remove support for type-of

lcnr · lcnr · commit feb13036efec · 2025-11-25T10:19:44.000+01:00
diff --git a/compiler/rustc_ast/src/ast.rs b/compiler/rustc_ast/src/ast.rs
@@ -2513,8 +2513,6 @@ pub enum TyKind {
     ImplTrait(NodeId, #[visitable(extra = BoundKind::Impl)] GenericBounds),
     /// No-op; kept solely so that we can pretty-print faithfully.
     Paren(Box<Ty>),
-    /// Unused for now.
-    Typeof(AnonConst),
     /// This means the type should be inferred instead of it having been
     /// specified. This can appear anywhere in a type.
     Infer,
diff --git a/compiler/rustc_ast/src/util/classify.rs b/compiler/rustc_ast/src/util/classify.rs
@@ -294,7 +294,6 @@ fn type_trailing_braced_mac_call(mut ty: &ast::Ty) -> Option<&ast::MacCall> {
             | ast::TyKind::Never
             | ast::TyKind::Tup(..)
             | ast::TyKind::Paren(..)
-            | ast::TyKind::Typeof(..)
             | ast::TyKind::Infer
             | ast::TyKind::ImplicitSelf
             | ast::TyKind::CVarArgs
diff --git a/compiler/rustc_ast_lowering/src/lib.rs b/compiler/rustc_ast_lowering/src/lib.rs
@@ -1367,7 +1367,6 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
                 self.lower_ty(ty, itctx),
                 self.lower_array_length_to_const_arg(length),
             ),
-            TyKind::Typeof(expr) => hir::TyKind::Typeof(self.lower_anon_const_to_anon_const(expr)),
             TyKind::TraitObject(bounds, kind) => {
                 let mut lifetime_bound = None;
                 let (bounds, lifetime_bound) = self.with_dyn_type_scope(true, |this| {
diff --git a/compiler/rustc_ast_pretty/src/pprust/state.rs b/compiler/rustc_ast_pretty/src/pprust/state.rs
@@ -1325,11 +1325,6 @@ impl<'a> State<'a> {
                 self.print_expr(&length.value, FixupContext::default());
                 self.word("]");
             }
-            ast::TyKind::Typeof(e) => {
-                self.word("typeof(");
-                self.print_expr(&e.value, FixupContext::default());
-                self.word(")");
-            }
             ast::TyKind::Infer => {
                 self.word("_");
             }
diff --git a/compiler/rustc_error_codes/src/error_codes/E0516.md b/compiler/rustc_error_codes/src/error_codes/E0516.md
@@ -1,3 +1,5 @@
+#### Note: this error code is no longer emitted by the compiler.
+
 The `typeof` keyword is currently reserved but unimplemented.
 
 Erroneous code example:
diff --git a/compiler/rustc_hir/src/hir.rs b/compiler/rustc_hir/src/hir.rs
@@ -3680,8 +3680,6 @@ pub enum TyKind<'hir, Unambig = ()> {
     /// We use pointer tagging to represent a `&'hir Lifetime` and `TraitObjectSyntax` pair
     /// as otherwise this type being `repr(C)` would result in `TyKind` increasing in size.
     TraitObject(&'hir [PolyTraitRef<'hir>], TaggedRef<'hir, Lifetime, TraitObjectSyntax>),
-    /// Unused for now.
-    Typeof(&'hir AnonConst),
     /// Placeholder for a type that has failed to be defined.
     Err(rustc_span::ErrorGuaranteed),
     /// Pattern types (`pattern_type!(u32 is 1..)`)
diff --git a/compiler/rustc_hir/src/intravisit.rs b/compiler/rustc_hir/src/intravisit.rs
@@ -1029,7 +1029,6 @@ pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v, AmbigArg>) -
             }
             try_visit!(visitor.visit_lifetime(lifetime));
         }
-        TyKind::Typeof(ref expression) => try_visit!(visitor.visit_anon_const(expression)),
         TyKind::InferDelegation(..) | TyKind::Err(_) => {}
         TyKind::Pat(ty, pat) => {
             try_visit!(visitor.visit_ty_unambig(ty));
diff --git a/compiler/rustc_hir_analysis/messages.ftl b/compiler/rustc_hir_analysis/messages.ftl
@@ -552,11 +552,6 @@ hir_analysis_ty_param_some = type parameter `{$param}` must be used as the type
 
 hir_analysis_type_of = {$ty}
 
-hir_analysis_typeof_reserved_keyword_used =
-    `typeof` is a reserved keyword but unimplemented
-    .suggestion = consider replacing `typeof(...)` with an actual type
-    .label = reserved keyword
-
 hir_analysis_unconstrained_generic_parameter = the {$param_def_kind} `{$param_name}` is not constrained by the impl trait, self type, or predicates
     .label = unconstrained {$param_def_kind}
     .const_param_note = expressions using a const parameter must map each value to a distinct output value
diff --git a/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs b/compiler/rustc_hir_analysis/src/coherence/inherent_impls.rs
@@ -195,10 +195,11 @@ impl<'tcx> InherentCollect<'tcx> {
             | ty::Closure(..)
             | ty::CoroutineClosure(..)
             | ty::Coroutine(..)
-            | ty::CoroutineWitness(..) => {
-                Err(self.tcx.dcx().delayed_bug("cannot define inherent `impl` for closure types"))
-            }
-            ty::Alias(ty::Free, _) | ty::Bound(..) | ty::Placeholder(_) | ty::Infer(_) => {
+            | ty::CoroutineWitness(..)
+            | ty::Alias(ty::Free, _)
+            | ty::Bound(..)
+            | ty::Placeholder(_)
+            | ty::Infer(_) => {
                 bug!("unexpected impl self type of impl: {:?} {:?}", id, self_ty);
             }
             // We could bail out here, but that will silence other useful errors.
diff --git a/compiler/rustc_hir_analysis/src/coherence/orphan.rs b/compiler/rustc_hir_analysis/src/coherence/orphan.rs
@@ -217,21 +217,19 @@ pub(crate) fn orphan_check_impl(
             | ty::Slice(..)
             | ty::RawPtr(..)
             | ty::Ref(..)
-            | ty::FnDef(..)
             | ty::FnPtr(..)
             | ty::Never
             | ty::Tuple(..)
             | ty::UnsafeBinder(_) => (LocalImpl::Allow, NonlocalImpl::DisallowOther),
 
-            ty::Closure(..)
+            ty::FnDef(..)
+            | ty::Closure(..)
             | ty::CoroutineClosure(..)
             | ty::Coroutine(..)
-            | ty::CoroutineWitness(..) => {
-                return Err(tcx
-                    .dcx()
-                    .delayed_bug("cannot define inherent `impl` for closure types"));
-            }
-            ty::Bound(..) | ty::Placeholder(..) | ty::Infer(..) => {
+            | ty::CoroutineWitness(..)
+            | ty::Bound(..)
+            | ty::Placeholder(..)
+            | ty::Infer(..) => {
                 let sp = tcx.def_span(impl_def_id);
                 span_bug!(sp, "weird self type for autotrait impl")
             }
diff --git a/compiler/rustc_hir_analysis/src/collect/type_of.rs b/compiler/rustc_hir_analysis/src/collect/type_of.rs
@@ -7,15 +7,12 @@ use rustc_hir::{self as hir, AmbigArg, HirId};
 use rustc_middle::query::plumbing::CyclePlaceholder;
 use rustc_middle::ty::print::with_forced_trimmed_paths;
 use rustc_middle::ty::util::IntTypeExt;
-use rustc_middle::ty::{
-    self, DefiningScopeKind, IsSuggestable, Ty, TyCtxt, TypeVisitableExt, fold_regions,
-};
+use rustc_middle::ty::{self, DefiningScopeKind, IsSuggestable, Ty, TyCtxt, TypeVisitableExt};
 use rustc_middle::{bug, span_bug};
 use rustc_span::{DUMMY_SP, Ident, Span};
 
 use super::{HirPlaceholderCollector, ItemCtxt, bad_placeholder};
 use crate::check::wfcheck::check_static_item;
-use crate::errors::TypeofReservedKeywordUsed;
 use crate::hir_ty_lowering::HirTyLowerer;
 
 mod opaque;
@@ -48,21 +45,6 @@ fn anon_const_type_of<'tcx>(icx: &ItemCtxt<'tcx>, def_id: LocalDefId) -> Ty<'tcx
         Node::Variant(Variant { disr_expr: Some(e), .. }) if e.hir_id == hir_id => {
             tcx.adt_def(tcx.hir_get_parent_item(hir_id)).repr().discr_type().to_ty(tcx)
         }
-        // Sort of affects the type system, but only for the purpose of diagnostics
-        // so no need for ConstArg.
-        Node::Ty(&hir::Ty { kind: TyKind::Typeof(ref e), span, .. }) if e.hir_id == hir_id => {
-            let ty = tcx.typeck(def_id).node_type(tcx.local_def_id_to_hir_id(def_id));
-            let ty = fold_regions(tcx, 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, None) {
-                (ty, Some((span, Applicability::MachineApplicable)))
-            } else {
-                (ty, None)
-            };
-            tcx.dcx().emit_err(TypeofReservedKeywordUsed { span, ty, opt_sugg });
-            return ty;
-        }
 
         Node::Field(&hir::FieldDef { default: Some(c), def_id: field_def_id, .. })
             if c.hir_id == hir_id =>
diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs
@@ -378,17 +378,6 @@ pub(crate) struct ParenthesizedFnTraitExpansion {
     pub expanded_type: String,
 }
 
-#[derive(Diagnostic)]
-#[diag(hir_analysis_typeof_reserved_keyword_used, code = E0516)]
-pub(crate) struct TypeofReservedKeywordUsed<'tcx> {
-    pub ty: Ty<'tcx>,
-    #[primary_span]
-    #[label]
-    pub span: Span,
-    #[suggestion(style = "verbose", code = "{ty}")]
-    pub opt_sugg: Option<(Span, Applicability)>,
-}
-
 #[derive(Diagnostic)]
 #[diag(hir_analysis_value_of_associated_struct_already_specified, code = E0719)]
 pub(crate) struct ValueOfAssociatedStructAlreadySpecified {
diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/mod.rs
@@ -2582,7 +2582,6 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ {
                 let length = self.lower_const_arg(length, FeedConstTy::No);
                 Ty::new_array_with_const_len(tcx, self.lower_ty(ty), length)
             }
-            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
diff --git a/compiler/rustc_hir_pretty/src/lib.rs b/compiler/rustc_hir_pretty/src/lib.rs
@@ -445,11 +445,6 @@ impl<'a> State<'a> {
                 self.print_const_arg(length);
                 self.word("]");
             }
-            hir::TyKind::Typeof(ref e) => {
-                self.word("typeof(");
-                self.print_anon_const(e);
-                self.word(")");
-            }
             hir::TyKind::Err(_) => {
                 self.popen();
                 self.word("/*ERROR*/");
diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
@@ -296,11 +296,6 @@ fn infer_type_if_missing<'tcx>(fcx: &FnCtxt<'_, 'tcx>, node: Node<'tcx>) -> Opti
     } else if let Node::AnonConst(_) = node {
         let id = tcx.local_def_id_to_hir_id(def_id);
         match tcx.parent_hir_node(id) {
-            Node::Ty(&hir::Ty { kind: hir::TyKind::Typeof(anon_const), span, .. })
-                if anon_const.hir_id == id =>
-            {
-                Some(fcx.next_ty_var(span))
-            }
             Node::Expr(&hir::Expr { kind: hir::ExprKind::InlineAsm(asm), span, .. })
             | Node::Item(&hir::Item { kind: hir::ItemKind::GlobalAsm { asm, .. }, span, .. }) => {
                 asm.operands.iter().find_map(|(op, _op_sp)| match op {
diff --git a/compiler/rustc_lint/src/unused.rs b/compiler/rustc_lint/src/unused.rs
@@ -1660,18 +1660,6 @@ impl EarlyLintPass for UnusedBraces {
                 );
             }
 
-            ast::TyKind::Typeof(ref anon_const) => {
-                self.check_unused_delims_expr(
-                    cx,
-                    &anon_const.value,
-                    UnusedDelimsCtx::AnonConst,
-                    false,
-                    None,
-                    None,
-                    false,
-                );
-            }
-
             _ => {}
         }
     }
diff --git a/compiler/rustc_next_trait_solver/src/coherence.rs b/compiler/rustc_next_trait_solver/src/coherence.rs
@@ -336,7 +336,6 @@ where
             | ty::Uint(..)
             | ty::Float(..)
             | ty::Str
-            | ty::FnDef(..)
             | ty::Pat(..)
             | ty::FnPtr(..)
             | ty::Array(..)
@@ -403,7 +402,6 @@ where
                     // implement, so we don't use this behavior.
                     // Addendum: Moreover, revealing the underlying type is likely to cause cycle
                     // errors as we rely on coherence / the specialization graph during typeck.
-
                     self.found_non_local_ty(ty)
                 }
             }
@@ -435,31 +433,14 @@ where
                 }
             }
             ty::Error(_) => ControlFlow::Break(OrphanCheckEarlyExit::LocalTy(ty)),
-            ty::Closure(did, ..) => {
-                if self.def_id_is_local(did) {
-                    ControlFlow::Break(OrphanCheckEarlyExit::LocalTy(ty))
-                } else {
-                    self.found_non_local_ty(ty)
-                }
-            }
-            ty::CoroutineClosure(did, ..) => {
-                if self.def_id_is_local(did) {
-                    ControlFlow::Break(OrphanCheckEarlyExit::LocalTy(ty))
-                } else {
-                    self.found_non_local_ty(ty)
-                }
-            }
-            ty::Coroutine(did, ..) => {
-                if self.def_id_is_local(did) {
-                    ControlFlow::Break(OrphanCheckEarlyExit::LocalTy(ty))
-                } else {
-                    self.found_non_local_ty(ty)
-                }
+
+            ty::FnDef(..)
+            | ty::Closure(..)
+            | ty::CoroutineClosure(..)
+            | ty::Coroutine(..)
+            | ty::CoroutineWitness(..) => {
+                unreachable!("unnameable type in coherence: {ty:?}");
             }
-            // This should only be created when checking whether we have to check whether some
-            // auto trait impl applies. There will never be multiple impls, so we can just
-            // act as if it were a local type here.
-            ty::CoroutineWitness(..) => ControlFlow::Break(OrphanCheckEarlyExit::LocalTy(ty)),
         };
         // A bit of a hack, the `OrphanChecker` is only used to visit a `TraitRef`, so
         // the first type we visit is always the self type.
diff --git a/compiler/rustc_parse/src/parser/ty.rs b/compiler/rustc_parse/src/parser/ty.rs
@@ -7,7 +7,7 @@ use rustc_ast::{
     TyKind, UnsafeBinderTy,
 };
 use rustc_data_structures::stack::ensure_sufficient_stack;
-use rustc_errors::{Applicability, Diag, PResult};
+use rustc_errors::{Applicability, Diag, E0516, PResult};
 use rustc_span::{ErrorGuaranteed, Ident, Span, kw, sym};
 use thin_vec::{ThinVec, thin_vec};
 
@@ -328,7 +328,7 @@ impl<'a> Parser<'a> {
             self.expect_and()?;
             self.parse_borrowed_pointee()?
         } else if self.eat_keyword_noexpect(kw::Typeof) {
-            self.parse_typeof_ty()?
+            self.parse_typeof_ty(lo)?
         } else if self.eat_keyword(exp!(Underscore)) {
             // A type to be inferred `_`
             TyKind::Infer
@@ -784,13 +784,20 @@ impl<'a> Parser<'a> {
         }
     }
 
-    // Parses the `typeof(EXPR)`.
-    // To avoid ambiguity, the type is surrounded by parentheses.
-    fn parse_typeof_ty(&mut self) -> PResult<'a, TyKind> {
+    /// Parses the `typeof(EXPR)` for better diagnostics before returning
+    /// an error type.
+    fn parse_typeof_ty(&mut self, lo: Span) -> PResult<'a, TyKind> {
         self.expect(exp!(OpenParen))?;
-        let expr = self.parse_expr_anon_const()?;
+        let _expr = self.parse_expr_anon_const()?;
         self.expect(exp!(CloseParen))?;
-        Ok(TyKind::Typeof(expr))
+        let span = lo.to(self.prev_token.span);
+        let guar = self
+            .dcx()
+            .struct_span_err(span, "`typeof` is a reserved keyword but unimplemented")
+            .with_note("consider replacing `typeof(...)` with an actual type")
+            .with_code(E0516)
+            .emit();
+        Ok(TyKind::Err(guar))
     }
 
     /// Parses a function pointer type (`TyKind::FnPtr`).
diff --git a/compiler/rustc_passes/src/input_stats.rs b/compiler/rustc_passes/src/input_stats.rs
@@ -408,7 +408,6 @@ impl<'v> hir_visit::Visitor<'v> for StatCollector<'v> {
                 OpaqueDef,
                 TraitAscription,
                 TraitObject,
-                Typeof,
                 Infer,
                 Pat,
                 Err
@@ -683,7 +682,6 @@ impl<'v> ast_visit::Visitor<'v> for StatCollector<'v> {
                 TraitObject,
                 ImplTrait,
                 Paren,
-                Typeof,
                 Infer,
                 ImplicitSelf,
                 MacCall,
diff --git a/compiler/rustc_resolve/src/late.rs b/compiler/rustc_resolve/src/late.rs
@@ -954,9 +954,6 @@ impl<'ast, 'ra, 'tcx> Visitor<'ast> for LateResolutionVisitor<'_, 'ast, 'ra, 'tc
                 self.visit_ty(element_ty);
                 self.resolve_anon_const(length, AnonConstKind::ConstArg(IsRepeatExpr::No));
             }
-            TyKind::Typeof(ct) => {
-                self.resolve_anon_const(ct, AnonConstKind::ConstArg(IsRepeatExpr::No))
-            }
             _ => visit::walk_ty(self, ty),
         }
         self.diag_metadata.current_trait_object = prev;
diff --git a/src/tools/tidy/src/issues.txt b/src/tools/tidy/src/issues.txt
@@ -2983,9 +2983,6 @@ ui/typeck/issue-96530.rs
 ui/typeck/issue-96738.rs
 ui/typeck/issue-98260.rs
 ui/typeck/issue-98982.rs
-ui/typeof/issue-100183.rs
-ui/typeof/issue-29184.rs
-ui/typeof/issue-42060.rs
 ui/unboxed-closures/issue-18652.rs
 ui/unboxed-closures/issue-18661.rs
 ui/unboxed-closures/issue-30906.rs
diff --git a/tests/ui/closures/impl-closure-147146.rs b/tests/ui/closures/impl-closure-147146.rs
diff --git a/tests/ui/closures/impl-closure-147146.stderr b/tests/ui/closures/impl-closure-147146.stderr
diff --git a/tests/ui/error-codes/E0516.rs b/tests/ui/error-codes/E0516.rs
@@ -1,4 +1,3 @@
 fn main() {
     let x: typeof(92) = 92; //~ ERROR E0516
-                            //~| NOTE reserved keyword
 }
diff --git a/tests/ui/error-codes/E0516.stderr b/tests/ui/error-codes/E0516.stderr
diff --git a/tests/ui/typeof/issue-100183.rs b/tests/ui/typeof/issue-100183.rs
diff --git a/tests/ui/typeof/issue-100183.stderr b/tests/ui/typeof/issue-100183.stderr
diff --git a/tests/ui/typeof/issue-29184.rs b/tests/ui/typeof/issue-29184.rs
diff --git a/tests/ui/typeof/issue-29184.stderr b/tests/ui/typeof/issue-29184.stderr
diff --git a/tests/ui/typeof/issue-42060.rs b/tests/ui/typeof/issue-42060.rs
diff --git a/tests/ui/typeof/issue-42060.stderr b/tests/ui/typeof/issue-42060.stderr
diff --git a/tests/ui/typeof/type_mismatch.rs b/tests/ui/typeof/type_mismatch.rs
diff --git a/tests/ui/typeof/type_mismatch.stderr b/tests/ui/typeof/type_mismatch.stderr

Original file line number	Diff line number	Diff line change
`@@ -1325,11 +1325,6 @@ impl<'a> State<'a> {`
`1325`	`1325`	`self.print_expr(&length.value, FixupContext::default());`
`1326`	`1326`	`self.word("]");`
`1327`	`1327`	`}`
`1328`		`- ast::TyKind::Typeof(e) => {`
`1329`		`- self.word("typeof(");`
`1330`		`- self.print_expr(&e.value, FixupContext::default());`
`1331`		`- self.word(")");`
`1332`		`- }`
`1333`	`1328`	`ast::TyKind::Infer => {`
`1334`	`1329`	`self.word("_");`
`1335`	`1330`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,3 +1,5 @@`
	`1`	`+#### Note: this error code is no longer emitted by the compiler.`
	`2`	`+`
`1`	`3`	The `typeof` keyword is currently reserved but unimplemented.
`2`	`4`
`3`	`5`	`Erroneous code example:`
Original file line number	Diff line number	Diff line change
`@@ -1029,7 +1029,6 @@ pub fn walk_ty<'v, V: Visitor<'v>>(visitor: &mut V, typ: &'v Ty<'v, AmbigArg>) -`
`1029`	`1029`	`}`
`1030`	`1030`	`try_visit!(visitor.visit_lifetime(lifetime));`
`1031`	`1031`	`}`
`1032`		`- TyKind::Typeof(ref expression) => try_visit!(visitor.visit_anon_const(expression)),`
`1033`	`1032`	`TyKind::InferDelegation(..) \| TyKind::Err(_) => {}`
`1034`	`1033`	`TyKind::Pat(ty, pat) => {`
`1035`	`1034`	`try_visit!(visitor.visit_ty_unambig(ty));`