decl.c (gnat_to_gnu_entity): Look into expressions for external constants that are aggregates.

* gcc-interface/decl.c (gnat_to_gnu_entity) <E_Constant>: Look into
	expressions for external constants that are aggregates.
	* gcc-interface/utils2.c (build_simple_component_ref): If the field
	is an inherited component in an extension, look through the extension.

From-SVN: r164414

gcc/ada/ChangeLog

@@ -1,3 +1,10 @@
+2010-09-19  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gcc-interface/decl.c (gnat_to_gnu_entity) <E_Constant>: Look into
+	expressions for external constants that are aggregates.
+	* gcc-interface/utils2.c (build_simple_component_ref): If the field
+	is an inherited component in an extension, look through the extension.
+
 2010-09-10  Vincent Celier  <celier@adacore.com>
 
 	* projects.texi: Add documentation for package extensions

gcc/ada/gcc-interface/decl.c

@@ -421,17 +421,15 @@ gnat_to_gnu_entity (Entity_Id gnat_entity, tree gnu_expr, int definition)
 	}
 
       /* If we have an external constant that we are not defining, get the
-	 expression that is was defined to represent.  We may throw that
-	 expression away later if it is not a constant.  Do not retrieve the
-	 expression if it is an aggregate or allocator, because in complex
-	 instantiation contexts it may not be expanded  */
+	 expression that is was defined to represent.  We may throw it away
+	 later if it is not a constant.  But do not retrieve the expression
+	 if it is an allocator because the designated type might be dummy
+	 at this point.  */
       if (!definition
-	  && Present (Expression (Declaration_Node (gnat_entity)))
 	  && !No_Initialization (Declaration_Node (gnat_entity))
-	  && (Nkind (Expression (Declaration_Node (gnat_entity)))
-	      != N_Aggregate)
-	  && (Nkind (Expression (Declaration_Node (gnat_entity)))
-	      != N_Allocator))
+	  && Present (Expression (Declaration_Node (gnat_entity)))
+	  && Nkind (Expression (Declaration_Node (gnat_entity)))
+	     != N_Allocator)
 	gnu_expr = gnat_to_gnu (Expression (Declaration_Node (gnat_entity)));
 
       /* Ignore deferred constant definitions without address clause since

gcc/ada/gcc-interface/utils2.c

@@ -1603,10 +1603,9 @@ build_simple_component_ref (tree record_variable, tree component,
   if (!field)
     return NULL_TREE;
 
-  /* If this field is not in the specified record, see if we can find
-     something in the record whose original field is the same as this one. */
+  /* If this field is not in the specified record, see if we can find a field
+     in the specified record whose original field is the same as this one.  */
   if (DECL_CONTEXT (field) != record_type)
-    /* Check if there is a field with name COMPONENT in the record.  */
     {
       tree new_field;
 
@@ -1616,6 +1615,21 @@ build_simple_component_ref (tree record_variable, tree component,
 	if (SAME_FIELD_P (field, new_field))
 	  break;
 
+      /* Next, see if we're looking for an inherited component in an extension.
+	 If so, look thru the extension directly.  */
+      if (!new_field
+	  && TREE_CODE (record_variable) == VIEW_CONVERT_EXPR
+	  && TYPE_ALIGN_OK (record_type)
+	  && TREE_CODE (TREE_TYPE (TREE_OPERAND (record_variable, 0)))
+	     == RECORD_TYPE
+	  && TYPE_ALIGN_OK (TREE_TYPE (TREE_OPERAND (record_variable, 0))))
+	{
+	  ref = build_simple_component_ref (TREE_OPERAND (record_variable, 0),
+					    NULL_TREE, field, no_fold_p);
+	  if (ref)
+	    return ref;
+	}
+
       /* Next, loop thru DECL_INTERNAL_P components if we haven't found
          the component in the first search. Doing this search in 2 steps
          is required to avoiding hidden homonymous fields in the

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2010-09-19  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/specs/constant1.ads: New test.
+	* gnat.dg/specs/constant1_pkg.ads: New helper.
+
 2010-09-18  Jan Hubicka  <jh@suse.cz>
 
 	PR tree-optimization/45453

gcc/testsuite/gnat.dg/specs/constant1.ads

@@ -0,0 +1,22 @@
+-- { dg-do compile }
+
+with Constant1_Pkg;
+
+package Constant1 is
+
+  type Timer_Id_T is new Constant1_Pkg.Timer_Id_T with null record;
+
+  type Timer_Op_T (Pending : Boolean := False) is
+     record
+       case Pending is
+         when True =>
+           Timer_Id : Timer_Id_T;
+         when False =>
+           null;
+       end case;
+     end record;
+
+  Timer : Timer_Op_T
+    := (True, Timer_Id_T'(Constant1_Pkg.Null_Timer_Id with null record));
+
+end Constant1;

gcc/testsuite/gnat.dg/specs/constant1_pkg.ads

@@ -0,0 +1,11 @@
+package Constant1_Pkg is
+
+  type Id_T is mod Natural'Last + 1;
+
+  type Timer_Id_T is tagged record
+    Id : Id_T := Id_T'Last;
+  end record;
+
+  Null_Timer_Id : constant Timer_Id_T := (Id => Id_T'Last - 1);
+
+end Constant1_Pkg;