Re: [PATCH 3/3] clang-tidy: Don't insist on #ifdef over #if defined()

[Stefano Brivio <sbrivio@redhat.com>]

On Mon,  2 Mar 2026 15:31:35 +1100
David Gibson <david@gibson.dropbear.id.au> wrote:

> Commit 036fb8770 ("checksum: add VSX fast path for POWER8/POWER9") changed
> an #ifdef to #if defined, in order to match a newly introduced #if which
> needs to check two different symbols.  This causes clang-tidy to complain
> that the directive could be written more concisely.
> 
> In this case consistency with the other #if branch seems more important,
> and in general insisting on #ifdef over #if seems unhelpfully pedantic.
> Suppress that warning globally.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

Applied with:

Fixes: 036fb8770cc2 ("checksum: add VSX fast path for POWER8/POWER9")
Reported-by: Laurent Vivier <lvivier@redhat.com>

> ---
>  .clang-tidy | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/.clang-tidy b/.clang-tidy
> index 9d346ec2..773121f5 100644
> --- a/.clang-tidy
> +++ b/.clang-tidy
> @@ -81,6 +81,11 @@ Checks:
>      #	precedence over addition in modern mathematical notation. Adding
>      #	parentheses to reinforce that certainly won't improve readability.
>      - "-readability-math-missing-parentheses"
> +
> +    # #if defined(FOO) is fine, and can be more consistent with other
> +    # #if directives.  Don't insist on #ifdef instead.
> +    - "-readability-use-concise-preprocessor-directives"
> +
>  WarningsAsErrors: "*"
>  HeaderFileExtensions:
>      - h

-- 
Stefano