C++ VM::exception方法代码示例

EncodedJSValue JSC_HOST_CALL mapProtoFuncForEach(CallFrame* callFrame)
{
    MapData* data = getMapData(callFrame, callFrame->thisValue());
    if (!data)
        return JSValue::encode(jsUndefined());
    JSValue callBack = callFrame->argument(0);
    CallData callData;
    CallType callType = getCallData(callBack, callData);
    if (callType == CallTypeNone)
        return JSValue::encode(throwTypeError(callFrame, WTF::ASCIILiteral("Map.prototype.forEach called without callback")));
    JSValue thisValue = callFrame->argument(1);
    VM* vm = &callFrame->vm();
    if (callType == CallTypeJS) {
        JSFunction* function = jsCast<JSFunction*>(callBack);
        CachedCall cachedCall(callFrame, function, 2);
        for (auto ptr = data->begin(), end = data->end(); ptr != end && !vm->exception(); ++ptr) {
            cachedCall.setThis(thisValue);
            cachedCall.setArgument(0, ptr.value());
            cachedCall.setArgument(1, ptr.key());
            cachedCall.call();
        }
    } else {
        for (auto ptr = data->begin(), end = data->end(); ptr != end && !vm->exception(); ++ptr) {
            MarkedArgumentBuffer args;
            args.append(ptr.value());
            args.append(ptr.key());
            JSC::call(callFrame, callBack, callType, callData, thisValue, args);
        }
    }
    return JSValue::encode(jsUndefined());
}

static void* handleHostCall(ExecState* execCallee, JSValue callee, CodeSpecializationKind kind)
{
    ExecState* exec = execCallee->callerFrame();
    VM* vm = &exec->vm();

    execCallee->setScope(exec->scope());
    execCallee->setCodeBlock(0);

    if (kind == CodeForCall) {
        CallData callData;
        CallType callType = getCallData(callee, callData);
    
        ASSERT(callType != CallTypeJS);
    
        if (callType == CallTypeHost) {
            NativeCallFrameTracer tracer(vm, execCallee);
            execCallee->setCallee(asObject(callee));
            vm->hostCallReturnValue = JSValue::decode(callData.native.function(execCallee));
            if (vm->exception())
                return vm->getCTIStub(throwExceptionFromCallSlowPathGenerator).code().executableAddress();

            return reinterpret_cast<void*>(getHostCallReturnValue);
        }
    
        ASSERT(callType == CallTypeNone);
        exec->vm().throwException(exec, createNotAFunctionError(exec, callee));
        return vm->getCTIStub(throwExceptionFromCallSlowPathGenerator).code().executableAddress();
    }

    ASSERT(kind == CodeForConstruct);
    
    ConstructData constructData;
    ConstructType constructType = getConstructData(callee, constructData);
    
    ASSERT(constructType != ConstructTypeJS);
    
    if (constructType == ConstructTypeHost) {
        NativeCallFrameTracer tracer(vm, execCallee);
        execCallee->setCallee(asObject(callee));
        vm->hostCallReturnValue = JSValue::decode(constructData.native.function(execCallee));
        if (vm->exception())
            return vm->getCTIStub(throwExceptionFromCallSlowPathGenerator).code().executableAddress();

        return reinterpret_cast<void*>(getHostCallReturnValue);
    }
    
    ASSERT(constructType == ConstructTypeNone);
    exec->vm().throwException(exec, createNotAConstructorError(exec, callee));
    return vm->getCTIStub(throwExceptionFromCallSlowPathGenerator).code().executableAddress();
}

ALWAYS_INLINE static void JIT_OPERATION operationPutByValInternal(ExecState* exec, EncodedJSValue encodedBase, EncodedJSValue encodedProperty, EncodedJSValue encodedValue)
{
    VM* vm = &exec->vm();
    NativeCallFrameTracer tracer(vm, exec);

    JSValue baseValue = JSValue::decode(encodedBase);
    JSValue property = JSValue::decode(encodedProperty);
    JSValue value = JSValue::decode(encodedValue);

    if (LIKELY(property.isUInt32())) {
        putByVal<strict, direct>(exec, baseValue, property.asUInt32(), value);
        return;
    }

    if (property.isDouble()) {
        double propertyAsDouble = property.asDouble();
        uint32_t propertyAsUInt32 = static_cast<uint32_t>(propertyAsDouble);
        if (propertyAsDouble == propertyAsUInt32) {
            putByVal<strict, direct>(exec, baseValue, propertyAsUInt32, value);
            return;
        }
    }

    // Don't put to an object if toString throws an exception.
    PropertyName propertyName = property.toPropertyKey(exec);
    if (!vm->exception()) {
        PutPropertySlot slot(baseValue, strict);
        if (direct) {
            RELEASE_ASSERT(baseValue.isObject());
            asObject(baseValue)->putDirect(*vm, propertyName, value, slot);
        } else
            baseValue.put(exec, propertyName, value, slot);
    }
}

void* callToThrow(ExecState* exec, Instruction* pc)
{
#if LLINT_SLOW_PATH_TRACING
    VM* vm = &exec->vm();
    dataLog("Throwing exception ", vm->exception(), " (callToThrow).\n");
#endif
    doThrow(exec, pc);
    return LLInt::getCodePtr(llint_throw_during_call_trampoline);
}

Instruction* returnToThrow(ExecState* exec, Instruction* pc)
{
#if LLINT_SLOW_PATH_TRACING
    VM* vm = &exec->vm();
    dataLog("Throwing exception ", vm->exception(), " (returnToThrow).\n");
#endif
    doThrow(exec, pc);
    return LLInt::exceptionInstructions();
}

void interpreterThrowInCaller(ExecState* exec, JSObject* error)
{
    VM* vm = &exec->vm();
    NativeCallFrameTracer tracer(vm, exec);
    auto scope = DECLARE_THROW_SCOPE(*vm);

    throwException(exec, scope, error);
#if LLINT_SLOW_PATH_TRACING
    dataLog("Throwing exception ", vm->exception(), ".\n");
#endif
}

EncodedJSValue JSC_HOST_CALL mapProtoFuncForEach(CallFrame* callFrame)
{
    JSMap* map = getMap(callFrame, callFrame->thisValue());
    if (!map)
        return JSValue::encode(jsUndefined());
    JSValue callBack = callFrame->argument(0);
    CallData callData;
    CallType callType = getCallData(callBack, callData);
    if (callType == CallTypeNone)
        return JSValue::encode(throwTypeError(callFrame, WTF::ASCIILiteral("Map.prototype.forEach called without callback")));
    JSValue thisValue = callFrame->argument(1);
    VM* vm = &callFrame->vm();
    JSMapIterator* iterator = JSMapIterator::create(*vm, callFrame->callee()->globalObject()->mapIteratorStructure(), map, MapIterateKeyValue);
    JSValue key, value;
    if (callType == CallTypeJS) {
        JSFunction* function = jsCast<JSFunction*>(callBack);
        CachedCall cachedCall(callFrame, function, 3);
        while (iterator->nextKeyValue(key, value) && !vm->exception()) {
            cachedCall.setThis(thisValue);
            cachedCall.setArgument(0, value);
            cachedCall.setArgument(1, key);
            cachedCall.setArgument(2, map);
            cachedCall.call();
        }
        iterator->finish();
    } else {
        while (iterator->nextKeyValue(key, value) && !vm->exception()) {
            MarkedArgumentBuffer args;
            args.append(value);
            args.append(key);
            args.append(map);
            JSC::call(callFrame, callBack, callType, callData, thisValue, args);
        }
        iterator->finish();
    }
    return JSValue::encode(jsUndefined());
}

ALWAYS_INLINE static void JIT_OPERATION operationPutByValInternal(ExecState* exec, EncodedJSValue encodedBase, EncodedJSValue encodedProperty, EncodedJSValue encodedValue)
{
    VM* vm = &exec->vm();
    NativeCallFrameTracer tracer(vm, exec);

    JSValue baseValue = JSValue::decode(encodedBase);
    JSValue property = JSValue::decode(encodedProperty);
    JSValue value = JSValue::decode(encodedValue);

    if (LIKELY(property.isUInt32())) {
        // Despite its name, JSValue::isUInt32 will return true only for positive boxed int32_t; all those values are valid array indices.
        ASSERT(isIndex(property.asUInt32()));
        putByVal<strict, direct>(exec, baseValue, property.asUInt32(), value);
        return;
    }

    if (property.isDouble()) {
        double propertyAsDouble = property.asDouble();
        uint32_t propertyAsUInt32 = static_cast<uint32_t>(propertyAsDouble);
        if (propertyAsDouble == propertyAsUInt32 && isIndex(propertyAsUInt32)) {
            putByVal<strict, direct>(exec, baseValue, propertyAsUInt32, value);
            return;
        }
    }

    // Don't put to an object if toString throws an exception.
    auto propertyName = property.toPropertyKey(exec);
    if (vm->exception())
        return;

    PutPropertySlot slot(baseValue, strict);
    if (direct) {
        RELEASE_ASSERT(baseValue.isObject());
        if (Optional<uint32_t> index = parseIndex(propertyName))
            asObject(baseValue)->putDirectIndex(exec, index.value(), value, 0, strict ? PutDirectIndexShouldThrow : PutDirectIndexShouldNotThrow);
        else
            asObject(baseValue)->putDirect(*vm, propertyName, value, slot);
    } else
        baseValue.put(exec, propertyName, value, slot);
}

JSValue collectMatches(VM& vm, ExecState* exec, JSString* string, const String& s, RegExpConstructor* constructor, RegExp* regExp, const FixEndFunc& fixEnd)
{
    auto scope = DECLARE_THROW_SCOPE(vm);

    MatchResult result = constructor->performMatch(vm, regExp, string, s, 0);
    if (!result)
        return jsNull();
    
    static unsigned maxSizeForDirectPath = 100000;
    
    JSArray* array = constructEmptyArray(exec, nullptr);
    if (UNLIKELY(vm.exception()))
        return jsUndefined();

    auto iterate = [&] () {
        size_t end = result.end;
        size_t length = end - result.start;
        array->push(exec, JSRopeString::createSubstringOfResolved(vm, string, result.start, length));
        if (!length)
            end = fixEnd(end);
        result = constructor->performMatch(vm, regExp, string, s, end);
    };
    
    do {
        if (array->length() >= maxSizeForDirectPath) {
            // First do a throw-away match to see how many matches we'll get.
            unsigned matchCount = 0;
            MatchResult savedResult = result;
            do {
                if (array->length() + matchCount >= MAX_STORAGE_VECTOR_LENGTH) {
                    throwOutOfMemoryError(exec, scope);
                    return jsUndefined();
                }
                
                size_t end = result.end;
                matchCount++;
                if (result.empty())
                    end = fixEnd(end);
                
                // Using RegExpConstructor::performMatch() instead of calling RegExp::match()
                // directly is a surprising but profitable choice: it means that when we do OOM, we
                // will leave the cached result in the state it ought to have had just before the
                // OOM! On the other hand, if this loop concludes that the result is small enough,
                // then the iterate() loop below will overwrite the cached result anyway.
                result = constructor->performMatch(vm, regExp, string, s, end);
            } while (result);
            
            // OK, we have a sensible number of matches. Now we can create them for reals.
            result = savedResult;
            do
                iterate();
            while (result);
            
            return array;
        }
        
        iterate();
    } while (result);
    
    return array;
}

static void doThrow(ExecState* exec, Instruction* pc)
{
    VM* vm = &exec->vm();
    NativeCallFrameTracer tracer(vm, exec);
    genericThrow(vm, exec, vm->exception(), pc - exec->codeBlock()->instructions().begin());
}

void compileOSRExit(ExecState* exec)
{
    if (exec->vm().callFrameForCatch)
        RELEASE_ASSERT(exec->vm().callFrameForCatch == exec);
    
    CodeBlock* codeBlock = exec->codeBlock();
    ASSERT(codeBlock);
    ASSERT(codeBlock->jitType() == JITCode::DFGJIT);

    VM* vm = &exec->vm();
    
    // It's sort of preferable that we don't GC while in here. Anyways, doing so wouldn't
    // really be profitable.
    DeferGCForAWhile deferGC(vm->heap);

    uint32_t exitIndex = vm->osrExitIndex;
    OSRExit& exit = codeBlock->jitCode()->dfg()->osrExit[exitIndex];
    
    if (vm->callFrameForCatch)
        ASSERT(exit.m_kind == GenericUnwind);
    if (exit.isExceptionHandler())
        ASSERT(!!vm->exception());
        
    
    prepareCodeOriginForOSRExit(exec, exit.m_codeOrigin);
    
    // Compute the value recoveries.
    Operands<ValueRecovery> operands;
    codeBlock->jitCode()->dfg()->variableEventStream.reconstruct(codeBlock, exit.m_codeOrigin, codeBlock->jitCode()->dfg()->minifiedDFG, exit.m_streamIndex, operands);
    
    SpeculationRecovery* recovery = 0;
    if (exit.m_recoveryIndex != UINT_MAX)
        recovery = &codeBlock->jitCode()->dfg()->speculationRecovery[exit.m_recoveryIndex];

    {
        CCallHelpers jit(vm, codeBlock);
        OSRExitCompiler exitCompiler(jit);

        if (exit.m_kind == GenericUnwind) {
            // We are acting as a defacto op_catch because we arrive here from genericUnwind().
            // So, we must restore our call frame and stack pointer.
            jit.restoreCalleeSavesFromVMEntryFrameCalleeSavesBuffer();
            jit.loadPtr(vm->addressOfCallFrameForCatch(), GPRInfo::callFrameRegister);
            jit.addPtr(CCallHelpers::TrustedImm32(codeBlock->stackPointerOffset() * sizeof(Register)),
                GPRInfo::callFrameRegister, CCallHelpers::stackPointerRegister);
        }

        jit.jitAssertHasValidCallFrame();
        
        if (vm->m_perBytecodeProfiler && codeBlock->jitCode()->dfgCommon()->compilation) {
            Profiler::Database& database = *vm->m_perBytecodeProfiler;
            Profiler::Compilation* compilation = codeBlock->jitCode()->dfgCommon()->compilation.get();
            
            Profiler::OSRExit* profilerExit = compilation->addOSRExit(
                exitIndex, Profiler::OriginStack(database, codeBlock, exit.m_codeOrigin),
                exit.m_kind, exit.m_kind == UncountableInvalidation);
            jit.add64(CCallHelpers::TrustedImm32(1), CCallHelpers::AbsoluteAddress(profilerExit->counterAddress()));
        }

        exitCompiler.compileExit(exit, operands, recovery);
        
        LinkBuffer patchBuffer(*vm, jit, codeBlock);
        exit.m_code = FINALIZE_CODE_IF(
            shouldDumpDisassembly() || Options::verboseOSR(),
            patchBuffer,
            ("DFG OSR exit #%u (%s, %s) from %s, with operands = %s",
                exitIndex, toCString(exit.m_codeOrigin).data(),
                exitKindToString(exit.m_kind), toCString(*codeBlock).data(),
                toCString(ignoringContext<DumpContext>(operands)).data()));
    }
    
    MacroAssembler::repatchJump(exit.codeLocationForRepatch(codeBlock), CodeLocationLabel(exit.m_code.code()));
    
    vm->osrExitJumpDestination = exit.m_code.code().executableAddress();
}