Martin Storsjö 7af584ed87 [libunwind] Try to add --unwindlib=none while configuring and building libunwind ...

If Clang is set up to link directly against libunwind (via the
--unwindlib option, or the corresponding builtin default option),
configuring libunwind will fail while bootstrapping (before the
initial libunwind is built), because every cmake test will
fail due to -lunwind not being found, and linking the shared library
will fail similarly.

Check if --unwindlib=none is supported, and add it in that case.
Using check_c_compiler_flag on its own doesn't work, because that only
adds the tested flag to the compilation command, and if -lunwind is
missing, the linking step would still fail - instead try adding it
to CMAKE_REQUIRED_FLAGS and restore the variable if it doesn't work.

This avoids having to pass --unwindlib=none while building libunwind.

Differential Revision: https://reviews.llvm.org/D112126

2021-11-05 10:10:19 +02:00

..

CheckLinkerFlag.cmake

[libunwind] Try to add --unwindlib=none while configuring and building libunwind

2021-11-05 10:10:19 +02:00

EnableLanguageNolink.cmake

[libunwind] Try to add --unwindlib=none while configuring and building libunwind

2021-11-05 10:10:19 +02:00

HandleCompilerRT.cmake

[CMake] Cache the compiler-rt library search results

2021-10-27 17:53:03 -07:00