C++ CCallHelpers::abortWithReason方法代码示例

void JSCallBase::emit(CCallHelpers& jit, State& /*state*/, int32_t osrExitFromGenericUnwindStackSpillSlot)
{
    RELEASE_ASSERT(!!m_callSiteIndex);

#if FTL_USES_B3
    UNUSED_PARAM(osrExitFromGenericUnwindStackSpillSlot);
#else // FTL_USES_B3
    if (m_correspondingGenericUnwindOSRExit)
        m_correspondingGenericUnwindOSRExit->spillRegistersToSpillSlot(jit, osrExitFromGenericUnwindStackSpillSlot);
#endif // FTL_USES_B3

    jit.store32(CCallHelpers::TrustedImm32(m_callSiteIndex.bits()), CCallHelpers::tagFor(static_cast<VirtualRegister>(JSStack::ArgumentCount)));

    m_callLinkInfo = jit.codeBlock()->addCallLinkInfo();
    
    if (CallLinkInfo::callModeFor(m_type) == CallMode::Tail)
        jit.emitRestoreCalleeSaves();

    CCallHelpers::Jump slowPath = jit.branchPtrWithPatch(
        CCallHelpers::NotEqual, GPRInfo::regT0, m_targetToCheck,
        CCallHelpers::TrustedImmPtr(0));

    CCallHelpers::Jump done;

    if (CallLinkInfo::callModeFor(m_type) == CallMode::Tail) {
        jit.prepareForTailCallSlow();
        m_fastCall = jit.nearTailCall();
    } else {
        m_fastCall = jit.nearCall();
        done = jit.jump();
    }

    slowPath.link(&jit);

    jit.move(CCallHelpers::TrustedImmPtr(m_callLinkInfo), GPRInfo::regT2);
    m_slowCall = jit.nearCall();

    if (CallLinkInfo::callModeFor(m_type) == CallMode::Tail)
        jit.abortWithReason(JITDidReturnFromTailCall);
    else
        done.link(&jit);

    m_callLinkInfo->setUpCall(m_type, m_semanticeOrigin, GPRInfo::regT0);
}

void JSCallVarargs::emit(CCallHelpers& jit, State& state, int32_t spillSlotsOffset, int32_t osrExitFromGenericUnwindSpillSlots)
{
    // We are passed three pieces of information:
    // - The callee.
    // - The arguments object, if it's not a forwarding call.
    // - The "this" value, if it's a constructor call.

    CallVarargsData* data = m_node->callVarargsData();
    
    GPRReg calleeGPR = GPRInfo::argumentGPR0;
    
    GPRReg argumentsGPR = InvalidGPRReg;
    GPRReg thisGPR = InvalidGPRReg;
    
    bool forwarding = false;
    
    switch (m_node->op()) {
    case CallVarargs:
    case TailCallVarargs:
    case TailCallVarargsInlinedCaller:
    case ConstructVarargs:
        argumentsGPR = GPRInfo::argumentGPR1;
        thisGPR = GPRInfo::argumentGPR2;
        break;
    case CallForwardVarargs:
    case TailCallForwardVarargs:
    case TailCallForwardVarargsInlinedCaller:
    case ConstructForwardVarargs:
        thisGPR = GPRInfo::argumentGPR1;
        forwarding = true;
        break;
    default:
        RELEASE_ASSERT_NOT_REACHED();
        break;
    }
    
    const unsigned calleeSpillSlot = 0;
    const unsigned argumentsSpillSlot = 1;
    const unsigned thisSpillSlot = 2;
    const unsigned stackPointerSpillSlot = 3;
    
    // Get some scratch registers.
    RegisterSet usedRegisters;
    usedRegisters.merge(RegisterSet::stackRegisters());
    usedRegisters.merge(RegisterSet::reservedHardwareRegisters());
    usedRegisters.merge(RegisterSet::calleeSaveRegisters());
    usedRegisters.set(calleeGPR);
    if (argumentsGPR != InvalidGPRReg)
        usedRegisters.set(argumentsGPR);
    ASSERT(thisGPR);
    usedRegisters.set(thisGPR);
    ScratchRegisterAllocator allocator(usedRegisters);
    GPRReg scratchGPR1 = allocator.allocateScratchGPR();
    GPRReg scratchGPR2 = allocator.allocateScratchGPR();
    GPRReg scratchGPR3 = allocator.allocateScratchGPR();

    RELEASE_ASSERT(!allocator.numberOfReusedRegisters());
    
    auto computeUsedStack = [&] (GPRReg targetGPR, unsigned extra) {
        if (isARM64()) {
            // Have to do this the weird way because $sp on ARM64 means zero when used in a subtraction.
            jit.move(CCallHelpers::stackPointerRegister, targetGPR);
            jit.negPtr(targetGPR);
            jit.addPtr(GPRInfo::callFrameRegister, targetGPR);
        } else {
            jit.move(GPRInfo::callFrameRegister, targetGPR);
            jit.subPtr(CCallHelpers::stackPointerRegister, targetGPR);
        }
        if (extra)
            jit.subPtr(CCallHelpers::TrustedImm32(extra), targetGPR);
        jit.urshiftPtr(CCallHelpers::Imm32(3), targetGPR);
    };
    
    auto callWithExceptionCheck = [&] (void* callee) {
        jit.move(CCallHelpers::TrustedImmPtr(callee), GPRInfo::nonPreservedNonArgumentGPR);
        jit.call(GPRInfo::nonPreservedNonArgumentGPR);
        m_exceptions.append(jit.emitExceptionCheck(AssemblyHelpers::NormalExceptionCheck, AssemblyHelpers::FarJumpWidth));
    };
    
    if (isARM64()) {
        jit.move(CCallHelpers::stackPointerRegister, scratchGPR1);
        jit.storePtr(scratchGPR1, CCallHelpers::addressFor(spillSlotsOffset + stackPointerSpillSlot));
    } else
        jit.storePtr(CCallHelpers::stackPointerRegister, CCallHelpers::addressFor(spillSlotsOffset + stackPointerSpillSlot));

    unsigned extraStack = sizeof(CallerFrameAndPC) +
        WTF::roundUpToMultipleOf(stackAlignmentBytes(), 5 * sizeof(void*));

    if (forwarding) {
        CCallHelpers::JumpList slowCase;
        computeUsedStack(scratchGPR2, 0);
        emitSetupVarargsFrameFastCase(jit, scratchGPR2, scratchGPR1, scratchGPR2, scratchGPR3, m_node->child2()->origin.semantic.inlineCallFrame, data->firstVarArgOffset, slowCase);
        
        CCallHelpers::Jump done = jit.jump();
        slowCase.link(&jit);
        jit.subPtr(CCallHelpers::TrustedImm32(extraStack), CCallHelpers::stackPointerRegister);
        jit.setupArgumentsExecState();
        callWithExceptionCheck(bitwise_cast<void*>(operationThrowStackOverflowForVarargs));
        jit.abortWithReason(DFGVarargsThrowingPathDidNotThrow);
        
//.........这里部分代码省略.........

void JSTailCall::emit(JITCode& jitCode, CCallHelpers& jit)
{
    StackMaps::Record* record { nullptr };
    
    for (unsigned i = jitCode.stackmaps.records.size(); i--;) {
        record = &jitCode.stackmaps.records[i];
        if (record->patchpointID == m_stackmapID)
            break;
    }

    RELEASE_ASSERT(record->patchpointID == m_stackmapID);

    m_callLinkInfo = jit.codeBlock()->addCallLinkInfo();

    CallFrameShuffleData shuffleData;

    // The callee was the first passed argument, and must be in a GPR because
    // we used the "anyregcc" calling convention
    auto calleeLocation =
        FTL::Location::forStackmaps(nullptr, record->locations[0]);
    GPRReg calleeGPR = calleeLocation.directGPR();
    shuffleData.callee = ValueRecovery::inGPR(calleeGPR, DataFormatJS);

    // The tag type number was the second argument, if there was one
    auto tagTypeNumberLocation =
        FTL::Location::forStackmaps(&jitCode.stackmaps, record->locations[1]);
    if (tagTypeNumberLocation.isGPR() && !tagTypeNumberLocation.addend())
        shuffleData.tagTypeNumber = tagTypeNumberLocation.directGPR();

    shuffleData.args.grow(numArguments());
    HashMap<Reg, Vector<std::pair<ValueRecovery*, int32_t>>> withAddend;
    size_t numAddends { 0 };
    for (size_t i = 0; i < numArguments(); ++i) {
        shuffleData.args[i] = recoveryFor(m_arguments[i], *record, jitCode.stackmaps);
        if (FTL::Location addend = getRegisterWithAddend(m_arguments[i], *record, jitCode.stackmaps)) {
            withAddend.add(
                addend.reg(),
                Vector<std::pair<ValueRecovery*, int32_t>>()).iterator->value.append(
                    std::make_pair(&shuffleData.args[i], addend.addend()));
            numAddends++;
        }
    }

    numAddends = WTF::roundUpToMultipleOf(stackAlignmentRegisters(), numAddends);

    shuffleData.numLocals = static_cast<int64_t>(jitCode.stackmaps.stackSizeForLocals()) / sizeof(void*) + numAddends;

    ASSERT(!numAddends == withAddend.isEmpty());

    if (!withAddend.isEmpty()) {
        jit.subPtr(MacroAssembler::TrustedImm32(numAddends * sizeof(void*)), MacroAssembler::stackPointerRegister);
        VirtualRegister spillBase { 1 - static_cast<int>(shuffleData.numLocals) };
        for (auto entry : withAddend) {
            for (auto pair : entry.value) {
                ASSERT(numAddends > 0);
                VirtualRegister spillSlot { spillBase + --numAddends };
                ASSERT(entry.key.isGPR());
                jit.addPtr(MacroAssembler::TrustedImm32(pair.second), entry.key.gpr());
                jit.storePtr(entry.key.gpr(), CCallHelpers::addressFor(spillSlot));
                jit.subPtr(MacroAssembler::TrustedImm32(pair.second), entry.key.gpr());
                *pair.first = ValueRecovery::displacedInJSStack(spillSlot, pair.first->dataFormat());
            }
        }
        ASSERT(numAddends < stackAlignmentRegisters());
    }

    shuffleData.args.resize(numArguments());
    for (size_t i = 0; i < numArguments(); ++i)
        shuffleData.args[i] = recoveryFor(m_arguments[i], *record, jitCode.stackmaps);

    shuffleData.setupCalleeSaveRegisters(jit.codeBlock());

    CCallHelpers::Jump slowPath = jit.branchPtrWithPatch(
        CCallHelpers::NotEqual, calleeGPR, m_targetToCheck,
        CCallHelpers::TrustedImmPtr(0));

    m_callLinkInfo->setFrameShuffleData(shuffleData);
    CallFrameShuffler(jit, shuffleData).prepareForTailCall();

    m_fastCall = jit.nearTailCall();

    slowPath.link(&jit);

    CallFrameShuffler slowPathShuffler(jit, shuffleData);
    slowPathShuffler.setCalleeJSValueRegs(JSValueRegs { GPRInfo::regT0 });
    slowPathShuffler.prepareForSlowPath();

    jit.move(CCallHelpers::TrustedImmPtr(m_callLinkInfo), GPRInfo::regT2);

    m_slowCall = jit.nearCall();

    jit.abortWithReason(JITDidReturnFromTailCall);

    m_callLinkInfo->setUpCall(m_type, m_semanticeOrigin, calleeGPR);
}