Le 13/06/2026 à 10:04 PM, Gary Guo a écrit :
> From: Gary Guo <[email protected]>
>
> Currently rustdoc will generate function names like
> "_doctest_main__home_gary_Projects_linux_rust_kernel_io_rs_824_0" for a
> doctest located at rust/kernel/io.rs:824, when building with separate
> outdir using `O=`. This creates overlong symbol names and is also not
> reproducible.
>
> Fix it by doing a custom remapping to trim it to something like
> `_doctest_main_rust_kernel_io_rs_824_0`.
>
> Signed-off-by: Gary Guo <[email protected]>
> ---
Hi Gary,
This seems to break older versions of rustc. For example, with
rust 1.93.1, the build now fails with errors like:
ERROR:root:error[E0425]: cannot find function
`_doctest_main_rust_kernel_alloc_allocator_rs_176_0` in this scope
--> rust/doctests_kernel_generated.rs:74:27
|
74 | } let test_return_value =
_doctest_main_rust_kernel_alloc_allocator_rs_176_0();
assert!(test_return_value.is_ok()); }
|
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope
Am I missing something? I'm using kunit.py to build:
./tools/testing/kunit/kunit.py run --kconfig_add CONFIG_RUST=y
rust_doctests_kernel
Seems to be working okay with 1.96, though.
Cheers,
-- David
> scripts/rustdoc_test_builder.rs | 14 +++++++++-----
> 1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/scripts/rustdoc_test_builder.rs b/scripts/rustdoc_test_builder.rs
> index 2b1f9ba01839..fda7284355f8 100644
> --- a/scripts/rustdoc_test_builder.rs
> +++ b/scripts/rustdoc_test_builder.rs
> @@ -47,11 +47,18 @@ fn main() {
> })
> .expect("No test function found in `rustdoc`'s output.");
>
> + // Figure out a smaller test name based on the generated function name.
> + let name = rustdoc_function_name.split_once("_rust_kernel_").unwrap().1;
> +
> + // The rustdoc function name can include the absolute path when building
> with `O=` which is
> + // undesireable and create overlong symbol names. Remap it to relative
> path.
> + let trimmed_function_name = format!("_doctest_main_rust_kernel_{name}");
> +
> // 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> {{"
> + "{trimmed_function_name}() -> ::core::result::Result<(), impl
> ::core::fmt::Debug> {{"
> ),
> );
>
> @@ -62,12 +69,9 @@ fn main() {
> // 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()); }}"),
> + &format!("}} let test_return_value = {trimmed_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();
