Replace NotFound lifetime kind with a delayed bug

Author: eggyal

compiler/rustc_ast_lowering/src/lib.rs

@@ -1931,30 +1931,33 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         source: LifetimeSource,
         syntax: LifetimeSyntax,
     ) -> &'hir hir::Lifetime {
-        let res =
-            self.resolver.get_lifetime_res(id).map_or(
-                hir::LifetimeKind::NotFound,
-                |res| match res {
-                    LifetimeRes::Param { param, .. } => hir::LifetimeKind::Param(param),
-                    LifetimeRes::Fresh { param, .. } => {
-                        assert_eq!(ident.name, kw::UnderscoreLifetime);
-                        let param = self.local_def_id(param);
-                        hir::LifetimeKind::Param(param)
-                    }
-                    LifetimeRes::Infer => {
-                        assert_eq!(ident.name, kw::UnderscoreLifetime);
-                        hir::LifetimeKind::Infer
-                    }
-                    LifetimeRes::Static { .. } => {
-                        assert!(matches!(ident.name, kw::StaticLifetime | kw::UnderscoreLifetime));
-                        hir::LifetimeKind::Static
-                    }
-                    LifetimeRes::Error(guar) => hir::LifetimeKind::Error(guar),
-                    LifetimeRes::ElidedAnchor { .. } => {
-                        panic!("Unexpected `ElidedAnchar` {:?} at {:?}", ident, ident.span);
-                    }
-                },
-            );
+        let res = self.resolver.get_lifetime_res(id).map_or_else(
+            || {
+                hir::LifetimeKind::Error(
+                    self.tcx.dcx().span_delayed_bug(ident.span, "unresolved lifetime"),
+                )
+            },
+            |res| match res {
+                LifetimeRes::Param { param, .. } => hir::LifetimeKind::Param(param),
+                LifetimeRes::Fresh { param, .. } => {
+                    assert_eq!(ident.name, kw::UnderscoreLifetime);
+                    let param = self.local_def_id(param);
+                    hir::LifetimeKind::Param(param)
+                }
+                LifetimeRes::Infer => {
+                    assert_eq!(ident.name, kw::UnderscoreLifetime);
+                    hir::LifetimeKind::Infer
+                }
+                LifetimeRes::Static { .. } => {
+                    assert!(matches!(ident.name, kw::StaticLifetime | kw::UnderscoreLifetime));
+                    hir::LifetimeKind::Static
+                }
+                LifetimeRes::Error(guar) => hir::LifetimeKind::Error(guar),
+                LifetimeRes::ElidedAnchor { .. } => {
+                    panic!("Unexpected `ElidedAnchar` {:?} at {:?}", ident, ident.span);
+                }
+            },
+        );
 
         debug!(?res);
         self.arena.alloc(hir::Lifetime::new(

compiler/rustc_hir/src/hir.rs

@@ -239,7 +239,6 @@ pub enum LifetimeKind {
     /// Indicates an error during lowering (usually `'_` in wrong place)
     /// that was already reported.
     Error(ErrorGuaranteed),
-    NotFound,
 
     /// User wrote an anonymous lifetime, either `'_` or nothing (which gets
     /// converted to `'_`). The semantics of this lifetime should be inferred
@@ -259,10 +258,7 @@ impl LifetimeKind {
             // -- but this is because, as far as the code in the compiler is
             // concerned -- `Fresh` variants act equivalently to "some fresh name".
             // They correspond to early-bound regions on an impl, in other words.
-            LifetimeKind::Error(..)
-            | LifetimeKind::NotFound
-            | LifetimeKind::Param(..)
-            | LifetimeKind::Static => false,
+            LifetimeKind::Error(..) | LifetimeKind::Param(..) | LifetimeKind::Static => false,
         }
     }
 }

compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs

@@ -663,7 +663,7 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
                 LifetimeKind::Param(def_id) => {
                     self.resolve_lifetime_ref(def_id, lt);
                 }
-                LifetimeKind::Error(..) | LifetimeKind::NotFound => {}
+                LifetimeKind::Error(..) => {}
                 LifetimeKind::ImplicitObjectLifetimeDefault
                 | LifetimeKind::Infer
                 | LifetimeKind::Static => {
@@ -804,7 +804,7 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
                         // If the user wrote an explicit name, use that.
                         self.visit_lifetime(&*lifetime);
                     }
-                    LifetimeKind::Error(..) | LifetimeKind::NotFound => {}
+                    LifetimeKind::Error(..) => {}
                 }
             }
             hir::TyKind::Ref(lifetime_ref, ref mt) => {
@@ -891,8 +891,6 @@ impl<'a, 'tcx> Visitor<'tcx> for BoundVarContext<'a, 'tcx> {
             hir::LifetimeKind::Param(param_def_id) => {
                 self.resolve_lifetime_ref(param_def_id, lifetime_ref)
             }
-            // Just ignore `lifetime_ref` if it couldn't be resolved
-            hir::LifetimeKind::NotFound => {}
             // Keep track of lifetimes about which errors have already been reported
             hir::LifetimeKind::Error(guar) => {
                 self.insert_lifetime(lifetime_ref, ResolvedArg::Error(guar))