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webkit / WebKit / 47784d6d61aff810e1f065cf372ed2f0af57142c / . / Source / JavaScriptCore / bytecompiler / BytecodeGenerator.cpp
blob: 97eb5402e1824f341a20ffeabba64478ae48e9d4 [file] [log] [blame]
/*
* Copyright (C) 2008, 2009, 2012, 2013 Apple Inc. All rights reserved.
* Copyright (C) 2008 Cameron Zwarich <cwzwarich@uwaterloo.ca>
* Copyright (C) 2012 Igalia, S.L.
*
* 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 Computer, 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.
*/
#include "config.h"
#include "BytecodeGenerator.h"
#include "Interpreter.h"
#include "JSActivation.h"
#include "JSFunction.h"
#include "JSNameScope.h"
#include "LowLevelInterpreter.h"
#include "Operations.h"
#include "Options.h"
#include "StrongInlines.h"
#include "UnlinkedCodeBlock.h"
#include <wtf/StdLibExtras.h>
#include <wtf/text/WTFString.h>
using namespace std;
namespace JSC {
void Label::setLocation(unsigned location)
{
m_location = location;
unsigned size = m_unresolvedJumps.size();
for (unsigned i = 0; i < size; ++i)
m_generator->m_instructions[m_unresolvedJumps[i].second].u.operand = m_location - m_unresolvedJumps[i].first;
}
ParserError BytecodeGenerator::generate()
{
SamplingRegion samplingRegion("Bytecode Generation");
m_codeBlock->setThisRegister(m_thisRegister.virtualRegister());
m_scopeNode->emitBytecode(*this);
m_staticPropertyAnalyzer.kill();
for (unsigned i = 0; i < m_tryRanges.size(); ++i) {
TryRange& range = m_tryRanges[i];
int start = range.start->bind();
int end = range.end->bind();
// This will happen for empty try blocks and for some cases of finally blocks:
//
// try {
// try {
// } finally {
// return 42;
// // *HERE*
// }
// } finally {
// print("things");
// }
//
// The return will pop scopes to execute the outer finally block. But this includes
// popping the try context for the inner try. The try context is live in the fall-through
// part of the finally block not because we will emit a handler that overlaps the finally,
// but because we haven't yet had a chance to plant the catch target. Then when we finish
// emitting code for the outer finally block, we repush the try contex, this time with a
// new start index. But that means that the start index for the try range corresponding
// to the inner-finally-following-the-return (marked as "*HERE*" above) will be greater
// than the end index of the try block. This is harmless since end < start handlers will
// never get matched in our logic, but we do the runtime a favor and choose to not emit
// such handlers at all.
if (end <= start)
continue;
ASSERT(range.tryData->targetScopeDepth != UINT_MAX);
UnlinkedHandlerInfo info = {
static_cast<uint32_t>(start), static_cast<uint32_t>(end),
static_cast<uint32_t>(range.tryData->target->bind()),
range.tryData->targetScopeDepth
};
m_codeBlock->addExceptionHandler(info);
}
m_codeBlock->instructions() = RefCountedArray<UnlinkedInstruction>(m_instructions);
m_codeBlock->shrinkToFit();
if (m_expressionTooDeep)
return ParserError(ParserError::OutOfMemory);
return ParserError(ParserError::ErrorNone);
}
bool BytecodeGenerator::addVar(const Identifier& ident, bool isConstant, RegisterID*& r0)
{
ConcurrentJITLocker locker(symbolTable().m_lock);
int index = virtualRegisterForLocal(m_calleeRegisters.size()).offset();
SymbolTableEntry newEntry(index, isConstant ? ReadOnly : 0);
SymbolTable::Map::AddResult result = symbolTable().add(locker, ident.impl(), newEntry);
if (!result.isNewEntry) {
r0 = &registerFor(result.iterator->value.getIndex());
return false;
}
r0 = addVar();
return true;
}
void BytecodeGenerator::preserveLastVar()
{
if ((m_firstConstantIndex = m_calleeRegisters.size()) != 0)
m_lastVar = &m_calleeRegisters.last();
}
BytecodeGenerator::BytecodeGenerator(VM& vm, ProgramNode* programNode, UnlinkedProgramCodeBlock* codeBlock, DebuggerMode debuggerMode, ProfilerMode profilerMode)
: m_shouldEmitDebugHooks(debuggerMode == DebuggerOn)
, m_shouldEmitProfileHooks(profilerMode == ProfilerOn)
, m_symbolTable(0)
, m_scopeNode(programNode)
, m_codeBlock(vm, codeBlock)
, m_thisRegister(CallFrame::thisArgumentOffset())
, m_emptyValueRegister(0)
, m_globalObjectRegister(0)
, m_finallyDepth(0)
, m_localScopeDepth(0)
, m_codeType(GlobalCode)
, m_nextConstantOffset(0)
, m_globalConstantIndex(0)
, m_hasCreatedActivation(true)
, m_firstLazyFunction(0)
, m_lastLazyFunction(0)
, m_staticPropertyAnalyzer(&m_instructions)
, m_vm(&vm)
, m_lastOpcodeID(op_end)
#ifndef NDEBUG
, m_lastOpcodePosition(0)
#endif
, m_stack(vm, wtfThreadData().stack())
, m_usesExceptions(false)
, m_expressionTooDeep(false)
{
if (m_shouldEmitDebugHooks)
m_codeBlock->setNeedsFullScopeChain(true);
m_codeBlock->setNumParameters(1); // Allocate space for "this"
emitOpcode(op_enter);
const VarStack& varStack = programNode->varStack();
const FunctionStack& functionStack = programNode->functionStack();
for (size_t i = 0; i < functionStack.size(); ++i) {
FunctionBodyNode* function = functionStack[i];
UnlinkedFunctionExecutable* unlinkedFunction = makeFunction(function);
codeBlock->addFunctionDeclaration(*m_vm, function->ident(), unlinkedFunction);
}
for (size_t i = 0; i < varStack.size(); ++i)
codeBlock->addVariableDeclaration(varStack[i].first, !!(varStack[i].second & DeclarationStacks::IsConstant));
}
BytecodeGenerator::BytecodeGenerator(VM& vm, FunctionBodyNode* functionBody, UnlinkedFunctionCodeBlock* codeBlock, DebuggerMode debuggerMode, ProfilerMode profilerMode)
: m_shouldEmitDebugHooks(debuggerMode == DebuggerOn)
, m_shouldEmitProfileHooks(profilerMode == ProfilerOn)
, m_symbolTable(codeBlock->symbolTable())
, m_scopeNode(functionBody)
, m_codeBlock(vm, codeBlock)
, m_activationRegister(0)
, m_emptyValueRegister(0)
, m_globalObjectRegister(0)
, m_finallyDepth(0)
, m_localScopeDepth(0)
, m_codeType(FunctionCode)
, m_nextConstantOffset(0)
, m_globalConstantIndex(0)
, m_hasCreatedActivation(false)
, m_firstLazyFunction(0)
, m_lastLazyFunction(0)
, m_staticPropertyAnalyzer(&m_instructions)
, m_vm(&vm)
, m_lastOpcodeID(op_end)
#ifndef NDEBUG
, m_lastOpcodePosition(0)
#endif
, m_stack(vm, wtfThreadData().stack())
, m_usesExceptions(false)
, m_expressionTooDeep(false)
{
if (m_shouldEmitDebugHooks)
m_codeBlock->setNeedsFullScopeChain(true);
m_symbolTable->setUsesNonStrictEval(codeBlock->usesEval() && !codeBlock->isStrictMode());
Vector<Identifier> boundParameterProperties;
FunctionParameters& parameters = *functionBody->parameters();
for (size_t i = 0; i < parameters.size(); i++) {
auto pattern = parameters.at(i);
if (pattern->isBindingNode())
continue;
pattern->collectBoundIdentifiers(boundParameterProperties);
continue;
}
m_symbolTable->setParameterCountIncludingThis(functionBody->parameters()->size() + 1);
emitOpcode(op_enter);
if (m_codeBlock->needsFullScopeChain()) {
m_activationRegister = addVar();
emitInitLazyRegister(m_activationRegister);
m_codeBlock->setActivationRegister(m_activationRegister->virtualRegister());
}
m_symbolTable->setCaptureStart(virtualRegisterForLocal(m_codeBlock->m_numVars).offset());
if (functionBody->usesArguments() || codeBlock->usesEval()) { // May reify arguments object.
RegisterID* unmodifiedArgumentsRegister = addVar(); // Anonymous, so it can't be modified by user code.
RegisterID* argumentsRegister = addVar(propertyNames().arguments, false); // Can be changed by assigning to 'arguments'.
// We can save a little space by hard-coding the knowledge that the two
// 'arguments' values are stored in consecutive registers, and storing
// only the index of the assignable one.
codeBlock->setArgumentsRegister(argumentsRegister->virtualRegister());
ASSERT_UNUSED(unmodifiedArgumentsRegister, unmodifiedArgumentsRegister->virtualRegister() == JSC::unmodifiedArgumentsRegister(codeBlock->argumentsRegister()));
emitInitLazyRegister(argumentsRegister);
emitInitLazyRegister(unmodifiedArgumentsRegister);
if (shouldTearOffArgumentsEagerly()) {
emitOpcode(op_create_arguments);
instructions().append(argumentsRegister->index());
}
}
bool shouldCaptureAllTheThings = m_shouldEmitDebugHooks || codeBlock->usesEval();
bool capturesAnyArgumentByName = false;
Vector<RegisterID*, 0, UnsafeVectorOverflow> capturedArguments;
if (functionBody->hasCapturedVariables() || shouldCaptureAllTheThings) {
FunctionParameters& parameters = *functionBody->parameters();
capturedArguments.resize(parameters.size());
for (size_t i = 0; i < parameters.size(); ++i) {
capturedArguments[i] = 0;
auto pattern = parameters.at(i);
if (!pattern->isBindingNode())
continue;
const Identifier& ident = static_cast<const BindingNode*>(pattern)->boundProperty();
if (!functionBody->captures(ident) && !shouldCaptureAllTheThings)
continue;
capturesAnyArgumentByName = true;
capturedArguments[i] = addVar();
}
}
if (capturesAnyArgumentByName && !shouldTearOffArgumentsEagerly()) {
size_t parameterCount = m_symbolTable->parameterCount();
auto slowArguments = std::make_unique<SlowArgument[]>(parameterCount);
for (size_t i = 0; i < parameterCount; ++i) {
if (!capturedArguments[i]) {
ASSERT(slowArguments[i].status == SlowArgument::Normal);
slowArguments[i].index = CallFrame::argumentOffset(i);
continue;
}
slowArguments[i].status = SlowArgument::Captured;
slowArguments[i].index = capturedArguments[i]->index();
}
m_symbolTable->setSlowArguments(std::move(slowArguments));
}
RegisterID* calleeRegister = resolveCallee(functionBody); // May push to the scope chain and/or add a captured var.
const DeclarationStacks::FunctionStack& functionStack = functionBody->functionStack();
const DeclarationStacks::VarStack& varStack = functionBody->varStack();
// Captured variables and functions go first so that activations don't have
// to step over the non-captured locals to mark them.
m_hasCreatedActivation = false;
if (functionBody->hasCapturedVariables()) {
for (size_t i = 0; i < functionStack.size(); ++i) {
FunctionBodyNode* function = functionStack[i];
const Identifier& ident = function->ident();
if (functionBody->captures(ident)) {
if (!m_hasCreatedActivation) {
m_hasCreatedActivation = true;
emitOpcode(op_create_activation);
instructions().append(m_activationRegister->index());
}
m_functions.add(ident.impl());
emitNewFunction(addVar(ident, false), function);
}
}
for (size_t i = 0; i < varStack.size(); ++i) {
const Identifier& ident = varStack[i].first;
if (functionBody->captures(ident))
addVar(ident, varStack[i].second & DeclarationStacks::IsConstant);
}
}
bool canLazilyCreateFunctions = !functionBody->needsActivationForMoreThanVariables() && !m_shouldEmitDebugHooks;
if (!canLazilyCreateFunctions && !m_hasCreatedActivation) {
m_hasCreatedActivation = true;
emitOpcode(op_create_activation);
instructions().append(m_activationRegister->index());
}
m_symbolTable->setCaptureEnd(virtualRegisterForLocal(codeBlock->m_numVars).offset());
m_firstLazyFunction = codeBlock->m_numVars;
for (size_t i = 0; i < functionStack.size(); ++i) {
FunctionBodyNode* function = functionStack[i];
const Identifier& ident = function->ident();
if (!functionBody->captures(ident)) {
m_functions.add(ident.impl());
RefPtr<RegisterID> reg = addVar(ident, false);
// Don't lazily create functions that override the name 'arguments'
// as this would complicate lazy instantiation of actual arguments.
if (!canLazilyCreateFunctions || ident == propertyNames().arguments)
emitNewFunction(reg.get(), function);
else {
emitInitLazyRegister(reg.get());
m_lazyFunctions.set(reg->virtualRegister().toLocal(), function);
}
}
}
m_lastLazyFunction = canLazilyCreateFunctions ? codeBlock->m_numVars : m_firstLazyFunction;
for (size_t i = 0; i < varStack.size(); ++i) {
const Identifier& ident = varStack[i].first;
if (!functionBody->captures(ident))
addVar(ident, varStack[i].second & DeclarationStacks::IsConstant);
}
if (shouldCaptureAllTheThings)
m_symbolTable->setCaptureEnd(virtualRegisterForLocal(codeBlock->m_numVars).offset());
m_parameters.grow(parameters.size() + 1); // reserve space for "this"
// Add "this" as a parameter
int nextParameterIndex = CallFrame::thisArgumentOffset();
m_thisRegister.setIndex(nextParameterIndex++);
m_codeBlock->addParameter();
Vector<std::pair<RegisterID*, const DeconstructionPatternNode*>> deconstructedParameters;
for (size_t i = 0; i < parameters.size(); ++i, ++nextParameterIndex) {
int index = nextParameterIndex;
auto pattern = parameters.at(i);
if (!pattern->isBindingNode()) {
m_codeBlock->addParameter();
RegisterID& parameter = registerFor(index);
parameter.setIndex(index);
deconstructedParameters.append(make_pair(&parameter, pattern));
continue;
}
auto simpleParameter = static_cast<const BindingNode*>(pattern);
if (capturedArguments.size() && capturedArguments[i]) {
ASSERT((functionBody->hasCapturedVariables() && functionBody->captures(simpleParameter->boundProperty())) || shouldCaptureAllTheThings);
index = capturedArguments[i]->index();
RegisterID original(nextParameterIndex);
emitMove(capturedArguments[i], &original);
}
addParameter(simpleParameter->boundProperty(), index);
}
preserveLastVar();
// We declare the callee's name last because it should lose to a var, function, and/or parameter declaration.
addCallee(functionBody, calleeRegister);
if (isConstructor()) {
emitCreateThis(&m_thisRegister);
} else if (functionBody->usesThis() || codeBlock->usesEval() || m_shouldEmitDebugHooks) {
m_codeBlock->addPropertyAccessInstruction(instructions().size());
emitOpcode(op_to_this);
instructions().append(kill(&m_thisRegister));
instructions().append(0);
}
for (size_t i = 0; i < deconstructedParameters.size(); i++) {
auto& entry = deconstructedParameters[i];
entry.second->bindValue(*this, entry.first);
}
}
BytecodeGenerator::BytecodeGenerator(VM& vm, EvalNode* evalNode, UnlinkedEvalCodeBlock* codeBlock, DebuggerMode debuggerMode, ProfilerMode profilerMode)
: m_shouldEmitDebugHooks(debuggerMode == DebuggerOn)
, m_shouldEmitProfileHooks(profilerMode == ProfilerOn)
, m_symbolTable(codeBlock->symbolTable())
, m_scopeNode(evalNode)
, m_codeBlock(vm, codeBlock)
, m_thisRegister(CallFrame::thisArgumentOffset())
, m_emptyValueRegister(0)
, m_globalObjectRegister(0)
, m_finallyDepth(0)
, m_localScopeDepth(0)
, m_codeType(EvalCode)
, m_nextConstantOffset(0)
, m_globalConstantIndex(0)
, m_hasCreatedActivation(true)
, m_firstLazyFunction(0)
, m_lastLazyFunction(0)
, m_staticPropertyAnalyzer(&m_instructions)
, m_vm(&vm)
, m_lastOpcodeID(op_end)
#ifndef NDEBUG
, m_lastOpcodePosition(0)
#endif
, m_stack(vm, wtfThreadData().stack())
, m_usesExceptions(false)
, m_expressionTooDeep(false)
{
m_codeBlock->setNeedsFullScopeChain(true);
m_symbolTable->setUsesNonStrictEval(codeBlock->usesEval() && !codeBlock->isStrictMode());
m_codeBlock->setNumParameters(1);
emitOpcode(op_enter);
const DeclarationStacks::FunctionStack& functionStack = evalNode->functionStack();
for (size_t i = 0; i < functionStack.size(); ++i)
m_codeBlock->addFunctionDecl(makeFunction(functionStack[i]));
const DeclarationStacks::VarStack& varStack = evalNode->varStack();
unsigned numVariables = varStack.size();
Vector<Identifier, 0, UnsafeVectorOverflow> variables;
variables.reserveCapacity(numVariables);
for (size_t i = 0; i < numVariables; ++i) {
ASSERT(varStack[i].first.impl()->isIdentifier());
variables.append(varStack[i].first);
}
codeBlock->adoptVariables(variables);
preserveLastVar();
}
BytecodeGenerator::~BytecodeGenerator()
{
}
RegisterID* BytecodeGenerator::emitInitLazyRegister(RegisterID* reg)
{
emitOpcode(op_init_lazy_reg);
instructions().append(reg->index());
return reg;
}
RegisterID* BytecodeGenerator::resolveCallee(FunctionBodyNode* functionBodyNode)
{
if (functionBodyNode->ident().isNull() || !functionBodyNode->functionNameIsInScope())
return 0;
m_calleeRegister.setIndex(JSStack::Callee);
// If non-strict eval is in play, we use a separate object in the scope chain for the callee's name.
if ((m_codeBlock->usesEval() && !m_codeBlock->isStrictMode()) || m_shouldEmitDebugHooks)
emitPushNameScope(functionBodyNode->ident(), &m_calleeRegister, ReadOnly | DontDelete);
if (!functionBodyNode->captures(functionBodyNode->ident()))
return &m_calleeRegister;
// Move the callee into the captured section of the stack.
return emitMove(addVar(), &m_calleeRegister);
}
void BytecodeGenerator::addCallee(FunctionBodyNode* functionBodyNode, RegisterID* calleeRegister)
{
if (functionBodyNode->ident().isNull() || !functionBodyNode->functionNameIsInScope())
return;
// If non-strict eval is in play, we use a separate object in the scope chain for the callee's name.
if ((m_codeBlock->usesEval() && !m_codeBlock->isStrictMode()) || m_shouldEmitDebugHooks)
return;
ASSERT(calleeRegister);
symbolTable().add(functionBodyNode->ident().impl(), SymbolTableEntry(calleeRegister->index(), ReadOnly));
}
void BytecodeGenerator::addParameter(const Identifier& ident, int parameterIndex)
{
// Parameters overwrite var declarations, but not function declarations.
StringImpl* rep = ident.impl();
if (!m_functions.contains(rep)) {
symbolTable().set(rep, parameterIndex);
RegisterID& parameter = registerFor(parameterIndex);
parameter.setIndex(parameterIndex);
}
// To maintain the calling convention, we have to allocate unique space for
// each parameter, even if the parameter doesn't make it into the symbol table.
m_codeBlock->addParameter();
}
bool BytecodeGenerator::willResolveToArguments(const Identifier& ident)
{
if (ident != propertyNames().arguments)
return false;
if (!shouldOptimizeLocals())
return false;
SymbolTableEntry entry = symbolTable().get(ident.impl());
if (entry.isNull())
return false;
if (m_codeBlock->usesArguments() && m_codeType == FunctionCode)
return true;
return false;
}
RegisterID* BytecodeGenerator::uncheckedRegisterForArguments()
{
ASSERT(willResolveToArguments(propertyNames().arguments));
SymbolTableEntry entry = symbolTable().get(propertyNames().arguments.impl());
ASSERT(!entry.isNull());
return &registerFor(entry.getIndex());
}
RegisterID* BytecodeGenerator::createLazyRegisterIfNecessary(RegisterID* reg)
{
if (!reg->virtualRegister().isLocal())
return reg;
int localVariableNumber = reg->virtualRegister().toLocal();
if (m_lastLazyFunction <= localVariableNumber || localVariableNumber < m_firstLazyFunction)
return reg;
emitLazyNewFunction(reg, m_lazyFunctions.get(localVariableNumber));
return reg;
}
RegisterID* BytecodeGenerator::newRegister()
{
m_calleeRegisters.append(virtualRegisterForLocal(m_calleeRegisters.size()));
m_codeBlock->m_numCalleeRegisters = max<int>(m_codeBlock->m_numCalleeRegisters, m_calleeRegisters.size());
return &m_calleeRegisters.last();
}
RegisterID* BytecodeGenerator::newTemporary()
{
// Reclaim free register IDs.
while (m_calleeRegisters.size() && !m_calleeRegisters.last().refCount())
m_calleeRegisters.removeLast();
RegisterID* result = newRegister();
result->setTemporary();
return result;
}
LabelScopePtr BytecodeGenerator::newLabelScope(LabelScope::Type type, const Identifier* name)
{
// Reclaim free label scopes.
while (m_labelScopes.size() && !m_labelScopes.last().refCount())
m_labelScopes.removeLast();
// Allocate new label scope.
LabelScope scope(type, name, scopeDepth(), newLabel(), type == LabelScope::Loop ? newLabel() : PassRefPtr<Label>()); // Only loops have continue targets.
m_labelScopes.append(scope);
return LabelScopePtr(&m_labelScopes, m_labelScopes.size() - 1);
}
PassRefPtr<Label> BytecodeGenerator::newLabel()
{
// Reclaim free label IDs.
while (m_labels.size() && !m_labels.last().refCount())
m_labels.removeLast();
// Allocate new label ID.
m_labels.append(this);
return &m_labels.last();
}
PassRefPtr<Label> BytecodeGenerator::emitLabel(Label* l0)
{
unsigned newLabelIndex = instructions().size();
l0->setLocation(newLabelIndex);
if (m_codeBlock->numberOfJumpTargets()) {
unsigned lastLabelIndex = m_codeBlock->lastJumpTarget();
ASSERT(lastLabelIndex <= newLabelIndex);
if (newLabelIndex == lastLabelIndex) {
// Peephole optimizations have already been disabled by emitting the last label
return l0;
}
}
m_codeBlock->addJumpTarget(newLabelIndex);
// This disables peephole optimizations when an instruction is a jump target
m_lastOpcodeID = op_end;
return l0;
}
void BytecodeGenerator::emitOpcode(OpcodeID opcodeID)
{
#ifndef NDEBUG
size_t opcodePosition = instructions().size();
ASSERT(opcodePosition - m_lastOpcodePosition == opcodeLength(m_lastOpcodeID) || m_lastOpcodeID == op_end);
m_lastOpcodePosition = opcodePosition;
#endif
instructions().append(opcodeID);
m_lastOpcodeID = opcodeID;
}
UnlinkedArrayProfile BytecodeGenerator::newArrayProfile()
{
#if ENABLE(VALUE_PROFILER)
return m_codeBlock->addArrayProfile();
#else
return 0;
#endif
}
UnlinkedArrayAllocationProfile BytecodeGenerator::newArrayAllocationProfile()
{
#if ENABLE(VALUE_PROFILER)
return m_codeBlock->addArrayAllocationProfile();
#else
return 0;
#endif
}
UnlinkedObjectAllocationProfile BytecodeGenerator::newObjectAllocationProfile()
{
return m_codeBlock->addObjectAllocationProfile();
}
UnlinkedValueProfile BytecodeGenerator::emitProfiledOpcode(OpcodeID opcodeID)
{
#if ENABLE(VALUE_PROFILER)
UnlinkedValueProfile result = m_codeBlock->addValueProfile();
#else
UnlinkedValueProfile result = 0;
#endif
emitOpcode(opcodeID);
return result;
}
void BytecodeGenerator::emitLoopHint()
{
emitOpcode(op_loop_hint);
}
void BytecodeGenerator::retrieveLastBinaryOp(int& dstIndex, int& src1Index, int& src2Index)
{
ASSERT(instructions().size() >= 4);
size_t size = instructions().size();
dstIndex = instructions().at(size - 3).u.operand;
src1Index = instructions().at(size - 2).u.operand;
src2Index = instructions().at(size - 1).u.operand;
}
void BytecodeGenerator::retrieveLastUnaryOp(int& dstIndex, int& srcIndex)
{
ASSERT(instructions().size() >= 3);
size_t size = instructions().size();
dstIndex = instructions().at(size - 2).u.operand;
srcIndex = instructions().at(size - 1).u.operand;
}
void ALWAYS_INLINE BytecodeGenerator::rewindBinaryOp()
{
ASSERT(instructions().size() >= 4);
instructions().shrink(instructions().size() - 4);
m_lastOpcodeID = op_end;
}
void ALWAYS_INLINE BytecodeGenerator::rewindUnaryOp()
{
ASSERT(instructions().size() >= 3);
instructions().shrink(instructions().size() - 3);
m_lastOpcodeID = op_end;
}
PassRefPtr<Label> BytecodeGenerator::emitJump(Label* target)
{
size_t begin = instructions().size();
emitOpcode(op_jmp);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
PassRefPtr<Label> BytecodeGenerator::emitJumpIfTrue(RegisterID* cond, Label* target)
{
if (m_lastOpcodeID == op_less) {
int dstIndex;
int src1Index;
int src2Index;
retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
rewindBinaryOp();
size_t begin = instructions().size();
emitOpcode(op_jless);
instructions().append(src1Index);
instructions().append(src2Index);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
} else if (m_lastOpcodeID == op_lesseq) {
int dstIndex;
int src1Index;
int src2Index;
retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
rewindBinaryOp();
size_t begin = instructions().size();
emitOpcode(op_jlesseq);
instructions().append(src1Index);
instructions().append(src2Index);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
} else if (m_lastOpcodeID == op_greater) {
int dstIndex;
int src1Index;
int src2Index;
retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
rewindBinaryOp();
size_t begin = instructions().size();
emitOpcode(op_jgreater);
instructions().append(src1Index);
instructions().append(src2Index);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
} else if (m_lastOpcodeID == op_greatereq) {
int dstIndex;
int src1Index;
int src2Index;
retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
rewindBinaryOp();
size_t begin = instructions().size();
emitOpcode(op_jgreatereq);
instructions().append(src1Index);
instructions().append(src2Index);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
} else if (m_lastOpcodeID == op_eq_null && target->isForward()) {
int dstIndex;
int srcIndex;
retrieveLastUnaryOp(dstIndex, srcIndex);
if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
rewindUnaryOp();
size_t begin = instructions().size();
emitOpcode(op_jeq_null);
instructions().append(srcIndex);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
} else if (m_lastOpcodeID == op_neq_null && target->isForward()) {
int dstIndex;
int srcIndex;
retrieveLastUnaryOp(dstIndex, srcIndex);
if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
rewindUnaryOp();
size_t begin = instructions().size();
emitOpcode(op_jneq_null);
instructions().append(srcIndex);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
}
size_t begin = instructions().size();
emitOpcode(op_jtrue);
instructions().append(cond->index());
instructions().append(target->bind(begin, instructions().size()));
return target;
}
PassRefPtr<Label> BytecodeGenerator::emitJumpIfFalse(RegisterID* cond, Label* target)
{
if (m_lastOpcodeID == op_less && target->isForward()) {
int dstIndex;
int src1Index;
int src2Index;
retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
rewindBinaryOp();
size_t begin = instructions().size();
emitOpcode(op_jnless);
instructions().append(src1Index);
instructions().append(src2Index);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
} else if (m_lastOpcodeID == op_lesseq && target->isForward()) {
int dstIndex;
int src1Index;
int src2Index;
retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
rewindBinaryOp();
size_t begin = instructions().size();
emitOpcode(op_jnlesseq);
instructions().append(src1Index);
instructions().append(src2Index);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
} else if (m_lastOpcodeID == op_greater && target->isForward()) {
int dstIndex;
int src1Index;
int src2Index;
retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
rewindBinaryOp();
size_t begin = instructions().size();
emitOpcode(op_jngreater);
instructions().append(src1Index);
instructions().append(src2Index);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
} else if (m_lastOpcodeID == op_greatereq && target->isForward()) {
int dstIndex;
int src1Index;
int src2Index;
retrieveLastBinaryOp(dstIndex, src1Index, src2Index);
if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
rewindBinaryOp();
size_t begin = instructions().size();
emitOpcode(op_jngreatereq);
instructions().append(src1Index);
instructions().append(src2Index);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
} else if (m_lastOpcodeID == op_not) {
int dstIndex;
int srcIndex;
retrieveLastUnaryOp(dstIndex, srcIndex);
if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
rewindUnaryOp();
size_t begin = instructions().size();
emitOpcode(op_jtrue);
instructions().append(srcIndex);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
} else if (m_lastOpcodeID == op_eq_null && target->isForward()) {
int dstIndex;
int srcIndex;
retrieveLastUnaryOp(dstIndex, srcIndex);
if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
rewindUnaryOp();
size_t begin = instructions().size();
emitOpcode(op_jneq_null);
instructions().append(srcIndex);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
} else if (m_lastOpcodeID == op_neq_null && target->isForward()) {
int dstIndex;
int srcIndex;
retrieveLastUnaryOp(dstIndex, srcIndex);
if (cond->index() == dstIndex && cond->isTemporary() && !cond->refCount()) {
rewindUnaryOp();
size_t begin = instructions().size();
emitOpcode(op_jeq_null);
instructions().append(srcIndex);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
}
size_t begin = instructions().size();
emitOpcode(op_jfalse);
instructions().append(cond->index());
instructions().append(target->bind(begin, instructions().size()));
return target;
}
PassRefPtr<Label> BytecodeGenerator::emitJumpIfNotFunctionCall(RegisterID* cond, Label* target)
{
size_t begin = instructions().size();
emitOpcode(op_jneq_ptr);
instructions().append(cond->index());
instructions().append(Special::CallFunction);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
PassRefPtr<Label> BytecodeGenerator::emitJumpIfNotFunctionApply(RegisterID* cond, Label* target)
{
size_t begin = instructions().size();
emitOpcode(op_jneq_ptr);
instructions().append(cond->index());
instructions().append(Special::ApplyFunction);
instructions().append(target->bind(begin, instructions().size()));
return target;
}
unsigned BytecodeGenerator::addConstant(const Identifier& ident)
{
StringImpl* rep = ident.impl();
IdentifierMap::AddResult result = m_identifierMap.add(rep, m_codeBlock->numberOfIdentifiers());
if (result.isNewEntry)
m_codeBlock->addIdentifier(ident);
return result.iterator->value;
}
// We can't hash JSValue(), so we use a dedicated data member to cache it.
RegisterID* BytecodeGenerator::addConstantEmptyValue()
{
if (!m_emptyValueRegister) {
int index = m_nextConstantOffset;
m_constantPoolRegisters.append(FirstConstantRegisterIndex + m_nextConstantOffset);
++m_nextConstantOffset;
m_codeBlock->addConstant(JSValue());
m_emptyValueRegister = &m_constantPoolRegisters[index];
}
return m_emptyValueRegister;
}
RegisterID* BytecodeGenerator::addConstantValue(JSValue v)
{
if (!v)
return addConstantEmptyValue();
int index = m_nextConstantOffset;
JSValueMap::AddResult result = m_jsValueMap.add(JSValue::encode(v), m_nextConstantOffset);
if (result.isNewEntry) {
m_constantPoolRegisters.append(FirstConstantRegisterIndex + m_nextConstantOffset);
++m_nextConstantOffset;
m_codeBlock->addConstant(v);
} else
index = result.iterator->value;
return &m_constantPoolRegisters[index];
}
unsigned BytecodeGenerator::addRegExp(RegExp* r)
{
return m_codeBlock->addRegExp(r);
}
RegisterID* BytecodeGenerator::emitMove(RegisterID* dst, RegisterID* src)
{
m_staticPropertyAnalyzer.mov(dst->index(), src->index());
emitOpcode(op_mov);
instructions().append(dst->index());
instructions().append(src->index());
return dst;
}
RegisterID* BytecodeGenerator::emitUnaryOp(OpcodeID opcodeID, RegisterID* dst, RegisterID* src)
{
emitOpcode(opcodeID);
instructions().append(dst->index());
instructions().append(src->index());
return dst;
}
RegisterID* BytecodeGenerator::emitInc(RegisterID* srcDst)
{
emitOpcode(op_inc);
instructions().append(srcDst->index());
return srcDst;
}
RegisterID* BytecodeGenerator::emitDec(RegisterID* srcDst)
{
emitOpcode(op_dec);
instructions().append(srcDst->index());
return srcDst;
}
RegisterID* BytecodeGenerator::emitBinaryOp(OpcodeID opcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2, OperandTypes types)
{
emitOpcode(opcodeID);
instructions().append(dst->index());
instructions().append(src1->index());
instructions().append(src2->index());
if (opcodeID == op_bitor || opcodeID == op_bitand || opcodeID == op_bitxor ||
opcodeID == op_add || opcodeID == op_mul || opcodeID == op_sub || opcodeID == op_div)
instructions().append(types.toInt());
return dst;
}
RegisterID* BytecodeGenerator::emitEqualityOp(OpcodeID opcodeID, RegisterID* dst, RegisterID* src1, RegisterID* src2)
{
if (m_lastOpcodeID == op_typeof) {
int dstIndex;
int srcIndex;
retrieveLastUnaryOp(dstIndex, srcIndex);
if (src1->index() == dstIndex
&& src1->isTemporary()
&& m_codeBlock->isConstantRegisterIndex(src2->index())
&& m_codeBlock->constantRegister(src2->index()).get().isString()) {
const String& value = asString(m_codeBlock->constantRegister(src2->index()).get())->tryGetValue();
if (value == "undefined") {
rewindUnaryOp();
emitOpcode(op_is_undefined);
instructions().append(dst->index());
instructions().append(srcIndex);
return dst;
}
if (value == "boolean") {
rewindUnaryOp();
emitOpcode(op_is_boolean);
instructions().append(dst->index());
instructions().append(srcIndex);
return dst;
}
if (value == "number") {
rewindUnaryOp();
emitOpcode(op_is_number);
instructions().append(dst->index());
instructions().append(srcIndex);
return dst;
}
if (value == "string") {
rewindUnaryOp();
emitOpcode(op_is_string);
instructions().append(dst->index());
instructions().append(srcIndex);
return dst;
}
if (value == "object") {
rewindUnaryOp();
emitOpcode(op_is_object);
instructions().append(dst->index());
instructions().append(srcIndex);
return dst;
}
if (value == "function") {
rewindUnaryOp();
emitOpcode(op_is_function);
instructions().append(dst->index());
instructions().append(srcIndex);
return dst;
}
}
}
emitOpcode(opcodeID);
instructions().append(dst->index());
instructions().append(src1->index());
instructions().append(src2->index());
return dst;
}
RegisterID* BytecodeGenerator::emitLoad(RegisterID* dst, bool b)
{
return emitLoad(dst, jsBoolean(b));
}
RegisterID* BytecodeGenerator::emitLoad(RegisterID* dst, double number)
{
// FIXME: Our hash tables won't hold infinity, so we make a new JSValue each time.
// Later we can do the extra work to handle that like the other cases. They also don't
// work correctly with NaN as a key.
if (std::isnan(number) || number == HashTraits<double>::emptyValue() || HashTraits<double>::isDeletedValue(number))
return emitLoad(dst, jsNumber(number));
JSValue& valueInMap = m_numberMap.add(number, JSValue()).iterator->value;
if (!valueInMap)
valueInMap = jsNumber(number);
return emitLoad(dst, valueInMap);
}
RegisterID* BytecodeGenerator::emitLoad(RegisterID* dst, const Identifier& identifier)
{
JSString*& stringInMap = m_stringMap.add(identifier.impl(), nullptr).iterator->value;
if (!stringInMap)
stringInMap = jsOwnedString(vm(), identifier.string());
return emitLoad(dst, JSValue(stringInMap));
}
RegisterID* BytecodeGenerator::emitLoad(RegisterID* dst, JSValue v)
{
RegisterID* constantID = addConstantValue(v);
if (dst)
return emitMove(dst, constantID);
return constantID;
}
RegisterID* BytecodeGenerator::emitLoadGlobalObject(RegisterID* dst)
{
if (!m_globalObjectRegister) {
int index = m_nextConstantOffset;
m_constantPoolRegisters.append(FirstConstantRegisterIndex + m_nextConstantOffset);
++m_nextConstantOffset;
m_codeBlock->addConstant(JSValue());
m_globalObjectRegister = &m_constantPoolRegisters[index];
m_codeBlock->setGlobalObjectRegister(VirtualRegister(index));
}
if (dst)
emitMove(dst, m_globalObjectRegister);
return m_globalObjectRegister;
}
Local BytecodeGenerator::local(const Identifier& property)
{
if (property == propertyNames().thisIdentifier)
return Local(thisRegister(), ReadOnly);
if (property == propertyNames().arguments)
createArgumentsIfNecessary();
if (!shouldOptimizeLocals())
return Local();
SymbolTableEntry entry = symbolTable().get(property.impl());
if (entry.isNull())
return Local();
RegisterID* local = createLazyRegisterIfNecessary(&registerFor(entry.getIndex()));
return Local(local, entry.getAttributes());
}
Local BytecodeGenerator::constLocal(const Identifier& property)
{
if (m_codeType != FunctionCode)
return Local();
SymbolTableEntry entry = symbolTable().get(property.impl());
if (entry.isNull())
return Local();
RegisterID* local = createLazyRegisterIfNecessary(&registerFor(entry.getIndex()));
return Local(local, entry.getAttributes());
}
void BytecodeGenerator::emitCheckHasInstance(RegisterID* dst, RegisterID* value, RegisterID* base, Label* target)
{
size_t begin = instructions().size();
emitOpcode(op_check_has_instance);
instructions().append(dst->index());
instructions().append(value->index());
instructions().append(base->index());
instructions().append(target->bind(begin, instructions().size()));
}
// Indicates the least upper bound of resolve type based on local scope. The bytecode linker
// will start with this ResolveType and compute the least upper bound including intercepting scopes.
ResolveType BytecodeGenerator::resolveType()
{
if (m_localScopeDepth)
return Dynamic;
if (m_symbolTable && m_symbolTable->usesNonStrictEval())
return GlobalPropertyWithVarInjectionChecks;
return GlobalProperty;
}
RegisterID* BytecodeGenerator::emitResolveScope(RegisterID* dst, const Identifier& identifier)
{
ASSERT(!m_symbolTable || !m_symbolTable->contains(identifier.impl()) || resolveType() == Dynamic);
// resolve_scope dst, id, ResolveType, depth
emitOpcode(op_resolve_scope);
instructions().append(kill(dst));
instructions().append(addConstant(identifier));
instructions().append(resolveType());
instructions().append(0);
return dst;
}
RegisterID* BytecodeGenerator::emitGetFromScope(RegisterID* dst, RegisterID* scope, const Identifier& identifier, ResolveMode resolveMode)
{
m_codeBlock->addPropertyAccessInstruction(instructions().size());
// get_from_scope dst, scope, id, ResolveModeAndType, Structure, Operand
UnlinkedValueProfile profile = emitProfiledOpcode(op_get_from_scope);
instructions().append(kill(dst));
instructions().append(scope->index());
instructions().append(addConstant(identifier));
instructions().append(ResolveModeAndType(resolveMode, resolveType()).operand());
instructions().append(0);
instructions().append(0);
instructions().append(profile);
return dst;
}
RegisterID* BytecodeGenerator::emitPutToScope(RegisterID* scope, const Identifier& identifier, RegisterID* value, ResolveMode resolveMode)
{
m_codeBlock->addPropertyAccessInstruction(instructions().size());
// put_to_scope scope, id, value, ResolveModeAndType, Structure, Operand
emitOpcode(op_put_to_scope);
instructions().append(scope->index());
instructions().append(addConstant(identifier));
instructions().append(value->index());
instructions().append(ResolveModeAndType(resolveMode, resolveType()).operand());
instructions().append(0);
instructions().append(0);
return value;
}
RegisterID* BytecodeGenerator::emitInstanceOf(RegisterID* dst, RegisterID* value, RegisterID* basePrototype)
{
emitOpcode(op_instanceof);
instructions().append(dst->index());
instructions().append(value->index());
instructions().append(basePrototype->index());
return dst;
}
RegisterID* BytecodeGenerator::emitInitGlobalConst(const Identifier& identifier, RegisterID* value)
{
ASSERT(m_codeType == GlobalCode);
emitOpcode(op_init_global_const_nop);
instructions().append(0);
instructions().append(value->index());
instructions().append(0);
instructions().append(addConstant(identifier));
return value;
}
RegisterID* BytecodeGenerator::emitGetById(RegisterID* dst, RegisterID* base, const Identifier& property)
{
m_codeBlock->addPropertyAccessInstruction(instructions().size());
UnlinkedValueProfile profile = emitProfiledOpcode(op_get_by_id);
instructions().append(kill(dst));
instructions().append(base->index());
instructions().append(addConstant(property));
instructions().append(0);
instructions().append(0);
instructions().append(0);
instructions().append(0);
instructions().append(profile);
return dst;
}
RegisterID* BytecodeGenerator::emitGetArgumentsLength(RegisterID* dst, RegisterID* base)
{
emitOpcode(op_get_arguments_length);
instructions().append(dst->index());
ASSERT(base->virtualRegister() == m_codeBlock->argumentsRegister());
instructions().append(base->index());
instructions().append(addConstant(propertyNames().length));
return dst;
}
RegisterID* BytecodeGenerator::emitPutById(RegisterID* base, const Identifier& property, RegisterID* value)
{
unsigned propertyIndex = addConstant(property);
m_staticPropertyAnalyzer.putById(base->index(), propertyIndex);
m_codeBlock->addPropertyAccessInstruction(instructions().size());
emitOpcode(op_put_by_id);
instructions().append(base->index());
instructions().append(propertyIndex);
instructions().append(value->index());
instructions().append(0);
instructions().append(0);
instructions().append(0);
instructions().append(0);
instructions().append(0);
return value;
}
RegisterID* BytecodeGenerator::emitDirectPutById(RegisterID* base, const Identifier& property, RegisterID* value)
{
unsigned propertyIndex = addConstant(property);
m_staticPropertyAnalyzer.putById(base->index(), propertyIndex);
m_codeBlock->addPropertyAccessInstruction(instructions().size());
emitOpcode(op_put_by_id);
instructions().append(base->index());
instructions().append(propertyIndex);
instructions().append(value->index());
instructions().append(0);
instructions().append(0);
instructions().append(0);
instructions().append(0);
instructions().append(
property != m_vm->propertyNames->underscoreProto
&& PropertyName(property).asIndex() == PropertyName::NotAnIndex);
return value;
}
void BytecodeGenerator::emitPutGetterSetter(RegisterID* base, const Identifier& property, RegisterID* getter, RegisterID* setter)
{
unsigned propertyIndex = addConstant(property);
m_staticPropertyAnalyzer.putById(base->index(), propertyIndex);
emitOpcode(op_put_getter_setter);
instructions().append(base->index());
instructions().append(propertyIndex);
instructions().append(getter->index());
instructions().append(setter->index());
}
RegisterID* BytecodeGenerator::emitDeleteById(RegisterID* dst, RegisterID* base, const Identifier& property)
{
emitOpcode(op_del_by_id);
instructions().append(dst->index());
instructions().append(base->index());
instructions().append(addConstant(property));
return dst;
}
RegisterID* BytecodeGenerator::emitGetArgumentByVal(RegisterID* dst, RegisterID* base, RegisterID* property)
{
UnlinkedArrayProfile arrayProfile = newArrayProfile();
UnlinkedValueProfile profile = emitProfiledOpcode(op_get_argument_by_val);
instructions().append(kill(dst));
ASSERT(base->virtualRegister() == m_codeBlock->argumentsRegister());
instructions().append(base->index());
instructions().append(property->index());
instructions().append(arrayProfile);
instructions().append(profile);
return dst;
}
RegisterID* BytecodeGenerator::emitGetByVal(RegisterID* dst, RegisterID* base, RegisterID* property)
{
for (size_t i = m_forInContextStack.size(); i > 0; i--) {
ForInContext& context = m_forInContextStack[i - 1];
if (context.propertyRegister == property) {
emitOpcode(op_get_by_pname);
instructions().append(dst->index());
instructions().append(base->index());
instructions().append(property->index());
instructions().append(context.expectedSubscriptRegister->index());
instructions().append(context.iterRegister->index());
instructions().append(context.indexRegister->index());
return dst;
}
}
UnlinkedArrayProfile arrayProfile = newArrayProfile();
UnlinkedValueProfile profile = emitProfiledOpcode(op_get_by_val);
instructions().append(kill(dst));
instructions().append(base->index());
instructions().append(property->index());
instructions().append(arrayProfile);
instructions().append(profile);
return dst;
}
RegisterID* BytecodeGenerator::emitPutByVal(RegisterID* base, RegisterID* property, RegisterID* value)
{
UnlinkedArrayProfile arrayProfile = newArrayProfile();
emitOpcode(op_put_by_val);
instructions().append(base->index());
instructions().append(property->index());
instructions().append(value->index());
instructions().append(arrayProfile);
return value;
}
RegisterID* BytecodeGenerator::emitDirectPutByVal(RegisterID* base, RegisterID* property, RegisterID* value)
{
UnlinkedArrayProfile arrayProfile = newArrayProfile();
emitOpcode(op_put_by_val_direct);
instructions().append(base->index());
instructions().append(property->index());
instructions().append(value->index());
instructions().append(arrayProfile);
return value;
}
RegisterID* BytecodeGenerator::emitDeleteByVal(RegisterID* dst, RegisterID* base, RegisterID* property)
{
emitOpcode(op_del_by_val);
instructions().append(dst->index());
instructions().append(base->index());
instructions().append(property->index());
return dst;
}
RegisterID* BytecodeGenerator::emitPutByIndex(RegisterID* base, unsigned index, RegisterID* value)
{
emitOpcode(op_put_by_index);
instructions().append(base->index());
instructions().append(index);
instructions().append(value->index());
return value;
}
RegisterID* BytecodeGenerator::emitCreateThis(RegisterID* dst)
{
RefPtr<RegisterID> func = newTemporary();
m_codeBlock->addPropertyAccessInstruction(instructions().size());
emitOpcode(op_get_callee);
instructions().append(func->index());
instructions().append(0);
size_t begin = instructions().size();
m_staticPropertyAnalyzer.createThis(m_thisRegister.index(), begin + 3);
emitOpcode(op_create_this);
instructions().append(m_thisRegister.index());
instructions().append(func->index());
instructions().append(0);
return dst;
}
RegisterID* BytecodeGenerator::emitNewObject(RegisterID* dst)
{
size_t begin = instructions().size();
m_staticPropertyAnalyzer.newObject(dst->index(), begin + 2);
emitOpcode(op_new_object);
instructions().append(dst->index());
instructions().append(0);
instructions().append(newObjectAllocationProfile());
return dst;
}
unsigned BytecodeGenerator::addConstantBuffer(unsigned length)
{
return m_codeBlock->addConstantBuffer(length);
}
JSString* BytecodeGenerator::addStringConstant(const Identifier& identifier)
{
JSString*& stringInMap = m_stringMap.add(identifier.impl(), nullptr).iterator->value;
if (!stringInMap) {
stringInMap = jsString(vm(), identifier.string());
addConstantValue(stringInMap);
}
return stringInMap;
}
RegisterID* BytecodeGenerator::emitNewArray(RegisterID* dst, ElementNode* elements, unsigned length)
{
#if !ASSERT_DISABLED
unsigned checkLength = 0;
#endif
bool hadVariableExpression = false;
if (length) {
for (ElementNode* n = elements; n; n = n->next()) {
if (!n->value()->isConstant()) {
hadVariableExpression = true;
break;
}
if (n->elision())
break;
#if !ASSERT_DISABLED
checkLength++;
#endif
}
if (!hadVariableExpression) {
ASSERT(length == checkLength);
unsigned constantBufferIndex = addConstantBuffer(length);
JSValue* constantBuffer = m_codeBlock->constantBuffer(constantBufferIndex).data();
unsigned index = 0;
for (ElementNode* n = elements; index < length; n = n->next()) {
ASSERT(n->value()->isConstant());
constantBuffer[index++] = static_cast<ConstantNode*>(n->value())->jsValue(*this);
}
emitOpcode(op_new_array_buffer);
instructions().append(dst->index());
instructions().append(constantBufferIndex);
instructions().append(length);
instructions().append(newArrayAllocationProfile());
return dst;
}
}
Vector<RefPtr<RegisterID>, 16, UnsafeVectorOverflow> argv;
for (ElementNode* n = elements; n; n = n->next()) {
if (!length)
break;
length--;
ASSERT(!n->value()->isSpreadExpression());
argv.append(newTemporary());
// op_new_array requires the initial values to be a sequential range of registers
ASSERT(argv.size() == 1 || argv[argv.size() - 1]->index() == argv[argv.size() - 2]->index() - 1);
emitNode(argv.last().get(), n->value());
}
ASSERT(!length);
emitOpcode(op_new_array);
instructions().append(dst->index());
instructions().append(argv.size() ? argv[0]->index() : 0); // argv
instructions().append(argv.size()); // argc
instructions().append(newArrayAllocationProfile());
return dst;
}
RegisterID* BytecodeGenerator::emitNewFunction(RegisterID* dst, FunctionBodyNode* function)
{
return emitNewFunctionInternal(dst, m_codeBlock->addFunctionDecl(makeFunction(function)), false);
}
RegisterID* BytecodeGenerator::emitLazyNewFunction(RegisterID* dst, FunctionBodyNode* function)
{
FunctionOffsetMap::AddResult ptr = m_functionOffsets.add(function, 0);
if (ptr.isNewEntry)
ptr.iterator->value = m_codeBlock->addFunctionDecl(makeFunction(function));
return emitNewFunctionInternal(dst, ptr.iterator->value, true);
}
RegisterID* BytecodeGenerator::emitNewFunctionInternal(RegisterID* dst, unsigned index, bool doNullCheck)
{
createActivationIfNecessary();
emitOpcode(op_new_func);
instructions().append(dst->index());
instructions().append(index);
instructions().append(doNullCheck);
return dst;
}
RegisterID* BytecodeGenerator::emitNewRegExp(RegisterID* dst, RegExp* regExp)
{
emitOpcode(op_new_regexp);
instructions().append(dst->index());
instructions().append(addRegExp(regExp));
return dst;
}
RegisterID* BytecodeGenerator::emitNewFunctionExpression(RegisterID* r0, FuncExprNode* n)
{
FunctionBodyNode* function = n->body();
unsigned index = m_codeBlock->addFunctionExpr(makeFunction(function));
createActivationIfNecessary();
emitOpcode(op_new_func_exp);
instructions().append(r0->index());
instructions().append(index);
return r0;
}
RegisterID* BytecodeGenerator::emitCall(RegisterID* dst, RegisterID* func, ExpectedFunction expectedFunction, CallArguments& callArguments, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd)
{
return emitCall(op_call, dst, func, expectedFunction, callArguments, divot, divotStart, divotEnd);
}
void BytecodeGenerator::createArgumentsIfNecessary()
{
if (m_codeType != FunctionCode)
return;
if (!m_codeBlock->usesArguments())
return;
if (shouldTearOffArgumentsEagerly())
return;
emitOpcode(op_create_arguments);
instructions().append(m_codeBlock->argumentsRegister().offset());
}
void BytecodeGenerator::createActivationIfNecessary()
{
if (m_hasCreatedActivation)
return;
if (!m_codeBlock->needsFullScopeChain())
return;
emitOpcode(op_create_activation);
instructions().append(m_activationRegister->index());
}
RegisterID* BytecodeGenerator::emitCallEval(RegisterID* dst, RegisterID* func, CallArguments& callArguments, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd)
{
return emitCall(op_call_eval, dst, func, NoExpectedFunction, callArguments, divot, divotStart, divotEnd);
}
ExpectedFunction BytecodeGenerator::expectedFunctionForIdentifier(const Identifier& identifier)
{
if (identifier == m_vm->propertyNames->Object)
return ExpectObjectConstructor;
if (identifier == m_vm->propertyNames->Array)
return ExpectArrayConstructor;
return NoExpectedFunction;
}
ExpectedFunction BytecodeGenerator::emitExpectedFunctionSnippet(RegisterID* dst, RegisterID* func, ExpectedFunction expectedFunction, CallArguments& callArguments, Label* done)
{
RefPtr<Label> realCall = newLabel();
switch (expectedFunction) {
case ExpectObjectConstructor: {
// If the number of arguments is non-zero, then we can't do anything interesting.
if (callArguments.argumentCountIncludingThis() >= 2)
return NoExpectedFunction;
size_t begin = instructions().size();
emitOpcode(op_jneq_ptr);
instructions().append(func->index());
instructions().append(Special::ObjectConstructor);
instructions().append(realCall->bind(begin, instructions().size()));
if (dst != ignoredResult())
emitNewObject(dst);
break;
}
case ExpectArrayConstructor: {
// If you're doing anything other than "new Array()" or "new Array(foo)" then we
// don't do inline it, for now. The only reason is that call arguments are in
// the opposite order of what op_new_array expects, so we'd either need to change
// how op_new_array works or we'd need an op_new_array_reverse. Neither of these
// things sounds like it's worth it.
if (callArguments.argumentCountIncludingThis() > 2)
return NoExpectedFunction;
size_t begin = instructions().size();
emitOpcode(op_jneq_ptr);
instructions().append(func->index());
instructions().append(Special::ArrayConstructor);
instructions().append(realCall->bind(begin, instructions().size()));
if (dst != ignoredResult()) {
if (callArguments.argumentCountIncludingThis() == 2) {
emitOpcode(op_new_array_with_size);
instructions().append(dst->index());
instructions().append(callArguments.argumentRegister(0)->index());
instructions().append(newArrayAllocationProfile());
} else {
ASSERT(callArguments.argumentCountIncludingThis() == 1);
emitOpcode(op_new_array);
instructions().append(dst->index());
instructions().append(0);
instructions().append(0);
instructions().append(newArrayAllocationProfile());
}
}
break;
}
default:
ASSERT(expectedFunction == NoExpectedFunction);
return NoExpectedFunction;
}
size_t begin = instructions().size();
emitOpcode(op_jmp);
instructions().append(done->bind(begin, instructions().size()));
emitLabel(realCall.get());
return expectedFunction;
}
RegisterID* BytecodeGenerator::emitCall(OpcodeID opcodeID, RegisterID* dst, RegisterID* func, ExpectedFunction expectedFunction, CallArguments& callArguments, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd)
{
ASSERT(opcodeID == op_call || opcodeID == op_call_eval);
ASSERT(func->refCount());
if (m_shouldEmitProfileHooks)
emitMove(callArguments.profileHookRegister(), func);
// Generate code for arguments.
unsigned argument = 0;
if (callArguments.argumentsNode()) {
ArgumentListNode* n = callArguments.argumentsNode()->m_listNode;
if (n && n->m_expr->isSpreadExpression()) {
RELEASE_ASSERT(!n->m_next);
auto expression = static_cast<SpreadExpressionNode*>(n->m_expr)->expression();
expression->emitBytecode(*this, callArguments.argumentRegister(0));
return emitCallVarargs(dst, func, callArguments.thisRegister(), callArguments.argumentRegister(0), newTemporary(), callArguments.profileHookRegister(), divot, divotStart, divotEnd);
}
for (; n; n = n->m_next)
emitNode(callArguments.argumentRegister(argument++), n);
}
// Reserve space for call frame.
Vector<RefPtr<RegisterID>, JSStack::CallFrameHeaderSize, UnsafeVectorOverflow> callFrame;
for (int i = 0; i < JSStack::CallFrameHeaderSize; ++i)
callFrame.append(newTemporary());
if (m_shouldEmitProfileHooks) {
emitOpcode(op_profile_will_call);
instructions().append(callArguments.profileHookRegister()->index());
}
emitExpressionInfo(divot, divotStart, divotEnd);
RefPtr<Label> done = newLabel();
expectedFunction = emitExpectedFunctionSnippet(dst, func, expectedFunction, callArguments, done.get());
// Emit call.
UnlinkedArrayProfile arrayProfile = newArrayProfile();
UnlinkedValueProfile profile = emitProfiledOpcode(opcodeID);
ASSERT(dst);
ASSERT(dst != ignoredResult());
instructions().append(dst->index()); // result
instructions().append(func->index()); // func
instructions().append(callArguments.argumentCountIncludingThis()); // argCount
instructions().append(callArguments.registerOffset()); // registerOffset
#if ENABLE(LLINT)
instructions().append(m_codeBlock->addLLIntCallLinkInfo());
#else
instructions().append(0);
#endif
instructions().append(arrayProfile);
instructions().append(profile);
if (expectedFunction != NoExpectedFunction)
emitLabel(done.get());
if (m_shouldEmitProfileHooks) {
emitOpcode(op_profile_did_call);
instructions().append(callArguments.profileHookRegister()->index());
}
return dst;
}
RegisterID* BytecodeGenerator::emitCallVarargs(RegisterID* dst, RegisterID* func, RegisterID* thisRegister, RegisterID* arguments, RegisterID* firstFreeRegister, RegisterID* profileHookRegister, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd)
{
if (m_shouldEmitProfileHooks) {
emitMove(profileHookRegister, func);
emitOpcode(op_profile_will_call);
instructions().append(profileHookRegister->index());
}
emitExpressionInfo(divot, divotStart, divotEnd);
// Emit call.
UnlinkedValueProfile profile = emitProfiledOpcode(op_call_varargs);
ASSERT(dst != ignoredResult());
instructions().append(dst->index());
instructions().append(func->index());
instructions().append(thisRegister->index());
instructions().append(arguments->index());
instructions().append(firstFreeRegister->index());
instructions().append(0); // Pad to make it as big as an op_call.
instructions().append(profile);
if (m_shouldEmitProfileHooks) {
emitOpcode(op_profile_did_call);
instructions().append(profileHookRegister->index());
}
return dst;
}
RegisterID* BytecodeGenerator::emitReturn(RegisterID* src)
{
if (m_codeBlock->needsFullScopeChain()) {
emitOpcode(op_tear_off_activation);
instructions().append(m_activationRegister->index());
}
if (m_codeBlock->usesArguments() && m_codeBlock->numParameters() != 1 && !isStrictMode()) {
emitOpcode(op_tear_off_arguments);
instructions().append(m_codeBlock->argumentsRegister().offset());
instructions().append(m_activationRegister ? m_activationRegister->index() : emitLoad(0, JSValue())->index());
}
// Constructors use op_ret_object_or_this to check the result is an
// object, unless we can trivially determine the check is not
// necessary (currently, if the return value is 'this').
if (isConstructor() && (src->index() != m_thisRegister.index())) {
emitOpcode(op_ret_object_or_this);
instructions().append(src->index());
instructions().append(m_thisRegister.index());
return src;
}
return emitUnaryNoDstOp(op_ret, src);
}
RegisterID* BytecodeGenerator::emitUnaryNoDstOp(OpcodeID opcodeID, RegisterID* src)
{
emitOpcode(opcodeID);
instructions().append(src->index());
return src;
}
RegisterID* BytecodeGenerator::emitConstruct(RegisterID* dst, RegisterID* func, ExpectedFunction expectedFunction, CallArguments& callArguments, const JSTextPosition& divot, const JSTextPosition& divotStart, const JSTextPosition& divotEnd)
{
ASSERT(func->refCount());
if (m_shouldEmitProfileHooks)
emitMove(callArguments.profileHookRegister(), func);
// Generate code for arguments.
unsigned argument = 0;
if (ArgumentsNode* argumentsNode = callArguments.argumentsNode()) {
for (ArgumentListNode* n = argumentsNode->m_listNode; n; n = n->m_next)
emitNode(callArguments.argumentRegister(argument++), n);
}
if (m_shouldEmitProfileHooks) {
emitOpcode(op_profile_will_call);
instructions().append(callArguments.profileHookRegister()->index());
}
// Reserve space for call frame.
Vector<RefPtr<RegisterID>, JSStack::CallFrameHeaderSize, UnsafeVectorOverflow> callFrame;
for (int i = 0; i < JSStack::CallFrameHeaderSize; ++i)
callFrame.append(newTemporary());
emitExpressionInfo(divot, divotStart, divotEnd);
RefPtr<Label> done = newLabel();
expectedFunction = emitExpectedFunctionSnippet(dst, func, expectedFunction, callArguments, done.get());
UnlinkedValueProfile profile = emitProfiledOpcode(op_construct);
ASSERT(dst != ignoredResult());
instructions().append(dst->index());
instructions().append(func->index()); // func
instructions().append(callArguments.argumentCountIncludingThis()); // argCount
instructions().append(callArguments.registerOffset()); // registerOffset
#if ENABLE(LLINT)
instructions().append(m_codeBlock->addLLIntCallLinkInfo());
#else
instructions().append(0);
#endif
instructions().append(0);
instructions().append(profile);
if (expectedFunction != NoExpectedFunction)
emitLabel(done.get());
if (m_shouldEmitProfileHooks) {
emitOpcode(op_profile_did_call);
instructions().append(callArguments.profileHookRegister()->index());
}
return dst;
}
RegisterID* BytecodeGenerator::emitStrcat(RegisterID* dst, RegisterID* src, int count)
{
emitOpcode(op_strcat);
instructions().append(dst->index());
instructions().append(src->index());
instructions().append(count);
return dst;
}
void BytecodeGenerator::emitToPrimitive(RegisterID* dst, RegisterID* src)
{
emitOpcode(op_to_primitive);
instructions().append(dst->index());
instructions().append(src->index());
}
RegisterID* BytecodeGenerator::emitPushWithScope(RegisterID* scope)
{
ControlFlowContext context;
context.isFinallyBlock = false;
m_scopeContextStack.append(context);
m_localScopeDepth++;
return emitUnaryNoDstOp(op_push_with_scope, scope);
}
void BytecodeGenerator::emitPopScope()
{
ASSERT(m_scopeContextStack.size());
ASSERT(!m_scopeContextStack.last().isFinallyBlock);
emitOpcode(op_pop_scope);
m_scopeContextStack.removeLast();
m_localScopeDepth--;
}
void BytecodeGenerator::emitDebugHook(DebugHookID debugHookID, unsigned line, unsigned charOffset, unsigned lineStart)
{
#if ENABLE(DEBUG_WITH_BREAKPOINT)
if (debugHookID != DidReachBreakpoint)
return;
#else
if (!m_shouldEmitDebugHooks)
return;
#endif
JSTextPosition divot(line, charOffset, lineStart);
emitExpressionInfo(divot, divot, divot);
emitOpcode(op_debug);
instructions().append(debugHookID);
}
void BytecodeGenerator::pushFinallyContext(StatementNode* finallyBlock)
{
ControlFlowContext scope;
scope.isFinallyBlock = true;
FinallyContext context = {
finallyBlock,
static_cast<unsigned>(m_scopeContextStack.size()),
static_cast<unsigned>(m_switchContextStack.size()),
static_cast<unsigned>(m_forInContextStack.size()),
static_cast<unsigned>(m_tryContextStack.size()),
static_cast<unsigned>(m_labelScopes.size()),
m_finallyDepth,
m_localScopeDepth
};
scope.finallyContext = context;
m_scopeContextStack.append(scope);
m_finallyDepth++;
}
void BytecodeGenerator::popFinallyContext()
{
ASSERT(m_scopeContextStack.size());
ASSERT(m_scopeContextStack.last().isFinallyBlock);
ASSERT(m_finallyDepth > 0);
m_scopeContextStack.removeLast();
m_finallyDepth--;
}
LabelScope* BytecodeGenerator::breakTarget(const Identifier& name)
{
// Reclaim free label scopes.
//
// The condition was previously coded as 'm_labelScopes.size() && !m_labelScopes.last().refCount()',
// however sometimes this appears to lead to GCC going a little haywire and entering the loop with
// size 0, leading to segfaulty badness. We are yet to identify a valid cause within our code to
// cause the GCC codegen to misbehave in this fashion, and as such the following refactoring of the
// loop condition is a workaround.
while (m_labelScopes.size()) {
if (m_labelScopes.last().refCount())
break;
m_labelScopes.removeLast();
}
if (!m_labelScopes.size())
return 0;
// We special-case the following, which is a syntax error in Firefox:
// label:
// break;
if (name.isEmpty()) {
for (int i = m_labelScopes.size() - 1; i >= 0; --i) {
LabelScope* scope = &m_labelScopes[i];
if (scope->type() != LabelScope::NamedLabel) {
ASSERT(scope->breakTarget());
return scope;
}
}
return 0;
}
for (int i = m_labelScopes.size() - 1; i >= 0; --i) {
LabelScope* scope = &m_labelScopes[i];
if (scope->name() && *scope->name() == name) {
ASSERT(scope->breakTarget());
return scope;
}
}
return 0;
}
LabelScope* BytecodeGenerator::continueTarget(const Identifier& name)
{
// Reclaim free label scopes.
while (m_labelScopes.size() && !m_labelScopes.last().refCount())
m_labelScopes.removeLast();
if (!m_labelScopes.size())
return 0;
if (name.isEmpty()) {
for (int i = m_labelScopes.size() - 1; i >= 0; --i) {
LabelScope* scope = &m_labelScopes[i];
if (scope->type() == LabelScope::Loop) {
ASSERT(scope->continueTarget());
return scope;
}
}
return 0;
}
// Continue to the loop nested nearest to the label scope that matches
// 'name'.
LabelScope* result = 0;
for (int i = m_labelScopes.size() - 1; i >= 0; --i) {
LabelScope* scope = &m_labelScopes[i];
if (scope->type() == LabelScope::Loop) {
ASSERT(scope->continueTarget());
result = scope;
}
if (scope->name() && *scope->name() == name)
return result; // may be 0
}
return 0;
}
void BytecodeGenerator::emitComplexPopScopes(ControlFlowContext* topScope, ControlFlowContext* bottomScope)
{
while (topScope > bottomScope) {
// First we count the number of dynamic scopes we need to remove to get
// to a finally block.
int nNormalScopes = 0;
while (topScope > bottomScope) {
if (topScope->isFinallyBlock)
break;
++nNormalScopes;
--topScope;
}
if (nNormalScopes) {
// We need to remove a number of dynamic scopes to get to the next
// finally block
while (nNormalScopes--)
emitOpcode(op_pop_scope);
// If topScope == bottomScope then there isn't a finally block left to emit.
if (topScope == bottomScope)
return;
}
Vector<ControlFlowContext> savedScopeContextStack;
Vector<SwitchInfo> savedSwitchContextStack;
Vector<ForInContext> savedForInContextStack;
Vector<TryContext> poppedTryContexts;
LabelScopeStore savedLabelScopes;
while (topScope > bottomScope && topScope->isFinallyBlock) {
RefPtr<Label> beforeFinally = emitLabel(newLabel().get());
// Save the current state of the world while instating the state of the world
// for the finally block.
FinallyContext finallyContext = topScope->finallyContext;
bool flipScopes = finallyContext.scopeContextStackSize != m_scopeContextStack.size();
bool flipSwitches = finallyContext.switchContextStackSize != m_switchContextStack.size();
bool flipForIns = finallyContext.forInContextStackSize != m_forInContextStack.size();
bool flipTries = finallyContext.tryContextStackSize != m_tryContextStack.size();
bool flipLabelScopes = finallyContext.labelScopesSize != m_labelScopes.size();
int topScopeIndex = -1;
int bottomScopeIndex = -1;
if (flipScopes) {
topScopeIndex = topScope - m_scopeContextStack.begin();
bottomScopeIndex = bottomScope - m_scopeContextStack.begin();
savedScopeContextStack = m_scopeContextStack;
m_scopeContextStack.shrink(finallyContext.scopeContextStackSize);
}
if (flipSwitches) {
savedSwitchContextStack = m_switchContextStack;
m_switchContextStack.shrink(finallyContext.switchContextStackSize);
}
if (flipForIns) {
savedForInContextStack = m_forInContextStack;
m_forInContextStack.shrink(finallyContext.forInContextStackSize);
}
if (flipTries) {
while (m_tryContextStack.size() != finallyContext.tryContextStackSize) {
ASSERT(m_tryContextStack.size() > finallyContext.tryContextStackSize);
TryContext context = m_tryContextStack.last();
m_tryContextStack.removeLast();
TryRange range;
range.start = context.start;
range.end = beforeFinally;
range.tryData = context.tryData;
m_tryRanges.append(range);
poppedTryContexts.append(context);
}
}
if (flipLabelScopes) {
savedLabelScopes = m_labelScopes;
while (m_labelScopes.size() > finallyContext.labelScopesSize)
m_labelScopes.removeLast();
}
int savedFinallyDepth = m_finallyDepth;
m_finallyDepth = finallyContext.finallyDepth;
int savedDynamicScopeDepth = m_localScopeDepth;
m_localScopeDepth = finallyContext.dynamicScopeDepth;
// Emit the finally block.
emitNode(finallyContext.finallyBlock);
RefPtr<Label> afterFinally = emitLabel(newLabel().get());
// Restore the state of the world.
if (flipScopes) {
m_scopeContextStack = savedScopeContextStack;
topScope = &m_scopeContextStack[topScopeIndex]; // assert it's within bounds
bottomScope = m_scopeContextStack.begin() + bottomScopeIndex; // don't assert, since it the index might be -1.
}
if (flipSwitches)
m_switchContextStack = savedSwitchContextStack;
if (flipForIns)
m_forInContextStack = savedForInContextStack;
if (flipTries) {
ASSERT(m_tryContextStack.size() == finallyContext.tryContextStackSize);
for (unsigned i = poppedTryContexts.size(); i--;) {
TryContext context = poppedTryContexts[i];
context.start = afterFinally;
m_tryContextStack.append(context);
}
poppedTryContexts.clear();
}
if (flipLabelScopes)
m_labelScopes = savedLabelScopes;
m_finallyDepth = savedFinallyDepth;
m_localScopeDepth = savedDynamicScopeDepth;
--topScope;
}
}
}
void BytecodeGenerator::emitPopScopes(int targetScopeDepth)
{
ASSERT(scopeDepth() - targetScopeDepth >= 0);
size_t scopeDelta = scopeDepth() - targetScopeDepth;
ASSERT(scopeDelta <= m_scopeContextStack.size());
if (!scopeDelta)
return;
if (!m_finallyDepth) {
while (scopeDelta--)
emitOpcode(op_pop_scope);
return;
}
emitComplexPopScopes(&m_scopeContextStack.last(), &m_scopeContextStack.last() - scopeDelta);
}
RegisterID* BytecodeGenerator::emitGetPropertyNames(RegisterID* dst, RegisterID* base, RegisterID* i, RegisterID* size, Label* breakTarget)
{
size_t begin = instructions().size();
emitOpcode(op_get_pnames);
instructions().append(dst->index());
instructions().append(base->index());
instructions().append(i->index());
instructions().append(size->index());
instructions().append(breakTarget->bind(begin, instructions().size()));
return dst;
}
RegisterID* BytecodeGenerator::emitNextPropertyName(RegisterID* dst, RegisterID* base, RegisterID* i, RegisterID* size, RegisterID* iter, Label* target)
{
size_t begin = instructions().size();
emitOpcode(op_next_pname);
instructions().append(dst->index());
instructions().append(base->index());
instructions().append(i->index());
instructions().append(size->index());
instructions().append(iter->index());
instructions().append(target->bind(begin, instructions().size()));
return dst;
}
TryData* BytecodeGenerator::pushTry(Label* start)
{
TryData tryData;
tryData.target = newLabel();
tryData.targetScopeDepth = UINT_MAX;
m_tryData.append(tryData);
TryData* result = &m_tryData.last();
TryContext tryContext;
tryContext.start = start;
tryContext.tryData = result;
m_tryContextStack.append(tryContext);
return result;
}
RegisterID* BytecodeGenerator::popTryAndEmitCatch(TryData* tryData, RegisterID* targetRegister, Label* end)
{
m_usesExceptions = true;
ASSERT_UNUSED(tryData, m_tryContextStack.last().tryData == tryData);
TryRange tryRange;
tryRange.start = m_tryContextStack.last().start;
tryRange.end = end;
tryRange.tryData = m_tryContextStack.last().tryData;
m_tryRanges.append(tryRange);
m_tryContextStack.removeLast();
emitLabel(tryRange.tryData->target.get());
tryRange.tryData->targetScopeDepth = m_localScopeDepth;
emitOpcode(op_catch);
instructions().append(targetRegister->index());
return targetRegister;
}
void BytecodeGenerator::emitThrowReferenceError(const String& message)
{
emitOpcode(op_throw_static_error);
instructions().append(addConstantValue(addStringConstant(Identifier(m_vm, message)))->index());
instructions().append(true);
}
void BytecodeGenerator::emitPushNameScope(const Identifier& property, RegisterID* value, unsigned attributes)
{
ControlFlowContext context;
context.isFinallyBlock = false;
m_scopeContextStack.append(context);
m_localScopeDepth++;
emitOpcode(op_push_name_scope);
instructions().append(addConstant(property));
instructions().append(value->index());
instructions().append(attributes);
}
void BytecodeGenerator::beginSwitch(RegisterID* scrutineeRegister, SwitchInfo::SwitchType type)
{
SwitchInfo info = { static_cast<uint32_t>(instructions().size()), type };
switch (type) {
case SwitchInfo::SwitchImmediate:
emitOpcode(op_switch_imm);
break;
case SwitchInfo::SwitchCharacter:
emitOpcode(op_switch_char);
break;
case SwitchInfo::SwitchString:
emitOpcode(op_switch_string);
break;
default:
RELEASE_ASSERT_NOT_REACHED();
}
instructions().append(0); // place holder for table index
instructions().append(0); // place holder for default target
instructions().append(scrutineeRegister->index());
m_switchContextStack.append(info);
}
static int32_t keyForImmediateSwitch(ExpressionNode* node, int32_t min, int32_t max)
{
UNUSED_PARAM(max);
ASSERT(node->isNumber());
double value = static_cast<NumberNode*>(node)->value();
int32_t key = static_cast<int32_t>(value);
ASSERT(key == value);
ASSERT(key >= min);
ASSERT(key <= max);
return key - min;
}
static int32_t keyForCharacterSwitch(ExpressionNode* node, int32_t min, int32_t max)
{
UNUSED_PARAM(max);
ASSERT(node->isString());
StringImpl* clause = static_cast<StringNode*>(node)->value().impl();
ASSERT(clause->length() == 1);
int32_t key = (*clause)[0];
ASSERT(key >= min);
ASSERT(key <= max);
return key - min;
}
static void prepareJumpTableForSwitch(
UnlinkedSimpleJumpTable& jumpTable, int32_t switchAddress, uint32_t clauseCount,
RefPtr<Label>* labels, ExpressionNode** nodes, int32_t min, int32_t max,
int32_t (*keyGetter)(ExpressionNode*, int32_t min, int32_t max))
{
jumpTable.min = min;
jumpTable.branchOffsets.resize(max - min + 1);
jumpTable.branchOffsets.fill(0);
for (uint32_t i = 0; i < clauseCount; ++i) {
// We're emitting this after the clause labels should have been fixed, so
// the labels should not be "forward" references
ASSERT(!labels[i]->isForward());
jumpTable.add(keyGetter(nodes[i], min, max), labels[i]->bind(switchAddress, switchAddress + 3));
}
}
static void prepareJumpTableForStringSwitch(UnlinkedStringJumpTable& jumpTable, int32_t switchAddress, uint32_t clauseCount, RefPtr<Label>* labels, ExpressionNode** nodes)
{
for (uint32_t i = 0; i < clauseCount; ++i) {
// We're emitting this after the clause labels should have been fixed, so
// the labels should not be "forward" references
ASSERT(!labels[i]->isForward());
ASSERT(nodes[i]->isString());
StringImpl* clause = static_cast<StringNode*>(nodes[i])->value().impl();
jumpTable.offsetTable.add(clause, labels[i]->bind(switchAddress, switchAddress + 3));
}
}
void BytecodeGenerator::endSwitch(uint32_t clauseCount, RefPtr<Label>* labels, ExpressionNode** nodes, Label* defaultLabel, int32_t min, int32_t max)
{
SwitchInfo switchInfo = m_switchContextStack.last();
m_switchContextStack.removeLast();
switch (switchInfo.switchType) {
case SwitchInfo::SwitchImmediate:
case SwitchInfo::SwitchCharacter: {
instructions()[switchInfo.bytecodeOffset + 1] = m_codeBlock->numberOfSwitchJumpTables();
instructions()[switchInfo.bytecodeOffset + 2] = defaultLabel->bind(switchInfo.bytecodeOffset, switchInfo.bytecodeOffset + 3);
UnlinkedSimpleJumpTable& jumpTable = m_codeBlock->addSwitchJumpTable();
prepareJumpTableForSwitch(
jumpTable, switchInfo.bytecodeOffset, clauseCount, labels, nodes, min, max,
switchInfo.switchType == SwitchInfo::SwitchImmediate
? keyForImmediateSwitch
: keyForCharacterSwitch);
break;
}
case SwitchInfo::SwitchString: {
instructions()[switchInfo.bytecodeOffset + 1] = m_codeBlock->numberOfStringSwitchJumpTables();
instructions()[switchInfo.bytecodeOffset + 2] = defaultLabel->bind(switchInfo.bytecodeOffset, switchInfo.bytecodeOffset + 3);
UnlinkedStringJumpTable& jumpTable = m_codeBlock->addStringSwitchJumpTable();
prepareJumpTableForStringSwitch(jumpTable, switchInfo.bytecodeOffset, clauseCount, labels, nodes);
break;
}
default:
RELEASE_ASSERT_NOT_REACHED();
break;
}
}
RegisterID* BytecodeGenerator::emitThrowExpressionTooDeepException()
{
// It would be nice to do an even better job of identifying exactly where the expression is.
// And we could make the caller pass the node pointer in, if there was some way of getting
// that from an arbitrary node. However, calling emitExpressionInfo without any useful data
// is still good enough to get us an accurate line number.
m_expressionTooDeep = true;
return newTemporary();
}
void BytecodeGenerator::setIsNumericCompareFunction(bool isNumericCompareFunction)
{
m_codeBlock->setIsNumericCompareFunction(isNumericCompareFunction);
}
bool BytecodeGenerator::isArgumentNumber(const Identifier& ident, int argumentNumber)
{
RegisterID* registerID = local(ident).get();
if (!registerID || registerID->index() >= 0)
return 0;
return registerID->index() == CallFrame::argumentOffset(argumentNumber);
}
void BytecodeGenerator::emitReadOnlyExceptionIfNeeded()
{
if (!isStrictMode())
return;
emitOpcode(op_throw_static_error);
instructions().append(addConstantValue(addStringConstant(Identifier(m_vm, StrictModeReadonlyPropertyWriteError)))->index());
instructions().append(false);
}
void BytecodeGenerator::emitEnumeration(ThrowableExpressionData* node, ExpressionNode* subjectNode, const std::function<void(BytecodeGenerator&, RegisterID*)>& callBack)
{
LabelScopePtr scope = newLabelScope(LabelScope::Loop);
RefPtr<RegisterID> subject = newTemporary();
emitNode(subject.get(), subjectNode);
RefPtr<RegisterID> iterator = emitGetById(newTemporary(), subject.get(), propertyNames().iteratorPrivateName);
{
CallArguments args(*this, 0);
emitMove(args.thisRegister(), subject.get());
emitCall(iterator.get(), iterator.get(), NoExpectedFunction, args, node->divot(), node->divotStart(), node->divotEnd());
}
RefPtr<RegisterID> iteratorNext = emitGetById(newTemporary(), iterator.get(), propertyNames().iteratorNextPrivateName);
RefPtr<RegisterID> value = newTemporary();
emitLoad(value.get(), jsUndefined());
emitJump(scope->continueTarget());
RefPtr<Label> loopStart = newLabel();
emitLabel(loopStart.get());
emitLoopHint();
callBack(*this, value.get());
emitLabel(scope->continueTarget());
CallArguments nextArguments(*this, 0, 1);
emitMove(nextArguments.thisRegister(), iterator.get());
emitMove(nextArguments.argumentRegister(0), value.get());
emitCall(value.get(), iteratorNext.get(), NoExpectedFunction, nextArguments, node->divot(), node->divotStart(), node->divotEnd());
RefPtr<RegisterID> result = newTemporary();
emitJumpIfFalse(emitEqualityOp(op_stricteq, result.get(), value.get(), emitLoad(0, JSValue(vm()->iterationTerminator.get()))), loopStart.get());
emitLabel(scope->breakTarget());
}
} // namespace JSC