Merge rust-lang#3426

3426: Fix `use_self` false positive on `use` statements r=flip1995 a=mikerite

Fixes rust-lang#3425 

Co-authored-by: Michael Wright <[email protected]>

Author: bors[bot]

clippy_lints/src/use_self.rs

@@ -16,6 +16,7 @@ use crate::rustc::lint::{LateContext, LateLintPass, LintArray, LintPass};
 use crate::rustc::ty;
 use crate::rustc::{declare_tool_lint, lint_array};
 use crate::syntax_pos::symbol::keywords::SelfType;
+use crate::syntax::ast::NodeId;
 
 /// **What it does:** Checks for unnecessary repetition of structure name when a
 /// replacement with `Self` is applicable.
@@ -234,6 +235,10 @@ impl<'a, 'tcx> Visitor<'tcx> for UseSelfVisitor<'a, 'tcx> {
         walk_path(self, path);
     }
 
+    fn visit_use(&mut self, _path: &'tcx Path, _id: NodeId, _hir_id: HirId) {
+        // Don't check use statements
+    }
+
     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
         NestedVisitorMap::All(&self.cx.tcx.hir)
     }

tests/ui/use_self.rs

@@ -225,11 +225,22 @@ mod issue3410 {
     struct A;
     struct B;
 
-    trait Trait<T>: Sized {
+    trait Trait<T> {
         fn a(v: T);
     }
 
     impl Trait<Vec<A>> for Vec<B> {
         fn a(_: Vec<A>) {}
     }
 }
+
+mod issue3425 {
+    enum Enum {
+        A,
+    }
+    impl Enum {
+        fn a () {
+            use self::Enum::*;
+        }
+    }
+}