Auto merge of #6222 - JohnTitor:redundant-local-def-id, r=flip1995

Remove redundant `expect_local()` call

The field `owner` of `HirId` is `LocalDefId` and `hir_id.owner.to_def_id().expect_local()` is redundant. I wonder they were introduced in some rustups.

changelog: none

clippy_lints/src/functions.rs

@@ -579,9 +579,8 @@ fn is_mutable_pat(cx: &LateContext<'_>, pat: &hir::Pat<'_>, tys: &mut FxHashSet<
     if let hir::PatKind::Wild = pat.kind {
         return false; // ignore `_` patterns
     }
-    let def_id = pat.hir_id.owner.to_def_id();
-    if cx.tcx.has_typeck_results(def_id) {
-        is_mutable_ty(cx, &cx.tcx.typeck(def_id.expect_local()).pat_ty(pat), pat.span, tys)
+    if cx.tcx.has_typeck_results(pat.hir_id.owner.to_def_id()) {
+        is_mutable_ty(cx, &cx.tcx.typeck(pat.hir_id.owner).pat_ty(pat), pat.span, tys)
     } else {
         false
     }
@@ -694,11 +693,10 @@ fn visit_expr(&mut self, expr: &'tcx hir::Expr<'_>) {
             Call(_, args) | MethodCall(_, _, args, _) => {
                 let mut tys = FxHashSet::default();
                 for arg in args {
-                    let def_id = arg.hir_id.owner.to_def_id();
-                    if self.cx.tcx.has_typeck_results(def_id)
+                    if self.cx.tcx.has_typeck_results(arg.hir_id.owner.to_def_id())
                         && is_mutable_ty(
                             self.cx,
-                            self.cx.tcx.typeck(def_id.expect_local()).expr_ty(arg),
+                            self.cx.tcx.typeck(arg.hir_id.owner).expr_ty(arg),
                             arg.span,
                             &mut tys,
                         )

clippy_lints/src/loops.rs

@@ -2051,12 +2051,11 @@ fn check_for_mutation<'tcx>(
         span_low: None,
         span_high: None,
     };
-    let def_id = body.hir_id.owner.to_def_id();
     cx.tcx.infer_ctxt().enter(|infcx| {
         ExprUseVisitor::new(
             &mut delegate,
             &infcx,
-            def_id.expect_local(),
+            body.hir_id.owner,
             cx.param_env,
             cx.typeck_results(),
         )

clippy_lints/src/utils/mod.rs

@@ -299,7 +299,7 @@ pub fn qpath_res(cx: &LateContext<'_>, qpath: &hir::QPath<'_>, id: hir::HirId) -
         hir::QPath::Resolved(_, path) => path.res,
         hir::QPath::TypeRelative(..) | hir::QPath::LangItem(..) => {
             if cx.tcx.has_typeck_results(id.owner.to_def_id()) {
-                cx.tcx.typeck(id.owner.to_def_id().expect_local()).qpath_res(qpath, id)
+                cx.tcx.typeck(id.owner).qpath_res(qpath, id)
             } else {
                 Res::Err
             }

clippy_lints/src/utils/usage.rs

@@ -19,12 +19,11 @@ pub fn mutated_variables<'tcx>(expr: &'tcx Expr<'_>, cx: &LateContext<'tcx>) ->
         used_mutably: FxHashSet::default(),
         skip: false,
     };
-    let def_id = expr.hir_id.owner.to_def_id();
     cx.tcx.infer_ctxt().enter(|infcx| {
         ExprUseVisitor::new(
             &mut delegate,
             &infcx,
-            def_id.expect_local(),
+            expr.hir_id.owner,
             cx.param_env,
             cx.typeck_results(),
         )