[libcxx] Refactor CMakeLists.txt handling of compile and link flags to suppress warnings.
Summary:
Currently we have 5 variables that are used to specify options for building libcxx
1. `LIBCXX_CXX_FEATURE_FLAGS`
2. `LIBCXX_CXX_WARNING_FLAGS`
3. `LIBCXX_CXX_REQUIRED_FLAGS`
4. `compile_flags` (in libcxx/lib)
5. `link_flags` (in libcxx/lib)
The first three all get put into `CMAKE_CXX_FLAGS`.
This changes the way flags are handled by only using 3 different options:
1. `LIBCXX_CXX_FLAGS` - general compile and link flags.
2. `LIBCXX_COMPILE_FLAGS` - compile only flags.
3. `LIBCXX_LINK_FLAGS` - link only flags.
This patch also removes the warning about `-nostdinc++` being unused during linking.
Reviewers: mclow.lists, danalbert
Reviewed By: danalbert
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D6277
git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@222080 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed