diff options
| -rw-r--r-- | clippy_lints/src/unwrap.rs | 51 |
1 files changed, 22 insertions, 29 deletions
diff --git a/clippy_lints/src/unwrap.rs b/clippy_lints/src/unwrap.rs index f152d62bf49..a6a91876346 100644 --- a/clippy_lints/src/unwrap.rs +++ b/clippy_lints/src/unwrap.rs @@ -4,15 +4,15 @@ use clippy_utils::usage::is_potentially_local_place; use clippy_utils::{higher, path_to_local, sym}; use rustc_errors::Applicability; use rustc_hir::intravisit::{FnKind, Visitor, walk_expr, walk_fn}; -use rustc_hir::{BinOpKind, Body, Expr, ExprKind, FnDecl, HirId, Node, PathSegment, UnOp}; +use rustc_hir::{BinOpKind, Body, Expr, ExprKind, FnDecl, HirId, Node, UnOp}; use rustc_hir_typeck::expr_use_visitor::{Delegate, ExprUseVisitor, PlaceWithHirId}; use rustc_lint::{LateContext, LateLintPass}; use rustc_middle::hir::nested_filter; use rustc_middle::mir::FakeReadCause; use rustc_middle::ty::{self, Ty, TyCtxt}; use rustc_session::declare_lint_pass; -use rustc_span::Span; use rustc_span::def_id::LocalDefId; +use rustc_span::{Span, Symbol}; declare_clippy_lint! { /// ### What it does @@ -111,7 +111,7 @@ struct UnwrapInfo<'tcx> { /// The check, like `x.is_ok()` check: &'tcx Expr<'tcx>, /// The check's name, like `is_ok` - check_name: &'tcx PathSegment<'tcx>, + check_name: Symbol, /// The branch where the check takes place, like `if x.is_ok() { .. }` branch: &'tcx Expr<'tcx>, /// Whether `is_some()` or `is_ok()` was called (as opposed to `is_err()` or `is_none()`). @@ -133,12 +133,12 @@ fn collect_unwrap_info<'tcx>( invert: bool, is_entire_condition: bool, ) -> Vec<UnwrapInfo<'tcx>> { - fn is_relevant_option_call(cx: &LateContext<'_>, ty: Ty<'_>, method_name: &str) -> bool { - is_type_diagnostic_item(cx, ty, sym::Option) && ["is_some", "is_none"].contains(&method_name) + fn is_relevant_option_call(cx: &LateContext<'_>, ty: Ty<'_>, method_name: Symbol) -> bool { + is_type_diagnostic_item(cx, ty, sym::Option) && matches!(method_name, sym::is_none | sym::is_some) } - fn is_relevant_result_call(cx: &LateContext<'_>, ty: Ty<'_>, method_name: &str) -> bool { - is_type_diagnostic_item(cx, ty, sym::Result) && ["is_ok", "is_err"].contains(&method_name) + fn is_relevant_result_call(cx: &LateContext<'_>, ty: Ty<'_>, method_name: Symbol) -> bool { + is_type_diagnostic_item(cx, ty, sym::Result) && matches!(method_name, sym::is_err | sym::is_ok) } if let ExprKind::Binary(op, left, right) = &expr.kind { @@ -155,14 +155,10 @@ fn collect_unwrap_info<'tcx>( } else if let ExprKind::MethodCall(method_name, receiver, [], _) = &expr.kind && let Some(local_id) = path_to_local(receiver) && let ty = cx.typeck_results().expr_ty(receiver) - && let name = method_name.ident.as_str() + && let name = method_name.ident.name && (is_relevant_option_call(cx, ty, name) || is_relevant_result_call(cx, ty, name)) { - let unwrappable = match name { - "is_some" | "is_ok" => true, - "is_err" | "is_none" => false, - _ => unreachable!(), - }; + let unwrappable = matches!(name, sym::is_some | sym::is_ok); let safe_to_unwrap = unwrappable != invert; let kind = if is_type_diagnostic_item(cx, ty, sym::Option) { UnwrappableKind::Option @@ -174,7 +170,7 @@ fn collect_unwrap_info<'tcx>( local_id, if_expr, check: expr, - check_name: method_name, + check_name: name, branch, safe_to_unwrap, kind, @@ -184,12 +180,12 @@ fn collect_unwrap_info<'tcx>( Vec::new() } -/// A HIR visitor delegate that checks if a local variable of type `Option<_>` is mutated, -/// *except* for if `Option::as_mut` is called. +/// A HIR visitor delegate that checks if a local variable of type `Option` or `Result` is mutated, +/// *except* for if `.as_mut()` is called. /// The reason for why we allow that one specifically is that `.as_mut()` cannot change -/// the option to `None`, and that is important because this lint relies on the fact that +/// the variant, and that is important because this lint relies on the fact that /// `is_some` + `unwrap` is equivalent to `if let Some(..) = ..`, which it would not be if -/// the option is changed to None between `is_some` and `unwrap`. +/// the option is changed to None between `is_some` and `unwrap`, ditto for `Result`. /// (And also `.as_mut()` is a somewhat common method that is still worth linting on.) struct MutationVisitor<'tcx> { is_mutated: bool, @@ -198,13 +194,13 @@ struct MutationVisitor<'tcx> { } /// Checks if the parent of the expression pointed at by the given `HirId` is a call to -/// `Option::as_mut`. +/// `.as_mut()`. /// /// Used by the mutation visitor to specifically allow `.as_mut()` calls. /// In particular, the `HirId` that the visitor receives is the id of the local expression /// (i.e. the `x` in `x.as_mut()`), and that is the reason for why we care about its parent /// expression: that will be where the actual method call is. -fn is_option_as_mut_use(tcx: TyCtxt<'_>, expr_id: HirId) -> bool { +fn is_as_mut_use(tcx: TyCtxt<'_>, expr_id: HirId) -> bool { if let Node::Expr(mutating_expr) = tcx.parent_hir_node(expr_id) && let ExprKind::MethodCall(path, _, [], _) = mutating_expr.kind { @@ -218,7 +214,7 @@ impl<'tcx> Delegate<'tcx> for MutationVisitor<'tcx> { fn borrow(&mut self, cat: &PlaceWithHirId<'tcx>, diag_expr_id: HirId, bk: ty::BorrowKind) { if let ty::BorrowKind::Mutable = bk && is_potentially_local_place(self.local_id, &cat.place) - && !is_option_as_mut_use(self.tcx, diag_expr_id) + && !is_as_mut_use(self.tcx, diag_expr_id) { self.is_mutated = true; } @@ -278,12 +274,10 @@ enum AsRefKind { /// If it isn't, the expression itself is returned. fn consume_option_as_ref<'tcx>(expr: &'tcx Expr<'tcx>) -> (&'tcx Expr<'tcx>, Option<AsRefKind>) { if let ExprKind::MethodCall(path, recv, [], _) = expr.kind { - if path.ident.name == sym::as_ref { - (recv, Some(AsRefKind::AsRef)) - } else if path.ident.name == sym::as_mut { - (recv, Some(AsRefKind::AsMut)) - } else { - (expr, None) + match path.ident.name { + sym::as_ref => (recv, Some(AsRefKind::AsRef)), + sym::as_mut => (recv, Some(AsRefKind::AsMut)), + _ => (expr, None), } } else { (expr, None) @@ -334,8 +328,7 @@ impl<'tcx> Visitor<'tcx> for UnwrappableVariablesVisitor<'_, 'tcx> { expr.span, format!( "called `{}` on `{unwrappable_variable_name}` after checking its variant with `{}`", - method_name.ident.name, - unwrappable.check_name.ident.as_str(), + method_name.ident.name, unwrappable.check_name, ), |diag| { if is_entire_condition { |