dolfin team mailing list archive

[Anders Logg <logg@xxxxxxxxx>]

On Tue, Jul 05, 2005 at 02:08:19PM -0500, Matthew Knepley wrote:
> Anders Logg <logg@xxxxxxxxx> writes:
> 
>        I think this is a really bad model. First, the examples below assume
> a single build, whereas PETSc can have many builds with vastly different
> flags. How would petsc-config distinguish these? Whatever the mechanism, it
> would still be new since no standard exists.

Couldn't you just add an extra flag or two? Should be possible since
there is a finite set of ways to compile PETSc.

>        Moreover, these options become a single text string with all
> semantics stripped out. All this information is in the pickled configure
> along with the smenatics in bmake/$PETSC_ARCH/RDict.db. It would be
> possible to get all the information from Python that you get from the
> make system. No one does it yet, but I like this model. Eventually, our
> build will be all Python since make is notoriously limited and not portable.

But all I need to compile against PETSc is a single text string and I get
the same string every time I do 'make getincludedirs'.

>       However, we have compromised and provided a simple way to get the
> flags. Does it matter whether the script is called makefile or petsc-config?
> You would still need all the bmake stuff to get the right answer anyway. Right?

It matters since if it were called petsc-config I wouldn't have had to
ask you how to do it.

/Anders

>     Matt
> 
> > A user just needs a simple way to get the cflags and libs. It
> > shouldn't be hard to generate this script at compile-time (we do it in
> > DOLFIN, see src/config/). Many large projects like GTK use this:
> >
> > galerkin:~> gtk-config 
> > Usage: gtk-config [OPTIONS] [LIBRARIES]
> > Options:
> >         [--prefix[=DIR]]
> >         [--exec-prefix[=DIR]]
> >         [--version]
> >         [--libs]
> >         [--cflags]
> > Libraries:
> >         gtk
> >         gthread
> >
> > galerkin:~> gtk-config --cflags
> > -I/usr/include/gtk-1.2 -I/usr/include/glib-1.2 -I/usr/lib/glib/include
> >
> > galerkin:~> gtk-config --libs
> > -L/usr/lib -L/usr/X11R6/lib -lgtk -lgdk -rdynamic -lgmodule -lglib
> > -ldl -lXi -lXext -lX11 -lm
> >
> > This script could provide different options for compiling against an
> > installed version of PETSc (in $prefix/include, $prefix/lib and then
> > PETSC_DIR should not be needed) or to compile against the PETSc
> > source tree. DOLFIN has options for this:
> >
> > galerkin:~> dolfin-config 
> > Usage: dolfin-config [options]
> >
> >        --version  (get version number)
> >        --cflags   (get compiler flags)
> >        --libs     (get libraries for linking)
> >        --compiler (get compiler)
> >
> >        --cflags_dolfin (for demo programs in the source tree)
> >        --libs_dolfin   (for demo programs in the source tree)
> >
> >> 1)  If "make getincludedirs" and "make getlinklibs" do not work properly for 
> >> installed versions of PETSc that is a bug we need to fix! I can change the
> >> install process to also copy over the top level makefile, but this does not
> >> make sense because having ${INSTALL_DIR}/makefile makes no sense if 
> >> ${INSTALL_DIR} is something like /usr/local! I could copy it into the bmake
> >> subdirectory BUT then it is inconsistent with a "non installed" built PETSc.
> >> Is there a good solution? Maybe most of what is in makefile should really
> >> be in bmake/makefile?
> >> 
> >> 2) We could keep the XXXXimpl.h files in a subdirectory of include, instead
> >> of "where they belong with each component :-)" or have the "make all" and
> >> "make install" make copies down to a subdirectory of include (I'm inclined to
> >> do the later) so everyone can link against them in the same place.
> >> 
> >>    What do you think? Suggestions?
> >
> > It doesn't matter to me as long as we can access it.
> >
> >>     Barry
> >> 
> >>   Of course, this does not resolve the neverending problem of not being 
> >> able to debug installed code :-(
> >
> > I think the majority of users would rather send an email to the
> > maintainers than debugging PETSc themselves, so I don't think it's a
> > big issue. Someone who knows how to debug can easily download the
> > source and compile against it.
> >
> > /Anders
> >
> >> 
> >> 
> >> 
> >> On Mon, 4 Jul 2005, Johan Jansson wrote:
> >> 
> >> > Hi!
> >> > 
> >> > We've implemented a PetSc preconditioner in DOLFIN, but it seems the
> >> > preconditioner implementation API (pcimpl.h) isn't a public API
> >> > (i.e. user code cannot see it). We've solved this by copying pcimpl.h
> >> > into DOLFIN, but this is not a good solution. Could you consider
> >> > making the preconditioner implementation API public?
> >> > 
> >> > The reason the preconditioner is implemented in DOLFIN and not in
> >> > PetSc is because the preconditioner depends on DOLFIN. The idea is to
> >> > solve a nonlinear system in a time-stepping method for ODEs by
> >> > Newton's method with a Krylov solver preconditioned with a fixed-point
> >> > solver. The fixed-point solver is part of DOLFIN. There are likely
> >> > other such applications of externally implemented preconditioners.
> >> > 
> >> > Thank you,
> >> >   Johan
> >> > 
> >> > 
> >> > On Mon, Jul 04, 2005 at 11:44:47PM -0400, Faheem Mitha wrote:
> >> > >
> >> > >
> >> > > On Mon, 4 Jul 2005, Faheem Mitha wrote:
> >> > >
> >> > > >On Mon, 4 Jul 2005, Anders Logg wrote:
> >> > >
> >> > > >>Look through the PETSc makefile and
> >> > > >>see if you find the target "getincludedirs".
> >> > > >>
> >> > > >>In my petsc-2.2.1/makefile:
> >> > > >>
> >> > > >>   include ${PETSC_DIR}/bmake/common/base
> >> > > >
> >> > > >Yes, it's there.
> >> > >
> >> > > Just to clarify, this is in the sources, but not in the installed library.
> >> > > You weren't expecting it to be there, were you?
> >> >
> >> > Yes, I was. DOLFIN needs to figure out where to find PETSc and it then
> >> > uses the getincludedirs flag with make to get the correct flags.
> >> >
> >> > If possible, I would rather do a 'make install' in PETSc like with any
> >> > other library (without needing to set PETSC_DIR to something special),
> >> > but then I don't know how to get compiler flags and link libraries
> >> > correctly. It would be nice to have a petsc-config script (like
> >> > gtk-config, xml2-config, dolfin-config, etc) that spits out the flags.
> >> 
> >
> >
> >
> >
> 

-- 
Anders Logg
Research Assistant Professor
Toyota Technological Institute at Chicago
http://www.tti-c.org/logg/