Re: [PING #5] add support for dwarf AT_descriptive_type

[Jason Merrill <jason at redhat dot com>]

> On Thu, Sep 02, 2010 at 04:38:49PM +0200, Olivier Hainque wrote:

Sorry about the slow review.

> > In addition, even if only the Ada compiler uses this today, there is
> > no strong reason for the attribute to be explictly GNAT specific, so
> > the patch renames AT_GNAT_descriptive_type into AT_GNU_descriptive_type.

From the earlier discussion, it sounded like this format isn't actually 
any more expressive than normal DWARF, this patch just provides better 
debugging functionality as a transitionary measure until we implement 
better Ada DWARF support.  So giving it a more generic name seems 
undesirable.

> > Index: ada/gcc-interface/trans.c
> > ===================================================================
> > *** ada/gcc-interface/trans.c	(revision 163722)
> > --- ada/gcc-interface/trans.c	(working copy)
> > *************** gigi (Node_Id gnat_root, int max_gnat_no
> > *** 295,301 ****
> >          dwarf2out_set_type_encoding_func (extract_encoding);
> >          dwarf2out_set_demangle_name_func (decode_name);
> >        }
> > -   dwarf2out_set_descriptive_type_func (get_parallel_type);
> >    #endif

This code doesn't seem to be in FSF GCC.  How does it work?

Jason