[all-commits] [llvm/llvm-project] 98c89c: [MSVC] Don't add -nostdinc++ -isystem to runtimes ...

[Reid Kleckner via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 98c89ccfbd7467f946874c2af170d0f504355dd1
      https://github.com/llvm/llvm-project/commit/98c89ccfbd7467f946874c2af170d0f504355dd1
  Author: Reid Kleckner <rnk at google.com>
  Date:   2021-01-15 (Fri, 15 Jan 2021)

  Changed paths:
    M runtimes/CMakeLists.txt

  Log Message:
  -----------
  [MSVC] Don't add -nostdinc++ -isystem to runtimes builds

If the host compiler is MSVC or clang-cl, then the compiler used to
buidl the runtimes will be clang-cl, and it doesn't support either of
those flags.

Worse, because -isystem is a space separated flag, it causes all cmake
try_compile tests to fail, so none of the -Wno-* flags make it to the
compiler in libcxx. I noticed that we weren't passing
-Wno-user-defined-literals to clang-cl and were getting warnings in the
build, and this fixes that for me.

Differential Revision: https://reviews.llvm.org/D94817