Mirror of the gdb-patches mailing list
 help / color / mirror / Atom feed
From: Joel Brobecker <brobecker@adacore.com>
To: Simon Marchi <simon.marchi@polymtl.ca>
Cc: Simon Marchi <simon.marchi@efficios.com>,
	Simon Marchi via Gdb-patches <gdb-patches@sourceware.org>
Subject: Re: [PATCH 4/4] gdb: fix value_subscript when array upper bound is not known
Date: Tue, 8 Dec 2020 07:14:31 +0400	[thread overview]
Message-ID: <20201208031431.GG3202@adacore.com> (raw)
In-Reply-To: <8a48f527-bd8f-5aa9-f232-7523359515fa@polymtl.ca>

[just for the sake of discussing generalities, rather than suggesting
modifications to your patch]

> > Now, the bigger question is: Why are we even getting to this point?
> > Shouldn't the bounds simply be resolved before we do the subscripting?
> 
> If the array is c-style, there's no concept of high bound, so I don't think
> there's a point resolving the high bound then.

I believe you sometimes do, for intance in...

    char something[5];

> Again, I've never really been a user of such a language.  Intuitively, I'd
> like the debugger to work as close to the source language as possible, so
> I'd like it to validate the bounds in my expression.  But it might be that
> people who use these languages sometimes need to side-step the language's
> protections.

Speaking for myself, sometimes I indeed want to go beyond.

Even in C, when we have structures looking like this (don't know if we
have any of those in our code anymore):

    struct something
    {
      size_t n_elems;
      int buf[0];
    };

You'd know that you need to go beyond the first element of the array
to get to the rest of the data...


-- 
Joel

  reply	other threads:[~2020-12-08  3:14 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-23 16:21 [PATCH 0/4] Fix bug in value_subscript when range's high " Simon Marchi via Gdb-patches
2020-11-23 16:21 ` [PATCH 1/4] gdb: make discrete_position return optional Simon Marchi via Gdb-patches
2020-12-06  5:25   ` Joel Brobecker
2020-12-06  5:38   ` Joel Brobecker
2020-12-07 14:58     ` Simon Marchi via Gdb-patches
2020-12-08  3:06       ` Joel Brobecker
2020-12-08 11:41         ` Maciej W. Rozycki
2020-12-09 19:29           ` Simon Marchi via Gdb-patches
2020-12-09 19:53             ` Maciej W. Rozycki
2020-11-23 16:21 ` [PATCH 2/4] gdb: make get_discrete_bounds return bool Simon Marchi via Gdb-patches
2020-12-06  6:03   ` Joel Brobecker
2020-12-07 15:19     ` Simon Marchi via Gdb-patches
2020-11-23 16:21 ` [PATCH 3/4] gdb: split get_discrete_bounds in two Simon Marchi via Gdb-patches
2020-12-06  7:29   ` Joel Brobecker
2020-12-07 15:49     ` Simon Marchi via Gdb-patches
2020-11-23 16:21 ` [PATCH 4/4] gdb: fix value_subscript when array upper bound is not known Simon Marchi via Gdb-patches
2020-12-06  7:54   ` Joel Brobecker
2020-12-07 16:06     ` Simon Marchi via Gdb-patches
2020-12-08  3:14       ` Joel Brobecker [this message]
2020-12-09 18:50         ` Simon Marchi via Gdb-patches
2020-12-09 19:57     ` Simon Marchi via Gdb-patches

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201208031431.GG3202@adacore.com \
    --to=brobecker@adacore.com \
    --cc=gdb-patches@sourceware.org \
    --cc=simon.marchi@efficios.com \
    --cc=simon.marchi@polymtl.ca \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox