Bug 820665 part 3. WebIDL spec updates to changes in how callback interfaces work. r=khuey

Specifically, any object that's not a Date or RegExp can implement a callback interface.

dom/bindings/BindingUtils.h

@@ -233,6 +233,12 @@ IsConvertibleToDictionary(JSContext* cx, JS::Value val)
     (val.isObject() && IsConvertibleToDictionary(cx, &val.toObject()));
 }
 
+MOZ_ALWAYS_INLINE bool
+IsConvertibleToCallbackInterface(JSContext* cx, JSObject* obj)
+{
+  return IsNotDateOrRegExp(cx, obj);
+}
+
 inline bool
 IsPlatformObject(JSContext* cx, JSObject* obj)
 {

dom/bindings/Codegen.py

@@ -1936,12 +1936,16 @@ class CallbackObjectUnwrapper:
                               "codeOnFailure" : CGIndenter(CGGeneric(codeOnFailure)).define() }
 
     def __str__(self):
+        checkObjectType = CGIfWrapper(
+            CGGeneric(self.substitution["codeOnFailure"]),
+            "!IsConvertibleToCallbackInterface(cx, %(source)s)" %
+            self.substitution).define() + "\n\n"
         if self.descriptor.workers:
-            return string.Template(
+            return checkObjectType + string.Template(
                 "${target} = ${source};"
                 ).substitute(self.substitution)
 
-        return string.Template(
+        return checkObjectType + string.Template(
             """nsresult rv;
 XPCCallContext ccx(JS_CALLER, cx);
 if (!ccx.IsValid()) {
@@ -2348,11 +2352,6 @@ for (uint32_t i = 0; i < length; ++i) {
         else:
             callbackObject = None
 
-        if callbackObject and callbackMemberTypes[0].isCallbackInterface():
-            callbackObject = CGWrapper(CGIndenter(callbackObject),
-                                       pre="if (!IsPlatformObject(cx, &argObj)) {\n",
-                                       post="\n}")
-
         dictionaryMemberTypes = filter(lambda t: t.isDictionary(), memberTypes)
         if len(dictionaryMemberTypes) > 0:
             raise TypeError("No support for unwrapping dictionaries as member "
@@ -4032,16 +4031,13 @@ class CGMethodCall(CGThing):
             # 3)  A RegExp object being passed to a RegExp or "object" arg.
             # 4)  A callable object being passed to a callback or "object" arg.
             # 5)  Any non-Date and non-RegExp object being passed to a
-            #     dictionary or array or sequence or "object" arg.
-            # 6)  Some other kind of object being passed to a callback
-            #     interface or "object" arg.
+            #     array or sequence or callback interface dictionary or
+            #     "object" arg.
             #
-            # Unfortunately, we cannot push the "some other kind of object"
-            # check down into case 6, because callbacks interfaces _can_ normally be
-            # initialized from platform objects. But we can coalesce the other
-            # five cases together, as long as we make sure to check whether our
-            # object works as an interface argument before checking whether it
-            # works as an arraylike or dictionary or callback function.
+            # We can can coalesce these five cases together, as long as we make
+            # sure to check whether our object works as an interface argument
+            # before checking whether it works as an arraylike or dictionary or
+            # callback function or callback interface.
 
             # First grab all the overloads that have a non-callback interface
             # (which includes typed arrays and arraybuffers) at the
@@ -4062,11 +4058,12 @@ class CGMethodCall(CGThing):
                               if distinguishingType(s).isCallback())
 
             # Now append all the overloads that take an array or sequence or
-            # dictionary:
+            # dictionary or callback interface:
             objectSigs.extend(s for s in possibleSignatures
                               if (distinguishingType(s).isArray() or
                                   distinguishingType(s).isSequence() or
-                                  distinguishingType(s).isDictionary()))
+                                  distinguishingType(s).isDictionary() or
+                                  distinguishingType(s).isCallbackInterface()))
 
             # There might be more than one thing in objectSigs; we need to check
             # which ones we unwrap to.
@@ -4092,11 +4089,6 @@ class CGMethodCall(CGThing):
 
                 caseBody.append(CGGeneric("}"))
 
-            # Check for vanilla JS objects
-            pickFirstSignature("%s.isObject() && !IsPlatformObject(cx, &%s.toObject())" %
-                               (distinguishingArg, distinguishingArg),
-                               lambda s: distinguishingType(s).isCallbackInterface())
-
             # The remaining cases are mutually exclusive.  The
             # pickFirstSignature calls are what change caseBody
             # Check for strings or enums

dom/bindings/test/TestBindingHeader.h

@@ -482,8 +482,15 @@ public:
   // Overload resolution tests
   bool Overload1(TestInterface&);
   TestInterface* Overload1(const nsAString&, TestInterface&);
+  void Overload2(TestInterface&);
   void Overload2(const Dict&);
   void Overload2(const nsAString&);
+  void Overload3(TestInterface&);
+  void Overload3(const TestCallback&);
+  void Overload3(const nsAString&);
+  void Overload4(TestInterface&);
+  void Overload4(TestCallbackInterface&);
+  void Overload4(const nsAString&);
 
   // Variadic handling
   void PassVariadicThirdArg(const nsAString&, int32_t,

dom/bindings/test/TestCodeGen.webidl

@@ -432,8 +432,15 @@ interface TestInterface {
   //void overload1(DOMString... strs);
   boolean overload1(TestInterface arg);
   TestInterface overload1(DOMString strs, TestInterface arg);
+  void overload2(TestInterface arg);
   void overload2(optional Dict arg);
   void overload2(DOMString arg);
+  void overload3(TestInterface arg);
+  void overload3(TestCallback arg);
+  void overload3(DOMString arg);
+  void overload4(TestInterface arg);
+  void overload4(TestCallbackInterface arg);
+  void overload4(DOMString arg);
 
   // Variadic handling
   void passVariadicThirdArg(DOMString arg1, long arg2, TestInterface... arg3);

dom/bindings/test/TestExampleGen.webidl

@@ -351,8 +351,15 @@ interface TestExampleInterface {
   //void overload1(DOMString... strs);
   boolean overload1(TestInterface arg);
   TestInterface overload1(DOMString strs, TestInterface arg);
+  void overload2(TestInterface arg);
   void overload2(optional Dict arg);
   void overload2(DOMString arg);
+  void overload3(TestInterface arg);
+  void overload3(TestCallback arg);
+  void overload3(DOMString arg);
+  void overload4(TestInterface arg);
+  void overload4(TestCallbackInterface arg);
+  void overload4(DOMString arg);
 
   // Variadic handling
   void passVariadicThirdArg(DOMString arg1, long arg2, TestInterface... arg3);