1-- CXAA013.A
2--
3--                             Grant of Unlimited Rights
4--
5--     Under contracts F33600-87-D-0337, F33600-84-D-0280, MDA903-79-C-0687,
6--     F08630-91-C-0015, and DCA100-97-D-0025, the U.S. Government obtained
7--     unlimited rights in the software and documentation contained herein.
8--     Unlimited rights are defined in DFAR 252.227-7013(a)(19).  By making
9--     this public release, the Government intends to confer upon all
10--     recipients unlimited rights  equal to those held by the Government.
11--     These rights include rights to use, duplicate, release or disclose the
12--     released technical data and computer software in whole or in part, in
13--     any manner and for any purpose whatsoever, and to have or permit others
14--     to do so.
15--
16--                                    DISCLAIMER
17--
18--     ALL MATERIALS OR INFORMATION HEREIN RELEASED, MADE AVAILABLE OR
19--     DISCLOSED ARE AS IS.  THE GOVERNMENT MAKES NO EXPRESS OR IMPLIED
20--     WARRANTY AS TO ANY MATTER WHATSOEVER, INCLUDING THE CONDITIONS OF THE
21--     SOFTWARE, DOCUMENTATION OR OTHER INFORMATION RELEASED, MADE AVAILABLE
22--     OR DISCLOSED, OR THE OWNERSHIP, MERCHANTABILITY, OR FITNESS FOR A
23--     PARTICULAR PURPOSE OF SAID MATERIAL.
24--*
25--
26-- OBJECTIVE:
27--      Check that the exception Mode_Error is raised when an attempt is made
28--      to skip a line or page using the predefined Skip_Line and Skip_Page
29--      procedures on a text file with mode Append_File.
30--
31-- TEST DESCRIPTION:
32--      A scenario is created that demonstrates the potential for the
33--      incorrect usage of predefined text processing subprograms, which
34--      results in the raising of a Mode_Error exception.
35--      A count is kept to ensure that each anticipated exception is in fact
36--      raised and handled properly.
37--
38-- APPLICABILITY CRITERIA:
39--      This test is applicable only to implementations that support text
40--      files.
41--
42--
43-- CHANGE HISTORY:
44--      06 Dec 94   SAIC    ACVC 2.0
45--      28 Feb 97   PWB.CTA Allowed for non-support of some IO operations
46--!
47
48with Ada.Text_IO;
49with Report;
50
51procedure CXAA013 is
52   use Ada;
53   Text_File     : Text_IO.File_Type;
54   Text_Filename : constant String :=
55                              Report.Legal_File_Name ( Nam => "CXAA013" );
56   Incomplete : exception;
57
58begin
59
60         Report.Test ("CXAA013", "Check that the exception Mode_Error is " &
61                                 "raised when an attempt is made to skip " &
62                                 "a line or page using the predefined "    &
63                                 "Skip_Line and Skip_Page procedures on "  &
64                                 "a text file with mode Append_File");
65
66         Test_for_Text_IO_Support:
67         begin
68
69-- An application creates a text file with mode Append_File.
70-- Use_Error will be raised if Text_IO operations or external files are not
71-- supported.
72
73            Text_IO.Create (Text_File, Text_IO.Append_File, Text_Filename);
74
75   exception
76
77       when Text_IO.Use_Error | Text_IO.Name_Error =>
78          Report.Not_Applicable
79             ( "Files not supported - Create as Append_File for Text_IO" );
80          raise Incomplete;
81
82   end Test_for_Text_IO_Support;
83
84-- The application writes some amount of data to the file.
85
86   Text_IO.Put_Line (Text_File, "Data entered into the file");
87
88   Operational_Test_Block:
89   declare
90      TC_Number_Of_Forced_Mode_Errors : constant Natural := 2;
91      TC_Mode_Errors : Natural := 0;
92   begin
93
94      Test_for_Skip_Line:
95      declare
96         TC_Spacing : constant Text_IO.Count := 3;
97      begin
98
99-- During the course of its processing, the application may attempt to
100-- invoke the Skip_Line procedure on a file that is currently in Append_File
101-- mode (instead of the anticipated In_File mode).  This results in the
102-- raising of Mode_Error.
103
104         Text_IO.Skip_Line (Text_File, TC_Spacing);
105         Report.Failed ("Exception not raised by Skip_Line");
106
107-- An exception handler present within the application handles the exception
108-- and processing can continue.
109
110      exception
111         when Text_IO.Mode_Error =>
112            TC_Mode_Errors := TC_Mode_Errors + 1;
113         when others =>
114            Report.Failed("Exception in Skip_Line processing");
115      end Test_for_Skip_Line;
116
117      Test_for_Skip_Page:
118      begin
119
120-- Again, during the course of its processing, the application incorrectly
121-- assumes that the file mode is In_File, this time attempting to call the
122-- Skip_Page procedure for the file (that is currently in Append_File mode).
123
124         Text_IO.Skip_Page (Text_File);
125         Report.Failed ("Exception not raised by Skip_Page");
126
127-- Once again, an exception handler present within the application handles
128-- the exception and processing continues.
129
130      exception
131         when Text_IO.Mode_Error =>
132            TC_Mode_Errors := TC_Mode_Errors + 1;
133         when others =>
134            Report.Failed("Exception in Skip_Page processing");
135      end Test_for_Skip_Page;
136
137      if (TC_Mode_Errors /= TC_Number_Of_Forced_Mode_Errors) then
138         Report.Failed ("Incorrect number of exceptions handled");
139      end if;
140
141   end Operational_Test_Block;
142
143   Deletion:
144   begin
145      -- Delete the external file.
146      if Text_IO.Is_Open (Text_File) then
147         Text_IO.Delete (Text_File);
148      else
149         Text_IO.Open (Text_File, Text_IO.In_File, Text_Filename);
150         Text_IO.Delete (Text_File);
151      end if;
152   exception
153      when others =>
154         Report.Failed
155            ( "Delete not properly implemented for Text_IO" );
156   end Deletion;
157
158   Report.Result;
159
160exception
161   when Incomplete =>
162      Report.Result;
163   when others     =>
164      Report.Failed ( "Unexpected exception" );
165      Report.Result;
166
167end CXAA013;
168