rev 1199 : 8072595: nashorn should not use obj.getClass() for null checks
Reviewed-by: hannesw, attila
1 /*
2 * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.nashorn.internal.codegen;
27
28 import java.io.Serializable;
29 import java.util.Set;
30 import java.util.TreeSet;
31 import jdk.nashorn.internal.ir.CompileUnitHolder;
32
33 /**
34 * Used to track split class compilation. Note that instances of the class are serializable, but all fields are
35 * transient, making the serialized version of the class only useful for tracking the referential topology of other
36 * AST nodes referencing the same or different compile units. We do want to preserve this topology though as
37 * {@link CompileUnitHolder}s in a deserialized AST will undergo reinitialization.
38 */
39 public final class CompileUnit implements Comparable<CompileUnit>, Serializable {
40 private static final long serialVersionUID = 1L;
41
42 /** Current class name */
43 private transient final String className;
44
45 /** Current class generator */
46 private transient ClassEmitter classEmitter;
47
48 private transient long weight;
49
50 private transient Class<?> clazz;
51
52 private transient boolean isUsed;
53
54 private static int emittedUnitCount;
55
56 CompileUnit(final String className, final ClassEmitter classEmitter, final long initialWeight) {
57 this.className = className;
58 this.weight = initialWeight;
59 this.classEmitter = classEmitter;
60 }
61
62 static Set<CompileUnit> createCompileUnitSet() {
63 return new TreeSet<>();
64 }
65
66 static void increaseEmitCount() {
67 emittedUnitCount++;
68 }
69
70 /**
71 * Get the amount of emitted compile units so far in the system
72 * @return emitted compile unit count
73 */
74 public static int getEmittedUnitCount() {
75 return emittedUnitCount;
76 }
77
78 /**
79 * Check if this compile unit is used
80 * @return true if tagged as in use - i.e active code that needs to be generated
81 */
82 public boolean isUsed() {
83 return isUsed;
84 }
85
86 /**
87 * Check if a compile unit has code, not counting inits and clinits
88 * @return true of if there is "real code" in the compile unit
89 */
90 public boolean hasCode() {
91 return (classEmitter.getMethodCount() - classEmitter.getInitCount() - classEmitter.getClinitCount()) > 0;
92 }
93
94 /**
95 * Tag this compile unit as used
96 */
97 public void setUsed() {
98 this.isUsed = true;
99 }
100
101 /**
102 * Return the class that contains the code for this unit, null if not
103 * generated yet
104 *
105 * @return class with compile unit code
106 */
107 public Class<?> getCode() {
108 return clazz;
109 }
110
111 /**
112 * Set class when it exists. Only accessible from compiler
113 * @param clazz class with code for this compile unit
114 */
115 void setCode(final Class<?> clazz) {
116 clazz.getClass(); // null check
117 this.clazz = clazz;
118 // Revisit this - refactor to avoid null-ed out non-final fields
119 // null out emitter
120 this.classEmitter = null;
121 }
122
123 /**
124 * Add weight to this compile unit
125 * @param w weight to add
126 */
127 void addWeight(final long w) {
128 this.weight += w;
129 }
130
131 /**
132 * Check if this compile unit can hold {@code weight} more units of weight
133 * @param w weight to check if can be added
134 * @return true if weight fits in this compile unit
135 */
136 public boolean canHold(final long w) {
137 return (this.weight + w) < Splitter.SPLIT_THRESHOLD;
138 }
139
140 /**
141 * Get the class emitter for this compile unit
142 * @return class emitter
143 */
144 public ClassEmitter getClassEmitter() {
145 return classEmitter;
146 }
147
148 /**
149 * Get the class name for this compile unit
150 * @return the class name
151 */
152 public String getUnitClassName() {
153 return className;
154 }
155
156 private static String shortName(final String name) {
157 return name == null ? null : name.lastIndexOf('/') == -1 ? name : name.substring(name.lastIndexOf('/') + 1);
158 }
159
160 @Override
161 public String toString() {
162 final String methods = classEmitter != null ? classEmitter.getMethodNames().toString() : "<anon>";
163 return "[CompileUnit className=" + shortName(className) + " weight=" + weight + '/' + Splitter.SPLIT_THRESHOLD + " hasCode=" + methods + ']';
164 }
165
166 @Override
167 public int compareTo(final CompileUnit o) {
168 return className.compareTo(o.className);
169 }
170 }
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