CMake/Help/variable/CMAKE_CURRENT_LIST_FILE.rst

CMAKE_CURRENT_LIST_FILE
-----------------------

Full path to the listfile currently being processed.

As CMake processes the listfiles in your project this variable will
always be set to the one currently being processed.  The value has
dynamic scope.  When CMake starts processing commands in a source file
it sets this variable to the location of the file.  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 file invoking the bottom-most entry on the call stack, not the
file containing the macro or function definition.

See also CMAKE_PARENT_LIST_FILE.