[all-commits] [llvm/llvm-project] 0d1741: Prevent building with MSVC 14.24

[Nico Weber via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 0d17410e919124b3a9194b9bdbe2ce39dd779941
      https://github.com/llvm/llvm-project/commit/0d17410e919124b3a9194b9bdbe2ce39dd779941
  Author: Nico Weber <thakis at chromium.org>
  Date:   2020-01-28 (Tue, 28 Jan 2020)

  Changed paths:
    M llvm/include/llvm/Support/Compiler.h

  Log Message:
  -----------
  Prevent building with MSVC 14.24

MSVC 14.24 miscompiles some of LLVM's code, which makes at least these tests fail:

    LLVM :: MC/MachO/gen-dwarf-cpp.s
    LLVM :: MC/MachO/gen-dwarf-macro-cpp.s
    LLVM :: MC/MachO/gen-dwarf-producer.s
    LLVM :: MC/MachO/gen-dwarf.s

It seems better to diagnose that at build time. Since both the previous
and the next version have a fix, this might be good enough and we might
not need a real workaround. (We ran into this at
https://crbug.com/1045948)

If you hit this, use either a newer or an older version of MSVC,
or use clang-cl as host compiler.

Differential Revision: https://reviews.llvm.org/D73550