CMAKE_CURRENT_LIST_DIR
----------------------

Full directory of the listfile currently being processed.

As CMake processes the listfiles in your project this variable will
always be set to the directory where the listfile which is currently
being processed (CMAKE_CURRENT_LIST_FILE) is located.  The value has
dynamic scope.  When CMake starts processing commands in a source file
it sets this variable to the directory where this file is located.
When CMake finishes processing commands from the file it restores the
previous value.  Therefore the value of the variable inside a macro or
function is the directory of the file invoking the bottom-most entry
on the call stack, not the directory of the file containing the macro
or function definition.

See also CMAKE_CURRENT_LIST_FILE.