diff options
Diffstat (limited to 'rust/macros')
| -rw-r--r-- | rust/macros/concat_idents.rs | 23 | ||||
| -rw-r--r-- | rust/macros/export.rs | 29 | ||||
| -rw-r--r-- | rust/macros/fmt.rs | 94 | ||||
| -rw-r--r-- | rust/macros/helpers.rs | 130 | ||||
| -rw-r--r-- | rust/macros/kunit.rs | 206 | ||||
| -rw-r--r-- | rust/macros/lib.rs | 477 | ||||
| -rw-r--r-- | rust/macros/module.rs | 545 | ||||
| -rw-r--r-- | rust/macros/paste.rs | 113 | ||||
| -rw-r--r-- | rust/macros/quote.rs | 182 | ||||
| -rw-r--r-- | rust/macros/vtable.rs | 96 |
10 files changed, 1895 insertions, 0 deletions
diff --git a/rust/macros/concat_idents.rs b/rust/macros/concat_idents.rs new file mode 100644 index 000000000000..7e4b450f3a50 --- /dev/null +++ b/rust/macros/concat_idents.rs @@ -0,0 +1,23 @@ +// SPDX-License-Identifier: GPL-2.0 + +use proc_macro::{token_stream, Ident, TokenStream, TokenTree}; + +use crate::helpers::expect_punct; + +fn expect_ident(it: &mut token_stream::IntoIter) -> Ident { + if let Some(TokenTree::Ident(ident)) = it.next() { + ident + } else { + panic!("Expected Ident") + } +} + +pub(crate) fn concat_idents(ts: TokenStream) -> TokenStream { + let mut it = ts.into_iter(); + let a = expect_ident(&mut it); + assert_eq!(expect_punct(&mut it), ','); + let b = expect_ident(&mut it); + assert!(it.next().is_none(), "only two idents can be concatenated"); + let res = Ident::new(&format!("{a}{b}"), b.span()); + TokenStream::from_iter([TokenTree::Ident(res)]) +} diff --git a/rust/macros/export.rs b/rust/macros/export.rs new file mode 100644 index 000000000000..a08f6337d5c8 --- /dev/null +++ b/rust/macros/export.rs @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0 + +use crate::helpers::function_name; +use proc_macro::TokenStream; + +/// Please see [`crate::export`] for documentation. +pub(crate) fn export(_attr: TokenStream, ts: TokenStream) -> TokenStream { + let Some(name) = function_name(ts.clone()) else { + return "::core::compile_error!(\"The #[export] attribute must be used on a function.\");" + .parse::<TokenStream>() + .unwrap(); + }; + + // This verifies that the function has the same signature as the declaration generated by + // bindgen. It makes use of the fact that all branches of an if/else must have the same type. + let signature_check = quote!( + const _: () = { + if true { + ::kernel::bindings::#name + } else { + #name + }; + }; + ); + + let no_mangle = quote!(#[no_mangle]); + + TokenStream::from_iter([signature_check, no_mangle, ts]) +} diff --git a/rust/macros/fmt.rs b/rust/macros/fmt.rs new file mode 100644 index 000000000000..2f4b9f6e2211 --- /dev/null +++ b/rust/macros/fmt.rs @@ -0,0 +1,94 @@ +// SPDX-License-Identifier: GPL-2.0 + +use proc_macro::{Ident, TokenStream, TokenTree}; +use std::collections::BTreeSet; + +/// Please see [`crate::fmt`] for documentation. +pub(crate) fn fmt(input: TokenStream) -> TokenStream { + let mut input = input.into_iter(); + + let first_opt = input.next(); + let first_owned_str; + let mut names = BTreeSet::new(); + let first_span = { + let Some((mut first_str, first_span)) = (match first_opt.as_ref() { + Some(TokenTree::Literal(first_lit)) => { + first_owned_str = first_lit.to_string(); + Some(first_owned_str.as_str()).and_then(|first| { + let first = first.strip_prefix('"')?; + let first = first.strip_suffix('"')?; + Some((first, first_lit.span())) + }) + } + _ => None, + }) else { + return first_opt.into_iter().chain(input).collect(); + }; + + // Parse `identifier`s from the format string. + // + // See https://doc.rust-lang.org/std/fmt/index.html#syntax. + while let Some((_, rest)) = first_str.split_once('{') { + first_str = rest; + if let Some(rest) = first_str.strip_prefix('{') { + first_str = rest; + continue; + } + if let Some((name, rest)) = first_str.split_once('}') { + first_str = rest; + let name = name.split_once(':').map_or(name, |(name, _)| name); + if !name.is_empty() && !name.chars().all(|c| c.is_ascii_digit()) { + names.insert(name); + } + } + } + first_span + }; + + let adapter = quote_spanned!(first_span => ::kernel::fmt::Adapter); + + let mut args = TokenStream::from_iter(first_opt); + { + let mut flush = |args: &mut TokenStream, current: &mut TokenStream| { + let current = std::mem::take(current); + if !current.is_empty() { + let (lhs, rhs) = (|| { + let mut current = current.into_iter(); + let mut acc = TokenStream::new(); + while let Some(tt) = current.next() { + // Split on `=` only once to handle cases like `a = b = c`. + if matches!(&tt, TokenTree::Punct(p) if p.as_char() == '=') { + names.remove(acc.to_string().as_str()); + // Include the `=` itself to keep the handling below uniform. + acc.extend([tt]); + return (Some(acc), current.collect::<TokenStream>()); + } + acc.extend([tt]); + } + (None, acc) + })(); + args.extend(quote_spanned!(first_span => #lhs #adapter(&#rhs))); + } + }; + + let mut current = TokenStream::new(); + for tt in input { + match &tt { + TokenTree::Punct(p) if p.as_char() == ',' => { + flush(&mut args, &mut current); + &mut args + } + _ => &mut current, + } + .extend([tt]); + } + flush(&mut args, &mut current); + } + + for name in names { + let name = Ident::new(name, first_span); + args.extend(quote_spanned!(first_span => , #name = #adapter(&#name))); + } + + quote_spanned!(first_span => ::core::format_args!(#args)) +} diff --git a/rust/macros/helpers.rs b/rust/macros/helpers.rs new file mode 100644 index 000000000000..365d7eb499c0 --- /dev/null +++ b/rust/macros/helpers.rs @@ -0,0 +1,130 @@ +// SPDX-License-Identifier: GPL-2.0 + +use proc_macro::{token_stream, Group, Ident, TokenStream, 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_sign(it: &mut token_stream::IntoIter) -> Option<char> { + let peek = it.clone().next(); + match peek { + Some(TokenTree::Punct(punct)) if punct.as_char() == '-' => { + let _ = it.next(); + Some(punct.as_char()) + } + _ => 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_string(it: &mut token_stream::IntoIter) -> Option<String> { + try_literal(it).and_then(|string| { + if string.starts_with('\"') && string.ends_with('\"') { + let content = &string[1..string.len() - 1]; + if content.contains('\\') { + panic!("Escape sequences in string literals not yet handled"); + } + Some(content.to_string()) + } else if string.starts_with("r\"") { + panic!("Raw string literals are not yet handled"); + } 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_string(it: &mut token_stream::IntoIter) -> String { + try_string(it).expect("Expected string") +} + +pub(crate) fn expect_string_ascii(it: &mut token_stream::IntoIter) -> String { + let string = try_string(it).expect("Expected string"); + assert!(string.is_ascii(), "Expected ASCII string"); + string +} + +pub(crate) fn expect_group(it: &mut token_stream::IntoIter) -> Group { + if let TokenTree::Group(group) = it.next().expect("Reached end of token stream for Group") { + group + } else { + panic!("Expected Group"); + } +} + +pub(crate) fn expect_end(it: &mut token_stream::IntoIter) { + if it.next().is_some() { + panic!("Expected end"); + } +} + +/// Given a function declaration, finds the name of the function. +pub(crate) fn function_name(input: TokenStream) -> Option<Ident> { + let mut input = input.into_iter(); + while let Some(token) = input.next() { + match token { + TokenTree::Ident(i) if i.to_string() == "fn" => { + if let Some(TokenTree::Ident(i)) = input.next() { + return Some(i); + } + return None; + } + _ => continue, + } + } + None +} + +pub(crate) fn file() -> String { + #[cfg(not(CONFIG_RUSTC_HAS_SPAN_FILE))] + { + proc_macro::Span::call_site() + .source_file() + .path() + .to_string_lossy() + .into_owned() + } + + #[cfg(CONFIG_RUSTC_HAS_SPAN_FILE)] + #[allow(clippy::incompatible_msrv)] + { + proc_macro::Span::call_site().file() + } +} + +/// Parse a token stream of the form `expected_name: "value",` and return the +/// string in the position of "value". +/// +/// # Panics +/// +/// - On parse error. +pub(crate) fn expect_string_field(it: &mut token_stream::IntoIter, expected_name: &str) -> String { + assert_eq!(expect_ident(it), expected_name); + assert_eq!(expect_punct(it), ':'); + let string = expect_string(it); + assert_eq!(expect_punct(it), ','); + string +} diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs new file mode 100644 index 000000000000..b395bb053695 --- /dev/null +++ b/rust/macros/kunit.rs @@ -0,0 +1,206 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Procedural macro to run KUnit tests using a user-space like syntax. +//! +//! Copyright (c) 2023 José Expósito <jose.exposito89@gmail.com> + +use proc_macro::{Delimiter, Group, TokenStream, TokenTree}; +use std::collections::HashMap; +use std::fmt::Write; + +pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream { + let attr = attr.to_string(); + + if attr.is_empty() { + panic!("Missing test name in `#[kunit_tests(test_name)]` macro") + } + + if attr.len() > 255 { + panic!("The test suite name `{attr}` exceeds the maximum length of 255 bytes") + } + + let mut tokens: Vec<_> = ts.into_iter().collect(); + + // Scan for the `mod` keyword. + tokens + .iter() + .find_map(|token| match token { + TokenTree::Ident(ident) => match ident.to_string().as_str() { + "mod" => Some(true), + _ => None, + }, + _ => None, + }) + .expect("`#[kunit_tests(test_name)]` attribute should only be applied to modules"); + + // Retrieve the main body. The main body should be the last token tree. + let body = match tokens.pop() { + Some(TokenTree::Group(group)) if group.delimiter() == Delimiter::Brace => group, + _ => panic!("Cannot locate main body of module"), + }; + + // Get the functions set as tests. Search for `[test]` -> `fn`. + let mut body_it = body.stream().into_iter(); + let mut tests = Vec::new(); + let mut attributes: HashMap<String, TokenStream> = HashMap::new(); + while let Some(token) = body_it.next() { + match token { + TokenTree::Punct(ref p) if p.as_char() == '#' => match body_it.next() { + Some(TokenTree::Group(g)) if g.delimiter() == Delimiter::Bracket => { + if let Some(TokenTree::Ident(name)) = g.stream().into_iter().next() { + // Collect attributes because we need to find which are tests. We also + // need to copy `cfg` attributes so tests can be conditionally enabled. + attributes + .entry(name.to_string()) + .or_default() + .extend([token, TokenTree::Group(g)]); + } + continue; + } + _ => (), + }, + TokenTree::Ident(i) if i.to_string() == "fn" && attributes.contains_key("test") => { + if let Some(TokenTree::Ident(test_name)) = body_it.next() { + tests.push((test_name, attributes.remove("cfg").unwrap_or_default())) + } + } + + _ => (), + } + attributes.clear(); + } + + // Add `#[cfg(CONFIG_KUNIT="y")]` before the module declaration. + let config_kunit = "#[cfg(CONFIG_KUNIT=\"y\")]".to_owned().parse().unwrap(); + tokens.insert( + 0, + TokenTree::Group(Group::new(Delimiter::None, config_kunit)), + ); + + // Generate the test KUnit test suite and a test case for each `#[test]`. + // The code generated for the following test module: + // + // ``` + // #[kunit_tests(kunit_test_suit_name)] + // mod tests { + // #[test] + // fn foo() { + // assert_eq!(1, 1); + // } + // + // #[test] + // fn bar() { + // assert_eq!(2, 2); + // } + // } + // ``` + // + // Looks like: + // + // ``` + // unsafe extern "C" fn kunit_rust_wrapper_foo(_test: *mut ::kernel::bindings::kunit) { foo(); } + // unsafe extern "C" fn kunit_rust_wrapper_bar(_test: *mut ::kernel::bindings::kunit) { bar(); } + // + // static mut TEST_CASES: [::kernel::bindings::kunit_case; 3] = [ + // ::kernel::kunit::kunit_case(::kernel::c_str!("foo"), kunit_rust_wrapper_foo), + // ::kernel::kunit::kunit_case(::kernel::c_str!("bar"), kunit_rust_wrapper_bar), + // ::kernel::kunit::kunit_case_null(), + // ]; + // + // ::kernel::kunit_unsafe_test_suite!(kunit_test_suit_name, TEST_CASES); + // ``` + let mut kunit_macros = "".to_owned(); + let mut test_cases = "".to_owned(); + let mut assert_macros = "".to_owned(); + let path = crate::helpers::file(); + let num_tests = tests.len(); + for (test, cfg_attr) in tests { + let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{test}"); + // Append any `cfg` attributes the user might have written on their tests so we don't + // attempt to call them when they are `cfg`'d out. An extra `use` is used here to reduce + // the length of the assert message. + let kunit_wrapper = format!( + r#"unsafe extern "C" fn {kunit_wrapper_fn_name}(_test: *mut ::kernel::bindings::kunit) + {{ + (*_test).status = ::kernel::bindings::kunit_status_KUNIT_SKIPPED; + {cfg_attr} {{ + (*_test).status = ::kernel::bindings::kunit_status_KUNIT_SUCCESS; + use ::kernel::kunit::is_test_result_ok; + assert!(is_test_result_ok({test}())); + }} + }}"#, + ); + writeln!(kunit_macros, "{kunit_wrapper}").unwrap(); + writeln!( + test_cases, + " ::kernel::kunit::kunit_case(::kernel::c_str!(\"{test}\"), {kunit_wrapper_fn_name})," + ) + .unwrap(); + writeln!( + assert_macros, + r#" +/// Overrides the usual [`assert!`] macro with one that calls KUnit instead. +#[allow(unused)] +macro_rules! assert {{ + ($cond:expr $(,)?) => {{{{ + kernel::kunit_assert!("{test}", "{path}", 0, $cond); + }}}} +}} + +/// Overrides the usual [`assert_eq!`] macro with one that calls KUnit instead. +#[allow(unused)] +macro_rules! assert_eq {{ + ($left:expr, $right:expr $(,)?) => {{{{ + kernel::kunit_assert_eq!("{test}", "{path}", 0, $left, $right); + }}}} +}} + "# + ) + .unwrap(); + } + + writeln!(kunit_macros).unwrap(); + writeln!( + kunit_macros, + "static mut TEST_CASES: [::kernel::bindings::kunit_case; {}] = [\n{test_cases} ::kernel::kunit::kunit_case_null(),\n];", + num_tests + 1 + ) + .unwrap(); + + writeln!( + kunit_macros, + "::kernel::kunit_unsafe_test_suite!({attr}, TEST_CASES);" + ) + .unwrap(); + + // Remove the `#[test]` macros. + // We do this at a token level, in order to preserve span information. + let mut new_body = vec![]; + let mut body_it = body.stream().into_iter(); + + while let Some(token) = body_it.next() { + match token { + TokenTree::Punct(ref c) if c.as_char() == '#' => match body_it.next() { + Some(TokenTree::Group(group)) if group.to_string() == "[test]" => (), + Some(next) => { + new_body.extend([token, next]); + } + _ => { + new_body.push(token); + } + }, + _ => { + new_body.push(token); + } + } + } + + let mut final_body = TokenStream::new(); + final_body.extend::<TokenStream>(assert_macros.parse().unwrap()); + final_body.extend(new_body); + final_body.extend::<TokenStream>(kunit_macros.parse().unwrap()); + + tokens.push(TokenTree::Group(Group::new(Delimiter::Brace, final_body))); + + tokens.into_iter().collect() +} diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs new file mode 100644 index 000000000000..b38002151871 --- /dev/null +++ b/rust/macros/lib.rs @@ -0,0 +1,477 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Crate for all kernel procedural macros. + +// When fixdep scans this, it will find this string `CONFIG_RUSTC_VERSION_TEXT` +// and thus add a dependency on `include/config/RUSTC_VERSION_TEXT`, which is +// touched by Kconfig when the version string from the compiler changes. + +// Stable since Rust 1.88.0 under a different name, `proc_macro_span_file`, +// which was added in Rust 1.88.0. This is why `cfg_attr` is used here, i.e. +// to avoid depending on the full `proc_macro_span` on Rust >= 1.88.0. +#![cfg_attr(not(CONFIG_RUSTC_HAS_SPAN_FILE), feature(proc_macro_span))] + +#[macro_use] +mod quote; +mod concat_idents; +mod export; +mod fmt; +mod helpers; +mod kunit; +mod module; +mod paste; +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. +/// +/// The `params` field describe module parameters. Each entry has the form +/// +/// ```ignore +/// parameter_name: type { +/// default: default_value, +/// description: "Description", +/// } +/// ``` +/// +/// `type` may be one of +/// +/// - [`i8`] +/// - [`u8`] +/// - [`i8`] +/// - [`u8`] +/// - [`i16`] +/// - [`u16`] +/// - [`i32`] +/// - [`u32`] +/// - [`i64`] +/// - [`u64`] +/// - [`isize`] +/// - [`usize`] +/// +/// C header: [`include/linux/moduleparam.h`](srctree/include/linux/moduleparam.h) +/// +/// [`Module`]: ../kernel/trait.Module.html +/// +/// # Examples +/// +/// ``` +/// use kernel::prelude::*; +/// +/// module!{ +/// type: MyModule, +/// name: "my_kernel_module", +/// authors: ["Rust for Linux Contributors"], +/// description: "My very own kernel module!", +/// license: "GPL", +/// alias: ["alternate_module_name"], +/// params: { +/// my_parameter: i64 { +/// default: 1, +/// description: "This parameter has a default of 1", +/// }, +/// }, +/// } +/// +/// struct MyModule(i32); +/// +/// impl kernel::Module for MyModule { +/// fn init(_module: &'static ThisModule) -> Result<Self> { +/// let foo: i32 = 42; +/// pr_info!("I contain: {}\n", foo); +/// pr_info!("i32 param is: {}\n", module_parameters::my_parameter.read()); +/// Ok(Self(foo)) +/// } +/// } +/// # fn main() {} +/// ``` +/// +/// ## Firmware +/// +/// The following example shows how to declare a kernel module that needs +/// to load binary firmware files. You need to specify the file names of +/// the firmware in the `firmware` field. The information is embedded +/// in the `modinfo` section of the kernel module. For example, a tool to +/// build an initramfs uses this information to put the firmware files into +/// the initramfs image. +/// +/// ``` +/// use kernel::prelude::*; +/// +/// module!{ +/// type: MyDeviceDriverModule, +/// name: "my_device_driver_module", +/// authors: ["Rust for Linux Contributors"], +/// description: "My device driver requires firmware", +/// license: "GPL", +/// firmware: ["my_device_firmware1.bin", "my_device_firmware2.bin"], +/// } +/// +/// struct MyDeviceDriverModule; +/// +/// impl kernel::Module for MyDeviceDriverModule { +/// fn init(_module: &'static ThisModule) -> Result<Self> { +/// Ok(Self) +/// } +/// } +/// # fn main() {} +/// ``` +/// +/// # Supported argument types +/// - `type`: type which implements the [`Module`] trait (required). +/// - `name`: ASCII string literal of the name of the kernel module (required). +/// - `authors`: array of ASCII string literals of the authors of the kernel module. +/// - `description`: string literal of the description of the kernel module. +/// - `license`: ASCII string literal of the license of the kernel module (required). +/// - `alias`: array of ASCII string literals of the alias names of the kernel module. +/// - `firmware`: array of ASCII string literals of the firmware files 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 closes that gap. A trait can be annotated with the +/// `#[vtable]` attribute. Implementers of the trait will then also have to +/// annotate the trait with `#[vtable]`. This attribute generates a `HAS_*` +/// associated constant bool for each method in the trait that is set to true if +/// the implementer has overridden the associated method. +/// +/// For a trait method to be optional, it must have a default implementation. +/// This is also the case for traits annotated with `#[vtable]`, but in this +/// case the default implementation will never be executed. The reason for this +/// is that the functions will be called through function pointers installed in +/// C side vtables. When an optional method is not implemented on a `#[vtable]` +/// trait, a NULL entry is installed in the vtable. Thus the default +/// implementation is never called. Since these traits are not designed to be +/// used on the Rust side, it should not be possible to call the default +/// implementation. This is done to ensure that we call the vtable methods +/// through the C vtable, and not through the Rust vtable. Therefore, the +/// default implementation should call `build_error!`, which prevents +/// calls to this function at compile time: +/// +/// ```compile_fail +/// # // Intentionally missing `use`s to simplify `rusttest`. +/// build_error!(VTABLE_DEFAULT_ERROR) +/// ``` +/// +/// Note that you might need to import [`kernel::error::VTABLE_DEFAULT_ERROR`]. +/// +/// This macro should not be used when all functions are required. +/// +/// # Examples +/// +/// ``` +/// use kernel::error::VTABLE_DEFAULT_ERROR; +/// use kernel::prelude::*; +/// +/// // Declares a `#[vtable]` trait +/// #[vtable] +/// pub trait Operations: Send + Sync + Sized { +/// fn foo(&self) -> Result<()> { +/// build_error!(VTABLE_DEFAULT_ERROR) +/// } +/// +/// fn bar(&self) -> Result<()> { +/// build_error!(VTABLE_DEFAULT_ERROR) +/// } +/// } +/// +/// 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); +/// ``` +/// +/// [`kernel::error::VTABLE_DEFAULT_ERROR`]: ../kernel/error/constant.VTABLE_DEFAULT_ERROR.html +#[proc_macro_attribute] +pub fn vtable(attr: TokenStream, ts: TokenStream) -> TokenStream { + vtable::vtable(attr, ts) +} + +/// Export a function so that C code can call it via a header file. +/// +/// Functions exported using this macro can be called from C code using the declaration in the +/// appropriate header file. It should only be used in cases where C calls the function through a +/// header file; cases where C calls into Rust via a function pointer in a vtable (such as +/// `file_operations`) should not use this macro. +/// +/// This macro has the following effect: +/// +/// * Disables name mangling for this function. +/// * Verifies at compile-time that the function signature matches the declaration in the header +/// file. +/// +/// You must declare the signature of the Rust function in a header file that is included by +/// `rust/bindings/bindings_helper.h`. +/// +/// This macro is *not* the same as the C macros `EXPORT_SYMBOL_*`. All Rust symbols are currently +/// automatically exported with `EXPORT_SYMBOL_GPL`. +#[proc_macro_attribute] +pub fn export(attr: TokenStream, ts: TokenStream) -> TokenStream { + export::export(attr, ts) +} + +/// Like [`core::format_args!`], but automatically wraps arguments in [`kernel::fmt::Adapter`]. +/// +/// This macro allows generating `fmt::Arguments` while ensuring that each argument is wrapped with +/// `::kernel::fmt::Adapter`, which customizes formatting behavior for kernel logging. +/// +/// Named arguments used in the format string (e.g. `{foo}`) are detected and resolved from local +/// bindings. All positional and named arguments are automatically wrapped. +/// +/// This macro is an implementation detail of other kernel logging macros like [`pr_info!`] and +/// should not typically be used directly. +/// +/// [`kernel::fmt::Adapter`]: ../kernel/fmt/struct.Adapter.html +/// [`pr_info!`]: ../kernel/macro.pr_info.html +#[proc_macro] +pub fn fmt(input: TokenStream) -> TokenStream { + fmt::fmt(input) +} + +/// 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 +/// +/// ``` +/// # const binder_driver_return_protocol_BR_OK: u32 = 0; +/// # const binder_driver_return_protocol_BR_ERROR: u32 = 1; +/// # const binder_driver_return_protocol_BR_TRANSACTION: u32 = 2; +/// # const binder_driver_return_protocol_BR_REPLY: u32 = 3; +/// # const binder_driver_return_protocol_BR_DEAD_REPLY: u32 = 4; +/// # const binder_driver_return_protocol_BR_TRANSACTION_COMPLETE: u32 = 5; +/// # const binder_driver_return_protocol_BR_INCREFS: u32 = 6; +/// # const binder_driver_return_protocol_BR_ACQUIRE: u32 = 7; +/// # const binder_driver_return_protocol_BR_RELEASE: u32 = 8; +/// # const binder_driver_return_protocol_BR_DECREFS: u32 = 9; +/// # const binder_driver_return_protocol_BR_NOOP: u32 = 10; +/// # const binder_driver_return_protocol_BR_SPAWN_LOOPER: u32 = 11; +/// # const binder_driver_return_protocol_BR_DEAD_BINDER: u32 = 12; +/// # const binder_driver_return_protocol_BR_CLEAR_DEATH_NOTIFICATION_DONE: u32 = 13; +/// # const binder_driver_return_protocol_BR_FAILED_REPLY: u32 = 14; +/// use kernel::macros::concat_idents; +/// +/// macro_rules! pub_no_prefix { +/// ($prefix:ident, $($newname:ident),+) => { +/// $(pub(crate) const $newname: u32 = concat_idents!($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) +} + +/// Paste identifiers together. +/// +/// Within the `paste!` macro, identifiers inside `[<` and `>]` are concatenated together to form a +/// single identifier. +/// +/// This is similar to the [`paste`] crate, but with pasting feature limited to identifiers and +/// literals (lifetimes and documentation strings are not supported). There is a difference in +/// supported modifiers as well. +/// +/// # Examples +/// +/// ``` +/// # const binder_driver_return_protocol_BR_OK: u32 = 0; +/// # const binder_driver_return_protocol_BR_ERROR: u32 = 1; +/// # const binder_driver_return_protocol_BR_TRANSACTION: u32 = 2; +/// # const binder_driver_return_protocol_BR_REPLY: u32 = 3; +/// # const binder_driver_return_protocol_BR_DEAD_REPLY: u32 = 4; +/// # const binder_driver_return_protocol_BR_TRANSACTION_COMPLETE: u32 = 5; +/// # const binder_driver_return_protocol_BR_INCREFS: u32 = 6; +/// # const binder_driver_return_protocol_BR_ACQUIRE: u32 = 7; +/// # const binder_driver_return_protocol_BR_RELEASE: u32 = 8; +/// # const binder_driver_return_protocol_BR_DECREFS: u32 = 9; +/// # const binder_driver_return_protocol_BR_NOOP: u32 = 10; +/// # const binder_driver_return_protocol_BR_SPAWN_LOOPER: u32 = 11; +/// # const binder_driver_return_protocol_BR_DEAD_BINDER: u32 = 12; +/// # const binder_driver_return_protocol_BR_CLEAR_DEATH_NOTIFICATION_DONE: u32 = 13; +/// # const binder_driver_return_protocol_BR_FAILED_REPLY: u32 = 14; +/// macro_rules! pub_no_prefix { +/// ($prefix:ident, $($newname:ident),+) => { +/// ::kernel::macros::paste! { +/// $(pub(crate) const $newname: u32 = [<$prefix $newname>];)+ +/// } +/// }; +/// } +/// +/// pub_no_prefix!( +/// binder_driver_return_protocol_, +/// BR_OK, +/// BR_ERROR, +/// BR_TRANSACTION, +/// BR_REPLY, +/// BR_DEAD_REPLY, +/// BR_TRANSACTION_COMPLETE, +/// BR_INCREFS, +/// BR_ACQUIRE, +/// BR_RELEASE, +/// BR_DECREFS, +/// BR_NOOP, +/// BR_SPAWN_LOOPER, +/// BR_DEAD_BINDER, +/// BR_CLEAR_DEATH_NOTIFICATION_DONE, +/// BR_FAILED_REPLY +/// ); +/// +/// assert_eq!(BR_OK, binder_driver_return_protocol_BR_OK); +/// ``` +/// +/// # Modifiers +/// +/// For each identifier, it is possible to attach one or multiple modifiers to +/// it. +/// +/// Currently supported modifiers are: +/// * `span`: change the span of concatenated identifier to the span of the specified token. By +/// default the span of the `[< >]` group is used. +/// * `lower`: change the identifier to lower case. +/// * `upper`: change the identifier to upper case. +/// +/// ``` +/// # const binder_driver_return_protocol_BR_OK: u32 = 0; +/// # const binder_driver_return_protocol_BR_ERROR: u32 = 1; +/// # const binder_driver_return_protocol_BR_TRANSACTION: u32 = 2; +/// # const binder_driver_return_protocol_BR_REPLY: u32 = 3; +/// # const binder_driver_return_protocol_BR_DEAD_REPLY: u32 = 4; +/// # const binder_driver_return_protocol_BR_TRANSACTION_COMPLETE: u32 = 5; +/// # const binder_driver_return_protocol_BR_INCREFS: u32 = 6; +/// # const binder_driver_return_protocol_BR_ACQUIRE: u32 = 7; +/// # const binder_driver_return_protocol_BR_RELEASE: u32 = 8; +/// # const binder_driver_return_protocol_BR_DECREFS: u32 = 9; +/// # const binder_driver_return_protocol_BR_NOOP: u32 = 10; +/// # const binder_driver_return_protocol_BR_SPAWN_LOOPER: u32 = 11; +/// # const binder_driver_return_protocol_BR_DEAD_BINDER: u32 = 12; +/// # const binder_driver_return_protocol_BR_CLEAR_DEATH_NOTIFICATION_DONE: u32 = 13; +/// # const binder_driver_return_protocol_BR_FAILED_REPLY: u32 = 14; +/// macro_rules! pub_no_prefix { +/// ($prefix:ident, $($newname:ident),+) => { +/// ::kernel::macros::paste! { +/// $(pub(crate) const fn [<$newname:lower:span>]() -> u32 { [<$prefix $newname:span>] })+ +/// } +/// }; +/// } +/// +/// pub_no_prefix!( +/// binder_driver_return_protocol_, +/// BR_OK, +/// BR_ERROR, +/// BR_TRANSACTION, +/// BR_REPLY, +/// BR_DEAD_REPLY, +/// BR_TRANSACTION_COMPLETE, +/// BR_INCREFS, +/// BR_ACQUIRE, +/// BR_RELEASE, +/// BR_DECREFS, +/// BR_NOOP, +/// BR_SPAWN_LOOPER, +/// BR_DEAD_BINDER, +/// BR_CLEAR_DEATH_NOTIFICATION_DONE, +/// BR_FAILED_REPLY +/// ); +/// +/// assert_eq!(br_ok(), binder_driver_return_protocol_BR_OK); +/// ``` +/// +/// # Literals +/// +/// Literals can also be concatenated with other identifiers: +/// +/// ``` +/// macro_rules! create_numbered_fn { +/// ($name:literal, $val:literal) => { +/// ::kernel::macros::paste! { +/// fn [<some_ $name _fn $val>]() -> u32 { $val } +/// } +/// }; +/// } +/// +/// create_numbered_fn!("foo", 100); +/// +/// assert_eq!(some_foo_fn100(), 100) +/// ``` +/// +/// [`paste`]: https://docs.rs/paste/ +#[proc_macro] +pub fn paste(input: TokenStream) -> TokenStream { + let mut tokens = input.into_iter().collect(); + paste::expand(&mut tokens); + tokens.into_iter().collect() +} + +/// Registers a KUnit test suite and its test cases using a user-space like syntax. +/// +/// This macro should be used on modules. If `CONFIG_KUNIT` (in `.config`) is `n`, the target module +/// is ignored. +/// +/// # Examples +/// +/// ```ignore +/// # use kernel::prelude::*; +/// #[kunit_tests(kunit_test_suit_name)] +/// mod tests { +/// #[test] +/// fn foo() { +/// assert_eq!(1, 1); +/// } +/// +/// #[test] +/// fn bar() { +/// assert_eq!(2, 2); +/// } +/// } +/// ``` +#[proc_macro_attribute] +pub fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream { + kunit::kunit_tests(attr, ts) +} diff --git a/rust/macros/module.rs b/rust/macros/module.rs new file mode 100644 index 000000000000..80cb9b16f5aa --- /dev/null +++ b/rust/macros/module.rs @@ -0,0 +1,545 @@ +// SPDX-License-Identifier: GPL-2.0 + +use crate::helpers::*; +use proc_macro::{token_stream, Delimiter, Literal, TokenStream, TokenTree}; +use std::fmt::Write; + +fn expect_string_array(it: &mut token_stream::IntoIter) -> Vec<String> { + let group = expect_group(it); + assert_eq!(group.delimiter(), Delimiter::Bracket); + let mut values = Vec::new(); + let mut it = group.stream().into_iter(); + + while let Some(val) = try_string(&mut it) { + assert!(val.is_ascii(), "Expected ASCII string"); + values.push(val); + match it.next() { + Some(TokenTree::Punct(punct)) => assert_eq!(punct.as_char(), ','), + None => break, + _ => panic!("Expected ',' or end of array"), + } + } + values +} + +struct ModInfoBuilder<'a> { + module: &'a str, + counter: usize, + buffer: String, + param_buffer: String, +} + +impl<'a> ModInfoBuilder<'a> { + fn new(module: &'a str) -> Self { + ModInfoBuilder { + module, + counter: 0, + buffer: String::new(), + param_buffer: String::new(), + } + } + + fn emit_base(&mut self, field: &str, content: &str, builtin: bool, param: 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") + }; + + let buffer = if param { + &mut self.param_buffer + } else { + &mut self.buffer + }; + + write!( + buffer, + " + {cfg} + #[doc(hidden)] + #[cfg_attr(not(target_os = \"macos\"), link_section = \".modinfo\")] + #[used(compiler)] + 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, param: bool) { + self.emit_base(field, content, true, param) + } + + fn emit_only_loadable(&mut self, field: &str, content: &str, param: bool) { + self.emit_base(field, content, false, param) + } + + fn emit(&mut self, field: &str, content: &str) { + self.emit_internal(field, content, false); + } + + fn emit_internal(&mut self, field: &str, content: &str, param: bool) { + self.emit_only_builtin(field, content, param); + self.emit_only_loadable(field, content, param); + } + + fn emit_param(&mut self, field: &str, param: &str, content: &str) { + let content = format!("{param}:{content}", param = param, content = content); + self.emit_internal(field, &content, true); + } + + fn emit_params(&mut self, info: &ModuleInfo) { + let Some(params) = &info.params else { + return; + }; + + for param in params { + let ops = param_ops_path(¶m.ptype); + + // Note: The spelling of these fields is dictated by the user space + // tool `modinfo`. + self.emit_param("parmtype", ¶m.name, ¶m.ptype); + self.emit_param("parm", ¶m.name, ¶m.description); + + write!( + self.param_buffer, + " + pub(crate) static {param_name}: + ::kernel::module_param::ModuleParamAccess<{param_type}> = + ::kernel::module_param::ModuleParamAccess::new({param_default}); + + const _: () = {{ + #[link_section = \"__param\"] + #[used] + static __{module_name}_{param_name}_struct: + ::kernel::module_param::KernelParam = + ::kernel::module_param::KernelParam::new( + ::kernel::bindings::kernel_param {{ + name: if ::core::cfg!(MODULE) {{ + ::kernel::c_str!(\"{param_name}\").to_bytes_with_nul() + }} else {{ + ::kernel::c_str!(\"{module_name}.{param_name}\") + .to_bytes_with_nul() + }}.as_ptr(), + // SAFETY: `__this_module` is constructed by the kernel at load + // time and will not be freed until the module is unloaded. + #[cfg(MODULE)] + mod_: unsafe {{ + core::ptr::from_ref(&::kernel::bindings::__this_module) + .cast_mut() + }}, + #[cfg(not(MODULE))] + mod_: ::core::ptr::null_mut(), + ops: core::ptr::from_ref(&{ops}), + perm: 0, // Will not appear in sysfs + level: -1, + flags: 0, + __bindgen_anon_1: ::kernel::bindings::kernel_param__bindgen_ty_1 {{ + arg: {param_name}.as_void_ptr() + }}, + }} + ); + }}; + ", + module_name = info.name, + param_type = param.ptype, + param_default = param.default, + param_name = param.name, + ops = ops, + ) + .unwrap(); + } + } +} + +fn param_ops_path(param_type: &str) -> &'static str { + match param_type { + "i8" => "::kernel::module_param::PARAM_OPS_I8", + "u8" => "::kernel::module_param::PARAM_OPS_U8", + "i16" => "::kernel::module_param::PARAM_OPS_I16", + "u16" => "::kernel::module_param::PARAM_OPS_U16", + "i32" => "::kernel::module_param::PARAM_OPS_I32", + "u32" => "::kernel::module_param::PARAM_OPS_U32", + "i64" => "::kernel::module_param::PARAM_OPS_I64", + "u64" => "::kernel::module_param::PARAM_OPS_U64", + "isize" => "::kernel::module_param::PARAM_OPS_ISIZE", + "usize" => "::kernel::module_param::PARAM_OPS_USIZE", + t => panic!("Unsupported parameter type {}", t), + } +} + +fn expect_param_default(param_it: &mut token_stream::IntoIter) -> String { + assert_eq!(expect_ident(param_it), "default"); + assert_eq!(expect_punct(param_it), ':'); + let sign = try_sign(param_it); + let default = try_literal(param_it).expect("Expected default param value"); + assert_eq!(expect_punct(param_it), ','); + let mut value = sign.map(String::from).unwrap_or_default(); + value.push_str(&default); + value +} + +#[derive(Debug, Default)] +struct ModuleInfo { + type_: String, + license: String, + name: String, + authors: Option<Vec<String>>, + description: Option<String>, + alias: Option<Vec<String>>, + firmware: Option<Vec<String>>, + imports_ns: Option<Vec<String>>, + params: Option<Vec<Parameter>>, +} + +#[derive(Debug)] +struct Parameter { + name: String, + ptype: String, + default: String, + description: String, +} + +fn expect_params(it: &mut token_stream::IntoIter) -> Vec<Parameter> { + let params = expect_group(it); + assert_eq!(params.delimiter(), Delimiter::Brace); + let mut it = params.stream().into_iter(); + let mut parsed = Vec::new(); + + loop { + let param_name = match it.next() { + Some(TokenTree::Ident(ident)) => ident.to_string(), + Some(_) => panic!("Expected Ident or end"), + None => break, + }; + + assert_eq!(expect_punct(&mut it), ':'); + let param_type = expect_ident(&mut it); + let group = expect_group(&mut it); + assert_eq!(group.delimiter(), Delimiter::Brace); + assert_eq!(expect_punct(&mut it), ','); + + let mut param_it = group.stream().into_iter(); + let param_default = expect_param_default(&mut param_it); + let param_description = expect_string_field(&mut param_it, "description"); + expect_end(&mut param_it); + + parsed.push(Parameter { + name: param_name, + ptype: param_type, + default: param_default, + description: param_description, + }) + } + + parsed +} + +impl ModuleInfo { + fn parse(it: &mut token_stream::IntoIter) -> Self { + let mut info = ModuleInfo::default(); + + const EXPECTED_KEYS: &[&str] = &[ + "type", + "name", + "authors", + "description", + "license", + "alias", + "firmware", + "imports_ns", + "params", + ]; + 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 \"{key}\". Keys can only be specified once."); + } + + assert_eq!(expect_punct(it), ':'); + + match key.as_str() { + "type" => info.type_ = expect_ident(it), + "name" => info.name = expect_string_ascii(it), + "authors" => info.authors = Some(expect_string_array(it)), + "description" => info.description = Some(expect_string(it)), + "license" => info.license = expect_string_ascii(it), + "alias" => info.alias = Some(expect_string_array(it)), + "firmware" => info.firmware = Some(expect_string_array(it)), + "imports_ns" => info.imports_ns = Some(expect_string_array(it)), + "params" => info.params = Some(expect_params(it)), + _ => panic!("Unknown key \"{key}\". Valid keys are: {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); + + // Rust does not allow hyphens in identifiers, use underscore instead. + let ident = info.name.replace('-', "_"); + let mut modinfo = ModInfoBuilder::new(ident.as_ref()); + if let Some(authors) = &info.authors { + for author in authors { + modinfo.emit("author", author); + } + } + if let Some(description) = &info.description { + modinfo.emit("description", description); + } + modinfo.emit("license", &info.license); + if let Some(aliases) = &info.alias { + for alias in aliases { + modinfo.emit("alias", alias); + } + } + if let Some(firmware) = &info.firmware { + for fw in firmware { + modinfo.emit("firmware", fw); + } + } + if let Some(imports) = &info.imports_ns { + for ns in imports { + modinfo.emit("import_ns", ns); + } + } + + // 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, false); + + modinfo.emit_params(&info); + + format!( + " + /// The module name. + /// + /// Used by the printing macros, e.g. [`info!`]. + const __LOG_PREFIX: &[u8] = b\"{name}\\0\"; + + // 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 {{ + extern \"C\" {{ + static __this_module: ::kernel::types::Opaque<::kernel::bindings::module>; + }} + + ::kernel::ThisModule::from_ptr(__this_module.get()) + }}; + #[cfg(not(MODULE))] + static THIS_MODULE: ::kernel::ThisModule = unsafe {{ + ::kernel::ThisModule::from_ptr(::core::ptr::null_mut()) + }}; + + /// The `LocalModule` type is the type of the module created by `module!`, + /// `module_pci_driver!`, `module_platform_driver!`, etc. + type LocalModule = {type_}; + + impl ::kernel::ModuleMetadata for {type_} {{ + const NAME: &'static ::kernel::str::CStr = c\"{name}\"; + }} + + // Double nested modules, since then nobody can access the public items inside. + mod __module_init {{ + mod __module_init {{ + use super::super::{type_}; + use pin_init::PinInit; + + /// The \"Rust loadable module\" mark. + // + // 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(compiler)] + static __IS_RUST_MODULE: () = (); + + static mut __MOD: ::core::mem::MaybeUninit<{type_}> = + ::core::mem::MaybeUninit::uninit(); + + // Loadable modules need to export the `{{init,cleanup}}_module` identifiers. + /// # Safety + /// + /// This function must not be called after module initialization, because it may be + /// freed after that completes. + #[cfg(MODULE)] + #[doc(hidden)] + #[no_mangle] + #[link_section = \".init.text\"] + pub unsafe extern \"C\" fn init_module() -> ::kernel::ffi::c_int {{ + // SAFETY: This function is inaccessible to the outside due to the double + // module wrapping it. It is called exactly once by the C side via its + // unique name. + unsafe {{ __init() }} + }} + + #[cfg(MODULE)] + #[doc(hidden)] + #[used(compiler)] + #[link_section = \".init.data\"] + static __UNIQUE_ID___addressable_init_module: unsafe extern \"C\" fn() -> i32 = init_module; + + #[cfg(MODULE)] + #[doc(hidden)] + #[no_mangle] + #[link_section = \".exit.text\"] + pub extern \"C\" fn cleanup_module() {{ + // SAFETY: + // - This function is inaccessible to the outside due to the double + // module wrapping it. It is called exactly once by the C side via its + // unique name, + // - furthermore it is only called after `init_module` has returned `0` + // (which delegates to `__init`). + unsafe {{ __exit() }} + }} + + #[cfg(MODULE)] + #[doc(hidden)] + #[used(compiler)] + #[link_section = \".exit.data\"] + static __UNIQUE_ID___addressable_cleanup_module: extern \"C\" fn() = cleanup_module; + + // 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(compiler)] + pub static __{ident}_initcall: extern \"C\" fn() -> + ::kernel::ffi::c_int = __{ident}_init; + + #[cfg(not(MODULE))] + #[cfg(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)] + ::core::arch::global_asm!( + r#\".section \"{initcall_section}\", \"a\" + __{ident}_initcall: + .long __{ident}_init - . + .previous + \"# + ); + + #[cfg(not(MODULE))] + #[doc(hidden)] + #[no_mangle] + pub extern \"C\" fn __{ident}_init() -> ::kernel::ffi::c_int {{ + // SAFETY: This function is inaccessible to the outside due to the double + // module wrapping it. It is called exactly once by the C side via its + // placement above in the initcall section. + unsafe {{ __init() }} + }} + + #[cfg(not(MODULE))] + #[doc(hidden)] + #[no_mangle] + pub extern \"C\" fn __{ident}_exit() {{ + // SAFETY: + // - This function is inaccessible to the outside due to the double + // module wrapping it. It is called exactly once by the C side via its + // unique name, + // - furthermore it is only called after `__{ident}_init` has + // returned `0` (which delegates to `__init`). + unsafe {{ __exit() }} + }} + + /// # Safety + /// + /// This function must only be called once. + unsafe fn __init() -> ::kernel::ffi::c_int {{ + let initer = + <{type_} as ::kernel::InPlaceModule>::init(&super::super::THIS_MODULE); + // SAFETY: No data race, since `__MOD` can only be accessed by this module + // and there only `__init` and `__exit` access it. These functions are only + // called once and `__exit` cannot be called before or during `__init`. + match unsafe {{ initer.__pinned_init(__MOD.as_mut_ptr()) }} {{ + Ok(m) => 0, + Err(e) => e.to_errno(), + }} + }} + + /// # Safety + /// + /// This function must + /// - only be called once, + /// - be called after `__init` has been called and returned `0`. + unsafe fn __exit() {{ + // SAFETY: No data race, since `__MOD` can only be accessed by this module + // and there only `__init` and `__exit` access it. These functions are only + // called once and `__init` was already called. + unsafe {{ + // Invokes `drop()` on `__MOD`, which should be used for cleanup. + __MOD.assume_init_drop(); + }} + }} + {modinfo} + }} + }} + mod module_parameters {{ + {params} + }} + ", + type_ = info.type_, + name = info.name, + ident = ident, + modinfo = modinfo.buffer, + params = modinfo.param_buffer, + initcall_section = ".initcall6.init" + ) + .parse() + .expect("Error parsing formatted string into token stream.") +} diff --git a/rust/macros/paste.rs b/rust/macros/paste.rs new file mode 100644 index 000000000000..cce712d19855 --- /dev/null +++ b/rust/macros/paste.rs @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0 + +use proc_macro::{Delimiter, Group, Ident, Spacing, Span, TokenTree}; + +fn concat_helper(tokens: &[TokenTree]) -> Vec<(String, Span)> { + let mut tokens = tokens.iter(); + let mut segments = Vec::new(); + let mut span = None; + loop { + match tokens.next() { + None => break, + Some(TokenTree::Literal(lit)) => { + // Allow us to concat string literals by stripping quotes + let mut value = lit.to_string(); + if value.starts_with('"') && value.ends_with('"') { + value.remove(0); + value.pop(); + } + segments.push((value, lit.span())); + } + Some(TokenTree::Ident(ident)) => { + let mut value = ident.to_string(); + if value.starts_with("r#") { + value.replace_range(0..2, ""); + } + segments.push((value, ident.span())); + } + Some(TokenTree::Punct(p)) if p.as_char() == ':' => { + let Some(TokenTree::Ident(ident)) = tokens.next() else { + panic!("expected identifier as modifier"); + }; + + let (mut value, sp) = segments.pop().expect("expected identifier before modifier"); + match ident.to_string().as_str() { + // Set the overall span of concatenated token as current span + "span" => { + assert!( + span.is_none(), + "span modifier should only appear at most once" + ); + span = Some(sp); + } + "lower" => value = value.to_lowercase(), + "upper" => value = value.to_uppercase(), + v => panic!("unknown modifier `{v}`"), + }; + segments.push((value, sp)); + } + Some(TokenTree::Group(group)) if group.delimiter() == Delimiter::None => { + let tokens = group.stream().into_iter().collect::<Vec<TokenTree>>(); + segments.append(&mut concat_helper(tokens.as_slice())); + } + token => panic!("unexpected token in paste segments: {token:?}"), + }; + } + + segments +} + +fn concat(tokens: &[TokenTree], group_span: Span) -> TokenTree { + let segments = concat_helper(tokens); + let pasted: String = segments.into_iter().map(|x| x.0).collect(); + TokenTree::Ident(Ident::new(&pasted, group_span)) +} + +pub(crate) fn expand(tokens: &mut Vec<TokenTree>) { + for token in tokens.iter_mut() { + if let TokenTree::Group(group) = token { + let delimiter = group.delimiter(); + let span = group.span(); + let mut stream: Vec<_> = group.stream().into_iter().collect(); + // Find groups that looks like `[< A B C D >]` + if delimiter == Delimiter::Bracket + && stream.len() >= 3 + && matches!(&stream[0], TokenTree::Punct(p) if p.as_char() == '<') + && matches!(&stream[stream.len() - 1], TokenTree::Punct(p) if p.as_char() == '>') + { + // Replace the group with concatenated token + *token = concat(&stream[1..stream.len() - 1], span); + } else { + // Recursively expand tokens inside the group + expand(&mut stream); + let mut group = Group::new(delimiter, stream.into_iter().collect()); + group.set_span(span); + *token = TokenTree::Group(group); + } + } + } + + // Path segments cannot contain invisible delimiter group, so remove them if any. + for i in (0..tokens.len().saturating_sub(3)).rev() { + // Looking for a double colon + if matches!( + (&tokens[i + 1], &tokens[i + 2]), + (TokenTree::Punct(a), TokenTree::Punct(b)) + if a.as_char() == ':' && a.spacing() == Spacing::Joint && b.as_char() == ':' + ) { + match &tokens[i + 3] { + TokenTree::Group(group) if group.delimiter() == Delimiter::None => { + tokens.splice(i + 3..i + 4, group.stream()); + } + _ => (), + } + + match &tokens[i] { + TokenTree::Group(group) if group.delimiter() == Delimiter::None => { + tokens.splice(i..i + 1, group.stream()); + } + _ => (), + } + } + } +} diff --git a/rust/macros/quote.rs b/rust/macros/quote.rs new file mode 100644 index 000000000000..ddfc21577539 --- /dev/null +++ b/rust/macros/quote.rs @@ -0,0 +1,182 @@ +// SPDX-License-Identifier: Apache-2.0 OR MIT + +use proc_macro::{TokenStream, TokenTree}; + +pub(crate) trait ToTokens { + fn to_tokens(&self, tokens: &mut TokenStream); +} + +impl<T: ToTokens> ToTokens for Option<T> { + fn to_tokens(&self, tokens: &mut TokenStream) { + if let Some(v) = self { + v.to_tokens(tokens); + } + } +} + +impl ToTokens for proc_macro::Group { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.extend([TokenTree::from(self.clone())]); + } +} + +impl ToTokens for proc_macro::Ident { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.extend([TokenTree::from(self.clone())]); + } +} + +impl ToTokens for TokenTree { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.extend([self.clone()]); + } +} + +impl ToTokens for TokenStream { + fn to_tokens(&self, tokens: &mut TokenStream) { + tokens.extend(self.clone()); + } +} + +/// Converts tokens into [`proc_macro::TokenStream`] and performs variable interpolations with +/// the given span. +/// +/// This is a similar to the +/// [`quote_spanned!`](https://docs.rs/quote/latest/quote/macro.quote_spanned.html) macro from the +/// `quote` crate but provides only just enough functionality needed by the current `macros` crate. +macro_rules! quote_spanned { + ($span:expr => $($tt:tt)*) => {{ + let mut tokens = ::proc_macro::TokenStream::new(); + { + #[allow(unused_variables)] + let span = $span; + quote_spanned!(@proc tokens span $($tt)*); + } + tokens + }}; + (@proc $v:ident $span:ident) => {}; + (@proc $v:ident $span:ident #$id:ident $($tt:tt)*) => { + $crate::quote::ToTokens::to_tokens(&$id, &mut $v); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident #(#$id:ident)* $($tt:tt)*) => { + for token in $id { + $crate::quote::ToTokens::to_tokens(&token, &mut $v); + } + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident ( $($inner:tt)* ) $($tt:tt)*) => { + #[allow(unused_mut)] + let mut tokens = ::proc_macro::TokenStream::new(); + quote_spanned!(@proc tokens $span $($inner)*); + $v.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new( + ::proc_macro::Delimiter::Parenthesis, + tokens, + ))]); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident [ $($inner:tt)* ] $($tt:tt)*) => { + let mut tokens = ::proc_macro::TokenStream::new(); + quote_spanned!(@proc tokens $span $($inner)*); + $v.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new( + ::proc_macro::Delimiter::Bracket, + tokens, + ))]); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident { $($inner:tt)* } $($tt:tt)*) => { + let mut tokens = ::proc_macro::TokenStream::new(); + quote_spanned!(@proc tokens $span $($inner)*); + $v.extend([::proc_macro::TokenTree::Group(::proc_macro::Group::new( + ::proc_macro::Delimiter::Brace, + tokens, + ))]); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident :: $($tt:tt)*) => { + $v.extend([::proc_macro::Spacing::Joint, ::proc_macro::Spacing::Alone].map(|spacing| { + ::proc_macro::TokenTree::Punct(::proc_macro::Punct::new(':', spacing)) + })); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident : $($tt:tt)*) => { + $v.extend([::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new(':', ::proc_macro::Spacing::Alone), + )]); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident , $($tt:tt)*) => { + $v.extend([::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new(',', ::proc_macro::Spacing::Alone), + )]); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident @ $($tt:tt)*) => { + $v.extend([::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new('@', ::proc_macro::Spacing::Alone), + )]); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident ! $($tt:tt)*) => { + $v.extend([::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new('!', ::proc_macro::Spacing::Alone), + )]); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident ; $($tt:tt)*) => { + $v.extend([::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new(';', ::proc_macro::Spacing::Alone), + )]); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident + $($tt:tt)*) => { + $v.extend([::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new('+', ::proc_macro::Spacing::Alone), + )]); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident = $($tt:tt)*) => { + $v.extend([::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new('=', ::proc_macro::Spacing::Alone), + )]); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident # $($tt:tt)*) => { + $v.extend([::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new('#', ::proc_macro::Spacing::Alone), + )]); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident & $($tt:tt)*) => { + $v.extend([::proc_macro::TokenTree::Punct( + ::proc_macro::Punct::new('&', ::proc_macro::Spacing::Alone), + )]); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident _ $($tt:tt)*) => { + $v.extend([::proc_macro::TokenTree::Ident( + ::proc_macro::Ident::new("_", $span), + )]); + quote_spanned!(@proc $v $span $($tt)*); + }; + (@proc $v:ident $span:ident $id:ident $($tt:tt)*) => { + $v.extend([::proc_macro::TokenTree::Ident( + ::proc_macro::Ident::new(stringify!($id), $span), + )]); + quote_spanned!(@proc $v $span $($tt)*); + }; +} + +/// Converts tokens into [`proc_macro::TokenStream`] and performs variable interpolations with +/// mixed site span ([`Span::mixed_site()`]). +/// +/// This is a similar to the [`quote!`](https://docs.rs/quote/latest/quote/macro.quote.html) macro +/// from the `quote` crate but provides only just enough functionality needed by the current +/// `macros` crate. +/// +/// [`Span::mixed_site()`]: https://doc.rust-lang.org/proc_macro/struct.Span.html#method.mixed_site +macro_rules! quote { + ($($tt:tt)*) => { + quote_spanned!(::proc_macro::Span::mixed_site() => $($tt)*) + } +} diff --git a/rust/macros/vtable.rs b/rust/macros/vtable.rs new file mode 100644 index 000000000000..ee06044fcd4f --- /dev/null +++ b/rust/macros/vtable.rs @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0 + +use proc_macro::{Delimiter, Group, TokenStream, TokenTree}; +use std::collections::HashSet; +use std::fmt::Write; + +pub(crate) fn vtable(_attr: TokenStream, ts: TokenStream) -> TokenStream { + let mut tokens: Vec<_> = ts.into_iter().collect(); + + // Scan for the `trait` or `impl` keyword. + let is_trait = tokens + .iter() + .find_map(|token| match token { + TokenTree::Ident(ident) => match ident.to_string().as_str() { + "trait" => Some(true), + "impl" => Some(false), + _ => None, + }, + _ => None, + }) + .expect("#[vtable] attribute should only be applied to trait or impl block"); + + // Retrieve the main body. The main body should be the last token tree. + let body = match tokens.pop() { + Some(TokenTree::Group(group)) if group.delimiter() == Delimiter::Brace => group, + _ => panic!("cannot locate main body of trait or impl block"), + }; + + let mut body_it = body.stream().into_iter(); + let mut functions = Vec::new(); + let mut consts = HashSet::new(); + while let Some(token) = body_it.next() { + match token { + TokenTree::Ident(ident) if ident.to_string() == "fn" => { + let fn_name = match body_it.next() { + Some(TokenTree::Ident(ident)) => ident.to_string(), + // Possibly we've encountered a fn pointer type instead. + _ => continue, + }; + functions.push(fn_name); + } + TokenTree::Ident(ident) if ident.to_string() == "const" => { + let const_name = match body_it.next() { + Some(TokenTree::Ident(ident)) => ident.to_string(), + // Possibly we've encountered an inline const block instead. + _ => continue, + }; + consts.insert(const_name); + } + _ => (), + } + } + + let mut const_items; + if is_trait { + const_items = " + /// A marker to prevent implementors from forgetting to use [`#[vtable]`](vtable) + /// attribute when implementing this trait. + const USE_VTABLE_ATTR: (); + " + .to_owned(); + + for f in functions { + let gen_const_name = format!("HAS_{}", f.to_uppercase()); + // Skip if it's declared already -- this allows user override. + if consts.contains(&gen_const_name) { + continue; + } + // We don't know on the implementation-site whether a method is required or provided + // so we have to generate a const for all methods. + write!( + const_items, + "/// Indicates if the `{f}` method is overridden by the implementor. + const {gen_const_name}: bool = false;", + ) + .unwrap(); + consts.insert(gen_const_name); + } + } else { + const_items = "const USE_VTABLE_ATTR: () = ();".to_owned(); + + for f in functions { + let gen_const_name = format!("HAS_{}", f.to_uppercase()); + if consts.contains(&gen_const_name) { + continue; + } + write!(const_items, "const {gen_const_name}: bool = true;").unwrap(); + } + } + + let new_body = vec![const_items.parse().unwrap(), body.stream()] + .into_iter() + .collect(); + tokens.push(TokenTree::Group(Group::new(Delimiter::Brace, new_body))); + tokens.into_iter().collect() +} |