Source/JavaScriptCore/debugger/DebuggerScope.cpp - WebKit - Git at Google

 /*
  * Copyright (C) 2008-2009, 2014, 2016 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 "DebuggerScope.h"

 #include "JSLexicalEnvironment.h"
 #include "JSCInlines.h"
 #include "JSWithScope.h"

 namespace JSC {

 STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(DebuggerScope);

 const ClassInfo DebuggerScope::s_info = { "DebuggerScope", &Base::s_info, nullptr, nullptr, CREATE_METHOD_TABLE(DebuggerScope) };

 DebuggerScope* DebuggerScope::create(VM& vm, JSScope* scope)
 {
     Structure* structure = scope->globalObject()->debuggerScopeStructure();
     DebuggerScope* debuggerScope = new (NotNull, allocateCell<DebuggerScope>(vm.heap)) DebuggerScope(vm, structure, scope);
     debuggerScope->finishCreation(vm);
     return debuggerScope;
 }

 DebuggerScope::DebuggerScope(VM& vm, Structure* structure, JSScope* scope)
     : JSNonFinalObject(vm, structure)
 {
     ASSERT(scope);
     m_scope.set(vm, this, scope);
 }

 void DebuggerScope::finishCreation(VM& vm)
 {
     Base::finishCreation(vm);
 }

 void DebuggerScope::visitChildren(JSCell* cell, SlotVisitor& visitor)
 {
     DebuggerScope* thisObject = jsCast<DebuggerScope*>(cell);
     ASSERT_GC_OBJECT_INHERITS(thisObject, info());
     JSObject::visitChildren(thisObject, visitor);
     visitor.append(thisObject->m_scope);
     visitor.append(thisObject->m_next);
 }

 String DebuggerScope::className(const JSObject* object)
 {
     const DebuggerScope* scope = jsCast<const DebuggerScope*>(object);
     // We cannot assert that scope->isValid() because the TypeProfiler may encounter an invalidated
     // DebuggerScope in its log entries. We just need to handle it appropriately as below.
     if (!scope->isValid())
         return String();
     JSObject* thisObject = JSScope::objectAtScope(scope->jsScope());
     return thisObject->methodTable()->className(thisObject);
 }

 bool DebuggerScope::getOwnPropertySlot(JSObject* object, ExecState* exec, PropertyName propertyName, PropertySlot& slot)
 {
     DebuggerScope* scope = jsCast<DebuggerScope*>(object);
     if (!scope->isValid())
         return false;
     JSObject* thisObject = JSScope::objectAtScope(scope->jsScope());
     slot.setThisValue(JSValue(thisObject));

     // By default, JSObject::getPropertySlot() will look in the DebuggerScope's prototype
     // chain and not the wrapped scope, and JSObject::getPropertySlot() cannot be overridden
     // to behave differently for the DebuggerScope.
     //
     // Instead, we'll treat all properties in the wrapped scope and its prototype chain as
     // the own properties of the DebuggerScope. This is fine because the WebInspector
     // does not presently need to distinguish between what's owned at each level in the
     // prototype chain. Hence, we'll invoke getPropertySlot() on the wrapped scope here
     // instead of getOwnPropertySlot().
     bool result = thisObject->getPropertySlot(exec, propertyName, slot);
     if (result && slot.isValue() && slot.getValue(exec, propertyName) == jsTDZValue()) {
         // FIXME:
         // We hit a scope property that has the TDZ empty value.
         // Currently, we just lie to the inspector and claim that this property is undefined.
         // This is not ideal and we should fix it.
         // https://bugs.webkit.org/show_bug.cgi?id=144977
         slot.setValue(slot.slotBase(), static_cast<unsigned>(PropertyAttribute::DontEnum), jsUndefined());
         return true;
     }
     return result;
 }

 bool DebuggerScope::put(JSCell* cell, ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
 {
     DebuggerScope* scope = jsCast<DebuggerScope*>(cell);
     ASSERT(scope->isValid());
     if (!scope->isValid())
         return false;
     JSObject* thisObject = JSScope::objectAtScope(scope->jsScope());
     slot.setThisValue(JSValue(thisObject));
     return thisObject->methodTable()->put(thisObject, exec, propertyName, value, slot);
 }

 bool DebuggerScope::deleteProperty(JSCell* cell, ExecState* exec, PropertyName propertyName)
 {
     DebuggerScope* scope = jsCast<DebuggerScope*>(cell);
     ASSERT(scope->isValid());
     if (!scope->isValid())
         return false;
     JSObject* thisObject = JSScope::objectAtScope(scope->jsScope());
     return thisObject->methodTable()->deleteProperty(thisObject, exec, propertyName);
 }

 void DebuggerScope::getOwnPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
 {
     DebuggerScope* scope = jsCast<DebuggerScope*>(object);
     ASSERT(scope->isValid());
     if (!scope->isValid())
         return;
     JSObject* thisObject = JSScope::objectAtScope(scope->jsScope());
     thisObject->methodTable()->getPropertyNames(thisObject, exec, propertyNames, mode);
 }

 bool DebuggerScope::defineOwnProperty(JSObject* object, ExecState* exec, PropertyName propertyName, const PropertyDescriptor& descriptor, bool shouldThrow)
 {
     DebuggerScope* scope = jsCast<DebuggerScope*>(object);
     ASSERT(scope->isValid());
     if (!scope->isValid())
         return false;
     JSObject* thisObject = JSScope::objectAtScope(scope->jsScope());
     return thisObject->methodTable()->defineOwnProperty(thisObject, exec, propertyName, descriptor, shouldThrow);
 }

 DebuggerScope* DebuggerScope::next()
 {
     ASSERT(isValid());
     if (!m_next && m_scope->next()) {
         VM& vm = *m_scope->vm();
         DebuggerScope* nextScope = create(vm, m_scope->next());
         m_next.set(vm, this, nextScope);
     }
     return m_next.get();
 }

 void DebuggerScope::invalidateChain()
 {
     if (!isValid())
         return;

     DebuggerScope* scope = this;
     while (scope) {
         DebuggerScope* nextScope = scope->m_next.get();
         scope->m_next.clear();
         scope->m_scope.clear(); // This also marks this scope as invalid.
         scope = nextScope;
     }
 }

 bool DebuggerScope::isCatchScope() const
 {
     return m_scope->isCatchScope();
 }

 bool DebuggerScope::isFunctionNameScope() const
 {
     return m_scope->isFunctionNameScopeObject();
 }

 bool DebuggerScope::isWithScope() const
 {
     return m_scope->isWithScope();
 }

 bool DebuggerScope::isGlobalScope() const
 {
     return m_scope->isGlobalObject();
 }

 bool DebuggerScope::isGlobalLexicalEnvironment() const
 {
     return m_scope->isGlobalLexicalEnvironment();
 }

 bool DebuggerScope::isClosureScope() const
 {
     // In the current debugger implementation, every function or eval will create an
     // lexical environment object. Hence, a lexical environment object implies a
     // function or eval scope.
     return m_scope->isVarScope() || m_scope->isLexicalScope();
 }

 bool DebuggerScope::isNestedLexicalScope() const
 {
     return m_scope->isNestedLexicalScope();
 }

 String DebuggerScope::name() const
 {
     SymbolTable* symbolTable = m_scope->symbolTable(*vm());
     if (!symbolTable)
         return String();

     CodeBlock* codeBlock = symbolTable->rareDataCodeBlock();
     if (!codeBlock)
         return String();

     return String::fromUTF8(codeBlock->inferredName());
 }

 DebuggerLocation DebuggerScope::location() const
 {
     SymbolTable* symbolTable = m_scope->symbolTable(*vm());
     if (!symbolTable)
         return DebuggerLocation();

     CodeBlock* codeBlock = symbolTable->rareDataCodeBlock();
     if (!codeBlock)
         return DebuggerLocation();

     ScriptExecutable* executable = codeBlock->ownerScriptExecutable();
     return DebuggerLocation(executable);
 }

 JSValue DebuggerScope::caughtValue(ExecState* exec) const
 {
     ASSERT(isCatchScope());
     JSLexicalEnvironment* catchEnvironment = jsCast<JSLexicalEnvironment*>(m_scope.get());
     SymbolTable* catchSymbolTable = catchEnvironment->symbolTable();
     RELEASE_ASSERT(catchSymbolTable->size() == 1);
     PropertyName errorName(catchSymbolTable->begin(catchSymbolTable->m_lock)->key.get());
     PropertySlot slot(m_scope.get(), PropertySlot::InternalMethodType::Get);
     bool success = catchEnvironment->getOwnPropertySlot(catchEnvironment, exec, errorName, slot);
     RELEASE_ASSERT(success && slot.isValue());
     return slot.getValue(exec, errorName);
 }

 } // namespace JSC
	/*
	* Copyright (C) 2008-2009, 2014, 2016 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 "DebuggerScope.h"

	#include "JSLexicalEnvironment.h"
	#include "JSCInlines.h"
	#include "JSWithScope.h"

	namespace JSC {

	STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(DebuggerScope);

	const ClassInfo DebuggerScope::s_info = { "DebuggerScope", &Base::s_info, nullptr, nullptr, CREATE_METHOD_TABLE(DebuggerScope) };

	DebuggerScope* DebuggerScope::create(VM& vm, JSScope* scope)
	{
	Structure* structure = scope->globalObject()->debuggerScopeStructure();
	DebuggerScope* debuggerScope = new (NotNull, allocateCell<DebuggerScope>(vm.heap)) DebuggerScope(vm, structure, scope);
	debuggerScope->finishCreation(vm);
	return debuggerScope;
	}

	DebuggerScope::DebuggerScope(VM& vm, Structure* structure, JSScope* scope)
	: JSNonFinalObject(vm, structure)
	{
	ASSERT(scope);
	m_scope.set(vm, this, scope);
	}

	void DebuggerScope::finishCreation(VM& vm)
	{
	Base::finishCreation(vm);
	}

	void DebuggerScope::visitChildren(JSCell* cell, SlotVisitor& visitor)
	{
	DebuggerScope* thisObject = jsCast<DebuggerScope*>(cell);
	ASSERT_GC_OBJECT_INHERITS(thisObject, info());
	JSObject::visitChildren(thisObject, visitor);
	visitor.append(thisObject->m_scope);
	visitor.append(thisObject->m_next);
	}

	String DebuggerScope::className(const JSObject* object)
	{
	const DebuggerScope* scope = jsCast<const DebuggerScope*>(object);
	// We cannot assert that scope->isValid() because the TypeProfiler may encounter an invalidated
	// DebuggerScope in its log entries. We just need to handle it appropriately as below.
	if (!scope->isValid())
	return String();
	JSObject* thisObject = JSScope::objectAtScope(scope->jsScope());
	return thisObject->methodTable()->className(thisObject);
	}

	bool DebuggerScope::getOwnPropertySlot(JSObject* object, ExecState* exec, PropertyName propertyName, PropertySlot& slot)
	{
	DebuggerScope* scope = jsCast<DebuggerScope*>(object);
	if (!scope->isValid())
	return false;
	JSObject* thisObject = JSScope::objectAtScope(scope->jsScope());
	slot.setThisValue(JSValue(thisObject));

	// By default, JSObject::getPropertySlot() will look in the DebuggerScope's prototype
	// chain and not the wrapped scope, and JSObject::getPropertySlot() cannot be overridden
	// to behave differently for the DebuggerScope.
	//
	// Instead, we'll treat all properties in the wrapped scope and its prototype chain as
	// the own properties of the DebuggerScope. This is fine because the WebInspector
	// does not presently need to distinguish between what's owned at each level in the
	// prototype chain. Hence, we'll invoke getPropertySlot() on the wrapped scope here
	// instead of getOwnPropertySlot().
	bool result = thisObject->getPropertySlot(exec, propertyName, slot);
	if (result && slot.isValue() && slot.getValue(exec, propertyName) == jsTDZValue()) {
	// FIXME:
	// We hit a scope property that has the TDZ empty value.
	// Currently, we just lie to the inspector and claim that this property is undefined.
	// This is not ideal and we should fix it.
	// https://bugs.webkit.org/show_bug.cgi?id=144977
	slot.setValue(slot.slotBase(), static_cast<unsigned>(PropertyAttribute::DontEnum), jsUndefined());
	return true;
	}
	return result;
	}

	bool DebuggerScope::put(JSCell* cell, ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
	{
	DebuggerScope* scope = jsCast<DebuggerScope*>(cell);
	ASSERT(scope->isValid());
	if (!scope->isValid())
	return false;
	JSObject* thisObject = JSScope::objectAtScope(scope->jsScope());
	slot.setThisValue(JSValue(thisObject));
	return thisObject->methodTable()->put(thisObject, exec, propertyName, value, slot);
	}

	bool DebuggerScope::deleteProperty(JSCell* cell, ExecState* exec, PropertyName propertyName)
	{
	DebuggerScope* scope = jsCast<DebuggerScope*>(cell);
	ASSERT(scope->isValid());
	if (!scope->isValid())
	return false;
	JSObject* thisObject = JSScope::objectAtScope(scope->jsScope());
	return thisObject->methodTable()->deleteProperty(thisObject, exec, propertyName);
	}

	void DebuggerScope::getOwnPropertyNames(JSObject* object, ExecState* exec, PropertyNameArray& propertyNames, EnumerationMode mode)
	{
	DebuggerScope* scope = jsCast<DebuggerScope*>(object);
	ASSERT(scope->isValid());
	if (!scope->isValid())
	return;
	JSObject* thisObject = JSScope::objectAtScope(scope->jsScope());
	thisObject->methodTable()->getPropertyNames(thisObject, exec, propertyNames, mode);
	}

	bool DebuggerScope::defineOwnProperty(JSObject* object, ExecState* exec, PropertyName propertyName, const PropertyDescriptor& descriptor, bool shouldThrow)
	{
	DebuggerScope* scope = jsCast<DebuggerScope*>(object);
	ASSERT(scope->isValid());
	if (!scope->isValid())
	return false;
	JSObject* thisObject = JSScope::objectAtScope(scope->jsScope());
	return thisObject->methodTable()->defineOwnProperty(thisObject, exec, propertyName, descriptor, shouldThrow);
	}

	DebuggerScope* DebuggerScope::next()
	{
	ASSERT(isValid());
	if (!m_next && m_scope->next()) {
	VM& vm = *m_scope->vm();
	DebuggerScope* nextScope = create(vm, m_scope->next());
	m_next.set(vm, this, nextScope);
	}
	return m_next.get();
	}

	void DebuggerScope::invalidateChain()
	{
	if (!isValid())
	return;

	DebuggerScope* scope = this;
	while (scope) {
	DebuggerScope* nextScope = scope->m_next.get();
	scope->m_next.clear();
	scope->m_scope.clear(); // This also marks this scope as invalid.
	scope = nextScope;
	}
	}

	bool DebuggerScope::isCatchScope() const
	{
	return m_scope->isCatchScope();
	}

	bool DebuggerScope::isFunctionNameScope() const
	{
	return m_scope->isFunctionNameScopeObject();
	}

	bool DebuggerScope::isWithScope() const
	{
	return m_scope->isWithScope();
	}

	bool DebuggerScope::isGlobalScope() const
	{
	return m_scope->isGlobalObject();
	}

	bool DebuggerScope::isGlobalLexicalEnvironment() const
	{
	return m_scope->isGlobalLexicalEnvironment();
	}

	bool DebuggerScope::isClosureScope() const
	{
	// In the current debugger implementation, every function or eval will create an
	// lexical environment object. Hence, a lexical environment object implies a
	// function or eval scope.
	return m_scope->isVarScope() \|\| m_scope->isLexicalScope();
	}

	bool DebuggerScope::isNestedLexicalScope() const
	{
	return m_scope->isNestedLexicalScope();
	}

	String DebuggerScope::name() const
	{
	SymbolTable* symbolTable = m_scope->symbolTable(*vm());
	if (!symbolTable)
	return String();

	CodeBlock* codeBlock = symbolTable->rareDataCodeBlock();
	if (!codeBlock)
	return String();

	return String::fromUTF8(codeBlock->inferredName());
	}

	DebuggerLocation DebuggerScope::location() const
	{
	SymbolTable* symbolTable = m_scope->symbolTable(*vm());
	if (!symbolTable)
	return DebuggerLocation();

	CodeBlock* codeBlock = symbolTable->rareDataCodeBlock();
	if (!codeBlock)
	return DebuggerLocation();

	ScriptExecutable* executable = codeBlock->ownerScriptExecutable();
	return DebuggerLocation(executable);
	}

	JSValue DebuggerScope::caughtValue(ExecState* exec) const
	{
	ASSERT(isCatchScope());
	JSLexicalEnvironment* catchEnvironment = jsCast<JSLexicalEnvironment*>(m_scope.get());
	SymbolTable* catchSymbolTable = catchEnvironment->symbolTable();
	RELEASE_ASSERT(catchSymbolTable->size() == 1);
	PropertyName errorName(catchSymbolTable->begin(catchSymbolTable->m_lock)->key.get());
	PropertySlot slot(m_scope.get(), PropertySlot::InternalMethodType::Get);
	bool success = catchEnvironment->getOwnPropertySlot(catchEnvironment, exec, errorName, slot);
	RELEASE_ASSERT(success && slot.isValue());
	return slot.getValue(exec, errorName);
	}

	} // namespace JSC