Re: fhpd vs RuntimeExceptions

[Andrew Cagney <cagney at redhat dot com>]

Mark Wielaard wrote:
> By using different exception types, so a higher level can distinquish
> between a "recoverable" warning and a "unrecoverable" error.
>
>   
> > Take this example. I manufactured this warning to happen, but all the 
> > message is telling the user is that it cannot read at the peek() address 
> > given. It's not an error, just a cannot do. But the huge ugly backtrace 
> > that follows is not very useful.
> >
> > (fhpd) core /home/pmuldoon/core.12463 /bin/bash
> > Internal debugger error:  peek() at address 6992f8 cannot be found in 
> > metadata table.
> > java.lang.RuntimeException: peek() at address 6992f8 cannot be found in 
> > metadata table.
> >    at frysk.proc.dead.CorefileByteBuffer.peek(fhpd)
> >    at inua.eio.ByteBuffer.peek(fhpd)
> >    at inua.eio.ByteBuffer.peekFully(fhpd)
> >    at inua.eio.ByteBuffer.peekLittle(fhpd)
> >    at inua.eio.ByteBuffer.peekLittle(fhpd)
> >    at inua.eio.ByteOrdered$2.peekULong(fhpd)
> >    at inua.eio.ByteBuffer.getULong(fhpd)
> >    at inua.eio.WordSized$3.getUWord(fhpd)
> >    at inua.eio.ByteBuffer.getUWord(fhpd)
> >    at frysk.proc.dead.LinuxProc.sendrecMaps(fhpd)
> >    at frysk.proc.Proc.getMaps(fhpd)
> >    at frysk.dwfl.DwflFactory.updateDwfl(fhpd)
> >    at frysk.dwfl.DwflCache.getDwfl(fhpd)
> >    at frysk.debuginfo.DebugInfoFrame.getScopes(fhpd)
> >    at frysk.debuginfo.DebugInfoStackFactory.createVirtualStackTrace(fhpd)
> >    at frysk.hpd.CoreCommand.interpret(fhpd)
> >    at frysk.hpd.ParameterizedCommand.interpret(fhpd)
> >    at frysk.hpd.MultiLevelCommand.interpret(fhpd)
> >    at frysk.hpd.CLI.execCommand(fhpd)
> >    at frysk.bindir.fhpd.main(fhpd)
> >
> > If this is the way forward, I'll have to gobble exceptions locally in 
> > CoreCommand, and just deal with them locally.
> >     
>
> Yes, I think that is the way forward.

Er, no.  We're not going to make all commands gobble all exceptions 
locally.  It's a loosing battle.  And we've far more important battles 
to be focused on right now.


>  Something terribly failed. And
> just passing the "address 6992f8 cannot be found in metadata table."
> message to the user is clearly not very helpful if the user just wanted
> to run a specific command. Only the command knows if this is something
> fatal or not and should catch it at the appropriate level and report
> what the exact action was that was attempted and which structure
> couldn't be created because of the error.
>
> Cheers,
>
> Mark
>
>