[PATCH] D83800: Support PC relative relocation on AArch64 and PPC64 in RelocationResolver

[Yichao Yu via Phabricator via llvm-commits]

yuyichao created this revision.
yuyichao added reviewers: mstorsjo, Hsiang-Kai.
Herald added subscribers: llvm-commits, danielkiss, hiraditya, kristof.beyls, aprantl.
Herald added a project: LLVM.

Ref https://github.com/JuliaLang/julia/issues/35460

When compiled with `--code-model=large --relocation-model=static`, LLVM emits PC relative relocations in the `.eh_frame` section. Loading it then causes a waring to be printed.

AFAICT, the actual relocation is not actually used by any existing tools which is why I'm not adding any test. This also seems to be the case for X86 ref https://reviews.llvm.org/D67779 . The only test done is confirming that this fixes the warning with `llvm-dwarfdump`.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D83800

Files:
  llvm/lib/Object/RelocationResolver.cpp


Index: llvm/lib/Object/RelocationResolver.cpp
===================================================================
--- llvm/lib/Object/RelocationResolver.cpp
+++ llvm/lib/Object/RelocationResolver.cpp
@@ -62,6 +62,8 @@
   switch (Type) {
   case ELF::R_AARCH64_ABS32:
   case ELF::R_AARCH64_ABS64:
+  case ELF::R_AARCH64_PREL32:
+  case ELF::R_AARCH64_PREL64:
     return true;
   default:
     return false;
@@ -74,6 +76,9 @@
     return (S + getELFAddend(R)) & 0xFFFFFFFF;
   case ELF::R_AARCH64_ABS64:
     return S + getELFAddend(R);
+  case ELF::R_AARCH64_PREL32:
+  case ELF::R_AARCH64_PREL64:
+    return S + getELFAddend(R) - R.getOffset();
   default:
     llvm_unreachable("Invalid relocation type");
   }
@@ -152,6 +157,8 @@
   switch (Type) {
   case ELF::R_PPC64_ADDR32:
   case ELF::R_PPC64_ADDR64:
+  case ELF::R_PPC64_REL32:
+  case ELF::R_PPC64_REL64:
     return true;
   default:
     return false;
@@ -164,6 +171,9 @@
     return (S + getELFAddend(R)) & 0xFFFFFFFF;
   case ELF::R_PPC64_ADDR64:
     return S + getELFAddend(R);
+  case ELF::R_PPC64_REL32:
+  case ELF::R_PPC64_REL64:
+    return S + getELFAddend(R) - R.getOffset();
   default:
     llvm_unreachable("Invalid relocation type");
   }


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