title: How to compile and link additional source code without including it explicitly into the project?
body: <p>I have a tool that generates additional source code on a build phase in a run script section. I would like to include resulting files of this section into compilation and linking. How it is possible to do? I know  that it is possible to write clang calls in additional run script section but I am looking alternative options, since it will be too complex to keep run script section with clang and project compiler settings in sync. </p>
  
  <p>Files that I am generating is a set of categories to classes currently included into the project. I do not need to worry about importing categories into the project, since all the code that generated automatically imported into generated-categories.h which is imported by default into precompiled header.</p>