shambolic shambolic - 4 months ago 19
C++ Question

How should I detect unnecessary #include files in a large C++ project?

I am working on a large C++ project in Visual Studio 2008, and there are a lot of files with unnecessary

#include
directives. Sometimes the
#include
s are just artifacts and everything will compile fine with them removed, and in other cases classes could be forward declared and the #include could be moved to the
.cpp
file. Are there any good tools for detecting both of these cases?

Answer

While it won't reveal unneeded include files, Visual studio has a setting /showIncludes (right click on a .cpp file, Properties->C/C++->Advanced) that will output a tree of all included files at compile time. This can help in identifying files that shouldn't need to be included.

You can also take a look at the pimpl idiom to let you get away with fewer header file dependencies to make it easier to see the cruft that you can remove.