This is the mail archive of the
java@gcc.gnu.org
mailing list for the Java project.
Re: sysdep/i386/backtrace.h infinite loop?
Andrew Haley wrote:
Marco Trudel writes:
> Andrew Haley wrote:
> > Marco Trudel writes:
> > > Maybe a stupid question, but how can this loop in
> > > sysdep/i386/backtrace.h ever end:
> > >
> > > register _Jv_uintptr_t *_ebp __asm__ ("ebp");
> > > _Jv_uintptr_t rfp;
> > > for (rfp = *_ebp; rfp; rfp = *(_Jv_uintptr_t *)rfp)
> > > {
> > > // only read access for rfp
> > > }
> > >
> > > Maybe because "*(_Jv_uintptr_t *)rfp" is changing it, but I can't see how...
> >
> > It looks to me like it's walking down a linked list until it hits NULL.
>
> Yeah, but where happens the down-walking? In my opinion we do
> always-the-same-value-walking...
What, in your opinion, does
rfp = *(_Jv_uintptr_t *)rfp;
do?
Nothing. But as I said already this is probably doing something. But I
can't see what. On second thought, what about: Setting rfp to the value
stored at the location which was addressed by the value of the old rfp?
Ok, I see. Something is being done and I should work on my C knowledge
if I don't understand it. Will do :-)
thanks
Marco