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Diffstat (limited to 'src/proguard/classfile/editor/NameAndTypeShrinker.java')
| -rw-r--r-- | src/proguard/classfile/editor/NameAndTypeShrinker.java | 195 |
1 files changed, 0 insertions, 195 deletions
diff --git a/src/proguard/classfile/editor/NameAndTypeShrinker.java b/src/proguard/classfile/editor/NameAndTypeShrinker.java deleted file mode 100644 index 40181b2..0000000 --- a/src/proguard/classfile/editor/NameAndTypeShrinker.java +++ /dev/null @@ -1,195 +0,0 @@ -/* - * ProGuard -- shrinking, optimization, obfuscation, and preverification - * of Java bytecode. - * - * Copyright (c) 2002-2014 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.*; -import proguard.classfile.attribute.visitor.AttributeVisitor; -import proguard.classfile.constant.*; -import proguard.classfile.constant.visitor.ConstantVisitor; -import proguard.classfile.util.SimplifiedVisitor; -import proguard.classfile.visitor.ClassVisitor; - -import java.util.Arrays; - - -/** - * This ClassVisitor removes NameAndType constant pool entries that are not - * used. - * - * @author Eric Lafortune - */ -public class NameAndTypeShrinker -extends SimplifiedVisitor -implements ClassVisitor, - ConstantVisitor, - AttributeVisitor -{ - // A visitor info flag to indicate the NameAndType constant pool entry is being used. - private static final Object USED = new Object(); - - private int[] constantIndexMap; - private final ConstantPoolRemapper constantPoolRemapper = new ConstantPoolRemapper(); - - - // Implementations for ClassVisitor. - - public void visitProgramClass(ProgramClass programClass) - { - // Mark the NameAndType entries referenced by all other constant pool - // entries. - programClass.constantPoolEntriesAccept(this); - - // Mark the NameAndType entries referenced by all EnclosingMethod - // attributes. - programClass.attributesAccept(this); - - // Shift the used constant pool entries together, filling out the - // index map. - int newConstantPoolCount = - shrinkConstantPool(programClass.constantPool, - programClass.u2constantPoolCount); - - // Remap the references to the constant pool if it has shrunk. - if (newConstantPoolCount < programClass.u2constantPoolCount) - { - programClass.u2constantPoolCount = newConstantPoolCount; - - // Remap all constant pool references. - constantPoolRemapper.setConstantIndexMap(constantIndexMap); - constantPoolRemapper.visitProgramClass(programClass); - } - } - - - // Implementations for ConstantVisitor. - - public void visitAnyConstant(Clazz clazz, Constant constant) {} - - - public void visitInvokeDynamicConstant(Clazz clazz, InvokeDynamicConstant invokeDynamicConstant) - { - markNameAndTypeConstant(clazz, invokeDynamicConstant.u2nameAndTypeIndex); - } - - - public void visitAnyRefConstant(Clazz clazz, RefConstant refConstant) - { - markNameAndTypeConstant(clazz, refConstant.u2nameAndTypeIndex); - } - - - // Implementations for AttributeVisitor. - - public void visitAnyAttribute(Clazz clazz, Attribute attribute) {} - - - public void visitEnclosingMethodAttribute(Clazz clazz, EnclosingMethodAttribute enclosingMethodAttribute) - { - if (enclosingMethodAttribute.u2nameAndTypeIndex != 0) - { - markNameAndTypeConstant(clazz, enclosingMethodAttribute.u2nameAndTypeIndex); - } - } - - - // Small utility methods. - - /** - * Marks the given UTF-8 constant pool entry of the given class. - */ - private void markNameAndTypeConstant(Clazz clazz, int index) - { - markAsUsed((NameAndTypeConstant)((ProgramClass)clazz).getConstant(index)); - } - - - /** - * Marks the given VisitorAccepter as being used. - * In this context, the VisitorAccepter will be a NameAndTypeConstant object. - */ - private void markAsUsed(VisitorAccepter visitorAccepter) - { - visitorAccepter.setVisitorInfo(USED); - } - - - /** - * Returns whether the given VisitorAccepter has been marked as being used. - * In this context, the VisitorAccepter will be a NameAndTypeConstant object. - */ - private boolean isUsed(VisitorAccepter visitorAccepter) - { - return visitorAccepter.getVisitorInfo() == USED; - } - - - /** - * Removes all NameAndType entries that are not marked as being used - * from the given constant pool. - * @return the new number of entries. - */ - private int shrinkConstantPool(Constant[] constantPool, int length) - { - // Create a new index map, if necessary. - if (constantIndexMap == null || - constantIndexMap.length < length) - { - constantIndexMap = new int[length]; - } - - int counter = 1; - boolean isUsed = false; - - // Shift the used constant pool entries together. - for (int index = 1; index < length; index++) - { - Constant constant = constantPool[index]; - - // Is the constant being used? Don't update the flag if this is the - // second half of a long entry. - if (constant != null) - { - isUsed = constant.getTag() != ClassConstants.CONSTANT_NameAndType || - isUsed(constant); - } - - if (isUsed) - { - // Remember the new index. - constantIndexMap[index] = counter; - - // Shift the constant pool entry. - constantPool[counter++] = constant; - } - else - { - // Remember an invalid index. - constantIndexMap[index] = -1; - } - } - - // Clear the remaining constant pool elements. - Arrays.fill(constantPool, counter, length, null); - - return counter; - } -} |