| Message ID | 20250214074051.1619256-3-davidgow@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | rust: kunit: Support KUnit tests with a user-space like syntax | expand |
On Fri, Feb 14, 2025 at 2:41 AM David Gow <davidgow@google.com> 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> > Co-developed-by: Boqun Feng <boqun.feng@gmail.com> > Signed-off-by: Boqun Feng <boqun.feng@gmail.com> > Co-developed-by: Miguel Ojeda <ojeda@kernel.org> > Signed-off-by: Miguel Ojeda <ojeda@kernel.org> > Signed-off-by: David Gow <davidgow@google.com> > --- > Changes since v5: > https://lore.kernel.org/all/20241213081035.2069066-3-davidgow@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-davidgow@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-davidgow@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-davidgow@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-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 | 12 ++++ > rust/macros/kunit.rs | 161 +++++++++++++++++++++++++++++++++++++++++++ > rust/macros/lib.rs | 29 ++++++++ > 4 files changed, 203 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 d34a92075174..9e27b74a605b 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. > @@ -275,6 +277,7 @@ macro_rules! kunit_unsafe_test_suite { > }; > > #[used] > + #[allow(unused_unsafe)] > #[link_section = ".kunit_test_suites"] > static mut KUNIT_TEST_SUITE_ENTRY: *const ::kernel::bindings::kunit_suite = > // SAFETY: `KUNIT_TEST_SUITE` is static. > @@ -282,3 +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.exposito89@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); > + // ``` This is a really helpful comment. It got me wondering: can we have host-side unit tests for our proc macros? Code is better than comments, of course. > + 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. This makes sense. I wonder if we should think about being able to declare a test that runs both on host and in KUnit. > + // 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 > >
On Fri, Feb 14, 2025 at 3:41 PM Tamir Duberstein <tamird@gmail.com> wrote: > > This is a really helpful comment. It got me wondering: can we have > host-side unit tests for our proc macros? Code is better than > comments, of course. That makes sense (in fact, e.g. Benno wanted them for pinned-init), but I will defer that until we have the new build system to avoid adding more things to our plate. > This makes sense. I wonder if we should think about being able to > declare a test that runs both on host and in KUnit. Yeah, when we originally discussed `#[test]`s (years ago), we wanted to have "attributes" or "tags" like `#[test(host, kernel)]`. But, again, something for later -- I would rather we finally land `#[test]`s. Cheers, Miguel
On Fri, Feb 14, 2025 at 1:38 PM Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> wrote: > > On Fri, Feb 14, 2025 at 3:41 PM Tamir Duberstein <tamird@gmail.com> wrote: > > > > This is a really helpful comment. It got me wondering: can we have > > host-side unit tests for our proc macros? Code is better than > > comments, of course. > > That makes sense (in fact, e.g. Benno wanted them for pinned-init), > but I will defer that until we have the new build system to avoid > adding more things to our plate. > > > This makes sense. I wonder if we should think about being able to > > declare a test that runs both on host and in KUnit. > > Yeah, when we originally discussed `#[test]`s (years ago), we wanted > to have "attributes" or "tags" like `#[test(host, kernel)]`. > > But, again, something for later -- I would rather we finally land `#[test]`s. > > Cheers, > Miguel Works for me. Could you link to issues tracking these, if they exist? Reviewed-by: Tamir Duberstein <tamird@gmail.com>
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 d34a92075174..9e27b74a605b 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. @@ -275,6 +277,7 @@ macro_rules! kunit_unsafe_test_suite { }; #[used] + #[allow(unused_unsafe)] #[link_section = ".kunit_test_suites"] static mut KUNIT_TEST_SUITE_ENTRY: *const ::kernel::bindings::kunit_suite = // SAFETY: `KUNIT_TEST_SUITE` is static. @@ -282,3 +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.exposito89@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) +}