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1 | /* |
2 | * JSON lexer | |
3 | * | |
4 | * Copyright IBM, Corp. 2009 | |
5 | * | |
6 | * Authors: | |
7 | * Anthony Liguori <[email protected]> | |
8 | * | |
9 | * This work is licensed under the terms of the GNU LGPL, version 2.1 or later. | |
10 | * See the COPYING.LIB file in the top-level directory. | |
11 | * | |
12 | */ | |
13 | ||
14 | #include "qstring.h" | |
15 | #include "qlist.h" | |
16 | #include "qdict.h" | |
17 | #include "qint.h" | |
18 | #include "qemu-common.h" | |
19 | #include "json-lexer.h" | |
20 | ||
21 | /* | |
22 | * \"([^\\\"]|(\\\"\\'\\\\\\/\\b\\f\\n\\r\\t\\u[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]))*\" | |
23 | * '([^\\']|(\\\"\\'\\\\\\/\\b\\f\\n\\r\\t\\u[0-9a-fA-F][0-9a-fA-F][0-9a-fA-F][0-9a-fA-F]))*' | |
24 | * 0|([1-9][0-9]*(.[0-9]+)?([eE]([-+])?[0-9]+)) | |
25 | * [{}\[\],:] | |
26 | * [a-z]+ | |
27 | * | |
28 | */ | |
29 | ||
30 | enum json_lexer_state { | |
31 | ERROR = 0, | |
32 | IN_DONE_STRING, | |
33 | IN_DQ_UCODE3, | |
34 | IN_DQ_UCODE2, | |
35 | IN_DQ_UCODE1, | |
36 | IN_DQ_UCODE0, | |
37 | IN_DQ_STRING_ESCAPE, | |
38 | IN_DQ_STRING, | |
39 | IN_SQ_UCODE3, | |
40 | IN_SQ_UCODE2, | |
41 | IN_SQ_UCODE1, | |
42 | IN_SQ_UCODE0, | |
43 | IN_SQ_STRING_ESCAPE, | |
44 | IN_SQ_STRING, | |
45 | IN_ZERO, | |
46 | IN_DIGITS, | |
47 | IN_DIGIT, | |
48 | IN_EXP_E, | |
49 | IN_MANTISSA, | |
50 | IN_MANTISSA_DIGITS, | |
51 | IN_NONZERO_NUMBER, | |
52 | IN_NEG_NONZERO_NUMBER, | |
53 | IN_KEYWORD, | |
54 | IN_ESCAPE, | |
55 | IN_ESCAPE_L, | |
56 | IN_ESCAPE_LL, | |
57 | IN_ESCAPE_DONE, | |
58 | IN_WHITESPACE, | |
59 | IN_OPERATOR_DONE, | |
60 | IN_START, | |
61 | }; | |
62 | ||
63 | #define TERMINAL(state) [0 ... 0x7F] = (state) | |
64 | ||
65 | static const uint8_t json_lexer[][256] = { | |
66 | [IN_DONE_STRING] = { | |
67 | TERMINAL(JSON_STRING), | |
68 | }, | |
69 | ||
70 | /* double quote string */ | |
71 | [IN_DQ_UCODE3] = { | |
72 | ['0' ... '9'] = IN_DQ_STRING, | |
73 | ['a' ... 'f'] = IN_DQ_STRING, | |
74 | ['A' ... 'F'] = IN_DQ_STRING, | |
75 | }, | |
76 | [IN_DQ_UCODE2] = { | |
77 | ['0' ... '9'] = IN_DQ_UCODE3, | |
78 | ['a' ... 'f'] = IN_DQ_UCODE3, | |
79 | ['A' ... 'F'] = IN_DQ_UCODE3, | |
80 | }, | |
81 | [IN_DQ_UCODE1] = { | |
82 | ['0' ... '9'] = IN_DQ_UCODE2, | |
83 | ['a' ... 'f'] = IN_DQ_UCODE2, | |
84 | ['A' ... 'F'] = IN_DQ_UCODE2, | |
85 | }, | |
86 | [IN_DQ_UCODE0] = { | |
87 | ['0' ... '9'] = IN_DQ_UCODE1, | |
88 | ['a' ... 'f'] = IN_DQ_UCODE1, | |
89 | ['A' ... 'F'] = IN_DQ_UCODE1, | |
90 | }, | |
91 | [IN_DQ_STRING_ESCAPE] = { | |
92 | ['b'] = IN_DQ_STRING, | |
93 | ['f'] = IN_DQ_STRING, | |
94 | ['n'] = IN_DQ_STRING, | |
95 | ['r'] = IN_DQ_STRING, | |
96 | ['t'] = IN_DQ_STRING, | |
97 | ['\''] = IN_DQ_STRING, | |
98 | ['\"'] = IN_DQ_STRING, | |
99 | ['u'] = IN_DQ_UCODE0, | |
100 | }, | |
101 | [IN_DQ_STRING] = { | |
102 | [1 ... 0xFF] = IN_DQ_STRING, | |
103 | ['\\'] = IN_DQ_STRING_ESCAPE, | |
104 | ['"'] = IN_DONE_STRING, | |
105 | }, | |
106 | ||
107 | /* single quote string */ | |
108 | [IN_SQ_UCODE3] = { | |
109 | ['0' ... '9'] = IN_SQ_STRING, | |
110 | ['a' ... 'f'] = IN_SQ_STRING, | |
111 | ['A' ... 'F'] = IN_SQ_STRING, | |
112 | }, | |
113 | [IN_SQ_UCODE2] = { | |
114 | ['0' ... '9'] = IN_SQ_UCODE3, | |
115 | ['a' ... 'f'] = IN_SQ_UCODE3, | |
116 | ['A' ... 'F'] = IN_SQ_UCODE3, | |
117 | }, | |
118 | [IN_SQ_UCODE1] = { | |
119 | ['0' ... '9'] = IN_SQ_UCODE2, | |
120 | ['a' ... 'f'] = IN_SQ_UCODE2, | |
121 | ['A' ... 'F'] = IN_SQ_UCODE2, | |
122 | }, | |
123 | [IN_SQ_UCODE0] = { | |
124 | ['0' ... '9'] = IN_SQ_UCODE1, | |
125 | ['a' ... 'f'] = IN_SQ_UCODE1, | |
126 | ['A' ... 'F'] = IN_SQ_UCODE1, | |
127 | }, | |
128 | [IN_SQ_STRING_ESCAPE] = { | |
129 | ['b'] = IN_SQ_STRING, | |
130 | ['f'] = IN_SQ_STRING, | |
131 | ['n'] = IN_SQ_STRING, | |
132 | ['r'] = IN_SQ_STRING, | |
133 | ['t'] = IN_SQ_STRING, | |
134 | ['\''] = IN_SQ_STRING, | |
135 | ['\"'] = IN_SQ_STRING, | |
136 | ['u'] = IN_SQ_UCODE0, | |
137 | }, | |
138 | [IN_SQ_STRING] = { | |
139 | [1 ... 0xFF] = IN_SQ_STRING, | |
140 | ['\\'] = IN_SQ_STRING_ESCAPE, | |
141 | ['\''] = IN_DONE_STRING, | |
142 | }, | |
143 | ||
144 | /* Zero */ | |
145 | [IN_ZERO] = { | |
146 | TERMINAL(JSON_INTEGER), | |
147 | ['0' ... '9'] = ERROR, | |
148 | ['.'] = IN_MANTISSA, | |
149 | }, | |
150 | ||
151 | /* Float */ | |
152 | [IN_DIGITS] = { | |
153 | TERMINAL(JSON_FLOAT), | |
154 | ['0' ... '9'] = IN_DIGITS, | |
155 | }, | |
156 | ||
157 | [IN_DIGIT] = { | |
158 | ['0' ... '9'] = IN_DIGITS, | |
159 | }, | |
160 | ||
161 | [IN_EXP_E] = { | |
162 | ['-'] = IN_DIGIT, | |
163 | ['+'] = IN_DIGIT, | |
164 | ['0' ... '9'] = IN_DIGITS, | |
165 | }, | |
166 | ||
167 | [IN_MANTISSA_DIGITS] = { | |
168 | TERMINAL(JSON_FLOAT), | |
169 | ['0' ... '9'] = IN_MANTISSA_DIGITS, | |
170 | ['e'] = IN_EXP_E, | |
171 | ['E'] = IN_EXP_E, | |
172 | }, | |
173 | ||
174 | [IN_MANTISSA] = { | |
175 | ['0' ... '9'] = IN_MANTISSA_DIGITS, | |
176 | }, | |
177 | ||
178 | /* Number */ | |
179 | [IN_NONZERO_NUMBER] = { | |
180 | TERMINAL(JSON_INTEGER), | |
181 | ['0' ... '9'] = IN_NONZERO_NUMBER, | |
182 | ['e'] = IN_EXP_E, | |
183 | ['E'] = IN_EXP_E, | |
184 | ['.'] = IN_MANTISSA, | |
185 | }, | |
186 | ||
187 | [IN_NEG_NONZERO_NUMBER] = { | |
188 | ['0'] = IN_ZERO, | |
189 | ['1' ... '9'] = IN_NONZERO_NUMBER, | |
190 | }, | |
191 | ||
192 | /* keywords */ | |
193 | [IN_KEYWORD] = { | |
194 | TERMINAL(JSON_KEYWORD), | |
195 | ['a' ... 'z'] = IN_KEYWORD, | |
196 | }, | |
197 | ||
198 | /* whitespace */ | |
199 | [IN_WHITESPACE] = { | |
200 | TERMINAL(JSON_SKIP), | |
201 | [' '] = IN_WHITESPACE, | |
202 | ['\t'] = IN_WHITESPACE, | |
203 | ['\r'] = IN_WHITESPACE, | |
204 | ['\n'] = IN_WHITESPACE, | |
205 | }, | |
206 | ||
207 | /* operator */ | |
208 | [IN_OPERATOR_DONE] = { | |
209 | TERMINAL(JSON_OPERATOR), | |
210 | }, | |
211 | ||
212 | /* escape */ | |
213 | [IN_ESCAPE_DONE] = { | |
214 | TERMINAL(JSON_ESCAPE), | |
215 | }, | |
216 | ||
217 | [IN_ESCAPE_LL] = { | |
218 | ['d'] = IN_ESCAPE_DONE, | |
219 | }, | |
220 | ||
221 | [IN_ESCAPE_L] = { | |
222 | ['d'] = IN_ESCAPE_DONE, | |
223 | ['l'] = IN_ESCAPE_LL, | |
224 | }, | |
225 | ||
226 | [IN_ESCAPE] = { | |
227 | ['d'] = IN_ESCAPE_DONE, | |
228 | ['i'] = IN_ESCAPE_DONE, | |
229 | ['p'] = IN_ESCAPE_DONE, | |
230 | ['s'] = IN_ESCAPE_DONE, | |
231 | ['f'] = IN_ESCAPE_DONE, | |
232 | ['l'] = IN_ESCAPE_L, | |
233 | }, | |
234 | ||
235 | /* top level rule */ | |
236 | [IN_START] = { | |
237 | ['"'] = IN_DQ_STRING, | |
238 | ['\''] = IN_SQ_STRING, | |
239 | ['0'] = IN_ZERO, | |
240 | ['1' ... '9'] = IN_NONZERO_NUMBER, | |
241 | ['-'] = IN_NEG_NONZERO_NUMBER, | |
242 | ['{'] = IN_OPERATOR_DONE, | |
243 | ['}'] = IN_OPERATOR_DONE, | |
244 | ['['] = IN_OPERATOR_DONE, | |
245 | [']'] = IN_OPERATOR_DONE, | |
246 | [','] = IN_OPERATOR_DONE, | |
247 | [':'] = IN_OPERATOR_DONE, | |
248 | ['a' ... 'z'] = IN_KEYWORD, | |
249 | ['%'] = IN_ESCAPE, | |
250 | [' '] = IN_WHITESPACE, | |
251 | ['\t'] = IN_WHITESPACE, | |
252 | ['\r'] = IN_WHITESPACE, | |
253 | ['\n'] = IN_WHITESPACE, | |
254 | }, | |
255 | }; | |
256 | ||
257 | void json_lexer_init(JSONLexer *lexer, JSONLexerEmitter func) | |
258 | { | |
259 | lexer->emit = func; | |
260 | lexer->state = IN_START; | |
261 | lexer->token = qstring_new(); | |
262 | } | |
263 | ||
264 | static int json_lexer_feed_char(JSONLexer *lexer, char ch) | |
265 | { | |
266 | char buf[2]; | |
267 | ||
268 | lexer->x++; | |
269 | if (ch == '\n') { | |
270 | lexer->x = 0; | |
271 | lexer->y++; | |
272 | } | |
273 | ||
274 | lexer->state = json_lexer[lexer->state][(uint8_t)ch]; | |
275 | ||
276 | switch (lexer->state) { | |
277 | case JSON_OPERATOR: | |
278 | case JSON_ESCAPE: | |
279 | case JSON_INTEGER: | |
280 | case JSON_FLOAT: | |
281 | case JSON_KEYWORD: | |
282 | case JSON_STRING: | |
283 | lexer->emit(lexer, lexer->token, lexer->state, lexer->x, lexer->y); | |
284 | case JSON_SKIP: | |
285 | lexer->state = json_lexer[IN_START][(uint8_t)ch]; | |
286 | QDECREF(lexer->token); | |
287 | lexer->token = qstring_new(); | |
288 | break; | |
289 | case ERROR: | |
290 | return -EINVAL; | |
291 | default: | |
292 | break; | |
293 | } | |
294 | ||
295 | buf[0] = ch; | |
296 | buf[1] = 0; | |
297 | ||
298 | qstring_append(lexer->token, buf); | |
299 | ||
300 | return 0; | |
301 | } | |
302 | ||
303 | int json_lexer_feed(JSONLexer *lexer, const char *buffer, size_t size) | |
304 | { | |
305 | size_t i; | |
306 | ||
307 | for (i = 0; i < size; i++) { | |
308 | int err; | |
309 | ||
310 | err = json_lexer_feed_char(lexer, buffer[i]); | |
311 | if (err < 0) { | |
312 | return err; | |
313 | } | |
314 | } | |
315 | ||
316 | return 0; | |
317 | } | |
318 | ||
319 | int json_lexer_flush(JSONLexer *lexer) | |
320 | { | |
321 | return json_lexer_feed_char(lexer, 0); | |
322 | } | |
323 | ||
324 | void json_lexer_destroy(JSONLexer *lexer) | |
325 | { | |
326 | QDECREF(lexer->token); | |
327 | } |