|  | /* | 
|  | * Copyright (C) 2009-2019 Apple Inc. All rights reserved. | 
|  | * | 
|  | * 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. | 
|  | * | 
|  | * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 INC. OR | 
|  | * 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 "BatchedTransitionOptimizer.h" | 
|  | #include "CodeCache.h" | 
|  | #include "Debugger.h" | 
|  |  | 
|  | namespace JSC { | 
|  |  | 
|  | const ClassInfo ProgramExecutable::s_info = { "ProgramExecutable", &Base::s_info, nullptr, nullptr, CREATE_METHOD_TABLE(ProgramExecutable) }; | 
|  |  | 
|  | ProgramExecutable::ProgramExecutable(JSGlobalObject* globalObject, const SourceCode& source) | 
|  | : Base(globalObject->vm().programExecutableStructure.get(), globalObject->vm(), source, false, DerivedContextType::None, false, false, EvalContextType::None, NoIntrinsic) | 
|  | { | 
|  | ASSERT(source.provider()->sourceType() == SourceProviderSourceType::Program); | 
|  | VM& vm = globalObject->vm(); | 
|  | if (vm.typeProfiler() || vm.controlFlowProfiler()) | 
|  | vm.functionHasExecutedCache()->insertUnexecutedRange(sourceID(), typeProfilingStartOffset(vm), typeProfilingEndOffset(vm)); | 
|  | } | 
|  |  | 
|  | void ProgramExecutable::destroy(JSCell* cell) | 
|  | { | 
|  | static_cast<ProgramExecutable*>(cell)->ProgramExecutable::~ProgramExecutable(); | 
|  | } | 
|  |  | 
|  | // http://www.ecma-international.org/ecma-262/6.0/index.html#sec-hasrestrictedglobalproperty | 
|  | enum class GlobalPropertyLookUpStatus { | 
|  | NotFound, | 
|  | Configurable, | 
|  | NonConfigurable, | 
|  | }; | 
|  | static GlobalPropertyLookUpStatus hasRestrictedGlobalProperty(JSGlobalObject* globalObject, PropertyName propertyName) | 
|  | { | 
|  | PropertyDescriptor descriptor; | 
|  | if (!globalObject->getOwnPropertyDescriptor(globalObject, propertyName, descriptor)) | 
|  | return GlobalPropertyLookUpStatus::NotFound; | 
|  | if (descriptor.configurable()) | 
|  | return GlobalPropertyLookUpStatus::Configurable; | 
|  | return GlobalPropertyLookUpStatus::NonConfigurable; | 
|  | } | 
|  |  | 
|  | JSObject* ProgramExecutable::initializeGlobalProperties(VM& vm, JSGlobalObject* globalObject, JSScope* scope) | 
|  | { | 
|  | auto throwScope = DECLARE_THROW_SCOPE(vm); | 
|  | RELEASE_ASSERT(scope); | 
|  | ASSERT(globalObject == scope->globalObject(vm)); | 
|  | RELEASE_ASSERT(globalObject); | 
|  | ASSERT(&globalObject->vm() == &vm); | 
|  |  | 
|  | ParserError error; | 
|  | JSParserStrictMode strictMode = isInStrictContext() ? JSParserStrictMode::Strict : JSParserStrictMode::NotStrict; | 
|  | OptionSet<CodeGenerationMode> codeGenerationMode = globalObject->defaultCodeGenerationMode(); | 
|  | UnlinkedProgramCodeBlock* unlinkedCodeBlock = vm.codeCache()->getUnlinkedProgramCodeBlock( | 
|  | vm, this, source(), strictMode, codeGenerationMode, error); | 
|  |  | 
|  | if (globalObject->hasDebugger()) | 
|  | globalObject->debugger()->sourceParsed(globalObject, source().provider(), error.line(), error.message()); | 
|  |  | 
|  | if (error.isValid()) | 
|  | return error.toErrorObject(globalObject, source()); | 
|  |  | 
|  | JSValue nextPrototype = globalObject->getPrototypeDirect(vm); | 
|  | while (nextPrototype && nextPrototype.isObject()) { | 
|  | if (UNLIKELY(asObject(nextPrototype)->type() == ProxyObjectType)) | 
|  | return createTypeError(globalObject, "Proxy is not allowed in the global prototype chain."_s); | 
|  | nextPrototype = asObject(nextPrototype)->getPrototypeDirect(vm); | 
|  | } | 
|  |  | 
|  | 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 | 
|  | { | 
|  | // Check for intersection of "var" and "let"/"const"/"class" | 
|  | for (auto& entry : lexicalDeclarations) { | 
|  | if (variableDeclarations.contains(entry.key)) | 
|  | return createSyntaxError(globalObject, 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 (with configurable = false), or "var"/"let"/"const" variables. | 
|  | // It's an error to introduce a shadow. | 
|  | for (auto& entry : lexicalDeclarations) { | 
|  | // The ES6 spec says that RestrictedGlobalProperty can't be shadowed. | 
|  | GlobalPropertyLookUpStatus status = hasRestrictedGlobalProperty(globalObject, entry.key.get()); | 
|  | RETURN_IF_EXCEPTION(throwScope, nullptr); | 
|  | switch (status) { | 
|  | case GlobalPropertyLookUpStatus::NonConfigurable: | 
|  | return createSyntaxError(globalObject, makeString("Can't create duplicate variable that shadows a global property: '", String(entry.key.get()), "'")); | 
|  | case GlobalPropertyLookUpStatus::Configurable: | 
|  | // Lexical bindings can shadow global properties if the given property's attribute is configurable. | 
|  | // https://tc39.github.io/ecma262/#sec-globaldeclarationinstantiation step 5-c, `hasRestrictedGlobal` becomes false | 
|  | // However we may emit GlobalProperty look up in bytecodes already and it may cache the value for the global scope. | 
|  | // To make it invalid, | 
|  | // 1. In LLInt and Baseline, we bump the global lexical binding epoch and it works. | 
|  | // 3. In DFG and FTL, we watch the watchpoint and jettison once it is fired. | 
|  | break; | 
|  | case GlobalPropertyLookUpStatus::NotFound: | 
|  | break; | 
|  | } | 
|  |  | 
|  | bool hasProperty = globalLexicalEnvironment->hasProperty(globalObject, entry.key.get()); | 
|  | RETURN_IF_EXCEPTION(throwScope, nullptr); | 
|  | if (hasProperty) { | 
|  | if (UNLIKELY(entry.value.isConst() && !vm.globalConstRedeclarationShouldThrow() && !isInStrictContext())) { | 
|  | // 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(globalObject, 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(globalObject, entry.key.get()); | 
|  | RETURN_IF_EXCEPTION(throwScope, nullptr); | 
|  | if (hasProperty) | 
|  | return createSyntaxError(globalObject, 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(globalObject, 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(globalObject, Identifier::fromUid(vm, entry.key.get())); | 
|  | throwScope.assertNoException(); | 
|  | } | 
|  |  | 
|  | { | 
|  | 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() && !isInStrictContext())) { | 
|  | if (symbolTable->contains(locker, entry.key.get())) | 
|  | continue; | 
|  | } | 
|  | ScopeOffset offset = symbolTable->takeNextScopeOffset(locker); | 
|  | SymbolTableEntry newEntry(VarOffset(offset), static_cast<unsigned>(entry.value.isConst() ? PropertyAttribute::ReadOnly : PropertyAttribute::None)); | 
|  | newEntry.prepareToWatch(); | 
|  | symbolTable->add(locker, entry.key.get(), newEntry); | 
|  |  | 
|  | ScopeOffset offsetForAssert = globalLexicalEnvironment->addVariables(1, jsTDZValue()); | 
|  | RELEASE_ASSERT(offsetForAssert == offset); | 
|  | } | 
|  | } | 
|  | if (lexicalDeclarations.size()) { | 
|  | #if ENABLE(DFG_JIT) | 
|  | for (auto& entry : lexicalDeclarations) { | 
|  | // If WatchpointSet exists, just fire it. Since DFG WatchpointSet addition is also done on the main thread, we can sync them. | 
|  | // So that we do not create WatchpointSet here. DFG will create if necessary on the main thread. | 
|  | // And it will only create not-invalidated watchpoint set if the global lexical environment binding doesn't exist, which is why this code works. | 
|  | if (auto* watchpointSet = globalObject->getReferencedPropertyWatchpointSet(entry.key.get())) | 
|  | watchpointSet->fireAll(vm, "Lexical binding shadows an existing global property"); | 
|  | } | 
|  | #endif | 
|  | globalObject->bumpGlobalLexicalBindingEpoch(vm); | 
|  | } | 
|  | return nullptr; | 
|  | } | 
|  |  | 
|  | auto ProgramExecutable::ensureTemplateObjectMap(VM&) -> TemplateObjectMap& | 
|  | { | 
|  | return ensureTemplateObjectMapImpl(m_templateObjectMap); | 
|  | } | 
|  |  | 
|  | void ProgramExecutable::visitChildren(JSCell* cell, SlotVisitor& visitor) | 
|  | { | 
|  | ProgramExecutable* thisObject = jsCast<ProgramExecutable*>(cell); | 
|  | ASSERT_GC_OBJECT_INHERITS(thisObject, info()); | 
|  | Base::visitChildren(thisObject, visitor); | 
|  | visitor.append(thisObject->m_unlinkedProgramCodeBlock); | 
|  | visitor.append(thisObject->m_programCodeBlock); | 
|  | if (TemplateObjectMap* map = thisObject->m_templateObjectMap.get()) { | 
|  | auto locker = holdLock(thisObject->cellLock()); | 
|  | for (auto& entry : *map) | 
|  | visitor.append(entry.value); | 
|  | } | 
|  | } | 
|  |  | 
|  | } // namespace JSC |