Skip use_self inside macro expansion of impl Self items

Author: tesuji

clippy_lints/src/use_self.rs

@@ -128,6 +128,11 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
     }
 
     fn check_impl_item(&mut self, cx: &LateContext<'_>, impl_item: &hir::ImplItem<'_>) {
+        // Checking items of `impl Self` blocks in which macro expands into.
+        if impl_item.span.from_expansion() {
+            self.stack.push(StackItem::NoCheck);
+            return;
+        }
         // We want to skip types in trait `impl`s that aren't declared as `Self` in the trait
         // declaration. The collection of those types is all this method implementation does.
         if let ImplItemKind::Fn(FnSig { decl, .. }, ..) = impl_item.kind
@@ -183,6 +188,13 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
         }
     }
 
+    fn check_impl_item_post(&mut self, _: &LateContext<'_>, impl_item: &hir::ImplItem<'_>) {
+        if impl_item.span.from_expansion()
+            && let Some(StackItem::NoCheck) = self.stack.last()
+        {
+            self.stack.pop();
+        }
+    }
 
     fn check_ty(&mut self, cx: &LateContext<'tcx>, hir_ty: &Ty<'tcx, AmbigArg>) {
         if !hir_ty.span.from_expansion()
@@ -197,7 +209,7 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
                 Res::SelfTyParam { .. } | Res::SelfTyAlias { .. } | Res::Def(DefKind::TyParam, _)
             )
             && !types_to_skip.contains(&hir_ty.hir_id)
-            && let ty = ty_from_hir_ty(cx, hir_ty)
+            && let ty = ty_from_hir_ty(cx, hir_ty.as_unambig_ty())
             && let impl_ty = cx.tcx.type_of(impl_id).instantiate_identity()
             && same_type_and_consts(ty, impl_ty)
             // Ensure the type we encounter and the one from the impl have the same lifetime parameters. It may be that

tests/ui/use_self.fixed

@@ -682,12 +682,12 @@ mod issue_13092 {
     struct MyStruct;
 
     impl MyStruct {
-        macro_inner_item!(Self);
+        macro_inner_item!(MyStruct);
     }
 
     impl MyStruct {
         thread_local! {
-            static SPECIAL: RefCell<Self> = RefCell::default();
+            static SPECIAL: RefCell<MyStruct> = RefCell::default();
         }
     }
 }

tests/ui/use_self.stderr

@@ -259,25 +259,5 @@ error: unnecessary structure name repetition
 LL |                 E::A => {},
    |                 ^ help: use the applicable keyword: `Self`
 
-error: unnecessary structure name repetition
-  --> tests/ui/use_self.rs:685:27
-   |
-LL |         macro_inner_item!(MyStruct);
-   |                           ^^^^^^^^ help: use the applicable keyword: `Self`
-
-error: unnecessary structure name repetition
-  --> tests/ui/use_self.rs:690:37
-   |
-LL |             static SPECIAL: RefCell<MyStruct> = RefCell::default();
-   |                                     ^^^^^^^^ help: use the applicable keyword: `Self`
-
-error: unnecessary structure name repetition
-  --> tests/ui/use_self.rs:690:37
-   |
-LL |             static SPECIAL: RefCell<MyStruct> = RefCell::default();
-   |                                     ^^^^^^^^ help: use the applicable keyword: `Self`
-   |
-   = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no`
-
-error: aborting due to 46 previous errors
+error: aborting due to 43 previous errors