1 ------------------------------------------------------------------------------
3 -- GNAT COMPILER COMPONENTS --
5 -- S Y S T E M . V A L _ U T I L --
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
.Case_Util
; use System
.Case_Util
;
34 package body System
.Val_Util
is
36 ----------------------
37 -- Normalize_String --
38 ----------------------
40 procedure Normalize_String
48 -- Scan for leading spaces
50 while F
<= L
and then S
(F
) = ' ' loop
54 -- Check for case when the string contained no characters
57 raise Constraint_Error
;
60 -- Scan for trailing spaces
62 while S
(L
) = ' ' loop
66 -- Except in the case of a character literal, convert to upper case
70 S
(J
) := To_Upper
(S
(J
));
79 function Scan_Exponent
81 Ptr
: not null access Integer;
83 Real
: Boolean := False) return Integer
85 P
: Natural := Ptr
.all;
91 or else (Str
(P
) /= 'E' and then Str
(P
) /= 'e')
96 -- We have an E/e, see if sign follows
100 if Str
(P
) = '+' then
109 elsif Str
(P
) = '-' then
112 if P
> Max
or else not Real
then
122 if Str
(P
) not in '0' .. '9' then
126 -- Scan out the exponent value as an unsigned integer. Values larger
127 -- than (Integer'Last / 10) are simply considered large enough here.
128 -- This assumption is correct for all machines we know of (e.g. in
129 -- the case of 16 bit integers it allows exponents up to 3276, which
130 -- is large enough for the largest floating types in base 2.)
135 if X
< (Integer'Last / 10) then
136 X
:= X
* 10 + (Character'Pos (Str
(P
)) - Character'Pos ('0'));
143 if Str
(P
) = '_' then
144 Scan_Underscore
(Str
, P
, Ptr
, Max
, False);
146 exit when Str
(P
) not in '0' .. '9';
162 procedure Scan_Plus_Sign
164 Ptr
: not null access Integer;
166 Start
: out Positive)
168 P
: Natural := Ptr
.all;
172 raise Constraint_Error
;
175 -- Scan past initial blanks
177 while Str
(P
) = ' ' loop
182 raise Constraint_Error
;
188 -- Skip past an initial plus sign
190 if Str
(P
) = '+' then
195 raise Constraint_Error
;
208 Ptr
: not null access Integer;
211 Start
: out Positive)
213 P
: Natural := Ptr
.all;
216 -- Deal with case of null string (all blanks!). As per spec, we
217 -- raise constraint error, with Ptr unchanged, and thus > Max.
220 raise Constraint_Error
;
223 -- Scan past initial blanks
225 while Str
(P
) = ' ' loop
230 raise Constraint_Error
;
236 -- Remember an initial minus sign
238 if Str
(P
) = '-' then
244 raise Constraint_Error
;
247 -- Skip past an initial plus sign
249 elsif Str
(P
) = '+' then
255 raise Constraint_Error
;
265 --------------------------
266 -- Scan_Trailing_Blanks --
267 --------------------------
269 procedure Scan_Trailing_Blanks
(Str
: String; P
: Positive) is
271 for J
in P
.. Str
'Last loop
272 if Str
(J
) /= ' ' then
273 raise Constraint_Error
;
276 end Scan_Trailing_Blanks
;
278 ---------------------
279 -- Scan_Underscore --
280 ---------------------
282 procedure Scan_Underscore
285 Ptr
: not null access Integer;
294 -- If underscore is at the end of string, then this is an error and
295 -- we raise Constraint_Error, leaving the pointer past the underscore.
296 -- This seems a bit strange. It means e.g. that if the field is:
300 -- that Constraint_Error is raised. You might think that the RM in
301 -- this case would scan out the 345 as a valid integer, leaving the
302 -- pointer at the underscore, but the ACVC suite clearly requires
303 -- an error in this situation (see for example CE3704M).
307 raise Constraint_Error
;
310 -- Similarly, if no digit follows the underscore raise an error. This
311 -- also catches the case of double underscore which is also an error.
317 (Ext
and then (C
in 'A' .. 'F' or else C
in 'a' .. 'f'))
322 raise Constraint_Error
;