Auto merge of #120715 - matthiaskrgr:rollup-sp1pp74, r=matthiaskrgr

Rollup of 12 pull requests

Successful merges:

 - #120520 (Some cleanups around diagnostic levels.)
 - #120575 (Simplify codegen diagnostic handling)
 - #120597 (Suggest `[tail @ ..]` on `[..tail]` and `[...tail]` where `tail` is unresolved)
 - #120602 (rustc_monomorphize: fix outdated comment in partition)
 - #120609 (hir: Stop keeping prefixes for most of `use` list stems)
 - #120631 (Emit a diagnostic for invalid target options)
 - #120632 (For E0223, suggest associated functions that are similar to the path)
 - #120670 (cleanup effect var handling)
 - #120673 (rustc_metadata: fix typo)
 - #120683 (miri: fix ICE with symbolic alignment check on extern static)
 - #120690 (Remove b-naber from the compiler review rotation)
 - #120713 (Make async closures test use async bound modifier)

r? `@ghost`
`@rustbot` modify labels: rollup

2 files changed, 14 insertions, 8 deletions

diff --git a/compiler/rustc_codegen_llvm/src/errors.rs b/compiler/rustc_codegen_llvm/src/errors.rs
index e839d278bea..587c5e9e8d2 100644
--- a/compiler/rustc_codegen_llvm/src/errors.rs
+++ b/compiler/rustc_codegen_llvm/src/errors.rs
@@ -253,3 +253,9 @@ pub struct MismatchedDataLayout<'a> {
     pub llvm_target: &'a str,
     pub llvm_layout: &'a str,
 }
+
+#[derive(Diagnostic)]
+#[diag(codegen_llvm_invalid_target_feature_prefix)]
+pub(crate) struct InvalidTargetFeaturePrefix<'a> {
+    pub feature: &'a str,
+}
diff --git a/compiler/rustc_codegen_llvm/src/llvm_util.rs b/compiler/rustc_codegen_llvm/src/llvm_util.rs
index 99f4488ac0f..4bb400b1879 100644
--- a/compiler/rustc_codegen_llvm/src/llvm_util.rs
+++ b/compiler/rustc_codegen_llvm/src/llvm_util.rs
@@ -1,7 +1,7 @@
 use crate::back::write::create_informational_target_machine;
 use crate::errors::{
-    PossibleFeature, TargetFeatureDisableOrEnable, UnknownCTargetFeature,
-    UnknownCTargetFeaturePrefix, UnstableCTargetFeature,
+    InvalidTargetFeaturePrefix, PossibleFeature, TargetFeatureDisableOrEnable,
+    UnknownCTargetFeature, UnknownCTargetFeaturePrefix, UnstableCTargetFeature,
 };
 use crate::llvm;
 use libc::c_int;
@@ -511,7 +511,7 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str
         sess.target
             .features
             .split(',')
-            .filter(|v| !v.is_empty() && backend_feature_name(v).is_some())
+            .filter(|v| !v.is_empty() && backend_feature_name(sess, v).is_some())
             .map(String::from),
     );
 
@@ -535,7 +535,7 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str
                 }
             };
 
-            let feature = backend_feature_name(s)?;
+            let feature = backend_feature_name(sess, s)?;
             // Warn against use of LLVM specific feature names and unstable features on the CLI.
             if diagnostics {
                 let feature_state = supported_features.iter().find(|&&(v, _)| v == feature);
@@ -611,11 +611,11 @@ pub(crate) fn global_llvm_features(sess: &Session, diagnostics: bool) -> Vec<Str
 /// Returns a feature name for the given `+feature` or `-feature` string.
 ///
 /// Only allows features that are backend specific (i.e. not [`RUSTC_SPECIFIC_FEATURES`].)
-fn backend_feature_name(s: &str) -> Option<&str> {
+fn backend_feature_name<'a>(sess: &Session, s: &'a str) -> Option<&'a str> {
     // features must start with a `+` or `-`.
-    let feature = s.strip_prefix(&['+', '-'][..]).unwrap_or_else(|| {
-        bug!("target feature `{}` must begin with a `+` or `-`", s);
-    });
+    let feature = s
+        .strip_prefix(&['+', '-'][..])
+        .unwrap_or_else(|| sess.dcx().emit_fatal(InvalidTargetFeaturePrefix { feature: s }));
     // Rustc-specific feature requests like `+crt-static` or `-crt-static`
     // are not passed down to LLVM.
     if RUSTC_SPECIFIC_FEATURES.contains(&feature) {