/*

 * Copyright (c) 2002, 2017, 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

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 */

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.Option.TARGET;

/** 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),

    /** JDK 5, codename Tiger. */

    JDK1_5("1.5", 49, 0),

    /** JDK 6. */

    JDK1_6("1.6", 50, 0),

    /** JDK 7. */

    JDK1_7("1.7", 51, 0),

    /** JDK 8. */

    JDK1_8("1.8", 52, 0),

    /** JDK 9. */

    JDK1_9("1.9", 53, 0),

    private static final Context.Key<Target> targetKey = new Context.Key<>();

    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;

    }

    public static final Target MIN = Target.JDK1_6;

    private static final Target MAX = values()[values().length - 1];

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

    static {

        for (Target t : values()) {

            tab.put(t.name, t);

        }

        tab.put("5", JDK1_5);

        tab.put("6", JDK1_6);

        tab.put("7", JDK1_7);

        tab.put("8", JDK1_8);

        tab.put("9", JDK1_9);

        tab.put("10", JDK1_10);

    }

    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 = values()[values().length - 1];

    public static Target lookup(String name) {

        return tab.get(name);

    }

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

     *  identifiers, where not specified by the JLS.

     */

    public char syntheticNameChar() {

        return '$';

    }

    /** Does the VM support an invokedynamic instruction?

     */

    public boolean hasInvokedynamic() {

        return compareTo(JDK1_7) >= 0;

    }

    /** Does the target JDK contains the java.util.Objects class?

     */

    public boolean hasObjects() {

        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();

    }

    /** Does the target JDK contain StringConcatFactory class?

     */

    public boolean hasStringConcatFactory() {

        return compareTo(JDK1_9) >= 0;

    }

    /** Value of platform release used to access multi-release jar files

     */

    public String multiReleaseValue() {

        return Integer.toString(this.ordinal() - Target.JDK1_1.ordinal() + 1);

    }

}