[gclist] Two conservative collectors

[Kragen Sitaker]

Charles Fiterman writes:
> Its not good enough for a GC but C++ users use our GC primarily as a
> debugging tool. We have multiple libraries some of which use debug info and
> some don't.

Someone posted here not long ago saying that 50% of Geodesic's
customers buy GC planning to ship with it, and 90% actually do ship
with it.  How does this relate to your statement above?

(As an aside, if you're using debugging info to decide what's not a
pointer, and the debugging info is as bad as you and Hans say, then GC
will erroneously free things.  This will change it from a debugging
tool to an enbugging tool. :)

> >       f() + g(13)
> >
> >where f returns a pointer (and has been evaluated first) and g returns an
> >integer,
> 
> In this construct the language doesn't even have to do the +. Suppose it
> does and the pointer is on the stack and we have to report on it for
> some reason. We don't know the pointer's type but we can find the target
> and report that and if it has a vtbl report that.

I'm not sure what you mean by "doesn't have to do the +", but I think
Hans's point is that the debug information is insufficient to explain
to the user why something is being incorrectly retained, in sufficient
detail that said user can fix it.  Your tone sounds like you are
arguing, but your words seem to be agreeing with him.  What am I
misinterpreting?

-- 
<kragen@pobox.com>       Kragen Sitaker     <http://www.pobox.com/~kragen/>
The Internet stock bubble didn't burst on 1999-11-08.  Hurrah!
<URL:http://www.pobox.com/~kragen/bubble.html>