gcc/ada/switch.adb

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                               S W I T C H                                --
   6 --                                                                          --
   7 --                                 B o d y                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2002, 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 -- GNAT was originally developed  by the GNAT team at  New York University. --
  23 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  24 --                                                                          --
  25 ------------------------------------------------------------------------------
  26
  27 package body Switch is
  28
  29    -------------------------
  30    -- Is_Front_End_Switch --
  31    -------------------------
  32
  33    function Is_Front_End_Switch (Switch_Chars : String) return Boolean is
  34       Ptr : constant Positive := Switch_Chars'First;
  35
  36    begin
  37       return Is_Switch (Switch_Chars)
  38         and then
  39         (Switch_Chars (Ptr + 1) = 'I'
  40          or else (Switch_Chars'Length >= 5
  41                   and then Switch_Chars (Ptr + 1 .. Ptr + 4) = "gnat")
  42          or else (Switch_Chars'Length >= 5
  43                   and then Switch_Chars (Ptr + 1 .. Ptr + 4) = "fRTS"));
  44    end Is_Front_End_Switch;
  45
  46    ---------------
  47    -- Is_Switch --
  48    ---------------
  49
  50    function Is_Switch (Switch_Chars : String) return Boolean is
  51    begin
  52       return Switch_Chars'Length > 1
  53         and then Switch_Chars (Switch_Chars'First) = '-';
  54    end Is_Switch;
  55
  56    ------------------------
  57    --------------
  58    -- Scan_Nat --
  59    --------------
  60
  61    procedure Scan_Nat
  62      (Switch_Chars : String;
  63       Max          : Integer;
  64       Ptr          : in out Integer;
  65       Result       : out Nat)
  66    is
  67    begin
  68       Result := 0;
  69
  70       if Ptr > Max or else Switch_Chars (Ptr) not in '0' .. '9' then
  71          raise Missing_Switch_Value;
  72       end if;
  73
  74       while Ptr <= Max and then Switch_Chars (Ptr) in '0' .. '9' loop
  75          Result := Result * 10 +
  76            Character'Pos (Switch_Chars (Ptr)) - Character'Pos ('0');
  77          Ptr := Ptr + 1;
  78
  79          if Result > Switch_Max_Value then
  80             raise Bad_Switch_Value;
  81          end if;
  82       end loop;
  83    end Scan_Nat;
  84
  85    --------------
  86    -- Scan_Pos --
  87    --------------
  88
  89    procedure Scan_Pos
  90      (Switch_Chars : String;
  91       Max          : Integer;
  92       Ptr          : in out Integer;
  93       Result       : out Pos) is
  94
  95       Temp : Nat;
  96
  97    begin
  98       Scan_Nat (Switch_Chars, Max, Ptr, Temp);
  99
 100       if Temp = 0 then
 101          raise Bad_Switch_Value;
 102       end if;
 103
 104       Result := Temp;
 105    end Scan_Pos;
 106
 107 end Switch;