[all-commits] [llvm/llvm-project] 710949: [clang][Driver] Don't hardcode --as-needed/--no-as...

[rorth via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 710949482edb96a329104317164909979f2387aa
      https://github.com/llvm/llvm-project/commit/710949482edb96a329104317164909979f2387aa
  Author: Rainer Orth <ro at gcc.gnu.org>
  Date:   2020-08-06 (Thu, 06 Aug 2020)

  Changed paths:
    M clang/lib/Driver/ToolChains/CommonArgs.cpp

  Log Message:
  -----------
  [clang][Driver] Don't hardcode --as-needed/--no-as-needed on Illumos

`ninja check-all` currently fails on Illumos:

  [84/716] Generating default/Asan-i386-inline-Test
  FAILED: projects/compiler-rt/lib/asan/tests/default/Asan-i386-inline-Test
  cd /var/llvm/dist-amd64-release/projects/compiler-rt/lib/asan/tests && /var/llvm/dist-amd64-release/./bin/clang ASAN_INST_TEST_OBJECTS.gtest-all.cc.i386-inline.o ASAN_INST_TEST_OBJECTS.asan_globals_test.cpp.i386-inline.o ASAN_INST_TEST_OBJECTS.asan_interface_test.cpp.i386-inline.o ASAN_INST_TEST_OBJECTS.asan_internal_interface_test.cpp.i386-inline.o ASAN_INST_TEST_OBJECTS.asan_test.cpp.i386-inline.o ASAN_INST_TEST_OBJECTS.asan_oob_test.cpp.i386-inline.o ASAN_INST_TEST_OBJECTS.asan_mem_test.cpp.i386-inline.o ASAN_INST_TEST_OBJECTS.asan_str_test.cpp.i386-inline.o ASAN_INST_TEST_OBJECTS.asan_test_main.cpp.i386-inline.o -o /var/llvm/dist-amd64-release/projects/compiler-rt/lib/asan/tests/default/./Asan-i386-inline-Test -g --driver-mode=g++ -fsanitize=address -m32
  ld: fatal: unrecognized option '--no-as-needed'
  ld: fatal: use the -z help option for usage information
  clang-11: error: linker command failed with exit code 1 (use -v to see invocation)

`clang` unconditionally passes `--as-needed`/`--no-as-needed` to the
linker.  This works on Solaris 11.[34] which added a couple of option
aliases to the native linker to improve compatibility with GNU `ld`.
Illumos `ld` didn't do this, so one needs to use the corresponding
native options `-z ignore`/`-z record` instead.

Because this works on both Solaris and Illumos, the current patch always
passes the native options on Solaris.  This isn't fully correct, however:
when using GNU `ld` on Solaris (not yet supported; I'm working on that),
one still needs `--as-needed` instead.

I'm hardcoding this decision because a generic detection via a `cmake` test
is hard: many systems have their own implementation of `getDefaultLinker`
and `cmake` would have to duplicate the information encoded there.
Besides, it would still break when `-fuse-ld` is used.

Tested on `amd64-pc-solaris2.11` (Solaris 11.4 and OpenIndiana 2020.04),
`sparcv9-sun-solaris2.11`, and `x86_64-pc-linux-gnu`.

Differential Revision: https://reviews.llvm.org/D84412