JSValue CallFrame::uncheckedActivation() const
{
CodeBlock* codeBlock = this->codeBlock();
RELEASE_ASSERT(codeBlock->needsActivation());
VirtualRegister activationRegister = codeBlock->activationRegister();
return registers()[activationRegister.offset()].jsValue();
}
void CallFrame::setActivation(JSLexicalEnvironment* lexicalEnvironment)
{
CodeBlock* codeBlock = this->codeBlock();
RELEASE_ASSERT(codeBlock->needsActivation());
VirtualRegister activationRegister = codeBlock->activationRegister();
registers()[activationRegister.offset()] = lexicalEnvironment;
}
JSLexicalEnvironment* CallFrame::lexicalEnvironment() const
{
CodeBlock* codeBlock = this->codeBlock();
RELEASE_ASSERT(codeBlock->needsActivation());
VirtualRegister activationRegister = codeBlock->activationRegister();
return registers()[activationRegister.offset()].Register::lexicalEnvironment();
}
EncodedJSValue JSLexicalEnvironment::argumentsGetter(ExecState*, JSObject* slotBase, EncodedJSValue, PropertyName)
{
JSLexicalEnvironment* lexicalEnvironment = jsCast<JSLexicalEnvironment*>(slotBase);
CallFrame* callFrame = CallFrame::create(reinterpret_cast<Register*>(lexicalEnvironment->m_registers));
return JSValue::encode(jsUndefined());
VirtualRegister argumentsRegister = callFrame->codeBlock()->argumentsRegister();
if (JSValue arguments = callFrame->uncheckedR(argumentsRegister.offset()).jsValue())
return JSValue::encode(arguments);
int realArgumentsRegister = unmodifiedArgumentsRegister(argumentsRegister).offset();
JSValue arguments = JSValue(Arguments::create(callFrame->vm(), callFrame));
callFrame->uncheckedR(argumentsRegister.offset()) = arguments;
callFrame->uncheckedR(realArgumentsRegister) = arguments;
ASSERT(callFrame->uncheckedR(realArgumentsRegister).jsValue().inherits(Arguments::info()));
return JSValue::encode(callFrame->uncheckedR(realArgumentsRegister).jsValue());
}
EncodedJSValue JSActivation::argumentsGetter(ExecState*, EncodedJSValue slotBase, EncodedJSValue, PropertyName)
{
JSActivation* activation = jsCast<JSActivation*>(JSValue::decode(slotBase));
CallFrame* callFrame = CallFrame::create(reinterpret_cast<Register*>(activation->m_registers));
ASSERT(!activation->isTornOff() && (callFrame->codeBlock()->usesArguments() || callFrame->codeBlock()->usesEval()));
if (activation->isTornOff() || !(callFrame->codeBlock()->usesArguments() || callFrame->codeBlock()->usesEval()))
return JSValue::encode(jsUndefined());
VirtualRegister argumentsRegister = callFrame->codeBlock()->argumentsRegister();
if (JSValue arguments = callFrame->uncheckedR(argumentsRegister.offset()).jsValue())
return JSValue::encode(arguments);
int realArgumentsRegister = unmodifiedArgumentsRegister(argumentsRegister).offset();
JSValue arguments = JSValue(Arguments::create(callFrame->vm(), callFrame));
callFrame->uncheckedR(argumentsRegister.offset()) = arguments;
callFrame->uncheckedR(realArgumentsRegister) = arguments;
ASSERT(callFrame->uncheckedR(realArgumentsRegister).jsValue().inherits(Arguments::info()));
return JSValue::encode(callFrame->uncheckedR(realArgumentsRegister).jsValue());
}
void emitSetupVarargsFrameFastCase(CCallHelpers& jit, GPRReg numUsedSlotsGPR, GPRReg scratchGPR1, GPRReg scratchGPR2, GPRReg scratchGPR3, ValueRecovery argCountRecovery, VirtualRegister firstArgumentReg, unsigned firstVarArgOffset, CCallHelpers::JumpList& slowCase)
{
CCallHelpers::JumpList end;
if (argCountRecovery.isConstant()) {
// FIXME: We could constant-fold a lot of the computation below in this case.
// https://bugs.webkit.org/show_bug.cgi?id=141486
jit.move(CCallHelpers::TrustedImm32(argCountRecovery.constant().asInt32()), scratchGPR1);
} else
jit.load32(CCallHelpers::payloadFor(argCountRecovery.virtualRegister()), scratchGPR1);
if (firstVarArgOffset) {
CCallHelpers::Jump sufficientArguments = jit.branch32(CCallHelpers::GreaterThan, scratchGPR1, CCallHelpers::TrustedImm32(firstVarArgOffset + 1));
jit.move(CCallHelpers::TrustedImm32(1), scratchGPR1);
CCallHelpers::Jump endVarArgs = jit.jump();
sufficientArguments.link(&jit);
jit.sub32(CCallHelpers::TrustedImm32(firstVarArgOffset), scratchGPR1);
endVarArgs.link(&jit);
}
slowCase.append(jit.branch32(CCallHelpers::Above, scratchGPR1, CCallHelpers::TrustedImm32(maxArguments + 1)));
emitSetVarargsFrame(jit, scratchGPR1, true, numUsedSlotsGPR, scratchGPR2);
slowCase.append(jit.branchPtr(CCallHelpers::Above, CCallHelpers::AbsoluteAddress(jit.vm()->addressOfStackLimit()), scratchGPR2));
// Initialize ArgumentCount.
jit.store32(scratchGPR1, CCallHelpers::Address(scratchGPR2, JSStack::ArgumentCount * static_cast<int>(sizeof(Register)) + PayloadOffset));
// Copy arguments.
jit.signExtend32ToPtr(scratchGPR1, scratchGPR1);
CCallHelpers::Jump done = jit.branchSubPtr(CCallHelpers::Zero, CCallHelpers::TrustedImm32(1), scratchGPR1);
// scratchGPR1: argumentCount
CCallHelpers::Label copyLoop = jit.label();
int argOffset = (firstArgumentReg.offset() - 1 + firstVarArgOffset) * static_cast<int>(sizeof(Register));
#if USE(JSVALUE64)
jit.load64(CCallHelpers::BaseIndex(GPRInfo::callFrameRegister, scratchGPR1, CCallHelpers::TimesEight, argOffset), scratchGPR3);
jit.store64(scratchGPR3, CCallHelpers::BaseIndex(scratchGPR2, scratchGPR1, CCallHelpers::TimesEight, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register))));
#else // USE(JSVALUE64), so this begins the 32-bit case
jit.load32(CCallHelpers::BaseIndex(GPRInfo::callFrameRegister, scratchGPR1, CCallHelpers::TimesEight, argOffset + TagOffset), scratchGPR3);
jit.store32(scratchGPR3, CCallHelpers::BaseIndex(scratchGPR2, scratchGPR1, CCallHelpers::TimesEight, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register)) + TagOffset));
jit.load32(CCallHelpers::BaseIndex(GPRInfo::callFrameRegister, scratchGPR1, CCallHelpers::TimesEight, argOffset + PayloadOffset), scratchGPR3);
jit.store32(scratchGPR3, CCallHelpers::BaseIndex(scratchGPR2, scratchGPR1, CCallHelpers::TimesEight, CallFrame::thisArgumentOffset() * static_cast<int>(sizeof(Register)) + PayloadOffset));
#endif // USE(JSVALUE64), end of 32-bit case
jit.branchSubPtr(CCallHelpers::NonZero, CCallHelpers::TrustedImm32(1), scratchGPR1).linkTo(copyLoop, &jit);
done.link(&jit);
}
void BytecodeGeneratorification::run()
{
// We calculate the liveness at each merge point. This gives us the information which registers should be saved and resumed conservatively.
{
GeneratorLivenessAnalysis pass(*this);
pass.run();
}
UnlinkedCodeBlock* codeBlock = m_graph.codeBlock();
BytecodeRewriter rewriter(m_graph);
// Setup the global switch for the generator.
{
unsigned nextToEnterPoint = enterPoint() + opcodeLength(op_enter);
unsigned switchTableIndex = m_graph.codeBlock()->numberOfSwitchJumpTables();
VirtualRegister state = virtualRegisterForArgument(static_cast<int32_t>(JSGeneratorFunction::GeneratorArgument::State));
auto& jumpTable = m_graph.codeBlock()->addSwitchJumpTable();
jumpTable.min = 0;
jumpTable.branchOffsets.resize(m_yields.size() + 1);
jumpTable.branchOffsets.fill(0);
jumpTable.add(0, nextToEnterPoint);
for (unsigned i = 0; i < m_yields.size(); ++i)
jumpTable.add(i + 1, m_yields[i].point);
rewriter.insertFragmentBefore(nextToEnterPoint, [&](BytecodeRewriter::Fragment& fragment) {
fragment.appendInstruction(op_switch_imm, switchTableIndex, nextToEnterPoint, state.offset());
});
}
for (const YieldData& data : m_yields) {
VirtualRegister scope = virtualRegisterForArgument(static_cast<int32_t>(JSGeneratorFunction::GeneratorArgument::Frame));
// Emit save sequence.
rewriter.insertFragmentBefore(data.point, [&](BytecodeRewriter::Fragment& fragment) {
data.liveness.forEachSetBit([&](size_t index) {
VirtualRegister operand = virtualRegisterForLocal(index);
Storage storage = storageForGeneratorLocal(index);
fragment.appendInstruction(
op_put_to_scope,
scope.offset(), // scope
storage.identifierIndex, // identifier
operand.offset(), // value
GetPutInfo(DoNotThrowIfNotFound, LocalClosureVar, InitializationMode::NotInitialization).operand(), // info
m_generatorFrameSymbolTableIndex, // symbol table constant index
storage.scopeOffset.offset() // scope offset
);
});
// Insert op_ret just after save sequence.
fragment.appendInstruction(op_ret, data.argument);
});
// Emit resume sequence.
rewriter.insertFragmentAfter(data.point, [&](BytecodeRewriter::Fragment& fragment) {
data.liveness.forEachSetBit([&](size_t index) {
VirtualRegister operand = virtualRegisterForLocal(index);
Storage storage = storageForGeneratorLocal(index);
UnlinkedValueProfile profile = codeBlock->addValueProfile();
fragment.appendInstruction(
op_get_from_scope,
operand.offset(), // dst
scope.offset(), // scope
storage.identifierIndex, // identifier
GetPutInfo(DoNotThrowIfNotFound, LocalClosureVar, InitializationMode::NotInitialization).operand(), // info
0, // local scope depth
storage.scopeOffset.offset(), // scope offset
profile // profile
);
});
});
// Clip the unnecessary bytecodes.
rewriter.removeBytecode(data.point);
}
rewriter.execute();
}
void handleBlockForTryCatch(BasicBlock* block, InsertionSet& insertionSet)
{
HandlerInfo* currentExceptionHandler = nullptr;
FastBitVector liveAtCatchHead;
liveAtCatchHead.resize(m_graph.block(0)->variablesAtTail.numberOfLocals());
HandlerInfo* cachedHandlerResult;
CodeOrigin cachedCodeOrigin;
auto catchHandler = [&] (CodeOrigin origin) -> HandlerInfo* {
ASSERT(origin);
if (origin == cachedCodeOrigin)
return cachedHandlerResult;
unsigned bytecodeIndexToCheck = origin.bytecodeIndex;
cachedCodeOrigin = origin;
while (1) {
InlineCallFrame* inlineCallFrame = origin.inlineCallFrame;
CodeBlock* codeBlock = m_graph.baselineCodeBlockFor(inlineCallFrame);
if (HandlerInfo* handler = codeBlock->handlerForBytecodeOffset(bytecodeIndexToCheck)) {
liveAtCatchHead.clearAll();
unsigned catchBytecodeIndex = handler->target;
m_graph.forAllLocalsLiveInBytecode(CodeOrigin(catchBytecodeIndex, inlineCallFrame), [&] (VirtualRegister operand) {
liveAtCatchHead[operand.toLocal()] = true;
});
cachedHandlerResult = handler;
break;
}
if (!inlineCallFrame) {
cachedHandlerResult = nullptr;
break;
}
bytecodeIndexToCheck = inlineCallFrame->directCaller.bytecodeIndex;
origin = inlineCallFrame->directCaller;
}
return cachedHandlerResult;
};
Operands<VariableAccessData*> currentBlockAccessData(block->variablesAtTail.numberOfArguments(), block->variablesAtTail.numberOfLocals(), nullptr);
HashSet<InlineCallFrame*> seenInlineCallFrames;
auto flushEverything = [&] (NodeOrigin origin, unsigned index) {
RELEASE_ASSERT(currentExceptionHandler);
auto flush = [&] (VirtualRegister operand, bool alwaysInsert) {
if ((operand.isLocal() && liveAtCatchHead[operand.toLocal()])
|| operand.isArgument()
|| alwaysInsert) {
ASSERT(isValidFlushLocation(block, index, operand));
VariableAccessData* accessData = currentBlockAccessData.operand(operand);
if (!accessData)
accessData = newVariableAccessData(operand);
currentBlockAccessData.operand(operand) = accessData;
insertionSet.insertNode(index, SpecNone,
Flush, origin, OpInfo(accessData));
}
};
for (unsigned local = 0; local < block->variablesAtTail.numberOfLocals(); local++)
flush(virtualRegisterForLocal(local), false);
for (InlineCallFrame* inlineCallFrame : seenInlineCallFrames)
flush(VirtualRegister(inlineCallFrame->stackOffset + CallFrame::thisArgumentOffset()), true);
flush(VirtualRegister(CallFrame::thisArgumentOffset()), true);
seenInlineCallFrames.clear();
};
for (unsigned nodeIndex = 0; nodeIndex < block->size(); nodeIndex++) {
Node* node = block->at(nodeIndex);
{
HandlerInfo* newHandler = catchHandler(node->origin.semantic);
if (newHandler != currentExceptionHandler && currentExceptionHandler)
flushEverything(node->origin, nodeIndex);
currentExceptionHandler = newHandler;
}
if (currentExceptionHandler && (node->op() == SetLocal || node->op() == SetArgument)) {
InlineCallFrame* inlineCallFrame = node->origin.semantic.inlineCallFrame;
if (inlineCallFrame)
seenInlineCallFrames.add(inlineCallFrame);
VirtualRegister operand = node->local();
int stackOffset = inlineCallFrame ? inlineCallFrame->stackOffset : 0;
if ((operand.isLocal() && liveAtCatchHead[operand.toLocal()])
|| operand.isArgument()
|| (operand.offset() == stackOffset + CallFrame::thisArgumentOffset())) {
ASSERT(isValidFlushLocation(block, nodeIndex, operand));
VariableAccessData* variableAccessData = currentBlockAccessData.operand(operand);
if (!variableAccessData)
variableAccessData = newVariableAccessData(operand);
insertionSet.insertNode(nodeIndex, SpecNone,
Flush, node->origin, OpInfo(variableAccessData));
}
}
if (node->accessesStack(m_graph))
currentBlockAccessData.operand(node->local()) = node->variableAccessData();
}
if (currentExceptionHandler) {
NodeOrigin origin = block->at(block->size() - 1)->origin;
flushEverything(origin, block->size());
}
}
