# output_required_files

Disallowed since version 3.0. See CMake Policy `CMP0032`.

Approximate C preprocessor dependency scanning.

This command exists only because ancient CMake versions provided it. CMake handles preprocessor dependency scanning automatically using a more advanced scanner.

    output_required_files(srcfile outputfile)

Outputs a list of all the source files that are required by the specified `srcfile`. This list is written into `outputfile`. This is similar to writing out the dependencies for `srcfile` except that it jumps from `.h` files into `.cxx`, `.c` and `.cpp` files if possible.