JDK14/Java14源码在线阅读

/*
 * 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * This file is available under and governed by the GNU General Public
 * License version 2 only, as published by the Free Software Foundation.
 * However, the following notice accompanied the original version of this
 * file:
 *
 * ASM: a very small and fast Java bytecode manipulation framework
 * Copyright (c) 2000-2011 INRIA, France Telecom
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */
package jdk.internal.org.objectweb.asm;

/**
 * A {@link FieldVisitor} that generates a corresponding 'field_info' structure, as defined in the
 * Java Virtual Machine Specification (JVMS).
 *
 * @see <a href="https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.5">JVMS
 *     4.5</a>
 * @author Eric Bruneton
 */
final class FieldWriter extends FieldVisitor {

    /** Where the constants used in this FieldWriter must be stored. */
    private final SymbolTable symbolTable;

    // Note: fields are ordered as in the field_info structure, and those related to attributes are
    // ordered as in Section 4.7 of the JVMS.

    /**
      * The access_flags field of the field_info JVMS structure. This field can contain ASM specific
      * access flags, such as {@link Opcodes#ACC_DEPRECATED}, which are removed when generating the
      * ClassFile structure.
      */
    private final int accessFlags;

    /** The name_index field of the field_info JVMS structure. */
    private final int nameIndex;

    /** The descriptor_index field of the field_info JVMS structure. */
    private final int descriptorIndex;

    /**
      * The signature_index field of the Signature attribute of this field_info, or 0 if there is no
      * Signature attribute.
      */
    private int signatureIndex;

    /**
      * The constantvalue_index field of the ConstantValue attribute of this field_info, or 0 if there
      * is no ConstantValue attribute.
      */
    private int constantValueIndex;

    /**
      * The last runtime visible annotation of this field. The previous ones can be accessed with the
      * {@link AnnotationWriter#previousAnnotation} field. May be {@literal null}.
      */
    private AnnotationWriter lastRuntimeVisibleAnnotation;

    /**
      * The last runtime invisible annotation of this field. The previous ones can be accessed with the
      * {@link AnnotationWriter#previousAnnotation} field. May be {@literal null}.
      */
    private AnnotationWriter lastRuntimeInvisibleAnnotation;

    /**
      * The last runtime visible type annotation of this field. The previous ones can be accessed with
      * the {@link AnnotationWriter#previousAnnotation} field. May be {@literal null}.
      */
    private AnnotationWriter lastRuntimeVisibleTypeAnnotation;

    /**
      * The last runtime invisible type annotation of this field. The previous ones can be accessed
      * with the {@link AnnotationWriter#previousAnnotation} field. May be {@literal null}.
      */
    private AnnotationWriter lastRuntimeInvisibleTypeAnnotation;

    /**
      * The first non standard attribute of this field. The next ones can be accessed with the {@link
      * Attribute#nextAttribute} field. May be {@literal null}.
      *
      * <p><b>WARNING</b>: this list stores the attributes in the <i>reverse</i> order of their visit.
      * firstAttribute is actually the last attribute visited in {@link #visitAttribute}. The {@link
      * #putFieldInfo} method writes the attributes in the order defined by this list, i.e. in the
      * reverse order specified by the user.
      */
    private Attribute firstAttribute;

    // -----------------------------------------------------------------------------------------------
    // Constructor
    // -----------------------------------------------------------------------------------------------

    /**
      * Constructs a new {@link FieldWriter}.
      *
      * @param symbolTable where the constants used in this FieldWriter must be stored.
      * @param access the field's access flags (see {@link Opcodes}).
      * @param name the field's name.
      * @param descriptor the field's descriptor (see {@link Type}).
      * @param signature the field's signature. May be {@literal null}.
      * @param constantValue the field's constant value. May be {@literal null}.
      */
    FieldWriter(
            final SymbolTable symbolTable,
            final int access,
            final String name,
            final String descriptor,
            final String signature,
            final Object constantValue) {
        super(Opcodes.ASM7);
        this.symbolTable = symbolTable;
        this.accessFlags = access;
        this.nameIndex = symbolTable.addConstantUtf8(name);
        this.descriptorIndex = symbolTable.addConstantUtf8(descriptor);
        if (signature != null) {
            this.signatureIndex = symbolTable.addConstantUtf8(signature);
        }
        if (constantValue != null) {
            this.constantValueIndex = symbolTable.addConstant(constantValue).index;
        }
    }

    // -----------------------------------------------------------------------------------------------
    // Implementation of the FieldVisitor abstract class
    // -----------------------------------------------------------------------------------------------

    @Override
    public AnnotationVisitor visitAnnotation(final String descriptor, final boolean visible) {
        // Create a ByteVector to hold an 'annotation' JVMS structure.
        // See https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.16.
        ByteVector annotation = new ByteVector();
        // Write type_index and reserve space for num_element_value_pairs.
        annotation.putShort(symbolTable.addConstantUtf8(descriptor)).putShort(0);
        if (visible) {
            return lastRuntimeVisibleAnnotation =
                    new AnnotationWriter(symbolTable, annotation, lastRuntimeVisibleAnnotation);
        } else {
            return lastRuntimeInvisibleAnnotation =
                    new AnnotationWriter(symbolTable, annotation, lastRuntimeInvisibleAnnotation);
        }
    }

    @Override
    public AnnotationVisitor visitTypeAnnotation(
            final int typeRef, final TypePath typePath, final String descriptor, final boolean visible) {
        // Create a ByteVector to hold a 'type_annotation' JVMS structure.
        // See https://docs.oracle.com/javase/specs/jvms/se9/html/jvms-4.html#jvms-4.7.20.
        ByteVector typeAnnotation = new ByteVector();
        // Write target_type, target_info, and target_path.
        TypeReference.putTarget(typeRef, typeAnnotation);
        TypePath.put(typePath, typeAnnotation);
        // Write type_index and reserve space for num_element_value_pairs.
        typeAnnotation.putShort(symbolTable.addConstantUtf8(descriptor)).putShort(0);
        if (visible) {
            return lastRuntimeVisibleTypeAnnotation =
                    new AnnotationWriter(symbolTable, typeAnnotation, lastRuntimeVisibleTypeAnnotation);
        } else {
            return lastRuntimeInvisibleTypeAnnotation =
                    new AnnotationWriter(symbolTable, typeAnnotation, lastRuntimeInvisibleTypeAnnotation);
        }
    }

    @Override
    public void visitAttribute(final Attribute attribute) {
        // Store the attributes in the <i>reverse</i> order of their visit by this method.
        attribute.nextAttribute = firstAttribute;
        firstAttribute = attribute;
    }

    @Override
    public void visitEnd() {
        // Nothing to do.
    }

    // -----------------------------------------------------------------------------------------------
    // Utility methods
    // -----------------------------------------------------------------------------------------------

    /**
      * Returns the size of the field_info JVMS structure generated by this FieldWriter. Also adds the
      * names of the attributes of this field in the constant pool.
      *
      * @return the size in bytes of the field_info JVMS structure.
      */
    int computeFieldInfoSize() {
        // The access_flags, name_index, descriptor_index and attributes_count fields use 8 bytes.
        int size = 8;
        // For ease of reference, we use here the same attribute order as in Section 4.7 of the JVMS.
        if (constantValueIndex != 0) {
            // ConstantValue attributes always use 8 bytes.
            symbolTable.addConstantUtf8(Constants.CONSTANT_VALUE);
            size += 8;
        }
        // Before Java 1.5, synthetic fields are represented with a Synthetic attribute.
        if ((accessFlags & Opcodes.ACC_SYNTHETIC) != 0
                && symbolTable.getMajorVersion() < Opcodes.V1_5) {
            // Synthetic attributes always use 6 bytes.
            symbolTable.addConstantUtf8(Constants.SYNTHETIC);
            size += 6;
        }
        if (signatureIndex != 0) {
            // Signature attributes always use 8 bytes.
            symbolTable.addConstantUtf8(Constants.SIGNATURE);
            size += 8;
        }
        // ACC_DEPRECATED is ASM specific, the ClassFile format uses a Deprecated attribute instead.
        if ((accessFlags & Opcodes.ACC_DEPRECATED) != 0) {
            // Deprecated attributes always use 6 bytes.
            symbolTable.addConstantUtf8(Constants.DEPRECATED);
            size += 6;
        }
        if (lastRuntimeVisibleAnnotation != null) {
            size +=
                    lastRuntimeVisibleAnnotation.computeAnnotationsSize(
                            Constants.RUNTIME_VISIBLE_ANNOTATIONS);
        }
        if (lastRuntimeInvisibleAnnotation != null) {
            size +=
                    lastRuntimeInvisibleAnnotation.computeAnnotationsSize(
                            Constants.RUNTIME_INVISIBLE_ANNOTATIONS);
        }
        if (lastRuntimeVisibleTypeAnnotation != null) {
            size +=
                    lastRuntimeVisibleTypeAnnotation.computeAnnotationsSize(
                            Constants.RUNTIME_VISIBLE_TYPE_ANNOTATIONS);
        }
        if (lastRuntimeInvisibleTypeAnnotation != null) {
            size +=
                    lastRuntimeInvisibleTypeAnnotation.computeAnnotationsSize(
                            Constants.RUNTIME_INVISIBLE_TYPE_ANNOTATIONS);
        }
        if (firstAttribute != null) {
            size += firstAttribute.computeAttributesSize(symbolTable);
        }
        return size;
    }

    /**
      * Puts the content of the field_info JVMS structure generated by this FieldWriter into the given
      * ByteVector.
      *
      * @param output where the field_info structure must be put.
      */
    void putFieldInfo(final ByteVector output) {
        boolean useSyntheticAttribute = symbolTable.getMajorVersion() < Opcodes.V1_5;
        // Put the access_flags, name_index and descriptor_index fields.
        int mask = useSyntheticAttribute ? Opcodes.ACC_SYNTHETIC : 0;
        output.putShort(accessFlags & ~mask).putShort(nameIndex).putShort(descriptorIndex);
        // Compute and put the attributes_count field.
        // For ease of reference, we use here the same attribute order as in Section 4.7 of the JVMS.
        int attributesCount = 0;
        if (constantValueIndex != 0) {
            ++attributesCount;
        }
        if ((accessFlags & Opcodes.ACC_SYNTHETIC) != 0 && useSyntheticAttribute) {
            ++attributesCount;
        }
        if (signatureIndex != 0) {
            ++attributesCount;
        }
        if ((accessFlags & Opcodes.ACC_DEPRECATED) != 0) {
            ++attributesCount;
        }
        if (lastRuntimeVisibleAnnotation != null) {
            ++attributesCount;
        }
        if (lastRuntimeInvisibleAnnotation != null) {
            ++attributesCount;
        }
        if (lastRuntimeVisibleTypeAnnotation != null) {
            ++attributesCount;
        }
        if (lastRuntimeInvisibleTypeAnnotation != null) {
            ++attributesCount;
        }
        if (firstAttribute != null) {
            attributesCount += firstAttribute.getAttributeCount();
        }
        output.putShort(attributesCount);
        // Put the field_info attributes.
        // For ease of reference, we use here the same attribute order as in Section 4.7 of the JVMS.
        if (constantValueIndex != 0) {
            output
                    .putShort(symbolTable.addConstantUtf8(Constants.CONSTANT_VALUE))
                    .putInt(2)
                    .putShort(constantValueIndex);
        }
        if ((accessFlags & Opcodes.ACC_SYNTHETIC) != 0 && useSyntheticAttribute) {
            output.putShort(symbolTable.addConstantUtf8(Constants.SYNTHETIC)).putInt(0);
        }

/**代码未完, 请加载全部代码(NowJava.com).**/