[gfortran] Fix nr 8 from PR 16404

[Tobias Schlüter <tobias dot schlueter at physik dot uni-muenchen dot de>]

Page 149, lines 6 and 7 have the following restriction on items being read or
written:
---
If a derived type ultimately contains a pointer component, an object of this
type shall not appear as an input item nor as the result of the evaluation of
an output item list item.
---

This was obviously missed when installing gfortran.dg/der_io_1.f90, which
tests that exactly this works. I suggest XFAILing this test with a dg-error,
and installing the patch appended below, which implements this restriction,
and which took me only a few seconds of copy and pasting from some other code
copyrighted by the FSF, and a few cleanups.

Built and tested, ok?

- Tobi

2004-08-31  Tobias Schlueter  <tobias.schlueter@physik.uni-muenchen.de>

	(port from g95)
	* resolve.c (resolve_transfer): New function.
	(resolve_code): Call resolve_transfer in case of EXEC_TRANSFER.

Index: resolve.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/fortran/resolve.c,v
retrieving revision 1.16
diff -u -p -r1.16 resolve.c
--- resolve.c   27 Aug 2004 14:49:34 -0000      1.16
+++ resolve.c   31 Aug 2004 21:56:54 -0000
@@ -2962,6 +2962,40 @@ resolve_select (gfc_code * code)
 }


+/* Resolve a transfer statement. This is mainly just making sure that
+   a derived type being transferred has only non-pointer components.  */
+
+static try
+resolve_transfer (gfc_code * code)
+{
+  gfc_typespec *typespec;
+  gfc_symbol *sym;
+  gfc_ref *ref;
+
+  if (code->expr->expr_type != EXPR_VARIABLE)
+    return SUCCESS;
+
+  sym = code->expr->symtree->n.sym;
+  typespec = &sym->ts;
+
+  /* Go to actual component transferred.  */
+  for (ref = code->expr->ref; ref; ref = ref->next)
+    if (ref->type == REF_COMPONENT)
+      typespec = &ref->u.c.component->ts;
+
+  /* Check that transferred derived type doesn't contain POINTER
+     components.  */
+  if (typespec->type == BT_DERIVED && derived_pointer (typespec->derived))
+    {
+      gfc_error ("Data transfer element at %L cannot have POINTER components",
+                &code->loc);
+      return FAILURE;
+    }
+
+  return SUCCESS;
+}
+
+
 /*********** Toplevel code resolution subroutines ***********/

 /* Given a branch to a label and a namespace, if the branch is conforming.
@@ -3568,7 +3602,6 @@ resolve_code (gfc_code * code, gfc_names
        case EXEC_EXIT:
        case EXEC_CONTINUE:
        case EXEC_DT_END:
-       case EXEC_TRANSFER:
        case EXEC_ENTRY:
          break;

@@ -3754,6 +3787,10 @@ resolve_code (gfc_code * code, gfc_names
          resolve_branch (code->ext.dt->eor, code);
          break;

+       case EXEC_TRANSFER:
+         resolve_transfer (code);
+         break;
+
        case EXEC_FORALL:
          resolve_forall_iterators (code->ext.forall_iterator);