Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20200117-1' into...
[qemu.git] / qobject / qjson.c
1 /*
2 * QObject JSON integration
3 *
4 * Copyright IBM, Corp. 2009
5 *
6 * Authors:
7 * Anthony Liguori <aliguori@us.ibm.com>
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 "qemu/osdep.h"
15 #include "qapi/error.h"
16 #include "qapi/qmp/json-parser.h"
17 #include "qapi/qmp/qjson.h"
18 #include "qapi/qmp/qbool.h"
19 #include "qapi/qmp/qdict.h"
20 #include "qapi/qmp/qlist.h"
21 #include "qapi/qmp/qnum.h"
22 #include "qapi/qmp/qstring.h"
23 #include "qemu/unicode.h"
24
25 typedef struct JSONParsingState
26 {
27 JSONMessageParser parser;
28 QObject *result;
29 Error *err;
30 } JSONParsingState;
31
32 static void consume_json(void *opaque, QObject *json, Error *err)
33 {
34 JSONParsingState *s = opaque;
35
36 assert(!json != !err);
37 assert(!s->result || !s->err);
38
39 if (s->result) {
40 qobject_unref(s->result);
41 s->result = NULL;
42 error_setg(&s->err, "Expecting at most one JSON value");
43 }
44 if (s->err) {
45 qobject_unref(json);
46 error_free(err);
47 return;
48 }
49 s->result = json;
50 s->err = err;
51 }
52
53 /*
54 * Parse @string as JSON value.
55 * If @ap is non-null, interpolate %-escapes.
56 * Takes ownership of %p arguments.
57 * On success, return the JSON value.
58 * On failure, store an error through @errp and return NULL.
59 * Ownership of %p arguments becomes indeterminate then. To avoid
60 * leaks, callers passing %p must terminate on error, e.g. by passing
61 * &error_abort.
62 */
63 static QObject *qobject_from_jsonv(const char *string, va_list *ap,
64 Error **errp)
65 {
66 JSONParsingState state = {};
67
68 json_message_parser_init(&state.parser, consume_json, &state, ap);
69 json_message_parser_feed(&state.parser, string, strlen(string));
70 json_message_parser_flush(&state.parser);
71 json_message_parser_destroy(&state.parser);
72
73 if (!state.result && !state.err) {
74 error_setg(&state.err, "Expecting a JSON value");
75 }
76
77 error_propagate(errp, state.err);
78 return state.result;
79 }
80
81 QObject *qobject_from_json(const char *string, Error **errp)
82 {
83 return qobject_from_jsonv(string, NULL, errp);
84 }
85
86 /*
87 * Parse @string as JSON value with %-escapes interpolated.
88 * Abort on error. Do not use with untrusted @string.
89 * Return the resulting QObject. It is never null.
90 */
91 QObject *qobject_from_vjsonf_nofail(const char *string, va_list ap)
92 {
93 va_list ap_copy;
94 QObject *obj;
95
96 /* va_copy() is needed when va_list is an array type */
97 va_copy(ap_copy, ap);
98 obj = qobject_from_jsonv(string, &ap_copy, &error_abort);
99 va_end(ap_copy);
100
101 assert(obj);
102 return obj;
103 }
104
105 /*
106 * Parse @string as JSON value with %-escapes interpolated.
107 * Abort on error. Do not use with untrusted @string.
108 * Return the resulting QObject. It is never null.
109 */
110 QObject *qobject_from_jsonf_nofail(const char *string, ...)
111 {
112 QObject *obj;
113 va_list ap;
114
115 va_start(ap, string);
116 obj = qobject_from_vjsonf_nofail(string, ap);
117 va_end(ap);
118
119 return obj;
120 }
121
122 /*
123 * Parse @string as JSON object with %-escapes interpolated.
124 * Abort on error. Do not use with untrusted @string.
125 * Return the resulting QDict. It is never null.
126 */
127 QDict *qdict_from_vjsonf_nofail(const char *string, va_list ap)
128 {
129 QDict *qdict;
130
131 qdict = qobject_to(QDict, qobject_from_vjsonf_nofail(string, ap));
132 assert(qdict);
133 return qdict;
134 }
135
136 /*
137 * Parse @string as JSON object with %-escapes interpolated.
138 * Abort on error. Do not use with untrusted @string.
139 * Return the resulting QDict. It is never null.
140 */
141 QDict *qdict_from_jsonf_nofail(const char *string, ...)
142 {
143 QDict *qdict;
144 va_list ap;
145
146 va_start(ap, string);
147 qdict = qdict_from_vjsonf_nofail(string, ap);
148 va_end(ap);
149 return qdict;
150 }
151
152 typedef struct ToJsonIterState
153 {
154 int indent;
155 int pretty;
156 int count;
157 QString *str;
158 } ToJsonIterState;
159
160 static void to_json(const QObject *obj, QString *str, int pretty, int indent);
161
162 static void to_json_dict_iter(const char *key, QObject *obj, void *opaque)
163 {
164 ToJsonIterState *s = opaque;
165 QString *qkey;
166 int j;
167
168 if (s->count) {
169 qstring_append(s->str, s->pretty ? "," : ", ");
170 }
171
172 if (s->pretty) {
173 qstring_append(s->str, "\n");
174 for (j = 0 ; j < s->indent ; j++)
175 qstring_append(s->str, " ");
176 }
177
178 qkey = qstring_from_str(key);
179 to_json(QOBJECT(qkey), s->str, s->pretty, s->indent);
180 qobject_unref(qkey);
181
182 qstring_append(s->str, ": ");
183 to_json(obj, s->str, s->pretty, s->indent);
184 s->count++;
185 }
186
187 static void to_json_list_iter(QObject *obj, void *opaque)
188 {
189 ToJsonIterState *s = opaque;
190 int j;
191
192 if (s->count) {
193 qstring_append(s->str, s->pretty ? "," : ", ");
194 }
195
196 if (s->pretty) {
197 qstring_append(s->str, "\n");
198 for (j = 0 ; j < s->indent ; j++)
199 qstring_append(s->str, " ");
200 }
201
202 to_json(obj, s->str, s->pretty, s->indent);
203 s->count++;
204 }
205
206 static void to_json(const QObject *obj, QString *str, int pretty, int indent)
207 {
208 switch (qobject_type(obj)) {
209 case QTYPE_QNULL:
210 qstring_append(str, "null");
211 break;
212 case QTYPE_QNUM: {
213 QNum *val = qobject_to(QNum, obj);
214 char *buffer = qnum_to_string(val);
215 qstring_append(str, buffer);
216 g_free(buffer);
217 break;
218 }
219 case QTYPE_QSTRING: {
220 QString *val = qobject_to(QString, obj);
221 const char *ptr;
222 int cp;
223 char buf[16];
224 char *end;
225
226 ptr = qstring_get_str(val);
227 qstring_append(str, "\"");
228
229 for (; *ptr; ptr = end) {
230 cp = mod_utf8_codepoint(ptr, 6, &end);
231 switch (cp) {
232 case '\"':
233 qstring_append(str, "\\\"");
234 break;
235 case '\\':
236 qstring_append(str, "\\\\");
237 break;
238 case '\b':
239 qstring_append(str, "\\b");
240 break;
241 case '\f':
242 qstring_append(str, "\\f");
243 break;
244 case '\n':
245 qstring_append(str, "\\n");
246 break;
247 case '\r':
248 qstring_append(str, "\\r");
249 break;
250 case '\t':
251 qstring_append(str, "\\t");
252 break;
253 default:
254 if (cp < 0) {
255 cp = 0xFFFD; /* replacement character */
256 }
257 if (cp > 0xFFFF) {
258 /* beyond BMP; need a surrogate pair */
259 snprintf(buf, sizeof(buf), "\\u%04X\\u%04X",
260 0xD800 + ((cp - 0x10000) >> 10),
261 0xDC00 + ((cp - 0x10000) & 0x3FF));
262 } else if (cp < 0x20 || cp >= 0x7F) {
263 snprintf(buf, sizeof(buf), "\\u%04X", cp);
264 } else {
265 buf[0] = cp;
266 buf[1] = 0;
267 }
268 qstring_append(str, buf);
269 }
270 };
271
272 qstring_append(str, "\"");
273 break;
274 }
275 case QTYPE_QDICT: {
276 ToJsonIterState s;
277 QDict *val = qobject_to(QDict, obj);
278
279 s.count = 0;
280 s.str = str;
281 s.indent = indent + 1;
282 s.pretty = pretty;
283 qstring_append(str, "{");
284 qdict_iter(val, to_json_dict_iter, &s);
285 if (pretty) {
286 int j;
287 qstring_append(str, "\n");
288 for (j = 0 ; j < indent ; j++)
289 qstring_append(str, " ");
290 }
291 qstring_append(str, "}");
292 break;
293 }
294 case QTYPE_QLIST: {
295 ToJsonIterState s;
296 QList *val = qobject_to(QList, obj);
297
298 s.count = 0;
299 s.str = str;
300 s.indent = indent + 1;
301 s.pretty = pretty;
302 qstring_append(str, "[");
303 qlist_iter(val, (void *)to_json_list_iter, &s);
304 if (pretty) {
305 int j;
306 qstring_append(str, "\n");
307 for (j = 0 ; j < indent ; j++)
308 qstring_append(str, " ");
309 }
310 qstring_append(str, "]");
311 break;
312 }
313 case QTYPE_QBOOL: {
314 QBool *val = qobject_to(QBool, obj);
315
316 if (qbool_get_bool(val)) {
317 qstring_append(str, "true");
318 } else {
319 qstring_append(str, "false");
320 }
321 break;
322 }
323 default:
324 abort();
325 }
326 }
327
328 QString *qobject_to_json(const QObject *obj)
329 {
330 QString *str = qstring_new();
331
332 to_json(obj, str, 0, 0);
333
334 return str;
335 }
336
337 QString *qobject_to_json_pretty(const QObject *obj)
338 {
339 QString *str = qstring_new();
340
341 to_json(obj, str, 1, 0);
342
343 return str;
344 }