CMAKE_CURRENT_SOURCE_DIR

The path to the source directory currently being processed.

This is the full path to the source directory that is currently being processed by cmake.

When run in cmake -P script mode, CMake sets the variables CMAKE_BINARY_DIR, CMAKE_SOURCE_DIR, CMAKE_CURRENT_BINARY_DIR and CMAKE_CURRENT_SOURCE_DIR to the current working directory.

Modifying CMAKE_CURRENT_SOURCE_DIR has undefined behavior.