-- CB41004.A
--
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--                                    DISCLAIMER
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--     DISCLOSED ARE AS IS.  THE GOVERNMENT MAKES NO EXPRESS OR IMPLIED
--     WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS OF THE
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--     OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A
--     PARTICULAR PURPOSE OF SAID MATERIAL.
--*
--
-- OBJECTIVE:
--      Check that Raise_Exception and Reraise_Occurrence have no effect in
--      the case of Null_Id or Null_Occurrence.  Check that Exception_Message,
--      Exception_Identity, Exception_Name, and Exception_Information raise
--      Constraint_Error for a Null_Occurrence input parameter.
--      Check that calling the Save_Occurrence subprograms with the
--      Null_Occurrence input parameter saves the Null_Occurrence to the
--      appropriate target object, and does not raise Constraint_Error.
--      Check that Null_Id is the default initial value of type Exception_Id.
--
-- TEST DESCRIPTION:
--      This test performs a series of calls to many of the subprograms
--      defined in package Ada.Exceptions, using either Null_Id or
--      Null_Occurrence (based on their parameter profile).  In the cases of
--      Raise_Exception and Reraise_Occurrence, these null input values
--      should result in no exceptions being raised, and Constraint_Error
--      should not be raised in response to these calls.  Test failure will
--      result if any exception is raised in these cases.
--      For the Save_Occurrence subprograms, calling them with the
--      Null_Occurrence input parameter does not raise Constraint_Error, but
--      simply results in the Null_Occurrence being saved into the appropriate
--      target (either a Exception_Occurrence out parameter, or as an
--      Exception_Occurrence_Access value).
--      In the cases of the other mentioned subprograms, calls performed with
--      a Null_Occurrence input parameter must result in Constraint_Error
--      being raised.  This exception will be handled, with test failure the
--      result if the exception is not raised.
--
--
-- CHANGE HISTORY:
--      06 Dec 94   SAIC    ACVC 2.0
--      08 Dec 00   RLB     Removed Exception_Identity subtest, pending
--                          resolution of AI95-00241.
--                          Notes for future: Replace Exception_Identity
--                          subtest with whatever the resolution is.
--                          Add a subtest for Exception_Name(Null_Id), which
--                          is missing from this test.
--!

with Report;
with Ada.Exceptions;

procedure CB41004 is
begin

   Report.Test ("CB41004", "Check that Null_Id and Null_Occurrence input " &
                           "parameters have the appropriate effect when "  &
                           "used in calls of the subprograms found in "    &
                           "package Ada.Exceptions");

   Test_Block:
   declare

      use Ada.Exceptions;

      -- No initial values given for these two declarations; they default
      -- to Null_Id and Null_Occurrence respectively.
      A_Null_Exception_Id         : Ada.Exceptions.Exception_Id;
      A_Null_Exception_Occurrence : Ada.Exceptions.Exception_Occurrence;

      TC_Flag : Boolean := False;

   begin

      -- Verify that Null_Id is the default initial value of type
      -- Exception_Id.

      if not (A_Null_Exception_Id = Ada.Exceptions.Null_Id) then
         Report.Failed("The default initial value of an object of type " &
                       "Exception_Id was not Null_Id");
      end if;


      -- Verify that Reraise_Occurrence has no effect in the case of
      -- Null_Occurrence.
      begin
         Ada.Exceptions.Reraise_Occurrence(A_Null_Exception_Occurrence);
         TC_Flag := True;
      exception
         when others =>
            Report.Failed
              ("Exception raised by procedure Reraise_Occurrence " &
               "when called with a Null_Occurrence input parameter");
      end;

      if not TC_Flag then
         Report.Failed("Incorrect processing following the call to " &
                       "Reraise_Occurrence with a Null_Occurrence "  &
                       "input parameter");
      end if;


      -- Verify that function Exception_Message raises Constraint_Error for
      -- a Null_Occurrence input parameter.
      begin
         declare
            Msg : constant String :=
              Ada.Exceptions.Exception_Message(A_Null_Exception_Occurrence);
         begin
            Report.Failed
              ("Constraint_Error not raised by Function Exception_Message " &
               "when called with a Null_Occurrence input parameter");
         end;
      exception
         when Constraint_Error => null; -- OK, expected exception.
         when others =>
            Report.Failed
              ("Unexpected exception raised by Function Exception_Message " &
               "when called with a Null_Occurrence input parameter");
      end;


--      -- Verify that function Exception_Identity raises Constraint_Error for
--      -- a Null_Occurrence input parameter.
--      -- Note: (RLB, 2000/12/08) This behavior may be modified by AI-00241.
--      -- As such, this test case has been removed pending a resolution.
--      begin
--         declare
--            Id : Ada.Exceptions.Exception_Id :=
--              Ada.Exceptions.Exception_Identity(A_Null_Exception_Occurrence);
--         begin
--            Report.Failed
--              ("Constraint_Error not raised by Function Exception_Identity " &
--               "when called with a Null_Occurrence input parameter");
--         end;
--      exception
--         when Constraint_Error => null; -- OK, expected exception.
--         when others =>
--            Report.Failed
--              ("Unexpected exception raised by Function Exception_Identity " &
--               "when called with a Null_Occurrence input parameter");
--      end;


      -- Verify that function Exception_Name raises Constraint_Error for
      -- a Null_Occurrence input parameter.
      begin
         declare
            Name : constant String :=
              Ada.Exceptions.Exception_Name(A_Null_Exception_Occurrence);
         begin
            Report.Failed
              ("Constraint_Error not raised by Function Exception_Name " &
               "when called with a Null_Occurrence input parameter");
         end;
      exception
         when Constraint_Error => null; -- OK, expected exception.
         when others =>
            Report.Failed
              ("Unexpected exception raised by Function Exception_Null " &
               "when called with a Null_Occurrence input parameter");
      end;


      -- Verify that function Exception_Information raises Constraint_Error
      -- for a Null_Occurrence input parameter.
      begin
         declare
            Info : constant String :=
              Ada.Exceptions.Exception_Information
                               (A_Null_Exception_Occurrence);
         begin
            Report.Failed
              ("Constraint_Error not raised by Function "  &
               "Exception_Information when called with a " &
               "Null_Occurrence input parameter");
         end;
      exception
         when Constraint_Error => null; -- OK, expected exception.
         when others =>
            Report.Failed
              ("Unexpected exception raised by Function Exception_Null " &
               "when called with a Null_Occurrence input parameter");
      end;


      -- Verify that calling the Save_Occurrence procedure with a
      -- Null_Occurrence input parameter saves the Null_Occurrence to the
      -- target object, and does not raise Constraint_Error.
      declare
         use Ada.Exceptions;
         Saved_Occurrence : Exception_Occurrence;
      begin

         -- Initialize the Saved_Occurrence variable with a value other than
         -- Null_Occurrence (default).
         begin
            raise Program_Error;
         exception
            when Exc : others => Save_Occurrence(Saved_Occurrence, Exc);
         end;

         -- Save a Null_Occurrence input parameter.
         begin
            Save_Occurrence(Target => Saved_Occurrence,
                            Source => Ada.Exceptions.Null_Occurrence);
         exception
            when others =>
               Report.Failed
                 ("Unexpected exception raised by procedure "           &
                  "Save_Occurrence when called with a Null_Occurrence " &
                  "input parameter");
         end;

         -- Verify that the occurrence that was saved above is a
         -- Null_Occurrence value.

         begin
            Reraise_Occurrence(Saved_Occurrence);
         exception
            when others =>
               Report.Failed("Value saved from Procedure Save_Occurrence " &
                             "resulted in an exception, i.e., was not a "  &
                             "value of Null_Occurrence");
         end;

      exception
         when others =>
            Report.Failed("Unexpected exception raised during evaluation " &
                          "of Procedure Save_Occurrence");
      end;


      -- Verify that calling the Save_Occurrence function with a
      -- Null_Occurrence input parameter returns the Null_Occurrence as the
      -- function result, and does not raise Constraint_Error.
      declare
         Occurrence_Ptr : Ada.Exceptions.Exception_Occurrence_Access;
      begin
         -- Save a Null_Occurrence input parameter.
         begin
            Occurrence_Ptr :=
              Ada.Exceptions.Save_Occurrence(Ada.Exceptions.Null_Occurrence);
         exception
            when others =>
               Report.Failed
                 ("Unexpected exception raised by function "            &
                  "Save_Occurrence when called with a Null_Occurrence " &
                  "input parameter");
         end;

         -- Verify that the occurrence that was saved above is a
         -- Null_Occurrence value.

         begin
            -- Dereferenced value of type Exception_Occurrence_Access
            -- should be a Null_Occurrence value, based on the action
            -- of Function Save_Occurrence above.  Providing this as an
            -- input parameter to Reraise_Exception should not result in
            -- any exception being raised.

            Ada.Exceptions.Reraise_Occurrence(Occurrence_Ptr.all);

         exception
            when others =>
               Report.Failed("Value saved from Function Save_Occurrence " &
                             "resulted in an exception, i.e., was not a "  &
                             "value of Null_Occurrence");
         end;
      exception
         when others =>
            Report.Failed("Unexpected exception raised during evaluation " &
                          "of Function Save_Occurrence");
      end;


   exception
      when others => Report.Failed ("Exception raised in Test_Block");
   end Test_Block;

   Report.Result;

end CB41004;