Ignore trait implementations

Author: hkmatsumoto

clippy_lints/src/unnecessary_wrap.rs

@@ -1,11 +1,11 @@
 use crate::utils::{
-    in_macro, is_type_diagnostic_item, match_path, match_qpath, paths, return_ty, snippet, span_lint_and_then,
-    trait_ref_of_method, visitors::find_all_ret_expressions,
+    in_macro, is_type_diagnostic_item, match_qpath, paths, return_ty, snippet, span_lint_and_then,
+    visitors::find_all_ret_expressions,
 };
 use if_chain::if_chain;
 use rustc_errors::Applicability;
 use rustc_hir::intravisit::FnKind;
-use rustc_hir::{Body, ExprKind, FnDecl, HirId};
+use rustc_hir::{Body, ExprKind, FnDecl, HirId, ItemKind, Node};
 use rustc_lint::{LateContext, LateLintPass};
 use rustc_middle::ty::subst::GenericArgKind;
 use rustc_session::{declare_lint_pass, declare_tool_lint};
@@ -63,14 +63,6 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryWrap {
         span: Span,
         hir_id: HirId,
     ) {
-        if_chain! {
-            if let Some(trait_ref) = trait_ref_of_method(cx, hir_id);
-            if match_path(trait_ref.path, &paths::PARTIAL_ORD);
-            then {
-                return;
-            }
-        }
-
         match fn_kind {
             FnKind::ItemFn(.., visibility, _) | FnKind::Method(.., Some(visibility), _) => {
                 if visibility.node.is_pub() {
@@ -81,6 +73,12 @@ impl<'tcx> LateLintPass<'tcx> for UnnecessaryWrap {
             _ => (),
         }
 
+        if let Some(Node::Item(item)) = cx.tcx.hir().find(cx.tcx.hir().get_parent_node(hir_id)) {
+            if matches!(item.kind, ItemKind::Impl{ of_trait: Some(_), ..} | ItemKind::Trait(..)) {
+                return;
+            }
+        }
+
         let (return_type, path) = if is_type_diagnostic_item(cx, return_ty(cx, hir_id), sym!(option_type)) {
             ("Option", &paths::OPTION_SOME)
         } else if is_type_diagnostic_item(cx, return_ty(cx, hir_id), sym!(result_type)) {

clippy_lints/src/utils/paths.rs

@@ -81,7 +81,6 @@ pub const OS_STR_TO_OS_STRING: [&str; 5] = ["std", "ffi", "os_str", "OsStr", "to
 pub const PARKING_LOT_MUTEX_GUARD: [&str; 2] = ["parking_lot", "MutexGuard"];
 pub const PARKING_LOT_RWLOCK_READ_GUARD: [&str; 2] = ["parking_lot", "RwLockReadGuard"];
 pub const PARKING_LOT_RWLOCK_WRITE_GUARD: [&str; 2] = ["parking_lot", "RwLockWriteGuard"];
-pub const PARTIAL_ORD: [&str; 3] = ["std", "cmp", "PartialOrd"];
 pub const PATH: [&str; 3] = ["std", "path", "Path"];
 pub const PATH_BUF: [&str; 3] = ["std", "path", "PathBuf"];
 pub const PATH_BUF_AS_PATH: [&str; 4] = ["std", "path", "PathBuf", "as_path"];

tests/ui/unnecessary_wrap.rs

@@ -95,6 +95,20 @@ impl A {
     }
 }
 
+trait B {
+    // trait impls are not linted
+    fn func13() -> Option<i32> {
+        Some(1)
+    }
+}
+
+impl A for B {
+    // trait impls are not linted
+    fn func13() -> Option<i32> {
+        Some(0)
+    }
+}
+
 fn main() {
     // method calls are not linted
     func1(true, true);