(j3.2006) Question about lbound of an assumed-rank entity

[Bader, Reinhold]

Maybe, but the text in  the *second* paragraph cited by OP appears to be inconsistent with this interpretation.
Perhaps some exception (or at least clarifying text)  is needed for the case of interoperable interfaces? 
The same would also seem to apply for assumed-shape arrays.


> -----Urspr?ngliche Nachricht-----
> Von: j3-bounces at mailman.j3-fortran.org [mailto:j3-bounces at mailman.j3-
> fortran.org] Im Auftrag von Bill Long
> Gesendet: Montag, 27. Februar 2017 14:59
> An: fortran standards email list for J3 <j3 at mailman.j3-fortran.org>
> Betreff: Re: (j3.2006) Question about lbound of an assumed-rank entity
> 
> 
> On Feb 27, 2017, at 7:35 AM, Bader, Reinhold <Reinhold.Bader at lrz.de>
> wrote:
> 
> > Hello all,
> >
> > The answer I arrive at for the program output is
> >
> > D)
> > 2
> > 2
> > 2
> >
> > I believe the first paragraph cited below only applies to an
> > implementation of c_sub in C. An implementation in Fortran does not
> expose the C descriptor.
> 
> When calling a procedure with BIND(C) a Fortran caller does not know what
> language was used to write the callee. What it does know is that the BIND(C)
> callee uses the C calling conventions.  So the callee will get the address of a C
> descriptor as the incoming argument.  Even if it was written in Fortran.
> 
> Cheers,
> Bill
> 
> > (Whether it was a good idea to *not* remap bounds for the nonpointer
> > case of an assumed rank array within Fortran is a separate issue ...)
> >
> > Cheers
> > Reinhold
> >
> > Von: j3-bounces at mailman.j3-fortran.org
> > [mailto:j3-bounces at mailman.j3-fortran.org] Im Auftrag von Daniel C
> > Chen
> > Gesendet: Donnerstag, 23. Februar 2017 17:28
> > An: j3 at mailman.j3-fortran.org
> > Betreff: (j3.2006) Question about lbound of an assumed-rank entity
> >
> > Consider the following sample code:
> >
> > use, intrinsic :: iso_c_binding
> > integer(c_int) :: arr(2:4)
> > interface
> > subroutine c_sub(arg) BIND(C)
> > import
> > integer(c_int) :: arg(..)
> > end
> > subroutine sub(arg)
> > integer :: arg(..)
> > end
> > end interface
> >
> > Print*, lbound(arr, 1)
> > call c_sub(arr)
> > call sub(arr)
> > end
> >
> > subroutine c_sub(arg) BIND(C)
> > use, intrinsic :: iso_c_binding
> > integer(c_int) :: arg(..)
> > print *, lbound(arg, 1)
> > end
> >
> > subroutine sub(arg)
> > integer :: arg(..)
> > print *, lbound(arg, 1)
> > End
> >
> > Question: Should the output be:
> > A):
> > 2
> > 0
> > 2
> >
> > B):
> > 2
> > 1
> > 1
> >
> > C):
> > 2
> > 1
> > 2
> >
> > The standard says: (17-007)
> >
> > [497: 12-15]:
> > For a C descriptor of an array pointer or allocatable array, the value
> > of the lower_bound member of each element of the dim member of the
> descriptor is determined by argument association, allocation, or pointer
> association.
> > For a C descriptor of a nonallocatable nonpointer object, the value of
> > the lower_bound member of each element of the dim member of the
> descriptor is zero.
> >
> > [318: 31-36]:
> > An actual argument of any rank may correspond to an assumed-rank
> dummy
> > argument. The rank and shape of the dummy argument are the rank and
> > shape of the corresponding actual argument. If the rank is nonzero,
> > the lower and upper bounds of the dummy argument are those that would
> > be given by the intrinsic functions LBOUND and UBOUND respectively if
> > applied to the actual argument, except that when the actual argument is
> assumed-size, the upper bound of the last dimension of the dummy
> argument is 2 less than the lower bound of that dimension.
> >
> > Based on the above statement, answer A seems to be the correct one...
> >
> > Thanks,
> >
> > Daniel
> >
> > XL Fortran Development, Fortran Standard Representative IBM Toronto
> > Software Lab
> > Phone: 905-413-3056
> > Tie: 969-3056
> > Email: cdchen at ca.ibm.com
> > http://www.ibm.com/software/awdtools/fortran/xlfortran
> >
> > _______________________________________________
> > J3 mailing list
> > J3 at mailman.j3-fortran.org
> > http://mailman.j3-fortran.org/mailman/listinfo/j3
> 
> Bill Long                                                                       longb at cray.com
> Fortran Technical Support  &                                  voice:  651-605-9024
> Bioinformatics Software Development                     fax:  651-605-9142
> Cray Inc./ Cray Plaza, Suite 210/ 380 Jackson St./ St. Paul, MN 55101
> 
> 
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