rust: kunit: use pin_init::zeroed instead of custom null value

The last null element can be created (constly) using `pin_init::zeroed`,
so prefer to use it instead of adding a custom way of building it.

Reviewed-by: Tamir Duberstein <tamird@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: David Gow <davidgow@google.com>
Link: https://patch.msgid.link/20260112170919.1888584-12-gary@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: nbdd0121

rust/kernel/kunit.rs

@@ -189,9 +189,6 @@ pub fn is_test_result_ok(t: impl TestResult) -> bool {
 }
 
 /// Represents an individual test case.
-///
-/// The [`kunit_unsafe_test_suite!`] macro expects a `NULL`-terminated list of valid test cases.
-/// Use [`kunit_case_null`] to generate such a delimiter.
 #[doc(hidden)]
 pub const fn kunit_case(
     name: &'static kernel::str::CStr,
@@ -212,27 +209,6 @@ pub const fn kunit_case(
     }
 }
 
-/// Represents the `NULL` test case delimiter.
-///
-/// The [`kunit_unsafe_test_suite!`] macro expects a `NULL`-terminated list of test cases. This
-/// function returns such a delimiter.
-#[doc(hidden)]
-pub 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(),
-        param_init: None,
-        param_exit: None,
-    }
-}
-
 /// Registers a KUnit test suite.
 ///
 /// # Safety
@@ -251,7 +227,7 @@ pub const fn kunit_case_null() -> kernel::bindings::kunit_case {
 ///
 /// static mut KUNIT_TEST_CASES: [kernel::bindings::kunit_case; 2] = [
 ///     kernel::kunit::kunit_case(c"name", test_fn),
-///     kernel::kunit::kunit_case_null(),
+///     pin_init::zeroed(),
 /// ];
 /// kernel::kunit_unsafe_test_suite!(suite_name, KUNIT_TEST_CASES);
 /// ```

rust/macros/kunit.rs

@@ -74,7 +74,7 @@ pub(crate) fn kunit_tests(test_suite: Ident, mut module: ItemMod) -> Result<Toke
     // static mut TEST_CASES: [::kernel::bindings::kunit_case; 3] = [
     //     ::kernel::kunit::kunit_case(c"foo", kunit_rust_wrapper_foo),
     //     ::kernel::kunit::kunit_case(c"bar", kunit_rust_wrapper_bar),
-    //     ::kernel::kunit::kunit_case_null(),
+    //     ::pin_init::zeroed(),
     // ];
     //
     // ::kernel::kunit_unsafe_test_suite!(kunit_test_suit_name, TEST_CASES);
@@ -159,7 +159,7 @@ pub(crate) fn kunit_tests(test_suite: Ident, mut module: ItemMod) -> Result<Toke
     processed_items.push(parse_quote! {
         static mut TEST_CASES: [::kernel::bindings::kunit_case; #num_tests_plus_1] = [
             #(#test_cases,)*
-            ::kernel::kunit::kunit_case_null(),
+            ::pin_init::zeroed(),
         ];
     });
     processed_items.push(parse_quote! {