Re: configure.ac and Dolfin.h

[Rik]

On 02/19/2014 01:13 AM, address@hidden wrote:
> Message: 1
> Date: Tue, 18 Feb 2014 19:00:11 +0100
> From: Juan Pablo Carbajal <address@hidden>
> To: Marco Vassallo <address@hidden>
> Cc: Octave Maintainers List <address@hidden>, "c."
>       <address@hidden>
> Subject: Re: [FORGE] Fem-fenics installation fails
> Message-ID:
>       <address@hidden>
> Content-Type: text/plain; charset=ISO-8859-1
> 
> On Tue, Feb 18, 2014 at 6:13 PM, Marco Vassallo
> <address@hidden> wrote:
>> >
>> > On Tue, Feb 18, 2014 at 5:08 PM, Juan Pablo Carbajal <address@hidden>
>> > wrote:
>>> >>
>>> >> On Tue, Feb 18, 2014 at 6:03 PM, Marco Vassallo
>>> >> <address@hidden> wrote:
>>>> >> >
>>>> >> >
>>>> >> >
>>>> >> > On Tue, Feb 18, 2014 at 4:42 PM, Juan Pablo Carbajal
>>>> >> > <address@hidden>
>>>> >> > wrote:
>>>>> >> >>
>>>>> >> >> It seems to work. It installs and all examples run.
>>>>> >> >>
>>>> >> > Thanks for testing. Now I should figure out if it is possible to
>>>> >> > use a different code depending on the FeniCS version used.
>>>> >> >
>>>> >> > You are also able to plot everything? Which version of Octave are you
>>>> >> > using?
>>>> >> > For me, with the octave-gui sometimes crashes.
>>>> >> >
>>>>> >> >>
>>>>> >> >> On Tue, Feb 18, 2014 at 4:44 PM, Marco Vassallo
>>>>> >> >> <address@hidden> wrote:
>>>>>> >> >> > (Is there any way in which I can automatize it ? )
>>>>> >> >>
>>>>> >> >> Can we not just add Dense to the ac_check in the configure ac?
>>>>> >> >> something like
>>>>> >> >> AC_CHECK_HEADERs([Dense.h dolfin.h],
>>>>> >> >>  ...
>>>>> >> >>
>>>>> >> >>
>>>>> >> >> Also I think you shouldn't need to define -DHAVE_DOLFIN_H since this
>>>>> >> >> is exactly what AC_CHECK_HEADERS do, isn't it?
>>>>> >> >> What you could do is to check compilation by adding
>>>>> >> >>
>>>> >> >
>>>> >> > -DHAVE_DOLFIN_H is used only for the msh pkg, which I will try to fix 
>>>> >> > in
>>>> >> > the
>>>> >> > next few days.
>>>> >> > We were using HAVE_DOLFIN_H as you suggest, but there was some 
>>>> >> > problem,
>>>> >> > and I and Carne during the OctConf decided to use -DHAVE_DOLFIN_H.
>>>> >> > Please give a look here [1] and tell me if you have any suggestion and
>>>> >> > if it
>>>> >> > can be
>>>> >> > done in a better way.
>>>> >> >
>>>> >> > Thanks a lot
>>>> >> >
>>>> >> > Marco
>>>> >> >
>>>> >> > [1] http://gedeone-gsoc.blogspot.co.uk/2013/07/update-7.html
>>>> >> >
>>>>> >> >> #ifdef HAVE_DOLFIN_H
>>>>> >> >> #include <dolfin.h>
>>>>> >> >> #endif
>>>>> >> >>
>>>>> >> >> This will check that dolfin.h is compilable (I guess the API errors
>>>>> >> >> will jump up here).
>>>> >> >
>>>> >> >
>>> >>
>>> >> Hi Marco,
>>> >>
>>> >> Indeed, example 4 sometimes crashes
>>> >> octave-cli-3.8.0: ../../stable/libinterp/parse-tree/lex.ll:2489: void
>>> >> octave_base_lexer::handle_number(): Assertion `nread == 1' failed.
>>> >> panic: Aborted -- stopping myself...
>>> >> Aborted (core dumped)
>>> >>
>>> >> The plots work, yes.
>>> >>
>>> >> I recommend you just support the latest version of fenics.
>> >
>> >
>> > Ok thanks. I will do a new release of the pkg supporting FEniCS 1.3.0 very
>> > soon.
>> >
>> > Marco
> Great, I will try to see if I can help you with the configure.ac.
> As I see it, the trick you are doing might be ok, though it seems
> something is wrong with autotiols, then cause it should define
> HAVE_DOLFINN_H only if the header was found. Also one could check for
> Eigen/Dense and modify CPPFLAGS to include  path to system location,
> e.g. using locate or other trick @Rik?
> I have sen many examples where the action_if_found is a small program
> that includes the file and checks some feature. Example
> 
> AC_PREREQ([2.67])
> AC_INIT([tmp], [0.0])
> 
> AC_PROG_CXX
> 
> AC_LANG(C++)
> 
> AC_CHECK_HEADERS([eigen3/Eigen/Dense],
>                  [*** Here modify the ncludes path so dolfin.h knows
> where to find dense***],
>                  [AC_MSG_ERROR([Dofin won't compile])])
> 
> AC_CHECK_HEADERS([dolfin.h],
>       [#ifdef HAVE_DOLFIN_H
>        #include<dolfin.h>
>        #endif],
>       [AC_MSG_WARN([dolfin headers could not be found,
>                     some functionalities will be disabled,
>                     don't worry your package will still be
>                     working, though.])])

Juan,

I'm really busy at the moment so this can be my only contribution on this
subject.

AC_CHECK_HEADERS will find files that are in an ordinary location such as
/usr/include, /usr/local/include, etc.  If you have something that is in a
weird location you can do a few things.  The first would be to override the
environment variable CPPFLAGS when calling configure.

CPPFLAGS="-I/weird/directory" ./configure

A second approach is to ask the user to specify where cpp should look.  For
example, Octave's configure supports '--with-pkg-includedir=DIR' for a
number of packages like Qhull, curl, etc.  The autoconf code can be
extracted from m4/acinclude.m4 OCTAVE_CHECK_LIB macro.  Look for the
AC_ARG_WITH macro.

A third approach depends on having a pkg-config working for the Dense
package.  If that were the case you could directly query the package about
where to look.  This example is taken from the GraphicsMagick setup

MAGICK_CPPFLAGS=`$PKG_CONFIG --cflags-only-I $magick++`

Finally, I think you want to write the last code stanza as

AC_CHECK_HEADERS([dolfin.h], [], [],
  [#ifdef HAVE_DOLFIN_H
   #include<dolfin.h>
   #endif])

if test |a dolfin variable, maybe HAVE_DOLFIN_H|; then
  AC_MSG_WARN([dolfin headers could not be found,
                some functionalities will be disabled,
                don't worry your package will still be
                working, though.])
fi

See the bottom of AC_CHECK_HEADERS here
http://www.gnu.org/software/autoconf/manual/autoconf-2.68/html_node/Generic-Headers.html
for an example.

Good luck,
Rik