Why does doxygen always reprocess every file?

Question

When a project is built, only the files that changed after the last build are recompiled. Is it possible to get a similar behavior in doxygen?

Now it seems that doxygen always makes a clean/rebuild of its generated files whenever it is run.

With big projects such an optimization would save a lot of time.

Answer 1

Unfortunately, doxygen is a one-shot program: it reads some source files and writes some html files.

To be able to work like C/C++, it would need to have separate "compilation" (parse the source and write possible incoming and outgoing references to an "object" file) and "link" (read "object" files and resolve all references) steps. Implementing that is left as an exercise :)

And then you'd have to worry about source vs. header files... It's more hassle that it's worth so nobody implemented it.