1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . V A L _ U T I L --
9 -- Copyright (C) 1992-2008, 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, 51 Franklin Street, Fifth Floor, --
20 -- Boston, MA 02110-1301, 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));
81 function Scan_Exponent
83 Ptr : not null access Integer;
85 Real : Boolean := False) return Integer
87 P : Natural := Ptr.all;
93 or else (Str (P) /= 'E' and then Str (P) /= 'e')
98 -- We have an E/e, see if sign follows
102 if Str (P) = '+' then
111 elsif Str (P) = '-' then
114 if P > Max or else not Real then
124 if Str (P) not in '0' .. '9' then
128 -- Scan out the exponent value as an unsigned integer. Values larger
129 -- than (Integer'Last / 10) are simply considered large enough here.
130 -- This assumption is correct for all machines we know of (e.g. in
131 -- the case of 16 bit integers it allows exponents up to 3276, which
132 -- is large enough for the largest floating types in base 2.)
137 if X < (Integer'Last / 10) then
138 X := X * 10 + (Character'Pos (Str (P)) - Character'Pos ('0'));
145 if Str (P) = '_' then
146 Scan_Underscore (Str, P, Ptr, Max, False);
148 exit when Str (P) not in '0' .. '9';
164 procedure Scan_Plus_Sign
166 Ptr : not null access Integer;
168 Start : out Positive)
170 P : Natural := Ptr.all;
174 raise Constraint_Error;
177 -- Scan past initial blanks
179 while Str (P) = ' ' loop
184 raise Constraint_Error;
190 -- Skip past an initial plus sign
192 if Str (P) = '+' then
197 raise Constraint_Error;
210 Ptr : not null access Integer;
213 Start : out Positive)
215 P : Natural := Ptr.all;
218 -- Deal with case of null string (all blanks!). As per spec, we
219 -- raise constraint error, with Ptr unchanged, and thus > Max.
222 raise Constraint_Error;
225 -- Scan past initial blanks
227 while Str (P) = ' ' loop
232 raise Constraint_Error;
238 -- Remember an initial minus sign
240 if Str (P) = '-' then
246 raise Constraint_Error;
249 -- Skip past an initial plus sign
251 elsif Str (P) = '+' then
257 raise Constraint_Error;
267 --------------------------
268 -- Scan_Trailing_Blanks --
269 --------------------------
271 procedure Scan_Trailing_Blanks (Str : String; P : Positive) is
273 for J in P .. Str'Last loop
274 if Str (J) /= ' ' then
275 raise Constraint_Error;
278 end Scan_Trailing_Blanks;
280 ---------------------
281 -- Scan_Underscore --
282 ---------------------
284 procedure Scan_Underscore
287 Ptr : not null access Integer;
296 -- If underscore is at the end of string, then this is an error and
297 -- we raise Constraint_Error, leaving the pointer past the undescore.
298 -- This seems a bit strange. It means e,g, that if the field is:
302 -- that Constraint_Error is raised. You might think that the RM in
303 -- this case would scan out the 345 as a valid integer, leaving the
304 -- pointer at the underscore, but the ACVC suite clearly requires
305 -- an error in this situation (see for example CE3704M).
309 raise Constraint_Error;
312 -- Similarly, if no digit follows the underscore raise an error. This
313 -- also catches the case of double underscore which is also an error.
319 (Ext and then (C in 'A' .. 'F' or else C in 'a' .. 'f'))
324 raise Constraint_Error;