[multiple changes]

2010-06-17  Ed Schonberg  <schonberg@adacore.com>

	* sem_ch10.adb (Is_Ancestor_Unit): Subsidiary to
	Install_Limited_Context_Clauses, to determine whether a limited_with in
	some parent of the current unit designates some other parent, in which
	case the limited_with clause must not be installed.
	(In_Context): Refine test.

2010-06-17  Gary Dismukes  <dismukes@adacore.com>

	* sem_util.adb (Collect_Primitive_Operations): In the of an untagged
	type with a dispatching equality operator that is overridden (for a
	tagged full type), don't include the overridden equality in the list of
	primitives. The overridden equality is detected by testing for an
	Aliased field that references the overriding equality.

2010-06-17  Robert Dewar  <dewar@adacore.com>

	* freeze.adb: Minor reformatting.

From-SVN: r160924

4 files changed, 78 insertions, 5 deletions

diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index d70d736..278b183 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,3 +1,23 @@
+2010-06-17  Ed Schonberg  <schonberg@adacore.com>
+
+	* sem_ch10.adb (Is_Ancestor_Unit): Subsidiary to
+	Install_Limited_Context_Clauses, to determine whether a limited_with in
+	some parent of the current unit designates some other parent, in which
+	case the limited_with clause must not be installed.
+	(In_Context): Refine test.
+
+2010-06-17  Gary Dismukes  <dismukes@adacore.com>
+
+	* sem_util.adb (Collect_Primitive_Operations): In the of an untagged
+	type with a dispatching equality operator that is overridden (for a
+	tagged full type), don't include the overridden equality in the list of
+	primitives. The overridden equality is detected by testing for an
+	Aliased field that references the overriding equality.
+
+2010-06-17  Robert Dewar  <dewar@adacore.com>
+
+	* freeze.adb: Minor reformatting.
+
 2010-06-17  Joel Brobecker  <brobecker@adacore.com brobecker>
 
 	* gnat_ugn.texi: Add a section introducing gdbserver.
diff --git a/gcc/ada/freeze.adb b/gcc/ada/freeze.adb
index 8900060..f976832 100644
--- a/gcc/ada/freeze.adb
+++ b/gcc/ada/freeze.adb
@@ -5306,7 +5306,7 @@ package body Freeze is
             return True;
          end;
 
-      --  For the designated type of an access to subprogram. all types in
+      --  For the designated type of an access to subprogram, all types in
       --  the profile must be fully defined.
 
       elsif Ekind (T) = E_Subprogram_Type then
diff --git a/gcc/ada/sem_ch10.adb b/gcc/ada/sem_ch10.adb
index 29d33b7..6b61a87 100644
--- a/gcc/ada/sem_ch10.adb
+++ b/gcc/ada/sem_ch10.adb
@@ -3373,6 +3373,11 @@ package body Sem_Ch10 is
       --  units. The shadow entities are created when the inserted clause is
       --  analyzed. Implements Ada 2005 (AI-50217).
 
+      function Is_Ancestor_Unit (U1 : Node_Id; U2 : Node_Id) return Boolean;
+      --  When compiling a unit Q descended from some parent unit P, a limited
+      --  with_clause in the context of P that names some other ancestor of Q
+      --  must not be installed because the ancestor is immediately visible.
+
       ---------------------
       -- Check_Renamings --
       ---------------------
@@ -3645,6 +3650,22 @@ package body Sem_Ch10 is
          New_Nodes_OK := New_Nodes_OK - 1;
       end Expand_Limited_With_Clause;
 
+      ----------------------
+      -- Is_Ancestor_Unit --
+      ----------------------
+
+      function Is_Ancestor_Unit (U1 : Node_Id; U2 : Node_Id) return Boolean is
+         E1 : constant Entity_Id := Defining_Entity (Unit (U1));
+         E2 : Entity_Id;
+      begin
+         if Nkind_In (Unit (U2), N_Package_Body, N_Subprogram_Body) then
+            E2 := Defining_Entity (Unit (Library_Unit (U2)));
+            return Is_Ancestor_Package (E1, E2);
+         else
+            return False;
+         end if;
+      end Is_Ancestor_Unit;
+
    --  Start of processing for Install_Limited_Context_Clauses
 
    begin
@@ -3678,6 +3699,9 @@ package body Sem_Ch10 is
 
             if Library_Unit (Item) /= Cunit (Current_Sem_Unit)
               and then not Limited_View_Installed (Item)
+              and then
+                not Is_Ancestor_Unit
+                      (Library_Unit (Item), Cunit (Current_Sem_Unit))
             then
                if not Private_Present (Item)
                  or else Private_Present (N)
@@ -4013,7 +4037,8 @@ package body Sem_Ch10 is
                   function In_Context return Boolean;
                   --  Scan context of current unit, to check whether there is
                   --  a with_clause on the same unit as a private with-clause
-                  --  on a parent, in which case child unit is visible.
+                  --  on a parent, in which case child unit is visible. If the
+                  --  unit is a grand-child, the same applies to its parent.
 
                   ----------------
                   -- In_Context --
@@ -4027,10 +4052,15 @@ package body Sem_Ch10 is
                         if Nkind (Clause) = N_With_Clause
                           and then Comes_From_Source (Clause)
                           and then Is_Entity_Name (Name (Clause))
-                          and then Entity (Name (Clause)) = Id
                           and then not Private_Present (Clause)
                         then
-                           return True;
+                           if Entity (Name (Clause)) = Id
+                             or else
+                               (Nkind (Name (Clause)) = N_Expanded_Name
+                                 and then Entity (Prefix (Name (Clause))) = Id)
+                           then
+                              return True;
+                           end if;
                         end if;
 
                         Next (Clause);
diff --git a/gcc/ada/sem_util.adb b/gcc/ada/sem_util.adb
index dcd6848..06676ea 100644
--- a/gcc/ada/sem_util.adb
+++ b/gcc/ada/sem_util.adb
@@ -1670,7 +1670,30 @@ package body Sem_Util is
                  and then (not Formal_Derived
                             or else Present (Alias (Id)))
                then
-                  Append_Elmt (Id, Op_List);
+                  --  In the special case of an equality operator aliased to
+                  --  an overriding dispatching equality belonging to the same
+                  --  type, we don't include it in the list of primitives.
+                  --  This avoids inheriting multiple equality operators when
+                  --  deriving from untagged private types whose full type is
+                  --  tagged, which can otherwise cause ambiguities. Note that
+                  --  this should only happen for this kind of untagged parent
+                  --  type, since normally dispatching operations are inherited
+                  --  using the type's Primitive_Operations list.
+
+                  if Chars (Id) = Name_Op_Eq
+                    and then Is_Dispatching_Operation (Id)
+                    and then Present (Alias (Id))
+                    and then Is_Overriding_Operation (Alias (Id))
+                    and then Base_Type (Etype (First_Entity (Id))) =
+                               Base_Type (Etype (First_Entity (Alias (Id))))
+                  then
+                     null;
+
+                  --  Include the subprogram in the list of primitives
+
+                  else
+                     Append_Elmt (Id, Op_List);
+                  end if;
                end if;
             end if;