Don't forget that the lifetime on hir types is 'tcx

compiler/rustc_hir/src/hir.rs

@@ -248,7 +248,7 @@ pub struct InferArg {
 }
 
 impl InferArg {
-    pub fn to_ty(&self) -> Ty<'_> {
+    pub fn to_ty(&self) -> Ty<'static> {
         Ty { kind: TyKind::Infer, span: self.span, hir_id: self.hir_id }
     }
 }

compiler/rustc_hir_analysis/src/astconv/bounds.rs

@@ -108,14 +108,16 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
     /// `param_ty` and `ast_bounds`. See `instantiate_poly_trait_ref`
     /// for more details.
     #[instrument(level = "debug", skip(self, ast_bounds, bounds))]
-    pub(crate) fn add_bounds<'hir, I: Iterator<Item = &'hir hir::GenericBound<'hir>>>(
+    pub(crate) fn add_bounds<'hir, I: Iterator<Item = &'hir hir::GenericBound<'tcx>>>(
         &self,
         param_ty: Ty<'tcx>,
         ast_bounds: I,
         bounds: &mut Bounds<'tcx>,
         bound_vars: &'tcx ty::List<ty::BoundVariableKind>,
         only_self_bounds: OnlySelfBounds,
-    ) {
+    ) where
+        'tcx: 'hir,
+    {
         for ast_bound in ast_bounds {
             match ast_bound {
                 hir::GenericBound::Trait(poly_trait_ref, modifier) => {
@@ -179,7 +181,7 @@ impl<'tcx> dyn AstConv<'tcx> + '_ {
     pub(crate) fn compute_bounds(
         &self,
         param_ty: Ty<'tcx>,
-        ast_bounds: &[hir::GenericBound<'_>],
+        ast_bounds: &[hir::GenericBound<'tcx>],
         filter: PredicateFilter,
     ) -> Bounds<'tcx> {
         let mut bounds = Bounds::default();

compiler/rustc_hir_analysis/src/astconv/generics.rs

@@ -168,7 +168,7 @@ fn generic_arg_mismatch_err(
 ///   instantiate a `GenericArg`.
 /// - `inferred_kind`: if no parameter was provided, and inference is enabled, then
 ///   creates a suitable inference variable.
-pub fn create_args_for_parent_generic_args<'tcx, 'a>(
+pub fn create_args_for_parent_generic_args<'tcx: 'a, 'a>(
     tcx: TyCtxt<'tcx>,
     def_id: DefId,
     parent_args: &[ty::GenericArg<'tcx>],

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -122,7 +122,7 @@ pub trait AstConv<'tcx> {
         &self,
         span: Span,
         item_def_id: DefId,
-        item_segment: &hir::PathSegment<'_>,
+        item_segment: &hir::PathSegment<'tcx>,
         poly_trait_ref: ty::PolyTraitRef<'tcx>,
     ) -> Ty<'tcx>;
 
@@ -156,14 +156,14 @@ struct ConvertedBinding<'a, 'tcx> {
     hir_id: hir::HirId,
     item_name: Ident,
     kind: ConvertedBindingKind<'a, 'tcx>,
-    gen_args: &'a GenericArgs<'a>,
+    gen_args: &'tcx GenericArgs<'tcx>,
     span: Span,
 }
 
 #[derive(Debug)]
 enum ConvertedBindingKind<'a, 'tcx> {
     Equality(Spanned<ty::Term<'tcx>>),
-    Constraint(&'a [hir::GenericBound<'a>]),
+    Constraint(&'a [hir::GenericBound<'tcx>]),
 }
 
 /// New-typed boolean indicating whether explicit late-bound lifetimes
@@ -215,12 +215,12 @@ pub struct GenericArgCountResult {
 }
 
 pub trait CreateSubstsForGenericArgsCtxt<'a, 'tcx> {
-    fn args_for_def_id(&mut self, def_id: DefId) -> (Option<&'a GenericArgs<'a>>, bool);
+    fn args_for_def_id(&mut self, def_id: DefId) -> (Option<&'a GenericArgs<'tcx>>, bool);
 
     fn provided_kind(
         &mut self,
         param: &ty::GenericParamDef,
-        arg: &GenericArg<'_>,
+        arg: &GenericArg<'tcx>,
     ) -> ty::GenericArg<'tcx>;
 
     fn inferred_kind(
@@ -294,7 +294,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         &self,
         span: Span,
         def_id: DefId,
-        item_segment: &hir::PathSegment<'_>,
+        item_segment: &hir::PathSegment<'tcx>,
     ) -> GenericArgsRef<'tcx> {
         let (args, _) = self.create_args_for_ast_path(
             span,
@@ -351,7 +351,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         def_id: DefId,
         parent_args: &[ty::GenericArg<'tcx>],
         seg: &hir::PathSegment<'_>,
-        generic_args: &'a hir::GenericArgs<'_>,
+        generic_args: &'a hir::GenericArgs<'tcx>,
         infer_args: bool,
         self_ty: Option<Ty<'tcx>>,
         constness: ty::BoundConstness,
@@ -406,14 +406,14 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         struct SubstsForAstPathCtxt<'a, 'tcx> {
             astconv: &'a (dyn AstConv<'tcx> + 'a),
             def_id: DefId,
-            generic_args: &'a GenericArgs<'a>,
+            generic_args: &'a GenericArgs<'tcx>,
             span: Span,
             inferred_params: Vec<Span>,
             infer_args: bool,
         }
 
         impl<'a, 'tcx> CreateSubstsForGenericArgsCtxt<'a, 'tcx> for SubstsForAstPathCtxt<'a, 'tcx> {
-            fn args_for_def_id(&mut self, did: DefId) -> (Option<&'a GenericArgs<'a>>, bool) {
+            fn args_for_def_id(&mut self, did: DefId) -> (Option<&'a GenericArgs<'tcx>>, bool) {
                 if did == self.def_id {
                     (Some(self.generic_args), self.infer_args)
                 } else {
@@ -425,11 +425,11 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             fn provided_kind(
                 &mut self,
                 param: &ty::GenericParamDef,
-                arg: &GenericArg<'_>,
+                arg: &GenericArg<'tcx>,
             ) -> ty::GenericArg<'tcx> {
                 let tcx = self.astconv.tcx();
 
-                let mut handle_ty_args = |has_default, ty: &hir::Ty<'_>| {
+                let mut handle_ty_args = |has_default, ty: &hir::Ty<'tcx>| {
                     if has_default {
                         tcx.check_optional_stability(
                             param.def_id,
@@ -592,7 +592,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
 
     fn create_assoc_bindings_for_generic_args<'a>(
         &self,
-        generic_args: &'a hir::GenericArgs<'_>,
+        generic_args: &'a hir::GenericArgs<'tcx>,
     ) -> Vec<ConvertedBinding<'a, 'tcx>> {
         // Convert associated-type bindings or constraints into a separate vector.
         // Example: Given this:
@@ -640,7 +640,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         &self,
         span: Span,
         item_def_id: DefId,
-        item_segment: &hir::PathSegment<'_>,
+        item_segment: &hir::PathSegment<'tcx>,
         parent_args: GenericArgsRef<'tcx>,
     ) -> GenericArgsRef<'tcx> {
         debug!(
@@ -673,7 +673,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
     /// are disallowed. Otherwise, they are pushed onto the vector given.
     pub fn instantiate_mono_trait_ref(
         &self,
-        trait_ref: &hir::TraitRef<'_>,
+        trait_ref: &hir::TraitRef<'tcx>,
         self_ty: Ty<'tcx>,
     ) -> ty::TraitRef<'tcx> {
         self.prohibit_generics(trait_ref.path.segments.split_last().unwrap().1.iter(), |_| {});
@@ -710,7 +710,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
     #[instrument(level = "debug", skip(self, span, constness, bounds, speculative))]
     pub(crate) fn instantiate_poly_trait_ref(
         &self,
-        trait_ref: &hir::TraitRef<'_>,
+        trait_ref: &hir::TraitRef<'tcx>,
         span: Span,
         constness: ty::BoundConstness,
         polarity: ty::ImplPolarity,
@@ -788,7 +788,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         span: Span,
         trait_def_id: DefId,
         self_ty: Ty<'tcx>,
-        trait_segment: &hir::PathSegment<'_>,
+        trait_segment: &hir::PathSegment<'tcx>,
         is_impl: bool,
         // FIXME(effects) move all host param things in astconv to hir lowering
         constness: ty::BoundConstness,
@@ -813,7 +813,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         span: Span,
         trait_def_id: DefId,
         self_ty: Ty<'tcx>,
-        trait_segment: &'a hir::PathSegment<'a>,
+        trait_segment: &'a hir::PathSegment<'tcx>,
         is_impl: bool,
         constness: ty::BoundConstness,
     ) -> (GenericArgsRef<'tcx>, GenericArgCountResult) {
@@ -847,7 +847,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         &self,
         span: Span,
         did: DefId,
-        item_segment: &hir::PathSegment<'_>,
+        item_segment: &hir::PathSegment<'tcx>,
     ) -> Ty<'tcx> {
         let tcx = self.tcx();
         let args = self.ast_path_args_for_ty(span, did, item_segment);
@@ -1153,7 +1153,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         span: Span,
         qself_ty: Ty<'tcx>,
         qself: &hir::Ty<'_>,
-        assoc_segment: &hir::PathSegment<'_>,
+        assoc_segment: &hir::PathSegment<'tcx>,
         permit_variants: bool,
     ) -> Result<(Ty<'tcx>, DefKind, DefId), ErrorGuaranteed> {
         let tcx = self.tcx();
@@ -1428,7 +1428,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
     fn lookup_inherent_assoc_ty(
         &self,
         name: Ident,
-        segment: &hir::PathSegment<'_>,
+        segment: &hir::PathSegment<'tcx>,
         adt_did: DefId,
         self_ty: Ty<'tcx>,
         block: hir::HirId,
@@ -1702,8 +1702,8 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         span: Span,
         opt_self_ty: Option<Ty<'tcx>>,
         item_def_id: DefId,
-        trait_segment: &hir::PathSegment<'_>,
-        item_segment: &hir::PathSegment<'_>,
+        trait_segment: &hir::PathSegment<'tcx>,
+        item_segment: &hir::PathSegment<'tcx>,
         constness: ty::BoundConstness,
     ) -> Ty<'tcx> {
         let tcx = self.tcx();
@@ -2021,7 +2021,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
     pub fn res_to_ty(
         &self,
         opt_self_ty: Option<Ty<'tcx>>,
-        path: &hir::Path<'_>,
+        path: &hir::Path<'tcx>,
         hir_id: hir::HirId,
         permit_variants: bool,
     ) -> Ty<'tcx> {
@@ -2311,13 +2311,13 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
 
     /// Parses the programmer's textual representation of a type into our
     /// internal notion of a type.
-    pub fn ast_ty_to_ty(&self, ast_ty: &hir::Ty<'_>) -> Ty<'tcx> {
+    pub fn ast_ty_to_ty(&self, ast_ty: &hir::Ty<'tcx>) -> Ty<'tcx> {
         self.ast_ty_to_ty_inner(ast_ty, false, false)
     }
 
     /// Parses the programmer's textual representation of a type into our
     /// internal notion of a type. This is meant to be used within a path.
-    pub fn ast_ty_to_ty_in_path(&self, ast_ty: &hir::Ty<'_>) -> Ty<'tcx> {
+    pub fn ast_ty_to_ty_in_path(&self, ast_ty: &hir::Ty<'tcx>) -> Ty<'tcx> {
         self.ast_ty_to_ty_inner(ast_ty, false, true)
     }
 
@@ -2432,7 +2432,12 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
     /// Turns a `hir::Ty` into a `Ty`. For diagnostics' purposes we keep track of whether trait
     /// objects are borrowed like `&dyn Trait` to avoid emitting redundant errors.
     #[instrument(level = "debug", skip(self), ret)]
-    fn ast_ty_to_ty_inner(&self, ast_ty: &hir::Ty<'_>, borrowed: bool, in_path: bool) -> Ty<'tcx> {
+    fn ast_ty_to_ty_inner(
+        &self,
+        ast_ty: &hir::Ty<'tcx>,
+        borrowed: bool,
+        in_path: bool,
+    ) -> Ty<'tcx> {
         let tcx = self.tcx();
 
         let result_ty = match &ast_ty.kind {
@@ -2609,7 +2614,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         }
     }
 
-    pub fn ty_of_arg(&self, ty: &hir::Ty<'_>, expected_ty: Option<Ty<'tcx>>) -> Ty<'tcx> {
+    pub fn ty_of_arg(&self, ty: &hir::Ty<'tcx>, expected_ty: Option<Ty<'tcx>>) -> Ty<'tcx> {
         match ty.kind {
             hir::TyKind::Infer if expected_ty.is_some() => {
                 self.record_ty(ty.hir_id, expected_ty.unwrap(), ty.span);
@@ -2625,7 +2630,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         hir_id: hir::HirId,
         unsafety: hir::Unsafety,
         abi: abi::Abi,
-        decl: &hir::FnDecl<'_>,
+        decl: &hir::FnDecl<'tcx>,
         generics: Option<&hir::Generics<'_>>,
         hir_ty: Option<&hir::Ty<'_>>,
     ) -> ty::PolyFnSig<'tcx> {

compiler/rustc_hir_analysis/src/astconv/object_safety.rs

@@ -22,7 +22,7 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
         &self,
         span: Span,
         hir_id: hir::HirId,
-        hir_trait_bounds: &[hir::PolyTraitRef<'_>],
+        hir_trait_bounds: &[hir::PolyTraitRef<'tcx>],
         lifetime: &hir::Lifetime,
         borrowed: bool,
         representation: DynKind,

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -1790,7 +1790,7 @@ fn receiver_is_implemented<'tcx>(
 fn check_variances_for_type_defn<'tcx>(
     tcx: TyCtxt<'tcx>,
     item: &hir::Item<'tcx>,
-    hir_generics: &hir::Generics<'_>,
+    hir_generics: &hir::Generics<'tcx>,
 ) {
     let identity_args = ty::GenericArgs::identity_for_item(tcx, item.owner_id);
 

compiler/rustc_hir_analysis/src/collect.rs

@@ -348,7 +348,7 @@ impl<'tcx> ItemCtxt<'tcx> {
         ItemCtxt { tcx, item_def_id, tainted_by_errors: Cell::new(None) }
     }
 
-    pub fn to_ty(&self, ast_ty: &hir::Ty<'_>) -> Ty<'tcx> {
+    pub fn to_ty(&self, ast_ty: &hir::Ty<'tcx>) -> Ty<'tcx> {
         self.astconv().ast_ty_to_ty(ast_ty)
     }
 
@@ -412,7 +412,7 @@ impl<'tcx> AstConv<'tcx> for ItemCtxt<'tcx> {
         &self,
         span: Span,
         item_def_id: DefId,
-        item_segment: &hir::PathSegment<'_>,
+        item_segment: &hir::PathSegment<'tcx>,
         poly_trait_ref: ty::PolyTraitRef<'tcx>,
     ) -> Ty<'tcx> {
         if let Some(trait_ref) = poly_trait_ref.no_bound_vars() {
@@ -1148,7 +1148,7 @@ fn fn_sig(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::EarlyBinder<ty::PolyFnSig<
 
 fn infer_return_ty_for_fn_sig<'tcx>(
     tcx: TyCtxt<'tcx>,
-    sig: &hir::FnSig<'_>,
+    sig: &hir::FnSig<'tcx>,
     generics: &hir::Generics<'_>,
     def_id: LocalDefId,
     icx: &ItemCtxt<'tcx>,
@@ -1352,14 +1352,14 @@ fn impl_trait_ref(
                 let last_arg = args.args.len() - 1;
                 assert!(matches!(args.args[last_arg], hir::GenericArg::Const(anon_const) if anon_const.is_desugared_from_effects));
                 args.args = &args.args[..args.args.len() - 1];
-                path_segments[last_segment].args = Some(&args);
+                path_segments[last_segment].args = Some(tcx.hir_arena.alloc(args));
                 let path = hir::Path {
                     span: ast_trait_ref.path.span,
                     res: ast_trait_ref.path.res,
-                    segments: &path_segments,
+                    segments: tcx.hir_arena.alloc_slice(&path_segments),
                 };
-                let trait_ref = hir::TraitRef { path: &path, hir_ref_id: ast_trait_ref.hir_ref_id };
-                icx.astconv().instantiate_mono_trait_ref(&trait_ref, selfty)
+                let trait_ref = tcx.hir_arena.alloc(hir::TraitRef { path: tcx.hir_arena.alloc(path), hir_ref_id: ast_trait_ref.hir_ref_id });
+                icx.astconv().instantiate_mono_trait_ref(trait_ref, selfty)
             } else {
                 icx.astconv().instantiate_mono_trait_ref(ast_trait_ref, selfty)
             }

compiler/rustc_hir_analysis/src/lib.rs

@@ -225,7 +225,7 @@ pub fn check_crate(tcx: TyCtxt<'_>) -> Result<(), ErrorGuaranteed> {
 
 /// A quasi-deprecated helper used in rustdoc and clippy to get
 /// the type from a HIR node.
-pub fn hir_ty_to_ty<'tcx>(tcx: TyCtxt<'tcx>, hir_ty: &hir::Ty<'_>) -> Ty<'tcx> {
+pub fn hir_ty_to_ty<'tcx>(tcx: TyCtxt<'tcx>, hir_ty: &hir::Ty<'tcx>) -> Ty<'tcx> {
     // In case there are any projections, etc., find the "environment"
     // def-ID that will be used to determine the traits/predicates in
     // scope. This is derived from the enclosing item-like thing.
@@ -236,7 +236,7 @@ pub fn hir_ty_to_ty<'tcx>(tcx: TyCtxt<'tcx>, hir_ty: &hir::Ty<'_>) -> Ty<'tcx> {
 
 pub fn hir_trait_to_predicates<'tcx>(
     tcx: TyCtxt<'tcx>,
-    hir_trait: &hir::TraitRef<'_>,
+    hir_trait: &hir::TraitRef<'tcx>,
     self_ty: Ty<'tcx>,
 ) -> Bounds<'tcx> {
     // In case there are any projections, etc., find the "environment"