[PATCH] D92808: [ObjC][ARC] Annotate calls with attributes instead of emitting retainRV or claimRV calls in the IR

[John McCall via Phabricator via cfe-commits]

rjmccall added a comment.

I think the plan should be to use this code pattern on all targets, but starting it with arm64 seems fine.



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Comment at: clang/lib/CodeGen/CGObjC.cpp:2342
+    attrs = attrs.addAttribute(CGF.getLLVMContext(),
+                               llvm::AttributeList::ReturnIndex, "rv_marker");
+    callBase->setAttributes(attrs);
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It's weird that these attributes use two different capitalization styles.  Also, why are they both needed?  Did you consider making the role (retain/claim) be the value of the attribute rather than a separate attribute?

Should the attribute be namespaced, like `clang.arc.rv_marker`?

Let's go ahead and add globals for these strings so we can refer to them symbolically, like you did with `retainRVMarkerKey`.  Is there an LLVM header for ARC optimization we could reasonably pull them from, or are we doomed to repeat ourselves across projects?


Repository:
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https://reviews.llvm.org/D92808