diff options
Diffstat (limited to 'rust/macros/lib.rs')
| -rw-r--r-- | rust/macros/lib.rs | 131 |
1 files changed, 125 insertions, 6 deletions
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs index 91764bfb1f89..397e1496da28 100644 --- a/rust/macros/lib.rs +++ b/rust/macros/lib.rs @@ -2,8 +2,10 @@ //! Crate for all kernel procedural macros. +mod concat_idents; mod helpers; mod module; +mod vtable; use proc_macro::TokenStream; @@ -23,20 +25,20 @@ use proc_macro::TokenStream; /// /// module!{ /// type: MyModule, -/// name: b"my_kernel_module", -/// author: b"Rust for Linux Contributors", -/// description: b"My very own kernel module!", -/// license: b"GPL", +/// name: "my_kernel_module", +/// author: "Rust for Linux Contributors", +/// description: "My very own kernel module!", +/// license: "GPL", /// params: { /// my_i32: i32 { /// default: 42, /// permissions: 0o000, -/// description: b"Example of i32", +/// description: "Example of i32", /// }, /// writeable_i32: i32 { /// default: 42, /// permissions: 0o644, -/// description: b"Example of i32", +/// description: "Example of i32", /// }, /// }, /// } @@ -66,7 +68,124 @@ use proc_macro::TokenStream; /// - `description`: byte array of the description of the kernel module. /// - `license`: byte array of the license of the kernel module (required). /// - `alias`: byte array of alias name of the kernel module. +/// - `alias_rtnl_link`: byte array of the `rtnl_link_alias` of the kernel module +/// (mutually exclusive with `alias`). +/// - `params`: parameters for the kernel module, as described below. +/// +/// # Supported parameter types +/// +/// - `bool`: Corresponds to C `bool` param type. +/// - `i8`: No equivalent C param type. +/// - `u8`: Corresponds to C `char` param type. +/// - `i16`: Corresponds to C `short` param type. +/// - `u16`: Corresponds to C `ushort` param type. +/// - `i32`: Corresponds to C `int` param type. +/// - `u32`: Corresponds to C `uint` param type. +/// - `i64`: No equivalent C param type. +/// - `u64`: Corresponds to C `ullong` param type. +/// - `isize`: No equivalent C param type. +/// - `usize`: No equivalent C param type. +/// - `str`: Corresponds to C `charp` param type. Reading returns a byte slice. +/// - `ArrayParam<T,N>`: Corresponds to C parameters created using `module_param_array`. +/// An array of `T`'s of length at **most** `N`. +/// +/// `invbool` is unsupported: it was only ever used in a few modules. +/// Consider using a `bool` and inverting the logic instead. #[proc_macro] pub fn module(ts: TokenStream) -> TokenStream { module::module(ts) } + +/// Declares or implements a vtable trait. +/// +/// Linux's use of pure vtables is very close to Rust traits, but they differ +/// in how unimplemented functions are represented. In Rust, traits can provide +/// default implementation for all non-required methods (and the default +/// implementation could just return `Error::EINVAL`); Linux typically use C +/// `NULL` pointers to represent these functions. +/// +/// This attribute is intended to close the gap. Traits can be declared and +/// implemented with the `#[vtable]` attribute, and a `HAS_*` associated constant +/// will be generated for each method in the trait, indicating if the implementor +/// has overridden a method. +/// +/// This attribute is not needed if all methods are required. +/// +/// # Examples +/// +/// ```ignore +/// use kernel::prelude::*; +/// +/// // Declares a `#[vtable]` trait +/// #[vtable] +/// pub trait Operations: Send + Sync + Sized { +/// fn foo(&self) -> Result<()> { +/// Err(EINVAL) +/// } +/// +/// fn bar(&self) -> Result<()> { +/// Err(EINVAL) +/// } +/// } +/// +/// struct Foo; +/// +/// // Implements the `#[vtable]` trait +/// #[vtable] +/// impl Operations for Foo { +/// fn foo(&self) -> Result<()> { +/// # Err(EINVAL) +/// // ... +/// } +/// } +/// +/// assert_eq!(<Foo as Operations>::HAS_FOO, true); +/// assert_eq!(<Foo as Operations>::HAS_BAR, false); +/// ``` +#[proc_macro_attribute] +pub fn vtable(attr: TokenStream, ts: TokenStream) -> TokenStream { + vtable::vtable(attr, ts) +} + +/// Concatenate two identifiers. +/// +/// This is useful in macros that need to declare or reference items with names +/// starting with a fixed prefix and ending in a user specified name. The resulting +/// identifier has the span of the second argument. +/// +/// # Examples +/// +/// ```ignore +/// use kernel::macro::concat_idents; +/// +/// macro_rules! pub_no_prefix { +/// ($prefix:ident, $($newname:ident),+) => { +/// $(pub(crate) const $newname: u32 = kernel::macros::concat_idents!($prefix, $newname);)+ +/// }; +/// } +/// +/// pub_no_prefix!( +/// binder_driver_return_protocol_, +/// BR_OK, +/// BR_ERROR, +/// BR_TRANSACTION, +/// BR_REPLY, +/// BR_DEAD_REPLY, +/// BR_TRANSACTION_COMPLETE, +/// BR_INCREFS, +/// BR_ACQUIRE, +/// BR_RELEASE, +/// BR_DECREFS, +/// BR_NOOP, +/// BR_SPAWN_LOOPER, +/// BR_DEAD_BINDER, +/// BR_CLEAR_DEATH_NOTIFICATION_DONE, +/// BR_FAILED_REPLY +/// ); +/// +/// assert_eq!(BR_OK, binder_driver_return_protocol_BR_OK); +/// ``` +#[proc_macro] +pub fn concat_idents(ts: TokenStream) -> TokenStream { + concat_idents::concat_idents(ts) +} |