| /* |
| * ProGuard -- shrinking, optimization, obfuscation, and preverification |
| * of Java bytecode. |
| * |
| * Copyright (c) 2002-2009 Eric Lafortune (eric@graphics.cornell.edu) |
| * |
| * 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.editor; |
| |
| import proguard.classfile.*; |
| import proguard.classfile.attribute.*; |
| |
| /** |
| * This class can add and delete attributes to and from classes, fields, |
| * methods, and code attributes. Attributes to be added must be filled out |
| * beforehand, including their references to the constant pool. Existing |
| * attributes of the same type are always replaced. |
| * |
| * @author Eric Lafortune |
| */ |
| public class AttributesEditor |
| { |
| private final ProgramClass targetClass; |
| private final ProgramMember targetMember; |
| private final CodeAttribute targetAttribute; |
| private final boolean replaceAttributes; |
| |
| |
| /** |
| * Creates a new AttributeAdder that will edit attributes in the given |
| * target class. |
| */ |
| public AttributesEditor(ProgramClass targetClass, |
| boolean replaceAttributes) |
| { |
| this(targetClass, null, null, replaceAttributes); |
| } |
| |
| |
| /** |
| * Creates a new AttributeAdder that will edit attributes in the given |
| * target class member. |
| */ |
| public AttributesEditor(ProgramClass targetClass, |
| ProgramMember targetMember, |
| boolean replaceAttributes) |
| { |
| this(targetClass, targetMember, null, replaceAttributes); |
| } |
| |
| |
| /** |
| * Creates a new AttributeAdder that will edit attributes in the given |
| * target code attribute. |
| */ |
| public AttributesEditor(ProgramClass targetClass, |
| ProgramMember targetMember, |
| CodeAttribute targetAttribute, |
| boolean replaceAttributes) |
| { |
| this.targetClass = targetClass; |
| this.targetMember = targetMember; |
| this.targetAttribute = targetAttribute; |
| this.replaceAttributes = replaceAttributes; |
| } |
| |
| |
| /** |
| * Adds the given attribute to the target. |
| */ |
| public void addAttribute(Attribute attribute) |
| { |
| // What's the target? |
| if (targetAttribute != null) |
| { |
| // Try to replace an existing attribute. |
| if (!replaceAttributes || |
| !replaceAttribute(targetAttribute.u2attributesCount, |
| targetAttribute.attributes, |
| attribute)) |
| { |
| // Otherwise append the attribute. |
| targetAttribute.attributes = |
| addAttribute(targetAttribute.u2attributesCount, |
| targetAttribute.attributes, |
| attribute); |
| |
| targetAttribute.u2attributesCount++; |
| } |
| } |
| else if (targetMember != null) |
| { |
| // Try to replace an existing attribute. |
| if (!replaceAttributes || |
| !replaceAttribute(targetMember.u2attributesCount, |
| targetMember.attributes, |
| attribute)) |
| { |
| // Otherwise append the attribute. |
| targetMember.attributes = |
| addAttribute(targetMember.u2attributesCount, |
| targetMember.attributes, |
| attribute); |
| |
| targetMember.u2attributesCount++; |
| } |
| } |
| else |
| { |
| // Try to replace an existing attribute. |
| if (!replaceAttributes || |
| !replaceAttribute(targetClass.u2attributesCount, |
| targetClass.attributes, |
| attribute)) |
| { |
| // Otherwise append the attribute. |
| targetClass.attributes = |
| addAttribute(targetClass.u2attributesCount, |
| targetClass.attributes, |
| attribute); |
| |
| targetClass.u2attributesCount++; |
| } |
| } |
| } |
| |
| |
| /** |
| * Deletes the specified attribute from the target. |
| */ |
| public void deleteAttribute(String attributeName) |
| { |
| // What's the target? |
| if (targetAttribute != null) |
| { |
| targetAttribute.u2attributesCount = |
| deleteAttribute(targetAttribute.u2attributesCount, |
| targetAttribute.attributes, |
| attributeName); |
| } |
| else if (targetMember != null) |
| { |
| targetMember.u2attributesCount = |
| deleteAttribute(targetMember.u2attributesCount, |
| targetMember.attributes, |
| attributeName); |
| } |
| else |
| { |
| targetClass.u2attributesCount = |
| deleteAttribute(targetClass.u2attributesCount, |
| targetClass.attributes, |
| attributeName); |
| } |
| } |
| |
| |
| // Small utility methods. |
| |
| /** |
| * Tries put the given attribute in place of an existing attribute of the |
| * same name, returning whether it was present. |
| */ |
| private boolean replaceAttribute(int attributesCount, |
| Attribute[] attributes, |
| Attribute attribute) |
| { |
| // Find the attribute with the same name. |
| int index = findAttribute(attributesCount, |
| attributes, |
| attribute.getAttributeName(targetClass)); |
| if (index < 0) |
| { |
| return false; |
| } |
| |
| attributes[index] = attribute; |
| |
| return true; |
| } |
| |
| |
| /** |
| * Appends the given attribute to the given array of attributes, creating a |
| * new array if necessary. |
| */ |
| private Attribute[] addAttribute(int attributesCount, |
| Attribute[] attributes, |
| Attribute attribute) |
| { |
| // Is the array too small to contain the additional attribute? |
| if (attributes.length <= attributesCount) |
| { |
| // Create a new array and copy the attributes into it. |
| Attribute[] newAttributes = new Attribute[attributesCount + 1]; |
| System.arraycopy(attributes, 0, |
| newAttributes, 0, |
| attributesCount); |
| attributes = newAttributes; |
| } |
| |
| // Append the attribute. |
| attributes[attributesCount] = attribute; |
| |
| return attributes; |
| } |
| |
| |
| /** |
| * Deletes the attributes with the given name from the given array of |
| * attributes, returning the new number of attributes. |
| */ |
| private int deleteAttribute(int attributesCount, |
| Attribute[] attributes, |
| String attributeName) |
| { |
| // Find the attribute. |
| int index = findAttribute(attributesCount, |
| attributes, |
| attributeName); |
| if (index < 0) |
| { |
| return attributesCount; |
| } |
| |
| // Shift the other attributes in the array. |
| System.arraycopy(attributes, index + 1, |
| attributes, index, |
| attributesCount - index - 1); |
| |
| // Clear the last entry in the array. |
| attributes[--attributesCount] = null; |
| |
| return attributesCount; |
| } |
| |
| |
| /** |
| * Finds the index of the attribute with the given name in the given |
| * array of attributes. |
| */ |
| private int findAttribute(int attributesCount, |
| Attribute[] attributes, |
| String attributeName) |
| { |
| for (int index = 0; index < attributesCount; index++) |
| { |
| if (attributes[index].getAttributeName(targetClass).equals(attributeName)) |
| { |
| return index; |
| } |
| } |
| |
| return -1; |
| } |
| } |