c3a0007.a

来自「linux下编程用 编译软件」· A 代码 · 共 235 行

-- C3A0007.A
--
--                             Grant of Unlimited Rights
--
--     Under contracts F33600-87-D-0337, F33600-84-D-0280, MDA903-79-C-0687,
--     F08630-91-C-0015, and DCA100-97-D-0025, the U.S. Government obtained 
--     unlimited rights in the software and documentation contained herein.
--     Unlimited rights are defined in DFAR 252.227-7013(a)(19).  By making 
--     this public release, the Government intends to confer upon all 
--     recipients unlimited rights  equal to those held by the Government.  
--     These rights include rights to use, duplicate, release or disclose the 
--     released technical data and computer software in whole or in part, in 
--     any manner and for any purpose whatsoever, and to have or permit others 
--     to do so.
--
--                                    DISCLAIMER
--
--     ALL MATERIALS OR INFORMATION HEREIN RELEASED, MADE AVAILABLE OR
--     DISCLOSED ARE AS IS.  THE GOVERNMENT MAKES NO EXPRESS OR IMPLIED 
--     WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS OF THE
--     SOFTWARE, DOCUMENTATION OR OTHER INFORMATION RELEASED, MADE AVAILABLE 
--     OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A
--     PARTICULAR PURPOSE OF SAID MATERIAL.
--*
--
-- OBJECTIVE:
--      Check that a call to a subprogram via an access-to-subprogram value
--      stored in a data structure will correctly dispatch according to the
--      tag of the class-wide parameter passed via that call.
-- 
-- TEST DESCRIPTION:
--      Declare an access to procedure type in a package specification. 
--      Declare a root tagged type with the access to procedure type as a 
--      component.  Declare three primitive procedures for the type that 
--      can be referred to by the access to procedure type.  Use the access 
--      to procedure type to initialize the component of a record.
--
--      Extend the root type with a record extension in another package
--      specification. Declare a new primitive procedure for the extension
--      (in addition to its three inherited subprograms).
--
--      In the main program, declare an operation for the root tagged type 
--      which can be passed as an access value to change the initial value
--      of the component.  Call the inherited operation indirectly by 
--      dereferencing the access value to check on the initial value of the 
--      extension.  Call inherited operations indirectly by dereferencing 
--      the access value to replace the initial value.  Call the primitive 
--      procedure indirectly by dereferencing the access value to modify the 
--      extension.
--
--          type Button
--            procedure Push(Button)
--            procedure Set_Response(Button,Button_Response_Ptr)
--            procedure Default_Response(Button)
--
--          type Priority_Button (new Button)
--            procedures Push, Set_Response inherited
--            procedure Default_Response
--            procedure Set_Priority
--
--
-- CHANGE HISTORY:
--      06 Dec 94   SAIC    ACVC 2.0
--
--!

package C3A0007_0 is

   Default_Call   : Boolean := False;

   type Button is tagged private;

   type Button_Response_Ptr is access procedure
      (B : in out Button'Class);

   procedure Push (B : in out Button);               -- to be inherited

   procedure Set_Response (B : in out Button;        -- to be inherited
                           R : in Button_Response_Ptr);

   procedure Response  (B : in out Button);          -- to be inherited

private
   procedure Default_Response(B: in out Button'Class);
   type Button is tagged                             -- root tagged type
      record
         Action :  Button_Response_Ptr 
                  := Default_Response'Access;   
      end record;
end C3A0007_0;

with C3A0007_0;
package C3A0007_1 is

   type Priority_Button is new C3A0007_0.Button
     with record
        Priority : Integer := 0;
      end record;

   -- Inherits procedure Push from Button
   -- Inherits procedure Set_Response from Button

   -- Override procedure Response from Button
   procedure Response (B : in out Priority_Button);

   -- Primitive operation of the extension
   procedure Set_Priority (B : in out Priority_Button);

end C3A0007_1;

with C3A0007_0;
package C3A0007_2 is

   Emergency_Call : Boolean := False;

   procedure Emergency (B : in out C3A0007_0.Button'Class);
end C3A0007_2;

-----------------------------------------------------------------------------

with TCTouch;
package body C3A0007_0 is

   procedure Push (B : in out Button) is
   begin
      TCTouch.Touch( 'P' ); --------------------------------------------- P
      -- Invoking subprogram designated by access value
      B.Action (B);
   end Push;


   procedure Set_Response (B : in out Button;
                           R : in     Button_Response_Ptr) is
   begin
      TCTouch.Touch( 'S' ); --------------------------------------------- S
      -- Set procedure value in record
      B.Action := R;
   end Set_Response;


   procedure Response (B : in out Button) is
   begin
      TCTouch.Touch( 'D' ); --------------------------------------------- D
      Default_Call := True;
   end Response;

   procedure Default_Response (B : in out Button'Class) is
   begin
      TCTouch.Touch( 'C' ); --------------------------------------------- C
      Response(B);
   end Default_Response;

end C3A0007_0;

with TCTouch;
package body C3A0007_1 is

   procedure Set_Priority (B : in out Priority_Button) is
   begin
      TCTouch.Touch( 's' ); --------------------------------------------- s
      B.Priority := 1;
   end Set_Priority;

   procedure Response (B : in out Priority_Button) is
   begin
      TCTouch.Touch( 'd' ); --------------------------------------------- d
   end Response;

end C3A0007_1;

with TCTouch;
package body C3A0007_2 is
   procedure Emergency (B : in out C3A0007_0.Button'Class) is
      begin
        TCTouch.Touch( 'E' ); ------------------------------------------- E
        Emergency_Call := True;
      end Emergency;
end C3A0007_2;

-----------------------------------------------------------------------------

with Report;
with TCTouch;

with C3A0007_0; 
with C3A0007_1; 
with C3A0007_2;
procedure C3A0007 is

   Pink_Button  : C3A0007_0.Button;
   Green_Button : C3A0007_1.Priority_Button;

begin

   Report.Test ("C3A0007", "Check that a call to a subprogram via an "
                         & "access-to-subprogram value stored in a data "
                         & "structure will correctly dispatch according to "
                         & "the tag of the class-wide parameter passed "
                         & "via that call" );

   -- Call inherited operation Push to set Default_Response value 
   -- in the extension.

   C3A0007_1.Push (Green_Button);
   TCTouch.Validate("PCd", "First Green Button Push");

   TCTouch.Assert_Not(C3A0007_0.Default_Call,
                         "Incorrect Green Default_Response");

   C3A0007_0.Push (Pink_Button);
   TCTouch.Validate("PCD", "First Pink Button Push");

   -- Call inherited operations Set_Response and Push to set 
   -- Emergency value in the extension.
   C3A0007_1.Set_Response (Green_Button, C3A0007_2.Emergency'Access);  
   C3A0007_1.Push (Green_Button);
   TCTouch.Validate("SPE", "Second Green Button Push");

   TCTouch.Assert(C3A0007_2.Emergency_Call, "Incorrect Green Emergency");

   C3A0007_0.Set_Response (Pink_Button, C3A0007_2.Emergency'Access);  
   C3A0007_0.Push (Pink_Button);
   TCTouch.Validate("SPE", "Second Pink Button Push");

   -- Call primitive operation to set priority value 
   -- in the extension.
   C3A0007_1.Set_Priority (Green_Button);
   TCTouch.Validate("s", "Green Button Priority");

   TCTouch.Assert(Green_Button.Priority = 1, "Incorrect Set_Priority");

   Report.Result;

end C3A0007;