| 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | |
| 3 | //! Our own `compiler_builtins`. |
| 4 | //! |
| 5 | //! Rust provides [`compiler_builtins`] as a port of LLVM's [`compiler-rt`]. |
| 6 | //! Since we do not need the vast majority of them, we avoid the dependency |
| 7 | //! by providing this file. |
| 8 | //! |
| 9 | //! At the moment, some builtins are required that should not be. For instance, |
| 10 | //! [`core`] has 128-bit integers functionality which we should not be compiling |
| 11 | //! in. We will work with upstream [`core`] to provide feature flags to disable |
| 12 | //! the parts we do not need. For the moment, we define them to [`panic!`] at |
| 13 | //! runtime for simplicity to catch mistakes, instead of performing surgery |
| 14 | //! on `core.o`. |
| 15 | //! |
| 16 | //! In any case, all these symbols are weakened to ensure we do not override |
| 17 | //! those that may be provided by the rest of the kernel. |
| 18 | //! |
| 19 | //! [`compiler_builtins`]: https://github.com/rust-lang/compiler-builtins |
| 20 | //! [`compiler-rt`]: https://compiler-rt.llvm.org/ |
| 21 | |
| 22 | #![feature(compiler_builtins)] |
| 23 | #![compiler_builtins] |
| 24 | #![no_builtins] |
| 25 | #![no_std] |
| 26 | |
| 27 | macro_rules! define_panicking_intrinsics( |
| 28 | ($reason: tt, { $($ident: ident, )* }) => { |
| 29 | $( |
| 30 | #[doc(hidden)] |
| 31 | #[export_name = concat!("__rust", stringify!($ident))] |
| 32 | pub extern "C" fn $ident() { |
| 33 | panic!($reason); |
| 34 | } |
| 35 | )* |
| 36 | } |
| 37 | ); |
| 38 | |
| 39 | define_panicking_intrinsics!("`f32` should not be used", { |
| 40 | __eqsf2, |
| 41 | __gesf2, |
| 42 | __lesf2, |
| 43 | __nesf2, |
| 44 | __unordsf2, |
| 45 | }); |
| 46 | |
| 47 | define_panicking_intrinsics!("`f64` should not be used", { |
| 48 | __unorddf2, |
| 49 | }); |
| 50 | |
| 51 | define_panicking_intrinsics!("`i128` should not be used", { |
| 52 | __ashrti3, |
| 53 | __muloti4, |
| 54 | __multi3, |
| 55 | }); |
| 56 | |
| 57 | define_panicking_intrinsics!("`u128` should not be used", { |
| 58 | __ashlti3, |
| 59 | __lshrti3, |
| 60 | __udivmodti4, |
| 61 | __udivti3, |
| 62 | __umodti3, |
| 63 | }); |
| 64 | |
| 65 | // NOTE: if you are adding a new intrinsic here, you should also add it to |
| 66 | // `redirect-intrinsics` in `rust/Makefile`. |