tool to analyze/cleanup #include dependencies?

Doxygen can be used for that... It can build dependency graphes.

And there a few tricks that can be used to do some cleanup by hand.

1) Select a problematic file and add a #pragma error Is it used in it. Then compile that project. Any file that include that won't compile. Then you can analyse those to see if included are needed or not.

2) Comment out some portion of an header file and see if it still compile. You might be able to split a file so that definition that are changing a lot are not in the same file as complex declaration that seldom changes for example.

Some time ago I was faced with similar problems and spent two days solving it 'manually' by taking all the #includes out of the header files and inserting them in any cpp file that stopped compiling. Only exceptions were #includes to base classes and a few exceptions that I couldn't easily move because of external dependencies. That alone increased compile times by a factor of 2-3!

Later I've found a product that might have been helpful: IncludeManager. I didn't yet take the time to test it, but since it offers a free trial you might just as well give it a try. I'd expect that it's graphs give you a good idea where optimization might pay off most.

Rather than dependent on a tool.
i would suggest you to use ur header files under the key word
#pragma once

you may also do as follows:


SampleHeader.h

if !defined SAMPLE_HEADER_H // where SAMPLE_HEADER_H is a alias name for this header declaration
@define SAMPLE_HEADER_H
#endif //SAMPLE_HEADER_H

This will take care ur header file being defined once and not more than that!