| Message ID | 20230720-rustbind-v1-2-c80db349e3b5@google.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | rust: kunit: Support KUnit tests with a user-space like syntax | expand |
On Thu, Jul 20, 2023 at 02:38:53PM +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> > --- > MAINTAINERS | 1 + > rust/kernel/kunit.rs | 11 ++++ > rust/macros/kunit.rs | 149 +++++++++++++++++++++++++++++++++++++++++++++++++++ > rust/macros/lib.rs | 29 ++++++++++ > 4 files changed, 190 insertions(+) > > diff --git a/MAINTAINERS b/MAINTAINERS > index 2a942fe59144..c32ba6b29a96 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -11373,6 +11373,7 @@ 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 4cffc71e463b..44ea67028316 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. > @@ -253,3 +255,12 @@ 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/kunit.rs b/rust/macros/kunit.rs > new file mode 100644 > index 000000000000..69dac253232f > --- /dev/null > +++ b/rust/macros/kunit.rs > @@ -0,0 +1,149 @@ > +// 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 { > + if attr.to_string().is_empty() { > + panic!("Missing test name in #[kunit_tests(test_name)] macro") > + } > + > + 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(); > + // } > + // static mut KUNIT_CASE_FOO: kernel::bindings::kunit_case = > + // kernel::kunit_case!(foo, kunit_rust_wrapper_foo); > + // > + // unsafe extern "C" fn kunit_rust_wrapper_bar(_test: * mut kernel::bindings::kunit) { > + // bar(); > + // } > + // static mut KUNIT_CASE_BAR: kernel::bindings::kunit_case = > + // kernel::kunit_case!(bar, kunit_rust_wrapper_bar); > + // > + // static mut KUNIT_CASE_NULL: kernel::bindings::kunit_case = kernel::kunit_case!(); > + // > + // static mut TEST_CASES : &mut[kernel::bindings::kunit_case] = unsafe { > + // &mut [KUNIT_CASE_FOO, KUNIT_CASE_BAR, 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_case_name = format!("KUNIT_CASE_{}", test.to_uppercase()); > + let kunit_wrapper = format!( > + "unsafe extern \"C\" fn {}(_test: *mut kernel::bindings::kunit) {{ {}(); }}", > + kunit_wrapper_fn_name, test > + ); > + let kunit_case = format!( > + "static mut {}: kernel::bindings::kunit_case = kernel::kunit_case!({}, {});", > + kunit_case_name, test, kunit_wrapper_fn_name > + ); > + writeln!(kunit_macros, "{kunit_wrapper}").unwrap(); > + writeln!(kunit_macros, "{kunit_case}").unwrap(); > + writeln!(test_cases, "{kunit_case_name},").unwrap(); > + } > + > + writeln!( > + kunit_macros, > + "static mut KUNIT_CASE_NULL: kernel::bindings::kunit_case = kernel::kunit_case!();" > + ) > + .unwrap(); > + > + writeln!( > + kunit_macros, > + "static mut TEST_CASES : &mut[kernel::bindings::kunit_case] = unsafe {{ &mut[{test_cases} KUNIT_CASE_NULL] }};" > + ) > + .unwrap(); > + > + writeln!( > + kunit_macros, > + "kernel::kunit_unsafe_test_suite!({attr}, TEST_CASES);" > + ) > + .unwrap(); > + > + let new_body: TokenStream = vec![body.stream(), kunit_macros.parse().unwrap()] > + .into_iter() > + .collect(); > + > + // Remove the `#[test]` macros. > + let new_body = new_body.to_string().replace("#[test]", ""); I've played this with some extra tests, one thing I notice is that Span/code location information is lost if we do this, for example, if I have a compile error in the test code (I introduced one on purpose in the `rust_kernel_kunit` test), I will get information like: error[E0384]: cannot assign twice to immutable variable `running` --> ../rust/kernel/kunit.rs:329:1 | 329 | #[kunit_tests(rust_kernel_kunit)] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | | | cannot assign twice to immutable variable | help: consider making this binding mutable: `mut running` the location information is not very usefull. However if we do the following: diff --git a/rust/macros/kunit.rs b/rust/macros/kunit.rs index 69dac253232f..913879765d24 100644 --- a/rust/macros/kunit.rs +++ b/rust/macros/kunit.rs @@ -134,15 +134,29 @@ pub(crate) fn kunit_tests(attr: TokenStream, ts: TokenStream) -> TokenStream { ) .unwrap(); - let new_body: TokenStream = vec![body.stream(), kunit_macros.parse().unwrap()] - .into_iter() - .collect(); - // Remove the `#[test]` macros. - let new_body = new_body.to_string().replace("#[test]", ""); + 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(g)) if g.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.parse().unwrap(), + new_body ))); tokens.into_iter().collect() then we get better information: --> ../rust/kernel/kunit.rs:335:13 | 335 | let running = true; | ^^^^^^^ | = help: maybe it is overwritten before being read? = note: `#[warn(unused_assignments)]` on by default error[E0384]: cannot assign twice to immutable variable `running` --> ../rust/kernel/kunit.rs:336:9 | 335 | let running = true; | ------- | | | first assignment to `running` | help: consider making this binding mutable: `mut running` 336 | running = false; | ^^^^^^^^^^^^^^^ cannot assign twice to immutable variable Regards, Boqun > + tokens.push(TokenTree::Group(Group::new( > + Delimiter::Brace, > + new_body.parse().unwrap(), > + ))); > + > + tokens.into_iter().collect() > +} > diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs > index 3fc74cb4ea19..cd0b720514ff 100644 > --- a/rust/macros/lib.rs > +++ b/rust/macros/lib.rs > @@ -6,6 +6,7 @@ > mod quote; > mod concat_idents; > mod helpers; > +mod kunit; > mod module; > mod pin_data; > mod pinned_drop; > @@ -246,3 +247,31 @@ pub fn pin_data(inner: TokenStream, item: TokenStream) -> TokenStream { > pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream { > pinned_drop::pinned_drop(args, 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) > +} > > -- > 2.41.0.255.g8b1d071c50-goog >
On Thu, Jul 20, 2023 at 8:40 AM David Gow <davidgow@google.com> wrote: > > The only difference with user-space tests is that instead of using > `#[cfg(test)]`, `#[kunit_tests(kunit_test_suit_name)]` is used. I may be missing something, but this does not appear to map the `assert*!`s to the KUnit APIs, is that correct? (i.e. like we do for `rustdoc`-tests). I made an assertion fail, and it seems to use the standard library macros, thus panicking and ending up in `BUG()` (rather than a failed test): rust_kernel: panicked at 'assertion failed: `(left == right)` left: `true`, right: `false`', rust/kernel/kunit.rs:329:1 ------------[ cut here ]------------ kernel BUG at rust/helpers.c:34! Then the test times out eventually and things break: # rust_test_kunit_kunit_tests: try timed out ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. > + // 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)), > + ); I wonder about compile-time here with this approach. As far as I understand, having the `cfg` explicitly outside the proc macro would avoid invoking it. Do we know the potential compile-time impact, especially when we will have many tests? ventually it would be ideal to have an approach closer to the `rustdoc` one, where the compiler finds the tests for us and we generate the needed code in the build system, i.e. outside a proc macro. Cheers, Miguel
diff --git a/MAINTAINERS b/MAINTAINERS index 2a942fe59144..c32ba6b29a96 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11373,6 +11373,7 @@ 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 4cffc71e463b..44ea67028316 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. @@ -253,3 +255,12 @@ 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/kunit.rs b/rust/macros/kunit.rs new file mode 100644 index 000000000000..69dac253232f --- /dev/null +++ b/rust/macros/kunit.rs @@ -0,0 +1,149 @@ +// 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 { + if attr.to_string().is_empty() { + panic!("Missing test name in #[kunit_tests(test_name)] macro") + } + + 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(); + // } + // static mut KUNIT_CASE_FOO: kernel::bindings::kunit_case = + // kernel::kunit_case!(foo, kunit_rust_wrapper_foo); + // + // unsafe extern "C" fn kunit_rust_wrapper_bar(_test: * mut kernel::bindings::kunit) { + // bar(); + // } + // static mut KUNIT_CASE_BAR: kernel::bindings::kunit_case = + // kernel::kunit_case!(bar, kunit_rust_wrapper_bar); + // + // static mut KUNIT_CASE_NULL: kernel::bindings::kunit_case = kernel::kunit_case!(); + // + // static mut TEST_CASES : &mut[kernel::bindings::kunit_case] = unsafe { + // &mut [KUNIT_CASE_FOO, KUNIT_CASE_BAR, 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_case_name = format!("KUNIT_CASE_{}", test.to_uppercase()); + let kunit_wrapper = format!( + "unsafe extern \"C\" fn {}(_test: *mut kernel::bindings::kunit) {{ {}(); }}", + kunit_wrapper_fn_name, test + ); + let kunit_case = format!( + "static mut {}: kernel::bindings::kunit_case = kernel::kunit_case!({}, {});", + kunit_case_name, test, kunit_wrapper_fn_name + ); + writeln!(kunit_macros, "{kunit_wrapper}").unwrap(); + writeln!(kunit_macros, "{kunit_case}").unwrap(); + writeln!(test_cases, "{kunit_case_name},").unwrap(); + } + + writeln!( + kunit_macros, + "static mut KUNIT_CASE_NULL: kernel::bindings::kunit_case = kernel::kunit_case!();" + ) + .unwrap(); + + writeln!( + kunit_macros, + "static mut TEST_CASES : &mut[kernel::bindings::kunit_case] = unsafe {{ &mut[{test_cases} KUNIT_CASE_NULL] }};" + ) + .unwrap(); + + writeln!( + kunit_macros, + "kernel::kunit_unsafe_test_suite!({attr}, TEST_CASES);" + ) + .unwrap(); + + let new_body: TokenStream = vec![body.stream(), kunit_macros.parse().unwrap()] + .into_iter() + .collect(); + + // Remove the `#[test]` macros. + let new_body = new_body.to_string().replace("#[test]", ""); + tokens.push(TokenTree::Group(Group::new( + Delimiter::Brace, + new_body.parse().unwrap(), + ))); + + tokens.into_iter().collect() +} diff --git a/rust/macros/lib.rs b/rust/macros/lib.rs index 3fc74cb4ea19..cd0b720514ff 100644 --- a/rust/macros/lib.rs +++ b/rust/macros/lib.rs @@ -6,6 +6,7 @@ mod quote; mod concat_idents; mod helpers; +mod kunit; mod module; mod pin_data; mod pinned_drop; @@ -246,3 +247,31 @@ pub fn pin_data(inner: TokenStream, item: TokenStream) -> TokenStream { pub fn pinned_drop(args: TokenStream, input: TokenStream) -> TokenStream { pinned_drop::pinned_drop(args, 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) +}