// 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 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);
}
if (
signatureIndex != 0) {
output
.
putShort(
symbolTable.
addConstantUtf8(
Constants.
SIGNATURE))
.
putInt(2)
.
putShort(
signatureIndex);
}
if ((
accessFlags &
Opcodes.
ACC_DEPRECATED) != 0) {
output.
putShort(
symbolTable.
addConstantUtf8(
Constants.
DEPRECATED)).
putInt(0);
}
if (
lastRuntimeVisibleAnnotation != null) {
lastRuntimeVisibleAnnotation.
putAnnotations(
symbolTable.
addConstantUtf8(
Constants.
RUNTIME_VISIBLE_ANNOTATIONS),
output);
}
if (
lastRuntimeInvisibleAnnotation != null) {
lastRuntimeInvisibleAnnotation.
putAnnotations(
symbolTable.
addConstantUtf8(
Constants.
RUNTIME_INVISIBLE_ANNOTATIONS),
output);
}
if (
lastRuntimeVisibleTypeAnnotation != null) {
lastRuntimeVisibleTypeAnnotation.
putAnnotations(
symbolTable.
addConstantUtf8(
Constants.
RUNTIME_VISIBLE_TYPE_ANNOTATIONS),
output);
}
if (
lastRuntimeInvisibleTypeAnnotation != null) {
lastRuntimeInvisibleTypeAnnotation.
putAnnotations(
symbolTable.
addConstantUtf8(
Constants.
RUNTIME_INVISIBLE_TYPE_ANNOTATIONS),
output);
}
if (
firstAttribute != null) {
firstAttribute.
putAttributes(
symbolTable,
output);
}
}
/**
* Collects the attributes of this field into the given set of attribute prototypes.
*
* @param attributePrototypes a set of attribute prototypes.
*/
final void
collectAttributePrototypes(final
Attribute.
Set attributePrototypes) {
attributePrototypes.
addAttributes(
firstAttribute);
}
}