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/*
* Copyright (C) 2012-2018 Apple Inc. All rights reserved.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 INC. OR
* 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.
*/
#include "config.h"
#include "CallLinkInfo.h"
#include "BaselineJITRegisters.h"
#include "CCallHelpers.h"
#include "CallFrameShuffleData.h"
#include "DFGJITCode.h"
#include "DisallowMacroScratchRegisterUsage.h"
#include "FunctionCodeBlock.h"
#include "JITThunks.h"
#include "JSCellInlines.h"
#include "JSWebAssemblyModule.h"
#include "LLIntEntrypoint.h"
#include "LinkBuffer.h"
#include "Opcode.h"
#include "Repatch.h"
#include "ThunkGenerators.h"
#include <wtf/ListDump.h>
namespace JSC {
CallLinkInfo::CallType CallLinkInfo::callTypeFor(OpcodeID opcodeID)
{
switch (opcodeID) {
case op_tail_call_varargs:
return TailCallVarargs;
case op_call:
case op_call_ignore_result:
case op_call_direct_eval:
case op_iterator_open:
case op_iterator_next:
case op_async_iterator_open:
case op_async_iterator_next:
return Call;
case op_call_varargs:
case op_call_varargs_with_spread:
return CallVarargs;
case op_construct:
case op_super_construct:
return Construct;
case op_construct_varargs:
case op_super_construct_varargs:
return ConstructVarargs;
case op_tail_call:
return TailCall;
default:
break;
}
RELEASE_ASSERT_NOT_REACHED();
return Call;
}
CallLinkInfo::~CallLinkInfo()
{
clearStub();
}
void CallLinkInfo::clearStub()
{
if (!stub())
return;
m_stub->unlinkForcefully();
m_stub = nullptr;
}
void CallLinkInfo::unlinkOrUpgradeImpl(VM& vm, CodeBlock* oldCodeBlock, CodeBlock* newCodeBlock)
{
// We could be called even if we're not linked anymore because of how polymorphic calls
// work. Each callsite within the polymorphic call stub may separately ask us to unlink().
if (isOnList())
remove();
dataLogLnIf(Options::dumpDisassembly(), "Unlinking CallLinkInfo: ", RawPointer(this));
Mode mode = this->mode();
switch (mode) {
case Mode::Monomorphic: {
if (newCodeBlock && oldCodeBlock == m_codeBlock) {
// Upgrading Monomorphic DataIC with newCodeBlock.
ArityCheckMode arityCheck = oldCodeBlock->jitCode()->addressForCall(ArityCheckMode::ArityCheckNotRequired) == m_monomorphicCallDestination ? ArityCheckMode::ArityCheckNotRequired : ArityCheckMode::MustCheckArity;
auto target = newCodeBlock->jitCode()->addressForCall(arityCheck);
m_codeBlock = newCodeBlock;
m_monomorphicCallDestination = target;
newCodeBlock->linkIncomingCall(nullptr, this); // This is just relinking. So owner and caller frame can be nullptr.
return;
}
revertCall(vm);
break;
}
case Mode::Polymorphic: {
revertCall(vm);
break;
}
case Mode::Init:
case Mode::Virtual: {
break;
}
}
// Either we were unlinked, in which case we should not have been on any list, or we unlinked
// ourselves so that we're not on any list anymore.
RELEASE_ASSERT(!isOnList(), static_cast<unsigned>(mode));
}
void CallLinkInfo::setMonomorphicCallee(VM& vm, JSCell* owner, JSObject* callee, CodeBlock* codeBlock, CodePtr<JSEntryPtrTag> codePtr)
{
RELEASE_ASSERT(!(std::bit_cast<uintptr_t>(callee) & polymorphicCalleeMask));
m_callee.set(vm, owner, callee);
m_codeBlock = codeBlock;
m_monomorphicCallDestination = codePtr;
m_mode = static_cast<unsigned>(Mode::Monomorphic);
}
void CallLinkInfo::clearCallee()
{
m_callee.clear();
m_codeBlock = nullptr;
m_monomorphicCallDestination = nullptr;
}
JSObject* CallLinkInfo::callee()
{
RELEASE_ASSERT(!(std::bit_cast<uintptr_t>(m_callee.get()) & polymorphicCalleeMask));
return m_callee.get();
}
void CallLinkInfo::setLastSeenCallee(VM& vm, const JSCell* owner, JSObject* callee)
{
m_lastSeenCallee.set(vm, owner, callee);
}
JSObject* CallLinkInfo::lastSeenCallee() const
{
return m_lastSeenCallee.get();
}
bool CallLinkInfo::haveLastSeenCallee() const
{
return !!m_lastSeenCallee;
}
void CallLinkInfo::reconcileWeakReferencesAtGCEnd(VM& vm)
{
auto handleSpecificCallee = [&] (JSFunction* callee) {
if (vm.heap.isMarked(callee->executable()))
m_hasSeenClosure = true;
else
m_clearedByGC = true;
};
switch (mode()) {
case Mode::Init:
case Mode::Virtual:
break;
case Mode::Polymorphic: {
if (stub()) {
if (!stub()->reconcileWeakReferencesAtGCEnd(vm)) {
dataLogLnIf(Options::verboseOSR(), "At ", codeOrigin(), ", ", RawPointer(this), ": clearing call stub to ", listDump(stub()->variants()), ", stub routine ", RawPointer(stub()), ".");
unlinkOrUpgrade(vm, nullptr, nullptr);
m_clearedByGC = true;
}
}
break;
}
case Mode::Monomorphic: {
auto* callee = m_callee.get();
if (callee && !vm.heap.isMarked(callee)) {
if (callee->type() == JSFunctionType) {
dataLogLnIf(Options::verboseOSR(), "Clearing call to ", RawPointer(callee), " (", static_cast<JSFunction*>(callee)->executable()->hashFor(specializationKind()), ").");
handleSpecificCallee(static_cast<JSFunction*>(callee));
} else {
dataLogLnIf(Options::verboseOSR(), "Clearing call to ", RawPointer(callee), ".");
m_clearedByGC = true;
}
unlinkOrUpgrade(vm, nullptr, nullptr);
}
break;
}
}
if (haveLastSeenCallee() && !vm.heap.isMarked(lastSeenCallee())) {
if (lastSeenCallee()->type() == JSFunctionType)
handleSpecificCallee(uncheckedDowncast<JSFunction>(lastSeenCallee()));
else
m_clearedByGC = true;
m_lastSeenCallee.clear();
}
}
void CallLinkInfo::revertCallToStub()
{
RELEASE_ASSERT(stub());
// The start of our JIT code is now a jump to the polymorphic stub. Rewrite the first instruction
// to be what we need for non stub ICs.
// this runs into some branch compaction crap I'd like to avoid for now. Essentially, the branch
// doesn't know if it can be compacted or not. So we end up with 28 bytes of machine code, for
// what in all likelihood fits in 24. So we just splat out the first instruction. Long term, we
// need something cleaner. But this works on arm64 for now.
m_callee.clear();
m_codeBlock = nullptr;
m_monomorphicCallDestination = nullptr;
}
void DataOnlyCallLinkInfo::initialize(VM& vm, CodeBlock* owner, CallType callType, CodeOrigin codeOrigin)
{
m_owner = owner;
m_type = static_cast<unsigned>(Type::DataOnly);
ASSERT(Type::DataOnly == type());
m_codeOrigin = codeOrigin;
m_callType = callType;
m_mode = static_cast<unsigned>(Mode::Init);
if (!Options::useLLIntICs()) [[unlikely]]
setVirtualCall(vm);
}
std::tuple<CodeBlock*, BytecodeIndex> CallLinkInfo::retrieveCaller(JSCell* owner)
{
auto* codeBlock = dynamicDowncast<CodeBlock>(owner);
if (!codeBlock)
return { };
CodeOrigin codeOrigin = this->codeOrigin();
if (auto* baselineCodeBlock = codeOrigin.codeOriginOwner())
return std::tuple { baselineCodeBlock, codeOrigin.bytecodeIndex() };
return std::tuple { codeBlock, codeOrigin.bytecodeIndex() };
}
void CallLinkInfo::reset(VM&)
{
if (stub())
revertCallToStub();
clearCallee(); // This also clears the inline cache both for data and code-based caches.
clearSeen();
clearStub();
if (isOnList())
remove();
m_mode = static_cast<unsigned>(Mode::Init);
}
void CallLinkInfo::revertCall(VM& vm)
{
if (!Options::useLLIntICs() && type() == CallLinkInfo::Type::DataOnly) [[unlikely]]
setVirtualCall(vm);
else
reset(vm);
}
void CallLinkInfo::setVirtualCall(VM& vm)
{
reset(vm);
m_callee.clear();
*std::bit_cast<uintptr_t*>(m_callee.slot()) = polymorphicCalleeMask;
m_codeBlock = nullptr; // PolymorphicCallStubRoutine will set CodeBlock inside it.
m_monomorphicCallDestination = vm.getCTIVirtualCall(callMode()).code().template retagged<JSEntryPtrTag>();
setClearedByVirtual();
m_mode = static_cast<unsigned>(Mode::Virtual);
}
JSGlobalObject* CallLinkInfo::globalObjectForSlowPath(JSCell* owner)
{
auto [codeBlock, bytecodeIndex] = retrieveCaller(owner);
if (codeBlock)
return codeBlock->globalObject();
#if ENABLE(WEBASSEMBLY)
auto* module = dynamicDowncast<JSWebAssemblyModule>(owner);
if (module)
return module->realm();
#endif
RELEASE_ASSERT_NOT_REACHED();
return nullptr;
}
void CallLinkInfo::setStub(Ref<PolymorphicCallStubRoutine>&& newStub)
{
clearStub();
m_stub = WTF::move(newStub);
m_callee.clear();
*std::bit_cast<uintptr_t*>(m_callee.slot()) = polymorphicCalleeMask;
m_codeBlock = nullptr; // PolymorphicCallStubRoutine will set CodeBlock inside it.
m_monomorphicCallDestination = m_stub->code().code().retagged<JSEntryPtrTag>();
// The call link info no longer has a call cache apart from the jump to the polymorphic call stub.
if (isOnList())
remove();
m_mode = static_cast<unsigned>(Mode::Polymorphic);
}
#if ENABLE(JIT)
void CallLinkInfo::emitFastPathImpl(CallLinkInfo* callLinkInfo, CCallHelpers& jit, bool isTailCall, NOESCAPE const ScopedLambda<void()>& prepareForTailCall)
{
if (callLinkInfo)
jit.move(CCallHelpers::TrustedImmPtr(callLinkInfo), BaselineJITRegisters::Call::callLinkInfoGPR);
// For RISCV64, scratch register usage here collides with MacroAssembler's internal usage
// that's necessary for the test-and-branch operation but is avoidable by loading from the callee
// address for each branch operation. Other MacroAssembler implementations handle this better by
// using a wider range of scratch registers or more potent branching instructions.
CCallHelpers::JumpList found;
jit.loadPtr(CCallHelpers::Address(BaselineJITRegisters::Call::callLinkInfoGPR, offsetOfMonomorphicCallDestination()), BaselineJITRegisters::Call::callTargetGPR);
if constexpr (isRISCV64()) {
CCallHelpers::Address calleeAddress(BaselineJITRegisters::Call::callLinkInfoGPR, offsetOfCallee());
found.append(jit.branchPtr(CCallHelpers::Equal, calleeAddress, BaselineJITRegisters::Call::calleeGPR));
found.append(jit.branchTestPtr(CCallHelpers::NonZero, calleeAddress, CCallHelpers::TrustedImm32(polymorphicCalleeMask)));
} else {
GPRReg scratchGPR = jit.scratchRegister();
DisallowMacroScratchRegisterUsage disallowScratch(jit);
jit.loadPtr(CCallHelpers::Address(BaselineJITRegisters::Call::callLinkInfoGPR, offsetOfCallee()), scratchGPR);
found.append(jit.branchPtr(CCallHelpers::Equal, scratchGPR, BaselineJITRegisters::Call::calleeGPR));
found.append(jit.branchTestPtr(CCallHelpers::NonZero, scratchGPR, CCallHelpers::TrustedImm32(polymorphicCalleeMask)));
}
jit.move(CCallHelpers::TrustedImmPtr(LLInt::defaultCall().code().taggedPtr()), BaselineJITRegisters::Call::callTargetGPR);
found.link(&jit);
if (isTailCall) {
prepareForTailCall();
jit.transferPtr(CCallHelpers::Address(BaselineJITRegisters::Call::callLinkInfoGPR, offsetOfCodeBlock()), CCallHelpers::calleeFrameCodeBlockBeforeTailCall());
jit.farJump(BaselineJITRegisters::Call::callTargetGPR, JSEntryPtrTag);
} else {
jit.transferPtr(CCallHelpers::Address(BaselineJITRegisters::Call::callLinkInfoGPR, offsetOfCodeBlock()), CCallHelpers::calleeFrameCodeBlockBeforeCall());
jit.call(BaselineJITRegisters::Call::callTargetGPR, JSEntryPtrTag);
}
return;
}
void CallLinkInfo::emitDataICFastPath(CCallHelpers& jit)
{
emitFastPathImpl(nullptr, jit, false, nullptr);
}
void CallLinkInfo::emitTailCallDataICFastPath(CCallHelpers& jit, NOESCAPE const ScopedLambda<void()>& prepareForTailCall)
{
emitFastPathImpl(nullptr, jit, true, prepareForTailCall);
}
void CallLinkInfo::emitFastPath(CCallHelpers& jit, CompileTimeCallLinkInfo callLinkInfo)
{
if (std::holds_alternative<OptimizingCallLinkInfo*>(callLinkInfo))
return std::get<OptimizingCallLinkInfo*>(callLinkInfo)->emitFastPath(jit);
return CallLinkInfo::emitDataICFastPath(jit);
}
void CallLinkInfo::emitTailCallFastPath(CCallHelpers& jit, CompileTimeCallLinkInfo callLinkInfo, NOESCAPE const ScopedLambda<void()>& prepareForTailCall)
{
if (std::holds_alternative<OptimizingCallLinkInfo*>(callLinkInfo))
return std::get<OptimizingCallLinkInfo*>(callLinkInfo)->emitTailCallFastPath(jit, prepareForTailCall);
return CallLinkInfo::emitTailCallDataICFastPath(jit, prepareForTailCall);
}
void OptimizingCallLinkInfo::emitFastPath(CCallHelpers& jit)
{
RELEASE_ASSERT(!isTailCall());
emitFastPathImpl(this, jit, isTailCall(), nullptr);
}
void OptimizingCallLinkInfo::emitTailCallFastPath(CCallHelpers& jit, NOESCAPE const ScopedLambda<void()>& prepareForTailCall)
{
RELEASE_ASSERT(isTailCall());
emitFastPathImpl(this, jit, isTailCall(), prepareForTailCall);
}
#if ENABLE(DFG_JIT)
void OptimizingCallLinkInfo::initializeFromDFGUnlinkedCallLinkInfo(VM&, const DFG::UnlinkedCallLinkInfo& unlinkedCallLinkInfo, CodeBlock* owner)
{
m_owner = owner;
m_codeOrigin = unlinkedCallLinkInfo.codeOrigin;
m_callType = unlinkedCallLinkInfo.callType;
}
#endif
void DirectCallLinkInfo::reset()
{
if (isOnList())
remove();
#if ENABLE(JIT)
if (!isDataIC())
initialize();
#endif
m_target = { };
m_codeBlock = nullptr;
}
void DirectCallLinkInfo::unlinkOrUpgradeImpl(VM&, CodeBlock* oldCodeBlock, CodeBlock* newCodeBlock)
{
if (isOnList())
remove();
if (!!m_target) {
if (m_codeBlock && newCodeBlock && oldCodeBlock == m_codeBlock) {
ArityCheckMode arityCheck = oldCodeBlock->jitCode()->addressForCall(ArityCheckMode::ArityCheckNotRequired) == m_target ? ArityCheckMode::ArityCheckNotRequired : ArityCheckMode::MustCheckArity;
auto target = newCodeBlock->jitCode()->addressForCall(arityCheck);
setCallTarget(newCodeBlock, CodeLocationLabel { target });
newCodeBlock->linkIncomingCall(nullptr, this); // This is just relinking. So owner and caller frame can be nullptr.
return;
}
dataLogLnIf(Options::dumpDisassembly(), "Unlinking CallLinkInfo: ", RawPointer(this));
reset();
}
// Either we were unlinked, in which case we should not have been on any list, or we unlinked
// ourselves so that we're not on any list anymore.
RELEASE_ASSERT(!isOnList());
}
void DirectCallLinkInfo::reconcileWeakReferencesAtGCEnd(VM& vm)
{
if (m_codeBlock && !vm.heap.isMarked(m_codeBlock)) {
dataLogLnIf(Options::verboseOSR(), "Clearing call to ", RawPointer(m_codeBlock), " (", pointerDump(m_codeBlock), ").");
unlinkOrUpgrade(vm, nullptr, nullptr);
}
}
CCallHelpers::JumpList DirectCallLinkInfo::emitDirectFastPath(CCallHelpers& jit)
{
RELEASE_ASSERT(!isTailCall());
if (isDataIC()) {
CCallHelpers::JumpList slowPath;
jit.move(CCallHelpers::TrustedImmPtr(this), BaselineJITRegisters::Call::callLinkInfoGPR);
slowPath.append(jit.branchTestPtr(CCallHelpers::Zero, CCallHelpers::Address(BaselineJITRegisters::Call::callLinkInfoGPR, offsetOfTarget())));
jit.transferPtr(CCallHelpers::Address(BaselineJITRegisters::Call::callLinkInfoGPR, offsetOfCodeBlock()), CCallHelpers::calleeFrameCodeBlockBeforeCall());
jit.call(CCallHelpers::Address(BaselineJITRegisters::Call::callLinkInfoGPR, offsetOfTarget()), JSEntryPtrTag);
return slowPath;
}
auto codeBlockStore = jit.storePtrWithPatch(CCallHelpers::TrustedImmPtr(nullptr), CCallHelpers::calleeFrameCodeBlockBeforeCall());
auto call = jit.nearCall();
jit.addLinkTask([=, this] (LinkBuffer& linkBuffer) {
m_callLocation = linkBuffer.locationOfNearCall<JSInternalPtrTag>(call);
m_codeBlockLocation = linkBuffer.locationOf<JSInternalPtrTag>(codeBlockStore);
});
jit.addLateLinkTask([this](LinkBuffer&) {
repatchSpeculatively();
});
return { };
}
CCallHelpers::JumpList DirectCallLinkInfo::emitDirectTailCallFastPath(CCallHelpers& jit, NOESCAPE const ScopedLambda<void()>& prepareForTailCall)
{
RELEASE_ASSERT(isTailCall());
if (isDataIC()) {
CCallHelpers::JumpList slowPath;
jit.move(CCallHelpers::TrustedImmPtr(this), BaselineJITRegisters::Call::callLinkInfoGPR);
slowPath.append(jit.branchTestPtr(CCallHelpers::Zero, CCallHelpers::Address(BaselineJITRegisters::Call::callLinkInfoGPR, offsetOfTarget())));
prepareForTailCall();
jit.transferPtr(CCallHelpers::Address(BaselineJITRegisters::Call::callLinkInfoGPR, offsetOfCodeBlock()), CCallHelpers::calleeFrameCodeBlockBeforeTailCall());
jit.farJump(CCallHelpers::Address(BaselineJITRegisters::Call::callLinkInfoGPR, offsetOfTarget()), JSEntryPtrTag);
return slowPath;
}
auto fastPathStart = jit.label();
// - If we're not yet linked, this is a jump to the slow path.
// - Once we're linked to a fast path, this goes back to being nops so we fall through to the linked jump.
jit.emitNops(CCallHelpers::patchableJumpSize());
prepareForTailCall();
auto codeBlockStore = jit.storePtrWithPatch(CCallHelpers::TrustedImmPtr(nullptr), CCallHelpers::calleeFrameCodeBlockBeforeTailCall());
auto call = jit.nearTailCall();
jit.addLinkTask([=, this] (LinkBuffer& linkBuffer) {
m_fastPathStart = linkBuffer.locationOf<JSInternalPtrTag>(fastPathStart);
m_callLocation = linkBuffer.locationOfNearCall<JSInternalPtrTag>(call);
m_codeBlockLocation = linkBuffer.locationOf<JSInternalPtrTag>(codeBlockStore);
});
jit.addLateLinkTask([this](LinkBuffer&) {
repatchSpeculatively();
});
return { };
}
void DirectCallLinkInfo::initialize()
{
ASSERT(m_callLocation);
ASSERT(m_codeBlockLocation);
if (isTailCall()) {
RELEASE_ASSERT(fastPathStart());
CCallHelpers::replaceWithJump(fastPathStart(), slowPathStart());
} else
MacroAssembler::repatchNearCall(m_callLocation, slowPathStart());
}
void DirectCallLinkInfo::setCallTarget(CodeBlock* codeBlock, CodeLocationLabel<JSEntryPtrTag> target)
{
m_codeBlock = codeBlock;
m_target = target;
if (!isDataIC()) {
if (isTailCall()) {
RELEASE_ASSERT(fastPathStart());
// We reserved this many bytes for the jump at fastPathStart(). Make that
// code nops now so we fall through to the jump to the fast path.
CCallHelpers::replaceWithNops(fastPathStart(), CCallHelpers::patchableJumpSize());
}
MacroAssembler::repatchNearCall(m_callLocation, target);
MacroAssembler::repatchPointer(m_codeBlockLocation, codeBlock);
}
}
void DirectCallLinkInfo::setMaxArgumentCountIncludingThis(unsigned value)
{
RELEASE_ASSERT(value);
m_maxArgumentCountIncludingThis = value;
}
CodeBlock* DirectCallLinkInfo::retrieveCodeBlock(FunctionExecutable* functionExecutable)
{
CodeSpecializationKind kind = specializationKind();
CodeBlock* codeBlock = functionExecutable->codeBlockFor(kind);
if (!codeBlock)
return nullptr;
CodeBlock* ownerCodeBlock = dynamicDowncast<CodeBlock>(owner());
if (!ownerCodeBlock)
return nullptr;
if (ownerCodeBlock->alternative() == codeBlock)
return nullptr;
return codeBlock;
}
CodePtr<JSEntryPtrTag> DirectCallLinkInfo::retrieveCodePtr(const ConcurrentJSLocker& locker, CodeBlock* codeBlock)
{
unsigned argumentStackSlots = maxArgumentCountIncludingThis();
ArityCheckMode arityCheckMode = (argumentStackSlots < static_cast<size_t>(codeBlock->numParameters())) ? ArityCheckMode::MustCheckArity : ArityCheckMode::ArityCheckNotRequired;
return codeBlock->addressForCallConcurrently(locker, arityCheckMode);
}
void DirectCallLinkInfo::repatchSpeculatively()
{
if (m_executable->isHostFunction()) {
CodeSpecializationKind kind = specializationKind();
CodePtr<JSEntryPtrTag> codePtr;
if (kind == CodeSpecializationKind::CodeForCall)
codePtr = m_executable->generatedJITCodeWithArityCheckForCall();
else
codePtr = m_executable->generatedJITCodeWithArityCheckForConstruct();
if (codePtr)
setCallTarget(nullptr, CodeLocationLabel { codePtr });
else
initialize();
return;
}
FunctionExecutable* functionExecutable = dynamicDowncast<FunctionExecutable>(m_executable);
if (!functionExecutable) {
initialize();
return;
}
auto* codeBlock = retrieveCodeBlock(functionExecutable);
if (codeBlock) {
auto codePtr = retrieveCodePtr(ConcurrentJSLocker { codeBlock->m_lock }, codeBlock);
if (codePtr) {
m_codeBlock = codeBlock;
m_target = codePtr;
// Do not chain |this| to the calle codeBlock concurrently. It will be done in the main thread if the speculatively repatched one is still valid.
setCallTarget(codeBlock, CodeLocationLabel { codePtr });
return;
}
}
initialize();
}
void DirectCallLinkInfo::validateSpeculativeRepatchOnMainThread(VM&)
{
constexpr bool verbose = false;
FunctionExecutable* functionExecutable = dynamicDowncast<FunctionExecutable>(m_executable);
if (!functionExecutable)
return;
auto* codeBlock = retrieveCodeBlock(functionExecutable);
CodePtr<JSEntryPtrTag> codePtr = nullptr;
if (codeBlock)
codePtr = retrieveCodePtr(ConcurrentJSLocker { NoLockingNecessary }, codeBlock);
if (m_codeBlock != codeBlock || m_target != codePtr) {
if (codeBlock && codePtr)
setCallTarget(codeBlock, CodeLocationLabel { codePtr });
else
reset();
} else
dataLogLnIf(verbose, "Speculative repatching succeeded ", RawPointer(m_codeBlock), " ", m_target);
if (m_codeBlock)
m_codeBlock->linkIncomingCall(owner(), this);
}
#endif
} // namespace JSC