1 |
779 |
jeremybenn |
/* gnu.classpath.tools.gjdoc.expr.Evaluator
|
2 |
|
|
Copyright (C) 2004 Free Software Foundation, Inc.
|
3 |
|
|
|
4 |
|
|
This file is part of GNU Classpath.
|
5 |
|
|
|
6 |
|
|
GNU Classpath is free software; you can redistribute it and/or modify
|
7 |
|
|
it under the terms of the GNU General Public License as published by
|
8 |
|
|
the Free Software Foundation; either version 2, or (at your option)
|
9 |
|
|
any later version.
|
10 |
|
|
|
11 |
|
|
GNU Classpath is distributed in the hope that it will be useful, but
|
12 |
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
13 |
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
14 |
|
|
General Public License for more details.
|
15 |
|
|
|
16 |
|
|
You should have received a copy of the GNU General Public License
|
17 |
|
|
along with GNU Classpath; see the file COPYING. If not, write to the
|
18 |
|
|
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
19 |
|
|
02111-1307 USA.
|
20 |
|
|
|
21 |
|
|
Linking this library statically or dynamically with other modules is
|
22 |
|
|
making a combined work based on this library. Thus, the terms and
|
23 |
|
|
conditions of the GNU General Public License cover the whole
|
24 |
|
|
combination.
|
25 |
|
|
|
26 |
|
|
As a special exception, the copyright holders of this library give you
|
27 |
|
|
permission to link this library with independent modules to produce an
|
28 |
|
|
executable, regardless of the license terms of these independent
|
29 |
|
|
modules, and to copy and distribute the resulting executable under
|
30 |
|
|
terms of your choice, provided that you also meet, for each linked
|
31 |
|
|
independent module, the terms and conditions of the license of that
|
32 |
|
|
module. An independent module is a module which is not derived from
|
33 |
|
|
or based on this library. If you modify this library, you may extend
|
34 |
|
|
this exception to your version of the library, but you are not
|
35 |
|
|
obligated to do so. If you do not wish to do so, delete this
|
36 |
|
|
exception statement from your version. */
|
37 |
|
|
|
38 |
|
|
package gnu.classpath.tools.gjdoc.expr;
|
39 |
|
|
|
40 |
|
|
import java.io.StringReader;
|
41 |
|
|
import java.math.BigInteger;
|
42 |
|
|
import antlr.RecognitionException;
|
43 |
|
|
import antlr.TokenStreamException;
|
44 |
|
|
import java.util.Set;
|
45 |
|
|
|
46 |
|
|
public class Evaluator
|
47 |
|
|
{
|
48 |
|
|
/**
|
49 |
|
|
* Try to evaluate the given Java expression in the context of the
|
50 |
|
|
* given environment.
|
51 |
|
|
*
|
52 |
|
|
* @param expression the Java expression to evaluate. The
|
53 |
|
|
* expression string must not include a terminating semicolon.
|
54 |
|
|
*
|
55 |
|
|
* @param source the FieldDoc (part of) whose constant field value
|
56 |
|
|
* expression is being evaluated. Used to prevent circular
|
57 |
|
|
* references.
|
58 |
|
|
*
|
59 |
|
|
* @param environment callback hook used by the Evaluator to query
|
60 |
|
|
* the value of static fields referenced in the expression.
|
61 |
|
|
*
|
62 |
|
|
* @return a Java object representing the value of the expression,
|
63 |
|
|
* or <code>null</code> if the expression evaluates to
|
64 |
|
|
* <code>null</code>.
|
65 |
|
|
*
|
66 |
|
|
* @throws IllegalExpressionException if the expression is
|
67 |
|
|
* invalid, uses unsupported syntax constructs (e.g. method calls,
|
68 |
|
|
* array access) or references unknown static fields.
|
69 |
|
|
*/
|
70 |
|
|
public static Object evaluate(String expression,
|
71 |
|
|
Set visitedFields,
|
72 |
|
|
EvaluatorEnvironment environment)
|
73 |
|
|
throws IllegalExpressionException
|
74 |
|
|
{
|
75 |
|
|
try {
|
76 |
|
|
JavaLexer lexer = new JavaLexer(new StringReader(expression));
|
77 |
|
|
JavaRecognizer recognizer = new JavaRecognizer(lexer);
|
78 |
|
|
Expression e = recognizer.expression();
|
79 |
|
|
ConstantExpression value = e.evaluate(new Context(environment, visitedFields));
|
80 |
|
|
return value.asObject();
|
81 |
|
|
}
|
82 |
|
|
catch (RecognitionException e) {
|
83 |
|
|
throw new IllegalExpressionException(e);
|
84 |
|
|
}
|
85 |
|
|
catch (TokenStreamException e) {
|
86 |
|
|
throw new IllegalExpressionException(e);
|
87 |
|
|
}
|
88 |
|
|
}
|
89 |
|
|
|
90 |
|
|
static int parseInt(String stringValue)
|
91 |
|
|
{
|
92 |
|
|
int base = 10;
|
93 |
|
|
|
94 |
|
|
if (stringValue.startsWith("0x")) {
|
95 |
|
|
base = 16;
|
96 |
|
|
stringValue = stringValue.substring(2);
|
97 |
|
|
}
|
98 |
|
|
else if (stringValue.length() > 1 && stringValue.startsWith("0")) {
|
99 |
|
|
base = 8;
|
100 |
|
|
stringValue = stringValue.substring(1);
|
101 |
|
|
}
|
102 |
|
|
while (stringValue.length() > 1 && stringValue.startsWith("0")) {
|
103 |
|
|
stringValue = stringValue.substring(1);
|
104 |
|
|
}
|
105 |
|
|
|
106 |
|
|
if (10 == base) {
|
107 |
|
|
return Integer.parseInt(stringValue);
|
108 |
|
|
}
|
109 |
|
|
else {
|
110 |
|
|
long result = Long.parseLong(stringValue, base);
|
111 |
|
|
|
112 |
|
|
if (result > Integer.MAX_VALUE) {
|
113 |
|
|
result -= 0x100000000L;
|
114 |
|
|
}
|
115 |
|
|
|
116 |
|
|
if (result > Integer.MAX_VALUE) {
|
117 |
|
|
throw new NumberFormatException(result + " > " + Integer.MAX_VALUE);
|
118 |
|
|
}
|
119 |
|
|
else if (result < Integer.MIN_VALUE) {
|
120 |
|
|
throw new NumberFormatException(result + " < " + Integer.MIN_VALUE);
|
121 |
|
|
}
|
122 |
|
|
else {
|
123 |
|
|
return (int)result;
|
124 |
|
|
}
|
125 |
|
|
}
|
126 |
|
|
}
|
127 |
|
|
|
128 |
|
|
static long parseLong(String stringValue)
|
129 |
|
|
{
|
130 |
|
|
int base = 10;
|
131 |
|
|
|
132 |
|
|
if (stringValue.startsWith("0x")) {
|
133 |
|
|
base = 16;
|
134 |
|
|
stringValue = stringValue.substring(2);
|
135 |
|
|
}
|
136 |
|
|
else if (stringValue.length() > 1 && stringValue.startsWith("0")) {
|
137 |
|
|
base = 8;
|
138 |
|
|
stringValue = stringValue.substring(1);
|
139 |
|
|
}
|
140 |
|
|
while (stringValue.length() > 1 && stringValue.startsWith("0")) {
|
141 |
|
|
stringValue = stringValue.substring(1);
|
142 |
|
|
}
|
143 |
|
|
|
144 |
|
|
BigInteger bigInt = new BigInteger(stringValue, base);
|
145 |
|
|
long result = bigInt.longValue();
|
146 |
|
|
return result;
|
147 |
|
|
}
|
148 |
|
|
}
|