[Bug fortran/51268] New: [Regression] A subroutine can not know anymore its own interface

["bardeau at iram dot fr" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51268

             Bug #: 51268
           Summary: [Regression] A subroutine can not know anymore its own
                    interface
    Classification: Unclassified
           Product: gcc
           Version: fortran-dev
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: bardeau@iram.fr


Created attachment 25881
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25881
Declare a subroutine interface and use this interface in the subroutine

This a regression which appeared in the last months: problem is in 4.7.0
20111119 but not in 4.7.0 20110507

In the latest version, a subroutine can not know its own interface and an error
is raised about duplicate symbols (see example attached):

test.f90:15.6:

  use myinterfaces
      1
Error: 'mysub' of module 'myinterfaces', imported at (1), is also the name of
the current program unit

>From our developer point of view, this is a very annoying regression, since we
are in charge of several libraries, with hundreds of subroutines in each. We
made the choice to provide all the interfaces of all the subroutines to all of
them, in order to ensure a correct use of the subroutines everywhere. For each
library we thus have a dedicated interface module which is used everywhere.
Forbidding a subroutine to know its own interface would imply to use the
statement "use only", which is definitely not well suited for large programs.

Thanks for your help.