[Bug fortran/57423] New: Incorrect keyword argument names in Fortran OpenMP procedure interfaces in omp_lib

["spam.brian.taylor at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57423

            Bug ID: 57423
           Summary: Incorrect keyword argument names in Fortran OpenMP
                    procedure interfaces in omp_lib
           Product: gcc
           Version: 4.8.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: spam.brian.taylor at gmail dot com

Created attachment 30197
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=30197&action=edit
Test omp_lib keyword arguments

The argument names of many of the the OpenMP procedure interfaces in gfortran's
omp_lib.f90 differ from those listed in the OpenMP 3.0 standard.  Starting with
Fortran 90, dummy argument names in procedures with explicit interfaces are, in
a sense, part of the API.  Section 3.1 of the OpenMP 3.0 standard defines the
various procedure interfaces.

For example, one should be able write code like:

call omp_set_num_threads(num_threads=1)

This does not work with the present implementation in omp_lib.f90, as the
interface is declared with an argument named "set" rather than "num_threads".

Page 108, line 18 of the OpenMP 3.0 standard states, "The OpenMP Fortran API
runtime library routines are external procedures."  However, lines 20-23 read,
"Interface declarations for the OpenMP Fortran runtime library routines
described in this chapter shall be provided in the form of a Fortran include
file named omp_lib.h or a Fortran 90 module named omp_lib. It is implementation
defined whether the include file or the module file (or both) is provided."  It
is perhaps arguable, then, if it is intended for keyword arguments to be part
of the OpenMP Fortran interface, but if explicit interfaces are to be declared
in omp_lib.f90, it can't hurt to make the implementation match up more closely
with the standard.

Of the procedures that take arguments declared in omp_lib.f90, only
omp_set_schedule, omp_set_max_active_levels, omp_get_ancestor_thread_num, and
omp_get_team_size have correct argument name(s).

The attached test case illustrates these problems.  It should be compiled with:

gfortran -fopenmp -c openmp_keyword_arguments.F90