diff options
Diffstat (limited to 'clippy_lints/src/dereference.rs')
| -rw-r--r-- | clippy_lints/src/dereference.rs | 45 |
1 files changed, 28 insertions, 17 deletions
diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs index 0e7efd53390..8a9d978a106 100644 --- a/clippy_lints/src/dereference.rs +++ b/clippy_lints/src/dereference.rs @@ -12,12 +12,11 @@ use rustc_ast::util::parser::{PREC_POSTFIX, PREC_PREFIX}; use rustc_data_structures::fx::FxIndexMap; use rustc_data_structures::graph::iterate::{CycleDetector, TriColorDepthFirstSearch}; use rustc_errors::Applicability; +use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::intravisit::{walk_ty, Visitor}; use rustc_hir::{ - self as hir, - def_id::{DefId, LocalDefId}, - BindingAnnotation, Body, BodyId, BorrowKind, Closure, Expr, ExprKind, FnRetTy, GenericArg, HirId, ImplItem, - ImplItemKind, Item, ItemKind, Local, MatchSource, Mutability, Node, Pat, PatKind, Path, QPath, TraitItem, + self as hir, BindingAnnotation, Body, BodyId, BorrowKind, Closure, Expr, ExprKind, FnRetTy, GenericArg, HirId, + ImplItem, ImplItemKind, Item, ItemKind, Local, MatchSource, Mutability, Node, Pat, PatKind, Path, QPath, TraitItem, TraitItemKind, TyKind, UnOp, }; use rustc_index::bit_set::BitSet; @@ -30,9 +29,11 @@ use rustc_middle::ty::{ ProjectionPredicate, Ty, TyCtxt, TypeVisitableExt, TypeckResults, }; use rustc_session::{declare_tool_lint, impl_lint_pass}; -use rustc_span::{symbol::sym, Span, Symbol}; +use rustc_span::symbol::sym; +use rustc_span::{Span, Symbol}; use rustc_trait_selection::infer::InferCtxtExt as _; -use rustc_trait_selection::traits::{query::evaluate_obligation::InferCtxtExt as _, Obligation, ObligationCause}; +use rustc_trait_selection::traits::query::evaluate_obligation::InferCtxtExt as _; +use rustc_trait_selection::traits::{Obligation, ObligationCause}; use std::collections::VecDeque; declare_clippy_lint! { @@ -77,6 +78,11 @@ declare_clippy_lint! { /// 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 fun(_a: &i32) {} @@ -589,7 +595,7 @@ impl<'tcx> LateLintPass<'tcx> for Dereferencing<'tcx> { pat.spans, "this pattern creates a reference to a reference", |diag| { - diag.multipart_suggestion("try this", replacements, app); + diag.multipart_suggestion("try", replacements, app); }, ); } @@ -1123,7 +1129,9 @@ fn needless_borrow_impl_arg_position<'tcx>( let destruct_trait_def_id = cx.tcx.lang_items().destruct_trait(); let sized_trait_def_id = cx.tcx.lang_items().sized_trait(); - let Some(callee_def_id) = fn_def_id(cx, parent) else { return Position::Other(precedence) }; + let Some(callee_def_id) = fn_def_id(cx, parent) else { + return Position::Other(precedence); + }; let fn_sig = cx.tcx.fn_sig(callee_def_id).instantiate_identity().skip_binder(); let args_with_expr_ty = cx .typeck_results() @@ -1252,7 +1260,12 @@ fn has_ref_mut_self_method(cx: &LateContext<'_>, trait_def_id: DefId) -> bool { .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]; + 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 @@ -1296,8 +1309,8 @@ fn referent_used_exactly_once<'tcx>( possible_borrowers: &mut Vec<(LocalDefId, PossibleBorrowerMap<'tcx, 'tcx>)>, reference: &Expr<'tcx>, ) -> bool { - let mir = enclosing_mir(cx.tcx, reference.hir_id); - if let Some(local) = expr_local(cx.tcx, reference) + 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 @@ -1442,9 +1455,7 @@ fn ty_auto_deref_stability<'tcx>( ty::Adt(..) if ty.has_placeholders() || ty.has_opaque_types() => { Position::ReborrowStable(precedence).into() }, - ty::Adt(_, args) if args.has_non_region_param() => { - TyPosition::new_deref_stable_for_result(precedence, ty) - }, + ty::Adt(_, args) if args.has_non_region_param() => TyPosition::new_deref_stable_for_result(precedence, ty), ty::Bool | ty::Char | ty::Int(_) @@ -1531,7 +1542,7 @@ fn report<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, state: State, data Mutability::Not => "explicit `deref` method call", Mutability::Mut => "explicit `deref_mut` method call", }, - "try this", + "try", format!("{addr_of_str}{deref_str}{expr_str}"), app, ); @@ -1593,7 +1604,7 @@ fn report<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, state: State, data } else { format!("{prefix}{snip}") }; - diag.span_suggestion(data.span, "try this", sugg, app); + diag.span_suggestion(data.span, "try", sugg, app); }, ); }, @@ -1620,7 +1631,7 @@ fn report<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, state: State, data |diag| { let mut app = Applicability::MachineApplicable; let snip = snippet_with_context(cx, expr.span, data.span.ctxt(), "..", &mut app).0; - diag.span_suggestion(data.span, "try this", snip.into_owned(), app); + diag.span_suggestion(data.span, "try", snip.into_owned(), app); }, ); }, |