[PATCH] D87225: [clangd] When finding refs for a renaming alias, do not return refs to underlying decls

[Haojian Wu via Phabricator via cfe-commits]

hokein added inline comments.


================
Comment at: clang-tools-extra/clangd/XRefs.cpp:1150
+      if (llvm::isa<UsingDecl>(D) || llvm::isa<UnresolvedUsingValueDecl>(D)) {
+        Decls = getDeclAtPosition(AST, *CurLoc,
+                                  Relations | DeclRelation::Underlying);
----------------
I think it should not happen in practice (Decls just have 1 element in most cases), but the code feels hacky, we are throwing other decls if one of the `Decls` is a using decl.

I suppose if we're using the same workaround as `locateASTReferent`, then we should follow that way by only adjusting the UsingDecl/UnresolvedValueDecl results and keeping others.


In general, I think we probably need to remove this workaround (see the  `FIXME` in `locateASTReferent`) by refining TargetDecl API. The current `DeclRelation::Underlying` enum is not enough to support our use case where we only want underlying decls for *non-renaming* alias. One rough idea to fix it is to split the `Underlying` to two `RenameAliasUnderlying` and `RemainingUnderlying` -- this would need some API design work, so no need to do it in this patch.





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  https://reviews.llvm.org/D87225/new/

https://reviews.llvm.org/D87225