[PATCH] D75181: [AArch64] Handle BTI/PAC in case of generated functions.

[Momchil Velikov via Phabricator via cfe-commits]

chill added inline comments.


================
Comment at: clang/lib/CodeGen/TargetInfo.cpp:5149-5152
+          if (BPI.BranchTargetEnforcement)
+            Fn->addFnAttr("branch-target-enforcement", "true");
+          else
+            Fn->addFnAttr("branch-target-enforcement", "false");
----------------
danielkiss wrote:
> I'm going to rebase the patch. I add there a new attribute here "ignore-branch-target-enforcement"
> so then the "branch-target-enforcement"="true"/"false" could be just "branch-target-enforcement".
> 
> 
TBH, that's worse, IMHO.

Ideally, I *think* we'd like *every* LLVM IR function that the backend sees,
regardless of how, why and by whom it is created, to have (or not have)
the three existing PACBTI attributes "sign-return-address", "sign-return-address-key", and "branch-target-enforcement", so the backend can generate code accordingly.

The module attributes are LLVM IR metadata,  and  AFAIK LLVM IR metadata is an optional extra, 
it should not affect correctness.
Indeed, *module* metadata is a somwhat grey area,  better not use it if there a way around it.





CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D75181/new/

https://reviews.llvm.org/D75181