[clang] [llvm] [clang][llvm][AArch64] Set hardening fn attrs on synthetic functions (PR #211013)

[Daniil Kovalev via cfe-commits]

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@@ -1561,6 +1540,27 @@ void CodeGenModule::Release() {
                                 "sign-return-address-with-bkey", 2);
   }
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kovdan01 wrote:

> On the other hand, I would definitely prefer `max` as a safer option for the **new** flags

Yes, I agree with that and that's the intention of this patch :)

For existing flags - I would prefer to keep scope of this patch to ptrauth attributes and flags only. I believe that @DanielKristofKiss and other people more involved into context of other CFI-related flags like sign-return-address family and branch-target-enforcement would handle them better (if any changes are even needed). Anyway, it seems that there is some non-trivial history of changing the flag/attribute shape there, and I would avoid touching that w/o deep involvement in the context.

And since we are targeting to strictly enhance things and do no accidental harm (and cherry-pick after merge) - probably better to keep scope narrower and safer :)

https://github.com/llvm/llvm-project/pull/211013