[ELF2] getLocalRelTarget should handle R_PPC64_TOC directly

R_PPC64_TOC does not have an associated symbol, but does have a non-zero VA
that target-specific code must compute using some non-trivial rule. We
handled this as a special case in PPC64TargetInfo::relocateOne, where
we knew to write this special address, but that did not work when creating shared
libraries. The special TOC address needs to be the subject of a
R_PPC64_RELATIVE relocation, and so we also need to know how to encode this
special address in the addend of that relocation.

Thus, some target-specific logic is necessary when creating R_PPC64_RELATIVE as
well. To solve this problem, we teach getLocalRelTarget to handle R_PPC64_TOC
as a special case. This allows us to remove the special case in
PPC64TargetInfo::relocateOne (simplifying code there), and naturally allows the
existing logic to do the right thing when creating associated R_PPC64_RELATIVE
relocations for shared libraries.

llvm-svn: 250555

1 files changed, 2 insertions, 0 deletions

diff --git a/lld/ELF/Target.h b/lld/ELF/Target.h
index ff770e1a477..1faaf02931d 100644
--- a/lld/ELF/Target.h
+++ b/lld/ELF/Target.h
@@ -58,6 +58,8 @@ protected:
   unsigned PltEntrySize = 8;
 };
 
+uint64_t getPPC64TocBase();
+
 extern std::unique_ptr<TargetInfo> Target;
 TargetInfo *createTarget();
 }