Commit 0d17410e authored by Nico Weber's avatar Nico Weber
Browse files

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
parent 9d212e83

llvm/include/llvm/Support/Compiler.h

+7 −0
Original line number Diff line number Diff line
@@ -24,6 +24,13 @@ 


#if defined(_MSC_VER)

#include <sal.h>



#if _MSC_VER == 1924

// See https://developercommunity.visualstudio.com/content/problem/845933/miscompile-boolean-condition-deduced-to-be-always.html

// and thread "[llvm-dev] Longstanding failing tests - clang-tidy, MachO, Polly"

// on llvm-dev Jan 21-23 2020.

#error "MSVC 19.24 version of MSVC is known to miscompile LLVM."

#endif

#endif



#ifndef __has_feature