DebuggerScope.cpp   [plain text]

/*
 * Copyright (C) 2008-2009, 2014 Apple Inc. All rights reserved.
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 *    notice, this list of conditions and the following disclaimer in the
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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#include "config.h"
#include "DebuggerScope.h"

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

namespace JSC {

STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(DebuggerScope);

const ClassInfo DebuggerScope::s_info = { "DebuggerScope", &Base::s_info, 0, CREATE_METHOD_TABLE(DebuggerScope) };

DebuggerScope::DebuggerScope(VM& vm, JSScope* scope)
    : JSNonFinalObject(vm, scope->globalObject()->debuggerScopeStructure())
{
    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);
    ASSERT(scope->isValid());
    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);
    ASSERT(scope->isValid());
    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().
    return thisObject->getPropertySlot(exec, propertyName, slot);
}

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

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::isFunctionOrEvalScope() 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->isActivationObject();
}

JSValue DebuggerScope::caughtValue() const
{
    ASSERT(isCatchScope());
    return reinterpret_cast<JSNameScope*>(m_scope.get())->value();
}

} // namespace JSC