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Merged
rust-bors merged 1 commit into from
Mar 11, 2026
Merged

improve target feature diagnostic #153676

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17 changes: 15 additions & 2 deletions compiler/rustc_codegen_ssa/src/errors.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -1248,8 +1248,21 @@ pub(crate) struct FeatureNotValid<'a> {
#[primary_span]
#[label("`{$feature}` is not valid for this target")]
pub span: Span,
#[help("consider removing the leading `+` in the feature name")]
pub plus_hint: bool,
#[subdiagnostic]
pub plus_hint: Option<RemovePlusFromFeatureName<'a>>,
}

#[derive(Subdiagnostic)]
#[suggestion(
"consider removing the leading `+` in the feature name",
code = "enable = \"{stripped}\"",
applicability = "maybe-incorrect",
style = "verbose"
)]
pub struct RemovePlusFromFeatureName<'a> {
#[primary_span]
pub span: Span,
pub stripped: &'a str,
}

#[derive(Diagnostic)]
Expand Down
5 changes: 3 additions & 2 deletions compiler/rustc_codegen_ssa/src/target_features.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -14,7 +14,7 @@ use rustc_target::spec::Arch;
use rustc_target::target_features::{RUSTC_SPECIFIC_FEATURES, Stability};
use smallvec::SmallVec;

use crate::errors::FeatureNotValid;
use crate::errors::{FeatureNotValid, RemovePlusFromFeatureName};
use crate::{errors, target_features};

/// Compute the enabled target features from the `#[target_feature]` function attribute.
Expand All @@ -34,7 +34,8 @@ pub(crate) fn from_target_feature_attr(
let Some(stability) = rust_target_features.get(feature_str) else {
let plus_hint = feature_str
.strip_prefix('+')
.is_some_and(|stripped| rust_target_features.contains_key(stripped));
.filter(|stripped| rust_target_features.contains_key(*stripped))
.map(|stripped| RemovePlusFromFeatureName { span: feature_span, stripped });
tcx.dcx().emit_err(FeatureNotValid {
feature: feature_str,
span: feature_span,
Expand Down
2 changes: 2 additions & 0 deletions tests/auxiliary/minicore.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -236,6 +236,8 @@ impl_marker_trait!(
]
);

impl Sync for () {}

@folkertdev folkertdev Mar 10, 2026

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() does not work with the macro right above. So this will have to do.


#[lang = "drop_in_place"]
fn drop_in_place<T>(_: *mut T) {}

Expand Down
17 changes: 14 additions & 3 deletions tests/ui/target-feature/invalid-attribute.rs
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@@ -1,14 +1,20 @@
//@ only-x86_64
//@ add-minicore
//@ compile-flags: --target=x86_64-unknown-linux-gnu
//@ needs-llvm-components: x86

#![warn(unused_attributes)]
#![feature(no_core)]
#![no_core]

use minicore::*;

#[target_feature(enable = "sse2")]
//~^ ERROR attribute cannot be used on
extern crate alloc;
extern crate minicore;

#[target_feature(enable = "sse2")]
//~^ ERROR attribute cannot be used on
use alloc::alloc::alloc;
use minicore::mem::transmute;

#[target_feature(enable = "sse2")]
//~^ ERROR attribute cannot be used on
Expand Down Expand Up @@ -112,3 +118,8 @@ fn main() {
//~^ ERROR `+sse2` is not valid for this target
//~| NOTE `+sse2` is not valid for this target
unsafe fn hey() {}

#[target_feature(enable = "+sse5")]
//~^ ERROR `+sse5` is not valid for this target
//~| NOTE `+sse5` is not valid for this target
unsafe fn typo() {}
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64 changes: 37 additions & 27 deletions tests/ui/target-feature/invalid-attribute.stderr
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@@ -1,29 +1,29 @@
error: `#[target_feature]` attribute cannot be used on extern crates
--> $DIR/invalid-attribute.rs:5:1
--> $DIR/invalid-attribute.rs:11:1
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error: `#[target_feature]` attribute cannot be used on use statements
--> $DIR/invalid-attribute.rs:9:1
--> $DIR/invalid-attribute.rs:15:1
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error: `#[target_feature]` attribute cannot be used on foreign modules
--> $DIR/invalid-attribute.rs:13:1
--> $DIR/invalid-attribute.rs:19:1
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error[E0539]: malformed `target_feature` attribute input
--> $DIR/invalid-attribute.rs:17:1
--> $DIR/invalid-attribute.rs:23:1
|
LL | #[target_feature = "+sse2"]
| ^^^^^^^^^^^^^^^^^---------^
Expand All @@ -32,7 +32,7 @@ LL | #[target_feature = "+sse2"]
| help: must be of the form: `#[target_feature(enable = "feat1, feat2")]`

error[E0539]: malformed `target_feature` attribute input
--> $DIR/invalid-attribute.rs:23:1
--> $DIR/invalid-attribute.rs:29:1
|
LL | #[target_feature(bar)]
| ^^^^^^^^^^^^^^^^^---^^
Expand All @@ -41,7 +41,7 @@ LL | #[target_feature(bar)]
| help: must be of the form: `#[target_feature(enable = "feat1, feat2")]`

error[E0539]: malformed `target_feature` attribute input
--> $DIR/invalid-attribute.rs:26:1
--> $DIR/invalid-attribute.rs:32:1
|
LL | #[target_feature(disable = "baz")]
| ^^^^^^^^^^^^^^^^^-------^^^^^^^^^^
Expand All @@ -50,103 +50,103 @@ LL | #[target_feature(disable = "baz")]
| help: must be of the form: `#[target_feature(enable = "feat1, feat2")]`

error: `#[target_feature]` attribute cannot be used on modules
--> $DIR/invalid-attribute.rs:31:1
--> $DIR/invalid-attribute.rs:37:1
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error: `#[target_feature]` attribute cannot be used on constants
--> $DIR/invalid-attribute.rs:35:1
--> $DIR/invalid-attribute.rs:41:1
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error: `#[target_feature]` attribute cannot be used on structs
--> $DIR/invalid-attribute.rs:39:1
--> $DIR/invalid-attribute.rs:45:1
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error: `#[target_feature]` attribute cannot be used on enums
--> $DIR/invalid-attribute.rs:43:1
--> $DIR/invalid-attribute.rs:49:1
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error: `#[target_feature]` attribute cannot be used on unions
--> $DIR/invalid-attribute.rs:47:1
--> $DIR/invalid-attribute.rs:53:1
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error: `#[target_feature]` attribute cannot be used on type aliases
--> $DIR/invalid-attribute.rs:54:1
--> $DIR/invalid-attribute.rs:60:1
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error: `#[target_feature]` attribute cannot be used on traits
--> $DIR/invalid-attribute.rs:58:1
--> $DIR/invalid-attribute.rs:64:1
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error: `#[target_feature]` attribute cannot be used on statics
--> $DIR/invalid-attribute.rs:69:1
--> $DIR/invalid-attribute.rs:75:1
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error: `#[target_feature]` attribute cannot be used on trait impl blocks
--> $DIR/invalid-attribute.rs:73:1
--> $DIR/invalid-attribute.rs:79:1
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error: `#[target_feature]` attribute cannot be used on inherent impl blocks
--> $DIR/invalid-attribute.rs:79:1
--> $DIR/invalid-attribute.rs:85:1
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error: `#[target_feature]` attribute cannot be used on expressions
--> $DIR/invalid-attribute.rs:100:5
--> $DIR/invalid-attribute.rs:106:5
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can only be applied to functions

error: `#[target_feature]` attribute cannot be used on closures
--> $DIR/invalid-attribute.rs:106:5
--> $DIR/invalid-attribute.rs:112:5
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= help: `#[target_feature]` can be applied to functions and methods

error[E0658]: cannot use `#[inline(always)]` with `#[target_feature]`
--> $DIR/invalid-attribute.rs:62:1
--> $DIR/invalid-attribute.rs:68:1
|
LL | #[inline(always)]
| ^^^^^^^^^^^^^^^^^
Expand All @@ -156,13 +156,13 @@ LL | #[inline(always)]
= note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date

error: the feature named `foo` is not valid for this target
--> $DIR/invalid-attribute.rs:20:18
--> $DIR/invalid-attribute.rs:26:18
|
LL | #[target_feature(enable = "foo")]
| ^^^^^^^^^^^^^^ `foo` is not valid for this target

error[E0046]: not all trait items implemented, missing: `foo`
--> $DIR/invalid-attribute.rs:75:1
--> $DIR/invalid-attribute.rs:81:1
|
LL | impl Quux for u8 {}
| ^^^^^^^^^^^^^^^^ missing `foo` in implementation
Expand All @@ -171,7 +171,7 @@ LL | fn foo();
| --------- `foo` from trait

error: `#[target_feature(..)]` cannot be applied to safe trait method
--> $DIR/invalid-attribute.rs:89:5
--> $DIR/invalid-attribute.rs:95:5
|
LL | #[target_feature(enable = "sse2")]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ cannot be applied to safe trait method
Expand All @@ -180,28 +180,38 @@ LL | fn foo() {}
| -------- not an `unsafe` function

error[E0053]: method `foo` has an incompatible type for trait
--> $DIR/invalid-attribute.rs:92:5
--> $DIR/invalid-attribute.rs:98:5
|
LL | fn foo() {}
| ^^^^^^^^ expected safe fn, found unsafe fn
|
note: type in trait
--> $DIR/invalid-attribute.rs:84:5
--> $DIR/invalid-attribute.rs:90:5
|
LL | fn foo();
| ^^^^^^^^^
= note: expected signature `fn()`
found signature `#[target_features] fn()`

error: the feature named `+sse2` is not valid for this target
--> $DIR/invalid-attribute.rs:111:18
--> $DIR/invalid-attribute.rs:117:18
|
LL | #[target_feature(enable = "+sse2")]
| ^^^^^^^^^^^^^^^^ `+sse2` is not valid for this target
|
= help: consider removing the leading `+` in the feature name
help: consider removing the leading `+` in the feature name
|
LL - #[target_feature(enable = "+sse2")]
LL + #[target_feature(enable = "sse2")]
|

error: the feature named `+sse5` is not valid for this target
--> $DIR/invalid-attribute.rs:122:18
|
LL | #[target_feature(enable = "+sse5")]
| ^^^^^^^^^^^^^^^^ `+sse5` is not valid for this target

error: aborting due to 24 previous errors
error: aborting due to 25 previous errors

Some errors have detailed explanations: E0046, E0053, E0539, E0658.
For more information about an error, try `rustc --explain E0046`.
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