Thanks for the reminder, I'll take another look tomorrow.
On Wed, 2 Sept 2026 at 09:25, Odysseas Georgoudis <[email protected]> wrote:
>
> Hi Jonathan,
>
> Gentle ping for this patch.
>
> v2 addresses your review comments and includes the benchmark results for the
> normal path.
>
> Is this OK for trunk?
>
> Thanks,
> Odysseas
>
> ________________________________
> From: Odysseas Georgoudis <[email protected]>
> Sent: Thursday, 20 August 2026 01:38:00
> To: Jonathan Wakely <[email protected]>
> Cc: [email protected] <[email protected]>; [email protected]
> <[email protected]>
> Subject: RE: [PATCH v2] libstdc++: Make forward_list::sort exception-safe
> [PR124051]
>
> Hi Jonathan,
>
> Thanks for the review.
>
> I used an LLM as an additional review tool, but I wrote both the
> change and the test myself. I thought the added copyright
> block was needed. I have removed it in v2 and added the
> explicit return from main.
>
> I was not expecting a measurable regression on the normal path, because
> the added recovery code only runs when the comparator throws, but I
> benchmarked it to confirm. With the default comparator, the generated
> code was identical and timings were within noise. With an external
> potentially-throwing comparator, the worst result was about 1.9% slower.
>
> I kept the benchmark local, but I can send it if useful.
>
> Outlook sent the v1 patch as application/octet-stream, so I have
> attached v2 as PR124051-v2.patch.txt instead.
>
> Thanks,
> Odysseas
>
>
>
> ________________________________
> From: Jonathan Wakely <[email protected]>
> Sent: 19 August 2026 12:19
> To: Odysseas Georgoudis <[email protected]>
> Cc: [email protected] <[email protected]>; [email protected]
> <[email protected]>
> Subject: Re: [PATCH] libstdc++: Make forward_list::sort exception-safe
> [PR124051]
>
> On Sun, 16 Aug 2026 at 20:43 +0000, Odysseas Georgoudis wrote:
> >If a comparison called by forward_list::sort throws, the current
> >implementation can leave the list corrupted, which may cause a later
> >crash.
> >
> >This patch restores valid links before allowing the same exception to
> >continue. The element order remains unspecified, as permitted by the
> >standard, while iterators and references remain valid.
> >
> >Tested on x86_64-pc-linux-gnu.
> >
> >Thanks,
> >Odysseas
>
> Thanks for the patch to fix this.
>
> Have you tested whether this affects performance of the sort function?
> I hope it doesn't make much difference.
>
> Please don't attach patches as application/octet-stream - patches are
> plain text, not binary data. It makes it hard to review the patch by
> replying inline.
>
> Please read
> https://gcc.gnu.org/onlinedocs/libstdc++/manual/test.html#test.new_tests
> and adjust the new test accordingly. Based on the copyright notice in
> the test, it seems likely this was produced with the assistance of an
> LLM, is that correct?
>
