This series was originally written by José Expósito, and has been modified and updated by Matt Gilbride and myself. The original version can be found here: https://github.com/Rust-for-Linux/linux/pull/950
Add support for writing KUnit tests in Rust. While Rust doctests are already converted to KUnit tests and run, they're really better suited for examples, rather than as first-class unit tests.
This series implements a series of direct Rust bindings for KUnit tests, as well as a new macro which allows KUnit tests to be written using a close variant of normal Rust unit test syntax. The only change required is replacing '#[cfg(test)]' with '#[kunit_tests(kunit_test_suite_name)]'
An example test would look like: #[kunit_tests(rust_kernel_hid_driver)] mod tests { use super::*; use crate::{c_str, driver, hid, prelude::*}; use core::ptr;
struct SimpleTestDriver; impl Driver for SimpleTestDriver { type Data = (); }
#[test] fn rust_test_hid_driver_adapter() { let mut hid = bindings::hid_driver::default(); let name = c_str!("SimpleTestDriver"); static MODULE: ThisModule = unsafe { ThisModule::from_ptr(ptr::null_mut()) };
let res = unsafe { <hid::Adapter<SimpleTestDriver> as driver::DriverOps>::register(&mut hid, name, &MODULE) }; assert_eq!(res, Err(ENODEV)); // The mock returns -19 } }
Please give this a go, and make sure I haven't broken it! There's almost certainly a lot of improvements which can be made -- and there's a fair case to be made for replacing some of this with generated C code which can use the C macros -- but this is hopefully an adequate implementation for now, and the interface can (with luck) remain the same even if the implementation changes.
A few small notable missing features: - Attributes (like the speed of a test) are hardcoded to the default value. - Similarly, the module name attribute is hardcoded to NULL. In C, we use the KBUILD_MODNAME macro, but I couldn't find a way to use this from Rust which wasn't more ugly than just disabling it. - Assertions are not automatically rewritten to use KUnit assertions.
---
Changes since v1: https://lore.kernel.org/lkml/20230720-rustbind-v1-0-c80db349e3b5@google.com/... - Rebase on top of the latest rust-next (commit 718c4069896c) - Make kunit_case a const fn, rather than a macro (Thanks Boqun) - As a result, the null terminator is now created with kernel::kunit::kunit_case_null() - Use the C kunit_get_current_test() function to implement in_kunit_test(), rather than re-implementing it (less efficiently) ourselves.
Changes since the GitHub PR: - Rebased on top of kselftest/kunit - Add const_mut_refs feature This may conflict with https://lore.kernel.org/lkml/20230503090708.2524310-6-nmi@metaspace.dk/ - Add rust/macros/kunit.rs to the KUnit MAINTAINERS entry
--- José Expósito (3): rust: kunit: add KUnit case and suite macros rust: macros: add macro to easily run KUnit tests rust: kunit: allow to know if we are in a test
MAINTAINERS | 1 + rust/kernel/kunit.rs | 191 +++++++++++++++++++++++++++++++++++++++++++ rust/kernel/lib.rs | 1 + rust/macros/lib.rs | 29 +++++++ 4 files changed, 222 insertions(+)
From: José Expósito jose.exposito89@gmail.com
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@gmail.com Co-developed-by: Matt Gilbride mattgilbride@google.com Signed-off-by: Matt Gilbride mattgilbride@google.com Co-developed-by: David Gow davidgow@google.com Signed-off-by: David Gow davidgow@google.com ---
Changes since v1: https://lore.kernel.org/lkml/20230720-rustbind-v1-1-c80db349e3b5@google.com/ - 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 { + 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]; + + let mut i = 0; + while i < name_u8.len() { + ret[i] = name_u8[i] as i8; + i += 1; + } + + ret + }; + + static mut KUNIT_TEST_SUITE: core::cell::UnsafeCell<$crate::bindings::kunit_suite> = + core::cell::UnsafeCell::new($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() }; + }; + }; +} 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.
On Tue, Oct 29, 2024 at 10:24 AM David Gow davidgow@google.com wrote:
From: José Expósito jose.exposito89@gmail.com
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@gmail.com Co-developed-by: Matt Gilbride mattgilbride@google.com Signed-off-by: Matt Gilbride mattgilbride@google.com Co-developed-by: David Gow davidgow@google.com Signed-off-by: David Gow davidgow@google.com
Changes since v1: https://lore.kernel.org/lkml/20230720-rustbind-v1-1-c80db349e3b5@google.com/
- 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 == $right); }}; }
+/// Represents an individual test case. +/// +/// The test case should have the signature +/// `unsafe extern "C" fn test_case(test: *mut crate::bindings::kunit)`. +/// +/// The `kunit_unsafe_test_suite!` macro expects a NULL-terminated list of test cases. +/// Use `kunit_case_null` to generate such a delimeter. +const fn kunit_case(name: &kernel::str::CStr, run_case: unsafe extern "C" fn(*mut kernel::bindings::kunit)) -> kernel::bindings::kunit_case {
This should probably say `name: &'static CStr` to require that the name lives forever.
+/// Registers a KUnit test suite. +/// +/// # Safety +/// +/// `test_cases` must be a NULL terminated array of test cases. +/// +/// # Examples +/// +/// ```ignore +/// unsafe extern "C" fn test_fn(_test: *mut crate::bindings::kunit) { +/// let actual = 1 + 1; +/// let expected = 2; +/// assert_eq!(actual, expected); +/// } +/// +/// static mut KUNIT_TEST_CASE: crate::bindings::kunit_case = crate::kunit_case(name, test_fn); +/// static mut KUNIT_NULL_CASE: crate::bindings::kunit_case = crate::kunit_case_null(); +/// static mut KUNIT_TEST_CASES: &mut[crate::bindings::kunit_case] = unsafe { +/// &mut[KUNIT_TEST_CASE, KUNIT_NULL_CASE] +/// }; +/// crate::kunit_unsafe_test_suite!(suite_name, KUNIT_TEST_CASES); +/// ``` +#[macro_export] +macro_rules! kunit_unsafe_test_suite {
- ($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.
static mut KUNIT_TEST_SUITE: core::cell::UnsafeCell<$crate::bindings::kunit_suite> =
You don't actually need UnsafeCell here since it's already `static mut`.
core::cell::UnsafeCell::new($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?
Alice
On Tue, 29 Oct 2024 at 20:08, Alice Ryhl aliceryhl@google.com wrote:
On Tue, Oct 29, 2024 at 10:24 AM David Gow davidgow@google.com wrote:
From: José Expósito jose.exposito89@gmail.com
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@gmail.com Co-developed-by: Matt Gilbride mattgilbride@google.com Signed-off-by: Matt Gilbride mattgilbride@google.com Co-developed-by: David Gow davidgow@google.com Signed-off-by: David Gow davidgow@google.com
Changes since v1: https://lore.kernel.org/lkml/20230720-rustbind-v1-1-c80db349e3b5@google.com/
- 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
On Wed, Oct 30, 2024 at 5:59 AM David Gow davidgow@google.com wrote:
On Tue, 29 Oct 2024 at 20:08, Alice Ryhl aliceryhl@google.com wrote:
On Tue, Oct 29, 2024 at 10:24 AM David Gow davidgow@google.com wrote:
From: José Expósito jose.exposito89@gmail.com
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@gmail.com Co-developed-by: Matt Gilbride mattgilbride@google.com Signed-off-by: Matt Gilbride mattgilbride@google.com Co-developed-by: David Gow davidgow@google.com Signed-off-by: David Gow davidgow@google.com
Changes since v1: https://lore.kernel.org/lkml/20230720-rustbind-v1-1-c80db349e3b5@google.com/
- 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.
You should be able to just panic! if it happens.
Also, I believe it should be i < 255 instead of 256?
Alice
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 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/lib.rs | 29 +++++++++++++++++++++++++++++ 3 files changed, 41 insertions(+)
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 fc2d259db458..abcf0229ffee 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/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) +}
Hi David,
On Tue, Oct 29, 2024 at 05:24:18PM +0800, David Gow wrote:
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 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/lib.rs | 29 +++++++++++++++++++++++++++++ 3 files changed, 41 insertions(+)
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
I cannot find this file in this series, and it's not in the current rust-next either.
(Did you do the same thing as I sometimes did: forget to `git add` a new file?)
Regards, Boqun
F: scripts/rustdoc_test_* F: tools/testing/kunit/ diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index fc2d259db458..abcf0229ffee 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/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)
+}
2.47.0.163.g1226f6d8fa-goog
On Tue, 29 Oct 2024 at 20:28, Boqun Feng boqun.feng@gmail.com wrote:
Hi David,
On Tue, Oct 29, 2024 at 05:24:18PM +0800, David Gow wrote:
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 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/lib.rs | 29 +++++++++++++++++++++++++++++ 3 files changed, 41 insertions(+)
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
I cannot find this file in this series, and it's not in the current rust-next either.
(Did you do the same thing as I sometimes did: forget to `git add` a new file?)
Whoops! Thanks for catching this: I somehow managed to unstage it while editing things. Fixed in v3: https://lore.kernel.org/linux-kselftest/20241030045719.3085147-6-davidgow@go...
Cheers, -- David
From: José Expósito jose.exposito89@gmail.com
In some cases, we need to call test-only code from outside the test case, for example, to mock a function or a module.
In order to check whether we are in a test or not, we need to test if `CONFIG_KUNIT` is set. Unfortunately, we cannot rely only on this condition because: - a test could be running in another thread, - some distros compile KUnit in production kernels, so checking at runtime that `current->kunit_test != NULL` is required.
Forturately, KUnit provides an optimised check in `kunit_get_current_test()`, which checks CONFIG_KUNIT, a global static key, and then the current thread's running KUnit test.
Add a safe wrapper function around this to know whether or not we are in a KUnit test and examples showing how to mock a function and a module.
Signed-off-by: José Expósito jose.exposito89@gmail.com Co-developed-by: David Gow davidgow@google.com Signed-off-by: David Gow davidgow@google.com ---
Changes since v1: https://lore.kernel.org/lkml/20230720-rustbind-v1-3-c80db349e3b5@google.com/ - Rebased on top of rust-next. - Use the `kunit_get_current_test()` C function, which wasn't previously available, instead of rolling our own. - (Thanks also to Boqun for suggesting a nicer way of implementing this, which I tried, but the `kunit_get_current_test()` version obsoleted.)
--- rust/kernel/kunit.rs | 72 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+)
diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs index abcf0229ffee..bfc80394546a 100644 --- a/rust/kernel/kunit.rs +++ b/rust/kernel/kunit.rs @@ -272,11 +272,83 @@ macro_rules! kunit_unsafe_test_suite { }; }
+/// In some cases, you need to call test-only code from outside the test case, for example, to +/// create a function mock. This function can be invoked to know whether we are currently running a +/// KUnit test or not. +/// +/// # Examples +/// +/// This example shows how a function can be mocked to return a well-known value while testing: +/// +/// ``` +/// # use kernel::kunit::in_kunit_test; +/// # +/// fn fn_mock_example(n: i32) -> i32 { +/// if in_kunit_test() { +/// 100 +/// } else { +/// n + 1 +/// } +/// } +/// +/// let mock_res = fn_mock_example(5); +/// assert_eq!(mock_res, 100); +/// ``` +/// +/// Sometimes, you don't control the code that needs to be mocked. This example shows how the +/// `bindings` module can be mocked: +/// +/// ``` +/// // Import our mock naming it as the real module. +/// #[cfg(CONFIG_KUNIT)] +/// use bindings_mock_example as bindings; +/// +/// // This module mocks `bindings`. +/// mod bindings_mock_example { +/// use kernel::kunit::in_kunit_test; +/// use kernel::bindings::u64_; +/// +/// // Make the other binding functions available. +/// pub(crate) use kernel::bindings::*; +/// +/// // Mock `ktime_get_boot_fast_ns` to return a well-known value when running a KUnit test. +/// pub(crate) unsafe fn ktime_get_boot_fast_ns() -> u64_ { +/// if in_kunit_test() { +/// 1234 +/// } else { +/// unsafe { kernel::bindings::ktime_get_boot_fast_ns() } +/// } +/// } +/// } +/// +/// // This is the function we want to test. Since `bindings` has been mocked, we can use its +/// // functions seamlessly. +/// fn get_boot_ns() -> u64 { +/// unsafe { bindings::ktime_get_boot_fast_ns() } +/// } +/// +/// let time = get_boot_ns(); +/// assert_eq!(time, 1234); +/// ``` +pub fn in_kunit_test() -> bool { + // SAFETY: kunit_get_current_test() is always safe to call from C (it has fallbacks for + // when KUnit is not enabled), and we're only comparing the result to NULL. + unsafe { !bindings::kunit_get_current_test().is_null() } +} + #[kunit_tests(rust_kernel_kunit)] mod tests { + use super::*; + #[test] fn rust_test_kunit_kunit_tests() { let running = true; assert_eq!(running, true); } + + #[test] + fn rust_test_kunit_in_kunit_test() { + let in_kunit = in_kunit_test(); + assert_eq!(in_kunit, true); + } }
linux-kselftest-mirror@lists.linaro.org
-
Alice Ryhl -
Boqun Feng -
David Gow