From d49c56368c0cc98cdf02ae21dd275eba92f1c333 Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Fri, 5 Sep 2025 19:12:06 +0200 Subject: rust: pin-init: rename `project` -> `project_this` in doctest The next commit makes the `#[pin_data]` attribute generate a `project` function that would collide with any existing ones. Signed-off-by: Benno Lossin --- rust/pin-init/src/lib.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'rust/pin-init/src') diff --git a/rust/pin-init/src/lib.rs b/rust/pin-init/src/lib.rs index 62e013a5cc20..2d0d9fd12524 100644 --- a/rust/pin-init/src/lib.rs +++ b/rust/pin-init/src/lib.rs @@ -994,7 +994,7 @@ macro_rules! try_init { /// } /// /// impl Foo { -/// fn project(self: Pin<&mut Self>) -> Pin<&mut T> { +/// fn project_this(self: Pin<&mut Self>) -> Pin<&mut T> { /// assert_pinned!(Foo, elem, T, inline); /// /// // SAFETY: The field is structurally pinned. -- cgit v1.2.3 From 619db96daf942dad974c6c8157ed06d52f7bb969 Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Fri, 5 Sep 2025 19:12:07 +0200 Subject: rust: pin-init: add pin projections to `#[pin_data]` Make the `#[pin_data]` macro generate a `*Projection` struct that holds either `Pin<&mut Field>` or `&mut Field` for every field of the original struct. Which version is chosen depends on weather there is a `#[pin]` or not respectively. Access to this projected version is enabled through generating `fn project(self: Pin<&mut Self>) -> SelfProjection<'_>`. [ Adapt workqueue to use the new projection instead of its own, custom one - Benno ] Reviewed-by: Gary Guo Reviewed-by: Boqun Feng Signed-off-by: Benno Lossin --- rust/pin-init/src/macros.rs | 61 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) (limited to 'rust/pin-init/src') diff --git a/rust/pin-init/src/macros.rs b/rust/pin-init/src/macros.rs index 9ced630737b8..668dcee9b7af 100644 --- a/rust/pin-init/src/macros.rs +++ b/rust/pin-init/src/macros.rs @@ -831,6 +831,17 @@ macro_rules! __pin_data { $($fields)* } + $crate::__pin_data!(make_pin_projections: + @vis($vis), + @name($name), + @impl_generics($($impl_generics)*), + @ty_generics($($ty_generics)*), + @decl_generics($($decl_generics)*), + @where($($whr)*), + @pinned($($pinned)*), + @not_pinned($($not_pinned)*), + ); + // We put the rest into this const item, because it then will not be accessible to anything // outside. const _: () = { @@ -980,6 +991,56 @@ macro_rules! __pin_data { stringify!($($rest)*), ); }; + (make_pin_projections: + @vis($vis:vis), + @name($name:ident), + @impl_generics($($impl_generics:tt)*), + @ty_generics($($ty_generics:tt)*), + @decl_generics($($decl_generics:tt)*), + @where($($whr:tt)*), + @pinned($($(#[$($p_attr:tt)*])* $pvis:vis $p_field:ident : $p_type:ty),* $(,)?), + @not_pinned($($(#[$($attr:tt)*])* $fvis:vis $field:ident : $type:ty),* $(,)?), + ) => { + $crate::macros::paste! { + #[doc(hidden)] + $vis struct [< $name Projection >] <'__pin, $($decl_generics)*> { + $($(#[$($p_attr)*])* $pvis $p_field : ::core::pin::Pin<&'__pin mut $p_type>,)* + $($(#[$($attr)*])* $fvis $field : &'__pin mut $type,)* + ___pin_phantom_data: ::core::marker::PhantomData<&'__pin mut ()>, + } + + impl<$($impl_generics)*> $name<$($ty_generics)*> + where $($whr)* + { + /// Pin-projects all fields of `Self`. + /// + /// These fields are structurally pinned: + $(#[doc = ::core::concat!(" - `", ::core::stringify!($p_field), "`")])* + /// + /// These fields are **not** structurally pinned: + $(#[doc = ::core::concat!(" - `", ::core::stringify!($field), "`")])* + #[inline] + $vis fn project<'__pin>( + self: ::core::pin::Pin<&'__pin mut Self>, + ) -> [< $name Projection >] <'__pin, $($ty_generics)*> { + // SAFETY: we only give access to `&mut` for fields not structurally pinned. + let this = unsafe { ::core::pin::Pin::get_unchecked_mut(self) }; + [< $name Projection >] { + $( + // SAFETY: `$p_field` is structurally pinned. + $(#[$($p_attr)*])* + $p_field : unsafe { ::core::pin::Pin::new_unchecked(&mut this.$p_field) }, + )* + $( + $(#[$($attr)*])* + $field : &mut this.$field, + )* + ___pin_phantom_data: ::core::marker::PhantomData, + } + } + } + } + }; (make_pin_data: @pin_data($pin_data:ident), @impl_generics($($impl_generics:tt)*), -- cgit v1.2.3 From 1fa516794fdd27b96cee77f8b12ac916b8b6a9a7 Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Fri, 5 Sep 2025 16:05:31 +0200 Subject: rust: pin-init: add code blocks to `[try_][pin_]init!` macros Allow writing `_: { /* any number of statements */ }` in initializers to run arbitrary code during initialization. try_init!(MyStruct { _: { if check_something() { return Err(MyError); } }, foo: Foo::new(val), _: { println!("successfully initialized `MyStruct`"); }, }) Tested-by: Alexandre Courbot Reviewed-by: Gary Guo Reviewed-by: Alice Ryhl Tested-by: Danilo Krummrich Reviewed-by: Danilo Krummrich Signed-off-by: Benno Lossin --- rust/pin-init/src/lib.rs | 2 ++ rust/pin-init/src/macros.rs | 29 +++++++++++++++++++++++++++++ 2 files changed, 31 insertions(+) (limited to 'rust/pin-init/src') diff --git a/rust/pin-init/src/lib.rs b/rust/pin-init/src/lib.rs index 2d0d9fd12524..dd553212836e 100644 --- a/rust/pin-init/src/lib.rs +++ b/rust/pin-init/src/lib.rs @@ -740,6 +740,8 @@ macro_rules! stack_try_pin_init { /// As already mentioned in the examples above, inside of `pin_init!` a `struct` initializer with /// the following modifications is expected: /// - Fields that you want to initialize in-place have to use `<-` instead of `:`. +/// - You can use `_: { /* run any user-code here */ },` anywhere where you can place fields in +/// order to run arbitrary code. /// - In front of the initializer you can write `&this in` to have access to a [`NonNull`] /// pointer named `this` inside of the initializer. /// - Using struct update syntax one can place `..Zeroable::init_zeroed()` at the very end of the diff --git a/rust/pin-init/src/macros.rs b/rust/pin-init/src/macros.rs index 668dcee9b7af..c3462080b7b6 100644 --- a/rust/pin-init/src/macros.rs +++ b/rust/pin-init/src/macros.rs @@ -1263,6 +1263,21 @@ macro_rules! __init_internal { // have been initialized. Therefore we can now dismiss the guards by forgetting them. $(::core::mem::forget($guards);)* }; + (init_slot($($use_data:ident)?): + @data($data:ident), + @slot($slot:ident), + @guards($($guards:ident,)*), + // arbitrary code block + @munch_fields(_: { $($code:tt)* }, $($rest:tt)*), + ) => { + { $($code)* } + $crate::__init_internal!(init_slot($($use_data)?): + @data($data), + @slot($slot), + @guards($($guards,)*), + @munch_fields($($rest)*), + ); + }; (init_slot($use_data:ident): // `use_data` is present, so we use the `data` to init fields. @data($data:ident), @slot($slot:ident), @@ -1358,6 +1373,20 @@ macro_rules! __init_internal { ); } }; + (make_initializer: + @slot($slot:ident), + @type_name($t:path), + @munch_fields(_: { $($code:tt)* }, $($rest:tt)*), + @acc($($acc:tt)*), + ) => { + // code blocks are ignored for the initializer check + $crate::__init_internal!(make_initializer: + @slot($slot), + @type_name($t), + @munch_fields($($rest)*), + @acc($($acc)*), + ); + }; (make_initializer: @slot($slot:ident), @type_name($t:path), -- cgit v1.2.3 From 42415d163e5df6db799c7de6262d707e402c2c7e Mon Sep 17 00:00:00 2001 From: Benno Lossin Date: Fri, 5 Sep 2025 16:00:46 +0200 Subject: rust: pin-init: add references to previously initialized fields After initializing a field in an initializer macro, create a variable holding a reference that points at that field. The type is either `Pin<&mut T>` or `&mut T` depending on the field's structural pinning kind. [ Applied fixes to devres and rust_driver_pci sample - Benno] Reviewed-by: Danilo Krummrich Signed-off-by: Benno Lossin --- rust/pin-init/src/macros.rs | 149 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 115 insertions(+), 34 deletions(-) (limited to 'rust/pin-init/src') diff --git a/rust/pin-init/src/macros.rs b/rust/pin-init/src/macros.rs index c3462080b7b6..d6acf2cd291e 100644 --- a/rust/pin-init/src/macros.rs +++ b/rust/pin-init/src/macros.rs @@ -1049,38 +1049,56 @@ macro_rules! __pin_data { @pinned($($(#[$($p_attr:tt)*])* $pvis:vis $p_field:ident : $p_type:ty),* $(,)?), @not_pinned($($(#[$($attr:tt)*])* $fvis:vis $field:ident : $type:ty),* $(,)?), ) => { - // For every field, we create a projection function according to its projection type. If a - // field is structurally pinned, then it must be initialized via `PinInit`, if it is not - // structurally pinned, then it can be initialized via `Init`. - // - // The functions are `unsafe` to prevent accidentally calling them. - #[allow(dead_code)] - #[expect(clippy::missing_safety_doc)] - impl<$($impl_generics)*> $pin_data<$($ty_generics)*> - where $($whr)* - { - $( - $(#[$($p_attr)*])* - $pvis unsafe fn $p_field( - self, - slot: *mut $p_type, - init: impl $crate::PinInit<$p_type, E>, - ) -> ::core::result::Result<(), E> { - // SAFETY: TODO. - unsafe { $crate::PinInit::__pinned_init(init, slot) } - } - )* - $( - $(#[$($attr)*])* - $fvis unsafe fn $field( - self, - slot: *mut $type, - init: impl $crate::Init<$type, E>, - ) -> ::core::result::Result<(), E> { - // SAFETY: TODO. - unsafe { $crate::Init::__init(init, slot) } - } - )* + $crate::macros::paste! { + // For every field, we create a projection function according to its projection type. If a + // field is structurally pinned, then it must be initialized via `PinInit`, if it is not + // structurally pinned, then it can be initialized via `Init`. + // + // The functions are `unsafe` to prevent accidentally calling them. + #[allow(dead_code)] + #[expect(clippy::missing_safety_doc)] + impl<$($impl_generics)*> $pin_data<$($ty_generics)*> + where $($whr)* + { + $( + $(#[$($p_attr)*])* + $pvis unsafe fn $p_field( + self, + slot: *mut $p_type, + init: impl $crate::PinInit<$p_type, E>, + ) -> ::core::result::Result<(), E> { + // SAFETY: TODO. + unsafe { $crate::PinInit::__pinned_init(init, slot) } + } + + $(#[$($p_attr)*])* + $pvis unsafe fn [<__project_ $p_field>]<'__slot>( + self, + slot: &'__slot mut $p_type, + ) -> ::core::pin::Pin<&'__slot mut $p_type> { + ::core::pin::Pin::new_unchecked(slot) + } + )* + $( + $(#[$($attr)*])* + $fvis unsafe fn $field( + self, + slot: *mut $type, + init: impl $crate::Init<$type, E>, + ) -> ::core::result::Result<(), E> { + // SAFETY: TODO. + unsafe { $crate::Init::__init(init, slot) } + } + + $(#[$($attr)*])* + $fvis unsafe fn [<__project_ $field>]<'__slot>( + self, + slot: &'__slot mut $type, + ) -> &'__slot mut $type { + slot + } + )* + } } }; } @@ -1292,6 +1310,13 @@ macro_rules! __init_internal { // return when an error/panic occurs. // We also use the `data` to require the correct trait (`Init` or `PinInit`) for `$field`. unsafe { $data.$field(::core::ptr::addr_of_mut!((*$slot).$field), init)? }; + // SAFETY: + // - the project function does the correct field projection, + // - the field has been initialized, + // - the reference is only valid until the end of the initializer. + #[allow(unused_variables)] + let $field = $crate::macros::paste!(unsafe { $data.[< __project_ $field >](&mut (*$slot).$field) }); + // Create the drop guard: // // We rely on macro hygiene to make it impossible for users to access this local variable. @@ -1323,6 +1348,14 @@ macro_rules! __init_internal { // SAFETY: `slot` is valid, because we are inside of an initializer closure, we // return when an error/panic occurs. unsafe { $crate::Init::__init(init, ::core::ptr::addr_of_mut!((*$slot).$field))? }; + + // SAFETY: + // - the field is not structurally pinned, since the line above must compile, + // - the field has been initialized, + // - the reference is only valid until the end of the initializer. + #[allow(unused_variables)] + let $field = unsafe { &mut (*$slot).$field }; + // Create the drop guard: // // We rely on macro hygiene to make it impossible for users to access this local variable. @@ -1341,7 +1374,48 @@ macro_rules! __init_internal { ); } }; - (init_slot($($use_data:ident)?): + (init_slot(): // No `use_data`, so all fields are not structurally pinned + @data($data:ident), + @slot($slot:ident), + @guards($($guards:ident,)*), + // Init by-value. + @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*), + ) => { + { + $(let $field = $val;)? + // Initialize the field. + // + // SAFETY: The memory at `slot` is uninitialized. + unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) }; + } + + #[allow(unused_variables)] + // SAFETY: + // - the field is not structurally pinned, since no `use_data` was required to create this + // initializer, + // - the field has been initialized, + // - the reference is only valid until the end of the initializer. + let $field = unsafe { &mut (*$slot).$field }; + + // Create the drop guard: + // + // We rely on macro hygiene to make it impossible for users to access this local variable. + // We use `paste!` to create new hygiene for `$field`. + $crate::macros::paste! { + // SAFETY: We forget the guard later when initialization has succeeded. + let [< __ $field _guard >] = unsafe { + $crate::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) + }; + + $crate::__init_internal!(init_slot(): + @data($data), + @slot($slot), + @guards([< __ $field _guard >], $($guards,)*), + @munch_fields($($rest)*), + ); + } + }; + (init_slot($use_data:ident): @data($data:ident), @slot($slot:ident), @guards($($guards:ident,)*), @@ -1355,6 +1429,13 @@ macro_rules! __init_internal { // SAFETY: The memory at `slot` is uninitialized. unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) }; } + // SAFETY: + // - the project function does the correct field projection, + // - the field has been initialized, + // - the reference is only valid until the end of the initializer. + #[allow(unused_variables)] + let $field = $crate::macros::paste!(unsafe { $data.[< __project_ $field >](&mut (*$slot).$field) }); + // Create the drop guard: // // We rely on macro hygiene to make it impossible for users to access this local variable. @@ -1365,7 +1446,7 @@ macro_rules! __init_internal { $crate::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field)) }; - $crate::__init_internal!(init_slot($($use_data)?): + $crate::__init_internal!(init_slot($use_data): @data($data), @slot($slot), @guards([< __ $field _guard >], $($guards,)*), -- cgit v1.2.3