[multiple changes]

2017-04-25  Claire Dross  <dross@adacore.com>

	* sem_prag.adb (Collect_Inherited_Class_Wide_Conditions): Go to
	ultimate alias when accessing overridden operation. Indeed, if the
	overridden operation is itself inherited, it won't have any explicit
	contract.

2017-04-25  Ed Schonberg  <schonberg@adacore.com>

	* sem_warn.adb (Warn_On_Overlapping_Actuals): There can be no
	overlap if the two formals have different types, because formally
	the corresponding actuals cannot designate the same objects.

2017-04-25  Ed Schonberg  <schonberg@adacore.com>

	* sem_dim.adb (Dimensions_Of_Operand): minot cleanups: a) If
	dimensions are present from context, use them.	b) If operand is
	a static constant rewritten as a literal, obtain the dimensions
	from the original declaration, otherwise use dimensions of type
	established from context.

2017-04-25  Yannick Moy  <moy@adacore.com>

	* sem_util.adb (Is_Effectively_Volatile): Protect against base type
	of array that is private.

From-SVN: r247209

gcc/ada/ChangeLog

+2017-04-25  Claire Dross  <dross@adacore.com>
+
+	* sem_prag.adb (Collect_Inherited_Class_Wide_Conditions): Go to
+	ultimate alias when accessing overridden operation. Indeed, if the
+	overridden operation is itself inherited, it won't have any explicit
+	contract.
+
+2017-04-25  Ed Schonberg  <schonberg@adacore.com>
+
+	* sem_warn.adb (Warn_On_Overlapping_Actuals): There can be no
+	overlap if the two formals have different types, because formally
+	the corresponding actuals cannot designate the same objects.
+
+2017-04-25  Ed Schonberg  <schonberg@adacore.com>
+
+	* sem_dim.adb (Dimensions_Of_Operand): minot cleanups: a) If
+	dimensions are present from context, use them.	b) If operand is
+	a static constant rewritten as a literal, obtain the dimensions
+	from the original declaration, otherwise use dimensions of type
+	established from context.
+
+2017-04-25  Yannick Moy  <moy@adacore.com>
+
+	* sem_util.adb (Is_Effectively_Volatile): Protect against base type
+	of array that is private.
+
 2017-04-25  Gary Dismukes  <dismukes@adacore.com>
 
 	* sem_ch3.adb, exp_util.adb, sem_prag.adb, exp_ch4.adb: Minor

gcc/ada/sem_dim.adb

@@ -1343,7 +1343,11 @@ package body Sem_Dim is
       function Dimensions_Of_Operand (N : Node_Id) return Dimension_Type;
       --  If the operand is a numeric literal that comes from a declared
       --  constant, use the dimensions of the constant which were computed
-      --  from the expression of the constant declaration.
+      --  from the expression of the constant declaration. Otherwise the
+      --  dimensions are those of the operand, or the type of the operand.
+      --  This takes care of node rewritings from validity checks, where the
+      --  dimensions of the operand itself may not be preserved, while the
+      --  type comes from context and must have dimension information.
 
       procedure Error_Dim_Msg_For_Binary_Op (N, L, R : Node_Id);
       --  Error using Error_Msg_NE and Error_Msg_N at node N. Output the
@@ -1354,13 +1358,28 @@ package body Sem_Dim is
       ---------------------------
 
       function Dimensions_Of_Operand (N : Node_Id) return Dimension_Type is
+         Dims : constant Dimension_Type := Dimensions_Of (N);
+
       begin
-         if Nkind (N) = N_Real_Literal
-           and then Present (Original_Entity (N))
-         then
-            return Dimensions_Of (Original_Entity (N));
+         if Exists (Dims) then
+            return Dims;
+
+         elsif Is_Entity_Name (N) then
+            return Dimensions_Of (Etype (Entity (N)));
+
+         elsif Nkind (N) = N_Real_Literal then
+
+            if Present (Original_Entity (N)) then
+               return Dimensions_Of (Original_Entity (N));
+
+            else
+               return Dimensions_Of (Etype (N));
+            end if;
+
+         --  Otherwise return the default dimensions
+
          else
-            return Dimensions_Of (N);
+            return Dims;
          end if;
       end Dimensions_Of_Operand;
 

gcc/ada/sem_prag.adb

@@ -27915,8 +27915,12 @@ package body Sem_Prag is
    ---------------------------------------------
 
    procedure Collect_Inherited_Class_Wide_Conditions (Subp : Entity_Id) is
-      Parent_Subp  : constant Entity_Id := Overridden_Operation (Subp);
-      Prags        : constant Node_Id   := Contract (Parent_Subp);
+      Parent_Subp : constant Entity_Id :=
+                      Ultimate_Alias (Overridden_Operation (Subp));
+      --  The Overridden_Operation may itself be inherited and as such have no
+      --  explicit contract.
+
+      Prags        : constant Node_Id := Contract (Parent_Subp);
       In_Spec_Expr : Boolean;
       Installed    : Boolean;
       Prag         : Node_Id;

gcc/ada/sem_util.adb

@@ -12805,10 +12805,18 @@ package body Sem_Util is
          --  effectively volatile.
 
          elsif Is_Array_Type (Id) then
-            return
-              Has_Volatile_Components (Id)
-                or else
-              Is_Effectively_Volatile (Component_Type (Base_Type (Id)));
+            declare
+               Anc : Entity_Id := Base_Type (Id);
+            begin
+               if Ekind (Anc) in Private_Kind then
+                  Anc := Full_View (Anc);
+               end if;
+
+               return
+                 Has_Volatile_Components (Id)
+                   or else
+                 Is_Effectively_Volatile (Component_Type (Anc));
+            end;
 
          --  A protected type is always volatile
 

gcc/ada/sem_warn.adb

@@ -3487,13 +3487,12 @@ package body Sem_Warn is
    ---------------------------------
 
    procedure Warn_On_Overlapping_Actuals (Subp : Entity_Id; N : Node_Id) is
-      Act1, Act2   : Node_Id;
-      Form1, Form2 : Entity_Id;
-
       function Is_Covered_Formal (Formal : Node_Id) return Boolean;
       --  Return True if Formal is covered by the rule
 
-      function Refer_Same_Object (Act1, Act2 : Node_Id) return Boolean;
+      function Refer_Same_Object
+        (Act1 : Node_Id;
+         Act2 : Node_Id) return Boolean;
       --  Two names are known to refer to the same object if the two names
       --  are known to denote the same object; or one of the names is a
       --  selected_component, indexed_component, or slice and its prefix is
@@ -3503,16 +3502,6 @@ package body Sem_Warn is
       --  (RM 6.4.1(6.11/3))
 
       -----------------------
-      -- Refer_Same_Object --
-      -----------------------
-
-      function Refer_Same_Object (Act1, Act2 : Node_Id) return Boolean is
-      begin
-         return Denotes_Same_Object (Act1, Act2)
-           or else Denotes_Same_Prefix (Act1, Act2);
-      end Refer_Same_Object;
-
-      -----------------------
       -- Is_Covered_Formal --
       -----------------------
 
@@ -3525,7 +3514,31 @@ package body Sem_Warn is
                         or else Is_Array_Type (Etype (Formal)));
       end Is_Covered_Formal;
 
+      -----------------------
+      -- Refer_Same_Object --
+      -----------------------
+
+      function Refer_Same_Object
+        (Act1 : Node_Id;
+         Act2 : Node_Id) return Boolean
+      is
+      begin
+         return
+           Denotes_Same_Object (Act1, Act2)
+             or else Denotes_Same_Prefix (Act1, Act2);
+      end Refer_Same_Object;
+
+      --  Local variables
+
+      Act1  : Node_Id;
+      Act2  : Node_Id;
+      Form1 : Entity_Id;
+      Form2 : Entity_Id;
+
+   --  Start of processing for Warn_On_Overlapping_Actuals
+
    begin
+
       if Ada_Version < Ada_2012 and then not Warn_On_Overlap then
          return;
       end if;
@@ -3593,6 +3606,14 @@ package body Sem_Warn is
                   then
                      null;
 
+                  --  If the types of the formals are different there can
+                  --  be no aliasing (even though there might be overlap
+                  --  through address clauses, which must be intentional).
+
+                  elsif Base_Type (Etype (Form1)) /= Base_Type (Etype (Form2))
+                  then
+                     null;
+
                   --  Here we may need to issue overlap message
 
                   else