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forbid toggling x87 and fpregs on hard-float targets

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This commit is contained in:
Ralf Jung 2024-11-16 10:26:46 +01:00
parent 2d887a5c5c
commit d6ddc73dae
20 changed files with 129 additions and 8 deletions
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12
compiler/rustc_target/src/spec/mod.rs
View file

@ -2603,6 +2603,18 @@ impl TargetOptions {
.collect();
}
}
pub(crate) fn has_feature(&self, search_feature: &str) -> bool {
self.features.split(',').any(|f| {
if let Some(f) = f.strip_prefix('+')
&& f == search_feature
{
true
} else {
false
}
})
}
}
impl Default for TargetOptions {

36
compiler/rustc_target/src/target_features.rs
View file

@ -32,6 +32,8 @@ pub enum Stability<AllowToggle> {
/// This target feature is unstable. It is only present in `#[cfg(target_feature)]` on
/// nightly and using it in `#[target_feature]` requires enabling the given nightly feature.
Unstable {
/// This must be a *language* feature, or else rustc will ICE when reporting a missing
/// feature gate!
nightly_feature: Symbol,
/// See `Stable::allow_toggle` comment above.
allow_toggle: AllowToggle,
@ -168,6 +170,22 @@ const ARM_FEATURES: &[(&str, StabilityUncomputed, ImpliedFeatures)] = &[
("dotprod", unstable(sym::arm_target_feature), &["neon"]),
("dsp", unstable(sym::arm_target_feature), &[]),
("fp-armv8", unstable(sym::arm_target_feature), &["vfp4"]),
(
"fpregs",
Stability::Unstable {
nightly_feature: sym::arm_target_feature,
allow_toggle: |target: &Target| {
// Only allow toggling this if the target has `soft-float` set. With `soft-float`,
// `fpregs` isn't needed so changing it cannot affect the ABI.
if target.has_feature("soft-float") {
Ok(())
} else {
Err("unsound on hard-float targets because it changes float ABI")
}
},
},
&[],
),
("i8mm", unstable(sym::arm_target_feature), &["neon"]),
("mclass", unstable(sym::arm_target_feature), &[]),
("neon", unstable(sym::arm_target_feature), &["vfp3"]),
@ -191,7 +209,6 @@ const ARM_FEATURES: &[(&str, StabilityUncomputed, ImpliedFeatures)] = &[
("vfp4", unstable(sym::arm_target_feature), &["vfp3"]),
("virtualization", unstable(sym::arm_target_feature), &[]),
// tidy-alphabetical-end
// FIXME: need to also forbid turning off `fpregs` on hardfloat targets
];
const AARCH64_FEATURES: &[(&str, StabilityUncomputed, ImpliedFeatures)] = &[
@ -450,13 +467,28 @@ const X86_FEATURES: &[(&str, StabilityUncomputed, ImpliedFeatures)] = &[
("tbm", unstable(sym::tbm_target_feature), &[]),
("vaes", unstable(sym::avx512_target_feature), &["avx2", "aes"]),
("vpclmulqdq", unstable(sym::avx512_target_feature), &["avx", "pclmulqdq"]),
(
"x87",
Stability::Unstable {
nightly_feature: sym::x87_target_feature,
allow_toggle: |target: &Target| {
// Only allow toggling this if the target has `soft-float` set. With `soft-float`,
// `fpregs` isn't needed so changing it cannot affect the ABI.
if target.has_feature("soft-float") {
Ok(())
} else {
Err("unsound on hard-float targets because it changes float ABI")
}
},
},
&[],
),
("xop", unstable(sym::xop_target_feature), &[/*"fma4", */ "avx", "sse4a"]),
("xsave", STABLE, &[]),
("xsavec", STABLE, &["xsave"]),
("xsaveopt", STABLE, &["xsave"]),
("xsaves", STABLE, &["xsave"]),
// tidy-alphabetical-end
// FIXME: need to also forbid turning off `x87` on hardfloat targets
];
const HEXAGON_FEATURES: &[(&str, StabilityUncomputed, ImpliedFeatures)] = &[