Auto merge of #4221 - lzutao:redundant-lifetime, r=matthiaskrgr

Fix warnings about unnecessary lifetime bounds

Rustup #61172

changelog: none

clippy_lints/src/assign_ops.rs

@@ -236,13 +236,13 @@ fn is_commutative(op: hir::BinOpKind) -> bool {
     }
 }
 
-struct ExprVisitor<'a, 'tcx: 'a> {
+struct ExprVisitor<'a, 'tcx> {
     assignee: &'a hir::Expr,
     counter: u8,
     cx: &'a LateContext<'a, 'tcx>,
 }
 
-impl<'a, 'tcx: 'a> Visitor<'tcx> for ExprVisitor<'a, 'tcx> {
+impl<'a, 'tcx> Visitor<'tcx> for ExprVisitor<'a, 'tcx> {
     fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
         if SpanlessEq::new(self.cx).ignore_fn().eq_expr(self.assignee, expr) {
             self.counter += 1;

clippy_lints/src/block_in_if_condition.rs

@@ -44,12 +44,12 @@ declare_clippy_lint! {
 
 declare_lint_pass!(BlockInIfCondition => [BLOCK_IN_IF_CONDITION_EXPR, BLOCK_IN_IF_CONDITION_STMT]);
 
-struct ExVisitor<'a, 'tcx: 'a> {
+struct ExVisitor<'a, 'tcx> {
     found_block: Option<&'tcx Expr>,
     cx: &'a LateContext<'a, 'tcx>,
 }
 
-impl<'a, 'tcx: 'a> Visitor<'tcx> for ExVisitor<'a, 'tcx> {
+impl<'a, 'tcx> Visitor<'tcx> for ExVisitor<'a, 'tcx> {
     fn visit_expr(&mut self, expr: &'tcx Expr) {
         if let ExprKind::Closure(_, _, eid, _, _) = expr.node {
             let body = self.cx.tcx.hir().body(eid);

clippy_lints/src/booleans.rs

@@ -68,12 +68,12 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for NonminimalBool {
     }
 }
 
-struct NonminimalBoolVisitor<'a, 'tcx: 'a> {
+struct NonminimalBoolVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
 }
 
 use quine_mc_cluskey::Bool;
-struct Hir2Qmm<'a, 'tcx: 'a, 'v> {
+struct Hir2Qmm<'a, 'tcx, 'v> {
     terminals: Vec<&'v Expr>,
     cx: &'a LateContext<'a, 'tcx>,
 }
@@ -155,7 +155,7 @@ impl<'a, 'tcx, 'v> Hir2Qmm<'a, 'tcx, 'v> {
     }
 }
 
-struct SuggestContext<'a, 'tcx: 'a, 'v> {
+struct SuggestContext<'a, 'tcx, 'v> {
     terminals: &'v [&'v Expr],
     cx: &'a LateContext<'a, 'tcx>,
     output: String,

clippy_lints/src/cognitive_complexity.rs

@@ -41,7 +41,7 @@ impl CognitiveComplexity {
 impl_lint_pass!(CognitiveComplexity => [COGNITIVE_COMPLEXITY]);
 
 impl CognitiveComplexity {
-    fn check<'a, 'tcx: 'a>(&mut self, cx: &'a LateContext<'a, 'tcx>, body: &'tcx Body, span: Span) {
+    fn check<'a, 'tcx>(&mut self, cx: &'a LateContext<'a, 'tcx>, body: &'tcx Body, span: Span) {
         if in_macro_or_desugar(span) {
             return;
         }
@@ -132,7 +132,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for CognitiveComplexity {
     }
 }
 
-struct CCHelper<'a, 'tcx: 'a> {
+struct CCHelper<'a, 'tcx> {
     match_arms: u64,
     divergence: u64,
     returns: u64,

clippy_lints/src/consts.rs

@@ -210,7 +210,7 @@ pub fn constant_context<'c, 'cc>(
     }
 }
 
-pub struct ConstEvalLateContext<'a, 'tcx: 'a> {
+pub struct ConstEvalLateContext<'a, 'tcx> {
     lcx: &'a LateContext<'a, 'tcx>,
     tables: &'a ty::TypeckTables<'tcx>,
     param_env: ty::ParamEnv<'tcx>,

clippy_lints/src/entry.rs

@@ -112,7 +112,7 @@ fn check_cond<'a, 'tcx, 'b>(
     None
 }
 
-struct InsertVisitor<'a, 'tcx: 'a, 'b> {
+struct InsertVisitor<'a, 'tcx, 'b> {
     cx: &'a LateContext<'a, 'tcx>,
     span: Span,
     ty: &'static str,

clippy_lints/src/escape.rs

@@ -43,7 +43,7 @@ fn is_non_trait_box(ty: Ty<'_>) -> bool {
     ty.is_box() && !ty.boxed_ty().is_trait()
 }
 
-struct EscapeDelegate<'a, 'tcx: 'a> {
+struct EscapeDelegate<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
     set: HirIdSet,
     too_large_for_stack: u64,

clippy_lints/src/eval_order_dependence.rs

@@ -92,7 +92,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for EvalOrderDependence {
     }
 }
 
-struct DivergenceVisitor<'a, 'tcx: 'a> {
+struct DivergenceVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
 }
 
@@ -272,7 +272,7 @@ fn check_stmt<'a, 'tcx>(vis: &mut ReadVisitor<'a, 'tcx>, stmt: &'tcx Stmt) -> St
 }
 
 /// A visitor that looks for reads from a variable.
-struct ReadVisitor<'a, 'tcx: 'a> {
+struct ReadVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
     /// The ID of the variable we're looking for.
     var: HirId,

clippy_lints/src/fallible_impl_from.rs

@@ -49,13 +49,13 @@ fn lint_impl_body<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, impl_span: Span, impl_it
     use rustc::hir::intravisit::{self, NestedVisitorMap, Visitor};
     use rustc::hir::*;
 
-    struct FindPanicUnwrap<'a, 'tcx: 'a> {
+    struct FindPanicUnwrap<'a, 'tcx> {
         lcx: &'a LateContext<'a, 'tcx>,
         tables: &'tcx ty::TypeckTables<'tcx>,
         result: Vec<Span>,
     }
 
-    impl<'a, 'tcx: 'a> Visitor<'tcx> for FindPanicUnwrap<'a, 'tcx> {
+    impl<'a, 'tcx> Visitor<'tcx> for FindPanicUnwrap<'a, 'tcx> {
         fn visit_expr(&mut self, expr: &'tcx Expr) {
             // check for `begin_panic`
             if_chain! {

clippy_lints/src/functions.rs

@@ -291,7 +291,7 @@ fn raw_ptr_arg(arg: &hir::Arg, ty: &hir::Ty) -> Option<hir::HirId> {
     }
 }
 
-struct DerefVisitor<'a, 'tcx: 'a> {
+struct DerefVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
     ptrs: FxHashSet<hir::HirId>,
     tables: &'a ty::TypeckTables<'tcx>,
@@ -330,7 +330,7 @@ impl<'a, 'tcx> hir::intravisit::Visitor<'tcx> for DerefVisitor<'a, 'tcx> {
     }
 }
 
-impl<'a, 'tcx: 'a> DerefVisitor<'a, 'tcx> {
+impl<'a, 'tcx> DerefVisitor<'a, 'tcx> {
     fn check_arg(&self, ptr: &hir::Expr) {
         if let hir::ExprKind::Path(ref qpath) = ptr.node {
             if let Res::Local(id) = self.cx.tables.qpath_res(qpath, ptr.hir_id) {

clippy_lints/src/let_if_seq.rs

@@ -135,7 +135,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for LetIfSeq {
     }
 }
 
-struct UsedVisitor<'a, 'tcx: 'a> {
+struct UsedVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
     id: hir::HirId,
     used: bool,
@@ -194,7 +194,7 @@ fn check_assign<'a, 'tcx>(
     None
 }
 
-fn used_in_expr<'a, 'tcx: 'a>(cx: &LateContext<'a, 'tcx>, id: hir::HirId, expr: &'tcx hir::Expr) -> bool {
+fn used_in_expr<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, id: hir::HirId, expr: &'tcx hir::Expr) -> bool {
     let mut v = UsedVisitor { cx, id, used: false };
     hir::intravisit::walk_expr(&mut v, expr);
     v.used

clippy_lints/src/lifetimes.rs

@@ -147,7 +147,7 @@ fn check_fn_inner<'a, 'tcx>(
     report_extra_lifetimes(cx, decl, generics);
 }
 
-fn could_use_elision<'a, 'tcx: 'a>(
+fn could_use_elision<'a, 'tcx>(
     cx: &LateContext<'a, 'tcx>,
     func: &'tcx FnDecl,
     body: Option<BodyId>,
@@ -264,7 +264,7 @@ fn unique_lifetimes(lts: &[RefLt]) -> usize {
 }
 
 /// A visitor usable for `rustc_front::visit::walk_ty()`.
-struct RefVisitor<'a, 'tcx: 'a> {
+struct RefVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
     lts: Vec<RefLt>,
     abort: bool,
@@ -377,7 +377,7 @@ impl<'a, 'tcx> Visitor<'tcx> for RefVisitor<'a, 'tcx> {
 
 /// Are any lifetimes mentioned in the `where` clause? If so, we don't try to
 /// reason about elision.
-fn has_where_lifetimes<'a, 'tcx: 'a>(cx: &LateContext<'a, 'tcx>, where_clause: &'tcx WhereClause) -> bool {
+fn has_where_lifetimes<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, where_clause: &'tcx WhereClause) -> bool {
     for predicate in &where_clause.predicates {
         match *predicate {
             WherePredicate::RegionPredicate(..) => return true,
@@ -445,7 +445,7 @@ impl<'tcx> Visitor<'tcx> for LifetimeChecker {
     }
 }
 
-fn report_extra_lifetimes<'a, 'tcx: 'a>(cx: &LateContext<'a, 'tcx>, func: &'tcx FnDecl, generics: &'tcx Generics) {
+fn report_extra_lifetimes<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, func: &'tcx FnDecl, generics: &'tcx Generics) {
     let hs = generics
         .params
         .iter()

clippy_lints/src/loops.rs

@@ -1723,13 +1723,13 @@ impl<'tcx> Visitor<'tcx> for UsedVisitor {
     }
 }
 
-struct LocalUsedVisitor<'a, 'tcx: 'a> {
+struct LocalUsedVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
     local: HirId,
     used: bool,
 }
 
-impl<'a, 'tcx: 'a> Visitor<'tcx> for LocalUsedVisitor<'a, 'tcx> {
+impl<'a, 'tcx> Visitor<'tcx> for LocalUsedVisitor<'a, 'tcx> {
     fn visit_expr(&mut self, expr: &'tcx Expr) {
         if same_var(self.cx, expr, self.local) {
             self.used = true;
@@ -1743,7 +1743,7 @@ impl<'a, 'tcx: 'a> Visitor<'tcx> for LocalUsedVisitor<'a, 'tcx> {
     }
 }
 
-struct VarVisitor<'a, 'tcx: 'a> {
+struct VarVisitor<'a, 'tcx> {
     /// context reference
     cx: &'a LateContext<'a, 'tcx>,
     /// var name to look for as index
@@ -1914,7 +1914,7 @@ impl<'a, 'tcx> Visitor<'tcx> for VarVisitor<'a, 'tcx> {
     }
 }
 
-fn is_used_inside<'a, 'tcx: 'a>(cx: &'a LateContext<'a, 'tcx>, expr: &'tcx Expr, container: &'tcx Expr) -> bool {
+fn is_used_inside<'a, 'tcx>(cx: &'a LateContext<'a, 'tcx>, expr: &'tcx Expr, container: &'tcx Expr) -> bool {
     let def_id = match var_def_id(cx, expr) {
         Some(id) => id,
         None => return false,
@@ -1927,7 +1927,7 @@ fn is_used_inside<'a, 'tcx: 'a>(cx: &'a LateContext<'a, 'tcx>, expr: &'tcx Expr,
     false
 }
 
-fn is_iterator_used_after_while_let<'a, 'tcx: 'a>(cx: &LateContext<'a, 'tcx>, iter_expr: &'tcx Expr) -> bool {
+fn is_iterator_used_after_while_let<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, iter_expr: &'tcx Expr) -> bool {
     let def_id = match var_def_id(cx, iter_expr) {
         Some(id) => id,
         None => return false,
@@ -1945,7 +1945,7 @@ fn is_iterator_used_after_while_let<'a, 'tcx: 'a>(cx: &LateContext<'a, 'tcx>, it
     visitor.var_used_after_while_let
 }
 
-struct VarUsedAfterLoopVisitor<'a, 'tcx: 'a> {
+struct VarUsedAfterLoopVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
     def_id: HirId,
     iter_expr_id: HirId,
@@ -2051,7 +2051,7 @@ enum VarState {
 }
 
 /// Scan a for loop for variables that are incremented exactly once.
-struct IncrementVisitor<'a, 'tcx: 'a> {
+struct IncrementVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,      // context reference
     states: FxHashMap<HirId, VarState>, // incremented variables
     depth: u32,                         // depth of conditional expressions
@@ -2105,7 +2105,7 @@ impl<'a, 'tcx> Visitor<'tcx> for IncrementVisitor<'a, 'tcx> {
 }
 
 /// Checks whether a variable is initialized to zero at the start of a loop.
-struct InitializeVisitor<'a, 'tcx: 'a> {
+struct InitializeVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>, // context reference
     end_expr: &'tcx Expr,          // the for loop. Stop scanning here.
     var_id: HirId,
@@ -2374,7 +2374,7 @@ fn check_infinite_loop<'a, 'tcx>(cx: &LateContext<'a, 'tcx>, cond: &'tcx Expr, e
 /// Stops analysis if a function call is found
 /// Note: In some cases such as `self`, there are no mutable annotation,
 /// All variables definition IDs are collected
-struct VarCollectorVisitor<'a, 'tcx: 'a> {
+struct VarCollectorVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
     ids: FxHashSet<HirId>,
     def_ids: FxHashMap<def_id::DefId, bool>,

clippy_lints/src/matches.rs

@@ -763,7 +763,7 @@ where
     T: Copy + Ord,
 {
     #[derive(Copy, Clone, Debug, Eq, PartialEq)]
-    enum Kind<'a, T: 'a> {
+    enum Kind<'a, T> {
         Start(T, &'a SpannedRange<T>),
         End(Bound<T>, &'a SpannedRange<T>),
     }

clippy_lints/src/methods/mod.rs

@@ -1046,15 +1046,15 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for Methods {
 
 /// Checks for the `OR_FUN_CALL` lint.
 #[allow(clippy::too_many_lines)]
-fn lint_or_fun_call<'a, 'tcx: 'a>(
+fn lint_or_fun_call<'a, 'tcx>(
     cx: &LateContext<'a, 'tcx>,
     expr: &hir::Expr,
     method_span: Span,
     name: &str,
     args: &'tcx [hir::Expr],
 ) {
     // Searches an expression for method calls or function calls that aren't ctors
-    struct FunCallFinder<'a, 'tcx: 'a> {
+    struct FunCallFinder<'a, 'tcx> {
         cx: &'a LateContext<'a, 'tcx>,
         found: bool,
     }
@@ -1142,7 +1142,7 @@ fn lint_or_fun_call<'a, 'tcx: 'a>(
 
     /// Checks for `*or(foo())`.
     #[allow(clippy::too_many_arguments)]
-    fn check_general_case<'a, 'tcx: 'a>(
+    fn check_general_case<'a, 'tcx>(
         cx: &LateContext<'a, 'tcx>,
         name: &str,
         method_span: Span,

clippy_lints/src/methods/option_map_unwrap_or.rs

@@ -77,12 +77,12 @@ pub(super) fn lint<'a, 'tcx>(
     }
 }
 
-struct UnwrapVisitor<'a, 'tcx: 'a> {
+struct UnwrapVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
     identifiers: FxHashSet<Symbol>,
 }
 
-impl<'a, 'tcx: 'a> Visitor<'tcx> for UnwrapVisitor<'a, 'tcx> {
+impl<'a, 'tcx> Visitor<'tcx> for UnwrapVisitor<'a, 'tcx> {
     fn visit_path(&mut self, path: &'tcx Path, _id: HirId) {
         self.identifiers.insert(ident(path));
         walk_path(self, path);
@@ -93,13 +93,13 @@ impl<'a, 'tcx: 'a> Visitor<'tcx> for UnwrapVisitor<'a, 'tcx> {
     }
 }
 
-struct MapExprVisitor<'a, 'tcx: 'a> {
+struct MapExprVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
     identifiers: FxHashSet<Symbol>,
     found_identifier: bool,
 }
 
-impl<'a, 'tcx: 'a> Visitor<'tcx> for MapExprVisitor<'a, 'tcx> {
+impl<'a, 'tcx> Visitor<'tcx> for MapExprVisitor<'a, 'tcx> {
     fn visit_path(&mut self, path: &'tcx Path, _id: HirId) {
         if self.identifiers.contains(&ident(path)) {
             self.found_identifier = true;

clippy_lints/src/methods/unnecessary_filter_map.rs

@@ -53,7 +53,7 @@ pub(super) fn lint(cx: &LateContext<'_, '_>, expr: &hir::Expr, args: &[hir::Expr
 }
 
 // returns (found_mapping, found_filtering)
-fn check_expression<'a, 'tcx: 'a>(
+fn check_expression<'a, 'tcx>(
     cx: &'a LateContext<'a, 'tcx>,
     arg_id: hir::HirId,
     expr: &'tcx hir::Expr,
@@ -104,7 +104,7 @@ fn check_expression<'a, 'tcx: 'a>(
     }
 }
 
-struct ReturnVisitor<'a, 'tcx: 'a> {
+struct ReturnVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
     arg_id: hir::HirId,
     // Found a non-None return that isn't Some(input)
@@ -113,7 +113,7 @@ struct ReturnVisitor<'a, 'tcx: 'a> {
     found_filtering: bool,
 }
 
-impl<'a, 'tcx: 'a> ReturnVisitor<'a, 'tcx> {
+impl<'a, 'tcx> ReturnVisitor<'a, 'tcx> {
     fn new(cx: &'a LateContext<'a, 'tcx>, arg_id: hir::HirId) -> ReturnVisitor<'a, 'tcx> {
         ReturnVisitor {
             cx,

clippy_lints/src/mut_mut.rs

@@ -37,7 +37,7 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for MutMut {
     }
 }
 
-pub struct MutVisitor<'a, 'tcx: 'a> {
+pub struct MutVisitor<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
 }
 

clippy_lints/src/needless_pass_by_value.rs

@@ -326,7 +326,7 @@ fn requires_exact_signature(attrs: &[Attribute]) -> bool {
     })
 }
 
-struct MovedVariablesCtxt<'a, 'tcx: 'a> {
+struct MovedVariablesCtxt<'a, 'tcx> {
     cx: &'a LateContext<'a, 'tcx>,
     moved_vars: FxHashSet<HirId>,
     /// Spans which need to be prefixed with `*` for dereferencing the