How do I define a C macro for a dependency?

[kwsp]

I need a macro to be defined for one of the dependencies I'm building with VCPKG. Preferrably I can configure this in my project's vcpkg.json file so builds are reproducible.

Specifically, I want to define

#define WINVER 0x0601
#define _WIN32_WINNT 0x0601

where 0x0601 is Windows 7. I need this defined so Intel TBB doesn't use a new Windows system call introduced in Windows 8.

https://github.com/oneapi-src/oneTBB/blob/d238e987a53f43f84b41d0c14dbc0089c45e5e65/src/tbb/global_control.cpp#L92-L101

I have to maintain software for a super legacy system running Win 7 and the only thing preventing my builds from work on Windows 7 is this macro.

[Osyotr]

Either set(VCPKG_CXX_FLAGS "/DWINVER=0x0601 /D_WIN32_WINNT=0x0601") (same for VCPKG_C_FLAGS) in your custom triplet or provide a custom toolchain where you can set these definitions.
https://learn.microsoft.com/en-us/vcpkg/users/triplets#vcpkg_cxx_flags

[dretax]

@Osyotr can you actually pass arguments somehow to vcpkg.exe or in the vcpkg.json to declare macros?

[Osyotr]

Maybe something like this --cmake-args=-DVCPKG_CXX_FLAGS=\"/DWINVER=0x0601\" though I would really write a custom triplet.

[dretax]

@Osyotr I made my triplet file. Is there a way to use user_settings.h from wolfssl in some way?
Platforms somehow have their own dirs, and i just included WIN/user_settings.h in my own project atleast when i used to compile manually.

[Osyotr]

What do you mean "use user_settings.h from wolfssl"?

[dretax]

@Osyotr wolfssl declares lots of macros based on many header files.
Basically like including certain settings per platform like WIN,ARDUINO, etc...
In the end i ended up declaring all the windows macros manually...

Only problem I see rn, Is that I'm not getting the x86 wolfssl built when set to x86 platform.

[kwsp]

Thanks @Osyotr ! I solved my problem with the following:

Custom triplet file at <project root>/triplets/x64-windows7.cmake

# From x64-windows.cmake
set(VCPKG_TARGET_ARCHITECTURE x64)
set(VCPKG_CRT_LINKAGE dynamic)
set(VCPKG_LIBRARY_LINKAGE dynamic)

# Define macros for Windows 7.
if (PORT MATCHES "tbb")
  set(VCPKG_CXX_FLAGS "/DWINVER=0x0601 /D_WIN32_WINNT=0x0601")
  set(VCPKG_C_FLAGS "/DWINVER=0x0601 /D_WIN32_WINNT=0x0601")
endif()

vcpkg.json

{
    ...
    "vcpkg-configuration": {
      "overlay-triplets": ["./triplets"]
    }
}

I had to use the if (PORT MATCHES "tbb") guard in the triplet because the /DWINVER define format only works for MSVC, and would break on my other deps that build with MinGW (e.g. Lapack). Do you have any tricks to make this work for all dependencies that build with MSVC?

[Neumann-A]

Put it in the toolchain for MSVC? Also you can use - flags with MSVC so -DWINVER=0x0601 will also be accepted