From: Miguel Ojeda <ojeda@xxxxxxxxxx> Rust provides `compiler_builtins` as a port of LLVM's `compiler-rt`. Since we do not need the vast majority of them, we avoid the dependency by providing our own crate. Co-developed-by: Alex Gaynor <alex.gaynor@xxxxxxxxx> Signed-off-by: Alex Gaynor <alex.gaynor@xxxxxxxxx> Co-developed-by: Geoffrey Thomas <geofft@xxxxxxxxxxxxx> Signed-off-by: Geoffrey Thomas <geofft@xxxxxxxxxxxxx> Co-developed-by: Finn Behrens <me@xxxxxxxxx> Signed-off-by: Finn Behrens <me@xxxxxxxxx> Co-developed-by: Adam Bratschi-Kaye <ark.email@xxxxxxxxx> Signed-off-by: Adam Bratschi-Kaye <ark.email@xxxxxxxxx> Co-developed-by: Wedson Almeida Filho <wedsonaf@xxxxxxxxxx> Signed-off-by: Wedson Almeida Filho <wedsonaf@xxxxxxxxxx> Co-developed-by: Boqun Feng <boqun.feng@xxxxxxxxx> Signed-off-by: Boqun Feng <boqun.feng@xxxxxxxxx> Co-developed-by: Sumera Priyadarsini <sylphrenadin@xxxxxxxxx> Signed-off-by: Sumera Priyadarsini <sylphrenadin@xxxxxxxxx> Co-developed-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Co-developed-by: Sven Van Asbroeck <thesven73@xxxxxxxxx> Signed-off-by: Sven Van Asbroeck <thesven73@xxxxxxxxx> Co-developed-by: Gary Guo <gary@xxxxxxxxxxx> Signed-off-by: Gary Guo <gary@xxxxxxxxxxx> Co-developed-by: Boris-Chengbiao Zhou <bobo1239@xxxxxx> Signed-off-by: Boris-Chengbiao Zhou <bobo1239@xxxxxx> Co-developed-by: Fox Chen <foxhlchen@xxxxxxxxx> Signed-off-by: Fox Chen <foxhlchen@xxxxxxxxx> Co-developed-by: Ayaan Zaidi <zaidi.ayaan@xxxxxxxxx> Signed-off-by: Ayaan Zaidi <zaidi.ayaan@xxxxxxxxx> Co-developed-by: Douglas Su <d0u9.su@xxxxxxxxxxx> Signed-off-by: Douglas Su <d0u9.su@xxxxxxxxxxx> Co-developed-by: Yuki Okushi <jtitor@xxxxxxxx> Signed-off-by: Yuki Okushi <jtitor@xxxxxxxx> Signed-off-by: Miguel Ojeda <ojeda@xxxxxxxxxx> --- rust/compiler_builtins.rs | 146 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 146 insertions(+) create mode 100644 rust/compiler_builtins.rs diff --git a/rust/compiler_builtins.rs b/rust/compiler_builtins.rs new file mode 100644 index 00000000000..cb4bbf7be4e --- /dev/null +++ b/rust/compiler_builtins.rs @@ -0,0 +1,146 @@ +// SPDX-License-Identifier: GPL-2.0 + +//! Our own `compiler_builtins`. +//! +//! Rust provides [`compiler_builtins`] as a port of LLVM's [`compiler-rt`]. +//! Since we do not need the vast majority of them, we avoid the dependency +//! by providing this file. +//! +//! At the moment, some builtins are required that should not be. For instance, +//! [`core`] has floating-point functionality which we should not be compiling +//! in. We will work with upstream [`core`] to provide feature flags to disable +//! the parts we do not need. For the moment, we define them to [`panic!`] at +//! runtime for simplicity to catch mistakes, instead of performing surgery +//! on `core.o`. +//! +//! In any case, all these symbols are weakened to ensure we do not override +//! those that may be provided by the rest of the kernel. +//! +//! [`compiler_builtins`]: https://github.com/rust-lang/compiler-builtins +//! [`compiler-rt`]: https://compiler-rt.llvm.org/ + +#![feature(compiler_builtins)] +#![compiler_builtins] +#![no_builtins] +#![no_std] + +macro_rules! define_panicking_intrinsics( + ($reason: tt, { $($ident: ident, )* }) => { + $( + #[doc(hidden)] + #[no_mangle] + pub extern "C" fn $ident() { + panic!($reason); + } + )* + } +); + +define_panicking_intrinsics!("`f32` should not be used", { + __addsf3, + __addsf3vfp, + __aeabi_fcmpeq, + __aeabi_ul2f, + __divsf3, + __divsf3vfp, + __eqsf2, + __eqsf2vfp, + __fixsfdi, + __fixsfsi, + __fixsfti, + __fixunssfdi, + __fixunssfsi, + __fixunssfti, + __floatdisf, + __floatsisf, + __floattisf, + __floatundisf, + __floatunsisf, + __floatuntisf, + __gesf2, + __gesf2vfp, + __gtsf2, + __gtsf2vfp, + __lesf2, + __lesf2vfp, + __ltsf2, + __ltsf2vfp, + __mulsf3, + __mulsf3vfp, + __nesf2, + __nesf2vfp, + __powisf2, + __subsf3, + __subsf3vfp, + __unordsf2, +}); + +define_panicking_intrinsics!("`f64` should not be used", { + __adddf3, + __adddf3vfp, + __aeabi_dcmpeq, + __aeabi_ul2d, + __divdf3, + __divdf3vfp, + __eqdf2, + __eqdf2vfp, + __fixdfdi, + __fixdfsi, + __fixdfti, + __fixunsdfdi, + __fixunsdfsi, + __fixunsdfti, + __floatdidf, + __floatsidf, + __floattidf, + __floatundidf, + __floatunsidf, + __floatuntidf, + __gedf2, + __gedf2vfp, + __gtdf2, + __gtdf2vfp, + __ledf2, + __ledf2vfp, + __ltdf2, + __ltdf2vfp, + __muldf3, + __muldf3vfp, + __nedf2, + __nedf2vfp, + __powidf2, + __subdf3, + __subdf3vfp, + __unorddf2, +}); + +define_panicking_intrinsics!("`i128` should not be used", { + __ashrti3, + __muloti4, + __multi3, +}); + +define_panicking_intrinsics!("`u128` should not be used", { + __ashlti3, + __lshrti3, + __udivmodti4, + __udivti3, + __umodti3, +}); + +#[cfg(target_arch = "arm")] +define_panicking_intrinsics!("`u64` division/modulo should not be used", { + __aeabi_uldivmod, + __mulodi4, +}); + +extern "C" { + fn rust_helper_BUG() -> !; +} + +#[panic_handler] +fn panic(_info: &core::panic::PanicInfo<'_>) -> ! { + unsafe { + rust_helper_BUG(); + } +} -- 2.32.0
