[Patch, Fortran, F03] PR 80046: Explicit interface required: pointer argument

[Janus Weil]

Hi all,

here is a patch that enhances the diagnostics for procedure-pointer
assignments, so that procedure-pointer components that need an
explicit interface are correctly rejected.

Regtests cleanly on x86_64-linux-gnu. Ok for trunk?

Cheers,
Janus


2017-03-29  Janus Weil  <ja...@gcc.gnu.org>

    PR fortran/80046
    * expr.c (gfc_check_pointer_assign): Check if procedure pointer
    components in a pointer assignment need an explicit interface.

2017-03-29  Janus Weil  <ja...@gcc.gnu.org>

    PR fortran/80046
    * gfortran.dg/proc_ptr_comp_48.f90: New test case.

Index: gcc/fortran/expr.c
===================================================================
--- gcc/fortran/expr.c  (revision 246573)
+++ gcc/fortran/expr.c  (working copy)
@@ -3595,25 +3595,41 @@ gfc_check_pointer_assign (gfc_expr *lvalue, gfc_ex
          return false;
        }
 
-      if (s1 == s2 || !s1 || !s2)
-       return true;
-
       /* F08:7.2.2.4 (4)  */
-      if (s1->attr.if_source == IFSRC_UNKNOWN
-         && gfc_explicit_interface_required (s2, err, sizeof(err)))
+      if (s2 && gfc_explicit_interface_required (s2, err, sizeof(err)))
        {
-         gfc_error ("Explicit interface required for %qs at %L: %s",
-                    s1->name, &lvalue->where, err);
-         return false;
+         if (comp1 && !s1)
+           {
+             gfc_error ("Explicit interface required for component %qs at %L: 
%s",
+                        comp1->name, &lvalue->where, err);
+             return false;
+           }
+         else if (s1->attr.if_source == IFSRC_UNKNOWN)
+           {
+             gfc_error ("Explicit interface required for %qs at %L: %s",
+                        s1->name, &lvalue->where, err);
+             return false;
+           }
        }
-      if (s2->attr.if_source == IFSRC_UNKNOWN
-         && gfc_explicit_interface_required (s1, err, sizeof(err)))
+      if (s1 && gfc_explicit_interface_required (s1, err, sizeof(err)))
        {
-         gfc_error ("Explicit interface required for %qs at %L: %s",
-                    s2->name, &rvalue->where, err);
-         return false;
+         if (comp2 && !s2)
+           {
+             gfc_error ("Explicit interface required for component %qs at %L: 
%s",
+                        comp2->name, &rvalue->where, err);
+             return false;
+           }
+         else if (s2->attr.if_source == IFSRC_UNKNOWN)
+           {
+             gfc_error ("Explicit interface required for %qs at %L: %s",
+                        s2->name, &rvalue->where, err);
+             return false;
+           }
        }
 
+      if (s1 == s2 || !s1 || !s2)
+       return true;
+
       if (!gfc_compare_interfaces (s1, s2, name, 0, 1,
                                   err, sizeof(err), NULL, NULL))
        {

! { dg-do compile }
!
! PR 80046: [F03] Explicit interface required: pointer argument
!
! Contributed by Joachim Herb <joachim.h...@gmx.de>

program p
  implicit none

  type :: Node_t
    procedure(NodeCloner), nopass, pointer :: cloneProc => NULL()
    procedure(), nopass, pointer :: noIfc => NULL()
  end type

  interface
    subroutine NodeCloner( tgt, src )
      import Node_t
      type(Node_t), pointer, intent(out) :: tgt
      type(Node_t),           intent(in) :: src
    end subroutine
  end interface

  type(Node_t) :: node
  procedure(NodeCloner), pointer :: cloneNode
  procedure(), pointer :: noIfc

  cloneNode => node%noIfc       ! { dg-error "Explicit interface required" }
  node%noIfc => cloneNode       ! { dg-error "Explicit interface required" }

  noIfc => node%cloneProc       ! { dg-error "Explicit interface required" }
  node%cloneProc => noIfc       ! { dg-error "Explicit interface required" }

  node%cloneProc => node%noIfc  ! { dg-error "Explicit interface required" }
  node%noIfc => node%cloneProc  ! { dg-error "Explicit interface required" }

  ! the following cases are legal

  node%noIfc => node%noIfc
  node%cloneProc => node%cloneProc

  cloneNode => node%cloneProc
  node%cloneProc => cloneNode

  noIfc => node%noIfc
  node%noIfc => noIfc

end