rust: opp: Make the doctest example depend on CONFIG_OF

[PATCH] rust: opp: Make the doctest example depend on CONFIG_OF

Posted by Viresh Kumar 6 months, 3 weeks ago

The doctest example uses a function only available for CONFIG_OF and so
the build with doc tests fails when it isn't enabled.

  error[E0599]: no function or associated item named `from_of_cpumask`
  found for struct `rust_doctest_kernel_alloc_kbox_rs_4::kernel::opp::Table`
  in the current scope

Fix this by making the doctest depend on CONFIG_OF.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202505260856.ZQWHW2xT-lkp@intel.com/
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
Rafael,

Please apply this directly, if no one objects to it. Thanks.

 rust/kernel/opp.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/rust/kernel/opp.rs b/rust/kernel/opp.rs
index 212555dacd45..c2bdc11f3999 100644
--- a/rust/kernel/opp.rs
+++ b/rust/kernel/opp.rs
@@ -582,6 +582,7 @@ extern "C" fn config_regulators(
 /// use kernel::opp::Table;
 /// use kernel::types::ARef;
 ///
+/// #[cfg(CONFIG_OF)]
 /// fn get_table(dev: &ARef<Device>, mask: &mut Cpumask, freq: Hertz) -> Result<Table> {
 ///     let mut opp_table = Table::from_of_cpumask(dev, mask)?;
 ///
-- 
2.31.1.272.g89b43f80a514

Re: [PATCH] rust: opp: Make the doctest example depend on CONFIG_OF

Posted by Miguel Ojeda 6 months, 3 weeks ago

On Mon, May 26, 2025 at 7:35 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> +/// #[cfg(CONFIG_OF)]
>  /// fn get_table(dev: &ARef<Device>, mask: &mut Cpumask, freq: Hertz) -> Result<Table> {

Quick note related to this patch for the future/discussion: I think it
is a good idea to keep `cfg`s as local as possible, like it is done
here, although for documentation I wonder if it may be best to put it
at the top and hide it, e.g.

    /// ```
    /// # #![cfg(CONFIG_OPP)]
    /// use kernel::clk::Hertz;

(We took that approach in another example recently)

It is nice that the `CONFIG_`s appear at the top, so that one knows at
a glance when the example applies, as if it was configuration for the
example.

On the other hand, it may be useful for the reader to see immediately
that they will need the `cfg`s. But it may be distracting from the
actual examples, and there could be a need to add it too many times
(e.g. in every related example).

Cheers,
Miguel

Re: [PATCH] rust: opp: Make the doctest example depend on CONFIG_OF

Posted by Rafael J. Wysocki 6 months, 3 weeks ago

On Mon, May 26, 2025 at 7:35 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> The doctest example uses a function only available for CONFIG_OF and so
> the build with doc tests fails when it isn't enabled.
>
>   error[E0599]: no function or associated item named `from_of_cpumask`
>   found for struct `rust_doctest_kernel_alloc_kbox_rs_4::kernel::opp::Table`
>   in the current scope
>
> Fix this by making the doctest depend on CONFIG_OF.
>
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202505260856.ZQWHW2xT-lkp@intel.com/
> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
> ---
> Rafael,
>
> Please apply this directly, if no one objects to it. Thanks.

Done, thanks!

>
>  rust/kernel/opp.rs | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/rust/kernel/opp.rs b/rust/kernel/opp.rs
> index 212555dacd45..c2bdc11f3999 100644
> --- a/rust/kernel/opp.rs
> +++ b/rust/kernel/opp.rs
> @@ -582,6 +582,7 @@ extern "C" fn config_regulators(
>  /// use kernel::opp::Table;
>  /// use kernel::types::ARef;
>  ///
> +/// #[cfg(CONFIG_OF)]
>  /// fn get_table(dev: &ARef<Device>, mask: &mut Cpumask, freq: Hertz) -> Result<Table> {
>  ///     let mut opp_table = Table::from_of_cpumask(dev, mask)?;
>  ///
> --
> 2.31.1.272.g89b43f80a514
>