[lld] r250101 - [ELF2] Add a base set of PPC64 relocations

[Rafael Espíndola via llvm-commits]

> +  // FIXME: This obviously does not do the right thing when there is no .got
> +  // section, but there is a .toc or .tocbss section.
> +  uint64_t TocVA = Out<ELF64BE>::Got->getVA();
> +  if (!TocVA)
> +    TocVA = Out<ELF64BE>::Plt->getVA();

There is always a got if there is a plt, so this could be an assert, no?

> +  switch (Type) {
> +  default: return false;

git-clang-format.



> +
>  bool PPC64TargetInfo::relocNeedsPlt(uint32_t Type, const SymbolBody &S) const {
> -  return false;
> +  if (Type != R_PPC64_REL24)
> +    return false;
> +
> +  // These are function calls that need to be redirected through a PLT stub.
> +  return S.isShared() || (S.isUndefined() && S.isWeak());
>  }

Why the extra "(S.isUndefined() && S.isWeak())"?

Is this here for the same reason as X86_64 and i386? If so, you only
need the S.isShared(), no?


> +  // For a TOC-relative relocation, adjust the addend and proceed in terms of
> +  // the corresponding ADDR16 relocation type.
>    switch (Type) {
> -  case R_PPC64_ADDR64:
> -    write64be(Loc, SymVA + Rel.r_addend);
> +  case R_PPC64_TOC16:       Type = R_PPC64_ADDR16;       A -= TB; break;
> +  case R_PPC64_TOC16_DS:    Type = R_PPC64_ADDR16_DS;    A -= TB; break;
> +  case R_PPC64_TOC16_LO:    Type = R_PPC64_ADDR16_LO;    A -= TB; break;
> +  case R_PPC64_TOC16_LO_DS: Type = R_PPC64_ADDR16_LO_DS; A -= TB; break;
> +  case R_PPC64_TOC16_HI:    Type = R_PPC64_ADDR16_HI;    A -= TB; break;
> +  case R_PPC64_TOC16_HA:    Type = R_PPC64_ADDR16_HA;    A -= TB; break;
> +  default: break;

git-clang-format.