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Date: Sat, 29 Nov 2025 16:29:47 +0100
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Subject: Re: Cleanup shadows variable warnings, round 1
To: Chao Li <li.evan.chao@gmail.com>,
 Postgres hackers <pgsql-hackers@lists.postgresql.org>
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From: Peter Eisentraut <peter@eisentraut.org>
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On 28.11.25 09:16, Chao Li wrote:
> Hi Hackers,
> 
> While reviewing [1], it makes me recall an experience where I had a 
> patch ready locally, but CommitFest CI failed with a shadows-variable 
> warning. Now I understand that -Wall doesn't by default enable -Wshadows 
> with some compilers like clang.
> 
> I did a clean build with manually enabling -Wshadow and 
> surprisingly found there are a lot of such warnings in the current code 
> base, roughly ~200 occurrences.
> 
> As there are too many, I plan to fix them all in 3-4 rounds. For round 1 
> patch, I'd see any objection, then decide if to proceed more rounds.

See 
<https://www.postgresql.org/message-id/flat/20220817145434.GC26426%40telsasoft.com> 
for a previous long thread on this, which led to the addition of the 
-Wshadow=compatible-local flag.

I think this is a slightly unsatisfactory state, because that is a 
gcc-specific option, and maybe you are using clang or something else. 
So maybe some further cleanup is useful, but please check the previous 
discussions.