[all-commits] [llvm/llvm-project] fbf2f6: [ELF] Update flag propagation rule to ignore disca...

[Fangrui Song via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: fbf2f6640067dec144f9aef8231d58c740e3d014
      https://github.com/llvm/llvm-project/commit/fbf2f6640067dec144f9aef8231d58c740e3d014
  Author: Fangrui Song <i at maskray.me>
  Date:   2022-02-01 (Tue, 01 Feb 2022)

  Changed paths:
    M lld/ELF/LinkerScript.cpp
    M lld/test/ELF/linkerscript/insert-before.test

  Log Message:
  -----------
  [ELF] Update flag propagation rule to ignore discarded output sections

See the updated insert-before.test for the effects: many synthetic
sections are SHF_ALLOC|SHF_WRITE. If they are discarded, we don't want
to propagate their flags to subsequent output section descriptions.

`getFirstInputSection(sec) == nullptr` can technically be merged into
`isDiscardable` but I'd like to postpone that as not sharing code may give more
refactoring opportunity.

Depends on D118529.

Reviewed By: peter.smith, bluca

Differential Revision: https://reviews.llvm.org/D118530