------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S Y S T E M . V A L _ I N T -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2018, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. -- -- -- -- As a special exception under Section 7 of GPL version 3, you are granted -- -- additional permissions described in the GCC Runtime Library Exception, -- -- version 3.1, as published by the Free Software Foundation. -- -- -- -- You should have received a copy of the GNU General Public License and -- -- a copy of the GCC Runtime Library Exception along with this program; -- -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- -- . -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with System.Unsigned_Types; use System.Unsigned_Types; with System.Val_Uns; use System.Val_Uns; with System.Val_Util; use System.Val_Util; package body System.Val_Int is ------------------ -- Scan_Integer -- ------------------ function Scan_Integer (Str : String; Ptr : not null access Integer; Max : Integer) return Integer is Uval : Unsigned; -- Unsigned result Minus : Boolean := False; -- Set to True if minus sign is present, otherwise to False Start : Positive; -- Saves location of first non-blank (not used in this case) begin Scan_Sign (Str, Ptr, Max, Minus, Start); if Str (Ptr.all) not in '0' .. '9' then Ptr.all := Start; Bad_Value (Str); end if; Uval := Scan_Raw_Unsigned (Str, Ptr, Max); -- Deal with overflow cases, and also with maximum negative number if Uval > Unsigned (Integer'Last) then if Minus and then Uval = Unsigned (-(Integer'First)) then return Integer'First; else Bad_Value (Str); end if; -- Negative values elsif Minus then return -(Integer (Uval)); -- Positive values else return Integer (Uval); end if; end Scan_Integer; ------------------- -- Value_Integer -- ------------------- function Value_Integer (Str : String) return Integer is begin -- We have to special case Str'Last = Positive'Last because the normal -- circuit ends up setting P to Str'Last + 1 which is out of bounds. We -- deal with this by converting to a subtype which fixes the bounds. if Str'Last = Positive'Last then declare subtype NT is String (1 .. Str'Length); begin return Value_Integer (NT (Str)); end; -- Normal case where Str'Last < Positive'Last else declare V : Integer; P : aliased Integer := Str'First; begin V := Scan_Integer (Str, P'Access, Str'Last); Scan_Trailing_Blanks (Str, P); return V; end; end if; end Value_Integer; end System.Val_Int;