1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
|
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . V A L _ U T I L --
-- --
-- B o d y --
-- --
-- --
-- Copyright (C) 1992-2001, 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 2, 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. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNAT was originally developed by the GNAT team at New York University. --
-- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
with GNAT.Case_Util; use GNAT.Case_Util;
package body System.Val_Util is
----------------------
-- Normalize_String --
----------------------
procedure Normalize_String
(S : in out String;
F, L : out Integer)
is
begin
F := S'First;
L := S'Last;
-- Scan for leading spaces
while F <= L and then S (F) = ' ' loop
F := F + 1;
end loop;
-- Check for case when the string contained no characters
if F > L then
raise Constraint_Error;
end if;
-- Scan for trailing spaces
while S (L) = ' ' loop
L := L - 1;
end loop;
-- Except in the case of a character literal, convert to upper case
if S (F) /= ''' then
for J in F .. L loop
S (J) := To_Upper (S (J));
end loop;
end if;
end Normalize_String;
-------------------
-- Scan_Exponent --
-------------------
function Scan_Exponent
(Str : String;
Ptr : access Integer;
Max : Integer;
Real : Boolean := False)
return Integer
is
P : Natural := Ptr.all;
M : Boolean;
X : Integer;
begin
if P >= Max
or else (Str (P) /= 'E' and then Str (P) /= 'e')
then
return 0;
end if;
-- We have an E/e, see if sign follows
P := P + 1;
if Str (P) = '+' then
P := P + 1;
if P > Max then
return 0;
else
M := False;
end if;
elsif Str (P) = '-' then
P := P + 1;
if P > Max or else not Real then
return 0;
else
M := True;
end if;
else
M := False;
end if;
if Str (P) not in '0' .. '9' then
return 0;
end if;
-- Scan out the exponent value as an unsigned integer. Values larger
-- than (Integer'Last / 10) are simply considered large enough here.
-- This assumption is correct for all machines we know of (e.g. in
-- the case of 16 bit integers it allows exponents up to 3276, which
-- is large enough for the largest floating types in base 2.)
X := 0;
loop
if X < (Integer'Last / 10) then
X := X * 10 + (Character'Pos (Str (P)) - Character'Pos ('0'));
end if;
P := P + 1;
exit when P > Max;
if Str (P) = '_' then
Scan_Underscore (Str, P, Ptr, Max, False);
else
exit when Str (P) not in '0' .. '9';
end if;
end loop;
if M then
X := -X;
end if;
Ptr.all := P;
return X;
end Scan_Exponent;
---------------
-- Scan_Sign --
---------------
procedure Scan_Sign
(Str : String;
Ptr : access Integer;
Max : Integer;
Minus : out Boolean;
Start : out Positive)
is
P : Natural := Ptr.all;
begin
-- Deal with case of null string (all blanks!). As per spec, we
-- raise constraint error, with Ptr unchanged, and thus > Max.
if P > Max then
raise Constraint_Error;
end if;
-- Scan past initial blanks
while Str (P) = ' ' loop
P := P + 1;
if P > Max then
Ptr.all := P;
raise Constraint_Error;
end if;
end loop;
Start := P;
-- Remember an initial minus sign
if Str (P) = '-' then
Minus := True;
P := P + 1;
if P > Max then
Ptr.all := Start;
raise Constraint_Error;
end if;
-- Skip past an initial plus sign
elsif Str (P) = '+' then
Minus := False;
P := P + 1;
if P > Max then
Ptr.all := Start;
raise Constraint_Error;
end if;
else
Minus := False;
end if;
Ptr.all := P;
end Scan_Sign;
--------------------------
-- Scan_Trailing_Blanks --
--------------------------
procedure Scan_Trailing_Blanks (Str : String; P : Positive) is
begin
for J in P .. Str'Last loop
if Str (J) /= ' ' then
raise Constraint_Error;
end if;
end loop;
end Scan_Trailing_Blanks;
---------------------
-- Scan_Underscore --
---------------------
procedure Scan_Underscore
(Str : String;
P : in out Natural;
Ptr : access Integer;
Max : Integer;
Ext : Boolean)
is
C : Character;
begin
P := P + 1;
-- If underscore is at the end of string, then this is an error and
-- we raise Constraint_Error, leaving the pointer past the undescore.
-- This seems a bit strange. It means e,g, that if the field is:
-- 345_
-- that Constraint_Error is raised. You might think that the RM in
-- this case would scan out the 345 as a valid integer, leaving the
-- pointer at the underscore, but the ACVC suite clearly requires
-- an error in this situation (see for example CE3704M).
if P > Max then
Ptr.all := P;
raise Constraint_Error;
end if;
-- Similarly, if no digit follows the underscore raise an error. This
-- also catches the case of double underscore which is also an error.
C := Str (P);
if C in '0' .. '9'
or else
(Ext and then (C in 'A' .. 'F' or else C in 'a' .. 'f'))
then
return;
else
Ptr.all := P;
raise Constraint_Error;
end if;
end Scan_Underscore;
end System.Val_Util;
|
