The Tor Browser: js/xpconnect/src/XPCWrappedJSClass.cpp@a63d609f5ebe (annotated)

js/xpconnect/src/XPCWrappedJSClass.cpp@a63d609f5ebe (annotated)

js/xpconnect/src/XPCWrappedJSClass.cpp

Thu, 15 Jan 2015 15:55:04 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 15 Jan 2015 15:55:04 +0100
branch: TOR_BUG_9701
changeset 9: a63d609f5ebe
permissions: -rw-r--r--

Back out 97036ab72558 which inappropriately compared turds to third parties.

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
 /* vim: set ts=8 sts=4 et sw=4 tw=99: */
 /* 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/. */
 /* Sharable code and data for wrapper around JSObjects. */
 #include "xpcprivate.h"
 #include "jsprf.h"
 #include "nsArrayEnumerator.h"
 #include "nsContentUtils.h"
 #include "nsWrapperCache.h"
 #include "AccessCheck.h"
 #include "nsJSUtils.h"
 #include "mozilla/Attributes.h"
 #include "mozilla/dom/BindingUtils.h"
 #include "mozilla/dom/DOMException.h"
 #include "mozilla/dom/DOMExceptionBinding.h"
 #include "jsapi.h"
 #include "jsfriendapi.h"
 using namespace xpc;
 using namespace JS;
 using namespace mozilla;
 NS_IMPL_ISUPPORTS(nsXPCWrappedJSClass, nsIXPCWrappedJSClass)
 // the value of this variable is never used - we use its address as a sentinel
 static uint32_t zero_methods_descriptor;
 bool AutoScriptEvaluate::StartEvaluating(HandleObject scope, JSErrorReporter errorReporter)
 {
     NS_PRECONDITION(!mEvaluated, "AutoScriptEvaluate::Evaluate should only be called once");
     if (!mJSContext)
         return true;
     mEvaluated = true;
     if (!JS_GetErrorReporter(mJSContext)) {
         JS_SetErrorReporter(mJSContext, errorReporter);
         mErrorReporterSet = true;
     }
     JS_BeginRequest(mJSContext);
     mAutoCompartment.construct(mJSContext, scope);
     // Saving the exception state keeps us from interfering with another script
     // that may also be running on this context.  This occurred first with the
     // js debugger, as described in
     // http://bugzilla.mozilla.org/show_bug.cgi?id=88130 but presumably could
     // show up in any situation where a script calls into a wrapped js component
     // on the same context, while the context has a nonzero exception state.
     mState.construct(mJSContext);
     return true;
 }
 AutoScriptEvaluate::~AutoScriptEvaluate()
 {
     if (!mJSContext || !mEvaluated)
         return;
     mState.ref().restore();
     JS_EndRequest(mJSContext);
     if (mErrorReporterSet)
         JS_SetErrorReporter(mJSContext, nullptr);
 }
 // It turns out that some errors may be not worth reporting. So, this
 // function is factored out to manage that.
 bool xpc_IsReportableErrorCode(nsresult code)
 {
     if (NS_SUCCEEDED(code))
         return false;
     switch (code) {
         // Error codes that we don't want to report as errors...
         // These generally indicate bad interface design AFAIC.
         case NS_ERROR_FACTORY_REGISTER_AGAIN:
         case NS_BASE_STREAM_WOULD_BLOCK:
             return false;
         default:
             return true;
     }
 }
 // static
 already_AddRefed<nsXPCWrappedJSClass>
 nsXPCWrappedJSClass::GetNewOrUsed(JSContext* cx, REFNSIID aIID)
 {
     XPCJSRuntime* rt = nsXPConnect::GetRuntimeInstance();
     IID2WrappedJSClassMap* map = rt->GetWrappedJSClassMap();
     nsRefPtr<nsXPCWrappedJSClass> clasp = map->Find(aIID);
     if (!clasp) {
         nsCOMPtr<nsIInterfaceInfo> info;
         nsXPConnect::XPConnect()->GetInfoForIID(&aIID, getter_AddRefs(info));
         if (info) {
             bool canScript, isBuiltin;
             if (NS_SUCCEEDED(info->IsScriptable(&canScript)) && canScript &&
                 NS_SUCCEEDED(info->IsBuiltinClass(&isBuiltin)) && !isBuiltin &&
                 nsXPConnect::IsISupportsDescendant(info))
             {
                 clasp = new nsXPCWrappedJSClass(cx, aIID, info);
                 if (!clasp->mDescriptors)
                     clasp = nullptr;
             }
         }
     }
     return clasp.forget();
 }
 nsXPCWrappedJSClass::nsXPCWrappedJSClass(JSContext* cx, REFNSIID aIID,
                                          nsIInterfaceInfo* aInfo)
     : mRuntime(nsXPConnect::GetRuntimeInstance()),
       mInfo(aInfo),
       mName(nullptr),
       mIID(aIID),
       mDescriptors(nullptr)
 {
     mRuntime->GetWrappedJSClassMap()->Add(this);
     uint16_t methodCount;
     if (NS_SUCCEEDED(mInfo->GetMethodCount(&methodCount))) {
         if (methodCount) {
             int wordCount = (methodCount/32)+1;
             if (nullptr != (mDescriptors = new uint32_t[wordCount])) {
                 int i;
                 // init flags to 0;
                 for (i = wordCount-1; i >= 0; i--)
                     mDescriptors[i] = 0;
                 for (i = 0; i < methodCount; i++) {
                     const nsXPTMethodInfo* info;
                     if (NS_SUCCEEDED(mInfo->GetMethodInfo(i, &info)))
                         SetReflectable(i, XPCConvert::IsMethodReflectable(*info));
                     else {
                         delete [] mDescriptors;
                         mDescriptors = nullptr;
                         break;
                     }
                 }
             }
         } else {
             mDescriptors = &zero_methods_descriptor;
         }
     }
 }
 nsXPCWrappedJSClass::~nsXPCWrappedJSClass()
 {
     if (mDescriptors && mDescriptors != &zero_methods_descriptor)
         delete [] mDescriptors;
     if (mRuntime)
         mRuntime->GetWrappedJSClassMap()->Remove(this);
     if (mName)
         nsMemory::Free(mName);
 }
 JSObject*
 nsXPCWrappedJSClass::CallQueryInterfaceOnJSObject(JSContext* cx,
                                                   JSObject* jsobjArg,
                                                   REFNSIID aIID)
 {
     RootedObject jsobj(cx, jsobjArg);
     JSObject* id;
     RootedValue retval(cx);
     RootedObject retObj(cx);
     bool success = false;
     RootedValue fun(cx);
     // Don't call the actual function on a content object. We'll determine
     // whether or not a content object is capable of implementing the
     // interface (i.e. whether the interface is scriptable) and most content
     // objects don't have QI implementations anyway. Also see bug 503926.
     if (!xpc::AccessCheck::isChrome(js::GetObjectCompartment(jsobj))) {
         return nullptr;
     }
     // OK, it looks like we'll be calling into JS code.
     AutoScriptEvaluate scriptEval(cx);
     // XXX we should install an error reporter that will send reports to
     // the JS error console service.
     if (!scriptEval.StartEvaluating(jsobj))
         return nullptr;
     // check upfront for the existence of the function property
     HandleId funid = mRuntime->GetStringID(XPCJSRuntime::IDX_QUERY_INTERFACE);
     if (!JS_GetPropertyById(cx, jsobj, funid, &fun) || JSVAL_IS_PRIMITIVE(fun))
         return nullptr;
     // Ensure that we are asking for a scriptable interface.
     // NB:  It's important for security that this check is here rather
     // than later, since it prevents untrusted objects from implementing
     // some interfaces in JS and aggregating a trusted object to
     // implement intentionally (for security) unscriptable interfaces.
     // We so often ask for nsISupports that we can short-circuit the test...
     if (!aIID.Equals(NS_GET_IID(nsISupports))) {
         nsCOMPtr<nsIInterfaceInfo> info;
         nsXPConnect::XPConnect()->GetInfoForIID(&aIID, getter_AddRefs(info));
         if (!info)
             return nullptr;
         bool canScript, isBuiltin;
         if (NS_FAILED(info->IsScriptable(&canScript)) || !canScript ||
             NS_FAILED(info->IsBuiltinClass(&isBuiltin)) || isBuiltin)
             return nullptr;
     }
     id = xpc_NewIDObject(cx, jsobj, aIID);
     if (id) {
         // Throwing NS_NOINTERFACE is the prescribed way to fail QI from JS. It
         // is not an exception that is ever worth reporting, but we don't want
         // to eat all exceptions either.
         {
             AutoSaveContextOptions asco(cx);
             ContextOptionsRef(cx).setDontReportUncaught(true);
             RootedValue arg(cx, JS::ObjectValue(*id));
             success = JS_CallFunctionValue(cx, jsobj, fun, arg, &retval);
         }
         if (!success && JS_IsExceptionPending(cx)) {
             RootedValue jsexception(cx, NullValue());
             if (JS_GetPendingException(cx, &jsexception)) {
                 nsresult rv;
                 if (jsexception.isObject()) {
                     // XPConnect may have constructed an object to represent a
                     // C++ QI failure. See if that is the case.
                     using namespace mozilla::dom;
                     Exception *e = nullptr;
                     UNWRAP_OBJECT(Exception, &jsexception.toObject(), e);
                     if (e &&
                         NS_SUCCEEDED(e->GetResult(&rv)) &&
                         rv == NS_NOINTERFACE) {
                         JS_ClearPendingException(cx);
                     }
                 } else if (JSVAL_IS_NUMBER(jsexception)) {
                     // JS often throws an nsresult.
                     if (JSVAL_IS_DOUBLE(jsexception))
                         // Visual Studio 9 doesn't allow casting directly from
                         // a double to an enumeration type, contrary to
                         // 5.2.9(10) of C++11, so add an intermediate cast.
                         rv = (nsresult)(uint32_t)(JSVAL_TO_DOUBLE(jsexception));
                     else
                         rv = (nsresult)(JSVAL_TO_INT(jsexception));
                     if (rv == NS_NOINTERFACE)
                         JS_ClearPendingException(cx);
                 }
             }
             // Don't report if reporting was disabled by someone else.
             if (!ContextOptionsRef(cx).dontReportUncaught())
                 JS_ReportPendingException(cx);
         } else if (!success) {
             NS_WARNING("QI hook ran OOMed - this is probably a bug!");
         }
     }
     if (success)
         success = JS_ValueToObject(cx, retval, &retObj);
     return success ? retObj.get() : nullptr;
 }
 /***************************************************************************/
 static bool
 GetNamedPropertyAsVariantRaw(XPCCallContext& ccx,
                              HandleObject aJSObj,
                              HandleId aName,
                              nsIVariant** aResult,
                              nsresult* pErr)
 {
     nsXPTType type = nsXPTType((uint8_t)TD_INTERFACE_TYPE);
     RootedValue val(ccx);
     return JS_GetPropertyById(ccx, aJSObj, aName, &val) &&
            // Note that this always takes the T_INTERFACE path through
            // JSData2Native, so the value passed for useAllocator
            // doesn't really matter. We pass true for consistency.
            XPCConvert::JSData2Native(aResult, val, type, true,
                                      &NS_GET_IID(nsIVariant), pErr);
 }
 // static
 nsresult
 nsXPCWrappedJSClass::GetNamedPropertyAsVariant(XPCCallContext& ccx,
                                                JSObject* aJSObjArg,
                                                const nsAString& aName,
                                                nsIVariant** aResult)
 {
     JSContext* cx = ccx.GetJSContext();
     RootedObject aJSObj(cx, aJSObjArg);
     AutoScriptEvaluate scriptEval(cx);
     if (!scriptEval.StartEvaluating(aJSObj))
         return NS_ERROR_FAILURE;
     // Wrap the string in a jsval after the AutoScriptEvaluate, so that the
     // resulting value ends up in the correct compartment.
     nsStringBuffer* buf;
     RootedValue value(cx);
     if (!XPCStringConvert::ReadableToJSVal(ccx, aName, &buf, &value))
         return NS_ERROR_OUT_OF_MEMORY;
     if (buf)
         buf->AddRef();
     RootedId id(cx);
     nsresult rv = NS_OK;
     if (!JS_ValueToId(cx, value, &id) ||
         !GetNamedPropertyAsVariantRaw(ccx, aJSObj, id, aResult, &rv)) {
         if (NS_FAILED(rv))
             return rv;
         return NS_ERROR_FAILURE;
     }
     return NS_OK;
 }
 /***************************************************************************/
 // static
 nsresult
 nsXPCWrappedJSClass::BuildPropertyEnumerator(XPCCallContext& ccx,
                                              JSObject* aJSObjArg,
                                              nsISimpleEnumerator** aEnumerate)
 {
     JSContext* cx = ccx.GetJSContext();
     RootedObject aJSObj(cx, aJSObjArg);
     AutoScriptEvaluate scriptEval(cx);
     if (!scriptEval.StartEvaluating(aJSObj))
         return NS_ERROR_FAILURE;
     AutoIdArray idArray(cx, JS_Enumerate(cx, aJSObj));
     if (!idArray)
         return NS_ERROR_FAILURE;
     nsCOMArray<nsIProperty> propertyArray(idArray.length());
     RootedId idName(cx);
     for (size_t i = 0; i < idArray.length(); i++) {
         idName = idArray[i];
         nsCOMPtr<nsIVariant> value;
         nsresult rv;
         if (!GetNamedPropertyAsVariantRaw(ccx, aJSObj, idName,
                                           getter_AddRefs(value), &rv)) {
             if (NS_FAILED(rv))
                 return rv;
             return NS_ERROR_FAILURE;
         }
         RootedValue jsvalName(cx);
         if (!JS_IdToValue(cx, idName, &jsvalName))
             return NS_ERROR_FAILURE;
         JSString* name = ToString(cx, jsvalName);
         if (!name)
             return NS_ERROR_FAILURE;
         size_t length;
         const jschar *chars = JS_GetStringCharsAndLength(cx, name, &length);
         if (!chars)
             return NS_ERROR_FAILURE;
         nsCOMPtr<nsIProperty> property =
             new xpcProperty(chars, (uint32_t) length, value);
         if (!propertyArray.AppendObject(property))
             return NS_ERROR_FAILURE;
     }
     return NS_NewArrayEnumerator(aEnumerate, propertyArray);
 }
 /***************************************************************************/
 NS_IMPL_ISUPPORTS(xpcProperty, nsIProperty)
 xpcProperty::xpcProperty(const char16_t* aName, uint32_t aNameLen,
                          nsIVariant* aValue)
     : mName(aName, aNameLen), mValue(aValue)
 {
 }
 /* readonly attribute AString name; */
 NS_IMETHODIMP xpcProperty::GetName(nsAString & aName)
 {
     aName.Assign(mName);
     return NS_OK;
 }
 /* readonly attribute nsIVariant value; */
 NS_IMETHODIMP xpcProperty::GetValue(nsIVariant * *aValue)
 {
     nsCOMPtr<nsIVariant> rval = mValue;
     rval.forget(aValue);
     return NS_OK;
 }
 /***************************************************************************/
 // This 'WrappedJSIdentity' class and singleton allow us to figure out if
 // any given nsISupports* is implemented by a WrappedJS object. This is done
 // using a QueryInterface call on the interface pointer with our ID. If
 // that call returns NS_OK and the pointer is to our singleton, then the
 // interface must be implemented by a WrappedJS object. NOTE: the
 // 'WrappedJSIdentity' object is not a real XPCOM object and should not be
 // used for anything else (hence it is declared in this implementation file).
 // {5C5C3BB0-A9BA-11d2-BA64-00805F8A5DD7}
 #define NS_IXPCONNECT_WRAPPED_JS_IDENTITY_CLASS_IID                           \
 { 0x5c5c3bb0, 0xa9ba, 0x11d2,                                                 \
   { 0xba, 0x64, 0x0, 0x80, 0x5f, 0x8a, 0x5d, 0xd7 } }
 class WrappedJSIdentity
 {
     // no instance methods...
 public:
     NS_DECLARE_STATIC_IID_ACCESSOR(NS_IXPCONNECT_WRAPPED_JS_IDENTITY_CLASS_IID)
     static void* GetSingleton()
     {
         static WrappedJSIdentity* singleton = nullptr;
         if (!singleton)
             singleton = new WrappedJSIdentity();
         return (void*) singleton;
     }
 };
 NS_DEFINE_STATIC_IID_ACCESSOR(WrappedJSIdentity,
                               NS_IXPCONNECT_WRAPPED_JS_IDENTITY_CLASS_IID)
 /***************************************************************************/
 // static
 bool
 nsXPCWrappedJSClass::IsWrappedJS(nsISupports* aPtr)
 {
     void* result;
     NS_PRECONDITION(aPtr, "null pointer");
     return aPtr &&
            NS_OK == aPtr->QueryInterface(NS_GET_IID(WrappedJSIdentity), &result) &&
            result == WrappedJSIdentity::GetSingleton();
 }
 // NB: This will return the top JSContext on the JSContext stack if there is one,
 // before attempting to get the context from the wrapped JS object.
 static JSContext *
 GetContextFromObjectOrDefault(nsXPCWrappedJS* wrapper)
 {
     // First, try the cx stack.
     XPCJSContextStack* stack = XPCJSRuntime::Get()->GetJSContextStack();
     if (stack->Peek())
         return stack->Peek();
     // If the cx stack is empty, try the wrapper's JSObject.
     JSCompartment *c = js::GetObjectCompartment(wrapper->GetJSObject());
     XPCContext *xpcc = EnsureCompartmentPrivate(c)->scope->GetContext();
     if (xpcc) {
         JSContext *cx = xpcc->GetJSContext();
         JS_AbortIfWrongThread(JS_GetRuntime(cx));
         return cx;
     }
     // Fall back to the safe JSContext.
     return stack->GetSafeJSContext();
 }
 NS_IMETHODIMP
 nsXPCWrappedJSClass::DelegatedQueryInterface(nsXPCWrappedJS* self,
                                              REFNSIID aIID,
                                              void** aInstancePtr)
 {
     if (aIID.Equals(NS_GET_IID(nsIXPConnectJSObjectHolder))) {
         NS_ADDREF(self);
         *aInstancePtr = (void*) static_cast<nsIXPConnectJSObjectHolder*>(self);
         return NS_OK;
     }
     // Objects internal to xpconnect are the only objects that even know *how*
     // to ask for this iid. And none of them bother refcounting the thing.
     if (aIID.Equals(NS_GET_IID(WrappedJSIdentity))) {
         // asking to find out if this is a wrapper object
         *aInstancePtr = WrappedJSIdentity::GetSingleton();
         return NS_OK;
     }
     if (aIID.Equals(NS_GET_IID(nsIPropertyBag))) {
         // We only want to expose one implementation from our aggregate.
         nsXPCWrappedJS* root = self->GetRootWrapper();
         if (!root->IsValid()) {
             *aInstancePtr = nullptr;
             return NS_NOINTERFACE;
         }
         NS_ADDREF(root);
         *aInstancePtr = (void*) static_cast<nsIPropertyBag*>(root);
         return NS_OK;
     }
     // We can't have a cached wrapper.
     if (aIID.Equals(NS_GET_IID(nsWrapperCache))) {
         *aInstancePtr = nullptr;
         return NS_NOINTERFACE;
     }
     AutoPushJSContext context(GetContextFromObjectOrDefault(self));
     XPCCallContext ccx(NATIVE_CALLER, context);
     if (!ccx.IsValid()) {
         *aInstancePtr = nullptr;
         return NS_NOINTERFACE;
     }
     // We support nsISupportsWeakReference iff the root wrapped JSObject
     // claims to support it in its QueryInterface implementation.
     if (aIID.Equals(NS_GET_IID(nsISupportsWeakReference))) {
         // We only want to expose one implementation from our aggregate.
         nsXPCWrappedJS* root = self->GetRootWrapper();
         // Fail if JSObject doesn't claim support for nsISupportsWeakReference
         if (!root->IsValid() ||
             !CallQueryInterfaceOnJSObject(ccx, root->GetJSObject(), aIID)) {
             *aInstancePtr = nullptr;
             return NS_NOINTERFACE;
         }
         NS_ADDREF(root);
         *aInstancePtr = (void*) static_cast<nsISupportsWeakReference*>(root);
         return NS_OK;
     }
     // Checks for any existing wrapper explicitly constructed for this iid.
     // This includes the current 'self' wrapper. This also deals with the
     // nsISupports case (for which it returns mRoot).
     // Also check if asking for an interface from which one of our wrappers inherits.
     if (nsXPCWrappedJS* sibling = self->FindOrFindInherited(aIID)) {
         NS_ADDREF(sibling);
         *aInstancePtr = sibling->GetXPTCStub();
         return NS_OK;
     }
     // else we do the more expensive stuff...
     // check if the JSObject claims to implement this interface
     RootedObject jsobj(ccx, CallQueryInterfaceOnJSObject(ccx, self->GetJSObject(),
                                                          aIID));
     if (jsobj) {
         // We can't use XPConvert::JSObject2NativeInterface() here
         // since that can find a XPCWrappedNative directly on the
         // proto chain, and we don't want that here. We need to find
         // the actual JS object that claimed it supports the interface
         // we're looking for or we'll potentially bypass security
         // checks etc by calling directly through to a native found on
         // the prototype chain.
         //
         // Instead, simply do the nsXPCWrappedJS part of
         // XPConvert::JSObject2NativeInterface() here to make sure we
         // get a new (or used) nsXPCWrappedJS.
         nsXPCWrappedJS* wrapper;
         nsresult rv = nsXPCWrappedJS::GetNewOrUsed(jsobj, aIID, &wrapper);
         if (NS_SUCCEEDED(rv) && wrapper) {
             // We need to go through the QueryInterface logic to make
             // this return the right thing for the various 'special'
             // interfaces; e.g.  nsIPropertyBag.
             rv = wrapper->QueryInterface(aIID, aInstancePtr);
             NS_RELEASE(wrapper);
             return rv;
         }
     }
     // else...
     // no can do
     *aInstancePtr = nullptr;
     return NS_NOINTERFACE;
 }
 JSObject*
 nsXPCWrappedJSClass::GetRootJSObject(JSContext* cx, JSObject* aJSObjArg)
 {
     RootedObject aJSObj(cx, aJSObjArg);
     JSObject* result = CallQueryInterfaceOnJSObject(cx, aJSObj,
                                                     NS_GET_IID(nsISupports));
     if (!result)
         return aJSObj;
     JSObject* inner = js::UncheckedUnwrap(result);
     if (inner)
         return inner;
     return result;
 }
 void
 xpcWrappedJSErrorReporter(JSContext *cx, const char *message,
                           JSErrorReport *report)
 {
     if (report) {
         // If it is an exception report, then we can just deal with the
         // exception later (if not caught in the JS code).
         if (JSREPORT_IS_EXCEPTION(report->flags)) {
             // XXX We have a problem with error reports from uncaught exceptions.
             //
             // http://bugzilla.mozilla.org/show_bug.cgi?id=66453
             //
             // The issue is...
             //
             // We can't assume that the exception will *stay* uncaught. So, if
             // we build an nsIXPCException here and the underlying exception
             // really is caught before our script is done running then we blow
             // it by returning failure to our caller when the script didn't
             // really fail. However, This report contains error location info
             // that is no longer available after the script is done. So, if the
             // exception really is not caught (and is a non-engine exception)
             // then we've lost the oportunity to capture the script location
             // info that we *could* have captured here.
             //
             // This is expecially an issue with nested evaluations.
             //
             // Perhaps we could capture an expception here and store it as
             // 'provisional' and then later if there is a pending exception
             // when the script is done then we could maybe compare that in some
             // way with the 'provisional' one in which we captured location info.
             // We would not want to assume that the one discovered here is the
             // same one that is later detected. This could cause us to lie.
             //
             // The thing is. we do not currently store the right stuff to compare
             // these two nsIXPCExceptions (triggered by the same exception jsval
             // in the engine). Maybe we should store the jsval and compare that?
             // Maybe without even rooting it since we will not dereference it.
             // This is inexact, but maybe the right thing to do?
             //
             // if (report->errorNumber == JSMSG_UNCAUGHT_EXCEPTION)) ...
             //
             return;
         }
         if (JSREPORT_IS_WARNING(report->flags)) {
             // XXX printf the warning (#ifdef DEBUG only!).
             // XXX send the warning to the console service.
             return;
         }
     }
     XPCCallContext ccx(NATIVE_CALLER, cx);
     if (!ccx.IsValid())
         return;
     nsCOMPtr<nsIException> e;
     XPCConvert::JSErrorToXPCException(message, nullptr, nullptr, report,
                                       getter_AddRefs(e));
     if (e)
         ccx.GetXPCContext()->SetException(e);
 }
 bool
 nsXPCWrappedJSClass::GetArraySizeFromParam(JSContext* cx,
                                            const XPTMethodDescriptor* method,
                                            const nsXPTParamInfo& param,
                                            uint16_t methodIndex,
                                            uint8_t paramIndex,
                                            nsXPTCMiniVariant* nativeParams,
                                            uint32_t* result)
 {
     uint8_t argnum;
     nsresult rv;
     rv = mInfo->GetSizeIsArgNumberForParam(methodIndex, &param, 0, &argnum);
     if (NS_FAILED(rv))
         return false;
     const nsXPTParamInfo& arg_param = method->params[argnum];
     // This should be enforced by the xpidl compiler, but it's not.
     // See bug 695235.
     MOZ_ASSERT(arg_param.GetType().TagPart() == nsXPTType::T_U32,
                "size_is references parameter of invalid type.");
     if (arg_param.IsIndirect())
         *result = *(uint32_t*)nativeParams[argnum].val.p;
     else
         *result = nativeParams[argnum].val.u32;
     return true;
 }
 bool
 nsXPCWrappedJSClass::GetInterfaceTypeFromParam(JSContext* cx,
                                                const XPTMethodDescriptor* method,
                                                const nsXPTParamInfo& param,
                                                uint16_t methodIndex,
                                                const nsXPTType& type,
                                                nsXPTCMiniVariant* nativeParams,
                                                nsID* result)
 {
     uint8_t type_tag = type.TagPart();
     if (type_tag == nsXPTType::T_INTERFACE) {
         if (NS_SUCCEEDED(GetInterfaceInfo()->
                          GetIIDForParamNoAlloc(methodIndex, &param, result))) {
             return true;
         }
     } else if (type_tag == nsXPTType::T_INTERFACE_IS) {
         uint8_t argnum;
         nsresult rv;
         rv = mInfo->GetInterfaceIsArgNumberForParam(methodIndex,
                                                     &param, &argnum);
         if (NS_FAILED(rv))
             return false;
         const nsXPTParamInfo& arg_param = method->params[argnum];
         const nsXPTType& arg_type = arg_param.GetType();
         if (arg_type.TagPart() == nsXPTType::T_IID) {
             if (arg_param.IsIndirect()) {
                 nsID** p = (nsID**) nativeParams[argnum].val.p;
                 if (!p || !*p)
                     return false;
                 *result = **p;
             } else {
                 nsID* p = (nsID*) nativeParams[argnum].val.p;
                 if (!p)
                     return false;
                 *result = *p;
             }
             return true;
         }
     }
     return false;
 }
 void
 nsXPCWrappedJSClass::CleanupPointerArray(const nsXPTType& datum_type,
                                          uint32_t array_count,
                                          void** arrayp)
 {
     if (datum_type.IsInterfacePointer()) {
         nsISupports** pp = (nsISupports**) arrayp;
         for (uint32_t k = 0; k < array_count; k++) {
             nsISupports* p = pp[k];
             NS_IF_RELEASE(p);
         }
     } else {
         void** pp = (void**) arrayp;
         for (uint32_t k = 0; k < array_count; k++) {
             void* p = pp[k];
             if (p) nsMemory::Free(p);
         }
     }
 }
 void
 nsXPCWrappedJSClass::CleanupPointerTypeObject(const nsXPTType& type,
                                               void** pp)
 {
     MOZ_ASSERT(pp,"null pointer");
     if (type.IsInterfacePointer()) {
         nsISupports* p = *((nsISupports**)pp);
         if (p) p->Release();
     } else {
         void* p = *((void**)pp);
         if (p) nsMemory::Free(p);
     }
 }
 class AutoClearPendingException
 {
 public:
   AutoClearPendingException(JSContext *cx) : mCx(cx) { }
   ~AutoClearPendingException() { JS_ClearPendingException(mCx); }
 private:
   JSContext* mCx;
 };
 nsresult
 nsXPCWrappedJSClass::CheckForException(XPCCallContext & ccx,
                                        const char * aPropertyName,
                                        const char * anInterfaceName,
                                        bool aForceReport)
 {
     XPCContext * xpcc = ccx.GetXPCContext();
     JSContext * cx = ccx.GetJSContext();
     nsCOMPtr<nsIException> xpc_exception;
     /* this one would be set by our error reporter */
     xpcc->GetException(getter_AddRefs(xpc_exception));
     if (xpc_exception)
         xpcc->SetException(nullptr);
     // get this right away in case we do something below to cause JS code
     // to run on this JSContext
     nsresult pending_result = xpcc->GetPendingResult();
     RootedValue js_exception(cx);
     bool is_js_exception = JS_GetPendingException(cx, &js_exception);
     /* JS might throw an expection whether the reporter was called or not */
     if (is_js_exception) {
         if (!xpc_exception)
             XPCConvert::JSValToXPCException(&js_exception, anInterfaceName,
                                             aPropertyName,
                                             getter_AddRefs(xpc_exception));
         /* cleanup and set failed even if we can't build an exception */
         if (!xpc_exception) {
             XPCJSRuntime::Get()->SetPendingException(nullptr); // XXX necessary?
         }
     }
     AutoClearPendingException acpe(cx);
     if (xpc_exception) {
         nsresult e_result;
         if (NS_SUCCEEDED(xpc_exception->GetResult(&e_result))) {
             // Figure out whether or not we should report this exception.
             bool reportable = xpc_IsReportableErrorCode(e_result);
             if (reportable) {
                 // Always want to report forced exceptions and XPConnect's own
                 // errors.
                 reportable = aForceReport ||
                     NS_ERROR_GET_MODULE(e_result) == NS_ERROR_MODULE_XPCONNECT;
                 // See if an environment variable was set or someone has told us
                 // that a user pref was set indicating that we should report all
                 // exceptions.
                 if (!reportable)
                     reportable = nsXPConnect::ReportAllJSExceptions();
                 // Finally, check to see if this is the last JS frame on the
                 // stack. If so then we always want to report it.
                 if (!reportable)
                     reportable = !JS::DescribeScriptedCaller(cx);
                 // Ugly special case for GetInterface. It's "special" in the
                 // same way as QueryInterface in that a failure is not
                 // exceptional and shouldn't be reported. We have to do this
                 // check here instead of in xpcwrappedjs (like we do for QI) to
                 // avoid adding extra code to all xpcwrappedjs objects.
                 if (reportable && e_result == NS_ERROR_NO_INTERFACE &&
                     !strcmp(anInterfaceName, "nsIInterfaceRequestor") &&
                     !strcmp(aPropertyName, "getInterface")) {
                     reportable = false;
                 }
                 // More special case, see bug 877760.
                 if (e_result == NS_ERROR_XPC_JSOBJECT_HAS_NO_FUNCTION_NAMED) {
                     reportable = false;
                 }
             }
             // Try to use the error reporter set on the context to handle this
             // error if it came from a JS exception.
             if (reportable && is_js_exception &&
                 JS_GetErrorReporter(cx) != xpcWrappedJSErrorReporter)
             {
                 // If the error reporter ignores the error, it will call
                 // xpc->MarkErrorUnreported().
                 xpcc->ClearUnreportedError();
                 reportable = !JS_ReportPendingException(cx);
                 if (!xpcc->WasErrorReported())
                     reportable = true;
             }
             if (reportable) {
                 if (nsContentUtils::DOMWindowDumpEnabled()) {
                     static const char line[] =
                         "************************************************************\n";
                     static const char preamble[] =
                         "* Call to xpconnect wrapped JSObject produced this error:  *\n";
                     static const char cant_get_text[] =
                         "FAILED TO GET TEXT FROM EXCEPTION\n";
                     fputs(line, stdout);
                     fputs(preamble, stdout);
                     nsCString text;
                     if (NS_SUCCEEDED(xpc_exception->ToString(text)) &&
                         !text.IsEmpty()) {
                         fputs(text.get(), stdout);
                         fputs("\n", stdout);
                     } else
                         fputs(cant_get_text, stdout);
                     fputs(line, stdout);
                 }
                 // Log the exception to the JS Console, so that users can do
                 // something with it.
                 nsCOMPtr<nsIConsoleService> consoleService
                     (do_GetService(XPC_CONSOLE_CONTRACTID));
                 if (nullptr != consoleService) {
                     nsresult rv;
                     nsCOMPtr<nsIScriptError> scriptError;
                     nsCOMPtr<nsISupports> errorData;
                     rv = xpc_exception->GetData(getter_AddRefs(errorData));
                     if (NS_SUCCEEDED(rv))
                         scriptError = do_QueryInterface(errorData);
                     if (nullptr == scriptError) {
                         // No luck getting one from the exception, so
                         // try to cook one up.
                         scriptError = do_CreateInstance(XPC_SCRIPT_ERROR_CONTRACTID);
                         if (nullptr != scriptError) {
                             nsCString newMessage;
                             rv = xpc_exception->ToString(newMessage);
                             if (NS_SUCCEEDED(rv)) {
                                 // try to get filename, lineno from the first
                                 // stack frame location.
                                 int32_t lineNumber = 0;
                                 nsString sourceName;
                                 nsCOMPtr<nsIStackFrame> location;
                                 xpc_exception->
                                     GetLocation(getter_AddRefs(location));
                                 if (location) {
                                     // Get line number w/o checking; 0 is ok.
                                     location->GetLineNumber(&lineNumber);
                                     // get a filename.
                                     rv = location->GetFilename(sourceName);
                                 }
                                 rv = scriptError->InitWithWindowID(NS_ConvertUTF8toUTF16(newMessage),
                                                                    sourceName,
                                                                    EmptyString(),
                                                                    lineNumber, 0, 0,
                                                                    "XPConnect JavaScript",
                                                                    nsJSUtils::GetCurrentlyRunningCodeInnerWindowID(cx));
                                 if (NS_FAILED(rv))
                                     scriptError = nullptr;
                             }
                         }
                     }
                     if (nullptr != scriptError)
                         consoleService->LogMessage(scriptError);
                 }
             }
             // Whether or not it passes the 'reportable' test, it might
             // still be an error and we have to do the right thing here...
             if (NS_FAILED(e_result)) {
                 XPCJSRuntime::Get()->SetPendingException(xpc_exception);
                 return e_result;
             }
         }
     } else {
         // see if JS code signaled failure result without throwing exception
         if (NS_FAILED(pending_result)) {
             return pending_result;
         }
     }
     return NS_ERROR_FAILURE;
 }
 NS_IMETHODIMP
 nsXPCWrappedJSClass::CallMethod(nsXPCWrappedJS* wrapper, uint16_t methodIndex,
                                 const XPTMethodDescriptor* info_,
                                 nsXPTCMiniVariant* nativeParams)
 {
     jsval* sp = nullptr;
     jsval* argv = nullptr;
     uint8_t i;
     nsresult retval = NS_ERROR_FAILURE;
     nsresult pending_result = NS_OK;
     bool success;
     bool readyToDoTheCall = false;
     nsID  param_iid;
     const nsXPTMethodInfo* info = static_cast<const nsXPTMethodInfo*>(info_);
     const char* name = info->name;
     bool foundDependentParam;
     // Make sure not to set the callee on ccx until after we've gone through
     // the whole nsIXPCFunctionThisTranslator bit.  That code uses ccx to
     // convert natives to JSObjects, but we do NOT plan to pass those JSObjects
     // to our real callee.
     AutoPushJSContext context(GetContextFromObjectOrDefault(wrapper));
     XPCCallContext ccx(NATIVE_CALLER, context);
     if (!ccx.IsValid())
         return retval;
     XPCContext *xpcc = ccx.GetXPCContext();
     JSContext *cx = ccx.GetJSContext();
     if (!cx || !xpcc || !IsReflectable(methodIndex))
         return NS_ERROR_FAILURE;
     // [implicit_jscontext] and [optional_argc] have a different calling
     // convention, which we don't support for JS-implemented components.
     if (info->WantsOptArgc() || info->WantsContext()) {
         const char *str = "IDL methods marked with [implicit_jscontext] "
                           "or [optional_argc] may not be implemented in JS";
         // Throw and warn for good measure.
         JS_ReportError(cx, str);
         NS_WARNING(str);
         return NS_ERROR_FAILURE;
     }
     RootedValue fval(cx);
     RootedObject obj(cx, wrapper->GetJSObject());
     RootedObject thisObj(cx, obj);
     JSAutoCompartment ac(cx, obj);
     AutoValueVector args(cx);
     AutoScriptEvaluate scriptEval(cx);
     // XXX ASSUMES that retval is last arg. The xpidl compiler ensures this.
     uint8_t paramCount = info->num_args;
     uint8_t argc = paramCount -
         (paramCount && XPT_PD_IS_RETVAL(info->params[paramCount-1].flags) ? 1 : 0);
     if (!scriptEval.StartEvaluating(obj, xpcWrappedJSErrorReporter))
         goto pre_call_clean_up;
     xpcc->SetPendingResult(pending_result);
     xpcc->SetException(nullptr);
     XPCJSRuntime::Get()->SetPendingException(nullptr);
     // We use js_Invoke so that the gcthings we use as args will be rooted by
     // the engine as we do conversions and prepare to do the function call.
     // setup stack
     // if this isn't a function call then we don't need to push extra stuff
     if (!(XPT_MD_IS_SETTER(info->flags) || XPT_MD_IS_GETTER(info->flags))) {
         // We get fval before allocating the stack to avoid gc badness that can
         // happen if the GetProperty call leaves our request and the gc runs
         // while the stack we allocate contains garbage.
         // If the interface is marked as a [function] then we will assume that
         // our JSObject is a function and not an object with a named method.
         bool isFunction;
         if (NS_FAILED(mInfo->IsFunction(&isFunction)))
             goto pre_call_clean_up;
         // In the xpidl [function] case we are making sure now that the
         // JSObject is callable. If it is *not* callable then we silently
         // fallback to looking up the named property...
         // (because jst says he thinks this fallback is 'The Right Thing'.)
         //
         // In the normal (non-function) case we just lookup the property by
         // name and as long as the object has such a named property we go ahead
         // and try to make the call. If it turns out the named property is not
         // a callable object then the JS engine will throw an error and we'll
         // pass this along to the caller as an exception/result code.
         fval = ObjectValue(*obj);
         if (isFunction &&
             JS_TypeOfValue(ccx, fval) == JSTYPE_FUNCTION) {
             // We may need to translate the 'this' for the function object.
             if (paramCount) {
                 const nsXPTParamInfo& firstParam = info->params[0];
                 if (firstParam.IsIn()) {
                     const nsXPTType& firstType = firstParam.GetType();
                     if (firstType.IsInterfacePointer()) {
                         nsIXPCFunctionThisTranslator* translator;
                         IID2ThisTranslatorMap* map =
                             mRuntime->GetThisTranslatorMap();
                         translator = map->Find(mIID);
                         if (translator) {
                             nsCOMPtr<nsISupports> newThis;
                             if (NS_FAILED(translator->
                                           TranslateThis((nsISupports*)nativeParams[0].val.p,
                                                         getter_AddRefs(newThis)))) {
                                 goto pre_call_clean_up;
                             }
                             if (newThis) {
                                 RootedValue v(cx);
                                 xpcObjectHelper helper(newThis);
                                 bool ok =
                                   XPCConvert::NativeInterface2JSObject(
                                       &v, nullptr, helper, nullptr,
                                       nullptr, false, nullptr);
                                 if (!ok) {
                                     goto pre_call_clean_up;
                                 }
                                 thisObj = JSVAL_TO_OBJECT(v);
                                 if (!JS_WrapObject(cx, &thisObj))
                                     goto pre_call_clean_up;
                             }
                         }
                     }
                 }
             }
         } else {
             if (!JS_GetProperty(cx, obj, name, &fval))
                 goto pre_call_clean_up;
             // XXX We really want to factor out the error reporting better and
             // specifically report the failure to find a function with this name.
             // This is what we do below if the property is found but is not a
             // function. We just need to factor better so we can get to that
             // reporting path from here.
             thisObj = obj;
         }
     }
     if (!args.resize(argc)) {
         retval = NS_ERROR_OUT_OF_MEMORY;
         goto pre_call_clean_up;
     }
     argv = args.begin();
     sp = argv;
     // build the args
     // NB: This assignment *looks* wrong because we haven't yet called our
     // function. However, we *have* already entered the compartmen that we're
     // about to call, and that's the global that we want here. In other words:
     // we're trusting the JS engine to come up with a good global to use for
     // our object (whatever it was).
     for (i = 0; i < argc; i++) {
         const nsXPTParamInfo& param = info->params[i];
         const nsXPTType& type = param.GetType();
         nsXPTType datum_type;
         uint32_t array_count;
         bool isArray = type.IsArray();
         RootedValue val(cx, NullValue());
         bool isSizedString = isArray ?
                 false :
                 type.TagPart() == nsXPTType::T_PSTRING_SIZE_IS ||
                 type.TagPart() == nsXPTType::T_PWSTRING_SIZE_IS;
         // verify that null was not passed for 'out' param
         if (param.IsOut() && !nativeParams[i].val.p) {
             retval = NS_ERROR_INVALID_ARG;
             goto pre_call_clean_up;
         }
         if (isArray) {
             if (NS_FAILED(mInfo->GetTypeForParam(methodIndex, &param, 1,
                                                  &datum_type)))
                 goto pre_call_clean_up;
         } else
             datum_type = type;
         if (param.IsIn()) {
             nsXPTCMiniVariant* pv;
             if (param.IsIndirect())
                 pv = (nsXPTCMiniVariant*) nativeParams[i].val.p;
             else
                 pv = &nativeParams[i];
             if (datum_type.IsInterfacePointer() &&
                 !GetInterfaceTypeFromParam(cx, info, param, methodIndex,
                                            datum_type, nativeParams,
                                            &param_iid))
                 goto pre_call_clean_up;
             if (isArray || isSizedString) {
                 if (!GetArraySizeFromParam(cx, info, param, methodIndex,
                                            i, nativeParams, &array_count))
                     goto pre_call_clean_up;
             }
             if (isArray) {
                 if (!XPCConvert::NativeArray2JS(&val,
                                                 (const void**)&pv->val,
                                                 datum_type, &param_iid,
                                                 array_count, nullptr))
                     goto pre_call_clean_up;
             } else if (isSizedString) {
                 if (!XPCConvert::NativeStringWithSize2JS(&val,
                                                          (const void*)&pv->val,
                                                          datum_type,
                                                          array_count, nullptr))
                     goto pre_call_clean_up;
             } else {
                 if (!XPCConvert::NativeData2JS(&val, &pv->val, type,
                                                &param_iid, nullptr))
                     goto pre_call_clean_up;
             }
         }
         if (param.IsOut() || param.IsDipper()) {
             // create an 'out' object
             RootedObject out_obj(cx, NewOutObject(cx, obj));
             if (!out_obj) {
                 retval = NS_ERROR_OUT_OF_MEMORY;
                 goto pre_call_clean_up;
             }
             if (param.IsIn()) {
                 if (!JS_SetPropertyById(cx, out_obj,
                                         mRuntime->GetStringID(XPCJSRuntime::IDX_VALUE),
                                         val)) {
                     goto pre_call_clean_up;
                 }
             }
             *sp++ = OBJECT_TO_JSVAL(out_obj);
         } else
             *sp++ = val;
     }
     readyToDoTheCall = true;
 pre_call_clean_up:
     // clean up any 'out' params handed in
     for (i = 0; i < paramCount; i++) {
         const nsXPTParamInfo& param = info->params[i];
         if (!param.IsOut())
             continue;
         const nsXPTType& type = param.GetType();
         if (!type.deprecated_IsPointer())
             continue;
         void* p;
         if (!(p = nativeParams[i].val.p))
             continue;
         if (param.IsIn()) {
             if (type.IsArray()) {
                 void** pp;
                 if (nullptr != (pp = *((void***)p))) {
                     // we need to get the array length and iterate the items
                     uint32_t array_count;
                     nsXPTType datum_type;
                     if (NS_SUCCEEDED(mInfo->GetTypeForParam(methodIndex, &param,
 , &datum_type)) &&
                         datum_type.deprecated_IsPointer() &&
                         GetArraySizeFromParam(cx, info, param, methodIndex,
                                               i, nativeParams, &array_count) &&
                         array_count) {
                         CleanupPointerArray(datum_type, array_count, pp);
                     }
                     // always release the array if it is inout
                     nsMemory::Free(pp);
                 }
             } else
                 CleanupPointerTypeObject(type, (void**)p);
         }
         *((void**)p) = nullptr;
     }
     // Make sure "this" doesn't get deleted during this call.
     nsCOMPtr<nsIXPCWrappedJSClass> kungFuDeathGrip(this);
     if (!readyToDoTheCall)
         return retval;
     // do the deed - note exceptions
     JS_ClearPendingException(cx);
     RootedValue rval(cx);
     if (XPT_MD_IS_GETTER(info->flags)) {
         success = JS_GetProperty(cx, obj, name, &rval);
     } else if (XPT_MD_IS_SETTER(info->flags)) {
         rval = *argv;
         success = JS_SetProperty(cx, obj, name, rval);
     } else {
         if (!JSVAL_IS_PRIMITIVE(fval)) {
             AutoSaveContextOptions asco(cx);
             ContextOptionsRef(cx).setDontReportUncaught(true);
             success = JS_CallFunctionValue(cx, thisObj, fval, args, &rval);
         } else {
             // The property was not an object so can't be a function.
             // Let's build and 'throw' an exception.
             static const nsresult code =
                     NS_ERROR_XPC_JSOBJECT_HAS_NO_FUNCTION_NAMED;
             static const char format[] = "%s \"%s\"";
             const char * msg;
             char* sz = nullptr;
             if (nsXPCException::NameAndFormatForNSResult(code, nullptr, &msg) && msg)
                 sz = JS_smprintf(format, msg, name);
             nsCOMPtr<nsIException> e;
             XPCConvert::ConstructException(code, sz, GetInterfaceName(), name,
                                            nullptr, getter_AddRefs(e), nullptr, nullptr);
             xpcc->SetException(e);
             if (sz)
                 JS_smprintf_free(sz);
             success = false;
         }
     }
     if (!success) {
         bool forceReport;
         if (NS_FAILED(mInfo->IsFunction(&forceReport)))
             forceReport = false;
         // May also want to check if we're moving from content->chrome and force
         // a report in that case.
         return CheckForException(ccx, name, GetInterfaceName(), forceReport);
     }
     XPCJSRuntime::Get()->SetPendingException(nullptr); // XXX necessary?
     // convert out args and result
     // NOTE: this is the total number of native params, not just the args
     // Convert 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.
     foundDependentParam = false;
     for (i = 0; i < paramCount; i++) {
         const nsXPTParamInfo& param = info->params[i];
         MOZ_ASSERT(!param.IsShared(), "[shared] implies [noscript]!");
         if (!param.IsOut() && !param.IsDipper())
             continue;
         const nsXPTType& type = param.GetType();
         if (type.IsDependent()) {
             foundDependentParam = true;
             continue;
         }
         RootedValue val(cx);
         uint8_t type_tag = type.TagPart();
         nsXPTCMiniVariant* pv;
         if (param.IsDipper())
             pv = (nsXPTCMiniVariant*) &nativeParams[i].val.p;
         else
             pv = (nsXPTCMiniVariant*) nativeParams[i].val.p;
         if (param.IsRetval())
             val = rval;
         else if (argv[i].isPrimitive())
             break;
         else {
             RootedObject obj(cx, &argv[i].toObject());
             if (!JS_GetPropertyById(cx, obj,
                                     mRuntime->GetStringID(XPCJSRuntime::IDX_VALUE),
                                     &val))
                 break;
         }
         // setup allocator and/or iid
         if (type_tag == nsXPTType::T_INTERFACE) {
             if (NS_FAILED(GetInterfaceInfo()->
                           GetIIDForParamNoAlloc(methodIndex, &param,
                                                 &param_iid)))
                 break;
         }
 // see bug #961488
 #if (defined(XP_UNIX) && !defined(XP_MACOSX) && !defined(_AIX)) && \
     ((defined(__sparc) && !defined(__sparcv9) && !defined(__sparcv9__)) || \
     (defined(__powerpc__) && !defined (__powerpc64__)))
         if (type_tag == nsXPTType::T_JSVAL) {
             if (!XPCConvert::JSData2Native(*(void**)(&pv->val), val, type,
                                            !param.IsDipper(), &param_iid, nullptr))
                 break;
         } else
 #endif
         {
             if (!XPCConvert::JSData2Native(&pv->val, val, type,
                                            !param.IsDipper(), &param_iid, nullptr))
                 break;
         }
     }
     // if any params were dependent, then we must iterate again to convert them.
     if (foundDependentParam && i == paramCount) {
         for (i = 0; i < paramCount; i++) {
             const nsXPTParamInfo& param = info->params[i];
             if (!param.IsOut())
                 continue;
             const nsXPTType& type = param.GetType();
             if (!type.IsDependent())
                 continue;
             RootedValue val(cx);
             nsXPTCMiniVariant* pv;
             nsXPTType datum_type;
             uint32_t array_count;
             bool isArray = type.IsArray();
             bool isSizedString = isArray ?
                     false :
                     type.TagPart() == nsXPTType::T_PSTRING_SIZE_IS ||
                     type.TagPart() == nsXPTType::T_PWSTRING_SIZE_IS;
             pv = (nsXPTCMiniVariant*) nativeParams[i].val.p;
             if (param.IsRetval())
                 val = rval;
             else {
                 RootedObject obj(cx, &argv[i].toObject());
                 if (!JS_GetPropertyById(cx, obj,
                                         mRuntime->GetStringID(XPCJSRuntime::IDX_VALUE),
                                         &val))
                     break;
             }
             // setup allocator and/or iid
             if (isArray) {
                 if (NS_FAILED(mInfo->GetTypeForParam(methodIndex, &param, 1,
                                                      &datum_type)))
                     break;
             } else
                 datum_type = type;
             if (datum_type.IsInterfacePointer()) {
                if (!GetInterfaceTypeFromParam(cx, info, param, methodIndex,
                                               datum_type, nativeParams,
                                               &param_iid))
                    break;
             }
             if (isArray || isSizedString) {
                 if (!GetArraySizeFromParam(cx, info, param, methodIndex,
                                            i, nativeParams, &array_count))
                     break;
             }
             if (isArray) {
                 if (array_count &&
                     !XPCConvert::JSArray2Native((void**)&pv->val, val,
                                                 array_count, datum_type,
                                                 &param_iid, nullptr))
                     break;
             } else if (isSizedString) {
                 if (!XPCConvert::JSStringWithSize2Native((void*)&pv->val, val,
                                                          array_count, datum_type,
                                                          nullptr))
                     break;
             } else {
                 if (!XPCConvert::JSData2Native(&pv->val, val, type,
                                                true, &param_iid,
                                                nullptr))
                     break;
             }
         }
     }
     if (i != paramCount) {
         // We didn't manage all the result conversions!
         // We have to cleanup any junk that *did* get converted.
         for (uint8_t k = 0; k < i; k++) {
             const nsXPTParamInfo& param = info->params[k];
             if (!param.IsOut())
                 continue;
             const nsXPTType& type = param.GetType();
             if (!type.deprecated_IsPointer())
                 continue;
             void* p;
             if (!(p = nativeParams[k].val.p))
                 continue;
             if (type.IsArray()) {
                 void** pp;
                 if (nullptr != (pp = *((void***)p))) {
                     // we need to get the array length and iterate the items
                     uint32_t array_count;
                     nsXPTType datum_type;
                     if (NS_SUCCEEDED(mInfo->GetTypeForParam(methodIndex, &param,
 , &datum_type)) &&
                         datum_type.deprecated_IsPointer() &&
                         GetArraySizeFromParam(cx, info, param, methodIndex,
                                               k, nativeParams, &array_count) &&
                         array_count) {
                         CleanupPointerArray(datum_type, array_count, pp);
                     }
                     nsMemory::Free(pp);
                 }
             } else
                 CleanupPointerTypeObject(type, (void**)p);
             *((void**)p) = nullptr;
         }
     } else {
         // set to whatever the JS code might have set as the result
         retval = pending_result;
     }
     return retval;
 }
 const char*
 nsXPCWrappedJSClass::GetInterfaceName()
 {
     if (!mName)
         mInfo->GetName(&mName);
     return mName;
 }
 static void
 FinalizeStub(JSFreeOp *fop, JSObject *obj)
 {
 }
 static const JSClass XPCOutParamClass = {
     "XPCOutParam",
 ,
     JS_PropertyStub,
     JS_DeletePropertyStub,
     JS_PropertyStub,
     JS_StrictPropertyStub,
     JS_EnumerateStub,
     JS_ResolveStub,
     JS_ConvertStub,
     FinalizeStub,
     nullptr,   /* call */
     nullptr,   /* hasInstance */
     nullptr,   /* construct */
     nullptr    /* trace */
 };
 bool
 xpc::IsOutObject(JSContext* cx, JSObject* obj)
 {
     return js::GetObjectJSClass(obj) == &XPCOutParamClass;
 }
 JSObject*
 xpc::NewOutObject(JSContext* cx, JSObject* scope)
 {
     RootedObject global(cx, JS_GetGlobalForObject(cx, scope));
     return JS_NewObject(cx, nullptr, NullPtr(), global);
 }
 NS_IMETHODIMP
 nsXPCWrappedJSClass::DebugDump(int16_t depth)
 {
 #ifdef DEBUG
     depth-- ;
     XPC_LOG_ALWAYS(("nsXPCWrappedJSClass @ %x with mRefCnt = %d", this, mRefCnt.get()));
     XPC_LOG_INDENT();
         char* name;
         mInfo->GetName(&name);
         XPC_LOG_ALWAYS(("interface name is %s", name));
         if (name)
             nsMemory::Free(name);
         char * iid = mIID.ToString();
         XPC_LOG_ALWAYS(("IID number is %s", iid ? iid : "invalid"));
         if (iid)
             NS_Free(iid);
         XPC_LOG_ALWAYS(("InterfaceInfo @ %x", mInfo.get()));
         uint16_t methodCount = 0;
         if (depth) {
             uint16_t i;
             nsCOMPtr<nsIInterfaceInfo> parent;
             XPC_LOG_INDENT();
             mInfo->GetParent(getter_AddRefs(parent));
             XPC_LOG_ALWAYS(("parent @ %x", parent.get()));
             mInfo->GetMethodCount(&methodCount);
             XPC_LOG_ALWAYS(("MethodCount = %d", methodCount));
             mInfo->GetConstantCount(&i);
             XPC_LOG_ALWAYS(("ConstantCount = %d", i));
             XPC_LOG_OUTDENT();
         }
         XPC_LOG_ALWAYS(("mRuntime @ %x", mRuntime));
         XPC_LOG_ALWAYS(("mDescriptors @ %x count = %d", mDescriptors, methodCount));
         if (depth && mDescriptors && methodCount) {
             depth--;
             XPC_LOG_INDENT();
             for (uint16_t i = 0; i < methodCount; i++) {
                 XPC_LOG_ALWAYS(("Method %d is %s%s", \
                                 i, IsReflectable(i) ? "":" NOT ","reflectable"));
             }
             XPC_LOG_OUTDENT();
             depth++;
         }
     XPC_LOG_OUTDENT();
 #endif
     return NS_OK;
 }

The Tor Browser / annotate

js/xpconnect/src/XPCWrappedJSClass.cpp@a63d609f5ebe (annotated)

js/xpconnect/src/XPCWrappedJSClass.cpp