Re: [PATCH] perf: arm_v7_pmu: suppress -Winitializer-overrides for perf maps

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential
issue to consider:
- [High] perf: arm_v7_pmu: Clang-only -Winitializer-overrides breaks GCC
  builds
--

commit 56df4775a501226704b362f4cef9ce6d443becbf
Author: Rosen Penev <rosenp@gmail.com>

perf: arm_v7_pmu: suppress -Winitializer-overrides for perf maps

This commit wraps the perf_map and cache_map array definitions in
drivers/perf/arm_v7_pmu.c with __diag_push(), __diag_ignore_all(), and
__diag_pop() to suppress designated initializer override warnings.

> diff --git a/drivers/perf/arm_v7_pmu.c b/drivers/perf/arm_v7_pmu.c
> index a1e438101114a..9ac28c8adf801 100644
> --- a/drivers/perf/arm_v7_pmu.c
> +++ b/drivers/perf/arm_v7_pmu.c
> @@ -146,6 +146,15 @@
>  
>  #define SCORPION_ITLB_MISS				0x12021
>  
> +/*
> + * The perf_map and cache_map arrays use range initializers to fill all
> + * entries with HW_OP_UNSUPPORTED / CACHE_OP_UNSUPPORTED, then override
> + * specific entries with supported event codes. This is valid C99 but
> + * triggers Clang's -Winitializer-overrides.
> + */
> +__diag_push();
> +__diag_ignore_all("-Winitializer-overrides", "");

[Severity: High]
Does passing "-Winitializer-overrides" to __diag_ignore_all() break GCC
builds with CONFIG_WERROR=y?

__diag_ignore_all() expands on both Clang and GCC, producing a
"#pragma GCC diagnostic ignored" directive on GCC.  Because
-Winitializer-overrides is a Clang-specific flag name, GCC rejects the
pragma with a -Wpragmas warning and leaves its own -Woverride-init warning
unsuppressed in W=1 builds.  Using "-Woverride-init" (with a non-empty
comment argument) works on both compilers since Clang supports it as an
alias for -Winitializer-overrides.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261111023326.70922-1-rosenp@gmail.com?part=1