| -- CC54004.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 the designated type of a generic formal pool-specific |
| -- access type may be class-wide. Check that calls to primitive |
| -- subprograms in the instance dispatch to the appropriate bodies when |
| -- the controlling operand is a dereference of an object of the access- |
| -- to-class-wide type. |
| -- |
| -- TEST DESCRIPTION: |
| -- A hierarchy of types is declared in two packages. The root type of |
| -- the class is declared as abstract in a separate package. It possesses |
| -- an abstract primitive subprogram Handle. A concrete type extends the |
| -- root type in a second package with a component of an enumeration type. |
| -- A second type extends this extension in the same package. Both |
| -- derivatives override the root type's primitive subprogram with a |
| -- non-abstract subprogram. |
| -- |
| -- The generic implements a heterogeneous stack of access-to-class-wide |
| -- objects in the root type's class. A subprogram declared in the |
| -- generic calls Handle using dereferences of each of the class-wide |
| -- objects on the stack as operand. Each call to Handle should dispatch |
| -- to the appropriate body based on the tag of the operand. The |
| -- overriding versions of Handle each set the component of the type to |
| -- a different value. The value of the component is checked to verify |
| -- that the calls dispatched correctly. |
| -- |
| -- |
| -- CHANGE HISTORY: |
| -- 06 Dec 94 SAIC ACVC 2.0 |
| -- 10 Apr 96 SAIC ACVC 2.1: Added pragma Elaborate to context clause |
| -- preceding CC54004_3. |
| -- |
| --! |
| |
| package CC54004_0 is |
| |
| -- The types and operations defined here are artificial. The component |
| -- TC_Code is the only component required for testing purposes. |
| |
| type TC_Code_Type is (None, Low, Medium); |
| |
| type Alert is abstract tagged record -- Abstract type. |
| TC_Code : TC_Code_Type; -- Testing flag. |
| end record; |
| |
| procedure Handle (A : in out Alert); -- Non-abstract primitive |
| -- subprogram. |
| -- ...Other operations. |
| |
| type Alert_Ptr is access Alert'Class; -- Access-to-class-wide |
| -- type. |
| end CC54004_0; |
| |
| |
| --===================================================================-- |
| |
| |
| package body CC54004_0 is |
| |
| procedure Handle (A : in out Alert) is |
| begin |
| A.TC_Code := None; |
| end Handle; |
| |
| end CC54004_0; |
| |
| |
| --===================================================================-- |
| |
| |
| with CC54004_0; |
| use CC54004_0; |
| package CC54004_1 is |
| |
| type Low_Alert is new CC54004_0.Alert with record |
| C1 : String (1 .. 5) := "Dummy"; |
| -- ...Other components. |
| end record; |
| |
| procedure Handle (A : in out Low_Alert); -- Overrides parent's |
| -- operations. |
| --...Other operations. |
| |
| |
| type Medium_Alert is new Low_Alert with record |
| C : Integer := 6; |
| -- ...Other components. |
| end record; |
| |
| procedure Handle (A : in out Medium_Alert); -- Overrides parent's |
| -- operations. |
| --...Other operations. |
| |
| end CC54004_1; |
| |
| |
| --===================================================================-- |
| |
| package body CC54004_1 is |
| |
| procedure Handle (A : in out Low_Alert) is |
| begin |
| A.TC_Code := Low; |
| end Handle; |
| |
| procedure Handle (A : in out Medium_Alert) is |
| begin |
| A.TC_Code := Medium; |
| end Handle; |
| |
| end CC54004_1; |
| |
| |
| --===================================================================-- |
| |
| |
| with CC54004_0; |
| generic |
| type Element_Type is abstract new CC54004_0.Alert with private; |
| type Element_Ptr is access Element_Type'Class; |
| package CC54004_2 is |
| |
| type Stack_Type is private; |
| |
| procedure Push (Stack : in out Stack_Type; |
| Elem_Ptr : in Element_Ptr); |
| |
| procedure Pop (Stack : in out Stack_Type; |
| Elem_Ptr : out Element_Ptr); |
| |
| procedure Process_Stack (Stack : in out Stack_Type); |
| |
| -- ... Other operations. |
| |
| private |
| |
| subtype Index is Positive range 1 .. 5; |
| type Stack_Type is array (Index) of Element_Ptr; |
| |
| Top : Index := 1; |
| |
| end CC54004_2; |
| |
| |
| --===================================================================-- |
| |
| |
| package body CC54004_2 is |
| |
| procedure Push (Stack : in out Stack_Type; |
| Elem_Ptr : in Element_Ptr) is |
| begin |
| Stack(Top) := Elem_Ptr; |
| Top := Top + 1; -- Artificial: no Constraint_Error protection. |
| end Push; |
| |
| |
| procedure Pop (Stack : in out Stack_Type; |
| Elem_Ptr : out Element_Ptr)is |
| begin |
| Top := Top - 1; -- Artificial: no Constraint_Error protection. |
| Elem_Ptr := Stack(Top); |
| end Pop; |
| |
| |
| -- Call Handle for each element on the stack. Since the dereferenced access |
| -- object is of a class-wide type, all calls to Handle are dispatching. The |
| -- version of Handle called will be that declared for the type |
| -- corresponding to the tag of the operand. |
| |
| procedure Process_Stack (Stack : in out Stack_Type) is |
| begin -- Artificial: no Constraint_Error protection. |
| for I in reverse Index'First .. (Top - 1) loop |
| Handle (Stack(I).all); -- Call dispatches based on |
| end loop; -- tag of operand. |
| end Process_Stack; |
| |
| end CC54004_2; |
| |
| |
| --===================================================================-- |
| |
| |
| with CC54004_0; |
| with CC54004_1; |
| with CC54004_2; |
| pragma Elaborate (CC54004_2); |
| |
| package CC54004_3 is |
| |
| package Alert_Stacks is new CC54004_2 (Element_Type => CC54004_0.Alert, |
| Element_Ptr => CC54004_0.Alert_Ptr); |
| |
| -- All overriding versions of Handle visible at the point of instantiation. |
| |
| Alert_List : Alert_Stacks.Stack_Type; |
| |
| procedure TC_Create_Alert_Stack; |
| |
| end CC54004_3; |
| |
| |
| --===================================================================-- |
| |
| |
| package body CC54004_3 is |
| |
| procedure TC_Create_Alert_Stack is |
| begin |
| Alert_Stacks.Push (Alert_List, new CC54004_1.Low_Alert); |
| Alert_Stacks.Push (Alert_List, new CC54004_1.Medium_Alert); |
| end TC_Create_Alert_Stack; |
| |
| end CC54004_3; |
| |
| |
| --===================================================================-- |
| |
| |
| with CC54004_0; |
| with CC54004_1; |
| with CC54004_3; |
| |
| with Report; |
| procedure CC54004 is |
| TC_Low_Ptr, TC_Med_Ptr : CC54004_0.Alert_Ptr; |
| TC_Low_Actual : CC54004_1.Low_Alert; |
| TC_Med_Actual : CC54004_1.Medium_Alert; |
| |
| use type CC54004_0.TC_Code_Type; |
| begin |
| Report.Test ("CC54004", "Check that the designated type of a generic " & |
| "formal pool-specific access type may be class-wide"); |
| |
| |
| -- Create stack of elements: |
| |
| CC54004_3.TC_Create_Alert_Stack; |
| |
| |
| -- Commence dispatching operations on stack elements: |
| |
| CC54004_3.Alert_Stacks.Process_Stack (CC54004_3.Alert_List); |
| |
| |
| -- Pop "handled" alerts off stack: |
| |
| CC54004_3.Alert_Stacks.Pop (CC54004_3.Alert_List, TC_Med_Ptr); |
| CC54004_3.Alert_Stacks.Pop (CC54004_3.Alert_List, TC_Low_Ptr); |
| |
| |
| -- Verify results: |
| |
| if TC_Low_Ptr.all not in CC54004_1.Low_Alert or else |
| TC_Med_Ptr.all not in CC54004_1.Medium_Alert |
| then |
| Report.Failed ("Class-wide objects do not have expected tags"); |
| |
| -- The explicit dereference of the "Pop"ed pointers results in views of |
| -- the designated objects, the nominal subtypes of which are class-wide. |
| -- In order to be able to reference the component TC_Code, these views |
| -- must be converted to a specific type possessing that component. |
| |
| elsif CC54004_1.Low_Alert(TC_Low_Ptr.all).TC_Code /= CC54004_0.Low or |
| CC54004_1.Medium_Alert(TC_Med_Ptr.all).TC_Code /= CC54004_0.Medium |
| then |
| Report.Failed ("Calls did not dispatch to expected operations"); |
| end if; |
| |
| Report.Result; |
| end CC54004; |
