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

[Rafael Ávila de Espíndola via Phabricator via llvm-commits]

rafael created this revision.
Herald added subscribers: kristof.beyls, javed.absar, emaste, rengolin, aemerson.

Given

.weak target
 .global _start
_start:
 b target

The intention is that the branch goes to the instruction after the branch, effectively turning it on a nop.  The branch adds the runtime PC, but we were adding it statically too.

I noticed the oddity by inspection, but llvm-objdump seems to agree, since it now prints things like:

b       #-4 <_start+0x4>


https://reviews.llvm.org/D34061

Files:
  ELF/InputSection.cpp
  test/ELF/aarch64-undefined-weak.s
  test/ELF/arm-thumb-no-undefined-thunk.s
  test/ELF/arm-thumb-undefined-weak.s
  test/ELF/arm-undefined-weak.s

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