/* -*- 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 "mozilla/jsipc/CrossProcessObjectWrappers.h"
#include "jsapi.h"
#include "jsfriendapi.h"
using namespace xpc;
using namespace JS;
using namespace mozilla;
using namespace mozilla::dom;
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)
{
NS_PRECONDITION(!mEvaluated, "AutoScriptEvaluate::Evaluate should only be called once");
if (!mJSContext)
return true;
mEvaluated = true;
JS_BeginRequest(mJSContext);
mAutoCompartment.emplace(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.emplace(mJSContext);
return true;
}
AutoScriptEvaluate::~AutoScriptEvaluate()
{
if (!mJSContext || !mEvaluated)
return;
mState->restore();
JS_EndRequest(mJSContext);
}
// 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;
}
}
// A little stack-based RAII class to help management of the XPCJSContext
// PendingResult.
class MOZ_STACK_CLASS AutoSavePendingResult {
public:
explicit AutoSavePendingResult(XPCJSContext* xpccx) :
mXPCContext(xpccx)
{
// Save any existing pending result and reset to NS_OK for this invocation.
mSavedResult = xpccx->GetPendingResult();
xpccx->SetPendingResult(NS_OK);
}
~AutoSavePendingResult() {
mXPCContext->SetPendingResult(mSavedResult);
}
private:
XPCJSContext* mXPCContext;
nsresult mSavedResult;
};
// static
already_AddRefed<nsXPCWrappedJSClass>
nsXPCWrappedJSClass::GetNewOrUsed(JSContext* cx, REFNSIID aIID, bool allowNonScriptable)
{
XPCJSContext* xpccx = nsXPConnect::GetContextInstance();
IID2WrappedJSClassMap* map = xpccx->GetWrappedJSClassMap();
RefPtr<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 || allowNonScriptable) &&
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)
: mContext(nsXPConnect::GetContextInstance()),
mInfo(aInfo),
mName(nullptr),
mIID(aIID),
mDescriptors(nullptr)
{
mContext->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 (mContext)
mContext->GetWrappedJSClassMap()->Remove(this);
if (mName)
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);
// In bug 503926, we added a security check to make sure that we don't
// invoke content QI functions. In the modern world, this is probably
// unnecessary, because invoking QI involves passing an IID object to
// content, which will fail. But we do a belt-and-suspenders check to
// make sure that content can never trigger the rat's nest of code below.
// Once we completely turn off XPConnect for the web, this can definitely
// go away.
if (!AccessCheck::isChrome(jsobj) ||
!AccessCheck::isChrome(js::UncheckedUnwrap(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 = mContext->GetStringID(XPCJSContext::IDX_QUERY_INTERFACE);
if (!JS_GetPropertyById(cx, jsobj, funid, &fun) || fun.isPrimitive())
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))) {
bool allowNonScriptable = mozilla::jsipc::IsWrappedCPOW(jsobj);
nsCOMPtr<nsIInterfaceInfo> info;
nsXPConnect::XPConnect()->GetInfoForIID(&aIID, getter_AddRefs(info));
if (!info)
return nullptr;
bool canScript, isBuiltin;
if (NS_FAILED(info->IsScriptable(&canScript)) || (!canScript && !allowNonScriptable) ||
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.
{
RootedValue arg(cx, JS::ObjectValue(*id));
success = JS_CallFunctionValue(cx, jsobj, fun, HandleValueArray(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.
JS::Rooted<JSObject*> exceptionObj(cx, &jsexception.toObject());
Exception* e = nullptr;
UNWRAP_OBJECT(Exception, &exceptionObj, e);
if (e &&
NS_SUCCEEDED(e->GetResult(&rv)) &&
rv == NS_NOINTERFACE) {
JS_ClearPendingException(cx);
}
} else if (jsexception.isNumber()) {
// JS often throws an nsresult.
if (jsexception.isDouble())
// 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)(jsexception.toDouble());
else
rv = (nsresult)(jsexception.toInt32());
if (rv == NS_NOINTERFACE)
JS_ClearPendingException(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) &&
XPCConvert::JSData2Native(aResult, val, type,
&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 Value 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;
Rooted<IdVector> idArray(cx, IdVector(cx));
if (!JS_Enumerate(cx, aJSObj, &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;
nsAutoJSString autoStr;
if (!autoStr.init(cx, name))
return NS_ERROR_FAILURE;
nsCOMPtr<nsIProperty> property =
new xpcProperty(autoStr.get(), (uint32_t)autoStr.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)
{
}
NS_IMETHODIMP xpcProperty::GetName(nsAString & aName)
{
aName.Assign(mName);
return NS_OK;
}
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();
}
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;
}
// QI on an XPCWrappedJS can run script, so we need an AutoEntryScript.
// This is inherently Gecko-specific.
// We check both nativeGlobal and nativeGlobal->GetGlobalJSObject() even
// though we have derived nativeGlobal from the JS global, because we know
// there are cases where this can happen. See bug 1094953.
nsIGlobalObject* nativeGlobal =
NativeGlobal(js::GetGlobalForObjectCrossCompartment(self->GetJSObject()));
NS_ENSURE_TRUE(nativeGlobal, NS_ERROR_FAILURE);
NS_ENSURE_TRUE(nativeGlobal->GetGlobalJSObject(), NS_ERROR_FAILURE);
AutoEntryScript aes(nativeGlobal, "XPCWrappedJS QueryInterface",
/* aIsMainThread = */ true);
XPCCallContext ccx(aes.cx());
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;
}
// Check if the desired interface is a function interface. If so, we don't
// want to QI, because the function almost certainly doesn't have a QueryInterface
// property, and doesn't need one.
bool isFunc = false;
nsCOMPtr<nsIInterfaceInfo> info;
nsXPConnect::XPConnect()->GetInfoForIID(&aIID, getter_AddRefs(info));
if (info && NS_SUCCEEDED(info->IsFunction(&isFunc)) && isFunc) {
RefPtr<nsXPCWrappedJS> wrapper;
RootedObject obj(RootingCx(), self->GetJSObject());
nsresult rv = nsXPCWrappedJS::GetNewOrUsed(obj, aIID, getter_AddRefs(wrapper));
// Do the same thing we do for the "check for any existing wrapper" case above.
if (NS_SUCCEEDED(rv) && wrapper) {
*aInstancePtr = wrapper.forget().take()->GetXPTCStub();
}
return rv;
}
// 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.
RefPtr<nsXPCWrappedJS> wrapper;
nsresult rv = nsXPCWrappedJS::GetNewOrUsed(jsobj, aIID, getter_AddRefs(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);
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)
result = aJSObj;
JSObject* inner = js::UncheckedUnwrap(result);
if (inner)
return inner;
return result;
}
bool
nsXPCWrappedJSClass::GetArraySizeFromParam(JSContext* cx,
const XPTMethodDescriptor* method,
const nsXPTParamInfo& param,
uint16_t methodIndex,
uint8_t paramIndex,
nsXPTCMiniVariant* nativeParams,
uint32_t* result) const
{
uint8_t argnum;
nsresult rv;
rv = mInfo->GetSizeIsArgNumberForParam(methodIndex, ¶m, 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) const
{
uint8_t type_tag = type.TagPart();
if (type_tag == nsXPTType::T_INTERFACE) {
if (NS_SUCCEEDED(GetInterfaceInfo()->
GetIIDForParamNoAlloc(methodIndex, ¶m, result))) {
return true;
}
} else if (type_tag == nsXPTType::T_INTERFACE_IS) {
uint8_t argnum;
nsresult rv;
rv = mInfo->GetInterfaceIsArgNumberForParam(methodIndex,
¶m, &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;
}
/* static */ 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) free(p);
}
}
}
/* static */ 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) free(p);
}
}
void
nsXPCWrappedJSClass::CleanupOutparams(JSContext* cx, uint16_t methodIndex,
const nsXPTMethodInfo* info, nsXPTCMiniVariant* nativeParams,
bool inOutOnly, uint8_t n) const
{
// clean up any 'out' params handed in
for (uint8_t i = 0; i < n; i++) {
const nsXPTParamInfo& param = info->params[i];
if (!param.IsOut())
continue;
const nsXPTType& type = param.GetType();
if (!type.deprecated_IsPointer())
continue;
void* p = nativeParams[i].val.p;
if (!p)
continue;
// The inOutOnly flag was introduced when consolidating two very
// similar code paths in CallMethod in bug 1175513. I don't know
// if and why the difference is necessary.
if (!inOutOnly || param.IsIn()) {
if (type.IsArray()) {
void** pp = *static_cast<void***>(p);
if (pp) {
// we need to get the array length and iterate the items
uint32_t array_count;
nsXPTType datum_type;
if (NS_SUCCEEDED(mInfo->GetTypeForParam(methodIndex, ¶m,
1, &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
free(pp);
}
} else {
CleanupPointerTypeObject(type, static_cast<void**>(p));
}
}
*static_cast<void**>(p) = nullptr;
}
}
nsresult
nsXPCWrappedJSClass::CheckForException(XPCCallContext & ccx,
AutoEntryScript& aes,
const char * aPropertyName,
const char * anInterfaceName,
nsIException* aSyntheticException)
{
JSContext * cx = ccx.GetJSContext();
MOZ_ASSERT(cx == aes.cx());
nsCOMPtr<nsIException> xpc_exception = aSyntheticException;
/* this one would be set by our error reporter */
XPCJSContext* xpccx = XPCJSContext::Get();
// Get this right away in case we do something below to cause JS code
// to run.
nsresult pending_result = xpccx->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) {
xpccx->SetPendingException(nullptr); // XXX necessary?
}
}
// Clear the pending exception now, because xpc_exception might be JS-
// implemented, so invoking methods on it might re-enter JS, which we can't
// do with an exception on the stack.
aes.ClearException();
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) {
// 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 (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)
{
// Note that we cleared the exception above, so we need to set it again,
// just so that we can tell the JS engine to pass it back to us via the
// error reporting callback. This is all very dumb.
JS_SetPendingException(cx, js_exception);
aes.ReportException();
reportable = false;
}
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(cx, 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(cx, 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(cx, &lineNumber);
// get a filename.
rv = location->GetFilename(cx, 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)) {
xpccx->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)
{
Value* sp = nullptr;
Value* argv = nullptr;
uint8_t i;
nsresult retval = NS_ERROR_FAILURE;
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.
//
// We're about to call into script via an XPCWrappedJS, so we need an
// AutoEntryScript. This is probably Gecko-specific at this point, and
// definitely will be when we turn off XPConnect for the web.
nsIGlobalObject* nativeGlobal =
NativeGlobal(js::GetGlobalForObjectCrossCompartment(wrapper->GetJSObject()));
AutoEntryScript aes(nativeGlobal, "XPCWrappedJS method call",
/* aIsMainThread = */ true);
XPCCallContext ccx(aes.cx());
if (!ccx.IsValid())
return retval;
JSContext* cx = ccx.GetJSContext();
if (!cx || !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_ReportErrorASCII(cx, "%s", str);
NS_WARNING(str);
return CheckForException(ccx, aes, name, GetInterfaceName());
}
RootedValue fval(cx);
RootedObject obj(cx, wrapper->GetJSObject());
RootedObject thisObj(cx, obj);
JSAutoCompartment ac(cx, obj);
AutoValueVector args(cx);
AutoScriptEvaluate scriptEval(cx);
XPCJSContext* xpccx = XPCJSContext::Get();
AutoSavePendingResult apr(xpccx);
// 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))
goto pre_call_clean_up;
xpccx->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 =
mContext->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,
false, nullptr);
if (!ok) {
goto pre_call_clean_up;
}
thisObj = v.toObjectOrNull();
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, ¶m, 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,
¶m_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, ¶m_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,
¶m_iid, nullptr))
goto pre_call_clean_up;
}
}
if (param.IsOut() || param.IsDipper()) {
// create an 'out' object
RootedObject out_obj(cx, NewOutObject(cx));
if (!out_obj) {
retval = NS_ERROR_OUT_OF_MEMORY;
goto pre_call_clean_up;
}
if (param.IsIn()) {
if (!JS_SetPropertyById(cx, out_obj,
mContext->GetStringID(XPCJSContext::IDX_VALUE),
val)) {
goto pre_call_clean_up;
}
}
*sp++ = JS::ObjectValue(*out_obj);
} else
*sp++ = val;
}
readyToDoTheCall = true;
pre_call_clean_up:
// clean up any 'out' params handed in
CleanupOutparams(cx, methodIndex, info, nativeParams, /* inOutOnly = */ true, paramCount);
// Make sure "this" doesn't get deleted during this call.
nsCOMPtr<nsIXPCWrappedJSClass> kungFuDeathGrip(this);
if (!readyToDoTheCall)
return retval;
// do the deed - note exceptions
MOZ_ASSERT(!aes.HasException());
nsCOMPtr<nsIException> syntheticException;
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 (!fval.isPrimitive()) {
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);
XPCConvert::ConstructException(code, sz, GetInterfaceName(), name,
nullptr, getter_AddRefs(syntheticException),
nullptr, nullptr);
if (sz)
JS_smprintf_free(sz);
success = false;
}
}
if (!success)
return CheckForException(ccx, aes, name, GetInterfaceName(),
syntheticException);
XPCJSContext::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,
mContext->GetStringID(XPCJSContext::IDX_VALUE),
&val))
break;
}
// setup allocator and/or iid
if (type_tag == nsXPTType::T_INTERFACE) {
if (NS_FAILED(GetInterfaceInfo()->
GetIIDForParamNoAlloc(methodIndex, ¶m,
¶m_iid)))
break;
}
if (!XPCConvert::JSData2Native(&pv->val, val, type,
¶m_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,
mContext->GetStringID(XPCJSContext::IDX_VALUE),
&val))
break;
}
// setup allocator and/or iid
if (isArray) {
if (NS_FAILED(mInfo->GetTypeForParam(methodIndex, ¶m, 1,
&datum_type)))
break;
} else
datum_type = type;
if (datum_type.IsInterfacePointer()) {
if (!GetInterfaceTypeFromParam(cx, info, param, methodIndex,
datum_type, nativeParams,
¶m_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,
¶m_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,
¶m_iid,
nullptr))
break;
}
}
}
if (i != paramCount) {
// We didn't manage all the result conversions!
// We have to cleanup any junk that *did* get converted.
CleanupOutparams(cx, methodIndex, info, nativeParams, /* inOutOnly = */ false, i);
} else {
// set to whatever the JS code might have set as the result
retval = xpccx->GetPendingResult();
}
return retval;
}
const char*
nsXPCWrappedJSClass::GetInterfaceName()
{
if (!mName)
mInfo->GetName(&mName);
return mName;
}
static const JSClass XPCOutParamClass = {
"XPCOutParam",
0,
JS_NULL_CLASS_OPS
};
bool
xpc::IsOutObject(JSContext* cx, JSObject* obj)
{
return js::GetObjectJSClass(obj) == &XPCOutParamClass;
}
JSObject*
xpc::NewOutObject(JSContext* cx)
{
return JS_NewObject(cx, &XPCOutParamClass);
}
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)
free(name);
char * iid = mIID.ToString();
XPC_LOG_ALWAYS(("IID number is %s", iid ? iid : "invalid"));
if (iid)
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(("mContext @ %x", mContext));
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;
}