[LLVMdev] [PATCH] SelectionDAG Debugging

[David Greene]

On Friday 15 January 2010 18:14, Dan Gohman wrote:

> > Ah, one thing.  dumpr uses DumpNodesr which does the "once" thing.
> > I actually would prefer a full dump.  Perhaps we shouldn't try to
> > unify them, or maybe provide a flag to control behavior.  In the
> > past separate APIs have been preferred over flags.  I can rename
> > the ones I added to be more consistent with the existing stuff.
> >
> > Opinions?
>
> I use the GraphViz viewer almost exclusively, so I don't have a
> strong opinion.
>
> Methods with lots of flags are inconvenient to call from a debugger.
> I'd suggesting coming up with a few common use cases, and providing
> interfaces to cover those use cases, and not trying to provide
> lots of extra generality.

The interfaces I added are exactly the ones I needed to debug a problem.
So I think they are pretty minimal.

> If SDNode::dumpr() had built-in cycle detection, and indicated
> cycles with big capital letters, would you still want a recursive
> dump which doesn't do the "once" thing?  Or, if the "once" thing
> had a more human-oriented syntax, would it be usable?

No, I don't think either would be sufficient.  I really, really, really
want to see the real DAG.  I can't think of how "once" could give the
same information.

                                    -Dave