[all-commits] [llvm/llvm-project] 48e4b0: [runtimes] Revert the libc++ __config_site change

[Louis Dionne via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 48e4b0fd3a3d68cc9774699964cf4c6c2be38cf3
      https://github.com/llvm/llvm-project/commit/48e4b0fd3a3d68cc9774699964cf4c6c2be38cf3
  Author: Louis Dionne <ldionne at apple.com>
  Date:   2020-10-23 (Fri, 23 Oct 2020)

  Changed paths:
    M libcxx/CMakeLists.txt
    M libcxx/benchmarks/CMakeLists.txt
    M libcxx/cmake/Modules/HandleLibCXXABI.cmake
    M libcxx/docs/TestingLibcxx.rst
    M libcxx/include/CMakeLists.txt
    M libcxx/include/__config
    M libcxx/test/configs/legacy.cfg.in
    M libcxx/utils/libcxx/test/config.py
    M libcxxabi/CMakeLists.txt
    M libcxxabi/src/CMakeLists.txt
    M libcxxabi/test/libcxxabi/test/config.py
    M libunwind/test/libunwind/test/config.py
    M llvm/runtimes/CMakeLists.txt

  Log Message:
  -----------
  [runtimes] Revert the libc++ __config_site change

This is a massive revert of the following commits (from most revent to oldest):

	2b9b7b5775a1d8fcd7aa5abaa8fc0bc303434f1a.
	529ac33197f6408952ae995075ac5e2dc5287e81
	28270234f1478047e35879f4ba8838b47edfcc14
	69c2087283cf7b17ca75f69daebf4ffc158b754a
	b5aa67446e01bd277727b05710a42e69ac41e74b
	5d796645d6c8cadeb003715c33e231a8ba05b6de

After checking-in the __config_site change, a lot of things started breaking
due to widespread reliance on various aspects of libc++'s build, notably the
fact that we can include the headers from the source tree, but also reliance
on various "internal" CMake variables used by the runtimes build and compiler-rt.

These were unintended consequences of the change, and after two days, we
still haven't restored all the bots to being green. Instead, now that I
understand what specific areas this will blow up in, I should be able to
chop up the patch into smaller ones that are easier to digest.

See https://reviews.llvm.org/D89041 for more details on this adventure.