Re: Patch: Remove exception catching from normal path in Arrays.equals.

[Mohan Embar <gnustuff at thisiscool dot com>]

Hi Andrew,

> >  > While we're on this subject, there are myriad places (natClass.cc,
> >  > natRuntime.cc, natArray.cc, natConstructor.cc, natField.cc, natMethod.cc,
> >  > natResourceBundle.cc) where gnu.gcj.StackTrace is being used
> >  > like this (example from natArray.cc):
> >  > 
> >  > try
> >  > {
> >  >   for (int i = 1; !caller; i++)
> >  >     {
> >  >       caller = t->classAt (i);
> >  >     }
> >  >   caller_loader = caller->getClassLoaderInternal();
> >  > }
> >  > catch (::java::lang::ArrayIndexOutOfBoundsException *e)
> >  > {
> >  > }
> >  
> > Note that the catch clause will not be invoked unless there is a bug in gcj.
>
>... so the last part should perhaps read
>
>catch (::java::lang::ArrayIndexOutOfBoundsException *e)
>{
>  throw new RuntimeError (e);
>}

...with Ranjit's initial cross-configury patch and also for cygwin gcj,
the backtrace() function was non-existent and stacktraces where therefore
broken. The ArrayIndexOutOfBoundsException was eaten alive, causing
null pointer problems down the road. Throwing a RuntimeError would be
better.

I'm probably belaboring something not worth belaboring, but it seems
the right thing to do to refactor this into a helper function in
StackTrace. In this way, we can implement the correct behavior only
once. (And I agree that findCallerClass() is better than
tryTofindFirstNonNullClassStartingAtIndex() :). However, this
may not be worth our time given that it's a fringe case and you
said this code is going to be revised.

Let me know if you want me to submit a patch. Otherwise, I'll walk
away from this.

-- Mohan
http://www.thisiscool.com/
http://www.animalsong.org/