[all-commits] [llvm/llvm-project] 6ed8e2: [ELF] Ignore the maximum of input section alignmen...

[Fangrui Song via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 6ed8e2014330b6a48d238cdc4357e788cdd6d445
      https://github.com/llvm/llvm-project/commit/6ed8e2014330b6a48d238cdc4357e788cdd6d445
  Author: Fangrui Song <maskray at google.com>
  Date:   2020-02-21 (Fri, 21 Feb 2020)

  Changed paths:
    M lld/ELF/LinkerScript.cpp
    M lld/ELF/Writer.cpp
    M lld/test/ELF/linkerscript/lma-align.test
    M lld/test/ELF/linkerscript/outsections-addr.s
    A lld/test/ELF/linkerscript/section-align2.test

  Log Message:
  -----------
  [ELF] Ignore the maximum of input section alignments for two cases

Follow-up for D74286.

Notations:

* alignExpr: the computed ALIGN value
* max_input_align: the maximum of input section alignments

This patch changes the following two cases to match GNU ld:

* When ALIGN is present, GNU ld sets output sh_addr to alignExpr, while lld use max(alignExpr, max_input_align)
* When addrExpr is specified but alignExpr is not, GNU ld sets output sh_addr to addrExpr, while lld uses `advance(0, max_input_align)`

Note, sh_addralign is still set to max(alignExpr, max_input_align).

lma-align.test is enhanced a bit to check we don't overalign sh_addr.

fixSectionAlignments() sets addrExpr but not alignExpr for the `!hasSectionsCommand` case.
This patch sets alignExpr as well so that max_input_align will be respected.

Reviewed By: grimar

Differential Revision: https://reviews.llvm.org/D74736