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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . V A L U E _ I --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2022, 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 --
-- <http://www.gnu.org/licenses/>. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- Extensive contributions were provided by Ada Core Technologies Inc. --
-- --
------------------------------------------------------------------------------
with System.Val_Util; use System.Val_Util;
package body System.Value_I is
------------------
-- Scan_Integer --
------------------
procedure Scan_Integer
(Str : String;
Ptr : not null access Integer;
Max : Integer;
Res : out Int)
is
Uval : Uns;
-- 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;
Scan_Raw_Unsigned (Str, Ptr, Max, Uval);
-- Deal with overflow cases, and also with largest negative number
if Uval > Uns (Int'Last) then
if Minus and then Uval = Uns (-(Int'First)) then
Res := Int'First;
else
Bad_Value (Str);
end if;
-- Negative values
elsif Minus then
Res := -(Int (Uval));
-- Positive values
else
Res := Int (Uval);
end if;
end Scan_Integer;
-------------------
-- Value_Integer --
-------------------
function Value_Integer (Str : String) return Int 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 : Int;
P : aliased Integer := Str'First;
begin
Scan_Integer (Str, P'Access, Str'Last, V);
Scan_Trailing_Blanks (Str, P);
return V;
end;
end if;
end Value_Integer;
end System.Value_I;
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