diff --git a/CHANGELOG.md b/CHANGELOG.md index 9aca13a6c..3717b15ac 100644 --- a/CHANGELOG.md +++ b/CHANGELOG.md @@ -5171,6 +5171,7 @@ Released 2018-09-13 [`needless_bool_assign`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_bool_assign [`needless_borrow`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow [`needless_borrowed_reference`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrowed_reference +[`needless_borrows_for_generic_args`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrows_for_generic_args [`needless_collect`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_collect [`needless_continue`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_continue [`needless_doctest_main`]: https://rust-lang.github.io/rust-clippy/master/index.html#needless_doctest_main diff --git a/clippy_lints/src/declared_lints.rs b/clippy_lints/src/declared_lints.rs index ecf44e059..c4d5bee38 100644 --- a/clippy_lints/src/declared_lints.rs +++ b/clippy_lints/src/declared_lints.rs @@ -479,6 +479,7 @@ pub(crate) static LINTS: &[&crate::LintInfo] = &[ crate::needless_bool::NEEDLESS_BOOL_INFO, crate::needless_bool::NEEDLESS_BOOL_ASSIGN_INFO, crate::needless_borrowed_ref::NEEDLESS_BORROWED_REFERENCE_INFO, + crate::needless_borrows_for_generic_args::NEEDLESS_BORROWS_FOR_GENERIC_ARGS_INFO, crate::needless_continue::NEEDLESS_CONTINUE_INFO, crate::needless_else::NEEDLESS_ELSE_INFO, crate::needless_for_each::NEEDLESS_FOR_EACH_INFO, diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs index d0a898adf..aa80d60a4 100644 --- a/clippy_lints/src/dereference.rs +++ b/clippy_lints/src/dereference.rs @@ -1,40 +1,24 @@ use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_hir_and_then}; -use clippy_utils::mir::{enclosing_mir, expr_local, local_assignments, used_exactly_once, PossibleBorrowerMap}; -use clippy_utils::msrvs::{self, Msrv}; use clippy_utils::source::{snippet_with_applicability, snippet_with_context}; use clippy_utils::sugg::has_enclosing_paren; -use clippy_utils::ty::{implements_trait, is_copy, peel_mid_ty_refs}; +use clippy_utils::ty::{implements_trait, peel_mid_ty_refs}; use clippy_utils::{ expr_use_ctxt, get_parent_expr, get_parent_node, is_lint_allowed, path_to_local, DefinedTy, ExprUseNode, }; - -use hir::def::DefKind; -use hir::MatchSource; use rustc_ast::util::parser::{PREC_POSTFIX, PREC_PREFIX}; use rustc_data_structures::fx::FxIndexMap; use rustc_errors::Applicability; -use rustc_hir::def::Res; -use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::intravisit::{walk_ty, Visitor}; use rustc_hir::{ - self as hir, BindingAnnotation, Body, BodyId, BorrowKind, Expr, ExprKind, HirId, Mutability, Node, Pat, PatKind, - Path, QPath, TyKind, UnOp, + self as hir, BindingAnnotation, Body, BodyId, BorrowKind, Expr, ExprKind, HirId, MatchSource, Mutability, Node, + Pat, PatKind, Path, QPath, TyKind, UnOp, }; -use rustc_index::bit_set::BitSet; -use rustc_infer::infer::TyCtxtInferExt; use rustc_lint::{LateContext, LateLintPass}; -use rustc_middle::mir::{Rvalue, StatementKind}; use rustc_middle::ty::adjustment::{Adjust, Adjustment, AutoBorrow, AutoBorrowMutability}; -use rustc_middle::ty::{ - self, ClauseKind, EarlyBinder, FnSig, GenericArg, GenericArgKind, List, ParamEnv, ParamTy, ProjectionPredicate, Ty, - TyCtxt, TypeVisitableExt, TypeckResults, -}; +use rustc_middle::ty::{self, ParamEnv, Ty, TyCtxt, TypeVisitableExt, TypeckResults}; use rustc_session::{declare_tool_lint, impl_lint_pass}; use rustc_span::symbol::sym; use rustc_span::{Span, Symbol}; -use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _; -use rustc_trait_selection::traits::{Obligation, ObligationCause}; -use std::collections::VecDeque; declare_clippy_lint! { /// ### What it does @@ -182,24 +166,6 @@ pub struct Dereferencing<'tcx> { /// /// e.g. `m!(x) | Foo::Bar(ref x)` ref_locals: FxIndexMap>, - - /// Stack of (body owner, `PossibleBorrowerMap`) pairs. Used by - /// `needless_borrow_impl_arg_position` to determine when a borrowed expression can instead - /// be moved. - possible_borrowers: Vec<(LocalDefId, PossibleBorrowerMap<'tcx, 'tcx>)>, - - // `IntoIterator` for arrays requires Rust 1.53. - msrv: Msrv, -} - -impl<'tcx> Dereferencing<'tcx> { - #[must_use] - pub fn new(msrv: Msrv) -> Self { - Self { - msrv, - ..Dereferencing::default() - } - } } #[derive(Debug)] @@ -354,52 +320,6 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { )); }, (Some(use_cx), RefOp::AddrOf(mutability)) => { - let defined_ty = use_cx.node.defined_ty(cx); - - // Check needless_borrow for generic arguments. - if !use_cx.is_ty_unified - && let Some(DefinedTy::Mir(ty)) = defined_ty - && let ty::Param(ty) = *ty.value.skip_binder().kind() - && let Some((hir_id, fn_id, i)) = match use_cx.node { - ExprUseNode::MethodArg(_, _, 0) => None, - ExprUseNode::MethodArg(hir_id, None, i) => { - typeck.type_dependent_def_id(hir_id).map(|id| (hir_id, id, i)) - }, - ExprUseNode::FnArg(&Expr { kind: ExprKind::Path(ref p), hir_id, .. }, i) - if !path_has_args(p) => match typeck.qpath_res(p, hir_id) { - Res::Def(DefKind::Fn | DefKind::Ctor(..) | DefKind::AssocFn, id) => { - Some((hir_id, id, i)) - }, - _ => None, - }, - _ => None, - } && let count = needless_borrow_generic_arg_count( - cx, - &mut self.possible_borrowers, - fn_id, - typeck.node_args(hir_id), - i, - ty, - expr, - &self.msrv, - ) && count != 0 - { - self.state = Some(( - State::DerefedBorrow(DerefedBorrow { - count: count - 1, - msg: "the borrowed expression implements the required traits", - stability: TyCoercionStability::None, - for_field_access: None, - }), - StateData { - span: expr.span, - hir_id: expr.hir_id, - adjusted_ty: use_cx.adjustments.last().map_or(expr_ty, |a| a.target), - }, - )); - return; - } - // Find the number of times the borrow is auto-derefed. let mut iter = use_cx.adjustments.iter(); let mut deref_count = 0usize; @@ -418,7 +338,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { }; }; - let stability = defined_ty.map_or(TyCoercionStability::None, |ty| { + let stability = use_cx.node.defined_ty(cx).map_or(TyCoercionStability::None, |ty| { TyCoercionStability::for_defined_ty(cx, ty, use_cx.node.is_return()) }); let can_auto_borrow = match use_cx.node { @@ -699,12 +619,6 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { } fn check_body_post(&mut self, cx: &LateContext<'tcx>, body: &'tcx Body<'_>) { - if self.possible_borrowers.last().map_or(false, |&(local_def_id, _)| { - local_def_id == cx.tcx.hir().body_owner_def_id(body.id()) - }) { - self.possible_borrowers.pop(); - } - if Some(body.id()) == self.current_body { for pat in self.ref_locals.drain(..).filter_map(|(_, x)| x) { let replacements = pat.replacements; @@ -728,8 +642,6 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { self.current_body = None; } } - - extract_msrv_attr!(LateContext); } fn try_parse_ref_op<'tcx>( @@ -787,13 +699,6 @@ fn deref_method_same_type<'tcx>(result_ty: Ty<'tcx>, arg_ty: Ty<'tcx>) -> bool { } } -fn path_has_args(p: &QPath<'_>) -> bool { - match *p { - QPath::Resolved(_, Path { segments: [.., s], .. }) | QPath::TypeRelative(_, s) => s.args.is_some(), - _ => false, - } -} - fn in_postfix_position<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> bool { if let Some(parent) = get_parent_expr(cx, e) && parent.span.ctxt() == e.span.ctxt() @@ -980,272 +885,6 @@ fn ty_contains_infer(ty: &hir::Ty<'_>) -> bool { v.0 } -/// Checks for the number of borrow expressions which can be removed from the given expression -/// where the expression is used as an argument to a function expecting a generic type. -/// -/// The following constraints will be checked: -/// * The borrowed expression meets all the generic type's constraints. -/// * The generic type appears only once in the functions signature. -/// * The borrowed value will not be moved if it is used later in the function. -#[expect(clippy::too_many_arguments)] -fn needless_borrow_generic_arg_count<'tcx>( - cx: &LateContext<'tcx>, - possible_borrowers: &mut Vec<(LocalDefId, PossibleBorrowerMap<'tcx, 'tcx>)>, - fn_id: DefId, - callee_args: &'tcx List>, - arg_index: usize, - param_ty: ParamTy, - mut expr: &Expr<'tcx>, - msrv: &Msrv, -) -> usize { - let destruct_trait_def_id = cx.tcx.lang_items().destruct_trait(); - let sized_trait_def_id = cx.tcx.lang_items().sized_trait(); - - let fn_sig = cx.tcx.fn_sig(fn_id).instantiate_identity().skip_binder(); - let predicates = cx.tcx.param_env(fn_id).caller_bounds(); - let projection_predicates = predicates - .iter() - .filter_map(|predicate| { - if let ClauseKind::Projection(projection_predicate) = predicate.kind().skip_binder() { - Some(projection_predicate) - } else { - None - } - }) - .collect::>(); - - let mut trait_with_ref_mut_self_method = false; - - // If no traits were found, or only the `Destruct`, `Sized`, or `Any` traits were found, return. - if predicates - .iter() - .filter_map(|predicate| { - if let ClauseKind::Trait(trait_predicate) = predicate.kind().skip_binder() - && trait_predicate.trait_ref.self_ty() == param_ty.to_ty(cx.tcx) - { - Some(trait_predicate.trait_ref.def_id) - } else { - None - } - }) - .inspect(|trait_def_id| { - trait_with_ref_mut_self_method |= has_ref_mut_self_method(cx, *trait_def_id); - }) - .all(|trait_def_id| { - Some(trait_def_id) == destruct_trait_def_id - || Some(trait_def_id) == sized_trait_def_id - || cx.tcx.is_diagnostic_item(sym::Any, trait_def_id) - }) - { - return 0; - } - - // See: - // - https://github.com/rust-lang/rust-clippy/pull/9674#issuecomment-1289294201 - // - https://github.com/rust-lang/rust-clippy/pull/9674#issuecomment-1292225232 - if projection_predicates - .iter() - .any(|projection_predicate| is_mixed_projection_predicate(cx, fn_id, projection_predicate)) - { - return 0; - } - - // `args_with_referent_ty` can be constructed outside of `check_referent` because the same - // elements are modified each time `check_referent` is called. - let mut args_with_referent_ty = callee_args.to_vec(); - - let mut check_reference_and_referent = |reference, referent| { - let referent_ty = cx.typeck_results().expr_ty(referent); - - if !is_copy(cx, referent_ty) - && (referent_ty.has_significant_drop(cx.tcx, cx.param_env) - || !referent_used_exactly_once(cx, possible_borrowers, reference)) - { - return false; - } - - // https://github.com/rust-lang/rust-clippy/pull/9136#pullrequestreview-1037379321 - if trait_with_ref_mut_self_method && !matches!(referent_ty.kind(), ty::Ref(_, _, Mutability::Mut)) { - return false; - } - - if !replace_types( - cx, - param_ty, - referent_ty, - fn_sig, - arg_index, - &projection_predicates, - &mut args_with_referent_ty, - ) { - return false; - } - - predicates.iter().all(|predicate| { - if let ClauseKind::Trait(trait_predicate) = predicate.kind().skip_binder() - && cx.tcx.is_diagnostic_item(sym::IntoIterator, trait_predicate.trait_ref.def_id) - && let ty::Param(param_ty) = trait_predicate.self_ty().kind() - && let GenericArgKind::Type(ty) = args_with_referent_ty[param_ty.index as usize].unpack() - && ty.is_array() - && !msrv.meets(msrvs::ARRAY_INTO_ITERATOR) - { - return false; - } - - let predicate = EarlyBinder::bind(predicate).instantiate(cx.tcx, &args_with_referent_ty); - let obligation = Obligation::new(cx.tcx, ObligationCause::dummy(), cx.param_env, predicate); - let infcx = cx.tcx.infer_ctxt().build(); - infcx.predicate_must_hold_modulo_regions(&obligation) - }) - }; - - let mut count = 0; - while let ExprKind::AddrOf(_, _, referent) = expr.kind { - if !check_reference_and_referent(expr, referent) { - break; - } - expr = referent; - count += 1; - } - count -} - -fn has_ref_mut_self_method(cx: &LateContext<'_>, trait_def_id: DefId) -> bool { - cx.tcx - .associated_items(trait_def_id) - .in_definition_order() - .any(|assoc_item| { - if assoc_item.fn_has_self_parameter { - let self_ty = cx - .tcx - .fn_sig(assoc_item.def_id) - .instantiate_identity() - .skip_binder() - .inputs()[0]; - matches!(self_ty.kind(), ty::Ref(_, _, Mutability::Mut)) - } else { - false - } - }) -} - -fn is_mixed_projection_predicate<'tcx>( - cx: &LateContext<'tcx>, - callee_def_id: DefId, - projection_predicate: &ProjectionPredicate<'tcx>, -) -> bool { - let generics = cx.tcx.generics_of(callee_def_id); - // The predicate requires the projected type to equal a type parameter from the parent context. - if let Some(term_ty) = projection_predicate.term.ty() - && let ty::Param(term_param_ty) = term_ty.kind() - && (term_param_ty.index as usize) < generics.parent_count - { - // The inner-most self type is a type parameter from the current function. - let mut projection_ty = projection_predicate.projection_ty; - loop { - match projection_ty.self_ty().kind() { - ty::Alias(ty::Projection, inner_projection_ty) => { - projection_ty = *inner_projection_ty; - } - ty::Param(param_ty) => { - return (param_ty.index as usize) >= generics.parent_count; - } - _ => { - return false; - } - } - } - } else { - false - } -} - -fn referent_used_exactly_once<'tcx>( - cx: &LateContext<'tcx>, - possible_borrowers: &mut Vec<(LocalDefId, PossibleBorrowerMap<'tcx, 'tcx>)>, - reference: &Expr<'tcx>, -) -> bool { - if let Some(mir) = enclosing_mir(cx.tcx, reference.hir_id) - && let Some(local) = expr_local(cx.tcx, reference) - && let [location] = *local_assignments(mir, local).as_slice() - && let Some(statement) = mir.basic_blocks[location.block].statements.get(location.statement_index) - && let StatementKind::Assign(box (_, Rvalue::Ref(_, _, place))) = statement.kind - && !place.is_indirect_first_projection() - { - let body_owner_local_def_id = cx.tcx.hir().enclosing_body_owner(reference.hir_id); - if possible_borrowers - .last() - .map_or(true, |&(local_def_id, _)| local_def_id != body_owner_local_def_id) - { - possible_borrowers.push((body_owner_local_def_id, PossibleBorrowerMap::new(cx, mir))); - } - let possible_borrower = &mut possible_borrowers.last_mut().unwrap().1; - // If `only_borrowers` were used here, the `copyable_iterator::warn` test would fail. The reason is - // that `PossibleBorrowerVisitor::visit_terminator` considers `place.local` a possible borrower of - // itself. See the comment in that method for an explanation as to why. - possible_borrower.bounded_borrowers(&[local], &[local, place.local], place.local, location) - && used_exactly_once(mir, place.local).unwrap_or(false) - } else { - false - } -} - -// Iteratively replaces `param_ty` with `new_ty` in `args`, and similarly for each resulting -// projected type that is a type parameter. Returns `false` if replacing the types would have an -// effect on the function signature beyond substituting `new_ty` for `param_ty`. -// See: https://github.com/rust-lang/rust-clippy/pull/9136#discussion_r927212757 -fn replace_types<'tcx>( - cx: &LateContext<'tcx>, - param_ty: ParamTy, - new_ty: Ty<'tcx>, - fn_sig: FnSig<'tcx>, - arg_index: usize, - projection_predicates: &[ProjectionPredicate<'tcx>], - args: &mut [ty::GenericArg<'tcx>], -) -> bool { - let mut replaced = BitSet::new_empty(args.len()); - - let mut deque = VecDeque::with_capacity(args.len()); - deque.push_back((param_ty, new_ty)); - - while let Some((param_ty, new_ty)) = deque.pop_front() { - // If `replaced.is_empty()`, then `param_ty` and `new_ty` are those initially passed in. - if !fn_sig - .inputs_and_output - .iter() - .enumerate() - .all(|(i, ty)| (replaced.is_empty() && i == arg_index) || !ty.contains(param_ty.to_ty(cx.tcx))) - { - return false; - } - - args[param_ty.index as usize] = ty::GenericArg::from(new_ty); - - // The `replaced.insert(...)` check provides some protection against infinite loops. - if replaced.insert(param_ty.index) { - for projection_predicate in projection_predicates { - if projection_predicate.projection_ty.self_ty() == param_ty.to_ty(cx.tcx) - && let Some(term_ty) = projection_predicate.term.ty() - && let ty::Param(term_param_ty) = term_ty.kind() - { - let projection = cx.tcx.mk_ty_from_kind(ty::Alias( - ty::Projection, - projection_predicate.projection_ty.with_self_ty(cx.tcx, new_ty), - )); - - if let Ok(projected_ty) = cx.tcx.try_normalize_erasing_regions(cx.param_env, projection) - && args[term_param_ty.index as usize] != ty::GenericArg::from(projected_ty) - { - deque.push_back((*term_param_ty, projected_ty)); - } - } - } - } - } - - true -} - fn ty_contains_field(ty: Ty<'_>, name: Symbol) -> bool { if let ty::Adt(adt, _) = *ty.kind() { adt.is_struct() && adt.all_fields().any(|f| f.name == name) diff --git a/clippy_lints/src/lib.rs b/clippy_lints/src/lib.rs index 3f6bdb2b6..614ddcda8 100644 --- a/clippy_lints/src/lib.rs +++ b/clippy_lints/src/lib.rs @@ -228,6 +228,7 @@ mod mutex_atomic; mod needless_arbitrary_self_type; mod needless_bool; mod needless_borrowed_ref; +mod needless_borrows_for_generic_args; mod needless_continue; mod needless_else; mod needless_for_each; @@ -880,7 +881,7 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(move |_| Box::new(wildcard_imports::WildcardImports::new(warn_on_all_wildcard_imports))); store.register_late_pass(|_| Box::::default()); store.register_late_pass(|_| Box::new(unnamed_address::UnnamedAddress)); - store.register_late_pass(move |_| Box::new(dereference::Dereferencing::new(msrv()))); + store.register_late_pass(|_| Box::>::default()); store.register_late_pass(|_| Box::new(option_if_let_else::OptionIfLetElse)); store.register_late_pass(|_| Box::new(future_not_send::FutureNotSend)); let future_size_threshold = conf.future_size_threshold; @@ -1104,6 +1105,11 @@ pub fn register_plugins(store: &mut rustc_lint::LintStore, sess: &Session, conf: store.register_late_pass(|_| Box::new(implied_bounds_in_impls::ImpliedBoundsInImpls)); store.register_late_pass(|_| Box::new(missing_asserts_for_indexing::MissingAssertsForIndexing)); store.register_late_pass(|_| Box::new(unnecessary_map_on_constructor::UnnecessaryMapOnConstructor)); + store.register_late_pass(move |_| { + Box::new(needless_borrows_for_generic_args::NeedlessBorrowsForGenericArgs::new( + msrv(), + )) + }); // add lints here, do not remove this comment, it's used in `new_lint` } diff --git a/clippy_lints/src/needless_borrows_for_generic_args.rs b/clippy_lints/src/needless_borrows_for_generic_args.rs new file mode 100644 index 000000000..d55c77a92 --- /dev/null +++ b/clippy_lints/src/needless_borrows_for_generic_args.rs @@ -0,0 +1,410 @@ +use clippy_utils::diagnostics::span_lint_and_then; +use clippy_utils::mir::{enclosing_mir, expr_local, local_assignments, used_exactly_once, PossibleBorrowerMap}; +use clippy_utils::msrvs::{self, Msrv}; +use clippy_utils::source::snippet_with_context; +use clippy_utils::ty::is_copy; +use clippy_utils::{expr_use_ctxt, peel_n_hir_expr_refs, DefinedTy, ExprUseNode}; +use rustc_errors::Applicability; +use rustc_hir::def::{DefKind, Res}; +use rustc_hir::def_id::{DefId, LocalDefId}; +use rustc_hir::{Body, Expr, ExprKind, Mutability, Path, QPath}; +use rustc_index::bit_set::BitSet; +use rustc_infer::infer::TyCtxtInferExt; +use rustc_lint::{LateContext, LateLintPass}; +use rustc_middle::mir::{Rvalue, StatementKind}; +use rustc_middle::ty::{ + self, ClauseKind, EarlyBinder, FnSig, GenericArg, GenericArgKind, List, ParamTy, ProjectionPredicate, Ty, +}; +use rustc_session::{declare_tool_lint, impl_lint_pass}; +use rustc_span::symbol::sym; +use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _; +use rustc_trait_selection::traits::{Obligation, ObligationCause}; +use std::collections::VecDeque; + +declare_clippy_lint! { + /// ### What it does + /// Checks for borrow operations (`&`) that used as a generic argument to a + /// function when the borrowed value could be used. + /// + /// ### Why is this bad? + /// Suggests that the receiver of the expression borrows + /// the expression. + /// + /// ### Known problems + /// The lint cannot tell when the implementation of a trait + /// for `&T` and `T` do different things. Removing a borrow + /// in such a case can change the semantics of the code. + /// + /// ### Example + /// ```rust + /// fn f(_: impl AsRef) {} + /// + /// let x = "foo"; + /// f(&x); + /// ``` + /// + /// Use instead: + /// ```rust + /// fn f(_: impl AsRef) {} + /// + /// let x = "foo"; + /// f(x); + /// ``` + #[clippy::version = "pre 1.29.0"] + pub NEEDLESS_BORROWS_FOR_GENERIC_ARGS, + style, + "taking a reference that is going to be automatically dereferenced" +} + +pub struct NeedlessBorrowsForGenericArgs<'tcx> { + /// Stack of (body owner, `PossibleBorrowerMap`) pairs. Used by + /// `needless_borrow_impl_arg_position` to determine when a borrowed expression can instead + /// be moved. + possible_borrowers: Vec<(LocalDefId, PossibleBorrowerMap<'tcx, 'tcx>)>, + + // `IntoIterator` for arrays requires Rust 1.53. + msrv: Msrv, +} +impl_lint_pass!(NeedlessBorrowsForGenericArgs<'_> => [NEEDLESS_BORROWS_FOR_GENERIC_ARGS]); + +impl NeedlessBorrowsForGenericArgs<'_> { + #[must_use] + pub fn new(msrv: Msrv) -> Self { + Self { + possible_borrowers: Vec::new(), + msrv, + } + } +} + +impl<'tcx> LateLintPass<'tcx> for NeedlessBorrowsForGenericArgs<'tcx> { + fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { + if matches!(expr.kind, ExprKind::AddrOf(..)) + && !expr.span.from_expansion() + && let Some(use_cx) = expr_use_ctxt(cx, expr) + && !use_cx.is_ty_unified + && let Some(DefinedTy::Mir(ty)) = use_cx.node.defined_ty(cx) + && let ty::Param(ty) = *ty.value.skip_binder().kind() + && let Some((hir_id, fn_id, i)) = match use_cx.node { + ExprUseNode::MethodArg(_, _, 0) => None, + ExprUseNode::MethodArg(hir_id, None, i) => { + cx.typeck_results().type_dependent_def_id(hir_id).map(|id| (hir_id, id, i)) + }, + ExprUseNode::FnArg(&Expr { kind: ExprKind::Path(ref p), hir_id, .. }, i) + if !path_has_args(p) => match cx.typeck_results().qpath_res(p, hir_id) { + Res::Def(DefKind::Fn | DefKind::Ctor(..) | DefKind::AssocFn, id) => { + Some((hir_id, id, i)) + }, + _ => None, + }, + _ => None, + } && let count = needless_borrow_count( + cx, + &mut self.possible_borrowers, + fn_id, + cx.typeck_results().node_args(hir_id), + i, + ty, + expr, + &self.msrv, + ) && count != 0 + { + span_lint_and_then( + cx, + NEEDLESS_BORROWS_FOR_GENERIC_ARGS, + expr.span, + "the borrowed expression implements the required traits", + |diag| { + let mut app = Applicability::MachineApplicable; + let snip_span = peel_n_hir_expr_refs(expr, count).0.span; + let snip = snippet_with_context(cx, snip_span, expr.span.ctxt(), "..", &mut app).0; + diag.span_suggestion(expr.span, "change this to", snip.into_owned(), app); + } + ); + } + } + + fn check_body_post(&mut self, cx: &LateContext<'tcx>, body: &'tcx Body<'_>) { + if self.possible_borrowers.last().map_or(false, |&(local_def_id, _)| { + local_def_id == cx.tcx.hir().body_owner_def_id(body.id()) + }) { + self.possible_borrowers.pop(); + } + } + + extract_msrv_attr!(LateContext); +} + +fn path_has_args(p: &QPath<'_>) -> bool { + match *p { + QPath::Resolved(_, Path { segments: [.., s], .. }) | QPath::TypeRelative(_, s) => s.args.is_some(), + _ => false, + } +} + +/// Checks for the number of borrow expressions which can be removed from the given expression +/// where the expression is used as an argument to a function expecting a generic type. +/// +/// The following constraints will be checked: +/// * The borrowed expression meets all the generic type's constraints. +/// * The generic type appears only once in the functions signature. +/// * The borrowed value will not be moved if it is used later in the function. +#[expect(clippy::too_many_arguments)] +fn needless_borrow_count<'tcx>( + cx: &LateContext<'tcx>, + possible_borrowers: &mut Vec<(LocalDefId, PossibleBorrowerMap<'tcx, 'tcx>)>, + fn_id: DefId, + callee_args: &'tcx List>, + arg_index: usize, + param_ty: ParamTy, + mut expr: &Expr<'tcx>, + msrv: &Msrv, +) -> usize { + let destruct_trait_def_id = cx.tcx.lang_items().destruct_trait(); + let sized_trait_def_id = cx.tcx.lang_items().sized_trait(); + + let fn_sig = cx.tcx.fn_sig(fn_id).instantiate_identity().skip_binder(); + let predicates = cx.tcx.param_env(fn_id).caller_bounds(); + let projection_predicates = predicates + .iter() + .filter_map(|predicate| { + if let ClauseKind::Projection(projection_predicate) = predicate.kind().skip_binder() { + Some(projection_predicate) + } else { + None + } + }) + .collect::>(); + + let mut trait_with_ref_mut_self_method = false; + + // If no traits were found, or only the `Destruct`, `Sized`, or `Any` traits were found, return. + if predicates + .iter() + .filter_map(|predicate| { + if let ClauseKind::Trait(trait_predicate) = predicate.kind().skip_binder() + && trait_predicate.trait_ref.self_ty() == param_ty.to_ty(cx.tcx) + { + Some(trait_predicate.trait_ref.def_id) + } else { + None + } + }) + .inspect(|trait_def_id| { + trait_with_ref_mut_self_method |= has_ref_mut_self_method(cx, *trait_def_id); + }) + .all(|trait_def_id| { + Some(trait_def_id) == destruct_trait_def_id + || Some(trait_def_id) == sized_trait_def_id + || cx.tcx.is_diagnostic_item(sym::Any, trait_def_id) + }) + { + return 0; + } + + // See: + // - https://github.com/rust-lang/rust-clippy/pull/9674#issuecomment-1289294201 + // - https://github.com/rust-lang/rust-clippy/pull/9674#issuecomment-1292225232 + if projection_predicates + .iter() + .any(|projection_predicate| is_mixed_projection_predicate(cx, fn_id, projection_predicate)) + { + return 0; + } + + // `args_with_referent_ty` can be constructed outside of `check_referent` because the same + // elements are modified each time `check_referent` is called. + let mut args_with_referent_ty = callee_args.to_vec(); + + let mut check_reference_and_referent = |reference, referent| { + let referent_ty = cx.typeck_results().expr_ty(referent); + + if !is_copy(cx, referent_ty) + && (referent_ty.has_significant_drop(cx.tcx, cx.param_env) + || !referent_used_exactly_once(cx, possible_borrowers, reference)) + { + return false; + } + + // https://github.com/rust-lang/rust-clippy/pull/9136#pullrequestreview-1037379321 + if trait_with_ref_mut_self_method && !matches!(referent_ty.kind(), ty::Ref(_, _, Mutability::Mut)) { + return false; + } + + if !replace_types( + cx, + param_ty, + referent_ty, + fn_sig, + arg_index, + &projection_predicates, + &mut args_with_referent_ty, + ) { + return false; + } + + predicates.iter().all(|predicate| { + if let ClauseKind::Trait(trait_predicate) = predicate.kind().skip_binder() + && cx.tcx.is_diagnostic_item(sym::IntoIterator, trait_predicate.trait_ref.def_id) + && let ty::Param(param_ty) = trait_predicate.self_ty().kind() + && let GenericArgKind::Type(ty) = args_with_referent_ty[param_ty.index as usize].unpack() + && ty.is_array() + && !msrv.meets(msrvs::ARRAY_INTO_ITERATOR) + { + return false; + } + + let predicate = EarlyBinder::bind(predicate).instantiate(cx.tcx, &args_with_referent_ty); + let obligation = Obligation::new(cx.tcx, ObligationCause::dummy(), cx.param_env, predicate); + let infcx = cx.tcx.infer_ctxt().build(); + infcx.predicate_must_hold_modulo_regions(&obligation) + }) + }; + + let mut count = 0; + while let ExprKind::AddrOf(_, _, referent) = expr.kind { + if !check_reference_and_referent(expr, referent) { + break; + } + expr = referent; + count += 1; + } + count +} + +fn has_ref_mut_self_method(cx: &LateContext<'_>, trait_def_id: DefId) -> bool { + cx.tcx + .associated_items(trait_def_id) + .in_definition_order() + .any(|assoc_item| { + if assoc_item.fn_has_self_parameter { + let self_ty = cx + .tcx + .fn_sig(assoc_item.def_id) + .instantiate_identity() + .skip_binder() + .inputs()[0]; + matches!(self_ty.kind(), ty::Ref(_, _, Mutability::Mut)) + } else { + false + } + }) +} + +fn is_mixed_projection_predicate<'tcx>( + cx: &LateContext<'tcx>, + callee_def_id: DefId, + projection_predicate: &ProjectionPredicate<'tcx>, +) -> bool { + let generics = cx.tcx.generics_of(callee_def_id); + // The predicate requires the projected type to equal a type parameter from the parent context. + if let Some(term_ty) = projection_predicate.term.ty() + && let ty::Param(term_param_ty) = term_ty.kind() + && (term_param_ty.index as usize) < generics.parent_count + { + // The inner-most self type is a type parameter from the current function. + let mut projection_ty = projection_predicate.projection_ty; + loop { + match projection_ty.self_ty().kind() { + ty::Alias(ty::Projection, inner_projection_ty) => { + projection_ty = *inner_projection_ty; + } + ty::Param(param_ty) => { + return (param_ty.index as usize) >= generics.parent_count; + } + _ => { + return false; + } + } + } + } else { + false + } +} + +fn referent_used_exactly_once<'tcx>( + cx: &LateContext<'tcx>, + possible_borrowers: &mut Vec<(LocalDefId, PossibleBorrowerMap<'tcx, 'tcx>)>, + reference: &Expr<'tcx>, +) -> bool { + if let Some(mir) = enclosing_mir(cx.tcx, reference.hir_id) + && let Some(local) = expr_local(cx.tcx, reference) + && let [location] = *local_assignments(mir, local).as_slice() + && let block_data = &mir.basic_blocks[location.block] + && let Some(statement) = block_data.statements.get(location.statement_index) + && let StatementKind::Assign(box (_, Rvalue::Ref(_, _, place))) = statement.kind + && !place.is_indirect_first_projection() + { + let body_owner_local_def_id = cx.tcx.hir().enclosing_body_owner(reference.hir_id); + if possible_borrowers + .last() + .map_or(true, |&(local_def_id, _)| local_def_id != body_owner_local_def_id) + { + possible_borrowers.push((body_owner_local_def_id, PossibleBorrowerMap::new(cx, mir))); + } + let possible_borrower = &mut possible_borrowers.last_mut().unwrap().1; + // If `only_borrowers` were used here, the `copyable_iterator::warn` test would fail. The reason is + // that `PossibleBorrowerVisitor::visit_terminator` considers `place.local` a possible borrower of + // itself. See the comment in that method for an explanation as to why. + possible_borrower.bounded_borrowers(&[local], &[local, place.local], place.local, location) + && used_exactly_once(mir, place.local).unwrap_or(false) + } else { + false + } +} + +// Iteratively replaces `param_ty` with `new_ty` in `args`, and similarly for each resulting +// projected type that is a type parameter. Returns `false` if replacing the types would have an +// effect on the function signature beyond substituting `new_ty` for `param_ty`. +// See: https://github.com/rust-lang/rust-clippy/pull/9136#discussion_r927212757 +fn replace_types<'tcx>( + cx: &LateContext<'tcx>, + param_ty: ParamTy, + new_ty: Ty<'tcx>, + fn_sig: FnSig<'tcx>, + arg_index: usize, + projection_predicates: &[ProjectionPredicate<'tcx>], + args: &mut [ty::GenericArg<'tcx>], +) -> bool { + let mut replaced = BitSet::new_empty(args.len()); + + let mut deque = VecDeque::with_capacity(args.len()); + deque.push_back((param_ty, new_ty)); + + while let Some((param_ty, new_ty)) = deque.pop_front() { + // If `replaced.is_empty()`, then `param_ty` and `new_ty` are those initially passed in. + if !fn_sig + .inputs_and_output + .iter() + .enumerate() + .all(|(i, ty)| (replaced.is_empty() && i == arg_index) || !ty.contains(param_ty.to_ty(cx.tcx))) + { + return false; + } + + args[param_ty.index as usize] = ty::GenericArg::from(new_ty); + + // The `replaced.insert(...)` check provides some protection against infinite loops. + if replaced.insert(param_ty.index) { + for projection_predicate in projection_predicates { + if projection_predicate.projection_ty.self_ty() == param_ty.to_ty(cx.tcx) + && let Some(term_ty) = projection_predicate.term.ty() + && let ty::Param(term_param_ty) = term_ty.kind() + { + let projection = cx.tcx.mk_ty_from_kind(ty::Alias( + ty::Projection, + projection_predicate.projection_ty.with_self_ty(cx.tcx, new_ty), + )); + + if let Ok(projected_ty) = cx.tcx.try_normalize_erasing_regions(cx.param_env, projection) + && args[term_param_ty.index as usize] != ty::GenericArg::from(projected_ty) + { + deque.push_back((*term_param_ty, projected_ty)); + } + } + } + } + } + + true +} diff --git a/tests/ui/needless_borrow.fixed b/tests/ui/needless_borrow.fixed index 0a52b2522..c2c5f765a 100644 --- a/tests/ui/needless_borrow.fixed +++ b/tests/ui/needless_borrow.fixed @@ -131,21 +131,6 @@ fn main() { 0 } } - - let _ = std::process::Command::new("ls").args(["-a", "-l"]).status().unwrap(); - let _ = std::path::Path::new(".").join("."); - deref_target_is_x(X); - multiple_constraints([[""]]); - multiple_constraints_normalizes_to_same(X, X); - let _ = Some("").unwrap_or(""); - let _ = std::fs::write("x", "".to_string()); - - only_sized(&""); // Don't lint. `Sized` is only bound - let _ = std::any::Any::type_id(&""); // Don't lint. `Any` is only bound - let _ = Box::new(&""); // Don't lint. Type parameter appears in return type - ref_as_ref_path(&""); // Don't lint. Argument type is not a type parameter - refs_only(&()); // Don't lint. `&T` implements trait, but `T` doesn't - multiple_constraints_normalizes_to_different(&[[""]], &[""]); // Don't lint. Projected type appears in arguments } #[allow(clippy::needless_borrowed_reference)] @@ -201,103 +186,6 @@ mod issue9160 { } } -#[derive(Clone, Copy)] -struct X; - -impl std::ops::Deref for X { - type Target = X; - fn deref(&self) -> &Self::Target { - self - } -} - -fn deref_target_is_x(_: T) -where - T: std::ops::Deref, -{ -} - -fn multiple_constraints(_: T) -where - T: IntoIterator + IntoIterator, - U: IntoIterator, - V: AsRef, - X: IntoIterator, - Y: AsRef, -{ -} - -fn multiple_constraints_normalizes_to_same(_: T, _: V) -where - T: std::ops::Deref, - U: std::ops::Deref, -{ -} - -fn only_sized(_: T) {} - -fn ref_as_ref_path(_: &'static T) -where - &'static T: AsRef, -{ -} - -trait RefsOnly { - type Referent; -} - -impl RefsOnly for &T { - type Referent = T; -} - -fn refs_only(_: T) -where - T: RefsOnly, -{ -} - -fn multiple_constraints_normalizes_to_different(_: T, _: U) -where - T: IntoIterator, - U: IntoIterator, - V: AsRef, -{ -} - -// https://github.com/rust-lang/rust-clippy/pull/9136#pullrequestreview-1037379321 -mod copyable_iterator { - #[derive(Clone, Copy)] - struct Iter; - impl Iterator for Iter { - type Item = (); - fn next(&mut self) -> Option { - None - } - } - fn takes_iter(_: impl Iterator) {} - fn dont_warn(mut x: Iter) { - takes_iter(&mut x); - } - #[allow(unused_mut)] - fn warn(mut x: &mut Iter) { - takes_iter(x) - } -} - -#[clippy::msrv = "1.52.0"] -mod under_msrv { - fn foo() { - let _ = std::process::Command::new("ls").args(&["-a", "-l"]).status().unwrap(); - } -} - -#[clippy::msrv = "1.53.0"] -mod meets_msrv { - fn foo() { - let _ = std::process::Command::new("ls").args(["-a", "-l"]).status().unwrap(); - } -} - fn issue9383() { // Should not lint because unions need explicit deref when accessing field use std::mem::ManuallyDrop; @@ -326,184 +214,6 @@ fn issue9383() { } } -fn closure_test() { - let env = "env".to_owned(); - let arg = "arg".to_owned(); - let f = |arg| { - let loc = "loc".to_owned(); - let _ = std::fs::write("x", &env); // Don't lint. In environment - let _ = std::fs::write("x", arg); - let _ = std::fs::write("x", loc); - }; - let _ = std::fs::write("x", &env); // Don't lint. Borrowed by `f` - f(arg); -} - -mod significant_drop { - #[derive(Debug)] - struct X; - - #[derive(Debug)] - struct Y; - - impl Drop for Y { - fn drop(&mut self) {} - } - - fn foo(x: X, y: Y) { - debug(x); - debug(&y); // Don't lint. Has significant drop - } - - fn debug(_: impl std::fmt::Debug) {} -} - -mod used_exactly_once { - fn foo(x: String) { - use_x(x); - } - fn use_x(_: impl AsRef) {} -} - -mod used_more_than_once { - fn foo(x: String) { - use_x(&x); - use_x_again(&x); - } - fn use_x(_: impl AsRef) {} - fn use_x_again(_: impl AsRef) {} -} - -// https://github.com/rust-lang/rust-clippy/issues/9111#issuecomment-1277114280 -mod issue_9111 { - struct A; - - impl Extend for A { - fn extend>(&mut self, _: T) { - unimplemented!() - } - } - - impl<'a> Extend<&'a u8> for A { - fn extend>(&mut self, _: T) { - unimplemented!() - } - } - - fn main() { - let mut a = A; - a.extend(&[]); // vs a.extend([]); - } -} - -mod issue_9710 { - fn main() { - let string = String::new(); - for _i in 0..10 { - f(&string); - } - } - - fn f>(_: T) {} -} - -mod issue_9739 { - fn foo(_it: impl IntoIterator) {} - - fn main() { - foo(if std::env::var_os("HI").is_some() { - &[0] - } else { - &[] as &[u32] - }); - } -} - -mod issue_9739_method_variant { - struct S; - - impl S { - fn foo(&self, _it: impl IntoIterator) {} - } - - fn main() { - S.foo(if std::env::var_os("HI").is_some() { - &[0] - } else { - &[] as &[u32] - }); - } -} - -mod issue_9782 { - fn foo>(t: T) { - println!("{}", std::mem::size_of::()); - let _t: &[u8] = t.as_ref(); - } - - fn main() { - let a: [u8; 100] = [0u8; 100]; - - // 100 - foo::<[u8; 100]>(a); - foo(a); - - // 16 - foo::<&[u8]>(&a); - foo(a.as_slice()); - - // 8 - foo::<&[u8; 100]>(&a); - foo(a); - } -} - -mod issue_9782_type_relative_variant { - struct S; - - impl S { - fn foo>(t: T) { - println!("{}", std::mem::size_of::()); - let _t: &[u8] = t.as_ref(); - } - } - - fn main() { - let a: [u8; 100] = [0u8; 100]; - - S::foo::<&[u8; 100]>(&a); - } -} - -mod issue_9782_method_variant { - struct S; - - impl S { - fn foo>(&self, t: T) { - println!("{}", std::mem::size_of::()); - let _t: &[u8] = t.as_ref(); - } - } - - fn main() { - let a: [u8; 100] = [0u8; 100]; - - S.foo::<&[u8; 100]>(&a); - } -} - -mod issue_10535 { - static SOME_STATIC: String = String::new(); - - static UNIT: () = compute(&SOME_STATIC); - - pub const fn compute(_: T) - where - T: Copy, - { - } -} - mod issue_10253 { struct S; trait X { diff --git a/tests/ui/needless_borrow.rs b/tests/ui/needless_borrow.rs index 34a95d184..0cd6e41b8 100644 --- a/tests/ui/needless_borrow.rs +++ b/tests/ui/needless_borrow.rs @@ -131,21 +131,6 @@ fn main() { 0 } } - - let _ = std::process::Command::new("ls").args(&["-a", "-l"]).status().unwrap(); - let _ = std::path::Path::new(".").join(&&"."); - deref_target_is_x(&X); - multiple_constraints(&[[""]]); - multiple_constraints_normalizes_to_same(&X, X); - let _ = Some("").unwrap_or(&""); - let _ = std::fs::write("x", &"".to_string()); - - only_sized(&""); // Don't lint. `Sized` is only bound - let _ = std::any::Any::type_id(&""); // Don't lint. `Any` is only bound - let _ = Box::new(&""); // Don't lint. Type parameter appears in return type - ref_as_ref_path(&""); // Don't lint. Argument type is not a type parameter - refs_only(&()); // Don't lint. `&T` implements trait, but `T` doesn't - multiple_constraints_normalizes_to_different(&[[""]], &[""]); // Don't lint. Projected type appears in arguments } #[allow(clippy::needless_borrowed_reference)] @@ -201,103 +186,6 @@ mod issue9160 { } } -#[derive(Clone, Copy)] -struct X; - -impl std::ops::Deref for X { - type Target = X; - fn deref(&self) -> &Self::Target { - self - } -} - -fn deref_target_is_x(_: T) -where - T: std::ops::Deref, -{ -} - -fn multiple_constraints(_: T) -where - T: IntoIterator + IntoIterator, - U: IntoIterator, - V: AsRef, - X: IntoIterator, - Y: AsRef, -{ -} - -fn multiple_constraints_normalizes_to_same(_: T, _: V) -where - T: std::ops::Deref, - U: std::ops::Deref, -{ -} - -fn only_sized(_: T) {} - -fn ref_as_ref_path(_: &'static T) -where - &'static T: AsRef, -{ -} - -trait RefsOnly { - type Referent; -} - -impl RefsOnly for &T { - type Referent = T; -} - -fn refs_only(_: T) -where - T: RefsOnly, -{ -} - -fn multiple_constraints_normalizes_to_different(_: T, _: U) -where - T: IntoIterator, - U: IntoIterator, - V: AsRef, -{ -} - -// https://github.com/rust-lang/rust-clippy/pull/9136#pullrequestreview-1037379321 -mod copyable_iterator { - #[derive(Clone, Copy)] - struct Iter; - impl Iterator for Iter { - type Item = (); - fn next(&mut self) -> Option { - None - } - } - fn takes_iter(_: impl Iterator) {} - fn dont_warn(mut x: Iter) { - takes_iter(&mut x); - } - #[allow(unused_mut)] - fn warn(mut x: &mut Iter) { - takes_iter(&mut x) - } -} - -#[clippy::msrv = "1.52.0"] -mod under_msrv { - fn foo() { - let _ = std::process::Command::new("ls").args(&["-a", "-l"]).status().unwrap(); - } -} - -#[clippy::msrv = "1.53.0"] -mod meets_msrv { - fn foo() { - let _ = std::process::Command::new("ls").args(&["-a", "-l"]).status().unwrap(); - } -} - fn issue9383() { // Should not lint because unions need explicit deref when accessing field use std::mem::ManuallyDrop; @@ -326,184 +214,6 @@ fn issue9383() { } } -fn closure_test() { - let env = "env".to_owned(); - let arg = "arg".to_owned(); - let f = |arg| { - let loc = "loc".to_owned(); - let _ = std::fs::write("x", &env); // Don't lint. In environment - let _ = std::fs::write("x", &arg); - let _ = std::fs::write("x", &loc); - }; - let _ = std::fs::write("x", &env); // Don't lint. Borrowed by `f` - f(arg); -} - -mod significant_drop { - #[derive(Debug)] - struct X; - - #[derive(Debug)] - struct Y; - - impl Drop for Y { - fn drop(&mut self) {} - } - - fn foo(x: X, y: Y) { - debug(&x); - debug(&y); // Don't lint. Has significant drop - } - - fn debug(_: impl std::fmt::Debug) {} -} - -mod used_exactly_once { - fn foo(x: String) { - use_x(&x); - } - fn use_x(_: impl AsRef) {} -} - -mod used_more_than_once { - fn foo(x: String) { - use_x(&x); - use_x_again(&x); - } - fn use_x(_: impl AsRef) {} - fn use_x_again(_: impl AsRef) {} -} - -// https://github.com/rust-lang/rust-clippy/issues/9111#issuecomment-1277114280 -mod issue_9111 { - struct A; - - impl Extend for A { - fn extend>(&mut self, _: T) { - unimplemented!() - } - } - - impl<'a> Extend<&'a u8> for A { - fn extend>(&mut self, _: T) { - unimplemented!() - } - } - - fn main() { - let mut a = A; - a.extend(&[]); // vs a.extend([]); - } -} - -mod issue_9710 { - fn main() { - let string = String::new(); - for _i in 0..10 { - f(&string); - } - } - - fn f>(_: T) {} -} - -mod issue_9739 { - fn foo(_it: impl IntoIterator) {} - - fn main() { - foo(if std::env::var_os("HI").is_some() { - &[0] - } else { - &[] as &[u32] - }); - } -} - -mod issue_9739_method_variant { - struct S; - - impl S { - fn foo(&self, _it: impl IntoIterator) {} - } - - fn main() { - S.foo(if std::env::var_os("HI").is_some() { - &[0] - } else { - &[] as &[u32] - }); - } -} - -mod issue_9782 { - fn foo>(t: T) { - println!("{}", std::mem::size_of::()); - let _t: &[u8] = t.as_ref(); - } - - fn main() { - let a: [u8; 100] = [0u8; 100]; - - // 100 - foo::<[u8; 100]>(a); - foo(a); - - // 16 - foo::<&[u8]>(&a); - foo(a.as_slice()); - - // 8 - foo::<&[u8; 100]>(&a); - foo(&a); - } -} - -mod issue_9782_type_relative_variant { - struct S; - - impl S { - fn foo>(t: T) { - println!("{}", std::mem::size_of::()); - let _t: &[u8] = t.as_ref(); - } - } - - fn main() { - let a: [u8; 100] = [0u8; 100]; - - S::foo::<&[u8; 100]>(&a); - } -} - -mod issue_9782_method_variant { - struct S; - - impl S { - fn foo>(&self, t: T) { - println!("{}", std::mem::size_of::()); - let _t: &[u8] = t.as_ref(); - } - } - - fn main() { - let a: [u8; 100] = [0u8; 100]; - - S.foo::<&[u8; 100]>(&a); - } -} - -mod issue_10535 { - static SOME_STATIC: String = String::new(); - - static UNIT: () = compute(&SOME_STATIC); - - pub const fn compute(_: T) - where - T: Copy, - { - } -} - mod issue_10253 { struct S; trait X { diff --git a/tests/ui/needless_borrow.stderr b/tests/ui/needless_borrow.stderr index 8e27014d5..e91b78b0a 100644 --- a/tests/ui/needless_borrow.stderr +++ b/tests/ui/needless_borrow.stderr @@ -121,101 +121,17 @@ error: this expression creates a reference which is immediately dereferenced by LL | (&&5).foo(); | ^^^^^ help: change this to: `(&5)` -error: the borrowed expression implements the required traits - --> $DIR/needless_borrow.rs:135:51 - | -LL | let _ = std::process::Command::new("ls").args(&["-a", "-l"]).status().unwrap(); - | ^^^^^^^^^^^^^ help: change this to: `["-a", "-l"]` - -error: the borrowed expression implements the required traits - --> $DIR/needless_borrow.rs:136:44 - | -LL | let _ = std::path::Path::new(".").join(&&"."); - | ^^^^^ help: change this to: `"."` - -error: the borrowed expression implements the required traits - --> $DIR/needless_borrow.rs:137:23 - | -LL | deref_target_is_x(&X); - | ^^ help: change this to: `X` - -error: the borrowed expression implements the required traits - --> $DIR/needless_borrow.rs:138:26 - | -LL | multiple_constraints(&[[""]]); - | ^^^^^^^ help: change this to: `[[""]]` - -error: the borrowed expression implements the required traits - --> $DIR/needless_borrow.rs:139:45 - | -LL | multiple_constraints_normalizes_to_same(&X, X); - | ^^ help: change this to: `X` - -error: this expression creates a reference which is immediately dereferenced by the compiler - --> $DIR/needless_borrow.rs:140:32 - | -LL | let _ = Some("").unwrap_or(&""); - | ^^^ help: change this to: `""` - -error: the borrowed expression implements the required traits - --> $DIR/needless_borrow.rs:141:33 - | -LL | let _ = std::fs::write("x", &"".to_string()); - | ^^^^^^^^^^^^^^^ help: change this to: `"".to_string()` - error: this expression borrows a value the compiler would automatically borrow - --> $DIR/needless_borrow.rs:190:13 + --> $DIR/needless_borrow.rs:175:13 | LL | (&self.f)() | ^^^^^^^^^ help: change this to: `(self.f)` error: this expression borrows a value the compiler would automatically borrow - --> $DIR/needless_borrow.rs:199:13 + --> $DIR/needless_borrow.rs:184:13 | LL | (&mut self.f)() | ^^^^^^^^^^^^^ help: change this to: `(self.f)` -error: the borrowed expression implements the required traits - --> $DIR/needless_borrow.rs:283:20 - | -LL | takes_iter(&mut x) - | ^^^^^^ help: change this to: `x` - -error: the borrowed expression implements the required traits - --> $DIR/needless_borrow.rs:297:55 - | -LL | let _ = std::process::Command::new("ls").args(&["-a", "-l"]).status().unwrap(); - | ^^^^^^^^^^^^^ help: change this to: `["-a", "-l"]` - -error: the borrowed expression implements the required traits - --> $DIR/needless_borrow.rs:335:37 - | -LL | let _ = std::fs::write("x", &arg); - | ^^^^ help: change this to: `arg` - -error: the borrowed expression implements the required traits - --> $DIR/needless_borrow.rs:336:37 - | -LL | let _ = std::fs::write("x", &loc); - | ^^^^ help: change this to: `loc` - -error: the borrowed expression implements the required traits - --> $DIR/needless_borrow.rs:354:15 - | -LL | debug(&x); - | ^^ help: change this to: `x` - -error: the borrowed expression implements the required traits - --> $DIR/needless_borrow.rs:363:15 - | -LL | use_x(&x); - | ^^ help: change this to: `x` - -error: the borrowed expression implements the required traits - --> $DIR/needless_borrow.rs:457:13 - | -LL | foo(&a); - | ^^ help: change this to: `a` - -error: aborting due to 36 previous errors +error: aborting due to 22 previous errors diff --git a/tests/ui/needless_borrows_for_generic_args.fixed b/tests/ui/needless_borrows_for_generic_args.fixed new file mode 100644 index 000000000..2a335516f --- /dev/null +++ b/tests/ui/needless_borrows_for_generic_args.fixed @@ -0,0 +1,287 @@ +#![warn(clippy::needless_borrows_for_generic_args)] +#![allow( + clippy::unnecessary_to_owned, + clippy::unnecessary_literal_unwrap, + clippy::needless_borrow +)] + +use core::ops::Deref; +use std::any::Any; +use std::ffi::OsStr; +use std::fmt::{Debug, Display}; +use std::path::Path; +use std::process::Command; + +fn main() { + let _ = Command::new("ls").args(["-a", "-l"]).status().unwrap(); + let _ = Path::new(".").join("."); + let _ = Any::type_id(&""); // Don't lint. `Any` is only bound + let _ = Box::new(&""); // Don't lint. Type parameter appears in return type + let _ = Some("").unwrap_or(&""); + let _ = std::fs::write("x", "".to_string()); + + { + #[derive(Clone, Copy)] + struct X; + + impl Deref for X { + type Target = X; + fn deref(&self) -> &Self::Target { + self + } + } + + fn deref_target_is_x>(_: T) {} + + deref_target_is_x(X); + } + { + fn multiple_constraints(_: T) + where + T: IntoIterator + IntoIterator, + U: IntoIterator, + V: AsRef, + X: IntoIterator, + Y: AsRef, + { + } + + multiple_constraints([[""]]); + } + { + #[derive(Clone, Copy)] + struct X; + + impl Deref for X { + type Target = X; + fn deref(&self) -> &Self::Target { + self + } + } + + fn multiple_constraints_normalizes_to_same(_: T, _: V) + where + T: Deref, + U: Deref, + { + } + + multiple_constraints_normalizes_to_same(X, X); + } + { + fn only_sized(_: T) {} + only_sized(&""); // Don't lint. `Sized` is only bound + } + { + fn ref_as_ref_path(_: &'static T) + where + &'static T: AsRef, + { + } + + ref_as_ref_path(&""); // Don't lint. Argument type is not a type parameter + } + { + trait RefsOnly { + type Referent; + } + + impl RefsOnly for &T { + type Referent = T; + } + + fn refs_only(_: T) + where + T: RefsOnly, + { + } + + refs_only(&()); // Don't lint. `&T` implements trait, but `T` doesn't + } + { + fn multiple_constraints_normalizes_to_different(_: T, _: U) + where + T: IntoIterator, + U: IntoIterator, + V: AsRef, + { + } + multiple_constraints_normalizes_to_different(&[[""]], &[""]); // Don't lint. Projected type appears in arguments + } + // https://github.com/rust-lang/rust-clippy/pull/9136#pullrequestreview-1037379321 + { + #[derive(Clone, Copy)] + struct Iter; + impl Iterator for Iter { + type Item = (); + fn next(&mut self) -> Option { + None + } + } + fn takes_iter(_: impl Iterator) {} + fn dont_warn(mut x: Iter) { + takes_iter(&mut x); + } + #[allow(unused_mut)] + fn warn(mut x: &mut Iter) { + takes_iter(x) + } + } + #[clippy::msrv = "1.52.0"] + { + let _ = Command::new("ls").args(&["-a", "-l"]).status().unwrap(); + }; + #[clippy::msrv = "1.53.0"] + { + let _ = Command::new("ls").args(["-a", "-l"]).status().unwrap(); + }; + { + let env = "env".to_owned(); + let arg = "arg".to_owned(); + let f = |arg| { + let loc = "loc".to_owned(); + let _ = std::fs::write("x", &env); // Don't lint. In environment + let _ = std::fs::write("x", arg); + let _ = std::fs::write("x", loc); + }; + let _ = std::fs::write("x", &env); // Don't lint. Borrowed by `f` + f(arg); + } + { + #[derive(Debug)] + struct X; + + impl Drop for X { + fn drop(&mut self) {} + } + + fn f(_: impl Debug) {} + + let x = X; + f(&x); // Don't lint. Has significant drop + } + { + fn f(_: impl AsRef) {} + + let x = String::new(); + f(x); + } + { + fn f(_: impl AsRef) {} + fn f2(_: impl AsRef) {} + + let x = String::new(); + f(&x); + f2(&x); + } + // https://github.com/rust-lang/rust-clippy/issues/9111#issuecomment-1277114280 + // issue 9111 + { + struct A; + + impl Extend for A { + fn extend>(&mut self, _: T) { + unimplemented!() + } + } + + impl<'a> Extend<&'a u8> for A { + fn extend>(&mut self, _: T) { + unimplemented!() + } + } + + let mut a = A; + a.extend(&[]); // vs a.extend([]); + } + // issue 9710 + { + fn f(_: impl AsRef) {} + + let x = String::new(); + for _ in 0..10 { + f(&x); + } + } + // issue 9739 + { + fn foo(_it: impl IntoIterator) {} + foo(if std::env::var_os("HI").is_some() { + &[0] + } else { + &[] as &[u32] + }); + } + { + struct S; + + impl S { + fn foo(&self, _it: impl IntoIterator) {} + } + + S.foo(if std::env::var_os("HI").is_some() { + &[0] + } else { + &[] as &[u32] + }); + } + // issue 9782 + { + fn foo>(t: T) { + println!("{}", std::mem::size_of::()); + let _t: &[u8] = t.as_ref(); + } + + let a: [u8; 100] = [0u8; 100]; + + // 100 + foo::<[u8; 100]>(a); + foo(a); + + // 16 + foo::<&[u8]>(&a); + foo(a.as_slice()); + + // 8 + foo::<&[u8; 100]>(&a); + foo(a); + } + { + struct S; + + impl S { + fn foo>(t: T) { + println!("{}", std::mem::size_of::()); + let _t: &[u8] = t.as_ref(); + } + } + + let a: [u8; 100] = [0u8; 100]; + S::foo::<&[u8; 100]>(&a); + } + { + struct S; + + impl S { + fn foo>(&self, t: T) { + println!("{}", std::mem::size_of::()); + let _t: &[u8] = t.as_ref(); + } + } + + let a: [u8; 100] = [0u8; 100]; + S.foo::<&[u8; 100]>(&a); + } + // issue 10535 + { + static SOME_STATIC: String = String::new(); + + static UNIT: () = compute(&SOME_STATIC); + + pub const fn compute(_: T) + where + T: Copy, + { + } + } +} diff --git a/tests/ui/needless_borrows_for_generic_args.rs b/tests/ui/needless_borrows_for_generic_args.rs new file mode 100644 index 000000000..f0567f486 --- /dev/null +++ b/tests/ui/needless_borrows_for_generic_args.rs @@ -0,0 +1,287 @@ +#![warn(clippy::needless_borrows_for_generic_args)] +#![allow( + clippy::unnecessary_to_owned, + clippy::unnecessary_literal_unwrap, + clippy::needless_borrow +)] + +use core::ops::Deref; +use std::any::Any; +use std::ffi::OsStr; +use std::fmt::{Debug, Display}; +use std::path::Path; +use std::process::Command; + +fn main() { + let _ = Command::new("ls").args(&["-a", "-l"]).status().unwrap(); + let _ = Path::new(".").join(&&"."); + let _ = Any::type_id(&""); // Don't lint. `Any` is only bound + let _ = Box::new(&""); // Don't lint. Type parameter appears in return type + let _ = Some("").unwrap_or(&""); + let _ = std::fs::write("x", &"".to_string()); + + { + #[derive(Clone, Copy)] + struct X; + + impl Deref for X { + type Target = X; + fn deref(&self) -> &Self::Target { + self + } + } + + fn deref_target_is_x>(_: T) {} + + deref_target_is_x(&X); + } + { + fn multiple_constraints(_: T) + where + T: IntoIterator + IntoIterator, + U: IntoIterator, + V: AsRef, + X: IntoIterator, + Y: AsRef, + { + } + + multiple_constraints(&[[""]]); + } + { + #[derive(Clone, Copy)] + struct X; + + impl Deref for X { + type Target = X; + fn deref(&self) -> &Self::Target { + self + } + } + + fn multiple_constraints_normalizes_to_same(_: T, _: V) + where + T: Deref, + U: Deref, + { + } + + multiple_constraints_normalizes_to_same(&X, X); + } + { + fn only_sized(_: T) {} + only_sized(&""); // Don't lint. `Sized` is only bound + } + { + fn ref_as_ref_path(_: &'static T) + where + &'static T: AsRef, + { + } + + ref_as_ref_path(&""); // Don't lint. Argument type is not a type parameter + } + { + trait RefsOnly { + type Referent; + } + + impl RefsOnly for &T { + type Referent = T; + } + + fn refs_only(_: T) + where + T: RefsOnly, + { + } + + refs_only(&()); // Don't lint. `&T` implements trait, but `T` doesn't + } + { + fn multiple_constraints_normalizes_to_different(_: T, _: U) + where + T: IntoIterator, + U: IntoIterator, + V: AsRef, + { + } + multiple_constraints_normalizes_to_different(&[[""]], &[""]); // Don't lint. Projected type appears in arguments + } + // https://github.com/rust-lang/rust-clippy/pull/9136#pullrequestreview-1037379321 + { + #[derive(Clone, Copy)] + struct Iter; + impl Iterator for Iter { + type Item = (); + fn next(&mut self) -> Option { + None + } + } + fn takes_iter(_: impl Iterator) {} + fn dont_warn(mut x: Iter) { + takes_iter(&mut x); + } + #[allow(unused_mut)] + fn warn(mut x: &mut Iter) { + takes_iter(&mut x) + } + } + #[clippy::msrv = "1.52.0"] + { + let _ = Command::new("ls").args(&["-a", "-l"]).status().unwrap(); + }; + #[clippy::msrv = "1.53.0"] + { + let _ = Command::new("ls").args(&["-a", "-l"]).status().unwrap(); + }; + { + let env = "env".to_owned(); + let arg = "arg".to_owned(); + let f = |arg| { + let loc = "loc".to_owned(); + let _ = std::fs::write("x", &env); // Don't lint. In environment + let _ = std::fs::write("x", &arg); + let _ = std::fs::write("x", &loc); + }; + let _ = std::fs::write("x", &env); // Don't lint. Borrowed by `f` + f(arg); + } + { + #[derive(Debug)] + struct X; + + impl Drop for X { + fn drop(&mut self) {} + } + + fn f(_: impl Debug) {} + + let x = X; + f(&x); // Don't lint. Has significant drop + } + { + fn f(_: impl AsRef) {} + + let x = String::new(); + f(&x); + } + { + fn f(_: impl AsRef) {} + fn f2(_: impl AsRef) {} + + let x = String::new(); + f(&x); + f2(&x); + } + // https://github.com/rust-lang/rust-clippy/issues/9111#issuecomment-1277114280 + // issue 9111 + { + struct A; + + impl Extend for A { + fn extend>(&mut self, _: T) { + unimplemented!() + } + } + + impl<'a> Extend<&'a u8> for A { + fn extend>(&mut self, _: T) { + unimplemented!() + } + } + + let mut a = A; + a.extend(&[]); // vs a.extend([]); + } + // issue 9710 + { + fn f(_: impl AsRef) {} + + let x = String::new(); + for _ in 0..10 { + f(&x); + } + } + // issue 9739 + { + fn foo(_it: impl IntoIterator) {} + foo(if std::env::var_os("HI").is_some() { + &[0] + } else { + &[] as &[u32] + }); + } + { + struct S; + + impl S { + fn foo(&self, _it: impl IntoIterator) {} + } + + S.foo(if std::env::var_os("HI").is_some() { + &[0] + } else { + &[] as &[u32] + }); + } + // issue 9782 + { + fn foo>(t: T) { + println!("{}", std::mem::size_of::()); + let _t: &[u8] = t.as_ref(); + } + + let a: [u8; 100] = [0u8; 100]; + + // 100 + foo::<[u8; 100]>(a); + foo(a); + + // 16 + foo::<&[u8]>(&a); + foo(a.as_slice()); + + // 8 + foo::<&[u8; 100]>(&a); + foo(&a); + } + { + struct S; + + impl S { + fn foo>(t: T) { + println!("{}", std::mem::size_of::()); + let _t: &[u8] = t.as_ref(); + } + } + + let a: [u8; 100] = [0u8; 100]; + S::foo::<&[u8; 100]>(&a); + } + { + struct S; + + impl S { + fn foo>(&self, t: T) { + println!("{}", std::mem::size_of::()); + let _t: &[u8] = t.as_ref(); + } + } + + let a: [u8; 100] = [0u8; 100]; + S.foo::<&[u8; 100]>(&a); + } + // issue 10535 + { + static SOME_STATIC: String = String::new(); + + static UNIT: () = compute(&SOME_STATIC); + + pub const fn compute(_: T) + where + T: Copy, + { + } + } +} diff --git a/tests/ui/needless_borrows_for_generic_args.stderr b/tests/ui/needless_borrows_for_generic_args.stderr new file mode 100644 index 000000000..e2cde2c59 --- /dev/null +++ b/tests/ui/needless_borrows_for_generic_args.stderr @@ -0,0 +1,77 @@ +error: the borrowed expression implements the required traits + --> $DIR/needless_borrows_for_generic_args.rs:16:37 + | +LL | let _ = Command::new("ls").args(&["-a", "-l"]).status().unwrap(); + | ^^^^^^^^^^^^^ help: change this to: `["-a", "-l"]` + | + = note: `-D clippy::needless-borrows-for-generic-args` implied by `-D warnings` + = help: to override `-D warnings` add `#[allow(clippy::needless_borrows_for_generic_args)]` + +error: the borrowed expression implements the required traits + --> $DIR/needless_borrows_for_generic_args.rs:17:33 + | +LL | let _ = Path::new(".").join(&&"."); + | ^^^^^ help: change this to: `"."` + +error: the borrowed expression implements the required traits + --> $DIR/needless_borrows_for_generic_args.rs:21:33 + | +LL | let _ = std::fs::write("x", &"".to_string()); + | ^^^^^^^^^^^^^^^ help: change this to: `"".to_string()` + +error: the borrowed expression implements the required traits + --> $DIR/needless_borrows_for_generic_args.rs:36:27 + | +LL | deref_target_is_x(&X); + | ^^ help: change this to: `X` + +error: the borrowed expression implements the required traits + --> $DIR/needless_borrows_for_generic_args.rs:49:30 + | +LL | multiple_constraints(&[[""]]); + | ^^^^^^^ help: change this to: `[[""]]` + +error: the borrowed expression implements the required traits + --> $DIR/needless_borrows_for_generic_args.rs:69:49 + | +LL | multiple_constraints_normalizes_to_same(&X, X); + | ^^ help: change this to: `X` + +error: the borrowed expression implements the required traits + --> $DIR/needless_borrows_for_generic_args.rs:127:24 + | +LL | takes_iter(&mut x) + | ^^^^^^ help: change this to: `x` + +error: the borrowed expression implements the required traits + --> $DIR/needless_borrows_for_generic_args.rs:136:41 + | +LL | let _ = Command::new("ls").args(&["-a", "-l"]).status().unwrap(); + | ^^^^^^^^^^^^^ help: change this to: `["-a", "-l"]` + +error: the borrowed expression implements the required traits + --> $DIR/needless_borrows_for_generic_args.rs:144:41 + | +LL | let _ = std::fs::write("x", &arg); + | ^^^^ help: change this to: `arg` + +error: the borrowed expression implements the required traits + --> $DIR/needless_borrows_for_generic_args.rs:145:41 + | +LL | let _ = std::fs::write("x", &loc); + | ^^^^ help: change this to: `loc` + +error: the borrowed expression implements the required traits + --> $DIR/needless_borrows_for_generic_args.rs:167:11 + | +LL | f(&x); + | ^^ help: change this to: `x` + +error: the borrowed expression implements the required traits + --> $DIR/needless_borrows_for_generic_args.rs:247:13 + | +LL | foo(&a); + | ^^ help: change this to: `a` + +error: aborting due to 12 previous errors + diff --git a/tests/ui/regex.rs b/tests/ui/regex.rs index 5259d9ce0..094d9574a 100644 --- a/tests/ui/regex.rs +++ b/tests/ui/regex.rs @@ -2,7 +2,8 @@ unused, clippy::needless_raw_strings, clippy::needless_raw_string_hashes, - clippy::needless_borrow + clippy::needless_borrow, + clippy::needless_borrows_for_generic_args )] #![warn(clippy::invalid_regex, clippy::trivial_regex)] diff --git a/tests/ui/regex.stderr b/tests/ui/regex.stderr index 91f90157e..6d98d691d 100644 --- a/tests/ui/regex.stderr +++ b/tests/ui/regex.stderr @@ -1,5 +1,5 @@ error: trivial regex - --> $DIR/regex.rs:18:45 + --> $DIR/regex.rs:19:45 | LL | let pipe_in_wrong_position = Regex::new("|"); | ^^^ @@ -9,7 +9,7 @@ LL | let pipe_in_wrong_position = Regex::new("|"); = help: to override `-D warnings` add `#[allow(clippy::trivial_regex)]` error: trivial regex - --> $DIR/regex.rs:20:60 + --> $DIR/regex.rs:21:60 | LL | let pipe_in_wrong_position_builder = RegexBuilder::new("|"); | ^^^ @@ -17,7 +17,7 @@ LL | let pipe_in_wrong_position_builder = RegexBuilder::new("|"); = help: the regex is unlikely to be useful as it is error: regex syntax error: invalid character class range, the start must be <= the end - --> $DIR/regex.rs:22:42 + --> $DIR/regex.rs:23:42 | LL | let wrong_char_ranice = Regex::new("[z-a]"); | ^^^ @@ -26,7 +26,7 @@ LL | let wrong_char_ranice = Regex::new("[z-a]"); = help: to override `-D warnings` add `#[allow(clippy::invalid_regex)]` error: regex syntax error: invalid character class range, the start must be <= the end - --> $DIR/regex.rs:25:37 + --> $DIR/regex.rs:26:37 | LL | let some_unicode = Regex::new("[é-è]"); | ^^^ @@ -35,13 +35,13 @@ error: regex parse error: ( ^ error: unclosed group - --> $DIR/regex.rs:28:33 + --> $DIR/regex.rs:29:33 | LL | let some_regex = Regex::new(OPENING_PAREN); | ^^^^^^^^^^^^^ error: trivial regex - --> $DIR/regex.rs:30:53 + --> $DIR/regex.rs:31:53 | LL | let binary_pipe_in_wrong_position = BRegex::new("|"); | ^^^ @@ -52,7 +52,7 @@ error: regex parse error: ( ^ error: unclosed group - --> $DIR/regex.rs:32:41 + --> $DIR/regex.rs:33:41 | LL | let some_binary_regex = BRegex::new(OPENING_PAREN); | ^^^^^^^^^^^^^ @@ -61,7 +61,7 @@ error: regex parse error: ( ^ error: unclosed group - --> $DIR/regex.rs:33:56 + --> $DIR/regex.rs:34:56 | LL | let some_binary_regex_builder = BRegexBuilder::new(OPENING_PAREN); | ^^^^^^^^^^^^^ @@ -70,7 +70,7 @@ error: regex parse error: ( ^ error: unclosed group - --> $DIR/regex.rs:45:37 + --> $DIR/regex.rs:46:37 | LL | let set_error = RegexSet::new(&[OPENING_PAREN, r"[a-z]+\.(com|org|net)"]); | ^^^^^^^^^^^^^ @@ -79,7 +79,7 @@ error: regex parse error: ( ^ error: unclosed group - --> $DIR/regex.rs:46:39 + --> $DIR/regex.rs:47:39 | LL | let bset_error = BRegexSet::new(&[OPENING_PAREN, r"[a-z]+\.(com|org|net)"]); | ^^^^^^^^^^^^^ @@ -88,7 +88,7 @@ error: regex parse error: \b\c ^^ error: unrecognized escape sequence - --> $DIR/regex.rs:53:42 + --> $DIR/regex.rs:54:42 | LL | let escaped_string_span = Regex::new("\\b\\c"); | ^^^^^^^^ @@ -96,19 +96,19 @@ LL | let escaped_string_span = Regex::new("\\b\\c"); = help: consider using a raw string literal: `r".."` error: regex syntax error: duplicate flag - --> $DIR/regex.rs:55:34 + --> $DIR/regex.rs:56:34 | LL | let aux_span = Regex::new("(?ixi)"); | ^ ^ error: regex syntax error: pattern can match invalid UTF-8 - --> $DIR/regex.rs:61:53 + --> $DIR/regex.rs:62:53 | LL | let invalid_utf8_should_lint = Regex::new("(?-u)."); | ^ error: trivial regex - --> $DIR/regex.rs:66:33 + --> $DIR/regex.rs:67:33 | LL | let trivial_eq = Regex::new("^foobar$"); | ^^^^^^^^^^ @@ -116,7 +116,7 @@ LL | let trivial_eq = Regex::new("^foobar$"); = help: consider using `==` on `str`s error: trivial regex - --> $DIR/regex.rs:69:48 + --> $DIR/regex.rs:70:48 | LL | let trivial_eq_builder = RegexBuilder::new("^foobar$"); | ^^^^^^^^^^ @@ -124,7 +124,7 @@ LL | let trivial_eq_builder = RegexBuilder::new("^foobar$"); = help: consider using `==` on `str`s error: trivial regex - --> $DIR/regex.rs:72:42 + --> $DIR/regex.rs:73:42 | LL | let trivial_starts_with = Regex::new("^foobar"); | ^^^^^^^^^ @@ -132,7 +132,7 @@ LL | let trivial_starts_with = Regex::new("^foobar"); = help: consider using `str::starts_with` error: trivial regex - --> $DIR/regex.rs:75:40 + --> $DIR/regex.rs:76:40 | LL | let trivial_ends_with = Regex::new("foobar$"); | ^^^^^^^^^ @@ -140,7 +140,7 @@ LL | let trivial_ends_with = Regex::new("foobar$"); = help: consider using `str::ends_with` error: trivial regex - --> $DIR/regex.rs:78:39 + --> $DIR/regex.rs:79:39 | LL | let trivial_contains = Regex::new("foobar"); | ^^^^^^^^ @@ -148,7 +148,7 @@ LL | let trivial_contains = Regex::new("foobar"); = help: consider using `str::contains` error: trivial regex - --> $DIR/regex.rs:81:39 + --> $DIR/regex.rs:82:39 | LL | let trivial_contains = Regex::new(NOT_A_REAL_REGEX); | ^^^^^^^^^^^^^^^^ @@ -156,7 +156,7 @@ LL | let trivial_contains = Regex::new(NOT_A_REAL_REGEX); = help: consider using `str::contains` error: trivial regex - --> $DIR/regex.rs:84:40 + --> $DIR/regex.rs:85:40 | LL | let trivial_backslash = Regex::new("a\\.b"); | ^^^^^^^ @@ -164,7 +164,7 @@ LL | let trivial_backslash = Regex::new("a\\.b"); = help: consider using `str::contains` error: trivial regex - --> $DIR/regex.rs:88:36 + --> $DIR/regex.rs:89:36 | LL | let trivial_empty = Regex::new(""); | ^^ @@ -172,7 +172,7 @@ LL | let trivial_empty = Regex::new(""); = help: the regex is unlikely to be useful as it is error: trivial regex - --> $DIR/regex.rs:91:36 + --> $DIR/regex.rs:92:36 | LL | let trivial_empty = Regex::new("^"); | ^^^ @@ -180,7 +180,7 @@ LL | let trivial_empty = Regex::new("^"); = help: the regex is unlikely to be useful as it is error: trivial regex - --> $DIR/regex.rs:94:36 + --> $DIR/regex.rs:95:36 | LL | let trivial_empty = Regex::new("^$"); | ^^^^ @@ -188,7 +188,7 @@ LL | let trivial_empty = Regex::new("^$"); = help: consider using `str::is_empty` error: trivial regex - --> $DIR/regex.rs:97:44 + --> $DIR/regex.rs:98:44 | LL | let binary_trivial_empty = BRegex::new("^$"); | ^^^^ diff --git a/tests/ui/unnecessary_to_owned.fixed b/tests/ui/unnecessary_to_owned.fixed index 7b662ca92..67faabc53 100644 --- a/tests/ui/unnecessary_to_owned.fixed +++ b/tests/ui/unnecessary_to_owned.fixed @@ -1,4 +1,4 @@ -#![allow(clippy::needless_borrow, clippy::ptr_arg)] +#![allow(clippy::needless_borrow, clippy::needless_borrows_for_generic_args, clippy::ptr_arg)] #![warn(clippy::unnecessary_to_owned, clippy::redundant_clone)] use std::borrow::Cow; diff --git a/tests/ui/unnecessary_to_owned.rs b/tests/ui/unnecessary_to_owned.rs index d79778a6a..99f913642 100644 --- a/tests/ui/unnecessary_to_owned.rs +++ b/tests/ui/unnecessary_to_owned.rs @@ -1,4 +1,4 @@ -#![allow(clippy::needless_borrow, clippy::ptr_arg)] +#![allow(clippy::needless_borrow, clippy::needless_borrows_for_generic_args, clippy::ptr_arg)] #![warn(clippy::unnecessary_to_owned, clippy::redundant_clone)] use std::borrow::Cow;