diff --git a/src/librustc/hir/map/hir_id_validator.rs b/src/librustc/hir/map/hir_id_validator.rs
index 60465c04ec6..891a1956bc9 100644
--- a/src/librustc/hir/map/hir_id_validator.rs
+++ b/src/librustc/hir/map/hir_id_validator.rs
@@ -4,7 +4,7 @@ use crate::hir::itemlikevisit::ItemLikeVisitor;
 use rustc_data_structures::fx::FxHashSet;
 use rustc_data_structures::sync::{Lock, ParallelIterator, par_iter};
 
-pub fn check_crate<'hir>(hir_map: &hir::map::Map<'hir>) {
+pub fn check_crate(hir_map: &hir::map::Map<'_>) {
     hir_map.dep_graph.assert_ignored();
 
     let errors = Lock::new(Vec::new());
diff --git a/src/librustc/hir/map/mod.rs b/src/librustc/hir/map/mod.rs
index 3d591c9a1c6..037d04a5d8e 100644
--- a/src/librustc/hir/map/mod.rs
+++ b/src/librustc/hir/map/mod.rs
@@ -147,7 +147,7 @@ impl Forest {
         }
     }
 
-    pub fn krate<'hir>(&'hir self) -> &'hir Crate {
+    pub fn krate(&self) -> &Crate {
         self.dep_graph.read(DepNode::new_no_params(DepKind::Krate));
         &self.krate
     }
@@ -155,7 +155,7 @@ impl Forest {
     /// This is used internally in the dependency tracking system.
     /// Use the `krate` method to ensure your dependency on the
     /// crate is tracked.
-    pub fn untracked_krate<'hir>(&'hir self) -> &'hir Crate {
+    pub fn untracked_krate(&self) -> &Crate {
         &self.krate
     }
 }
@@ -1085,7 +1085,7 @@ impl<'a> NodesMatchingSuffix<'a> {
         // If `id` itself is a mod named `m` with parent `p`, then
         // returns `Some(id, m, p)`.  If `id` has no mod in its parent
         // chain, then returns `None`.
-        fn find_first_mod_parent<'a>(map: &'a Map<'_>, mut id: HirId) -> Option<(HirId, Name)> {
+        fn find_first_mod_parent(map: &Map<'_>, mut id: HirId) -> Option<(HirId, Name)> {
             loop {
                 if let Node::Item(item) = map.find(id)? {
                     if item_is_mod(&item) {
diff --git a/src/librustc/traits/coherence.rs b/src/librustc/traits/coherence.rs
index d8087af60ac..b6f0addd771 100644
--- a/src/librustc/traits/coherence.rs
+++ b/src/librustc/traits/coherence.rs
@@ -48,8 +48,8 @@ pub fn add_placeholder_note(err: &mut errors::DiagnosticBuilder<'_>) {
 /// If there are types that satisfy both impls, invokes `on_overlap`
 /// with a suitably-freshened `ImplHeader` with those types
 /// substituted. Otherwise, invokes `no_overlap`.
-pub fn overlapping_impls<'tcx, F1, F2, R>(
-    tcx: TyCtxt<'tcx>,
+pub fn overlapping_impls<F1, F2, R>(
+    tcx: TyCtxt<'_>,
     impl1_def_id: DefId,
     impl2_def_id: DefId,
     intercrate_mode: IntercrateMode,
@@ -247,10 +247,10 @@ pub enum OrphanCheckErr<'tcx> {
 ///
 /// 1. All type parameters in `Self` must be "covered" by some local type constructor.
 /// 2. Some local type must appear in `Self`.
-pub fn orphan_check<'tcx>(
-    tcx: TyCtxt<'tcx>,
+pub fn orphan_check(
+    tcx: TyCtxt<'_>,
     impl_def_id: DefId,
-) -> Result<(), OrphanCheckErr<'tcx>> {
+) -> Result<(), OrphanCheckErr<'_>> {
     debug!("orphan_check({:?})", impl_def_id);
 
     // We only except this routine to be invoked on implementations
diff --git a/src/librustc/traits/error_reporting.rs b/src/librustc/traits/error_reporting.rs
index f54575ff8fc..d6cc68bcdab 100644
--- a/src/librustc/traits/error_reporting.rs
+++ b/src/librustc/traits/error_reporting.rs
@@ -247,7 +247,7 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
     fn fuzzy_match_tys(&self, a: Ty<'tcx>, b: Ty<'tcx>) -> bool {
         /// returns the fuzzy category of a given type, or None
         /// if the type can be equated to any type.
-        fn type_category<'tcx>(t: Ty<'tcx>) -> Option<u32> {
+        fn type_category(t: Ty<'_>) -> Option<u32> {
             match t.sty {
                 ty::Bool => Some(0),
                 ty::Char => Some(1),
diff --git a/src/librustc/traits/object_safety.rs b/src/librustc/traits/object_safety.rs
index cfd5cfa897d..37eff852abd 100644
--- a/src/librustc/traits/object_safety.rs
+++ b/src/librustc/traits/object_safety.rs
@@ -702,6 +702,6 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 }
 
-pub(super) fn is_object_safe_provider<'tcx>(tcx: TyCtxt<'tcx>, trait_def_id: DefId) -> bool {
+pub(super) fn is_object_safe_provider(tcx: TyCtxt<'_>, trait_def_id: DefId) -> bool {
     tcx.object_safety_violations(trait_def_id).is_empty()
 }
diff --git a/src/librustc/traits/project.rs b/src/librustc/traits/project.rs
index 8bd8f941fb3..20acf443406 100644
--- a/src/librustc/traits/project.rs
+++ b/src/librustc/traits/project.rs
@@ -1509,8 +1509,8 @@ fn confirm_impl_candidate<'cx, 'tcx>(
 ///
 /// Based on the "projection mode", this lookup may in fact only examine the
 /// topmost impl. See the comments for `Reveal` for more details.
-fn assoc_ty_def<'cx, 'tcx>(
-    selcx: &SelectionContext<'cx, 'tcx>,
+fn assoc_ty_def(
+    selcx: &SelectionContext<'_, '_>,
     impl_def_id: DefId,
     assoc_ty_def_id: DefId,
 ) -> specialization_graph::NodeItem<ty::AssocItem> {
diff --git a/src/librustc/traits/util.rs b/src/librustc/traits/util.rs
index 2d295679be3..07d6f633143 100644
--- a/src/librustc/traits/util.rs
+++ b/src/librustc/traits/util.rs
@@ -417,7 +417,7 @@ pub struct SupertraitDefIds<'tcx> {
     visited: FxHashSet<DefId>,
 }
 
-pub fn supertrait_def_ids<'tcx>(tcx: TyCtxt<'tcx>, trait_def_id: DefId) -> SupertraitDefIds<'tcx> {
+pub fn supertrait_def_ids(tcx: TyCtxt<'_>, trait_def_id: DefId) -> SupertraitDefIds<'_> {
     SupertraitDefIds {
         tcx,
         stack: vec![trait_def_id],
diff --git a/src/librustc_codegen_ssa/traits/backend.rs b/src/librustc_codegen_ssa/traits/backend.rs
index 414871be611..9d5aaa7655d 100644
--- a/src/librustc_codegen_ssa/traits/backend.rs
+++ b/src/librustc_codegen_ssa/traits/backend.rs
@@ -44,7 +44,7 @@ pub trait ExtraBackendMethods: CodegenBackend + WriteBackendMethods + Sized + Se
         mods: &mut Self::Module,
         kind: AllocatorKind,
     );
-    fn compile_codegen_unit<'tcx>(&self, tcx: TyCtxt<'tcx>, cgu_name: InternedString);
+    fn compile_codegen_unit(&self, tcx: TyCtxt<'_>, cgu_name: InternedString);
     // If find_features is true this won't access `sess.crate_types` by assuming
     // that `is_pie_binary` is false. When we discover LLVM target features
     // `sess.crate_types` is uninitialized so we cannot access it.
diff --git a/src/librustc_codegen_ssa/traits/builder.rs b/src/librustc_codegen_ssa/traits/builder.rs
index 1c80e614db8..3a144f0b0e0 100644
--- a/src/librustc_codegen_ssa/traits/builder.rs
+++ b/src/librustc_codegen_ssa/traits/builder.rs
@@ -36,7 +36,7 @@ pub trait BuilderMethods<'a, 'tcx>:
 {
     fn new_block<'b>(cx: &'a Self::CodegenCx, llfn: Self::Value, name: &'b str) -> Self;
     fn with_cx(cx: &'a Self::CodegenCx) -> Self;
-    fn build_sibling_block<'b>(&self, name: &'b str) -> Self;
+    fn build_sibling_block(&self, name: &str) -> Self;
     fn cx(&self) -> &Self::CodegenCx;
     fn llbb(&self) -> Self::BasicBlock;
 
diff --git a/src/librustc_mir/transform/add_retag.rs b/src/librustc_mir/transform/add_retag.rs
index e01017d7c9b..de5af0a46b5 100644
--- a/src/librustc_mir/transform/add_retag.rs
+++ b/src/librustc_mir/transform/add_retag.rs
@@ -14,8 +14,8 @@ pub struct AddRetag;
 /// after the assignment, we can be sure to obtain the same place value.
 /// (Concurrent accesses by other threads are no problem as these are anyway non-atomic
 /// copies.  Data races are UB.)
-fn is_stable<'tcx>(
-    place: &Place<'tcx>,
+fn is_stable(
+    place: &Place<'_>,
 ) -> bool {
     use rustc::mir::Place::*;
 
diff --git a/src/librustc_mir/transform/check_unsafety.rs b/src/librustc_mir/transform/check_unsafety.rs
index 24df3549be4..9898ba89773 100644
--- a/src/librustc_mir/transform/check_unsafety.rs
+++ b/src/librustc_mir/transform/check_unsafety.rs
@@ -480,11 +480,11 @@ impl<'a, 'tcx> hir::intravisit::Visitor<'tcx> for UnusedUnsafeVisitor<'a> {
     }
 }
 
-fn check_unused_unsafe<'a, 'tcx>(
-    tcx: TyCtxt<'tcx>,
+fn check_unused_unsafe(
+    tcx: TyCtxt<'_>,
     def_id: DefId,
     used_unsafe: &FxHashSet<hir::HirId>,
-    unsafe_blocks: &'a mut Vec<(hir::HirId, bool)>,
+    unsafe_blocks: &mut Vec<(hir::HirId, bool)>,
 ) {
     let body_id =
         tcx.hir().as_local_hir_id(def_id).and_then(|hir_id| {
@@ -506,7 +506,7 @@ fn check_unused_unsafe<'a, 'tcx>(
     hir::intravisit::Visitor::visit_body(&mut visitor, body);
 }
 
-fn unsafety_check_result<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> UnsafetyCheckResult {
+fn unsafety_check_result(tcx: TyCtxt<'_>, def_id: DefId) -> UnsafetyCheckResult {
     debug!("unsafety_violations({:?})", def_id);
 
     // N.B., this borrow is valid because all the consumers of
@@ -545,7 +545,7 @@ fn unsafety_check_result<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> UnsafetyChec
     }
 }
 
-fn unsafe_derive_on_repr_packed<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) {
+fn unsafe_derive_on_repr_packed(tcx: TyCtxt<'_>, def_id: DefId) {
     let lint_hir_id = tcx.hir().as_local_hir_id(def_id).unwrap_or_else(||
         bug!("checking unsafety for non-local def id {:?}", def_id));
 
@@ -602,7 +602,7 @@ fn report_unused_unsafe(tcx: TyCtxt<'_>, used_unsafe: &FxHashSet<hir::HirId>, id
     db.emit();
 }
 
-fn builtin_derive_def_id<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Option<DefId> {
+fn builtin_derive_def_id(tcx: TyCtxt<'_>, def_id: DefId) -> Option<DefId> {
     debug!("builtin_derive_def_id({:?})", def_id);
     if let Some(impl_def_id) = tcx.impl_of_method(def_id) {
         if tcx.has_attr(impl_def_id, sym::automatically_derived) {
@@ -618,7 +618,7 @@ fn builtin_derive_def_id<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> Option<DefId
     }
 }
 
-pub fn check_unsafety<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) {
+pub fn check_unsafety(tcx: TyCtxt<'_>, def_id: DefId) {
     debug!("check_unsafety({:?})", def_id);
 
     // closures are handled by their parent fn.
diff --git a/src/librustc_mir/transform/dump_mir.rs b/src/librustc_mir/transform/dump_mir.rs
index 243820ba7d0..a6fb555f20b 100644
--- a/src/librustc_mir/transform/dump_mir.rs
+++ b/src/librustc_mir/transform/dump_mir.rs
@@ -14,7 +14,7 @@ use crate::util as mir_util;
 pub struct Marker(pub &'static str);
 
 impl MirPass for Marker {
-    fn name<'a>(&'a self) -> Cow<'a, str> {
+    fn name(&self) -> Cow<'_, str> {
         Cow::Borrowed(self.0)
     }
 
@@ -52,7 +52,7 @@ pub fn on_mir_pass<'tcx>(
     }
 }
 
-pub fn emit_mir<'tcx>(tcx: TyCtxt<'tcx>, outputs: &OutputFilenames) -> io::Result<()> {
+pub fn emit_mir(tcx: TyCtxt<'_>, outputs: &OutputFilenames) -> io::Result<()> {
     let path = outputs.path(OutputType::Mir);
     let mut f = File::create(&path)?;
     mir_util::write_mir_pretty(tcx, None, &mut f)?;
diff --git a/src/librustc_mir/transform/generator.rs b/src/librustc_mir/transform/generator.rs
index 1acebede2e4..2ed3f7d5c26 100644
--- a/src/librustc_mir/transform/generator.rs
+++ b/src/librustc_mir/transform/generator.rs
@@ -1028,14 +1028,14 @@ fn create_generator_resume_function<'tcx>(
     dump_mir(tcx, None, "generator_resume", &0, source, body, |_, _| Ok(()) );
 }
 
-fn source_info<'tcx>(body: &Body<'tcx>) -> SourceInfo {
+fn source_info(body: &Body<'_>) -> SourceInfo {
     SourceInfo {
         span: body.span,
         scope: OUTERMOST_SOURCE_SCOPE,
     }
 }
 
-fn insert_clean_drop<'tcx>(body: &mut Body<'tcx>) -> BasicBlock {
+fn insert_clean_drop(body: &mut Body<'_>) -> BasicBlock {
     let return_block = insert_term_block(body, TerminatorKind::Return);
 
     // Create a block to destroy an unresumed generators. This can only destroy upvars.
diff --git a/src/librustc_mir/transform/mod.rs b/src/librustc_mir/transform/mod.rs
index 81d91dcd0a9..7f43c4a3e89 100644
--- a/src/librustc_mir/transform/mod.rs
+++ b/src/librustc_mir/transform/mod.rs
@@ -50,13 +50,13 @@ pub(crate) fn provide(providers: &mut Providers<'_>) {
     };
 }
 
-fn is_mir_available<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> bool {
+fn is_mir_available(tcx: TyCtxt<'_>, def_id: DefId) -> bool {
     tcx.mir_keys(def_id.krate).contains(&def_id)
 }
 
 /// Finds the full set of `DefId`s within the current crate that have
 /// MIR associated with them.
-fn mir_keys<'tcx>(tcx: TyCtxt<'tcx>, krate: CrateNum) -> &'tcx DefIdSet {
+fn mir_keys(tcx: TyCtxt<'_>, krate: CrateNum) -> &DefIdSet {
     assert_eq!(krate, LOCAL_CRATE);
 
     let mut set = DefIdSet::default();
@@ -94,7 +94,7 @@ fn mir_keys<'tcx>(tcx: TyCtxt<'tcx>, krate: CrateNum) -> &'tcx DefIdSet {
     tcx.arena.alloc(set)
 }
 
-fn mir_built<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx Steal<Body<'tcx>> {
+fn mir_built(tcx: TyCtxt<'_>, def_id: DefId) -> &Steal<Body<'_>> {
     let mir = build::mir_build(tcx, def_id);
     tcx.alloc_steal_mir(mir)
 }
@@ -137,7 +137,7 @@ pub fn default_name<T: ?Sized>() -> Cow<'static, str> {
 /// pass will be named after the type, and it will consist of a main
 /// loop that goes over each available MIR and applies `run_pass`.
 pub trait MirPass {
-    fn name<'a>(&'a self) -> Cow<'a, str> {
+    fn name(&self) -> Cow<'_, str> {
         default_name::<Self>()
     }
 
@@ -192,7 +192,7 @@ pub fn run_passes(
     }
 }
 
-fn mir_const<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx Steal<Body<'tcx>> {
+fn mir_const(tcx: TyCtxt<'_>, def_id: DefId) -> &Steal<Body<'_>> {
     // Unsafety check uses the raw mir, so make sure it is run
     let _ = tcx.unsafety_check_result(def_id);
 
@@ -223,7 +223,7 @@ fn mir_validated(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx Steal<Body<'tcx>> {
     tcx.alloc_steal_mir(body)
 }
 
-fn optimized_mir<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx Body<'tcx> {
+fn optimized_mir(tcx: TyCtxt<'_>, def_id: DefId) -> &Body<'_> {
     if tcx.is_constructor(def_id) {
         // There's no reason to run all of the MIR passes on constructors when
         // we can just output the MIR we want directly. This also saves const
diff --git a/src/librustc_mir/transform/qualify_consts.rs b/src/librustc_mir/transform/qualify_consts.rs
index f082b5e5a04..3e52d3ee9bb 100644
--- a/src/librustc_mir/transform/qualify_consts.rs
+++ b/src/librustc_mir/transform/qualify_consts.rs
@@ -1473,7 +1473,7 @@ pub fn provide(providers: &mut Providers<'_>) {
     };
 }
 
-fn mir_const_qualif<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> (u8, &'tcx BitSet<Local>) {
+fn mir_const_qualif(tcx: TyCtxt<'_>, def_id: DefId) -> (u8, &BitSet<Local>) {
     // N.B., this `borrow()` is guaranteed to be valid (i.e., the value
     // cannot yet be stolen), because `mir_validated()`, which steals
     // from `mir_const(), forces this query to execute before
diff --git a/src/librustc_mir/transform/simplify.rs b/src/librustc_mir/transform/simplify.rs
index f226f15c009..2eed9d453f2 100644
--- a/src/librustc_mir/transform/simplify.rs
+++ b/src/librustc_mir/transform/simplify.rs
@@ -53,7 +53,7 @@ pub fn simplify_cfg(body: &mut Body<'_>) {
 }
 
 impl MirPass for SimplifyCfg {
-    fn name<'a>(&'a self) -> Cow<'a, str> {
+    fn name(&self) -> Cow<'_, str> {
         Cow::Borrowed(&self.label)
     }
 
diff --git a/src/librustc_mir/transform/simplify_branches.rs b/src/librustc_mir/transform/simplify_branches.rs
index 0c63a8d9c96..f39c71ef42d 100644
--- a/src/librustc_mir/transform/simplify_branches.rs
+++ b/src/librustc_mir/transform/simplify_branches.rs
@@ -15,7 +15,7 @@ impl SimplifyBranches {
 }
 
 impl MirPass for SimplifyBranches {
-    fn name<'a>(&'a self) -> Cow<'a, str> {
+    fn name(&self) -> Cow<'_, str> {
         Cow::Borrowed(&self.label)
     }