[Bug ada/22255] New: Reset on shared file causes Use_Error.

["brianstensrude at hotmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

GCC Version: 3.4.2
OS: Solaris 8
GCC build: ../gcc-3.4.2/configure --enable-languages=c,c++,ada --disable-
shared --srcdir=/tools/gcc-3.4.2/gcc-3.4.2

The following code will cause a "use_error" to be raised =>

with Direct_IO,
     Text_IO;

procedure testit is

    type Item is
        record
            Buffer : String (1..10) := (Others => ' ');
            Len    : Integer := 0;
        end record;

    package Dir_IO is new Direct_IO (item);
 
    FD : Dir_IO.File_Type;

    Itm : Item;

begin
    -- Create a file using DIRECT_IO
    Dir_IO.Create (FD,
                   Dir_IO.Out_File,
                   "testfile.txt")
    -- Put some data in file
    for Counter in 1..10 loop
        Dir_IO.Write (FD, Itm);
    end loop;

    -- Close file
    Dir_IO.Close (FD);

    -- Now reopen with shared file access
    Dir_IO.Open (FD,
                 Dir_IO.In_File,
                 "testfile.txt",
                 "shared=yes");   -- Open with shared file access

    Dir_IO.Reset (FD);   -- This will raise an error due to shared file access!

    Dir_IO.Close (FD);

    Text_IO.Put_Line ("Finished program.");

exception
    when Dir_IO.Use_Error =>
        Text_IO.Put_Line ("Use Error was raised!");
    when Others =>
        Text_IO.Put_Line ("Error was raised!");
end testit;

  
    When reseting a file that does not change mode, the Reset should rewind the 
file without any problem. The code is incorrect.

    The GCC ada file "s-fileio.adb" Reset procedure calls another Reset 
procedure that takes a mode parameter. This procedure then checks for a file in 
shared access mode, and then raises an error. This is not correct. If the Mode 
of the file did not change, then the file should be reset and no error should 
occur. The Reset procedure in "s-fileio.adb" should be rewitten as follows =>

   procedure Reset (File : in out AFCD_Ptr; Mode : in File_Mode) is
      Fopstr : aliased Fopen_String;

   begin
     Check_File_Open (File);

     if File.Name'Length <= 1
       or else File.Is_System_File
       or else (not File.Is_Regular_file_
     then
       raise Use_Error;

     elsif Mode = File.Mode
       and then Mode <= Inout_file
     then
        rewind (File.Stream);

     else
       -- Check to see if the mode is Shared. If it is, then raise a
       -- Use_Error becuase this mode is not allowed.
       if File.Shared_Status = Yes then
         raise Use_Error;
       end if;

       Fopen_Mode
         (Mode, File.Is_Text_File, False, File.Access_Method, Fopstr);

       File.Stream :=
         freopen (File.Name.all'Address, Fopstr'Address, File.Stream);

       if File.Stream = NULL_Stream then
         Close (File);
         raise Use_Error;

       else
         File.Mode := Model
         Append_Set (File);
       end if;
     end if;
  end Reset;

-- 
           Summary: Reset on shared file causes Use_Error.
           Product: gcc
           Version: 3.4.2
            Status: UNCONFIRMED
          Severity: critical
          Priority: P1
         Component: ada
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: brianstensrude at hotmail dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22255