[PATCH] D72197: [MC][ELF] Emit a relocation if target is defined in the same section and is non-local

[Peter Collingbourne via Phabricator via llvm-commits]

pcc added a comment.

It looks like this change caused us to start rejecting:

  .thumb
  .thumb_func
  .globl foo
  .hidden foo
  foo:
  adr lr, foo + 1

with:

  test.s:6:1: error: unsupported relocation on symbol
  adr lr, foo + 1
  ^

This is exposed by this Android ART code: https://cs.android.com/android/platform/superproject/+/master:art/runtime/arch/arm/quick_entrypoints_arm.S;l=1826

I see a couple of possible fixes for this:

1. We could go back to the previous behaviour for global hidden symbols.
2. We could teach MC and LLD about the `R_ARM_THM_ALU_PREL_11_0` relocation required to relocate this instruction. Arguably the ART code shouldn't be adding the 1 for Thumb here (because `R_ARM_THM_ALU_PREL_11_0` adds the 1 itself), so ART would then need to be fixed.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D72197/new/

https://reviews.llvm.org/D72197