On May 29, 2012, at 8:00 AM, Barry Smith wrote: >> >> Now I understand what you want. I agree with your goal of making the call >> standard and transparent. There is one issue with this approach for a >> function like PetscBagRegisterEnum (as far as I understand the C code), >> where you don't copy the string array in the bag item structure, but keep a >> reference to it (l. 80 in bag.c). After Carray and list1 are deallocated, >> the bag item->list points to some nonsense. I lost my mind trying to find a >> workaround last week. >> >> Would you be OK with requesting that each of the strings in list have some >> padding at the end, and be modified in the wrapper (adding the C_NULL_CHAR)? >> The alternative would be to modify PetscBagRegisterEnum, in order to store >> the content of list instead of just a reference, which may not be something >> you want to do right now. > > Actually. I think PetscBagRegisterEnum() should be modified to copy the > list, it is an unsafe function even from C now. Implicitly I assumed that > list was declared as a global static variable (hence the current > PetscBagRegisterEnum() is ok) but I should not have made that assumption.
I have changed PetscBagRegisterEnum() to now properly copy the list of enum strings values Barry > > Barry > >> >> Blaise >> >> >>> >>> Barry >>> >>> >>> >>> On May 27, 2012, at 10:16 AM, Blaise Bourdin wrote: >>> >>>> Barry, >>>> >>>> If I frame your email, will you sign it for me? ;) >>>> >>>> I am traveling so I did not have much time to do it, even in my sleep, but >>>> Tim's solution is essentially right. >>>> >>>> Have a look at the attached code. I had to write my own interface to >>>> PetscOptionsGetEnum, but I have to do the equivalent of FIXCHAR by myself >>>> (basically appending //C_NULL_CHAR). I checked in the debugger, and the >>>> list argument that is passed to PetscOptionsGetEList is the same as the >>>> one passed from C. Is this what you want? >>>> >>>> Do you want to do the FIXCHAR business in the C or fortran side? I suspect >>>> that you would prefer not having to append the C_NULL_CHAR in fortran, but >>>> I can't figure how to do that without allocating a new array of strings, >>>> and causing a memory leak. What do you think? >>>> >>>> If this is not what you want, could you meet me half way and write the >>>> fortran interface you would like to use, in which case I will try to write >>>> the missing fortran parts. >>>> >>>> Blaise >>>> <PetscF2003.F90> >>>>> >>>>> Tim, >>>>> >>>>> Thanks. But what I want is all bundled up a routine that takes in the >>>>> Fortran array of character strings and allocates and copies over them to >>>>> the C ptr business. Likely I could figure it out myself with but Blaise >>>>> is such a Fortran wizard he can do it optimally in his sleep :-) >>>>> >>>>> Barry >>>>> >>>>> On May 25, 2012, at 8:14 PM, Tim Gallagher wrote: >>>>> >>>>>> For what it's worth, I answered a question about how to pass string >>>>>> arrays awhile ago on StackOverflow: >>>>>> >>>>>> http://stackoverflow.com/questions/9686532/arrays-of-strings-in-fortran-c-bridges-using-iso-c-binding/9686741#9686741 >>>>>> >>>>>> Tim >>>>>> >>>>>> ----- Original Message ----- >>>>>> From: "Barry Smith" <bsmith at mcs.anl.gov> >>>>>> To: "For users of the development version of PETSc" <petsc-dev at >>>>>> mcs.anl.gov> >>>>>> Sent: Friday, May 25, 2012 8:57:52 PM >>>>>> Subject: Re: [petsc-dev] What needs to be done before a release? >>>>>> >>>>>> Blaise >>>>>> >>>>>> If you provide a fortran function to convert an array of Fortran strings >>>>>> to an array of C strings and tell us how to delete the result then we'll >>>>>> provide a PetscOptionsGetEnum() for Fortran. >>>>>> >>>>>> Barry >>>>>> >>>>>> On May 2, 2012, at 12:02 PM, Blaise Bourdin wrote: >>>>>> >>>>>>> Barry, >>>>>>> >>>>>>>>> Also, fortran wrappers over PetscOptionsEnum and PetscBagRegisterEnum >>>>>>>>> would be nice. I understand that it >>>>>>>>> is a bit tricky since it involves passing fortran arrays of strings. >>>>>>>> >>>>>>>> Yup. We'd be willing to support these from FORTRAN but someone else >>>>>>>> has to do the dirty work of figuring out how to handle those array of >>>>>>>> strings (maybe F2003?). >>>>>>> >>>>>>> I am attaching a simple proof of concept example that demonstrates how >>>>>>> to write a fortran interface and call petsc C functions from fortran >>>>>>> using F2003 C-interoperability instead of going through the fortran >>>>>>> bindings. >>>>>>> >>>>>>> Don't be put off by all the warnings if you use gfortran. They would be >>>>>>> easy to avoid. Basically, right now, you detect the fortran integer and >>>>>>> real kinds that match that of the C ones. It would be quite simple to >>>>>>> get the fortran C-interoperable integer and real types associated with >>>>>>> the C type of PetscInt, PetscReal etc. >>>>>>> >>>>>>> Basically, we (I?) could write a fortran interface and a fortran >>>>>>> function for the tricky functions involving arrays of string, instead >>>>>>> of creating a custom binding in C. Are you willing to let some fortran >>>>>>> pollution into the petsc code? Where would these function have to be? >>>>>>> >>>>>>> Blaise >>>>>>> >>>>>>> PS: you need FCFLAGS='-ffixed-line-length-none -ffree-line-length-none >>>>>>> -ffree-form' or some subset of these to compile with gfortran. I'm not >>>>>>> sure why these are not the default with a file suffix .F90 >>>>>>> >>>>>>> <PetscF2003Binding.F90> >>>>>>> -- >>>>>>> Department of Mathematics and Center for Computation & Technology >>>>>>> Louisiana State University, Baton Rouge, LA 70803, USA >>>>>>> Tel. +1 (225) 578 1612, Fax +1 (225) 578 4276 >>>>>>> http://www.math.lsu.edu/~bourdin >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>>> -- >>>> Department of Mathematics and Center for Computation & Technology >>>> Louisiana State University, Baton Rouge, LA 70803, USA >>>> Tel. +1 (225) 578 1612, Fax +1 (225) 578 4276 >>>> http://www.math.lsu.edu/~bourdin >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>> >>> <ex1f.F90> >> >> -- >> Department of Mathematics and Center for Computation & Technology >> Louisiana State University, Baton Rouge, LA 70803, USA >> Tel. +1 (225) 578 1612, Fax +1 (225) 578 4276 >> http://www.math.lsu.edu/~bourdin >> >> >> >> >> >> >> >
