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gecko/dom/bindings/BindingUtils.h

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/* -*- 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/. */
#ifndef mozilla_dom_BindingUtils_h__
#define mozilla_dom_BindingUtils_h__
#include "mozilla/dom/DOMJSClass.h"
#include "mozilla/dom/DOMJSProxyHandler.h"
#include "mozilla/dom/NonRefcountedDOMObject.h"
#include "mozilla/dom/workers/Workers.h"
#include "mozilla/ErrorResult.h"
#include "jsfriendapi.h"
#include "jswrapper.h"
#include "nsIXPConnect.h"
#include "qsObjectHelper.h"
#include "xpcpublic.h"
#include "nsTraceRefcnt.h"
#include "nsWrapperCacheInlines.h"
#include "mozilla/Likely.h"
#include "mozilla/dom/BindingDeclarations.h"
#include "mozilla/dom/CallbackObject.h"
namespace mozilla {
namespace dom {
bool
ThrowErrorMessage(JSContext* aCx, const ErrNum aErrorNumber, ...);
template<bool mainThread>
inline bool
Throw(JSContext* cx, nsresult rv)
{
using mozilla::dom::workers::exceptions::ThrowDOMExceptionForNSResult;
// XXX Introduce exception machinery.
if (mainThread) {
xpc::Throw(cx, rv);
} else {
if (!JS_IsExceptionPending(cx)) {
ThrowDOMExceptionForNSResult(cx, rv);
}
}
return false;
}
template<bool mainThread>
inline bool
ThrowMethodFailedWithDetails(JSContext* cx, ErrorResult& rv,
const char* /* ifaceName */,
const char* /* memberName */)
{
if (rv.IsTypeError()) {
rv.ReportTypeError(cx);
return false;
}
if (rv.IsJSException()) {
rv.ReportJSException(cx);
return false;
}
return Throw<mainThread>(cx, rv.ErrorCode());
}
// Returns true if the JSClass is used for DOM objects.
inline bool
IsDOMClass(const JSClass* clasp)
{
return clasp->flags & JSCLASS_IS_DOMJSCLASS;
}
inline bool
IsDOMClass(const js::Class* clasp)
{
return IsDOMClass(Jsvalify(clasp));
}
// Returns true if the JSClass is used for DOM interface and interface
// prototype objects.
inline bool
IsDOMIfaceAndProtoClass(const JSClass* clasp)
{
return clasp->flags & JSCLASS_IS_DOMIFACEANDPROTOJSCLASS;
}
inline bool
IsDOMIfaceAndProtoClass(const js::Class* clasp)
{
return IsDOMIfaceAndProtoClass(Jsvalify(clasp));
}
MOZ_STATIC_ASSERT(DOM_OBJECT_SLOT == js::JSSLOT_PROXY_PRIVATE,
"JSSLOT_PROXY_PRIVATE doesn't match DOM_OBJECT_SLOT. "
"Expect bad things");
template <class T>
inline T*
UnwrapDOMObject(JSObject* obj)
{
MOZ_ASSERT(IsDOMClass(js::GetObjectClass(obj)) || IsDOMProxy(obj),
"Don't pass non-DOM objects to this function");
JS::Value val = js::GetReservedSlot(obj, DOM_OBJECT_SLOT);
return static_cast<T*>(val.toPrivate());
}
inline const DOMClass*
GetDOMClass(JSObject* obj)
{
js::Class* clasp = js::GetObjectClass(obj);
if (IsDOMClass(clasp)) {
return &DOMJSClass::FromJSClass(clasp)->mClass;
}
if (js::IsObjectProxyClass(clasp) || js::IsFunctionProxyClass(clasp)) {
js::BaseProxyHandler* handler = js::GetProxyHandler(obj);
if (handler->family() == ProxyFamily()) {
return &static_cast<DOMProxyHandler*>(handler)->mClass;
}
}
return nullptr;
}
inline bool
UnwrapDOMObjectToISupports(JSObject* obj, nsISupports*& result)
{
const DOMClass* clasp = GetDOMClass(obj);
if (!clasp || !clasp->mDOMObjectIsISupports) {
return false;
}
result = UnwrapDOMObject<nsISupports>(obj);
return true;
}
inline bool
IsDOMObject(JSObject* obj)
{
js::Class* clasp = js::GetObjectClass(obj);
return IsDOMClass(clasp) || IsDOMProxy(obj, clasp);
}
// Some callers don't want to set an exception when unwrapping fails
// (for example, overload resolution uses unwrapping to tell what sort
// of thing it's looking at).
// U must be something that a T* can be assigned to (e.g. T* or an nsRefPtr<T>).
template <prototypes::ID PrototypeID, class T, typename U>
MOZ_ALWAYS_INLINE nsresult
UnwrapObject(JSContext* cx, JSObject* obj, U& value)
{
/* First check to see whether we have a DOM object */
const DOMClass* domClass = GetDOMClass(obj);
if (!domClass) {
/* Maybe we have a security wrapper or outer window? */
if (!js::IsWrapper(obj)) {
/* Not a DOM object, not a wrapper, just bail */
return NS_ERROR_XPC_BAD_CONVERT_JS;
}
obj = js::CheckedUnwrap(obj, /* stopAtOuter = */ false);
if (!obj) {
return NS_ERROR_XPC_SECURITY_MANAGER_VETO;
}
MOZ_ASSERT(!js::IsWrapper(obj));
domClass = GetDOMClass(obj);
if (!domClass) {
/* We don't have a DOM object */
return NS_ERROR_XPC_BAD_CONVERT_JS;
}
}
/* This object is a DOM object. Double-check that it is safely
castable to T by checking whether it claims to inherit from the
class identified by protoID. */
if (domClass->mInterfaceChain[PrototypeTraits<PrototypeID>::Depth] ==
PrototypeID) {
value = UnwrapDOMObject<T>(obj);
return NS_OK;
}
/* It's the wrong sort of DOM object */
return NS_ERROR_XPC_BAD_CONVERT_JS;
}
inline bool
IsNotDateOrRegExp(JSContext* cx, JS::Handle<JSObject*> obj)
{
MOZ_ASSERT(obj);
return !JS_ObjectIsDate(cx, obj) && !JS_ObjectIsRegExp(cx, obj);
}
MOZ_ALWAYS_INLINE bool
IsArrayLike(JSContext* cx, JS::Handle<JSObject*> obj)
{
return IsNotDateOrRegExp(cx, obj);
}
MOZ_ALWAYS_INLINE bool
IsObjectValueConvertibleToDictionary(JSContext* cx,
JS::Handle<JS::Value> objVal)
{
JS::Rooted<JSObject*> obj(cx, &objVal.toObject());
return IsNotDateOrRegExp(cx, obj);
}
MOZ_ALWAYS_INLINE bool
IsConvertibleToDictionary(JSContext* cx, JS::Handle<JS::Value> val)
{
return val.isNullOrUndefined() ||
(val.isObject() && IsObjectValueConvertibleToDictionary(cx, val));
}
MOZ_ALWAYS_INLINE bool
IsConvertibleToCallbackInterface(JSContext* cx, JS::Handle<JSObject*> obj)
{
return IsNotDateOrRegExp(cx, obj);
}
// U must be something that a T* can be assigned to (e.g. T* or an nsRefPtr<T>).
template <class T, typename U>
inline nsresult
UnwrapObject(JSContext* cx, JSObject* obj, U& value)
{
return UnwrapObject<static_cast<prototypes::ID>(
PrototypeIDMap<T>::PrototypeID), T>(cx, obj, value);
}
// The items in the protoAndIfaceArray are indexed by the prototypes::id::ID and
// constructors::id::ID enums, in that order. The end of the prototype objects
// should be the start of the interface objects.
MOZ_STATIC_ASSERT((size_t)constructors::id::_ID_Start ==
(size_t)prototypes::id::_ID_Count,
"Overlapping or discontiguous indexes.");
const size_t kProtoAndIfaceCacheCount = constructors::id::_ID_Count;
inline void
AllocateProtoAndIfaceCache(JSObject* obj)
{
MOZ_ASSERT(js::GetObjectClass(obj)->flags & JSCLASS_DOM_GLOBAL);
MOZ_ASSERT(js::GetReservedSlot(obj, DOM_PROTOTYPE_SLOT).isUndefined());
// Important: The () at the end ensure zero-initialization
JSObject** protoAndIfaceArray = new JSObject*[kProtoAndIfaceCacheCount]();
js::SetReservedSlot(obj, DOM_PROTOTYPE_SLOT,
JS::PrivateValue(protoAndIfaceArray));
}
inline void
TraceProtoAndIfaceCache(JSTracer* trc, JSObject* obj)
{
MOZ_ASSERT(js::GetObjectClass(obj)->flags & JSCLASS_DOM_GLOBAL);
if (!HasProtoAndIfaceArray(obj))
return;
JSObject** protoAndIfaceArray = GetProtoAndIfaceArray(obj);
for (size_t i = 0; i < kProtoAndIfaceCacheCount; ++i) {
if (protoAndIfaceArray[i]) {
JS_CallObjectTracer(trc, &protoAndIfaceArray[i], "protoAndIfaceArray[i]");
}
}
}
inline void
DestroyProtoAndIfaceCache(JSObject* obj)
{
MOZ_ASSERT(js::GetObjectClass(obj)->flags & JSCLASS_DOM_GLOBAL);
JSObject** protoAndIfaceArray = GetProtoAndIfaceArray(obj);
delete [] protoAndIfaceArray;
}
/**
* Add constants to an object.
*/
bool
DefineConstants(JSContext* cx, JS::Handle<JSObject*> obj,
const ConstantSpec* cs);
struct JSNativeHolder
{
JSNative mNative;
const NativePropertyHooks* mPropertyHooks;
};
struct NamedConstructor
{
const char* mName;
const JSNativeHolder mHolder;
unsigned mNargs;
};
/*
* Create a DOM interface object (if constructorClass is non-null) and/or a
* DOM interface prototype object (if protoClass is non-null).
*
* global is used as the parent of the interface object and the interface
* prototype object
* protoProto is the prototype to use for the interface prototype object.
* interfaceProto is the prototype to use for the interface object.
* protoClass is the JSClass to use for the interface prototype object.
* This is null if we should not create an interface prototype
* object.
* protoCache a pointer to a JSObject pointer where we should cache the
* interface prototype object. This must be null if protoClass is and
* vice versa.
* constructorClass is the JSClass to use for the interface object.
* This is null if we should not create an interface object or
* if it should be a function object.
* constructor holds the JSNative to back the interface object which should be a
* Function, unless constructorClass is non-null in which case it is
* ignored. If this is null and constructorClass is also null then
* we should not create an interface object at all.
* ctorNargs is the length of the constructor function; 0 if no constructor
* constructorCache a pointer to a JSObject pointer where we should cache the
* interface object. This must be null if both constructorClass
* and constructor are null, and non-null otherwise.
* domClass is the DOMClass of instance objects for this class. This can be
* null if this is not a concrete proto.
* properties contains the methods, attributes and constants to be defined on
* objects in any compartment.
* chromeProperties contains the methods, attributes and constants to be defined
* on objects in chrome compartments. This must be null if the
* interface doesn't have any ChromeOnly properties or if the
* object is being created in non-chrome compartment.
*
* At least one of protoClass, constructorClass or constructor should be
* non-null. If constructorClass or constructor are non-null, the resulting
* interface object will be defined on the given global with property name
* |name|, which must also be non-null.
*/
void
CreateInterfaceObjects(JSContext* cx, JS::Handle<JSObject*> global,
JS::Handle<JSObject*> protoProto,
JSClass* protoClass, JSObject** protoCache,
JS::Handle<JSObject*> interfaceProto,
JSClass* constructorClass, const JSNativeHolder* constructor,
unsigned ctorNargs, const NamedConstructor* namedConstructors,
JSObject** constructorCache, const DOMClass* domClass,
const NativeProperties* regularProperties,
const NativeProperties* chromeOnlyProperties,
const char* name);
/*
* Define the unforgeable attributes on an object.
*/
bool
DefineUnforgeableAttributes(JSContext* cx, JS::Handle<JSObject*> obj,
const Prefable<const JSPropertySpec>* props);
bool
DefineWebIDLBindingPropertiesOnXPCProto(JSContext* cx,
JS::Handle<JSObject*> proto,
const NativeProperties* properties);
#ifdef _MSC_VER
#define HAS_MEMBER_CHECK(_name) \
template<typename V> static yes& Check(char (*)[(&V::_name == 0) + 1])
#else
#define HAS_MEMBER_CHECK(_name) \
template<typename V> static yes& Check(char (*)[sizeof(&V::_name) + 1])
#endif
#define HAS_MEMBER(_name) \
template<typename T> \
class Has##_name##Member { \
typedef char yes[1]; \
typedef char no[2]; \
HAS_MEMBER_CHECK(_name); \
template<typename V> static no& Check(...); \
\
public: \
static bool const Value = sizeof(Check<T>(nullptr)) == sizeof(yes); \
};
HAS_MEMBER(AddRef)
HAS_MEMBER(Release)
HAS_MEMBER(QueryInterface)
template<typename T>
struct IsRefCounted
{
static bool const Value = HasAddRefMember<T>::Value &&
HasReleaseMember<T>::Value;
};
template<typename T>
struct IsISupports
{
static bool const Value = IsRefCounted<T>::Value &&
HasQueryInterfaceMember<T>::Value;
};
HAS_MEMBER(WrapObject)
// HasWrapObject<T>::Value will be true if T has a WrapObject member but it's
// not nsWrapperCache::WrapObject.
template<typename T>
struct HasWrapObject
{
private:
typedef char yes[1];
typedef char no[2];
typedef JSObject* (nsWrapperCache::*WrapObject)(JSContext*,
JS::Handle<JSObject*>);
template<typename U, U> struct SFINAE;
template <typename V> static no& Check(SFINAE<WrapObject, &V::WrapObject>*);
template <typename V> static yes& Check(...);
public:
static bool const Value = HasWrapObjectMember<T>::Value &&
sizeof(Check<T>(nullptr)) == sizeof(yes);
};
#ifdef DEBUG
template <class T, bool isISupports=IsISupports<T>::Value>
struct
CheckWrapperCacheCast
{
static bool Check()
{
return reinterpret_cast<uintptr_t>(
static_cast<nsWrapperCache*>(
reinterpret_cast<T*>(1))) == 1;
}
};
template <class T>
struct
CheckWrapperCacheCast<T, true>
{
static bool Check()
{
return true;
}
};
#endif
MOZ_ALWAYS_INLINE bool
CouldBeDOMBinding(void*)
{
return true;
}
MOZ_ALWAYS_INLINE bool
CouldBeDOMBinding(nsWrapperCache* aCache)
{
return aCache->IsDOMBinding();
}
// The DOM_OBJECT_SLOT_SOW slot contains a JS::ObjectValue which points to the
// cached system object wrapper (SOW) or JS::UndefinedValue if this class
// doesn't need SOWs.
inline const JS::Value&
GetSystemOnlyWrapperSlot(JSObject* obj)
{
MOZ_ASSERT(IsDOMClass(js::GetObjectJSClass(obj)) &&
!(js::GetObjectJSClass(obj)->flags & JSCLASS_DOM_GLOBAL));
return js::GetReservedSlot(obj, DOM_OBJECT_SLOT_SOW);
}
inline void
SetSystemOnlyWrapperSlot(JSObject* obj, const JS::Value& v)
{
MOZ_ASSERT(IsDOMClass(js::GetObjectJSClass(obj)) &&
!(js::GetObjectJSClass(obj)->flags & JSCLASS_DOM_GLOBAL));
js::SetReservedSlot(obj, DOM_OBJECT_SLOT_SOW, v);
}
inline bool
GetSameCompartmentWrapperForDOMBinding(JSObject*& obj)
{
js::Class* clasp = js::GetObjectClass(obj);
if (dom::IsDOMClass(clasp)) {
if (!(clasp->flags & JSCLASS_DOM_GLOBAL)) {
JS::Value v = GetSystemOnlyWrapperSlot(obj);
if (v.isObject()) {
obj = &v.toObject();
}
}
return true;
}
return IsDOMProxy(obj, clasp);
}
inline void
SetSystemOnlyWrapper(JSObject* obj, nsWrapperCache* cache, JSObject& wrapper)
{
SetSystemOnlyWrapperSlot(obj, JS::ObjectValue(wrapper));
cache->SetHasSystemOnlyWrapper();
}
// If *vp is a gcthing and is not in the compartment of cx, wrap *vp
// into the compartment of cx (typically by replacing it with an Xray or
// cross-compartment wrapper around the original object).
MOZ_ALWAYS_INLINE bool
MaybeWrapValue(JSContext* cx, JS::Value* vp)
{
if (vp->isString()) {
JSString* str = vp->toString();
if (JS::GetGCThingZone(str) != js::GetContextZone(cx)) {
return JS_WrapValue(cx, vp);
}
return true;
}
if (vp->isObject()) {
JSObject* obj = &vp->toObject();
if (js::GetObjectCompartment(obj) != js::GetContextCompartment(cx)) {
return JS_WrapValue(cx, vp);
}
// We're same-compartment, but even then we might need to wrap
// objects specially. Check for that.
if (GetSameCompartmentWrapperForDOMBinding(obj)) {
// We're a new-binding object, and "obj" now points to the right thing
*vp = JS::ObjectValue(*obj);
return true;
}
if (!IS_SLIM_WRAPPER(obj)) {
// We might need a SOW
return JS_WrapValue(cx, vp);
}
// Fall through to returning true
}
return true;
}
static inline void
WrapNewBindingForSameCompartment(JSContext* cx, JSObject* obj, void* value,
JS::Value* vp)
{
*vp = JS::ObjectValue(*obj);
}
static inline void
WrapNewBindingForSameCompartment(JSContext* cx, JSObject* obj,
nsWrapperCache* value, JS::Value* vp)
{
if (value->HasSystemOnlyWrapper()) {
*vp = GetSystemOnlyWrapperSlot(obj);
MOZ_ASSERT(vp->isObject());
} else {
*vp = JS::ObjectValue(*obj);
}
}
// Create a JSObject wrapping "value", if there isn't one already, and store it
// in *vp. "value" must be a concrete class that implements a
// GetWrapperPreserveColor() which can return its existing wrapper, if any, and
// a WrapObject() which will try to create a wrapper. Typically, this is done by
// having "value" inherit from nsWrapperCache.
template <class T>
MOZ_ALWAYS_INLINE bool
WrapNewBindingObject(JSContext* cx, JS::Handle<JSObject*> scope, T* value,
JS::Value* vp)
{
MOZ_ASSERT(value);
JSObject* obj = value->GetWrapperPreserveColor();
bool couldBeDOMBinding = CouldBeDOMBinding(value);
if (obj) {
xpc_UnmarkNonNullGrayObject(obj);
} else {
// Inline this here while we have non-dom objects in wrapper caches.
if (!couldBeDOMBinding) {
return false;
}
obj = value->WrapObject(cx, scope);
if (!obj) {
// At this point, obj is null, so just return false.
// Callers seem to be testing JS_IsExceptionPending(cx) to
// figure out whether WrapObject() threw.
return false;
}
}
#ifdef DEBUG
const DOMClass* clasp = GetDOMClass(obj);
// clasp can be null if the cache contained a non-DOM object from a
// different compartment than scope.
if (clasp) {
// Some sanity asserts about our object. Specifically:
// 1) If our class claims we're nsISupports, we better be nsISupports
// XXXbz ideally, we could assert that reinterpret_cast to nsISupports
// does the right thing, but I don't see a way to do it. :(
// 2) If our class doesn't claim we're nsISupports we better be
// reinterpret_castable to nsWrapperCache.
MOZ_ASSERT(clasp, "What happened here?");
MOZ_ASSERT_IF(clasp->mDOMObjectIsISupports, IsISupports<T>::Value);
MOZ_ASSERT(CheckWrapperCacheCast<T>::Check());
}
// When called via XrayWrapper, we end up here while running in the
// chrome compartment. But the obj we have would be created in
// whatever the content compartment is. So at this point we need to
// make sure it's correctly wrapped for the compartment of |scope|.
// cx should already be in the compartment of |scope| here.
MOZ_ASSERT(js::IsObjectInContextCompartment(scope, cx));
#endif
bool sameCompartment =
js::GetObjectCompartment(obj) == js::GetContextCompartment(cx);
if (sameCompartment && couldBeDOMBinding) {
WrapNewBindingForSameCompartment(cx, obj, value, vp);
return true;
}
*vp = JS::ObjectValue(*obj);
return (sameCompartment && IS_SLIM_WRAPPER(obj)) || JS_WrapValue(cx, vp);
}
// Create a JSObject wrapping "value", for cases when "value" is a
// non-wrapper-cached object using WebIDL bindings. "value" must implement a
// WrapObject() method taking a JSContext and a scope.
template <class T>
inline bool
WrapNewBindingNonWrapperCachedObject(JSContext* cx,
JS::Handle<JSObject*> scopeArg,
T* value, JS::Value* vp)
{
MOZ_ASSERT(value);
// We try to wrap in the compartment of the underlying object of "scope"
JS::Rooted<JSObject*> obj(cx);
{
// scope for the JSAutoCompartment so that we restore the compartment
// before we call JS_WrapValue.
Maybe<JSAutoCompartment> ac;
// Maybe<Handle> doesn't so much work, and in any case, adding
// more Maybe (one for a Rooted and one for a Handle) adds more
// code (and branches!) than just adding a single rooted.
JS::Rooted<JSObject*> scope(cx, scopeArg);
if (js::IsWrapper(scope)) {
scope = js::CheckedUnwrap(scope, /* stopAtOuter = */ false);
if (!scope)
return false;
ac.construct(cx, scope);
}
obj = value->WrapObject(cx, scope);
}
if (!obj) {
return false;
}
// We can end up here in all sorts of compartments, per above. Make
// sure to JS_WrapValue!
*vp = JS::ObjectValue(*obj);
return JS_WrapValue(cx, vp);
}
// Create a JSObject wrapping "value", for cases when "value" is a
// non-wrapper-cached owned object using WebIDL bindings. "value" must implement a
// WrapObject() method taking a JSContext, a scope, and a boolean outparam that
// is true if the JSObject took ownership
template <class T>
inline bool
WrapNewBindingNonWrapperCachedOwnedObject(JSContext* cx,
JS::Handle<JSObject*> scopeArg,
nsAutoPtr<T>& value, JS::Value* vp)
{
// We do a runtime check on value, because otherwise we might in
// fact end up wrapping a null and invoking methods on it later.
if (!value) {
NS_RUNTIMEABORT("Don't try to wrap null objects");
}
// We try to wrap in the compartment of the underlying object of "scope"
JS::Rooted<JSObject*> obj(cx);
{
// scope for the JSAutoCompartment so that we restore the compartment
// before we call JS_WrapValue.
Maybe<JSAutoCompartment> ac;
// Maybe<Handle> doesn't so much work, and in any case, adding
// more Maybe (one for a Rooted and one for a Handle) adds more
// code (and branches!) than just adding a single rooted.
JS::Rooted<JSObject*> scope(cx, scopeArg);
if (js::IsWrapper(scope)) {
scope = js::CheckedUnwrap(scope, /* stopAtOuter = */ false);
if (!scope)
return false;
ac.construct(cx, scope);
}
bool tookOwnership = false;
obj = value->WrapObject(cx, scope, &tookOwnership);
MOZ_ASSERT_IF(obj, tookOwnership);
if (tookOwnership) {
value.forget();
}
}
if (!obj) {
return false;
}
// We can end up here in all sorts of compartments, per above. Make
// sure to JS_WrapValue!
*vp = JS::ObjectValue(*obj);
return JS_WrapValue(cx, vp);
}
// Helper for smart pointers (nsAutoPtr/nsRefPtr/nsCOMPtr).
template <template <typename> class SmartPtr, typename T>
inline bool
WrapNewBindingNonWrapperCachedObject(JSContext* cx, JS::Handle<JSObject*> scope,
const SmartPtr<T>& value, JS::Value* vp)
{
return WrapNewBindingNonWrapperCachedObject(cx, scope, value.get(), vp);
}
// 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
NativeInterface2JSObjectAndThrowIfFailed(JSContext* aCx,
JS::Handle<JSObject*> aScope,
JS::Value* aRetval,
xpcObjectHelper& aHelper,
const nsIID* aIID,
bool aAllowNativeWrapper);
/**
* A method to handle new-binding wrap failure, by possibly falling back to
* wrapping as a non-new-binding object.
*/
template <class T>
MOZ_ALWAYS_INLINE bool
HandleNewBindingWrappingFailure(JSContext* cx, JS::Handle<JSObject*> scope,
T* value, JS::Value* vp)
{
if (JS_IsExceptionPending(cx)) {
return false;
}
qsObjectHelper helper(value, GetWrapperCache(value));
return NativeInterface2JSObjectAndThrowIfFailed(cx, scope, vp, helper,
nullptr, true);
}
// Helper for calling HandleNewBindingWrappingFailure with smart pointers
// (nsAutoPtr/nsRefPtr/nsCOMPtr) or references.
HAS_MEMBER(get)
template <class T, bool isSmartPtr=HasgetMember<T>::Value>
struct HandleNewBindingWrappingFailureHelper
{
static inline bool Wrap(JSContext* cx, JS::Handle<JSObject*> scope,
const T& value, JS::Value* vp)
{
return HandleNewBindingWrappingFailure(cx, scope, value.get(), vp);
}
};
template <class T>
struct HandleNewBindingWrappingFailureHelper<T, false>
{
static inline bool Wrap(JSContext* cx, JS::Handle<JSObject*> scope, T& value,
JS::Value* vp)
{
return HandleNewBindingWrappingFailure(cx, scope, &value, vp);
}
};
template<class T>
inline bool
HandleNewBindingWrappingFailure(JSContext* cx, JS::Handle<JSObject*> scope,
T& value, JS::Value* vp)
{
return HandleNewBindingWrappingFailureHelper<T>::Wrap(cx, scope, value, vp);
}
template<bool Fatal>
inline bool
EnumValueNotFound(JSContext* cx, const jschar* chars, size_t length,
const char* type)
{
return false;
}
template<>
inline bool
EnumValueNotFound<false>(JSContext* cx, const jschar* chars, size_t length,
const char* type)
{
// TODO: Log a warning to the console.
return true;
}
template<>
inline bool
EnumValueNotFound<true>(JSContext* cx, const jschar* chars, size_t length,
const char* type)
{
NS_LossyConvertUTF16toASCII deflated(static_cast<const PRUnichar*>(chars),
length);
return ThrowErrorMessage(cx, MSG_INVALID_ENUM_VALUE, deflated.get(), type);
}
template<bool InvalidValueFatal>
inline int
FindEnumStringIndex(JSContext* cx, JS::Value v, const EnumEntry* values,
const char* type, bool* ok)
{
// JS_StringEqualsAscii is slow as molasses, so don't use it here.
JSString* str = JS_ValueToString(cx, v);
if (!str) {
*ok = false;
return 0;
}
JS::Anchor<JSString*> anchor(str);
size_t length;
const jschar* chars = JS_GetStringCharsAndLength(cx, str, &length);
if (!chars) {
*ok = false;
return 0;
}
int i = 0;
for (const EnumEntry* value = values; value->value; ++value, ++i) {
if (length != value->length) {
continue;
}
bool equal = true;
const char* val = value->value;
for (size_t j = 0; j != length; ++j) {
if (unsigned(val[j]) != unsigned(chars[j])) {
equal = false;
break;
}
}
if (equal) {
*ok = true;
return i;
}
}
*ok = EnumValueNotFound<InvalidValueFatal>(cx, chars, length, type);
return -1;
}
inline nsWrapperCache*
GetWrapperCache(const ParentObject& aParentObject)
{
return aParentObject.mWrapperCache;
}
template<class T>
inline T*
GetParentPointer(T* aObject)
{
return aObject;
}
inline nsISupports*
GetParentPointer(const ParentObject& aObject)
{
return aObject.mObject;
}
template<class T>
inline void
ClearWrapper(T* p, nsWrapperCache* cache)
{
cache->ClearWrapper();
}
template<class T>
inline void
ClearWrapper(T* p, void*)
{
nsWrapperCache* cache;
CallQueryInterface(p, &cache);
ClearWrapper(p, cache);
}
// Attempt to preserve the wrapper, if any, for a Paris DOM bindings object.
// Return true if we successfully preserved the wrapper, or there is no wrapper
// to preserve. In the latter case we don't need to preserve the wrapper, because
// the object can only be obtained by JS once, or they cannot be meaningfully
// owned from the native side.
//
// This operation will return false only for non-nsISupports cycle-collected
// objects, because we cannot determine if they are wrappercached or not.
bool
TryPreserveWrapper(JSObject* obj);
// Can only be called with the immediate prototype of the instance object. Can
// only be called on the prototype of an object known to be a DOM instance.
JSBool
InstanceClassHasProtoAtDepth(JSHandleObject protoObject, uint32_t protoID,
uint32_t depth);
// 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, JS::Handle<JSObject*> scope,
xpcObjectHelper& helper, const nsIID* iid,
bool allowNativeWrapper, JS::Value* rval);
// Special-cased wrapping for variants
bool
VariantToJsval(JSContext* aCx, JS::Handle<JSObject*> aScope,
nsIVariant* aVariant, JS::Value* aRetval);
// Wrap an object "p" which is not using WebIDL bindings yet. This _will_
// actually work on WebIDL binding objects that are wrappercached, but will be
// much slower than WrapNewBindingObject. "cache" must either be null or be the
// nsWrapperCache for "p".
template<class T>
inline bool
WrapObject(JSContext* cx, JS::Handle<JSObject*> scope, T* p,
nsWrapperCache* cache, const nsIID* iid, JS::Value* vp)
{
if (xpc_FastGetCachedWrapper(cache, scope, vp))
return true;
qsObjectHelper helper(p, cache);
return XPCOMObjectToJsval(cx, scope, helper, iid, true, vp);
}
// A specialization of the above for nsIVariant, because that needs to
// do something different.
template<>
inline bool
WrapObject<nsIVariant>(JSContext* cx, JS::Handle<JSObject*> scope, nsIVariant* p,
nsWrapperCache* cache, const nsIID* iid, JS::Value* vp)
{
MOZ_ASSERT(iid);
MOZ_ASSERT(iid->Equals(NS_GET_IID(nsIVariant)));
return VariantToJsval(cx, scope, p, vp);
}
// Wrap an object "p" which is not using WebIDL bindings yet. Just like the
// variant that takes an nsWrapperCache above, but will try to auto-derive the
// nsWrapperCache* from "p".
template<class T>
inline bool
WrapObject(JSContext* cx, JS::Handle<JSObject*> scope, T* p, const nsIID* iid,
JS::Value* vp)
{
return WrapObject(cx, scope, p, GetWrapperCache(p), iid, vp);
}
// Just like the WrapObject above, but without requiring you to pick which
// interface you're wrapping as. This should only be used for objects that have
// classinfo, for which it doesn't matter what IID is used to wrap.
template<class T>
inline bool
WrapObject(JSContext* cx, JS::Handle<JSObject*> scope, T* p, JS::Value* vp)
{
return WrapObject(cx, scope, p, NULL, vp);
}
// Helper to make it possible to wrap directly out of an nsCOMPtr
template<class T>
inline bool
WrapObject(JSContext* cx, JS::Handle<JSObject*> scope, const nsCOMPtr<T>& p,
const nsIID* iid, JS::Value* vp)
{
return WrapObject(cx, scope, p.get(), iid, vp);
}
// Helper to make it possible to wrap directly out of an nsCOMPtr
template<class T>
inline bool
WrapObject(JSContext* cx, JS::Handle<JSObject*> scope, const nsCOMPtr<T>& p,
JS::Value* vp)
{
return WrapObject(cx, scope, p, NULL, vp);
}
// Helper to make it possible to wrap directly out of an nsRefPtr
template<class T>
inline bool
WrapObject(JSContext* cx, JS::Handle<JSObject*> scope, const nsRefPtr<T>& p,
const nsIID* iid, JS::Value* vp)
{
return WrapObject(cx, scope, p.get(), iid, vp);
}
// Helper to make it possible to wrap directly out of an nsRefPtr
template<class T>
inline bool
WrapObject(JSContext* cx, JS::Handle<JSObject*> scope, const nsRefPtr<T>& p,
JS::Value* vp)
{
return WrapObject(cx, scope, p, NULL, vp);
}
// Specialization to make it easy to use WrapObject in codegen.
template<>
inline bool
WrapObject<JSObject>(JSContext* cx, JS::Handle<JSObject*> scope, JSObject* p,
JS::Value* vp)
{
vp->setObjectOrNull(p);
return true;
}
inline bool
WrapObject(JSContext* cx, JS::Handle<JSObject*> scope, JSObject& p,
JS::Value* vp)
{
vp->setObject(p);
return true;
}
// Given an object "p" that inherits from nsISupports, wrap it and return the
// result. Null is returned on wrapping failure. This is somewhat similar to
// WrapObject() above, but does NOT allow Xrays around the result, since we
// don't want those for our parent object.
template<typename T>
static inline JSObject*
WrapNativeISupportsParent(JSContext* cx, JS::Handle<JSObject*> scope, T* p,
nsWrapperCache* cache)
{
qsObjectHelper helper(ToSupports(p), cache);
JS::Rooted<JS::Value> v(cx);
return XPCOMObjectToJsval(cx, scope, helper, nullptr, false, v.address()) ?
JSVAL_TO_OBJECT(v) :
nullptr;
}
// Fallback for when our parent is not a WebIDL binding object.
template<typename T, bool isISupports=IsISupports<T>::Value >
struct WrapNativeParentFallback
{
static inline JSObject* Wrap(JSContext* cx, JS::Handle<JSObject*> scope,
T* parent, nsWrapperCache* cache)
{
return nullptr;
}
};
// Fallback for when our parent is not a WebIDL binding object but _is_ an
// nsISupports object.
template<typename T >
struct WrapNativeParentFallback<T, true >
{
static inline JSObject* Wrap(JSContext* cx, JS::Handle<JSObject*> scope,
T* parent, nsWrapperCache* cache)
{
return WrapNativeISupportsParent(cx, scope, parent, cache);
}
};
// Wrapping of our native parent, for cases when it's a WebIDL object (though
// possibly preffed off).
template<typename T, bool hasWrapObject=HasWrapObject<T>::Value >
struct WrapNativeParentHelper
{
static inline JSObject* Wrap(JSContext* cx, JS::Handle<JSObject*> scope,
T* parent, nsWrapperCache* cache)
{
MOZ_ASSERT(cache);
JSObject* obj;
if ((obj = cache->GetWrapper())) {
return obj;
}
// Inline this here while we have non-dom objects in wrapper caches.
if (!CouldBeDOMBinding(parent)) {
obj = WrapNativeParentFallback<T>::Wrap(cx, scope, parent, cache);
} else {
obj = parent->WrapObject(cx, scope);
}
return obj;
}
};
// Wrapping of our native parent, for cases when it's not a WebIDL object. In
// this case it must be nsISupports.
template<typename T>
struct WrapNativeParentHelper<T, false >
{
static inline JSObject* Wrap(JSContext* cx, JS::Handle<JSObject*> scope,
T* parent, nsWrapperCache* cache)
{
JSObject* obj;
if (cache && (obj = cache->GetWrapper())) {
#ifdef DEBUG
NS_ASSERTION(WrapNativeISupportsParent(cx, scope, parent, cache) == obj,
"Unexpected object in nsWrapperCache");
#endif
return obj;
}
return WrapNativeISupportsParent(cx, scope, parent, cache);
}
};
// Wrapping of our native parent.
template<typename T>
static inline JSObject*
WrapNativeParent(JSContext* cx, JS::Handle<JSObject*> scope, T* p,
nsWrapperCache* cache)
{
if (!p) {
return scope;
}
return WrapNativeParentHelper<T>::Wrap(cx, scope, p, cache);
}
// Wrapping of our native parent, when we don't want to explicitly pass in
// things like the nsWrapperCache for it.
template<typename T>
static inline JSObject*
WrapNativeParent(JSContext* cx, JS::Handle<JSObject*> scope, const T& p)
{
return WrapNativeParent(cx, scope, GetParentPointer(p), GetWrapperCache(p));
}
// A way to differentiate between nodes, which use the parent object
// returned by native->GetParentObject(), and all other objects, which
// just use the parent's global.
static inline JSObject*
GetRealParentObject(void* aParent, JSObject* aParentObject)
{
return aParentObject ?
js::GetGlobalForObjectCrossCompartment(aParentObject) : nullptr;
}
static inline JSObject*
GetRealParentObject(Element* aParent, JSObject* aParentObject)
{
return aParentObject;
}
HAS_MEMBER(GetParentObject)
template<typename T, bool WrapperCached=HasGetParentObjectMember<T>::Value>
struct GetParentObject
{
static JSObject* Get(JSContext* cx, JS::Handle<JSObject*> obj)
{
T* native = UnwrapDOMObject<T>(obj);
return
GetRealParentObject(native,
WrapNativeParent(cx, obj, native->GetParentObject()));
}
};
template<typename T>
struct GetParentObject<T, false>
{
static JSObject* Get(JSContext* cx, JS::Handle<JSObject*> obj)
{
MOZ_CRASH();
return nullptr;
}
};
MOZ_ALWAYS_INLINE
JSObject* GetJSObjectFromCallback(CallbackObject* callback)
{
return callback->Callback();
}
MOZ_ALWAYS_INLINE
JSObject* GetJSObjectFromCallback(void* noncallback)
{
return nullptr;
}
template<typename T>
static inline JSObject*
WrapCallThisObject(JSContext* cx, JS::Handle<JSObject*> scope, const T& p)
{
// Callbacks are nsISupports, so WrapNativeParent will just happily wrap them
// up as an nsISupports XPCWrappedNative... which is not at all what we want.
// So we need to special-case them.
JS::Rooted<JSObject*> obj(cx, GetJSObjectFromCallback(p));
if (!obj) {
// WrapNativeParent is a bit of a Swiss army knife that will
// wrap anything for us.
obj = WrapNativeParent(cx, scope, p);
if (!obj) {
return nullptr;
}
}
// But all that won't necessarily put things in the compartment of cx.
if (!JS_WrapObject(cx, obj.address())) {
return nullptr;
}
return obj;
}
// Helper for calling WrapNewBindingObject with smart pointers
// (nsAutoPtr/nsRefPtr/nsCOMPtr) or references.
template <class T, bool isSmartPtr=HasgetMember<T>::Value>
struct WrapNewBindingObjectHelper
{
static inline bool Wrap(JSContext* cx, JS::Handle<JSObject*> scope,
const T& value, JS::Value* vp)
{
return WrapNewBindingObject(cx, scope, value.get(), vp);
}
};
template <class T>
struct WrapNewBindingObjectHelper<T, false>
{
static inline bool Wrap(JSContext* cx, JS::Handle<JSObject*> scope, T& value,
JS::Value* vp)
{
return WrapNewBindingObject(cx, scope, &value, vp);
}
};
template<class T>
inline bool
WrapNewBindingObject(JSContext* cx, JS::Handle<JSObject*> scope, T& value,
JS::Value* vp)
{
return WrapNewBindingObjectHelper<T>::Wrap(cx, scope, value, vp);
}
template <class T>
inline JSObject*
GetCallbackFromCallbackObject(T* aObj)
{
return aObj->Callback();
}
// Helper for getting the callback JSObject* of a smart ptr around a
// CallbackObject or a reference to a CallbackObject or something like
// that.
template <class T, bool isSmartPtr=HasgetMember<T>::Value>
struct GetCallbackFromCallbackObjectHelper
{
static inline JSObject* Get(const T& aObj)
{
return GetCallbackFromCallbackObject(aObj.get());
}
};
template <class T>
struct GetCallbackFromCallbackObjectHelper<T, false>
{
static inline JSObject* Get(T& aObj)
{
return GetCallbackFromCallbackObject(&aObj);
}
};
template<class T>
inline JSObject*
GetCallbackFromCallbackObject(T& aObj)
{
return GetCallbackFromCallbackObjectHelper<T>::Get(aObj);
}
static inline bool
InternJSString(JSContext* cx, jsid& id, const char* chars)
{
if (JSString *str = ::JS_InternString(cx, chars)) {
id = INTERNED_STRING_TO_JSID(cx, str);
return true;
}
return false;
}
// Spec needs a name property
template <typename Spec>
static bool
InitIds(JSContext* cx, const Prefable<Spec>* prefableSpecs, jsid* ids)
{
MOZ_ASSERT(prefableSpecs);
MOZ_ASSERT(prefableSpecs->specs);
do {
// We ignore whether the set of ids is enabled and just intern all the IDs,
// because this is only done once per application runtime.
Spec* spec = prefableSpecs->specs;
do {
if (!InternJSString(cx, *ids, spec->name)) {
return false;
}
} while (++ids, (++spec)->name);
// We ran out of ids for that pref. Put a JSID_VOID in on the id
// corresponding to the list terminator for the pref.
*ids = JSID_VOID;
++ids;
} while ((++prefableSpecs)->specs);
return true;
}
JSBool
QueryInterface(JSContext* cx, unsigned argc, JS::Value* vp);
JSBool
ThrowingConstructor(JSContext* cx, unsigned argc, JS::Value* vp);
bool
GetPropertyOnPrototype(JSContext* cx, JS::Handle<JSObject*> proxy,
JS::Handle<jsid> id, bool* found,
JS::Value* vp);
bool
HasPropertyOnPrototype(JSContext* cx, JS::Handle<JSObject*> proxy,
DOMProxyHandler* handler,
JS::Handle<jsid> id);
template<class T>
class NonNull
{
public:
NonNull()
#ifdef DEBUG
: inited(false)
#endif
{}
operator T&() {
MOZ_ASSERT(inited);
MOZ_ASSERT(ptr, "NonNull<T> was set to null");
return *ptr;
}
operator const T&() const {
MOZ_ASSERT(inited);
MOZ_ASSERT(ptr, "NonNull<T> was set to null");
return *ptr;
}
void operator=(T* t) {
ptr = t;
MOZ_ASSERT(ptr);
#ifdef DEBUG
inited = true;
#endif
}
template<typename U>
void operator=(U* t) {
ptr = t->ToAStringPtr();
MOZ_ASSERT(ptr);
#ifdef DEBUG
inited = true;
#endif
}
T** Slot() {
#ifdef DEBUG
inited = true;
#endif
return &ptr;
}
T* Ptr() {
MOZ_ASSERT(inited);
MOZ_ASSERT(ptr, "NonNull<T> was set to null");
return ptr;
}
// Make us work with smart-ptr helpers that expect a get()
T* get() const {
MOZ_ASSERT(inited);
MOZ_ASSERT(ptr);
return ptr;
}
protected:
T* ptr;
#ifdef DEBUG
bool inited;
#endif
};
template<class T>
class OwningNonNull
{
public:
OwningNonNull()
#ifdef DEBUG
: inited(false)
#endif
{}
operator T&() {
MOZ_ASSERT(inited);
MOZ_ASSERT(ptr, "OwningNonNull<T> was set to null");
return *ptr;
}
void operator=(T* t) {
init(t);
}
void operator=(const already_AddRefed<T>& t) {
init(t);
}
already_AddRefed<T> forget() {
#ifdef DEBUG
inited = false;
#endif
return ptr.forget();
}
// Make us work with smart-ptr helpers that expect a get()
T* get() const {
MOZ_ASSERT(inited);
MOZ_ASSERT(ptr);
return ptr;
}
protected:
template<typename U>
void init(U t) {
ptr = t;
MOZ_ASSERT(ptr);
#ifdef DEBUG
inited = true;
#endif
}
nsRefPtr<T> ptr;
#ifdef DEBUG
bool inited;
#endif
};
// A struct that has the same layout as an nsDependentString but much
// faster constructor and destructor behavior
struct FakeDependentString {
FakeDependentString() :
mFlags(nsDependentString::F_TERMINATED)
{
}
void SetData(const nsDependentString::char_type* aData,
nsDependentString::size_type aLength) {
MOZ_ASSERT(mFlags == nsDependentString::F_TERMINATED);
mData = aData;
mLength = aLength;
}
void Truncate() {
mData = nsDependentString::char_traits::sEmptyBuffer;
mLength = 0;
}
void SetNull() {
Truncate();
mFlags |= nsDependentString::F_VOIDED;
}
// If this ever changes, change the corresponding code in the
// Optional<nsAString> specialization as well.
const nsAString* ToAStringPtr() const {
return reinterpret_cast<const nsDependentString*>(this);
}
nsAString* ToAStringPtr() {
return reinterpret_cast<nsDependentString*>(this);
}
operator const nsAString& () const {
return *reinterpret_cast<const nsDependentString*>(this);
}
private:
const nsDependentString::char_type* mData;
nsDependentString::size_type mLength;
uint32_t mFlags;
// A class to use for our static asserts to ensure our object layout
// matches that of nsDependentString.
class DependentStringAsserter;
friend class DependentStringAsserter;
class DepedentStringAsserter : public nsDependentString {
public:
static void StaticAsserts() {
MOZ_STATIC_ASSERT(sizeof(FakeDependentString) == sizeof(nsDependentString),
"Must have right object size");
MOZ_STATIC_ASSERT(offsetof(FakeDependentString, mData) ==
offsetof(DepedentStringAsserter, mData),
"Offset of mData should match");
MOZ_STATIC_ASSERT(offsetof(FakeDependentString, mLength) ==
offsetof(DepedentStringAsserter, mLength),
"Offset of mLength should match");
MOZ_STATIC_ASSERT(offsetof(FakeDependentString, mFlags) ==
offsetof(DepedentStringAsserter, mFlags),
"Offset of mFlags should match");
}
};
};
enum StringificationBehavior {
eStringify,
eEmpty,
eNull
};
// pval must not be null and must point to a rooted JS::Value
static inline bool
ConvertJSValueToString(JSContext* cx, const JS::Value& v, JS::Value* pval,
StringificationBehavior nullBehavior,
StringificationBehavior undefinedBehavior,
FakeDependentString& result)
{
JSString *s;
if (v.isString()) {
s = v.toString();
} else {
StringificationBehavior behavior;
if (v.isNull()) {
behavior = nullBehavior;
} else if (v.isUndefined()) {
behavior = undefinedBehavior;
} else {
behavior = eStringify;
}
if (behavior != eStringify) {
if (behavior == eEmpty) {
result.Truncate();
} else {
result.SetNull();
}
return true;
}
s = JS_ValueToString(cx, v);
if (!s) {
return false;
}
pval->setString(s); // Root the new string.
}
size_t len;
const jschar *chars = JS_GetStringCharsZAndLength(cx, s, &len);
if (!chars) {
return false;
}
result.SetData(chars, len);
return true;
}
// Class for holding the type of members of a union. The union type has an enum
// to keep track of which of its UnionMembers has been constructed.
template<class T>
class UnionMember {
AlignedStorage2<T> storage;
public:
T& SetValue() {
new (storage.addr()) T();
return *storage.addr();
}
const T& Value() const {
return *storage.addr();
}
void Destroy() {
storage.addr()->~T();
}
};
// Class for simple sequence arguments, only used internally by codegen.
template<typename T>
class AutoSequence : public AutoFallibleTArray<T, 16>
{
public:
AutoSequence() : AutoFallibleTArray<T, 16>()
{}
// Allow converting to const sequences as needed
operator const Sequence<T>&() const {
return *reinterpret_cast<const Sequence<T>*>(this);
}
};
inline bool
IdEquals(jsid id, const char* string)
{
return JSID_IS_STRING(id) &&
JS_FlatStringEqualsAscii(JSID_TO_FLAT_STRING(id), string);
}
inline bool
AddStringToIDVector(JSContext* cx, JS::AutoIdVector& vector, const char* name)
{
return vector.growBy(1) &&
InternJSString(cx, vector[vector.length() - 1], name);
}
// Implementation of the bits that XrayWrapper needs
/**
* This resolves indexed or named properties of obj.
*
* wrapper is the Xray JS object.
* obj is the target object of the Xray, a binding's instance object or a
* interface or interface prototype object.
*/
bool
XrayResolveOwnProperty(JSContext* cx, JS::Handle<JSObject*> wrapper,
JS::Handle<JSObject*> obj,
JS::Handle<jsid> id,
JSPropertyDescriptor* desc, unsigned flags);
/**
* This resolves operations, attributes and constants of the interfaces for obj.
*
* wrapper is the Xray JS object.
* obj is the target object of the Xray, a binding's instance object or a
* interface or interface prototype object.
*/
bool
XrayResolveNativeProperty(JSContext* cx, JS::Handle<JSObject*> wrapper,
JS::Handle<JSObject*> obj,
JS::Handle<jsid> id, JSPropertyDescriptor* desc);
/**
* This enumerates indexed or named properties of obj and operations, attributes
* and constants of the interfaces for obj.
*
* wrapper is the Xray JS object.
* obj is the target object of the Xray, a binding's instance object or a
* interface or interface prototype object.
* flags are JSITER_* flags.
*/
bool
XrayEnumerateProperties(JSContext* cx, JS::Handle<JSObject*> wrapper,
JS::Handle<JSObject*> obj,
unsigned flags, JS::AutoIdVector& props);
extern NativePropertyHooks sWorkerNativePropertyHooks;
// We use one constructor JSNative to represent all DOM interface objects (so
// we can easily detect when we need to wrap them in an Xray wrapper). We store
// the real JSNative in the mNative member of a JSNativeHolder in the
// CONSTRUCTOR_NATIVE_HOLDER_RESERVED_SLOT slot of the JSFunction object for a
// specific interface object. We also store the NativeProperties in the
// JSNativeHolder. The CONSTRUCTOR_XRAY_EXPANDO_SLOT is used to store the
// expando chain of the Xray for the interface object.
// Note that some interface objects are not yet a JSFunction but a normal
// JSObject with a DOMJSClass, those do not use these slots.
enum {
CONSTRUCTOR_NATIVE_HOLDER_RESERVED_SLOT = 0,
CONSTRUCTOR_XRAY_EXPANDO_SLOT
};
JSBool
Constructor(JSContext* cx, unsigned argc, JS::Value* vp);
inline bool
UseDOMXray(JSObject* obj)
{
const js::Class* clasp = js::GetObjectClass(obj);
return IsDOMClass(clasp) ||
IsDOMProxy(obj, clasp) ||
JS_IsNativeFunction(obj, Constructor) ||
IsDOMIfaceAndProtoClass(clasp);
}
#ifdef DEBUG
inline bool
HasConstructor(JSObject* obj)
{
return JS_IsNativeFunction(obj, Constructor) ||
js::GetObjectClass(obj)->construct;
}
#endif
// Transfer reference in ptr to smartPtr.
template<class T>
inline void
Take(nsRefPtr<T>& smartPtr, T* ptr)
{
smartPtr = dont_AddRef(ptr);
}
// Transfer ownership of ptr to smartPtr.
template<class T>
inline void
Take(nsAutoPtr<T>& smartPtr, T* ptr)
{
smartPtr = ptr;
}
inline void
MustInheritFromNonRefcountedDOMObject(NonRefcountedDOMObject*)
{
}
// Set the chain of expando objects for various consumers of the given object.
// For Paris Bindings only. See the relevant infrastructure in XrayWrapper.cpp.
JSObject* GetXrayExpandoChain(JSObject *obj);
void SetXrayExpandoChain(JSObject *obj, JSObject *chain);
/**
* This creates a JSString containing the value that the toString function for
* obj should create according to the WebIDL specification, ignoring any
* modifications by script. The value is prefixed with pre and postfixed with
* post, unless this is called for an object that has a stringifier. It is
* specifically for use by Xray code.
*
* wrapper is the Xray JS object.
* obj is the target object of the Xray, a binding's instance object or a
* interface or interface prototype object.
* pre is a string that should be prefixed to the value.
* post is a string that should be prefixed to the value.
* v contains the JSString for the value if the function returns true.
*/
bool
NativeToString(JSContext* cx, JS::Handle<JSObject*> wrapper,
JS::Handle<JSObject*> obj, const char* pre,
const char* post, JS::Value* v);
HAS_MEMBER(JSBindingFinalized)
template<class T, bool hasCallback=HasJSBindingFinalizedMember<T>::Value>
struct JSBindingFinalized
{
static void Finalized(T* self)
{
}
};
template<class T>
struct JSBindingFinalized<T, true>
{
static void Finalized(T* self)
{
self->JSBindingFinalized();
}
};
// Helpers for creating a const version of a type.
template<typename T>
const T& Constify(T& arg)
{
return arg;
}
// Reparent the wrapper of aObj to whatever its native now thinks its
// parent should be.
nsresult
ReparentWrapper(JSContext* aCx, JS::HandleObject aObj);
/**
* Used to implement the hasInstance hook of an interface object.
*
* instance should not be a security wrapper.
*/
JSBool
InterfaceHasInstance(JSContext* cx, JS::Handle<JSObject*> obj,
JS::Handle<JSObject*> instance,
JSBool* bp);
JSBool
InterfaceHasInstance(JSContext* cx, JSHandleObject obj, JSMutableHandleValue vp,
JSBool* bp);
// Helper for lenient getters/setters to report to console. If this
// returns false, we couldn't even get a global.
bool
ReportLenientThisUnwrappingFailure(JSContext* cx, JS::Handle<JSObject*> obj);
inline JSObject*
GetUnforgeableHolder(JSObject* aGlobal, prototypes::ID aId)
{
JSObject** protoAndIfaceArray = GetProtoAndIfaceArray(aGlobal);
JSObject* interfaceProto = protoAndIfaceArray[aId];
return &js::GetReservedSlot(interfaceProto,
DOM_INTERFACE_PROTO_SLOTS_BASE).toObject();
}
} // namespace dom
} // namespace mozilla
#endif /* mozilla_dom_BindingUtils_h__ */
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