Re: Unifying the GCC Debugging Interface

[Martin Jambor <mjambor at suse dot cz>]

Hi,

On Fri, Nov 16, 2012 at 08:08:52AM -0500, Diego Novillo wrote:
> On Fri, Nov 16, 2012 at 4:38 AM, Martin Jambor <mjambor@suse.cz> wrote:
> 
> > So you do not plan to replace/rename at least some of them?  This
> > seems like unnecessary and confusing layering just to avoid the work
> > to do the right thing.
> 
> No, we plan to replace all the existing dumping routines.  We are just
> not planning to add *new* ones.  Duplicating the existing routines
> would indeed be useless.
> 
> >>
> >> dump_raw
> >>
> >>     This function overload set provides the raw oriented dump,
> >>     e.g. a tuple.
> >
> > I'm not sure I understand the whole raw thing.
> 
> This is to distinguish between:
> 
> a = b + c;
> 
> from
> 
> <modify_expr, plus_expr, a, b, c>
> 
> ASTs and RTL have something similar.  The raw output gives you a
> different view.  Not every data structure will have that distinction.
> 
> 
> > I'm afraid we can't really always rely on overloading.  For example,
> > even though I often use debug_tree to examine a tree, probably even
> > more often I just use debug_generic_expr.  When I write stuff into a
> > dump file, I rarely ever use the verbose variants but I certainly want
> > them to exist.  And there might be other similar cases, like the
> > .*_brief dumping functions that are sometimes also used.
> 
> Sure.  The idea is to provide these variants via symbolic TDF_ style
> flags.  For combinations that are very popular, we provide alternate
> entry names so that you don't have to be specifying the flags all the
> time.

Well, this is what I was actually afraid of.  If things like generic
or tree dump of a tree value is selected by new TDF_ flags, then you
are in danger of just replacing current mess in function names by a
mess of constants.  I'd much rather have functions dump_generic,
dump_tree (and dump_function!), with consistent parameters, for the
three very different dumps than TDF_gimple, TDF_tree and TDF_function
constants which would do some sort of second level function
overloading.  I understand my approach would not be a real grand
unification, but I believe that either way we'll have to remember a
few identifiers to make dumping useful.  Yes, there is a lot of space
for simplification so that we need to remember fewer and the
parameters should be made much more consistent but I think this is not
the place where overloading-only is appropriate for many uses.

Moreover, would the TDF_ constants be available in gdb?  IIRC hen I
use them from gdb, I always have to pass numbers.

Thanks,

Martin


> 
> 
> > Nevertheless, it would be great if we had fewer and consistent names
> > of dumping functions, even though perhaps not just three.  It would
> > also be nice if all the file variants had an integer indent parameter
> > ;-)
> 
> Ah, good idea.  Thanks.
> 
> 
> Diego.