gecko/dom/bindings/BindingUtils.cpp
Bobby Holley 50c7e8bc6b Bug 763341 - Handle wrappers in new dom binding QI. r=bz
The |ok| parent check goes away because it's ill-conceived. All it's really checking is that proxies are parented to the global, and it's impossible to port to SpecialPowers, because SpecialPowers will think that the proxy is parented to the SpecialPowers global. I don't think this check is very important, so I removed it.
2012-06-12 15:44:21 +02:00

402 lines
12 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-*/
/* vim: set ts=2 sw=2 et tw=79: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "BindingUtils.h"
#include "xpcprivate.h"
#include "XPCQuickStubs.h"
namespace mozilla {
namespace dom {
bool
DefineConstants(JSContext* cx, JSObject* obj, ConstantSpec* cs)
{
for (; cs->name; ++cs) {
JSBool ok =
JS_DefineProperty(cx, obj, cs->name, cs->value, NULL, NULL,
JSPROP_ENUMERATE | JSPROP_READONLY | JSPROP_PERMANENT);
if (!ok) {
return false;
}
}
return true;
}
static inline bool
Define(JSContext* cx, JSObject* obj, JSFunctionSpec* spec) {
return JS_DefineFunctions(cx, obj, spec);
}
static inline bool
Define(JSContext* cx, JSObject* obj, JSPropertySpec* spec) {
return JS_DefineProperties(cx, obj, spec);
}
static inline bool
Define(JSContext* cx, JSObject* obj, ConstantSpec* spec) {
return DefineConstants(cx, obj, spec);
}
template<typename T>
bool
DefinePrefable(JSContext* cx, JSObject* obj, Prefable<T>* props)
{
MOZ_ASSERT(props);
MOZ_ASSERT(props->specs);
do {
// Define if enabled
if (props->enabled) {
if (!Define(cx, obj, props->specs)) {
return false;
}
}
} while ((++props)->specs);
return true;
}
// We should use JSFunction objects for interface objects, but we need a custom
// hasInstance hook because we have new interface objects on prototype chains of
// old (XPConnect-based) bindings. Because Function.prototype.toString throws if
// passed a non-Function object we also need to provide our own toString method
// for interface objects.
enum {
TOSTRING_CLASS_RESERVED_SLOT = 0,
TOSTRING_NAME_RESERVED_SLOT = 1
};
JSBool
InterfaceObjectToString(JSContext* cx, unsigned argc, JS::Value *vp)
{
JSObject* callee = JSVAL_TO_OBJECT(JS_CALLEE(cx, vp));
JSObject* obj = JS_THIS_OBJECT(cx, vp);
if (!obj) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_CANT_CONVERT_TO,
"null", "object");
return false;
}
jsval v = js::GetFunctionNativeReserved(callee, TOSTRING_CLASS_RESERVED_SLOT);
JSClass* clasp = static_cast<JSClass*>(JSVAL_TO_PRIVATE(v));
v = js::GetFunctionNativeReserved(callee, TOSTRING_NAME_RESERVED_SLOT);
JSString* jsname = static_cast<JSString*>(JSVAL_TO_STRING(v));
size_t length;
const jschar* name = JS_GetInternedStringCharsAndLength(jsname, &length);
if (js::GetObjectJSClass(obj) != clasp) {
JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_INCOMPATIBLE_PROTO,
NS_ConvertUTF16toUTF8(name).get(), "toString",
"object");
return false;
}
JS::Value* argv = JS_ARGV(cx, vp);
uint32_t indent = 0;
if (argc != 0 && !JS_ValueToECMAUint32(cx, argv[0], &indent))
return false;
nsAutoString spaces;
while (indent-- > 0) {
spaces.Append(PRUnichar(' '));
}
nsString str;
str.Append(spaces);
str.AppendLiteral("function ");
str.Append(name, length);
str.AppendLiteral("() {");
str.Append('\n');
str.Append(spaces);
str.AppendLiteral(" [native code]");
str.Append('\n');
str.Append(spaces);
str.AppendLiteral("}");
return xpc::NonVoidStringToJsval(cx, str, vp);
}
static JSObject*
CreateInterfaceObject(JSContext* cx, JSObject* global, JSObject* receiver,
JSClass* constructorClass, JSNative constructorNative,
unsigned ctorNargs, JSObject* proto,
Prefable<JSFunctionSpec>* staticMethods,
Prefable<ConstantSpec>* constants,
const char* name)
{
JSObject* constructor;
if (constructorClass) {
JSObject* functionProto = JS_GetFunctionPrototype(cx, global);
if (!functionProto) {
return NULL;
}
constructor = JS_NewObject(cx, constructorClass, functionProto, global);
} else {
MOZ_ASSERT(constructorNative);
JSFunction* fun = JS_NewFunction(cx, constructorNative, ctorNargs,
JSFUN_CONSTRUCTOR, global, name);
if (!fun) {
return NULL;
}
constructor = JS_GetFunctionObject(fun);
}
if (!constructor) {
return NULL;
}
if (staticMethods && !DefinePrefable(cx, constructor, staticMethods)) {
return NULL;
}
if (constructorClass) {
JSFunction* toString = js::DefineFunctionWithReserved(cx, constructor,
"toString",
InterfaceObjectToString,
0, 0);
if (!toString) {
return NULL;
}
JSObject* toStringObj = JS_GetFunctionObject(toString);
js::SetFunctionNativeReserved(toStringObj, TOSTRING_CLASS_RESERVED_SLOT,
PRIVATE_TO_JSVAL(constructorClass));
JSString *str = ::JS_InternString(cx, name);
if (!str) {
return NULL;
}
js::SetFunctionNativeReserved(toStringObj, TOSTRING_NAME_RESERVED_SLOT,
STRING_TO_JSVAL(str));
}
if (constants && !DefinePrefable(cx, constructor, constants)) {
return NULL;
}
if (proto && !JS_LinkConstructorAndPrototype(cx, constructor, proto)) {
return NULL;
}
JSBool alreadyDefined;
if (!JS_AlreadyHasOwnProperty(cx, receiver, name, &alreadyDefined)) {
return NULL;
}
// This is Enumerable: False per spec.
if (!alreadyDefined &&
!JS_DefineProperty(cx, receiver, name, OBJECT_TO_JSVAL(constructor), NULL,
NULL, 0)) {
return NULL;
}
return constructor;
}
static JSObject*
CreateInterfacePrototypeObject(JSContext* cx, JSObject* global,
JSObject* parentProto, JSClass* protoClass,
Prefable<JSFunctionSpec>* methods,
Prefable<JSPropertySpec>* properties,
Prefable<ConstantSpec>* constants)
{
JSObject* ourProto = JS_NewObjectWithUniqueType(cx, protoClass, parentProto,
global);
if (!ourProto) {
return NULL;
}
if (methods && !DefinePrefable(cx, ourProto, methods)) {
return NULL;
}
if (properties && !DefinePrefable(cx, ourProto, properties)) {
return NULL;
}
if (constants && !DefinePrefable(cx, ourProto, constants)) {
return NULL;
}
return ourProto;
}
JSObject*
CreateInterfaceObjects(JSContext* cx, JSObject* global, JSObject *receiver,
JSObject* protoProto, JSClass* protoClass,
JSClass* constructorClass, JSNative constructor,
unsigned ctorNargs, Prefable<JSFunctionSpec>* methods,
Prefable<JSPropertySpec>* properties,
Prefable<ConstantSpec>* constants,
Prefable<JSFunctionSpec>* staticMethods, const char* name)
{
MOZ_ASSERT(protoClass || constructorClass || constructor,
"Need at least one class or a constructor!");
MOZ_ASSERT(!(methods || properties) || protoClass,
"Methods or properties but no protoClass!");
MOZ_ASSERT(!staticMethods || constructorClass || constructor,
"Static methods but no constructorClass or constructor!");
MOZ_ASSERT(bool(name) == bool(constructorClass || constructor),
"Must have name precisely when we have an interface object");
MOZ_ASSERT(!constructorClass || !constructor);
JSObject* proto;
if (protoClass) {
proto = CreateInterfacePrototypeObject(cx, global, protoProto, protoClass,
methods, properties, constants);
if (!proto) {
return NULL;
}
}
else {
proto = NULL;
}
JSObject* interface;
if (constructorClass || constructor) {
interface = CreateInterfaceObject(cx, global, receiver, constructorClass,
constructor, ctorNargs, proto,
staticMethods, constants, name);
if (!interface) {
return NULL;
}
}
return protoClass ? proto : interface;
}
static bool
NativeInterface2JSObjectAndThrowIfFailed(XPCLazyCallContext& aLccx,
JSContext* aCx,
JS::Value* aRetval,
xpcObjectHelper& aHelper,
const nsIID* aIID,
bool aAllowNativeWrapper)
{
nsresult rv;
if (!XPCConvert::NativeInterface2JSObject(aLccx, aRetval, NULL, aHelper, aIID,
NULL, aAllowNativeWrapper, &rv)) {
// I can't tell if NativeInterface2JSObject throws JS exceptions
// or not. This is a sloppy stab at the right semantics; the
// method really ought to be fixed to behave consistently.
if (!JS_IsExceptionPending(aCx)) {
Throw<true>(aCx, NS_FAILED(rv) ? rv : NS_ERROR_UNEXPECTED);
}
return false;
}
return true;
}
bool
DoHandleNewBindingWrappingFailure(JSContext* cx, JSObject* scope,
nsISupports* value, JS::Value* vp)
{
if (JS_IsExceptionPending(cx)) {
return false;
}
XPCLazyCallContext lccx(JS_CALLER, cx, scope);
if (value) {
xpcObjectHelper helper(value);
return NativeInterface2JSObjectAndThrowIfFailed(lccx, cx, vp, helper, NULL,
true);
}
return Throw<true>(cx, NS_ERROR_XPC_BAD_CONVERT_JS);
}
// Only set allowNativeWrapper to false if you really know you need it, if in
// doubt use true. Setting it to false disables security wrappers.
bool
XPCOMObjectToJsval(JSContext* cx, JSObject* scope, xpcObjectHelper &helper,
const nsIID* iid, bool allowNativeWrapper, JS::Value* rval)
{
XPCLazyCallContext lccx(JS_CALLER, cx, scope);
if (!NativeInterface2JSObjectAndThrowIfFailed(lccx, cx, rval, helper, iid,
allowNativeWrapper)) {
return false;
}
#ifdef DEBUG
JSObject* jsobj = JSVAL_TO_OBJECT(*rval);
if (jsobj && !js::GetObjectParent(jsobj))
NS_ASSERTION(js::GetObjectClass(jsobj)->flags & JSCLASS_IS_GLOBAL,
"Why did we recreate this wrapper?");
#endif
return true;
}
JSBool
QueryInterface(JSContext* cx, unsigned argc, JS::Value* vp)
{
JS::Value thisv = JS_THIS(cx, vp);
if (thisv == JSVAL_NULL)
return false;
// Get the object. It might be a security wrapper, in which case we do a checked
// unwrap.
JSObject* origObj = JSVAL_TO_OBJECT(thisv);
JSObject* obj = js::UnwrapObjectChecked(cx, origObj);
if (!obj)
return false;
JSClass* clasp = js::GetObjectJSClass(obj);
if (!IsDOMClass(clasp) ||
!DOMJSClass::FromJSClass(clasp)->mDOMObjectIsISupports) {
return Throw<true>(cx, NS_ERROR_FAILURE);
}
nsISupports* native = UnwrapDOMObject<nsISupports>(obj);
if (argc < 1) {
return Throw<true>(cx, NS_ERROR_XPC_NOT_ENOUGH_ARGS);
}
JS::Value* argv = JS_ARGV(cx, vp);
if (!argv[0].isObject()) {
return Throw<true>(cx, NS_ERROR_XPC_BAD_CONVERT_JS);
}
nsIJSIID* iid;
xpc_qsSelfRef iidRef;
if (NS_FAILED(xpc_qsUnwrapArg<nsIJSIID>(cx, argv[0], &iid, &iidRef.ptr,
&argv[0]))) {
return Throw<true>(cx, NS_ERROR_XPC_BAD_CONVERT_JS);
}
MOZ_ASSERT(iid);
if (iid->GetID()->Equals(NS_GET_IID(nsIClassInfo))) {
nsresult rv;
nsCOMPtr<nsIClassInfo> ci = do_QueryInterface(native, &rv);
if (NS_FAILED(rv)) {
return Throw<true>(cx, rv);
}
return WrapObject(cx, origObj, ci, &NS_GET_IID(nsIClassInfo), vp);
}
// Lie, otherwise we need to check classinfo or QI
*vp = thisv;
return true;
}
JSBool
ThrowingConstructor(JSContext* cx, unsigned argc, JS::Value* vp)
{
return Throw<true>(cx, NS_ERROR_FAILURE);
}
JSBool
ThrowingConstructorWorkers(JSContext* cx, unsigned argc, JS::Value* vp)
{
return Throw<false>(cx, NS_ERROR_FAILURE);
}
} // namespace dom
} // namespace mozilla