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mark core::arch::wasm32::unreachable as safe

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This intrinsic doesn't have any preconditions and is always safe to
call, so it can be safe.

This function is already stable, but dropping `unsafe` is a backwards
compatible change.

Note tha we already have a precedent for wasm intrinsics being safe --
wasm simd is safe.

It is relatively practically important to mark this safe --
wasm32::unreachable is directly useful in practice as more codesize
efficient `panic!()`.
This commit is contained in:
Aleksey Kladov 2021-08-11 20:14:39 +03:00 • committed by Amanieu d'Antras
parent 685e8d906d
commit e91f80fc22
1 changed files with 7 additions and 2 deletions
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9
library/stdarch/crates/core_arch/src/wasm32/mod.rs
View file

@ -12,10 +12,15 @@ pub use self::simd128::*;
mod memory;
pub use self::memory::*;
/// Generates the trap instruction `UNREACHABLE`
/// Generates the [`unreachable`] instruction, which causes an unconditional [trap].
///
/// This function is safe to call and immediately aborts the execution.
///
/// [`unreachable`]: https://webassembly.github.io/spec/core/syntax/instructions.html#syntax-instr-control
/// [trap]: https://webassembly.github.io/spec/core/intro/overview.html#trap
#[cfg_attr(test, assert_instr(unreachable))]
#[inline]
#[stable(feature = "unreachable_wasm32", since = "1.37.0")]
pub unsafe fn unreachable() -> ! {
pub fn unreachable() -> ! {
crate::intrinsics::abort()
}