From: Gary Guo <gary@garyguo.net> maillist inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5J75G CVE: NA Reference: https://lore.kernel.org/rust-for-linux/CANiq72nDcJLSB3pLhkdqGdLitfmqqCUVVfkY... -------------------------------- The `build_error` crate provides the `build_error` function which is then used to provide the `build_error!` and the `build_assert!` macros. `build_assert!` is intended to be used when `static_assert!` cannot be used, e.g. when the condition refers to generic parameters or parameters of an inline function. Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com> Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com> Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com> Signed-off-by: Gary Guo <gary@garyguo.net> Co-developed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Weilong Chen <chenweilong@huawei.com> --- rust/build_error.rs | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) create mode 100644 rust/build_error.rs diff --git a/rust/build_error.rs b/rust/build_error.rs new file mode 100644 index 000000000000..34e589149d3e --- /dev/null +++ b/rust/build_error.rs @@ -0,0 +1,29 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Build-time error. +//! +//! This crate provides a function `build_error`, which will panic in +//! compile-time if executed in 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, but those +//! functions could still be called in the runtime). + +#![no_std] + +/// Panics if executed in const context, or triggers a build error if not. +#[inline(never)] +#[cold] +#[no_mangle] +#[track_caller] +pub const fn build_error(msg: &'static str) -> ! { + panic!("{}", msg); +} + +#[cfg(CONFIG_RUST_BUILD_ASSERT_WARN)] +#[link_section = ".gnu.warning.build_error"] +#[used] +static BUILD_ERROR_WARNING: [u8; 45] = *b"call to build_error present after compilation"; -- 2.20.1