[all-commits] [llvm/llvm-project] fe3406: [lld] Add target support for SystemZ (s390x) (#75643)

[Ulrich Weigand via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: fe3406e349884e4ef61480dd0607f1e237102c74
      https://github.com/llvm/llvm-project/commit/fe3406e349884e4ef61480dd0607f1e237102c74
  Author: Ulrich Weigand <ulrich.weigand at de.ibm.com>
  Date:   2024-02-13 (Tue, 13 Feb 2024)

  Changed paths:
    A lld/ELF/Arch/SystemZ.cpp
    M lld/ELF/CMakeLists.txt
    M lld/ELF/Driver.cpp
    M lld/ELF/InputFiles.cpp
    M lld/ELF/InputSection.cpp
    M lld/ELF/Relocations.cpp
    M lld/ELF/Relocations.h
    M lld/ELF/ScriptParser.cpp
    M lld/ELF/SyntheticSections.cpp
    M lld/ELF/Target.cpp
    M lld/ELF/Target.h
    A lld/test/ELF/Inputs/systemz-init.s
    A lld/test/ELF/basic-systemz.s
    A lld/test/ELF/emulation-systemz.s
    A lld/test/ELF/lto/systemz.ll
    A lld/test/ELF/systemz-got.s
    A lld/test/ELF/systemz-gotent-relax-align.s
    A lld/test/ELF/systemz-gotent-relax-und-dso.s
    A lld/test/ELF/systemz-gotent-relax.s
    A lld/test/ELF/systemz-ifunc-nonpreemptible.s
    A lld/test/ELF/systemz-init-padding.s
    A lld/test/ELF/systemz-pie.s
    A lld/test/ELF/systemz-plt.s
    A lld/test/ELF/systemz-reloc-abs.s
    A lld/test/ELF/systemz-reloc-disp12.s
    A lld/test/ELF/systemz-reloc-disp20.s
    A lld/test/ELF/systemz-reloc-got.s
    A lld/test/ELF/systemz-reloc-gotrel.s
    A lld/test/ELF/systemz-reloc-pc16.s
    A lld/test/ELF/systemz-reloc-pc32.s
    A lld/test/ELF/systemz-reloc-pcdbl.s
    A lld/test/ELF/systemz-tls-gd.s
    A lld/test/ELF/systemz-tls-ie.s
    A lld/test/ELF/systemz-tls-ld.s
    A lld/test/ELF/systemz-tls-le.s
    M lld/test/lit.cfg.py

  Log Message:
  -----------
  [lld] Add target support for SystemZ (s390x) (#75643)

This patch adds full support for linking SystemZ (ELF s390x) object
files. Support should be generally complete:
- All relocation types are supported.
- Full shared library support (DYNAMIC, GOT, PLT, ifunc).
- Relaxation of TLS and GOT relocations where appropriate.
- Platform-specific test cases.

In addition to new platform code and the obvious changes, there were a
few additional changes to common code:

- Add three new RelExpr members (R_GOTPLT_OFF, R_GOTPLT_PC, and
R_PLT_GOTREL) needed to support certain s390x relocations. I chose not
to use a platform-specific name since nothing in the definition of these
relocs is actually platform-specific; it is well possible that other
platforms will need the same.

- A couple of tweaks to TLS relocation handling, as the particular
semantics of the s390x versions differ slightly. See comments in the
code.

This was tested by building and testing >1500 Fedora packages, with only
a handful of failures; as these also have issues when building with LLD
on other architectures, they seem unrelated.

Co-authored-by: Tulio Magno Quites Machado Filho <tuliom at redhat.com>