Target.java revision 3231:50467a1cf5b1 
1/*
2 * Copyright (c) 2002, 2014, 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
26package com.sun.tools.javac.jvm;
27
28import java.util.*;
29
30import com.sun.tools.javac.code.Flags;
31import com.sun.tools.javac.code.Symbol;
32import com.sun.tools.javac.util.*;
33
34import static com.sun.tools.javac.main.Option.TARGET;
35
36/** The classfile version target.
37 *
38 *  <p><b>This is NOT part of any supported API.
39 *  If you write code that depends on this, you do so at your own risk.
40 *  This code and its internal interfaces are subject to change or
41 *  deletion without notice.</b>
42 */
43public enum Target {
44    JDK1_1("1.1", 45, 3),
45    JDK1_2("1.2", 46, 0),
46    JDK1_3("1.3", 47, 0),
47
48    /** J2SE1.4 = Merlin. */
49    JDK1_4("1.4", 48, 0),
50
51    /** JDK 5, codename Tiger. */
52    JDK1_5("1.5", 49, 0),
53
54    /** JDK 6. */
55    JDK1_6("1.6", 50, 0),
56
57    /** JDK 7. */
58    JDK1_7("1.7", 51, 0),
59
60    /** JDK 8. */
61    JDK1_8("1.8", 52, 0),
62
63    /** JDK 9, initially an alias for 8. */
64    JDK1_9("1.9", 52, 0);
65
66    private static final Context.Key<Target> targetKey = new Context.Key<>();
67
68    public static Target instance(Context context) {
69        Target instance = context.get(targetKey);
70        if (instance == null) {
71            Options options = Options.instance(context);
72            String targetString = options.get(TARGET);
73            if (targetString != null) instance = lookup(targetString);
74            if (instance == null) instance = DEFAULT;
75            context.put(targetKey, instance);
76        }
77        return instance;
78    }
79
80    public static final Target MIN = Target.JDK1_6;
81
82    private static final Target MAX = values()[values().length - 1];
83
84    private static final Map<String,Target> tab = new HashMap<>();
85    static {
86        for (Target t : values()) {
87            tab.put(t.name, t);
88        }
89        tab.put("5", JDK1_5);
90        tab.put("6", JDK1_6);
91        tab.put("7", JDK1_7);
92        tab.put("8", JDK1_8);
93        tab.put("9", JDK1_9);
94    }
95
96    public final String name;
97    public final int majorVersion;
98    public final int minorVersion;
99    private Target(String name, int majorVersion, int minorVersion) {
100        this.name = name;
101        this.majorVersion = majorVersion;
102        this.minorVersion = minorVersion;
103    }
104
105    public static final Target DEFAULT = JDK1_9;
106
107    public static Target lookup(String name) {
108        return tab.get(name);
109    }
110
111    /** Return the character to be used in constructing synthetic
112     *  identifiers, where not specified by the JLS.
113     */
114    public char syntheticNameChar() {
115        return '$';
116    }
117
118    /** Does the VM support an invokedynamic instruction?
119     */
120    public boolean hasInvokedynamic() {
121        return compareTo(JDK1_7) >= 0;
122    }
123
124    /** Does the target JDK contains the java.util.Objects class?
125     */
126    public boolean hasObjects() {
127        return compareTo(JDK1_7) >= 0;
128    }
129
130    /** Does the VM support polymorphic method handle invocation?
131     *  Affects the linkage information output to the classfile.
132     *  An alias for {@code hasInvokedynamic}, since all the JSR 292 features appear together.
133     */
134    public boolean hasMethodHandles() {
135        return hasInvokedynamic();
136    }
137
138    /** Does the target JDK contain StringConcatFactory class?
139     */
140    public boolean hasStringConcatFactory() {
141        return compareTo(JDK1_9) >= 0;
142    }
143
144}
145