rust/tests/ui/sse-abi-checks.rs
Luca Versari c8b76bcf58 Emit warning when calling/declaring functions with unavailable vectors.
On some architectures, vector types may have a different ABI depending
on whether the relevant target features are enabled. (The ABI when the
feature is disabled is often not specified, but LLVM implements some
de-facto ABI.)

As discussed in rust-lang/lang-team#235, this turns out to very easily
lead to unsound code.

This commit makes it a post-monomorphization future-incompat warning to
declare or call functions using those vector types in a context in which
the corresponding target features are disabled, if using an ABI for
which the difference is relevant. This ensures that these functions are
always called with a consistent ABI.

See the [nomination comment](https://github.com/rust-lang/rust/pull/127731#issuecomment-2288558187)
for more discussion.

Part of #116558
2024-11-01 22:24:35 +01:00

25 lines
805 B
Rust

//! Ensure we trigger abi_unsupported_vector_types for target features that are usually enabled
//! on a target, but disabled in this file via a `-C` flag.
//@ compile-flags: --crate-type=rlib --target=i686-unknown-linux-gnu -C target-feature=-sse,-sse2
//@ build-pass
//@ ignore-pass (test emits codegen-time warnings)
//@ needs-llvm-components: x86
#![feature(no_core, lang_items, repr_simd)]
#![no_core]
#![allow(improper_ctypes_definitions)]
#[lang = "sized"]
trait Sized {}
#[lang = "copy"]
trait Copy {}
#[repr(simd)]
pub struct SseVector([i64; 2]);
#[no_mangle]
pub unsafe extern "C" fn f(_: SseVector) {
//~^ ABI error: this function definition uses a vector type that requires the `sse` target feature, which is not enabled
//~| WARNING this was previously accepted by the compiler
}