diff --git a/clippy_lints/src/indexing_slicing.rs b/clippy_lints/src/indexing_slicing.rs index 43797215ca5..7dee30547a0 100644 --- a/clippy_lints/src/indexing_slicing.rs +++ b/clippy_lints/src/indexing_slicing.rs @@ -3,12 +3,13 @@ use clippy_utils::consts::{constant, Constant}; use clippy_utils::diagnostics::{span_lint, span_lint_and_then}; use clippy_utils::higher; -use clippy_utils::ty::{adt_has_inherent_method, deref_chain}; +use clippy_utils::ty::{deref_chain, get_adt_inherent_method}; use rustc_ast::ast::RangeLimits; use rustc_hir::{Expr, ExprKind}; use rustc_lint::{LateContext, LateLintPass}; -use rustc_middle::ty; +use rustc_middle::ty::{self, Ty}; use rustc_session::impl_lint_pass; +use rustc_span::sym; declare_clippy_lint! { /// ### What it does @@ -111,7 +112,7 @@ fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) { && deref.any(|l| { l.peel_refs().is_slice() || l.peel_refs().is_array() - || adt_has_inherent_method(cx, l.peel_refs(), sym!(get)) + || ty_has_appliciable_get_function(cx, l.peel_refs(), expr_ty, expr) }) { let note = "the suggestion might not be applicable in constant blocks"; @@ -240,3 +241,36 @@ fn to_const_range(cx: &LateContext<'_>, range: higher::Range<'_>, array_size: u1 (start, end) } + +/// Checks if the output Ty of the `get` method on this Ty (if any) matches the Ty returned by the +/// indexing operation (if any). +fn ty_has_appliciable_get_function<'tcx>( + cx: &LateContext<'tcx>, + ty: Ty<'tcx>, + array_ty: Ty<'tcx>, + index_expr: &Expr<'_>, +) -> bool { + if let ty::Adt(_, array_args) = array_ty.kind() + && let Some(get_output_ty) = get_adt_inherent_method(cx, ty, sym!(get)).map(|m| { + cx.tcx + .fn_sig(m.def_id) + .instantiate(cx.tcx, array_args) + .output() + .skip_binder() + }) + && let ty::Adt(def, args) = get_output_ty.kind() + && cx.tcx.is_diagnostic_item(sym::Option, def.0.did) + && let Some(option_generic_param) = args.get(0) + && let generic_ty = option_generic_param.expect_ty().peel_refs() + && let _ = println!( + "{}, {}", + cx.typeck_results().expr_ty(index_expr).peel_refs(), + generic_ty.peel_refs() + ) + && cx.typeck_results().expr_ty(index_expr).peel_refs() == generic_ty.peel_refs() + { + true + } else { + false + } +} diff --git a/clippy_lints/src/iter_without_into_iter.rs b/clippy_lints/src/iter_without_into_iter.rs index 02fefd1b6a1..6b03f2597b0 100644 --- a/clippy_lints/src/iter_without_into_iter.rs +++ b/clippy_lints/src/iter_without_into_iter.rs @@ -1,7 +1,7 @@ use clippy_utils::diagnostics::span_lint_and_then; use clippy_utils::get_parent_as_impl; use clippy_utils::source::snippet; -use clippy_utils::ty::{adt_has_inherent_method, deref_chain, implements_trait, make_normalized_projection}; +use clippy_utils::ty::{deref_chain, get_adt_inherent_method, implements_trait, make_normalized_projection}; use rustc_ast::Mutability; use rustc_errors::Applicability; use rustc_hir::{FnRetTy, ImplItemKind, ImplicitSelfKind, ItemKind, TyKind}; @@ -139,7 +139,7 @@ fn check_item(&mut self, cx: &LateContext<'_>, item: &rustc_hir::Item<'_>) { } && !deref_chain(cx, ty).any(|ty| { // We can't check inherent impls for slices, but we know that they have an `iter(_mut)` method - ty.peel_refs().is_slice() || adt_has_inherent_method(cx, ty, expected_method_name) + ty.peel_refs().is_slice() || get_adt_inherent_method(cx, ty, expected_method_name).is_some() }) && let Some(iter_assoc_span) = imp.items.iter().find_map(|item| { if item.ident.name == sym!(IntoIter) { diff --git a/clippy_utils/src/ty.rs b/clippy_utils/src/ty.rs index 7dda01102c2..90360e85d8d 100644 --- a/clippy_utils/src/ty.rs +++ b/clippy_utils/src/ty.rs @@ -17,9 +17,9 @@ use rustc_middle::traits::EvaluationResult; use rustc_middle::ty::layout::ValidityRequirement; use rustc_middle::ty::{ - self, AdtDef, AliasTy, AssocKind, Binder, BoundRegion, FnSig, GenericArg, GenericArgKind, GenericArgsRef, - GenericParamDefKind, IntTy, ParamEnv, Region, RegionKind, TraitRef, Ty, TyCtxt, TypeSuperVisitable, TypeVisitable, - TypeVisitableExt, TypeVisitor, UintTy, Upcast, VariantDef, VariantDiscr, + self, AdtDef, AliasTy, AssocItem, AssocKind, Binder, BoundRegion, FnSig, GenericArg, GenericArgKind, + GenericArgsRef, GenericParamDefKind, IntTy, List, ParamEnv, Region, RegionKind, ToPredicate, TraitRef, Ty, TyCtxt, + TypeSuperVisitable, TypeVisitable, TypeVisitableExt, TypeVisitor, UintTy, VariantDef, VariantDiscr, }; use rustc_span::symbol::Ident; use rustc_span::{sym, Span, Symbol, DUMMY_SP}; @@ -1345,16 +1345,22 @@ pub fn deref_chain<'cx, 'tcx>(cx: &'cx LateContext<'tcx>, ty: Ty<'tcx>) -> impl /// Checks if a Ty<'_> has some inherent method Symbol. /// This does not look for impls in the type's `Deref::Target` type. /// If you need this, you should wrap this call in `clippy_utils::ty::deref_chain().any(...)`. -pub fn adt_has_inherent_method(cx: &LateContext<'_>, ty: Ty<'_>, method_name: Symbol) -> bool { +pub fn get_adt_inherent_method<'a>(cx: &'a LateContext<'_>, ty: Ty<'_>, method_name: Symbol) -> Option<&'a AssocItem> { if let Some(ty_did) = ty.ty_adt_def().map(ty::AdtDef::did) { - cx.tcx.inherent_impls(ty_did).into_iter().flatten().any(|&did| { - cx.tcx - .associated_items(did) - .filter_by_name_unhygienic(method_name) - .next() - .is_some_and(|item| item.kind == ty::AssocKind::Fn) - }) + cx.tcx + .inherent_impls(ty_did) + .into_iter() + .flatten() + .map(|&did| { + cx.tcx + .associated_items(did) + .filter_by_name_unhygienic(method_name) + .next() + .filter(|item| item.kind == ty::AssocKind::Fn) + }) + .next() + .flatten() } else { - false + None } } diff --git a/tests/ui/indexing_slicing_slice.rs b/tests/ui/indexing_slicing_slice.rs index 721ba8facec..87a914db6fd 100644 --- a/tests/ui/indexing_slicing_slice.rs +++ b/tests/ui/indexing_slicing_slice.rs @@ -2,7 +2,13 @@ // We also check the out_of_bounds_indexing lint here, because it lints similar things and // we want to avoid false positives. #![warn(clippy::out_of_bounds_indexing)] -#![allow(clippy::no_effect, clippy::unnecessary_operation, clippy::useless_vec)] +#![allow( + clippy::no_effect, + clippy::unnecessary_operation, + clippy::useless_vec, + unused_must_use, + unused +)] #![warn(clippy::indexing_slicing)] use std::ops::Index; @@ -19,6 +25,28 @@ fn index(&self, index: bool) -> &T { } } +struct BoolMapWithGet { + false_value: T, + true_value: T, +} + +impl Index for BoolMapWithGet { + type Output = T; + fn index(&self, index: bool) -> &Self::Output { + if index { &self.true_value } else { &self.false_value } + } +} + +impl BoolMapWithGet { + fn get(&self, index: bool) -> Option<&T> { + if index { + Some(&self.true_value) + } else { + Some(&self.false_value) + } + } +} + fn main() { let x = [1, 2, 3, 4]; let index: usize = 1; @@ -73,4 +101,12 @@ fn main() { }; map[true]; // Ok, because `get` does not exist (custom indexing) + + let map_with_get = BoolMapWithGet { + false_value: 2, + true_value: 4, + }; + + // Lint on this, because `get` does exist with same signature + map_with_get[true]; }