1 /*
  2  * Copyright (c) 2022, 2024, Oracle and/or its affiliates. All rights reserved.
  3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  4  *
  5  * This code is free software; you can redistribute it and/or modify it
  6  * under the terms of the GNU General Public License version 2 only, as
  7  * published by the Free Software Foundation.  Oracle designates this
  8  * particular file as subject to the "Classpath" exception as provided
  9  * by Oracle in the LICENSE file that accompanied this code.
 10  *
 11  * This code is distributed in the hope that it will be useful, but WITHOUT
 12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 14  * version 2 for more details (a copy is included in the LICENSE file that
 15  * accompanied this code).
 16  *
 17  * You should have received a copy of the GNU General Public License version
 18  * 2 along with this work; if not, write to the Free Software Foundation,
 19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 20  *
 21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 22  * or visit www.oracle.com if you need additional information or have any
 23  * questions.
 24  */
 25 package jdk.internal.classfile.impl;
 26 
 27 import java.lang.classfile.AccessFlags;
 28 import java.lang.classfile.Attribute;
 29 import java.lang.classfile.ClassModel;
 30 import java.lang.classfile.ClassReader;
 31 import java.lang.classfile.FieldElement;
 32 import java.lang.classfile.FieldModel;
 33 import java.lang.classfile.constantpool.Utf8Entry;
 34 import java.lang.reflect.AccessFlag;
 35 import java.util.List;
 36 import java.util.Optional;
 37 import java.util.function.Consumer;
 38 
 39 public final class FieldImpl
 40         extends AbstractElement
 41         implements FieldModel, Util.Writable {
 42 
 43     private final ClassReader reader;
 44     private final int startPos, endPos, attributesPos;
 45     private List<Attribute<?>> attributes;
 46 
 47     public FieldImpl(ClassReader reader, int startPos, int endPos, int attributesPos) {
 48         this.reader = reader;
 49         this.startPos = startPos;
 50         this.endPos = endPos;
 51         this.attributesPos = attributesPos;
 52     }
 53 
 54     @Override
 55     public AccessFlags flags() {
 56         return new AccessFlagsImpl(AccessFlag.Location.FIELD, reader.readU2(startPos));
 57     }
 58 
 59     @Override
 60     public Optional<ClassModel> parent() {
 61         if (reader instanceof ClassReaderImpl cri)
 62             return Optional.of(cri.getContainedClass());
 63         else
 64             return Optional.empty();
 65     }
 66 
 67     @Override
 68     public Utf8Entry fieldName() {
 69         return reader.readEntry(startPos + 2, Utf8Entry.class);
 70     }
 71 
 72     @Override
 73     public Utf8Entry fieldType() {
 74         return reader.readEntry(startPos + 4, Utf8Entry.class);
 75     }
 76 
 77     @Override
 78     public List<Attribute<?>> attributes() {
 79         if (attributes == null) {
 80             attributes = BoundAttribute.readAttributes(this, reader, attributesPos, reader.customAttributes());
 81         }
 82         return attributes;
 83     }
 84 
 85     @Override
 86     public void writeTo(BufWriterImpl buf) {
 87         if (buf.canWriteDirect(reader)) {
 88             reader.copyBytesTo(buf, startPos, endPos - startPos);
 89         }
 90         else {
 91             buf.writeU2U2U2(flags().flagsMask(),
 92                     buf.cpIndex(fieldName()),
 93                     buf.cpIndex(fieldType()));
 94             Util.writeAttributes(buf, attributes());
 95         }
 96     }
 97 
 98     // FieldModel
 99 
100     @Override
101     public void writeTo(DirectClassBuilder builder) {
102         if (builder.canWriteDirect(reader)) {
103             builder.withField(this);
104         }
105         else {
106             builder.withField(fieldName(), fieldType(), Util.writingAll(this));
107         }
108     }
109 
110     @Override
111     public void forEach(Consumer<? super FieldElement> consumer) {
112         consumer.accept(flags());
113         for (Attribute<?> attr : attributes()) {
114             if (attr instanceof FieldElement e)
115                 consumer.accept(e);
116         }
117     }
118 
119     @Override
120     public String toString() {
121         return String.format("FieldModel[fieldName=%s, fieldType=%s, flags=%d]",
122                 fieldName().stringValue(), fieldType().stringValue(), flags().flagsMask());
123     }
124 }