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Diffstat (limited to 'rust/macros/lib.rs')
| -rw-r--r-- | rust/macros/lib.rs | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs new file mode 100644 index 000000000..c1d385e34 --- /dev/null +++ b/rust/macros/lib.rs @@ -0,0 +1,168 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Crate for all kernel procedural macros. + +mod concat_idents; +mod helpers; +mod module; +mod vtable; + +use proc_macro::TokenStream; + +/// Declares a kernel module. +/// +/// The `type` argument should be a type which implements the [`Module`] +/// trait. Also accepts various forms of kernel metadata. +/// +/// C header: [`include/linux/moduleparam.h`](../../../include/linux/moduleparam.h) +/// +/// [`Module`]: ../kernel/trait.Module.html +/// +/// # Examples +/// +/// ```ignore +/// use kernel::prelude::*; +/// +/// module!{ +/// type: MyModule, +/// 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: "Example of i32", +/// }, +/// writeable_i32: i32 { +/// default: 42, +/// permissions: 0o644, +/// description: "Example of i32", +/// }, +/// }, +/// } +/// +/// struct MyModule; +/// +/// impl kernel::Module for MyModule { +/// fn init() -> Result<Self> { +/// // If the parameter is writeable, then the kparam lock must be +/// // taken to read the parameter: +/// { +/// let lock = THIS_MODULE.kernel_param_lock(); +/// pr_info!("i32 param is: {}\n", writeable_i32.read(&lock)); +/// } +/// // If the parameter is read only, it can be read without locking +/// // the kernel parameters: +/// pr_info!("i32 param is: {}\n", my_i32.read()); +/// Ok(Self) +/// } +/// } +/// ``` +/// +/// # Supported argument types +/// - `type`: type which implements the [`Module`] trait (required). +/// - `name`: byte array of the name of the kernel module (required). +/// - `author`: byte array of the author of the kernel module. +/// - `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. +#[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) +} |