gcc/ada/gnatvsn.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                              G N A T V S N                               --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2002 Free Software Foundation, Inc.               --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the Free Software Foundation,  59 Temple Place - Suite 330,  Boston, --
  20 -- MA 02111-1307, USA.                                                      --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 package body Gnatvsn is
  35
  36    --  Import the string constant defined in the (language-independent)
  37    --  source file version.c.
  38
  39    --  The size is a lie; we have no way of writing the truth (the size
  40    --  is variable and depends on the actual text of the constant).
  41
  42    --  FIXME: It should be possible to declare this to be a constant, but
  43    --  that is rejected by the compiler ("invalid context for deferred
  44    --  constant declaration").  Per Ada95 this constraint only applies to
  45    --  deferred constants completed by a full constant declaration, not
  46    --  deferred constants completed by a pragma Import.
  47
  48    Version_String : array (0 .. Ver_Len_Max) of aliased Character;
  49    pragma Import (C, Version_String, "version_string");
  50
  51    --  Convert that string constant to an Ada String and return it.
  52    --  This is essentially the same as the To_Ada routine in
  53    --  Interfaces.C; that package is not linked into gnat1 so
  54    --  we cannot use it.
  55
  56    function Gnat_Version_String return String
  57    is
  58       Count : Natural := 0;
  59
  60    begin
  61       loop
  62          if Version_String (Count) = Character'First then
  63             exit;
  64          else
  65             Count := Count + 1;
  66          end if;
  67       end loop;
  68
  69       declare
  70          R : String (1 .. Count);
  71
  72       begin
  73          for J in R'Range loop
  74             R (J) := Version_String (J - 1);
  75          end loop;
  76
  77          return R;
  78       end;
  79    end Gnat_Version_String;
  80
  81 end Gnatvsn;