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authorKalle Valo <kvalo@kernel.org>2023-01-17 13:36:25 +0200
committerKalle Valo <kvalo@kernel.org>2023-01-17 13:36:25 +0200
commitd0e99511834b6828c960e978d9a8cb6e5731250d (patch)
treee7b062c1f9d28a55083477a1462286a7923a57fd /rust/build_error.rs
parentde7d0ff301fccc75281d7d8eb98c4a47faacf32d (diff)
parent80f8a66dede0a4b4e9e846765a97809c6fe49ce5 (diff)
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Merge wireless into wireless-next
Due to the two cherry picked commits from wireless to wireless-next we have several conflicts in mt76. To avoid any bugs with conflicts merge wireless into wireless-next. 96f134dc1964 wifi: mt76: handle possible mt76_rx_token_consume failures fe13dad8992b wifi: mt76: dma: do not increment queue head if mt76_dma_add_buf fails
Diffstat (limited to 'rust/build_error.rs')
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diff --git a/rust/build_error.rs b/rust/build_error.rs
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+// 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);
+}