llvm dev - Feb 2020 - Coding style and warning spam: redundant std::move?

Hi all,

GCC 9 introduced a new warning, -Wredundant-move, which is enabled by
default when building LLVM and produces what looks like at least
thousands of hits.

https://reviews.llvm.org/D74672 is a sample of the kind of changes
pointed out by this warning, more explanations are in this blog post:
https://developers.redhat.com/blog/2019/04/12/understanding-when-not-to-stdmove-in-c/

What do people think should be done here?

1. Disable -Wredundant-move?
2. Fix it all (seems daunting to do manually)?
3. Encourage clang/clang-tidy developers to add this warning and add a
clang-tidy rule to fix it automatically?

My personal opinion is that while the review linked above should be
committed, it's ultimately a drop in the ocean and #3 is the way to
go.

In the meantime, I'm certainly going to disable -Wredundant-move
locally, but should that also be done by default for gcc in the
CMakeLists.txt?

Cheers,
Nicolai
-- 
Lerne, wie die Welt wirklich ist,
aber vergiss niemals, wie sie sein sollte.

On Sat, Feb 15, 2020 at 11:35 AM Nicolai Hähnle via llvm-dev <
llvm-dev at lists.llvm.org> wrote:
> Hi all,
>
> GCC 9 introduced a new warning, -Wredundant-move, which is enabled by
> default when building LLVM and produces what looks like at least
> thousands of hits.
>
> https://reviews.llvm.org/D74672 is a sample of the kind of changes
> pointed out by this warning, more explanations are in this blog post:
>
>
https://developers.redhat.com/blog/2019/04/12/understanding-when-not-to-stdmove-in-c/
>
> What do people think should be done here?
>
> 1. Disable -Wredundant-move?
> 2. Fix it all (seems daunting to do manually)?
> 3. Encourage clang/clang-tidy developers to add this warning and add a
> clang-tidy rule to fix it automatically?
>
> My personal opinion is that while the review linked above should be
> committed, it's ultimately a drop in the ocean and #3 is the way to
> go.
>
+1

>
> In the meantime, I'm certainly going to disable -Wredundant-move
> locally, but should that also be done by default for gcc in the
> CMakeLists.txt?
>
I'd support this as well!

Thanks!

-- 
Mehdi
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