1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . V A L _ I N T --
9 -- Copyright (C) 1992-2009, Free Software Foundation, Inc. --
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 3, 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. --
18 -- As a special exception under Section 7 of GPL version 3, you are granted --
19 -- additional permissions described in the GCC Runtime Library Exception, --
20 -- version 3.1, as published by the Free Software Foundation. --
22 -- You should have received a copy of the GNU General Public License and --
23 -- a copy of the GCC Runtime Library Exception along with this program; --
24 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
25 -- <http://www.gnu.org/licenses/>. --
27 -- GNAT was originally developed by the GNAT team at New York University. --
28 -- Extensive contributions were provided by Ada Core Technologies Inc. --
30 ------------------------------------------------------------------------------
32 with System.Unsigned_Types; use System.Unsigned_Types;
33 with System.Val_Uns; use System.Val_Uns;
34 with System.Val_Util; use System.Val_Util;
36 package body System.Val_Int is
44 Ptr : not null access Integer;
45 Max : Integer) return Integer
50 Minus : Boolean := False;
51 -- Set to True if minus sign is present, otherwise to False
54 -- Saves location of first non-blank (not used in this case)
57 Scan_Sign (Str, Ptr, Max, Minus, Start);
59 if Str (Ptr.all) not in '0' .. '9' then
61 raise Constraint_Error;
64 Uval := Scan_Raw_Unsigned (Str, Ptr, Max);
66 -- Deal with overflow cases, and also with maximum negative number
68 if Uval > Unsigned (Integer'Last) then
69 if Minus and then Uval = Unsigned (-(Integer'First)) then
72 raise Constraint_Error;
78 return -(Integer (Uval));
83 return Integer (Uval);
91 function Value_Integer (Str : String) return Integer is
93 P : aliased Integer := Str'First;
95 V := Scan_Integer (Str, P'Access, Str'Last);
96 Scan_Trailing_Blanks (Str, P);