remove lifetimes that can be elided (clippy::needless_lifetimes)

src/liballoc/collections/linked_list.rs

@@ -1427,7 +1427,7 @@ impl<'a, T> CursorMut<'a, T> {
     /// `CursorMut`, which means it cannot outlive the `CursorMut` and that the
     /// `CursorMut` is frozen for the lifetime of the `Cursor`.
     #[unstable(feature = "linked_list_cursors", issue = "58533")]
-    pub fn as_cursor<'cm>(&'cm self) -> Cursor<'cm, T> {
+    pub fn as_cursor(&self) -> Cursor<'_, T> {
         Cursor { list: self.list, current: self.current, index: self.index }
     }
 }

src/librustc/dep_graph/dep_node.rs

@@ -179,7 +179,7 @@ macro_rules! define_dep_nodes {
             $(
                 #[inline(always)]
                 #[allow(unreachable_code, non_snake_case)]
-                pub fn $variant<'tcx>(_tcx: TyCtxt<'tcx>, $(arg: $tuple_arg_ty)*) -> DepNode {
+                pub fn $variant(_tcx: TyCtxt<'_>, $(arg: $tuple_arg_ty)*) -> DepNode {
                     // tuple args
                     $({
                         erase!($tuple_arg_ty);

src/librustc/hir/map/collector.rs

@@ -340,7 +340,7 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     /// deep walking so that we walk nested items in the context of
     /// their outer items.
 
-    fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, Self::Map> {
+    fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map> {
         panic!("`visit_nested_xxx` must be manually implemented in this visitor");
     }
 

src/librustc/hir/map/hir_id_validator.rs

@@ -135,7 +135,7 @@ impl<'a, 'hir> HirIdValidator<'a, 'hir> {
 impl<'a, 'hir> intravisit::Visitor<'hir> for HirIdValidator<'a, 'hir> {
     type Map = Map<'hir>;
 
-    fn nested_visit_map<'this>(&'this mut self) -> intravisit::NestedVisitorMap<'this, Self::Map> {
+    fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<'_, Self::Map> {
         intravisit::NestedVisitorMap::OnlyBodies(self.hir_map)
     }
 

src/librustc/mir/mod.rs

@@ -403,7 +403,7 @@ pub enum ClearCrossCrate<T> {
 }
 
 impl<T> ClearCrossCrate<T> {
-    pub fn as_ref(&'a self) -> ClearCrossCrate<&'a T> {
+    pub fn as_ref(&self) -> ClearCrossCrate<&T> {
         match self {
             ClearCrossCrate::Clear => ClearCrossCrate::Clear,
             ClearCrossCrate::Set(v) => ClearCrossCrate::Set(v),
@@ -2503,7 +2503,7 @@ impl UserTypeProjection {
 
     pub(crate) fn variant(
         mut self,
-        adt_def: &'tcx AdtDef,
+        adt_def: &AdtDef,
         variant_index: VariantIdx,
         field: Field,
     ) -> Self {

src/librustc_codegen_llvm/common.rs

@@ -320,7 +320,7 @@ impl ConstMethods<'tcx> for CodegenCx<'ll, 'tcx> {
     }
 }
 
-pub fn val_ty(v: &'ll Value) -> &'ll Type {
+pub fn val_ty(v: &Value) -> &Type {
     unsafe { llvm::LLVMTypeOf(v) }
 }
 
@@ -342,6 +342,6 @@ fn hi_lo_to_u128(lo: u64, hi: u64) -> u128 {
     ((hi as u128) << 64) | (lo as u128)
 }
 
-fn try_as_const_integral(v: &'ll Value) -> Option<&'ll ConstantInt> {
+fn try_as_const_integral(v: &Value) -> Option<&ConstantInt> {
     unsafe { llvm::LLVMIsAConstantInt(v) }
 }

src/librustc_codegen_llvm/llvm/mod.rs

@@ -185,12 +185,12 @@ impl Drop for SectionIter<'a> {
     }
 }
 
-pub fn mk_section_iter(llof: &'a ffi::ObjectFile) -> SectionIter<'a> {
+pub fn mk_section_iter(llof: &ffi::ObjectFile) -> SectionIter<'_> {
     unsafe { SectionIter { llsi: LLVMGetSections(llof) } }
 }
 
 /// Safe wrapper around `LLVMGetParam`, because segfaults are no fun.
-pub fn get_param(llfn: &'a Value, index: c_uint) -> &'a Value {
+pub fn get_param(llfn: &Value, index: c_uint) -> &Value {
     unsafe {
         assert!(
             index < LLVMCountParams(llfn),
@@ -203,7 +203,7 @@ pub fn get_param(llfn: &'a Value, index: c_uint) -> &'a Value {
 }
 
 /// Safe wrapper for `LLVMGetValueName2` into a byte slice
-pub fn get_value_name(value: &'a Value) -> &'a [u8] {
+pub fn get_value_name(value: &Value) -> &[u8] {
     unsafe {
         let mut len = 0;
         let data = LLVMGetValueName2(value, &mut len);

src/librustc_codegen_llvm/type_.rs

@@ -240,7 +240,7 @@ impl Type {
         unsafe { llvm::LLVMIntTypeInContext(llcx, num_bits as c_uint) }
     }
 
-    pub fn i8p_llcx(llcx: &'ll llvm::Context) -> &'ll Type {
+    pub fn i8p_llcx(llcx: &llvm::Context) -> &Type {
         Type::i8_llcx(llcx).ptr_to()
     }
 

src/librustc_data_structures/graph/scc/mod.rs

@@ -97,7 +97,7 @@ impl<N: Idx, S: Idx> GraphSuccessors<'graph> for Sccs<N, S> {
 }
 
 impl<N: Idx, S: Idx> WithSuccessors for Sccs<N, S> {
-    fn successors<'graph>(&'graph self, node: S) -> <Self as GraphSuccessors<'graph>>::Iter {
+    fn successors(&self, node: S) -> <Self as GraphSuccessors<'_>>::Iter {
         self.successors(node).iter().cloned()
     }
 }

src/librustc_data_structures/graph/vec_graph/mod.rs

@@ -101,7 +101,7 @@ impl<N: Idx> GraphSuccessors<'graph> for VecGraph<N> {
 }
 
 impl<N: Idx> WithSuccessors for VecGraph<N> {
-    fn successors<'graph>(&'graph self, node: N) -> <Self as GraphSuccessors<'graph>>::Iter {
+    fn successors(&self, node: N) -> <Self as GraphSuccessors<'_>>::Iter {
         self.successors(node).iter().cloned()
     }
 }

src/librustc_driver/pretty.rs

@@ -96,7 +96,7 @@ trait PrinterSupport: pprust::PpAnn {
     ///
     /// (Rust does not yet support upcasting from a trait object to
     /// an object for one of its super-traits.)
-    fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn;
+    fn pp_ann(&self) -> &dyn pprust::PpAnn;
 }
 
 trait HirPrinterSupport<'hir>: pprust_hir::PpAnn {
@@ -106,13 +106,13 @@ trait HirPrinterSupport<'hir>: pprust_hir::PpAnn {
 
     /// Provides a uniform interface for re-extracting a reference to an
     /// `hir_map::Map` from a value that now owns it.
-    fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>>;
+    fn hir_map(&self) -> Option<&hir_map::Map<'hir>>;
 
     /// Produces the pretty-print annotation object.
     ///
     /// (Rust does not yet support upcasting from a trait object to
     /// an object for one of its super-traits.)
-    fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn;
+    fn pp_ann(&self) -> &dyn pprust_hir::PpAnn;
 
     /// Computes an user-readable representation of a path, if possible.
     fn node_path(&self, id: hir::HirId) -> Option<String> {
@@ -132,7 +132,7 @@ impl<'hir> PrinterSupport for NoAnn<'hir> {
         self.sess
     }
 
-    fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn {
+    fn pp_ann(&self) -> &dyn pprust::PpAnn {
         self
     }
 }
@@ -142,11 +142,11 @@ impl<'hir> HirPrinterSupport<'hir> for NoAnn<'hir> {
         self.sess
     }
 
-    fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>> {
+    fn hir_map(&self) -> Option<&hir_map::Map<'hir>> {
         self.tcx.map(|tcx| *tcx.hir())
     }
 
-    fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
+    fn pp_ann(&self) -> &dyn pprust_hir::PpAnn {
         self
     }
 }
@@ -170,7 +170,7 @@ impl<'hir> PrinterSupport for IdentifiedAnnotation<'hir> {
         self.sess
     }
 
-    fn pp_ann<'a>(&'a self) -> &'a dyn pprust::PpAnn {
+    fn pp_ann(&self) -> &dyn pprust::PpAnn {
         self
     }
 }
@@ -216,11 +216,11 @@ impl<'hir> HirPrinterSupport<'hir> for IdentifiedAnnotation<'hir> {
         self.sess
     }
 
-    fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'hir>> {
+    fn hir_map(&self) -> Option<&hir_map::Map<'hir>> {
         self.tcx.map(|tcx| *tcx.hir())
     }
 
-    fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
+    fn pp_ann(&self) -> &dyn pprust_hir::PpAnn {
         self
     }
 }
@@ -315,11 +315,11 @@ impl<'b, 'tcx> HirPrinterSupport<'tcx> for TypedAnnotation<'b, 'tcx> {
         &self.tcx.sess
     }
 
-    fn hir_map<'a>(&'a self) -> Option<&'a hir_map::Map<'tcx>> {
+    fn hir_map(&self) -> Option<&hir_map::Map<'tcx>> {
         Some(&self.tcx.hir())
     }
 
-    fn pp_ann<'a>(&'a self) -> &'a dyn pprust_hir::PpAnn {
+    fn pp_ann(&self) -> &dyn pprust_hir::PpAnn {
         self
     }
 

src/librustc_hir/intravisit.rs

@@ -284,7 +284,7 @@ pub trait Visitor<'v>: Sized {
     /// If you use this, you probably don't want to process the
     /// contents of nested item-like things, since the outer loop will
     /// visit them as well.
-    fn as_deep_visitor<'s>(&'s mut self) -> DeepVisitor<'s, Self> {
+    fn as_deep_visitor(&mut self) -> DeepVisitor<'_, Self> {
         DeepVisitor::new(self)
     }
 

src/librustc_incremental/assert_dep_graph.rs

@@ -162,7 +162,7 @@ impl IfThisChanged<'tcx> {
 impl Visitor<'tcx> for IfThisChanged<'tcx> {
     type Map = Map<'tcx>;
 
-    fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, Self::Map> {
+    fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map> {
         NestedVisitorMap::OnlyBodies(&self.tcx.hir())
     }
 

src/librustc_incremental/persist/dirty_clean.rs

@@ -548,7 +548,7 @@ impl FindAllAttrs<'tcx> {
 impl intravisit::Visitor<'tcx> for FindAllAttrs<'tcx> {
     type Map = Map<'tcx>;
 
-    fn nested_visit_map<'this>(&'this mut self) -> intravisit::NestedVisitorMap<'this, Self::Map> {
+    fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<'_, Self::Map> {
         intravisit::NestedVisitorMap::All(&self.tcx.hir())
     }
 

src/librustc_infer/infer/error_reporting/need_type_info.rs

@@ -69,7 +69,7 @@ impl<'a, 'tcx> FindLocalByTypeVisitor<'a, 'tcx> {
 impl<'a, 'tcx> Visitor<'tcx> for FindLocalByTypeVisitor<'a, 'tcx> {
     type Map = Map<'tcx>;
 
-    fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, Self::Map> {
+    fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map> {
         NestedVisitorMap::OnlyBodies(&self.hir_map)
     }
 

src/librustc_infer/infer/error_reporting/nice_region_error/find_anon_type.rs

@@ -93,7 +93,7 @@ struct FindNestedTypeVisitor<'tcx> {
 impl Visitor<'tcx> for FindNestedTypeVisitor<'tcx> {
     type Map = Map<'tcx>;
 
-    fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, Self::Map> {
+    fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map> {
         NestedVisitorMap::OnlyBodies(&self.tcx.hir())
     }
 

src/librustc_infer/traits/coherence.rs

@@ -451,7 +451,7 @@ fn def_id_is_local(def_id: DefId, in_crate: InCrate) -> bool {
     }
 }
 
-fn ty_is_non_local_constructor<'tcx>(ty: Ty<'tcx>, in_crate: InCrate) -> Option<Ty<'tcx>> {
+fn ty_is_non_local_constructor(ty: Ty<'_>, in_crate: InCrate) -> Option<Ty<'_>> {
     debug!("ty_is_non_local_constructor({:?})", ty);
 
     match ty.kind {

src/librustc_lint/late.rs

@@ -33,7 +33,7 @@ use std::slice;
 
 /// Extract the `LintStore` from the query context.
 /// This function exists because we've erased `LintStore` as `dyn Any` in the context.
-crate fn unerased_lint_store<'tcx>(tcx: TyCtxt<'tcx>) -> &'tcx LintStore {
+crate fn unerased_lint_store(tcx: TyCtxt<'_>) -> &LintStore {
     let store: &dyn Any = &*tcx.lint_store;
     store.downcast_ref().unwrap()
 }
@@ -99,7 +99,7 @@ impl<'a, 'tcx, T: LateLintPass<'a, 'tcx>> hir_visit::Visitor<'tcx>
     /// Because lints are scoped lexically, we want to walk nested
     /// items in the context of the outer item, so enable
     /// deep-walking.
-    fn nested_visit_map<'this>(&'this mut self) -> hir_visit::NestedVisitorMap<'this, Self::Map> {
+    fn nested_visit_map(&mut self) -> hir_visit::NestedVisitorMap<'_, Self::Map> {
         hir_visit::NestedVisitorMap::All(&self.context.tcx.hir())
     }
 

src/librustc_lint/levels.rs

@@ -438,7 +438,7 @@ impl LintLevelMapBuilder<'_, '_> {
 impl<'tcx> intravisit::Visitor<'tcx> for LintLevelMapBuilder<'_, 'tcx> {
     type Map = Map<'tcx>;
 
-    fn nested_visit_map<'this>(&'this mut self) -> intravisit::NestedVisitorMap<'this, Self::Map> {
+    fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<'_, Self::Map> {
         intravisit::NestedVisitorMap::All(&self.tcx.hir())
     }
 

src/librustc_mir/const_eval/mod.rs

@@ -43,7 +43,7 @@ pub(crate) fn const_field<'tcx>(
     op_to_const(&ecx, field)
 }
 
-pub(crate) fn const_caller_location<'tcx>(
+pub(crate) fn const_caller_location(
     tcx: TyCtxt<'tcx>,
     (file, line, col): (Symbol, u32, u32),
 ) -> ConstValue<'tcx> {

src/librustc_mir/transform/add_retag.rs

@@ -34,7 +34,7 @@ fn is_stable(place: PlaceRef<'_>) -> bool {
 }
 
 /// Determine whether this type may be a reference (or box), and thus needs retagging.
-fn may_be_reference<'tcx>(ty: Ty<'tcx>) -> bool {
+fn may_be_reference(ty: Ty<'tcx>) -> bool {
     match ty.kind {
         // Primitive types that are not references
         ty::Bool

src/librustc_mir/transform/check_unsafety.rs

@@ -453,7 +453,7 @@ struct UnusedUnsafeVisitor<'a> {
 impl<'a, 'tcx> intravisit::Visitor<'tcx> for UnusedUnsafeVisitor<'a> {
     type Map = Map<'tcx>;
 
-    fn nested_visit_map<'this>(&'this mut self) -> intravisit::NestedVisitorMap<'this, Self::Map> {
+    fn nested_visit_map(&mut self) -> intravisit::NestedVisitorMap<'_, Self::Map> {
         intravisit::NestedVisitorMap::None
     }
 

src/librustc_mir/transform/mod.rs

@@ -87,7 +87,7 @@ fn mir_keys(tcx: TyCtxt<'_>, krate: CrateNum) -> &DefIdSet {
             intravisit::walk_struct_def(self, v)
         }
         type Map = Map<'tcx>;
-        fn nested_visit_map<'b>(&'b mut self) -> NestedVisitorMap<'b, Self::Map> {
+        fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map> {
             NestedVisitorMap::None
         }
     }

src/librustc_parse/lib.rs

@@ -271,11 +271,11 @@ pub fn stream_to_parser<'a>(
 /// The main usage of this function is outside of rustc, for those who uses
 /// librustc_ast as a library. Please do not remove this function while refactoring
 /// just because it is not used in rustc codebase!
-pub fn stream_to_parser_with_base_dir<'a>(
-    sess: &'a ParseSess,
+pub fn stream_to_parser_with_base_dir(
+    sess: &ParseSess,
     stream: TokenStream,
     base_dir: Directory,
-) -> Parser<'a> {
+) -> Parser<'_> {
     Parser::new(sess, stream, Some(base_dir), true, false, None)
 }
 

src/librustc_passes/check_attr.rs

@@ -418,7 +418,7 @@ impl CheckAttrVisitor<'tcx> {
 impl Visitor<'tcx> for CheckAttrVisitor<'tcx> {
     type Map = Map<'tcx>;
 
-    fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, Self::Map> {
+    fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map> {
         NestedVisitorMap::OnlyBodies(&self.tcx.hir())
     }
 

src/librustc_passes/lang_items.rs

@@ -143,7 +143,7 @@ impl LanguageItemCollector<'tcx> {
 }
 
 /// Traverses and collects all the lang items in all crates.
-fn collect<'tcx>(tcx: TyCtxt<'tcx>) -> LanguageItems {
+fn collect(tcx: TyCtxt<'_>) -> LanguageItems {
     // Initialize the collector.
     let mut collector = LanguageItemCollector::new(tcx);
 

src/librustc_passes/upvars.rs

@@ -46,7 +46,7 @@ struct LocalCollector {
 impl Visitor<'tcx> for LocalCollector {
     type Map = Map<'tcx>;
 
-    fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, Self::Map> {
+    fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map> {
         NestedVisitorMap::None
     }
 
@@ -75,7 +75,7 @@ impl CaptureCollector<'_, '_> {
 impl Visitor<'tcx> for CaptureCollector<'a, 'tcx> {
     type Map = Map<'tcx>;
 
-    fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, Self::Map> {
+    fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map> {
         NestedVisitorMap::None
     }
 

src/librustc_traits/lowering/mod.rs

@@ -603,7 +603,7 @@ impl ClauseDumper<'tcx> {
 impl Visitor<'tcx> for ClauseDumper<'tcx> {
     type Map = Map<'tcx>;
 
-    fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, Self::Map> {
+    fn nested_visit_map(&mut self) -> NestedVisitorMap<'_, Self::Map> {
         NestedVisitorMap::OnlyBodies(&self.tcx.hir())
     }
 

src/librustc_ty/ty.rs

@@ -210,7 +210,7 @@ fn associated_item_def_ids(tcx: TyCtxt<'_>, def_id: DefId) -> &[DefId] {
     }
 }
 
-fn associated_items<'tcx>(tcx: TyCtxt<'tcx>, def_id: DefId) -> &'tcx ty::AssociatedItems {
+fn associated_items(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::AssociatedItems {
     let items = tcx.associated_item_def_ids(def_id).iter().map(|did| tcx.associated_item(*did));
     tcx.arena.alloc(ty::AssociatedItems::new(items))
 }

src/librustc_typeck/check/coercion.rs

@@ -111,7 +111,7 @@ fn identity(_: Ty<'_>) -> Vec<Adjustment<'_>> {
     vec![]
 }
 
-fn simple<'tcx>(kind: Adjust<'tcx>) -> impl FnOnce(Ty<'tcx>) -> Vec<Adjustment<'tcx>> {
+fn simple(kind: Adjust<'tcx>) -> impl FnOnce(Ty<'tcx>) -> Vec<Adjustment<'tcx>> {
     move |target| vec![Adjustment { kind, target }]
 }
 

src/librustc_typeck/check/op.rs

@@ -860,7 +860,7 @@ enum Op {
 }
 
 /// Dereferences a single level of immutable referencing.
-fn deref_ty_if_possible<'tcx>(ty: Ty<'tcx>) -> Ty<'tcx> {
+fn deref_ty_if_possible(ty: Ty<'tcx>) -> Ty<'tcx> {
     match ty.kind {
         ty::Ref(_, ty, hir::Mutability::Not) => ty,
         _ => ty,

src/librustc_typeck/coherence/builtin.rs

@@ -322,7 +322,7 @@ fn visit_implementation_of_dispatch_from_dyn(tcx: TyCtxt<'_>, impl_did: DefId) {
     }
 }
 
-pub fn coerce_unsized_info<'tcx>(tcx: TyCtxt<'tcx>, impl_did: DefId) -> CoerceUnsizedInfo {
+pub fn coerce_unsized_info(tcx: TyCtxt<'tcx>, impl_did: DefId) -> CoerceUnsizedInfo {
     debug!("compute_coerce_unsized_info(impl_did={:?})", impl_did);
     let coerce_unsized_trait = tcx.lang_items().coerce_unsized_trait().unwrap();