summaryrefslogtreecommitdiff
path: root/rust
diff options
context:
space:
mode:
authorBenno Lossin <benno.lossin@proton.me>2024-03-09 15:54:04 +0000
committerMiguel Ojeda <ojeda@kernel.org>2024-04-07 22:03:42 +0200
commit22eed6068d76d1d9672f33334740657208a91483 (patch)
treec1af740527ce07ab52d9ada7f6bdd0ae4e1c67ac /rust
parent9762dca54a4fec433b50eb83fdd8ff0a876cccf2 (diff)
rust: macros: allow generic parameter default values in `#[pin_data]`
Add support for generic parameters defaults in `#[pin_data]` by using the newly introduced `decl_generics` instead of the `impl_generics`. Before this would not compile: #[pin_data] struct Foo<const N: usize = 0> { // ... } because it would be expanded to this: struct Foo<const N: usize = 0> { // ... } const _: () = { struct __ThePinData<const N: usize = 0> { __phantom: ::core::marker::PhantomData<fn(Foo<N>) -> Foo<N>>, } impl<const N: usize = 0> ::core::clone::Clone for __ThePinData<N> { fn clone(&self) -> Self { *self } } // [...] rest of expansion omitted }; The problem is with the `impl<const N: usize = 0>`, since that is invalid Rust syntax. It should not mention the default value at all, since default values only make sense on type definitions. The new `impl_generics` do not contain the default values, thus generating correct Rust code. This is used by the next commit that puts `#[pin_data]` on `kernel::workqueue::Work`. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Tested-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240309155243.482334-2-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Diffstat (limited to 'rust')
-rw-r--r--rust/kernel/init/macros.rs19
-rw-r--r--rust/macros/helpers.rs1
-rw-r--r--rust/macros/pin_data.rs3
3 files changed, 20 insertions, 3 deletions
diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs
index cb6e61b6c50b..624e9108e3b4 100644
--- a/rust/kernel/init/macros.rs
+++ b/rust/kernel/init/macros.rs
@@ -538,6 +538,7 @@ macro_rules! __pin_data {
),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
+ @decl_generics($($decl_generics:tt)*),
@body({ $($fields:tt)* }),
) => {
// We now use token munching to iterate through all of the fields. While doing this we
@@ -560,6 +561,9 @@ macro_rules! __pin_data {
@impl_generics($($impl_generics)*),
// The 'ty generics', the generics that will need to be specified on the impl blocks.
@ty_generics($($ty_generics)*),
+ // The 'decl generics', the generics that need to be specified on the struct
+ // definition.
+ @decl_generics($($decl_generics)*),
// The where clause of any impl block and the declaration.
@where($($($whr)*)?),
// The remaining fields tokens that need to be processed.
@@ -585,6 +589,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
+ @decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// We found a PhantomPinned field, this should generally be pinned!
@fields_munch($field:ident : $($($(::)?core::)?marker::)?PhantomPinned, $($rest:tt)*),
@@ -607,6 +612,7 @@ macro_rules! __pin_data {
@name($name),
@impl_generics($($impl_generics)*),
@ty_generics($($ty_generics)*),
+ @decl_generics($($decl_generics)*),
@where($($whr)*),
@fields_munch($($rest)*),
@pinned($($pinned)* $($accum)* $field: ::core::marker::PhantomPinned,),
@@ -623,6 +629,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
+ @decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// We reached the field declaration.
@fields_munch($field:ident : $type:ty, $($rest:tt)*),
@@ -640,6 +647,7 @@ macro_rules! __pin_data {
@name($name),
@impl_generics($($impl_generics)*),
@ty_generics($($ty_generics)*),
+ @decl_generics($($decl_generics)*),
@where($($whr)*),
@fields_munch($($rest)*),
@pinned($($pinned)* $($accum)* $field: $type,),
@@ -656,6 +664,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
+ @decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// We reached the field declaration.
@fields_munch($field:ident : $type:ty, $($rest:tt)*),
@@ -673,6 +682,7 @@ macro_rules! __pin_data {
@name($name),
@impl_generics($($impl_generics)*),
@ty_generics($($ty_generics)*),
+ @decl_generics($($decl_generics)*),
@where($($whr)*),
@fields_munch($($rest)*),
@pinned($($pinned)*),
@@ -689,6 +699,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
+ @decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// We found the `#[pin]` attr.
@fields_munch(#[pin] $($rest:tt)*),
@@ -705,6 +716,7 @@ macro_rules! __pin_data {
@name($name),
@impl_generics($($impl_generics)*),
@ty_generics($($ty_generics)*),
+ @decl_generics($($decl_generics)*),
@where($($whr)*),
@fields_munch($($rest)*),
// We do not include `#[pin]` in the list of attributes, since it is not actually an
@@ -724,6 +736,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
+ @decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// We reached the field declaration with visibility, for simplicity we only munch the
// visibility and put it into `$accum`.
@@ -741,6 +754,7 @@ macro_rules! __pin_data {
@name($name),
@impl_generics($($impl_generics)*),
@ty_generics($($ty_generics)*),
+ @decl_generics($($decl_generics)*),
@where($($whr)*),
@fields_munch($field $($rest)*),
@pinned($($pinned)*),
@@ -757,6 +771,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
+ @decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// Some other attribute, just put it into `$accum`.
@fields_munch(#[$($attr:tt)*] $($rest:tt)*),
@@ -773,6 +788,7 @@ macro_rules! __pin_data {
@name($name),
@impl_generics($($impl_generics)*),
@ty_generics($($ty_generics)*),
+ @decl_generics($($decl_generics)*),
@where($($whr)*),
@fields_munch($($rest)*),
@pinned($($pinned)*),
@@ -789,6 +805,7 @@ macro_rules! __pin_data {
@name($name:ident),
@impl_generics($($impl_generics:tt)*),
@ty_generics($($ty_generics:tt)*),
+ @decl_generics($($decl_generics:tt)*),
@where($($whr:tt)*),
// We reached the end of the fields, plus an optional additional comma, since we added one
// before and the user is also allowed to put a trailing comma.
@@ -802,7 +819,7 @@ macro_rules! __pin_data {
) => {
// Declare the struct with all fields in the correct order.
$($struct_attrs)*
- $vis struct $name <$($impl_generics)*>
+ $vis struct $name <$($decl_generics)*>
where $($whr)*
{
$($fields)*
diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs
index 2497d6519f2f..563dcd2b7ace 100644
--- a/rust/macros/helpers.rs
+++ b/rust/macros/helpers.rs
@@ -95,7 +95,6 @@ pub(crate) struct Generics {
/// The generics with bounds and default values (e.g. `T: Clone, const N: usize = 0`).
///
/// Use this on type definitions e.g. `struct Foo<$decl_generics> ...` (or `union`/`enum`).
- #[allow(dead_code)]
pub(crate) decl_generics: Vec<TokenTree>,
/// The generics with bounds (e.g. `T: Clone, const N: usize`).
///
diff --git a/rust/macros/pin_data.rs b/rust/macros/pin_data.rs
index 022e68e9720d..1d4a3547c684 100644
--- a/rust/macros/pin_data.rs
+++ b/rust/macros/pin_data.rs
@@ -10,7 +10,7 @@ pub(crate) fn pin_data(args: TokenStream, input: TokenStream) -> TokenStream {
let (
Generics {
impl_generics,
- decl_generics: _,
+ decl_generics,
ty_generics,
},
rest,
@@ -77,6 +77,7 @@ pub(crate) fn pin_data(args: TokenStream, input: TokenStream) -> TokenStream {
@sig(#(#rest)*),
@impl_generics(#(#impl_generics)*),
@ty_generics(#(#ty_generics)*),
+ @decl_generics(#(#decl_generics)*),
@body(#last),
});
quoted.extend(errs);