llvm-capstone/libcxxabi
Louis Dionne 8ac71b026e [libc++] Remove internal "build-with-external-thread-library" configuration
Our threading support layer is currently a huge mess. There are too many
configurations with too many confusing names, and none of them are tested
in the usual CI. Here's a list of names related to these configurations:

  LIBCXX_BUILD_EXTERNAL_THREAD_LIBRARY
  _LIBCPP_BUILDING_THREAD_LIBRARY_EXTERNAL

  LIBCXXABI_BUILD_EXTERNAL_THREAD_LIBRARY
  _LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL

  LIBCXX_HAS_EXTERNAL_THREAD_API
  _LIBCPP_HAS_THREAD_API_EXTERNAL

This patch cleans this up by removing the ability to build libc++ with
an "external" threading library for testing purposes, removing 4 out of
6 "names" above. That setting was meant to be used by libc++ developers,
but we don't use it in-tree and it's not part of our CI.

I know the ability to use an external threading API is used by some folks
out-of-tree, and this patch doesn't change that. This only changes the
way they will have to test their external threading support. After this
patch, the intent would be for them to set `-DLIBCXX_HAS_EXTERNAL_THREAD_API=ON`
when building the library, and to provide their usual `<__external_threading>`
header when they are testing the library. This can be done easily now
that we support custom lit configuration files in test suites.

The motivation for this patch is that our threading support layer is
basically unmaintainable -- anything beyond adding a new "backend" in
the slot designed for it requires incredible attention. The complexity
added by this setting just doesn't pull its weigh considering the
available alternatives.

Concretely, this will also allow future patches to clean up
`<__threading_support>` significantly.

Differential Revision: https://reviews.llvm.org/D154466
2023-07-17 09:32:36 -04:00
..
cmake [runtimes] Remove add_target_flags* functions and use add_flags* instead 2023-02-21 13:16:44 +01:00
fuzz
include [libcxxabi] Omit dllimport in public headers in MinGW mode 2023-04-19 13:34:54 +03:00
lib
src [Demangle] use std::string_view::data rather than &*std::string_view::begin 2023-07-13 10:20:09 -07:00
test [libc++] Remove internal "build-with-external-thread-library" configuration 2023-07-17 09:32:36 -04:00
www Remove references to old mailing lists that have moved to discourse. Replace with links to discourse. 2022-07-22 09:59:03 -07:00
.clang-format [libcxx] Remove extraneous '---' lines in .clang-format files 2022-06-15 01:34:37 -07:00
.gitignore
CMakeLists.txt [libc++] Remove internal "build-with-external-thread-library" configuration 2023-07-17 09:32:36 -04:00
CREDITS.TXT
LICENSE.TXT