"No Target Architecture" when compiling libcxxwrap-julia using MSVC

[barche]

When compiling against the Julia nightlies using MSVC, the following error appears:

C:\Program Files (x86)\Windows Kits\10\Include\10.0.17763.0\um\winnt.h(154,1): fatal error C1189: #error:  "No Target Architecture" [C:\projects\libcxxwrap-julia\build\cxxwrap_julia.vcxproj]

This comes from including errhandlingapi.h directly, here:

julia/src/support/dtypes.h

Line 351 in 2835347

#include <errhandlingapi.h>

On my local machine, I found a crude workaround, but I doubt this will work in all cases:

#ifdef _OS_WINDOWS_

#define DWORD unsigned long
extern "C" __declspec(dllimport) DWORD __stdcall GetLastError();
extern "C" __declspec(dllimport) void __stdcall SetLastError(DWORD dwErrCode);

#endif

[barche]

I'll try to generalize my workaround above, since Julia 1.4 is now a release that has this problem and being able to use MSVC on windows is quite handy in the CxxWrap workflow for local development. Suggestions are welcome ;)

[Petr-Hlavenka]

I can confirm the @barche workaround works. I'm not sure but the problems seen here are caused by the non-standard use of windows SDK headers - usually in windows programming the errhandlingapi.h file is never used standalone, but by including windows.h. I do understand that making such a portable system across so many CPU architectures , OSs and compilers is a very complex task, nicely demonstrated by the complexity of the header files, where,as I understand, many preprocessor directives normally delivered by windows.h, are workarounded directly in julia's header files. I think, as MSVC is still a supported consumer of the julia.h incule file, we should have some testing infrastructure in Travis that would check that the API headers are parseable by MSVC.

[nsamsonov]

Also hitting this when trying to embed julia and include julia.h. The workaround does not work. The code is copy-pasted from the docs:

#include <iostream>
#include <julia.h>


int main()
{
    /* required: setup the Julia context */
    jl_init();

    /* run Julia commands */
    jl_eval_string("print(sqrt(2.0))");

    jl_atexit_hook(0);
    return 0;
}

[rpep]

#37957 also seems to be the same issue.

[toivoh]

Thanks to an answer I found on StackOverflow, I got it work by using

#include <uv.h>
#include <windows.h>
#include <julia.h>

I still get a compilation warning:

...\windows kits\10\include\10.0.17763.0\ucrt\signal.h(22): warning C4005: 'NSIG': macro redefinition
...\appdata\local\programs\julia-1.6.0\include\julia\uv\win.h(68): note: see previous definition of 'NSIG'

where the first definition defines NSIG to be 23 and the second 29, but the embedding seems to work if I also take care of #39595 as I described there (tried with Julia 1.6.0 in MSVC 2017).