kernel/linux.git/rust/pin-init/internal/src/lib.rs, branch v7.0-rc7

rust: pin-init: rewrite the initializer macros using `syn`

2026-01-17T09:51:42+00:00

Rewrite the initializer macros `[pin_]init!` using `syn`. No functional changes intended aside from improved error messages on syntactic and semantical errors. For example if one forgets to use `<-` with an initializer (and instead uses `:`): impl Bar { fn new() -> impl PinInit { ... } } impl Foo { fn new() -> impl PinInit { pin_init!(Self { bar: Bar::new() }) } } Then the declarative macro would report: error[E0308]: mismatched types --> tests/ui/compile-fail/init/colon_instead_of_arrow.rs:21:9 | 14 | fn new() -> impl PinInit { | ------------------ the found opaque type ... 21 | pin_init!(Self { bar: Bar::new() }) | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | | | expected `Bar`, found opaque type | arguments to this function are incorrect | = note: expected struct `Bar` found opaque type `impl pin_init::PinInit` note: function defined here --> $RUST/core/src/ptr/mod.rs | | pub const unsafe fn write(dst: *mut T, src: T) { | ^^^^^ = note: this error originates in the macro `$crate::__init_internal` which comes from the expansion of the macro `pin_init` (in Nightly builds, run with -Z macro-backtrace for more info) And the new error is: error[E0308]: mismatched types --> tests/ui/compile-fail/init/colon_instead_of_arrow.rs:21:31 | 14 | fn new() -> impl PinInit { | ------------------ the found opaque type ... 21 | pin_init!(Self { bar: Bar::new() }) | --- ^^^^^^^^^^ expected `Bar`, found opaque type | | | arguments to this function are incorrect | = note: expected struct `Bar` found opaque type `impl pin_init::PinInit` note: function defined here --> $RUST/core/src/ptr/mod.rs | | pub const unsafe fn write(dst: *mut T, src: T) { | ^^^^^ Importantly, this error gives much more accurate span locations, pointing to the offending field, rather than the entire macro invocation. Tested-by: Andreas Hindborg Reviewed-by: Gary Guo Signed-off-by: Benno Lossin

rust: pin-init: rewrite `#[pin_data]` using `syn`

2026-01-17T09:51:42+00:00

Rewrite the attribute macro `#[pin_data]` using `syn`. No functional changes intended aside from improved error messages on syntactic and semantical errors. For example if one forgets a comma at the end of a field: #[pin_data] struct Foo { a: Box b: Box } The declarative macro reports the following errors: error: expected `,`, or `}`, found `b` --> tests/ui/compile-fail/pin_data/missing_comma.rs:5:16 | 5 | a: Box | ^ help: try adding a comma: `,` error: recursion limit reached while expanding `$crate::__pin_data!` --> tests/ui/compile-fail/pin_data/missing_comma.rs:3:1 | 3 | #[pin_data] | ^^^^^^^^^^^ | = help: consider increasing the recursion limit by adding a `#![recursion_limit = "256"]` attribute to your crate (`$CRATE`) = note: this error originates in the macro `$crate::__pin_data` which comes from the expansion of the attribute macro `pin_data` (in Nightly builds, run with -Z macro-backtrace for more info) The new `syn` version reports: error: expected `,`, or `}`, found `b` --> tests/ui/compile-fail/pin_data/missing_comma.rs:5:16 | 5 | a: Box | ^ help: try adding a comma: `,` error: expected `,` --> tests/ui/compile-fail/pin_data/missing_comma.rs:6:5 | 6 | b: Box | ^ Tested-by: Andreas Hindborg Reviewed-by: Gary Guo Signed-off-by: Benno Lossin

rust: pin-init: rewrite the `#[pinned_drop]` attribute macro using `syn`

2026-01-17T09:51:42+00:00

Rewrite the attribute macro for implementing `PinnedDrop` using `syn`. Otherwise no functional changes intended aside from improved error messages on syntactic and semantical errors. For example: When missing the `drop` function in the implementation, the old error was: error: no rules expected `)` --> tests/ui/compile-fail/pinned_drop/no_fn.rs:6:1 | 6 | #[pinned_drop] | ^^^^^^^^^^^^^^ no rules expected this token in macro call | note: while trying to match keyword `fn` --> src/macros.rs | | fn drop($($sig:tt)*) { | ^^ = note: this error originates in the attribute macro `pinned_drop` (in Nightly builds, run with -Z macro-backtrace for more info) And the new one is: error[E0046]: not all trait items implemented, missing: `drop` --> tests/ui/compile-fail/pinned_drop/no_fn.rs:7:1 | 7 | impl PinnedDrop for Foo {} | ^^^^^^^^^^^^^^^^^^^^^^^ missing `drop` in implementation | = help: implement the missing item: `fn drop(self: Pin<&mut Self>, _: OnlyCallFromDrop) { todo!() }` Tested-by: Andreas Hindborg Reviewed-by: Gary Guo Signed-off-by: Benno Lossin

rust: pin-init: rewrite `derive(Zeroable)` and `derive(MaybeZeroable)` using `syn`

2026-01-17T09:51:42+00:00

Rewrite the two derive macros for `Zeroable` using `syn`. One positive side effect of this change is that tuple structs are now supported by them. Additionally, syntax errors and the error emitted when trying to use one of the derive macros on an `enum` are improved. Otherwise no functional changes intended. For example: #[derive(Zeroable)] enum Num { A(u32), B(i32), } Produced this error before this commit: error: no rules expected keyword `enum` --> tests/ui/compile-fail/zeroable/enum.rs:5:1 | 5 | enum Num { | ^^^^ no rules expected this token in macro call | note: while trying to match keyword `struct` --> src/macros.rs | | $vis:vis struct $name:ident | ^^^^^^ Now the error is: error: cannot derive `Zeroable` for an enum --> tests/ui/compile-fail/zeroable/enum.rs:5:1 | 5 | enum Num { | ^^^^ error: cannot derive `Zeroable` for an enum Tested-by: Andreas Hindborg Reviewed-by: Gary Guo Signed-off-by: Benno Lossin

rust: pin-init: internal: add utility API for syn error handling

2026-01-17T09:51:21+00:00

The API is similar to diagnostics handling in rustc and uses a `ErrorGuaranteed` value to signify that an error has been emitted. It supports both fatal errors (which abort the macro expansion immediately by returning `Err(ErrorGuaranteed)`) and non-fatal ones at generation time. These errors are appended to the token stream after generation has finished normally. This allows giving good errors while still expanding most of the code as expected to avoid the user encountering additional errors (for example missing definitions). Suggested-by: Gary Guo Tested-by: Andreas Hindborg Reviewed-by: Gary Guo [ remove duplicate word in commit message - Benno ] Signed-off-by: Benno Lossin

rust: pin-init: add `syn` dependency and remove `proc-macro[2]` and `quote` workarounds

2026-01-17T09:49:31+00:00

`syn` makes parsing Rust from proc-macros a lot simpler. `pin-init` has not used `syn` up until now, because the we did not support it. That changed in commit 54e3eae85562 ("Merge patch series "`syn` support""), so we can finally utilize the added ergonomics of parsing proc-macro input with `syn`. Previously we only had the `proc-macro` library available, whereas the user-space version also used `proc-macro2` and `quote`. Now both are available, so remove the workarounds. Due to these changes, clippy emits warnings about unnecessary `.to_string()` as `proc-macro2` provides an additional `PartialEq` impl on `Ident`, so the warnings are fixed. [ Adjusted wording from upstream version and added build system changes for the kernel - Benno ] Co-developed-by: Gary Guo Signed-off-by: Gary Guo Reviewed-by: Tamir Duberstein Tested-by: Andreas Hindborg Signed-off-by: Benno Lossin

rust: pin-init: add `MaybeZeroable` derive macro

2025-05-01T16:15:26+00:00

This derive macro implements `Zeroable` for structs & unions precisely if all fields also implement `Zeroable` and does nothing otherwise. The plain `Zeroable` derive macro instead errors when it cannot derive `Zeroable` safely. The `MaybeZeroable` derive macro is useful in cases where manual checking is infeasible such as with the bindings crate. Move the zeroable generics parsing into a standalone function in order to avoid code duplication between the two derive macros. Link: https://github.com/Rust-for-Linux/pin-init/pull/42/commits/1165cdad1a391b923efaf30cf76bc61e38da022e Signed-off-by: Benno Lossin

rust: pin-init: internal: skip rustfmt formatting of kernel-only module

2025-04-21T21:18:42+00:00

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 Link: https://lore.kernel.org/all/20250414195928.129040-2-benno.lossin@proton.me Reviewed-by: Christian Schrefl Signed-off-by: Benno Lossin

rust: pin-init: miscellaneous synchronization with the user-space version

2025-03-16T20:59:19+00:00

Remove the last differences between the kernel version and the user-space version. Signed-off-by: Benno Lossin Reviewed-by: Andreas Hindborg Tested-by: Andreas Hindborg Reviewed-by: Fiona Behrens Link: https://lore.kernel.org/r/20250308110339.2997091-20-benno.lossin@proton.me Signed-off-by: Miguel Ojeda

rust: pin-init: internal: synchronize with user-space version

2025-03-16T20:59:19+00:00

Synchronize the internal macros crate with the user-space version that uses the quote crate [1] instead of a custom `quote!` macro. The imports in the different version are achieved using `cfg` on the kernel config value. This cfg is always set in the kernel and never set in the user-space version. Since the quote crate requires the proc_macro2 crate, imports also need to be adjusted and `.into()` calls have to be inserted. Link: https://crates.io/crates/quote [1] Signed-off-by: Benno Lossin Reviewed-by: Andreas Hindborg Tested-by: Andreas Hindborg Reviewed-by: Fiona Behrens Link: https://lore.kernel.org/r/20250308110339.2997091-19-benno.lossin@proton.me Signed-off-by: Miguel Ojeda