[PATCH 1/3] rust: pin-init: internal: skip rustfmt formatting of kernel-only module

[PATCH 1/3] rust: pin-init: internal: skip rustfmt formatting of kernel-only module

[Benno Lossin]

The `quote` module only is available in the kernel and thus running
`cargo fmt` or `rustfmt internal/src/lib.rs` in the user-space
repository [1] results in:

    error: couldn't read `~/pin-init/internal/src/../../../macros/quote.rs`: No such file or directory (os error 2)
      --> ~/pin-init/internal/src/lib.rs:25:1
       |
    25 | mod quote;
       | ^^^^^^^^^^

    Error writing files: failed to resolve mod `quote`: ~/pin-init/internal/src/../../../macros/quote.rs does not exist

Thus mark it with `rustfmt::skip` when compiling without kernel support.

Link: https://github.com/Rust-for-Linux/pin-init [1]
Link: https://github.com/Rust-for-Linux/pin-init/pull/33/commits/a6caf1945e51da38761aab4dffa56e63e2baa218
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
---
 rust/pin-init/internal/src/lib.rs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/rust/pin-init/internal/src/lib.rs b/rust/pin-init/internal/src/lib.rs
index babe5e878550..56aa9ecc1e1a 100644
--- a/rust/pin-init/internal/src/lib.rs
+++ b/rust/pin-init/internal/src/lib.rs
@@ -22,6 +22,7 @@
 #[cfg(kernel)]
 #[path = "../../../macros/quote.rs"]
 #[macro_use]
+#[cfg_attr(not(kernel), rustfmt::skip)]
 mod quote;
 #[cfg(not(kernel))]
 #[macro_use]
-- 
2.48.1

Re: [PATCH 1/3] rust: pin-init: internal: skip rustfmt formatting of kernel-only module

[Christian Schrefl]

On 14.04.25 10:00 PM, Benno Lossin wrote:
> The `quote` module only is available in the kernel and thus running
> `cargo fmt` or `rustfmt internal/src/lib.rs` in the user-space
> repository [1] results in:
> 
>     error: couldn't read `~/pin-init/internal/src/../../../macros/quote.rs`: No such file or directory (os error 2)
>       --> ~/pin-init/internal/src/lib.rs:25:1
>        |
>     25 | mod quote;
>        | ^^^^^^^^^^
> 
>     Error writing files: failed to resolve mod `quote`: ~/pin-init/internal/src/../../../macros/quote.rs does not exist
> 
> Thus mark it with `rustfmt::skip` when compiling without kernel support.
> 
> Link: https://github.com/Rust-for-Linux/pin-init [1]
> Link: https://github.com/Rust-for-Linux/pin-init/pull/33/commits/a6caf1945e51da38761aab4dffa56e63e2baa218
> Signed-off-by: Benno Lossin <benno.lossin@proton.me>
> ---
>  rust/pin-init/internal/src/lib.rs | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/rust/pin-init/internal/src/lib.rs b/rust/pin-init/internal/src/lib.rs
> index babe5e878550..56aa9ecc1e1a 100644
> --- a/rust/pin-init/internal/src/lib.rs
> +++ b/rust/pin-init/internal/src/lib.rs
> @@ -22,6 +22,7 @@
>  #[cfg(kernel)]
>  #[path = "../../../macros/quote.rs"]
>  #[macro_use]
> +#[cfg_attr(not(kernel), rustfmt::skip)]
>  mod quote;
>  #[cfg(not(kernel))]
>  #[macro_use]

Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com>

[PATCH 2/3] rust: pin-init: examples: conditionally enable `feature(lint_reasons)`

[Benno Lossin]

`lint_reasons` is unstable in Rust 1.80 and earlier, enable it
conditionally in the examples to allow compiling them with older
compilers.

Link: https://github.com/Rust-for-Linux/pin-init/pull/33/commits/ec494fe686b0a97d5b59b5be5a42d3858038ea6a
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
---
 rust/pin-init/examples/linked_list.rs   | 1 +
 rust/pin-init/examples/mutex.rs         | 1 +
 rust/pin-init/examples/pthread_mutex.rs | 2 ++
 rust/pin-init/examples/static_init.rs   | 1 +
 4 files changed, 5 insertions(+)

diff --git a/rust/pin-init/examples/linked_list.rs b/rust/pin-init/examples/linked_list.rs
index 6d7eb0a0ec0d..0bbc7b8d83a1 100644
--- a/rust/pin-init/examples/linked_list.rs
+++ b/rust/pin-init/examples/linked_list.rs
@@ -2,6 +2,7 @@
 
 #![allow(clippy::undocumented_unsafe_blocks)]
 #![cfg_attr(feature = "alloc", feature(allocator_api))]
+#![cfg_attr(not(RUSTC_LINT_REASONS_IS_STABLE), feature(lint_reasons))]
 
 use core::{
     cell::Cell,
diff --git a/rust/pin-init/examples/mutex.rs b/rust/pin-init/examples/mutex.rs
index 073bb79341d1..3e3630780c96 100644
--- a/rust/pin-init/examples/mutex.rs
+++ b/rust/pin-init/examples/mutex.rs
@@ -2,6 +2,7 @@
 
 #![allow(clippy::undocumented_unsafe_blocks)]
 #![cfg_attr(feature = "alloc", feature(allocator_api))]
+#![cfg_attr(not(RUSTC_LINT_REASONS_IS_STABLE), feature(lint_reasons))]
 #![allow(clippy::missing_safety_doc)]
 
 use core::{
diff --git a/rust/pin-init/examples/pthread_mutex.rs b/rust/pin-init/examples/pthread_mutex.rs
index 9164298c44c0..f020dd266506 100644
--- a/rust/pin-init/examples/pthread_mutex.rs
+++ b/rust/pin-init/examples/pthread_mutex.rs
@@ -3,6 +3,8 @@
 // inspired by https://github.com/nbdd0121/pin-init/blob/trunk/examples/pthread_mutex.rs
 #![allow(clippy::undocumented_unsafe_blocks)]
 #![cfg_attr(feature = "alloc", feature(allocator_api))]
+#![cfg_attr(not(RUSTC_LINT_REASONS_IS_STABLE), feature(lint_reasons))]
+
 #[cfg(not(windows))]
 mod pthread_mtx {
     #[cfg(feature = "alloc")]
diff --git a/rust/pin-init/examples/static_init.rs b/rust/pin-init/examples/static_init.rs
index 3487d761aa26..48531413ab94 100644
--- a/rust/pin-init/examples/static_init.rs
+++ b/rust/pin-init/examples/static_init.rs
@@ -2,6 +2,7 @@
 
 #![allow(clippy::undocumented_unsafe_blocks)]
 #![cfg_attr(feature = "alloc", feature(allocator_api))]
+#![cfg_attr(not(RUSTC_LINT_REASONS_IS_STABLE), feature(lint_reasons))]
 
 use core::{
     cell::{Cell, UnsafeCell},
-- 
2.48.1

Re: [PATCH 2/3] rust: pin-init: examples: conditionally enable `feature(lint_reasons)`

[Alice Ryhl]

On Mon, Apr 14, 2025 at 08:00:20PM +0000, Benno Lossin wrote:
> `lint_reasons` is unstable in Rust 1.80 and earlier, enable it
> conditionally in the examples to allow compiling them with older
> compilers.
> 
> Link: https://github.com/Rust-for-Linux/pin-init/pull/33/commits/ec494fe686b0a97d5b59b5be5a42d3858038ea6a
> Signed-off-by: Benno Lossin <benno.lossin@proton.me>

Why not just always use #![feature] together with -Astable_features like
the kernel does?

Alice

Re: [PATCH 2/3] rust: pin-init: examples: conditionally enable `feature(lint_reasons)`

[Benno Lossin]

On Tue Apr 15, 2025 at 11:26 AM CEST, Alice Ryhl wrote:
> On Mon, Apr 14, 2025 at 08:00:20PM +0000, Benno Lossin wrote:
>> `lint_reasons` is unstable in Rust 1.80 and earlier, enable it
>> conditionally in the examples to allow compiling them with older
>> compilers.
>> 
>> Link: https://github.com/Rust-for-Linux/pin-init/pull/33/commits/ec494fe686b0a97d5b59b5be5a42d3858038ea6a
>> Signed-off-by: Benno Lossin <benno.lossin@proton.me>
>
> Why not just always use #![feature] together with -Astable_features like
> the kernel does?

I'd like to know when a feature becomes stable, since I don't keep track
of them like Miguel does.

---
Cheers,
Benno

Re: [PATCH 2/3] rust: pin-init: examples: conditionally enable `feature(lint_reasons)`

[Benno Lossin]

On Wed Apr 16, 2025 at 11:58 PM CEST, Benno Lossin wrote:
> On Tue Apr 15, 2025 at 11:26 AM CEST, Alice Ryhl wrote:
>> On Mon, Apr 14, 2025 at 08:00:20PM +0000, Benno Lossin wrote:
>>> `lint_reasons` is unstable in Rust 1.80 and earlier, enable it
>>> conditionally in the examples to allow compiling them with older
>>> compilers.
>>> 
>>> Link: https://github.com/Rust-for-Linux/pin-init/pull/33/commits/ec494fe686b0a97d5b59b5be5a42d3858038ea6a
>>> Signed-off-by: Benno Lossin <benno.lossin@proton.me>
>>
>> Why not just always use #![feature] together with -Astable_features like
>> the kernel does?
>
> I'd like to know when a feature becomes stable, since I don't keep track
> of them like Miguel does.

Ah one more reason: `pin-init` must compile under stable (when not
enabling the `alloc` feature). And having `#![feature(..)]` is not
allowed under stable (even if the feature itself is stable).

---
Cheers,
Benno

[PATCH 3/3] rust: pin-init: examples: use `allow` instead of `expect`

[Benno Lossin]

Rust 1.78 doesn't emit a `dead_code` error on the annotated element,
resulting in the `unfulfilled_lint_expectations` error. Rust 1.85 does
emit the `dead_code` error, so we still need an `allow`.

Link: https://github.com/Rust-for-Linux/pin-init/pull/33/commits/0e28cbb895bd29f896a59b40e8ed506ea7bef13c
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
---
 rust/pin-init/examples/pthread_mutex.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rust/pin-init/examples/pthread_mutex.rs b/rust/pin-init/examples/pthread_mutex.rs
index f020dd266506..e28a0bfd4179 100644
--- a/rust/pin-init/examples/pthread_mutex.rs
+++ b/rust/pin-init/examples/pthread_mutex.rs
@@ -42,7 +42,7 @@ fn drop(self: Pin<&mut Self>) {
 
     #[derive(Debug)]
     pub enum Error {
-        #[expect(dead_code)]
+        #[allow(dead_code)]
         IO(std::io::Error),
         Alloc,
     }
-- 
2.48.1