gcc/testsuite/ada/acats/tests/cxa/cxaa012.a

   1 -- CXAA012.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 read from (perform a Get_Line) or use the predefined End_Of_File
  29 --      function 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, resulting
  34 --      from their use with files of the wrong Mode.  This results in the
  35 --      raising of Mode_Error exceptions, which is handled within blocks
  36 --      embedded in the test.
  37 --      A count is kept to ensure that each anticipated exception is in fact
  38 --      raised and handled properly.
  39 --
  40 -- APPLICABILITY CRITERIA:
  41 --      This test is applicable only to implementations that support text
  42 --      files.
  43 --
  44 --
  45 -- CHANGE HISTORY:
  46 --      06 Dec 94   SAIC    ACVC 2.0
  47 --      27 Feb 97   PWB.CTA Allowed for non-support of some IO operations
  48 --!
  49
  50 with Ada.Text_IO;
  51 with Report;
  52
  53 procedure CXAA012 is
  54    use Ada;
  55    Text_File     : Text_IO.File_Type;
  56    Text_Filename : constant String :=
  57                       Report.Legal_File_Name ( Nam => "CXAA012" );
  58    Incomplete : exception;
  59 begin
  60
  61         Report.Test ("CXAA012", "Check that the exception Mode_Error is " &
  62                                 "raised when an attempt is made to read " &
  63                                 "from (perform a Get_Line) or use the "   &
  64                                 "predefined End_Of_File function on a "   &
  65                                 "text file with mode Append_File");
  66
  67         Test_for_Text_IO_Support:
  68         begin
  69
  70         -- Use_Error or Name_Error will be raised if Text_IO operations
  71         -- or external files are not supported.
  72
  73            Text_IO.Create (Text_File, Text_IO.Out_File, Text_Filename);
  74
  75       exception
  76           when Text_IO.Use_Error | Text_IO.Name_Error =>
  77              Report.Not_Applicable
  78                 ( "Files not supported - Create as Out_File for Text_IO" );
  79              raise Incomplete;
  80       end Test_for_Text_IO_Support;
  81
  82       -- The application writes some amount of data to the file.
  83
  84            Text_IO.Put_Line (Text_File, "Data entered into the file");
  85
  86            Text_IO.Close (Text_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               Text_IO.Open (Text_File, Text_IO.Append_File, Text_Filename);
  95
  96               Test_for_Reading:
  97               declare
  98                  TC_Data   : String (1..80);
  99                  TC_Length : Natural := 0;
 100               begin
 101
 102 -- During the course of its processing, the application may become confused
 103 -- and erroneously attempt to read data from the file that is currently in
 104 -- Append_File mode (instead of the anticipated In_File mode).
 105 -- This would result in the raising of Mode_Error.
 106
 107                  Text_IO.Get_Line (Text_File, TC_Data, TC_Length);
 108                  Report.Failed ("Exception not raised by Get_Line");
 109
 110 -- An exception handler present within the application handles the exception
 111 -- and processing can continue.
 112
 113               exception
 114                  when Text_IO.Mode_Error =>
 115                     TC_Mode_Errors := TC_Mode_Errors + 1;
 116                  when others             =>
 117                     Report.Failed ("Exception in Get_Line processing");
 118               end Test_for_Reading;
 119
 120
 121               Test_for_End_Of_File:
 122               declare
 123                  TC_End_Of_File : Boolean;
 124               begin
 125
 126 -- Again, during the course of its processing, the application attempts to
 127 -- call the End_Of_File function for the file that is currently in
 128 -- Append_File mode (instead of the anticipated In_File mode).
 129
 130                  TC_End_Of_File := Text_IO.End_Of_File (Text_File);
 131                  Report.Failed ("Exception not raised by End_Of_File");
 132
 133 -- Once again, an exception handler present within the application handles
 134 -- the exception and processing continues.
 135
 136               exception
 137                  when Text_IO.Mode_Error =>
 138                     TC_Mode_Errors := TC_Mode_Errors + 1;
 139                  when others             =>
 140                     Report.Failed("Exception in End_Of_File processing");
 141               end Test_for_End_Of_File;
 142
 143
 144               if (TC_Mode_Errors /= TC_Number_Of_Forced_Mode_Errors) then
 145                  Report.Failed ("Incorrect number of exceptions handled");
 146               end if;
 147
 148            end Operational_Test_Block;
 149
 150            -- Delete the external file.
 151            if Text_IO.Is_Open (Text_File) then
 152               Text_IO.Delete (Text_File);
 153            else
 154               Text_IO.Open (Text_File, Text_IO.In_File, Text_Filename);
 155               Text_IO.Delete (Text_File);
 156            end if;
 157
 158         Report.Result;
 159
 160 exception
 161    when Incomplete =>
 162       Report.Result;
 163    when others     =>
 164       Report.Failed ( "Unexpected exception" );
 165       Report.Result;
 166
 167 end CXAA012;