change ct_infer to a delay_span_bug

Author: lcnr

compiler/rustc_middle/src/ty/context.rs

@@ -1209,11 +1209,25 @@ impl<'tcx> TyCtxt<'tcx> {
         self.mk_ty(Error(DelaySpanBugEmitted(())))
     }
 
-    /// Like `err` but for constants.
+    /// Like [`ty_error`] but for constants.
     #[track_caller]
     pub fn const_error(self, ty: Ty<'tcx>) -> &'tcx Const<'tcx> {
-        self.sess
-            .delay_span_bug(DUMMY_SP, "ty::ConstKind::Error constructed but no error reported.");
+        self.const_error_with_message(
+            ty,
+            DUMMY_SP,
+            "ty::ConstKind::Error constructed but no error reported",
+        )
+    }
+
+    /// Like [`ty_error_with_message`] but for constants.
+    #[track_caller]
+    pub fn const_error_with_message<S: Into<MultiSpan>>(
+        self,
+        ty: Ty<'tcx>,
+        span: S,
+        msg: &str,
+    ) -> &'tcx Const<'tcx> {
+        self.sess.delay_span_bug(span, msg);
         self.mk_const(ty::Const { val: ty::ConstKind::Error(DelaySpanBugEmitted(())), ty })
     }
 

compiler/rustc_typeck/src/collect.rs

@@ -386,7 +386,7 @@ impl<'tcx> AstConv<'tcx> for ItemCtxt<'tcx> {
     }
 
     fn ty_infer(&self, _: Option<&ty::GenericParamDef>, span: Span) -> Ty<'tcx> {
-        self.tcx().ty_error_with_message(span, "bad_placeholder_type")
+        self.tcx().ty_error_with_message(span, "bad placeholder type")
     }
 
     fn ct_infer(
@@ -395,13 +395,11 @@ impl<'tcx> AstConv<'tcx> for ItemCtxt<'tcx> {
         _: Option<&ty::GenericParamDef>,
         span: Span,
     ) -> &'tcx Const<'tcx> {
-        bad_placeholder(self.tcx(), "const", vec![span], "generic").emit();
-        // Typeck doesn't expect erased regions to be returned from `type_of`.
         let ty = self.tcx.fold_regions(ty, &mut false, |r, _| match r {
             ty::ReErased => self.tcx.lifetimes.re_static,
             _ => r,
         });
-        self.tcx().const_error(ty)
+        self.tcx().const_error_with_message(ty, span, "bad placeholder constant")
     }
 
     fn projected_ty_from_poly_trait_ref(