Forbid the use of `#[target_feature]` on `main`

2 files changed, 13 insertions, 0 deletions

diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs
index 8a697b4c514..5b445ead1d3 100644
--- a/compiler/rustc_hir_analysis/src/errors.rs
+++ b/compiler/rustc_hir_analysis/src/errors.rs
@@ -328,6 +328,14 @@ pub(crate) struct TrackCallerOnMain {
 }
 
 #[derive(Diagnostic)]
+#[diag(hir_analysis_target_feature_on_main)]
+pub(crate) struct TargetFeatureOnMain {
+    #[primary_span]
+    #[label(hir_analysis_target_feature_on_main)]
+    pub main: Span,
+}
+
+#[derive(Diagnostic)]
 #[diag(hir_analysis_start_not_track_caller)]
 pub(crate) struct StartTrackCaller {
     #[primary_span]
diff --git a/compiler/rustc_hir_analysis/src/lib.rs b/compiler/rustc_hir_analysis/src/lib.rs
index 6a4f5382878..098b003eaed 100644
--- a/compiler/rustc_hir_analysis/src/lib.rs
+++ b/compiler/rustc_hir_analysis/src/lib.rs
@@ -283,6 +283,11 @@ fn check_main_fn_ty(tcx: TyCtxt<'_>, main_def_id: DefId) {
         error = true;
     }
 
+    if !tcx.codegen_fn_attrs(main_def_id).target_features.is_empty() {
+        tcx.sess.emit_err(errors::TargetFeatureOnMain { main: main_span });
+        error = true;
+    }
+
     if error {
         return;
     }