diff options
Diffstat (limited to 'src/proguard/classfile/util/StringSharer.java')
-rw-r--r-- | src/proguard/classfile/util/StringSharer.java | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/src/proguard/classfile/util/StringSharer.java b/src/proguard/classfile/util/StringSharer.java new file mode 100644 index 0000000..56de7c5 --- /dev/null +++ b/src/proguard/classfile/util/StringSharer.java @@ -0,0 +1,155 @@ +/* + * 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.util; + +import proguard.classfile.*; +import proguard.classfile.attribute.Attribute; +import proguard.classfile.attribute.visitor.AttributeVisitor; +import proguard.classfile.constant.*; +import proguard.classfile.constant.visitor.ConstantVisitor; +import proguard.classfile.visitor.ClassVisitor; + +/** + * This ClassVisitor shares strings in the class files that it visits. + * + * @author Eric Lafortune + */ +public class StringSharer +extends SimplifiedVisitor +implements ClassVisitor, + ConstantVisitor, + AttributeVisitor +{ + // A fields acting as an argument for the visitor methods. + private String name; + private String type; + + + // Implementations for ClassVisitor. + + public void visitProgramClass(ProgramClass programClass) + { + // Replace name strings in the constant pool by shared strings. + programClass.constantPoolEntriesAccept(this); + + // Replace attribute name strings in the constant pool by internalized + // strings. + programClass.attributesAccept(this); + } + + + public void visitLibraryClass(LibraryClass libraryClass) + { + // Replace the super class name string by the shared name string. + Clazz superClass = libraryClass.superClass; + if (superClass != null) + { + libraryClass.superClassName = superClass.getName(); + } + } + + + // Implementations for ConstantVisitor. + + + public void visitAnyConstant(Clazz clazz, Constant constant) {} + + + public void visitAnyStringConstant(Clazz clazz, StringConstant stringConstant) + { + Member referencedMember = stringConstant.referencedMember; + if (referencedMember != null) + { + Clazz referencedClass = stringConstant.referencedClass; + + // Put the actual class member's name in the class pool. + name = referencedMember.getName(referencedClass); + clazz.constantPoolEntryAccept(stringConstant.u2stringIndex, this); + } + } + + + public void visitAnyRefConstant(Clazz clazz, RefConstant refConstant) + { + Member referencedMember = refConstant.referencedMember; + if (referencedMember != null) + { + Clazz referencedClass = refConstant.referencedClass; + + // Put the actual class member's name and type strings in the class + // pool. + name = referencedMember.getName(referencedClass); + type = referencedMember.getDescriptor(referencedClass); + clazz.constantPoolEntryAccept(refConstant.u2nameAndTypeIndex, this); + } + } + + + public void visitNameAndTypeConstant(Clazz clazz, NameAndTypeConstant nameAndTypeConstant) + { + if (name != null) + { + // Put the actual class member's name and type strings in the class + // pool. + clazz.constantPoolEntryAccept(nameAndTypeConstant.u2nameIndex, this); + name = type; + clazz.constantPoolEntryAccept(nameAndTypeConstant.u2descriptorIndex, this); + } + } + + + public void visitClassConstant(Clazz clazz, ClassConstant classConstant) + { + Clazz referencedClass = classConstant.referencedClass; + if (referencedClass != null) + { + // Put the actual class's name string in the class pool. + name = referencedClass.getName(); + clazz.constantPoolEntryAccept(classConstant.u2nameIndex, this); + } + } + + + public void visitUtf8Constant(Clazz clazz, Utf8Constant utf8Constant) + { + // Do we have a new string to put into this constant? + if (name != null) + { + // Replace the string, if it's actually the same. + if (name.equals(utf8Constant.getString())) + { + utf8Constant.setString(name); + } + + name = null; + } + } + + + // Implementations for AttributeVisitor. + + public void visitAnyAttribute(Clazz clazz, Attribute attribute) + { + // Put the internalized attribute's name string in the class pool. + name = attribute.getAttributeName(clazz).intern(); + clazz.constantPoolEntryAccept(attribute.u2attributeNameIndex, this); + } +} |