Piotr Caban (@piotr) commented about dlls/ucrtbase/ucrtbase.spec:
@ cdecl -arch=i386,x86_64,arm,arm64 -norelay __CxxFrameHandler(ptr ptr ptr ptr) @ cdecl -arch=i386,x86_64,arm,arm64 -norelay __CxxFrameHandler2(ptr ptr ptr ptr) __CxxFrameHandler @ cdecl -arch=i386,x86_64,arm,arm64 -norelay __CxxFrameHandler3(ptr ptr ptr ptr) __CxxFrameHandler +@ cdecl -arch=i386,x86_64,arm,arm64 -norelay __CxxFrameHandler4(ptr ptr ptr ptr) __CxxFrameHandler
The `__CxxFrameHandler4` is x86_64 only export. `__CxxFrameHandler` can't be used as the implementation (it stores exception related information differently).
The function is partially implemented in vcruntime140_1.dll. It would be best to move except_x86_64.c file to dlls/msvcrt directory and use PARENTSRC in vcruntime140 to avoid code duplication.