mirror of
https://github.com/torvalds/linux.git
synced 2024-12-25 04:11:49 +00:00
ecaa6ddff2
The `build_error` crate provides a function `build_error` which will panic at compile-time if executed in const context and, by default, will cause a build error if not executed at compile time and the optimizer does not optimise away the call. The `CONFIG_RUST_BUILD_ASSERT_ALLOW` kernel option allows to relax the default build failure and convert it to a runtime check. If the runtime check fails, `panic!` will be called. Its functionality will be exposed to users as a couple macros in the `kernel` crate in the following patch, thus some documentation here refers to them for simplicity. Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Wei Liu <wei.liu@kernel.org> [Reworded, adapted for upstream and applied latest changes] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
32 lines
1.3 KiB
Rust
32 lines
1.3 KiB
Rust
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
//! Build-time error.
|
|
//!
|
|
//! This crate provides a [const function][const-functions] `build_error`, which will panic in
|
|
//! compile-time if executed in [const context][const-context], and will cause a build error
|
|
//! if not executed at compile time and the optimizer does not optimise away the call.
|
|
//!
|
|
//! It is used by `build_assert!` in the kernel crate, allowing checking of
|
|
//! conditions that could be checked statically, but could not be enforced in
|
|
//! Rust yet (e.g. perform some checks in [const functions][const-functions], but those
|
|
//! functions could still be called in the runtime).
|
|
//!
|
|
//! For details on constant evaluation in Rust, please see the [Reference][const-eval].
|
|
//!
|
|
//! [const-eval]: https://doc.rust-lang.org/reference/const_eval.html
|
|
//! [const-functions]: https://doc.rust-lang.org/reference/const_eval.html#const-functions
|
|
//! [const-context]: https://doc.rust-lang.org/reference/const_eval.html#const-context
|
|
|
|
#![no_std]
|
|
|
|
/// Panics if executed in [const context][const-context], or triggers a build error if not.
|
|
///
|
|
/// [const-context]: https://doc.rust-lang.org/reference/const_eval.html#const-context
|
|
#[inline(never)]
|
|
#[cold]
|
|
#[export_name = "rust_build_error"]
|
|
#[track_caller]
|
|
pub const fn build_error(msg: &'static str) -> ! {
|
|
panic!("{}", msg);
|
|
}
|