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-rw-r--r--dom/xbl/nsXBLProtoImpl.cpp535
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diff --git a/dom/xbl/nsXBLProtoImpl.cpp b/dom/xbl/nsXBLProtoImpl.cpp
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/DebugOnly.h"
+
+#include "nsXBLProtoImpl.h"
+#include "nsIContent.h"
+#include "nsIDocument.h"
+#include "nsContentUtils.h"
+#include "nsIXPConnect.h"
+#include "nsIServiceManager.h"
+#include "nsIDOMNode.h"
+#include "nsXBLPrototypeBinding.h"
+#include "nsXBLProtoImplProperty.h"
+#include "nsIURI.h"
+#include "mozilla/AddonPathService.h"
+#include "mozilla/dom/ScriptSettings.h"
+#include "mozilla/dom/XULElementBinding.h"
+#include "xpcpublic.h"
+#include "js/CharacterEncoding.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+using js::GetGlobalForObjectCrossCompartment;
+using js::AssertSameCompartment;
+
+nsresult
+nsXBLProtoImpl::InstallImplementation(nsXBLPrototypeBinding* aPrototypeBinding,
+ nsXBLBinding* aBinding)
+{
+ // This function is called to install a concrete implementation on a bound element using
+ // this prototype implementation as a guide. The prototype implementation is compiled lazily,
+ // so for the first bound element that needs a concrete implementation, we also build the
+ // prototype implementation.
+ if (!mMembers && !mFields) // Constructor and destructor also live in mMembers
+ return NS_OK; // Nothing to do, so let's not waste time.
+
+ // If the way this gets the script context changes, fix
+ // nsXBLProtoImplAnonymousMethod::Execute
+ nsIDocument* document = aBinding->GetBoundElement()->OwnerDoc();
+
+ // This sometimes gets called when we have no outer window and if we don't
+ // catch this, we get leaks during crashtests and reftests.
+ if (NS_WARN_IF(!document->GetWindow())) {
+ return NS_OK;
+ }
+
+ // |propertyHolder| (below) can be an existing object, so in theory we might
+ // hit something that could end up running script. We never want that to
+ // happen here, so we use an AutoJSAPI instead of an AutoEntryScript.
+ dom::AutoJSAPI jsapi;
+ if (NS_WARN_IF(!jsapi.Init(document->GetScopeObject()))) {
+ return NS_OK;
+ }
+ JSContext* cx = jsapi.cx();
+
+ // InitTarget objects gives us back the JS object that represents the bound element and the
+ // class object in the bound document that represents the concrete version of this implementation.
+ // This function also has the side effect of building up the prototype implementation if it has
+ // not been built already.
+ JS::Rooted<JSObject*> targetClassObject(cx, nullptr);
+ bool targetObjectIsNew = false;
+ nsresult rv = InitTargetObjects(aPrototypeBinding,
+ aBinding->GetBoundElement(),
+ &targetClassObject,
+ &targetObjectIsNew);
+ NS_ENSURE_SUCCESS(rv, rv); // kick out if we were unable to properly intialize our target objects
+ MOZ_ASSERT(targetClassObject);
+
+ // If the prototype already existed, we don't need to install anything. return early.
+ if (!targetObjectIsNew)
+ return NS_OK;
+
+ // We want to define the canonical set of members in a safe place. If we're
+ // using a separate XBL scope, we want to define them there first (so that
+ // they'll be available for Xray lookups, among other things), and then copy
+ // the properties to the content-side prototype as needed. We don't need to
+ // bother about the field accessors here, since we don't use/support those
+ // for in-content bindings.
+
+ // First, start by entering the compartment of the XBL scope. This may or may
+ // not be the same compartment as globalObject.
+ JSAddonId* addonId = MapURIToAddonID(aPrototypeBinding->BindingURI());
+ JS::Rooted<JSObject*> globalObject(cx,
+ GetGlobalForObjectCrossCompartment(targetClassObject));
+ JS::Rooted<JSObject*> scopeObject(cx, xpc::GetScopeForXBLExecution(cx, globalObject, addonId));
+ NS_ENSURE_TRUE(scopeObject, NS_ERROR_OUT_OF_MEMORY);
+ MOZ_ASSERT(js::GetGlobalForObjectCrossCompartment(scopeObject) == scopeObject);
+ JSAutoCompartment ac(cx, scopeObject);
+
+ // Determine the appropriate property holder.
+ //
+ // Note: If |targetIsNew| is false, we'll early-return above. However, that only
+ // tells us if the content-side object is new, which may be the case even if
+ // we've already set up the binding on the XBL side. For example, if we apply
+ // a binding #foo to a <span> when we've already applied it to a <div>, we'll
+ // end up with a different content prototype, but we'll already have a property
+ // holder called |foo| in the XBL scope. Check for that to avoid wasteful and
+ // weird property holder duplication.
+ const char16_t* className = aPrototypeBinding->ClassName().get();
+ JS::Rooted<JSObject*> propertyHolder(cx);
+ JS::Rooted<JS::PropertyDescriptor> existingHolder(cx);
+ if (scopeObject != globalObject &&
+ !JS_GetOwnUCPropertyDescriptor(cx, scopeObject, className, &existingHolder)) {
+ return NS_ERROR_FAILURE;
+ }
+ bool propertyHolderIsNew = !existingHolder.object() || !existingHolder.value().isObject();
+
+ if (!propertyHolderIsNew) {
+ propertyHolder = &existingHolder.value().toObject();
+ } else if (scopeObject != globalObject) {
+
+ // This is just a property holder, so it doesn't need any special JSClass.
+ propertyHolder = JS_NewObjectWithGivenProto(cx, nullptr, nullptr);
+ NS_ENSURE_TRUE(propertyHolder, NS_ERROR_OUT_OF_MEMORY);
+
+ // Define it as a property on the scopeObject, using the same name used on
+ // the content side.
+ bool ok = JS_DefineUCProperty(cx, scopeObject, className, -1, propertyHolder,
+ JSPROP_PERMANENT | JSPROP_READONLY,
+ JS_STUBGETTER, JS_STUBSETTER);
+ NS_ENSURE_TRUE(ok, NS_ERROR_UNEXPECTED);
+ } else {
+ propertyHolder = targetClassObject;
+ }
+
+ // Walk our member list and install each one in turn on the XBL scope object.
+ if (propertyHolderIsNew) {
+ for (nsXBLProtoImplMember* curr = mMembers;
+ curr;
+ curr = curr->GetNext())
+ curr->InstallMember(cx, propertyHolder);
+ }
+
+ // Now, if we're using a separate XBL scope, enter the compartment of the
+ // bound node and copy exposable properties to the prototype there. This
+ // rewraps them appropriately, which should result in cross-compartment
+ // function wrappers.
+ if (propertyHolder != targetClassObject) {
+ AssertSameCompartment(propertyHolder, scopeObject);
+ AssertSameCompartment(targetClassObject, globalObject);
+ bool inContentXBLScope = xpc::IsInContentXBLScope(scopeObject);
+ for (nsXBLProtoImplMember* curr = mMembers; curr; curr = curr->GetNext()) {
+ if (!inContentXBLScope || curr->ShouldExposeToUntrustedContent()) {
+ JS::Rooted<jsid> id(cx);
+ JS::TwoByteChars chars(curr->GetName(), NS_strlen(curr->GetName()));
+ bool ok = JS_CharsToId(cx, chars, &id);
+ NS_ENSURE_TRUE(ok, NS_ERROR_UNEXPECTED);
+
+ bool found;
+ ok = JS_HasPropertyById(cx, propertyHolder, id, &found);
+ NS_ENSURE_TRUE(ok, NS_ERROR_UNEXPECTED);
+ if (!found) {
+ // Some members don't install anything in InstallMember (e.g.,
+ // nsXBLProtoImplAnonymousMethod). We need to skip copying in
+ // those cases.
+ continue;
+ }
+
+ ok = JS_CopyPropertyFrom(cx, id, targetClassObject, propertyHolder);
+ NS_ENSURE_TRUE(ok, NS_ERROR_UNEXPECTED);
+ }
+ }
+ }
+
+ // From here on out, work in the scope of the bound element.
+ JSAutoCompartment ac2(cx, targetClassObject);
+
+ // Install all of our field accessors.
+ for (nsXBLProtoImplField* curr = mFields;
+ curr;
+ curr = curr->GetNext())
+ curr->InstallAccessors(cx, targetClassObject);
+
+ return NS_OK;
+}
+
+nsresult
+nsXBLProtoImpl::InitTargetObjects(nsXBLPrototypeBinding* aBinding,
+ nsIContent* aBoundElement,
+ JS::MutableHandle<JSObject*> aTargetClassObject,
+ bool* aTargetIsNew)
+{
+ nsresult rv = NS_OK;
+
+ if (!mPrecompiledMemberHolder) {
+ rv = CompilePrototypeMembers(aBinding); // This is the first time we've ever installed this binding on an element.
+ // We need to go ahead and compile all methods and properties on a class
+ // in our prototype binding.
+ if (NS_FAILED(rv))
+ return rv;
+
+ MOZ_ASSERT(mPrecompiledMemberHolder);
+ }
+
+ nsIDocument *ownerDoc = aBoundElement->OwnerDoc();
+ nsIGlobalObject *sgo;
+
+ if (!(sgo = ownerDoc->GetScopeObject())) {
+ return NS_ERROR_UNEXPECTED;
+ }
+
+ // Because our prototype implementation has a class, we need to build up a corresponding
+ // class for the concrete implementation in the bound document.
+ AutoJSContext cx;
+ JS::Rooted<JSObject*> global(cx, sgo->GetGlobalJSObject());
+ JS::Rooted<JS::Value> v(cx);
+
+ JSAutoCompartment ac(cx, global);
+ // Make sure the interface object is created before the prototype object
+ // so that XULElement is hidden from content. See bug 909340.
+ bool defineOnGlobal = dom::XULElementBinding::ConstructorEnabled(cx, global);
+ dom::XULElementBinding::GetConstructorObjectHandle(cx, defineOnGlobal);
+
+ rv = nsContentUtils::WrapNative(cx, aBoundElement, &v,
+ /* aAllowWrapping = */ false);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ JS::Rooted<JSObject*> value(cx, &v.toObject());
+ JSAutoCompartment ac2(cx, value);
+
+ // All of the above code was just obtaining the bound element's script object and its immediate
+ // concrete base class. We need to alter the object so that our concrete class is interposed
+ // between the object and its base class. We become the new base class of the object, and the
+ // object's old base class becomes the new class' base class.
+ rv = aBinding->InitClass(mClassName, cx, value, aTargetClassObject, aTargetIsNew);
+ if (NS_FAILED(rv)) {
+ return rv;
+ }
+
+ aBoundElement->PreserveWrapper(aBoundElement);
+
+ return rv;
+}
+
+nsresult
+nsXBLProtoImpl::CompilePrototypeMembers(nsXBLPrototypeBinding* aBinding)
+{
+ // We want to pre-compile our implementation's members against a "prototype context". Then when we actually
+ // bind the prototype to a real xbl instance, we'll clone the pre-compiled JS into the real instance's
+ // context.
+ AutoJSAPI jsapi;
+ if (NS_WARN_IF(!jsapi.Init(xpc::CompilationScope())))
+ return NS_ERROR_FAILURE;
+ JSContext* cx = jsapi.cx();
+
+ mPrecompiledMemberHolder = JS_NewObjectWithGivenProto(cx, nullptr, nullptr);
+ if (!mPrecompiledMemberHolder)
+ return NS_ERROR_OUT_OF_MEMORY;
+
+ // Now that we have a class object installed, we walk our member list and compile each of our
+ // properties and methods in turn.
+ JS::Rooted<JSObject*> rootedHolder(cx, mPrecompiledMemberHolder);
+ for (nsXBLProtoImplMember* curr = mMembers;
+ curr;
+ curr = curr->GetNext()) {
+ nsresult rv = curr->CompileMember(jsapi, mClassName, rootedHolder);
+ if (NS_FAILED(rv)) {
+ DestroyMembers();
+ return rv;
+ }
+ }
+
+ return NS_OK;
+}
+
+bool
+nsXBLProtoImpl::LookupMember(JSContext* aCx, nsString& aName,
+ JS::Handle<jsid> aNameAsId,
+ JS::MutableHandle<JS::PropertyDescriptor> aDesc,
+ JS::Handle<JSObject*> aClassObject)
+{
+ for (nsXBLProtoImplMember* m = mMembers; m; m = m->GetNext()) {
+ if (aName.Equals(m->GetName())) {
+ return JS_GetPropertyDescriptorById(aCx, aClassObject, aNameAsId, aDesc);
+ }
+ }
+ return true;
+}
+
+void
+nsXBLProtoImpl::Trace(const TraceCallbacks& aCallbacks, void *aClosure)
+{
+ // If we don't have a class object then we either didn't compile members
+ // or we only have fields, in both cases there are no cycles through our
+ // members.
+ if (!mPrecompiledMemberHolder) {
+ return;
+ }
+
+ nsXBLProtoImplMember *member;
+ for (member = mMembers; member; member = member->GetNext()) {
+ member->Trace(aCallbacks, aClosure);
+ }
+}
+
+void
+nsXBLProtoImpl::UnlinkJSObjects()
+{
+ if (mPrecompiledMemberHolder) {
+ DestroyMembers();
+ }
+}
+
+nsXBLProtoImplField*
+nsXBLProtoImpl::FindField(const nsString& aFieldName) const
+{
+ for (nsXBLProtoImplField* f = mFields; f; f = f->GetNext()) {
+ if (aFieldName.Equals(f->GetName())) {
+ return f;
+ }
+ }
+
+ return nullptr;
+}
+
+bool
+nsXBLProtoImpl::ResolveAllFields(JSContext *cx, JS::Handle<JSObject*> obj) const
+{
+ for (nsXBLProtoImplField* f = mFields; f; f = f->GetNext()) {
+ nsDependentString name(f->GetName());
+ bool dummy;
+ if (!::JS_HasUCProperty(cx, obj, name.get(), name.Length(), &dummy)) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+void
+nsXBLProtoImpl::UndefineFields(JSContext *cx, JS::Handle<JSObject*> obj) const
+{
+ JSAutoRequest ar(cx);
+ for (nsXBLProtoImplField* f = mFields; f; f = f->GetNext()) {
+ nsDependentString name(f->GetName());
+
+ const char16_t* s = name.get();
+ bool hasProp;
+ if (::JS_AlreadyHasOwnUCProperty(cx, obj, s, name.Length(), &hasProp) &&
+ hasProp) {
+ JS::ObjectOpResult ignored;
+ ::JS_DeleteUCProperty(cx, obj, s, name.Length(), ignored);
+ }
+ }
+}
+
+void
+nsXBLProtoImpl::DestroyMembers()
+{
+ MOZ_ASSERT(mPrecompiledMemberHolder);
+
+ delete mMembers;
+ mMembers = nullptr;
+ mConstructor = nullptr;
+ mDestructor = nullptr;
+}
+
+nsresult
+nsXBLProtoImpl::Read(nsIObjectInputStream* aStream,
+ nsXBLPrototypeBinding* aBinding)
+{
+ AssertInCompilationScope();
+ AutoJSContext cx;
+ // Set up a class object first so that deserialization is possible
+ mPrecompiledMemberHolder = JS_NewObjectWithGivenProto(cx, nullptr, nullptr);
+ if (!mPrecompiledMemberHolder)
+ return NS_ERROR_OUT_OF_MEMORY;
+
+ nsXBLProtoImplField* previousField = nullptr;
+ nsXBLProtoImplMember* previousMember = nullptr;
+
+ do {
+ XBLBindingSerializeDetails type;
+ nsresult rv = aStream->Read8(&type);
+ NS_ENSURE_SUCCESS(rv, rv);
+ if (type == XBLBinding_Serialize_NoMoreItems)
+ break;
+
+ switch (type & XBLBinding_Serialize_Mask) {
+ case XBLBinding_Serialize_Field:
+ {
+ nsXBLProtoImplField* field =
+ new nsXBLProtoImplField(type & XBLBinding_Serialize_ReadOnly);
+ rv = field->Read(aStream);
+ if (NS_FAILED(rv)) {
+ delete field;
+ return rv;
+ }
+
+ if (previousField) {
+ previousField->SetNext(field);
+ }
+ else {
+ mFields = field;
+ }
+ previousField = field;
+
+ break;
+ }
+ case XBLBinding_Serialize_GetterProperty:
+ case XBLBinding_Serialize_SetterProperty:
+ case XBLBinding_Serialize_GetterSetterProperty:
+ {
+ nsAutoString name;
+ nsresult rv = aStream->ReadString(name);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ nsXBLProtoImplProperty* prop =
+ new nsXBLProtoImplProperty(name.get(), type & XBLBinding_Serialize_ReadOnly);
+ rv = prop->Read(aStream, type & XBLBinding_Serialize_Mask);
+ if (NS_FAILED(rv)) {
+ delete prop;
+ return rv;
+ }
+
+ previousMember = AddMember(prop, previousMember);
+ break;
+ }
+ case XBLBinding_Serialize_Method:
+ {
+ nsAutoString name;
+ rv = aStream->ReadString(name);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ nsXBLProtoImplMethod* method = new nsXBLProtoImplMethod(name.get());
+ rv = method->Read(aStream);
+ if (NS_FAILED(rv)) {
+ delete method;
+ return rv;
+ }
+
+ previousMember = AddMember(method, previousMember);
+ break;
+ }
+ case XBLBinding_Serialize_Constructor:
+ {
+ nsAutoString name;
+ rv = aStream->ReadString(name);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ mConstructor = new nsXBLProtoImplAnonymousMethod(name.get());
+ rv = mConstructor->Read(aStream);
+ if (NS_FAILED(rv)) {
+ delete mConstructor;
+ mConstructor = nullptr;
+ return rv;
+ }
+
+ previousMember = AddMember(mConstructor, previousMember);
+ break;
+ }
+ case XBLBinding_Serialize_Destructor:
+ {
+ nsAutoString name;
+ rv = aStream->ReadString(name);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ mDestructor = new nsXBLProtoImplAnonymousMethod(name.get());
+ rv = mDestructor->Read(aStream);
+ if (NS_FAILED(rv)) {
+ delete mDestructor;
+ mDestructor = nullptr;
+ return rv;
+ }
+
+ previousMember = AddMember(mDestructor, previousMember);
+ break;
+ }
+ default:
+ NS_ERROR("Unexpected binding member type");
+ break;
+ }
+ } while (1);
+
+ return NS_OK;
+}
+
+nsresult
+nsXBLProtoImpl::Write(nsIObjectOutputStream* aStream,
+ nsXBLPrototypeBinding* aBinding)
+{
+ nsresult rv;
+
+ if (!mPrecompiledMemberHolder) {
+ rv = CompilePrototypeMembers(aBinding);
+ NS_ENSURE_SUCCESS(rv, rv);
+ }
+
+ rv = aStream->WriteUtf8Z(mClassName.get());
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ for (nsXBLProtoImplField* curr = mFields; curr; curr = curr->GetNext()) {
+ rv = curr->Write(aStream);
+ NS_ENSURE_SUCCESS(rv, rv);
+ }
+ for (nsXBLProtoImplMember* curr = mMembers; curr; curr = curr->GetNext()) {
+ if (curr == mConstructor) {
+ rv = mConstructor->Write(aStream, XBLBinding_Serialize_Constructor);
+ }
+ else if (curr == mDestructor) {
+ rv = mDestructor->Write(aStream, XBLBinding_Serialize_Destructor);
+ }
+ else {
+ rv = curr->Write(aStream);
+ }
+ NS_ENSURE_SUCCESS(rv, rv);
+ }
+
+ return aStream->Write8(XBLBinding_Serialize_NoMoreItems);
+}
+
+void
+NS_NewXBLProtoImpl(nsXBLPrototypeBinding* aBinding,
+ const char16_t* aClassName,
+ nsXBLProtoImpl** aResult)
+{
+ nsXBLProtoImpl* impl = new nsXBLProtoImpl();
+ if (aClassName) {
+ impl->mClassName = aClassName;
+ } else {
+ nsCString spec;
+ nsresult rv = aBinding->BindingURI()->GetSpec(spec);
+ // XXX: should handle this better
+ MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
+ impl->mClassName = NS_ConvertUTF8toUTF16(spec);
+ }
+
+ aBinding->SetImplementation(impl);
+ *aResult = impl;
+}
+