[PATCH] D75574: RFC: Implement objc_direct_protocol attribute to remove protocol metadata

Fri Oct 2 11:35:03 PDT 2020

rjmccall added inline comments.

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Comment at: clang/lib/CodeGen/CGObjC.cpp:487
+
+  // Walk both lists to get the full set of implied protocols
+  llvm::DenseSet<const ObjCProtocolDecl *> AllImpliedProtocols;
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lanza wrote:
> rjmccall wrote:
> > You should add something like ", including all the runtime protocols but not the non-runtime protocols".
> Do you anticipate a usage of `getImpliedProtocols` other than this algorithm? I include the non-runtime protos in the all implied list simply because it simplifies the collection. e.g. you insert iff it's a runtime protocol and if not you have to check `contains` and then potentially add a non-runtime to the work queue as many times as it's seen. 
> 
> Ultimately their inclusion in the all-implied list is meaningless because we never attempt to insert a non-runtime protocol into the `RuntimePDs` list anyways. So it's either extra elements in the `AllImplied` list or extra work in the `getImpliedProtocols` method without any behavioral differences.
Ah, yes, that's a fair point.

Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D75574/new/

https://reviews.llvm.org/D75574