Bug 981036. Disallow calling DOM constructors as functions in non-release builds. r=bholley

dom/bindings/BindingUtils.cpp

@@ -867,6 +867,12 @@ ThrowingConstructor(JSContext* cx, unsigned argc, JS::Value* vp)
   return ThrowErrorMessage(cx, MSG_ILLEGAL_CONSTRUCTOR);
 }
 
+bool
+ThrowConstructorWithoutNew(JSContext* cx, const char* name)
+{
+  return ThrowErrorMessage(cx, MSG_CONSTRUCTOR_WITHOUT_NEW, name);
+}
+
 inline const NativePropertyHooks*
 GetNativePropertyHooks(JSContext *cx, JS::Handle<JSObject*> obj,
                        DOMObjectType& type)

dom/bindings/BindingUtils.h

@@ -117,6 +117,7 @@ ThrowMethodFailedWithDetails(JSContext* cx, ErrorResult& rv,
   }
   if (rv.IsNotEnoughArgsError()) {
     rv.ReportNotEnoughArgsError(cx, ifaceName, memberName);
+    return false;
   }
   return Throw(cx, rv.ErrorCode());
 }
@@ -1466,6 +1467,9 @@ WantsQueryInterface
 bool
 ThrowingConstructor(JSContext* cx, unsigned argc, JS::Value* vp);
 
+bool
+ThrowConstructorWithoutNew(JSContext* cx, const char* name);
+
 // vp is allowed to be null; in that case no get will be attempted,
 // and *found will simply indicate whether the property exists.
 bool

dom/bindings/Codegen.py

@@ -1183,26 +1183,43 @@ class CGClassConstructor(CGAbstractStaticMethod):
 
     def generate_code(self):
         preamble = """
-  JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
-  JS::Rooted<JSObject*> obj(cx, &args.callee());
+JS::CallArgs args = JS::CallArgsFromVp(argc, vp);
+JS::Rooted<JSObject*> obj(cx, &args.callee());
 """
         # [ChromeOnly] interfaces may only be constructed by chrome.
-        # Additionally, we want to throw if a non-chrome caller does a bareword invocation of a
-        # constructor without |new|. We don't enforce this for chrome to avoid the addon compat
-        # fallout of making that change. See bug 916644.
         if isChromeOnly(self._ctor):
-            mayInvokeCtor = "nsContentUtils::ThreadsafeIsCallerChrome()"
+            preamble += (
+                "if (!nsContentUtils::ThreadsafeIsCallerChrome()) {\n"
+                "  return ThrowingConstructor(cx, argc, vp);\n"
+                "}\n\n")
+
+        # Additionally, we want to throw if a caller does a bareword invocation
+        # of a constructor without |new|. We don't enforce this for chrome in
+        # realease builds to avoid the addon compat fallout of making that
+        # change. See bug 916644.
+        name = self._ctor.identifier.name
+        if name != "constructor":
+            ctorName = name
         else:
-            mayInvokeCtor = "(args.isConstructing() || nsContentUtils::ThreadsafeIsCallerChrome())"
-        preamble += """  if (!%s) {
-    return ThrowingConstructor(cx, argc, vp);
-  }
-""" % mayInvokeCtor
+            ctorName = self.descriptor.interface.identifier.name
+        preamble += (
+            "bool mayInvoke = args.isConstructing();\n"
+            "#ifdef RELEASE_BUILD\n"
+            "mayInvoke = mayInvoke || nsContentUtils::ThreadsafeIsCallerChrome();\n"
+            "#endif // RELEASE_BUILD\n"
+            "if (!mayInvoke) {\n"
+            "  // XXXbz wish I could get the name from the callee instead of\n"
+            "  // Adding more relocations\n"
+            '  return ThrowConstructorWithoutNew(cx, "%s");\n'
+            "}" % ctorName)
+
         name = self._ctor.identifier.name
         nativeName = MakeNativeName(self.descriptor.binaryNames.get(name, name))
         callGenerator = CGMethodCall(nativeName, True, self.descriptor,
-                                     self._ctor, isConstructor=True)
-        return preamble + callGenerator.define();
+                                     self._ctor, isConstructor=True,
+                                     constructorName=ctorName)
+        return CGList([CGIndenter(CGGeneric(preamble)), callGenerator],
+                      "\n").define()
 
 # Encapsulate the constructor in a helper method to share genConstructorBody with CGJSImplMethod.
 class CGConstructNavigatorObjectHelper(CGAbstractStaticMethod):
@@ -5420,10 +5437,14 @@ class CGMethodCall(CGThing):
     signatures and generation of a call to that signature.
     """
     def __init__(self, nativeMethodName, static, descriptor, method,
-                 isConstructor=False):
+                 isConstructor=False, constructorName=None):
         CGThing.__init__(self)
 
-        methodName = "%s.%s" % (descriptor.interface.identifier.name, method.identifier.name)
+        if isConstructor:
+            assert constructorName is not None
+            methodName = constructorName
+        else:
+            methodName = "%s.%s" % (descriptor.interface.identifier.name, method.identifier.name)
         argDesc = "argument %d of " + methodName
 
         def requiredArgCount(signature):

dom/bindings/Errors.msg

@@ -33,6 +33,7 @@ MSG_DEF(MSG_SETTER_THIS_UNWRAPPING_DENIED, 1, "Permission to call '{0}' setter d
 MSG_DEF(MSG_THIS_DOES_NOT_IMPLEMENT_INTERFACE, 1, "\"this\" object does not implement interface {0}.")
 MSG_DEF(MSG_NOT_IN_UNION, 2, "{0} could not be converted to any of: {1}.")
 MSG_DEF(MSG_ILLEGAL_CONSTRUCTOR, 0, "Illegal constructor.")
+MSG_DEF(MSG_CONSTRUCTOR_WITHOUT_NEW, 1, "Constructor {0} requires 'new'")
 MSG_DEF(MSG_NO_INDEXED_SETTER, 1, "{0} doesn't have an indexed property setter.")
 MSG_DEF(MSG_NO_NAMED_SETTER, 1, "{0} doesn't have a named property setter.")
 MSG_DEF(MSG_ENFORCE_RANGE_NON_FINITE, 1, "Non-finite value is out of range for {0}.")