1 /*
  2  * Copyright (c) 2022, 2025, 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, WritableField {
 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, fieldFlags());
 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 int fieldFlags() {
 79         return reader.readU2(startPos);
 80     }
 81 
 82     @Override
 83     public List<Attribute<?>> attributes() {
 84         if (attributes == null) {
 85             attributes = BoundAttribute.readAttributes(this, reader, attributesPos, reader.customAttributes());
 86         }
 87         return attributes;
 88     }
 89 
 90     @Override
 91     public void writeTo(BufWriterImpl buf) {
 92         if (buf.canWriteDirect(reader)) {
 93             reader.copyBytesTo(buf, startPos, endPos - startPos);
 94         }
 95         else {
 96             buf.writeU2U2U2(flags().flagsMask(),
 97                     buf.cpIndex(fieldName()),
 98                     buf.cpIndex(fieldType()));
 99             Util.writeAttributes(buf, attributes());
100         }
101     }
102 
103     // FieldModel
104 
105     @Override
106     public void writeTo(DirectClassBuilder builder) {
107         if (builder.canWriteDirect(reader)) {
108             builder.withField(this);
109         }
110         else {
111             builder.withField(fieldName(), fieldType(), Util.writingAll(this));
112         }
113     }
114 
115     @Override
116     public void forEach(Consumer<? super FieldElement> consumer) {
117         consumer.accept(flags());
118         for (Attribute<?> attr : attributes()) {
119             if (attr instanceof FieldElement e)
120                 consumer.accept(e);
121         }
122     }
123 
124     @Override
125     public String toString() {
126         return String.format("FieldModel[fieldName=%s, fieldType=%s, flags=%d]",
127                 fieldName().stringValue(), fieldType().stringValue(), flags().flagsMask());
128     }
129 }