2021-07-03 16:56:17 +02:00
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2024-09-02 18:55:31 +02:00
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2026-04-06 01:52:51 +02:00
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rust: kunit: support KUnit-mapped `assert!` macros in `#[test]`s
The KUnit `#[test]` support that landed recently is very basic and does
not map the `assert*!` macros into KUnit like the doctests do, so they
panic at the moment.
Thus implement the custom mapping in a similar way to doctests, reusing
the infrastructure there.
In Rust 1.88.0, the `file()` method in `Span` may be stable [1]. However,
it was changed recently (from `SourceFile`), so we need to do something
different in previous versions. Thus create a helper for it and use it
to get the path.
With this, a failing test suite like:
#[kunit_tests(my_test_suite)]
mod tests {
use super::*;
#[test]
fn my_first_test() {
assert_eq!(42, 43);
}
#[test]
fn my_second_test() {
assert!(42 >= 43);
}
}
will properly map back to KUnit, printing something like:
[ 1.924325] KTAP version 1
[ 1.924421] # Subtest: my_test_suite
[ 1.924506] # speed: normal
[ 1.924525] 1..2
[ 1.926385] # my_first_test: ASSERTION FAILED at rust/kernel/lib.rs:251
[ 1.926385] Expected 42 == 43 to be true, but is false
[ 1.928026] # my_first_test.speed: normal
[ 1.928075] not ok 1 my_first_test
[ 1.928723] # my_second_test: ASSERTION FAILED at rust/kernel/lib.rs:256
[ 1.928723] Expected 42 >= 43 to be true, but is false
[ 1.929834] # my_second_test.speed: normal
[ 1.929868] not ok 2 my_second_test
[ 1.930032] # my_test_suite: pass:0 fail:2 skip:0 total:2
[ 1.930153] # Totals: pass:0 fail:2 skip:0 total
Link: https://github.com/rust-lang/rust/pull/140514 [1]
Reviewed-by: David Gow <davidgow@google.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20250502215133.1923676-2-ojeda@kernel.org
[ Required `KUNIT=y` like for doctests. Used the `cfg_attr` from the
TODO comment and clarified its comment now that the stabilization is
in beta and thus quite likely stable in Rust 1.88.0. Simplified the
`new_body` code by introducing a new variable. Added
`#[allow(clippy::incompatible_msrv)]`. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-05-02 23:51:26 +02:00
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2022-11-10 17:41:17 +01:00
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rust: add #[export] macro
Rust has two different tools for generating function declarations to
call across the FFI boundary:
* bindgen. Generates Rust declarations from a C header.
* cbindgen. Generates C headers from Rust declarations.
However, we only use bindgen in the kernel. This means that when C code
calls a Rust function by name, its signature must be duplicated in both
Rust code and a C header, and the signature needs to be kept in sync
manually.
Introducing cbindgen as a mandatory dependency to build the kernel would
be a rather complex and large change, so we do not consider that at this
time. Instead, to eliminate this manual checking, introduce a new macro
that verifies at compile time that the two function declarations use the
same signature. The idea is to run the C declaration through bindgen,
and then have rustc verify that the function pointers have the same
type.
The signature must still be written twice, but at least you can no
longer get it wrong. If the signatures don't match, you will get errors
that look like this:
error[E0308]: `if` and `else` have incompatible types
--> <linux>/rust/kernel/print.rs:22:22
|
21 | #[export]
| --------- expected because of this
22 | unsafe extern "C" fn rust_fmt_argument(
| ^^^^^^^^^^^^^^^^^ expected `u8`, found `i8`
|
= note: expected fn item `unsafe extern "C" fn(*mut u8, *mut u8, *mut c_void) -> *mut u8 {bindings::rust_fmt_argument}`
found fn item `unsafe extern "C" fn(*mut i8, *mut i8, *const c_void) -> *mut i8 {print::rust_fmt_argument}`
It is unfortunate that the error message starts out by saying "`if` and
`else` have incompatible types", but I believe the rest of the error
message is reasonably clear and not too confusing.
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250303-export-macro-v3-3-41fbad85a27f@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-03 08:45:14 +00:00
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2025-10-18 15:16:36 -04:00
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rust: types: add `ForLt` trait for higher-ranked lifetime support
There are a few cases, e.g. when dealing with data referencing each
other, one might want to write code that is generic over lifetimes. For
example, if you want to take a function that takes `&'a Foo` and gives
`Bar<'a>`, you can write:
f: impl for<'a> FnOnce(&'a Foo) -> Bar<'a>,
However, it becomes tricky when you want that function to not have a
fixed `Bar`, but have it be generic again. In this case, one needs
something that is generic over types that are themselves generic over
lifetimes.
`ForLt` provides such support. It provides a trait `ForLt` which
describes a type generic over a lifetime. One may use `ForLt::Of<'a>` to
get an instance of a type for a specific lifetime.
For the case of cross referencing, one would almost always want the
lifetime to be covariant. Therefore this is also made a requirement for
the `ForLt` trait, so functions with `ForLt` trait bound can assume
covariance.
A macro `ForLt!()` is provided to be able to obtain a type that
implements `ForLt`. For example, `ForLt!(for<'a> Bar<'a>)` would yield a
type that `<TheType as ForLt>::Of<'a>` is `Bar<'a>`. This also works
with lifetime elision, e.g. `ForLt!(Bar<'_>)` or for types without
lifetime at all, e.g. `ForLt!(u32)`.
The API design draws inspiration from the higher-kinded-types [1] crate,
however a different design decision has been taken (e.g. covariance
requirement) and the implementation is independent.
License headers use "Apache-2.0 OR MIT" because I anticipate this to be
used in pin-init crate too which is licensed as such.
Link: https://docs.rs/higher-kinded-types/ [1]
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260525202921.124698-23-dakr@kernel.org
[ Handle macro_rules! invocations in the ForLt! proc macro's covariance
and WF checks. Since proc macros cannot expand macro_rules!, add a
visit_macro() implementation to conservatively assume macro
invocations may contain lifetimes, forcing them through the
compiler-assisted covariance proof.
Fix a few typos in the documentation and in the commit message, add
empty lines before samples, add missing periods and consistently use
markdown.
- Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-05-25 22:21:09 +02:00
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2021-07-03 16:56:17 +02:00
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2025-03-07 17:00:57 +08:00
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2021-07-03 16:56:17 +02:00
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2023-06-28 18:11:01 +01:00
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2022-11-10 17:41:18 +01:00
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2021-07-03 16:56:17 +02:00
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2026-01-12 17:07:14 +00:00
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2021-07-03 16:56:17 +02:00
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2025-09-24 14:39:28 +02:00
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2023-12-16 00:54:28 +01:00
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2021-07-03 16:56:17 +02:00
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2026-01-14 18:16:38 +00:00
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2021-07-03 16:56:17 +02:00
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2022-11-10 17:41:19 +01:00
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2025-03-09 14:57:11 -03:00
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2022-11-10 17:41:19 +01:00
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2024-05-12 11:23:20 +00:00
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2025-09-24 14:39:28 +02:00
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2021-07-03 16:56:17 +02:00
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2024-07-04 09:55:43 -05:00
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2021-07-03 16:56:17 +02:00
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2024-07-04 09:55:43 -05:00
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2025-09-24 14:39:28 +02:00
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2024-07-04 09:55:43 -05:00
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2021-07-03 16:56:17 +02:00
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2024-07-04 09:55:43 -05:00
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2021-07-03 16:56:17 +02:00
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2024-05-01 21:35:48 +09:00
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2024-07-04 09:55:43 -05:00
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2024-05-01 21:35:48 +09:00
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2025-03-09 14:57:11 -03:00
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2024-05-01 21:35:48 +09:00
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2024-07-04 09:55:43 -05:00
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2024-05-01 21:35:48 +09:00
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2024-07-04 09:55:43 -05:00
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2024-05-01 21:35:48 +09:00
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2021-07-03 16:56:17 +02:00
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2024-05-12 11:23:21 +00:00
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2025-03-09 14:57:11 -03:00
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2024-05-12 11:23:21 +00:00
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2024-05-01 21:35:48 +09:00
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2024-07-25 20:46:44 +02:00
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2021-07-03 16:56:17 +02:00
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rust: macros: use `syn` to parse `module!` macro
With `syn` being available in the kernel, use it to parse the complex
custom `module!` macro to replace existing helpers. Only parsing is
changed in this commit, the code generation is untouched.
This has the benefit of better error message when the macro is used
incorrectly, as it can point to a concrete span on what's going wrong.
For example, if a field is specified twice, previously it reads:
error: proc macro panicked
--> samples/rust/rust_minimal.rs:7:1
|
7 | / module! {
8 | | type: RustMinimal,
9 | | name: "rust_minimal",
10 | | author: "Rust for Linux Contributors",
11 | | description: "Rust minimal sample",
12 | | license: "GPL",
13 | | license: "GPL",
14 | | }
| |_^
|
= help: message: Duplicated key "license". Keys can only be specified once.
now it reads:
error: duplicated key "license". Keys can only be specified once.
--> samples/rust/rust_minimal.rs:13:5
|
13 | license: "GPL",
| ^^^^^^^
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Link: https://patch.msgid.link/20260112170919.1888584-5-gary@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-01-12 17:07:15 +00:00
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2021-07-03 16:56:17 +02:00
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2022-11-10 17:41:17 +01:00
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2022-11-10 17:41:18 +01:00
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2023-10-26 20:19:33 +00:00
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2022-11-10 17:41:18 +01:00
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2023-10-26 20:19:33 +00:00
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2025-11-30 22:12:33 +01:00
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2023-10-26 20:19:33 +00:00
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2024-11-23 23:28:49 +01:00
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2023-10-26 20:19:33 +00:00
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2024-07-04 09:55:42 -05:00
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2024-11-23 23:28:49 +01:00
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2023-10-26 20:19:33 +00:00
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2022-11-10 17:41:18 +01:00
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2024-07-04 09:55:45 -05:00
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2023-10-26 20:19:33 +00:00
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2022-11-10 17:41:18 +01:00
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2024-11-23 23:28:49 +01:00
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2022-11-10 17:41:18 +01:00
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2024-11-23 23:28:49 +01:00
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2022-11-10 17:41:18 +01:00
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2023-10-26 20:19:33 +00:00
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2022-11-10 17:41:18 +01:00
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2026-01-12 17:07:14 +00:00
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2022-11-10 17:41:18 +01:00
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rust: add #[export] macro
Rust has two different tools for generating function declarations to
call across the FFI boundary:
* bindgen. Generates Rust declarations from a C header.
* cbindgen. Generates C headers from Rust declarations.
However, we only use bindgen in the kernel. This means that when C code
calls a Rust function by name, its signature must be duplicated in both
Rust code and a C header, and the signature needs to be kept in sync
manually.
Introducing cbindgen as a mandatory dependency to build the kernel would
be a rather complex and large change, so we do not consider that at this
time. Instead, to eliminate this manual checking, introduce a new macro
that verifies at compile time that the two function declarations use the
same signature. The idea is to run the C declaration through bindgen,
and then have rustc verify that the function pointers have the same
type.
The signature must still be written twice, but at least you can no
longer get it wrong. If the signatures don't match, you will get errors
that look like this:
error[E0308]: `if` and `else` have incompatible types
--> <linux>/rust/kernel/print.rs:22:22
|
21 | #[export]
| --------- expected because of this
22 | unsafe extern "C" fn rust_fmt_argument(
| ^^^^^^^^^^^^^^^^^ expected `u8`, found `i8`
|
= note: expected fn item `unsafe extern "C" fn(*mut u8, *mut u8, *mut c_void) -> *mut u8 {bindings::rust_fmt_argument}`
found fn item `unsafe extern "C" fn(*mut i8, *mut i8, *const c_void) -> *mut i8 {print::rust_fmt_argument}`
It is unfortunate that the error message starts out by saying "`if` and
`else` have incompatible types", but I believe the rest of the error
message is reasonably clear and not too confusing.
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250303-export-macro-v3-3-41fbad85a27f@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-03 08:45:14 +00:00
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2026-01-12 17:07:17 +00:00
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rust: add #[export] macro
Rust has two different tools for generating function declarations to
call across the FFI boundary:
* bindgen. Generates Rust declarations from a C header.
* cbindgen. Generates C headers from Rust declarations.
However, we only use bindgen in the kernel. This means that when C code
calls a Rust function by name, its signature must be duplicated in both
Rust code and a C header, and the signature needs to be kept in sync
manually.
Introducing cbindgen as a mandatory dependency to build the kernel would
be a rather complex and large change, so we do not consider that at this
time. Instead, to eliminate this manual checking, introduce a new macro
that verifies at compile time that the two function declarations use the
same signature. The idea is to run the C declaration through bindgen,
and then have rustc verify that the function pointers have the same
type.
The signature must still be written twice, but at least you can no
longer get it wrong. If the signatures don't match, you will get errors
that look like this:
error[E0308]: `if` and `else` have incompatible types
--> <linux>/rust/kernel/print.rs:22:22
|
21 | #[export]
| --------- expected because of this
22 | unsafe extern "C" fn rust_fmt_argument(
| ^^^^^^^^^^^^^^^^^ expected `u8`, found `i8`
|
= note: expected fn item `unsafe extern "C" fn(*mut u8, *mut u8, *mut c_void) -> *mut u8 {bindings::rust_fmt_argument}`
found fn item `unsafe extern "C" fn(*mut i8, *mut i8, *const c_void) -> *mut i8 {print::rust_fmt_argument}`
It is unfortunate that the error message starts out by saying "`if` and
`else` have incompatible types", but I believe the rest of the error
message is reasonably clear and not too confusing.
Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250303-export-macro-v3-3-41fbad85a27f@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-03 08:45:14 +00:00
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2025-10-18 15:16:36 -04:00
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2026-01-12 17:07:13 +00:00
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2025-10-18 15:16:36 -04:00
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2022-11-10 17:41:17 +01:00
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2024-07-04 09:55:45 -05:00
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2022-11-10 17:41:17 +01:00
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2024-07-04 09:55:45 -05:00
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2022-11-10 17:41:17 +01:00
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2026-01-12 17:07:18 +00:00
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2022-11-10 17:41:17 +01:00
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2023-04-08 12:25:51 +00:00
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2023-06-28 18:11:01 +01:00
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2023-11-17 20:39:59 -05:00
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2023-06-28 18:11:01 +01:00
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2024-10-02 02:28:48 +00:00
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2023-06-28 18:11:01 +01:00
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2024-07-04 09:55:44 -05:00
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2023-06-28 18:11:01 +01:00
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2025-05-19 17:45:53 +01:00
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2023-06-28 18:11:01 +01:00
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2024-07-09 18:05:56 +02:00
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2023-06-28 18:11:01 +01:00
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2024-07-04 09:55:44 -05:00
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2023-06-28 18:11:01 +01:00
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2025-05-19 17:45:53 +01:00
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2024-10-19 09:22:08 +02:00
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2023-06-28 18:11:01 +01:00
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2023-11-17 20:39:59 -05:00
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2024-07-04 09:55:44 -05:00
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2023-11-17 20:39:59 -05:00
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2025-05-19 17:45:53 +01:00
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2023-11-17 20:39:59 -05:00
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2023-06-28 18:11:01 +01:00
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2026-01-12 17:07:13 +00:00
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2023-06-28 18:11:01 +01:00
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2026-01-12 17:07:13 +00:00
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2023-06-28 18:11:01 +01:00
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2025-03-07 17:00:57 +08:00
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2025-05-02 23:51:28 +02:00
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2025-03-07 17:00:57 +08:00
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2026-01-12 17:07:19 +00:00
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2025-03-07 17:00:57 +08:00
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|
rust: types: add `ForLt` trait for higher-ranked lifetime support
There are a few cases, e.g. when dealing with data referencing each
other, one might want to write code that is generic over lifetimes. For
example, if you want to take a function that takes `&'a Foo` and gives
`Bar<'a>`, you can write:
f: impl for<'a> FnOnce(&'a Foo) -> Bar<'a>,
However, it becomes tricky when you want that function to not have a
fixed `Bar`, but have it be generic again. In this case, one needs
something that is generic over types that are themselves generic over
lifetimes.
`ForLt` provides such support. It provides a trait `ForLt` which
describes a type generic over a lifetime. One may use `ForLt::Of<'a>` to
get an instance of a type for a specific lifetime.
For the case of cross referencing, one would almost always want the
lifetime to be covariant. Therefore this is also made a requirement for
the `ForLt` trait, so functions with `ForLt` trait bound can assume
covariance.
A macro `ForLt!()` is provided to be able to obtain a type that
implements `ForLt`. For example, `ForLt!(for<'a> Bar<'a>)` would yield a
type that `<TheType as ForLt>::Of<'a>` is `Bar<'a>`. This also works
with lifetime elision, e.g. `ForLt!(Bar<'_>)` or for types without
lifetime at all, e.g. `ForLt!(u32)`.
The API design draws inspiration from the higher-kinded-types [1] crate,
however a different design decision has been taken (e.g. covariance
requirement) and the implementation is independent.
License headers use "Apache-2.0 OR MIT" because I anticipate this to be
used in pin-init crate too which is licensed as such.
Link: https://docs.rs/higher-kinded-types/ [1]
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Eliot Courtney <ecourtney@nvidia.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260525202921.124698-23-dakr@kernel.org
[ Handle macro_rules! invocations in the ForLt! proc macro's covariance
and WF checks. Since proc macros cannot expand macro_rules!, add a
visit_macro() implementation to conservatively assume macro
invocations may contain lifetimes, forcing them through the
compiler-assisted covariance proof.
Fix a few typos in the documentation and in the commit message, add
empty lines before samples, add missing periods and consistently use
markdown.
- Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-05-25 22:21:09 +02:00
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