Am Freitag, den 22.07.2005, 23:59 +0200 schrieb Mark Wielaard: > Hi, > > On Fri, 2005-07-22 at 18:01 +0100, Andrew Haley wrote: > > Ingo Prötel writes: > > > > > I just implemented VMStackWalker for our VM and have some questions. > > > > > > The reference implementation of 'getCallingClass()' and > > > 'getCallingClassLoader()' just look at the third entry in the class > > > context. Would it not be better to return the first class that is not > > > assignable to the class in context[0] ? That way we could cope with > > > classes that first call some private or protected classes an then ends > > > up calling the stack walker. > > > > In gcj, we have a method called GetCallingClass(Class c). It searches > > firstly for a method declared in class c, then for a method not > > declared in c. We have found, after a certain amount of trouble, that > > this is the right way to do things; it means that an arbitrary number > > of stack frames can be between the direct caller of GetCallingClass > > and the user code, and it also means that you don't have to check for > > assignability, but for an exact match. > > I proposed something similar a while ago: > http://lists.gnu.org/archive/html/classpath-patches/2005-01/msg00138.html > > Jeroen did object strongly to this approach though since he felt that > having (and constructing) an extra argument for this function was too > much overhead for runtimes that didn't need it to begin with. > > It might be good to review that thread and see how/if we can have some > solution/compromise here since it seems that gcj actually needs this > functionality. For the other runtimes we did find some workarounds back > then (how fragile those are I don't actually know). > My proposal does not go that far and would not be as universal as adding a parameter.
I would like to get the common case where private or protected methods are called before the actual stack check happens. This changes the current semantic but I feel that it would be more useful and less fragile to changes of classes that want to use VMStackWalker. If there is a real need for a method with the current semantic we could just add a method to the interface for the new semantic. ingo -- Ingo Prötel [EMAIL PROTECTED] aicas GmbH http://www.aicas.com Haid-und-Neu-Str. 18 phone +49 721 663 968-32 76131 Karlsruhe fax +49 721 663 968-93 Germany _______________________________________________ Classpath mailing list Classpath@gnu.org http://lists.gnu.org/mailman/listinfo/classpath