[cmake] How to distinguish between msys2 and mingw-w64

[silverqx]

Is there any way how can I distinguish between these two, I need to target MSYS2 UCRT64 specifically but not mingw-w64. CMake doesn't support this, the if(MINGW) targets both.

This is the code I want to use in MSYS2 but need to exclude it in mingw-w64:

target_link_options(${target} INTERFACE
    $<$<CONFIG:Debug,RelWithDebInfo>:
        LINKER:--dynamicbase,--high-entropy-va,--nxcompat
        LINKER:--default-image-base-high>
    # Use faster linker ( GNU ld linker doesn't work with the Clang;
    # for both GCC and Clang )
    # TODO use LINKER_TYPE target property when min. version will be CMake v3.29 silverqx
    -fuse-ld=lld
)

[Biswa96]

I think "if WIN32 and not MSVC" would be appropriate in this case.

If you want to link with msys runtime then "if MSYS" would be correct one.

[silverqx]

As I expected this doesn't work:

if(MINGW)
    if(WIN32 AND NOT MSVC)
        message("||-- MSYS2 UCRT64")
    else()
        message("||-- mingw-w64")
    endif()
endif()

[silverqx]

Now I also tried this to be sure and doesn't work with Ninja:

if(MINGW)
    if(MSYS)
        message("||-- MSYS2 UCRT64")
    else()
        message("||-- mingw-w64")
    endif()
endif()

[MehdiChinoune]

MINGW is not defined in MSYS
But MSYS is defined when using 'MSYS Makefiles' generator.

[MehdiChinoune]

CMake doesn't distinguish between UCRT (runtime of UCRT64,CLANG64...) and MSVCRT (runtime of MINGW64 and MINGW32).
You could distinguish between them using try_run CMake function and define variable according to its results.

[silverqx]

MINGW is not defined in MSYS

This can be something, if it's true then I check it using eg. check_cxx_source_compiles() and decide based on the result.