[PATCH] D48795: [AArch64] Add support for SHF_ARM_PURECODE.

[Peter Smith via Phabricator via llvm-commits]

peter.smith added a comment.

I've left a comment about the ABI problems with using SHF_ARM_PURECODE. I've raised an issue to support execute only on AArch64 with the ABI team at Arm.



================
Comment at: ELF/OutputSections.cpp:47
+  if ((Config->EMachine != EM_ARM && Config->EMachine != EM_AARCH64 ) ||
+      !(Flags & SHF_ARM_PURECODE))
     Ret |= PF_R;
----------------
As mentioned in D48791 SHF_ARM_PURECODE is defined in the SHF_MASKPROC space and is currently defined for ARM Processor so we shouldn't be using that flag when the machine isn't EM_ARM. I think it is highly likely that a SHF_AARCH64_PURECODE flag gets defined. When that arises this code might be best extracted into a function such as isExecuteOnly(Flags) so that this becomes:

```
if (!isExecuteOnly(Flags))
  Ret |= PF_R;
```



Repository:
  rLLD LLVM Linker

https://reviews.llvm.org/D48795