trans-expr.c (conv_parent_component_references): New function to build missing parent references.

2008-07-29  Paul Thomas  <pault@gcc.gnu.org>

fortran/	
	* trans-expr.c (conv_parent_component_references): New function
	to build missing parent references.
	(gfc_conv_variable): Call it
	* symbol.c (gfc_add_component): Check that component name in a
	derived type extension does not appear in parent.
	(gfc_find_component): For a derived type extension, check if
	the component appears in the parent derived type by calling
	self. Separate errors for private components and private types.
	* decl.c (match_data_constant): Add extra arg to call to
	gfc_match_structure_constructor.
	(check_extended_derived_type): New function to check that a
	parent derived type exists and that it is OK for exension.
	(gfc_get_type_attr_spec): Add extra argument 'name' and return
	it if extends is specified.
	(gfc_match_derived_decl): Match derived type extension and
	build a first component of the parent derived type if OK. Add
	the f2k namespace if not present.
	* gfortran.h : Add the extension attribute.
	* module.c : Handle attribute 'extension'.
	* match.h : Modify prototypes for gfc_get_type_attr_spec and
	gfc_match_structure_constructor.
	* primary.c (build_actual_constructor): New function extracted
	from gfc_match_structure_constructor and modified to call self
	iteratively to build derived type extensions, when f2k named
	components are used.
	(gfc_match_structure_constructor): Do not throw error for too
	many components if a parent type is being handled. Use
	gfc_find_component to generate errors for non-existent or
	private components.  Iteratively call self for derived type
	extensions so that parent constructor is built.  If extension
	and components left over, throw error.
	(gfc_match_rvalue): Add extra arg to call to
	gfc_match_structure_constructor.
	* trans-array.c (gfc_conv_resolve_dependencies): If lhs and rhs
	are the same symbol, aliassing does not matter.
testsuite/
	* gfortran.dg/extends_1.f03: New test.
	* gfortran.dg/extends_2.f03: New test.
	* gfortran.dg/extends_3.f03: New test.
	* gfortran.dg/extends_4.f03: New test.
	* gfortran.dg/extends_5.f03: New test.
	* gfortran.dg/extends_6.f03: New test.
	* gfortran.dg/private_type_6.f90: Modify error message.
	* gfortran.dg/structure_constructor_7.f03: Modify error message.
	* gfortran.dg/structure_constructor_8.f03: Modify error message.

From-SVN: r138275

1 files changed, 39 insertions, 2 deletions

diff --git a/gcc/fortran/trans-expr.c b/gcc/fortran/trans-expr.c
index 05ee390..94b912f 100644
--- a/gcc/fortran/trans-expr.c
+++ b/gcc/fortran/trans-expr.c
@@ -1,6 +1,6 @@
 /* Expression translation
-   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008 Free Software
-   Foundation, Inc.
+   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008
+   Free Software Foundation, Inc.
    Contributed by Paul Brook <paul@nowt.org>
    and Steven Bosscher <s.bosscher@student.tudelft.nl>
 
@@ -395,6 +395,40 @@ gfc_conv_component_ref (gfc_se * se, gfc_ref * ref)
 }
 
 
+/* This function deals with component references to components of the
+   parent type for derived type extensons.  */
+static void
+conv_parent_component_references (gfc_se * se, gfc_ref * ref)
+{
+  gfc_component *c;
+  gfc_component *cmp;
+  gfc_symbol *dt;
+  gfc_ref parent;
+
+  dt = ref->u.c.sym;
+  c = ref->u.c.component;
+
+  /* Build a gfc_ref to recursively call gfc_conv_component_ref.  */
+  parent.type = REF_COMPONENT;
+  parent.next = NULL;
+  parent.u.c.sym = dt;
+  parent.u.c.component = dt->components;
+
+  if (dt->attr.extension && dt->components)
+    {
+      /* Return if the component is not in the parent type.  */
+      for (cmp = dt->components->next; cmp; cmp = cmp->next)
+	if (strcmp (c->name, cmp->name) == 0)
+	  return;
+	
+      /* Otherwise build the reference and call self.  */
+      gfc_conv_component_ref (se, &parent);
+      parent.u.c.sym = dt->components->ts.derived;
+      parent.u.c.component = c;
+      conv_parent_component_references (se, &parent);
+    }
+}
+
 /* Return the contents of a variable. Also handles reference/pointer
    variables (all Fortran pointer references are implicit).  */
 
@@ -561,6 +595,9 @@ gfc_conv_variable (gfc_se * se, gfc_expr * expr)
 	  break;
 
 	case REF_COMPONENT:
+	  if (ref->u.c.sym->attr.extension)
+	    conv_parent_component_references (se, ref);
+
 	  gfc_conv_component_ref (se, ref);
 	  break;