Mypal/js/xpconnect/src/XPCWrappedNative.cpp
2021-02-04 16:48:36 +02:00

2328 lines
81 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* 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 "mozilla/jsipc/CrossProcessObjectWrappers.h"
#include "nsWrapperCacheInlines.h"
#include "XPCLog.h"
#include "jsprf.h"
#include "jsfriendapi.h"
#include "AccessCheck.h"
#include "WrapperFactory.h"
#include "XrayWrapper.h"
#include "nsContentUtils.h"
#include "nsCycleCollectionNoteRootCallback.h"
#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 <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];
XPCNativeScriptableInfo* si = tmp->GetScriptableInfo();
if (si)
SprintfLiteral(name, "XPCWrappedNative (%s)", si->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(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(xpcObjectHelper& nativeHelper,
nsIPrincipal* principal,
bool initStandardClasses,
JS::CompartmentOptions& aOptions,
XPCWrappedNative** wrappedGlobal)
{
AutoJSContext cx;
nsISupports* identity = nativeHelper.GetCanonical();
// The object should specify that it's meant to be global.
MOZ_ASSERT(nativeHelper.GetScriptableFlags() & nsIXPCScriptable::IS_GLOBAL_OBJECT);
// We shouldn't be reusing globals.
MOZ_ASSERT(!nativeHelper.GetWrapperCache() ||
!nativeHelper.GetWrapperCache()->GetWrapperPreserveColor());
// Put together the ScriptableCreateInfo...
XPCNativeScriptableCreateInfo sciProto;
XPCNativeScriptableCreateInfo sciMaybe;
const XPCNativeScriptableCreateInfo& sciWrapper =
GatherScriptableCreateInfo(identity, nativeHelper.GetClassInfo(),
sciProto, sciMaybe);
// ...and then ScriptableInfo. We need all this stuff now because it's going
// to tell us the JSClass of the object we're going to create.
XPCNativeScriptableInfo* si = XPCNativeScriptableInfo::Construct(&sciWrapper);
MOZ_ASSERT(si);
// Finally, we get to the JSClass.
const JSClass* clasp = si->GetJSClass();
MOZ_ASSERT(clasp->flags & JSCLASS_IS_GLOBAL);
// Create the global.
aOptions.creationOptions().setTrace(XPCWrappedNative::Trace);
if (xpc::SharedMemoryEnabled())
aOptions.creationOptions().setSharedMemoryAndAtomicsEnabled(true);
RootedObject global(cx, xpc::CreateGlobalObject(cx, clasp, principal, aOptions));
if (!global)
return NS_ERROR_FAILURE;
XPCWrappedNativeScope* scope = CompartmentPrivate::Get(global)->scope;
// Immediately enter the global's compartment, so that everything else we
// create ends up there.
JSAutoCompartment ac(cx, global);
// If requested, initialize the standard classes on the global.
if (initStandardClasses && ! JS_InitStandardClasses(cx, global))
return NS_ERROR_FAILURE;
// Make a proto.
XPCWrappedNativeProto* proto =
XPCWrappedNativeProto::GetNewOrUsed(scope,
nativeHelper.GetClassInfo(), &sciProto,
/* callPostCreatePrototype = */ false);
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_SplicePrototype(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(nativeHelper.forgetCanonical(), proto);
//
// We don't call ::Init() on this wrapper, because our setup requirements
// are different for globals. We do our setup inline here, instead.
//
// Share mScriptableInfo with the proto.
//
// This is probably more trouble than it's worth, since we've already
// created an XPCNativeScriptableInfo for ourselves. Nevertheless, this is
// what ::Init() does, and we want to be as consistent as possible with
// that code.
XPCNativeScriptableInfo* siProto = proto->GetScriptableInfo();
if (siProto && siProto->GetCallback() == sciWrapper.GetCallback()) {
wrapper->mScriptableInfo = siProto;
// XPCNativeScriptableInfo uses manual memory management. If we're
// switching over to that of the proto, we need to destroy the one
// we've allocated.
delete si;
si = nullptr;
} else {
wrapper->mScriptableInfo = si;
}
// Set the JS object to the global we already created.
wrapper->mFlatJSObject = global;
wrapper->mFlatJSObject.setFlags(FLAT_JS_OBJECT_VALID);
// Set the private to the XPCWrappedNative.
JS_SetPrivate(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();
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(&NS_GET_IID(nsISupports));
MOZ_ASSERT(iface);
nsresult status;
success = wrapper->FindTearOff(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(scope, iface, nativeHelper.GetWrapperCache(),
wrapper, wrappedGlobal);
NS_ENSURE_SUCCESS(rv, rv);
return NS_OK;
}
// static
nsresult
XPCWrappedNative::GetNewOrUsed(xpcObjectHelper& helper,
XPCWrappedNativeScope* Scope,
XPCNativeInterface* Interface,
XPCWrappedNative** resultWrapper)
{
MOZ_ASSERT(Interface);
AutoJSContext cx;
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->GetContext()->GCIsRunning(),
"XPCWrappedNative::GetNewOrUsed called during GC");
nsISupports* identity = helper.GetCanonical();
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(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();
XPCNativeScriptableCreateInfo sciProto;
XPCNativeScriptableCreateInfo sci;
// 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.
const XPCNativeScriptableCreateInfo& sciWrapper =
isClassInfoSingleton ? sci :
GatherScriptableCreateInfo(identity, info, sciProto, sci);
RootedObject parent(cx, Scope->GetGlobalJSObject());
mozilla::Maybe<JSAutoCompartment> ac;
if (sciWrapper.GetFlags().WantPreCreate()) {
RootedObject plannedParent(cx, parent);
nsresult rv = sciWrapper.GetCallback()->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::GetGlobalForObjectCrossCompartment(parent) == parent,
"Non-global being used to parent XPCWrappedNative?");
ac.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(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(Interface, false, &rv)) {
MOZ_ASSERT(NS_FAILED(rv), "returning NS_OK on failure");
return rv;
}
wrapper.forget(resultWrapper);
return NS_OK;
}
} else {
ac.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(Scope, info, &sciProto);
if (!proto)
return NS_ERROR_FAILURE;
wrapper = new XPCWrappedNative(helper.forgetCanonical(), proto);
} else {
RefPtr<XPCNativeInterface> iface = Interface;
if (!iface)
iface = XPCNativeInterface::GetISupports();
XPCNativeSetKey key(iface);
RefPtr<XPCNativeSet> set =
XPCNativeSet::GetNewOrUsed(&key);
if (!set)
return NS_ERROR_FAILURE;
wrapper = new XPCWrappedNative(helper.forgetCanonical(), 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(&sciWrapper))
return NS_ERROR_FAILURE;
if (!wrapper->FindTearOff(Interface, false, &rv)) {
MOZ_ASSERT(NS_FAILED(rv), "returning NS_OK on failure");
return rv;
}
return FinishCreate(Scope, Interface, cache, wrapper, resultWrapper);
}
static nsresult
FinishCreate(XPCWrappedNativeScope* Scope,
XPCNativeInterface* Interface,
nsWrapperCache* cache,
XPCWrappedNative* inWrapper,
XPCWrappedNative** resultWrapper)
{
AutoJSContext cx;
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;
}
// static
nsresult
XPCWrappedNative::GetUsedOnly(nsISupports* Object,
XPCWrappedNativeScope* Scope,
XPCNativeInterface* Interface,
XPCWrappedNative** resultWrapper)
{
AutoJSContext cx;
MOZ_ASSERT(Object, "XPCWrappedNative::GetUsedOnly was called with a null Object");
MOZ_ASSERT(Interface);
RefPtr<XPCWrappedNative> wrapper;
nsWrapperCache* cache = nullptr;
CallQueryInterface(Object, &cache);
if (cache) {
RootedObject flat(cx, cache->GetWrapper());
if (!flat) {
*resultWrapper = nullptr;
return NS_OK;
}
wrapper = XPCWrappedNative::Get(flat);
} else {
nsCOMPtr<nsISupports> identity = do_QueryInterface(Object);
if (!identity) {
NS_ERROR("This XPCOM object fails in QueryInterface to nsISupports!");
return NS_ERROR_FAILURE;
}
Native2WrappedNativeMap* map = Scope->GetWrappedNativeMap();
wrapper = map->Find(identity);
if (!wrapper) {
*resultWrapper = nullptr;
return NS_OK;
}
}
nsresult rv;
if (!wrapper->FindTearOff(Interface, false, &rv)) {
MOZ_ASSERT(NS_FAILED(rv), "returning NS_OK on failure");
return rv;
}
wrapper.forget(resultWrapper);
return NS_OK;
}
// This ctor is used if this object will have a proto.
XPCWrappedNative::XPCWrappedNative(already_AddRefed<nsISupports>&& aIdentity,
XPCWrappedNativeProto* aProto)
: mMaybeProto(aProto),
mSet(aProto->GetSet()),
mScriptableInfo(nullptr)
{
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(already_AddRefed<nsISupports>&& aIdentity,
XPCWrappedNativeScope* aScope,
already_AddRefed<XPCNativeSet>&& aSet)
: mMaybeScope(TagScope(aScope)),
mSet(aSet),
mScriptableInfo(nullptr)
{
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()
{
XPCWrappedNativeProto* proto = GetProto();
if (mScriptableInfo &&
(!HasProto() ||
(proto && proto->GetScriptableInfo() != mScriptableInfo))) {
delete mScriptableInfo;
mScriptableInfo = nullptr;
}
XPCWrappedNativeScope* scope = GetScope();
if (scope) {
Native2WrappedNativeMap* map = scope->GetWrappedNativeMap();
// Post-1.9 we should not remove this wrapper from the map if it is
// uninitialized.
map->Remove(this);
}
if (mIdentity) {
XPCJSContext* cx = GetContext();
if (cx && cx->GetDoingFinalization()) {
DeferredFinalize(mIdentity.forget().take());
} else {
mIdentity = nullptr;
}
}
mMaybeScope = nullptr;
}
void
XPCWrappedNative::UpdateScriptableInfo(XPCNativeScriptableInfo* si)
{
MOZ_ASSERT(mScriptableInfo, "UpdateScriptableInfo expects an existing scriptable info");
mScriptableInfo = si;
}
void
XPCWrappedNative::SetProto(XPCWrappedNativeProto* p)
{
MOZ_ASSERT(!IsWrapperExpired(), "bad ptr!");
MOZ_ASSERT(HasProto());
// Write barrier for incremental GC.
JSContext* cx = GetContext()->Context();
GetProto()->WriteBarrierPre(cx);
mMaybeProto = p;
}
// This is factored out so that it can be called publicly
// static
void
XPCWrappedNative::GatherProtoScriptableCreateInfo(nsIClassInfo* classInfo,
XPCNativeScriptableCreateInfo& sciProto)
{
MOZ_ASSERT(classInfo, "bad param");
MOZ_ASSERT(!sciProto.GetCallback(), "bad param");
nsXPCClassInfo* classInfoHelper = nullptr;
CallQueryInterface(classInfo, &classInfoHelper);
if (classInfoHelper) {
nsCOMPtr<nsIXPCScriptable> helper =
dont_AddRef(static_cast<nsIXPCScriptable*>(classInfoHelper));
uint32_t flags = classInfoHelper->GetScriptableFlags();
sciProto.SetCallback(helper.forget());
sciProto.SetFlags(XPCNativeScriptableFlags(flags));
return;
}
nsCOMPtr<nsIXPCScriptable> helper;
nsresult rv = classInfo->GetScriptableHelper(getter_AddRefs(helper));
if (NS_SUCCEEDED(rv) && helper) {
uint32_t flags = helper->GetScriptableFlags();
sciProto.SetCallback(helper.forget());
sciProto.SetFlags(XPCNativeScriptableFlags(flags));
}
}
// static
const XPCNativeScriptableCreateInfo&
XPCWrappedNative::GatherScriptableCreateInfo(nsISupports* obj,
nsIClassInfo* classInfo,
XPCNativeScriptableCreateInfo& sciProto,
XPCNativeScriptableCreateInfo& sciWrapper)
{
MOZ_ASSERT(!sciWrapper.GetCallback(), "bad param");
// Get the class scriptable helper (if present)
if (classInfo) {
GatherProtoScriptableCreateInfo(classInfo, sciProto);
if (sciProto.GetFlags().DontAskInstanceForScriptable())
return sciProto;
}
// Do the same for the wrapper specific scriptable
nsCOMPtr<nsIXPCScriptable> helper(do_QueryInterface(obj));
if (helper) {
uint32_t flags = helper->GetScriptableFlags();
sciWrapper.SetCallback(helper.forget());
sciWrapper.SetFlags(XPCNativeScriptableFlags(flags));
// A whole series of assertions to catch bad uses of scriptable flags on
// the siWrapper...
MOZ_ASSERT(!(sciWrapper.GetFlags().WantPreCreate() &&
!sciProto.GetFlags().WantPreCreate()),
"Can't set WANT_PRECREATE on an instance scriptable "
"without also setting it on the class scriptable");
MOZ_ASSERT(!(sciWrapper.GetFlags().DontEnumQueryInterface() &&
!sciProto.GetFlags().DontEnumQueryInterface() &&
sciProto.GetCallback()),
"Can't set DONT_ENUM_QUERY_INTERFACE on an instance scriptable "
"without also setting it on the class scriptable (if present and shared)");
MOZ_ASSERT(!(sciWrapper.GetFlags().DontAskInstanceForScriptable() &&
!sciProto.GetFlags().DontAskInstanceForScriptable()),
"Can't set DONT_ASK_INSTANCE_FOR_SCRIPTABLE on an instance scriptable "
"without also setting it on the class scriptable");
MOZ_ASSERT(!(sciWrapper.GetFlags().ClassInfoInterfacesOnly() &&
!sciProto.GetFlags().ClassInfoInterfacesOnly() &&
sciProto.GetCallback()),
"Can't set CLASSINFO_INTERFACES_ONLY on an instance scriptable "
"without also setting it on the class scriptable (if present and shared)");
MOZ_ASSERT(!(sciWrapper.GetFlags().AllowPropModsDuringResolve() &&
!sciProto.GetFlags().AllowPropModsDuringResolve() &&
sciProto.GetCallback()),
"Can't set ALLOW_PROP_MODS_DURING_RESOLVE on an instance scriptable "
"without also setting it on the class scriptable (if present and shared)");
MOZ_ASSERT(!(sciWrapper.GetFlags().AllowPropModsToPrototype() &&
!sciProto.GetFlags().AllowPropModsToPrototype() &&
sciProto.GetCallback()),
"Can't set ALLOW_PROP_MODS_TO_PROTOTYPE on an instance scriptable "
"without also setting it on the class scriptable (if present and shared)");
return sciWrapper;
}
return sciProto;
}
bool
XPCWrappedNative::Init(const XPCNativeScriptableCreateInfo* sci)
{
AutoJSContext cx;
// setup our scriptable info...
if (sci->GetCallback()) {
if (HasProto()) {
XPCNativeScriptableInfo* siProto = GetProto()->GetScriptableInfo();
if (siProto && siProto->GetCallback() == sci->GetCallback())
mScriptableInfo = siProto;
}
if (!mScriptableInfo) {
mScriptableInfo = XPCNativeScriptableInfo::Construct(sci);
if (!mScriptableInfo)
return false;
}
}
XPCNativeScriptableInfo* si = mScriptableInfo;
// create our flatJSObject
const JSClass* jsclazz = si ? si->GetJSClass() : Jsvalify(&XPC_WN_NoHelper_JSClass);
// We should have the global jsclass flag if and only if we're a global.
MOZ_ASSERT_IF(si, !!si->GetFlags().IsGlobalObject() == !!(jsclazz->flags & JSCLASS_IS_GLOBAL));
MOZ_ASSERT(jsclazz &&
jsclazz->name &&
jsclazz->flags &&
jsclazz->getResolve() &&
jsclazz->hasFinalize(), "bad class");
// XXXbz JS_GetObjectPrototype wants an object, even though it then asserts
// that this object is same-compartment with cx, which means it could just
// use the cx global...
RootedObject global(cx, CurrentGlobalOrNull(cx));
RootedObject protoJSObject(cx, HasProto() ?
GetProto()->GetJSProtoObject() :
JS_GetObjectPrototype(cx, global));
if (!protoJSObject) {
return false;
}
mFlatJSObject = JS_NewObjectWithGivenProto(cx, jsclazz, protoJSObject);
if (!mFlatJSObject) {
mFlatJSObject.unsetFlags(FLAT_JS_OBJECT_VALID);
return false;
}
mFlatJSObject.setFlags(FLAT_JS_OBJECT_VALID);
JS_SetPrivate(mFlatJSObject, this);
return FinishInit();
}
bool
XPCWrappedNative::FinishInit()
{
AutoJSContext 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);
// A hack for bug 517665, increase the probability for GC.
JS_updateMallocCounter(cx, 2 * sizeof(XPCWrappedNative));
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_SetPrivate(jso, nullptr);
#ifdef DEBUG
JS_UpdateWeakPointerAfterGCUnbarriered(&jso);
MOZ_ASSERT(!jso);
#endif
to->JSObjectFinalized();
}
// We also need to release any native pointers held...
RefPtr<nsISupports> native = to->TakeNative();
if (native && GetContext()) {
DeferredFinalize(native.forget().take());
}
to->SetInterface(nullptr);
}
nsWrapperCache* cache = nullptr;
CallQueryInterface(mIdentity, &cache);
if (cache)
cache->ClearWrapper();
mFlatJSObject = nullptr;
mFlatJSObject.unsetFlags(FLAT_JS_OBJECT_VALID);
MOZ_ASSERT(mIdentity, "bad pointer!");
#ifdef XP_WIN
// Try to detect free'd pointer
MOZ_ASSERT(*(int*)mIdentity.get() != 0xdddddddd, "bad pointer!");
MOZ_ASSERT(*(int*)mIdentity.get() != 0, "bad pointer!");
#endif
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(obj);
MOZ_ASSERT(mFlatJSObject.unbarrieredGetPtr() == 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_SetPrivate(mFlatJSObject, nullptr);
mFlatJSObject = nullptr;
mFlatJSObject.unsetFlags(FLAT_JS_OBJECT_VALID);
XPCWrappedNativeProto* proto = GetProto();
if (HasProto())
proto->SystemIsBeingShutDown();
// We don't destroy mScriptableInfo here. The destructor will do it.
// Cleanup the tearoffs.
for (XPCWrappedNativeTearOff* to = &mFirstTearOff; to; to = to->GetNextTearOff()) {
if (JSObject* jso = to->GetJSObjectPreserveColor()) {
JS_SetPrivate(jso, nullptr);
to->SetJSObject(nullptr);
}
// We leak the tearoff mNative
// (for the same reason we leak mIdentity - see above).
Unused << to->TakeNative().take();
to->SetInterface(nullptr);
}
}
/***************************************************************************/
// Dynamically ensure that two objects don't end up with the same private.
class MOZ_STACK_CLASS AutoClonePrivateGuard {
public:
AutoClonePrivateGuard(JSContext* cx, JSObject* aOld, JSObject* aNew)
: mOldReflector(cx, aOld), mNewReflector(cx, aNew)
{
MOZ_ASSERT(JS_GetPrivate(aOld) == JS_GetPrivate(aNew));
}
~AutoClonePrivateGuard()
{
if (JS_GetPrivate(mOldReflector)) {
JS_SetPrivate(mNewReflector, nullptr);
}
}
private:
RootedObject mOldReflector;
RootedObject mNewReflector;
};
bool
XPCWrappedNative::ExtendSet(XPCNativeInterface* aInterface)
{
if (!mSet->HasInterface(aInterface)) {
XPCNativeSetKey key(mSet, aInterface);
RefPtr<XPCNativeSet> newSet =
XPCNativeSet::GetNewOrUsed(&key);
if (!newSet)
return false;
mSet = newSet.forget();
}
return true;
}
XPCWrappedNativeTearOff*
XPCWrappedNative::FindTearOff(XPCNativeInterface* aInterface,
bool needJSObject /* = false */,
nsresult* pError /* = nullptr */)
{
AutoJSContext cx;
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(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(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(const nsIID& iid) {
RefPtr<XPCNativeInterface> iface = XPCNativeInterface::GetNewOrUsed(&iid);
return iface ? FindTearOff(iface) : nullptr;
}
nsresult
XPCWrappedNative::InitTearOff(XPCWrappedNativeTearOff* aTearOff,
XPCNativeInterface* aInterface,
bool needJSObject)
{
AutoJSContext cx;
// 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;
// If the scriptable helper forbids us from reflecting additional
// interfaces, then don't even try the QI, just fail.
if (mScriptableInfo &&
mScriptableInfo->GetFlags().ClassInfoInterfacesOnly() &&
!mSet->HasInterface(aInterface) &&
!mSet->HasInterfaceWithAncestor(aInterface)) {
return NS_ERROR_NO_INTERFACE;
}
// 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
// The code in this block also does a check for the double wrapped
// nsIPropertyBag case.
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;
}
// Decide whether or not to expose nsIPropertyBag to calling
// JS code in the double wrapped case.
//
// Our rule here is that when JSObjects are double wrapped and
// exposed to other JSObjects then the nsIPropertyBag interface
// is only exposed on an 'opt-in' basis; i.e. if the underlying
// JSObject wants other JSObjects to be able to see this interface
// then it must implement QueryInterface and not throw an exception
// when asked for nsIPropertyBag. It need not actually *implement*
// nsIPropertyBag - xpconnect will do that work.
if (iid->Equals(NS_GET_IID(nsIPropertyBag)) && jso) {
RefPtr<nsXPCWrappedJSClass> clasp = nsXPCWrappedJSClass::GetNewOrUsed(cx, *iid);
if (clasp) {
RootedObject answer(cx, clasp->CallQueryInterfaceOnJSObject(cx, jso, *iid));
if (!answer) {
aTearOff->SetInterface(nullptr);
return NS_ERROR_NO_INTERFACE;
}
}
}
}
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(aInterface)) {
aTearOff->SetInterface(nullptr);
return NS_ERROR_NO_INTERFACE;
}
aTearOff->SetInterface(aInterface);
aTearOff->SetNative(qiResult);
if (needJSObject && !InitTearOffJSObject(aTearOff))
return NS_ERROR_OUT_OF_MEMORY;
return NS_OK;
}
bool
XPCWrappedNative::InitTearOffJSObject(XPCWrappedNativeTearOff* to)
{
AutoJSContext cx;
JSObject* obj = JS_NewObject(cx, Jsvalify(&XPC_WN_Tearoff_JSClass));
if (!obj)
return false;
JS_SetPrivate(obj, to);
to->SetJSObject(obj);
js::SetReservedSlot(obj, XPC_WN_TEAROFF_FLAT_OBJECT_SLOT,
JS::ObjectValue(*mFlatJSObject));
return true;
}
/***************************************************************************/
static bool Throw(nsresult errNum, XPCCallContext& ccx)
{
XPCThrower::Throw(errNum, ccx);
return false;
}
/***************************************************************************/
class MOZ_STACK_CLASS CallMethodHelper
{
XPCCallContext& mCallContext;
nsresult mInvokeResult;
nsIInterfaceInfo* 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(uint8_t paramIndex, HandleValue maybeArray, uint32_t* result);
MOZ_ALWAYS_INLINE bool
GetInterfaceTypeFromParam(uint8_t paramIndex,
const nsXPTType& datum_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 void CleanupParam(nsXPTCMiniVariant& param, nsXPTType& type);
MOZ_ALWAYS_INLINE bool AllocateStringClass(nsXPTCVariant* dp,
const nsXPTParamInfo& paramInfo);
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();
};
// static
bool
XPCWrappedNative::CallMethod(XPCCallContext& ccx,
CallMode mode /*= CALL_METHOD */)
{
nsresult rv = ccx.CanCallNow();
if (NS_FAILED(rv)) {
return Throw(rv, ccx);
}
return CallMethodHelper(ccx).Call();
}
bool
CallMethodHelper::Call()
{
mCallContext.SetRetVal(JS::UndefinedValue());
XPCJSContext::Get()->SetPendingException(nullptr);
if (mVTableIndex == 0) {
return QueryInterfaceFastPath();
}
if (!mMethodInfo) {
Throw(NS_ERROR_XPC_CANT_GET_METHOD_INFO, mCallContext);
return false;
}
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()
{
uint8_t paramCount = mMethodInfo->GetParamCount();
if (mDispatchParams.Length()) {
for (uint8_t i = 0; i < paramCount; i++) {
nsXPTCVariant* dp = GetDispatchParam(i);
const nsXPTParamInfo& paramInfo = mMethodInfo->GetParam(i);
if (paramInfo.GetType().IsArray()) {
void* p = dp->val.p;
if (!p)
continue;
// Clean up the array contents if necessary.
if (dp->DoesValNeedCleanup()) {
// We need some basic information to properly destroy the array.
uint32_t array_count = 0;
nsXPTType datum_type;
if (!GetArraySizeFromParam(i, UndefinedHandleValue, &array_count) ||
!NS_SUCCEEDED(mIFaceInfo->GetTypeForParam(mVTableIndex,
&paramInfo,
1, &datum_type))) {
// XXXbholley - I'm not convinced that the above calls will
// ever fail.
NS_ERROR("failed to get array information, we'll leak here");
continue;
}
// Loop over the array contents. For each one, we create a
// dummy 'val' and pass it to the cleanup helper.
for (uint32_t k = 0; k < array_count; k++) {
nsXPTCMiniVariant v;
v.val.p = static_cast<void**>(p)[k];
CleanupParam(v, datum_type);
}
}
// always free the array itself
free(p);
} else {
// Clean up single parameters (if requested).
if (dp->DoesValNeedCleanup())
CleanupParam(*dp, dp->type);
}
}
}
}
bool
CallMethodHelper::GetArraySizeFromParam(uint8_t paramIndex,
HandleValue maybeArray,
uint32_t* result)
{
nsresult rv;
const nsXPTParamInfo& paramInfo = mMethodInfo->GetParam(paramIndex);
// TODO fixup the various exceptions that are thrown
rv = mIFaceInfo->GetSizeIsArgNumberForParam(mVTableIndex, &paramInfo, 0, &paramIndex);
if (NS_FAILED(rv))
return Throw(NS_ERROR_XPC_CANT_GET_ARRAY_INFO, mCallContext);
// 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 (paramIndex >= mArgc && maybeArray.isObject()) {
MOZ_ASSERT(mMethodInfo->GetParam(paramIndex).IsOptional());
RootedObject arrayOrNull(mCallContext, maybeArray.isObject() ? &maybeArray.toObject()
: nullptr);
bool isArray;
if (!JS_IsArrayObject(mCallContext, maybeArray, &isArray) ||
!isArray ||
!JS_GetArrayLength(mCallContext, arrayOrNull, &GetDispatchParam(paramIndex)->val.u32))
{
return Throw(NS_ERROR_XPC_CANT_CONVERT_OBJECT_TO_ARRAY, mCallContext);
}
}
*result = GetDispatchParam(paramIndex)->val.u32;
return true;
}
bool
CallMethodHelper::GetInterfaceTypeFromParam(uint8_t paramIndex,
const nsXPTType& datum_type,
nsID* result) const
{
nsresult rv;
const nsXPTParamInfo& paramInfo = mMethodInfo->GetParam(paramIndex);
uint8_t tag = datum_type.TagPart();
// TODO fixup the various exceptions that are thrown
if (tag == nsXPTType::T_INTERFACE) {
rv = mIFaceInfo->GetIIDForParamNoAlloc(mVTableIndex, &paramInfo, result);
if (NS_FAILED(rv))
return ThrowBadParam(NS_ERROR_XPC_CANT_GET_PARAM_IFACE_INFO,
paramIndex, mCallContext);
} else if (tag == nsXPTType::T_INTERFACE_IS) {
rv = mIFaceInfo->GetInterfaceIsArgNumberForParam(mVTableIndex, &paramInfo,
&paramIndex);
if (NS_FAILED(rv))
return Throw(NS_ERROR_XPC_CANT_GET_ARRAY_INFO, mCallContext);
nsID* p = (nsID*) GetDispatchParam(paramIndex)->val.p;
if (!p)
return ThrowBadParam(NS_ERROR_XPC_CANT_GET_PARAM_IFACE_INFO,
paramIndex, mCallContext);
*result = *p;
}
return true;
}
bool
CallMethodHelper::GetOutParamSource(uint8_t paramIndex, MutableHandleValue srcp) const
{
const nsXPTParamInfo& paramInfo = mMethodInfo->GetParam(paramIndex);
MOZ_ASSERT(!paramInfo.IsDipper(), "Dipper params are handled separately");
if (paramInfo.IsOut() && !paramInfo.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() && !paramInfo.IsDipper())
continue;
const nsXPTType& type = paramInfo.GetType();
nsXPTCVariant* dp = GetDispatchParam(i);
RootedValue v(mCallContext, NullValue());
uint32_t array_count = 0;
nsXPTType datum_type;
bool isArray = type.IsArray();
bool isSizedString = isArray ?
false :
type.TagPart() == nsXPTType::T_PSTRING_SIZE_IS ||
type.TagPart() == nsXPTType::T_PWSTRING_SIZE_IS;
if (isArray) {
if (NS_FAILED(mIFaceInfo->GetTypeForParam(mVTableIndex, &paramInfo, 1,
&datum_type))) {
Throw(NS_ERROR_XPC_CANT_GET_ARRAY_INFO, mCallContext);
return false;
}
} else
datum_type = type;
if (isArray || isSizedString) {
if (!GetArraySizeFromParam(i, UndefinedHandleValue, &array_count))
return false;
}
nsID param_iid;
if (datum_type.IsInterfacePointer() &&
!GetInterfaceTypeFromParam(i, datum_type, &param_iid))
return false;
nsresult err;
if (isArray) {
if (!XPCConvert::NativeArray2JS(&v, (const void**)&dp->val,
datum_type, &param_iid,
array_count, &err)) {
// XXX need exception scheme for arrays to indicate bad element
ThrowBadParam(err, i, mCallContext);
return false;
}
} else if (isSizedString) {
if (!XPCConvert::NativeStringWithSize2JS(&v,
(const void*)&dp->val,
datum_type,
array_count, &err)) {
ThrowBadParam(err, i, mCallContext);
return false;
}
} else {
if (!XPCConvert::NativeData2JS(&v, &dp->val, datum_type,
&param_iid, &err)) {
ThrowBadParam(err, i, mCallContext);
return false;
}
}
if (paramInfo.IsRetval()) {
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;
}
const nsID* iid = xpc_JSObjectToID(mCallContext, &mArgv[0].toObject());
if (!iid) {
ThrowBadParam(NS_ERROR_XPC_BAD_CONVERT_JS, 0, mCallContext);
return false;
}
nsISupports* qiresult = nullptr;
mInvokeResult = mCallee->QueryInterface(*iid, (void**) &qiresult);
if (NS_FAILED(mInvokeResult)) {
ThrowBadResult(mInvokeResult, mCallContext);
return false;
}
RootedValue v(mCallContext, NullValue());
nsresult err;
bool success =
XPCConvert::NativeData2JS(&v, &qiresult,
nsXPTType::T_INTERFACE_IS,
iid, &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;
uint8_t hasRetval = 0;
// XXX ASSUMES that retval is last arg. The xpidl compiler ensures this.
if (paramCount && mMethodInfo->GetParam(paramCount-1).IsRetval()) {
hasRetval = 1;
requiredArgs--;
}
if (mArgc < requiredArgs || wantsOptArgc) {
if (wantsOptArgc)
mOptArgcIndex = requiredArgs;
// 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;
}
}
if (wantsJSContext) {
if (wantsOptArgc)
// Need to bump mOptArgcIndex up one here.
mJSContextIndex = mOptArgcIndex++;
else if (mMethodInfo->IsSetter() || mMethodInfo->IsGetter())
// For attributes, we always put the JSContext* first.
mJSContextIndex = 0;
else
mJSContextIndex = paramCount - hasRetval;
}
// iterate through the params to clear flags (for safe cleanup later)
for (uint8_t i = 0; i < paramCount + wantsJSContext + wantsOptArgc; i++) {
nsXPTCVariant* dp = mDispatchParams.AppendElement();
dp->ClearFlags();
dp->val.p = nullptr;
}
// Fill in the JSContext argument
if (wantsJSContext) {
nsXPTCVariant* dp = &mDispatchParams[mJSContextIndex];
dp->type = nsXPTType::T_VOID;
dp->val.p = mCallContext;
}
// Fill in the optional_argc argument
if (wantsOptArgc) {
nsXPTCVariant* dp = &mDispatchParams[mOptArgcIndex];
dp->type = nsXPTType::T_U8;
dp->val.u8 = std::min<uint32_t>(mArgc, paramCount) - requiredArgs;
}
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.GetType();
uint8_t type_tag = type.TagPart();
nsXPTCVariant* dp = GetDispatchParam(i);
dp->type = type;
MOZ_ASSERT(!paramInfo.IsShared(), "[shared] implies [noscript]!");
// String classes are always "in" - those that are marked "out" are converted
// by the XPIDL compiler to "in+dipper". See the note above IsDipper() in
// xptinfo.h.
//
// Also note that the fact that we bail out early for dipper parameters means
// that "inout" dipper parameters don't work - see bug 687612.
if (paramInfo.IsStringClass()) {
if (!AllocateStringClass(dp, paramInfo))
return false;
if (paramInfo.IsDipper()) {
// We've allocated our string class explicitly, so we don't need
// to do any conversions on the incoming argument. However, we still
// need to verify that it's an object, so that we don't get surprised
// later on when trying to assign the result to .value.
if (i < mArgc && !mArgv[i].isObject()) {
ThrowBadParam(NS_ERROR_XPC_NEED_OUT_OBJECT, i, mCallContext);
return false;
}
return true;
}
}
// Specify the correct storage/calling semantics.
if (paramInfo.IsIndirect())
dp->SetIndirect();
// The JSVal proper is always stored within the 'val' union and passed
// indirectly, regardless of in/out-ness.
if (type_tag == nsXPTType::T_JSVAL) {
// Root the value.
dp->val.j.asValueRef().setUndefined();
if (!js::AddRawValueRoot(mCallContext, &dp->val.j.asValueRef(),
"XPCWrappedNative::CallMethod param"))
{
return false;
}
}
// Flag cleanup for anything that isn't self-contained.
if (!type.IsArithmetic())
dp->SetValNeedsCleanup();
// 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");
if (i < mArgc)
src = mArgv[i];
else if (type_tag == nsXPTType::T_JSVAL)
src.setUndefined();
else
src.setNull();
}
nsID param_iid;
if (type_tag == nsXPTType::T_INTERFACE &&
NS_FAILED(mIFaceInfo->GetIIDForParamNoAlloc(mVTableIndex, &paramInfo,
&param_iid))) {
ThrowBadParam(NS_ERROR_XPC_CANT_GET_PARAM_IFACE_INFO, i, mCallContext);
return false;
}
// Don't allow CPOWs to be passed to native code (in case they try to cast
// to a concrete type).
if (src.isObject() &&
jsipc::IsWrappedCPOW(&src.toObject()) &&
type_tag == nsXPTType::T_INTERFACE &&
!param_iid.Equals(NS_GET_IID(nsISupports)))
{
// Allow passing CPOWs to XPCWrappedJS.
nsCOMPtr<nsIXPConnectWrappedJS> wrappedJS(do_QueryInterface(mCallee));
if (!wrappedJS) {
ThrowBadParam(NS_ERROR_XPC_CANT_PASS_CPOW_TO_NATIVE, i, mCallContext);
return false;
}
}
nsresult err;
if (!XPCConvert::JSData2Native(&dp->val, src, type, &param_iid, &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.GetType();
nsXPTType datum_type;
uint32_t array_count = 0;
bool isArray = type.IsArray();
bool isSizedString = isArray ?
false :
type.TagPart() == nsXPTType::T_PSTRING_SIZE_IS ||
type.TagPart() == nsXPTType::T_PWSTRING_SIZE_IS;
nsXPTCVariant* dp = GetDispatchParam(i);
dp->type = type;
if (isArray) {
if (NS_FAILED(mIFaceInfo->GetTypeForParam(mVTableIndex, &paramInfo, 1,
&datum_type))) {
Throw(NS_ERROR_XPC_CANT_GET_ARRAY_INFO, mCallContext);
return false;
}
MOZ_ASSERT(datum_type.TagPart() != nsXPTType::T_JSVAL,
"Arrays of JSVals not currently supported - see bug 693337.");
} else {
datum_type = type;
}
// Specify the correct storage/calling semantics.
if (paramInfo.IsIndirect())
dp->SetIndirect();
// We have 3 possible type of dependent parameters: Arrays, Sized Strings,
// and iid_is Interface pointers. The latter two always need cleanup, and
// arrays need cleanup for all non-arithmetic types. Since the latter two
// cases also happen to be non-arithmetic, we can just inspect datum_type
// here.
if (!datum_type.IsArithmetic())
dp->SetValNeedsCleanup();
// 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;
if (datum_type.IsInterfacePointer() &&
!GetInterfaceTypeFromParam(i, datum_type, &param_iid))
return false;
nsresult err;
if (isArray || isSizedString) {
if (!GetArraySizeFromParam(i, src, &array_count))
return false;
if (isArray) {
if (array_count &&
!XPCConvert::JSArray2Native((void**)&dp->val, src,
array_count, datum_type, &param_iid,
&err)) {
// XXX need exception scheme for arrays to indicate bad element
ThrowBadParam(err, i, mCallContext);
return false;
}
} else // if (isSizedString)
{
if (!XPCConvert::JSStringWithSize2Native((void*)&dp->val,
src, array_count,
datum_type, &err)) {
ThrowBadParam(err, i, mCallContext);
return false;
}
}
} else {
if (!XPCConvert::JSData2Native(&dp->val, src, type,
&param_iid, &err)) {
ThrowBadParam(err, i, mCallContext);
return false;
}
}
return true;
}
// Performs all necessary teardown on a parameter after method invocation.
//
// This method should only be called if the value in question was flagged
// for cleanup (ie, if dp->DoesValNeedCleanup()).
void
CallMethodHelper::CleanupParam(nsXPTCMiniVariant& param, nsXPTType& type)
{
// We handle array elements, but not the arrays themselves.
MOZ_ASSERT(type.TagPart() != nsXPTType::T_ARRAY, "Can't handle arrays.");
// Pointers may sometimes be null even if cleanup was requested. Combine
// the null checking for all the different types into one check here.
if (type.TagPart() != nsXPTType::T_JSVAL && param.val.p == nullptr)
return;
switch (type.TagPart()) {
case nsXPTType::T_JSVAL:
js::RemoveRawValueRoot(mCallContext, (Value*)&param.val);
break;
case nsXPTType::T_INTERFACE:
case nsXPTType::T_INTERFACE_IS:
((nsISupports*)param.val.p)->Release();
break;
case nsXPTType::T_ASTRING:
case nsXPTType::T_DOMSTRING:
nsXPConnect::GetContextInstance()->mScratchStrings.Destroy((nsString*)param.val.p);
break;
case nsXPTType::T_UTF8STRING:
case nsXPTType::T_CSTRING:
nsXPConnect::GetContextInstance()->mScratchCStrings.Destroy((nsCString*)param.val.p);
break;
default:
MOZ_ASSERT(!type.IsArithmetic(), "Cleanup requested on unexpected type.");
free(param.val.p);
break;
}
}
bool
CallMethodHelper::AllocateStringClass(nsXPTCVariant* dp,
const nsXPTParamInfo& paramInfo)
{
// Get something we can make comparisons with.
uint8_t type_tag = paramInfo.GetType().TagPart();
// There should be 4 cases, all strings. Verify that here.
MOZ_ASSERT(type_tag == nsXPTType::T_ASTRING ||
type_tag == nsXPTType::T_DOMSTRING ||
type_tag == nsXPTType::T_UTF8STRING ||
type_tag == nsXPTType::T_CSTRING,
"Unexpected string class type!");
// ASTRING and DOMSTRING are very similar, and both use nsString.
// UTF8_STRING and CSTRING are also quite similar, and both use nsCString.
if (type_tag == nsXPTType::T_ASTRING || type_tag == nsXPTType::T_DOMSTRING)
dp->val.p = nsXPConnect::GetContextInstance()->mScratchStrings.Create();
else
dp->val.p = nsXPConnect::GetContextInstance()->mScratchCStrings.Create();
// Check for OOM, in either case.
if (!dp->val.p) {
JS_ReportOutOfMemory(mCallContext);
return false;
}
// We allocated, so we need to deallocate after the method call completes.
dp->SetValNeedsCleanup();
return true;
}
nsresult
CallMethodHelper::Invoke()
{
uint32_t argc = mDispatchParams.Length();
nsXPTCVariant* argv = mDispatchParams.Elements();
return NS_InvokeByIndex(mCallee, mVTableIndex, argc, argv);
}
/***************************************************************************/
// interface methods
JSObject*
XPCWrappedNative::GetJSObject()
{
return GetFlatJSObject();
}
NS_IMETHODIMP XPCWrappedNative::GetNative(nsISupports * *aNative)
{
// No need to QI here, we already have the correct nsISupports
// vtable.
nsCOMPtr<nsISupports> rval = mIdentity;
rval.forget(aNative);
return NS_OK;
}
NS_IMETHODIMP XPCWrappedNative::GetJSObjectPrototype(JSObject * *aJSObjectPrototype)
{
*aJSObjectPrototype = HasProto() ?
GetProto()->GetJSProtoObject() : GetFlatJSObject();
return NS_OK;
}
nsIPrincipal*
XPCWrappedNative::GetObjectPrincipal() const
{
nsIPrincipal* principal = GetScope()->GetPrincipal();
#ifdef DEBUG
// Because of inner window reuse, we can have objects with one principal
// living in a scope with a different (but same-origin) principal. So
// just check same-origin here.
nsCOMPtr<nsIScriptObjectPrincipal> objPrin(do_QueryInterface(mIdentity));
if (objPrin) {
bool equal;
if (!principal)
equal = !objPrin->GetPrincipal();
else
principal->Equals(objPrin->GetPrincipal(), &equal);
MOZ_ASSERT(equal, "Principal mismatch. Expect bad things to happen");
}
#endif
return principal;
}
NS_IMETHODIMP XPCWrappedNative::FindInterfaceWithMember(HandleId name,
nsIInterfaceInfo * *_retval)
{
RefPtr<XPCNativeInterface> iface;
XPCNativeMember* member;
if (GetSet()->FindMember(name, &member, &iface) && iface) {
nsCOMPtr<nsIInterfaceInfo> temp = iface->GetInterfaceInfo();
temp.forget(_retval);
} else
*_retval = nullptr;
return NS_OK;
}
NS_IMETHODIMP XPCWrappedNative::FindInterfaceWithName(HandleId name,
nsIInterfaceInfo * *_retval)
{
XPCNativeInterface* iface = GetSet()->FindNamedInterface(name);
if (iface) {
nsCOMPtr<nsIInterfaceInfo> temp = iface->GetInterfaceInfo();
temp.forget(_retval);
} else
*_retval = nullptr;
return NS_OK;
}
NS_IMETHODIMP_(bool)
XPCWrappedNative::HasNativeMember(HandleId name)
{
XPCNativeMember* member = nullptr;
uint16_t ignored;
return GetSet()->FindMember(name, &member, &ignored) && !!member;
}
NS_IMETHODIMP XPCWrappedNative::DebugDump(int16_t depth)
{
#ifdef DEBUG
depth-- ;
XPC_LOG_ALWAYS(("XPCWrappedNative @ %x with mRefCnt = %d", this, mRefCnt.get()));
XPC_LOG_INDENT();
if (HasProto()) {
XPCWrappedNativeProto* proto = GetProto();
if (depth && proto)
proto->DebugDump(depth);
else
XPC_LOG_ALWAYS(("mMaybeProto @ %x", proto));
} else
XPC_LOG_ALWAYS(("Scope @ %x", GetScope()));
if (depth && mSet)
mSet->DebugDump(depth);
else
XPC_LOG_ALWAYS(("mSet @ %x", mSet.get()));
XPC_LOG_ALWAYS(("mFlatJSObject of %x", mFlatJSObject.unbarrieredGetPtr()));
XPC_LOG_ALWAYS(("mIdentity of %x", mIdentity.get()));
XPC_LOG_ALWAYS(("mScriptableInfo @ %x", mScriptableInfo));
if (depth && mScriptableInfo) {
XPC_LOG_INDENT();
XPC_LOG_ALWAYS(("mScriptable @ %x", mScriptableInfo->GetCallback()));
XPC_LOG_ALWAYS(("mFlags of %x", (uint32_t)mScriptableInfo->GetFlags()));
XPC_LOG_ALWAYS(("mJSClass @ %x", mScriptableInfo->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
char* sz = nullptr;
char* name = nullptr;
XPCNativeScriptableInfo* si = GetScriptableInfo();
if (si)
name = JS_smprintf("%s", si->GetJSClass()->name);
if (to) {
const char* fmt = name ? " (%s)" : "%s";
name = JS_sprintf_append(name, fmt,
to->GetInterface()->GetNameString());
} else if (!name) {
XPCNativeSet* set = GetSet();
XPCNativeInterface** array = set->GetInterfaceArray();
RefPtr<XPCNativeInterface> isupp = XPCNativeInterface::GetISupports();
uint16_t count = set->GetInterfaceCount();
if (count == 1)
name = JS_sprintf_append(name, "%s", array[0]->GetNameString());
else if (count == 2 && array[0] == isupp) {
name = JS_sprintf_append(name, "%s", array[1]->GetNameString());
} else {
for (uint16_t i = 0; i < count; i++) {
const char* fmt = (i == 0) ?
"(%s" : (i == count-1) ?
", %s)" : ", %s";
name = JS_sprintf_append(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 (si) {
fmt = "[object %s" FMT_ADDR FMT_STR(" (native") FMT_ADDR FMT_STR(")") "]";
}
sz = JS_smprintf(fmt, name PARAM_ADDR(this) PARAM_ADDR(mIdentity.get()));
JS_smprintf_free(name);
return sz;
#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);
nsIInterfaceInfo* info = iface->GetInterfaceInfo();
const nsIID* iid;
nsISupports* ptr;
info->GetIIDShared(&iid);
nsresult rv = obj->QueryInterface(*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->GetNameShared(&interfaceName);
clsInfo->GetContractID(&contractID);
if (wrapper->GetScriptableInfo()) {
wrapper->GetScriptableInfo()->GetCallback()->
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
NS_IMPL_ISUPPORTS(XPCJSObjectHolder, nsIXPConnectJSObjectHolder)
JSObject*
XPCJSObjectHolder::GetJSObject()
{
NS_PRECONDITION(mJSObj, "bad object state");
return mJSObj;
}
XPCJSObjectHolder::XPCJSObjectHolder(JSObject* obj)
: mJSObj(obj)
{
MOZ_ASSERT(obj);
XPCJSContext::Get()->AddObjectHolderRoot(this);
}
XPCJSObjectHolder::~XPCJSObjectHolder()
{
RemoveFromRootSet();
}
void
XPCJSObjectHolder::TraceJS(JSTracer* trc)
{
JS::TraceEdge(trc, &mJSObj, "XPCJSObjectHolder::mJSObj");
}