[all-commits] [llvm/llvm-project] 0e9a01: [libc++] Fix modules builds when features are removed

[Louis Dionne via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 0e9a01dcac99ccf599738cef394b840b126d5cc9
      https://github.com/llvm/llvm-project/commit/0e9a01dcac99ccf599738cef394b840b126d5cc9
  Author: Louis Dionne <ldionne.2 at gmail.com>
  Date:   2022-06-08 (Wed, 08 Jun 2022)

  Changed paths:
    M libcxx/docs/Contributing.rst
    M libcxx/include/CMakeLists.txt
    M libcxx/include/csignal
    R libcxx/include/module.modulemap
    A libcxx/include/module.modulemap.in
    M libcxx/test/libcxx/lint/lint_headers.sh.py
    M libcxx/test/libcxx/lint/lint_modulemap.sh.py
    M libcxx/test/libcxx/modules_include.sh.cpp
    M libcxx/utils/generate_header_tests.py
    M libcxx/utils/libcxx/test/dsl.py
    M libcxx/utils/libcxx/test/features.py

  Log Message:
  -----------
  [libc++] Fix modules builds when features are removed

When some headers are not available because we removed features like
localization or threads, the compiler should not try to include these
headers when building modules. To avoid that from happening, add a
requires-declaration that is never satisfied when the configuration
in use doesn't support a header.

rdar://93777687

Differential Revision: https://reviews.llvm.org/D127127