// 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) { if (JSActivation* activation = jsDynamicCast<JSActivation*>(scope)) { if (ident == exec->propertyNames().arguments) { // We know the property will be at this activation scope, but we don't know how to cache it. op = ResolveOp(Dynamic, 0, 0, 0, 0); return true; } SymbolTableEntry entry = activation->symbolTable()->get(ident.impl()); if (entry.isReadOnly() && getOrPut == Put) { // We know the property will be at this activation scope, but we don't know how to cache it. op = ResolveOp(Dynamic, 0, 0, 0, 0); return true; } if (!entry.isNull()) { op = ResolveOp(makeType(ClosureVar, needsVarInjectionChecks), depth, activation->structure(), 0, entry.getIndex()); return true; } if (activation->symbolTable()->usesNonStrictEval()) needsVarInjectionChecks = true; return false; } if (JSGlobalObject* globalObject = jsDynamicCast<JSGlobalObject*>(scope)) { SymbolTableEntry entry = globalObject->symbolTable()->get(ident.impl()); if (!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); return true; } op = ResolveOp( makeType(GlobalVar, needsVarInjectionChecks), depth, 0, entry.watchpointSet(), reinterpret_cast<uintptr_t>(globalObject->registerAt(entry.getIndex()).slot())); return true; } PropertySlot slot(globalObject); if (!globalObject->getOwnPropertySlot(globalObject, exec, ident, slot) || !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), depth, 0, 0, 0); return true; } op = ResolveOp(makeType(GlobalProperty, needsVarInjectionChecks), depth, globalObject->structure(), 0, slot.cachedOffset()); return true; } op = ResolveOp(Dynamic, 0, 0, 0, 0); return true; }
inline bool JSActivation::symbolTablePut(const Identifier& propertyName, JSValue value) { ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this)); SymbolTableEntry entry = symbolTable().inlineGet(propertyName.impl()); if (entry.isNull()) return false; if (entry.isReadOnly()) return true; ASSERT(entry.getIndex() < static_cast<int>(d()->functionExecutable->capturedVariableCount())); registerAt(entry.getIndex()) = value; return true; }
inline bool JSActivation::symbolTablePut(JSGlobalData& globalData, const Identifier& propertyName, JSValue value) { ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this)); SymbolTableEntry entry = symbolTable().inlineGet(propertyName.impl()); if (entry.isNull()) return false; if (entry.isReadOnly()) return true; if (entry.getIndex() >= m_numCapturedVars) return false; registerAt(entry.getIndex()).set(globalData, this, value); return true; }
inline bool JSActivation::symbolTablePut(ExecState* exec, PropertyName propertyName, JSValue value, bool shouldThrow) { JSGlobalData& globalData = exec->globalData(); ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this)); SymbolTableEntry entry = symbolTable().inlineGet(propertyName.impl()); if (entry.isNull()) return false; if (entry.isReadOnly()) { if (shouldThrow) throwTypeError(exec, StrictModeReadonlyPropertyWriteError); return true; } if (m_isTornOff && entry.getIndex() >= m_numCapturedVars) return false; registerAt(entry.getIndex()).set(globalData, this, value); return true; }
inline bool JSActivation::symbolTablePut(ExecState* exec, PropertyName propertyName, JSValue value, bool shouldThrow) { VM& vm = exec->vm(); ASSERT(!Heap::heap(value) || Heap::heap(value) == Heap::heap(this)); SymbolTableEntry entry = symbolTable()->inlineGet(propertyName.publicName()); if (entry.isNull()) return false; if (entry.isReadOnly()) { if (shouldThrow) throwTypeError(exec, StrictModeReadonlyPropertyWriteError); return true; } // Defend against the inspector asking for a var after it has been optimized out. if (isTornOff() && !isValid(entry)) return false; registerAt(entry.getIndex()).set(vm, this, value); return true; }
// 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) { if (JSActivation* activation = jsDynamicCast<JSActivation*>(scope)) { if (ident == exec->propertyNames().arguments) { // We know the property will be at this activation scope, but we don't know how to cache it. op = ResolveOp(Dynamic, 0, 0, 0, 0, 0); return true; } SymbolTableEntry entry = activation->symbolTable()->get(ident.impl()); if (entry.isReadOnly() && getOrPut == Put) { // We know the property will be at this activation scope, but we don't know how to cache it. op = ResolveOp(Dynamic, 0, 0, 0, 0, 0); return true; } if (!entry.isNull()) { op = ResolveOp(makeType(ClosureVar, needsVarInjectionChecks), depth, 0, activation, entry.watchpointSet(), entry.getIndex()); return true; } if (activation->symbolTable()->usesNonStrictEval()) needsVarInjectionChecks = true; return false; } if (JSGlobalObject* globalObject = jsDynamicCast<JSGlobalObject*>(scope)) { SymbolTableEntry entry = globalObject->symbolTable()->get(ident.impl()); if (!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->registerAt(entry.getIndex()).slot())); return true; } PropertySlot slot(globalObject); if (!globalObject->getOwnPropertySlot(globalObject, exec, ident, slot) || !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), depth, 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; }
// 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; } SymbolTableEntry entry = lexicalEnvironment->symbolTable()->get(ident.impl()); 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; } if (!entry.isNull()) { op = ResolveOp(makeType(ClosureVar, needsVarInjectionChecks), depth, 0, lexicalEnvironment, entry.watchpointSet(), entry.scopeOffset().offset()); return true; } if (scope->type() == ModuleEnvironmentType) { JSModuleEnvironment* moduleEnvironment = jsCast<JSModuleEnvironment*>(scope); JSModuleRecord* moduleRecord = moduleEnvironment->moduleRecord(); JSModuleRecord::Resolution resolution = moduleRecord->resolveImport(exec, ident); if (resolution.type == JSModuleRecord::Resolution::Type::Resolved) { JSModuleRecord* importedRecord = resolution.moduleRecord; JSModuleEnvironment* importedEnvironment = importedRecord->moduleEnvironment(); SymbolTableEntry entry = importedEnvironment->symbolTable()->get(resolution.localName.impl()); ASSERT(!entry.isNull()); op = ResolveOp(makeType(ModuleVar, needsVarInjectionChecks), depth, 0, importedEnvironment, entry.watchpointSet(), entry.scopeOffset().offset(), resolution.localName.impl()); return true; } } if (lexicalEnvironment->symbolTable()->usesNonStrictEval()) needsVarInjectionChecks = true; return false; } if (scope->isGlobalLexicalEnvironment()) { JSGlobalLexicalEnvironment* globalLexicalEnvironment = jsCast<JSGlobalLexicalEnvironment*>(scope); SymbolTableEntry entry = globalLexicalEnvironment->symbolTable()->get(ident.impl()); if (!entry.isNull()) { if (getOrPut == Put && entry.isReadOnly() && initializationMode != Initialization) { // 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 try to 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 == Initialization ? 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); SymbolTableEntry entry = globalObject->symbolTable()->get(ident.impl()); if (!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; }