Mercurial > jdk8-mips64-public > langtools / file revision

 /*

  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  */

 package com.sun.tools.javac.jvm;

 import java.util.*;

 import com.sun.tools.javac.code.Flags;

 import com.sun.tools.javac.code.Symbol;

 import com.sun.tools.javac.util.*;

 import static com.sun.tools.javac.main.OptionName.*;

 /** The classfile version target.

  *

  *  <p><b>This is NOT part of any supported API.

  *  If you write code that depends on this, you do so at your own risk.

  *  This code and its internal interfaces are subject to change or

  *  deletion without notice.</b>

  */

 public enum Target {

     JDK1_1("1.1", 45, 3),

     JDK1_2("1.2", 46, 0),

     JDK1_3("1.3", 47, 0),

     /** J2SE1.4 = Merlin. */

     JDK1_4("1.4", 48, 0),

     /** Support for the JSR14 prototype compiler (targeting 1.4 VMs

      *  augmented with a few support classes).  This is a transitional

      *  option that will not be supported in the product.  */

     JSR14("jsr14", 48, 0),

     /** The following are undocumented transitional targets that we

      *  had used to test VM fixes in update releases.  We do not

      *  promise to retain support for them.  */

     JDK1_4_1("1.4.1", 48, 0),

     JDK1_4_2("1.4.2", 48, 0),

     /** Tiger. */

     JDK1_5("1.5", 49, 0),

     /** JDK 6. */

     JDK1_6("1.6", 50, 0),

     /** JDK 7. */

     JDK1_7("1.7", 51, 0);

     private static final Context.Key<Target> targetKey =

         new Context.Key<Target>();

     public static Target instance(Context context) {

         Target instance = context.get(targetKey);

         if (instance == null) {

             Options options = Options.instance(context);

             String targetString = options.get(TARGET);

             if (targetString != null) instance = lookup(targetString);

             if (instance == null) instance = DEFAULT;

             context.put(targetKey, instance);

         }

         return instance;

     }

     private static Target MIN;

     public static Target MIN() { return MIN; }

     private static Target MAX;

     public static Target MAX() { return MAX; }

     private static Map<String,Target> tab = new HashMap<String,Target>();

     static {

         for (Target t : values()) {

             if (MIN == null) MIN = t;

             MAX = t;

             tab.put(t.name, t);

         }

         tab.put("5", JDK1_5);

         tab.put("6", JDK1_6);

         tab.put("7", JDK1_7);

     }

     public final String name;

     public final int majorVersion;

     public final int minorVersion;

     private Target(String name, int majorVersion, int minorVersion) {

         this.name = name;

         this.majorVersion = majorVersion;

         this.minorVersion = minorVersion;

     }

     public static final Target DEFAULT = JDK1_7;

     public static Target lookup(String name) {

         return tab.get(name);

     }

     /** In -target 1.1 and earlier, the compiler is required to emit

      *  synthetic method definitions in abstract classes for interface

      *  methods that are not overridden.  We call them "Miranda" methods.

      */

     public boolean requiresIproxy() {

         return compareTo(JDK1_1) <= 0;

     }

     /** Beginning in 1.4, we take advantage of the possibility of emitting

      *  code to initialize fields before calling the superclass constructor.

      *  This is allowed by the VM spec, but the verifier refused to allow

      *  it until 1.4.  This is necesary to translate some code involving

      *  inner classes.  See, for example, 4030374.

      */

     public boolean initializeFieldsBeforeSuper() {

         return compareTo(JDK1_4) >= 0;

     }

     /** Beginning with -target 1.2 we obey the JLS rules for binary

      *  compatibility, emitting as the qualifying type of a reference

      *  to a method or field the type of the qualifier.  In earlier

      *  targets we use as the qualifying type the class in which the

      *  member was found.  The following methods named

      *  *binaryCompatibility() indicate places where we vary from this

      *  general rule. */

     public boolean obeyBinaryCompatibility() {

         return compareTo(JDK1_2) >= 0;

     }

     /** Starting in 1.5, the compiler uses an array type as

      *  the qualifier for method calls (such as clone) where required by

      *  the language and VM spec.  Earlier versions of the compiler

      *  qualified them by Object.

      */

     public boolean arrayBinaryCompatibility() {

         return compareTo(JDK1_5) >= 0;

     }

     /** Beginning after 1.2, we follow the binary compatibility rules for

      *  interface fields.  The 1.2 VMs had bugs handling interface fields

      *  when compiled using binary compatibility (see 4400598), so this is

      *  an accommodation to them.

      */

     public boolean interfaceFieldsBinaryCompatibility() {

         return compareTo(JDK1_2) > 0;

     }

     /** Beginning in -target 1.5, we follow the binary compatibility

      *  rules for interface methods that redefine Object methods.

      *  Earlier VMs had bugs handling such methods compiled using binary

      *  compatibility (see 4392595, 4398791, 4392595, 4400415).

      *  The VMs were fixed during or soon after 1.4.  See 4392595.

      */

     public boolean interfaceObjectOverridesBinaryCompatibility() {

         return compareTo(JDK1_5) >= 0;

     }

     /** Beginning in -target 1.4.2, we make synthetic variables

      *  package-private instead of private.  This is to prevent the

      *  necessity of access methods, which effectively relax the

      *  protection of the field but bloat the class files and affect

      *  execution.

      */

     public boolean usePrivateSyntheticFields() {

         return compareTo(JDK1_4_2) < 0;

     }

     /** Sometimes we need to create a field to cache a value like a

      *  class literal of the assertions flag.  In -target 1.4.2 and

      *  later we create a new synthetic class for this instead of

      *  using the outermost class.  See 4401576.

      */

     public boolean useInnerCacheClass() {

         return compareTo(JDK1_4_2) >= 0;

     }

     /** Return true if cldc-style stack maps need to be generated. */

     public boolean generateCLDCStackmap() {

         return false;

     }

     /** Beginning in -target 6, we generate stackmap attribute in

      *  compact format. */

     public boolean generateStackMapTable() {

         return compareTo(JDK1_6) >= 0;

     }

     /** Beginning in -target 6, package-info classes are marked synthetic.

      */

     public boolean isPackageInfoSynthetic() {

         return compareTo(JDK1_6) >= 0;

     }

     /** Do we generate "empty" stackmap slots after double and long?

      */

     public boolean generateEmptyAfterBig() {

         return false;

     }

     /** Beginning in 1.5, we have an unsynchronized version of

      *  StringBuffer called StringBuilder that can be used by the

      *  compiler for string concatenation.

      */

     public boolean useStringBuilder() {

         return compareTo(JDK1_5) >= 0;

     }

     /** Beginning in 1.5, we have flag bits we can use instead of

      *  marker attributes.

      */

     public boolean useSyntheticFlag() {

         return compareTo(JDK1_5) >= 0;

     }

     public boolean useEnumFlag() {

         return compareTo(JDK1_5) >= 0;

     }

     public boolean useAnnotationFlag() {

         return compareTo(JDK1_5) >= 0;

     }

     public boolean useVarargsFlag() {

         return compareTo(JDK1_5) >= 0;

     }

     public boolean useBridgeFlag() {

         return compareTo(JDK1_5) >= 0;

     }

     /** Return the character to be used in constructing synthetic

      *  identifiers, where not specified by the JLS.

      */

     public char syntheticNameChar() {

         return '$';

     }

     /** Does the VM have direct support for class literals?

      */

     public boolean hasClassLiterals() {

         return compareTo(JDK1_5) >= 0;

     }

     /** Does the VM support an invokedynamic instruction?

      */

     public boolean hasInvokedynamic() {

         return compareTo(JDK1_7) >= 0;

     }

     /** Does the VM support polymorphic method handle invocation?

      *  Affects the linkage information output to the classfile.

      *  An alias for {@code hasInvokedynamic}, since all the JSR 292 features appear together.

      */

     public boolean hasMethodHandles() {

         return hasInvokedynamic();

     }

     /** Although we may not have support for class literals, should we

      *  avoid initializing the class that the literal refers to?

      *  See 4468823

      */

     public boolean classLiteralsNoInit() {

         return compareTo(JDK1_4_2) >= 0;

     }

     /** Although we may not have support for class literals, when we

      *  throw a NoClassDefFoundError, should we initialize its cause?

      */

     public boolean hasInitCause() {

         return compareTo(JDK1_4) >= 0;

     }

     /** For bootstrapping, we use J2SE1.4's wrapper class constructors

      *  to implement boxing.

      */

     public boolean boxWithConstructors() {

         return compareTo(JDK1_5) < 0;

     }

     /** For bootstrapping, we use J2SE1.4's java.util.Collection

      *  instead of java.lang.Iterable.

      */

     public boolean hasIterable() {

         return compareTo(JDK1_5) >= 0;

     }

     /** For bootstrapping javac only, we do without java.lang.Enum if

      *  necessary.

      */

     public boolean compilerBootstrap(Symbol c) {

         return

             this == JSR14 &&

             (c.flags() & Flags.ENUM) != 0 &&

             c.flatName().toString().startsWith("com.sun.tools.")

             // && !Target.class.getSuperclass().getName().equals("java.lang.Enum")

             ;

     }

     /** In J2SE1.5.0, we introduced the "EnclosingMethod" attribute

      *  for improved reflection support.

      */

     public boolean hasEnclosingMethodAttribute() {

         return compareTo(JDK1_5) >= 0 || this == JSR14;

     }

 }