From: José Expósito jose.exposito89@gmail.com
Add a new procedural macro (`#[kunit_tests(kunit_test_suit_name)]`) to run KUnit tests using a user-space like syntax.
The macro, that should be used on modules, transforms every `#[test]` in a `kunit_case!` and adds a `kunit_unsafe_test_suite!` registering all of them.
The only difference with user-space tests is that instead of using `#[cfg(test)]`, `#[kunit_tests(kunit_test_suit_name)]` is used.
Note that `#[cfg(CONFIG_KUNIT)]` is added so the test module is not compiled when `CONFIG_KUNIT` is set to `n`.
Reviewed-by: David Gow davidgow@google.com Signed-off-by: José Expósito jose.exposito89@gmail.com [Updated to use new const fn.] Signed-off-by: David Gow davidgow@google.com ---
Changes since v2: https://lore.kernel.org/linux-kselftest/20241029092422.2884505-3-davidgow@go... - Include missing rust/macros/kunit.rs file from v2. (Thanks Boqun!) - The proc macro now emits an error if the suite name is too long.
Changes since v1: https://lore.kernel.org/lkml/20230720-rustbind-v1-2-c80db349e3b5@google.com/ - Rebased on top of rust-next - Make use of the new const functions, rather than the kunit_case!() macro.
--- MAINTAINERS | 1 + rust/kernel/kunit.rs | 11 ++++ rust/macros/kunit.rs | 153 +++++++++++++++++++++++++++++++++++++++++++ rust/macros/lib.rs | 29 ++++++++ 4 files changed, 194 insertions(+) create mode 100644 rust/macros/kunit.rs
diff --git a/MAINTAINERS b/MAINTAINERS index b77f4495dcf4..b65035ede675 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12433,6 +12433,7 @@ F: Documentation/dev-tools/kunit/ F: include/kunit/ F: lib/kunit/ F: rust/kernel/kunit.rs +F: rust/macros/kunit.rs F: scripts/rustdoc_test_* F: tools/testing/kunit/
diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index 27bc4139d352..ac296467a552 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -40,6 +40,8 @@ pub fn info(args: fmt::Arguments<'_>) { } }
+use macros::kunit_tests; + /// Asserts that a boolean expression is `true` at runtime. /// /// Public but hidden since it should only be used from generated tests. @@ -269,3 +271,12 @@ macro_rules! kunit_unsafe_test_suite { }; }; } + +#[kunit_tests(rust_kernel_kunit)] +mod tests { + #[test] + fn rust_test_kunit_kunit_tests() { + let running = true; + assert_eq!(running, true); + } +} diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs new file mode 100644 index 000000000000..850d268cc96a --- /dev/null +++ b/rust/macros/kunit.rs @@ -0,0 +1,153 @@ +// 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::fmt::Write; + +pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream { + if attr.to_string().is_empty() { + panic!("Missing test name in #[kunit_tests(test_name)] macro") + } + + if attr.to_string().as_bytes().len() > 255 { + panic!("The test suite name `{}` exceeds the maximum length of 255 bytes.", attr) + } + + 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(); + while let Some(token) = body_it.next() { + match token { + TokenTree::Group(ident) if ident.to_string() == "[test]" => match body_it.next() { + Some(TokenTree::Ident(ident)) if ident.to_string() == "fn" => { + let test_name = match body_it.next() { + Some(TokenTree::Ident(ident)) => ident.to_string(), + _ => continue, + }; + tests.push(test_name); + } + _ => continue, + }, + _ => (), + } + } + + // Add `#[cfg(CONFIG_KUNIT)]` before the module declaration. + let config_kunit = "#[cfg(CONFIG_KUNIT)]".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(); + // } + // static mut KUNIT_CASE_FOO: kernel::bindings::kunit_case = + // kernel::kunit::kunit_case(foo, kunit_rust_wrapper_foo); + // + // unsafe extern "C" fn kunit_rust_wrapper_bar(_test: * mut kernel::bindings::kunit) { + // bar(); + // } + // static mut KUNIT_CASE_BAR: kernel::bindings::kunit_case = + // kernel::kunit::kunit_case(bar, kunit_rust_wrapper_bar); + // + // static mut KUNIT_CASE_NULL: kernel::bindings::kunit_case = kernel::kunit::kunit_case_null(); + // + // static mut TEST_CASES : &mut[kernel::bindings::kunit_case] = unsafe { + // &mut [KUNIT_CASE_FOO, KUNIT_CASE_BAR, 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(); + for test in tests { + let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{}", test); + let kunit_case_name = format!("KUNIT_CASE_{}", test.to_uppercase()); + let kunit_wrapper = format!( + "unsafe extern "C" fn {}(_test: *mut kernel::bindings::kunit) {{ {}(); }}", + kunit_wrapper_fn_name, test + ); + let kunit_case = format!( + "static mut {}: kernel::bindings::kunit_case = kernel::kunit::kunit_case(kernel::c_str!("{}"), {});", + kunit_case_name, test, kunit_wrapper_fn_name + ); + writeln!(kunit_macros, "{kunit_wrapper}").unwrap(); + writeln!(kunit_macros, "{kunit_case}").unwrap(); + writeln!(test_cases, "{kunit_case_name},").unwrap(); + } + + writeln!( + kunit_macros, + "static mut KUNIT_CASE_NULL: kernel::bindings::kunit_case = kernel::kunit::kunit_case_null();" + ) + .unwrap(); + + writeln!( + kunit_macros, + "static mut TEST_CASES : &mut[kernel::bindings::kunit_case] = unsafe {{ &mut[{test_cases} KUNIT_CASE_NULL] }};" + ) + .unwrap(); + + writeln!( + kunit_macros, + "kernel::kunit_unsafe_test_suite!({attr}, TEST_CASES);" + ) + .unwrap(); + + let new_body: TokenStream = vec![body.stream(), kunit_macros.parse().unwrap()] + .into_iter() + .collect(); + + // Remove the `#[test]` macros. + let new_body = new_body.to_string().replace("#[test]", ""); + tokens.push(TokenTree::Group(Group::new( + Delimiter::Brace, + new_body.parse().unwrap(), + ))); + + tokens.into_iter().collect() +} diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs index 939ae00b723a..098925b99982 100644 --- a/rust/macros/lib.rs +++ b/rust/macros/lib.rs @@ -10,6 +10,7 @@ mod quote; mod concat_idents; mod helpers; +mod kunit; mod module; mod paste; mod pin_data; @@ -430,3 +431,31 @@ pub fn paste(input: TokenStream) -> TokenStream { pub fn derive_zeroable(input: TokenStream) -> TokenStream { zeroable::derive(input) } + +/// 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 macros::kunit_tests; +/// +/// #[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) +}