diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index fbc89baf7de6..550cb967b668 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -3010,6 +3010,19 @@ config RUST_BUILD_ASSERT_ALLOW If unsure, say N. +config RUST_KERNEL_DOCTESTS + bool "Doctests for the `kernel` crate" if !KUNIT_ALL_TESTS + depends on RUST && KUNIT=y + default KUNIT_ALL_TESTS + help + This builds the documentation tests of the `kernel` crate + as KUnit tests. + + For more information on KUnit and unit tests in general, + please refer to the KUnit documentation in Documentation/dev-tools/kunit/. + + If unsure, say N. + endmenu # "Rust" endmenu # Kernel hacking diff --git a/rust/.gitignore b/rust/.gitignore index 21552992b401..d3829ffab80b 100644 --- a/rust/.gitignore +++ b/rust/.gitignore @@ -2,6 +2,8 @@ bindings_generated.rs bindings_helpers_generated.rs +doctests_kernel_generated.rs +doctests_kernel_generated_kunit.c uapi_generated.rs exports_*_generated.h doc/ diff --git a/rust/Makefile b/rust/Makefile index 7c9d9f11aec5..92482144c0bb 100644 --- a/rust/Makefile +++ b/rust/Makefile @@ -27,6 +27,12 @@ endif obj-$(CONFIG_RUST) += exports.o +always-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated.rs +always-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated_kunit.c + +obj-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated.o +obj-$(CONFIG_RUST_KERNEL_DOCTESTS) += doctests_kernel_generated_kunit.o + # Avoids running `$(RUSTC)` for the sysroot when it may not be available. ifdef CONFIG_RUST @@ -39,9 +45,11 @@ ifeq ($(quiet),silent_) cargo_quiet=-q rust_test_quiet=-q rustdoc_test_quiet=--test-args -q +rustdoc_test_kernel_quiet=>/dev/null else ifeq ($(quiet),quiet_) rust_test_quiet=-q rustdoc_test_quiet=--test-args -q +rustdoc_test_kernel_quiet=>/dev/null else cargo_quiet=--verbose endif @@ -157,6 +165,27 @@ quiet_cmd_rustdoc_test = RUSTDOC T $< -L$(objtree)/$(obj)/test --output $(objtree)/$(obj)/doc \ --crate-name $(subst rusttest-,,$@) $< +quiet_cmd_rustdoc_test_kernel = RUSTDOC TK $< + cmd_rustdoc_test_kernel = \ + rm -rf $(objtree)/$(obj)/test/doctests/kernel; \ + mkdir -p $(objtree)/$(obj)/test/doctests/kernel; \ + OBJTREE=$(abspath $(objtree)) \ + $(RUSTDOC) --test $(rust_flags) \ + @$(objtree)/include/generated/rustc_cfg \ + -L$(objtree)/$(obj) --extern alloc --extern kernel \ + --extern build_error --extern macros \ + --extern bindings --extern uapi \ + --no-run --crate-name kernel -Zunstable-options \ + --test-builder $(objtree)/scripts/rustdoc_test_builder \ + $< $(rustdoc_test_kernel_quiet); \ + $(objtree)/scripts/rustdoc_test_gen + +%/doctests_kernel_generated.rs %/doctests_kernel_generated_kunit.c: \ + $(src)/kernel/lib.rs $(obj)/kernel.o \ + $(objtree)/scripts/rustdoc_test_builder \ + $(objtree)/scripts/rustdoc_test_gen FORCE + $(call if_changed,rustdoc_test_kernel) + # We cannot use `-Zpanic-abort-tests` because some tests are dynamic, # so for the moment we skip `-Cpanic=abort`. quiet_cmd_rustc_test = RUSTC T $< diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index 3e601ce2548d..0f8d37c31ac2 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -6,6 +6,7 @@ * Sorted alphabetically. */ +#include #include #include #include diff --git a/rust/helpers.c b/rust/helpers.c index bb594da56137..49a5e1a4f0ae 100644 --- a/rust/helpers.c +++ b/rust/helpers.c @@ -18,6 +18,7 @@ * accidentally exposed. */ +#include #include #include #include @@ -135,6 +136,12 @@ void rust_helper_put_task_struct(struct task_struct *t) } EXPORT_SYMBOL_GPL(rust_helper_put_task_struct); +struct kunit *rust_helper_kunit_get_current_test(void) +{ + return kunit_get_current_test(); +} +EXPORT_SYMBOL_GPL(rust_helper_kunit_get_current_test); + /* * We use `bindgen`'s `--size_t-is-usize` option to bind the C `size_t` type * as the Rust `usize` type, so we can use it in contexts where Rust diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs new file mode 100644 index 000000000000..722655b2d62d --- /dev/null +++ b/rust/kernel/kunit.rs @@ -0,0 +1,163 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! KUnit-based macros for Rust unit tests. +//! +//! C header: [`include/kunit/test.h`](../../../../../include/kunit/test.h) +//! +//! Reference: + +use core::{ffi::c_void, fmt}; + +/// Prints a KUnit error-level message. +/// +/// Public but hidden since it should only be used from KUnit generated code. +#[doc(hidden)] +pub fn err(args: fmt::Arguments<'_>) { + // SAFETY: The format string is null-terminated and the `%pA` specifier matches the argument we + // are passing. + #[cfg(CONFIG_PRINTK)] + unsafe { + bindings::_printk( + b"\x013%pA\0".as_ptr() as _, + &args as *const _ as *const c_void, + ); + } +} + +/// Prints a KUnit info-level message. +/// +/// Public but hidden since it should only be used from KUnit generated code. +#[doc(hidden)] +pub fn info(args: fmt::Arguments<'_>) { + // SAFETY: The format string is null-terminated and the `%pA` specifier matches the argument we + // are passing. + #[cfg(CONFIG_PRINTK)] + unsafe { + bindings::_printk( + b"\x016%pA\0".as_ptr() as _, + &args as *const _ as *const c_void, + ); + } +} + +/// Asserts that a boolean expression is `true` at runtime. +/// +/// Public but hidden since it should only be used from generated tests. +/// +/// Unlike the one in `core`, this one does not panic; instead, it is mapped to the KUnit +/// facilities. See [`assert!`] for more details. +#[doc(hidden)] +#[macro_export] +macro_rules! kunit_assert { + ($name:literal, $file:literal, $diff:expr, $condition:expr $(,)?) => { + 'out: { + // Do nothing if the condition is `true`. + if $condition { + break 'out; + } + + static FILE: &'static $crate::str::CStr = $crate::c_str!($file); + static LINE: i32 = core::line!() as i32 - $diff; + static CONDITION: &'static $crate::str::CStr = $crate::c_str!(stringify!($condition)); + + // SAFETY: FFI call without safety requirements. + let kunit_test = unsafe { $crate::bindings::kunit_get_current_test() }; + if kunit_test.is_null() { + // The assertion failed but this task is not running a KUnit test, so we cannot call + // KUnit, but at least print an error to the kernel log. This may happen if this + // macro is called from an spawned thread in a test (see + // `scripts/rustdoc_test_gen.rs`) or if some non-test code calls this macro by + // mistake (it is hidden to prevent that). + // + // This mimics KUnit's failed assertion format. + $crate::kunit::err(format_args!( + " # {}: ASSERTION FAILED at {FILE}:{LINE}\n", + $name + )); + $crate::kunit::err(format_args!( + " Expected {CONDITION} to be true, but is false\n" + )); + $crate::kunit::err(format_args!( + " Failure not reported to KUnit since this is a non-KUnit task\n" + )); + break 'out; + } + + #[repr(transparent)] + struct Location($crate::bindings::kunit_loc); + + #[repr(transparent)] + struct UnaryAssert($crate::bindings::kunit_unary_assert); + + // SAFETY: There is only a static instance and in that one the pointer field points to + // an immutable C string. + unsafe impl Sync for Location {} + + // SAFETY: There is only a static instance and in that one the pointer field points to + // an immutable C string. + unsafe impl Sync for UnaryAssert {} + + static LOCATION: Location = Location($crate::bindings::kunit_loc { + file: FILE.as_char_ptr(), + line: LINE, + }); + static ASSERTION: UnaryAssert = UnaryAssert($crate::bindings::kunit_unary_assert { + assert: $crate::bindings::kunit_assert {}, + condition: CONDITION.as_char_ptr(), + expected_true: true, + }); + + // SAFETY: + // - FFI call. + // - The `kunit_test` pointer is valid because we got it from + // `kunit_get_current_test()` and it was not null. This means we are in a KUnit + // test, and that the pointer can be passed to KUnit functions and assertions. + // - The string pointers (`file` and `condition` above) point to null-terminated + // strings since they are `CStr`s. + // - The function pointer (`format`) points to the proper function. + // - The pointers passed will remain valid since they point to `static`s. + // - The format string is allowed to be null. + // - There are, however, problems with this: first of all, this will end up stopping + // the thread, without running destructors. While that is problematic in itself, + // it is considered UB to have what is effectively a forced foreign unwind + // with `extern "C"` ABI. One could observe the stack that is now gone from + // another thread. We should avoid pinning stack variables to prevent library UB, + // too. For the moment, given that test failures are reported immediately before the + // next test runs, that test failures should be fixed and that KUnit is explicitly + // documented as not suitable for production environments, we feel it is reasonable. + unsafe { + $crate::bindings::__kunit_do_failed_assertion( + kunit_test, + core::ptr::addr_of!(LOCATION.0), + $crate::bindings::kunit_assert_type_KUNIT_ASSERTION, + core::ptr::addr_of!(ASSERTION.0.assert), + Some($crate::bindings::kunit_unary_assert_format), + core::ptr::null(), + ); + } + + // SAFETY: FFI call; the `test` pointer is valid because this hidden macro should only + // be called by the generated documentation tests which forward the test pointer given + // by KUnit. + unsafe { + $crate::bindings::__kunit_abort(kunit_test); + } + } + }; +} + +/// Asserts that two expressions are equal to each other (using [`PartialEq`]). +/// +/// Public but hidden since it should only be used from generated tests. +/// +/// Unlike the one in `core`, this one does not panic; instead, it is mapped to the KUnit +/// facilities. See [`assert!`] for more details. +#[doc(hidden)] +#[macro_export] +macro_rules! kunit_assert_eq { + ($name:literal, $file:literal, $diff:expr, $left:expr, $right:expr $(,)?) => {{ + // For the moment, we just forward to the expression assert because, for binary asserts, + // KUnit supports only a few types (e.g. integers). + $crate::kunit_assert!($name, $file, $diff, $left == $right); + }}; +} diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs index 85b261209977..3642cadc34b1 100644 --- a/rust/kernel/lib.rs +++ b/rust/kernel/lib.rs @@ -34,6 +34,8 @@ pub mod error; pub mod init; pub mod ioctl; +#[cfg(CONFIG_KUNIT)] +pub mod kunit; pub mod prelude; pub mod print; mod static_assert; diff --git a/scripts/.gitignore b/scripts/.gitignore index 6e9ce6720a05..3dbb8bb2457b 100644 --- a/scripts/.gitignore +++ b/scripts/.gitignore @@ -5,6 +5,8 @@ /kallsyms /module.lds /recordmcount +/rustdoc_test_builder +/rustdoc_test_gen /sign-file /sorttable /target.json diff --git a/scripts/Makefile b/scripts/Makefile index 32b6ba722728..576cf64be667 100644 --- a/scripts/Makefile +++ b/scripts/Makefile @@ -9,6 +9,8 @@ hostprogs-always-$(CONFIG_BUILDTIME_TABLE_SORT) += sorttable hostprogs-always-$(CONFIG_ASN1) += asn1_compiler hostprogs-always-$(CONFIG_MODULE_SIG_FORMAT) += sign-file hostprogs-always-$(CONFIG_SYSTEM_EXTRA_CERTIFICATE) += insert-sys-cert +hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS) += rustdoc_test_builder +hostprogs-always-$(CONFIG_RUST_KERNEL_DOCTESTS) += rustdoc_test_gen always-$(CONFIG_RUST) += target.json filechk_rust_target = $< < include/config/auto.conf @@ -18,6 +20,8 @@ $(obj)/target.json: scripts/generate_rust_target include/config/auto.conf FORCE hostprogs += generate_rust_target generate_rust_target-rust := y +rustdoc_test_builder-rust := y +rustdoc_test_gen-rust := y HOSTCFLAGS_sorttable.o = -I$(srctree)/tools/include HOSTLDLIBS_sorttable = -lpthread diff --git a/scripts/rustdoc_test_builder.rs b/scripts/rustdoc_test_builder.rs new file mode 100644 index 000000000000..e5894652f12c --- /dev/null +++ b/scripts/rustdoc_test_builder.rs @@ -0,0 +1,72 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Test builder for `rustdoc`-generated tests. +//! +//! This script is a hack to extract the test from `rustdoc`'s output. Ideally, `rustdoc` would +//! have an option to generate this information instead, e.g. as JSON output. +//! +//! The `rustdoc`-generated test names look like `{file}_{line}_{number}`, e.g. +//! `...path_rust_kernel_sync_arc_rs_42_0`. `number` is the "test number", needed in cases like +//! a macro that expands into items with doctests is invoked several times within the same line. +//! +//! However, since these names are used for bisection in CI, the line number makes it not stable +//! at all. In the future, we would like `rustdoc` to give us the Rust item path associated with +//! the test, plus a "test number" (for cases with several examples per item) and generate a name +//! from that. For the moment, we generate ourselves a new name, `{file}_{number}` instead, in +//! the `gen` script (done there since we need to be aware of all the tests in a given file). + +use std::io::Read; + +fn main() { + let mut stdin = std::io::stdin().lock(); + let mut body = String::new(); + stdin.read_to_string(&mut body).unwrap(); + + // Find the generated function name looking for the inner function inside `main()`. + // + // The line we are looking for looks like one of the following: + // + // ``` + // fn main() { #[allow(non_snake_case)] fn _doctest_main_rust_kernel_file_rs_28_0() { + // fn main() { #[allow(non_snake_case)] fn _doctest_main_rust_kernel_file_rs_37_0() -> Result<(), impl core::fmt::Debug> { + // ``` + // + // It should be unlikely that doctest code matches such lines (when code is formatted properly). + let rustdoc_function_name = body + .lines() + .find_map(|line| { + Some( + line.split_once("fn main() {")? + .1 + .split_once("fn ")? + .1 + .split_once("()")? + .0, + ) + .filter(|x| x.chars().all(|c| c.is_alphanumeric() || c == '_')) + }) + .expect("No test function found in `rustdoc`'s output."); + + // Qualify `Result` to avoid the collision with our own `Result` coming from the prelude. + let body = body.replace( + &format!("{rustdoc_function_name}() -> Result<(), impl core::fmt::Debug> {{"), + &format!("{rustdoc_function_name}() -> core::result::Result<(), impl core::fmt::Debug> {{"), + ); + + // For tests that get generated with `Result`, like above, `rustdoc` generates an `unwrap()` on + // the return value to check there were no returned errors. Instead, we use our assert macro + // since we want to just fail the test, not panic the kernel. + // + // We save the result in a variable so that the failed assertion message looks nicer. + let body = body.replace( + &format!("}} {rustdoc_function_name}().unwrap() }}"), + &format!("}} let test_return_value = {rustdoc_function_name}(); assert!(test_return_value.is_ok()); }}"), + ); + + // Figure out a smaller test name based on the generated function name. + let name = rustdoc_function_name.split_once("_rust_kernel_").unwrap().1; + + let path = format!("rust/test/doctests/kernel/{name}"); + + std::fs::write(path, body.as_bytes()).unwrap(); +} diff --git a/scripts/rustdoc_test_gen.rs b/scripts/rustdoc_test_gen.rs new file mode 100644 index 000000000000..5ebd42ae4a3f --- /dev/null +++ b/scripts/rustdoc_test_gen.rs @@ -0,0 +1,260 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Generates KUnit tests from saved `rustdoc`-generated tests. +//! +//! KUnit passes a context (`struct kunit *`) to each test, which should be forwarded to the other +//! KUnit functions and macros. +//! +//! However, we want to keep this as an implementation detail because: +//! +//! - Test code should not care about the implementation. +//! +//! - Documentation looks worse if it needs to carry extra details unrelated to the piece +//! being described. +//! +//! - Test code should be able to define functions and call them, without having to carry +//! the context. +//! +//! - Later on, we may want to be able to test non-kernel code (e.g. `core`, `alloc` or +//! third-party crates) which likely use the standard library `assert*!` macros. +//! +//! For this reason, instead of the passed context, `kunit_get_current_test()` is used instead +//! (i.e. `current->kunit_test`). +//! +//! Note that this means other threads/tasks potentially spawned by a given test, if failing, will +//! report the failure in the kernel log but will not fail the actual test. Saving the pointer in +//! e.g. a `static` per test does not fully solve the issue either, because currently KUnit does +//! not support assertions (only expectations) from other tasks. Thus leave that feature for +//! the future, which simplifies the code here too. We could also simply not allow `assert`s in +//! other tasks, but that seems overly constraining, and we do want to support them, eventually. + +use std::{ + fs, + fs::File, + io::{BufWriter, Read, Write}, + path::{Path, PathBuf}, +}; + +/// Find the real path to the original file based on the `file` portion of the test name. +/// +/// `rustdoc` generated `file`s look like `sync_locked_by_rs`. Underscores (except the last one) +/// may represent an actual underscore in a directory/file, or a path separator. Thus the actual +/// file might be `sync_locked_by.rs`, `sync/locked_by.rs`, `sync_locked/by.rs` or +/// `sync/locked/by.rs`. This function walks the file system to determine which is the real one. +/// +/// This does require that ambiguities do not exist, but that seems fair, especially since this is +/// all supposed to be temporary until `rustdoc` gives us proper metadata to build this. If such +/// ambiguities are detected, they are diagnosed and the script panics. +fn find_real_path<'a>(srctree: &Path, valid_paths: &'a mut Vec, file: &str) -> &'a str { + valid_paths.clear(); + + let potential_components: Vec<&str> = file.strip_suffix("_rs").unwrap().split('_').collect(); + + find_candidates(srctree, valid_paths, Path::new(""), &potential_components); + fn find_candidates( + srctree: &Path, + valid_paths: &mut Vec, + prefix: &Path, + potential_components: &[&str], + ) { + // The base case: check whether all the potential components left, joined by underscores, + // is a file. + let joined_potential_components = potential_components.join("_") + ".rs"; + if srctree + .join("rust/kernel") + .join(prefix) + .join(&joined_potential_components) + .is_file() + { + // Avoid `srctree` here in order to keep paths relative to it in the KTAP output. + valid_paths.push( + Path::new("rust/kernel") + .join(prefix) + .join(joined_potential_components), + ); + } + + // In addition, check whether each component prefix, joined by underscores, is a directory. + // If not, there is no need to check for combinations with that prefix. + for i in 1..potential_components.len() { + let (components_prefix, components_rest) = potential_components.split_at(i); + let prefix = prefix.join(components_prefix.join("_")); + if srctree.join("rust/kernel").join(&prefix).is_dir() { + find_candidates(srctree, valid_paths, &prefix, components_rest); + } + } + } + + assert!( + valid_paths.len() > 0, + "No path candidates found. This is likely a bug in the build system, or some files went \ + away while compiling." + ); + + if valid_paths.len() > 1 { + eprintln!("Several path candidates found:"); + for path in valid_paths { + eprintln!(" {path:?}"); + } + panic!( + "Several path candidates found, please resolve the ambiguity by renaming a file or \ + folder." + ); + } + + valid_paths[0].to_str().unwrap() +} + +fn main() { + let srctree = std::env::var("srctree").unwrap(); + let srctree = Path::new(&srctree); + + let mut paths = fs::read_dir("rust/test/doctests/kernel") + .unwrap() + .map(|entry| entry.unwrap().path()) + .collect::>(); + + // Sort paths. + paths.sort(); + + let mut rust_tests = String::new(); + let mut c_test_declarations = String::new(); + let mut c_test_cases = String::new(); + let mut body = String::new(); + let mut last_file = String::new(); + let mut number = 0; + let mut valid_paths: Vec = Vec::new(); + let mut real_path: &str = ""; + for path in paths { + // The `name` follows the `{file}_{line}_{number}` pattern (see description in + // `scripts/rustdoc_test_builder.rs`). Discard the `number`. + let name = path.file_name().unwrap().to_str().unwrap().to_string(); + + // Extract the `file` and the `line`, discarding the `number`. + let (file, line) = name.rsplit_once('_').unwrap().0.rsplit_once('_').unwrap(); + + // Generate an ID sequence ("test number") for each one in the file. + if file == last_file { + number += 1; + } else { + number = 0; + last_file = file.to_string(); + + // Figure out the real path, only once per file. + real_path = find_real_path(srctree, &mut valid_paths, file); + } + + // Generate a KUnit name (i.e. test name and C symbol) for this test. + // + // We avoid the line number, like `rustdoc` does, to make things slightly more stable for + // bisection purposes. However, to aid developers in mapping back what test failed, we will + // print a diagnostics line in the KTAP report. + let kunit_name = format!("rust_doctest_kernel_{file}_{number}"); + + // Read the test's text contents to dump it below. + body.clear(); + File::open(path).unwrap().read_to_string(&mut body).unwrap(); + + // Calculate how many lines before `main` function (including the `main` function line). + let body_offset = body + .lines() + .take_while(|line| !line.contains("fn main() {")) + .count() + + 1; + + use std::fmt::Write; + write!( + rust_tests, + r#"/// Generated `{name}` KUnit test case from a Rust documentation test. +#[no_mangle] +pub extern "C" fn {kunit_name}(__kunit_test: *mut kernel::bindings::kunit) {{ + /// Overrides the usual [`assert!`] macro with one that calls KUnit instead. + #[allow(unused)] + macro_rules! assert {{ + ($cond:expr $(,)?) => {{{{ + kernel::kunit_assert!("{kunit_name}", "{real_path}", __DOCTEST_ANCHOR - {line}, $cond); + }}}} + }} + + /// Overrides the usual [`assert_eq!`] macro with one that calls KUnit instead. + #[allow(unused)] + macro_rules! assert_eq {{ + ($left:expr, $right:expr $(,)?) => {{{{ + kernel::kunit_assert_eq!("{kunit_name}", "{real_path}", __DOCTEST_ANCHOR - {line}, $left, $right); + }}}} + }} + + // Many tests need the prelude, so provide it by default. + #[allow(unused)] + use kernel::prelude::*; + + // Unconditionally print the location of the original doctest (i.e. rather than the location in + // the generated file) so that developers can easily map the test back to the source code. + // + // This information is also printed when assertions fail, but this helps in the successful cases + // when the user is running KUnit manually, or when passing `--raw_output` to `kunit.py`. + // + // This follows the syntax for declaring test metadata in the proposed KTAP v2 spec, which may + // be used for the proposed KUnit test attributes API. Thus hopefully this will make migration + // easier later on. + kernel::kunit::info(format_args!(" # {kunit_name}.location: {real_path}:{line}\n")); + + /// The anchor where the test code body starts. + #[allow(unused)] + static __DOCTEST_ANCHOR: i32 = core::line!() as i32 + {body_offset} + 1; + {{ + {body} + main(); + }} +}} + +"# + ) + .unwrap(); + + write!(c_test_declarations, "void {kunit_name}(struct kunit *);\n").unwrap(); + write!(c_test_cases, " KUNIT_CASE({kunit_name}),\n").unwrap(); + } + + let rust_tests = rust_tests.trim(); + let c_test_declarations = c_test_declarations.trim(); + let c_test_cases = c_test_cases.trim(); + + write!( + BufWriter::new(File::create("rust/doctests_kernel_generated.rs").unwrap()), + r#"//! `kernel` crate documentation tests. + +const __LOG_PREFIX: &[u8] = b"rust_doctests_kernel\0"; + +{rust_tests} +"# + ) + .unwrap(); + + write!( + BufWriter::new(File::create("rust/doctests_kernel_generated_kunit.c").unwrap()), + r#"/* + * `kernel` crate documentation tests. + */ + +#include + +{c_test_declarations} + +static struct kunit_case test_cases[] = {{ + {c_test_cases} + {{ }} +}}; + +static struct kunit_suite test_suite = {{ + .name = "rust_doctests_kernel", + .test_cases = test_cases, +}}; + +kunit_test_suite(test_suite); + +MODULE_LICENSE("GPL"); +"# + ) + .unwrap(); +}