Already poison the type_of result of the anon const used in the typeof expression

Author: oli-obk

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -12,7 +12,7 @@ use crate::astconv::errors::prohibit_assoc_ty_binding;
 use crate::astconv::generics::{check_generic_arg_count, create_args_for_parent_generic_args};
 use crate::bounds::Bounds;
 use crate::collect::HirPlaceholderCollector;
-use crate::errors::{AmbiguousLifetimeBound, TypeofReservedKeywordUsed};
+use crate::errors::AmbiguousLifetimeBound;
 use crate::middle::resolve_bound_vars as rbv;
 use crate::require_c_abi_if_c_variadic;
 use rustc_ast::TraitObjectSyntax;
@@ -30,8 +30,8 @@ use rustc_infer::infer::{InferCtxt, TyCtxtInferExt};
 use rustc_infer::traits::ObligationCause;
 use rustc_middle::middle::stability::AllowUnstable;
 use rustc_middle::ty::{
-    self, Const, GenericArgKind, GenericArgsRef, GenericParamDefKind, IsSuggestable, ParamEnv, Ty,
-    TyCtxt, TypeVisitableExt,
+    self, Const, GenericArgKind, GenericArgsRef, GenericParamDefKind, ParamEnv, Ty, TyCtxt,
+    TypeVisitableExt,
 };
 use rustc_session::lint::builtin::AMBIGUOUS_ASSOCIATED_ITEMS;
 use rustc_span::edit_distance::find_best_match_for_name;
@@ -2537,21 +2537,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
 
                 Ty::new_array_with_const_len(tcx, self.ast_ty_to_ty(ty), length)
             }
-            hir::TyKind::Typeof(e) => {
-                let ty_erased = tcx.type_of(e.def_id).instantiate_identity();
-                let ty = tcx.fold_regions(ty_erased, |r, _| {
-                    if r.is_erased() { tcx.lifetimes.re_static } else { r }
-                });
-                let span = ast_ty.span;
-                let (ty, opt_sugg) = if let Some(ty) = ty.make_suggestable(tcx, false) {
-                    (ty, Some((span, Applicability::MachineApplicable)))
-                } else {
-                    (ty, None)
-                };
-                tcx.dcx().emit_err(TypeofReservedKeywordUsed { span, ty, opt_sugg });
-
-                ty
-            }
+            hir::TyKind::Typeof(e) => tcx.type_of(e.def_id).instantiate_identity(),
             hir::TyKind::Infer => {
                 // Infer also appears as the type of arguments or return
                 // values in an ExprKind::Closure, or as

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -9,6 +9,8 @@ use rustc_middle::ty::{self, ImplTraitInTraitData, IsSuggestable, Ty, TyCtxt, Ty
 use rustc_span::symbol::Ident;
 use rustc_span::{Span, DUMMY_SP};
 
+use crate::errors::TypeofReservedKeywordUsed;
+
 use super::bad_placeholder;
 use super::ItemCtxt;
 pub use opaque::test_opaque_hidden_types;
@@ -39,8 +41,18 @@ fn anon_const_type_of<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Ty<'tcx> {
         {
             return tcx.types.usize;
         }
-        Node::Ty(&hir::Ty { kind: TyKind::Typeof(ref e), .. }) if e.hir_id == hir_id => {
-            return tcx.typeck(def_id).node_type(e.hir_id);
+        Node::Ty(&hir::Ty { kind: TyKind::Typeof(ref e), span, .. }) if e.hir_id == hir_id => {
+            let ty = tcx.typeck(def_id).node_type(e.hir_id);
+            let ty = tcx.fold_regions(ty, |r, _| {
+                if r.is_erased() { ty::Region::new_error_misc(tcx) } else { r }
+            });
+            let (ty, opt_sugg) = if let Some(ty) = ty.make_suggestable(tcx, false) {
+                (ty, Some((span, Applicability::MachineApplicable)))
+            } else {
+                (ty, None)
+            };
+            tcx.dcx().emit_err(TypeofReservedKeywordUsed { span, ty, opt_sugg });
+            return ty;
         }
         Node::Expr(&Expr { kind: ExprKind::InlineAsm(asm), .. })
         | Node::Item(&Item { kind: ItemKind::GlobalAsm(asm), .. })

tests/rustdoc-ui/issues/issue-102986.stderr

@@ -6,8 +6,8 @@ LL |     y: (typeof("hey"),),
    |
 help: consider replacing `typeof(...)` with an actual type
    |
-LL |     y: (&'static str,),
-   |         ~~~~~~~~~~~~
+LL |     y: (&str,),
+   |         ~~~~
 
 error: aborting due to 1 previous error