[PATCH] D61563: [ELF] Error on relocations to local undefined symbols

[Fangrui Song via Phabricator via llvm-commits]

MaskRay marked an inline comment as done.
MaskRay added inline comments.


================
Comment at: ELF/Relocations.cpp:1040
   if (oneof<R_HINT, R_NONE>(Expr))
     return;
 
----------------
grimar wrote:
> I tried to reorder/simplify the code slightly to avoid symbol index check:
> 
> ```
> const uint8_t *RelocatedAddr = Sec.data().begin() + Rel.r_offset;
> RelExpr Expr = Target->getRelExpr(Type, Sym, RelocatedAddr);
> 
> // Ignore "hint" relocations because they are only markers for relaxation.
> if (oneof<R_HINT, R_NONE>(Expr))
>   return;
> 
> // Skip if the target symbol is an erroneous undefined symbol.
> if (maybeReportUndefined(Sym, Sec, Rel.r_offset))
>   return;
> ```
> 
> With that the only test case that fails is mips-abs-got.s.
> I am not sure if we can do something with it, I am not a MIPS expert.
@atanasyan Can `R_MIPS_GOT_PAGE` be (reasonably) used with symbol index 0? If it is theoretically possible but unlikely emitted by compiles/humans in reality, `mips-abs-got.s` should probably be updated.


Repository:
  rLLD LLVM Linker

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D61563/new/

https://reviews.llvm.org/D61563