source.java

来自「是一款用JAVA 编写的编译器 具有很强的编译功能」· Java 代码 · 共 175 行

/*
 * Copyright 2002-2006 Sun Microsystems, Inc.  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.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 */

package com.sun.tools.javac.code;

import com.sun.tools.javac.util.*;
import com.sun.tools.javac.jvm.Target;
import javax.lang.model.SourceVersion;
import static javax.lang.model.SourceVersion.*;
import java.util.*;

/** The source language version accepted.
 *
 *  <p><b>This is NOT part of any API supported by Sun Microsystems.  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 Source {
    /** 1.0 had no inner classes, and so could not pass the JCK. */
    // public static final Source JDK1_0 =		new Source("1.0");

    /** 1.1 did not have strictfp, and so could not pass the JCK. */
    // public static final Source JDK1_1 =		new Source("1.1");

    /** 1.2 introduced strictfp. */
    JDK1_2("1.2"),

    /** 1.3 is the same language as 1.2. */
    JDK1_3("1.3"),

    /** 1.4 introduced assert. */
    JDK1_4("1.4"),

    /** 1.5 introduced generics, attributes, foreach, boxing, static import,
     *  covariant return, enums, varargs, et al. */
    JDK1_5("1.5"),

    /** 1.6 reports encoding problems as errors instead of warnings. */ 
    JDK1_6("1.6"),

    /** 1.7 covers the to be determined language features that will be added in JDK 7. */
    JDK1_7("1.7");

    private static final Context.Key<Source> sourceKey
	= new Context.Key<Source>();

    public static Source instance(Context context) {
	Source instance = context.get(sourceKey);
	if (instance == null) {
	    Options options = Options.instance(context);
	    String sourceString = options.get("-source");
	    if (sourceString != null) instance = lookup(sourceString);
	    if (instance == null) instance = DEFAULT;
	    context.put(sourceKey, instance);
	}
	return instance;
    }

    public final String name;

    private static Map<String,Source> tab = new HashMap<String,Source>();
    static {
	for (Source s : values()) {
	    tab.put(s.name, s);
	}
	tab.put("5", JDK1_5); // Make 5 an alias for 1.5
	tab.put("6", JDK1_6); // Make 6 an alias for 1.6
        tab.put("7", JDK1_7); // Make 7 an alias for 1.7
    }

    private Source(String name) {
	this.name = name;
    }

    public static final Source DEFAULT = JDK1_5;

    public static Source lookup(String name) {
	return tab.get(name);
    }

    public Target requiredTarget() {
        if (this.compareTo(JDK1_7) >= 0) return Target.JDK1_7;
	if (this.compareTo(JDK1_6) >= 0) return Target.JDK1_6;
	if (this.compareTo(JDK1_5) >= 0) return Target.JDK1_5;
	if (this.compareTo(JDK1_4) >= 0) return Target.JDK1_4;
	return Target.JDK1_1;
    }

    /** Allow encoding errors, giving only warnings. */
    public boolean allowEncodingErrors() {
	return compareTo(JDK1_6) < 0;
    }
    public boolean allowAsserts() {
	return compareTo(JDK1_4) >= 0;
    }
    public boolean allowCovariantReturns() {
	return compareTo(JDK1_5) >= 0;
    }
    public boolean allowGenerics() {
	return compareTo(JDK1_5) >= 0;
    }
    public boolean allowEnums() {
	return compareTo(JDK1_5) >= 0;
    }
    public boolean allowForeach() {
	return compareTo(JDK1_5) >= 0;
    }
    public boolean allowStaticImport() {
	return compareTo(JDK1_5) >= 0;
    }
    public boolean allowBoxing() {
	return compareTo(JDK1_5) >= 0;
    }
    public boolean allowVarargs() {
	return compareTo(JDK1_5) >= 0;
    }
    public boolean allowAnnotations() {
	return compareTo(JDK1_5) >= 0;
    }
    // hex floating-point literals supported?
    public boolean allowHexFloats() {
	return compareTo(JDK1_5) >= 0;
    }
    public boolean allowAnonOuterThis() {
	return compareTo(JDK1_5) >= 0;
    }
    public boolean addBridges() {
	return compareTo(JDK1_5) >= 0;
    }
    public boolean enforceMandatoryWarnings() {
	return compareTo(JDK1_5) >= 0;
    }
    public static SourceVersion toSourceVersion(Source source) {
	switch(source) {
	case JDK1_2:
	    return RELEASE_2;
	case JDK1_3:
	    return RELEASE_3;
	case JDK1_4:
	    return RELEASE_4;
	case JDK1_5:
	    return RELEASE_5;
	case JDK1_6:
	    return RELEASE_6;
	case JDK1_7:
	    return RELEASE_7;
	default:
	    return null;
	}
    }
}