Bug 655649 - Introduce an API to recompute wrappers based on various filters. r=billm

js/src/jswrapper.cpp

@@ -1189,3 +1189,45 @@ js::RemapAllWrappersForObject(JSContext *cx, JSObject *oldTarget,
 
     return true;
 }
+
+JS_FRIEND_API(bool)
+js::RecomputeWrappers(JSContext *cx, const CompartmentFilter &sourceFilter,
+                      const CompartmentFilter &targetFilter)
+{
+    AutoValueVector toRecompute(cx);
+
+    for (CompartmentsIter c(cx->runtime); !c.done(); c.next()) {
+        // Filter by source compartment.
+        if (!sourceFilter.match(c))
+            continue;
+
+        // Iterate over the wrappers, filtering appropriately.
+        WrapperMap &pmap = c->crossCompartmentWrappers;
+        for (WrapperMap::Enum e(pmap); !e.empty(); e.popFront()) {
+            // Filter out non-objects.
+            const CrossCompartmentKey &k = e.front().key;
+            if (k.kind != CrossCompartmentKey::ObjectWrapper)
+                continue;
+
+            // Filter by target compartment.
+            Value wrapper = e.front().value.get();
+            if (!targetFilter.match(k.wrapped->compartment()))
+                continue;
+
+            // Add it to the list.
+            if (!toRecompute.append(wrapper))
+                return false;
+        }
+    }
+
+    // Recompute all the wrappers in the list.
+    for (Value *begin = toRecompute.begin(), *end = toRecompute.end(); begin != end; ++begin)
+    {
+        JSObject *wrapper = &begin->toObject();
+        JSObject *wrapped = Wrapper::wrappedObject(wrapper);
+        if (!RemapWrapper(cx, wrapper, wrapped))
+            return false;
+    }
+
+    return true;
+}

js/src/jswrapper.h

@@ -340,6 +340,44 @@ RemapWrapper(JSContext *cx, JSObject *wobj, JSObject *newTarget);
 bool
 RemapAllWrappersForObject(JSContext *cx, JSObject *oldTarget,
                           JSObject *newTarget);
+
+// API to recompute all cross-compartment wrappers whose source and target
+// match the given filters.
+//
+// These filters are designed to be ephemeral stack classes, and thus don't
+// do any rooting or holding of their members.
+struct CompartmentFilter {
+    virtual bool match(JSCompartment *c) const = 0;
+};
+
+struct AllCompartments : public CompartmentFilter {
+    virtual bool match(JSCompartment *c) const { return true; };
+};
+
+struct ContentCompartmentsOnly : public CompartmentFilter {
+    virtual bool match(JSCompartment *c) const {
+        return !IsSystemCompartment(c);
+    };
+};
+
+struct SingleCompartment : public CompartmentFilter {
+    JSCompartment *ours;
+    SingleCompartment(JSCompartment *c) : ours(c) {};
+    virtual bool match(JSCompartment *c) const { return c == ours; };
+};
+
+struct CompartmentsWithPrincipals : public CompartmentFilter {
+    JSPrincipals *principals;
+    CompartmentsWithPrincipals(JSPrincipals *p) : principals(p) {};
+    virtual bool match(JSCompartment *c) const {
+        return JS_GetCompartmentPrincipals(c) == principals;
+    };
+};
+
+JS_FRIEND_API(bool)
+RecomputeWrappers(JSContext *cx, const CompartmentFilter &sourceFilter,
+                  const CompartmentFilter &targetFilter);
+
 } /* namespace js */
 
 #endif