[all-commits] [llvm/llvm-project] 690a46: [runtimes] Don't link against compiler-rt when we ...

[Louis Dionne via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 690a4692d1f34bd410f987acc9afcffd8c79bfa8
      https://github.com/llvm/llvm-project/commit/690a4692d1f34bd410f987acc9afcffd8c79bfa8
  Author: Louis Dionne <ldionne.2 at gmail.com>
  Date:   2022-08-24 (Wed, 24 Aug 2022)

  Changed paths:
    M libcxx/cmake/config-ix.cmake
    M libcxxabi/cmake/config-ix.cmake

  Log Message:
  -----------
  [runtimes] Don't link against compiler-rt when we don't find it

Otherwise, we would end up passing `-lNOTFOUND` to the compiler, which
caused various compiler checks to fail and ended up breaking the build
in the most obscure ways. For example, checks for -faligned-allocation
would fail because the compiler would complain about an unknown library
called NOTFOUND, and we would end up not passing -faligned-allocation
anywhere in our build. This is madness.

An even better alternative would be to simply FATAL_ERROR if we don't
find the builtins library. However, it seems like our build has been
working fine without finding it for a while, so instead of making a
bunch of builds fail, we can figure out why linking against compiler-rt
doesn't actually seem to be required in a follow-up, and perhaps
relax that.