asmlib.InfoAnnotationVisitor.java Source code

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Here is the source code for asmlib.InfoAnnotationVisitor.java

Source

/*
 * asmlib: a toolkit based on ASM for working with java bytecode
 * Copyright (C) 2015 Ivo Anjo <ivo.anjo@ist.utl.pt>
 *
 * This file is part of asmlib.
 *
 * asmlib is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * asmlib 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with asmlib.  If not, see <http://www.gnu.org/licenses/>.
 */

package asmlib;

import org.objectweb.asm.*;

/** FIXME: Triggering the loading of classes by the VM as a side-effect of their analysis with asmlib
  *       is a very bad idea. Nevertheless, this code works and the API has users, so it has been
  *      merged but is disabled by default, pending a proper rewrite to avoid using reflection.
  **/
public class InfoAnnotationVisitor extends AnnotationVisitor {

    private final InfoAnnotation _annotation;
    public static boolean _enableInfoAnnotationVisitor = false;

    public InfoAnnotationVisitor(InfoAnnotation ia) {
        super(Opcodes.ASM4);
        _annotation = ia;
    }

    @Override
    public void visit(String name, Object value) {
        _annotation.addValue(name, value);
    }

    @Override
    public void visitEnum(String name, String desc, String value) {
        if (!_enableInfoAnnotationVisitor)
            throw new Error("visitEnum not implemented");

        try {
            Class<?> enumClass = Class.forName(Type.fromBytecode(desc).commonName());

            for (Enum<?> enumElem : (Enum[]) enumClass.getEnumConstants()) {
                if (enumElem.name().equals(value)) {
                    _annotation.addValue(name, enumElem);
                    return;
                }
            }

            throw new AssertionError();
        } catch (Exception e) {
            throw new Error(e);
        }
    }

    @Override
    public void visitEnd() {
        if (!_enableInfoAnnotationVisitor)
            return;

        Exception inner = null;

        try {
            for (java.lang.reflect.Method m : Class.forName(_annotation.type().commonName()).getDeclaredMethods()) {
                if (!_annotation.hasValue(m.getName())) {
                    _annotation.addValue(m.getName(), m.getDefaultValue());
                }
            }
            return;
        } catch (SecurityException e) {
            inner = e;
        } catch (ClassNotFoundException e) {
            inner = e;
        }
        throw new Error("Error while using reflection to extract default value of annotations", inner);
    }

}