2022-11-10 17:05:21

by Miguel Ojeda

Subject: [PATCH v1 11/28] rust: prelude: add `error::code::*` constant items

From: Wedson Almeida Filho <[email protected]>

It is convenient to have all the `Error` constant items (such as
`EINVAL`) available as-is everywhere (i.e. for code using the kernel
prelude such as kernel modules).

Therefore, add all of them to the prelude.

For instance, this allows to write `Err(EINVAL)` to create
a kernel `Result`:

fn f() -> Result<...> {
...
Err(EINVAL)
}

Signed-off-by: Wedson Almeida Filho <[email protected]>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <[email protected]>
---
rust/kernel/prelude.rs | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs
index 7c4c35bf3c66..1e08b08e9420 100644
--- a/rust/kernel/prelude.rs
+++ b/rust/kernel/prelude.rs
@@ -19,6 +19,6 @@ pub use macros::{module, vtable};

pub use super::{pr_alert, pr_crit, pr_debug, pr_emerg, pr_err, pr_info, pr_notice, pr_warn};

-pub use super::error::{Error, Result};
+pub use super::error::{code::*, Error, Result};

pub use super::ThisModule;
--
2.38.1

2022-11-14 14:59:00

by Gary Guo

Subject: Re: [PATCH v1 11/28] rust: prelude: add `error::code::*` constant items

On Thu, 10 Nov 2022 17:41:23 +0100
Miguel Ojeda <[email protected]> wrote:

> From: Wedson Almeida Filho <[email protected]>
>
> It is convenient to have all the `Error` constant items (such as
> `EINVAL`) available as-is everywhere (i.e. for code using the kernel
> prelude such as kernel modules).
>
> Therefore, add all of them to the prelude.

Personally, I would prefer to have all error codes as associated
constants of the `kernel::Error` type so the code below would use
`Err(Error::EINVAL)` (more "Rusty" way of writing things). But IIRC
that we settled on the current approach because it's more similar to
existing C code.

>
> For instance, this allows to write `Err(EINVAL)` to create
> a kernel `Result`:
>
> fn f() -> Result<...> {
> ...
> Err(EINVAL)
> }
>
> Signed-off-by: Wedson Almeida Filho <[email protected]>
> [Reworded, adapted for upstream and applied latest changes]
> Signed-off-by: Miguel Ojeda <[email protected]>

Reviewed-by: Gary Guo <[email protected]>

> ---
> rust/kernel/prelude.rs | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs
> index 7c4c35bf3c66..1e08b08e9420 100644
> --- a/rust/kernel/prelude.rs
> +++ b/rust/kernel/prelude.rs
> @@ -19,6 +19,6 @@ pub use macros::{module, vtable};
>
> pub use super::{pr_alert, pr_crit, pr_debug, pr_emerg, pr_err, pr_info, pr_notice, pr_warn};
>
> -pub use super::error::{Error, Result};
> +pub use super::error::{code::*, Error, Result};
>
> pub use super::ThisModule;