|
1 |
/*
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2 |
* JSON Parser
|
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3 |
*
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|
4 |
* Copyright IBM, Corp. 2009
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|
5 |
*
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|
6 |
* Authors:
|
|
7 |
* Anthony Liguori <aliguori@us.ibm.com>
|
|
8 |
*
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|
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.
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|
11 |
*
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|
12 |
*/
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13 |
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|
14 |
#include <stdbool.h>
|
|
15 |
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|
16 |
#include "qemu-common.h"
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|
17 |
#include "qstring.h"
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|
18 |
#include "qint.h"
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|
19 |
#include "qdict.h"
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|
20 |
#include "qlist.h"
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|
21 |
#include "qfloat.h"
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|
22 |
#include "qbool.h"
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|
23 |
#include "json-parser.h"
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|
24 |
#include "json-lexer.h"
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25 |
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|
26 |
typedef struct JSONParserContext
|
|
27 |
{
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|
28 |
} JSONParserContext;
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29 |
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|
30 |
#define BUG_ON(cond) assert(!(cond))
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31 |
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|
32 |
/**
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|
33 |
* TODO
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|
34 |
*
|
|
35 |
* 0) make errors meaningful again
|
|
36 |
* 1) add geometry information to tokens
|
|
37 |
* 3) should we return a parsed size?
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|
38 |
* 4) deal with premature EOI
|
|
39 |
*/
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|
40 |
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|
41 |
static QObject *parse_value(JSONParserContext *ctxt, QList **tokens, va_list *ap);
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|
42 |
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|
43 |
/**
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|
44 |
* Token manipulators
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|
45 |
*
|
|
46 |
* tokens are dictionaries that contain a type, a string value, and geometry information
|
|
47 |
* about a token identified by the lexer. These are routines that make working with
|
|
48 |
* these objects a bit easier.
|
|
49 |
*/
|
|
50 |
static const char *token_get_value(QObject *obj)
|
|
51 |
{
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|
52 |
return qdict_get_str(qobject_to_qdict(obj), "token");
|
|
53 |
}
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|
54 |
|
|
55 |
static JSONTokenType token_get_type(QObject *obj)
|
|
56 |
{
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|
57 |
return qdict_get_int(qobject_to_qdict(obj), "type");
|
|
58 |
}
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|
59 |
|
|
60 |
static int token_is_operator(QObject *obj, char op)
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|
61 |
{
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|
62 |
const char *val;
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|
63 |
|
|
64 |
if (token_get_type(obj) != JSON_OPERATOR) {
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|
65 |
return 0;
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|
66 |
}
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|
67 |
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|
68 |
val = token_get_value(obj);
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|
69 |
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|
70 |
return (val[0] == op) && (val[1] == 0);
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|
71 |
}
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72 |
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|
73 |
static int token_is_keyword(QObject *obj, const char *value)
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|
74 |
{
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|
75 |
if (token_get_type(obj) != JSON_KEYWORD) {
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|
76 |
return 0;
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|
77 |
}
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|
78 |
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|
79 |
return strcmp(token_get_value(obj), value) == 0;
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|
80 |
}
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|
81 |
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|
82 |
static int token_is_escape(QObject *obj, const char *value)
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|
83 |
{
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|
84 |
if (token_get_type(obj) != JSON_ESCAPE) {
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|
85 |
return 0;
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|
86 |
}
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|
87 |
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|
88 |
return (strcmp(token_get_value(obj), value) == 0);
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|
89 |
}
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|
90 |
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|
91 |
/**
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|
92 |
* Error handler
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|
93 |
*/
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|
94 |
static void parse_error(JSONParserContext *ctxt, QObject *token, const char *msg, ...)
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|
95 |
{
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|
96 |
fprintf(stderr, "parse error: %s\n", msg);
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|
97 |
}
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|
98 |
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|
99 |
/**
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100 |
* String helpers
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|
101 |
*
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|
102 |
* These helpers are used to unescape strings.
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|
103 |
*/
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|
104 |
static void wchar_to_utf8(uint16_t wchar, char *buffer, size_t buffer_length)
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|
105 |
{
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|
106 |
if (wchar <= 0x007F) {
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|
107 |
BUG_ON(buffer_length < 2);
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|
108 |
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|
109 |
buffer[0] = wchar & 0x7F;
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|
110 |
buffer[1] = 0;
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|
111 |
} else if (wchar <= 0x07FF) {
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|
112 |
BUG_ON(buffer_length < 3);
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|
113 |
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|
114 |
buffer[0] = 0xC0 | ((wchar >> 6) & 0x1F);
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|
115 |
buffer[1] = 0x80 | (wchar & 0x3F);
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|
116 |
buffer[2] = 0;
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|
117 |
} else {
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|
118 |
BUG_ON(buffer_length < 4);
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|
119 |
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|
120 |
buffer[0] = 0xE0 | ((wchar >> 12) & 0x0F);
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|
121 |
buffer[1] = 0x80 | ((wchar >> 6) & 0x3F);
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|
122 |
buffer[2] = 0x80 | (wchar & 0x3F);
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|
123 |
buffer[3] = 0;
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|
124 |
}
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|
125 |
}
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126 |
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|
127 |
static int hex2decimal(char ch)
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|
128 |
{
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|
129 |
if (ch >= '0' && ch <= '9') {
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|
130 |
return (ch - '0');
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|
131 |
} else if (ch >= 'a' && ch <= 'f') {
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|
132 |
return 10 + (ch - 'a');
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|
133 |
} else if (ch >= 'A' && ch <= 'F') {
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|
134 |
return 10 + (ch - 'A');
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|
135 |
}
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136 |
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|
137 |
return -1;
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|
138 |
}
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|
139 |
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|
140 |
/**
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|
141 |
* parse_string(): Parse a json string and return a QObject
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142 |
*
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143 |
* string
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144 |
* ""
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145 |
* " chars "
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146 |
* chars
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147 |
* char
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148 |
* char chars
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149 |
* char
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150 |
* any-Unicode-character-
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151 |
* except-"-or-\-or-
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152 |
* control-character
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153 |
* \"
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154 |
* \\
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155 |
* \/
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156 |
* \b
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157 |
* \f
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158 |
* \n
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|
159 |
* \r
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160 |
* \t
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161 |
* \u four-hex-digits
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|
162 |
*/
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|
163 |
static QString *qstring_from_escaped_str(JSONParserContext *ctxt, QObject *token)
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|
164 |
{
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|
165 |
const char *ptr = token_get_value(token);
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|
166 |
QString *str;
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|
167 |
int double_quote = 1;
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|
168 |
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|
169 |
if (*ptr == '"') {
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|
170 |
double_quote = 1;
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|
171 |
} else {
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|
172 |
double_quote = 0;
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|
173 |
}
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|
174 |
ptr++;
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|
175 |
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|
176 |
str = qstring_new();
|
|
177 |
while (*ptr &&
|
|
178 |
((double_quote && *ptr != '"') || (!double_quote && *ptr != '\''))) {
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|
179 |
if (*ptr == '\\') {
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|
180 |
ptr++;
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|
181 |
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|
182 |
switch (*ptr) {
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|
183 |
case '"':
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|
184 |
qstring_append(str, "\"");
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|
185 |
ptr++;
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|
186 |
break;
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|
187 |
case '\'':
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|
188 |
qstring_append(str, "'");
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|
189 |
ptr++;
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|
190 |
break;
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|
191 |
case '\\':
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|
192 |
qstring_append(str, "\\");
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|
193 |
ptr++;
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|
194 |
break;
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195 |
case '/':
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|
196 |
qstring_append(str, "/");
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|
197 |
ptr++;
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|
198 |
break;
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|
199 |
case 'b':
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|
200 |
qstring_append(str, "\b");
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|
201 |
ptr++;
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202 |
break;
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203 |
case 'n':
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204 |
qstring_append(str, "\n");
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205 |
ptr++;
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206 |
break;
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|
207 |
case 'r':
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|
208 |
qstring_append(str, "\r");
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|
209 |
ptr++;
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|
210 |
break;
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|
211 |
case 't':
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|
212 |
qstring_append(str, "\t");
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213 |
ptr++;
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|
214 |
break;
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|
215 |
case 'u': {
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|
216 |
uint16_t unicode_char = 0;
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|
217 |
char utf8_char[4];
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|
218 |
int i = 0;
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|
219 |
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|
220 |
ptr++;
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|
221 |
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|
222 |
for (i = 0; i < 4; i++) {
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|
223 |
if (qemu_isxdigit(*ptr)) {
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|
224 |
unicode_char |= hex2decimal(*ptr) << ((3 - i) * 4);
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|
225 |
} else {
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|
226 |
parse_error(ctxt, token,
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|
227 |
"invalid hex escape sequence in string");
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228 |
goto out;
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|
229 |
}
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|
230 |
ptr++;
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|
231 |
}
|
|
232 |
|
|
233 |
wchar_to_utf8(unicode_char, utf8_char, sizeof(utf8_char));
|
|
234 |
qstring_append(str, utf8_char);
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|
235 |
} break;
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|
236 |
default:
|
|
237 |
parse_error(ctxt, token, "invalid escape sequence in string");
|
|
238 |
goto out;
|
|
239 |
}
|
|
240 |
} else {
|
|
241 |
char dummy[2];
|
|
242 |
|
|
243 |
dummy[0] = *ptr++;
|
|
244 |
dummy[1] = 0;
|
|
245 |
|
|
246 |
qstring_append(str, dummy);
|
|
247 |
}
|
|
248 |
}
|
|
249 |
|
|
250 |
ptr++;
|
|
251 |
|
|
252 |
return str;
|
|
253 |
|
|
254 |
out:
|
|
255 |
QDECREF(str);
|
|
256 |
return NULL;
|
|
257 |
}
|
|
258 |
|
|
259 |
/**
|
|
260 |
* Parsing rules
|
|
261 |
*/
|
|
262 |
static int parse_pair(JSONParserContext *ctxt, QDict *dict, QList **tokens, va_list *ap)
|
|
263 |
{
|
|
264 |
QObject *key, *token = NULL, *value, *peek;
|
|
265 |
QList *working = qlist_copy(*tokens);
|
|
266 |
|
|
267 |
peek = qlist_peek(working);
|
|
268 |
key = parse_value(ctxt, &working, ap);
|
|
269 |
if (qobject_type(key) != QTYPE_QSTRING) {
|
|
270 |
parse_error(ctxt, peek, "key is not a string in object");
|
|
271 |
goto out;
|
|
272 |
}
|
|
273 |
|
|
274 |
token = qlist_pop(working);
|
|
275 |
if (!token_is_operator(token, ':')) {
|
|
276 |
parse_error(ctxt, token, "missing : in object pair");
|
|
277 |
goto out;
|
|
278 |
}
|
|
279 |
|
|
280 |
value = parse_value(ctxt, &working, ap);
|
|
281 |
if (value == NULL) {
|
|
282 |
parse_error(ctxt, token, "Missing value in dict");
|
|
283 |
goto out;
|
|
284 |
}
|
|
285 |
|
|
286 |
qdict_put_obj(dict, qstring_get_str(qobject_to_qstring(key)), value);
|
|
287 |
|
|
288 |
qobject_decref(token);
|
|
289 |
qobject_decref(key);
|
|
290 |
QDECREF(*tokens);
|
|
291 |
*tokens = working;
|
|
292 |
|
|
293 |
return 0;
|
|
294 |
|
|
295 |
out:
|
|
296 |
qobject_decref(token);
|
|
297 |
qobject_decref(key);
|
|
298 |
QDECREF(working);
|
|
299 |
|
|
300 |
return -1;
|
|
301 |
}
|
|
302 |
|
|
303 |
static QObject *parse_object(JSONParserContext *ctxt, QList **tokens, va_list *ap)
|
|
304 |
{
|
|
305 |
QDict *dict = NULL;
|
|
306 |
QObject *token, *peek;
|
|
307 |
QList *working = qlist_copy(*tokens);
|
|
308 |
|
|
309 |
token = qlist_pop(working);
|
|
310 |
if (!token_is_operator(token, '{')) {
|
|
311 |
goto out;
|
|
312 |
}
|
|
313 |
qobject_decref(token);
|
|
314 |
token = NULL;
|
|
315 |
|
|
316 |
dict = qdict_new();
|
|
317 |
|
|
318 |
peek = qlist_peek(working);
|
|
319 |
if (!token_is_operator(peek, '}')) {
|
|
320 |
if (parse_pair(ctxt, dict, &working, ap) == -1) {
|
|
321 |
goto out;
|
|
322 |
}
|
|
323 |
|
|
324 |
token = qlist_pop(working);
|
|
325 |
while (!token_is_operator(token, '}')) {
|
|
326 |
if (!token_is_operator(token, ',')) {
|
|
327 |
parse_error(ctxt, token, "expected separator in dict");
|
|
328 |
goto out;
|
|
329 |
}
|
|
330 |
qobject_decref(token);
|
|
331 |
token = NULL;
|
|
332 |
|
|
333 |
if (parse_pair(ctxt, dict, &working, ap) == -1) {
|
|
334 |
goto out;
|
|
335 |
}
|
|
336 |
|
|
337 |
token = qlist_pop(working);
|
|
338 |
}
|
|
339 |
qobject_decref(token);
|
|
340 |
token = NULL;
|
|
341 |
} else {
|
|
342 |
token = qlist_pop(working);
|
|
343 |
qobject_decref(token);
|
|
344 |
token = NULL;
|
|
345 |
}
|
|
346 |
|
|
347 |
QDECREF(*tokens);
|
|
348 |
*tokens = working;
|
|
349 |
|
|
350 |
return QOBJECT(dict);
|
|
351 |
|
|
352 |
out:
|
|
353 |
qobject_decref(token);
|
|
354 |
QDECREF(working);
|
|
355 |
QDECREF(dict);
|
|
356 |
return NULL;
|
|
357 |
}
|
|
358 |
|
|
359 |
static QObject *parse_array(JSONParserContext *ctxt, QList **tokens, va_list *ap)
|
|
360 |
{
|
|
361 |
QList *list = NULL;
|
|
362 |
QObject *token, *peek;
|
|
363 |
QList *working = qlist_copy(*tokens);
|
|
364 |
|
|
365 |
token = qlist_pop(working);
|
|
366 |
if (!token_is_operator(token, '[')) {
|
|
367 |
goto out;
|
|
368 |
}
|
|
369 |
qobject_decref(token);
|
|
370 |
token = NULL;
|
|
371 |
|
|
372 |
list = qlist_new();
|
|
373 |
|
|
374 |
peek = qlist_peek(working);
|
|
375 |
if (!token_is_operator(peek, ']')) {
|
|
376 |
QObject *obj;
|
|
377 |
|
|
378 |
obj = parse_value(ctxt, &working, ap);
|
|
379 |
if (obj == NULL) {
|
|
380 |
parse_error(ctxt, token, "expecting value");
|
|
381 |
goto out;
|
|
382 |
}
|
|
383 |
|
|
384 |
qlist_append_obj(list, obj);
|
|
385 |
|
|
386 |
token = qlist_pop(working);
|
|
387 |
while (!token_is_operator(token, ']')) {
|
|
388 |
if (!token_is_operator(token, ',')) {
|
|
389 |
parse_error(ctxt, token, "expected separator in list");
|
|
390 |
goto out;
|
|
391 |
}
|
|
392 |
|
|
393 |
qobject_decref(token);
|
|
394 |
token = NULL;
|
|
395 |
|
|
396 |
obj = parse_value(ctxt, &working, ap);
|
|
397 |
if (obj == NULL) {
|
|
398 |
parse_error(ctxt, token, "expecting value");
|
|
399 |
goto out;
|
|
400 |
}
|
|
401 |
|
|
402 |
qlist_append_obj(list, obj);
|
|
403 |
|
|
404 |
token = qlist_pop(working);
|
|
405 |
}
|
|
406 |
|
|
407 |
qobject_decref(token);
|
|
408 |
token = NULL;
|
|
409 |
} else {
|
|
410 |
token = qlist_pop(working);
|
|
411 |
qobject_decref(token);
|
|
412 |
token = NULL;
|
|
413 |
}
|
|
414 |
|
|
415 |
QDECREF(*tokens);
|
|
416 |
*tokens = working;
|
|
417 |
|
|
418 |
return QOBJECT(list);
|
|
419 |
|
|
420 |
out:
|
|
421 |
qobject_decref(token);
|
|
422 |
QDECREF(working);
|
|
423 |
QDECREF(list);
|
|
424 |
return NULL;
|
|
425 |
}
|
|
426 |
|
|
427 |
static QObject *parse_keyword(JSONParserContext *ctxt, QList **tokens)
|
|
428 |
{
|
|
429 |
QObject *token, *ret;
|
|
430 |
QList *working = qlist_copy(*tokens);
|
|
431 |
|
|
432 |
token = qlist_pop(working);
|
|
433 |
|
|
434 |
if (token_get_type(token) != JSON_KEYWORD) {
|
|
435 |
goto out;
|
|
436 |
}
|
|
437 |
|
|
438 |
if (token_is_keyword(token, "true")) {
|
|
439 |
ret = QOBJECT(qbool_from_int(true));
|
|
440 |
} else if (token_is_keyword(token, "false")) {
|
|
441 |
ret = QOBJECT(qbool_from_int(false));
|
|
442 |
} else {
|
|
443 |
parse_error(ctxt, token, "invalid keyword `%s'", token_get_value(token));
|
|
444 |
goto out;
|
|
445 |
}
|
|
446 |
|
|
447 |
qobject_decref(token);
|
|
448 |
QDECREF(*tokens);
|
|
449 |
*tokens = working;
|
|
450 |
|
|
451 |
return ret;
|
|
452 |
|
|
453 |
out:
|
|
454 |
qobject_decref(token);
|
|
455 |
QDECREF(working);
|
|
456 |
|
|
457 |
return NULL;
|
|
458 |
}
|
|
459 |
|
|
460 |
static QObject *parse_escape(JSONParserContext *ctxt, QList **tokens, va_list *ap)
|
|
461 |
{
|
|
462 |
QObject *token = NULL, *obj;
|
|
463 |
QList *working = qlist_copy(*tokens);
|
|
464 |
|
|
465 |
if (ap == NULL) {
|
|
466 |
goto out;
|
|
467 |
}
|
|
468 |
|
|
469 |
token = qlist_pop(working);
|
|
470 |
|
|
471 |
if (token_is_escape(token, "%p")) {
|
|
472 |
obj = va_arg(*ap, QObject *);
|
|
473 |
} else if (token_is_escape(token, "%i")) {
|
|
474 |
obj = QOBJECT(qbool_from_int(va_arg(*ap, int)));
|
|
475 |
} else if (token_is_escape(token, "%d")) {
|
|
476 |
obj = QOBJECT(qint_from_int(va_arg(*ap, int)));
|
|
477 |
} else if (token_is_escape(token, "%ld")) {
|
|
478 |
obj = QOBJECT(qint_from_int(va_arg(*ap, long)));
|
|
479 |
} else if (token_is_escape(token, "%lld")) {
|
|
480 |
obj = QOBJECT(qint_from_int(va_arg(*ap, long long)));
|
|
481 |
} else if (token_is_escape(token, "%s")) {
|
|
482 |
obj = QOBJECT(qstring_from_str(va_arg(*ap, const char *)));
|
|
483 |
} else if (token_is_escape(token, "%f")) {
|
|
484 |
obj = QOBJECT(qfloat_from_double(va_arg(*ap, double)));
|
|
485 |
} else {
|
|
486 |
goto out;
|
|
487 |
}
|
|
488 |
|
|
489 |
qobject_decref(token);
|
|
490 |
QDECREF(*tokens);
|
|
491 |
*tokens = working;
|
|
492 |
|
|
493 |
return obj;
|
|
494 |
|
|
495 |
out:
|
|
496 |
qobject_decref(token);
|
|
497 |
QDECREF(working);
|
|
498 |
|
|
499 |
return NULL;
|
|
500 |
}
|
|
501 |
|
|
502 |
static QObject *parse_literal(JSONParserContext *ctxt, QList **tokens)
|
|
503 |
{
|
|
504 |
QObject *token, *obj;
|
|
505 |
QList *working = qlist_copy(*tokens);
|
|
506 |
|
|
507 |
token = qlist_pop(working);
|
|
508 |
switch (token_get_type(token)) {
|
|
509 |
case JSON_STRING:
|
|
510 |
obj = QOBJECT(qstring_from_escaped_str(ctxt, token));
|
|
511 |
break;
|
|
512 |
case JSON_INTEGER:
|
|
513 |
obj = QOBJECT(qint_from_int(strtoll(token_get_value(token), NULL, 10)));
|
|
514 |
break;
|
|
515 |
case JSON_FLOAT:
|
|
516 |
/* FIXME dependent on locale */
|
|
517 |
obj = QOBJECT(qfloat_from_double(strtod(token_get_value(token), NULL)));
|
|
518 |
break;
|
|
519 |
default:
|
|
520 |
goto out;
|
|
521 |
}
|
|
522 |
|
|
523 |
qobject_decref(token);
|
|
524 |
QDECREF(*tokens);
|
|
525 |
*tokens = working;
|
|
526 |
|
|
527 |
return obj;
|
|
528 |
|
|
529 |
out:
|
|
530 |
qobject_decref(token);
|
|
531 |
QDECREF(working);
|
|
532 |
|
|
533 |
return NULL;
|
|
534 |
}
|
|
535 |
|
|
536 |
static QObject *parse_value(JSONParserContext *ctxt, QList **tokens, va_list *ap)
|
|
537 |
{
|
|
538 |
QObject *obj;
|
|
539 |
|
|
540 |
obj = parse_object(ctxt, tokens, ap);
|
|
541 |
if (obj == NULL) {
|
|
542 |
obj = parse_array(ctxt, tokens, ap);
|
|
543 |
}
|
|
544 |
if (obj == NULL) {
|
|
545 |
obj = parse_escape(ctxt, tokens, ap);
|
|
546 |
}
|
|
547 |
if (obj == NULL) {
|
|
548 |
obj = parse_keyword(ctxt, tokens);
|
|
549 |
}
|
|
550 |
if (obj == NULL) {
|
|
551 |
obj = parse_literal(ctxt, tokens);
|
|
552 |
}
|
|
553 |
|
|
554 |
return obj;
|
|
555 |
}
|
|
556 |
|
|
557 |
QObject *json_parser_parse(QList *tokens, va_list *ap)
|
|
558 |
{
|
|
559 |
JSONParserContext ctxt = {};
|
|
560 |
QList *working = qlist_copy(tokens);
|
|
561 |
QObject *result;
|
|
562 |
|
|
563 |
result = parse_value(&ctxt, &working, ap);
|
|
564 |
|
|
565 |
QDECREF(working);
|
|
566 |
|
|
567 |
return result;
|
|
568 |
}
|