Bug 1027964 - Standardize proxy handler families. (r=jorendorff)

dom/bindings/DOMJSProxyHandler.cpp

@@ -29,8 +29,7 @@ DefineStaticJSVals(JSContext* cx)
   return InternJSString(cx, s_length_id, "length");
 }
 
-
+const char DOMProxyHandler::family = 0;
-const char HandlerFamily = 0;
 
 js::DOMProxyShadowsResult
 DOMProxyShadows(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id)
@@ -60,7 +59,7 @@ DOMProxyShadows(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id)
 struct SetDOMProxyInformation
 {
   SetDOMProxyInformation() {
-    js::SetDOMProxyInformation((const void*) &HandlerFamily,
+    js::SetDOMProxyInformation((const void*) &DOMProxyHandler::family,
                                js::PROXY_EXTRA_SLOT + JSPROXYSLOT_EXPANDO, DOMProxyShadows);
   }
 };
@@ -363,5 +362,25 @@ DOMProxyHandler::setCustom(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handl
   return true;
 }
 
+//static
+JSObject *
+DOMProxyHandler::GetExpandoObject(JSObject *obj)
+{
+  MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
+  JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
+  if (v.isObject()) {
+    return &v.toObject();
+  }
+
+  if (v.isUndefined()) {
+    return nullptr;
+  }
+
+  js::ExpandoAndGeneration* expandoAndGeneration =
+    static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
+  v = expandoAndGeneration->expando;
+  return v.isUndefined() ? nullptr : &v.toObject();
+}
+
 } // namespace dom
 } // namespace mozilla

dom/bindings/DOMJSProxyHandler.h

@@ -24,17 +24,6 @@ enum {
 
 template<typename T> struct Prefable;
 
-// This variable exists solely to provide a unique address for use as an identifier.
-extern const char HandlerFamily;
-inline const void* ProxyFamily() { return &HandlerFamily; }
-
-inline bool IsDOMProxy(JSObject *obj)
-{
-    const js::Class* clasp = js::GetObjectClass(obj);
-    return clasp->isProxy() &&
-           js::GetProxyHandler(obj)->family() == ProxyFamily();
-}
-
 class BaseDOMProxyHandler : public js::BaseProxyHandler
 {
 public:
@@ -89,7 +78,7 @@ class DOMProxyHandler : public BaseDOMProxyHandler
 {
 public:
   DOMProxyHandler()
-    : BaseDOMProxyHandler(ProxyFamily())
+    : BaseDOMProxyHandler(&family)
   {
   }
 
@@ -121,29 +110,23 @@ public:
   virtual bool setCustom(JSContext* cx, JS::Handle<JSObject*> proxy, JS::Handle<jsid> id,
                          JS::MutableHandle<JS::Value> vp, bool *done) const;
 
-  static JSObject* GetExpandoObject(JSObject* obj)
+  static JSObject* GetExpandoObject(JSObject* obj);
-  {
-    MOZ_ASSERT(IsDOMProxy(obj), "expected a DOM proxy object");
-    JS::Value v = js::GetProxyExtra(obj, JSPROXYSLOT_EXPANDO);
-    if (v.isObject()) {
-      return &v.toObject();
-    }
 
-    if (v.isUndefined()) {
-      return nullptr;
-    }
-
-    js::ExpandoAndGeneration* expandoAndGeneration =
-      static_cast<js::ExpandoAndGeneration*>(v.toPrivate());
-    v = expandoAndGeneration->expando;
-    return v.isUndefined() ? nullptr : &v.toObject();
-  }
   /* GetAndClearExpandoObject does not DROP or clear the preserving wrapper flag. */
   static JSObject* GetAndClearExpandoObject(JSObject* obj);
   static JSObject* EnsureExpandoObject(JSContext* cx,
                                        JS::Handle<JSObject*> obj);
+
+  static const char family;
 };
 
+inline bool IsDOMProxy(JSObject *obj)
+{
+    const js::Class* clasp = js::GetObjectClass(obj);
+    return clasp->isProxy() &&
+           js::GetProxyHandler(obj)->family() == &DOMProxyHandler::family;
+}
+
 inline const DOMProxyHandler*
 GetDOMProxyHandler(JSObject* obj)
 {

js/ipc/WrapperOwner.cpp

@@ -45,13 +45,11 @@ WrapperOwner::idOf(JSObject *obj)
     return objId;
 }
 
-int sCPOWProxyHandler;
-
 class CPOWProxyHandler : public BaseProxyHandler
 {
   public:
     CPOWProxyHandler()
-      : BaseProxyHandler(&sCPOWProxyHandler) {}
+      : BaseProxyHandler(&family) {}
     virtual ~CPOWProxyHandler() {}
 
     virtual bool finalizeInBackground(Value priv) const MOZ_OVERRIDE {
@@ -86,9 +84,11 @@ class CPOWProxyHandler : public BaseProxyHandler
     virtual const char* className(JSContext *cx, HandleObject proxy) const MOZ_OVERRIDE;
     virtual void finalize(JSFreeOp *fop, JSObject *proxy) const MOZ_OVERRIDE;
 
+    static const char family;
     static const CPOWProxyHandler singleton;
 };
 
+const char CPOWProxyHandler::family = 0;
 const CPOWProxyHandler CPOWProxyHandler::singleton;
 
 #define FORWARD(call, args)                                             \

js/src/jsfriendapi.cpp

@@ -601,7 +601,7 @@ JS_IsDeadWrapper(JSObject *obj)
         return false;
     }
 
-    return obj->as<ProxyObject>().handler()->family() == &DeadObjectProxy::sDeadObjectFamily;
+    return obj->as<ProxyObject>().handler()->family() == &DeadObjectProxy::family;
 }
 
 void

js/src/jsproxy.cpp

@@ -797,6 +797,7 @@ class ScriptedIndirectProxyHandler : public BaseProxyHandler
     virtual JSString *fun_toString(JSContext *cx, HandleObject proxy, unsigned indent) const MOZ_OVERRIDE;
     virtual bool isScripted() const MOZ_OVERRIDE { return true; }
 
+    static const char family;
     static const ScriptedIndirectProxyHandler singleton;
 };
 
@@ -818,10 +819,10 @@ static const Class CallConstructHolder = {
 } /* anonymous namespace */
 
 // This variable exists solely to provide a unique address for use as an identifier.
-static const char sScriptedIndirectProxyHandlerFamily = 0;
+const char ScriptedIndirectProxyHandler::family = 0;
 
 ScriptedIndirectProxyHandler::ScriptedIndirectProxyHandler()
-        : BaseProxyHandler(&sScriptedIndirectProxyHandlerFamily)
+        : BaseProxyHandler(&family)
 {
 }
 
@@ -1118,6 +1119,7 @@ class ScriptedDirectProxyHandler : public DirectProxyHandler {
     virtual bool construct(JSContext *cx, HandleObject proxy, const CallArgs &args) const MOZ_OVERRIDE;
     virtual bool isScripted() const MOZ_OVERRIDE { return true; }
 
+    static const char family;
     static const ScriptedDirectProxyHandler singleton;
 
     // The "proxy extra" slot index in which the handler is stored. Revocable proxies need to set
@@ -1128,9 +1130,6 @@ class ScriptedDirectProxyHandler : public DirectProxyHandler {
     static const int REVOKE_SLOT = 0;
 };
 
-// This variable exists solely to provide a unique address for use as an identifier.
-static const char sScriptedDirectProxyHandlerFamily = 0;
-
 static inline bool
 IsDataDescriptor(const PropertyDescriptor &desc)
 {
@@ -1389,7 +1388,7 @@ ArrayToIdVector(JSContext *cx, HandleObject proxy, HandleObject target, HandleVa
 }
 
 ScriptedDirectProxyHandler::ScriptedDirectProxyHandler()
-        : DirectProxyHandler(&sScriptedDirectProxyHandlerFamily)
+        : DirectProxyHandler(&family)
 {
 }
 
@@ -2208,6 +2207,7 @@ ScriptedDirectProxyHandler::construct(JSContext *cx, HandleObject proxy, const C
     return true;
 }
 
+const char ScriptedDirectProxyHandler::family = 0;
 const ScriptedDirectProxyHandler ScriptedDirectProxyHandler::singleton;
 
 #define INVOKE_ON_PROTOTYPE(cx, handler, proxy, protoCall)                   \

js/src/jsproxy.h

@@ -87,6 +87,14 @@ class JS_FRIEND_API(Wrapper);
  */
 class JS_FRIEND_API(BaseProxyHandler)
 {
+    /*
+     * Sometimes it's desirable to designate groups of proxy handlers as "similar".
+     * For this, we use the notion of a "family": A consumer-provided opaque pointer
+     * that designates the larger group to which this proxy belongs.
+     *
+     * If it will never be important to differentiate this proxy from others as
+     * part of a distinct group, nullptr may be used instead.
+     */
     const void *mFamily;
 
     /*

js/src/jswrapper.cpp

@@ -20,8 +20,6 @@
 using namespace js;
 using namespace js::gc;
 
-const char js::sWrapperFamily = 0;
-
 /*
  * Wrapper forwards this call directly to the wrapped object for efficiency
  * and transparency. In particular, the hint is needed to properly stringify
@@ -131,7 +129,7 @@ js::IsCrossCompartmentWrapper(JSObject *obj)
 }
 
 Wrapper::Wrapper(unsigned flags, bool hasPrototype, bool hasSecurityPolicy)
-  : DirectProxyHandler(&sWrapperFamily, hasPrototype, hasSecurityPolicy),
+  : DirectProxyHandler(&family, hasPrototype, hasSecurityPolicy),
     mFlags(flags)
 {
 }
@@ -140,6 +138,7 @@ Wrapper::~Wrapper()
 {
 }
 
+const char Wrapper::family = 0;
 const Wrapper Wrapper::singleton((unsigned)0);
 const Wrapper Wrapper::singletonWithPrototype((unsigned)0, true);
 JSObject *Wrapper::defaultProto = TaggedProto::LazyProto;
@@ -748,7 +747,7 @@ template class js::SecurityWrapper<Wrapper>;
 template class js::SecurityWrapper<CrossCompartmentWrapper>;
 
 DeadObjectProxy::DeadObjectProxy()
-  : BaseProxyHandler(&sDeadObjectFamily)
+  : BaseProxyHandler(&family)
 {
 }
 
@@ -885,8 +884,8 @@ DeadObjectProxy::getPrototypeOf(JSContext *cx, HandleObject proxy, MutableHandle
     return true;
 }
 
+const char DeadObjectProxy::family = 0;
 const DeadObjectProxy DeadObjectProxy::singleton;
-const char DeadObjectProxy::sDeadObjectFamily = 0;
 
 bool
 js::IsDeadProxyObject(JSObject *obj)

js/src/jswrapper.h

@@ -87,6 +87,7 @@ class JS_FRIEND_API(Wrapper) : public DirectProxyHandler
 
     virtual bool finalizeInBackground(Value priv) const MOZ_OVERRIDE;
 
+    static const char family;
     static const Wrapper singleton;
     static const Wrapper singletonWithPrototype;
 
@@ -207,9 +208,6 @@ typedef SecurityWrapper<CrossCompartmentWrapper> CrossCompartmentSecurityWrapper
 class JS_FRIEND_API(DeadObjectProxy) : public BaseProxyHandler
 {
   public:
-    // This variable exists solely to provide a unique address for use as an identifier.
-    static const char sDeadObjectFamily;
-
     explicit DeadObjectProxy();
 
     /* ES5 Harmony fundamental wrapper traps. */
@@ -243,6 +241,7 @@ class JS_FRIEND_API(DeadObjectProxy) : public BaseProxyHandler
     virtual bool getPrototypeOf(JSContext *cx, HandleObject proxy,
                                 MutableHandleObject protop) const MOZ_OVERRIDE;
 
+    static const char family;
     static const DeadObjectProxy singleton;
 };
 
@@ -250,15 +249,10 @@ extern JSObject *
 TransparentObjectWrapper(JSContext *cx, HandleObject existing, HandleObject obj,
                          HandleObject parent);
 
-// Proxy family for wrappers. Public so that IsWrapper() can be fully inlined by
-// jsfriendapi users.
-// This variable exists solely to provide a unique address for use as an identifier.
-extern JS_FRIEND_DATA(const char) sWrapperFamily;
-
 inline bool
 IsWrapper(JSObject *obj)
 {
-    return IsProxy(obj) && GetProxyHandler(obj)->family() == &sWrapperFamily;
+    return IsProxy(obj) && GetProxyHandler(obj)->family() == &Wrapper::family;
 }
 
 // Given a JSObject, returns that object stripped of wrappers. If

js/src/vm/ScopeObject.cpp

@@ -1323,7 +1323,7 @@ class DebugScopeProxy : public BaseProxyHandler
     }
 
   public:
-    static int family;
+    static const char family;
     static const DebugScopeProxy singleton;
 
     DebugScopeProxy() : BaseProxyHandler(&family) {}
@@ -1592,7 +1592,7 @@ class DebugScopeProxy : public BaseProxyHandler
 
 } /* anonymous namespace */
 
-int DebugScopeProxy::family = 0;
+const char DebugScopeProxy::family = 0;
 const DebugScopeProxy DebugScopeProxy::singleton;
 
 /* static */ DebugScopeObject *