On Thu, Sep 12, 2019 at 1:36 PM Alexandre Oliva <ol...@adacore.com> wrote: > > On Sep 12, 2019, Richard Biener <richard.guent...@gmail.com> wrote: > > > Is this PR91507? > > Looks like it. Interesting, I've had this patch sitting in my tree > since early June, waiting for the additional verification I completed > last night. That was long before the PR was filed. > > > How do you get around the gdb issue? > > I was not even aware of one. I focused on preserving at what I regarded > as the right place the information we currently dropped on the floor, > figuring if any consumers wouldn't take the type information from the > definition as overriding/completing that of the specification, they'd > eventually be adjusted to do so. > > > The approach I chose was to add the completion type to the definition, > not to the specification. I figured leaving the specification alone, > reflecting the information available at its source location, and > providing the complete type information at the source location that > supplies it, was the right thing to do, regardless of whatever debug > information consumers were able to do with that information.
Yes, I agree, this is what my patch in the PR does as well, albeit just in the place where we add the link to the specification DIE and the unconditionally if there's a disagreeing type DIE (we force a type DIE earlier in the caller). Your new predicate looks a bit excessive here given it builds the type again? But that's implementation detail I guess. So I'm obviously fine with your patch and I guess if we independently arrive at this solution that answers my question what "correct DWARF" is by a majority decision ;) So - maybe we can have the patch a bit cleaner by adding a flag to add_type_attribute saying we only want it if it's different from that already present (on the specification DIE)? Thanks, Richard. > There's room for dispute as to the correctness of this approach, > however. Someone might argue that we should have a separate (IMHO > excessive) completion non-defining declaration, pointing back to the > initial incomplete declaration with a DW_AT_specification, and perhaps > to omit the incomplete type from the incomplete specification, though > that doesn't seem to be in line with the common practice of overriding > declaration coordinates in the definition. > > -- > Alexandre Oliva, freedom fighter he/him https://FSFLA.org/blogs/lxo > Be the change, be Free! FSF.org & FSF Latin America board member > GNU Toolchain Engineer Free Software Evangelist > Hay que enGNUrecerse, pero sin perder la terGNUra jamás - Che GNUevara
