[all-commits] [llvm/llvm-project] 5f9be2: [SystemZ][ZOS] Prefer -nostdlib++ as opposed to -n...

[zibi2 via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5f9be2c3e37c0428ba56876dd84af04b8d9d8915
      https://github.com/llvm/llvm-project/commit/5f9be2c3e37c0428ba56876dd84af04b8d9d8915
  Author: Zbigniew Sarbinowski <zibi at ca.ibm.com>
  Date:   2021-02-16 (Tue, 16 Feb 2021)

  Changed paths:
    M libcxx/CMakeLists.txt
    M libcxx/cmake/config-ix.cmake
    M libcxxabi/cmake/config-ix.cmake
    M libcxxabi/src/CMakeLists.txt
    M libunwind/cmake/config-ix.cmake
    M libunwind/src/CMakeLists.txt

  Log Message:
  -----------
  [SystemZ][ZOS] Prefer -nostdlib++ as opposed to -nodefaultlibs when building c++ libraries

Let's use -nostdlib++ rather than -nodefaultlibs when building libc++/libc++abi/libunwind libraries. The default is -nostdlib++ if supported by a build compiler like it is the case with clang, otherwise -nodefaultlibs is used as before.

This change is needed to avoid additional changes at the link step and not to increase the maintenance costs. If clang with -nodefaultlibs is used all the libraries which are removed but required would have to be manually added in. This set of libraries are unique and will send out.

The propose change will allow to make the link step simple for other platforms as well.

Reviewed By: #libc, #libc_abi, ldionne

Differential Revision: https://reviews.llvm.org/D95875