Re: [PATCH 0/2] Avoid the comma operator

From: Karthik Nayak <karthik.188@gmail.com>
Date: Mar 25, 2025, 14:37 UTC
Message-ID: <CAOLa=ZQqknrcrkc=kGsybB5TJPgxH5HKAtL3HMu1uKYkX0NicQ@mail.gmail.com>
In-Reply-To: <Z-Kf9ovF8zAemgUP@pks.im>

Patrick Steinhardt <ps@pks.im> writes:

Show 17 quoted lines

> On Tue, Mar 25, 2025 at 08:01:48AM +0000, Johannes Schindelin via GitGitGadget wrote:
>> The comma operator
>> [https://en.cppreference.com/w/c/language/operator_other#Comma_operator] is
>> rarely used in C anymore, and typically indicates a typo. Just like in these
>> instances, where a semicolon was meant to be used, as there is no need to
>> discard the first statement's result here.
>
> The changes look obviously good to me, thanks. The reftable library and
> backend also had several instances where the operator was used by
> accident, and I've gotten rid of those over time. They typically don't
> do any harm as the result is essentially the same, but sometimes they
> may cause issues. And at the very least they cause confusion.
>
> It would be great if there was a compiler warning we could enable for
> cases where the operator likely isn't intentional. But I couldn't find
> any, unfortunately.
>

Clang does have '-Wcomma' [1], which seems to be exactly what we want.

[1]: https://clang.llvm.org/docs/DiagnosticsReference.html#wcomma

> Thanks!
>
> Patrick