[CMake] Re: [MODULES][UseSWIG] Dependencies automagically computed!

[Tristan Carel]

On 12/12/06, Axel Roebel <Axel.Roebel at ircam.fr> wrote:

Hi Axel,

>
> I have some more observations :
>
> 1)
> the error message SWIG_GET_WRAPPER_DEPENDENCIES
> uses ${SWIG} instead of ${SWIG_EXECUTABLE}

You're completely right!

> 2)
> The command line used to find the dependencies
> does not use the same flags as the command line used to
> compile the files:
>
> In the latter you have
>
>       ${swig_source_file_flags}
>       ${CMAKE_SWIG_FLAGS}
>       ${swig_special_flags}
>       ${swig_extra_flags}
>       ${swig_include_dirs}
>
> while in the former you only use
>
> ${swig_getdeps_extra_flags} -${language}
>
> in some of my projects I use  ${CMAKE_SWIG_FLAGS}
> to pass include directories which fails with an error
> during dependency generation because some of the
> include files are not found. While you may argue that
> I should use the INCLUDE_DIRECTORIES command  I preferred
>  ${CMAKE_SWIG_FLAGS} because that would prevent
> the c++ compiler from searching in the project common
> swig include directories.

Arf, I didn't notice this variable. The use of `CMAKE_SWIG_FLAGS'
avoids mixing C++ / Swig environments, I guess I will use it too.

I added a RC3 version on the bt
(http://www.cmake.org/Bug/bug.php?op=show&bugid=4147) which takes care
of your comments. It should be all right now. Do you copy?

Thank you very much.
CU

> On Monday 11 December 2006 21:52, Tristan Carel wrote:
> > On 12/9/06, Axel Roebel <Axel.Roebel at ircam.fr> wrote:
> > > Tristan Carel wrote:
> > > > Hi Swig lovers,
> > > >
> > > > Axel had the great idea to use the -swiglib option in order to improve
> > > > the module's efficiency to properly fill the prerequesites variables.
> > > > I guess it is the perfect example of using a tool to perform its
> > > > `configure' part.
> > > >
> > > > On the other hand, it's hard to maintain dependencies of the wrapper
> > > > generated by swig because the developper has to manually update the
> > > > CMakeLists.txt each time a change relative to the file inclusions in
> > > > the main swig file is performed. But Swig provides a couple of
> > > > options: -M, -MM, -MF, ...
> > > > which have the same behavior than gcc's: compute the dependencies for
> > > > us, lazy developpers!
> > > >
> > > > So I submitted a new macro in the `UseSWIG.cmake' few days ago:
> > > > http://www.cmake.org/Bug/bug.php?op=show&bugid=4147&pos=7
> > > >
> > > > #   SWIG_GET_WRAPPER_DEPENDENCIES(swigFile genWrapper language
> > > > DEST_VARIABLE) #     - Put dependencies of the wrapper genWrapper
> > > > generated by swig from #     swigFile in DEST_VARIABLE
> > > >
> > > > A full description (including behavior, use cases) is available on the
> > > > bug tracker.
> > > >
> > > > So as Axel wrote:
> > > > "Any comments or  volunteers to try?"
> > >
> > > Hi Tristan,
> > >
> > > do I get the idea right that you want that the wrapper will be recreated
> > > whenever any of its dependencies changed? That would be really nice!
> > >
> > > So I tried the usecase 1 (because usecase 2 is too involved for me ;-)
> > > like
> > >
> > >   SWIG_ADD_MODULE(eaSDIF perl  ${INTERFACE_SRC}  )
> > >   SWIG_LINK_LIBRARIES(eaSDIF ${PERL_LIBRARIES} Easdif)
> > >
> > > however it seems I don't get any dependencies besides the
> > > main interface file  ${INTERFACE_SRC}.
> > >
> > > I do get them if I add
> > >
> > >       DEPENDS ${SWIG_MODULE_${name}_EXTRA_DEPS}
> >
> > Yes, It's exactly what I meant in my previous post when I wrote:
> >
> > "[...] it's hard to maintain dependencies of the wrapper
> > generated by swig because the developper has to manually update the
> > CMakeLists.txt [...]"
> >
> > I asked to CMake maintainers to add the SWIG_MODULE_${name}_EXTRA_DEPS
> > variable few months ago, but I didn't know that it could be done
> > automatically with the `swig -M' option.
> >
> > I submitted a patch for `UseSWIG.cmake' in the bug tracker. You say
> > that the dependencies are not computed by default by the
> > `SWIG_ADD_SOURCE_TO_MODULE'  macro. You probably patched your
> > `UseSWIG.cmake' before but ... did you?
> >
> > > to the ADD_CUSTOM_COMMANDS in SWIG_ADD_SOURCE_TO_MODULE.
> > >
> > > The added dependencies are pretty cool then. So I suppose you just
> > > forgot to actually use them?
> >
> > I used them but now I'm fed up to update it each time I modify the
> > inclusions of the swig file.
> >
> > > If you add the DEPENDS line you probably need to check for
> > > the case that ${SWIG_MODULE_${name}_EXTRA_DEPS}
> > > is empty. Otherwise DEPENDS will probably complain if the
> > > argument is an empty list. I have this error all the time
> > > for COMPILE_FLAGS, but I am not sure whether
> > > DEPENDS behaves similarly.
> >
> > I've already used the  `SWIG_ADD_SOURCE_TO_MODULE'  without using the
> > `${SWIG_MODULE_${name}_EXTRA_DEPS' feature so I guess it properly
> > works even if the variable is empty.


-- 
Tristan Carel
Music with dinner is an insult both to the cook and the violinist.