bjoernager/rust
bjoernager/rust
1
Fork 0
Code Activity

Emit error when calling/declaring functions with unavailable vectors.

Browse source 
On some architectures, vector types may have a different ABI when
relevant target features are enabled.

As discussed in https://github.com/rust-lang/lang-team/issues/235, this
turns out to very easily lead to unsound code.

This commit makes it an error 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 commit is contained in:
Luca Versari 2024-07-13 19:35:05 +02:00
parent 7342830c05
commit 5af56cac38
16 changed files with 448 additions and 53 deletions
Download patch file Download diff file Expand all files Collapse all files

17
compiler/rustc_target/src/target_features.rs
View file

@ -522,6 +522,13 @@ pub fn all_known_features() -> impl Iterator<Item = (&'static str, Stability)> {
.map(|(f, s, _)| (f, s))
}
// These arrays represent the least-constraining feature that is required for vector types up to a
// certain size to have their "proper" ABI on each architecture.
// Note that they must be kept sorted by vector size.
const X86_FEATURES_FOR_CORRECT_VECTOR_ABI: &'static [(u64, &'static str)] =
&[(128, "sse"), (256, "avx"), (512, "avx512f")];
const AARCH64_FEATURES_FOR_CORRECT_VECTOR_ABI: &'static [(u64, &'static str)] = &[(128, "neon")];
impl super::spec::Target {
pub fn supported_target_features(
&self,
@ -543,6 +550,16 @@ impl super::spec::Target {
}
}
// Returns None if we do not support ABI checks on the given target yet.
pub fn features_for_correct_vector_abi(&self) -> Option<&'static [(u64, &'static str)]> {
match &*self.arch {
"x86" | "x86_64" => Some(X86_FEATURES_FOR_CORRECT_VECTOR_ABI),
"aarch64" => Some(AARCH64_FEATURES_FOR_CORRECT_VECTOR_ABI),
// FIXME: add support for non-tier1 architectures
_ => None,
}
}
pub fn tied_target_features(&self) -> &'static [&'static [&'static str]] {
match &*self.arch {
"aarch64" | "arm64ec" => AARCH64_TIED_FEATURES,