The CP2K Makefile automatically adopts to changes of the code base.

To add a file to the source tree, just create it. The Makefile will automatically discover it, compile it, and link it.

The file discovery is based on a simple naming convention:

• .F files are Fortran files. They are compiled into an object. They must contain either a MODULE or a PROGRAM.
• .f90 files are included Fortran files. They are not compiled into an object.
• .c files are C-files. They are compiled into an object.
• .cu files are Cuda-C-files. They are compiled into an object using Nvidia's nvcc.
• .h files are C-header files. They are included by .c or .cu files. They are not compiled into an object.

The code base is structured into directories. Every directory has to contain a files called PACKAGE . A typical PACKAGE looks like this:

{
"description": "Smart process pinning",
"requires": ("../common", "../dbcsr", "../machine", )
}

The entry requires list all the directories on which the code in the current directory may depend upon. This means, modules in the current directory may only use modules from the listed directories. The requirements between directories must not have cycles.

The Makefile allows to compile multiple version in parallel:

$ make ARCH=Linux-x86-64-gfortran VERSION="sopt sdb popt pdbg"