[all-commits] [llvm/llvm-project] 16af97: [MC][ELF] Support for zero flag section groups

[Petr Hosek via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 16af97393346ad636298605930a8b503a55eb40a
      https://github.com/llvm/llvm-project/commit/16af97393346ad636298605930a8b503a55eb40a
  Author: Petr Hosek <phosek at google.com>
  Date:   2021-02-16 (Tue, 16 Feb 2021)

  Changed paths:
    M llvm/include/llvm/MC/MCContext.h
    M llvm/include/llvm/MC/MCSectionELF.h
    M llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
    M llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
    M llvm/lib/MC/ELFObjectWriter.cpp
    M llvm/lib/MC/MCContext.cpp
    M llvm/lib/MC/MCELFStreamer.cpp
    M llvm/lib/MC/MCObjectFileInfo.cpp
    M llvm/lib/MC/MCParser/ELFAsmParser.cpp
    M llvm/lib/MC/MCSectionELF.cpp
    M llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
    M llvm/lib/Target/ARM/ARMTargetObjectFile.cpp
    M llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
    M llvm/lib/Target/Mips/MCTargetDesc/MipsOptionRecord.cpp
    M llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
    M llvm/lib/Target/XCore/XCoreTargetObjectFile.cpp
    A llvm/test/CodeGen/X86/elf-group.ll

  Log Message:
  -----------
  [MC][ELF] Support for zero flag section groups

This change introduces support for zero flag ELF section groups to LLVM.
LLVM already supports COMDAT sections, which in ELF are a special type
of ELF section groups. These are generally useful to enable linker GC
where you want a group of sections to always travel together, that is to
be either retained or discarded as a whole, but without the COMDAT
semantics. Other ELF assemblers already support zero flag ELF section
groups and this change helps us reach feature parity.

Differential Revision: https://reviews.llvm.org/D95851