On Thu Oct 2, 2025 at 11:16 AM JST, Elle Rhumsaa wrote:
> On 10/2/25 1:41 AM, Alexandre Courbot wrote:
>
>> On Tue Sep 30, 2025 at 11:45 PM JST, Joel Fernandes wrote:
>>> Add KUNIT tests to make sure the macro is working correctly.
>>>
>>> Signed-off-by: Joel Fernandes <joelagn...@nvidia.com>
>>> ---
>>> rust/kernel/bitfield.rs | 321 ++++++++++++++++++++++++++++++++++++++++
>>> 1 file changed, 321 insertions(+)
>>>
>>> diff --git a/rust/kernel/bitfield.rs b/rust/kernel/bitfield.rs
>>> index fed19918c3b9..9a20bcd2eb60 100644
>>> --- a/rust/kernel/bitfield.rs
>>> +++ b/rust/kernel/bitfield.rs
>>> @@ -402,3 +402,324 @@ fn default() -> Self {
>>> }
>>> };
>>> }
>>> +
>>> +#[::kernel::macros::kunit_tests(kernel_bitfield)]
>>> +mod tests {
>>> + use core::convert::TryFrom;
>>> +
>>> + // Enum types for testing => and ?=> conversions
>>> + #[derive(Debug, Clone, Copy, PartialEq)]
>>> + enum MemoryType {
>>> + Unmapped = 0,
>>> + Normal = 1,
>>> + Device = 2,
>>> + Reserved = 3,
>>> + }
>>> +
>>> + impl Default for MemoryType {
>>> + fn default() -> Self {
>>> + MemoryType::Unmapped
>>> + }
>>> + }
>> Tip: you can add `Default` to the `#[derive]` marker of `MemoryType` and
>> mark the variant you want as default with `#[default]` instead of
>> providing a full impl block:
>>
>> #[derive(Debug, Default, Clone, Copy, PartialEq)]
>> enum MemoryType {
>> #[default]
>> Unmapped = 0,
>> Normal = 1,
>> Device = 2,
>> Reserved = 3,
>> }
>
> I would alternatively recommend to provide a `MemoryType::new` impl with
> a `const` definition:
>
> ```rust
> impl MemoryType {
> pub const fn new() -> Self {
>
> Self::Unmapped
>
> }
> }
>
> impl Default for MemoryType {
> fn default() -> Self {
> Self::new()
> }
> }
> ```
>
> This pattern allows using `MemoryType::new()` in `const` contexts, while
> also providing the `Default` impl using the same default. It's somewhat
> of a workaround until we get `const` traits.
That's an elegant pattern generally speaking, but I don't think we would
benefit from using it in these unit tests.
