[PATCH] D113804: [clang-tidy] Fix behavior of `modernize-use-using` with nested structs/unions

[Aaron Ballman via Phabricator via cfe-commits]

aaron.ballman accepted this revision.
aaron.ballman added a comment.
This revision is now accepted and ready to land.

LGTM aside from a nit.



================
Comment at: clang-tools-extra/clang-tidy/modernize/UseUsingCheck.cpp:39-48
+  Finder->addMatcher(
+      tagDecl(
+          anyOf(allOf(unless(anyOf(isImplicit(),
+                                   classTemplateSpecializationDecl())),
+                      hasParent(decl().bind(ParentDeclName))),
+                // We want the parent of the ClassTemplateDecl, not the parent
+                // of the specialization.
----------------
I recall that using `hasParent()` and `hasAncestor()` tend to be expensive because they walk up the entire AST to the TU level, and so they can also match in surprising places. However, I can't seem to devise a test case that will fail, so I think this is probably okay.


================
Comment at: clang-tools-extra/test/clang-tidy/checkers/modernize-use-using.cpp:306
+
+// clang-format off
+
----------------
We don't typically use clang-format comments (especially not in tests; those are almost never formatted anyway). Same below.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D113804/new/

https://reviews.llvm.org/D113804