFence(); // This probably isn't needed. Oh well, paranoia is good.
 320         return result;
 321     }
 322
 323     bool hasBaselineJITProfiling() const
 324     {
 325         return jitType() == JITCode::BaselineJIT;
 326     }
 327
 328 #if ENABLE(JIT)
 329     CodeBlock* replacement();
 330
 331     DFG::CapabilityLevel computeCapabilityLevel();
 332     DFG::CapabilityLevel capabilityLevel();
 333     DFG::CapabilityLevel capabilityLevelState() { return static_cast<DFG::CapabilityLevel>(m_capabilityLevelState); }
 334
 335     bool hasOptimizedReplacement(JITCode::JITType typeToReplace);
 336     bool hasOptimizedReplacement(); // the typeToReplace is my JITType
 337 #endif
 338
 339     void jettison(Profiler::JettisonReason, ReoptimizationMode = DontCountReoptimization, const FireDetail* = nullptr);
 340
 341     ExecutableBase* ownerExecutable() const { return m_ownerExecutable.get(); }
 342     ScriptExecutable* ownerScriptExecutable() const { return jsCast<ScriptExecutable*>(m_ownerExecutable.get()); }
 343
 344     VM* vm() const { return m_vm; }
 345
 346     void setThisRegister(VirtualRegister thisRegister) { m_thisRegister = thisRegister; }
 347     VirtualRegister thisRegister() const { return m_thisRegister; }
 348
 349     bool usesEval() const { return m_unlinkedCode->usesEval(); }
 350
 351     void setScopeRegister(VirtualRegister scopeRegister)
 352     {
 353         ASSERT(scopeRegister.isLocal() || !scopeRegister.isValid());
 354         m_scopeRegister = scopeRegister;
 355     }
 356
 357     VirtualRegister scopeRegister() const
 358     {
 359         return m_scopeRegister;
 360     }
 361
 362     CodeType codeType() const
 363     {
 364         return static_cast<CodeType>(m_codeType);
 365     }
 366
 367     PutPropertySlot::Context putByIdContext() const
 368     {
 369         if (codeType() == EvalCode)
 370             return PutPropertySlot::PutByIdEval;
 371         return PutPropertySlot::PutById;
 372     }
 373
 374     SourceProvider* source() const { return m_source.get(); }
 375     unsigned sourceOffset() const { return m_sourceOffset; }
 376     unsigned firstLineColumnOffset() const { return m_firstLineColumnOffset; }
 377
 378     size_t numberOfJumpTargets() const { return m_unlinkedCode->numberOfJumpTargets(); }
 379     unsigned jumpTarget(int index) const { return m_unlinkedCode->jumpTarget(index); }
 380
 381     String nameForRegister(VirtualRegister);
 382
 383     unsigned numberOfArgumentValueProfiles()
 384     {
 385         ASSERT(m_numParameters >= 0);
 386         ASSERT(m_argumentValueProfiles.size() == static_cast<unsigned>(m_numParameters));
 387         return m_argumentValueProfiles.size();
 388     }
 389     ValueProfile* valueProfileForArgument(unsigned argumentIndex)
 390     {
 391         ValueProfile* result = &m_argumentValueProfiles[argumentIndex];
 392         ASSERT(result->m_bytecodeOffset == -1);
 393         return result;
 394     }
 395
 396     unsigned numberOfValueProfiles() { return m_valueProfiles.size(); }
 397     ValueProfile* valueProfile(int index) { return &m_valueProfiles[index]; }
 398     ValueProfile* valueProfileForBytecodeOffset(int bytecodeOffset);
 399     SpeculatedType valueProfilePredictionForBytecodeOffset(const ConcurrentJITLocker& locker, int bytecodeOffset)
 400     {
 401         return valueProfileForBytecodeOffset(bytecodeOffset)->computeUpdatedPrediction(locker);
 402     }
 403
 404     unsigned totalNumberOfValueProfiles()
 405     {
 406         return numberOfArgumentValueProfiles() + numberOfValueProfiles();
 407     }
 408     ValueProfile* getFromAllValueProfiles(unsigned index)
 409     {
 410         if (index < numberOfArgumentValueProfiles())
 411             return valueProfileForArgument(index);
 412         return valueProfile(index - numberOfArgumentValueProfiles());
 413     }
 414
 415     RareCaseProfile* addRareCaseProfile(int bytecodeOffset)
 416     {
 417         m_rareCaseProfiles.append(RareCaseProfile(bytecodeOffset));
 418         return &m_rareCaseProfiles.last();
 419     }
 420     unsigned numberOfRareCaseProfiles() { return m_rareCaseProfiles.size(); }
 421     RareCaseProfile* rareCaseProfileForBytecodeOffset(int bytecodeOffset);
 422     unsigned rareCaseProfileCountForBytecodeOffset(int bytecodeOffset);
 423
 424     bool likelyToTakeSlowCase(int bytecodeOffset)
 425     {
 426         if (!hasBaselineJITProfiling())
 427             return false;
 428         unsigned value = rareCaseProfileCountForBytecodeOffset(bytecodeOffset);
 429         return value >= Options::likelyToTakeSlowCaseMinimumCount();
 430     }
 431
 432     bool couldTakeSlowCase(int bytecodeOffset)
 433     {
 434         if (!hasBaselineJITProfiling())
 435             return false;
 436         unsigned value = rareCaseProfileCountForBytecodeOffset(bytecodeOffset);
 437         return value >= Options::couldTakeSlowCaseMinimumCount();
 438     }
 439
 440     ResultProfile* ensureResultProfile(int bytecodeOffset);
 441     ResultProfile* ensureResultProfile(const ConcurrentJITLocker&, int bytecodeOffset);
 442     unsigned numberOfResultProfiles() { return m_resultProfiles.size(); }
 443     ResultProfile* resultProfileForBytecodeOffset(int bytecodeOffset);
 444     ResultProfile* resultProfileForBytecodeOffset(const ConcurrentJITLocker&, int bytecodeOffset);
 445
 446     unsigned specialFastCaseProfileCountForBytecodeOffset(int bytecodeOffset)
 447     {
 448         ResultProfile* profile = resultProfileForBytecodeOffset(bytecodeOffset);
 449         if (!profile)
 450             return 0;
 451         return profile->specialFastPathCount();
 452     }
 453
 454     bool couldTakeSpecialFastCase(int bytecodeOffset)
 455     {
 456         if (!hasBaselineJITProfiling())
 457             return false;
 458         unsigned specialFastCaseCount = specialFastCaseProfileCountForBytecodeOffset(bytecodeOffset);
 459         return specialFastCaseCount >= Options::couldTakeSlowCaseMinimumCount();
 460     }
 461
 462     unsigned numberOfArrayProfiles() const { return m_arrayProfiles.size(); }
 463     const ArrayProfileVector& arrayProfiles() { return m_arrayProfiles; }
 464     ArrayProfile* addArrayProfile(unsigned bytecodeOffset)
 465     {
 466         m_arrayProfiles.append(ArrayProfile(bytecodeOffset));
 467         return &m_arrayProfiles.last();
 468     }
 469     ArrayProfile* getArrayProfile(unsigned bytecodeOffset);
 470     ArrayProfile* getOrAddArrayProfile(unsigned bytecodeOffset);
 471
 472     // Exception handling support
 473
 474     size_t numberOfExceptionHandlers() const { return m_rareData ? m_rareData->m_exceptionHandlers.size() : 0; }
 475     HandlerInfo& exceptionHandler(int index) { RELEASE_ASSERT(m_rareData); return m_rareData->m_exceptionHandlers[index]; }
 476
 477     bool hasExpressionInfo() { return m_unlinkedCode->hasExpressionInfo(); }
 478
 479 #if ENABLE(DFG_JIT)
 480     Vector<CodeOrigin, 0, UnsafeVectorOverflow>& codeOrigins();
 481
 482     // Having code origins implies that there has been some inlining.
 483     bool hasCodeOrigins()
 484     {
 485         return JITCode::isOptimizingJIT(jitType());
 486     }
 487
 488     bool canGetCodeOrigin(CallSiteIndex index)
 489     {
 490         if (!hasCodeOrigins())
 491             return false;
 492         return index.bits() < codeOrigins().size();
 493     }
 494
 495     CodeOrigin codeOrigin(CallSiteIndex index)
 496     {
 497         return codeOrigins()[index.bits()];
 498     }
 499
 500     bool addFrequentExitSite(const DFG::FrequentExitSite& site)
 501     {
 502         ASSERT(JITCode::isBaselineCode(jitType()));
 503         ConcurrentJITLocker locker(m_lock);
 504         return m_exitProfile.add(locker, this, site);
 505     }
 506
 507     bool hasExitSite(const ConcurrentJITLocker& locker, const DFG::FrequentExitSite& site) const
 508     {
 509         return m_exitProfile.hasExitSite(locker, site);
 510     }
 511     bool hasExitSite(const DFG::FrequentExitSite& site) const
 512     {
 513         ConcurrentJITLocker locker(m_lock);
 514         return hasExitSite(locker, site);
 515     }
 516
 517     DFG::ExitProfile& exitProfile() { return m_exitProfile; }
 518
 519     CompressedLazyOperandValueProfileHolder& lazyOperandValueProfiles()
 520     {
 521         return m_lazyOperandValueProfiles;
 522     }
 523 #endif // ENABLE(DFG_JIT)
 524
 525     // Constant Pool
 526 #if ENABLE(DFG_JIT)
 527     size_t numberOfIdentifiers() const { return m_unlinkedCode->numberOfIdentifiers() + numberOfDFGIdentifiers(); }
 528     size_t numberOfDFGIdentifiers() const;
 529     const Identifier& identifier(int index) const;
 530 #else
 531     size_t numberOfIdentifiers() const { return m_unlinkedCode->numberOfIdentifiers(); }
 532     const Identifier& identifier(int index) const { return m_unlinkedCode->identifier(index); }
 533 #endif
 534
 535     Vector<WriteBarrier<Unknown>>& constants() { return m_constantRegisters; }
 536     Vector<SourceCodeRepresentation>& constantsSourceCodeRepresentation() { return m_constantsSourceCodeRepresentation; }
 537     unsigned addConstant(JSValue v)
 538     {
 539         unsigned result = m_constantRegisters.size();
 540         m_constantRegisters.append(WriteBarrier<Unknown>());
 541         m_constantRegisters.last().set(m_globalObject->vm(), this, v);
 542         m_constantsSourceCodeRepresentation.append(SourceCodeRepresentation::Other);
 543         return result;
 544     }
 545
 546     unsigned addConstantLazily()
 547     {
 548         unsigned result = m_constantRegisters.size();
 549         m_constantRegisters.append(WriteBarrier<Unknown>());
 550         m_constantsSourceCodeRepresentation.append(SourceCodeRepresentation::Other);
 551         return result;
 552     }
 553
 554     WriteBarrier<Unknown>& constantRegister(int index) { return m_constantRegisters[index - FirstConstantRegisterIndex]; }
 555     ALWAYS_INLINE bool isConstantRegisterIndex(int index) const { return index >= FirstConstantRegisterIndex; }
 556     ALWAYS_INLINE JSValue getConstant(int index) const { return m_constantRegisters[index - FirstConstantRegisterIndex].get(); }
 557     ALWAYS_INLINE SourceCodeRepresentation constantSourceCodeRepresentation(int index) const { return m_constantsSourceCodeRepresentation[index - FirstConstantRegisterIndex]; }
 558
 559     FunctionExecutable* functionDecl(int index) { return m_functionDecls[index].get(); }
 560     int numberOfFunctionDecls() { return m_functionDecls.size(); }
 561     FunctionExecutable* functionExpr(int index) { return m_functionExprs[index].get(); }
 562
 563     RegExp* regexp(int index) const { return m_unlinkedCode->regexp(index); }
 564
 565     unsigned numberOfConstantBuffers() const
 566     {
 567         if (!m_rareData)
 568             return 0;
 569         return m_rareData->m_constantBuffers.size();
 570     }
 571     unsigned addConstantBuffer(const Vector<JSValue>& buffer)
 572     {
 573         createRareDataIfNecessary();
 574         unsigned size = m_rareData->m_constantBuffers.size();
 575         m_rareData->m_constantBuffers.append(buffer);
 576         return size;
 577     }
 578
 579     Vector<JSValue>& constantBufferAsVector(unsigned index)
 580     {
 581         ASSERT(m_rareData);
 582         return m_rareData->m_constantBuffers[index];
 583     }
 584     JSValue* constantBuffer(unsigned index)
 585     {
 586         return constantBufferAsVector(index).data();
 587     }
 588
 589     Heap* heap() const { return &m_vm->heap; }
 590     JSGlobalObject* globalObject() { return m_globalObject.get(); }
 591
 592     JSGlobalObject* globalObjectFor(CodeOrigin);
 593
 594     BytecodeLivenessAnalysis& livenessAnalysis()
 595     {
 596         {
 597             ConcurrentJITLocker locker(m_lock);
 598             if (!!m_livenessAnalysis)
 599                 return *m_livenessAnalysis;
 600         }
 601         std::unique_ptr<BytecodeLivenessAnalysis> analysis =
 602             std::make_unique<BytecodeLivenessAnalysis>(this);
 603         {
 604             ConcurrentJITLocker locker(m_lock);
 605             if (!m_livenessAnalysis)
 606                 m_livenessAnalysis = WTFMove(analysis);
 607             return *m_livenessAnalysis;
 608         }
 609     }
 610
 611     void validate();
 612
 613     // Jump Tables
 614
 615     size_t numberOfSwitchJumpTables() const { return m_rareData ? m_rareData->m_switchJumpTables.size() : 0; }
 616     SimpleJumpTable& addSwitchJumpTable() { createRareDataIfNecessary(); m_rareData->m_switchJumpTables.append(SimpleJumpTable()); return m_rareData->m_switchJumpTables.last(); }
 617     SimpleJumpTable& switchJumpTable(int tableIndex) { RELEASE_ASSERT(m_rareData); return m_rareData->m_switchJumpTables[tableIndex]; }
 618     void clearSwitchJumpTables()
 619     {
 620         if (!m_rareData)
 621             return;
 622         m_rareData->m_switchJumpTables.clear();
 623     }
 624
 625     size_t numberOfStringSwitchJumpTables() const { return m_rareData ? m_rareData->m_stringSwitchJumpTables.size() : 0; }
 626     StringJumpTable& addStringSwitchJumpTable() { createRareDataIfNecessary(); m_rareData->m_stringSwitchJumpTables.append(StringJumpTable()); return m_rareData->m_stringSwitchJumpTables.last(); }
 627     StringJumpTable& stringSwitchJumpTable(int tableIndex) { RELEASE_ASSERT(m_rareData); return m_rareData->m_stringSwitchJumpTables[tableIndex]; }
 628
 629     // Live callee registers at yield points.
 630     const FastBitVector& liveCalleeLocalsAtYield(unsigned index) const
 631     {
 632         RELEASE_ASSERT(m_rareData);
 633         return m_rareData->m_liveCalleeLocalsAtYield[index];
 634     }
 635     FastBitVector& liveCalleeLocalsAtYield(unsigned index)
 636     {
 637         RELEASE_ASSERT(m_rareData);
 638         return m_rareData->m_liveCalleeLocalsAtYield[index];
 639     }
 640
 641     EvalCodeCache& evalCodeCache() { createRareDataIfNecessary(); return m_rareData->m_evalCodeCache; }
 642
 643     enum ShrinkMode {
 644         // Shrink prior to generating machine code that may point directly into vectors.
 645         EarlyShrink,
 646
 647         // Shrink after generating machine code, and after possibly creating new vectors
 648         // and appending to others. At this time it is not safe to shrink certain vectors
 649         // because we would have generated machine code that references them directly.
 650         LateShrink
 651     };
 652     void shrinkToFit(ShrinkMode);
 653
 654     // Functions for controlling when JITting kicks in, in a mixed mode
 655     // execution world.
 656
 657     bool checkIfJITThresholdReached()
 658     {
 659         return m_llintExecuteCounter.checkIfThresholdCrossedAndSet(this);
 660     }
 661
 662     void dontJITAnytimeSoon()
 663     {
 664         m_llintExecuteCounter.deferIndefinitely();
 665     }
 666
 667     void jitAfterWarmUp()
 668     {
 669         m_llintExecuteCounter.setNewThreshold(Options::thresholdForJITAfterWarmUp(), this);
 670     }
 671
 672     void jitSoon()
 673     {
 674         m_llintExecuteCounter.setNewThreshold(Options::thresholdForJITSoon(), this);
 675     }
 676
 677     const BaselineExecutionCounter& llintExecuteCounter() const
 678     {
 679         return m_llintExecuteCounter;
 680     }
 681
 682     typedef HashMap<Structure*, Bag<LLIntPrototypeLoadAdaptiveStructureWatchpoint>> StructureWatchpointMap;
 683     StructureWatchpointMap& llintGetByIdWatchpointMap() { return m_llintGetByIdWatchpointMap; }
 684
 685     // Functions for controlling when tiered compilation kicks in. This
 686     // controls both when the optimizing compiler is invoked and when OSR
 687     // entry happens. Two triggers exist: the loop trigger and the return
 688     // trigger. In either case, when an addition to m_jitExecuteCounter
 689     // causes it to become non-negative, the optimizing compiler is
 690     // invoked. This includes a fast check to see if this CodeBlock has
 691     // already been optimized (i.e. replacement() returns a CodeBlock
 692     // that was optimized with a higher tier JIT than this one). In the
 693     // case of the loop trigger, if the optimized compilation succeeds
 694     // (or has already succeeded in the past) then OSR is attempted to
 695     // redirect program flow into the optimized code.
 696
 697     // These functions are called from within the optimization triggers,
 698     // and are used as a single point at which we define the heuristics
 699     // for how much warm-up is mandated before the next optimization
 700     // trigger files. All CodeBlocks start out with optimizeAfterWarmUp(),
 701     // as this is called from the CodeBlock constructor.
 702
 703     // When we observe a lot of speculation failures, we trigger a
 704     // reoptimization. But each time, we increase the optimization trigger
 705     // to avoid thrashing.
 706     JS_EXPORT_PRIVATE unsigned reoptimizationRetryCounter() const;
 707     void countReoptimization();
 708 #if ENABLE(JIT)
 709     static unsigned numberOfLLIntBaselineCalleeSaveRegisters() { return RegisterSet::llintBaselineCalleeSaveRegisters().numberOfSetRegisters(); }
 710     static size_t llintBaselineCalleeSaveSpaceAsVirtualRegisters();
 711     size_t calleeSaveSpaceAsVirtualRegisters();
 712
 713     unsigned numberOfDFGCompiles();
 714
 715     int32_t codeTypeThresholdMultiplier() const;
 716
 717     int32_t adjustedCounterValue(int32_t desiredThreshold);
 718
 719     int32_t* addressOfJITExecuteCounter()
 720     {
 721         return &m_jitExecuteCounter.m_counter;
 722     }
 723
 724     static ptrdiff_t offsetOfJITExecuteCounter() { return OBJECT_OFFSETOF(CodeBlock, m_jitExecuteCounter) + OBJECT_OFFSETOF(BaselineExecutionCounter, m_counter); }
 725     static ptrdiff_t offsetOfJITExecutionActiveThreshold() { return OBJECT_OFFSETOF(CodeBlock, m_jitExecuteCounter) + OBJECT_OFFSETOF(BaselineExecutionCounter, m_activeThreshold); }
 726     static ptrdiff_t offsetOfJITExecutionTotalCount() { return OBJECT_OFFSETOF(CodeBlock, m_jitExecuteCounter) + OBJECT_OFFSETOF(BaselineExecutionCounter, m_totalCount); }
 727
 728     const BaselineExecutionCounter& jitExecuteCounter() const { return m_jitExecuteCounter; }
 729
 730     unsigned optimizationDelayCounter() const { return m_optimizationDelayCounter; }
 731
 732     // Check if the optimization threshold has been reached, and if not,
 733     // adjust the heuristics accordingly. Returns true if the threshold has
 734     // been reached.
 735     bool checkIfOptimizationThresholdReached();
 736
 737     // Call this to force the next optimization trigger to fire. This is
 738     // rarely wise, since optimization triggers are typically more
 739     // expensive than executing baseline code.
 740     void optimizeNextInvocation();
 741
 742     // Call this to prevent optimization from happening again. Note that
 743     // optimization will still happen after roughly 2^29 invocations,
 744     // so this is really meant to delay that as much as possible. This
 745     // is called if optimization failed, and we expect it to fail in
 746     // the future as well.
 747     void dontOptimizeAnytimeSoon();
 748
 749     // Call this to reinitialize the counter to its starting state,
 750     // forcing a warm-up to happen before the next optimization trigger
 751     // fires. This is called in the CodeBlock constructor. It also
 752     // makes sense to call this if an OSR exit occurred. Note that
 753     // OSR exit code is code generated, so the value of the execute
 754     // counter that this corresponds to is also available directly.
 755     void optimizeAfterWarmUp();
 756
 757     // Call this to force an optimization trigger to fire only after
 758     // a lot of warm-up.
 759     void optimizeAfterLongWarmUp();
 760
 761     // Call this to cause an optimization trigger to fire soon, but
 762     // not necessarily the next one. This makes sense if optimization
 763     // succeeds. Successfuly optimization means that all calls are
 764     // relinked to the optimized code, so this only affects call
 765     // frames that are still executing this CodeBlock. The value here
 766     // is tuned to strike a balance between the cost of OSR entry
 767     // (which is too high to warrant making every loop back edge to
 768     // trigger OSR immediately) and the cost of executing baseline
 769     // code (which is high enough that we don't necessarily want to
 770     // have a full warm-up). The intuition for calling this instead of
 771     // optimizeNextInvocation() is for the case of recursive functions
 772     // with loops. Consider that there may be N call frames of some
 773     // recursive function, for a reasonably large value of N. The top
 774     // one triggers optimization, and then returns, and then all of
 775     // the others return. We don't want optimization to be triggered on
 776     // each return, as that would be superfluous. It only makes sense
 777     // to trigger optimization if one of those functions becomes hot
 778     // in the baseline code.
 779     void optimizeSoon();
 780
 781     void forceOptimizationSlowPathConcurrently();
 782
 783     void setOptimizationThresholdBasedOnCompilationResult(CompilationResult);
 784
 785     uint32_t osrExitCounter() const { return m_osrExitCounter; }
 786
 787     void countOSRExit() { m_osrExitCounter++; }
 788
 789     uint32_t* addressOfOSRExitCounter() { return &m_osrExitCounter; }
 790
 791     static ptrdiff_t offsetOfOSRExitCounter() { return OBJECT_OFFSETOF(CodeBlock, m_osrExitCounter); }
 792
 793     uint32_t adjustedExitCountThreshold(uint32_t desiredThreshold);
 794     uint32_t exitCountThresholdForReoptimization();
 795     uint32_t exitCountThresholdForReoptimizationFromLoop();
 796     bool shouldReoptimizeNow();
 797     bool shouldReoptimizeFromLoopNow();
 798
 799     void setCalleeSaveRegisters(RegisterSet);
 800     void setCalleeSaveRegisters(std::unique_ptr<RegisterAtOffsetList>);
 801
 802     RegisterAtOffsetList* calleeSaveRegisters() const { return m_calleeSaveRegisters.get(); }
 803 #else // No JIT
 804     static unsigned numberOfLLIntBaselineCalleeSaveRegisters() { return 0; }
 805     static size_t llintBaselineCalleeSaveSpaceAsVirtualRegisters() { return 0; };
 806     void optimizeAfterWarmUp() { }
 807     unsigned numberOfDFGCompiles() { return 0; }
 808 #endif
 809
 810     bool shouldOptimizeNow();
 811     void updateAllValueProfilePredictions();
 812     void updateAllArrayPredictions();
 813     void updateAllPredictions();
 814
 815     unsigned frameRegisterCount();
 816     int stackPointerOffset();
 817
 818     bool hasOpDebugForLineAndColumn(unsigned line, unsigned column);
 819
 820     bool hasDebuggerRequests() const { return m_debuggerRequests; }
 821     void* debuggerRequestsAddress() { return &m_debuggerRequests; }
 822
 823     void addBreakpoint(unsigned numBreakpoints);
 824     void removeBreakpoint(unsigned numBreakpoints)
 825     {
 826         ASSERT(m_numBreakpoints >= numBreakpoints);
 827         m_numBreakpoints -= numBreakpoints;
 828     }
 829
 830     enum SteppingMode {
 831         SteppingModeDisabled,
 832         SteppingModeEnabled
 833     };
 834     void setSteppingMode(SteppingMode);
 835
 836     void clearDebuggerRequests()
 837     {
 838         m_steppingMode = SteppingModeDisabled;
 839         m_numBreakpoints = 0;
 840     }
 841
 842     bool wasCompiledWithDebuggingOpcodes() const { return m_unlinkedCode->wasCompiledWithDebuggingOpcodes(); }
 843
 844     // FIXME: Make these remaining members private.
 845
 846     int m_numCalleeLocals;
 847     int m_numVars;
 848
 849     // This is intentionally public; it's the responsibility of anyone doing any
 850     // of the following to hold the lock:
 851     //
 852     // - Modifying any inline cache in this code block.
 853     //
 854     // - Quering any inline cache in this code block, from a thread other than
 855     //   the main thread.
 856     //
 857     // Additionally, it's only legal to modify the inline cache on the main
 858     // thread. This means that the main thread can query the inline cache without
 859     // locking. This is crucial since executing the inline cache is effectively
 860     // "querying" it.
 861     //
 862     // Another exception to the rules is that the GC can do whatever it wants
 863     // without holding any locks, because the GC is guaranteed to wait until any
 864     // concurrent compilation threads finish what they're doing.
 865     mutable ConcurrentJITLock m_lock;
 866
 867     Atomic<bool> m_visitWeaklyHasBeenCalled;
 868
 869     bool m_shouldAlwaysBeInlined; // Not a bitfield because the JIT wants to store to it.
 870
 871 #if ENABLE(JIT)
 872     unsigned m_capabilityLevelState : 2; // DFG::CapabilityLevel
 873 #endif
 874
 875     bool m_allTransitionsHaveBeenMarked : 1; // Initialized and used on every GC.
 876
 877     bool m_didFailFTLCompilation : 1;
 878     bool m_hasBeenCompiledWithFTL : 1;
 879     bool m_isConstructor : 1;
 880     bool m_isStrictMode : 1;
 881     unsigned m_codeType : 2; // CodeType
 882
 883     // Internal methods for use by validation code. It would be private if it wasn't
 884     // for the fact that we use it from anonymous namespaces.
 885     void beginValidationDidFail();
 886     NO_RETURN_DUE_TO_CRASH void endValidationDidFail();
 887
 888     struct RareData {
 889         WTF_MAKE_FAST_ALLOCATED;
 890     public:
 891         Vector<HandlerInfo> m_exceptionHandlers;
 892
 893         // Buffers used for large array literals
 894         Vector<Vector<JSValue>> m_constantBuffers;
 895
 896         // Jump Tables
 897         Vector<SimpleJumpTable> m_switchJumpTables;
 898         Vector<StringJumpTable> m_stringSwitchJumpTables;
 899
 900         Vector<FastBitVector> m_liveCalleeLocalsAtYield;
 901
 902         EvalCodeCache m_evalCodeCache;
 903     };
 904
 905     void clearExceptionHandlers()
 906     {
 907         if (m_rareData)
 908             m_rareData->m_exceptionHandlers.clear();
 909     }
 910
 911     void appendExceptionHandler(const HandlerInfo& handler)
 912     {
 913         createRareDataIfNecessary(); // We may be handling the exception of an inlined call frame.
 914         m_rareData->m_exceptionHandlers.append(handler);
 915     }
 916
 917     CallSiteIndex newExceptionHandlingCallSiteIndex(CallSiteIndex originalCallSite);
 918
 919 #if ENABLE(JIT)
 920     void setPCToCodeOriginMap(std::unique_ptr<PCToCodeOriginMap>&&);
 921     Optional<CodeOrigin> findPC(void* pc);
 922 #endif
 923
 924 protected:
 925     void finalizeLLIntInlineCaches();
 926     void finalizeBaselineJITInlineCaches();
 927
 928 #if ENABLE(DFG_JIT)
 929     void tallyFrequentExitSites();
 930 #else
 931     void tallyFrequentExitSites() { }
 932 #endif
 933
 934 private:
 935     friend class CodeBlockSet;
 936
 937     CodeBlock* specialOSREntryBlockOrNull();
 938
 939     void noticeIncomingCall(ExecState* callerFrame);
 940
 941     double optimizationThresholdScalingFactor();
 942
 943     void updateAllPredictionsAndCountLiveness(unsigned& numberOfLiveNonArgumentValueProfiles, unsigned& numberOfSamplesInProfiles);
 944
 945     void setConstantRegisters(const Vector<WriteBarrier<Unknown>>& constants, const Vector<SourceCodeRepresentation>& constantsSourceCodeRepresentation);
 946
 947     void replaceConstant(int index, JSValue value)
 948     {
 949         ASSERT(isConstantRegisterIndex(index) && static_cast<size_t>(index - FirstConstantRegisterIndex) < m_constantRegisters.size());
 950         m_constantRegisters[index - FirstConstantRegisterIndex].set(m_globalObject->vm(), this, value);
 951     }
 952
 953     void dumpBytecode(
 954         PrintStream&, ExecState*, const Instruction* begin, const Instruction*&,
 955         const StubInfoMap& = StubInfoMap(), const CallLinkInfoMap& = CallLinkInfoMap());
 956
 957     CString registerName(int r) const;
 958     CString constantName(int index) const;
 959     void printUnaryOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op);
 960     void printBinaryOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op);
 961     void printConditionalJump(PrintStream&, ExecState*, const Instruction*, const Instruction*&, int location, const char* op);
 962     void printGetByIdOp(PrintStream&, ExecState*, int location, const Instruction*&);
 963     void printGetByIdCacheStatus(PrintStream&, ExecState*, int location, const StubInfoMap&);
 964     enum CacheDumpMode { DumpCaches, DontDumpCaches };
 965     void printCallOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op, CacheDumpMode, bool& hasPrintedProfiling, const CallLinkInfoMap&);
 966     void printPutByIdOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op);
 967     void printPutByIdCacheStatus(PrintStream&, int location, const StubInfoMap&);
 968     void printLocationAndOp(PrintStream&, ExecState*, int location, const Instruction*&, const char* op);
 969     void printLocationOpAndRegisterOperand(PrintStream&, ExecState*, int location, const Instruction*& it, const char* op, int operand);
 970
 971     void beginDumpProfiling(PrintStream&, bool& hasPrintedProfiling);
 972     void dumpValueProfiling(PrintStream&, const Instruction*&, bool& hasPrintedProfiling);
 973     void dumpArrayProfiling(PrintStream&, const Instruction*&, bool& hasPrintedProfiling);
 974     void dumpRareCaseProfile(PrintStream&, const char* name, RareCaseProfile*, bool& hasPrintedProfiling);
 975     void dumpResultProfile(PrintStream&, ResultProfile*, bool& hasPrintedProfiling);
 976
 977     bool shouldVisitStrongly();
 978     bool shouldJettisonDueToWeakReference();
 979     bool shouldJettisonDueToOldAge();
 980
 981     void propagateTransitions(SlotVisitor&);
 982     void determineLiveness(SlotVisitor&);
 983
 984     void stronglyVisitStrongReferences(SlotVisitor&);
 985     void stronglyVisitWeakReferences(SlotVisitor&);
 986     void visitOSRExitTargets(SlotVisitor&);
 987
 988     std::chrono::milliseconds timeSinceCreation()
 989     {
 990         return std::chrono::duration_cast<std::chrono::milliseconds>(
 991             std::chrono::steady_clock::now() - m_creationTime);
 992     }
 993
 994     void createRareDataIfNecessary()
 995     {
 996         if (!m_rareData)
 997             m_rareData = std::make_unique<RareData>();
 998     }
 999
1000     void insertBasicBlockBoundariesForControlFlowProfiler(RefCountedArray<Instruction>&);
1001
1002     WriteBarrier<UnlinkedCodeBlock> m_unlinkedCode;
1003     int m_numParameters;
1004     union {
1005         unsigned m_debuggerRequests;
1006         struct {
1007             unsigned m_hasDebuggerStatement : 1;
1008             unsigned m_steppingMode : 1;
1009             unsigned m_numBreakpoints : 30;
1010         };
1011     };
1012     WriteBarrier<ExecutableBase> m_ownerExecutable;
1013     VM* m_vm;
1014
1015     RefCountedArray<Instruction> m_instructions;
1016     VirtualRegister m_thisRegister;
1017     VirtualRegister m_scopeRegister;
1018     mutable CodeBlockHash m_hash;
1019
1020     RefPtr<SourceProvider> m_source;
1021     unsigned m_sourceOffset;
1022     unsigned m_firstLineColumnOffset;
1023
1024     RefCountedArray<LLIntCallLinkInfo> m_llintCallLinkInfos;
1025     SentinelLinkedList<LLIntCallLinkInfo, BasicRawSentinelNode<LLIntCallLinkInfo>> m_incomingLLIntCalls;
1026     StructureWatchpointMap m_llintGetByIdWatchpointMap;
1027     RefPtr<JITCode> m_jitCode;
1028 #if ENABLE(JIT)
1029     std::unique_ptr<RegisterAtOffsetList> m_calleeSaveRegisters;
1030     Bag<StructureStubInfo> m_stubInfos;
1031     Bag<ByValInfo> m_byValInfos;
1032     Bag<CallLinkInfo> m_callLinkInfos;
1033     SentinelLinkedList<CallLinkInfo, BasicRawSentinelNode<CallLinkInfo>> m_incomingCalls;
1034     SentinelLinkedList<PolymorphicCallNode, BasicRawSentinelNode<PolymorphicCallNode>> m_incomingPolymorphicCalls;
1035     std::unique_ptr<PCToCodeOriginMap> m_pcToCodeOriginMap;
1036 #endif
1037     std::unique_ptr<CompactJITCodeMap> m_jitCodeMap;
1038 #if ENABLE(DFG_JIT)
1039     // This is relevant to non-DFG code blocks that serve as the profiled code block
1040     // for DFG code blocks.
1041     DFG::ExitProfile m_exitProfile;
1042     CompressedLazyOperandValueProfileHolder m_lazyOperandValueProfiles;
1043 #endif
1044     RefCountedArray<ValueProfile> m_argumentValueProfiles;
1045     RefCountedArray<ValueProfile> m_valueProfiles;
1046     SegmentedVector<RareCaseProfile, 8> m_rareCaseProfiles;
1047     SegmentedVector<ResultProfile, 8> m_resultProfiles;
1048     typedef HashMap<unsigned, unsigned, IntHash<unsigned>, WTF::UnsignedWithZeroKeyHashTraits<unsigned>> BytecodeOffsetToResultProfileIndexMap;
1049     std::unique_ptr<BytecodeOffsetToResultProfileIndexMap> m_bytecodeOffsetToResultProfileIndexMap;
1050     RefCountedArray<ArrayAllocationProfile> m_arrayAllocationProfiles;
1051     ArrayProfileVector m_arrayProfiles;
1052     RefCountedArray<ObjectAllocationProfile> m_objectAllocationProfiles;
1053
1054     // Constant Pool
1055     COMPILE_ASSERT(sizeof(Register) == sizeof(WriteBarrier<Unknown>), Register_must_be_same_size_as_WriteBarrier_Unknown);
1056     // TODO: This could just be a pointer to m_unlinkedCodeBlock's data, but the DFG mutates
1057     // it, so we're stuck with it for now.
1058     Vector<WriteBarrier<Unknown>> m_constantRegisters;
1059     Vector<SourceCodeRepresentation> m_constantsSourceCodeRepresentation;
1060     RefCountedArray<WriteBarrier<FunctionExecutable>> m_functionDecls;
1061     RefCountedArray<WriteBarrier<FunctionExecutable>> m_functionExprs;
1062
1063     WriteBarrier<CodeBlock> m_alternative;
1064
1065     BaselineExecutionCounter m_llintExecuteCounter;
1066
1067     BaselineExecutionCounter m_jitExecuteCounter;
1068     uint32_t m_osrExitCounter;
1069     uint16_t m_optimizationDelayCounter;
1070     uint16_t m_reoptimizationRetryCounter;
1071
1072     std::chrono::steady_clock::time_point m_creationTime;
1073
1074     std::unique_ptr<BytecodeLivenessAnalysis> m_livenessAnalysis;
1075
1076     std::unique_ptr<RareData> m_rareData;
1077
1078     UnconditionalFinalizer m_unconditionalFinalizer;
1079     WeakReferenceHarvester m_weakReferenceHarvester;
1080 };
1081
1082 // Program code is not marked by any function, so we make the global object
1083 // responsible for marking it.
1084
1085 class GlobalCodeBlock : public CodeBlock {
1086     typedef CodeBlock Base;
1087     DECLARE_INFO;
1088
1089 protected:
1090     GlobalCodeBlock(VM* vm, Structure* structure, CopyParsedBlockTag, GlobalCodeBlock& other)
1091         : CodeBlock(vm, structure, CopyParsedBlock, other)
1092     {
1093     }
1094
1095     GlobalCodeBlock(VM* vm, Structure* structure, ScriptExecutable* ownerExecutable, UnlinkedCodeBlock* unlinkedCodeBlock, JSScope* scope, PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset, unsigned firstLineColumnOffset)
1096         : CodeBlock(vm, structure, ownerExecutable, unlinkedCodeBlock, scope, sourceProvider, sourceOffset, firstLineColumnOffset)
1097     {
1098     }
1099 };
1100
1101 class ProgramCodeBlock : public GlobalCodeBlock {
1102 public:
1103     typedef GlobalCodeBlock Base;
1104     DECLARE_INFO;
1105
1106     static ProgramCodeBlock* create(VM* vm, CopyParsedBlockTag, ProgramCodeBlock& other)
1107     {
1108         ProgramCodeBlock* instance = new (NotNull, allocateCell<ProgramCodeBlock>(vm->heap))
1109             ProgramCodeBlock(vm, vm->programCodeBlockStructure.get(), CopyParsedBlock, other);
1110         instance->finishCreation(*vm, CopyParsedBlock, other);
1111         return instance;
1112     }
1113
1114     static ProgramCodeBlock* create(VM* vm, ProgramExecutable* ownerExecutable, UnlinkedProgramCodeBlock* unlinkedCodeBlock,
1115         JSScope* scope, PassRefPtr<SourceProvider> sourceProvider, unsigned firstLineColumnOffset)
1116     {
1117         ProgramCodeBlock* instance = new (NotNull, allocateCell<ProgramCodeBlock>(vm->heap))
1118             ProgramCodeBlock(vm, vm->programCodeBlockStructure.get(), ownerExecutable, unlinkedCodeBlock, scope, sourceProvider, firstLineColumnOffset);
1119         instance->finishCreation(*vm, ownerExecutable, unlinkedCodeBlock, scope);
1120         return instance;
1121     }
1122
1123     static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
1124     {
1125         return Structure::create(vm, globalObject, prototype, TypeInfo(CellType, StructureFlags), info());
1126     }
1127
1128 private:
1129     ProgramCodeBlock(VM* vm, Structure* structure, CopyParsedBlockTag, ProgramCodeBlock& other)
1130         : GlobalCodeBlock(vm, structure, CopyParsedBlock, other)
1131     {
1132     }
1133
1134     ProgramCodeBlock(VM* vm, Structure* structure, ProgramExecutable* ownerExecutable, UnlinkedProgramCodeBlock* unlinkedCodeBlock,
1135         JSScope* scope, PassRefPtr<SourceProvider> sourceProvider, unsigned firstLineColumnOffset)
1136         : GlobalCodeBlock(vm, structure, ownerExecutable, unlinkedCodeBlock, scope, sourceProvider, 0, firstLineColumnOffset)
1137     {
1138     }
1139
1140     static void destroy(JSCell*);
1141 };
1142
1143 class ModuleProgramCodeBlock : public GlobalCodeBlock {
1144 public:
1145     typedef GlobalCodeBlock Base;
1146     DECLARE_INFO;
1147
1148     static ModuleProgramCodeBlock* create(VM* vm, CopyParsedBlockTag, ModuleProgramCodeBlock& other)
1149     {
1150         ModuleProgramCodeBlock* instance = new (NotNull, allocateCell<ModuleProgramCodeBlock>(vm->heap))
1151             ModuleProgramCodeBlock(vm, vm->moduleProgramCodeBlockStructure.get(), CopyParsedBlock, other);
1152         instance->finishCreation(*vm, CopyParsedBlock, other);
1153         return instance;
1154     }
1155
1156     static ModuleProgramCodeBlock* create(VM* vm, ModuleProgramExecutable* ownerExecutable, UnlinkedModuleProgramCodeBlock* unlinkedCodeBlock,
1157         JSScope* scope, PassRefPtr<SourceProvider> sourceProvider, unsigned firstLineColumnOffset)
1158     {
1159         ModuleProgramCodeBlock* instance = new (NotNull, allocateCell<ModuleProgramCodeBlock>(vm->heap))
1160             ModuleProgramCodeBlock(vm, vm->moduleProgramCodeBlockStructure.get(), ownerExecutable, unlinkedCodeBlock, scope, sourceProvider, firstLineColumnOffset);
1161         instance->finishCreation(*vm, ownerExecutable, unlinkedCodeBlock, scope);
1162         return instance;
1163     }
1164
1165     static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
1166     {
1167         return Structure::create(vm, globalObject, prototype, TypeInfo(CellType, StructureFlags), info());
1168     }
1169
1170 private:
1171     ModuleProgramCodeBlock(VM* vm, Structure* structure, CopyParsedBlockTag, ModuleProgramCodeBlock& other)
1172         : GlobalCodeBlock(vm, structure, CopyParsedBlock, other)
1173     {
1174     }
1175
1176     ModuleProgramCodeBlock(VM* vm, Structure* structure, ModuleProgramExecutable* ownerExecutable, UnlinkedModuleProgramCodeBlock* unlinkedCodeBlock,
1177         JSScope* scope, PassRefPtr<SourceProvider> sourceProvider, unsigned firstLineColumnOffset)
1178         : GlobalCodeBlock(vm, structure, ownerExecutable, unlinkedCodeBlock, scope, sourceProvider, 0, firstLineColumnOffset)
1179     {
1180     }
1181
1182     static void destroy(JSCell*);
1183 };
1184
1185 class EvalCodeBlock : public GlobalCodeBlock {
1186 public:
1187     typedef GlobalCodeBlock Base;
1188     DECLARE_INFO;
1189
1190     static EvalCodeBlock* create(VM* vm, CopyParsedBlockTag, EvalCodeBlock& other)
1191     {
1192         EvalCodeBlock* instance = new (NotNull, allocateCell<EvalCodeBlock>(vm->heap))
1193             EvalCodeBlock(vm, vm->evalCodeBlockStructure.get(), CopyParsedBlock, other);
1194         instance->finishCreation(*vm, CopyParsedBlock, other);
1195         return instance;
1196     }
1197
1198     static EvalCodeBlock* create(VM* vm, EvalExecutable* ownerExecutable, UnlinkedEvalCodeBlock* unlinkedCodeBlock,
1199         JSScope* scope, PassRefPtr<SourceProvider> sourceProvider)
1200     {
1201         EvalCodeBlock* instance = new (NotNull, allocateCell<EvalCodeBlock>(vm->heap))
1202             EvalCodeBlock(vm, vm->evalCodeBlockStructure.get(), ownerExecutable, unlinkedCodeBlock, scope, sourceProvider);
1203         instance->finishCreation(*vm, ownerExecutable, unlinkedCodeBlock, scope);
1204         return instance;
1205     }
1206
1207     static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
1208     {
1209         return Structure::create(vm, globalObject, prototype, TypeInfo(CellType, StructureFlags), info());
1210     }
1211
1212     const Identifier& variable(unsigned index) { return unlinkedEvalCodeBlock()->variable(index); }
1213     unsigned numVariables() { return unlinkedEvalCodeBlock()->numVariables(); }
1214
1215 private:
1216     EvalCodeBlock(VM* vm, Structure* structure, CopyParsedBlockTag, EvalCodeBlock& other)
1217         : GlobalCodeBlock(vm, structure, CopyParsedBlock, other)
1218     {
1219     }
1220
1221     EvalCodeBlock(VM* vm, Structure* structure, EvalExecutable* ownerExecutable, UnlinkedEvalCodeBlock* unlinkedCodeBlock,
1222         JSScope* scope, PassRefPtr<SourceProvider> sourceProvider)
1223         : GlobalCodeBlock(vm, structure, ownerExecutable, unlinkedCodeBlock, scope, sourceProvider, 0, 1)
1224     {
1225     }
1226
1227     static void destroy(JSCell*);
1228
1229 private:
1230     UnlinkedEvalCodeBlock* unlinkedEvalCodeBlock() const { return jsCast<UnlinkedEvalCodeBlock*>(unlinkedCodeBlock()); }
1231 };
1232
1233 class FunctionCodeBlock : public CodeBlock {
1234 public:
1235     typedef CodeBlock Base;
1236     DECLARE_INFO;
1237
1238     static FunctionCodeBlock* create(VM* vm, CopyParsedBlockTag, FunctionCodeBlock& other)
1239     {
1240         FunctionCodeBlock* instance = new (NotNull, allocateCell<FunctionCodeBlock>(vm->heap))
1241             FunctionCodeBlock(vm, vm->functionCodeBlockStructure.get(), CopyParsedBlock, other);
1242         instance->finishCreation(*vm, CopyParsedBlock, other);
1243         return instance;
1244     }
1245
1246     static FunctionCodeBlock* create(VM* vm, FunctionExecutable* ownerExecutable, UnlinkedFunctionCodeBlock* unlinkedCodeBlock, JSScope* scope,
1247         PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset, unsigned firstLineColumnOffset)
1248     {
1249         FunctionCodeBlock* instance = new (NotNull, allocateCell<FunctionCodeBlock>(vm->heap))
1250             FunctionCodeBlock(vm, vm->functionCodeBlockStructure.get(), ownerExecutable, unlinkedCodeBlock, scope, sourceProvider, sourceOffset, firstLineColumnOffset);
1251         instance->finishCreation(*vm, ownerExecutable, unlinkedCodeBlock, scope);
1252         return instance;
1253     }
1254
1255     static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
1256     {
1257         return Structure::create(vm, globalObject, prototype, TypeInfo(CellType, StructureFlags), info());
1258     }
1259
1260 private:
1261     FunctionCodeBlock(VM* vm, Structure* structure, CopyParsedBlockTag, FunctionCodeBlock& other)
1262         : CodeBlock(vm, structure, CopyParsedBlock, other)
1263     {
1264     }
1265
1266     FunctionCodeBlock(VM* vm, Structure* structure, FunctionExecutable* ownerExecutable, UnlinkedFunctionCodeBlock* unlinkedCodeBlock, JSScope* scope,
1267         PassRefPtr<SourceProvider> sourceProvider, unsigned sourceOffset, unsigned firstLineColumnOffset)
1268         : CodeBlock(vm, structure, ownerExecutable, unlinkedCodeBlock, scope, sourceProvider, sourceOffset, firstLineColumnOffset)
1269     {
1270     }
1271
1272     static void destroy(JSCell*);
1273 };
1274
1275 #if ENABLE(WEBASSEMBLY)
1276 class WebAssemblyCodeBlock : public CodeBlock {
1277 public:
1278     typedef CodeBlock Base;
1279     DECLARE_INFO;
1280
1281     static WebAssemblyCodeBlock* create(VM* vm, CopyParsedBlockTag, WebAssemblyCodeBlock& other)
1282     {
1283         WebAssemblyCodeBlock* instance = new (NotNull, allocateCell<WebAssemblyCodeBlock>(vm->heap))
1284             WebAssemblyCodeBlock(vm, vm->webAssemblyCodeBlockStructure.get(), CopyParsedBlock, other);
1285         instance->finishCreation(*vm, CopyParsedBlock, other);
1286         return instance;
1287     }
1288
1289     static WebAssemblyCodeBlock* create(VM* vm, WebAssemblyExecutable* ownerExecutable, JSGlobalObject* globalObject)
1290     {
1291         WebAssemblyCodeBlock* instance = new (NotNull, allocateCell<WebAssemblyCodeBlock>(vm->heap))
1292             WebAssemblyCodeBlock(vm, vm->webAssemblyCodeBlockStructure.get(), ownerExecutable, globalObject);
1293         instance->finishCreation(*vm, ownerExecutable, globalObject);
1294         return instance;
1295     }
1296
1297     static Structure* createStructure(VM& vm, JSGlobalObject* globalObject, JSValue prototype)
1298     {
1299         return Structure::create(vm, globalObject, prototype, TypeInfo(CellType, StructureFlags), info());
1300     }
1301
1302 private:
1303     WebAssemblyCodeBlock(VM* vm, Structure* structure, CopyParsedBlockTag, WebAssemblyCodeBlock& other)
1304         : CodeBlock(vm, structure, CopyParsedBlock, other)
1305     {
1306     }
1307
1308     WebAssemblyCodeBlock(VM* vm, Structure* structure, WebAssemblyExecutable* ownerExecutable, JSGlobalObject* globalObject)
1309         : CodeBlock(vm, structure, ownerExecutable, globalObject)
1310     {
1311     }
1312
1313     static void destroy(JSCell*);
1314 };
1315 #endif
1316
1317 inline void clearLLIntGetByIdCache(Instruction* instruction)
1318 {
1319     instruction[0].u.opcode = LLInt::getOpcode(op_get_by_id);
1320     instruction[4].u.pointer = nullptr;
1321     instruction[5].u.pointer = nullptr;
1322     instruction[6].u.pointer = nullptr;
1323 }
1324
1325 inline Register& ExecState::r(int index)
1326 {
1327     CodeBlock* codeBlock = this->codeBlock();
1328     if (codeBlock->isConstantRegisterIndex(index))
1329         return *reinterpret_cast<Register*>(&codeBlock->constantRegister(index));
1330     return this[index];
1331 }
1332
1333 inline Register& ExecState::r(VirtualRegister reg)
1334 {
1335     return r(reg.offset());
1336 }
1337
1338 inline Register& ExecState::uncheckedR(int index)
1339 {
1340     RELEASE_ASSERT(index < FirstConstantRegisterIndex);
1341     return this[index];
1342 }
1343
1344 inline Register& ExecState::uncheckedR(VirtualRegister reg)
1345 {
1346     return uncheckedR(reg.offset());
1347 }
1348
1349 inline void CodeBlock::clearVisitWeaklyHasBeenCalled()
1350 {
1351     m_visitWeaklyHasBeenCalled.store(false, std::memory_order_relaxed);
1352 }
1353
1354 inline void CodeBlockSet::mark(const LockHolder& locker, void* candidateCodeBlock)
1355 {
1356     ASSERT(m_lock.isLocked());
1357     // We have to check for 0 and -1 because those are used by the HashMap as markers.
1358     uintptr_t value = reinterpret_cast<uintptr_t>(candidateCodeBlock);
1359
1360     // This checks for both of those nasty cases in one go.
1361     // 0 + 1 = 1
1362     // -1 + 1 = 0
1363     if (value + 1 <= 1)
1364         return;
1365
1366     CodeBlock* codeBlock = static_cast<CodeBlock*>(candidateCodeBlock);
1367     if (!m_oldCodeBlocks.contains(codeBlock) && !m_newCodeBlocks.contains(codeBlock))
1368         return;
1369
1370     mark(locker, codeBlock);
1371 }
1372
1373 inline void CodeBlockSet::mark(const LockHolder&, CodeBlock* codeBlock)
1374 {
1375     if (!codeBlock)
1376         return;
1377
1378     // Try to recover gracefully if we forget to execute a barrier for a
1379     // CodeBlock that does value profiling. This is probably overkill, but we
1380     // have always done it.
1381     Heap::heap(codeBlock)->writeBarrier(codeBlock);
1382
1383     m_currentlyExecuting.add(codeBlock);
1384 }
1385
1386 template <typename Functor> inline void ScriptExecutable::forEachCodeBlock(Functor&& functor)
1387 {
1388     switch (type()) {
1389     case ProgramExecutableType: {
1390         if (CodeBlock* codeBlock = static_cast<CodeBlock*>(jsCast<ProgramExecutable*>(this)->m_programCodeBlock.get()))
1391             codeBlock->forEachRelatedCodeBlock(std::forward<Functor>(functor));
1392         break;
1393     }
1394
1395     case EvalExecutableType: {
1396         if (CodeBlock* codeBlock = static_cast<CodeBlock*>(jsCast<EvalExecutable*>(this)->m_evalCodeBlock.get()))
1397             codeBlock->forEachRelatedCodeBlock(std::forward<Functor>(functor));
1398         break;
1399     }
1400
1401     case FunctionExecutableType: {
1402         Functor f(std::forward<Functor>(functor));
1403         FunctionExecutable* executable = jsCast<FunctionExecutable*>(this);
1404         if (CodeBlock* codeBlock = static_cast<CodeBlock*>(executable->m_codeBlockForCall.get()))
1405             codeBlock->forEachRelatedCodeBlock(f);
1406         if (CodeBlock* codeBlock = static_cast<CodeBlock*>(executable->m_codeBlockForConstruct.get()))
1407             codeBlock->forEachRelatedCodeBlock(f);
1408         break;
1409     }
1410
1411     case ModuleProgramExecutableType: {
1412         if (CodeBlock* codeBlock = static_cast<CodeBlock*>(jsCast<ModuleProgramExecutable*>(this)->m_moduleProgramCodeBlock.get()))
1413             codeBlock->forEachRelatedCodeBlock(std::forward<Functor>(functor));
1414         break;
1415     }
1416
1417     default:
1418         RELEASE_ASSERT_NOT_REACHED();
1419     }
1420 }
1421
1422 #define CODEBLOCK_LOG_EVENT(codeBlock, summary, details) \
1423     (codeBlock->vm()->logEvent(codeBlock, summary, [&] () { return toCString details; }))
1424
1425 } // namespace JSC
1426
1427 #endif // CodeBlock_h