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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 c = *start++; | |
169 // Make sure the escaped char is valid. | |
170 switch (c) { | |
171 case 'x': | |
172 if (!readHexDigits(start, end, &start, 2)) | |
173 return false; | |
174 break; | |
175 case 'u': | |
176 if (!readHexDigits(start, end, &start, 4)) | |
177 return false; | |
178 break; | |
179 case '\\': | |
180 case '/': | |
181 case 'b': | |
182 case 'f': | |
183 case 'n': | |
184 case 'r': | |
185 case 't': | |
186 case 'v': | |
187 case '"': | |
188 break; | |
189 default: | |
190 return false; | |
191 } | |
192 } else if ('"' == c) { | |
193 *tokenEnd = start; | |
194 return true; | |
195 } | |
196 } | |
197 return false; | |
198 } | |
199 | |
200 template<typename Char> | |
201 bool skipComment(const Char* start, const Char* end, const Char** commentEnd) | |
202 { | |
203 if (start == end) | |
204 return false; | |
205 | |
206 if (*start != '/' || start + 1 >= end) | |
207 return false; | |
208 ++start; | |
209 | |
210 if (*start == '/') { | |
211 // Single line comment, read to newline. | |
212 for (++start; start < end; ++start) { | |
213 if (*start == '\n' || *start == '\r') { | |
214 *commentEnd = start + 1; | |
215 return true; | |
216 } | |
217 } | |
218 *commentEnd = end; | |
219 // Comment reaches end-of-input, which is fine. | |
220 return true; | |
221 } | |
222 | |
223 if (*start == '*') { | |
224 Char previous = '\0'; | |
225 // Block comment, read until end marker. | |
226 for (++start; start < end; previous = *start++) { | |
227 if (previous == '*' && *start == '/') { | |
228 *commentEnd = start + 1; | |
229 return true; | |
230 } | |
231 } | |
232 // Block comment must close before end-of-input. | |
233 return false; | |
234 } | |
235 | |
236 return false; | |
237 } | |
238 | |
239 template<typename Char> | |
240 void skipWhitespaceAndComments(const Char* start, const Char* end, const Char**
whitespaceEnd) | |
241 { | |
242 while (start < end) { | |
243 if (isSpaceOrNewLine(*start)) { | |
244 ++start; | |
245 } else if (*start == '/') { | |
246 const Char* commentEnd; | |
247 if (!skipComment(start, end, &commentEnd)) | |
248 break; | |
249 start = commentEnd; | |
250 } else { | |
251 break; | |
252 } | |
253 } | |
254 *whitespaceEnd = start; | |
255 } | |
256 | |
257 template<typename Char> | |
258 Token parseToken(const Char* start, const Char* end, const Char** tokenStart, co
nst Char** tokenEnd) | |
259 { | |
260 skipWhitespaceAndComments(start, end, tokenStart); | |
261 start = *tokenStart; | |
262 | |
263 if (start == end) | |
264 return InvalidToken; | |
265 | |
266 switch (*start) { | |
267 case 'n': | |
268 if (parseConstToken(start, end, tokenEnd, nullString)) | |
269 return NullToken; | |
270 break; | |
271 case 't': | |
272 if (parseConstToken(start, end, tokenEnd, trueString)) | |
273 return BoolTrue; | |
274 break; | |
275 case 'f': | |
276 if (parseConstToken(start, end, tokenEnd, falseString)) | |
277 return BoolFalse; | |
278 break; | |
279 case '[': | |
280 *tokenEnd = start + 1; | |
281 return ArrayBegin; | |
282 case ']': | |
283 *tokenEnd = start + 1; | |
284 return ArrayEnd; | |
285 case ',': | |
286 *tokenEnd = start + 1; | |
287 return ListSeparator; | |
288 case '{': | |
289 *tokenEnd = start + 1; | |
290 return ObjectBegin; | |
291 case '}': | |
292 *tokenEnd = start + 1; | |
293 return ObjectEnd; | |
294 case ':': | |
295 *tokenEnd = start + 1; | |
296 return ObjectPairSeparator; | |
297 case '0': | |
298 case '1': | |
299 case '2': | |
300 case '3': | |
301 case '4': | |
302 case '5': | |
303 case '6': | |
304 case '7': | |
305 case '8': | |
306 case '9': | |
307 case '-': | |
308 if (parseNumberToken(start, end, tokenEnd)) | |
309 return Number; | |
310 break; | |
311 case '"': | |
312 if (parseStringToken(start + 1, end, tokenEnd)) | |
313 return StringLiteral; | |
314 break; | |
315 } | |
316 return InvalidToken; | |
317 } | |
318 | |
319 template<typename Char> | |
320 int hexToInt(Char c) | |
321 { | |
322 if ('0' <= c && c <= '9') | |
323 return c - '0'; | |
324 if ('A' <= c && c <= 'F') | |
325 return c - 'A' + 10; | |
326 if ('a' <= c && c <= 'f') | |
327 return c - 'a' + 10; | |
328 NOTREACHED(); | |
329 return 0; | |
330 } | |
331 | |
332 template<typename Char> | |
333 bool decodeString(const Char* start, const Char* end, StringBuilder* output) | |
334 { | |
335 while (start < end) { | |
336 uint16_t c = *start++; | |
337 if ('\\' != c) { | |
338 output->append(c); | |
339 continue; | |
340 } | |
341 c = *start++; | |
342 | |
343 if (c == 'x') { | |
344 // \x is not supported. | |
345 return false; | |
346 } | |
347 | |
348 switch (c) { | |
349 case '"': | |
350 case '/': | |
351 case '\\': | |
352 break; | |
353 case 'b': | |
354 c = '\b'; | |
355 break; | |
356 case 'f': | |
357 c = '\f'; | |
358 break; | |
359 case 'n': | |
360 c = '\n'; | |
361 break; | |
362 case 'r': | |
363 c = '\r'; | |
364 break; | |
365 case 't': | |
366 c = '\t'; | |
367 break; | |
368 case 'v': | |
369 c = '\v'; | |
370 break; | |
371 case 'u': | |
372 c = (hexToInt(*start) << 12) + | |
373 (hexToInt(*(start + 1)) << 8) + | |
374 (hexToInt(*(start + 2)) << 4) + | |
375 hexToInt(*(start + 3)); | |
376 start += 4; | |
377 break; | |
378 default: | |
379 return false; | |
380 } | |
381 output->append(c); | |
382 } | |
383 return true; | |
384 } | |
385 | |
386 template<typename Char> | |
387 bool decodeString(const Char* start, const Char* end, String* output) | |
388 { | |
389 if (start == end) { | |
390 *output = ""; | |
391 return true; | |
392 } | |
393 if (start > end) | |
394 return false; | |
395 StringBuilder buffer; | |
396 StringUtil::builderReserve(buffer, end - start); | |
397 if (!decodeString(start, end, &buffer)) | |
398 return false; | |
399 *output = buffer.toString(); | |
400 return true; | |
401 } | |
402 | |
403 template<typename Char> | |
404 std::unique_ptr<Value> buildValue(const Char* start, const Char* end, const Char
** valueTokenEnd, int depth) | |
405 { | |
406 if (depth > stackLimit) | |
407 return nullptr; | |
408 | |
409 std::unique_ptr<Value> result; | |
410 const Char* tokenStart; | |
411 const Char* tokenEnd; | |
412 Token token = parseToken(start, end, &tokenStart, &tokenEnd); | |
413 switch (token) { | |
414 case InvalidToken: | |
415 return nullptr; | |
416 case NullToken: | |
417 result = Value::null(); | |
418 break; | |
419 case BoolTrue: | |
420 result = FundamentalValue::create(true); | |
421 break; | |
422 case BoolFalse: | |
423 result = FundamentalValue::create(false); | |
424 break; | |
425 case Number: { | |
426 bool ok; | |
427 double value = charactersToDouble(tokenStart, tokenEnd - tokenStart, &ok
); | |
428 if (!ok) | |
429 return nullptr; | |
430 int number = static_cast<int>(value); | |
431 if (number == value) | |
432 result = FundamentalValue::create(number); | |
433 else | |
434 result = FundamentalValue::create(value); | |
435 break; | |
436 } | |
437 case StringLiteral: { | |
438 String value; | |
439 bool ok = decodeString(tokenStart + 1, tokenEnd - 1, &value); | |
440 if (!ok) | |
441 return nullptr; | |
442 result = StringValue::create(value); | |
443 break; | |
444 } | |
445 case ArrayBegin: { | |
446 std::unique_ptr<ListValue> array = ListValue::create(); | |
447 start = tokenEnd; | |
448 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
449 while (token != ArrayEnd) { | |
450 std::unique_ptr<Value> arrayNode = buildValue(start, end, &tokenEnd,
depth + 1); | |
451 if (!arrayNode) | |
452 return nullptr; | |
453 array->pushValue(std::move(arrayNode)); | |
454 | |
455 // After a list value, we expect a comma or the end of the list. | |
456 start = tokenEnd; | |
457 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
458 if (token == ListSeparator) { | |
459 start = tokenEnd; | |
460 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
461 if (token == ArrayEnd) | |
462 return nullptr; | |
463 } else if (token != ArrayEnd) { | |
464 // Unexpected value after list value. Bail out. | |
465 return nullptr; | |
466 } | |
467 } | |
468 if (token != ArrayEnd) | |
469 return nullptr; | |
470 result = std::move(array); | |
471 break; | |
472 } | |
473 case ObjectBegin: { | |
474 std::unique_ptr<DictionaryValue> object = DictionaryValue::create(); | |
475 start = tokenEnd; | |
476 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
477 while (token != ObjectEnd) { | |
478 if (token != StringLiteral) | |
479 return nullptr; | |
480 String key; | |
481 if (!decodeString(tokenStart + 1, tokenEnd - 1, &key)) | |
482 return nullptr; | |
483 start = tokenEnd; | |
484 | |
485 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
486 if (token != ObjectPairSeparator) | |
487 return nullptr; | |
488 start = tokenEnd; | |
489 | |
490 std::unique_ptr<Value> value = buildValue(start, end, &tokenEnd, dep
th + 1); | |
491 if (!value) | |
492 return nullptr; | |
493 object->setValue(key, std::move(value)); | |
494 start = tokenEnd; | |
495 | |
496 // After a key/value pair, we expect a comma or the end of the | |
497 // object. | |
498 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
499 if (token == ListSeparator) { | |
500 start = tokenEnd; | |
501 token = parseToken(start, end, &tokenStart, &tokenEnd); | |
502 if (token == ObjectEnd) | |
503 return nullptr; | |
504 } else if (token != ObjectEnd) { | |
505 // Unexpected value after last object value. Bail out. | |
506 return nullptr; | |
507 } | |
508 } | |
509 if (token != ObjectEnd) | |
510 return nullptr; | |
511 result = std::move(object); | |
512 break; | |
513 } | |
514 | |
515 default: | |
516 // We got a token that's not a value. | |
517 return nullptr; | |
518 } | |
519 | |
520 skipWhitespaceAndComments(tokenEnd, end, valueTokenEnd); | |
521 return result; | |
522 } | |
523 | |
524 template<typename Char> | |
525 std::unique_ptr<Value> parseJSONInternal(const Char* start, unsigned length) | |
526 { | |
527 const Char* end = start + length; | |
528 const Char *tokenEnd; | |
529 std::unique_ptr<Value> value = buildValue(start, end, &tokenEnd, 0); | |
530 if (!value || tokenEnd != end) | |
531 return nullptr; | |
532 return value; | |
533 } | |
534 | |
535 } // anonymous namespace | |
536 | |
537 std::unique_ptr<Value> parseJSON(const uint16_t* characters, unsigned length) | |
538 { | |
539 return parseJSONInternal<uint16_t>(characters, length); | |
540 } | |
541 | |
542 std::unique_ptr<Value> parseJSON(const uint8_t* characters, unsigned length) | |
543 { | |
544 return parseJSONInternal<uint8_t>(characters, length); | |
545 } | |
546 | |
547 {% for namespace in config.protocol.namespace %} | |
548 } // namespace {{namespace}} | |
549 {% endfor %} | |
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