Subj : Re: Calling non-existent object function crashes engine
To   : netscape.public.mozilla.jseng
From : Syd Logan
Date : Mon Sep 05 2005 05:12 pm



John Bandhauer wrote:
> Syd Logan wrote:
> 
>>     JSClass objectClass = {
>>         name.c_str(), JSCLASS_NEW_RESOLVE,
>>         JS_PropertyStub,  JS_PropertyStub,
>>         JS_PropertyStub,  JS_PropertyStub,
>>         JS_EnumerateStub,  JS_ResolveStub,
>>         JS_ConvertStub,   JS_FinalizeStub
>>     };
> 
> 
> 
> I'd say one mistake is in using JSCLASS_NEW_RESOLVE and passing 
> JS_ResolveStub. I believe that JSCLASS_NEW_RESOLVE tells the engine that 
> the resolve callback is of type JSNewResolveOp, but you are passing in a 
> callback of type JSResolveOp. That would be bad.

Does sound bad, I'll give that a try.

> 
> I'd also have to wonder if the name string you are passing is static 
> (name.c_str()) - the engine doesn't make a copy of it. As Brendan 
> pointed out, same story for the entire JSClass structure.

Right. It's not static, it lives on the stack. But I have a place for 
both of these, thanks for pointing out the problem.

> 
> You are either calling the wrong address if the JSClass* is not pointing 
> to data that doesn't change, or you are screwing up the stack on return 
> from JS_ResolveStub.
> 

> 
> John.

.