proguard.classfile.attribute.CodeAttribute Maven / Gradle / Ivy
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/*
* ProGuard -- shrinking, optimization, obfuscation, and preverification
* of Java bytecode.
*
* Copyright (c) 2002-2019 Guardsquare NV
*
* This program 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 2 of the License, or (at your option)
* any later version.
*
* This program 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 this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package proguard.classfile.attribute;
import proguard.classfile.*;
import proguard.classfile.attribute.visitor.*;
import proguard.classfile.instruction.*;
import proguard.classfile.instruction.visitor.InstructionVisitor;
/**
* This Attribute represents a code attribute.
*
* @author Eric Lafortune
*/
public class CodeAttribute extends Attribute
{
private static final byte[] EMPTY_CODE = new byte[0];
private static final ExceptionInfo[] EMPTY_EXCEPTION_TABLE = new ExceptionInfo[0];
private static final Attribute[] EMPTY_ATTRIBUTES = new Attribute[0];
public int u2maxStack;
public int u2maxLocals;
public int u4codeLength;
public byte[] code;
public int u2exceptionTableLength;
public ExceptionInfo[] exceptionTable;
public int u2attributesCount;
public Attribute[] attributes;
/**
* Creates an uninitialized CodeAttribute.
*/
public CodeAttribute()
{
}
/**
* Creates a partially initialized CodeAttribute without code, exceptions,
* or attributes.
*/
public CodeAttribute(int u2attributeNameIndex)
{
this(u2attributeNameIndex,
0,
0,
0,
EMPTY_CODE);
}
/**
* Creates an initialized CodeAttribute without exceptions or attributes.
*/
public CodeAttribute(int u2attributeNameIndex,
int u2maxStack,
int u2maxLocals,
int u4codeLength,
byte[] code)
{
this(u2attributeNameIndex,
u2maxStack,
u2maxLocals,
u4codeLength,
code,
0,
EMPTY_EXCEPTION_TABLE,
0,
EMPTY_ATTRIBUTES);
}
/**
* Creates an initialized CodeAttribute.
*/
public CodeAttribute(int u2attributeNameIndex,
int u2maxStack,
int u2maxLocals,
int u4codeLength,
byte[] code,
int u2exceptionTableLength,
ExceptionInfo[] exceptionTable,
int u2attributesCount,
Attribute[] attributes)
{
super(u2attributeNameIndex);
this.u2maxStack = u2maxStack;
this.u2maxLocals = u2maxLocals;
this.u4codeLength = u4codeLength;
this.code = code;
this.u2exceptionTableLength = u2exceptionTableLength;
this.exceptionTable = exceptionTable;
this.u2attributesCount = u2attributesCount;
this.attributes = attributes;
}
/**
* Returns the (first) attribute with the given name.
*/
public Attribute getAttribute(Clazz clazz, String name)
{
for (int index = 0; index < u2attributesCount; index++)
{
Attribute attribute = attributes[index];
if (attribute.getAttributeName(clazz).equals(name))
{
return attribute;
}
}
return null;
}
// Implementations for Attribute.
public void accept(Clazz clazz, Method method, AttributeVisitor attributeVisitor)
{
attributeVisitor.visitCodeAttribute(clazz, method, this);
}
/**
* Applies the given instruction visitor to all instructions.
*/
public void instructionsAccept(Clazz clazz, Method method, InstructionVisitor instructionVisitor)
{
instructionsAccept(clazz, method, 0, u4codeLength, instructionVisitor);
}
/**
* Applies the given instruction visitor to the instruction at the specified
* offset.
*/
public void instructionAccept(Clazz clazz, Method method, int offset, InstructionVisitor instructionVisitor)
{
Instruction instruction = InstructionFactory.create(code, offset);
instruction.accept(clazz, method, this, offset, instructionVisitor);
}
/**
* Applies the given instruction visitor to all instructions in the
* specified range of offsets.
*/
public void instructionsAccept(Clazz clazz, Method method, int startOffset, int endOffset, InstructionVisitor instructionVisitor)
{
int offset = startOffset;
while (offset < endOffset)
{
// Note that the instruction is only volatile.
Instruction instruction = InstructionFactory.create(code, offset);
int instructionLength = instruction.length(offset);
instruction.accept(clazz, method, this, offset, instructionVisitor);
offset += instructionLength;
}
}
/**
* Applies the given exception visitor to all exceptions.
*/
public void exceptionsAccept(Clazz clazz, Method method, ExceptionInfoVisitor exceptionInfoVisitor)
{
for (int index = 0; index < u2exceptionTableLength; index++)
{
// We don't need double dispatching here, since there is only one
// type of ExceptionInfo.
exceptionInfoVisitor.visitExceptionInfo(clazz, method, this, exceptionTable[index]);
}
}
/**
* Applies the given exception visitor to all exceptions that are applicable
* to the instruction at the specified offset.
*/
public void exceptionsAccept(Clazz clazz, Method method, int offset, ExceptionInfoVisitor exceptionInfoVisitor)
{
for (int index = 0; index < u2exceptionTableLength; index++)
{
ExceptionInfo exceptionInfo = exceptionTable[index];
if (exceptionInfo.isApplicable(offset))
{
exceptionInfoVisitor.visitExceptionInfo(clazz, method, this, exceptionInfo);
}
}
}
/**
* Applies the given exception visitor to all exceptions that are applicable
* to any of the instructions in the specified range of offsets.
*/
public void exceptionsAccept(Clazz clazz, Method method, int startOffset, int endOffset, ExceptionInfoVisitor exceptionInfoVisitor)
{
for (int index = 0; index < u2exceptionTableLength; index++)
{
ExceptionInfo exceptionInfo = exceptionTable[index];
if (exceptionInfo.isApplicable(startOffset, endOffset))
{
exceptionInfoVisitor.visitExceptionInfo(clazz, method, this, exceptionInfo);
}
}
}
/**
* Applies the given attribute visitor to all attributes.
*/
public void attributesAccept(Clazz clazz, Method method, AttributeVisitor attributeVisitor)
{
for (int index = 0; index < u2attributesCount; index++)
{
attributes[index].accept(clazz, method, this, attributeVisitor);
}
}
}