mirror of
https://github.com/torvalds/linux.git
synced 2024-11-21 19:41:42 +00:00
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>
This commit is contained in:
Miguel Ojeda
parent
db958dcf88
commit
1fbde52bde
51
rust/macros/helpers.rs
Normal file
51
rust/macros/helpers.rs
Normal file
@ -0,0 +1,51 @@
|
||||
// SPDX-License-Identifier: GPL-2.0
|
||||
|
||||
use proc_macro::{token_stream, TokenTree};
|
||||
|
||||
pub(crate) fn try_ident(it: &mut token_stream::IntoIter) -> Option<String> {
|
||||
if let Some(TokenTree::Ident(ident)) = it.next() {
|
||||
Some(ident.to_string())
|
||||
} else {
|
||||
None
|
||||
}
|
||||
}
|
||||
|
||||
pub(crate) fn try_literal(it: &mut token_stream::IntoIter) -> Option<String> {
|
||||
if let Some(TokenTree::Literal(literal)) = it.next() {
|
||||
Some(literal.to_string())
|
||||
} else {
|
||||
None
|
||||
}
|
||||
}
|
||||
|
||||
pub(crate) fn try_byte_string(it: &mut token_stream::IntoIter) -> Option<String> {
|
||||
try_literal(it).and_then(|byte_string| {
|
||||
if byte_string.starts_with("b\"") && byte_string.ends_with('\"') {
|
||||
Some(byte_string[2..byte_string.len() - 1].to_string())
|
||||
} else {
|
||||
None
|
||||
}
|
||||
})
|
||||
}
|
||||
|
||||
pub(crate) fn expect_ident(it: &mut token_stream::IntoIter) -> String {
|
||||
try_ident(it).expect("Expected Ident")
|
||||
}
|
||||
|
||||
pub(crate) fn expect_punct(it: &mut token_stream::IntoIter) -> char {
|
||||
if let TokenTree::Punct(punct) = it.next().expect("Reached end of token stream for Punct") {
|
||||
punct.as_char()
|
||||
} else {
|
||||
panic!("Expected Punct");
|
||||
}
|
||||
}
|
||||
|
||||
pub(crate) fn expect_byte_string(it: &mut token_stream::IntoIter) -> String {
|
||||
try_byte_string(it).expect("Expected byte string")
|
||||
}
|
||||
|
||||
pub(crate) fn expect_end(it: &mut token_stream::IntoIter) {
|
||||
if it.next().is_some() {
|
||||
panic!("Expected end");
|
||||
}
|
||||
}
|
||||
72
rust/macros/lib.rs
Normal file
72
rust/macros/lib.rs
Normal file
@ -0,0 +1,72 @@
|
||||
// SPDX-License-Identifier: GPL-2.0
|
||||
|
||||
//! Crate for all kernel procedural macros.
|
||||
|
||||
mod helpers;
|
||||
mod module;
|
||||
|
||||
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: b"my_kernel_module",
|
||||
/// author: b"Rust for Linux Contributors",
|
||||
/// description: b"My very own kernel module!",
|
||||
/// license: b"GPL",
|
||||
/// params: {
|
||||
/// my_i32: i32 {
|
||||
/// default: 42,
|
||||
/// permissions: 0o000,
|
||||
/// description: b"Example of i32",
|
||||
/// },
|
||||
/// writeable_i32: i32 {
|
||||
/// default: 42,
|
||||
/// permissions: 0o644,
|
||||
/// description: b"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)
|
||||
}
|
||||
282
rust/macros/module.rs
Normal file
282
rust/macros/module.rs
Normal file
@ -0,0 +1,282 @@
|
||||
// SPDX-License-Identifier: GPL-2.0
|
||||
|
||||
use crate::helpers::*;
|
||||
use proc_macro::{token_stream, Literal, TokenStream, TokenTree};
|
||||
use std::fmt::Write;
|
||||
|
||||
struct ModInfoBuilder<'a> {
|
||||
module: &'a str,
|
||||
counter: usize,
|
||||
buffer: String,
|
||||
}
|
||||
|
||||
impl<'a> ModInfoBuilder<'a> {
|
||||
fn new(module: &'a str) -> Self {
|
||||
ModInfoBuilder {
|
||||
module,
|
||||
counter: 0,
|
||||
buffer: String::new(),
|
||||
}
|
||||
}
|
||||
|
||||
fn emit_base(&mut self, field: &str, content: &str, builtin: bool) {
|
||||
let string = if builtin {
|
||||
// Built-in modules prefix their modinfo strings by `module.`.
|
||||
format!(
|
||||
"{module}.{field}={content}\0",
|
||||
module = self.module,
|
||||
field = field,
|
||||
content = content
|
||||
)
|
||||
} else {
|
||||
// Loadable modules' modinfo strings go as-is.
|
||||
format!("{field}={content}\0", field = field, content = content)
|
||||
};
|
||||
|
||||
write!(
|
||||
&mut self.buffer,
|
||||
"
|
||||
{cfg}
|
||||
#[doc(hidden)]
|
||||
#[link_section = \".modinfo\"]
|
||||
#[used]
|
||||
pub static __{module}_{counter}: [u8; {length}] = *{string};
|
||||
",
|
||||
cfg = if builtin {
|
||||
"#[cfg(not(MODULE))]"
|
||||
} else {
|
||||
"#[cfg(MODULE)]"
|
||||
},
|
||||
module = self.module.to_uppercase(),
|
||||
counter = self.counter,
|
||||
length = string.len(),
|
||||
string = Literal::byte_string(string.as_bytes()),
|
||||
)
|
||||
.unwrap();
|
||||
|
||||
self.counter += 1;
|
||||
}
|
||||
|
||||
fn emit_only_builtin(&mut self, field: &str, content: &str) {
|
||||
self.emit_base(field, content, true)
|
||||
}
|
||||
|
||||
fn emit_only_loadable(&mut self, field: &str, content: &str) {
|
||||
self.emit_base(field, content, false)
|
||||
}
|
||||
|
||||
fn emit(&mut self, field: &str, content: &str) {
|
||||
self.emit_only_builtin(field, content);
|
||||
self.emit_only_loadable(field, content);
|
||||
}
|
||||
}
|
||||
|
||||
#[derive(Debug, Default)]
|
||||
struct ModuleInfo {
|
||||
type_: String,
|
||||
license: String,
|
||||
name: String,
|
||||
author: Option<String>,
|
||||
description: Option<String>,
|
||||
alias: Option<String>,
|
||||
}
|
||||
|
||||
impl ModuleInfo {
|
||||
fn parse(it: &mut token_stream::IntoIter) -> Self {
|
||||
let mut info = ModuleInfo::default();
|
||||
|
||||
const EXPECTED_KEYS: &[&str] =
|
||||
&["type", "name", "author", "description", "license", "alias"];
|
||||
const REQUIRED_KEYS: &[&str] = &["type", "name", "license"];
|
||||
let mut seen_keys = Vec::new();
|
||||
|
||||
loop {
|
||||
let key = match it.next() {
|
||||
Some(TokenTree::Ident(ident)) => ident.to_string(),
|
||||
Some(_) => panic!("Expected Ident or end"),
|
||||
None => break,
|
||||
};
|
||||
|
||||
if seen_keys.contains(&key) {
|
||||
panic!(
|
||||
"Duplicated key \"{}\". Keys can only be specified once.",
|
||||
key
|
||||
);
|
||||
}
|
||||
|
||||
assert_eq!(expect_punct(it), ':');
|
||||
|
||||
match key.as_str() {
|
||||
"type" => info.type_ = expect_ident(it),
|
||||
"name" => info.name = expect_byte_string(it),
|
||||
"author" => info.author = Some(expect_byte_string(it)),
|
||||
"description" => info.description = Some(expect_byte_string(it)),
|
||||
"license" => info.license = expect_byte_string(it),
|
||||
"alias" => info.alias = Some(expect_byte_string(it)),
|
||||
_ => panic!(
|
||||
"Unknown key \"{}\". Valid keys are: {:?}.",
|
||||
key, EXPECTED_KEYS
|
||||
),
|
||||
}
|
||||
|
||||
assert_eq!(expect_punct(it), ',');
|
||||
|
||||
seen_keys.push(key);
|
||||
}
|
||||
|
||||
expect_end(it);
|
||||
|
||||
for key in REQUIRED_KEYS {
|
||||
if !seen_keys.iter().any(|e| e == key) {
|
||||
panic!("Missing required key \"{}\".", key);
|
||||
}
|
||||
}
|
||||
|
||||
let mut ordered_keys: Vec<&str> = Vec::new();
|
||||
for key in EXPECTED_KEYS {
|
||||
if seen_keys.iter().any(|e| e == key) {
|
||||
ordered_keys.push(key);
|
||||
}
|
||||
}
|
||||
|
||||
if seen_keys != ordered_keys {
|
||||
panic!(
|
||||
"Keys are not ordered as expected. Order them like: {:?}.",
|
||||
ordered_keys
|
||||
);
|
||||
}
|
||||
|
||||
info
|
||||
}
|
||||
}
|
||||
|
||||
pub(crate) fn module(ts: TokenStream) -> TokenStream {
|
||||
let mut it = ts.into_iter();
|
||||
|
||||
let info = ModuleInfo::parse(&mut it);
|
||||
|
||||
let mut modinfo = ModInfoBuilder::new(info.name.as_ref());
|
||||
if let Some(author) = info.author {
|
||||
modinfo.emit("author", &author);
|
||||
}
|
||||
if let Some(description) = info.description {
|
||||
modinfo.emit("description", &description);
|
||||
}
|
||||
modinfo.emit("license", &info.license);
|
||||
if let Some(alias) = info.alias {
|
||||
modinfo.emit("alias", &alias);
|
||||
}
|
||||
|
||||
// Built-in modules also export the `file` modinfo string.
|
||||
let file =
|
||||
std::env::var("RUST_MODFILE").expect("Unable to fetch RUST_MODFILE environmental variable");
|
||||
modinfo.emit_only_builtin("file", &file);
|
||||
|
||||
format!(
|
||||
"
|
||||
/// The module name.
|
||||
///
|
||||
/// Used by the printing macros, e.g. [`info!`].
|
||||
const __LOG_PREFIX: &[u8] = b\"{name}\\0\";
|
||||
|
||||
/// The \"Rust loadable module\" mark, for `scripts/is_rust_module.sh`.
|
||||
//
|
||||
// This may be best done another way later on, e.g. as a new modinfo
|
||||
// key or a new section. For the moment, keep it simple.
|
||||
#[cfg(MODULE)]
|
||||
#[doc(hidden)]
|
||||
#[used]
|
||||
static __IS_RUST_MODULE: () = ();
|
||||
|
||||
static mut __MOD: Option<{type_}> = None;
|
||||
|
||||
// SAFETY: `__this_module` is constructed by the kernel at load time and will not be
|
||||
// freed until the module is unloaded.
|
||||
#[cfg(MODULE)]
|
||||
static THIS_MODULE: kernel::ThisModule = unsafe {{
|
||||
kernel::ThisModule::from_ptr(&kernel::bindings::__this_module as *const _ as *mut _)
|
||||
}};
|
||||
#[cfg(not(MODULE))]
|
||||
static THIS_MODULE: kernel::ThisModule = unsafe {{
|
||||
kernel::ThisModule::from_ptr(core::ptr::null_mut())
|
||||
}};
|
||||
|
||||
// Loadable modules need to export the `{{init,cleanup}}_module` identifiers.
|
||||
#[cfg(MODULE)]
|
||||
#[doc(hidden)]
|
||||
#[no_mangle]
|
||||
pub extern \"C\" fn init_module() -> core::ffi::c_int {{
|
||||
__init()
|
||||
}}
|
||||
|
||||
#[cfg(MODULE)]
|
||||
#[doc(hidden)]
|
||||
#[no_mangle]
|
||||
pub extern \"C\" fn cleanup_module() {{
|
||||
__exit()
|
||||
}}
|
||||
|
||||
// Built-in modules are initialized through an initcall pointer
|
||||
// and the identifiers need to be unique.
|
||||
#[cfg(not(MODULE))]
|
||||
#[cfg(not(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS))]
|
||||
#[doc(hidden)]
|
||||
#[link_section = \"{initcall_section}\"]
|
||||
#[used]
|
||||
pub static __{name}_initcall: extern \"C\" fn() -> core::ffi::c_int = __{name}_init;
|
||||
|
||||
#[cfg(not(MODULE))]
|
||||
#[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)]
|
||||
core::arch::global_asm!(
|
||||
r#\".section \"{initcall_section}\", \"a\"
|
||||
__{name}_initcall:
|
||||
.long __{name}_init - .
|
||||
.previous
|
||||
\"#
|
||||
);
|
||||
|
||||
#[cfg(not(MODULE))]
|
||||
#[doc(hidden)]
|
||||
#[no_mangle]
|
||||
pub extern \"C\" fn __{name}_init() -> core::ffi::c_int {{
|
||||
__init()
|
||||
}}
|
||||
|
||||
#[cfg(not(MODULE))]
|
||||
#[doc(hidden)]
|
||||
#[no_mangle]
|
||||
pub extern \"C\" fn __{name}_exit() {{
|
||||
__exit()
|
||||
}}
|
||||
|
||||
fn __init() -> core::ffi::c_int {{
|
||||
match <{type_} as kernel::Module>::init(&THIS_MODULE) {{
|
||||
Ok(m) => {{
|
||||
unsafe {{
|
||||
__MOD = Some(m);
|
||||
}}
|
||||
return 0;
|
||||
}}
|
||||
Err(e) => {{
|
||||
return e.to_kernel_errno();
|
||||
}}
|
||||
}}
|
||||
}}
|
||||
|
||||
fn __exit() {{
|
||||
unsafe {{
|
||||
// Invokes `drop()` on `__MOD`, which should be used for cleanup.
|
||||
__MOD = None;
|
||||
}}
|
||||
}}
|
||||
|
||||
{modinfo}
|
||||
",
|
||||
type_ = info.type_,
|
||||
name = info.name,
|
||||
modinfo = modinfo.buffer,
|
||||
initcall_section = ".initcall6.init"
|
||||
)
|
||||
.parse()
|
||||
.expect("Error parsing formatted string into token stream.")
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user