[PATCH] D66349: [clangd] Fix one testcase in XRefsTests.

[Ilya Biryukov via Phabricator via cfe-commits]

ilya-biryukov added inline comments.


================
Comment at: clang-tools-extra/clangd/XRefs.cpp:389
     llvm::sort(References, [](const Reference &L, const Reference &R) {
-      return std::tie(L.Loc, L.CanonicalTarget, L.Role) <
-             std::tie(R.Loc, R.CanonicalTarget, R.Role);
+      return L.Loc < R.Loc;
     });
----------------
hokein wrote:
> ilya-biryukov wrote:
> > What are the elements `References` for the problematic case?
> > 
> > If we have duplicate elements, then `sort()` would now give us one of the items. Which exact `Decl` we're gonna end up seeing is not well-defined, i.e. it's non-deterministic.
> > What are the elements References for the problematic case?
> 
> The testcase is using declarations (see the existing test) -- we will get 3 refs on `using ::fo^o`, each ref has a different decl.  
> 
> ```
> void [[foo]](int);
> void [[foo]](double);
> 
> namespace ns {
> using ::[[fo^o]];
> }
> ```
> 
> > If we have duplicate elements, then sort() would now give us one of the items. Which exact Decl we're gonna end up seeing is not well-defined, i.e. it's non-deterministic.
> 
> I think we could make it deterministic, but only return one refs, WDYT?
> 
> 
To make sure I understand the problem: we used to get 4 references in total:
- 2 references to the functions (`foo(int)` and `foo(double)`)
- 2 references pointing to the using declaration, e.g. the `using ::[foo]]`

After this patch we would remove the duplicate `using ::[[foo]]` from the results and get only 3 references as a result.

Is that correct?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D66349/new/

https://reviews.llvm.org/D66349