llvm-project/runtimes
Martin Storsjö 4169b5251f [runtimes] [CMake] Fix checks for -Werror when building with incomplete toolchains
When we add `--unwindlib=none` during the CMake configure phase (to
make CMake linking tests succeed before the unwind library has been
built for the first time - when bootstrapping a cross toolchain from
scratch), we add it to `CMAKE_REQUIRED_FLAGS` to make later CMake tests
pass.

When the option is added to `CMAKE_REQUIRED_FLAGS`, it gets added to
both compilation and linking commands. When --unwindlib=none is added
to the compilation command, it causes warnings (about being unused
during compilation, as it only affects linking).

When all CMake test compilations produce warnings, later CMake tests
for `-Werror` fail.

Add `--{start,end}-no-unused-arguments` around `--unwindlib=none`, if
supported, to avoid unnecessary warnings due to this option.

If the CMake requirement is bumped to 3.14, we could use
`CMAKE_REQUIRED_LINK_OPTIONS` instead, removing the need for the
`--{start,end}-no-unused-arguments` options. (However, do note that
`CMAKE_REQUIRED_LINK_OPTIONS` is problematic in combination with
`CMAKE_TRY_COMPILE_TARGET_TYPE` set to `STATIC_LIBRARY`; see
https://gitlab.kitware.com/cmake/cmake/-/issues/23454.)

Differential Revision: https://reviews.llvm.org/D124377
2022-05-13 00:29:51 +03:00
..
CMakeLists.txt [runtimes] [CMake] Fix checks for -Werror when building with incomplete toolchains 2022-05-13 00:29:51 +03:00
Components.cmake.in
Tests.cmake.in Generalize "check-all" umbrella targets, use for check-clang-tools 2022-05-06 12:30:49 +02:00