[CMake] Include-Dir order problem

[Michael Hertling]

On 02/13/2011 01:27 AM, Andreas Pakulat wrote:
> Hi,
> 
> I've got a somewhat tricky problem here with include directories. I'm
> building a couple of source files and for some of them I need to add an
> include-directory to the front of the list that cmake passes to the
> compiler. At the same time other source files in that directory need to
> not have that include-dir in front of the list.
> 
> I can't see a way to do this, except by using COMPILE_FLAGS source file
> properties for each and every file to specify include-dirs and not use
> include_directories at all, as COMPILE_FLAGS always end up behind the
> includes.
> 
> So, am I missing something here? If not I guess I'll have to find that
> bugreport about making include-dirs a source-file property and vote for
> it so it gets included into 2.8.5...

Currently, AFAIK, it's not possible to set source-file-specific include
directories unless one (mis)uses COMPILE_FLAGS which is accompanied by
the shortcoming you've mentioned. Probably, the really clean solution
ATM would be a reorganisation of the sources, but I doubt if the need
for different include directories is an appropriate criterion for a
project's directory layout.

If there're only a few affected files, another possible workaround
consists of file-specific configured headers, i.e. find the special
include directories and inject them into config'd headers that are
included by the concerned source files, or even modify the latters
themselves in this manner. Of course, the sources must be touched
to do that.

IMO, from a conceptual point of view, INCLUDE_DIRECTORIES should be
also available as target and source file property, so I would vote
for 1968 and 8189 - seem to be relatives - and possibly 8874, too.
However, if this undertaking is addressed, one should think about
how the include directories are ordered on the compiler's command
line. Perhaps, there might be a convention that they appear from
most to least specific, i.e. in source-target-directory order.

Regards,

Michael