Subj : Re: Calling non-existent object function crashes engine
To   : netscape.public.mozilla.jseng
From : John Bandhauer
Date : Mon Sep 05 2005 04:08 pm

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
>     };

Hi Syd,

I'm not even going to ask why you'd want to do this. I guess this makes 
for an interesting book project. But, I'm still a believer that 
XPConnect was the right way to go :)

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.

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.

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.

BTW, it is good to say explicitly which js version you are using when 
asking for help so that folks can correlate line numbers in stack dumps 
with actual source lines.

John.

.