Update for rustc 1.19.0-nightly (4bf5c99af 2017-06-10).

[rust.git] / clippy_lints / src / assign_ops.rs

diff --git a/clippy_lints/src/assign_ops.rs b/clippy_lints/src/assign_ops.rs
index 84b61b1cba42b85720aecdb7a9db2618ed59c3ed..07d838bef2ede9eb9899882cb9c5a83c3ccca73a 100644 (file)
--- a/clippy_lints/src/assign_ops.rs
+++ b/clippy_lints/src/assign_ops.rs
@@ -1,5 +1,6 @@
 use rustc::hir;
 use rustc::lint::*;
+use syntax::ast;
 use utils::{span_lint_and_then, snippet_opt, SpanlessEq, get_trait_def_id, implements_trait};
 use utils::{higher, sugg};
 
@@ -66,8 +67,8 @@ fn get_lints(&self) -> LintArray {
     }
 }
 
-impl LateLintPass for AssignOps {
-    fn check_expr<'a, 'tcx: 'a>(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
+impl<'a, 'tcx> LateLintPass<'a, 'tcx> for AssignOps {
+    fn check_expr(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx hir::Expr) {
         match expr.node {
             hir::ExprAssignOp(op, ref lhs, ref rhs) => {
                 span_lint_and_then(cx, ASSIGN_OPS, expr.span, "assign operation detected", |db| {
@@ -81,25 +82,18 @@ fn check_expr<'a, 'tcx: 'a>(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx h
                 if let hir::ExprBinary(binop, ref l, ref r) = rhs.node {
                     if op.node == binop.node {
                         let lint = |assignee: &hir::Expr, rhs: &hir::Expr| {
-                            let ty = cx.tcx.tables().expr_ty(assignee);
-                            if ty.walk_shallow().next().is_some() {
-                                return; // implements_trait does not work with generics
-                            }
-                            let rty = cx.tcx.tables().expr_ty(rhs);
-                            if rty.walk_shallow().next().is_some() {
-                                return; // implements_trait does not work with generics
-                            }
                             span_lint_and_then(cx,
                                                MISREFACTORED_ASSIGN_OP,
                                                expr.span,
                                                "variable appears on both sides of an assignment operation",
-                                               |db| {
-                                                   if let (Some(snip_a), Some(snip_r)) = (snippet_opt(cx, assignee.span),
-                                                                                          snippet_opt(cx, rhs.span)) {
-                                                       db.span_suggestion(expr.span,
-                                                                          "replace it with",
-                                                                          format!("{} {}= {}", snip_a, op.node.as_str(), snip_r));
-                                                   }
+                                               |db| if let (Some(snip_a), Some(snip_r)) =
+                                                   (snippet_opt(cx, assignee.span), snippet_opt(cx, rhs.span)) {
+                                                   db.span_suggestion(expr.span,
+                                                                      "replace it with",
+                                                                      format!("{} {}= {}",
+                                                                              snip_a,
+                                                                              op.node.as_str(),
+                                                                              snip_r));
                                                });
                         };
                         // lhs op= l op r
@@ -112,20 +106,19 @@ fn check_expr<'a, 'tcx: 'a>(&mut self, cx: &LateContext<'a, 'tcx>, expr: &'tcx h
                         }
                     }
                 }
-            }
+            },
             hir::ExprAssign(ref assignee, ref e) => {
                 if let hir::ExprBinary(op, ref l, ref r) = e.node {
+                    #[allow(cyclomatic_complexity)]
                     let lint = |assignee: &hir::Expr, rhs: &hir::Expr| {
-                        let ty = cx.tcx.tables().expr_ty(assignee);
-                        if ty.walk_shallow().next().is_some() {
-                            return; // implements_trait does not work with generics
-                        }
-                        let rty = cx.tcx.tables().expr_ty(rhs);
-                        if rty.walk_shallow().next().is_some() {
-                            return; // implements_trait does not work with generics
-                        }
+                        let ty = cx.tables.expr_ty(assignee);
+                        let rty = cx.tables.expr_ty(rhs);
                         macro_rules! ops {
-                            ($op:expr, $cx:expr, $ty:expr, $rty:expr, $($trait_name:ident:$full_trait_name:ident),+) => {
+                            ($op:expr,
+                             $cx:expr,
+                             $ty:expr,
+                             $rty:expr,
+                             $($trait_name:ident:$full_trait_name:ident),+) => {
                                 match $op {
                                     $(hir::$full_trait_name => {
                                         let [krate, module] = ::utils::paths::OPS_MODULE;
@@ -135,7 +128,17 @@ macro_rules! ops {
                                         } else {
                                             return; // useless if the trait doesn't exist
                                         };
-                                        implements_trait($cx, $ty, trait_id, vec![$rty])
+                                        // check that we are not inside an `impl AssignOp` of this exact operation
+                                        let parent_fn = cx.tcx.hir.get_parent(e.id);
+                                        let parent_impl = cx.tcx.hir.get_parent(parent_fn);
+                                        // the crate node is the only one that is not in the map
+                                        if_let_chain!{[
+                                            parent_impl != ast::CRATE_NODE_ID,
+                                            let hir::map::Node::NodeItem(item) = cx.tcx.hir.get(parent_impl),
+                                            let hir::Item_::ItemImpl(_, _, _, _, Some(ref trait_ref), _, _) = item.node,
+                                            trait_ref.path.def.def_id() == trait_id
+                                        ], { return; }}
+                                        implements_trait($cx, $ty, trait_id, &[$rty])
                                     },)*
                                     _ => false,
                                 }
@@ -161,13 +164,14 @@ macro_rules! ops {
                                                ASSIGN_OP_PATTERN,
                                                expr.span,
                                                "manual implementation of an assign operation",
-                                               |db| {
-                                                   if let (Some(snip_a), Some(snip_r)) = (snippet_opt(cx, assignee.span),
-                                                                                          snippet_opt(cx, rhs.span)) {
-                                                       db.span_suggestion(expr.span,
-                                                                          "replace it with",
-                                                                          format!("{} {}= {}", snip_a, op.node.as_str(), snip_r));
-                                                   }
+                                               |db| if let (Some(snip_a), Some(snip_r)) =
+                                                   (snippet_opt(cx, assignee.span), snippet_opt(cx, rhs.span)) {
+                                                   db.span_suggestion(expr.span,
+                                                                      "replace it with",
+                                                                      format!("{} {}= {}",
+                                                                              snip_a,
+                                                                              op.node.as_str(),
+                                                                              snip_r));
                                                });
                         }
                     };
@@ -181,13 +185,13 @@ macro_rules! ops {
                             hir::BiAdd | hir::BiMul | hir::BiAnd | hir::BiOr | hir::BiBitXor | hir::BiBitAnd |
                             hir::BiBitOr => {
                                 lint(assignee, l);
-                            }
-                            _ => {}
+                            },
+                            _ => {},
                         }
                     }
                 }
-            }
-            _ => {}
+            },
+            _ => {},
         }
     }
 }
@@ -195,23 +199,7 @@ macro_rules! ops {
 fn is_commutative(op: hir::BinOp_) -> bool {
     use rustc::hir::BinOp_::*;
     match op {
-        BiAdd |
-        BiMul |
-        BiAnd |
-        BiOr |
-        BiBitXor |
-        BiBitAnd |
-        BiBitOr |
-        BiEq |
-        BiNe => true,
-        BiSub |
-        BiDiv |
-        BiRem |
-        BiShl |
-        BiShr |
-        BiLt |
-        BiLe |
-        BiGe |
-        BiGt => false,
+        BiAdd | BiMul | BiAnd | BiOr | BiBitXor | BiBitAnd | BiBitOr | BiEq | BiNe => true,
+        BiSub | BiDiv | BiRem | BiShl | BiShr | BiLt | BiLe | BiGe | BiGt => false,
     }
 }