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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 17:32:43 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 17:32:43 +0000
commit6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch)
treea68f146d7fa01f0134297619fbe7e33db084e0aa /js/xpconnect/src/XPCWrappedNative.cpp
parentInitial commit. (diff)
downloadthunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.tar.xz
thunderbird-6bf0a5cb5034a7e684dcc3500e841785237ce2dd.zip
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'js/xpconnect/src/XPCWrappedNative.cpp')
-rw-r--r--js/xpconnect/src/XPCWrappedNative.cpp1839
1 files changed, 1839 insertions, 0 deletions
diff --git a/js/xpconnect/src/XPCWrappedNative.cpp b/js/xpconnect/src/XPCWrappedNative.cpp
new file mode 100644
index 0000000000..21f5c3e003
--- /dev/null
+++ b/js/xpconnect/src/XPCWrappedNative.cpp
@@ -0,0 +1,1839 @@
+/* -*- 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/. */
+
+/* Wrapper object for reflecting native xpcom objects into JavaScript. */
+
+#include "xpcprivate.h"
+#include "XPCMaps.h"
+#include "nsWrapperCacheInlines.h"
+#include "XPCLog.h"
+#include "js/Array.h" // JS::GetArrayLength, JS::IsArrayObject
+#include "js/experimental/TypedData.h" // JS_GetTypedArrayLength, JS_IsTypedArrayObject
+#include "js/MemoryFunctions.h"
+#include "js/Object.h" // JS::GetPrivate, JS::SetPrivate, JS::SetReservedSlot
+#include "js/Printf.h"
+#include "js/PropertyAndElement.h" // JS_GetProperty, JS_GetPropertyById, JS_SetProperty, JS_SetPropertyById
+#include "jsfriendapi.h"
+#include "AccessCheck.h"
+#include "WrapperFactory.h"
+#include "XrayWrapper.h"
+
+#include "nsContentUtils.h"
+#include "nsCycleCollectionNoteRootCallback.h"
+
+#include <new>
+#include <stdint.h>
+#include "mozilla/DeferredFinalize.h"
+#include "mozilla/Likely.h"
+#include "mozilla/Unused.h"
+#include "mozilla/Sprintf.h"
+#include "mozilla/dom/BindingUtils.h"
+#include "mozilla/ProfilerLabels.h"
+#include <algorithm>
+
+using namespace xpc;
+using namespace mozilla;
+using namespace mozilla::dom;
+using namespace JS;
+
+/***************************************************************************/
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(XPCWrappedNative)
+
+// No need to unlink the JS objects: if the XPCWrappedNative is cycle
+// collected then its mFlatJSObject will be cycle collected too and
+// finalization of the mFlatJSObject will unlink the JS objects (see
+// XPC_WN_NoHelper_Finalize and FlatJSObjectFinalized).
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(XPCWrappedNative)
+ tmp->ExpireWrapper();
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(XPCWrappedNative)
+ if (!tmp->IsValid()) {
+ return NS_OK;
+ }
+
+ if (MOZ_UNLIKELY(cb.WantDebugInfo())) {
+ char name[72];
+ nsCOMPtr<nsIXPCScriptable> scr = tmp->GetScriptable();
+ if (scr) {
+ SprintfLiteral(name, "XPCWrappedNative (%s)", scr->GetJSClass()->name);
+ } else {
+ SprintfLiteral(name, "XPCWrappedNative");
+ }
+
+ cb.DescribeRefCountedNode(tmp->mRefCnt.get(), name);
+ } else {
+ NS_IMPL_CYCLE_COLLECTION_DESCRIBE(XPCWrappedNative, tmp->mRefCnt.get())
+ }
+
+ if (tmp->HasExternalReference()) {
+ // If our refcount is > 1, our reference to the flat JS object is
+ // considered "strong", and we're going to traverse it.
+ //
+ // If our refcount is <= 1, our reference to the flat JS object is
+ // considered "weak", and we're *not* going to traverse it.
+ //
+ // This reasoning is in line with the slightly confusing lifecycle rules
+ // for XPCWrappedNatives, described in a larger comment below and also
+ // on our wiki at http://wiki.mozilla.org/XPConnect_object_wrapping
+
+ JSObject* obj = tmp->GetFlatJSObjectPreserveColor();
+ NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mFlatJSObject");
+ cb.NoteJSChild(JS::GCCellPtr(obj));
+ }
+
+ // XPCWrappedNative keeps its native object alive.
+ NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "mIdentity");
+ cb.NoteXPCOMChild(tmp->GetIdentityObject());
+
+ tmp->NoteTearoffs(cb);
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+void XPCWrappedNative::Suspect(nsCycleCollectionNoteRootCallback& cb) {
+ if (!IsValid() || IsWrapperExpired()) {
+ return;
+ }
+
+ MOZ_ASSERT(NS_IsMainThread(),
+ "Suspecting wrapped natives from non-main thread");
+
+ // Only record objects that might be part of a cycle as roots, unless
+ // the callback wants all traces (a debug feature). Do this even if
+ // the XPCWN doesn't own the JS reflector object in case the reflector
+ // keeps alive other C++ things. This is safe because if the reflector
+ // had died the reference from the XPCWN to it would have been cleared.
+ JSObject* obj = GetFlatJSObjectPreserveColor();
+ if (JS::ObjectIsMarkedGray(obj) || cb.WantAllTraces()) {
+ cb.NoteJSRoot(obj);
+ }
+}
+
+void XPCWrappedNative::NoteTearoffs(nsCycleCollectionTraversalCallback& cb) {
+ // Tearoffs hold their native object alive. If their JS object hasn't been
+ // finalized yet we'll note the edge between the JS object and the native
+ // (see nsXPConnect::Traverse), but if their JS object has been finalized
+ // then the tearoff is only reachable through the XPCWrappedNative, so we
+ // record an edge here.
+ for (XPCWrappedNativeTearOff* to = &mFirstTearOff; to;
+ to = to->GetNextTearOff()) {
+ JSObject* jso = to->GetJSObjectPreserveColor();
+ if (!jso) {
+ NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "tearoff's mNative");
+ cb.NoteXPCOMChild(to->GetNative());
+ }
+ }
+}
+
+#ifdef XPC_CHECK_CLASSINFO_CLAIMS
+static void DEBUG_CheckClassInfoClaims(XPCWrappedNative* wrapper);
+#else
+# define DEBUG_CheckClassInfoClaims(wrapper) ((void)0)
+#endif
+
+/***************************************************************************/
+static nsresult FinishCreate(JSContext* cx, XPCWrappedNativeScope* Scope,
+ XPCNativeInterface* Interface,
+ nsWrapperCache* cache, XPCWrappedNative* inWrapper,
+ XPCWrappedNative** resultWrapper);
+
+// static
+//
+// This method handles the special case of wrapping a new global object.
+//
+// The normal code path for wrapping natives goes through
+// XPCConvert::NativeInterface2JSObject, XPCWrappedNative::GetNewOrUsed,
+// and finally into XPCWrappedNative::Init. Unfortunately, this path assumes
+// very early on that we have an XPCWrappedNativeScope and corresponding global
+// JS object, which are the very things we need to create here. So we special-
+// case the logic and do some things in a different order.
+nsresult XPCWrappedNative::WrapNewGlobal(JSContext* cx,
+ xpcObjectHelper& nativeHelper,
+ nsIPrincipal* principal,
+ bool initStandardClasses,
+ JS::RealmOptions& aOptions,
+ XPCWrappedNative** wrappedGlobal) {
+ nsCOMPtr<nsISupports> identity = do_QueryInterface(nativeHelper.Object());
+
+ // The object should specify that it's meant to be global.
+ MOZ_ASSERT(nativeHelper.GetScriptableFlags() &
+ XPC_SCRIPTABLE_IS_GLOBAL_OBJECT);
+
+ // We shouldn't be reusing globals.
+ MOZ_ASSERT(!nativeHelper.GetWrapperCache() ||
+ !nativeHelper.GetWrapperCache()->GetWrapperPreserveColor());
+
+ // Get the nsIXPCScriptable. This will tell us the JSClass of the object
+ // we're going to create.
+ nsCOMPtr<nsIXPCScriptable> scrProto;
+ nsCOMPtr<nsIXPCScriptable> scrWrapper;
+ GatherScriptable(identity, nativeHelper.GetClassInfo(),
+ getter_AddRefs(scrProto), getter_AddRefs(scrWrapper));
+ MOZ_ASSERT(scrWrapper);
+
+ // Finally, we get to the JSClass.
+ const JSClass* clasp = scrWrapper->GetJSClass();
+ MOZ_ASSERT(clasp->flags & JSCLASS_IS_GLOBAL);
+
+ // Create the global.
+ aOptions.creationOptions().setTrace(XPCWrappedNative::Trace);
+ xpc::SetPrefableRealmOptions(aOptions);
+
+ RootedObject global(cx,
+ xpc::CreateGlobalObject(cx, clasp, principal, aOptions));
+ if (!global) {
+ return NS_ERROR_FAILURE;
+ }
+ XPCWrappedNativeScope* scope = ObjectScope(global);
+
+ // Immediately enter the global's realm, so that everything else we
+ // create ends up there.
+ JSAutoRealm ar(cx, global);
+
+ // If requested, initialize the standard classes on the global.
+ if (initStandardClasses && !JS::InitRealmStandardClasses(cx)) {
+ return NS_ERROR_FAILURE;
+ }
+
+ // Make a proto.
+ XPCWrappedNativeProto* proto = XPCWrappedNativeProto::GetNewOrUsed(
+ cx, scope, nativeHelper.GetClassInfo(), scrProto);
+ if (!proto) {
+ return NS_ERROR_FAILURE;
+ }
+
+ // Set up the prototype on the global.
+ MOZ_ASSERT(proto->GetJSProtoObject());
+ RootedObject protoObj(cx, proto->GetJSProtoObject());
+ bool success = JS_SetPrototype(cx, global, protoObj);
+ if (!success) {
+ return NS_ERROR_FAILURE;
+ }
+
+ // Construct the wrapper, which takes over the strong reference to the
+ // native object.
+ RefPtr<XPCWrappedNative> wrapper =
+ new XPCWrappedNative(std::move(identity), proto);
+
+ //
+ // We don't call ::Init() on this wrapper, because our setup requirements
+ // are different for globals. We do our setup inline here, instead.
+ //
+
+ wrapper->mScriptable = scrWrapper;
+
+ // Set the JS object to the global we already created.
+ wrapper->SetFlatJSObject(global);
+
+ // Set the reserved slot to the XPCWrappedNative.
+ static_assert(JSCLASS_GLOBAL_APPLICATION_SLOTS > 0,
+ "Need at least one slot for JSCLASS_SLOT0_IS_NSISUPPORTS");
+ JS::SetObjectISupports(global, wrapper);
+
+ // There are dire comments elsewhere in the code about how a GC can
+ // happen somewhere after wrapper initialization but before the wrapper is
+ // added to the hashtable in FinishCreate(). It's not clear if that can
+ // happen here, but let's just be safe for now.
+ AutoMarkingWrappedNativePtr wrapperMarker(cx, wrapper);
+
+ // Call the common Init finish routine. This mainly just does an AddRef
+ // on behalf of XPConnect (the corresponding Release is in the finalizer
+ // hook), but it does some other miscellaneous things too, so we don't
+ // inline it.
+ success = wrapper->FinishInit(cx);
+ MOZ_ASSERT(success);
+
+ // Go through some extra work to find the tearoff. This is kind of silly
+ // on a conceptual level: the point of tearoffs is to cache the results
+ // of QI-ing mIdentity to different interfaces, and we don't need that
+ // since we're dealing with nsISupports. But lots of code expects tearoffs
+ // to exist for everything, so we just follow along.
+ RefPtr<XPCNativeInterface> iface =
+ XPCNativeInterface::GetNewOrUsed(cx, &NS_GET_IID(nsISupports));
+ MOZ_ASSERT(iface);
+ nsresult status;
+ success = wrapper->FindTearOff(cx, iface, false, &status);
+ if (!success) {
+ return status;
+ }
+
+ // Call the common creation finish routine. This does all of the bookkeeping
+ // like inserting the wrapper into the wrapper map and setting up the wrapper
+ // cache.
+ nsresult rv = FinishCreate(cx, scope, iface, nativeHelper.GetWrapperCache(),
+ wrapper, wrappedGlobal);
+ NS_ENSURE_SUCCESS(rv, rv);
+
+ return NS_OK;
+}
+
+// static
+nsresult XPCWrappedNative::GetNewOrUsed(JSContext* cx, xpcObjectHelper& helper,
+ XPCWrappedNativeScope* Scope,
+ XPCNativeInterface* Interface,
+ XPCWrappedNative** resultWrapper) {
+ MOZ_ASSERT(Interface);
+ nsWrapperCache* cache = helper.GetWrapperCache();
+
+ MOZ_ASSERT(!cache || !cache->GetWrapperPreserveColor(),
+ "We assume the caller already checked if it could get the "
+ "wrapper from the cache.");
+
+ nsresult rv;
+
+ MOZ_ASSERT(!Scope->GetRuntime()->GCIsRunning(),
+ "XPCWrappedNative::GetNewOrUsed called during GC");
+
+ nsCOMPtr<nsISupports> identity = do_QueryInterface(helper.Object());
+
+ if (!identity) {
+ NS_ERROR("This XPCOM object fails in QueryInterface to nsISupports!");
+ return NS_ERROR_FAILURE;
+ }
+
+ RefPtr<XPCWrappedNative> wrapper;
+
+ Native2WrappedNativeMap* map = Scope->GetWrappedNativeMap();
+ // Some things are nsWrapperCache subclasses but never use the cache, so go
+ // ahead and check our map even if we have a cache and it has no existing
+ // wrapper: we might have an XPCWrappedNative anyway.
+ wrapper = map->Find(identity);
+
+ if (wrapper) {
+ if (!wrapper->FindTearOff(cx, Interface, false, &rv)) {
+ MOZ_ASSERT(NS_FAILED(rv), "returning NS_OK on failure");
+ return rv;
+ }
+ wrapper.forget(resultWrapper);
+ return NS_OK;
+ }
+
+ // There is a chance that the object wants to have the self-same JSObject
+ // reflection regardless of the scope into which we are reflecting it.
+ // Many DOM objects require this. The scriptable helper specifies this
+ // in preCreate by indicating a 'parent' of a particular scope.
+ //
+ // To handle this we need to get the scriptable helper early and ask it.
+ // It is possible that we will then end up forwarding this entire call
+ // to this same function but with a different scope.
+
+ // If we are making a wrapper for an nsIClassInfo singleton then
+ // We *don't* want to have it use the prototype meant for instances
+ // of that class.
+ uint32_t classInfoFlags;
+ bool isClassInfoSingleton =
+ helper.GetClassInfo() == helper.Object() &&
+ NS_SUCCEEDED(helper.GetClassInfo()->GetFlags(&classInfoFlags)) &&
+ (classInfoFlags & nsIClassInfo::SINGLETON_CLASSINFO);
+
+ nsIClassInfo* info = helper.GetClassInfo();
+
+ nsCOMPtr<nsIXPCScriptable> scrProto;
+ nsCOMPtr<nsIXPCScriptable> scrWrapper;
+
+ // Gather scriptable create info if we are wrapping something
+ // other than an nsIClassInfo object. We need to not do this for
+ // nsIClassInfo objects because often nsIClassInfo implementations
+ // are also nsIXPCScriptable helper implementations, but the helper
+ // code is obviously intended for the implementation of the class
+ // described by the nsIClassInfo, not for the class info object
+ // itself.
+ if (!isClassInfoSingleton) {
+ GatherScriptable(identity, info, getter_AddRefs(scrProto),
+ getter_AddRefs(scrWrapper));
+ }
+
+ RootedObject parent(cx, Scope->GetGlobalForWrappedNatives());
+
+ mozilla::Maybe<JSAutoRealm> ar;
+
+ if (scrWrapper && scrWrapper->WantPreCreate()) {
+ RootedObject plannedParent(cx, parent);
+ nsresult rv = scrWrapper->PreCreate(identity, cx, parent, parent.address());
+ if (NS_FAILED(rv)) {
+ return rv;
+ }
+ rv = NS_OK;
+
+ MOZ_ASSERT(!xpc::WrapperFactory::IsXrayWrapper(parent),
+ "Xray wrapper being used to parent XPCWrappedNative?");
+
+ MOZ_ASSERT(JS_IsGlobalObject(parent),
+ "Non-global being used to parent XPCWrappedNative?");
+
+ ar.emplace(static_cast<JSContext*>(cx), parent);
+
+ if (parent != plannedParent) {
+ XPCWrappedNativeScope* betterScope = ObjectScope(parent);
+ MOZ_ASSERT(betterScope != Scope,
+ "How can we have the same scope for two different globals?");
+ return GetNewOrUsed(cx, helper, betterScope, Interface, resultWrapper);
+ }
+
+ // Take the performance hit of checking the hashtable again in case
+ // the preCreate call caused the wrapper to get created through some
+ // interesting path (the DOM code tends to make this happen sometimes).
+
+ if (cache) {
+ RootedObject cached(cx, cache->GetWrapper());
+ if (cached) {
+ wrapper = XPCWrappedNative::Get(cached);
+ }
+ } else {
+ wrapper = map->Find(identity);
+ }
+
+ if (wrapper) {
+ if (!wrapper->FindTearOff(cx, Interface, false, &rv)) {
+ MOZ_ASSERT(NS_FAILED(rv), "returning NS_OK on failure");
+ return rv;
+ }
+ wrapper.forget(resultWrapper);
+ return NS_OK;
+ }
+ } else {
+ ar.emplace(static_cast<JSContext*>(cx), parent);
+ }
+
+ AutoMarkingWrappedNativeProtoPtr proto(cx);
+
+ // If there is ClassInfo (and we are not building a wrapper for the
+ // nsIClassInfo interface) then we use a wrapper that needs a prototype.
+
+ // Note that the security check happens inside FindTearOff - after the
+ // wrapper is actually created, but before JS code can see it.
+
+ if (info && !isClassInfoSingleton) {
+ proto = XPCWrappedNativeProto::GetNewOrUsed(cx, Scope, info, scrProto);
+ if (!proto) {
+ return NS_ERROR_FAILURE;
+ }
+
+ wrapper = new XPCWrappedNative(std::move(identity), proto);
+ } else {
+ RefPtr<XPCNativeInterface> iface = Interface;
+ if (!iface) {
+ iface = XPCNativeInterface::GetISupports(cx);
+ }
+
+ XPCNativeSetKey key(cx, iface);
+ RefPtr<XPCNativeSet> set = XPCNativeSet::GetNewOrUsed(cx, &key);
+
+ if (!set) {
+ return NS_ERROR_FAILURE;
+ }
+
+ wrapper = new XPCWrappedNative(std::move(identity), Scope, set.forget());
+ }
+
+ MOZ_ASSERT(!xpc::WrapperFactory::IsXrayWrapper(parent),
+ "Xray wrapper being used to parent XPCWrappedNative?");
+
+ // We use an AutoMarkingPtr here because it is possible for JS gc to happen
+ // after we have Init'd the wrapper but *before* we add it to the hashtable.
+ // This would cause the mSet to get collected and we'd later crash. I've
+ // *seen* this happen.
+ AutoMarkingWrappedNativePtr wrapperMarker(cx, wrapper);
+
+ if (!wrapper->Init(cx, scrWrapper)) {
+ return NS_ERROR_FAILURE;
+ }
+
+ if (!wrapper->FindTearOff(cx, Interface, false, &rv)) {
+ MOZ_ASSERT(NS_FAILED(rv), "returning NS_OK on failure");
+ return rv;
+ }
+
+ return FinishCreate(cx, Scope, Interface, cache, wrapper, resultWrapper);
+}
+
+static nsresult FinishCreate(JSContext* cx, XPCWrappedNativeScope* Scope,
+ XPCNativeInterface* Interface,
+ nsWrapperCache* cache, XPCWrappedNative* inWrapper,
+ XPCWrappedNative** resultWrapper) {
+ MOZ_ASSERT(inWrapper);
+
+ Native2WrappedNativeMap* map = Scope->GetWrappedNativeMap();
+
+ RefPtr<XPCWrappedNative> wrapper;
+ // Deal with the case where the wrapper got created as a side effect
+ // of one of our calls out of this code. Add() returns the (possibly
+ // pre-existing) wrapper that ultimately ends up in the map, which is
+ // what we want.
+ wrapper = map->Add(inWrapper);
+ if (!wrapper) {
+ return NS_ERROR_FAILURE;
+ }
+
+ if (wrapper == inWrapper) {
+ JSObject* flat = wrapper->GetFlatJSObject();
+ MOZ_ASSERT(!cache || !cache->GetWrapperPreserveColor() ||
+ flat == cache->GetWrapperPreserveColor(),
+ "This object has a cached wrapper that's different from "
+ "the JSObject held by its native wrapper?");
+
+ if (cache && !cache->GetWrapperPreserveColor()) {
+ cache->SetWrapper(flat);
+ }
+ }
+
+ DEBUG_CheckClassInfoClaims(wrapper);
+ wrapper.forget(resultWrapper);
+ return NS_OK;
+}
+
+// This ctor is used if this object will have a proto.
+XPCWrappedNative::XPCWrappedNative(nsCOMPtr<nsISupports>&& aIdentity,
+ XPCWrappedNativeProto* aProto)
+ : mMaybeProto(aProto), mSet(aProto->GetSet()) {
+ MOZ_ASSERT(NS_IsMainThread());
+
+ mIdentity = aIdentity;
+ mFlatJSObject.setFlags(FLAT_JS_OBJECT_VALID);
+
+ MOZ_ASSERT(mMaybeProto, "bad ctor param");
+ MOZ_ASSERT(mSet, "bad ctor param");
+}
+
+// This ctor is used if this object will NOT have a proto.
+XPCWrappedNative::XPCWrappedNative(nsCOMPtr<nsISupports>&& aIdentity,
+ XPCWrappedNativeScope* aScope,
+ RefPtr<XPCNativeSet>&& aSet)
+ : mMaybeScope(TagScope(aScope)), mSet(std::move(aSet)) {
+ MOZ_ASSERT(NS_IsMainThread());
+
+ mIdentity = aIdentity;
+ mFlatJSObject.setFlags(FLAT_JS_OBJECT_VALID);
+
+ MOZ_ASSERT(aScope, "bad ctor param");
+ MOZ_ASSERT(mSet, "bad ctor param");
+}
+
+XPCWrappedNative::~XPCWrappedNative() { Destroy(); }
+
+void XPCWrappedNative::Destroy() {
+ mScriptable = nullptr;
+
+#ifdef DEBUG
+ // Check that this object has already been swept from the map.
+ XPCWrappedNativeScope* scope = GetScope();
+ if (scope) {
+ Native2WrappedNativeMap* map = scope->GetWrappedNativeMap();
+ MOZ_ASSERT(map->Find(GetIdentityObject()) != this);
+ }
+#endif
+
+ if (mIdentity) {
+ XPCJSRuntime* rt = GetRuntime();
+ if (rt && rt->GetDoingFinalization()) {
+ DeferredFinalize(mIdentity.forget().take());
+ } else {
+ mIdentity = nullptr;
+ }
+ }
+
+ mMaybeScope = nullptr;
+}
+
+// A hack for bug 517665, increase the probability for GC.
+// TODO: Try removing this and just using the actual size of the object.
+static const size_t GCMemoryFactor = 2;
+
+inline void XPCWrappedNative::SetFlatJSObject(JSObject* object) {
+ MOZ_ASSERT(!mFlatJSObject);
+ MOZ_ASSERT(object);
+
+ JS::AddAssociatedMemory(object, sizeof(*this) * GCMemoryFactor,
+ JS::MemoryUse::XPCWrappedNative);
+
+ mFlatJSObject = object;
+ mFlatJSObject.setFlags(FLAT_JS_OBJECT_VALID);
+}
+
+inline void XPCWrappedNative::UnsetFlatJSObject() {
+ MOZ_ASSERT(mFlatJSObject);
+
+ JS::RemoveAssociatedMemory(mFlatJSObject.unbarrieredGetPtr(),
+ sizeof(*this) * GCMemoryFactor,
+ JS::MemoryUse::XPCWrappedNative);
+
+ mFlatJSObject = nullptr;
+ mFlatJSObject.unsetFlags(FLAT_JS_OBJECT_VALID);
+}
+
+// This is factored out so that it can be called publicly.
+// static
+nsIXPCScriptable* XPCWrappedNative::GatherProtoScriptable(
+ nsIClassInfo* classInfo) {
+ MOZ_ASSERT(classInfo, "bad param");
+
+ nsCOMPtr<nsIXPCScriptable> helper;
+ nsresult rv = classInfo->GetScriptableHelper(getter_AddRefs(helper));
+ if (NS_SUCCEEDED(rv) && helper) {
+ return helper;
+ }
+
+ return nullptr;
+}
+
+// static
+void XPCWrappedNative::GatherScriptable(nsISupports* aObj,
+ nsIClassInfo* aClassInfo,
+ nsIXPCScriptable** aScrProto,
+ nsIXPCScriptable** aScrWrapper) {
+ MOZ_ASSERT(!*aScrProto, "bad param");
+ MOZ_ASSERT(!*aScrWrapper, "bad param");
+
+ nsCOMPtr<nsIXPCScriptable> scrProto;
+ nsCOMPtr<nsIXPCScriptable> scrWrapper;
+
+ // Get the class scriptable helper (if present)
+ if (aClassInfo) {
+ scrProto = GatherProtoScriptable(aClassInfo);
+ }
+
+ // Do the same for the wrapper specific scriptable
+ scrWrapper = do_QueryInterface(aObj);
+ if (scrWrapper) {
+ // A whole series of assertions to catch bad uses of scriptable flags on
+ // the scrWrapper...
+
+ // Can't set WANT_PRECREATE on an instance scriptable without also
+ // setting it on the class scriptable.
+ MOZ_ASSERT_IF(scrWrapper->WantPreCreate(),
+ scrProto && scrProto->WantPreCreate());
+
+ // Can't set DONT_ENUM_QUERY_INTERFACE on an instance scriptable
+ // without also setting it on the class scriptable (if present).
+ MOZ_ASSERT_IF(scrWrapper->DontEnumQueryInterface() && scrProto,
+ scrProto->DontEnumQueryInterface());
+
+ // Can't set ALLOW_PROP_MODS_DURING_RESOLVE on an instance scriptable
+ // without also setting it on the class scriptable (if present).
+ MOZ_ASSERT_IF(scrWrapper->AllowPropModsDuringResolve() && scrProto,
+ scrProto->AllowPropModsDuringResolve());
+ } else {
+ scrWrapper = scrProto;
+ }
+
+ scrProto.forget(aScrProto);
+ scrWrapper.forget(aScrWrapper);
+}
+
+bool XPCWrappedNative::Init(JSContext* cx, nsIXPCScriptable* aScriptable) {
+ // Setup our scriptable...
+ MOZ_ASSERT(!mScriptable);
+ mScriptable = aScriptable;
+
+ // create our flatJSObject
+
+ const JSClass* jsclazz =
+ mScriptable ? mScriptable->GetJSClass() : &XPC_WN_NoHelper_JSClass;
+
+ // We should have the global jsclass flag if and only if we're a global.
+ MOZ_ASSERT_IF(mScriptable, !!mScriptable->IsGlobalObject() ==
+ !!(jsclazz->flags & JSCLASS_IS_GLOBAL));
+
+ MOZ_ASSERT(jsclazz && jsclazz->name && jsclazz->flags &&
+ jsclazz->getResolve() && jsclazz->hasFinalize(),
+ "bad class");
+
+ RootedObject protoJSObject(cx, HasProto() ? GetProto()->GetJSProtoObject()
+ : JS::GetRealmObjectPrototype(cx));
+ if (!protoJSObject) {
+ return false;
+ }
+
+ JSObject* object = JS_NewObjectWithGivenProto(cx, jsclazz, protoJSObject);
+ if (!object) {
+ return false;
+ }
+
+ SetFlatJSObject(object);
+
+ JS::SetObjectISupports(mFlatJSObject, this);
+
+ return FinishInit(cx);
+}
+
+bool XPCWrappedNative::FinishInit(JSContext* cx) {
+ // This reference will be released when mFlatJSObject is finalized.
+ // Since this reference will push the refcount to 2 it will also root
+ // mFlatJSObject;
+ MOZ_ASSERT(1 == mRefCnt, "unexpected refcount value");
+ NS_ADDREF(this);
+
+ return true;
+}
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(XPCWrappedNative)
+ NS_INTERFACE_MAP_ENTRY(nsIXPConnectWrappedNative)
+ NS_INTERFACE_MAP_ENTRY(nsIXPConnectJSObjectHolder)
+ NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIXPConnectWrappedNative)
+NS_INTERFACE_MAP_END
+
+NS_IMPL_CYCLE_COLLECTING_ADDREF(XPCWrappedNative)
+
+// Release calls Destroy() immediately when the refcount drops to 0 to
+// clear the weak references nsXPConnect has to XPCWNs and to ensure there
+// are no pointers to dying protos.
+NS_IMPL_CYCLE_COLLECTING_RELEASE_WITH_LAST_RELEASE(XPCWrappedNative, Destroy())
+
+/*
+ * Wrapped Native lifetime management is messy!
+ *
+ * - At creation we push the refcount to 2 (only one of which is owned by
+ * the native caller that caused the wrapper creation).
+ * - During the JS GC Mark phase we mark any wrapper with a refcount > 1.
+ * - The *only* thing that can make the wrapper get destroyed is the
+ * finalization of mFlatJSObject. And *that* should only happen if the only
+ * reference is the single extra (internal) reference we hold.
+ *
+ * - The wrapper has a pointer to the nsISupports 'view' of the wrapped native
+ * object i.e... mIdentity. This is held until the wrapper's refcount goes
+ * to zero and the wrapper is released, or until an expired wrapper (i.e.,
+ * one unlinked by the cycle collector) has had its JS object finalized.
+ *
+ * - The wrapper also has 'tearoffs'. It has one tearoff for each interface
+ * that is actually used on the native object. 'Used' means we have either
+ * needed to QueryInterface to verify the availability of that interface
+ * of that we've had to QueryInterface in order to actually make a call
+ * into the wrapped object via the pointer for the given interface.
+ *
+ * - Each tearoff's 'mNative' member (if non-null) indicates one reference
+ * held by our wrapper on the wrapped native for the given interface
+ * associated with the tearoff. If we release that reference then we set
+ * the tearoff's 'mNative' to null.
+ *
+ * - We use the occasion of the JavaScript GCCallback for the JSGC_MARK_END
+ * event to scan the tearoffs of all wrappers for non-null mNative members
+ * that represent unused references. We can tell that a given tearoff's
+ * mNative is unused by noting that no live XPCCallContexts hold a pointer
+ * to the tearoff.
+ *
+ * - As a time/space tradeoff we may decide to not do this scanning on
+ * *every* JavaScript GC. We *do* want to do this *sometimes* because
+ * we want to allow for wrapped native's to do their own tearoff patterns.
+ * So, we want to avoid holding references to interfaces that we don't need.
+ * At the same time, we don't want to be bracketing every call into a
+ * wrapped native object with a QueryInterface/Release pair. And we *never*
+ * make a call into the object except via the correct interface for which
+ * we've QI'd.
+ *
+ * - Each tearoff *can* have a mJSObject whose lazily resolved properties
+ * represent the methods/attributes/constants of that specific interface.
+ * This is optionally reflected into JavaScript as "foo.nsIFoo" when "foo"
+ * is the name of mFlatJSObject and "nsIFoo" is the name of the given
+ * interface associated with the tearoff. When we create the tearoff's
+ * mJSObject we set it's parent to be mFlatJSObject. This way we know that
+ * when mFlatJSObject get's collected there are no outstanding reachable
+ * tearoff mJSObjects. Note that we must clear the private of any lingering
+ * mJSObjects at this point because we have no guarentee of the *order* of
+ * finalization within a given gc cycle.
+ */
+
+void XPCWrappedNative::FlatJSObjectFinalized() {
+ if (!IsValid()) {
+ return;
+ }
+
+ // Iterate the tearoffs and null out each of their JSObject's privates.
+ // This will keep them from trying to access their pointers to the
+ // dying tearoff object. We can safely assume that those remaining
+ // JSObjects are about to be finalized too.
+
+ for (XPCWrappedNativeTearOff* to = &mFirstTearOff; to;
+ to = to->GetNextTearOff()) {
+ JSObject* jso = to->GetJSObjectPreserveColor();
+ if (jso) {
+ JS::SetReservedSlot(jso, XPCWrappedNativeTearOff::TearOffSlot,
+ JS::UndefinedValue());
+ to->JSObjectFinalized();
+ }
+
+ // We also need to release any native pointers held...
+ RefPtr<nsISupports> native = to->TakeNative();
+ if (native && GetRuntime()) {
+ DeferredFinalize(native.forget().take());
+ }
+
+ to->SetInterface(nullptr);
+ }
+
+ nsWrapperCache* cache = nullptr;
+ CallQueryInterface(mIdentity, &cache);
+ if (cache) {
+ cache->ClearWrapper(mFlatJSObject.unbarrieredGetPtr());
+ }
+
+ UnsetFlatJSObject();
+
+ MOZ_ASSERT(mIdentity, "bad pointer!");
+
+ if (IsWrapperExpired()) {
+ Destroy();
+ }
+
+ // Note that it's not safe to touch mNativeWrapper here since it's
+ // likely that it has already been finalized.
+
+ Release();
+}
+
+void XPCWrappedNative::FlatJSObjectMoved(JSObject* obj, const JSObject* old) {
+ JS::AutoAssertGCCallback inCallback;
+ MOZ_ASSERT(mFlatJSObject == old);
+
+ nsWrapperCache* cache = nullptr;
+ CallQueryInterface(mIdentity, &cache);
+ if (cache) {
+ cache->UpdateWrapper(obj, old);
+ }
+
+ mFlatJSObject = obj;
+}
+
+void XPCWrappedNative::SystemIsBeingShutDown() {
+ if (!IsValid()) {
+ return;
+ }
+
+ // The long standing strategy is to leak some objects still held at shutdown.
+ // The general problem is that propagating release out of xpconnect at
+ // shutdown time causes a world of problems.
+
+ // We leak mIdentity (see above).
+
+ // Short circuit future finalization.
+ JS::SetObjectISupports(mFlatJSObject, nullptr);
+ UnsetFlatJSObject();
+
+ XPCWrappedNativeProto* proto = GetProto();
+
+ if (HasProto()) {
+ proto->SystemIsBeingShutDown();
+ }
+
+ // We don't clear mScriptable here. The destructor will do it.
+
+ // Cleanup the tearoffs.
+ for (XPCWrappedNativeTearOff* to = &mFirstTearOff; to;
+ to = to->GetNextTearOff()) {
+ if (JSObject* jso = to->GetJSObjectPreserveColor()) {
+ JS::SetReservedSlot(jso, XPCWrappedNativeTearOff::TearOffSlot,
+ JS::UndefinedValue());
+ to->SetJSObject(nullptr);
+ }
+ // We leak the tearoff mNative
+ // (for the same reason we leak mIdentity - see above).
+ Unused << to->TakeNative().take();
+ to->SetInterface(nullptr);
+ }
+}
+
+/***************************************************************************/
+
+bool XPCWrappedNative::ExtendSet(JSContext* aCx,
+ XPCNativeInterface* aInterface) {
+ if (!mSet->HasInterface(aInterface)) {
+ XPCNativeSetKey key(mSet, aInterface);
+ RefPtr<XPCNativeSet> newSet = XPCNativeSet::GetNewOrUsed(aCx, &key);
+ if (!newSet) {
+ return false;
+ }
+
+ mSet = std::move(newSet);
+ }
+ return true;
+}
+
+XPCWrappedNativeTearOff* XPCWrappedNative::FindTearOff(
+ JSContext* cx, XPCNativeInterface* aInterface,
+ bool needJSObject /* = false */, nsresult* pError /* = nullptr */) {
+ nsresult rv = NS_OK;
+ XPCWrappedNativeTearOff* to;
+ XPCWrappedNativeTearOff* firstAvailable = nullptr;
+
+ XPCWrappedNativeTearOff* lastTearOff;
+ for (lastTearOff = to = &mFirstTearOff; to;
+ lastTearOff = to, to = to->GetNextTearOff()) {
+ if (to->GetInterface() == aInterface) {
+ if (needJSObject && !to->GetJSObjectPreserveColor()) {
+ AutoMarkingWrappedNativeTearOffPtr tearoff(cx, to);
+ bool ok = InitTearOffJSObject(cx, to);
+ // During shutdown, we don't sweep tearoffs. So make sure
+ // to unmark manually in case the auto-marker marked us.
+ // We shouldn't ever be getting here _during_ our
+ // Mark/Sweep cycle, so this should be safe.
+ to->Unmark();
+ if (!ok) {
+ to = nullptr;
+ rv = NS_ERROR_OUT_OF_MEMORY;
+ }
+ }
+ if (pError) {
+ *pError = rv;
+ }
+ return to;
+ }
+ if (!firstAvailable && to->IsAvailable()) {
+ firstAvailable = to;
+ }
+ }
+
+ to = firstAvailable;
+
+ if (!to) {
+ to = lastTearOff->AddTearOff();
+ }
+
+ {
+ // Scope keeps |tearoff| from leaking across the rest of the function.
+ AutoMarkingWrappedNativeTearOffPtr tearoff(cx, to);
+ rv = InitTearOff(cx, to, aInterface, needJSObject);
+ // During shutdown, we don't sweep tearoffs. So make sure to unmark
+ // manually in case the auto-marker marked us. We shouldn't ever be
+ // getting here _during_ our Mark/Sweep cycle, so this should be safe.
+ to->Unmark();
+ if (NS_FAILED(rv)) {
+ to = nullptr;
+ }
+ }
+
+ if (pError) {
+ *pError = rv;
+ }
+ return to;
+}
+
+XPCWrappedNativeTearOff* XPCWrappedNative::FindTearOff(JSContext* cx,
+ const nsIID& iid) {
+ RefPtr<XPCNativeInterface> iface = XPCNativeInterface::GetNewOrUsed(cx, &iid);
+ return iface ? FindTearOff(cx, iface) : nullptr;
+}
+
+nsresult XPCWrappedNative::InitTearOff(JSContext* cx,
+ XPCWrappedNativeTearOff* aTearOff,
+ XPCNativeInterface* aInterface,
+ bool needJSObject) {
+ // Determine if the object really does this interface...
+
+ const nsIID* iid = aInterface->GetIID();
+ nsISupports* identity = GetIdentityObject();
+
+ // This is an nsRefPtr instead of an nsCOMPtr because it may not be the
+ // canonical nsISupports for this object.
+ RefPtr<nsISupports> qiResult;
+
+ // We are about to call out to other code.
+ // So protect our intended tearoff.
+
+ aTearOff->SetReserved();
+
+ if (NS_FAILED(identity->QueryInterface(*iid, getter_AddRefs(qiResult))) ||
+ !qiResult) {
+ aTearOff->SetInterface(nullptr);
+ return NS_ERROR_NO_INTERFACE;
+ }
+
+ // Guard against trying to build a tearoff for a shared nsIClassInfo.
+ if (iid->Equals(NS_GET_IID(nsIClassInfo))) {
+ nsCOMPtr<nsISupports> alternate_identity(do_QueryInterface(qiResult));
+ if (alternate_identity.get() != identity) {
+ aTearOff->SetInterface(nullptr);
+ return NS_ERROR_NO_INTERFACE;
+ }
+ }
+
+ // Guard against trying to build a tearoff for an interface that is
+ // aggregated and is implemented as a nsIXPConnectWrappedJS using this
+ // self-same JSObject. The XBL system does this. If we mutate the set
+ // of this wrapper then we will shadow the method that XBL has added to
+ // the JSObject that it has inserted in the JS proto chain between our
+ // JSObject and our XPCWrappedNativeProto's JSObject. If we let this
+ // set mutation happen then the interface's methods will be added to
+ // our JSObject, but calls on those methods will get routed up to
+ // native code and into the wrappedJS - which will do a method lookup
+ // on *our* JSObject and find the same method and make another call
+ // into an infinite loop.
+ // see: http://bugzilla.mozilla.org/show_bug.cgi?id=96725
+
+ nsCOMPtr<nsIXPConnectWrappedJS> wrappedJS(do_QueryInterface(qiResult));
+ if (wrappedJS) {
+ RootedObject jso(cx, wrappedJS->GetJSObject());
+ if (jso == mFlatJSObject) {
+ // The implementing JSObject is the same as ours! Just say OK
+ // without actually extending the set.
+ //
+ // XXX It is a little cheesy to have FindTearOff return an
+ // 'empty' tearoff. But this is the centralized place to do the
+ // QI activities on the underlying object. *And* most caller to
+ // FindTearOff only look for a non-null result and ignore the
+ // actual tearoff returned. The only callers that do use the
+ // returned tearoff make sure to check for either a non-null
+ // JSObject or a matching Interface before proceeding.
+ // I think we can get away with this bit of ugliness.
+
+ aTearOff->SetInterface(nullptr);
+ return NS_OK;
+ }
+ }
+
+ if (NS_FAILED(nsXPConnect::SecurityManager()->CanCreateWrapper(
+ cx, *iid, identity, GetClassInfo()))) {
+ // the security manager vetoed. It should have set an exception.
+ aTearOff->SetInterface(nullptr);
+ return NS_ERROR_XPC_SECURITY_MANAGER_VETO;
+ }
+
+ // If this is not already in our set we need to extend our set.
+ // Note: we do not cache the result of the previous call to HasInterface()
+ // because we unlocked and called out in the interim and the result of the
+ // previous call might not be correct anymore.
+
+ if (!mSet->HasInterface(aInterface) && !ExtendSet(cx, aInterface)) {
+ aTearOff->SetInterface(nullptr);
+ return NS_ERROR_NO_INTERFACE;
+ }
+
+ aTearOff->SetInterface(aInterface);
+ aTearOff->SetNative(qiResult);
+
+ if (needJSObject && !InitTearOffJSObject(cx, aTearOff)) {
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+
+ return NS_OK;
+}
+
+bool XPCWrappedNative::InitTearOffJSObject(JSContext* cx,
+ XPCWrappedNativeTearOff* to) {
+ JSObject* obj = JS_NewObject(cx, &XPC_WN_Tearoff_JSClass);
+ if (!obj) {
+ return false;
+ }
+
+ JS::SetReservedSlot(obj, XPCWrappedNativeTearOff::TearOffSlot,
+ JS::PrivateValue(to));
+ to->SetJSObject(obj);
+
+ JS::SetReservedSlot(obj, XPCWrappedNativeTearOff::FlatObjectSlot,
+ JS::ObjectValue(*mFlatJSObject));
+ return true;
+}
+
+/***************************************************************************/
+
+static bool Throw(nsresult errNum, XPCCallContext& ccx) {
+ XPCThrower::Throw(errNum, ccx);
+ return false;
+}
+
+/***************************************************************************/
+
+class MOZ_STACK_CLASS CallMethodHelper final {
+ XPCCallContext& mCallContext;
+ nsresult mInvokeResult;
+ const nsXPTInterfaceInfo* const mIFaceInfo;
+ const nsXPTMethodInfo* mMethodInfo;
+ nsISupports* const mCallee;
+ const uint16_t mVTableIndex;
+ HandleId mIdxValueId;
+
+ AutoTArray<nsXPTCVariant, 8> mDispatchParams;
+ uint8_t mJSContextIndex; // TODO make const
+ uint8_t mOptArgcIndex; // TODO make const
+
+ Value* const mArgv;
+ const uint32_t mArgc;
+
+ MOZ_ALWAYS_INLINE bool GetArraySizeFromParam(const nsXPTType& type,
+ HandleValue maybeArray,
+ uint32_t* result);
+
+ MOZ_ALWAYS_INLINE bool GetInterfaceTypeFromParam(const nsXPTType& type,
+ nsID* result) const;
+
+ MOZ_ALWAYS_INLINE bool GetOutParamSource(uint8_t paramIndex,
+ MutableHandleValue srcp) const;
+
+ MOZ_ALWAYS_INLINE bool GatherAndConvertResults();
+
+ MOZ_ALWAYS_INLINE bool QueryInterfaceFastPath();
+
+ nsXPTCVariant* GetDispatchParam(uint8_t paramIndex) {
+ if (paramIndex >= mJSContextIndex) {
+ paramIndex += 1;
+ }
+ if (paramIndex >= mOptArgcIndex) {
+ paramIndex += 1;
+ }
+ return &mDispatchParams[paramIndex];
+ }
+ const nsXPTCVariant* GetDispatchParam(uint8_t paramIndex) const {
+ return const_cast<CallMethodHelper*>(this)->GetDispatchParam(paramIndex);
+ }
+
+ MOZ_ALWAYS_INLINE bool InitializeDispatchParams();
+
+ MOZ_ALWAYS_INLINE bool ConvertIndependentParams(bool* foundDependentParam);
+ MOZ_ALWAYS_INLINE bool ConvertIndependentParam(uint8_t i);
+ MOZ_ALWAYS_INLINE bool ConvertDependentParams();
+ MOZ_ALWAYS_INLINE bool ConvertDependentParam(uint8_t i);
+
+ MOZ_ALWAYS_INLINE nsresult Invoke();
+
+ public:
+ explicit CallMethodHelper(XPCCallContext& ccx)
+ : mCallContext(ccx),
+ mInvokeResult(NS_ERROR_UNEXPECTED),
+ mIFaceInfo(ccx.GetInterface()->GetInterfaceInfo()),
+ mMethodInfo(nullptr),
+ mCallee(ccx.GetTearOff()->GetNative()),
+ mVTableIndex(ccx.GetMethodIndex()),
+ mIdxValueId(ccx.GetContext()->GetStringID(XPCJSContext::IDX_VALUE)),
+ mJSContextIndex(UINT8_MAX),
+ mOptArgcIndex(UINT8_MAX),
+ mArgv(ccx.GetArgv()),
+ mArgc(ccx.GetArgc())
+
+ {
+ // Success checked later.
+ mIFaceInfo->GetMethodInfo(mVTableIndex, &mMethodInfo);
+ }
+
+ ~CallMethodHelper();
+
+ MOZ_ALWAYS_INLINE bool Call();
+
+ // Trace implementation so we can put our CallMethodHelper in a Rooted<T>.
+ void trace(JSTracer* aTrc);
+};
+
+// static
+bool XPCWrappedNative::CallMethod(XPCCallContext& ccx,
+ CallMode mode /*= CALL_METHOD */) {
+ nsresult rv = ccx.CanCallNow();
+ if (NS_FAILED(rv)) {
+ return Throw(rv, ccx);
+ }
+
+ JS::Rooted<CallMethodHelper> helper(ccx, /* init = */ ccx);
+ return helper.get().Call();
+}
+
+bool CallMethodHelper::Call() {
+ mCallContext.SetRetVal(JS::UndefinedValue());
+
+ mCallContext.GetContext()->SetPendingException(nullptr);
+
+ using Flags = js::ProfilingStackFrame::Flags;
+ if (mVTableIndex == 0) {
+ AUTO_PROFILER_LABEL_DYNAMIC_FAST(mIFaceInfo->Name(), "QueryInterface", DOM,
+ mCallContext.GetJSContext(),
+ uint32_t(Flags::STRING_TEMPLATE_METHOD) |
+ uint32_t(Flags::RELEVANT_FOR_JS));
+
+ return QueryInterfaceFastPath();
+ }
+
+ if (!mMethodInfo) {
+ Throw(NS_ERROR_XPC_CANT_GET_METHOD_INFO, mCallContext);
+ return false;
+ }
+
+ // Add profiler labels matching the WebIDL profiler labels,
+ // which also use the DOM category.
+ Flags templateFlag = Flags::STRING_TEMPLATE_METHOD;
+ if (mMethodInfo->IsGetter()) {
+ templateFlag = Flags::STRING_TEMPLATE_GETTER;
+ }
+ if (mMethodInfo->IsSetter()) {
+ templateFlag = Flags::STRING_TEMPLATE_SETTER;
+ }
+ AUTO_PROFILER_LABEL_DYNAMIC_FAST(
+ mIFaceInfo->Name(), mMethodInfo->NameOrDescription(), DOM,
+ mCallContext.GetJSContext(),
+ uint32_t(templateFlag) | uint32_t(Flags::RELEVANT_FOR_JS));
+
+ if (!InitializeDispatchParams()) {
+ return false;
+ }
+
+ // Iterate through the params doing conversions of independent params only.
+ // When we later convert the dependent params (if any) we will know that
+ // the params upon which they depend will have already been converted -
+ // regardless of ordering.
+ bool foundDependentParam = false;
+ if (!ConvertIndependentParams(&foundDependentParam)) {
+ return false;
+ }
+
+ if (foundDependentParam && !ConvertDependentParams()) {
+ return false;
+ }
+
+ mInvokeResult = Invoke();
+
+ if (JS_IsExceptionPending(mCallContext)) {
+ return false;
+ }
+
+ if (NS_FAILED(mInvokeResult)) {
+ ThrowBadResult(mInvokeResult, mCallContext);
+ return false;
+ }
+
+ return GatherAndConvertResults();
+}
+
+CallMethodHelper::~CallMethodHelper() {
+ for (nsXPTCVariant& param : mDispatchParams) {
+ uint32_t arraylen = 0;
+ if (!GetArraySizeFromParam(param.type, UndefinedHandleValue, &arraylen)) {
+ continue;
+ }
+
+ xpc::DestructValue(param.type, &param.val, arraylen);
+ }
+}
+
+bool CallMethodHelper::GetArraySizeFromParam(const nsXPTType& type,
+ HandleValue maybeArray,
+ uint32_t* result) {
+ if (type.Tag() != nsXPTType::T_LEGACY_ARRAY &&
+ type.Tag() != nsXPTType::T_PSTRING_SIZE_IS &&
+ type.Tag() != nsXPTType::T_PWSTRING_SIZE_IS) {
+ *result = 0;
+ return true;
+ }
+
+ uint8_t argnum = type.ArgNum();
+ uint32_t* lengthp = &GetDispatchParam(argnum)->val.u32;
+
+ // TODO fixup the various exceptions that are thrown
+
+ // If the array length wasn't passed, it might have been listed as optional.
+ // When converting arguments from JS to C++, we pass the array as
+ // |maybeArray|, and give ourselves the chance to infer the length. Once we
+ // have it, we stick it in the right slot so that we can find it again when
+ // cleaning up the params. from the array.
+ if (argnum >= mArgc && maybeArray.isObject()) {
+ MOZ_ASSERT(mMethodInfo->Param(argnum).IsOptional());
+ RootedObject arrayOrNull(mCallContext, &maybeArray.toObject());
+
+ bool isArray;
+ bool ok = false;
+ if (JS::IsArrayObject(mCallContext, maybeArray, &isArray) && isArray) {
+ ok = JS::GetArrayLength(mCallContext, arrayOrNull, lengthp);
+ } else if (JS_IsTypedArrayObject(&maybeArray.toObject())) {
+ size_t len = JS_GetTypedArrayLength(&maybeArray.toObject());
+ if (len <= UINT32_MAX) {
+ *lengthp = len;
+ ok = true;
+ }
+ }
+
+ if (!ok) {
+ return Throw(NS_ERROR_XPC_CANT_CONVERT_OBJECT_TO_ARRAY, mCallContext);
+ }
+ }
+
+ *result = *lengthp;
+ return true;
+}
+
+bool CallMethodHelper::GetInterfaceTypeFromParam(const nsXPTType& type,
+ nsID* result) const {
+ result->Clear();
+
+ const nsXPTType& inner = type.InnermostType();
+ if (inner.Tag() == nsXPTType::T_INTERFACE) {
+ if (!inner.GetInterface()) {
+ return Throw(NS_ERROR_XPC_CANT_GET_PARAM_IFACE_INFO, mCallContext);
+ }
+
+ *result = inner.GetInterface()->IID();
+ } else if (inner.Tag() == nsXPTType::T_INTERFACE_IS) {
+ const nsXPTCVariant* param = GetDispatchParam(inner.ArgNum());
+ if (param->type.Tag() != nsXPTType::T_NSID &&
+ param->type.Tag() != nsXPTType::T_NSIDPTR) {
+ return Throw(NS_ERROR_UNEXPECTED, mCallContext);
+ }
+
+ const void* ptr = &param->val;
+ if (param->type.Tag() == nsXPTType::T_NSIDPTR) {
+ ptr = *static_cast<nsID* const*>(ptr);
+ }
+
+ if (!ptr) {
+ return ThrowBadParam(NS_ERROR_XPC_CANT_GET_PARAM_IFACE_INFO,
+ inner.ArgNum(), mCallContext);
+ }
+
+ *result = *static_cast<const nsID*>(ptr);
+ }
+ return true;
+}
+
+bool CallMethodHelper::GetOutParamSource(uint8_t paramIndex,
+ MutableHandleValue srcp) const {
+ const nsXPTParamInfo& paramInfo = mMethodInfo->GetParam(paramIndex);
+ bool isRetval = &paramInfo == mMethodInfo->GetRetval();
+
+ if (paramInfo.IsOut() && !isRetval) {
+ MOZ_ASSERT(paramIndex < mArgc || paramInfo.IsOptional(),
+ "Expected either enough arguments or an optional argument");
+ Value arg = paramIndex < mArgc ? mArgv[paramIndex] : JS::NullValue();
+ if (paramIndex < mArgc) {
+ RootedObject obj(mCallContext);
+ if (!arg.isPrimitive()) {
+ obj = &arg.toObject();
+ }
+ if (!obj || !JS_GetPropertyById(mCallContext, obj, mIdxValueId, srcp)) {
+ // Explicitly passed in unusable value for out param. Note
+ // that if i >= mArgc we already know that |arg| is JS::NullValue(),
+ // and that's ok.
+ ThrowBadParam(NS_ERROR_XPC_NEED_OUT_OBJECT, paramIndex, mCallContext);
+ return false;
+ }
+ }
+ }
+
+ return true;
+}
+
+bool CallMethodHelper::GatherAndConvertResults() {
+ // now we iterate through the native params to gather and convert results
+ uint8_t paramCount = mMethodInfo->GetParamCount();
+ for (uint8_t i = 0; i < paramCount; i++) {
+ const nsXPTParamInfo& paramInfo = mMethodInfo->GetParam(i);
+ if (!paramInfo.IsOut()) {
+ continue;
+ }
+
+ const nsXPTType& type = paramInfo.GetType();
+ nsXPTCVariant* dp = GetDispatchParam(i);
+ RootedValue v(mCallContext, NullValue());
+
+ uint32_t array_count = 0;
+ nsID param_iid;
+ if (!GetInterfaceTypeFromParam(type, &param_iid) ||
+ !GetArraySizeFromParam(type, UndefinedHandleValue, &array_count))
+ return false;
+
+ nsresult err;
+ if (!XPCConvert::NativeData2JS(mCallContext, &v, &dp->val, type, &param_iid,
+ array_count, &err)) {
+ ThrowBadParam(err, i, mCallContext);
+ return false;
+ }
+
+ if (&paramInfo == mMethodInfo->GetRetval()) {
+ mCallContext.SetRetVal(v);
+ } else if (i < mArgc) {
+ // we actually assured this before doing the invoke
+ MOZ_ASSERT(mArgv[i].isObject(), "out var is not object");
+ RootedObject obj(mCallContext, &mArgv[i].toObject());
+ if (!JS_SetPropertyById(mCallContext, obj, mIdxValueId, v)) {
+ ThrowBadParam(NS_ERROR_XPC_CANT_SET_OUT_VAL, i, mCallContext);
+ return false;
+ }
+ } else {
+ MOZ_ASSERT(paramInfo.IsOptional(),
+ "Expected either enough arguments or an optional argument");
+ }
+ }
+
+ return true;
+}
+
+bool CallMethodHelper::QueryInterfaceFastPath() {
+ MOZ_ASSERT(mVTableIndex == 0,
+ "Using the QI fast-path for a method other than QueryInterface");
+
+ if (mArgc < 1) {
+ Throw(NS_ERROR_XPC_NOT_ENOUGH_ARGS, mCallContext);
+ return false;
+ }
+
+ if (!mArgv[0].isObject()) {
+ ThrowBadParam(NS_ERROR_XPC_BAD_CONVERT_JS, 0, mCallContext);
+ return false;
+ }
+
+ JS::RootedValue iidarg(mCallContext, mArgv[0]);
+ Maybe<nsID> iid = xpc::JSValue2ID(mCallContext, iidarg);
+ if (!iid) {
+ ThrowBadParam(NS_ERROR_XPC_BAD_CONVERT_JS, 0, mCallContext);
+ return false;
+ }
+
+ nsISupports* qiresult = nullptr;
+ mInvokeResult = mCallee->QueryInterface(iid.ref(), (void**)&qiresult);
+
+ if (NS_FAILED(mInvokeResult)) {
+ ThrowBadResult(mInvokeResult, mCallContext);
+ return false;
+ }
+
+ RootedValue v(mCallContext, NullValue());
+ nsresult err;
+ bool success = XPCConvert::NativeData2JS(mCallContext, &v, &qiresult,
+ {nsXPTType::T_INTERFACE_IS},
+ iid.ptr(), 0, &err);
+ NS_IF_RELEASE(qiresult);
+
+ if (!success) {
+ ThrowBadParam(err, 0, mCallContext);
+ return false;
+ }
+
+ mCallContext.SetRetVal(v);
+ return true;
+}
+
+bool CallMethodHelper::InitializeDispatchParams() {
+ const uint8_t wantsOptArgc = mMethodInfo->WantsOptArgc() ? 1 : 0;
+ const uint8_t wantsJSContext = mMethodInfo->WantsContext() ? 1 : 0;
+ const uint8_t paramCount = mMethodInfo->GetParamCount();
+ uint8_t requiredArgs = paramCount;
+
+ // XXX ASSUMES that retval is last arg. The xpidl compiler ensures this.
+ if (mMethodInfo->HasRetval()) {
+ requiredArgs--;
+ }
+
+ if (mArgc < requiredArgs || wantsOptArgc) {
+ if (wantsOptArgc) {
+ // The implicit JSContext*, if we have one, comes first.
+ mOptArgcIndex = requiredArgs + wantsJSContext;
+ }
+
+ // skip over any optional arguments
+ while (requiredArgs &&
+ mMethodInfo->GetParam(requiredArgs - 1).IsOptional()) {
+ requiredArgs--;
+ }
+
+ if (mArgc < requiredArgs) {
+ Throw(NS_ERROR_XPC_NOT_ENOUGH_ARGS, mCallContext);
+ return false;
+ }
+ }
+
+ mJSContextIndex = mMethodInfo->IndexOfJSContext();
+
+ // Allocate enough space in mDispatchParams up-front.
+ // XXX(Bug 1631371) Check if this should use a fallible operation as it
+ // pretended earlier.
+ mDispatchParams.AppendElements(paramCount + wantsJSContext + wantsOptArgc);
+
+ // Initialize each parameter to a valid state (for safe cleanup later).
+ for (uint8_t i = 0, paramIdx = 0; i < mDispatchParams.Length(); i++) {
+ nsXPTCVariant& dp = mDispatchParams[i];
+
+ if (i == mJSContextIndex) {
+ // Fill in the JSContext argument
+ dp.type = nsXPTType::T_VOID;
+ dp.val.p = mCallContext;
+ } else if (i == mOptArgcIndex) {
+ // Fill in the optional_argc argument
+ dp.type = nsXPTType::T_U8;
+ dp.val.u8 = std::min<uint32_t>(mArgc, paramCount) - requiredArgs;
+ } else {
+ // Initialize normal arguments.
+ const nsXPTParamInfo& param = mMethodInfo->Param(paramIdx);
+ dp.type = param.Type();
+ xpc::InitializeValue(dp.type, &dp.val);
+
+ // Specify the correct storage/calling semantics. This will also set
+ // the `ptr` field to be self-referential.
+ if (param.IsIndirect()) {
+ dp.SetIndirect();
+ }
+
+ // Advance to the next normal parameter.
+ paramIdx++;
+ }
+ }
+
+ return true;
+}
+
+bool CallMethodHelper::ConvertIndependentParams(bool* foundDependentParam) {
+ const uint8_t paramCount = mMethodInfo->GetParamCount();
+ for (uint8_t i = 0; i < paramCount; i++) {
+ const nsXPTParamInfo& paramInfo = mMethodInfo->GetParam(i);
+
+ if (paramInfo.GetType().IsDependent()) {
+ *foundDependentParam = true;
+ } else if (!ConvertIndependentParam(i)) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+bool CallMethodHelper::ConvertIndependentParam(uint8_t i) {
+ const nsXPTParamInfo& paramInfo = mMethodInfo->GetParam(i);
+ const nsXPTType& type = paramInfo.Type();
+ nsXPTCVariant* dp = GetDispatchParam(i);
+
+ // Even if there's nothing to convert, we still need to examine the
+ // JSObject container for out-params. If it's null or otherwise invalid,
+ // we want to know before the call, rather than after.
+ //
+ // This is a no-op for 'in' params.
+ RootedValue src(mCallContext);
+ if (!GetOutParamSource(i, &src)) {
+ return false;
+ }
+
+ // All that's left to do is value conversion. Bail early if we don't need
+ // to do that.
+ if (!paramInfo.IsIn()) {
+ return true;
+ }
+
+ // Some types usually don't support default values, but we want to handle
+ // the default value if IsOptional is true.
+ if (i >= mArgc) {
+ MOZ_ASSERT(paramInfo.IsOptional(), "missing non-optional argument!");
+ if (type.Tag() == nsXPTType::T_NSID) {
+ // Use a default value of the null ID for optional NSID objects.
+ dp->ext.nsid.Clear();
+ return true;
+ }
+
+ if (type.Tag() == nsXPTType::T_ARRAY) {
+ // Use a default value of empty array for optional Array objects.
+ dp->ext.array.Clear();
+ return true;
+ }
+ }
+
+ // We're definitely some variety of 'in' now, so there's something to
+ // convert. The source value for conversion depends on whether we're
+ // dealing with an 'in' or an 'inout' parameter. 'inout' was handled above,
+ // so all that's left is 'in'.
+ if (!paramInfo.IsOut()) {
+ // Handle the 'in' case.
+ MOZ_ASSERT(i < mArgc || paramInfo.IsOptional(),
+ "Expected either enough arguments or an optional argument");
+ if (i < mArgc) {
+ src = mArgv[i];
+ } else if (type.Tag() == nsXPTType::T_JSVAL) {
+ src.setUndefined();
+ } else {
+ src.setNull();
+ }
+ }
+
+ nsID param_iid = {0};
+ const nsXPTType& inner = type.InnermostType();
+ if (inner.Tag() == nsXPTType::T_INTERFACE) {
+ if (!inner.GetInterface()) {
+ return ThrowBadParam(NS_ERROR_XPC_CANT_GET_PARAM_IFACE_INFO, i,
+ mCallContext);
+ }
+ param_iid = inner.GetInterface()->IID();
+ }
+
+ nsresult err;
+ if (!XPCConvert::JSData2Native(mCallContext, &dp->val, src, type, &param_iid,
+ 0, &err)) {
+ ThrowBadParam(err, i, mCallContext);
+ return false;
+ }
+
+ return true;
+}
+
+bool CallMethodHelper::ConvertDependentParams() {
+ const uint8_t paramCount = mMethodInfo->GetParamCount();
+ for (uint8_t i = 0; i < paramCount; i++) {
+ const nsXPTParamInfo& paramInfo = mMethodInfo->GetParam(i);
+
+ if (!paramInfo.GetType().IsDependent()) {
+ continue;
+ }
+ if (!ConvertDependentParam(i)) {
+ return false;
+ }
+ }
+
+ return true;
+}
+
+bool CallMethodHelper::ConvertDependentParam(uint8_t i) {
+ const nsXPTParamInfo& paramInfo = mMethodInfo->GetParam(i);
+ const nsXPTType& type = paramInfo.Type();
+ nsXPTCVariant* dp = GetDispatchParam(i);
+
+ // Even if there's nothing to convert, we still need to examine the
+ // JSObject container for out-params. If it's null or otherwise invalid,
+ // we want to know before the call, rather than after.
+ //
+ // This is a no-op for 'in' params.
+ RootedValue src(mCallContext);
+ if (!GetOutParamSource(i, &src)) {
+ return false;
+ }
+
+ // All that's left to do is value conversion. Bail early if we don't need
+ // to do that.
+ if (!paramInfo.IsIn()) {
+ return true;
+ }
+
+ // We're definitely some variety of 'in' now, so there's something to
+ // convert. The source value for conversion depends on whether we're
+ // dealing with an 'in' or an 'inout' parameter. 'inout' was handled above,
+ // so all that's left is 'in'.
+ if (!paramInfo.IsOut()) {
+ // Handle the 'in' case.
+ MOZ_ASSERT(i < mArgc || paramInfo.IsOptional(),
+ "Expected either enough arguments or an optional argument");
+ src = i < mArgc ? mArgv[i] : JS::NullValue();
+ }
+
+ nsID param_iid;
+ uint32_t array_count;
+ if (!GetInterfaceTypeFromParam(type, &param_iid) ||
+ !GetArraySizeFromParam(type, src, &array_count))
+ return false;
+
+ nsresult err;
+
+ if (!XPCConvert::JSData2Native(mCallContext, &dp->val, src, type, &param_iid,
+ array_count, &err)) {
+ ThrowBadParam(err, i, mCallContext);
+ return false;
+ }
+
+ return true;
+}
+
+nsresult CallMethodHelper::Invoke() {
+ uint32_t argc = mDispatchParams.Length();
+ nsXPTCVariant* argv = mDispatchParams.Elements();
+
+ return NS_InvokeByIndex(mCallee, mVTableIndex, argc, argv);
+}
+
+static void TraceParam(JSTracer* aTrc, void* aVal, const nsXPTType& aType,
+ uint32_t aArrayLen = 0) {
+ if (aType.Tag() == nsXPTType::T_JSVAL) {
+ JS::TraceRoot(aTrc, (JS::Value*)aVal, "XPCWrappedNative::CallMethod param");
+ } else if (aType.Tag() == nsXPTType::T_ARRAY) {
+ auto* array = (xpt::detail::UntypedTArray*)aVal;
+ const nsXPTType& elty = aType.ArrayElementType();
+
+ for (uint32_t i = 0; i < array->Length(); ++i) {
+ TraceParam(aTrc, elty.ElementPtr(array->Elements(), i), elty);
+ }
+ } else if (aType.Tag() == nsXPTType::T_LEGACY_ARRAY && *(void**)aVal) {
+ const nsXPTType& elty = aType.ArrayElementType();
+
+ for (uint32_t i = 0; i < aArrayLen; ++i) {
+ TraceParam(aTrc, elty.ElementPtr(*(void**)aVal, i), elty);
+ }
+ }
+}
+
+void CallMethodHelper::trace(JSTracer* aTrc) {
+ // We need to note each of our initialized parameters which contain jsvals.
+ for (nsXPTCVariant& param : mDispatchParams) {
+ // We only need to trace parameters which have an innermost JSVAL.
+ if (param.type.InnermostType().Tag() != nsXPTType::T_JSVAL) {
+ continue;
+ }
+
+ uint32_t arrayLen = 0;
+ if (!GetArraySizeFromParam(param.type, UndefinedHandleValue, &arrayLen)) {
+ continue;
+ }
+
+ TraceParam(aTrc, &param.val, param.type, arrayLen);
+ }
+}
+
+/***************************************************************************/
+// interface methods
+
+JSObject* XPCWrappedNative::GetJSObject() { return GetFlatJSObject(); }
+
+XPCWrappedNative* nsIXPConnectWrappedNative::AsXPCWrappedNative() {
+ return static_cast<XPCWrappedNative*>(this);
+}
+
+nsresult nsIXPConnectWrappedNative::DebugDump(int16_t depth) {
+ return AsXPCWrappedNative()->DebugDump(depth);
+}
+
+nsresult XPCWrappedNative::DebugDump(int16_t depth) {
+#ifdef DEBUG
+ depth--;
+ XPC_LOG_ALWAYS(
+ ("XPCWrappedNative @ %p with mRefCnt = %" PRIuPTR, this, mRefCnt.get()));
+ XPC_LOG_INDENT();
+
+ if (HasProto()) {
+ XPCWrappedNativeProto* proto = GetProto();
+ if (depth && proto) {
+ proto->DebugDump(depth);
+ } else {
+ XPC_LOG_ALWAYS(("mMaybeProto @ %p", proto));
+ }
+ } else
+ XPC_LOG_ALWAYS(("Scope @ %p", GetScope()));
+
+ if (depth && mSet) {
+ mSet->DebugDump(depth);
+ } else {
+ XPC_LOG_ALWAYS(("mSet @ %p", mSet.get()));
+ }
+
+ XPC_LOG_ALWAYS(("mFlatJSObject of %p", mFlatJSObject.unbarrieredGetPtr()));
+ XPC_LOG_ALWAYS(("mIdentity of %p", mIdentity.get()));
+ XPC_LOG_ALWAYS(("mScriptable @ %p", mScriptable.get()));
+
+ if (depth && mScriptable) {
+ XPC_LOG_INDENT();
+ XPC_LOG_ALWAYS(("mFlags of %x", mScriptable->GetScriptableFlags()));
+ XPC_LOG_ALWAYS(("mJSClass @ %p", mScriptable->GetJSClass()));
+ XPC_LOG_OUTDENT();
+ }
+ XPC_LOG_OUTDENT();
+#endif
+ return NS_OK;
+}
+
+/***************************************************************************/
+
+char* XPCWrappedNative::ToString(
+ XPCWrappedNativeTearOff* to /* = nullptr */) const {
+#ifdef DEBUG
+# define FMT_ADDR " @ 0x%p"
+# define FMT_STR(str) str
+# define PARAM_ADDR(w) , w
+#else
+# define FMT_ADDR ""
+# define FMT_STR(str)
+# define PARAM_ADDR(w)
+#endif
+
+ UniqueChars sz;
+ UniqueChars name;
+
+ nsCOMPtr<nsIXPCScriptable> scr = GetScriptable();
+ if (scr) {
+ name = JS_smprintf("%s", scr->GetJSClass()->name);
+ }
+ if (to) {
+ const char* fmt = name ? " (%s)" : "%s";
+ name = JS_sprintf_append(std::move(name), fmt,
+ to->GetInterface()->GetNameString());
+ } else if (!name) {
+ XPCNativeSet* set = GetSet();
+ XPCNativeInterface** array = set->GetInterfaceArray();
+ uint16_t count = set->GetInterfaceCount();
+ MOZ_RELEASE_ASSERT(count >= 1, "Expected at least one interface");
+ MOZ_ASSERT(*array[0]->GetIID() == NS_GET_IID(nsISupports),
+ "The first interface must be nsISupports");
+
+ // The first interface is always nsISupports, so don't print it, unless
+ // there are no others.
+ if (count == 1) {
+ name = JS_sprintf_append(std::move(name), "nsISupports");
+ } else if (count == 2) {
+ name =
+ JS_sprintf_append(std::move(name), "%s", array[1]->GetNameString());
+ } else {
+ for (uint16_t i = 1; i < count; i++) {
+ const char* fmt = (i == 1) ? "(%s"
+ : (i == count - 1) ? ", %s)"
+ : ", %s";
+ name =
+ JS_sprintf_append(std::move(name), fmt, array[i]->GetNameString());
+ }
+ }
+ }
+
+ if (!name) {
+ return nullptr;
+ }
+ const char* fmt = "[xpconnect wrapped %s" FMT_ADDR FMT_STR(" (native")
+ FMT_ADDR FMT_STR(")") "]";
+ if (scr) {
+ fmt = "[object %s" FMT_ADDR FMT_STR(" (native") FMT_ADDR FMT_STR(")") "]";
+ }
+ sz =
+ JS_smprintf(fmt, name.get() PARAM_ADDR(this) PARAM_ADDR(mIdentity.get()));
+
+ return sz.release();
+
+#undef FMT_ADDR
+#undef PARAM_ADDR
+}
+
+/***************************************************************************/
+
+#ifdef XPC_CHECK_CLASSINFO_CLAIMS
+static void DEBUG_CheckClassInfoClaims(XPCWrappedNative* wrapper) {
+ if (!wrapper || !wrapper->GetClassInfo()) {
+ return;
+ }
+
+ nsISupports* obj = wrapper->GetIdentityObject();
+ XPCNativeSet* set = wrapper->GetSet();
+ uint16_t count = set->GetInterfaceCount();
+ for (uint16_t i = 0; i < count; i++) {
+ nsIClassInfo* clsInfo = wrapper->GetClassInfo();
+ XPCNativeInterface* iface = set->GetInterfaceAt(i);
+ const nsXPTInterfaceInfo* info = iface->GetInterfaceInfo();
+ nsISupports* ptr;
+
+ nsresult rv = obj->QueryInterface(info->IID(), (void**)&ptr);
+ if (NS_SUCCEEDED(rv)) {
+ NS_RELEASE(ptr);
+ continue;
+ }
+ if (rv == NS_ERROR_OUT_OF_MEMORY) {
+ continue;
+ }
+
+ // Houston, We have a problem...
+
+ char* className = nullptr;
+ char* contractID = nullptr;
+ const char* interfaceName = info->Name();
+
+ clsInfo->GetContractID(&contractID);
+ if (wrapper->GetScriptable()) {
+ wrapper->GetScriptable()->GetClassName(&className);
+ }
+
+ printf(
+ "\n!!! Object's nsIClassInfo lies about its interfaces!!!\n"
+ " classname: %s \n"
+ " contractid: %s \n"
+ " unimplemented interface name: %s\n\n",
+ className ? className : "<unknown>",
+ contractID ? contractID : "<unknown>", interfaceName);
+
+ if (className) {
+ free(className);
+ }
+ if (contractID) {
+ free(contractID);
+ }
+ }
+}
+#endif