Bug 517574

Created attachment 357493 [details]
demo program with required interface

The correct form of the demo program.

--- array_display.f90   2009-08-14 13:31:34.000000000 -0500
+++ array_display_repaired.f90  2009-08-14 13:31:34.000000000 -0500
@@ -3,6 +3,13 @@
   integer, parameter:: dp=kind(0.d0)
   real(dp), pointer       :: p(:)
   real(dp)                :: x(1000)
+  interface
+    subroutine subr1(y,p)
+      integer, parameter:: dp=kind(0.d0)
+      real(dp), intent(in)    :: y(:)
+      real(dp), intent(in)    :: p(:)
+    end subroutine subr1
+  end interface
   allocate(p(1000))
   p(:) = 0._dp
   x(:) = 0._dp
@@ -21,6 +28,22 @@
   real(dp), allocatable   :: ar1(:)
   real(dp), allocatable   :: ar2(:,:)
   integer                 :: j
+  interface
+    subroutine subr2(r,t,s,u,v,w,ar1,ar2,j,y,p)
+      integer, parameter:: dp=kind(0.d0)
+      real(dp), intent(in)    :: r
+      real(dp), intent(in)    :: t(3)
+      real(dp), intent(in)    :: s
+      real(dp), intent(out)   :: u(3)
+      real(dp), intent(in)    :: v
+      real(dp), intent(in)    :: w
+      real(dp), intent(inout) :: ar1(:)
+      real(dp), intent(inout) :: ar2(:,:)
+      integer,  intent(inout) :: j
+      real(dp), intent(in)    :: y(:)
+      real(dp), intent(in)    :: p(:)
+    end subroutine subr2
+  end interface
   i = 4*size(p)
   allocate(ar1(i),ar2(3,i))
   call subr2(r,t,s,u,v,w,ar1,ar2,j,y,p)

Other compilers do give an error, for example:


$ pathf90 -g -O0 -o array_display_64_pathf90_3.1-g-O0 array_display.f90

subroutine subr1(y,p)
          ^         
pathf95-1277 pathf90: ERROR SUBR1, File = array_display.f90, Line = 12, Column = 12
 Procedure "SUBR1" is referenced at line 9 (array_display.f90).  It must have an explicit interface specified.

subroutine subr2(r,t,s,u,v,w,ar1,ar2,j,y,p)
          ^                                
pathf95-1277 pathf90: ERROR SUBR2, File = array_display.f90, Line = 29, Column = 12
 Procedure "SUBR2" is referenced at line 26 (array_display.f90).  It must have an explicit interface specified.

pathf95: PathScale(TM) Fortran Version 3.1 (f14) Thu Aug 13, 2009  15:08:15
pathf95: 45 source lines
pathf95: 2 Error(s), 0 Warning(s), 0 Other message(s), 0 ANSI(s)
pathf95: "explain pathf95-message number" gives more information about each message

$ /usr/local/tools/pathscale/bin/explain pathf95-1277
Error : Procedure "%s" is %s at line %s.  It must have an explicit interface
specified.

12.3.1.1 The Fortran standard requires an explicit interface in the following
        situations:

  A procedure other than a statement function shall have an explicit interface
  if the procedure is elemental or the procedure has
      (a) An optional dummy argument
      (b) A dummy argument that is an assumed-shape array, a pointer or a
          target
      (c) An array-valued result (functions only.)
      (d) A result that is a pointer (functions only)
      (e) A result whose character length parameter value is not assumed and
          not constant

  During global semantics the compiler has detected a call to an external
  procedure and has found an explicit interface for that procedure in
  another program unit during compilation.  The explicit interface for that
  procedure describes the procedure as having one or more of the above
  characteristics.  These characteristics require that an explicit interface
  be specified for this program unit in all program units that reference this
  procedure.

Oops, that should be gfortran44 in the steps to reproduce:
  Steps to Reproduce:
  1. gfortran44 -g -Wall -o array_display array_display.f90

See bug 517578 for the gfortan-4.1 clone of this bug.

This request was evaluated by Red Hat Product Management for
inclusion, but this component is not scheduled to be updated in
the current Red Hat Enterprise Linux release. If you would like
this request to be reviewed for the next minor release, ask your
support representative to set the next rhel-x.y flag to "?".

Fix not backportable to RHEL6 gcc, will be only wheneven gcc46-gfortran is added as a TechPreview (not earlier than next year).

Development Management has reviewed and declined this request.  You may appeal
this decision by reopening this request.

I can confirm that gcc 4.6.3 in F16 detects the error properly. Therefore DTS
and RHEL7 a1 should be OK.

[ben@snog Downloads]$ gfortran test-assumed.f95 
test-assumed.f95:26.12:

  call subr2(r,t,s,u,v,w,ar1,ar2,j,y,p)
            1
Error: Procedure 'subr2' at (1) with assumed-shape dummy argument 'ar1' must
have an explicit interface
test-assumed.f95:9.12:

  call subr1(x,p)
            1
Error: Procedure 'subr1' at (1) with assumed-shape dummy argument 'y' must have
an explicit interface
[ben@snog Downloads]$ gcc --version
gcc (GCC) 4.6.3 20120306 (Red Hat 4.6.3-2)
Copyright (C) 2011 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.