JSObject* ProgramExecutable::initializeGlobalProperties(VM& vm, CallFrame* callFrame, JSScope* scope)
{
RELEASE_ASSERT(scope);
JSGlobalObject* globalObject = scope->globalObject();
RELEASE_ASSERT(globalObject);
ASSERT(&globalObject->vm() == &vm);
JSObject* exception = 0;
UnlinkedProgramCodeBlock* unlinkedCodeBlock = globalObject->createProgramCodeBlock(callFrame, this, &exception);
if (exception)
return exception;
JSGlobalLexicalEnvironment* globalLexicalEnvironment = globalObject->globalLexicalEnvironment();
const VariableEnvironment& variableDeclarations = unlinkedCodeBlock->variableDeclarations();
const VariableEnvironment& lexicalDeclarations = unlinkedCodeBlock->lexicalDeclarations();
// The ES6 spec says that no vars/global properties/let/const can be duplicated in the global scope.
// This carried out section 15.1.8 of the ES6 spec: http://www.ecma-international.org/ecma-262/6.0/index.html#sec-globaldeclarationinstantiation
{
ExecState* exec = globalObject->globalExec();
// Check for intersection of "var" and "let"/"const"/"class"
for (auto& entry : lexicalDeclarations) {
if (variableDeclarations.contains(entry.key))
return createSyntaxError(exec, makeString("Can't create duplicate variable: '", String(entry.key.get()), "'"));
}
// Check if any new "let"/"const"/"class" will shadow any pre-existing global property names, or "var"/"let"/"const" variables.
// It's an error to introduce a shadow.
for (auto& entry : lexicalDeclarations) {
if (globalObject->hasProperty(exec, entry.key.get()))
return createSyntaxError(exec, makeString("Can't create duplicate variable that shadows a global property: '", String(entry.key.get()), "'"));
if (globalLexicalEnvironment->hasProperty(exec, entry.key.get()))
return createSyntaxError(exec, makeString("Can't create duplicate variable: '", String(entry.key.get()), "'"));
}
// Check if any new "var"s will shadow any previous "let"/"const"/"class" names.
// It's an error to introduce a shadow.
if (!globalLexicalEnvironment->isEmpty()) {
for (auto& entry : variableDeclarations) {
if (globalLexicalEnvironment->hasProperty(exec, entry.key.get()))
return createSyntaxError(exec, makeString("Can't create duplicate variable: '", String(entry.key.get()), "'"));
}
}
}
m_unlinkedProgramCodeBlock.set(vm, this, unlinkedCodeBlock);
BatchedTransitionOptimizer optimizer(vm, globalObject);
for (size_t i = 0, numberOfFunctions = unlinkedCodeBlock->numberOfFunctionDecls(); i < numberOfFunctions; ++i) {
UnlinkedFunctionExecutable* unlinkedFunctionExecutable = unlinkedCodeBlock->functionDecl(i);
ASSERT(!unlinkedFunctionExecutable->name().isEmpty());
globalObject->addFunction(callFrame, unlinkedFunctionExecutable->name());
if (vm.typeProfiler() || vm.controlFlowProfiler()) {
vm.functionHasExecutedCache()->insertUnexecutedRange(sourceID(),
unlinkedFunctionExecutable->typeProfilingStartOffset(),
unlinkedFunctionExecutable->typeProfilingEndOffset());
}
}
for (auto& entry : variableDeclarations) {
ASSERT(entry.value.isVar());
globalObject->addVar(callFrame, Identifier::fromUid(&vm, entry.key.get()));
}
{
JSGlobalLexicalEnvironment* globalLexicalEnvironment = jsCast<JSGlobalLexicalEnvironment*>(globalObject->globalScope());
SymbolTable* symbolTable = globalLexicalEnvironment->symbolTable();
ConcurrentJITLocker locker(symbolTable->m_lock);
for (auto& entry : lexicalDeclarations) {
ScopeOffset offset = symbolTable->takeNextScopeOffset(locker);
SymbolTableEntry newEntry(VarOffset(offset), entry.value.isConst() ? ReadOnly : 0);
newEntry.prepareToWatch();
symbolTable->add(locker, entry.key.get(), newEntry);
ScopeOffset offsetForAssert = globalLexicalEnvironment->addVariables(1, jsTDZValue());
RELEASE_ASSERT(offsetForAssert == offset);
}
}
return 0;
}
JSObject* ProgramExecutable::initializeGlobalProperties(VM& vm, CallFrame* callFrame, JSScope* scope)
{
auto throwScope = DECLARE_THROW_SCOPE(vm);
RELEASE_ASSERT(scope);
JSGlobalObject* globalObject = scope->globalObject();
RELEASE_ASSERT(globalObject);
ASSERT(&globalObject->vm() == &vm);
ParserError error;
JSParserStrictMode strictMode = isStrictMode() ? JSParserStrictMode::Strict : JSParserStrictMode::NotStrict;
DebuggerMode debuggerMode = globalObject->hasInteractiveDebugger() ? DebuggerOn : DebuggerOff;
UnlinkedProgramCodeBlock* unlinkedCodeBlock = vm.codeCache()->getUnlinkedProgramCodeBlock(
vm, this, source(), strictMode, debuggerMode, error);
if (globalObject->hasDebugger())
globalObject->debugger()->sourceParsed(callFrame, source().provider(), error.line(), error.message());
if (error.isValid())
return error.toErrorObject(globalObject, source());
JSValue nextPrototype = globalObject->getPrototypeDirect();
while (nextPrototype && nextPrototype.isObject()) {
if (UNLIKELY(asObject(nextPrototype)->type() == ProxyObjectType)) {
ExecState* exec = globalObject->globalExec();
return createTypeError(exec, ASCIILiteral("Proxy is not allowed in the global prototype chain."));
}
nextPrototype = asObject(nextPrototype)->getPrototypeDirect();
}
JSGlobalLexicalEnvironment* globalLexicalEnvironment = globalObject->globalLexicalEnvironment();
const VariableEnvironment& variableDeclarations = unlinkedCodeBlock->variableDeclarations();
const VariableEnvironment& lexicalDeclarations = unlinkedCodeBlock->lexicalDeclarations();
// The ES6 spec says that no vars/global properties/let/const can be duplicated in the global scope.
// This carried out section 15.1.8 of the ES6 spec: http://www.ecma-international.org/ecma-262/6.0/index.html#sec-globaldeclarationinstantiation
{
ExecState* exec = globalObject->globalExec();
// Check for intersection of "var" and "let"/"const"/"class"
for (auto& entry : lexicalDeclarations) {
if (variableDeclarations.contains(entry.key))
return createSyntaxError(exec, makeString("Can't create duplicate variable: '", String(entry.key.get()), "'"));
}
// Check if any new "let"/"const"/"class" will shadow any pre-existing global property names, or "var"/"let"/"const" variables.
// It's an error to introduce a shadow.
for (auto& entry : lexicalDeclarations) {
bool hasProperty = globalObject->hasProperty(exec, entry.key.get());
RETURN_IF_EXCEPTION(throwScope, throwScope.exception());
if (hasProperty) {
// The ES6 spec says that just RestrictedGlobalProperty can't be shadowed
// This carried out section 8.1.1.4.14 of the ES6 spec: http://www.ecma-international.org/ecma-262/6.0/index.html#sec-hasrestrictedglobalproperty
PropertyDescriptor descriptor;
globalObject->getOwnPropertyDescriptor(exec, entry.key.get(), descriptor);
if (descriptor.value() != jsUndefined() && !descriptor.configurable())
return createSyntaxError(exec, makeString("Can't create duplicate variable that shadows a global property: '", String(entry.key.get()), "'"));
}
hasProperty = globalLexicalEnvironment->hasProperty(exec, entry.key.get());
RETURN_IF_EXCEPTION(throwScope, throwScope.exception());
if (hasProperty) {
if (UNLIKELY(entry.value.isConst() && !vm.globalConstRedeclarationShouldThrow() && !isStrictMode())) {
// We only allow "const" duplicate declarations under this setting.
// For example, we don't "let" variables to be overridden by "const" variables.
if (globalLexicalEnvironment->isConstVariable(entry.key.get()))
continue;
}
return createSyntaxError(exec, makeString("Can't create duplicate variable: '", String(entry.key.get()), "'"));
}
}
// Check if any new "var"s will shadow any previous "let"/"const"/"class" names.
// It's an error to introduce a shadow.
if (!globalLexicalEnvironment->isEmpty()) {
for (auto& entry : variableDeclarations) {
bool hasProperty = globalLexicalEnvironment->hasProperty(exec, entry.key.get());
RETURN_IF_EXCEPTION(throwScope, throwScope.exception());
if (hasProperty)
return createSyntaxError(exec, makeString("Can't create duplicate variable: '", String(entry.key.get()), "'"));
}
}
}
m_unlinkedProgramCodeBlock.set(vm, this, unlinkedCodeBlock);
BatchedTransitionOptimizer optimizer(vm, globalObject);
for (size_t i = 0, numberOfFunctions = unlinkedCodeBlock->numberOfFunctionDecls(); i < numberOfFunctions; ++i) {
UnlinkedFunctionExecutable* unlinkedFunctionExecutable = unlinkedCodeBlock->functionDecl(i);
ASSERT(!unlinkedFunctionExecutable->name().isEmpty());
globalObject->addFunction(callFrame, unlinkedFunctionExecutable->name());
if (vm.typeProfiler() || vm.controlFlowProfiler()) {
vm.functionHasExecutedCache()->insertUnexecutedRange(sourceID(),
unlinkedFunctionExecutable->typeProfilingStartOffset(),
unlinkedFunctionExecutable->typeProfilingEndOffset());
}
}
for (auto& entry : variableDeclarations) {
ASSERT(entry.value.isVar());
globalObject->addVar(callFrame, Identifier::fromUid(&vm, entry.key.get()));
ASSERT(!throwScope.exception());
}
{
JSGlobalLexicalEnvironment* globalLexicalEnvironment = jsCast<JSGlobalLexicalEnvironment*>(globalObject->globalScope());
SymbolTable* symbolTable = globalLexicalEnvironment->symbolTable();
ConcurrentJSLocker locker(symbolTable->m_lock);
for (auto& entry : lexicalDeclarations) {
if (UNLIKELY(entry.value.isConst() && !vm.globalConstRedeclarationShouldThrow() && !isStrictMode())) {
if (symbolTable->contains(locker, entry.key.get()))
continue;
}
ScopeOffset offset = symbolTable->takeNextScopeOffset(locker);
SymbolTableEntry newEntry(VarOffset(offset), entry.value.isConst() ? ReadOnly : 0);
newEntry.prepareToWatch();
symbolTable->add(locker, entry.key.get(), newEntry);
ScopeOffset offsetForAssert = globalLexicalEnvironment->addVariables(1, jsTDZValue());
RELEASE_ASSERT(offsetForAssert == offset);
}
}
return nullptr;
}
// Returns true if we found enough information to terminate optimization.
static inline bool abstractAccess(ExecState* exec, JSScope* scope, const Identifier& ident, GetOrPut getOrPut, size_t depth, bool& needsVarInjectionChecks, ResolveOp& op, InitializationMode initializationMode)
{
if (scope->isJSLexicalEnvironment()) {
JSLexicalEnvironment* lexicalEnvironment = jsCast<JSLexicalEnvironment*>(scope);
if (ident == exec->propertyNames().arguments) {
// We know the property will be at this lexical environment scope, but we don't know how to cache it.
op = ResolveOp(Dynamic, 0, 0, 0, 0, 0);
return true;
}
SymbolTable* symbolTable = lexicalEnvironment->symbolTable();
{
ConcurrentJSLocker locker(symbolTable->m_lock);
auto iter = symbolTable->find(locker, ident.impl());
if (iter != symbolTable->end(locker)) {
SymbolTableEntry& entry = iter->value;
ASSERT(!entry.isNull());
if (entry.isReadOnly() && getOrPut == Put) {
// We know the property will be at this lexical environment scope, but we don't know how to cache it.
op = ResolveOp(Dynamic, 0, 0, 0, 0, 0);
return true;
}
op = ResolveOp(makeType(ClosureVar, needsVarInjectionChecks), depth, 0, lexicalEnvironment, entry.watchpointSet(), entry.scopeOffset().offset());
return true;
}
}
if (scope->type() == ModuleEnvironmentType) {
JSModuleEnvironment* moduleEnvironment = jsCast<JSModuleEnvironment*>(scope);
AbstractModuleRecord* moduleRecord = moduleEnvironment->moduleRecord();
AbstractModuleRecord::Resolution resolution = moduleRecord->resolveImport(exec, ident);
if (resolution.type == AbstractModuleRecord::Resolution::Type::Resolved) {
AbstractModuleRecord* importedRecord = resolution.moduleRecord;
JSModuleEnvironment* importedEnvironment = importedRecord->moduleEnvironment();
SymbolTable* symbolTable = importedEnvironment->symbolTable();
ConcurrentJSLocker locker(symbolTable->m_lock);
auto iter = symbolTable->find(locker, resolution.localName.impl());
ASSERT(iter != symbolTable->end(locker));
SymbolTableEntry& entry = iter->value;
ASSERT(!entry.isNull());
op = ResolveOp(makeType(ModuleVar, needsVarInjectionChecks), depth, 0, importedEnvironment, entry.watchpointSet(), entry.scopeOffset().offset(), resolution.localName.impl());
return true;
}
}
if (symbolTable->usesNonStrictEval())
needsVarInjectionChecks = true;
return false;
}
if (scope->isGlobalLexicalEnvironment()) {
JSGlobalLexicalEnvironment* globalLexicalEnvironment = jsCast<JSGlobalLexicalEnvironment*>(scope);
SymbolTable* symbolTable = globalLexicalEnvironment->symbolTable();
ConcurrentJSLocker locker(symbolTable->m_lock);
auto iter = symbolTable->find(locker, ident.impl());
if (iter != symbolTable->end(locker)) {
SymbolTableEntry& entry = iter->value;
ASSERT(!entry.isNull());
if (getOrPut == Put && entry.isReadOnly() && !isInitialization(initializationMode)) {
// We know the property will be at global lexical environment, but we don't know how to cache it.
op = ResolveOp(Dynamic, 0, 0, 0, 0, 0);
return true;
}
// We can force const Initialization to always go down the fast path. It is provably impossible to construct
// a program that needs a var injection check here. You can convince yourself of this as follows:
// Any other let/const/class would be a duplicate of this in the global scope, so we would never get here in that situation.
// Also, if we had an eval in the global scope that defined a const, it would also be a duplicate of this const, and so it would
// also throw an error. Therefore, we're *the only* thing that can assign to this "const" slot for the first (and only) time. Also,
// we will never have a Dynamic ResolveType here because if we were inside a "with" statement, that would mean the "const" definition
// isn't a global, it would be a local to the "with" block.
// We still need to make the slow path correct for when we need to fire a watchpoint.
ResolveType resolveType = initializationMode == InitializationMode::ConstInitialization ? GlobalLexicalVar : makeType(GlobalLexicalVar, needsVarInjectionChecks);
op = ResolveOp(
resolveType, depth, 0, 0, entry.watchpointSet(),
reinterpret_cast<uintptr_t>(globalLexicalEnvironment->variableAt(entry.scopeOffset()).slot()));
return true;
}
return false;
}
if (scope->isGlobalObject()) {
JSGlobalObject* globalObject = jsCast<JSGlobalObject*>(scope);
{
SymbolTable* symbolTable = globalObject->symbolTable();
ConcurrentJSLocker locker(symbolTable->m_lock);
auto iter = symbolTable->find(locker, ident.impl());
if (iter != symbolTable->end(locker)) {
SymbolTableEntry& entry = iter->value;
ASSERT(!entry.isNull());
if (getOrPut == Put && entry.isReadOnly()) {
// We know the property will be at global scope, but we don't know how to cache it.
op = ResolveOp(Dynamic, 0, 0, 0, 0, 0);
return true;
}
op = ResolveOp(
makeType(GlobalVar, needsVarInjectionChecks), depth, 0, 0, entry.watchpointSet(),
reinterpret_cast<uintptr_t>(globalObject->variableAt(entry.scopeOffset()).slot()));
return true;
}
}
PropertySlot slot(globalObject, PropertySlot::InternalMethodType::VMInquiry);
bool hasOwnProperty = globalObject->getOwnPropertySlot(globalObject, exec, ident, slot);
if (!hasOwnProperty) {
op = ResolveOp(makeType(UnresolvedProperty, needsVarInjectionChecks), 0, 0, 0, 0, 0);
return true;
}
if (!slot.isCacheableValue()
|| !globalObject->structure()->propertyAccessesAreCacheable()
|| (globalObject->structure()->hasReadOnlyOrGetterSetterPropertiesExcludingProto() && getOrPut == Put)) {
// We know the property will be at global scope, but we don't know how to cache it.
ASSERT(!scope->next());
op = ResolveOp(makeType(GlobalProperty, needsVarInjectionChecks), 0, 0, 0, 0, 0);
return true;
}
WatchpointState state = globalObject->structure()->ensurePropertyReplacementWatchpointSet(exec->vm(), slot.cachedOffset())->state();
if (state == IsWatched && getOrPut == Put) {
// The field exists, but because the replacement watchpoint is still intact. This is
// kind of dangerous. We have two options:
// 1) Invalidate the watchpoint set. That would work, but it's possible that this code
// path never executes - in which case this would be unwise.
// 2) Have the invalidation happen at run-time. All we have to do is leave the code
// uncached. The only downside is slightly more work when this does execute.
// We go with option (2) here because it seems less evil.
op = ResolveOp(makeType(GlobalProperty, needsVarInjectionChecks), depth, 0, 0, 0, 0);
} else
op = ResolveOp(makeType(GlobalProperty, needsVarInjectionChecks), depth, globalObject->structure(), 0, 0, slot.cachedOffset());
return true;
}
op = ResolveOp(Dynamic, 0, 0, 0, 0, 0);
return true;
}
