Remove in_band_lifetimes from rustc_middle

See #91867

This was mostly straightforward. In several places, I take advantage
of the fact that lifetimes are non-hygenic: a macro declares the
'tcx' lifetime, which is then used in types passed in as macro
arguments.

compiler/rustc_macros/src/type_foldable.rs

@@ -1,10 +1,15 @@
 use quote::quote;
+use syn::parse_quote;
 
 pub fn type_foldable_derive(mut s: synstructure::Structure<'_>) -> proc_macro2::TokenStream {
     if let syn::Data::Union(_) = s.ast().data {
         panic!("cannot derive on union")
     }
 
+    if !s.ast().generics.lifetimes().any(|lt| lt.lifetime.ident == "tcx") {
+        s.add_impl_generic(parse_quote! { 'tcx });
+    }
+
     s.add_bounds(synstructure::AddBounds::Generics);
     let body_visit = s.each(|bind| {
         quote! {

compiler/rustc_middle/src/dep_graph/dep_node.rs

@@ -201,7 +201,7 @@ crate fn make_compile_codegen_unit(tcx: TyCtxt<'_>, name: Symbol) -> DepNode {
 
 // WARNING: `construct` is generic and does not know that `CompileMonoItem` takes `MonoItem`s as keys.
 // Be very careful changing this type signature!
-crate fn make_compile_mono_item(tcx: TyCtxt<'tcx>, mono_item: &MonoItem<'tcx>) -> DepNode {
+crate fn make_compile_mono_item<'tcx>(tcx: TyCtxt<'tcx>, mono_item: &MonoItem<'tcx>) -> DepNode {
     DepNode::construct(tcx, DepKind::CompileMonoItem, mono_item)
 }
 
@@ -264,7 +264,7 @@ impl DepNodeExt for DepNode {
     /// DepNode. Condition (2) might not be fulfilled if a DepNode
     /// refers to something from the previous compilation session that
     /// has been removed.
-    fn extract_def_id(&self, tcx: TyCtxt<'tcx>) -> Option<DefId> {
+    fn extract_def_id<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Option<DefId> {
         if self.kind.fingerprint_style(tcx) == FingerprintStyle::DefPathHash {
             Some(tcx.def_path_hash_to_def_id(DefPathHash(self.hash.into())))
         } else {

compiler/rustc_middle/src/infer/canonical.rs

@@ -75,7 +75,7 @@ pub struct OriginalQueryValues<'tcx> {
     pub var_values: SmallVec<[GenericArg<'tcx>; 8]>,
 }
 
-impl Default for OriginalQueryValues<'tcx> {
+impl<'tcx> Default for OriginalQueryValues<'tcx> {
     fn default() -> Self {
         let mut universe_map = SmallVec::default();
         universe_map.push(ty::UniverseIndex::ROOT);

compiler/rustc_middle/src/infer/unify_key.rs

@@ -164,7 +164,7 @@ impl<'tcx> UnifyValue for ConstVarValue<'tcx> {
 
 impl<'tcx> EqUnifyValue for &'tcx ty::Const<'tcx> {}
 
-pub fn replace_if_possible<V, L>(
+pub fn replace_if_possible<'tcx, V, L>(
     table: &mut UnificationTable<InPlace<ty::ConstVid<'tcx>, V, L>>,
     c: &'tcx ty::Const<'tcx>,
 ) -> &'tcx ty::Const<'tcx>

compiler/rustc_middle/src/lib.rs

@@ -44,7 +44,6 @@
 #![feature(let_else)]
 #![feature(min_specialization)]
 #![feature(trusted_len)]
-#![feature(in_band_lifetimes)]
 #![feature(crate_visibility_modifier)]
 #![feature(associated_type_bounds)]
 #![feature(rustc_attrs)]

compiler/rustc_middle/src/lint.rs

@@ -212,7 +212,7 @@ pub fn struct_lint_level<'s, 'd>(
 ) {
     // Avoid codegen bloat from monomorphization by immediately doing dyn dispatch of `decorate` to
     // the "real" work.
-    fn struct_lint_level_impl(
+    fn struct_lint_level_impl<'s, 'd>(
         sess: &'s Session,
         lint: &'static Lint,
         level: Level,

compiler/rustc_middle/src/middle/stability.rs

@@ -229,7 +229,7 @@ pub fn deprecation_message_and_lint(
     )
 }
 
-pub fn early_report_deprecation(
+pub fn early_report_deprecation<'a>(
     lint_buffer: &'a mut LintBuffer,
     message: &str,
     suggestion: Option<Symbol>,

compiler/rustc_middle/src/mir/interpret/error.rs

@@ -63,7 +63,7 @@ impl fmt::Display for InterpErrorInfo<'_> {
     }
 }
 
-impl InterpErrorInfo<'tcx> {
+impl<'tcx> InterpErrorInfo<'tcx> {
     pub fn print_backtrace(&self) {
         if let Some(backtrace) = self.0.backtrace.as_ref() {
             print_backtrace(backtrace);

compiler/rustc_middle/src/mir/interpret/mod.rs

@@ -145,7 +145,7 @@ pub struct GlobalId<'tcx> {
     pub promoted: Option<mir::Promoted>,
 }
 
-impl GlobalId<'tcx> {
+impl<'tcx> GlobalId<'tcx> {
     pub fn display(self, tcx: TyCtxt<'tcx>) -> String {
         let instance_name = with_no_trimmed_paths(|| tcx.def_path_str(self.instance.def.def_id()));
         if let Some(promoted) = self.promoted {
@@ -273,7 +273,7 @@ pub struct AllocDecodingSession<'s> {
 
 impl<'s> AllocDecodingSession<'s> {
     /// Decodes an `AllocId` in a thread-safe way.
-    pub fn decode_alloc_id<D>(&self, decoder: &mut D) -> Result<AllocId, D::Error>
+    pub fn decode_alloc_id<'tcx, D>(&self, decoder: &mut D) -> Result<AllocId, D::Error>
     where
         D: TyDecoder<'tcx>,
     {
@@ -390,7 +390,7 @@ pub enum GlobalAlloc<'tcx> {
     Memory(&'tcx Allocation),
 }
 
-impl GlobalAlloc<'tcx> {
+impl<'tcx> GlobalAlloc<'tcx> {
     /// Panics if the `GlobalAlloc` does not refer to an `GlobalAlloc::Memory`
     #[track_caller]
     #[inline]

compiler/rustc_middle/src/mir/mod.rs

@@ -2033,7 +2033,7 @@ impl SourceScope {
     /// Finds the original HirId this MIR item came from.
     /// This is necessary after MIR optimizations, as otherwise we get a HirId
     /// from the function that was inlined instead of the function call site.
-    pub fn lint_root(
+    pub fn lint_root<'tcx>(
         self,
         source_scopes: &IndexVec<SourceScope, SourceScopeData<'tcx>>,
     ) -> Option<HirId> {
@@ -2543,7 +2543,7 @@ pub enum ConstantKind<'tcx> {
     Val(interpret::ConstValue<'tcx>, Ty<'tcx>),
 }
 
-impl Constant<'tcx> {
+impl<'tcx> Constant<'tcx> {
     pub fn check_static_ptr(&self, tcx: TyCtxt<'_>) -> Option<DefId> {
         match self.literal.const_for_ty()?.val.try_to_scalar() {
             Some(Scalar::Ptr(ptr, _size)) => match tcx.global_alloc(ptr.provenance) {
@@ -2562,14 +2562,14 @@ impl Constant<'tcx> {
     }
 }
 
-impl From<&'tcx ty::Const<'tcx>> for ConstantKind<'tcx> {
+impl<'tcx> From<&'tcx ty::Const<'tcx>> for ConstantKind<'tcx> {
     #[inline]
     fn from(ct: &'tcx ty::Const<'tcx>) -> Self {
         Self::Ty(ct)
     }
 }
 
-impl ConstantKind<'tcx> {
+impl<'tcx> ConstantKind<'tcx> {
     /// Returns `None` if the constant is not trivially safe for use in the type system.
     pub fn const_for_ty(&self) -> Option<&'tcx ty::Const<'tcx>> {
         match self {
@@ -2851,7 +2851,7 @@ impl<'tcx> Display for ConstantKind<'tcx> {
     }
 }
 
-fn pretty_print_const(
+fn pretty_print_const<'tcx>(
     c: &ty::Const<'tcx>,
     fmt: &mut Formatter<'_>,
     print_types: bool,
@@ -2866,7 +2866,7 @@ fn pretty_print_const(
     })
 }
 
-fn pretty_print_const_value(
+fn pretty_print_const_value<'tcx>(
     val: interpret::ConstValue<'tcx>,
     ty: Ty<'tcx>,
     fmt: &mut Formatter<'_>,
@@ -2913,12 +2913,12 @@ impl<'a, 'b> graph::GraphSuccessors<'b> for Body<'a> {
     type Iter = iter::Cloned<Successors<'b>>;
 }
 
-impl graph::GraphPredecessors<'graph> for Body<'tcx> {
+impl<'tcx, 'graph> graph::GraphPredecessors<'graph> for Body<'tcx> {
     type Item = BasicBlock;
     type Iter = std::iter::Copied<std::slice::Iter<'graph, BasicBlock>>;
 }
 
-impl graph::WithPredecessors for Body<'tcx> {
+impl<'tcx> graph::WithPredecessors for Body<'tcx> {
     #[inline]
     fn predecessors(&self, node: Self::Node) -> <Self as graph::GraphPredecessors<'_>>::Iter {
         self.predecessors()[node].iter().copied()

compiler/rustc_middle/src/mir/mono.rs

@@ -431,7 +431,7 @@ pub struct CodegenUnitNameBuilder<'tcx> {
     cache: FxHashMap<CrateNum, String>,
 }
 
-impl CodegenUnitNameBuilder<'tcx> {
+impl<'tcx> CodegenUnitNameBuilder<'tcx> {
     pub fn new(tcx: TyCtxt<'tcx>) -> Self {
         CodegenUnitNameBuilder { tcx, cache: Default::default() }
     }

compiler/rustc_middle/src/mir/pretty.rs

@@ -167,8 +167,8 @@ fn dump_matched_mir_node<'tcx, F>(
 
 /// Returns the file basename portion (without extension) of a filename path
 /// where we should dump a MIR representation output files.
-fn dump_file_basename(
-    tcx: TyCtxt<'_>,
+fn dump_file_basename<'tcx>(
+    tcx: TyCtxt<'tcx>,
     pass_num: Option<&dyn Display>,
     pass_name: &str,
     disambiguator: &dyn Display,
@@ -251,8 +251,8 @@ fn create_dump_file_with_basename(
 /// bit of MIR-related data. Used by `mir-dump`, but also by other
 /// bits of code (e.g., NLL inference) that dump graphviz data or
 /// other things, and hence takes the extension as an argument.
-pub fn create_dump_file(
-    tcx: TyCtxt<'_>,
+pub fn create_dump_file<'tcx>(
+    tcx: TyCtxt<'tcx>,
     extension: &str,
     pass_num: Option<&dyn Display>,
     pass_name: &str,
@@ -419,7 +419,7 @@ struct ExtraComments<'tcx> {
     comments: Vec<String>,
 }
 
-impl ExtraComments<'tcx> {
+impl<'tcx> ExtraComments<'tcx> {
     fn push(&mut self, lines: &str) {
         for line in lines.split('\n') {
             self.comments.push(line.to_string());
@@ -427,7 +427,7 @@ impl ExtraComments<'tcx> {
     }
 }
 
-fn use_verbose(ty: &&TyS<'tcx>, fn_def: bool) -> bool {
+fn use_verbose<'tcx>(ty: &&TyS<'tcx>, fn_def: bool) -> bool {
     match ty.kind() {
         ty::Int(_) | ty::Uint(_) | ty::Bool | ty::Char | ty::Float(_) => false,
         // Unit type
@@ -439,7 +439,7 @@ fn use_verbose(ty: &&TyS<'tcx>, fn_def: bool) -> bool {
     }
 }
 
-impl Visitor<'tcx> for ExtraComments<'tcx> {
+impl<'tcx> Visitor<'tcx> for ExtraComments<'tcx> {
     fn visit_constant(&mut self, constant: &Constant<'tcx>, location: Location) {
         self.super_constant(constant, location);
         let Constant { span, user_ty, literal } = constant;
@@ -762,7 +762,7 @@ pub fn write_allocations<'tcx>(
 /// After the hex dump, an ascii dump follows, replacing all unprintable characters (control
 /// characters or characters whose value is larger than 127) with a `.`
 /// This also prints relocations adequately.
-pub fn display_allocation<Tag, Extra>(
+pub fn display_allocation<'a, 'tcx, Tag, Extra>(
     tcx: TyCtxt<'tcx>,
     alloc: &'a Allocation<Tag, Extra>,
 ) -> RenderAllocation<'a, 'tcx, Tag, Extra> {
@@ -775,7 +775,7 @@ pub struct RenderAllocation<'a, 'tcx, Tag, Extra> {
     alloc: &'a Allocation<Tag, Extra>,
 }
 
-impl<Tag: Provenance, Extra> std::fmt::Display for RenderAllocation<'a, 'tcx, Tag, Extra> {
+impl<'a, 'tcx, Tag: Provenance, Extra> std::fmt::Display for RenderAllocation<'a, 'tcx, Tag, Extra> {
     fn fmt(&self, w: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         let RenderAllocation { tcx, alloc } = *self;
         write!(w, "size: {}, align: {})", alloc.size().bytes(), alloc.align.bytes())?;
@@ -818,7 +818,7 @@ fn write_allocation_newline(
 /// The `prefix` argument allows callers to add an arbitrary prefix before each line (even if there
 /// is only one line). Note that your prefix should contain a trailing space as the lines are
 /// printed directly after it.
-fn write_allocation_bytes<Tag: Provenance, Extra>(
+fn write_allocation_bytes<'tcx, Tag: Provenance, Extra>(
     tcx: TyCtxt<'tcx>,
     alloc: &Allocation<Tag, Extra>,
     w: &mut dyn std::fmt::Write,

compiler/rustc_middle/src/mir/traversal.rs

@@ -300,7 +300,7 @@ pub fn reachable<'a, 'tcx>(
 }
 
 /// Returns a `BitSet` containing all basic blocks reachable from the `START_BLOCK`.
-pub fn reachable_as_bitset(body: &Body<'tcx>) -> BitSet<BasicBlock> {
+pub fn reachable_as_bitset<'tcx>(body: &Body<'tcx>) -> BitSet<BasicBlock> {
     let mut iter = preorder(body);
     (&mut iter).for_each(drop);
     iter.visited

compiler/rustc_middle/src/mir/visit.rs

@@ -965,7 +965,7 @@ macro_rules! visit_place_fns {
             }
         }
 
-        fn process_projection(
+        fn process_projection<'a>(
             &mut self,
             projection: &'a [PlaceElem<'tcx>],
             location: Location,

compiler/rustc_middle/src/traits/mod.rs

@@ -101,7 +101,7 @@ impl<'tcx> fmt::Debug for ObligationCause<'tcx> {
     }
 }
 
-impl Deref for ObligationCause<'tcx> {
+impl<'tcx> Deref for ObligationCause<'tcx> {
     type Target = ObligationCauseData<'tcx>;
 
     #[inline(always)]

compiler/rustc_middle/src/traits/specialization_graph.rs

@@ -216,7 +216,7 @@ impl<'tcx> Ancestors<'tcx> {
 ///
 /// Returns `Err` if an error was reported while building the specialization
 /// graph.
-pub fn ancestors(
+pub fn ancestors<'tcx>(
     tcx: TyCtxt<'tcx>,
     trait_def_id: DefId,
     start_from_impl: DefId,

compiler/rustc_middle/src/traits/structural_impls.rs

@@ -74,7 +74,7 @@ impl<N: fmt::Debug> fmt::Debug for traits::ImplSourceBuiltinData<N> {
     }
 }
 
-impl<N: fmt::Debug> fmt::Debug for traits::ImplSourceTraitUpcastingData<'tcx, N> {
+impl<'tcx, N: fmt::Debug> fmt::Debug for traits::ImplSourceTraitUpcastingData<'tcx, N> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(
             f,

compiler/rustc_middle/src/ty/_match.rs

@@ -23,13 +23,13 @@ pub struct Match<'tcx> {
     param_env: ty::ParamEnv<'tcx>,
 }
 
-impl Match<'tcx> {
+impl<'tcx> Match<'tcx> {
     pub fn new(tcx: TyCtxt<'tcx>, param_env: ty::ParamEnv<'tcx>) -> Match<'tcx> {
         Match { tcx, param_env }
     }
 }
 
-impl TypeRelation<'tcx> for Match<'tcx> {
+impl<'tcx> TypeRelation<'tcx> for Match<'tcx> {
     fn tag(&self) -> &'static str {
         "Match"
     }

compiler/rustc_middle/src/ty/adjustment.rs

@@ -83,7 +83,7 @@ pub struct Adjustment<'tcx> {
     pub target: Ty<'tcx>,
 }
 
-impl Adjustment<'tcx> {
+impl<'tcx> Adjustment<'tcx> {
     pub fn is_region_borrow(&self) -> bool {
         matches!(self.kind, Adjust::Borrow(AutoBorrow::Ref(..)))
     }

compiler/rustc_middle/src/ty/assoc.rs

@@ -139,7 +139,7 @@ impl<'tcx> AssocItems<'tcx> {
     /// Multiple items may have the same name if they are in different `Namespace`s. For example,
     /// an associated type can have the same name as a method. Use one of the `find_by_name_and_*`
     /// methods below if you know which item you are looking for.
-    pub fn filter_by_name(
+    pub fn filter_by_name<'a>(
         &'a self,
         tcx: TyCtxt<'a>,
         ident: Ident,

compiler/rustc_middle/src/ty/closure.rs

@@ -156,7 +156,7 @@ pub struct CapturedPlace<'tcx> {
     pub mutability: hir::Mutability,
 }
 
-impl CapturedPlace<'tcx> {
+impl<'tcx> CapturedPlace<'tcx> {
     pub fn to_string(&self, tcx: TyCtxt<'tcx>) -> String {
         place_to_string_for_capture(tcx, &self.place)
     }
@@ -328,7 +328,7 @@ pub struct CaptureInfo<'tcx> {
     pub capture_kind: UpvarCapture<'tcx>,
 }
 
-pub fn place_to_string_for_capture(tcx: TyCtxt<'tcx>, place: &HirPlace<'tcx>) -> String {
+pub fn place_to_string_for_capture<'tcx>(tcx: TyCtxt<'tcx>, place: &HirPlace<'tcx>) -> String {
     let mut curr_string: String = match place.base {
         HirPlaceBase::Upvar(upvar_id) => tcx.hir().name(upvar_id.var_path.hir_id).to_string(),
         _ => bug!("Capture_information should only contain upvars"),

compiler/rustc_middle/src/ty/codec.rs

@@ -76,7 +76,7 @@ pub trait RefDecodable<'tcx, D: TyDecoder<'tcx>> {
 }
 
 /// Encode the given value or a previously cached shorthand.
-pub fn encode_with_shorthand<E, T, M>(encoder: &mut E, value: &T, cache: M) -> Result<(), E::Error>
+pub fn encode_with_shorthand<'tcx, E, T, M>(encoder: &mut E, value: &T, cache: M) -> Result<(), E::Error>
 where
     E: TyEncoder<'tcx>,
     M: for<'b> Fn(&'b mut E) -> &'b mut FxHashMap<T, usize>,

compiler/rustc_middle/src/ty/consts/int.rs

@@ -234,7 +234,7 @@ impl ScalarInt {
     }
 
     #[inline]
-    pub fn try_to_machine_usize(&self, tcx: TyCtxt<'tcx>) -> Result<u64, Size> {
+    pub fn try_to_machine_usize<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Result<u64, Size> {
         Ok(self.to_bits(tcx.data_layout.pointer_size)? as u64)
     }
 }

compiler/rustc_middle/src/ty/consts/valtree.rs

@@ -27,7 +27,7 @@ pub enum ValTree<'tcx> {
     Branch(&'tcx [ValTree<'tcx>]),
 }
 
-impl ValTree<'tcx> {
+impl<'tcx> ValTree<'tcx> {
     pub fn zst() -> Self {
         Self::Branch(&[])
     }

compiler/rustc_middle/src/ty/context.rs

@@ -824,7 +824,7 @@ pub struct CanonicalUserTypeAnnotation<'tcx> {
 /// Canonicalized user type annotation.
 pub type CanonicalUserType<'tcx> = Canonical<'tcx, UserType<'tcx>>;
 
-impl CanonicalUserType<'tcx> {
+impl<'tcx> CanonicalUserType<'tcx> {
     /// Returns `true` if this represents a substitution of the form `[?0, ?1, ?2]`,
     /// i.e., each thing is mapped to a canonical variable with the same index.
     pub fn is_identity(&self) -> bool {
@@ -1893,7 +1893,7 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn debug_stats(self) -> impl std::fmt::Debug + 'tcx {
         struct DebugStats<'tcx>(TyCtxt<'tcx>);
 
-        impl std::fmt::Debug for DebugStats<'tcx> {
+        impl<'tcx> std::fmt::Debug for DebugStats<'tcx> {
             fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
                 sty_debug_print!(
                     fmt,
@@ -2711,7 +2711,7 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 }
 
-impl TyCtxtAt<'tcx> {
+impl<'tcx> TyCtxtAt<'tcx> {
     /// Constructs a `TyKind::Error` type and registers a `delay_span_bug` to ensure it gets used.
     #[track_caller]
     pub fn ty_error(self) -> Ty<'tcx> {

compiler/rustc_middle/src/ty/erase_regions.rs

@@ -37,7 +37,7 @@ struct RegionEraserVisitor<'tcx> {
     tcx: TyCtxt<'tcx>,
 }
 
-impl TypeFolder<'tcx> for RegionEraserVisitor<'tcx> {
+impl<'tcx> TypeFolder<'tcx> for RegionEraserVisitor<'tcx> {
     fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
         self.tcx
     }

compiler/rustc_middle/src/ty/flags.rs

@@ -22,7 +22,7 @@ impl FlagComputation {
         result
     }
 
-    pub fn for_predicate(binder: ty::Binder<'tcx, ty::PredicateKind<'_>>) -> FlagComputation {
+    pub fn for_predicate<'tcx>(binder: ty::Binder<'tcx, ty::PredicateKind<'_>>) -> FlagComputation {
         let mut result = FlagComputation::new();
         result.add_predicate(binder);
         result
@@ -216,7 +216,7 @@ impl FlagComputation {
         }
     }
 
-    fn add_predicate(&mut self, binder: ty::Binder<'tcx, ty::PredicateKind<'_>>) {
+    fn add_predicate(&mut self, binder: ty::Binder<'_, ty::PredicateKind<'_>>) {
         self.bound_computation(binder, |computation, atom| computation.add_predicate_atom(atom));
     }
 
@@ -310,7 +310,7 @@ impl FlagComputation {
         }
     }
 
-    fn add_unevaluated_const<P>(&mut self, ct: ty::Unevaluated<'tcx, P>) {
+    fn add_unevaluated_const<P>(&mut self, ct: ty::Unevaluated<'_, P>) {
         // The generic arguments of unevaluated consts are a bit special,
         // see the `rustc-dev-guide` for more information.
         //

compiler/rustc_middle/src/ty/fold.rs

@@ -199,7 +199,7 @@ pub trait TypeFoldable<'tcx>: fmt::Debug + Clone {
     }
 }
 
-impl TypeFoldable<'tcx> for hir::Constness {
+impl<'tcx> TypeFoldable<'tcx> for hir::Constness {
     fn try_super_fold_with<F: TypeFolder<'tcx>>(self, _: &mut F) -> Result<Self, F::Error> {
         Ok(self)
     }
@@ -1060,13 +1060,13 @@ struct Shifter<'tcx> {
     amount: u32,
 }
 
-impl Shifter<'tcx> {
+impl<'tcx> Shifter<'tcx> {
     pub fn new(tcx: TyCtxt<'tcx>, amount: u32) -> Self {
         Shifter { tcx, current_index: ty::INNERMOST, amount }
     }
 }
 
-impl TypeFolder<'tcx> for Shifter<'tcx> {
+impl<'tcx> TypeFolder<'tcx> for Shifter<'tcx> {
     fn tcx<'b>(&'b self) -> TyCtxt<'tcx> {
         self.tcx
     }
@@ -1257,7 +1257,7 @@ struct HasTypeFlagsVisitor<'tcx> {
     flags: ty::TypeFlags,
 }
 
-impl std::fmt::Debug for HasTypeFlagsVisitor<'tcx> {
+impl<'tcx> std::fmt::Debug for HasTypeFlagsVisitor<'tcx> {
     fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         self.flags.fmt(fmt)
     }
@@ -1454,7 +1454,7 @@ struct LateBoundRegionsCollector<'tcx> {
     just_constrained: bool,
 }
 
-impl LateBoundRegionsCollector<'tcx> {
+impl<'tcx> LateBoundRegionsCollector<'tcx> {
     fn new(tcx: TyCtxt<'tcx>, just_constrained: bool) -> Self {
         LateBoundRegionsCollector {
             tcx,

compiler/rustc_middle/src/ty/inhabitedness/def_id_forest.rs

@@ -30,7 +30,7 @@ pub enum DefIdForest {
 
 /// Tests whether a slice of roots contains a given DefId.
 #[inline]
-fn slice_contains(tcx: TyCtxt<'tcx>, slice: &[DefId], id: DefId) -> bool {
+fn slice_contains<'tcx>(tcx: TyCtxt<'tcx>, slice: &[DefId], id: DefId) -> bool {
     slice.iter().any(|root_id| tcx.is_descendant_of(id, *root_id))
 }
 

compiler/rustc_middle/src/ty/instance.rs

@@ -635,7 +635,7 @@ fn polymorphize<'tcx>(
         tcx: TyCtxt<'tcx>,
     }
 
-    impl ty::TypeFolder<'tcx> for PolymorphizationFolder<'tcx> {
+    impl<'tcx> ty::TypeFolder<'tcx> for PolymorphizationFolder<'tcx> {
         fn tcx<'a>(&'a self) -> TyCtxt<'tcx> {
             self.tcx
         }

compiler/rustc_middle/src/ty/layout.rs

@@ -168,7 +168,7 @@ impl PrimitiveExt for Primitive {
     /// Return an *integer* type matching this primitive.
     /// Useful in particular when dealing with enum discriminants.
     #[inline]
-    fn to_int_ty(&self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> {
+    fn to_int_ty<'tcx>(&self, tcx: TyCtxt<'tcx>) -> Ty<'tcx> {
         match *self {
             Int(i, signed) => i.to_ty(tcx, signed),
             Pointer => tcx.types.usize,
@@ -2195,9 +2195,9 @@ pub trait LayoutOf<'tcx>: LayoutOfHelpers<'tcx> {
     }
 }
 
-impl<C: LayoutOfHelpers<'tcx>> LayoutOf<'tcx> for C {}
+impl<'tcx, C: LayoutOfHelpers<'tcx>> LayoutOf<'tcx> for C {}
 
-impl LayoutOfHelpers<'tcx> for LayoutCx<'tcx, TyCtxt<'tcx>> {
+impl<'tcx> LayoutOfHelpers<'tcx> for LayoutCx<'tcx, TyCtxt<'tcx>> {
     type LayoutOfResult = Result<TyAndLayout<'tcx>, LayoutError<'tcx>>;
 
     #[inline]
@@ -2206,7 +2206,7 @@ impl LayoutOfHelpers<'tcx> for LayoutCx<'tcx, TyCtxt<'tcx>> {
     }
 }
 
-impl LayoutOfHelpers<'tcx> for LayoutCx<'tcx, ty::query::TyCtxtAt<'tcx>> {
+impl<'tcx> LayoutOfHelpers<'tcx> for LayoutCx<'tcx, ty::query::TyCtxtAt<'tcx>> {
     type LayoutOfResult = Result<TyAndLayout<'tcx>, LayoutError<'tcx>>;
 
     #[inline]
@@ -2282,7 +2282,7 @@ where
             TyAndLayout(TyAndLayout<'tcx>),
         }
 
-        fn field_ty_or_layout(
+        fn field_ty_or_layout<'tcx>(
             this: TyAndLayout<'tcx>,
             cx: &(impl HasTyCtxt<'tcx> + HasParamEnv<'tcx>),
             i: usize,
@@ -2724,7 +2724,7 @@ impl<'tcx> ty::Instance<'tcx> {
 /// with `-Cpanic=abort` will look like they can't unwind when in fact they
 /// might (from a foreign exception or similar).
 #[inline]
-pub fn fn_can_unwind(
+pub fn fn_can_unwind<'tcx>(
     tcx: TyCtxt<'tcx>,
     codegen_fn_attr_flags: CodegenFnAttrFlags,
     abi: SpecAbi,
@@ -2842,7 +2842,7 @@ pub enum FnAbiError<'tcx> {
     AdjustForForeignAbi(call::AdjustForForeignAbiError),
 }
 
-impl From<LayoutError<'tcx>> for FnAbiError<'tcx> {
+impl<'tcx> From<LayoutError<'tcx>> for FnAbiError<'tcx> {
     fn from(err: LayoutError<'tcx>) -> Self {
         Self::Layout(err)
     }
@@ -2942,7 +2942,7 @@ pub trait FnAbiOf<'tcx>: FnAbiOfHelpers<'tcx> {
     }
 }
 
-impl<C: FnAbiOfHelpers<'tcx>> FnAbiOf<'tcx> for C {}
+impl<'tcx, C: FnAbiOfHelpers<'tcx>> FnAbiOf<'tcx> for C {}
 
 fn fn_abi_of_fn_ptr<'tcx>(
     tcx: TyCtxt<'tcx>,

compiler/rustc_middle/src/ty/mod.rs

@@ -852,7 +852,7 @@ pub trait ToPredicate<'tcx> {
     fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx>;
 }
 
-impl ToPredicate<'tcx> for Binder<'tcx, PredicateKind<'tcx>> {
+impl<'tcx> ToPredicate<'tcx> for Binder<'tcx, PredicateKind<'tcx>> {
     #[inline(always)]
     fn to_predicate(self, tcx: TyCtxt<'tcx>) -> Predicate<'tcx> {
         tcx.mk_predicate(self)
@@ -1418,7 +1418,7 @@ impl<'tcx> ParamEnv<'tcx> {
 
 // FIXME(ecstaticmorse): Audit all occurrences of `without_const().to_predicate(tcx)` to ensure that
 // the constness of trait bounds is being propagated correctly.
-impl PolyTraitRef<'tcx> {
+impl<'tcx> PolyTraitRef<'tcx> {
     #[inline]
     pub fn with_constness(self, constness: BoundConstness) -> PolyTraitPredicate<'tcx> {
         self.map_bound(|trait_ref| ty::TraitPredicate {

compiler/rustc_middle/src/ty/normalize_erasing_regions.rs

@@ -180,7 +180,7 @@ impl<'tcx> NormalizeAfterErasingRegionsFolder<'tcx> {
     }
 }
 
-impl TypeFolder<'tcx> for NormalizeAfterErasingRegionsFolder<'tcx> {
+impl<'tcx> TypeFolder<'tcx> for NormalizeAfterErasingRegionsFolder<'tcx> {
     fn tcx(&self) -> TyCtxt<'tcx> {
         self.tcx
     }
@@ -223,7 +223,7 @@ impl<'tcx> TryNormalizeAfterErasingRegionsFolder<'tcx> {
     }
 }
 
-impl TypeFolder<'tcx> for TryNormalizeAfterErasingRegionsFolder<'tcx> {
+impl<'tcx> TypeFolder<'tcx> for TryNormalizeAfterErasingRegionsFolder<'tcx> {
     type Error = NormalizationError<'tcx>;
 
     fn tcx(&self) -> TyCtxt<'tcx> {
@@ -231,7 +231,7 @@ impl TypeFolder<'tcx> for TryNormalizeAfterErasingRegionsFolder<'tcx> {
     }
 }
 
-impl FallibleTypeFolder<'tcx> for TryNormalizeAfterErasingRegionsFolder<'tcx> {
+impl<'tcx> FallibleTypeFolder<'tcx> for TryNormalizeAfterErasingRegionsFolder<'tcx> {
     fn try_fold_ty(&mut self, ty: Ty<'tcx>) -> Result<Ty<'tcx>, Self::Error> {
         match self.try_normalize_generic_arg_after_erasing_regions(ty.into()) {
             Ok(t) => Ok(t.expect_ty()),

compiler/rustc_middle/src/ty/print/mod.rs

@@ -37,7 +37,7 @@ pub trait Printer<'tcx>: Sized {
     type DynExistential;
     type Const;
 
-    fn tcx(&'a self) -> TyCtxt<'tcx>;
+    fn tcx<'a>(&'a self) -> TyCtxt<'tcx>;
 
     fn print_def_path(
         self,

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -1513,7 +1513,7 @@ pub struct FmtPrinterData<'a, 'tcx, F> {
     pub name_resolver: Option<Box<&'a dyn Fn(ty::TyVid) -> Option<String>>>,
 }
 
-impl<F> Deref for FmtPrinter<'a, 'tcx, F> {
+impl<'a, 'tcx, F> Deref for FmtPrinter<'a, 'tcx, F> {
     type Target = FmtPrinterData<'a, 'tcx, F>;
     fn deref(&self) -> &Self::Target {
         &self.0
@@ -1526,7 +1526,7 @@ impl<F> DerefMut for FmtPrinter<'_, '_, F> {
     }
 }
 
-impl<F> FmtPrinter<'a, 'tcx, F> {
+impl<'a, 'tcx, F> FmtPrinter<'a, 'tcx, F> {
     pub fn new(tcx: TyCtxt<'tcx>, fmt: F, ns: Namespace) -> Self {
         FmtPrinter(Box::new(FmtPrinterData {
             tcx,
@@ -1563,7 +1563,7 @@ fn guess_def_namespace(tcx: TyCtxt<'_>, def_id: DefId) -> Namespace {
     }
 }
 
-impl TyCtxt<'t> {
+impl<'t> TyCtxt<'t> {
     /// Returns a string identifying this `DefId`. This string is
     /// suitable for user output.
     pub fn def_path_str(self, def_id: DefId) -> String {
@@ -1585,7 +1585,7 @@ impl<F: fmt::Write> fmt::Write for FmtPrinter<'_, '_, F> {
     }
 }
 
-impl<F: fmt::Write> Printer<'tcx> for FmtPrinter<'_, 'tcx, F> {
+impl<'tcx, F: fmt::Write> Printer<'tcx> for FmtPrinter<'_, 'tcx, F> {
     type Error = fmt::Error;
 
     type Path = Self;
@@ -1594,7 +1594,7 @@ impl<F: fmt::Write> Printer<'tcx> for FmtPrinter<'_, 'tcx, F> {
     type DynExistential = Self;
     type Const = Self;
 
-    fn tcx(&'a self) -> TyCtxt<'tcx> {
+    fn tcx<'a>(&'a self) -> TyCtxt<'tcx> {
         self.tcx
     }
 
@@ -1796,7 +1796,7 @@ impl<F: fmt::Write> Printer<'tcx> for FmtPrinter<'_, 'tcx, F> {
     }
 }
 
-impl<F: fmt::Write> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx, F> {
+impl<'tcx, F: fmt::Write> PrettyPrinter<'tcx> for FmtPrinter<'_, 'tcx, F> {
     fn infer_ty_name(&self, id: ty::TyVid) -> Option<String> {
         self.0.name_resolver.as_ref().and_then(|func| func(id))
     }
@@ -2062,7 +2062,7 @@ impl<'a, 'tcx> ty::TypeFolder<'tcx> for RegionFolder<'a, 'tcx> {
 
 // HACK(eddyb) limited to `FmtPrinter` because of `binder_depth`,
 // `region_index` and `used_region_names`.
-impl<F: fmt::Write> FmtPrinter<'_, 'tcx, F> {
+impl<'tcx, F: fmt::Write> FmtPrinter<'_, 'tcx, F> {
     pub fn name_all_regions<T>(
         mut self,
         value: &ty::Binder<'tcx, T>,
@@ -2316,7 +2316,8 @@ where
 
 macro_rules! forward_display_to_print {
     ($($ty:ty),+) => {
-        $(impl fmt::Display for $ty {
+        // Some of the $ty arguments may not actually use 'tcx
+        $(#[allow(unused_lifetimes)] impl<'tcx> fmt::Display for $ty {
             fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
                 ty::tls::with(|tcx| {
                     tcx.lift(*self)
@@ -2364,7 +2365,7 @@ impl fmt::Display for ty::RegionKind {
 #[derive(Copy, Clone, TypeFoldable, Lift)]
 pub struct TraitRefPrintOnlyTraitPath<'tcx>(ty::TraitRef<'tcx>);
 
-impl fmt::Debug for TraitRefPrintOnlyTraitPath<'tcx> {
+impl<'tcx> fmt::Debug for TraitRefPrintOnlyTraitPath<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Display::fmt(self, f)
     }
@@ -2376,13 +2377,13 @@ impl fmt::Debug for TraitRefPrintOnlyTraitPath<'tcx> {
 #[derive(Copy, Clone, TypeFoldable, Lift)]
 pub struct TraitRefPrintOnlyTraitName<'tcx>(ty::TraitRef<'tcx>);
 
-impl fmt::Debug for TraitRefPrintOnlyTraitName<'tcx> {
+impl<'tcx> fmt::Debug for TraitRefPrintOnlyTraitName<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         fmt::Display::fmt(self, f)
     }
 }
 
-impl ty::TraitRef<'tcx> {
+impl<'tcx> ty::TraitRef<'tcx> {
     pub fn print_only_trait_path(self) -> TraitRefPrintOnlyTraitPath<'tcx> {
         TraitRefPrintOnlyTraitPath(self)
     }
@@ -2392,7 +2393,7 @@ impl ty::TraitRef<'tcx> {
     }
 }
 
-impl ty::Binder<'tcx, ty::TraitRef<'tcx>> {
+impl<'tcx> ty::Binder<'tcx, ty::TraitRef<'tcx>> {
     pub fn print_only_trait_path(self) -> ty::Binder<'tcx, TraitRefPrintOnlyTraitPath<'tcx>> {
         self.map_bound(|tr| tr.print_only_trait_path())
     }

compiler/rustc_middle/src/ty/query.rs

@@ -69,7 +69,7 @@ pub struct TyCtxtAt<'tcx> {
     pub span: Span,
 }
 
-impl Deref for TyCtxtAt<'tcx> {
+impl<'tcx> Deref for TyCtxtAt<'tcx> {
     type Target = TyCtxt<'tcx>;
     #[inline(always)]
     fn deref(&self) -> &Self::Target {
@@ -82,7 +82,7 @@ pub struct TyCtxtEnsure<'tcx> {
     pub tcx: TyCtxt<'tcx>,
 }
 
-impl TyCtxt<'tcx> {
+impl<'tcx> TyCtxt<'tcx> {
     /// Returns a transparent wrapper for `TyCtxt`, which ensures queries
     /// are executed instead of just returning their results.
     #[inline(always)]
@@ -207,7 +207,7 @@ macro_rules! define_callbacks {
             $($(#[$attr])* pub $name: QueryCacheStore<query_storage::$name<$tcx>>,)*
         }
 
-        impl TyCtxtEnsure<$tcx> {
+        impl<$tcx> TyCtxtEnsure<$tcx> {
             $($(#[$attr])*
             #[inline(always)]
             pub fn $name(self, key: query_helper_param_ty!($($K)*)) {
@@ -225,7 +225,7 @@ macro_rules! define_callbacks {
             })*
         }
 
-        impl TyCtxt<$tcx> {
+        impl<$tcx> TyCtxt<$tcx> {
             $($(#[$attr])*
             #[inline(always)]
             #[must_use]
@@ -235,7 +235,7 @@ macro_rules! define_callbacks {
             })*
         }
 
-        impl TyCtxtAt<$tcx> {
+        impl<$tcx> TyCtxtAt<$tcx> {
             $($(#[$attr])*
             #[inline(always)]
             pub fn $name(self, key: query_helper_param_ty!($($K)*)) -> query_stored::$name<$tcx>
@@ -357,7 +357,7 @@ mod sealed {
 
 use sealed::IntoQueryParam;
 
-impl TyCtxt<'tcx> {
+impl<'tcx> TyCtxt<'tcx> {
     pub fn def_kind(self, def_id: impl IntoQueryParam<DefId>) -> DefKind {
         let def_id = def_id.into_query_param();
         self.opt_def_kind(def_id)
@@ -365,7 +365,7 @@ impl TyCtxt<'tcx> {
     }
 }
 
-impl TyCtxtAt<'tcx> {
+impl<'tcx> TyCtxtAt<'tcx> {
     pub fn def_kind(self, def_id: impl IntoQueryParam<DefId>) -> DefKind {
         let def_id = def_id.into_query_param();
         self.opt_def_kind(def_id)

compiler/rustc_middle/src/ty/relate.rs

@@ -132,7 +132,7 @@ pub fn relate_type_and_mut<'tcx, R: TypeRelation<'tcx>>(
     }
 }
 
-pub fn relate_substs<R: TypeRelation<'tcx>>(
+pub fn relate_substs<'tcx, R: TypeRelation<'tcx>>(
     relation: &mut R,
     variances: Option<&[ty::Variance]>,
     a_subst: SubstsRef<'tcx>,
@@ -353,7 +353,7 @@ impl<'tcx> Relate<'tcx> for Ty<'tcx> {
 /// The main "type relation" routine. Note that this does not handle
 /// inference artifacts, so you should filter those out before calling
 /// it.
-pub fn super_relate_tys<R: TypeRelation<'tcx>>(
+pub fn super_relate_tys<'tcx, R: TypeRelation<'tcx>>(
     relation: &mut R,
     a: Ty<'tcx>,
     b: Ty<'tcx>,
@@ -526,7 +526,7 @@ pub fn super_relate_tys<R: TypeRelation<'tcx>>(
 /// The main "const relation" routine. Note that this does not handle
 /// inference artifacts, so you should filter those out before calling
 /// it.
-pub fn super_relate_consts<R: TypeRelation<'tcx>>(
+pub fn super_relate_consts<'tcx, R: TypeRelation<'tcx>>(
     relation: &mut R,
     a: &'tcx ty::Const<'tcx>,
     b: &'tcx ty::Const<'tcx>,
@@ -599,7 +599,7 @@ pub fn super_relate_consts<R: TypeRelation<'tcx>>(
     if is_match { Ok(a) } else { Err(TypeError::ConstMismatch(expected_found(relation, a, b))) }
 }
 
-fn check_const_value_eq<R: TypeRelation<'tcx>>(
+fn check_const_value_eq<'tcx, R: TypeRelation<'tcx>>(
     relation: &mut R,
     a_val: ConstValue<'tcx>,
     b_val: ConstValue<'tcx>,
@@ -832,7 +832,7 @@ impl<'tcx> Relate<'tcx> for ty::ProjectionPredicate<'tcx> {
 ///////////////////////////////////////////////////////////////////////////
 // Error handling
 
-pub fn expected_found<R, T>(relation: &mut R, a: T, b: T) -> ExpectedFound<T>
+pub fn expected_found<'tcx, R, T>(relation: &mut R, a: T, b: T) -> ExpectedFound<T>
 where
     R: TypeRelation<'tcx>,
 {

compiler/rustc_middle/src/ty/structural_impls.rs

@@ -47,19 +47,19 @@ impl fmt::Debug for ty::UpvarId {
     }
 }
 
-impl fmt::Debug for ty::UpvarBorrow<'tcx> {
+impl<'tcx> fmt::Debug for ty::UpvarBorrow<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "UpvarBorrow({:?}, {:?})", self.kind, self.region)
     }
 }
 
-impl fmt::Debug for ty::ExistentialTraitRef<'tcx> {
+impl<'tcx> fmt::Debug for ty::ExistentialTraitRef<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         with_no_trimmed_paths(|| fmt::Display::fmt(self, f))
     }
 }
 
-impl fmt::Debug for ty::adjustment::Adjustment<'tcx> {
+impl<'tcx> fmt::Debug for ty::adjustment::Adjustment<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{:?} -> {}", self.kind, self.target)
     }
@@ -111,7 +111,7 @@ impl fmt::Debug for ty::FreeRegion {
     }
 }
 
-impl fmt::Debug for ty::FnSig<'tcx> {
+impl<'tcx> fmt::Debug for ty::FnSig<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "({:?}; c_variadic: {})->{:?}", self.inputs(), self.c_variadic, self.output())
     }
@@ -129,13 +129,13 @@ impl fmt::Debug for ty::RegionVid {
     }
 }
 
-impl fmt::Debug for ty::TraitRef<'tcx> {
+impl<'tcx> fmt::Debug for ty::TraitRef<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         with_no_trimmed_paths(|| fmt::Display::fmt(self, f))
     }
 }
 
-impl fmt::Debug for Ty<'tcx> {
+impl<'tcx> fmt::Debug for Ty<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         with_no_trimmed_paths(|| fmt::Display::fmt(self, f))
     }
@@ -153,7 +153,7 @@ impl fmt::Debug for ty::ParamConst {
     }
 }
 
-impl fmt::Debug for ty::TraitPredicate<'tcx> {
+impl<'tcx> fmt::Debug for ty::TraitPredicate<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         if let ty::BoundConstness::ConstIfConst = self.constness {
             write!(f, "~const ")?;
@@ -162,19 +162,19 @@ impl fmt::Debug for ty::TraitPredicate<'tcx> {
     }
 }
 
-impl fmt::Debug for ty::ProjectionPredicate<'tcx> {
+impl<'tcx> fmt::Debug for ty::ProjectionPredicate<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "ProjectionPredicate({:?}, {:?})", self.projection_ty, self.ty)
     }
 }
 
-impl fmt::Debug for ty::Predicate<'tcx> {
+impl<'tcx> fmt::Debug for ty::Predicate<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         write!(f, "{:?}", self.kind())
     }
 }
 
-impl fmt::Debug for ty::PredicateKind<'tcx> {
+impl<'tcx> fmt::Debug for ty::PredicateKind<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match *self {
             ty::PredicateKind::Trait(ref a) => a.fmt(f),

compiler/rustc_middle/src/ty/sty.rs

@@ -198,7 +198,7 @@ pub enum TyKind<'tcx> {
     Error(DelaySpanBugEmitted),
 }
 
-impl TyKind<'tcx> {
+impl<'tcx> TyKind<'tcx> {
     #[inline]
     pub fn is_primitive(&self) -> bool {
         matches!(self, Bool | Char | Int(_) | Uint(_) | Float(_))

compiler/rustc_middle/src/ty/subst.rs

@@ -67,7 +67,7 @@ impl<'tcx> GenericArgKind<'tcx> {
     }
 }
 
-impl fmt::Debug for GenericArg<'tcx> {
+impl<'tcx> fmt::Debug for GenericArg<'tcx> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self.unpack() {
             GenericArgKind::Lifetime(lt) => lt.fmt(f),

compiler/rustc_middle/src/ty/util.rs

@@ -981,7 +981,7 @@ impl<'tcx> ExplicitSelf<'tcx> {
 /// Returns a list of types such that the given type needs drop if and only if
 /// *any* of the returned types need drop. Returns `Err(AlwaysRequiresDrop)` if
 /// this type always needs drop.
-pub fn needs_drop_components(
+pub fn needs_drop_components<'tcx>(
     ty: Ty<'tcx>,
     target_layout: &TargetDataLayout,
 ) -> Result<SmallVec<[Ty<'tcx>; 2]>, AlwaysRequiresDrop> {
@@ -1083,7 +1083,7 @@ pub struct AlwaysRequiresDrop;
 
 /// Normalizes all opaque types in the given value, replacing them
 /// with their underlying types.
-pub fn normalize_opaque_types(
+pub fn normalize_opaque_types<'tcx>(
     tcx: TyCtxt<'tcx>,
     val: &'tcx List<ty::Predicate<'tcx>>,
 ) -> &'tcx List<ty::Predicate<'tcx>> {

compiler/rustc_middle/src/ty/walk.rs

@@ -69,7 +69,7 @@ impl<'tcx> Iterator for TypeWalker<'tcx> {
     }
 }
 
-impl GenericArg<'tcx> {
+impl<'tcx> GenericArg<'tcx> {
     /// Iterator that walks `self` and any types reachable from
     /// `self`, in depth-first order. Note that just walks the types
     /// that appear in `self`, it does not descend into the fields of