On Tue, 29 Oct 2024 at 20:08, Alice Ryhl <aliceryhl@xxxxxxxxxx> wrote: > > On Tue, Oct 29, 2024 at 10:24 AM David Gow <davidgow@xxxxxxxxxx> wrote: > > > > 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 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 | 108 +++++++++++++++++++++++++++++++++++++++++++ > > rust/kernel/lib.rs | 1 + > > 2 files changed, 109 insertions(+) > > > > diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs > > index 824da0e9738a..fc2d259db458 100644 > > --- a/rust/kernel/kunit.rs > > +++ b/rust/kernel/kunit.rs > > @@ -161,3 +161,111 @@ macro_rules! kunit_assert_eq { > > $crate::kunit_assert!($name, $file, $diff, $left == $right); > > }}; > > } > > + > > +/// Represents an individual test case. > > +/// > > +/// The test case should have the signature > > +/// `unsafe extern "C" fn test_case(test: *mut crate::bindings::kunit)`. > > +/// > > +/// The `kunit_unsafe_test_suite!` macro expects a NULL-terminated list of test cases. > > +/// Use `kunit_case_null` to generate such a delimeter. > > +const fn kunit_case(name: &kernel::str::CStr, run_case: unsafe extern "C" fn(*mut kernel::bindings::kunit)) -> kernel::bindings::kunit_case { > > This should probably say `name: &'static CStr` to require that the > name lives forever. Fixed in v3, thanks. > > +/// Registers a KUnit test suite. > > +/// > > +/// # Safety > > +/// > > +/// `test_cases` must be a NULL terminated array of test cases. > > +/// > > +/// # Examples > > +/// > > +/// ```ignore > > +/// unsafe extern "C" fn test_fn(_test: *mut crate::bindings::kunit) { > > +/// let actual = 1 + 1; > > +/// let expected = 2; > > +/// assert_eq!(actual, expected); > > +/// } > > +/// > > +/// static mut KUNIT_TEST_CASE: crate::bindings::kunit_case = crate::kunit_case(name, test_fn); > > +/// static mut KUNIT_NULL_CASE: crate::bindings::kunit_case = crate::kunit_case_null(); > > +/// static mut KUNIT_TEST_CASES: &mut[crate::bindings::kunit_case] = unsafe { > > +/// &mut[KUNIT_TEST_CASE, KUNIT_NULL_CASE] > > +/// }; > > +/// crate::kunit_unsafe_test_suite!(suite_name, KUNIT_TEST_CASES); > > +/// ``` > > +#[macro_export] > > +macro_rules! kunit_unsafe_test_suite { > > + ($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]; > > + > > + let mut i = 0; > > + while i < name_u8.len() { > > + ret[i] = name_u8[i] as i8; > > + i += 1; > > + } > > I assume the name must be zero-terminated? If so, you probably need to > enforce that somehow, e.g. by failing if `name_u8` is longer than 255 > bytes. Nice catch. I'm not sure how to nicely throw a compile time error in this function, so I'm truncating it here and doing a compile error in the macro in patch #2. This isn't ideal, but seems to work. > > + > > + static mut KUNIT_TEST_SUITE: core::cell::UnsafeCell<$crate::bindings::kunit_suite> = > > You don't actually need UnsafeCell here since it's already `static mut`. > Thanks, this works. > > + core::cell::UnsafeCell::new($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 { KUNIT_TEST_SUITE.get() }; > > If you change `KUNIT_TEST_SUITE` to not be an UnsafeCell, then you'll > want to do `core::ptr::addr_of_mut!(KUNIT_TEST_SUITE` instead. > > > 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)] > > Is this still needed with the above changes? > Yes, this seems to still be needed for the kunit_unsafe_test_suite!() macro. Thanks, -- David
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