[CMake] Check whether C++ headers are self-sufficient

[Andreas Naumann]

Why do you want to use one library per header? I think, it would be 
sufficient to have one cc-file per header and one library per folder. 
The library would simply contain all files.
Why do you worry about large build directories?

Regards,
Andreas

Am 14.03.2015 um 13:19 schrieb Christoph Grüninger:
> Dear CMakers,
> I want to have all my C++ headers self-sufficient (self-contained),
> i.e., a header can be included without additional includes. This is not
> only handy but also part of Google's C++ styleguide [2].
>
> It would be great to have a make target (let's call it headercheck),
> that can check for this, by compiling a simple test.cc file for each
> current_header.h:
>    #include <config.h>
>    #include "current_header.h"
>    #include "current_header.h"
>
> Additionally it would be great to have such a target for every folder
> (checking all headers recursively) and every header that is explicitly
> passed as an argument.
>
> We tried this with CMake: We generate a test.cc file per header and
> create a library for every cc file. The problem is, that we get hundreds
> of additional targets, we generate a lot of folders and files which can
> increase our build directory size by an order of magnitude and it does
> not work properly on a per file or per directory basis.
>
> What do you think, is there a good way to have such a target headercheck
> with CMake? Or would it be better to include it as a CTest? Or better as
> an external (bash) script as proposed in [1]?
>
> If it can be done in a good way with CMake, would it be of interest to
> include it as a feature in CMake? Or as an external project similar to
> UseLATEX.cmake?
>
> Bye
> Christoph
>
> [1]
> http://stackoverflow.com/questions/1892043/self-sufficient-header-files-in-c-c
> [2]
> http://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Self_contained_Headers
>