001: /*
002: * Copyright 2002-2006 Sun Microsystems, Inc. All Rights Reserved.
003: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004: *
005: * This code is free software; you can redistribute it and/or modify it
006: * under the terms of the GNU General Public License version 2 only, as
007: * published by the Free Software Foundation. Sun designates this
008: * particular file as subject to the "Classpath" exception as provided
009: * by Sun in the LICENSE file that accompanied this code.
010: *
011: * This code is distributed in the hope that it will be useful, but WITHOUT
012: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
014: * version 2 for more details (a copy is included in the LICENSE file that
015: * accompanied this code).
016: *
017: * You should have received a copy of the GNU General Public License version
018: * 2 along with this work; if not, write to the Free Software Foundation,
019: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020: *
021: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022: * CA 95054 USA or visit www.sun.com if you need additional information or
023: * have any questions.
024: */
025:
026: package com.sun.tools.javac.jvm;
027:
028: import java.util.*;
029:
030: import com.sun.tools.javac.code.Flags;
031: import com.sun.tools.javac.code.Symbol;
032: import com.sun.tools.javac.util.*;
033:
034: /** The classfile version target.
035: *
036: * <p><b>This is NOT part of any API supported by Sun Microsystems. If
037: * you write code that depends on this, you do so at your own risk.
038: * This code and its internal interfaces are subject to change or
039: * deletion without notice.</b>
040: */
041: @Version("@(#)Target.java 1.50 07/05/05")
042: public enum Target {
043: JDK1_1("1.1", 45, 3), JDK1_2("1.2", 46, 0), JDK1_3("1.3", 47, 0),
044:
045: /** J2SE1.4 = Merlin. */
046: JDK1_4("1.4", 48, 0),
047:
048: /** Support for the JSR14 prototype compiler (targeting 1.4 VMs
049: * augmented with a few support classes). This is a transitional
050: * option that will not be supported in the product. */
051: JSR14("jsr14", 48, 0),
052:
053: /** The following are undocumented transitional targets that we
054: * had used to test VM fixes in update releases. We do not
055: * promise to retain support for them. */
056: JDK1_4_1("1.4.1", 48, 0), JDK1_4_2("1.4.2", 48, 0),
057:
058: /** Tiger. */
059: JDK1_5("1.5", 49, 0),
060:
061: /** JDK 6. */
062: JDK1_6("1.6", 50, 0),
063:
064: /** JDK 7. */
065: JDK1_7("1.7", 51, 0);
066:
067: private static final Context.Key<Target> targetKey = new Context.Key<Target>();
068:
069: public static Target instance(Context context) {
070: Target instance = context.get(targetKey);
071: if (instance == null) {
072: Options options = Options.instance(context);
073: String targetString = options.get("-target");
074: if (targetString != null)
075: instance = lookup(targetString);
076: if (instance == null)
077: instance = DEFAULT;
078: context.put(targetKey, instance);
079: }
080: return instance;
081: }
082:
083: private static Target MIN;
084:
085: public static Target MIN() {
086: return MIN;
087: }
088:
089: private static Target MAX;
090:
091: public static Target MAX() {
092: return MAX;
093: }
094:
095: private static Map<String, Target> tab = new HashMap<String, Target>();
096: static {
097: for (Target t : values()) {
098: if (MIN == null)
099: MIN = t;
100: MAX = t;
101: tab.put(t.name, t);
102: }
103: tab.put("5", JDK1_5);
104: tab.put("6", JDK1_6);
105: tab.put("7", JDK1_7);
106: }
107:
108: public final String name;
109: public final int majorVersion;
110: public final int minorVersion;
111:
112: private Target(String name, int majorVersion, int minorVersion) {
113: this .name = name;
114: this .majorVersion = majorVersion;
115: this .minorVersion = minorVersion;
116: }
117:
118: public static final Target DEFAULT = JDK1_6;
119:
120: public static Target lookup(String name) {
121: return tab.get(name);
122: }
123:
124: /** In -target 1.1 and earlier, the compiler is required to emit
125: * synthetic method definitions in abstract classes for interface
126: * methods that are not overridden. We call them "Miranda" methods.
127: */
128: public boolean requiresIproxy() {
129: return compareTo(JDK1_1) <= 0;
130: }
131:
132: /** Beginning in 1.4, we take advantage of the possibility of emitting
133: * code to initialize fields before calling the superclass constructor.
134: * This is allowed by the VM spec, but the verifier refused to allow
135: * it until 1.4. This is necesary to translate some code involving
136: * inner classes. See, for example, 4030374.
137: */
138: public boolean initializeFieldsBeforeSuper() {
139: return compareTo(JDK1_4) >= 0;
140: }
141:
142: /** Beginning with -target 1.2 we obey the JLS rules for binary
143: * compatibility, emitting as the qualifying type of a reference
144: * to a method or field the type of the qualifier. In earlier
145: * targets we use as the qualifying type the class in which the
146: * member was found. The following methods named
147: * *binaryCompatibility() indicate places where we vary from this
148: * general rule. */
149: public boolean obeyBinaryCompatibility() {
150: return compareTo(JDK1_2) >= 0;
151: }
152:
153: /** Starting in 1.5, the compiler uses an array type as
154: * the qualifier for method calls (such as clone) where required by
155: * the language and VM spec. Earlier versions of the compiler
156: * qualified them by Object.
157: */
158: public boolean arrayBinaryCompatibility() {
159: return compareTo(JDK1_5) >= 0;
160: }
161:
162: /** Beginning after 1.2, we follow the binary compatibility rules for
163: * interface fields. The 1.2 VMs had bugs handling interface fields
164: * when compiled using binary compatibility (see 4400598), so this is
165: * an accommodation to them.
166: */
167: public boolean interfaceFieldsBinaryCompatibility() {
168: return compareTo(JDK1_2) > 0;
169: }
170:
171: /** Beginning in -target 1.5, we follow the binary compatibility
172: * rules for interface methods that redefine Object methods.
173: * Earlier VMs had bugs handling such methods compiled using binary
174: * compatibility (see 4392595, 4398791, 4392595, 4400415).
175: * The VMs were fixed during or soon after 1.4. See 4392595.
176: */
177: public boolean interfaceObjectOverridesBinaryCompatibility() {
178: return compareTo(JDK1_5) >= 0;
179: }
180:
181: /** Beginning in -target 1.4.2, we make synthetic variables
182: * package-private instead of private. This is to prevent the
183: * necessity of access methods, which effectively relax the
184: * protection of the field but bloat the class files and affect
185: * execution.
186: */
187: public boolean usePrivateSyntheticFields() {
188: return compareTo(JDK1_4_2) < 0;
189: }
190:
191: /** Sometimes we need to create a field to cache a value like a
192: * class literal of the assertions flag. In -target 1.4.2 and
193: * later we create a new synthetic class for this instead of
194: * using the outermost class. See 4401576.
195: */
196: public boolean useInnerCacheClass() {
197: return compareTo(JDK1_4_2) >= 0;
198: }
199:
200: /** Return true if cldc-style stack maps need to be generated. */
201: public boolean generateCLDCStackmap() {
202: return false;
203: }
204:
205: /** Beginning in -target 6, we generate stackmap attribute in
206: * compact format. */
207: public boolean generateStackMapTable() {
208: return compareTo(JDK1_6) >= 0;
209: }
210:
211: /** Do we generate "empty" stackmap slots after double and long?
212: */
213: public boolean generateEmptyAfterBig() {
214: return false;
215: }
216:
217: /** Beginning in 1.5, we have an unsynchronized version of
218: * StringBuffer called StringBuilder that can be used by the
219: * compiler for string concatenation.
220: */
221: public boolean useStringBuilder() {
222: return compareTo(JDK1_5) >= 0;
223: }
224:
225: /** Beginning in 1.5, we have flag bits we can use instead of
226: * marker attributes.
227: */
228: public boolean useSyntheticFlag() {
229: return compareTo(JDK1_5) >= 0;
230: }
231:
232: public boolean useEnumFlag() {
233: return compareTo(JDK1_5) >= 0;
234: }
235:
236: public boolean useAnnotationFlag() {
237: return compareTo(JDK1_5) >= 0;
238: }
239:
240: public boolean useVarargsFlag() {
241: return compareTo(JDK1_5) >= 0;
242: }
243:
244: public boolean useBridgeFlag() {
245: return compareTo(JDK1_5) >= 0;
246: }
247:
248: /** Return the character to be used in constructing synthetic
249: * identifiers, where not specified by the JLS.
250: */
251: public char syntheticNameChar() {
252: return '$';
253: }
254:
255: /** Does the VM have direct support for class literals?
256: */
257: public boolean hasClassLiterals() {
258: return compareTo(JDK1_5) >= 0;
259: }
260:
261: /** Although we may not have support for class literals, should we
262: * avoid initializing the class that the literal refers to?
263: * See 4468823
264: */
265: public boolean classLiteralsNoInit() {
266: return compareTo(JDK1_4_2) >= 0;
267: }
268:
269: /** Although we may not have support for class literals, when we
270: * throw a NoClassDefFoundError, should we initialize its cause?
271: */
272: public boolean hasInitCause() {
273: return compareTo(JDK1_4) >= 0;
274: }
275:
276: /** For bootstrapping, we use J2SE1.4's wrapper class constructors
277: * to implement boxing.
278: */
279: public boolean boxWithConstructors() {
280: return compareTo(JDK1_5) < 0;
281: }
282:
283: /** For bootstrapping, we use J2SE1.4's java.util.Collection
284: * instead of java.lang.Iterable.
285: */
286: public boolean hasIterable() {
287: return compareTo(JDK1_5) >= 0;
288: }
289:
290: /** For bootstrapping javac only, we do without java.lang.Enum if
291: * necessary.
292: */
293: public boolean compilerBootstrap(Symbol c) {
294: return this == JSR14 && (c.flags() & Flags.ENUM) != 0
295: && c.flatName().toString().startsWith("com.sun.tools.")
296: // && !Target.class.getSuperclass().getName().equals("java.lang.Enum")
297: ;
298: }
299:
300: /** In J2SE1.5.0, we introduced the "EnclosingMethod" attribute
301: * for improved reflection support.
302: */
303: public boolean hasEnclosingMethodAttribute() {
304: return compareTo(JDK1_5) >= 0 || this == JSR14;
305: }
306: }
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