rust-for-linux.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Miguel Ojeda <ojeda@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: rust-for-linux@vger.kernel.org, linux-kbuild@vger.kernel.org,
	linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
	Gary Guo <gary@garyguo.net>, Alex Gaynor <alex.gaynor@gmail.com>,
	Wedson Almeida Filho <wedsonaf@google.com>,
	Miguel Ojeda <ojeda@kernel.org>
Subject: [PATCH 07/19] rust: add `build_error` crate
Date: Mon,  6 Dec 2021 15:03:01 +0100	[thread overview]
Message-ID: <20211206140313.5653-8-ojeda@kernel.org> (raw)
In-Reply-To: <20211206140313.5653-1-ojeda@kernel.org>

From: Gary Guo <gary@garyguo.net>

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>
---
 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";
-- 
2.34.0


  parent reply	other threads:[~2021-12-06 14:05 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-06 14:02 [PATCH 00/19] Rust support Miguel Ojeda
2021-12-06 14:02 ` [PATCH 01/19] kallsyms: support "big" kernel symbols Miguel Ojeda
2021-12-06 14:18   ` Matthew Wilcox
2021-12-06 17:00     ` Miguel Ojeda
2021-12-06 14:02 ` [PATCH 02/19] kallsyms: increase maximum kernel symbol length to 512 Miguel Ojeda
2021-12-06 14:02 ` [PATCH 03/19] kallsyms: use the correct buffer size for symbols Miguel Ojeda
2021-12-06 14:02 ` [PATCH 04/19] rust: add C helpers Miguel Ojeda
2021-12-06 14:02 ` [PATCH 05/19] rust: add `compiler_builtins` crate Miguel Ojeda
2021-12-07 23:01   ` Nick Desaulniers
2021-12-09 19:34     ` Miguel Ojeda
2021-12-06 14:03 ` Miguel Ojeda [this message]
2021-12-06 14:03 ` [PATCH 08/19] rust: add `macros` crate Miguel Ojeda
2021-12-06 14:03 ` [PATCH 10/19] rust: export generated symbols Miguel Ojeda
2021-12-06 14:03 ` [PATCH 11/19] vsprintf: add new `%pA` format specifier Miguel Ojeda
2021-12-06 15:02   ` Greg Kroah-Hartman
2021-12-06 15:56     ` Miguel Ojeda
2021-12-06 16:02       ` Greg Kroah-Hartman
2021-12-06 19:52         ` Nick Desaulniers
2021-12-06 19:55           ` Matthew Wilcox
2021-12-06 20:02             ` Nick Desaulniers
2021-12-06 14:03 ` [PATCH 12/19] scripts: add `generate_rust_analyzer.py` Miguel Ojeda
2021-12-06 14:03 ` [PATCH 13/19] scripts: decode_stacktrace: demangle Rust symbols Miguel Ojeda
2021-12-06 14:03 ` [PATCH 14/19] docs: add Rust documentation Miguel Ojeda
2021-12-08  1:29   ` Nick Desaulniers
2021-12-08 23:07     ` Miguel Ojeda
2021-12-06 14:03 ` [PATCH 15/19] Kbuild: add Rust support Miguel Ojeda
2021-12-07 22:45   ` Nick Desaulniers
2021-12-07 23:21     ` Nick Desaulniers
2021-12-07 23:25       ` Wedson Almeida Filho
2021-12-08  0:05         ` Nick Desaulniers
2021-12-08 22:52     ` Miguel Ojeda
2021-12-11 15:53   ` Masahiro Yamada
2022-01-17  4:45     ` Miguel Ojeda
2021-12-06 14:03 ` [PATCH 16/19] samples: add Rust examples Miguel Ojeda
2021-12-06 14:03 ` [PATCH 17/19] MAINTAINERS: Rust Miguel Ojeda
2021-12-06 14:03 ` [RFC PATCH 18/19] drivers: gpio: PrimeCell PL061 in Rust Miguel Ojeda
     [not found] ` <20211206140313.5653-20-ojeda@kernel.org>
2021-12-06 15:01   ` [RFC PATCH 19/19] drivers: android: Binder IPC " Greg Kroah-Hartman
2021-12-06 15:59     ` Wedson Almeida Filho
2021-12-06 16:02       ` Greg Kroah-Hartman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20211206140313.5653-8-ojeda@kernel.org \
    --to=ojeda@kernel.org \
    --cc=alex.gaynor@gmail.com \
    --cc=gary@garyguo.net \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-kbuild@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=rust-for-linux@vger.kernel.org \
    --cc=torvalds@linux-foundation.org \
    --cc=wedsonaf@google.com \
    --subject='Re: [PATCH 07/19] rust: add `build_error` crate' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).