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1 // Copyright 2016 The Chromium Authors. All rights reserved. | |
2 // Use of this source code is governed by a BSD-style license that can be | |
3 // found in the LICENSE file. | |
4 | |
5 {% for namespace in config.protocol.namespace %} | |
6 namespace {{namespace}} { | |
7 {% endfor %} | |
8 | |
9 namespace { | |
10 | |
11 const int stackLimit = 1000; | |
12 | |
13 enum Token { | |
14 ObjectBegin, | |
15 ObjectEnd, | |
16 ArrayBegin, | |
17 ArrayEnd, | |
18 StringLiteral, | |
19 Number, | |
20 BoolTrue, | |
21 BoolFalse, | |
22 NullToken, | |
23 ListSeparator, | |
24 ObjectPairSeparator, | |
25 InvalidToken, | |
26 }; | |
27 | |
28 const char* const nullString = "null"; | |
29 const char* const trueString = "true"; | |
30 const char* const falseString = "false"; | |
31 | |
32 bool isASCII(uint16_t c) | |
33 { | |
34 return !(c & ~0x7F); | |
35 } | |
36 | |
37 bool isSpaceOrNewLine(uint16_t c) | |
38 { | |
39 return isASCII(c) && c <= ' ' && (c == ' ' || (c <= 0xD && c >= 0x9)); | |
40 } | |
41 | |
42 double charactersToDouble(const uint16_t* characters, size_t length, bool* ok) | |
43 { | |
44 std::vector<char> buffer; | |
45 buffer.reserve(length + 1); | |
46 for (size_t i = 0; i < length; ++i) { | |
47 if (!isASCII(characters[i])) { | |
48 *ok = false; | |
49 return 0; | |
50 } | |
51 buffer.push_back(static_cast<char>(characters[i])); | |
52 } | |
53 buffer.push_back('\0'); | |
54 char* endptr; | |
55 double result = std::strtod(buffer.data(), &endptr); | |
56 *ok = !(*endptr); | |
57 return result; | |
58 } | |
59 | |
60 double charactersToDouble(const uint8_t* characters, size_t length, bool* ok) | |
61 { | |
62 std::string buffer(reinterpret_cast<const char*>(characters), length); | |
63 char* endptr; | |
64 double result = std::strtod(buffer.data(), &endptr); | |
65 *ok = !(*endptr); | |
66 return result; | |
67 } | |
68 | |
69 template<typename Char> | |
70 bool parseConstToken(const Char* start, const Char* end, const Char** tokenEnd,
const char* token) | |
71 { | |
72 while (start < end && *token != '\0' && *start++ == *token++) { } | |
73 if (*token != '\0') | |
74 return false; | |
75 *tokenEnd = start; | |
76 return true; | |
77 } | |
78 | |
79 template<typename Char> | |
80 bool readInt(const Char* start, const Char* end, const Char** tokenEnd, bool can
HaveLeadingZeros) | |
81 { | |
82 if (start == end) | |
83 return false; | |
84 bool haveLeadingZero = '0' == *start; | |
85 int length = 0; | |
86 while (start < end && '0' <= *start && *start <= '9') { | |
87 ++start; | |
88 ++length; | |
89 } | |
90 if (!length) | |
91 return false; | |
92 if (!canHaveLeadingZeros && length > 1 && haveLeadingZero) | |
93 return false; | |
94 *tokenEnd = start; | |
95 return true; | |
96 } | |
97 | |
98 template<typename Char> | |
99 bool parseNumberToken(const Char* start, const Char* end, const Char** tokenEnd) | |
100 { | |
101 // We just grab the number here. We validate the size in DecodeNumber. | |
102 // According to RFC4627, a valid number is: [minus] int [frac] [exp] | |
103 if (start == end) | |
104 return false; | |
105 Char c = *start; | |
106 if ('-' == c) | |
107 ++start; | |
108 | |
109 if (!readInt(start, end, &start, false)) | |
110 return false; | |
111 if (start == end) { | |
112 *tokenEnd = start; | |
113 return true; | |
114 } | |
115 | |
116 // Optional fraction part | |
117 c = *start; | |
118 if ('.' == c) { | |
119 ++start; | |
120 if (!readInt(start, end, &start, true)) | |
121 return false; | |
122 if (start == end) { | |
123 *tokenEnd = start; | |
124 return true; | |
125 } | |
126 c = *start; | |
127 } | |
128 | |
129 // Optional exponent part | |
130 if ('e' == c || 'E' == c) { | |
131 ++start; | |
132 if (start == end) | |
133 return false; | |
134 c = *start; | |
135 if ('-' == c || '+' == c) { | |
136 ++start; | |
137 if (start == end) | |
138 return false; | |
139 } | |
140 if (!readInt(start, end, &start, true)) | |
141 return false; | |
142 } | |
143 | |
144 *tokenEnd = start; | |
145 return true; | |
146 } | |
147 | |
148 template<typename Char> | |
149 bool readHexDigits(const Char* start, const Char* end, const Char** tokenEnd, in
t digits) | |
150 { | |
151 if (end - start < digits) | |
152 return false; | |
153 for (int i = 0; i < digits; ++i) { | |
154 Char c = *start++; | |
155 if (!(('0' <= c && c <= '9') || ('a' <= c && c <= 'f') || ('A' <= c && c
<= 'F'))) | |
156 return false; | |
157 } | |
158 *tokenEnd = start; | |
159 return true; | |
160 } | |
161 | |
162 template<typename Char> | |
163 bool parseStringToken(const Char* start, const Char* end, const Char** tokenEnd) | |
164 { | |
165 while (start < end) { | |
166 Char c = *start++; | |
167 if ('\\' == c) { | |
168 if (start == end) | |
169 return false; | |
170 c = *start++; | |
171 // Make sure the escaped char is valid. | |
172 switch (c) { | |
173 case 'x': | |
174 if (!readHexDigits(start, end, &start, 2)) | |
175 return false; | |
176 break; | |
177 case 'u': | |
178 if (!readHexDigits(start, end, &start, 4)) | |
179 return false; | |
180 break; | |
181 case '\\': | |
182 case '/': | |
183 case 'b': | |
184 case 'f': | |
185 case 'n': | |
186 case 'r': | |
187 case 't': | |
188 case 'v': | |
189 case '"': | |
190 break; | |
191 default: | |
192 return false; | |
193 } | |
194 } else if ('"' == c) { | |
195 *tokenEnd = start; | |
196 return true; | |
197 } | |
198 } | |
199 return false; | |
200 } | |
201 | |
202 template<typename Char> | |
203 bool skipComment(const Char* start, const Char* end, const Char** commentEnd) | |
204 { | |
205 if (start == end) | |
206 return false; | |
207 | |
208 if (*start != '/' || start + 1 >= end) | |
209 return false; | |
210 ++start; | |
211 | |
212 if (*start == '/') { | |
213 // Single line comment, read to newline. | |
214 for (++start; start < end; ++start) { | |
215 if (*start == '\n' || *start == '\r') { | |
216 *commentEnd = start + 1; | |
217 return true; | |
218 } | |
219 } | |
220 *commentEnd = end; | |
221 // Comment reaches end-of-input, which is fine. | |
222 return true; | |
223 } | |
224 | |
225 if (*start == '*') { | |
226 Char previous = '\0'; | |
227 // Block comment, read until end marker. | |
228 for (++start; start < end; previous = *start++) { | |
229 if (previous == '*' && *start == '/') { | |
230 *commentEnd = start + 1; | |
231 return true; | |
232 } | |
233 } | |
234 // Block comment must close before end-of-input. | |
235 return false; | |
236 } | |
237 | |
238 return false; | |
239 } | |
240 | |
241 template<typename Char> | |
242 void skipWhitespaceAndComments(const Char* start, const Char* end, const Char**
whitespaceEnd) | |
243 { | |
244 while (start < end) { | |
245 if (isSpaceOrNewLine(*start)) { | |
246 ++start; | |
247 } else if (*start == '/') { | |
248 const Char* commentEnd; | |
249 if (!skipComment(start, end, &commentEnd)) | |
250 break; | |
251 start = commentEnd; | |
252 } else { | |
253 break; | |
254 } | |
255 } | |
256 *whitespaceEnd = start; | |
257 } | |
258 | |
259 template<typename Char> | |
260 Token parseToken(const Char* start, const Char* end, const Char** tokenStart, co
nst Char** tokenEnd) | |
261 { | |
262 skipWhitespaceAndComments(start, end, tokenStart); | |
263 start = *tokenStart; | |
264 | |
265 if (start == end) | |
266 return InvalidToken; | |
267 | |
268 switch (*start) { | |
269 case 'n': | |
270 if (parseConstToken(start, end, tokenEnd, nullString)) | |
271 return NullToken; | |
272 break; | |
273 case 't': | |
274 if (parseConstToken(start, end, tokenEnd, trueString)) | |
275 return BoolTrue; | |
276 break; | |
277 case 'f': | |
278 if (parseConstToken(start, end, tokenEnd, falseString)) | |
279 return BoolFalse; | |
280 break; | |
281 case '[': | |
282 *tokenEnd = start + 1; | |
283 return ArrayBegin; | |
284 case ']': | |
285 *tokenEnd = start + 1; | |
286 return ArrayEnd; | |
287 case ',': | |
288 *tokenEnd = start + 1; | |
289 return ListSeparator; | |
290 case '{': | |
291 *tokenEnd = start + 1; | |
292 return ObjectBegin; | |
293 case '}': | |
294 *tokenEnd = start + 1; | |
295 return ObjectEnd; | |
296 case ':': | |
297 *tokenEnd = start + 1; | |
298 return ObjectPairSeparator; | |
299 case '0': | |
300 case '1': | |
301 case '2': | |
302 case '3': | |
303 case '4': | |
304 case '5': | |
305 case '6': | |
306 case '7': | |
307 case '8': | |
308 case '9': | |
309 case '-': | |
310 if (parseNumberToken(start, end, tokenEnd)) | |
311 return Number; | |
312 break; | |
313 case '"': | |
314 if (parseStringToken(start + 1, end, tokenEnd)) | |
315 return StringLiteral; | |
316 break; | |
317 } | |
318 return InvalidToken; | |
319 } | |
320 | |
321 template<typename Char> | |
322 int hexToInt(Char c) | |
323 { | |
324 if ('0' <= c && c <= '9') | |
325 return c - '0'; | |
326 if ('A' <= c && c <= 'F') | |
327 return c - 'A' + 10; | |
328 if ('a' <= c && c <= 'f') | |
329 return c - 'a' + 10; | |
330 DCHECK(false); | |
331 return 0; | |
332 } | |
333 | |
334 template<typename Char> | |
335 bool decodeString(const Char* start, const Char* end, StringBuilder* output) | |
336 { | |
337 while (start < end) { | |
338 uint16_t c = *start++; | |
339 if ('\\' != c) { | |
340 output->append(c); | |
341 continue; | |
342 } | |
343 if (start == end) | |
344 return false; | |
345 c = *start++; | |
346 | |
347 if (c == 'x') { | |
348 // \x is not supported. | |
349 return false; | |
350 } | |
351 | |
352 switch (c) { | |
353 case '"': | |
354 case '/': | |
355 case '\\': | |
356 break; | |
357 case 'b': | |
358 c = '\b'; | |
359 break; | |
360 case 'f': | |
361 c = '\f'; | |
362 break; | |
363 case 'n': | |
364 c = '\n'; | |
365 break; | |
366 case 'r': | |
367 c = '\r'; | |
368 break; | |
369 case 't': | |
370 c = '\t'; | |
371 break; | |
372 case 'v': | |
373 c = '\v'; | |
374 break; | |
375 case 'u': | |
376 c = (hexToInt(*start) << 12) + | |
377 (hexToInt(*(start + 1)) << 8) + | |
378 (hexToInt(*(start + 2)) << 4) + | |
379 hexToInt(*(start + 3)); | |
380 start += 4; | |
381 break; | |
382 default: | |
383 return false; | |
384 } | |
385 output->append(c); | |
386 } | |
387 return true; | |
388 } | |
389 | |
390 template<typename Char> | |
391 bool decodeString(const Char* start, const Char* end, String* output) | |
392 { | |
393 if (start == end) { | |
394 *output = ""; | |
395 return true; | |
396 } | |
397 if (start > end) | |
398 return false; | |
399 StringBuilder buffer; | |
400 StringUtil::builderReserve(buffer, end - start); | |
401 if (!decodeString(start, end, &buffer)) | |
402 return false; | |
403 *output = buffer.toString(); | |
404 return true; | |
405 } | |
406 | |
407 template<typename Char> | |
408 std::unique_ptr<Value> buildValue(const Char* start, const Char* end, const Char
** valueTokenEnd, int depth) | |
409 { | |
410 if (depth > stackLimit) | |
411 return nullptr; | |
412 | |
413 std::unique_ptr<Value> result; | |
414 const Char* tokenStart; | |
415 const Char* tokenEnd; | |
416 Token token = parseToken(start, end, &tokenStart, &tokenEnd); | |
417 switch (token) { | |
418 case InvalidToken: | |
419 return nullptr; | |
420 case NullToken: | |
421 result = Value::null(); | |
422 break; | |
423 case BoolTrue: | |
424 result = FundamentalValue::create(true); | |
425 break; | |
426 case BoolFalse: | |
427 result = FundamentalValue::create(false); | |
428 break; | |
429 case Number: { | |
430 bool ok; | |
431 double value = charactersToDouble(tokenStart, tokenEnd - tokenStart, &ok
); | |
432 if (!ok) | |
433 return nullptr; | |
434 int number = static_cast<int>(value); | |
435 if (number == value) | |
436 result = FundamentalValue::create(number); | |
437 else | |
438 result = FundamentalValue::create(value); | |
439 break; | |
440 } | |
441 case StringLiteral: { | |
442 String value; | |
443 bool ok = decodeString(tokenStart + 1, tokenEnd - 1, &value); | |
444 if (!ok) | |
445 return nullptr; | |
446 result = StringValue::create(value); | |
447 break; | |
448 } | |
449 case ArrayBegin: { | |
450 std::unique_ptr<ListValue> array = ListValue::create(); | |
451 start = tokenEnd; | |
452 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
453 while (token != ArrayEnd) { | |
454 std::unique_ptr<Value> arrayNode = buildValue(start, end, &tokenEnd,
depth + 1); | |
455 if (!arrayNode) | |
456 return nullptr; | |
457 array->pushValue(std::move(arrayNode)); | |
458 | |
459 // After a list value, we expect a comma or the end of the list. | |
460 start = tokenEnd; | |
461 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
462 if (token == ListSeparator) { | |
463 start = tokenEnd; | |
464 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
465 if (token == ArrayEnd) | |
466 return nullptr; | |
467 } else if (token != ArrayEnd) { | |
468 // Unexpected value after list value. Bail out. | |
469 return nullptr; | |
470 } | |
471 } | |
472 if (token != ArrayEnd) | |
473 return nullptr; | |
474 result = std::move(array); | |
475 break; | |
476 } | |
477 case ObjectBegin: { | |
478 std::unique_ptr<DictionaryValue> object = DictionaryValue::create(); | |
479 start = tokenEnd; | |
480 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
481 while (token != ObjectEnd) { | |
482 if (token != StringLiteral) | |
483 return nullptr; | |
484 String key; | |
485 if (!decodeString(tokenStart + 1, tokenEnd - 1, &key)) | |
486 return nullptr; | |
487 start = tokenEnd; | |
488 | |
489 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
490 if (token != ObjectPairSeparator) | |
491 return nullptr; | |
492 start = tokenEnd; | |
493 | |
494 std::unique_ptr<Value> value = buildValue(start, end, &tokenEnd, dep
th + 1); | |
495 if (!value) | |
496 return nullptr; | |
497 object->setValue(key, std::move(value)); | |
498 start = tokenEnd; | |
499 | |
500 // After a key/value pair, we expect a comma or the end of the | |
501 // object. | |
502 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
503 if (token == ListSeparator) { | |
504 start = tokenEnd; | |
505 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
506 if (token == ObjectEnd) | |
507 return nullptr; | |
508 } else if (token != ObjectEnd) { | |
509 // Unexpected value after last object value. Bail out. | |
510 return nullptr; | |
511 } | |
512 } | |
513 if (token != ObjectEnd) | |
514 return nullptr; | |
515 result = std::move(object); | |
516 break; | |
517 } | |
518 | |
519 default: | |
520 // We got a token that's not a value. | |
521 return nullptr; | |
522 } | |
523 | |
524 skipWhitespaceAndComments(tokenEnd, end, valueTokenEnd); | |
525 return result; | |
526 } | |
527 | |
528 template<typename Char> | |
529 std::unique_ptr<Value> parseJSONInternal(const Char* start, unsigned length) | |
530 { | |
531 const Char* end = start + length; | |
532 const Char *tokenEnd; | |
533 std::unique_ptr<Value> value = buildValue(start, end, &tokenEnd, 0); | |
534 if (!value || tokenEnd != end) | |
535 return nullptr; | |
536 return value; | |
537 } | |
538 | |
539 } // anonymous namespace | |
540 | |
541 std::unique_ptr<Value> parseJSON(const uint16_t* characters, unsigned length) | |
542 { | |
543 return parseJSONInternal<uint16_t>(characters, length); | |
544 } | |
545 | |
546 std::unique_ptr<Value> parseJSON(const uint8_t* characters, unsigned length) | |
547 { | |
548 return parseJSONInternal<uint8_t>(characters, length); | |
549 } | |
550 | |
551 {% for namespace in config.protocol.namespace %} | |
552 } // namespace {{namespace}} | |
553 {% endfor %} | |
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