re PR libfortran/80850 (Sourced allocate() fails to allocate a pointer)

2017-10-30  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/80850
	* trans_expr.c (gfc_conv_procedure_call): When passing a class
	argument to an unlimited polymorphic dummy, it is wrong to cast
	the passed expression as unlimited, unless it is unlimited. The
	correct way is to assign to each of the fields and set the _len
	field to zero.

2017-10-30  Paul Thomas  <pault@gcc.gnu.org>

	PR fortran/80850
	* gfortran.dg/class_64_f90 : New test.

From-SVN: r254244

4 files changed, 86 insertions, 5 deletions

diff --git a/gcc/fortran/ChangeLog b/gcc/fortran/ChangeLog
index 0d4a873..99f96dd 100644
--- a/gcc/fortran/ChangeLog
+++ b/gcc/fortran/ChangeLog
@@ -1,6 +1,15 @@
+2017-10-30  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/80850
+	* trans_expr.c (gfc_conv_procedure_call): When passing a class
+	argument to an unlimited polymorphic dummy, it is wrong to cast
+	the passed expression as unlimited, unless it is unlimited. The
+	correct way is to assign to each of the fields and set the _len
+	field to zero.
+
 2017-10-30  Steven G. Kargl   <kargl@gcc.gnu.org>
 
-	* resolve.c (resolve_transfer): Set derived to correct symbol for 
+	* resolve.c (resolve_transfer): Set derived to correct symbol for
 	BT_CLASS.
 
 2017-10-29  Jim Wilson  <wilson@tuliptree.org>
diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
index 71ec176..1a3e3d4 100644
--- a/gcc/fortran/trans-expr.c
+++ b/gcc/fortran/trans-expr.c
@@ -5173,10 +5173,39 @@ gfc_conv_procedure_call (gfc_se * se, gfc_symbol * sym,
 			}
 		      else
 			{
-			  gfc_add_modify (&parmse.pre, var,
-					  fold_build1_loc (input_location,
-							   VIEW_CONVERT_EXPR,
-							   type, parmse.expr));
+			  /* Since the internal representation of unlimited
+			     polymorphic expressions includes an extra field
+			     that other class objects do not, a cast to the
+			     formal type does not work.  */
+			  if (!UNLIMITED_POLY (e) && UNLIMITED_POLY (fsym))
+			    {
+			      tree efield;
+
+			      /* Set the _data field.  */
+			      tmp = gfc_class_data_get (var);
+			      efield = fold_convert (TREE_TYPE (tmp),
+					gfc_class_data_get (parmse.expr));
+			      gfc_add_modify (&parmse.pre, tmp, efield);
+
+			      /* Set the _vptr field.  */
+			      tmp = gfc_class_vptr_get (var);
+			      efield = fold_convert (TREE_TYPE (tmp),
+					gfc_class_vptr_get (parmse.expr));
+			      gfc_add_modify (&parmse.pre, tmp, efield);
+
+			      /* Set the _len field.  */
+			      tmp = gfc_class_len_get (var);
+			      gfc_add_modify (&parmse.pre, tmp,
+					      build_int_cst (TREE_TYPE (tmp), 0));
+			    }
+			  else
+			    {
+			      tmp = fold_build1_loc (input_location,
+						     VIEW_CONVERT_EXPR,
+						     type, parmse.expr);
+			      gfc_add_modify (&parmse.pre, var, tmp);
+					      ;
+			    }
 			  parmse.expr = gfc_build_addr_expr (NULL_TREE, var);
 			}
 		    }
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 7b1bf85..e17c94d 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2017-10-30  Paul Thomas  <pault@gcc.gnu.org>
+
+	PR fortran/80850
+	* gfortran.dg/class_64_f90 : New test.
+
 2017-10-30  Uros Bizjak  <ubizjak@gmail.com>
 
 	* g++.dg/pr82725.C: Move to ...
diff --git a/gcc/testsuite/gfortran.dg/class_64.f90 b/gcc/testsuite/gfortran.dg/class_64.f90
new file mode 100644
index 0000000..059ebaa
--- /dev/null
+++ b/gcc/testsuite/gfortran.dg/class_64.f90
@@ -0,0 +1,38 @@
+! { dg-do compile }
+! { dg-options "-fdump-tree-original" }
+!
+! Test the fix for PR80850 in which the _len field was not being
+! set for 'arg' in the call to 'foo'.
+!
+  type :: mytype
+    integer :: i
+  end type
+  class (mytype), pointer :: c
+
+  allocate (c, source = mytype (99_8))
+
+  call foo(c)
+  call bar(c)
+
+  deallocate (c)
+
+contains
+
+  subroutine foo (arg)
+    class(*) :: arg
+    select type (arg)
+      type is (mytype)
+        if (arg%i .ne. 99_8) call abort
+    end select
+  end subroutine
+
+  subroutine bar (arg)
+    class(mytype) :: arg
+    select type (arg)
+      type is (mytype)
+        if (arg%i .ne. 99_8) call abort
+    end select
+  end subroutine
+
+end
+! { dg-final { scan-tree-dump-times "arg.*._len" 1 "original" } }