[all-commits] [llvm/llvm-project] 96e237: [ELF] Don't special case weak symbols for pie with...

[Fangrui Song via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 96e2376d02f0840e82b96314108660ecabe63c7f
      https://github.com/llvm/llvm-project/commit/96e2376d02f0840e82b96314108660ecabe63c7f
  Author: Fangrui Song <maskray at google.com>
  Date:   2020-01-08 (Wed, 08 Jan 2020)

  Changed paths:
    M lld/ELF/Symbols.cpp
    M lld/test/ELF/ppc32-weak-undef-call.s
    R lld/test/ELF/weak-undef-no-shared-libs.s

  Log Message:
  -----------
  [ELF] Don't special case weak symbols for pie with no shared objects

D59275 added the following clause to Symbol::includeInDynsym()

  if (isUndefWeak() && Config->Pie && SharedFiles.empty())
    return false;

D59549 explored the possibility to generalize it for -no-pie.

GNU ld's rules are architecture dependent and partly controlled by -z
{,no-}dynamic-undefined-weak. Our attempts to mimic its rules are
actually half-baked and don't provide perceivable benefits (it can save
a few more weak undefined symbols in .dynsym in a -static-pie
executable). Let's just delete the rule for simplicity. We will expect
cosmetic inconsistencies with ld.bfd in certain -static-pie scenarios.

This permits a simplification in D71795.

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D71794