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1 | ------------------------------------------------------------------------------ |
2 | -- -- | |
3 | -- GNAT COMPILER COMPONENTS -- | |
4 | -- -- | |
5 | -- S Y S T E M . V A L _ L L U -- | |
6 | -- -- | |
84fdd8a3 | 7 | -- B o d y -- |
cacbc350 | 8 | -- -- |
4b490c1e | 9 | -- Copyright (C) 1992-2020, Free Software Foundation, Inc. -- |
cacbc350 RK |
10 | -- -- |
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- -- | |
748086b7 | 13 | -- ware Foundation; either version 3, or (at your option) any later ver- -- |
cacbc350 RK |
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 -- | |
748086b7 JJ |
16 | -- or FITNESS FOR A PARTICULAR PURPOSE. -- |
17 | -- -- | |
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. -- | |
21 | -- -- | |
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/>. -- | |
cacbc350 RK |
26 | -- -- |
27 | -- GNAT was originally developed by the GNAT team at New York University. -- | |
71ff80dc | 28 | -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
cacbc350 RK |
29 | -- -- |
30 | ------------------------------------------------------------------------------ | |
31 | ||
32 | with System.Unsigned_Types; use System.Unsigned_Types; | |
33 | with System.Val_Util; use System.Val_Util; | |
34 | ||
35 | package body System.Val_LLU is | |
36 | ||
bfe7c10c BD |
37 | --------------------------------- |
38 | -- Scan_Raw_Long_Long_Unsigned -- | |
39 | --------------------------------- | |
cacbc350 | 40 | |
bfe7c10c | 41 | function Scan_Raw_Long_Long_Unsigned |
9de61fcb | 42 | (Str : String; |
d90e94c7 | 43 | Ptr : not null access Integer; |
9de61fcb | 44 | Max : Integer) return Long_Long_Unsigned |
cacbc350 RK |
45 | is |
46 | P : Integer; | |
47 | -- Local copy of the pointer | |
48 | ||
49 | Uval : Long_Long_Unsigned; | |
50 | -- Accumulated unsigned integer result | |
51 | ||
52 | Expon : Integer; | |
53 | -- Exponent value | |
54 | ||
cacbc350 RK |
55 | Overflow : Boolean := False; |
56 | -- Set True if overflow is detected at any point | |
57 | ||
cacbc350 RK |
58 | Base_Char : Character; |
59 | -- Base character (# or :) in based case | |
60 | ||
61 | Base : Long_Long_Unsigned := 10; | |
62 | -- Base value (reset in based case) | |
63 | ||
64 | Digit : Long_Long_Unsigned; | |
65 | -- Digit value | |
66 | ||
67 | begin | |
1a779058 AC |
68 | -- We do not tolerate strings with Str'Last = Positive'Last |
69 | ||
70 | if Str'Last = Positive'Last then | |
71 | raise Program_Error with | |
72 | "string upper bound is Positive'Last, not supported"; | |
73 | end if; | |
74 | ||
cacbc350 RK |
75 | P := Ptr.all; |
76 | Uval := Character'Pos (Str (P)) - Character'Pos ('0'); | |
77 | P := P + 1; | |
78 | ||
79 | -- Scan out digits of what is either the number or the base. | |
80 | -- In either case, we are definitely scanning out in base 10. | |
81 | ||
82 | declare | |
83 | Umax : constant := (Long_Long_Unsigned'Last - 9) / 10; | |
84 | -- Max value which cannot overflow on accumulating next digit | |
85 | ||
86 | Umax10 : constant := Long_Long_Unsigned'Last / 10; | |
87 | -- Numbers bigger than Umax10 overflow if multiplied by 10 | |
88 | ||
89 | begin | |
90 | -- Loop through decimal digits | |
91 | loop | |
92 | exit when P > Max; | |
93 | ||
94 | Digit := Character'Pos (Str (P)) - Character'Pos ('0'); | |
95 | ||
96 | -- Non-digit encountered | |
97 | ||
98 | if Digit > 9 then | |
99 | if Str (P) = '_' then | |
100 | Scan_Underscore (Str, P, Ptr, Max, False); | |
101 | else | |
102 | exit; | |
103 | end if; | |
104 | ||
105 | -- Accumulate result, checking for overflow | |
106 | ||
107 | else | |
108 | if Uval <= Umax then | |
109 | Uval := 10 * Uval + Digit; | |
110 | ||
111 | elsif Uval > Umax10 then | |
112 | Overflow := True; | |
113 | ||
114 | else | |
115 | Uval := 10 * Uval + Digit; | |
116 | ||
117 | if Uval < Umax10 then | |
118 | Overflow := True; | |
119 | end if; | |
120 | end if; | |
121 | ||
122 | P := P + 1; | |
123 | end if; | |
124 | end loop; | |
125 | end; | |
126 | ||
127 | Ptr.all := P; | |
128 | ||
72eaa365 AC |
129 | -- Deal with based case. We recognize either the standard '#' or the |
130 | -- allowed alternative replacement ':' (see RM J.2(3)). | |
cacbc350 | 131 | |
72eaa365 | 132 | if P < Max and then (Str (P) = '#' or else Str (P) = ':') then |
cacbc350 RK |
133 | Base_Char := Str (P); |
134 | P := P + 1; | |
135 | Base := Uval; | |
136 | Uval := 0; | |
137 | ||
138 | -- Check base value. Overflow is set True if we find a bad base, or | |
139 | -- a digit that is out of range of the base. That way, we scan out | |
140 | -- the numeral that is still syntactically correct, though illegal. | |
141 | -- We use a safe base of 16 for this scan, to avoid zero divide. | |
142 | ||
143 | if Base not in 2 .. 16 then | |
144 | Overflow := True; | |
c8307596 | 145 | Base := 16; |
cacbc350 RK |
146 | end if; |
147 | ||
148 | -- Scan out based integer | |
149 | ||
150 | declare | |
151 | Umax : constant Long_Long_Unsigned := | |
152 | (Long_Long_Unsigned'Last - Base + 1) / Base; | |
153 | -- Max value which cannot overflow on accumulating next digit | |
154 | ||
155 | UmaxB : constant Long_Long_Unsigned := | |
156 | Long_Long_Unsigned'Last / Base; | |
157 | -- Numbers bigger than UmaxB overflow if multiplied by base | |
158 | ||
159 | begin | |
160 | -- Loop to scan out based integer value | |
161 | ||
162 | loop | |
163 | -- We require a digit at this stage | |
164 | ||
165 | if Str (P) in '0' .. '9' then | |
166 | Digit := Character'Pos (Str (P)) - Character'Pos ('0'); | |
167 | ||
168 | elsif Str (P) in 'A' .. 'F' then | |
169 | Digit := | |
170 | Character'Pos (Str (P)) - (Character'Pos ('A') - 10); | |
171 | ||
172 | elsif Str (P) in 'a' .. 'f' then | |
173 | Digit := | |
174 | Character'Pos (Str (P)) - (Character'Pos ('a') - 10); | |
175 | ||
176 | -- If we don't have a digit, then this is not a based number | |
177 | -- after all, so we use the value we scanned out as the base | |
178 | -- (now in Base), and the pointer to the base character was | |
179 | -- already stored in Ptr.all. | |
180 | ||
181 | else | |
182 | Uval := Base; | |
183 | exit; | |
184 | end if; | |
185 | ||
186 | -- If digit is too large, just signal overflow and continue. | |
187 | -- The idea here is to keep scanning as long as the input is | |
188 | -- syntactically valid, even if we have detected overflow | |
189 | ||
190 | if Digit >= Base then | |
191 | Overflow := True; | |
192 | ||
193 | -- Here we accumulate the value, checking overflow | |
194 | ||
195 | elsif Uval <= Umax then | |
196 | Uval := Base * Uval + Digit; | |
197 | ||
198 | elsif Uval > UmaxB then | |
199 | Overflow := True; | |
200 | ||
201 | else | |
202 | Uval := Base * Uval + Digit; | |
203 | ||
204 | if Uval < UmaxB then | |
205 | Overflow := True; | |
206 | end if; | |
207 | end if; | |
208 | ||
209 | -- If at end of string with no base char, not a based number | |
210 | -- but we signal Constraint_Error and set the pointer past | |
211 | -- the end of the field, since this is what the ACVC tests | |
212 | -- seem to require, see CE3704N, line 204. | |
213 | ||
214 | P := P + 1; | |
215 | ||
216 | if P > Max then | |
217 | Ptr.all := P; | |
37ae92c4 | 218 | Bad_Value (Str); |
cacbc350 RK |
219 | end if; |
220 | ||
221 | -- If terminating base character, we are done with loop | |
222 | ||
223 | if Str (P) = Base_Char then | |
224 | Ptr.all := P + 1; | |
225 | exit; | |
226 | ||
227 | -- Deal with underscore | |
228 | ||
229 | elsif Str (P) = '_' then | |
230 | Scan_Underscore (Str, P, Ptr, Max, True); | |
231 | end if; | |
232 | ||
233 | end loop; | |
234 | end; | |
235 | end if; | |
236 | ||
237 | -- Come here with scanned unsigned value in Uval. The only remaining | |
238 | -- required step is to deal with exponent if one is present. | |
239 | ||
240 | Expon := Scan_Exponent (Str, Ptr, Max); | |
241 | ||
242 | if Expon /= 0 and then Uval /= 0 then | |
243 | ||
244 | -- For non-zero value, scale by exponent value. No need to do this | |
245 | -- efficiently, since use of exponent in integer literals is rare, | |
246 | -- and in any case the exponent cannot be very large. | |
247 | ||
248 | declare | |
249 | UmaxB : constant Long_Long_Unsigned := | |
250 | Long_Long_Unsigned'Last / Base; | |
251 | -- Numbers bigger than UmaxB overflow if multiplied by base | |
252 | ||
253 | begin | |
254 | for J in 1 .. Expon loop | |
255 | if Uval > UmaxB then | |
256 | Overflow := True; | |
257 | exit; | |
258 | end if; | |
259 | ||
260 | Uval := Uval * Base; | |
261 | end loop; | |
262 | end; | |
263 | end if; | |
264 | ||
265 | -- Return result, dealing with sign and overflow | |
266 | ||
bfe7c10c | 267 | if Overflow then |
37ae92c4 | 268 | Bad_Value (Str); |
cacbc350 RK |
269 | else |
270 | return Uval; | |
271 | end if; | |
bfe7c10c BD |
272 | end Scan_Raw_Long_Long_Unsigned; |
273 | ||
274 | ----------------------------- | |
275 | -- Scan_Long_Long_Unsigned -- | |
276 | ----------------------------- | |
277 | ||
278 | function Scan_Long_Long_Unsigned | |
279 | (Str : String; | |
d90e94c7 | 280 | Ptr : not null access Integer; |
bfe7c10c BD |
281 | Max : Integer) return Long_Long_Unsigned |
282 | is | |
283 | Start : Positive; | |
284 | -- Save location of first non-blank character | |
285 | ||
286 | begin | |
287 | Scan_Plus_Sign (Str, Ptr, Max, Start); | |
288 | ||
289 | if Str (Ptr.all) not in '0' .. '9' then | |
290 | Ptr.all := Start; | |
291 | raise Constraint_Error; | |
292 | end if; | |
293 | ||
294 | return Scan_Raw_Long_Long_Unsigned (Str, Ptr, Max); | |
cacbc350 RK |
295 | end Scan_Long_Long_Unsigned; |
296 | ||
297 | ------------------------------ | |
298 | -- Value_Long_Long_Unsigned -- | |
299 | ------------------------------ | |
300 | ||
301 | function Value_Long_Long_Unsigned | |
84fdd8a3 | 302 | (Str : String) return Long_Long_Unsigned |
cacbc350 | 303 | is |
cacbc350 | 304 | begin |
61ae296d RD |
305 | -- We have to special case Str'Last = Positive'Last because the normal |
306 | -- circuit ends up setting P to Str'Last + 1 which is out of bounds. We | |
307 | -- deal with this by converting to a subtype which fixes the bounds. | |
308 | ||
309 | if Str'Last = Positive'Last then | |
310 | declare | |
311 | subtype NT is String (1 .. Str'Length); | |
312 | begin | |
313 | return Value_Long_Long_Unsigned (NT (Str)); | |
314 | end; | |
315 | ||
316 | -- Normal case where Str'Last < Positive'Last | |
317 | ||
318 | else | |
319 | declare | |
320 | V : Long_Long_Unsigned; | |
321 | P : aliased Integer := Str'First; | |
322 | begin | |
323 | V := Scan_Long_Long_Unsigned (Str, P'Access, Str'Last); | |
324 | Scan_Trailing_Blanks (Str, P); | |
325 | return V; | |
326 | end; | |
327 | end if; | |
cacbc350 RK |
328 | end Value_Long_Long_Unsigned; |
329 | ||
330 | end System.Val_LLU; |