RE: [PATCH v3 00/13] C99 variable length array support

Agovic, Sanimir
2014-01-16T17:00:29Z

Thanks for your review.

> -----Original Message-----
> From: gdb-patches-owner@sourceware.org [mailto:gdb-patches-owner@sourceware.org] On Behalf
> Of Joel Brobecker
> Sent: Wednesday, January 15, 2014 12:42 PM
> To: Agovic, Sanimir
> Cc: tromey@redhat.com; palves@redhat.com; xdje42@gmail.com; gdb-patches@sourceware.org;
> Boell, Keven
> Subject: Re: [PATCH v3 00/13] C99 variable length array support
>
> Hello,
>
> > this patch series (v3) add C99 variable length support to gdb.
> >
> > It allows the user to evaluate a vla like an ordinary static array e.g. print
> > its elements instead of printing the pointer to the array. In addition
> > the size of a vla can be retrieved with gdbs builtin sizeof operator.
>
> We've started working internally at AdaCore on getting rid of some
> of the "GNAT encodings", with the goal of replacing them with pure
> dwarf constructs. One of the issues we've noticed is precisely
> the lack of support for dynamically-sized arrays, and I think
> this patch series would be a very good stepping stone towards that.
>
It would be great if gnat could benefit from c99 and the upcoming fortran vla
support. I hacked on the D and go-lang compiler and could get variable length
arrays working without additional changes to gdb, simply by changing what the
compiler emits for ranges.

> I remember I had one patch that made me a little nervous (patch #5/13,
> adding type re-fecthing after some value_* calls), but I also said
> that I would be OK if the patch went in as is. Apart from that,
> it seems to me that most/all? comments have been addressed?
> Perhaps, all we're missing is just v4 of the patch series?
>
If it is OK for you I`d like to keep #5 as-is. AFAIK struct value
is opaque outside of its definition so any knowledge about how it works
(e.g. how values are constructed) means we leak implementation details.

> Any chance we could make progress on those? If there is anything
> I can do to assist, please let me know as well!
>
Sure, I`m back and willing to address the missing parts =D

-Sanimir

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