From: José Expósito <jose.exposit...@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 <david...@google.com> Signed-off-by: José Expósito <jose.exposit...@gmail.com> Co-developed-by: Boqun Feng <boqun.f...@gmail.com> Signed-off-by: Boqun Feng <boqun.f...@gmail.com> Co-developed-by: Miguel Ojeda <oj...@kernel.org> Signed-off-by: Miguel Ojeda <oj...@kernel.org> Reviewed-by: Tamir Duberstein <tam...@gmail.com> Signed-off-by: David Gow <david...@google.com> --- Changes since v6: https://lore.kernel.org/rust-for-linux/20250214074051.1619256-3-david...@google.com/ - Fixed an [allow(unused_unsafe)] which ended up in patch 2 instead of patch 1. (Thanks, Tamir!) - Add Tamir's Reviewed-by tag. Changes since v5: https://lore.kernel.org/all/20241213081035.2069066-3-david...@google.com/ - Fix some rustfmt-related formatting shenanigans. (Thanks, Miguel) - Fix some documentation comment formatting as well. (Thanks, Miguel) - Tidy up the generated code to avoid unneeded &mut[] everywhere. (Thanks, Miguel) - Fix a new clippy warning for using .as_bytes().len() instead of .len() directly. Changes since v4: https://lore.kernel.org/linux-kselftest/20241101064505.3820737-3-david...@google.com/ - Rebased against 6.13-rc1 - "Expect" that the sample assert_eq!(1+1, 2) produces a clippy warning due to a redundant assertion. (Thanks Boqun, Miguel) Changes since v3: https://lore.kernel.org/linux-kselftest/20241030045719.3085147-6-david...@google.com/ - The #[kunit_tests()] macro now preserves span information, so errors can be better reported. (Thanks, Boqun!) - The example test has been replaced to no longer use assert_eq!() with a constant bool argument (which triggered a clippy warning now we have the span info). It now checks 1 + 1 == 2, to match the C example. - (The in_kunit_test() test in the next patch uses assert!() to check a bool, so having something different here seemed to make a better example.) Changes since v2: https://lore.kernel.org/linux-kselftest/20241029092422.2884505-3-david...@google.com/ - 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-c80db349e...@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 | 161 +++++++++++++++++++++++++++++++++++++++++++ rust/macros/lib.rs | 29 ++++++++ 4 files changed, 202 insertions(+) create mode 100644 rust/macros/kunit.rs diff --git a/MAINTAINERS b/MAINTAINERS index c8d9e8187eb0..4e7a6d2f2c49 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -12677,6 +12677,7 @@ 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 ffb3606f748c..2131443a5f1e 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. @@ -283,3 +285,12 @@ macro_rules! kunit_unsafe_test_suite { }; }; } + +#[kunit_tests(rust_kernel_kunit)] +mod tests { + #[test] + fn rust_test_kunit_example_test() { + #![expect(clippy::eq_op)] + assert_eq!(1 + 1, 2); + } +} diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs new file mode 100644 index 000000000000..4f553ecf40c0 --- /dev/null +++ b/rust/macros/kunit.rs @@ -0,0 +1,161 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Procedural macro to run KUnit tests using a user-space like syntax. +//! +//! Copyright (c) 2023 José Expósito <jose.exposit...@gmail.com> + +use proc_macro::{Delimiter, Group, TokenStream, TokenTree}; +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 `{}` 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(); } + // 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(); + for test in &tests { + let kunit_wrapper_fn_name = format!("kunit_rust_wrapper_{}", test); + let kunit_wrapper = format!( + "unsafe extern \"C\" fn {}(_test: *mut kernel::bindings::kunit) {{ {}(); }}", + kunit_wrapper_fn_name, test + ); + writeln!(kunit_macros, "{kunit_wrapper}").unwrap(); + writeln!( + test_cases, + " kernel::kunit::kunit_case(kernel::c_str!(\"{}\"), {}),", + test, kunit_wrapper_fn_name + ) + .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];", + tests.len() + 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 new_body = TokenStream::from_iter(new_body); + new_body.extend::<TokenStream>(kunit_macros.parse().unwrap()); + + tokens.push(TokenTree::Group(Group::new(Delimiter::Brace, new_body))); + + tokens.into_iter().collect() +} diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs index d61bc6a56425..50b58259c577 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; @@ -492,3 +493,31 @@ 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) +} -- 2.48.1.601.g30ceb7b040-goog
