From: José Expósito <jose.exposito89@xxxxxxxxx> Add a couple of Rust const functions and macros to allow to develop KUnit tests without relying on generated C code: - The `kunit_unsafe_test_suite!` Rust macro is similar to the `kunit_test_suite` C macro. It requires a NULL-terminated array of test cases (see below). - The `kunit_case` Rust function is similar to the `KUNIT_CASE` C macro. It generates as case from the name and function. - The `kunit_case_null` Rust function generates a NULL test case, which is to be used as delimiter in `kunit_test_suite!`. While these functions and macros can be used on their own, a future patch will introduce another macro to create KUnit tests using a user-space like syntax. Signed-off-by: José Expósito <jose.exposito89@xxxxxxxxx> Co-developed-by: Matt Gilbride <mattgilbride@xxxxxxxxxx> Signed-off-by: Matt Gilbride <mattgilbride@xxxxxxxxxx> Co-developed-by: David Gow <davidgow@xxxxxxxxxx> Signed-off-by: David Gow <davidgow@xxxxxxxxxx> --- Changes since v3: https://lore.kernel.org/linux-kselftest/20241030045719.3085147-4-davidgow@xxxxxxxxxx/ - The kunit_unsafe_test_suite!() macro now panic!s if the suite name is too long, triggering a compile error. (Thanks, Alice!) Changes since v2: https://lore.kernel.org/linux-kselftest/20241029092422.2884505-2-davidgow@xxxxxxxxxx/ - The kunit_unsafe_test_suite!() macro will truncate the name of the suite if it is too long. (Thanks Alice!) - We no longer needlessly use UnsafeCell<> in kunit_unsafe_test_suite!(). (Thanks Alice!) Changes since v1: https://lore.kernel.org/lkml/20230720-rustbind-v1-1-c80db349e3b5@xxxxxxxxxx/ - Rebase on top of rust-next - As a result, KUnit attributes are new set. These are hardcoded to the defaults of "normal" speed and no module name. - Split the kunit_case!() macro into two const functions, kunit_case() and kunit_case_null() (for the NULL terminator). --- rust/kernel/kunit.rs | 112 +++++++++++++++++++++++++++++++++++++++++++ rust/kernel/lib.rs | 1 + 2 files changed, 113 insertions(+) diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index 824da0e9738a..85bc1faff0d5 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -161,3 +161,115 @@ macro_rules! kunit_assert_eq { $crate::kunit_assert!($name, $file, $diff, $left == $right); }}; } + +/// Represents an individual test case. +/// +/// The test case should have the signature +/// `unsafe extern "C" fn test_case(test: *mut crate::bindings::kunit)`. +/// +/// The `kunit_unsafe_test_suite!` macro expects a NULL-terminated list of test cases. +/// Use `kunit_case_null` to generate such a delimeter. +const fn kunit_case(name: &'static kernel::str::CStr, run_case: unsafe extern "C" fn(*mut kernel::bindings::kunit)) -> kernel::bindings::kunit_case { + kernel::bindings::kunit_case { + run_case: Some(run_case), + name: name.as_char_ptr(), + attr: kernel::bindings::kunit_attributes { + speed: kernel::bindings::kunit_speed_KUNIT_SPEED_NORMAL, + }, + generate_params: None, + status: kernel::bindings::kunit_status_KUNIT_SUCCESS, + module_name: core::ptr::null_mut(), + log: core::ptr::null_mut(), + } +} + +/// Represents the NULL test case delimiter. +/// +/// The `kunit_unsafe_test_suite!` macro expects a NULL-terminated list of test cases. This +/// function retuns such a delimiter. +const fn kunit_case_null() -> kernel::bindings::kunit_case { + kernel::bindings::kunit_case { + run_case: None, + name: core::ptr::null_mut(), + generate_params: None, + attr: kernel::bindings::kunit_attributes { + speed: kernel::bindings::kunit_speed_KUNIT_SPEED_NORMAL, + }, + status: kernel::bindings::kunit_status_KUNIT_SUCCESS, + module_name: core::ptr::null_mut(), + log: core::ptr::null_mut(), + } +} + + +/// Registers a KUnit test suite. +/// +/// # Safety +/// +/// `test_cases` must be a NULL terminated array of test cases. +/// +/// # Examples +/// +/// ```ignore +/// unsafe extern "C" fn test_fn(_test: *mut crate::bindings::kunit) { +/// let actual = 1 + 1; +/// let expected = 2; +/// assert_eq!(actual, expected); +/// } +/// +/// static mut KUNIT_TEST_CASE: crate::bindings::kunit_case = crate::kunit_case(name, test_fn); +/// static mut KUNIT_NULL_CASE: crate::bindings::kunit_case = crate::kunit_case_null(); +/// static mut KUNIT_TEST_CASES: &mut[crate::bindings::kunit_case] = unsafe { +/// &mut[KUNIT_TEST_CASE, KUNIT_NULL_CASE] +/// }; +/// crate::kunit_unsafe_test_suite!(suite_name, KUNIT_TEST_CASES); +/// ``` +#[macro_export] +macro_rules! kunit_unsafe_test_suite { + ($name:ident, $test_cases:ident) => { + const _: () = { + static KUNIT_TEST_SUITE_NAME: [i8; 256] = { + let name_u8 = core::stringify!($name).as_bytes(); + let mut ret = [0; 256]; + + if name_u8.len() > 255 { + panic!(concat!("The test suite name `", core::stringify!($name), "` exceeds the maximum length of 255 bytes.")); + } + + let mut i = 0; + while i < name_u8.len() { + ret[i] = name_u8[i] as i8; + i += 1; + } + + ret + }; + + static mut KUNIT_TEST_SUITE: $crate::bindings::kunit_suite = + $crate::bindings::kunit_suite { + name: KUNIT_TEST_SUITE_NAME, + // SAFETY: User is expected to pass a correct `test_cases`, hence this macro + // named 'unsafe'. + test_cases: unsafe { $test_cases.as_mut_ptr() }, + suite_init: None, + suite_exit: None, + init: None, + exit: None, + attr: $crate::bindings::kunit_attributes { + speed: $crate::bindings::kunit_speed_KUNIT_SPEED_NORMAL, + }, + status_comment: [0; 256usize], + debugfs: core::ptr::null_mut(), + log: core::ptr::null_mut(), + suite_init_err: 0, + is_init: false, + }; + + #[used] + #[link_section = ".kunit_test_suites"] + static mut KUNIT_TEST_SUITE_ENTRY: *const $crate::bindings::kunit_suite = + // SAFETY: `KUNIT_TEST_SUITE` is static. + unsafe { core::ptr::addr_of_mut!(KUNIT_TEST_SUITE) }; + }; + }; +} diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index b62451f64f6e..d662aa37070f 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -18,6 +18,7 @@ #![feature(inline_const)] #![feature(lint_reasons)] #![feature(unsize)] +#![feature(const_mut_refs)] // Ensure conditional compilation based on the kernel configuration works; // otherwise we may silently break things like initcall handling. -- 2.47.0.199.ga7371fff76-goog
