1 : /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
2 : * vim: set ts=8 sw=4 et tw=99:
3 : *
4 : * ***** BEGIN LICENSE BLOCK *****
5 : * Version: MPL 1.1/GPL 2.0/LGPL 2.1
6 : *
7 : * The contents of this file are subject to the Mozilla Public License Version
8 : * 1.1 (the "License"); you may not use this file except in compliance with
9 : * the License. You may obtain a copy of the License at
10 : * http://www.mozilla.org/MPL/
11 : *
12 : * Software distributed under the License is distributed on an "AS IS" basis,
13 : * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
14 : * for the specific language governing rights and limitations under the
15 : * License.
16 : *
17 : * The Original Code is SpiderMonkey JSON.
18 : *
19 : * The Initial Developer of the Original Code is
20 : * the Mozilla Foundation.
21 : * Portions created by the Initial Developer are Copyright (C) 2011
22 : * the Initial Developer. All Rights Reserved.
23 : *
24 : * Contributor(s):
25 : * Jeff Walden <jwalden+code@mit.edu> (original author)
26 : *
27 : * Alternatively, the contents of this file may be used under the terms of
28 : * either of the GNU General Public License Version 2 or later (the "GPL"),
29 : * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
30 : * in which case the provisions of the GPL or the LGPL are applicable instead
31 : * of those above. If you wish to allow use of your version of this file only
32 : * under the terms of either the GPL or the LGPL, and not to allow others to
33 : * use your version of this file under the terms of the MPL, indicate your
34 : * decision by deleting the provisions above and replace them with the notice
35 : * and other provisions required by the GPL or the LGPL. If you do not delete
36 : * the provisions above, a recipient may use your version of this file under
37 : * the terms of any one of the MPL, the GPL or the LGPL.
38 : *
39 : * ***** END LICENSE BLOCK ***** */
40 :
41 : #ifndef jsonparser_h___
42 : #define jsonparser_h___
43 :
44 : #include "mozilla/Attributes.h"
45 : #include "mozilla/RangedPtr.h"
46 :
47 : #include "jscntxt.h"
48 : #include "jsstr.h"
49 :
50 : /*
51 : * NB: This class must only be used on the stack as it contains a js::Value.
52 : */
53 : class JSONParser
54 : {
55 : JSONParser(const JSONParser &other) MOZ_DELETE;
56 : void operator=(const JSONParser &other) MOZ_DELETE;
57 :
58 : public:
59 : enum ErrorHandling { RaiseError, NoError };
60 : enum ParsingMode { StrictJSON, LegacyJSON };
61 :
62 : private:
63 : /* Data members */
64 :
65 : JSContext * const cx;
66 : mozilla::RangedPtr<const jschar> current;
67 : const mozilla::RangedPtr<const jschar> end;
68 :
69 : js::Value v;
70 :
71 : const ParsingMode parsingMode;
72 : const ErrorHandling errorHandling;
73 :
74 : enum Token { String, Number, True, False, Null,
75 : ArrayOpen, ArrayClose,
76 : ObjectOpen, ObjectClose,
77 : Colon, Comma,
78 : OOM, Error };
79 : #ifdef DEBUG
80 : Token lastToken;
81 : #endif
82 :
83 : public:
84 : /* Public API */
85 :
86 : /*
87 : * Create a parser for the provided JSON data. The parser will accept
88 : * certain legacy, non-JSON syntax if decodingMode is LegacyJSON.
89 : * Description of this syntax is deliberately omitted: new code should only
90 : * use strict JSON parsing.
91 : */
92 13506 : JSONParser(JSContext *cx, const jschar *data, size_t length,
93 : ParsingMode parsingMode = StrictJSON,
94 : ErrorHandling errorHandling = RaiseError)
95 : : cx(cx),
96 : current(data, length),
97 : end(data + length, data, length),
98 : parsingMode(parsingMode),
99 : errorHandling(errorHandling)
100 : #ifdef DEBUG
101 13506 : , lastToken(Error)
102 : #endif
103 : {
104 13506 : JS_ASSERT(current <= end);
105 13506 : }
106 :
107 : /*
108 : * Parse the JSON data specified at construction time. If it parses
109 : * successfully, store the prescribed value in *vp and return true. If an
110 : * internal error (e.g. OOM) occurs during parsing, return false.
111 : * Otherwise, if invalid input was specifed but no internal error occurred,
112 : * behavior depends upon the error handling specified at construction: if
113 : * error handling is RaiseError then throw a SyntaxError and return false,
114 : * otherwise return true and set *vp to |undefined|. (JSON syntax can't
115 : * represent |undefined|, so the JSON data couldn't have specified it.)
116 : */
117 : bool parse(js::Value *vp);
118 :
119 : private:
120 63617 : js::Value numberValue() const {
121 63617 : JS_ASSERT(lastToken == Number);
122 63617 : JS_ASSERT(v.isNumber());
123 63617 : return v;
124 : }
125 :
126 350880 : js::Value stringValue() const {
127 350880 : JS_ASSERT(lastToken == String);
128 350880 : JS_ASSERT(v.isString());
129 350880 : return v;
130 : }
131 :
132 211445 : js::Value atomValue() const {
133 211445 : js::Value strval = stringValue();
134 211445 : JS_ASSERT(strval.toString()->isAtom());
135 : return strval;
136 : }
137 :
138 540335 : Token token(Token t) {
139 540335 : JS_ASSERT(t != String);
140 540335 : JS_ASSERT(t != Number);
141 : #ifdef DEBUG
142 540335 : lastToken = t;
143 : #endif
144 540335 : return t;
145 : }
146 :
147 350880 : Token stringToken(JSString *str) {
148 350880 : this->v = js::StringValue(str);
149 : #ifdef DEBUG
150 350880 : lastToken = String;
151 : #endif
152 350880 : return String;
153 : }
154 :
155 63617 : Token numberToken(double d) {
156 63617 : this->v = js::NumberValue(d);
157 : #ifdef DEBUG
158 63617 : lastToken = Number;
159 : #endif
160 63617 : return Number;
161 : }
162 :
163 : enum StringType { PropertyName, LiteralValue };
164 : template<StringType ST> Token readString();
165 :
166 : Token readNumber();
167 :
168 : Token advance();
169 : Token advancePropertyName();
170 : Token advancePropertyColon();
171 : Token advanceAfterProperty();
172 : Token advanceAfterObjectOpen();
173 : Token advanceAfterArrayElement();
174 :
175 : void error(const char *msg);
176 : bool errorReturn();
177 : };
178 :
179 : #endif /* jsonparser_h___ */
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