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/*
* Copyright (C) 2008-2019 Apple Inc. All rights reserved.
* Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of Apple Inc. ("Apple") nor the names of
* its contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "ArrayProfile.h"
#include "BytecodeConventions.h"
#include "CallLinkInfo.h"
#include "CodeBlockHash.h"
#include "CodeOrigin.h"
#include "CodeType.h"
#include "CompilationResult.h"
#include "ConcurrentJSLock.h"
#include "DFGCommon.h"
#include "DirectEvalCodeCache.h"
#include "EvalExecutable.h"
#include "ExecutionCounter.h"
#include "ExpressionRangeInfo.h"
#include "FunctionExecutable.h"
#include "HandlerInfo.h"
#include "ICStatusMap.h"
#include "Instruction.h"
#include "InstructionStream.h"
#include "JITCode.h"
#include "JITCodeMap.h"
#include "JITMathICForwards.h"
#include "JSCast.h"
#include "JSGlobalObject.h"
#include "JumpTable.h"
#include "LLIntCallLinkInfo.h"
#include "LazyOperandValueProfile.h"
#include "MetadataTable.h"
#include "ModuleProgramExecutable.h"
#include "ObjectAllocationProfile.h"
#include "Options.h"
#include "Printer.h"
#include "ProfilerJettisonReason.h"
#include "ProgramExecutable.h"
#include "PutPropertySlot.h"
#include "ValueProfile.h"
#include "VirtualRegister.h"
#include "Watchpoint.h"
#include <wtf/Bag.h>
#include <wtf/FastMalloc.h>
#include <wtf/RefCountedArray.h>
#include <wtf/RefPtr.h>
#include <wtf/SegmentedVector.h>
#include <wtf/Vector.h>
#include <wtf/text/WTFString.h>
namespace JSC {
#if ENABLE(DFG_JIT)
namespace DFG {
struct OSRExitState;
} // namespace DFG
#endif
class UnaryArithProfile;
class BinaryArithProfile;
class BytecodeLivenessAnalysis;
class CodeBlockSet;
class ExecutableToCodeBlockEdge;
class JSModuleEnvironment;
class LLIntOffsetsExtractor;
class LLIntPrototypeLoadAdaptiveStructureWatchpoint;
class MetadataTable;
class PCToCodeOriginMap;
class RegisterAtOffsetList;
class StructureStubInfo;
struct ByValInfo;
DECLARE_ALLOCATOR_WITH_HEAP_IDENTIFIER(CodeBlockRareData);
enum class AccessType : int8_t;
struct OpCatch;
enum ReoptimizationMode { DontCountReoptimization, CountReoptimization };
class CodeBlock : public JSCell {
typedef JSCell Base;
friend class BytecodeLivenessAnalysis;
friend class JIT;
friend class LLIntOffsetsExtractor;
public:
enum CopyParsedBlockTag { CopyParsedBlock };
static constexpr unsigned StructureFlags = Base::StructureFlags | StructureIsImmortal;
static constexpr bool needsDestruction = true;
template<typename, SubspaceAccess>
static void subspaceFor(VM&)
{
RELEASE_ASSERT_NOT_REACHED();
}
// GC strongly assumes CodeBlock is not a PreciseAllocation for now.
static constexpr uint8_t numberOfLowerTierCells = 0;
DECLARE_INFO;
protected:
CodeBlock(VM&, Structure*, CopyParsedBlockTag, CodeBlock& other);
CodeBlock(VM&, Structure*, ScriptExecutable* ownerExecutable, UnlinkedCodeBlock*, JSScope*);
void finishCreation(VM&, CopyParsedBlockTag, CodeBlock& other);
bool finishCreation(VM&, ScriptExecutable* ownerExecutable, UnlinkedCodeBlock*, JSScope*);
void finishCreationCommon(VM&);
WriteBarrier<JSGlobalObject> m_globalObject;
public:
JS_EXPORT_PRIVATE ~CodeBlock();
UnlinkedCodeBlock* unlinkedCodeBlock() const { return m_unlinkedCode.get(); }
CString inferredName() const;
CodeBlockHash hash() const;
bool hasHash() const;
bool isSafeToComputeHash() const;
CString hashAsStringIfPossible() const;
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.
CString sourceCodeOnOneLine() const; // As sourceCodeForTools(), but replaces all whitespace runs with a single space.
void dumpAssumingJITType(PrintStream&, JITType) const;
JS_EXPORT_PRIVATE void dump(PrintStream&) const;
MetadataTable* metadataTable() const { return m_metadata.get(); }
int numParameters() const { return m_numParameters; }
void setNumParameters(int newValue);
int numberOfArgumentsToSkip() const { return m_numberOfArgumentsToSkip; }
int numCalleeLocals() const { return m_numCalleeLocals; }
int numVars() const { return m_numVars; }
int numTmps() const { return m_unlinkedCode->hasCheckpoints() * maxNumCheckpointTmps; }
int* addressOfNumParameters() { return &m_numParameters; }
static ptrdiff_t offsetOfNumParameters() { return OBJECT_OFFSETOF(CodeBlock, m_numParameters); }
CodeBlock* alternative() const { return static_cast<CodeBlock*>(m_alternative.get()); }
void setAlternative(VM&, CodeBlock*);
template <typename Functor> void forEachRelatedCodeBlock(Functor&& functor)
{
Functor f(std::forward<Functor>(functor));
Vector<CodeBlock*, 4> codeBlocks;
codeBlocks.append(this);
while (!codeBlocks.isEmpty()) {
CodeBlock* currentCodeBlock = codeBlocks.takeLast();
f(currentCodeBlock);
if (CodeBlock* alternative = currentCodeBlock->alternative())
codeBlocks.append(alternative);
if (CodeBlock* osrEntryBlock = currentCodeBlock->specialOSREntryBlockOrNull())
codeBlocks.append(osrEntryBlock);
}
}
CodeSpecializationKind specializationKind() const
{
return specializationFromIsConstruct(isConstructor());
}
CodeBlock* alternativeForJettison();
JS_EXPORT_PRIVATE CodeBlock* baselineAlternative();
// FIXME: Get rid of this.
// https://bugs.webkit.org/show_bug.cgi?id=123677
CodeBlock* baselineVersion();
static size_t estimatedSize(JSCell*, VM&);
static void visitChildren(JSCell*, SlotVisitor&);
static void destroy(JSCell*);
void visitChildren(SlotVisitor&);
void finalizeUnconditionally(VM&);
void notifyLexicalBindingUpdate();
void dumpSource();
void dumpSource(PrintStream&);
void dumpBytecode();
void dumpBytecode(PrintStream&);
void dumpBytecode(PrintStream& out, const InstructionStream::Ref& it, const ICStatusMap& = ICStatusMap());
void dumpBytecode(PrintStream& out, unsigned bytecodeOffset, const ICStatusMap& = ICStatusMap());
void dumpExceptionHandlers(PrintStream&);
void printStructures(PrintStream&, const Instruction*);
void printStructure(PrintStream&, const char* name, const Instruction*, int operand);
void dumpMathICStats();
bool isConstructor() const { return m_unlinkedCode->isConstructor(); }
CodeType codeType() const { return m_unlinkedCode->codeType(); }
JSParserScriptMode scriptMode() const { return m_unlinkedCode->scriptMode(); }
bool hasInstalledVMTrapBreakpoints() const;
bool installVMTrapBreakpoints();
inline bool isKnownCell(VirtualRegister reg)
{
// FIXME: Consider adding back the optimization where we return true if `reg` is `this` and we're in sloppy mode.
// https://bugs.webkit.org/show_bug.cgi?id=210145
if (reg.isConstant())
return getConstant(reg).isCell();
return false;
}
ALWAYS_INLINE bool isTemporaryRegister(VirtualRegister reg)
{
return reg.offset() >= m_numVars;
}
HandlerInfo* handlerForBytecodeIndex(BytecodeIndex, RequiredHandler = RequiredHandler::AnyHandler);
HandlerInfo* handlerForIndex(unsigned, RequiredHandler = RequiredHandler::AnyHandler);
void removeExceptionHandlerForCallSite(DisposableCallSiteIndex);
unsigned lineNumberForBytecodeIndex(BytecodeIndex);
unsigned columnNumberForBytecodeIndex(BytecodeIndex);
void expressionRangeForBytecodeIndex(BytecodeIndex, int& divot,
int& startOffset, int& endOffset, unsigned& line, unsigned& column) const;
Optional<BytecodeIndex> bytecodeIndexFromCallSiteIndex(CallSiteIndex);
// Because we might throw out baseline JIT code and all its baseline JIT data (m_jitData),
// you need to be careful about the lifetime of when you use the return value of this function.
// The return value may have raw pointers into this data structure that gets thrown away.
// Specifically, you need to ensure that no GC can be finalized (typically that means no
// allocations) between calling this and the last use of it.
void getICStatusMap(const ConcurrentJSLocker&, ICStatusMap& result);
void getICStatusMap(ICStatusMap& result);
#if ENABLE(JIT)
struct JITData {
WTF_MAKE_STRUCT_FAST_ALLOCATED;
Bag<StructureStubInfo> m_stubInfos;
Bag<JITAddIC> m_addICs;
Bag<JITMulIC> m_mulICs;
Bag<JITNegIC> m_negICs;
Bag<JITSubIC> m_subICs;
Bag<ByValInfo> m_byValInfos;
Bag<CallLinkInfo> m_callLinkInfos;
SentinelLinkedList<CallLinkInfo, PackedRawSentinelNode<CallLinkInfo>> m_incomingCalls;
SentinelLinkedList<PolymorphicCallNode, PackedRawSentinelNode<PolymorphicCallNode>> m_incomingPolymorphicCalls;
RefCountedArray<RareCaseProfile> m_rareCaseProfiles;
std::unique_ptr<PCToCodeOriginMap> m_pcToCodeOriginMap;
std::unique_ptr<RegisterAtOffsetList> m_calleeSaveRegisters;
JITCodeMap m_jitCodeMap;
};
JITData& ensureJITData(const ConcurrentJSLocker& locker)
{
if (LIKELY(m_jitData))
return *m_jitData;
return ensureJITDataSlow(locker);
}
JITData& ensureJITDataSlow(const ConcurrentJSLocker&);
JITAddIC* addJITAddIC(BinaryArithProfile*);
JITMulIC* addJITMulIC(BinaryArithProfile*);
JITNegIC* addJITNegIC(UnaryArithProfile*);
JITSubIC* addJITSubIC(BinaryArithProfile*);
template <typename Generator, typename = typename std::enable_if<std::is_same<Generator, JITAddGenerator>::value>::type>
JITAddIC* addMathIC(BinaryArithProfile* profile) { return addJITAddIC(profile); }
template <typename Generator, typename = typename std::enable_if<std::is_same<Generator, JITMulGenerator>::value>::type>
JITMulIC* addMathIC(BinaryArithProfile* profile) { return addJITMulIC(profile); }
template <typename Generator, typename = typename std::enable_if<std::is_same<Generator, JITNegGenerator>::value>::type>
JITNegIC* addMathIC(UnaryArithProfile* profile) { return addJITNegIC(profile); }
template <typename Generator, typename = typename std::enable_if<std::is_same<Generator, JITSubGenerator>::value>::type>
JITSubIC* addMathIC(BinaryArithProfile* profile) { return addJITSubIC(profile); }
StructureStubInfo* addStubInfo(AccessType);
// O(n) operation. Use getICStatusMap() unless you really only intend to get one stub info.
StructureStubInfo* findStubInfo(CodeOrigin);
// O(n) operation. Use getICStatusMap() unless you really only intend to get one by-val-info.
ByValInfo* findByValInfo(CodeOrigin);
ByValInfo* addByValInfo();
CallLinkInfo* addCallLinkInfo();
// This is a slow function call used primarily for compiling OSR exits in the case
// that there had been inlining. Chances are if you want to use this, you're really
// looking for a CallLinkInfoMap to amortize the cost of calling this.
CallLinkInfo* getCallLinkInfoForBytecodeIndex(BytecodeIndex);
void setJITCodeMap(JITCodeMap&& jitCodeMap)
{
ConcurrentJSLocker locker(m_lock);
ensureJITData(locker).m_jitCodeMap = WTFMove(jitCodeMap);
}
const JITCodeMap& jitCodeMap()
{
ConcurrentJSLocker locker(m_lock);
return ensureJITData(locker).m_jitCodeMap;
}
void setPCToCodeOriginMap(std::unique_ptr<PCToCodeOriginMap>&&);
Optional<CodeOrigin> findPC(void* pc);
void setCalleeSaveRegisters(RegisterSet);
void setCalleeSaveRegisters(std::unique_ptr<RegisterAtOffsetList>);
void setRareCaseProfiles(RefCountedArray<RareCaseProfile>&&);
RareCaseProfile* rareCaseProfileForBytecodeIndex(const ConcurrentJSLocker&, BytecodeIndex);
unsigned rareCaseProfileCountForBytecodeIndex(const ConcurrentJSLocker&, BytecodeIndex);
bool likelyToTakeSlowCase(BytecodeIndex bytecodeIndex)
{
if (!hasBaselineJITProfiling())
return false;
ConcurrentJSLocker locker(m_lock);
unsigned value = rareCaseProfileCountForBytecodeIndex(locker, bytecodeIndex);
return value >= Options::likelyToTakeSlowCaseMinimumCount();
}
bool couldTakeSlowCase(BytecodeIndex bytecodeIndex)
{
if (!hasBaselineJITProfiling())
return false;
ConcurrentJSLocker locker(m_lock);
unsigned value = rareCaseProfileCountForBytecodeIndex(locker, bytecodeIndex);
return value >= Options::couldTakeSlowCaseMinimumCount();
}
// We call this when we want to reattempt compiling something with the baseline JIT. Ideally
// the baseline JIT would not add data to CodeBlock, but instead it would put its data into
// a newly created JITCode, which could be thrown away if we bail on JIT compilation. Then we
// would be able to get rid of this silly function.
// FIXME: https://bugs.webkit.org/show_bug.cgi?id=159061
void resetJITData();
#endif // ENABLE(JIT)
void unlinkIncomingCalls();
#if ENABLE(JIT)
void linkIncomingCall(CallFrame* callerFrame, CallLinkInfo*);
void linkIncomingPolymorphicCall(CallFrame* callerFrame, PolymorphicCallNode*);
#endif // ENABLE(JIT)
void linkIncomingCall(CallFrame* callerFrame, LLIntCallLinkInfo*);
const Instruction* outOfLineJumpTarget(const Instruction* pc);
int outOfLineJumpOffset(InstructionStream::Offset offset)
{
return m_unlinkedCode->outOfLineJumpOffset(offset);
}
int outOfLineJumpOffset(const Instruction* pc);
int outOfLineJumpOffset(const InstructionStream::Ref& instruction)
{
return outOfLineJumpOffset(instruction.ptr());
}
inline unsigned bytecodeOffset(const Instruction* returnAddress)
{
const auto* instructionsBegin = instructions().at(0).ptr();
const auto* instructionsEnd = reinterpret_cast<const Instruction*>(reinterpret_cast<uintptr_t>(instructionsBegin) + instructions().size());
RELEASE_ASSERT(returnAddress >= instructionsBegin && returnAddress < instructionsEnd);
return returnAddress - instructionsBegin;
}
inline BytecodeIndex bytecodeIndex(const Instruction* returnAddress)
{
return BytecodeIndex(bytecodeOffset(returnAddress));
}
const InstructionStream& instructions() const { return m_unlinkedCode->instructions(); }
const Instruction* instructionAt(BytecodeIndex index) const { return instructions().at(index).ptr(); }
size_t predictedMachineCodeSize();
unsigned instructionsSize() const { return instructions().size(); }
unsigned bytecodeCost() const { return m_bytecodeCost; }
// Exactly equivalent to codeBlock->ownerExecutable()->newReplacementCodeBlockFor(codeBlock->specializationKind())
CodeBlock* newReplacement();
void setJITCode(Ref<JITCode>&& code)
{
if (!code->isShared())
heap()->reportExtraMemoryAllocated(code->size());
ConcurrentJSLocker locker(m_lock);
WTF::storeStoreFence(); // This is probably not needed because the lock will also do something similar, but it's good to be paranoid.
m_jitCode = WTFMove(code);
}
RefPtr<JITCode> jitCode() { return m_jitCode; }
static ptrdiff_t jitCodeOffset() { return OBJECT_OFFSETOF(CodeBlock, m_jitCode); }
JITType jitType() const
{
JITCode* jitCode = m_jitCode.get();
WTF::loadLoadFence();
JITType result = JITCode::jitTypeFor(jitCode);
WTF::loadLoadFence(); // This probably isn't needed. Oh well, paranoia is good.
return result;
}
bool hasBaselineJITProfiling() const
{
return jitType() == JITType::BaselineJIT;
}
#if ENABLE(JIT)
CodeBlock* replacement();
DFG::CapabilityLevel computeCapabilityLevel();
DFG::CapabilityLevel capabilityLevel();
DFG::CapabilityLevel capabilityLevelState() { return static_cast<DFG::CapabilityLevel>(m_capabilityLevelState); }
CodeBlock* optimizedReplacement(JITType typeToReplace);
CodeBlock* optimizedReplacement(); // the typeToReplace is my JITType
bool hasOptimizedReplacement(JITType typeToReplace);
bool hasOptimizedReplacement(); // the typeToReplace is my JITType
#endif
void jettison(Profiler::JettisonReason, ReoptimizationMode = DontCountReoptimization, const FireDetail* = nullptr);
ScriptExecutable* ownerExecutable() const { return m_ownerExecutable.get(); }
ExecutableToCodeBlockEdge* ownerEdge() const { return m_ownerEdge.get(); }
VM& vm() const { return *m_vm; }
VirtualRegister thisRegister() const { return m_unlinkedCode->thisRegister(); }
bool usesEval() const { return m_unlinkedCode->usesEval(); }
void setScopeRegister(VirtualRegister scopeRegister)
{
ASSERT(scopeRegister.isLocal() || !scopeRegister.isValid());
m_scopeRegister = scopeRegister;
}
VirtualRegister scopeRegister() const
{
return m_scopeRegister;
}
PutPropertySlot::Context putByIdContext() const
{
if (codeType() == EvalCode)
return PutPropertySlot::PutByIdEval;
return PutPropertySlot::PutById;
}
const SourceCode& source() const { return m_ownerExecutable->source(); }
unsigned sourceOffset() const { return m_ownerExecutable->source().startOffset(); }
unsigned firstLineColumnOffset() const { return m_ownerExecutable->startColumn(); }
size_t numberOfJumpTargets() const { return m_unlinkedCode->numberOfJumpTargets(); }
unsigned jumpTarget(int index) const { return m_unlinkedCode->jumpTarget(index); }
String nameForRegister(VirtualRegister);
unsigned numberOfArgumentValueProfiles()
{
ASSERT(m_numParameters >= 0);
ASSERT(m_argumentValueProfiles.size() == static_cast<unsigned>(m_numParameters) || !vm().canUseJIT());
return m_argumentValueProfiles.size();
}
ValueProfile& valueProfileForArgument(unsigned argumentIndex)
{
ASSERT(vm().canUseJIT()); // This is only called from the various JIT compilers or places that first check numberOfArgumentValueProfiles before calling this.
ValueProfile& result = m_argumentValueProfiles[argumentIndex];
return result;
}
ValueProfile& valueProfileForBytecodeIndex(BytecodeIndex);
SpeculatedType valueProfilePredictionForBytecodeIndex(const ConcurrentJSLocker&, BytecodeIndex);
template<typename Functor> void forEachValueProfile(const Functor&);
template<typename Functor> void forEachArrayProfile(const Functor&);
template<typename Functor> void forEachArrayAllocationProfile(const Functor&);
template<typename Functor> void forEachObjectAllocationProfile(const Functor&);
template<typename Functor> void forEachLLIntCallLinkInfo(const Functor&);
BinaryArithProfile* binaryArithProfileForBytecodeIndex(BytecodeIndex);
UnaryArithProfile* unaryArithProfileForBytecodeIndex(BytecodeIndex);
BinaryArithProfile* binaryArithProfileForPC(const Instruction*);
UnaryArithProfile* unaryArithProfileForPC(const Instruction*);
bool couldTakeSpecialArithFastCase(BytecodeIndex bytecodeOffset);
ArrayProfile* getArrayProfile(const ConcurrentJSLocker&, BytecodeIndex);
ArrayProfile* getArrayProfile(BytecodeIndex);
// Exception handling support
size_t numberOfExceptionHandlers() const { return m_rareData ? m_rareData->m_exceptionHandlers.size() : 0; }
HandlerInfo& exceptionHandler(int index) { RELEASE_ASSERT(m_rareData); return m_rareData->m_exceptionHandlers[index]; }
bool hasExpressionInfo() { return m_unlinkedCode->hasExpressionInfo(); }
#if ENABLE(DFG_JIT)
Vector<CodeOrigin, 0, UnsafeVectorOverflow>& codeOrigins();
// Having code origins implies that there has been some inlining.
bool hasCodeOrigins()
{
return JITCode::isOptimizingJIT(jitType());
}
bool canGetCodeOrigin(CallSiteIndex index)
{
if (!hasCodeOrigins())
return false;
return index.bits() < codeOrigins().size();
}
CodeOrigin codeOrigin(CallSiteIndex index)
{
return codeOrigins()[index.bits()];
}
CompressedLazyOperandValueProfileHolder& lazyOperandValueProfiles(const ConcurrentJSLocker&)
{
return m_lazyOperandValueProfiles;
}
#endif // ENABLE(DFG_JIT)
// Constant Pool
#if ENABLE(DFG_JIT)
size_t numberOfIdentifiers() const { return m_unlinkedCode->numberOfIdentifiers() + numberOfDFGIdentifiers(); }
size_t numberOfDFGIdentifiers() const;
const Identifier& identifier(int index) const;
#else
size_t numberOfIdentifiers() const { return m_unlinkedCode->numberOfIdentifiers(); }
const Identifier& identifier(int index) const { return m_unlinkedCode->identifier(index); }
#endif
Vector<WriteBarrier<Unknown>>& constants() { return m_constantRegisters; }
Vector<SourceCodeRepresentation>& constantsSourceCodeRepresentation() { return m_constantsSourceCodeRepresentation; }
unsigned addConstant(const ConcurrentJSLocker&, JSValue v)
{
unsigned result = m_constantRegisters.size();
m_constantRegisters.append(WriteBarrier<Unknown>());
m_constantRegisters.last().set(*m_vm, this, v);
m_constantsSourceCodeRepresentation.append(SourceCodeRepresentation::Other);
return result;
}
unsigned addConstantLazily(const ConcurrentJSLocker&)
{
unsigned result = m_constantRegisters.size();
m_constantRegisters.append(WriteBarrier<Unknown>());
m_constantsSourceCodeRepresentation.append(SourceCodeRepresentation::Other);
return result;
}
const Vector<WriteBarrier<Unknown>>& constantRegisters() { return m_constantRegisters; }
WriteBarrier<Unknown>& constantRegister(VirtualRegister reg) { return m_constantRegisters[reg.toConstantIndex()]; }
ALWAYS_INLINE JSValue getConstant(VirtualRegister reg) const { return m_constantRegisters[reg.toConstantIndex()].get(); }
ALWAYS_INLINE SourceCodeRepresentation constantSourceCodeRepresentation(VirtualRegister reg) const { return m_constantsSourceCodeRepresentation[reg.toConstantIndex()]; }
FunctionExecutable* functionDecl(int index) { return m_functionDecls[index].get(); }
int numberOfFunctionDecls() { return m_functionDecls.size(); }
FunctionExecutable* functionExpr(int index) { return m_functionExprs[index].get(); }
const BitVector& bitVector(size_t i) { return m_unlinkedCode->bitVector(i); }
Heap* heap() const { return &m_vm->heap; }
JSGlobalObject* globalObject() { return m_globalObject.get(); }
JSGlobalObject* globalObjectFor(CodeOrigin);
BytecodeLivenessAnalysis& livenessAnalysis()
{
return m_unlinkedCode->livenessAnalysis(this);
}
void validate();
// Jump Tables
size_t numberOfSwitchJumpTables() const { return m_rareData ? m_rareData->m_switchJumpTables.size() : 0; }
SimpleJumpTable& switchJumpTable(int tableIndex) { RELEASE_ASSERT(m_rareData); return m_rareData->m_switchJumpTables[tableIndex]; }
void clearSwitchJumpTables()
{
if (!m_rareData)
return;
m_rareData->m_switchJumpTables.clear();
}
#if ENABLE(DFG_JIT)
void addSwitchJumpTableFromProfiledCodeBlock(SimpleJumpTable& profiled)
{
createRareDataIfNecessary();
m_rareData->m_switchJumpTables.append(profiled.cloneNonJITPart());
}
#endif
size_t numberOfStringSwitchJumpTables() const { return m_rareData ? m_rareData->m_stringSwitchJumpTables.size() : 0; }
StringJumpTable& stringSwitchJumpTable(int tableIndex) { RELEASE_ASSERT(m_rareData); return m_rareData->m_stringSwitchJumpTables[tableIndex]; }
DirectEvalCodeCache& directEvalCodeCache() { createRareDataIfNecessary(); return m_rareData->m_directEvalCodeCache; }
enum class ShrinkMode {
// Shrink prior to generating machine code that may point directly into vectors.
EarlyShrink,
// Shrink after generating machine code, and after possibly creating new vectors
// and appending to others. At this time it is not safe to shrink certain vectors
// because we would have generated machine code that references them directly.
LateShrink,
};
void shrinkToFit(const ConcurrentJSLocker&, ShrinkMode);
// Functions for controlling when JITting kicks in, in a mixed mode
// execution world.
bool checkIfJITThresholdReached()
{
return m_llintExecuteCounter.checkIfThresholdCrossedAndSet(this);
}
void dontJITAnytimeSoon()
{
m_llintExecuteCounter.deferIndefinitely();
}
int32_t thresholdForJIT(int32_t threshold);
void jitAfterWarmUp();
void jitSoon();
const BaselineExecutionCounter& llintExecuteCounter() const
{
return m_llintExecuteCounter;
}
typedef HashMap<std::tuple<StructureID, unsigned>, Vector<LLIntPrototypeLoadAdaptiveStructureWatchpoint>> StructureWatchpointMap;
StructureWatchpointMap& llintGetByIdWatchpointMap() { return m_llintGetByIdWatchpointMap; }
// Functions for controlling when tiered compilation kicks in. This
// controls both when the optimizing compiler is invoked and when OSR
// entry happens. Two triggers exist: the loop trigger and the return
// trigger. In either case, when an addition to m_jitExecuteCounter
// causes it to become non-negative, the optimizing compiler is
// invoked. This includes a fast check to see if this CodeBlock has
// already been optimized (i.e. replacement() returns a CodeBlock
// that was optimized with a higher tier JIT than this one). In the
// case of the loop trigger, if the optimized compilation succeeds
// (or has already succeeded in the past) then OSR is attempted to
// redirect program flow into the optimized code.
// These functions are called from within the optimization triggers,
// and are used as a single point at which we define the heuristics
// for how much warm-up is mandated before the next optimization
// trigger files. All CodeBlocks start out with optimizeAfterWarmUp(),
// as this is called from the CodeBlock constructor.
// When we observe a lot of speculation failures, we trigger a
// reoptimization. But each time, we increase the optimization trigger
// to avoid thrashing.
JS_EXPORT_PRIVATE unsigned reoptimizationRetryCounter() const;
void countReoptimization();
#if !ENABLE(C_LOOP)
const RegisterAtOffsetList* calleeSaveRegisters() const;
static unsigned numberOfLLIntBaselineCalleeSaveRegisters() { return RegisterSet::llintBaselineCalleeSaveRegisters().numberOfSetRegisters(); }
static size_t llintBaselineCalleeSaveSpaceAsVirtualRegisters();
size_t calleeSaveSpaceAsVirtualRegisters();
#else
static unsigned numberOfLLIntBaselineCalleeSaveRegisters() { return 0; }
static size_t llintBaselineCalleeSaveSpaceAsVirtualRegisters() { return 1; };
size_t calleeSaveSpaceAsVirtualRegisters() { return 0; }
#endif
#if ENABLE(JIT)
unsigned numberOfDFGCompiles();
int32_t codeTypeThresholdMultiplier() const;
int32_t adjustedCounterValue(int32_t desiredThreshold);
int32_t* addressOfJITExecuteCounter()
{
return &m_jitExecuteCounter.m_counter;
}
static ptrdiff_t offsetOfJITExecuteCounter() { return OBJECT_OFFSETOF(CodeBlock, m_jitExecuteCounter) + OBJECT_OFFSETOF(BaselineExecutionCounter, m_counter); }
static ptrdiff_t offsetOfJITExecutionActiveThreshold() { return OBJECT_OFFSETOF(CodeBlock, m_jitExecuteCounter) + OBJECT_OFFSETOF(BaselineExecutionCounter, m_activeThreshold); }
static ptrdiff_t offsetOfJITExecutionTotalCount() { return OBJECT_OFFSETOF(CodeBlock, m_jitExecuteCounter) + OBJECT_OFFSETOF(BaselineExecutionCounter, m_totalCount); }
const BaselineExecutionCounter& jitExecuteCounter() const { return m_jitExecuteCounter; }
unsigned optimizationDelayCounter() const { return m_optimizationDelayCounter; }
// Check if the optimization threshold has been reached, and if not,
// adjust the heuristics accordingly. Returns true if the threshold has
// been reached.
bool checkIfOptimizationThresholdReached();
// Call this to force the next optimization trigger to fire. This is
// rarely wise, since optimization triggers are typically more
// expensive than executing baseline code.
void optimizeNextInvocation();
// Call this to prevent optimization from happening again. Note that
// optimization will still happen after roughly 2^29 invocations,
// so this is really meant to delay that as much as possible. This
// is called if optimization failed, and we expect it to fail in
// the future as well.
void dontOptimizeAnytimeSoon();
// Call this to reinitialize the counter to its starting state,
// forcing a warm-up to happen before the next optimization trigger
// fires. This is called in the CodeBlock constructor. It also
// makes sense to call this if an OSR exit occurred. Note that
// OSR exit code is code generated, so the value of the execute
// counter that this corresponds to is also available directly.
void optimizeAfterWarmUp();
// Call this to force an optimization trigger to fire only after
// a lot of warm-up.
void optimizeAfterLongWarmUp();
// Call this to cause an optimization trigger to fire soon, but
// not necessarily the next one. This makes sense if optimization
// succeeds. Successful optimization means that all calls are
// relinked to the optimized code, so this only affects call
// frames that are still executing this CodeBlock. The value here
// is tuned to strike a balance between the cost of OSR entry
// (which is too high to warrant making every loop back edge to
// trigger OSR immediately) and the cost of executing baseline
// code (which is high enough that we don't necessarily want to
// have a full warm-up). The intuition for calling this instead of
// optimizeNextInvocation() is for the case of recursive functions
// with loops. Consider that there may be N call frames of some
// recursive function, for a reasonably large value of N. The top
// one triggers optimization, and then returns, and then all of
// the others return. We don't want optimization to be triggered on
// each return, as that would be superfluous. It only makes sense
// to trigger optimization if one of those functions becomes hot
// in the baseline code.
void optimizeSoon();
void forceOptimizationSlowPathConcurrently();
void setOptimizationThresholdBasedOnCompilationResult(CompilationResult);
BytecodeIndex bytecodeIndexForExit(BytecodeIndex) const;
uint32_t osrExitCounter() const { return m_osrExitCounter; }
void countOSRExit() { m_osrExitCounter++; }
enum class OptimizeAction { None, ReoptimizeNow };
#if ENABLE(DFG_JIT)
OptimizeAction updateOSRExitCounterAndCheckIfNeedToReoptimize(DFG::OSRExitState&);
#endif
static ptrdiff_t offsetOfOSRExitCounter() { return OBJECT_OFFSETOF(CodeBlock, m_osrExitCounter); }
uint32_t adjustedExitCountThreshold(uint32_t desiredThreshold);
uint32_t exitCountThresholdForReoptimization();
uint32_t exitCountThresholdForReoptimizationFromLoop();
bool shouldReoptimizeNow();
bool shouldReoptimizeFromLoopNow();
#else // No JIT
void optimizeAfterWarmUp() { }
unsigned numberOfDFGCompiles() { return 0; }
#endif
bool shouldOptimizeNow();
void updateAllValueProfilePredictions();
void updateAllArrayPredictions();
void updateAllPredictions();
unsigned frameRegisterCount();
int stackPointerOffset();
bool hasOpDebugForLineAndColumn(unsigned line, Optional<unsigned> column);
bool hasDebuggerRequests() const { return m_debuggerRequests; }
void* debuggerRequestsAddress() { return &m_debuggerRequests; }
void addBreakpoint(unsigned numBreakpoints);
void removeBreakpoint(unsigned numBreakpoints)
{
ASSERT(m_numBreakpoints >= numBreakpoints);
m_numBreakpoints -= numBreakpoints;
}
enum SteppingMode {
SteppingModeDisabled,
SteppingModeEnabled
};
void setSteppingMode(SteppingMode);
void clearDebuggerRequests()
{
m_steppingMode = SteppingModeDisabled;
m_numBreakpoints = 0;
}
bool wasCompiledWithDebuggingOpcodes() const { return m_unlinkedCode->wasCompiledWithDebuggingOpcodes(); }
// This is intentionally public; it's the responsibility of anyone doing any
// of the following to hold the lock:
//
// - Modifying any inline cache in this code block.
//
// - Quering any inline cache in this code block, from a thread other than
// the main thread.
//
// Additionally, it's only legal to modify the inline cache on the main
// thread. This means that the main thread can query the inline cache without
// locking. This is crucial since executing the inline cache is effectively
// "querying" it.
//
// Another exception to the rules is that the GC can do whatever it wants
// without holding any locks, because the GC is guaranteed to wait until any
// concurrent compilation threads finish what they're doing.
mutable ConcurrentJSLock m_lock;
bool m_shouldAlwaysBeInlined; // Not a bitfield because the JIT wants to store to it.
#if ENABLE(JIT)
unsigned m_capabilityLevelState : 2; // DFG::CapabilityLevel
#endif
bool m_allTransitionsHaveBeenMarked : 1; // Initialized and used on every GC.
bool m_didFailJITCompilation : 1;
bool m_didFailFTLCompilation : 1;
bool m_hasBeenCompiledWithFTL : 1;
bool m_hasLinkedOSRExit : 1;
bool m_isEligibleForLLIntDowngrade : 1;
// Internal methods for use by validation code. It would be private if it wasn't
// for the fact that we use it from anonymous namespaces.
void beginValidationDidFail();
NO_RETURN_DUE_TO_CRASH void endValidationDidFail();
struct RareData {
WTF_MAKE_STRUCT_FAST_ALLOCATED_WITH_HEAP_IDENTIFIER(CodeBlockRareData);
public:
Vector<HandlerInfo> m_exceptionHandlers;
// Jump Tables
Vector<SimpleJumpTable> m_switchJumpTables;
Vector<StringJumpTable> m_stringSwitchJumpTables;
Vector<std::unique_ptr<ValueProfileAndVirtualRegisterBuffer>> m_catchProfiles;
DirectEvalCodeCache m_directEvalCodeCache;
};
void clearExceptionHandlers()
{
if (m_rareData)
m_rareData->m_exceptionHandlers.clear();
}
void appendExceptionHandler(const HandlerInfo& handler)
{
createRareDataIfNecessary(); // We may be handling the exception of an inlined call frame.
m_rareData->m_exceptionHandlers.append(handler);
}
DisposableCallSiteIndex newExceptionHandlingCallSiteIndex(CallSiteIndex originalCallSite);
void ensureCatchLivenessIsComputedForBytecodeIndex(BytecodeIndex);
bool hasTailCalls() const { return m_unlinkedCode->hasTailCalls(); }
template<typename Metadata>
Metadata& metadata(OpcodeID opcodeID, unsigned metadataID)
{
ASSERT(m_metadata);
return bitwise_cast<Metadata*>(m_metadata->get(opcodeID))[metadataID];
}
size_t metadataSizeInBytes()
{
return m_unlinkedCode->metadataSizeInBytes();
}
MetadataTable* metadataTable() { return m_metadata.get(); }
const void* instructionsRawPointer() { return m_instructionsRawPointer; }
protected:
void finalizeLLIntInlineCaches();
#if ENABLE(JIT)
void finalizeBaselineJITInlineCaches();
#endif
#if ENABLE(DFG_JIT)
void tallyFrequentExitSites();
#else
void tallyFrequentExitSites() { }
#endif
private:
friend class CodeBlockSet;
friend class ExecutableToCodeBlockEdge;
BytecodeLivenessAnalysis& livenessAnalysisSlow();
CodeBlock* specialOSREntryBlockOrNull();
void noticeIncomingCall(CallFrame* callerFrame);
double optimizationThresholdScalingFactor();
void updateAllValueProfilePredictionsAndCountLiveness(unsigned& numberOfLiveNonArgumentValueProfiles, unsigned& numberOfSamplesInProfiles);
void setConstantIdentifierSetRegisters(VM&, const RefCountedArray<ConstantIdentifierSetEntry>& constants);
void setConstantRegisters(const RefCountedArray<WriteBarrier<Unknown>>& constants, const RefCountedArray<SourceCodeRepresentation>& constantsSourceCodeRepresentation, ScriptExecutable* topLevelExecutable);
void replaceConstant(VirtualRegister reg, JSValue value)
{
ASSERT(reg.isConstant() && static_cast<size_t>(reg.toConstantIndex()) < m_constantRegisters.size());
m_constantRegisters[reg.toConstantIndex()].set(*m_vm, this, value);
}
bool shouldVisitStrongly(const ConcurrentJSLocker&);
bool shouldJettisonDueToWeakReference(VM&);
bool shouldJettisonDueToOldAge(const ConcurrentJSLocker&);
void propagateTransitions(const ConcurrentJSLocker&, SlotVisitor&);
void determineLiveness(const ConcurrentJSLocker&, SlotVisitor&);
void stronglyVisitStrongReferences(const ConcurrentJSLocker&, SlotVisitor&);
void stronglyVisitWeakReferences(const ConcurrentJSLocker&, SlotVisitor&);
void visitOSRExitTargets(const ConcurrentJSLocker&, SlotVisitor&);
unsigned numberOfNonArgumentValueProfiles() { return m_numberOfNonArgumentValueProfiles; }
unsigned totalNumberOfValueProfiles() { return numberOfArgumentValueProfiles() + numberOfNonArgumentValueProfiles(); }
ValueProfile* tryGetValueProfileForBytecodeIndex(BytecodeIndex);
Seconds timeSinceCreation()
{
return MonotonicTime::now() - m_creationTime;
}
void createRareDataIfNecessary()
{
if (!m_rareData) {
auto rareData = makeUnique<RareData>();
WTF::storeStoreFence(); // m_catchProfiles can be touched from compiler threads.
m_rareData = WTFMove(rareData);
}
}
void insertBasicBlockBoundariesForControlFlowProfiler();
void ensureCatchLivenessIsComputedForBytecodeIndexSlow(const OpCatch&, BytecodeIndex);
int m_numCalleeLocals;
int m_numVars;
int m_numParameters;
int m_numberOfArgumentsToSkip { 0 };
unsigned m_numberOfNonArgumentValueProfiles { 0 };
union {
unsigned m_debuggerRequests;
struct {
unsigned m_hasDebuggerStatement : 1;
unsigned m_steppingMode : 1;
unsigned m_numBreakpoints : 30;
};
};
unsigned m_bytecodeCost { 0 };
VirtualRegister m_scopeRegister;
mutable CodeBlockHash m_hash;
WriteBarrier<UnlinkedCodeBlock> m_unlinkedCode;
WriteBarrier<ScriptExecutable> m_ownerExecutable;
WriteBarrier<ExecutableToCodeBlockEdge> m_ownerEdge;
// m_vm must be a pointer (instead of a reference) because the JSCLLIntOffsetsExtractor
// cannot handle it being a reference.
VM* m_vm;
const void* m_instructionsRawPointer { nullptr };
SentinelLinkedList<LLIntCallLinkInfo, PackedRawSentinelNode<LLIntCallLinkInfo>> m_incomingLLIntCalls;
StructureWatchpointMap m_llintGetByIdWatchpointMap;
RefPtr<JITCode> m_jitCode;
#if ENABLE(JIT)
std::unique_ptr<JITData> m_jitData;
#endif
#if ENABLE(DFG_JIT)
// This is relevant to non-DFG code blocks that serve as the profiled code block
// for DFG code blocks.
CompressedLazyOperandValueProfileHolder m_lazyOperandValueProfiles;
#endif
RefCountedArray<ValueProfile> m_argumentValueProfiles;
// Constant Pool
COMPILE_ASSERT(sizeof(Register) == sizeof(WriteBarrier<Unknown>), Register_must_be_same_size_as_WriteBarrier_Unknown);
// TODO: This could just be a pointer to m_unlinkedCodeBlock's data, but the DFG mutates
// it, so we're stuck with it for now.
Vector<WriteBarrier<Unknown>> m_constantRegisters;
Vector<SourceCodeRepresentation> m_constantsSourceCodeRepresentation;
RefCountedArray<WriteBarrier<FunctionExecutable>> m_functionDecls;
RefCountedArray<WriteBarrier<FunctionExecutable>> m_functionExprs;
WriteBarrier<CodeBlock> m_alternative;
BaselineExecutionCounter m_llintExecuteCounter;
BaselineExecutionCounter m_jitExecuteCounter;
uint32_t m_osrExitCounter;
uint16_t m_optimizationDelayCounter;
uint16_t m_reoptimizationRetryCounter;
RefPtr<MetadataTable> m_metadata;
MonotonicTime m_creationTime;
double m_previousCounter { 0 };
std::unique_ptr<RareData> m_rareData;
};
template <typename ExecutableType>
Exception* ScriptExecutable::prepareForExecution(VM& vm, JSFunction* function, JSScope* scope, CodeSpecializationKind kind, CodeBlock*& resultCodeBlock)
{
if (hasJITCodeFor(kind)) {
if constexpr (std::is_same<ExecutableType, EvalExecutable>::value) {
resultCodeBlock = jsCast<CodeBlock*>(jsCast<ExecutableType*>(this)->codeBlock());
return nullptr;
}
if constexpr (std::is_same<ExecutableType, ProgramExecutable>::value) {
resultCodeBlock = jsCast<CodeBlock*>(jsCast<ExecutableType*>(this)->codeBlock());
return nullptr;
}
if constexpr (std::is_same<ExecutableType, ModuleProgramExecutable>::value) {
resultCodeBlock = jsCast<CodeBlock*>(jsCast<ExecutableType*>(this)->codeBlock());
return nullptr;
}
if constexpr (std::is_same<ExecutableType, FunctionExecutable>::value) {
resultCodeBlock = jsCast<CodeBlock*>(jsCast<ExecutableType*>(this)->codeBlockFor(kind));
return nullptr;
}
RELEASE_ASSERT_NOT_REACHED();
return nullptr;
}
return prepareForExecutionImpl(vm, function, scope, kind, resultCodeBlock);
}
#define CODEBLOCK_LOG_EVENT(codeBlock, summary, details) \
do { \
if (codeBlock) \
(codeBlock->vm().logEvent(codeBlock, summary, [&] () { return toCString details; })); \
} while (0)
void setPrinter(Printer::PrintRecord&, CodeBlock*);
} // namespace JSC
namespace WTF {
JS_EXPORT_PRIVATE void printInternal(PrintStream&, JSC::CodeBlock*);
} // namespace WTF