[PATCH] D57936: [CodeGenObjC] When available, emit a direct call to objc_alloc_init(cls) instead of [objc_alloc(cls) init]

[John McCall via Phabricator via cfe-commits]

rjmccall accepted this revision.
rjmccall added inline comments.
This revision is now accepted and ready to land.


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Comment at: clang/lib/CodeGen/CGObjC.cpp:475-483
   case ObjCMessageExpr::Class: {
     ReceiverType = E->getClassReceiver();
     const ObjCObjectType *ObjTy = ReceiverType->getAs<ObjCObjectType>();
     assert(ObjTy && "Invalid Objective-C class message send");
     OID = ObjTy->getInterface();
     assert(OID && "Invalid Objective-C class message send");
     Receiver = Runtime.GetClass(*this, OID);
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erik.pilkington wrote:
> > Also, I think getInterface() can return null here, although it might need to be contrived to fit the other requirements. Class<SomeProtocol>, where that protocol declares +alloc? If there isn't a way to just emit the receiver pointer of a normal message send from an ObjCMessageExpr, that's really too bad.
> 
> Are you sure? It looks like we unconditionally dereference  getInterface() here, and we would take this path if not for the new check above.
It looks like `ObjCMessageExpr::Class` is only for messages to type names, and Sema rejects types in that case that aren't just an ObjC class, so you're right, I misunderstood.


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  https://reviews.llvm.org/D57936/new/

https://reviews.llvm.org/D57936