[PATCH] D84005: Introduce ns_error_domain attribute.

[Bruno Ricci via Phabricator via cfe-commits]

riccibruno added inline comments.


================
Comment at: clang/lib/Sema/SemaDeclAttr.cpp:5344
+  if (!S.LookupName(lookupResult, S.TUScope) ||
+      !lookupResult.getAsSingle<VarDecl>()) {
+    S.Diag(IdentLoc->Loc, diag::err_nserrordomain_invalid_decl)
----------------
Just a note that `LookupResult::getAsSingle` has tricky semantics (returns null if the result is not exactly `LookupResultKind::Found`) and has been (and still is) the source of many bugs in clang.

(Example: my favourite one is still the silly:
```
struct S {
  void not_overloaded();
  enum { not_overloaded }; // error; redefinition of 'not_overloaded'

  void overloaded();
  void overloaded(int);
  enum { overloaded }; // clang is fine with this!
};
```
)

I don't know if it is a problem here or not though.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D84005/new/

https://reviews.llvm.org/D84005