1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . V A L _ U T I L --
9 -- Copyright (C) 1992-2002, 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 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. --
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. --
29 -- GNAT was originally developed by the GNAT team at New York University. --
30 -- Extensive contributions were provided by Ada Core Technologies Inc. --
32 ------------------------------------------------------------------------------
34 with System.Case_Util; use System.Case_Util;
36 package body System.Val_Util is
38 ----------------------
39 -- Normalize_String --
40 ----------------------
42 procedure Normalize_String
50 -- Scan for leading spaces
52 while F <= L and then S (F) = ' ' loop
56 -- Check for case when the string contained no characters
59 raise Constraint_Error;
62 -- Scan for trailing spaces
64 while S (L) = ' ' loop
68 -- Except in the case of a character literal, convert to upper case
72 S (J) := To_Upper (S (J));
82 function Scan_Exponent
86 Real : Boolean := False)
89 P : Natural := Ptr.all;
95 or else (Str (P) /= 'E' and then Str (P) /= 'e')
100 -- We have an E/e, see if sign follows
104 if Str (P) = '+' then
113 elsif Str (P) = '-' then
116 if P > Max or else not Real then
126 if Str (P) not in '0' .. '9' then
130 -- Scan out the exponent value as an unsigned integer. Values larger
131 -- than (Integer'Last / 10) are simply considered large enough here.
132 -- This assumption is correct for all machines we know of (e.g. in
133 -- the case of 16 bit integers it allows exponents up to 3276, which
134 -- is large enough for the largest floating types in base 2.)
139 if X < (Integer'Last / 10) then
140 X := X * 10 + (Character'Pos (Str (P)) - Character'Pos ('0'));
147 if Str (P) = '_' then
148 Scan_Underscore (Str, P, Ptr, Max, False);
150 exit when Str (P) not in '0' .. '9';
169 Ptr : access Integer;
172 Start : out Positive)
174 P : Natural := Ptr.all;
177 -- Deal with case of null string (all blanks!). As per spec, we
178 -- raise constraint error, with Ptr unchanged, and thus > Max.
181 raise Constraint_Error;
184 -- Scan past initial blanks
186 while Str (P) = ' ' loop
191 raise Constraint_Error;
197 -- Remember an initial minus sign
199 if Str (P) = '-' then
205 raise Constraint_Error;
208 -- Skip past an initial plus sign
210 elsif Str (P) = '+' then
216 raise Constraint_Error;
226 --------------------------
227 -- Scan_Trailing_Blanks --
228 --------------------------
230 procedure Scan_Trailing_Blanks (Str : String; P : Positive) is
232 for J in P .. Str'Last loop
233 if Str (J) /= ' ' then
234 raise Constraint_Error;
237 end Scan_Trailing_Blanks;
239 ---------------------
240 -- Scan_Underscore --
241 ---------------------
243 procedure Scan_Underscore
246 Ptr : access Integer;
255 -- If underscore is at the end of string, then this is an error and
256 -- we raise Constraint_Error, leaving the pointer past the undescore.
257 -- This seems a bit strange. It means e,g, that if the field is:
261 -- that Constraint_Error is raised. You might think that the RM in
262 -- this case would scan out the 345 as a valid integer, leaving the
263 -- pointer at the underscore, but the ACVC suite clearly requires
264 -- an error in this situation (see for example CE3704M).
268 raise Constraint_Error;
271 -- Similarly, if no digit follows the underscore raise an error. This
272 -- also catches the case of double underscore which is also an error.
278 (Ext and then (C in 'A' .. 'F' or else C in 'a' .. 'f'))
283 raise Constraint_Error;