[PATCH] D105217: [LLD] Adding support for RELA for CG Profile.

Wed Jun 30 11:40:29 PDT 2021

ayermolo added a comment.

In D105217#2850892 <https://reviews.llvm.org/D105217#2850892>, @MaskRay wrote:

> I have changed MC to unconditionally emit REL, so this change is not needed.

Unfortunately when running strip -S on ELF object files it converts REL to RELA.

Before:

  [85] .llvm.call-graph-profile LLVM_CALL_GRAPH_PROFILE 0000000000000000 00db01 000168 08   E 92   0  1
  [86] .rel.llvm.call-graph-profile REL  0000000000000000 01ec18 0005a0 10     92  85  8

After:

  [76] .llvm.call-graph-profile LLVM_CALL_GRAPH_PROFILE 0000000000000000 0056aa 000168 08   E  0   0  1
  [77] .rela.llvm.call-graph-profile RELA 0000000000000000 00dd18 000870 18   I 81  76  8

Supporting usage model of running strip -S on object files before linking was original motivation for this changing CG Call graph to use relocations.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D105217/new/

https://reviews.llvm.org/D105217