Merge pull request #2511 from flip1995/sus_impl

UnNeg and UnNot count as additional operations now
rust-lang · Mar 6, 2018 · 7d5ecd5 · 7d5ecd5
2 parents 9683f38 + ed45356
commit 7d5ecd5
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Showing 2 changed files with 32 additions and 9 deletions.
diff --git a/clippy_lints/src/suspicious_trait_impl.rs b/clippy_lints/src/suspicious_trait_impl.rs
@@ -61,18 +61,18 @@ impl<'a, 'tcx> LateLintPass<'a, 'tcx> for SuspiciousImpl {
     fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
         use rustc::hir::BinOp_::*;
         if let hir::ExprBinary(binop, _, _) = expr.node {
-            // Check if the binary expression is part of another binary expression
+            // Check if the binary expression is part of another bi/unary expression
             // as a child node
             let mut parent_expr = cx.tcx.hir.get_parent_node(expr.id);
             while parent_expr != ast::CRATE_NODE_ID {
-                if_chain! {
-                    if let hir::map::Node::NodeExpr(e) = cx.tcx.hir.get(parent_expr);
-                    if let hir::ExprBinary(_, _, _) = e.node;
-                    then {
-                        return
+                if let hir::map::Node::NodeExpr(e) = cx.tcx.hir.get(parent_expr) {
+                    match e.node {
+                        hir::ExprBinary(..)
+                        | hir::ExprUnary(hir::UnOp::UnNot, _)
+                        | hir::ExprUnary(hir::UnOp::UnNeg, _) => return,
+                        _ => {},
                     }
                 }
-
                 parent_expr = cx.tcx.hir.get_parent_node(parent_expr);
             }
             // as a parent node
@@ -180,8 +180,13 @@ struct BinaryExprVisitor {
 
 impl<'a, 'tcx: 'a> Visitor<'tcx> for BinaryExprVisitor {
     fn visit_expr(&mut self, expr: &'tcx hir::Expr) {
-        if let hir::ExprBinary(_, _, _) = expr.node {
-            self.in_binary_expr = true;
+        match expr.node {
+            hir::ExprBinary(..)
+            | hir::ExprUnary(hir::UnOp::UnNot, _)
+            | hir::ExprUnary(hir::UnOp::UnNeg, _) => {
+                self.in_binary_expr = true
+            },
+            _ => {},
         }
 
         walk_expr(self, expr);

diff --git a/tests/ui/suspicious_arithmetic_impl.rs b/tests/ui/suspicious_arithmetic_impl.rs
@@ -45,6 +45,24 @@ impl Div for Foo {
     }
 }
 
+struct Bar(i32);
+
+impl Add for Bar {
+    type Output = Bar;
+
+    fn add(self, other: Self) -> Self {
+        Bar(self.0 & !other.0) // OK: UnNot part of BiExpr as child node
+    }
+}
+
+impl Sub for Bar {
+    type Output = Bar;
+
+    fn sub(self, other: Self) -> Self {
+        Bar(-(self.0 & other.0)) // OK: UnNeg part of BiExpr as parent node
+    }
+}
+
 fn main() {}
 
 fn do_nothing(x: u32) -> u32 {