CMAKE_TRY_COMPILE_PLATFORM_VARIABLES

New in version 3.6.

List of variables that the try_compile() command source file signature must propagate into the test project in order to target the same platform as the host project.

This variable should not be set by project code. It is meant to be set by CMake's platform information modules for the current toolchain, or by a toolchain file when used with CMAKE_TOOLCHAIN_FILE.

Variables meaningful to CMake, such as CMAKE_<LANG>_FLAGS, are propagated automatically. The CMAKE_TRY_COMPILE_PLATFORM_VARIABLES variable may be set to pass custom variables meaningful to a toolchain file. For example, a toolchain file may contain:

set(CMAKE_SYSTEM_NAME ...)
set(CMAKE_TRY_COMPILE_PLATFORM_VARIABLES MY_CUSTOM_VARIABLE)
# ... use MY_CUSTOM_VARIABLE ...

If a user passes -DMY_CUSTOM_VARIABLE=SomeValue to CMake then this setting will be made visible to the toolchain file both for the main project and for test projects generated by the try_compile() command source file signature.