4 * Copyright IBM, Corp. 2009
7 * Anthony Liguori <aliguori@us.ibm.com>
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.
16 #include "qemu-common.h"
23 #include "json-parser.h"
24 #include "json-lexer.h"
27 typedef struct JSONParserContext
32 #define BUG_ON(cond) assert(!(cond))
37 * 0) make errors meaningful again
38 * 1) add geometry information to tokens
39 * 3) should we return a parsed size?
40 * 4) deal with premature EOI
43 static QObject
*parse_value(JSONParserContext
*ctxt
, QList
**tokens
, va_list *ap
);
48 * tokens are dictionaries that contain a type, a string value, and geometry information
49 * about a token identified by the lexer. These are routines that make working with
50 * these objects a bit easier.
52 static const char *token_get_value(QObject
*obj
)
54 return qdict_get_str(qobject_to_qdict(obj
), "token");
57 static JSONTokenType
token_get_type(QObject
*obj
)
59 return qdict_get_int(qobject_to_qdict(obj
), "type");
62 static int token_is_operator(QObject
*obj
, char op
)
66 if (token_get_type(obj
) != JSON_OPERATOR
) {
70 val
= token_get_value(obj
);
72 return (val
[0] == op
) && (val
[1] == 0);
75 static int token_is_keyword(QObject
*obj
, const char *value
)
77 if (token_get_type(obj
) != JSON_KEYWORD
) {
81 return strcmp(token_get_value(obj
), value
) == 0;
84 static int token_is_escape(QObject
*obj
, const char *value
)
86 if (token_get_type(obj
) != JSON_ESCAPE
) {
90 return (strcmp(token_get_value(obj
), value
) == 0);
96 static void GCC_FMT_ATTR(3, 4) parse_error(JSONParserContext
*ctxt
,
97 QObject
*token
, const char *msg
, ...)
102 vsnprintf(message
, sizeof(message
), msg
, ap
);
105 error_free(ctxt
->err
);
108 error_set(&ctxt
->err
, QERR_JSON_PARSE_ERROR
, message
);
114 * These helpers are used to unescape strings.
116 static void wchar_to_utf8(uint16_t wchar
, char *buffer
, size_t buffer_length
)
118 if (wchar
<= 0x007F) {
119 BUG_ON(buffer_length
< 2);
121 buffer
[0] = wchar
& 0x7F;
123 } else if (wchar
<= 0x07FF) {
124 BUG_ON(buffer_length
< 3);
126 buffer
[0] = 0xC0 | ((wchar
>> 6) & 0x1F);
127 buffer
[1] = 0x80 | (wchar
& 0x3F);
130 BUG_ON(buffer_length
< 4);
132 buffer
[0] = 0xE0 | ((wchar
>> 12) & 0x0F);
133 buffer
[1] = 0x80 | ((wchar
>> 6) & 0x3F);
134 buffer
[2] = 0x80 | (wchar
& 0x3F);
139 static int hex2decimal(char ch
)
141 if (ch
>= '0' && ch
<= '9') {
143 } else if (ch
>= 'a' && ch
<= 'f') {
144 return 10 + (ch
- 'a');
145 } else if (ch
>= 'A' && ch
<= 'F') {
146 return 10 + (ch
- 'A');
153 * parse_string(): Parse a json string and return a QObject
162 * any-Unicode-character-
175 static QString
*qstring_from_escaped_str(JSONParserContext
*ctxt
, QObject
*token
)
177 const char *ptr
= token_get_value(token
);
179 int double_quote
= 1;
190 ((double_quote
&& *ptr
!= '"') || (!double_quote
&& *ptr
!= '\''))) {
196 qstring_append(str
, "\"");
200 qstring_append(str
, "'");
204 qstring_append(str
, "\\");
208 qstring_append(str
, "/");
212 qstring_append(str
, "\b");
216 qstring_append(str
, "\f");
220 qstring_append(str
, "\n");
224 qstring_append(str
, "\r");
228 qstring_append(str
, "\t");
232 uint16_t unicode_char
= 0;
238 for (i
= 0; i
< 4; i
++) {
239 if (qemu_isxdigit(*ptr
)) {
240 unicode_char
|= hex2decimal(*ptr
) << ((3 - i
) * 4);
242 parse_error(ctxt
, token
,
243 "invalid hex escape sequence in string");
249 wchar_to_utf8(unicode_char
, utf8_char
, sizeof(utf8_char
));
250 qstring_append(str
, utf8_char
);
253 parse_error(ctxt
, token
, "invalid escape sequence in string");
262 qstring_append(str
, dummy
);
276 static int parse_pair(JSONParserContext
*ctxt
, QDict
*dict
, QList
**tokens
, va_list *ap
)
278 QObject
*key
, *token
= NULL
, *value
, *peek
;
279 QList
*working
= qlist_copy(*tokens
);
281 peek
= qlist_peek(working
);
282 key
= parse_value(ctxt
, &working
, ap
);
283 if (!key
|| qobject_type(key
) != QTYPE_QSTRING
) {
284 parse_error(ctxt
, peek
, "key is not a string in object");
288 token
= qlist_pop(working
);
289 if (!token_is_operator(token
, ':')) {
290 parse_error(ctxt
, token
, "missing : in object pair");
294 value
= parse_value(ctxt
, &working
, ap
);
296 parse_error(ctxt
, token
, "Missing value in dict");
300 qdict_put_obj(dict
, qstring_get_str(qobject_to_qstring(key
)), value
);
302 qobject_decref(token
);
310 qobject_decref(token
);
317 static QObject
*parse_object(JSONParserContext
*ctxt
, QList
**tokens
, va_list *ap
)
320 QObject
*token
, *peek
;
321 QList
*working
= qlist_copy(*tokens
);
323 token
= qlist_pop(working
);
324 if (!token_is_operator(token
, '{')) {
327 qobject_decref(token
);
332 peek
= qlist_peek(working
);
333 if (!token_is_operator(peek
, '}')) {
334 if (parse_pair(ctxt
, dict
, &working
, ap
) == -1) {
338 token
= qlist_pop(working
);
339 while (!token_is_operator(token
, '}')) {
340 if (!token_is_operator(token
, ',')) {
341 parse_error(ctxt
, token
, "expected separator in dict");
344 qobject_decref(token
);
347 if (parse_pair(ctxt
, dict
, &working
, ap
) == -1) {
351 token
= qlist_pop(working
);
353 qobject_decref(token
);
356 token
= qlist_pop(working
);
357 qobject_decref(token
);
364 return QOBJECT(dict
);
367 qobject_decref(token
);
373 static QObject
*parse_array(JSONParserContext
*ctxt
, QList
**tokens
, va_list *ap
)
376 QObject
*token
, *peek
;
377 QList
*working
= qlist_copy(*tokens
);
379 token
= qlist_pop(working
);
380 if (!token_is_operator(token
, '[')) {
383 qobject_decref(token
);
388 peek
= qlist_peek(working
);
389 if (!token_is_operator(peek
, ']')) {
392 obj
= parse_value(ctxt
, &working
, ap
);
394 parse_error(ctxt
, token
, "expecting value");
398 qlist_append_obj(list
, obj
);
400 token
= qlist_pop(working
);
401 while (!token_is_operator(token
, ']')) {
402 if (!token_is_operator(token
, ',')) {
403 parse_error(ctxt
, token
, "expected separator in list");
407 qobject_decref(token
);
410 obj
= parse_value(ctxt
, &working
, ap
);
412 parse_error(ctxt
, token
, "expecting value");
416 qlist_append_obj(list
, obj
);
418 token
= qlist_pop(working
);
421 qobject_decref(token
);
424 token
= qlist_pop(working
);
425 qobject_decref(token
);
432 return QOBJECT(list
);
435 qobject_decref(token
);
441 static QObject
*parse_keyword(JSONParserContext
*ctxt
, QList
**tokens
)
443 QObject
*token
, *ret
;
444 QList
*working
= qlist_copy(*tokens
);
446 token
= qlist_pop(working
);
448 if (token_get_type(token
) != JSON_KEYWORD
) {
452 if (token_is_keyword(token
, "true")) {
453 ret
= QOBJECT(qbool_from_int(true));
454 } else if (token_is_keyword(token
, "false")) {
455 ret
= QOBJECT(qbool_from_int(false));
457 parse_error(ctxt
, token
, "invalid keyword `%s'", token_get_value(token
));
461 qobject_decref(token
);
468 qobject_decref(token
);
474 static QObject
*parse_escape(JSONParserContext
*ctxt
, QList
**tokens
, va_list *ap
)
476 QObject
*token
= NULL
, *obj
;
477 QList
*working
= qlist_copy(*tokens
);
483 token
= qlist_pop(working
);
485 if (token_is_escape(token
, "%p")) {
486 obj
= va_arg(*ap
, QObject
*);
487 } else if (token_is_escape(token
, "%i")) {
488 obj
= QOBJECT(qbool_from_int(va_arg(*ap
, int)));
489 } else if (token_is_escape(token
, "%d")) {
490 obj
= QOBJECT(qint_from_int(va_arg(*ap
, int)));
491 } else if (token_is_escape(token
, "%ld")) {
492 obj
= QOBJECT(qint_from_int(va_arg(*ap
, long)));
493 } else if (token_is_escape(token
, "%lld") ||
494 token_is_escape(token
, "%I64d")) {
495 obj
= QOBJECT(qint_from_int(va_arg(*ap
, long long)));
496 } else if (token_is_escape(token
, "%s")) {
497 obj
= QOBJECT(qstring_from_str(va_arg(*ap
, const char *)));
498 } else if (token_is_escape(token
, "%f")) {
499 obj
= QOBJECT(qfloat_from_double(va_arg(*ap
, double)));
504 qobject_decref(token
);
511 qobject_decref(token
);
517 static QObject
*parse_literal(JSONParserContext
*ctxt
, QList
**tokens
)
519 QObject
*token
, *obj
;
520 QList
*working
= qlist_copy(*tokens
);
522 token
= qlist_pop(working
);
523 switch (token_get_type(token
)) {
525 obj
= QOBJECT(qstring_from_escaped_str(ctxt
, token
));
528 obj
= QOBJECT(qint_from_int(strtoll(token_get_value(token
), NULL
, 10)));
531 /* FIXME dependent on locale */
532 obj
= QOBJECT(qfloat_from_double(strtod(token_get_value(token
), NULL
)));
538 qobject_decref(token
);
545 qobject_decref(token
);
551 static QObject
*parse_value(JSONParserContext
*ctxt
, QList
**tokens
, va_list *ap
)
555 obj
= parse_object(ctxt
, tokens
, ap
);
557 obj
= parse_array(ctxt
, tokens
, ap
);
560 obj
= parse_escape(ctxt
, tokens
, ap
);
563 obj
= parse_keyword(ctxt
, tokens
);
566 obj
= parse_literal(ctxt
, tokens
);
572 QObject
*json_parser_parse(QList
*tokens
, va_list *ap
)
574 return json_parser_parse_err(tokens
, ap
, NULL
);
577 QObject
*json_parser_parse_err(QList
*tokens
, va_list *ap
, Error
**errp
)
579 JSONParserContext ctxt
= {};
580 QList
*working
= qlist_copy(tokens
);
583 result
= parse_value(&ctxt
, &working
, ap
);
587 error_propagate(errp
, ctxt
.err
);