@@ -4,13 +4,12 @@ use clippy_utils::{
44 ty:: implements_trait,
55} ;
66use rustc_errors:: Applicability ;
7- use rustc_hir:: { def:: Res , Expr , ExprKind , ImplItem , ImplItemKind , ItemKind , LangItem , Node , PatKind , UnOp } ;
7+ use rustc_hir:: { def:: Res , Expr , ExprKind , ImplItem , ImplItemKind , ItemKind , LangItem , Node , UnOp } ;
88use rustc_hir_analysis:: hir_ty_to_ty;
99use rustc_lint:: { LateContext , LateLintPass } ;
1010use rustc_middle:: ty:: EarlyBinder ;
1111use rustc_session:: { declare_lint_pass, declare_tool_lint} ;
12- use rustc_span:: { sym, symbol} ;
13- use std:: borrow:: Cow ;
12+ use rustc_span:: { sym, symbol:: kw} ;
1413
1514declare_clippy_lint ! {
1615 /// ### What it does
@@ -61,31 +60,39 @@ declare_clippy_lint! {
6160 /// wrapping the result of `cmp` in `Some` for `partial_cmp`. Not doing this may silently
6261 /// introduce an error upon refactoring.
6362 ///
63+ /// ### Limitations
64+ /// Will not lint if `Self` and `Rhs` do not have the same type.
65+ ///
6466 /// ### Example
65- /// ```rust,ignore
67+ /// ```rust
68+ /// # use std::cmp::Ordering;
6669 /// #[derive(Eq, PartialEq)]
6770 /// struct A(u32);
6871 ///
6972 /// impl Ord for A {
7073 /// fn cmp(&self, other: &Self) -> Ordering {
71- /// todo!();
74+ /// // ...
75+ /// # todo!();
7276 /// }
7377 /// }
7478 ///
7579 /// impl PartialOrd for A {
7680 /// fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
77- /// todo!();
81+ /// // ...
82+ /// # todo!();
7883 /// }
7984 /// }
8085 /// ```
8186 /// Use instead:
82- /// ```rust,ignore
87+ /// ```rust
88+ /// # use std::cmp::Ordering;
8389 /// #[derive(Eq, PartialEq)]
8490 /// struct A(u32);
8591 ///
8692 /// impl Ord for A {
8793 /// fn cmp(&self, other: &Self) -> Ordering {
88- /// todo!();
94+ /// // ...
95+ /// # todo!();
8996 /// }
9097 /// }
9198 ///
@@ -105,8 +112,7 @@ declare_lint_pass!(IncorrectImpls => [INCORRECT_CLONE_IMPL_ON_COPY_TYPE, INCORRE
105112impl LateLintPass < ' _ > for IncorrectImpls {
106113 #[ expect( clippy:: too_many_lines) ]
107114 fn check_impl_item ( & mut self , cx : & LateContext < ' _ > , impl_item : & ImplItem < ' _ > ) {
108- let node = get_parent_node ( cx. tcx , impl_item. hir_id ( ) ) ;
109- let Some ( Node :: Item ( item) ) = node else {
115+ let Some ( Node :: Item ( item) ) = get_parent_node ( cx. tcx , impl_item. hir_id ( ) ) else {
110116 return ;
111117 } ;
112118 let ItemKind :: Impl ( imp) = item. kind else {
@@ -115,7 +121,6 @@ impl LateLintPass<'_> for IncorrectImpls {
115121 let Some ( trait_impl) = cx. tcx . impl_trait_ref ( item. owner_id ) . map ( EarlyBinder :: skip_binder) else {
116122 return ;
117123 } ;
118- let trait_impl_def_id = trait_impl. def_id ;
119124 if cx. tcx . is_automatically_derived ( item. owner_id . to_def_id ( ) ) {
120125 return ;
121126 }
@@ -127,7 +132,7 @@ impl LateLintPass<'_> for IncorrectImpls {
127132 return ;
128133 } ;
129134
130- if cx. tcx . is_diagnostic_item ( sym:: Clone , trait_impl_def_id )
135+ if cx. tcx . is_diagnostic_item ( sym:: Clone , trait_impl . def_id )
131136 && let Some ( copy_def_id) = cx. tcx . get_diagnostic_item ( sym:: Copy )
132137 && implements_trait (
133138 cx,
@@ -139,9 +144,9 @@ impl LateLintPass<'_> for IncorrectImpls {
139144 if impl_item. ident . name == sym:: clone {
140145 if block. stmts . is_empty ( )
141146 && let Some ( expr) = block. expr
142- && let ExprKind :: Unary ( UnOp :: Deref , inner ) = expr. kind
143- && let ExprKind :: Path ( qpath) = inner . kind
144- && last_path_segment ( & qpath) . ident . name == symbol :: kw:: SelfLower
147+ && let ExprKind :: Unary ( UnOp :: Deref , deref ) = expr. kind
148+ && let ExprKind :: Path ( qpath) = deref . kind
149+ && last_path_segment ( & qpath) . ident . name == kw:: SelfLower
145150 { } else {
146151 span_lint_and_sugg (
147152 cx,
@@ -163,7 +168,7 @@ impl LateLintPass<'_> for IncorrectImpls {
163168 INCORRECT_CLONE_IMPL_ON_COPY_TYPE ,
164169 impl_item. span ,
165170 "incorrect implementation of `clone_from` on a `Copy` type" ,
166- "remove this " ,
171+ "remove it " ,
167172 String :: new ( ) ,
168173 Applicability :: MaybeIncorrect ,
169174 ) ;
@@ -172,7 +177,7 @@ impl LateLintPass<'_> for IncorrectImpls {
172177 }
173178 }
174179
175- if cx. tcx . is_diagnostic_item ( sym:: PartialOrd , trait_impl_def_id )
180+ if cx. tcx . is_diagnostic_item ( sym:: PartialOrd , trait_impl . def_id )
176181 && impl_item. ident . name == sym:: partial_cmp
177182 && let Some ( ord_def_id) = cx
178183 . tcx
@@ -203,10 +208,7 @@ impl LateLintPass<'_> for IncorrectImpls {
203208 { } else {
204209 // If lhs and rhs are not the same type, bail. This makes creating a valid
205210 // suggestion tons more complex.
206- if let Some ( lhs) = trait_impl. substs . get ( 0 )
207- && let Some ( rhs) = trait_impl. substs . get ( 1 )
208- && lhs != rhs
209- {
211+ if let [ lhs, rhs, ..] = trait_impl. substs . as_slice ( ) && lhs != rhs {
210212 return ;
211213 }
212214
@@ -216,22 +218,23 @@ impl LateLintPass<'_> for IncorrectImpls {
216218 item. span ,
217219 "incorrect implementation of `partial_cmp` on an `Ord` type" ,
218220 |diag| {
219- let ( help, app) = if let Some ( other) = body. params . get ( 1 )
220- && let PatKind :: Binding ( _, _, other_ident, ..) = other. pat . kind
221- {
222- (
223- Cow :: Owned ( format ! ( "{{ Some(self.cmp({})) }}" , other_ident. name) ) ,
224- Applicability :: Unspecified ,
225- )
221+ let [ _, other] = body. params else {
222+ return ;
223+ } ;
224+
225+ let suggs = if let Some ( other_ident) = other. pat . simple_ident ( ) {
226+ vec ! [ ( block. span, format!( "{{ Some(self.cmp({})) }}" , other_ident. name) ) ]
226227 } else {
227- ( Cow :: Borrowed ( "{ Some(self.cmp(...)) }" ) , Applicability :: HasPlaceholders )
228+ vec ! [
229+ ( block. span, "{ Some(self.cmp(other)) }" . to_owned( ) ) ,
230+ ( other. pat. span, "other" . to_owned( ) ) ,
231+ ]
228232 } ;
229233
230- diag. span_suggestion (
231- block. span ,
234+ diag. multipart_suggestion (
232235 "change this to" ,
233- help ,
234- app ,
236+ suggs ,
237+ Applicability :: Unspecified ,
235238 ) ;
236239 }
237240 ) ;
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