[PATCH] D34061: Fix weak symbols on arm and aarch64

[Peter Smith via Phabricator via llvm-commits]

peter.smith accepted this revision.
peter.smith added a comment.
This revision is now accepted and ready to land.

Looks good to me, thanks for spotting the mistake and apologies for making it in the first place. I've made a minor suggestion about making the default case unreachable but I don't think that this is that important.



================
Comment at: ELF/InputSection.cpp:409
   default:
-    return A;
+    return P + A;
   }
----------------
Might be worth making the default case unreachable.

The ABI (ARM ELF 4.5.1.1) says:
During linking, the value of an undefined weak reference is:
- Zero if the relocation type is absolute
- The address of the place if the relocation type is pc-relative
- The nominal base address if the relocation type is base-relative.

The intention for just returning A was that default: would cover the absolute case. However as long as getARMUndefinedRelativeWeakVA is only called from pc-relative locations this wouldn't happen so I don't expect the default case to ever get hit.


https://reviews.llvm.org/D34061