One thing that I am struggling with in working in new development projects is how to deal with multiple vcproj projects and the include paths that go with them.  What is the best schema for dealing with include folders?  Currently, we copy files that we know are needed in other projects to a common include folder. 

For example, if we have projects A.vcproj and B.vcproj, and B.vcproj requires A.h from A.vcproj, then in A.vcproj we will have a custom build step for A.h to copy it to the common include folder.  B.vcproj will then add the common include folder to it’s include path.  This method avoids having to know which project and which directory contains the header file.  It works well for the 60 projects involved in our main solution file.

There is a caveat to this system:  sometimes it’s not possible to keep a strict dependency tree for projects.  For example, occasionally, there may be 2 projects which create a circular dependency based on include requirements.  We work very hard to avoid this for DLLs.  However, for LIBs, we are less strict.  As such, we cannot rely on one project’s header files being copied before it’s needed by another project.  Our solution was to create a pre-process build step that would parse the project files and perform the copy for all projects before the first one was built.

It’s not elegant, but it works.  And sometimes that’s what matters.

What I’m wondering now is how other companies deal with similar issues.  How do you deal with including files from other projects?  Do you use a common include folder?  Do you hard code the paths to the included files in your #include statement?  Or do you have another system that’s working well for you?