attribute.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 285 行

/*
 * Copyright 2003-2005 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 java.util.LinkedHashMap;
import java.util.Map;
import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.element.AnnotationValue;
import javax.lang.model.element.AnnotationValueVisitor;
import javax.lang.model.element.ExecutableElement;
import javax.lang.model.type.DeclaredType;
import com.sun.tools.javac.code.Symbol.*;
import com.sun.tools.javac.util.*;

import static com.sun.tools.javac.code.TypeTags.*;

/** An annotation value.
 *
 *  <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 abstract class Attribute implements AnnotationValue {

    /** The type of the annotation element. */
    public Type type;

    public Attribute(Type type) {
	this.type = type;
    }

    public abstract void accept(Visitor v);

    public Object getValue() {
	throw new UnsupportedOperationException();
    }

    public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {
	throw new UnsupportedOperationException();
    }


    /** The value for an annotation element of primitive type or String. */
    public static class Constant extends Attribute {
	public final Object value;
	public void accept(Visitor v) { v.visitConstant(this); }
	public Constant(Type type, Object value) {
	    super(type);
	    this.value = value;
	}
	public String toString() {
	    return Constants.format(value, type);
	}
	public Object getValue() {
	    return Constants.decode(value, type);
	}
	public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {
	    if (value instanceof String)
		return v.visitString((String) value, p);
	    if (value instanceof Integer) {
		int i = (Integer) value;
		switch (type.tag) {
		case BOOLEAN:	return v.visitBoolean(i != 0, p);
		case CHAR:	return v.visitChar((char) i, p);
		case BYTE:	return v.visitByte((byte) i, p);
		case SHORT:	return v.visitShort((short) i, p);
		case INT:	return v.visitInt(i, p);
		}
	    }
	    switch (type.tag) {
	    case LONG:		return v.visitLong((Long) value, p);
	    case FLOAT:		return v.visitFloat((Float) value, p);
	    case DOUBLE:	return v.visitDouble((Double) value, p);
	    }
	    throw new AssertionError("Bad annotation element value: " + value);
	}
    }

    /** The value for an annotation element of type java.lang.Class,
     *  represented as a ClassSymbol.
     */
    public static class Class extends Attribute {
	public final Type type;
	public void accept(Visitor v) { v.visitClass(this); }
	public Class(Types types, Type type) {
	    super(makeClassType(types, type));
	    this.type = type;
	}
        static Type makeClassType(Types types, Type type) {
            Type arg = type.isPrimitive()
                ? types.boxedClass(type).type
                : types.erasure(type);
            return new Type.ClassType(types.syms.classType.getEnclosingType(),
                                      List.of(arg),
                                      types.syms.classType.tsym);
        }
	public String toString() {
	    return type + ".class";
	}
	public Type getValue() {
	    return type;
	}
	public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {
	    return v.visitType(type, p);
	}
    }

    /** A compound annotation element value, the type of which is an
     *  attribute interface.
     */
    public static class Compound extends Attribute implements AnnotationMirror {
	/** The attributes values, as pairs.  Each pair contains a
	 *  reference to the accessing method in the attribute interface
	 *  and the value to be returned when that method is called to
	 *  access this attribute.
	 */
	public final List<Pair<MethodSymbol,Attribute>> values;
	public Compound(Type type,
			List<Pair<MethodSymbol,Attribute>> values) {
	    super(type);
	    this.values = values;
	}
	public void accept(Visitor v) { v.visitCompound(this); }

	/**
	 * Returns a string representation of this annotation.
	 * String is of one of the forms:
	 *     @com.example.foo(name1=val1, name2=val2)
	 *     @com.example.foo(val)
	 *     @com.example.foo
	 * Omit parens for marker annotations, and omit "value=" when allowed.
	 */
	public String toString() {
	    StringBuilder buf = new StringBuilder();
	    buf.append("@");
	    buf.append(type);
	    int len = values.length();
	    if (len > 0) {
		buf.append('(');
		boolean first = true;
		for (Pair<MethodSymbol, Attribute> value : values) {
		    if (!first) buf.append(", ");
		    first = false;

		    Name name = value.fst.name;
		    if (len > 1 || name != name.table.value) {
			buf.append(name);
			buf.append('=');
		    }
		    buf.append(value.snd);
		}
		buf.append(')');
	    }
	    return buf.toString();
	}

	public Attribute member(Name member) {
	    for (Pair<MethodSymbol,Attribute> pair : values)
		if (pair.fst.name == member) return pair.snd;
	    return null;
	}

	public Attribute.Compound getValue() {
	    return this;
	}

	public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {
	    return v.visitAnnotation(this, p);
	}

	public DeclaredType getAnnotationType() {
	    return (DeclaredType) type;
	}

	public Map<MethodSymbol, Attribute> getElementValues() {
	    Map<MethodSymbol, Attribute> valmap =
		new LinkedHashMap<MethodSymbol, Attribute>();
	    for (Pair<MethodSymbol, Attribute> value : values)
		valmap.put(value.fst, value.snd);
	    return valmap;
	}
    }

    /** The value for an annotation element of an array type.
     */
    public static class Array extends Attribute {
	public final Attribute[] values;
	public Array(Type type, Attribute[] values) {
	    super(type);
	    this.values = values;
	}
	public void accept(Visitor v) { v.visitArray(this); }
	public String toString() {
	    StringBuilder buf = new StringBuilder();
	    buf.append('{');
	    boolean first = true;
	    for (Attribute value : values) {
		if (!first)
		    buf.append(", ");
		first = false;
		buf.append(value);
	    }
	    buf.append('}');
	    return buf.toString();
	}
	public List<Attribute> getValue() {
	    return List.from(values);
	}
	public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {
	    return v.visitArray(getValue(), p);
	}
    }

    /** The value for an annotation element of an enum type.
     */
    public static class Enum extends Attribute {
	public VarSymbol value;
	public Enum(Type type, VarSymbol value) {
	    super(type);
	    assert value != null;
	    this.value = value;
	}
	public void accept(Visitor v) { v.visitEnum(this); }
	public String toString() {
	    return value.enclClass() + "." + value;	// qualified name
	}
	public VarSymbol getValue() {
	    return value;
	}
	public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {
	    return v.visitEnumConstant(value, p);
	}
    }

    public static class Error extends Attribute {
	public Error(Type type) {
	    super(type);
	}
	public void accept(Visitor v) { v.visitError(this); }
	public String toString() {
	    return "<error>";
	}
	public String getValue() {
	    return toString();
	}
	public <R, P> R accept(AnnotationValueVisitor<R, P> v, P p) {
	    return v.visitString(toString(), p);
	}
    }

    /** A visitor type for dynamic dispatch on the kind of attribute value. */
    public static interface Visitor {
	void visitConstant(Attribute.Constant value);
	void visitClass(Attribute.Class clazz);
	void visitCompound(Attribute.Compound compound);
	void visitArray(Attribute.Array array);
	void visitEnum(Attribute.Enum e);
	void visitError(Attribute.Error e);
    }
}