Commit Graph

17 Commits

Author SHA1 Message Date
Linus Torvalds
a031fe8d1d Rust changes for v6.6
In terms of lines, most changes this time are on the pinned-init API
 and infrastructure. While we have a Rust version upgrade, and thus a
 bunch of changes from the vendored 'alloc' crate as usual, this time
 those do not account for many lines.
 
 Toolchain and infrastructure:
 
  - Upgrade to Rust 1.71.1. This is the second such upgrade, which is a
    smaller jump compared to the last time.
 
    This version allows us to remove the '__rust_*' allocator functions
    -- the compiler now generates them as expected, thus now our
    'KernelAllocator' is used.
 
    It also introduces the 'offset_of!' macro in the standard library
    (as an unstable feature) which we will need soon. So far, we were
    using a declarative macro as a prerequisite in some not-yet-landed
    patch series, which did not support sub-fields (i.e. nested structs):
 
        #[repr(C)]
        struct S {
            a: u16,
            b: (u8, u8),
        }
 
        assert_eq!(offset_of!(S, b.1), 3);
 
  - Upgrade to bindgen 0.65.1. This is the first time we upgrade its
    version.
 
    Given it is a fairly big jump, it comes with a fair number of
    improvements/changes that affect us, such as a fix needed to support
    LLVM 16 as well as proper support for '__noreturn' C functions, which
    are now mapped to return the '!' type in Rust:
 
        void __noreturn f(void); // C
        pub fn f() -> !;         // Rust
 
  - 'scripts/rust_is_available.sh' improvements and fixes.
 
    This series takes care of all the issues known so far and adds a few
    new checks to cover for even more cases, plus adds some more help
    texts. All this together will hopefully make problematic setups
    easier to identify and to be solved by users building the kernel.
 
    In addition, it adds a test suite which covers all branches of the
    shell script, as well as tests for the issues found so far.
 
  - Support rust-analyzer for out-of-tree modules too.
 
  - Give 'cfg's to rust-analyzer for the 'core' and 'alloc' crates.
 
  - Drop 'scripts/is_rust_module.sh' since it is not needed anymore.
 
 Macros crate:
 
  - New 'paste!' proc macro.
 
    This macro is a more flexible version of 'concat_idents!': it allows
    the resulting identifier to be used to declare new items and it
    allows to transform the identifiers before concatenating them, e.g.
 
        let x_1 = 42;
        paste!(let [<x _2>] = [<x _1>];);
        assert!(x_1 == x_2);
 
    The macro is then used for several of the pinned-init API changes in
    this pull.
 
 Pinned-init API:
 
  - Make '#[pin_data]' compatible with conditional compilation of fields,
    allowing to write code like:
 
        #[pin_data]
        pub struct Foo {
            #[cfg(CONFIG_BAR)]
            a: Bar,
            #[cfg(not(CONFIG_BAR))]
            a: Baz,
        }
 
  - New '#[derive(Zeroable)]' proc macro for the 'Zeroable' trait, which
    allows 'unsafe' implementations for structs where every field
    implements the 'Zeroable' trait, e.g.:
 
        #[derive(Zeroable)]
        pub struct DriverData {
            id: i64,
            buf_ptr: *mut u8,
            len: usize,
        }
 
  - Add '..Zeroable::zeroed()' syntax to the 'pin_init!'  macro for
    zeroing all other fields, e.g.:
 
        pin_init!(Buf {
            buf: [1; 64],
            ..Zeroable::zeroed()
        });
 
  - New '{,pin_}init_array_from_fn()' functions to create array
    initializers given a generator function, e.g.:
 
        let b: Box<[usize; 1_000]> = Box::init::<Error>(
            init_array_from_fn(|i| i)
        ).unwrap();
 
        assert_eq!(b.len(), 1_000);
        assert_eq!(b[123], 123);
 
  - New '{,pin_}chain' methods for '{,Pin}Init<T, E>' that allow to
    execute a closure on the value directly after initialization, e.g.:
 
        let foo = init!(Foo {
            buf <- init::zeroed()
        }).chain(|foo| {
            foo.setup();
            Ok(())
        });
 
  - Support arbitrary paths in init macros, instead of just identifiers
    and generic types.
 
  - Implement the 'Zeroable' trait for the 'UnsafeCell<T>' and
    'Opaque<T>' types.
 
  - Make initializer values inaccessible after initialization.
 
  - Make guards in the init macros hygienic.
 
 'allocator' module:
 
  - Use 'krealloc_aligned()' in 'KernelAllocator::alloc' preventing
    misaligned allocations when the Rust 1.71.1 upgrade is applied later
    in this pull.
 
    The equivalent fix for the previous compiler version (where
    'KernelAllocator' is not yet used) was merged into 6.5 already,
    which added the 'krealloc_aligned()' function used here.
 
  - Implement 'KernelAllocator::{realloc, alloc_zeroed}' for performance,
    using 'krealloc_aligned()' too, which forwards the call to the C API.
 
 'types' module:
 
  - Make 'Opaque' be '!Unpin', removing the need to add a 'PhantomPinned'
    field to Rust structs that contain C structs which must not be moved.
 
  - Make 'Opaque' use 'UnsafeCell' as the outer type, rather than inner.
 
 Documentation:
 
  - Suggest obtaining the source code of the Rust's 'core' library using
    the tarball instead of the repository.
 
 MAINTAINERS:
 
  - Andreas and Alice, from Samsung and Google respectively, are joining
    as reviewers of the "RUST" entry.
 
 As well as a few other minor changes and cleanups.
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Merge tag 'rust-6.6' of https://github.com/Rust-for-Linux/linux

Pull rust updates from Miguel Ojeda:
 "In terms of lines, most changes this time are on the pinned-init API
  and infrastructure. While we have a Rust version upgrade, and thus a
  bunch of changes from the vendored 'alloc' crate as usual, this time
  those do not account for many lines.

  Toolchain and infrastructure:

   - Upgrade to Rust 1.71.1. This is the second such upgrade, which is a
     smaller jump compared to the last time.

     This version allows us to remove the '__rust_*' allocator functions
     -- the compiler now generates them as expected, thus now our
     'KernelAllocator' is used.

     It also introduces the 'offset_of!' macro in the standard library
     (as an unstable feature) which we will need soon. So far, we were
     using a declarative macro as a prerequisite in some not-yet-landed
     patch series, which did not support sub-fields (i.e. nested
     structs):

         #[repr(C)]
         struct S {
             a: u16,
             b: (u8, u8),
         }

         assert_eq!(offset_of!(S, b.1), 3);

   - Upgrade to bindgen 0.65.1. This is the first time we upgrade its
     version.

     Given it is a fairly big jump, it comes with a fair number of
     improvements/changes that affect us, such as a fix needed to
     support LLVM 16 as well as proper support for '__noreturn' C
     functions, which are now mapped to return the '!' type in Rust:

         void __noreturn f(void); // C
         pub fn f() -> !;         // Rust

   - 'scripts/rust_is_available.sh' improvements and fixes.

     This series takes care of all the issues known so far and adds a
     few new checks to cover for even more cases, plus adds some more
     help texts. All this together will hopefully make problematic
     setups easier to identify and to be solved by users building the
     kernel.

     In addition, it adds a test suite which covers all branches of the
     shell script, as well as tests for the issues found so far.

   - Support rust-analyzer for out-of-tree modules too.

   - Give 'cfg's to rust-analyzer for the 'core' and 'alloc' crates.

   - Drop 'scripts/is_rust_module.sh' since it is not needed anymore.

  Macros crate:

   - New 'paste!' proc macro.

     This macro is a more flexible version of 'concat_idents!': it
     allows the resulting identifier to be used to declare new items and
     it allows to transform the identifiers before concatenating them,
     e.g.

         let x_1 = 42;
         paste!(let [<x _2>] = [<x _1>];);
         assert!(x_1 == x_2);

     The macro is then used for several of the pinned-init API changes
     in this pull.

  Pinned-init API:

   - Make '#[pin_data]' compatible with conditional compilation of
     fields, allowing to write code like:

         #[pin_data]
         pub struct Foo {
             #[cfg(CONFIG_BAR)]
             a: Bar,
             #[cfg(not(CONFIG_BAR))]
             a: Baz,
         }

   - New '#[derive(Zeroable)]' proc macro for the 'Zeroable' trait,
     which allows 'unsafe' implementations for structs where every field
     implements the 'Zeroable' trait, e.g.:

         #[derive(Zeroable)]
         pub struct DriverData {
             id: i64,
             buf_ptr: *mut u8,
             len: usize,
         }

   - Add '..Zeroable::zeroed()' syntax to the 'pin_init!' macro for
     zeroing all other fields, e.g.:

         pin_init!(Buf {
             buf: [1; 64],
             ..Zeroable::zeroed()
         });

   - New '{,pin_}init_array_from_fn()' functions to create array
     initializers given a generator function, e.g.:

         let b: Box<[usize; 1_000]> = Box::init::<Error>(
             init_array_from_fn(|i| i)
         ).unwrap();

         assert_eq!(b.len(), 1_000);
         assert_eq!(b[123], 123);

   - New '{,pin_}chain' methods for '{,Pin}Init<T, E>' that allow to
     execute a closure on the value directly after initialization, e.g.:

         let foo = init!(Foo {
             buf <- init::zeroed()
         }).chain(|foo| {
             foo.setup();
             Ok(())
         });

   - Support arbitrary paths in init macros, instead of just identifiers
     and generic types.

   - Implement the 'Zeroable' trait for the 'UnsafeCell<T>' and
     'Opaque<T>' types.

   - Make initializer values inaccessible after initialization.

   - Make guards in the init macros hygienic.

  'allocator' module:

   - Use 'krealloc_aligned()' in 'KernelAllocator::alloc' preventing
     misaligned allocations when the Rust 1.71.1 upgrade is applied
     later in this pull.

     The equivalent fix for the previous compiler version (where
     'KernelAllocator' is not yet used) was merged into 6.5 already,
     which added the 'krealloc_aligned()' function used here.

   - Implement 'KernelAllocator::{realloc, alloc_zeroed}' for
     performance, using 'krealloc_aligned()' too, which forwards the
     call to the C API.

  'types' module:

   - Make 'Opaque' be '!Unpin', removing the need to add a
     'PhantomPinned' field to Rust structs that contain C structs which
     must not be moved.

   - Make 'Opaque' use 'UnsafeCell' as the outer type, rather than
     inner.

  Documentation:

   - Suggest obtaining the source code of the Rust's 'core' library
     using the tarball instead of the repository.

  MAINTAINERS:

   - Andreas and Alice, from Samsung and Google respectively, are
     joining as reviewers of the "RUST" entry.

  As well as a few other minor changes and cleanups"

* tag 'rust-6.6' of https://github.com/Rust-for-Linux/linux: (42 commits)
  rust: init: update expanded macro explanation
  rust: init: add `{pin_}chain` functions to `{Pin}Init<T, E>`
  rust: init: make `PinInit<T, E>` a supertrait of `Init<T, E>`
  rust: init: implement `Zeroable` for `UnsafeCell<T>` and `Opaque<T>`
  rust: init: add support for arbitrary paths in init macros
  rust: init: add functions to create array initializers
  rust: init: add `..Zeroable::zeroed()` syntax for zeroing all missing fields
  rust: init: make initializer values inaccessible after initializing
  rust: init: wrap type checking struct initializers in a closure
  rust: init: make guards in the init macros hygienic
  rust: add derive macro for `Zeroable`
  rust: init: make `#[pin_data]` compatible with conditional compilation of fields
  rust: init: consolidate init macros
  docs: rust: clarify what 'rustup override' does
  docs: rust: update instructions for obtaining 'core' source
  docs: rust: add command line to rust-analyzer section
  scripts: generate_rust_analyzer: provide `cfg`s for `core` and `alloc`
  rust: bindgen: upgrade to 0.65.1
  rust: enable `no_mangle_with_rust_abi` Clippy lint
  rust: upgrade to Rust 1.71.1
  ...
2023-08-29 08:19:46 -07:00
Benno Lossin
071cedc84e rust: add derive macro for Zeroable
Add a derive proc-macro for the `Zeroable` trait. The macro supports
structs where every field implements the `Zeroable` trait. This way
`unsafe` implementations can be avoided.

The macro is split into two parts:
- a proc-macro to parse generics into impl and ty generics,
- a declarative macro that expands to the impl block.

Suggested-by: Asahi Lina <lina@asahilina.net>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20230814084602.25699-4-benno.lossin@proton.me
[ Added `ignore` to the `lib.rs` example and cleaned trivial nit. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-21 14:31:48 +02:00
Andrea Righi
41bdc6decd btf, scripts: rust: drop is_rust_module.sh
With commit c1177979af ("btf, scripts: Exclude Rust CUs with pahole")
we are now able to use pahole directly to identify Rust compilation
units (CUs) and exclude them from generating BTF debugging information
(when DEBUG_INFO_BTF is enabled).

And if pahole doesn't support the --lang-exclude flag, we can't enable
both RUST and DEBUG_INFO_BTF at the same time.

So, in any case, the script is_rust_module.sh is just redundant and we
can drop it.

NOTE: we may also be able to drop the "Rust loadable module" mark
inside Rust modules, but it seems safer to keep it for now to make sure
we are not breaking any external tool that may potentially rely on it.

Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Eric Curtin <ecurtin@redhat.com>
Reviewed-by: Eric Curtin <ecurtin@redhat.com>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Acked-by: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/r/20230704052136.155445-1-andrea.righi@canonical.com
[ Picked the `Reviewed-by`s from the old patch too. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-10 22:28:04 +02:00
Gary Guo
823d4737d4 rust: macros: add paste! proc macro
This macro provides a flexible way to concatenated identifiers together
and it allows the resulting identifier to be used to declare new items,
which `concat_idents!` does not allow. It also allows identifiers to be
transformed before concatenated.

The `concat_idents!` example

    let x_1 = 42;
    let x_2 = concat_idents!(x, _1);
    assert!(x_1 == x_2);

can be written with `paste!` macro like this:

    let x_1 = 42;
    let x_2 = paste!([<x _1>]);
    assert!(x_1 == x_2);

However `paste!` macro is more flexible because it can be used to create
a new variable:

    let x_1 = 42;
    paste!(let [<x _2>] = [<x _1>];);
    assert!(x_1 == x_2);

While this is not possible with `concat_idents!`.

This macro is similar to the `paste!` crate [1], but this is a fresh
implementation to avoid vendoring large amount of code directly. Also, I
have augmented it to provide a way to specify span of the resulting
token, allowing precise control.

For example, this code is broken because the variable is declared inside
the macro, so Rust macro hygiene rules prevents access from the outside:

    macro_rules! m {
        ($id: ident) => {
            // The resulting token has hygiene of the macro.
            paste!(let [<$id>] = 1;)
        }
    }

    m!(a);
    let _ = a;

In this version of `paste!` macro I added a `span` modifier to allow
this:

    macro_rules! m {
        ($id: ident) => {
            // The resulting token has hygiene of `$id`.
            paste!(let [<$id:span>] = 1;)
        }
    }

    m!(a);
    let _ = a;

Link: http://docs.rs/paste/ [1]
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20230628171108.1150742-1-gary@garyguo.net
[ Added SPDX license identifier as discussed in the list and fixed typo. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-10 22:28:02 +02:00
Qingsong Chen
3fa7187ece rust: macros: vtable: fix HAS_* redefinition (gen_const_name)
If we define the same function name twice in a trait (using `#[cfg]`),
the `vtable` macro will redefine its `gen_const_name`, e.g. this will
define `HAS_BAR` twice:

    #[vtable]
    pub trait Foo {
        #[cfg(CONFIG_X)]
        fn bar();

        #[cfg(not(CONFIG_X))]
        fn bar(x: usize);
    }

Fixes: b44becc5ee ("rust: macros: add `#[vtable]` proc macro")
Signed-off-by: Qingsong Chen <changxian.cqs@antgroup.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Sergio González Collado <sergio.collado@gmail.com>
Link: https://lore.kernel.org/r/20230808025404.2053471-1-changxian.cqs@antgroup.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-09 21:15:07 +02:00
Benno Lossin
52b7bb46ae rust: macros: replace Self with the concrete type in #[pin_data]
When using `#[pin_data]` on a struct that used `Self` in the field
types, a type error would be emitted when trying to use `pin_init!`.
Since an internal type would be referenced by `Self` instead of the
defined struct.

This patch fixes this issue by replacing all occurrences of `Self` in
the `#[pin_data]` macro with the concrete type circumventing the issue.
Since rust allows type definitions inside of blocks, which are
expressions, the macro also checks for these and emits a compile error
when it finds `trait`, `enum`, `union`, `struct` or `impl`. These
keywords allow creating new `Self` contexts, which conflicts with the
current implementation of replacing every `Self` ident. If these were
allowed, some `Self` idents would be replaced incorrectly.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reported-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20230424081112.99890-3-benno.lossin@proton.me
[ Added newline in commit message ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31 18:53:09 +02:00
Benno Lossin
e957b9cda3 rust: macros: refactor generics parsing of #[pin_data] into its own function
Other macros might also want to parse generics. Additionally this makes
the code easier to read, as the next commit will introduce more code in
`#[pin_data]`. Also add more comments to explain how parsing generics
work.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20230424081112.99890-2-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31 18:53:09 +02:00
Benno Lossin
b8342addde rust: macros: fix usage of #[allow] in quote!
When using `quote!` as part of an expression that was not the last one
in a function, the `#[allow(clippy::vec_init_then_push)]` attribute
would be present on an expression, which is not allowed.
This patch refactors that part of the macro to use a statement instead.

Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20230424081112.99890-1-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31 18:53:09 +02:00
Benno Lossin
d0fdc39612 rust: init: add PinnedDrop trait and macros
The `PinnedDrop` trait that facilitates destruction of pinned types.
It has to be implemented via the `#[pinned_drop]` macro, since the
`drop` function should not be called by normal code, only by other
destructors. It also only works on structs that are annotated with
`#[pin_data(PinnedDrop)]`.

Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20230408122429.1103522-10-y86-dev@protonmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:05 +02:00
Benno Lossin
fc6c6baa1f rust: init: add initialization macros
Add the following initializer macros:
- `#[pin_data]` to annotate structurally pinned fields of structs,
  needed for `pin_init!` and `try_pin_init!` to select the correct
  initializer of fields.
- `pin_init!` create a pin-initializer for a struct with the
  `Infallible` error type.
- `try_pin_init!` create a pin-initializer for a struct with a custom
  error type (`kernel::error::Error` is the default).
- `init!` create an in-place-initializer for a struct with the
  `Infallible` error type.
- `try_init!` create an in-place-initializer for a struct with a custom
  error type (`kernel::error::Error` is the default).

Also add their needed internal helper traits and structs.

Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20230408122429.1103522-8-y86-dev@protonmail.com
[ Fixed three typos. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:05 +02:00
Gary Guo
70a21e54a4 rust: macros: add quote! macro
Add the `quote!` macro for creating `TokenStream`s directly via the
given Rust tokens. It also supports repetitions using iterators.

It will be used by the pin-init API proc-macros to generate code.

Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20230408122429.1103522-3-y86-dev@protonmail.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:05 +02:00
Asahi Lina
46384d0990 rust: error: Rename to_kernel_errno() -> to_errno()
This is kernel code, so specifying "kernel" is redundant. Let's simplify
things and just call it to_errno().

Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230224-rust-error-v3-1-03779bddc02b@asahilina.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12 18:41:04 +02:00
Asahi Lina
39867fec28 rust: macros: Allow specifying multiple module aliases
Modules can (and usually do) have multiple alias tags, in order to
specify multiple possible device matches for autoloading. Allow this by
changing the alias ModuleInfo field to an Option<Vec<String>>.

Note: For normal device IDs this is autogenerated by modpost (which is
not properly integrated with Rust support yet), so it is useful to be
able to manually add device match aliases for now, and should still be
useful in the future for corner cases that modpost does not handle.

This pulls in the expect_group() helper from the rfl/rust branch
(with credit to authors).

Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Co-developed-by: Finn Behrens <me@kloenk.dev>
Signed-off-by: Finn Behrens <me@kloenk.dev>
Co-developed-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Signed-off-by: Asahi Lina <lina@asahilina.net>
Link: https://lore.kernel.org/r/20230224-rust-macros-v2-1-7396e8b7018d@asahilina.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10 23:55:43 +02:00
Gary Guo
b13c9880f9 rust: macros: take string literals in module!
Instead of taking binary string literals, take string ones instead,
making it easier for users to define a module, i.e. instead of
calling `module!` like:

    module! {
        ...
        name: b"rust_minimal",
        ...
    }

now it is called as:

    module! {
        ...
        name: "rust_minimal",
        ...
    }

Module names, aliases and license strings are restricted to
ASCII only. However, the author and the description allows UTF-8.

For simplicity (avoid parsing), escape sequences and raw string
literals are not yet handled.

Link: https://github.com/Rust-for-Linux/linux/issues/252
Link: https://lore.kernel.org/lkml/YukvvPOOu8uZl7+n@yadro.com/
Signed-off-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Gary Guo
b44becc5ee rust: macros: add #[vtable] proc macro
This procedural macro attribute provides a simple way to declare
a trait with a set of operations that later users can partially
implement, providing compile-time `HAS_*` boolean associated
constants that indicate whether a particular operation was overridden.

This is useful as the Rust counterpart to structs like
`file_operations` where some pointers may be `NULL`, indicating
an operation is not provided.

For instance:

    #[vtable]
    trait Operations {
        fn read(...) -> Result<usize> {
            Err(EINVAL)
        }

        fn write(...) -> Result<usize> {
            Err(EINVAL)
        }
    }

    #[vtable]
    impl Operations for S {
        fn read(...) -> Result<usize> {
            ...
        }
    }

    assert_eq!(<S as Operations>::HAS_READ, true);
    assert_eq!(<S as Operations>::HAS_WRITE, false);

Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Sergio González Collado <sergio.collado@gmail.com>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:15 +01:00
Björn Roy Baron
60f18c225f rust: macros: add concat_idents! proc macro
This macro provides similar functionality to the unstable feature
`concat_idents` without having to rely on it.

For instance:

    let x_1 = 42;
    let x_2 = concat_idents!(x, _1);
    assert!(x_1 == x_2);

It has different behavior with respect to macro hygiene. Unlike
the unstable `concat_idents!` macro, it allows, for example,
referring to local variables by taking the span of the second
macro as span for the output identifier.

Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Reviewed-by: Finn Behrens <me@kloenk.dev>
Reviewed-by: Gary Guo <gary@garyguo.net>
[Reworded, adapted for upstream and applied latest changes]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04 01:59:04 +01:00
Miguel Ojeda
1fbde52bde rust: add macros crate
This crate contains all the procedural macros ("proc macros")
shared by all the kernel.

Procedural macros allow to create syntax extensions. They run at
compile-time and can consume as well as produce Rust syntax.

For instance, the `module!` macro that is used by Rust modules
is implemented here. It allows to easily declare the equivalent
information to the `MODULE_*` macros in C modules, e.g.:

    module! {
        type: RustMinimal,
        name: b"rust_minimal",
        author: b"Rust for Linux Contributors",
        description: b"Rust minimal sample",
        license: b"GPL",
    }

Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Finn Behrens <me@kloenk.de>
Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Matthew Bakhtiari <dev@mtbk.me>
Signed-off-by: Matthew Bakhtiari <dev@mtbk.me>
Co-developed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 08:58:00 +02:00