ca11009.a

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-- CA11009.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 private child package can use entities declared in the
--      visible part of the parent unit of its parent unit.
--
-- TEST DESCRIPTION:
--      Declare a parent package containing types and objects used by the 
--      system.  Declare a public child package that provides a visible 
--      interface to the system functionality.
--      Declare a private grandchild package that uses the visible grandparent
--      components to provide the actual functionality to the system. 
--
--      The public child (parent of the private grandchild) uses the 
--      functionality of its private child (grandchild package) to provide 
--      the visible interface to operations of the system.
--
--      The test itself will utilize the visible interface provided in the 
--      public child package to demonstrate a possible structure for
--      file management.
--
--
-- CHANGE HISTORY:
--      06 Dec 94   SAIC    ACVC 2.0
--      15 Apr 96   SAIC    ACVC 2.1: Added pragma Elaborate_body.
--
--!

package CA11009_0 is               -- Package OS.
   pragma Elaborate_Body (CA11009_0);

   type File_Descriptor_Type is new Integer;
   type File_Name_Type       is new String (1 .. 11);
   type Permission_Type      is (None, User, System, Bypass);
   type File_Mode_Type       is (Read_Only, Write_Only, Read_Write);
   type File_Status_Type     is (Open, Closed);

   Default_Descriptor : constant File_Descriptor_Type := 0;
   Default_Permission : constant Permission_Type      := None;
   Default_Mode       : constant File_Mode_Type       := Read_Only;
   Default_Status     : constant File_Status_Type     := Closed;
   Default_Filename   : constant File_Name_Type       := "           ";

   Max_Files          : constant File_Descriptor_Type := 10;
   An_Ada_File_Name   : constant File_Name_Type       := "AdaFileName";
   File_Counter       : Integer                       := 0;

   type File_Type is tagged
      record
         Descriptor     : File_Descriptor_Type := Default_Descriptor;
         Name           : File_Name_Type       := Default_Filename;
         Acct_Access    : Permission_Type      := Default_Permission;
         Mode           : File_Mode_Type       := Default_Mode;
         Current_Status : File_Status_Type     := Default_Status;
      end record;

   type File_Array_Type is array (1 .. Max_Files) of File_Type;

   File_Table : File_Array_Type;

   --

   function Get_File_Name return File_Name_Type;

end CA11009_0;                     -- Package OS.

     --=================================================================--

package body CA11009_0 is          -- Package body OS.

   function Get_File_Name return File_Name_Type is
   begin
      return (An_Ada_File_Name);   -- Processing would be replace by a user
                                   -- prompt in a functioning system.
   end Get_File_Name;           
                                
end CA11009_0;                     -- Package body OS.

     --=================================================================--

package CA11009_0.CA11009_1 is     -- Child Package OS.File_Manager

   -- This package simulates a visible interface for the Operating System.
   -- The actual processing performed by this routine is encapsulated
   -- in the routines of private child package Internals, which is "withed"
   -- by the body of this package.

   procedure Create_File (Mode      : in     File_Mode_Type;
                          File_Key  :    out File_Descriptor_Type);

end CA11009_0.CA11009_1;           -- Child Package OS.File_Manager

     --=================================================================--

-- Subprogram that performs the actual file operation is contained in a
-- private package so that it is not accessible to any client, and can be
-- modified/extended without requiring recompilation of the clients of the
-- parent (since this package is "withed" by the parent body only.)


                               -- Grandchild Package OS.File_Manager.Internals
private package CA11009_0.CA11009_1.CA11009_2 is  

   Initial_Permission : constant Permission_Type  := User;  -- Grandparent
   Initial_Status     : constant File_Status_Type := Open;  -- literals.
   Initial_Filename   : constant File_Name_Type   :=  -- Grandparent type.
     Get_File_Name;                                   -- Grandparent function.

   function Create (Mode : File_Mode_Type)                      
     return File_Descriptor_Type;                     -- Grandparent type.

end CA11009_0.CA11009_1.CA11009_2;   
                          -- Grandchild Package OS.File_Manager.Internals

     --=================================================================--

                          -- Grandchild Package body OS.File_Manager.Internals
package body CA11009_0.CA11009_1.CA11009_2 is  

   function Next_Available_File return File_Descriptor_Type is
   begin
      File_Counter := File_Counter + 1;              -- Grandparent object.
      return (File_Descriptor_Type(File_Counter));
   end Next_Available_File;
   -------------------------------------------------------------------------
   function Create (Mode : File_Mode_Type)           -- Grandparent literal.
     return File_Descriptor_Type is
      Number : File_Descriptor_Type;                 -- Grandparent type.
   begin
      Number := Next_Available_File;
      File_Table(Number).Descriptor     := Number;   -- Grandparent object.
      File_Table(Number).Name           := Initial_Filename;
      File_Table(Number).Mode           := Mode;     -- Parameter.
      File_Table(Number).Acct_Access    := Initial_Permission;
      File_Table(Number).Current_Status := Initial_Status;
      return (Number);
   end Create;

end CA11009_0.CA11009_1.CA11009_2;  
                          -- Grandchild Package body OS.File_Manager.Internals

     --=================================================================--

                                     -- "With" of a child package 
                                     -- by the parent body.
with CA11009_0.CA11009_1.CA11009_2;  -- Grandchild OS.File_Manager.Internals

package body CA11009_0.CA11009_1 is  -- Child Package body OS.File_Manager

   package Internal renames CA11009_0.CA11009_1.CA11009_2;            

   -- These subprograms utilize calls to subprograms contained in a private
   -- sibling to perform the actual processing.

   procedure Create_File (Mode      : in     File_Mode_Type;
                          File_Key  :    out File_Descriptor_Type) is
   begin
      File_Key := Internal.Create (Mode);
   end Create_File;

end CA11009_0.CA11009_1;        -- Child Package body OS.File_Manager

     --=================================================================--

with CA11009_0.CA11009_1;       -- with Child Package OS.File_Manager
with Report;

procedure CA11009 is

   package OS           renames CA11009_0;
   use OS;
   package File_Manager renames CA11009_0.CA11009_1;

   Data_Base_File_Key : File_Descriptor_Type := Default_Descriptor;
   New_Mode           : File_Mode_Type := Read_Write;

begin
   
   -- This test indicates one approach to file management.
   -- It is not intended to demonstrate full functionality, but rather
   -- that the use of a private child package could provide a solution
   -- to this type of situation.

   Report.Test ("CA11009", "Check that a private child package can use "   &
                           "entities declared in the visible part of the " &
                           "parent unit of its parent unit");

   -- Check initial conditions of the first entry in the file table.
   -- These are all default values provided in the declaration of the 
   -- type File_Type.                           

   if (not (Data_Base_File_Key      = Default_Descriptor)) and then
      (((not (File_Table(1).Name    = Default_Filename))   or 
      (File_Table(1).Descriptor     /= Default_Descriptor))  or else
      ((File_Table(1).Acct_Access   /= Default_Permission)  or
      (not (File_Table(1).Mode      = Default_Mode))       or
      (File_Table(1).Current_Status /= Default_Status)))
   then
      Report.Failed ("Initial condition failure");
   end if;

   -- Create/initialize file using the capability provided by the visible 
   -- interface to the operating system, OS.File_Manager.  The actual 
   -- processing routine is contained in the private grandchild package 
   -- Internals, which utilize the components from the grandparent package.

   File_Manager.Create_File (New_Mode, Data_Base_File_Key);

   -- Verify that the initial conditions of the file table component have
   -- been properly modified by the initialization function.

   if not ((File_Table(1).Descriptor          = Data_Base_File_Key)   and then
           (File_Table(1).Name                = An_Ada_File_Name)  and then
           (File_Table(1).Acct_Access         = User)              and then
           not ((File_Table(1).Mode           = Default_Mode)      or else
                (File_Table(1).Current_Status = Default_Status)))
   then
      Report.Failed ("File creation failure");
   end if;

   Report.Result;

end CA11009;