vcpkg/scripts/cmake/vcpkg_fail_port_install.cmake

## # vcpkg_fail_port_install
##
## Checks common requirements and fails the current portfile with a (default) error message
##
## ## Usage
## ```cmake
## vcpkg_fail_port_install(
##     [ALWAYS]
##     [MESSAGE <"Reason for failure">]
##     [ON_TARGET <Windows> [<OSX> ...]]
##     [ON_ARCH <x64> [<arm> ...]]
##     [ON_CRT_LINKAGE <static> [<dynamic> ...]])
##     [ON_LIBRARY_LINKAGE <static> [<dynamic> ...]]
## )
## ```
##
## ## Parameters
## ### MESSAGE
## Additional failure message. If none is given, a default message will be displayed depending on the failure condition.
##
## ### ALWAYS
## Will always fail early
##
## ### ON_TARGET
## Targets for which the build should fail early. Valid targets are `<target>` from `VCPKG_IS_TARGET_<target>` (see `vcpkg_common_definitions.cmake`).
##
## ### ON_ARCH
## Architecture for which the build should fail early.
##
## ### ON_CRT_LINKAGE
## CRT linkage for which the build should fail early.
##
## ### ON_LIBRARY_LINKAGE
## Library linkage for which the build should fail early.
##
## ## Examples
##
## * [aws-lambda-cpp](https://github.com/Microsoft/vcpkg/blob/master/ports/aws-lambda-cpp/portfile.cmake)
function(vcpkg_fail_port_install)
    cmake_parse_arguments(PARSE_ARGV 0 _csc "ALWAYS" "MESSAGE" "ON_TARGET;ON_ARCH;ON_CRT_LINKAGE;ON_LIBRARY_LINKAGE")
    if(DEFINED _csc_UNPARSED_ARGUMENTS)
        message(FATAL_ERROR "Unknown arguments passed to vcpkg_fail_port_install. Please correct the portfile!")
    endif()
    if(DEFINED _csc_MESSAGE)
        set(_csc_MESSAGE "${_csc_MESSAGE}\n")
    else()
        set(_csc_MESSAGE "")
    endif()

    unset(_fail_port)
    #Target fail check
    if(DEFINED _csc_ON_TARGET)
        foreach(_target ${_csc_ON_TARGET})
            string(TOUPPER ${_target} _target_upper)
            if(VCPKG_TARGET_IS_${_target_upper})
                set(_fail_port TRUE)
                set(_csc_MESSAGE "${_csc_MESSAGE}Target '${_target}' not supported by ${PORT}!\n")
            endif()
        endforeach()
    endif()

    #Architecture fail check
    if(DEFINED _csc_ON_ARCH)
        foreach(_arch ${_csc_ON_ARCH})
            if(${VCPKG_TARGET_ARCHITECTURE} MATCHES ${_arch})
                set(_fail_port TRUE)
                set(_csc_MESSAGE "${_csc_MESSAGE}Architecture '${_arch}' not supported by ${PORT}!\n")
            endif()
        endforeach()
    endif()

    #CRT linkage fail check
    if(DEFINED _csc_ON_CRT_LINKAGE)
        foreach(_crt_link ${_csc_ON_CRT_LINKAGE})
            if("${VCPKG_CRT_LINKAGE}" MATCHES "${_crt_link}")
                set(_fail_port TRUE)
                set(_csc_MESSAGE "${_csc_MESSAGE}CRT linkage '${VCPKG_CRT_LINKAGE}' not supported by ${PORT}!\n")
            endif()
        endforeach()
    endif()

    #Library linkage fail check
        if(DEFINED _csc_ON_LIBRARY_LINKAGE)
        foreach(_lib_link ${_csc_ON_LIBRARY_LINKAGE})
            if("${VCPKG_LIBRARY_LINKAGE}" MATCHES "${_lib_link}")
                set(_fail_port TRUE)
                set(_csc_MESSAGE "${_csc_MESSAGE}Library linkage '${VCPKG_LIBRARY_LINKAGE}' not supported by ${PORT}!\n")
            endif()
        endforeach()
    endif()

    if(_fail_port OR _csc_ALWAYS)
        message(FATAL_ERROR ${_csc_MESSAGE})
    endif()
endfunction()