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Diffstat (limited to 'src/proguard/classfile/editor/ConstantPoolShrinker.java')
| -rw-r--r-- | src/proguard/classfile/editor/ConstantPoolShrinker.java | 604 |
1 files changed, 0 insertions, 604 deletions
diff --git a/src/proguard/classfile/editor/ConstantPoolShrinker.java b/src/proguard/classfile/editor/ConstantPoolShrinker.java deleted file mode 100644 index 0172321..0000000 --- a/src/proguard/classfile/editor/ConstantPoolShrinker.java +++ /dev/null @@ -1,604 +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.annotation.*; -import proguard.classfile.attribute.annotation.visitor.*; -import proguard.classfile.attribute.preverification.*; -import proguard.classfile.attribute.preverification.visitor.*; -import proguard.classfile.attribute.visitor.*; -import proguard.classfile.constant.*; -import proguard.classfile.constant.visitor.ConstantVisitor; -import proguard.classfile.instruction.*; -import proguard.classfile.instruction.visitor.InstructionVisitor; -import proguard.classfile.util.SimplifiedVisitor; -import proguard.classfile.visitor.*; - -import java.util.Arrays; - -/** - * This ClassVisitor removes all unused entries from the constant pool. - * - * @author Eric Lafortune - */ -public class ConstantPoolShrinker -extends SimplifiedVisitor -implements ClassVisitor, - MemberVisitor, - ConstantVisitor, - AttributeVisitor, - BootstrapMethodInfoVisitor, - InnerClassesInfoVisitor, - ExceptionInfoVisitor, - StackMapFrameVisitor, - VerificationTypeVisitor, - ParameterInfoVisitor, - LocalVariableInfoVisitor, - LocalVariableTypeInfoVisitor, - AnnotationVisitor, - ElementValueVisitor, - InstructionVisitor -{ - // A visitor info flag to indicate the constant is being used. - private static final Object USED = new Object(); - - private int[] constantIndexMap = new int[ClassConstants.TYPICAL_CONSTANT_POOL_SIZE]; - private final ConstantPoolRemapper constantPoolRemapper = new ConstantPoolRemapper(); - - - // Implementations for ClassVisitor. - - public void visitProgramClass(ProgramClass programClass) - { - // Mark this class's name. - markConstant(programClass, programClass.u2thisClass); - - // Mark the superclass class constant. - programClass.superClassConstantAccept(this); - - // Mark the interface class constants. - programClass.interfaceConstantsAccept(this); - - // Mark the constants referenced by the class members. - programClass.fieldsAccept(this); - programClass.methodsAccept(this); - - // Mark the 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 MemberVisitor. - - public void visitProgramMember(ProgramClass programClass, ProgramMember programMember) - { - // Mark the name and descriptor. - markConstant(programClass, programMember.u2nameIndex); - markConstant(programClass, programMember.u2descriptorIndex); - - // Mark the attributes. - programMember.attributesAccept(programClass, this); - } - - - // Implementations for ConstantVisitor. - - public void visitAnyConstant(Clazz clazz, Constant constant) - { - markAsUsed(constant); - } - - - public void visitStringConstant(Clazz clazz, StringConstant stringConstant) - { - markAsUsed(stringConstant); - - markConstant(clazz, stringConstant.u2stringIndex); - } - - - public void visitInvokeDynamicConstant(Clazz clazz, InvokeDynamicConstant invokeDynamicConstant) - { - markAsUsed(invokeDynamicConstant); - - markConstant(clazz, invokeDynamicConstant.u2nameAndTypeIndex); - - // Mark the bootstrap methods attribute. - clazz.attributesAccept(this); - } - - - public void visitMethodHandleConstant(Clazz clazz, MethodHandleConstant methodHandleConstant) - { - markAsUsed(methodHandleConstant); - - markConstant(clazz, methodHandleConstant.u2referenceIndex); - } - - - public void visitAnyRefConstant(Clazz clazz, RefConstant refConstant) - { - markAsUsed(refConstant); - - markConstant(clazz, refConstant.u2classIndex); - markConstant(clazz, refConstant.u2nameAndTypeIndex); - } - - - public void visitClassConstant(Clazz clazz, ClassConstant classConstant) - { - markAsUsed(classConstant); - - markConstant(clazz, classConstant.u2nameIndex); - } - - - public void visitMethodTypeConstant(Clazz clazz, MethodTypeConstant methodTypeConstant) - { - markAsUsed(methodTypeConstant); - - markConstant(clazz, methodTypeConstant.u2descriptorIndex); - } - - - public void visitNameAndTypeConstant(Clazz clazz, NameAndTypeConstant nameAndTypeConstant) - { - markAsUsed(nameAndTypeConstant); - - markConstant(clazz, nameAndTypeConstant.u2nameIndex); - markConstant(clazz, nameAndTypeConstant.u2descriptorIndex); - } - - - // Implementations for AttributeVisitor. - - public void visitAnyAttribute(Clazz clazz, Attribute attribute) - { - markConstant(clazz, attribute.u2attributeNameIndex); - } - - - public void visitBootstrapMethodsAttribute(Clazz clazz, BootstrapMethodsAttribute bootstrapMethodsAttribute) - { - markConstant(clazz, bootstrapMethodsAttribute.u2attributeNameIndex); - - // Mark the bootstrap method entries. - bootstrapMethodsAttribute.bootstrapMethodEntriesAccept(clazz, this); - } - - - public void visitSourceFileAttribute(Clazz clazz, SourceFileAttribute sourceFileAttribute) - { - markConstant(clazz, sourceFileAttribute.u2attributeNameIndex); - markConstant(clazz, sourceFileAttribute.u2sourceFileIndex); - } - - - public void visitSourceDirAttribute(Clazz clazz, SourceDirAttribute sourceDirAttribute) - { - markConstant(clazz, sourceDirAttribute.u2attributeNameIndex); - markConstant(clazz, sourceDirAttribute.u2sourceDirIndex); - } - - - public void visitInnerClassesAttribute(Clazz clazz, InnerClassesAttribute innerClassesAttribute) - { - markConstant(clazz, innerClassesAttribute.u2attributeNameIndex); - - // Mark the outer class entries. - innerClassesAttribute.innerClassEntriesAccept(clazz, this); - } - - - public void visitEnclosingMethodAttribute(Clazz clazz, EnclosingMethodAttribute enclosingMethodAttribute) - { - markConstant(clazz, enclosingMethodAttribute.u2attributeNameIndex); - markConstant(clazz, enclosingMethodAttribute.u2classIndex); - - if (enclosingMethodAttribute.u2nameAndTypeIndex != 0) - { - markConstant(clazz, enclosingMethodAttribute.u2nameAndTypeIndex); - } - } - - - public void visitSignatureAttribute(Clazz clazz, SignatureAttribute signatureAttribute) - { - markConstant(clazz, signatureAttribute.u2attributeNameIndex); - markConstant(clazz, signatureAttribute.u2signatureIndex); - } - - - public void visitConstantValueAttribute(Clazz clazz, Field field, ConstantValueAttribute constantValueAttribute) - { - markConstant(clazz, constantValueAttribute.u2attributeNameIndex); - markConstant(clazz, constantValueAttribute.u2constantValueIndex); - } - - - public void visitMethodParametersAttribute(Clazz clazz, Method method, MethodParametersAttribute methodParametersAttribute) - { - markConstant(clazz, methodParametersAttribute.u2attributeNameIndex); - - // Mark the constant pool entries referenced by the parameter information. - methodParametersAttribute.parametersAccept(clazz, method, this); - } - - - public void visitExceptionsAttribute(Clazz clazz, Method method, ExceptionsAttribute exceptionsAttribute) - { - markConstant(clazz, exceptionsAttribute.u2attributeNameIndex); - - // Mark the constant pool entries referenced by the exceptions. - exceptionsAttribute.exceptionEntriesAccept((ProgramClass)clazz, this); - } - - - public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute) - { - markConstant(clazz, codeAttribute.u2attributeNameIndex); - - // Mark the constant pool entries referenced by the instructions, - // by the exceptions, and by the attributes. - codeAttribute.instructionsAccept(clazz, method, this); - codeAttribute.exceptionsAccept(clazz, method, this); - codeAttribute.attributesAccept(clazz, method, this); - } - - - public void visitStackMapAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, StackMapAttribute stackMapAttribute) - { - markConstant(clazz, stackMapAttribute.u2attributeNameIndex); - - // Mark the constant pool entries referenced by the stack map frames. - stackMapAttribute.stackMapFramesAccept(clazz, method, codeAttribute, this); - } - - - public void visitStackMapTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, StackMapTableAttribute stackMapTableAttribute) - { - markConstant(clazz, stackMapTableAttribute.u2attributeNameIndex); - - // Mark the constant pool entries referenced by the stack map frames. - stackMapTableAttribute.stackMapFramesAccept(clazz, method, codeAttribute, this); - } - - - public void visitLocalVariableTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTableAttribute localVariableTableAttribute) - { - markConstant(clazz, localVariableTableAttribute.u2attributeNameIndex); - - // Mark the constant pool entries referenced by the local variables. - localVariableTableAttribute.localVariablesAccept(clazz, method, codeAttribute, this); - } - - - public void visitLocalVariableTypeTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTypeTableAttribute localVariableTypeTableAttribute) - { - markConstant(clazz, localVariableTypeTableAttribute.u2attributeNameIndex); - - // Mark the constant pool entries referenced by the local variable types. - localVariableTypeTableAttribute.localVariablesAccept(clazz, method, codeAttribute, this); - } - - - public void visitAnyAnnotationsAttribute(Clazz clazz, AnnotationsAttribute annotationsAttribute) - { - markConstant(clazz, annotationsAttribute.u2attributeNameIndex); - - // Mark the constant pool entries referenced by the annotations. - annotationsAttribute.annotationsAccept(clazz, this); - } - - - public void visitAnyParameterAnnotationsAttribute(Clazz clazz, Method method, ParameterAnnotationsAttribute parameterAnnotationsAttribute) - { - markConstant(clazz, parameterAnnotationsAttribute.u2attributeNameIndex); - - // Mark the constant pool entries referenced by the annotations. - parameterAnnotationsAttribute.annotationsAccept(clazz, method, this); - } - - - public void visitAnnotationDefaultAttribute(Clazz clazz, Method method, AnnotationDefaultAttribute annotationDefaultAttribute) - { - markConstant(clazz, annotationDefaultAttribute.u2attributeNameIndex); - - // Mark the constant pool entries referenced by the element value. - annotationDefaultAttribute.defaultValueAccept(clazz, this); - } - - - // Implementations for BootstrapMethodInfoVisitor. - - public void visitBootstrapMethodInfo(Clazz clazz, BootstrapMethodInfo bootstrapMethodInfo) - { - markConstant(clazz, bootstrapMethodInfo.u2methodHandleIndex); - - // Mark the constant pool entries referenced by the arguments. - bootstrapMethodInfo.methodArgumentsAccept(clazz, this); - } - - - // Implementations for InnerClassesInfoVisitor. - - public void visitInnerClassesInfo(Clazz clazz, InnerClassesInfo innerClassesInfo) - { - innerClassesInfo.innerClassConstantAccept(clazz, this); - innerClassesInfo.outerClassConstantAccept(clazz, this); - innerClassesInfo.innerNameConstantAccept(clazz, this); - } - - - // Implementations for ExceptionInfoVisitor. - - public void visitExceptionInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, ExceptionInfo exceptionInfo) - { - if (exceptionInfo.u2catchType != 0) - { - markConstant(clazz, exceptionInfo.u2catchType); - } - } - - - // Implementations for StackMapFrameVisitor. - - public void visitAnyStackMapFrame(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, StackMapFrame stackMapFrame) {} - - - public void visitSameOneFrame(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, SameOneFrame sameOneFrame) - { - // Mark the constant pool entries referenced by the verification types. - sameOneFrame.stackItemAccept(clazz, method, codeAttribute, offset, this); - } - - - public void visitMoreZeroFrame(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, MoreZeroFrame moreZeroFrame) - { - // Mark the constant pool entries referenced by the verification types. - moreZeroFrame.additionalVariablesAccept(clazz, method, codeAttribute, offset, this); - } - - - public void visitFullFrame(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, FullFrame fullFrame) - { - // Mark the constant pool entries referenced by the verification types. - fullFrame.variablesAccept(clazz, method, codeAttribute, offset, this); - fullFrame.stackAccept(clazz, method, codeAttribute, offset, this); - } - - - // Implementations for VerificationTypeVisitor. - - public void visitAnyVerificationType(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, VerificationType verificationType) {} - - - public void visitObjectType(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, ObjectType objectType) - { - markConstant(clazz, objectType.u2classIndex); - } - - - // Implementations for ParameterInfoVisitor. - - public void visitParameterInfo(Clazz clazz, Method method, int parameterIndex, ParameterInfo parameterInfo) - { - markConstant(clazz, parameterInfo.u2nameIndex); - } - - - // Implementations for LocalVariableInfoVisitor. - - public void visitLocalVariableInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableInfo localVariableInfo) - { - markConstant(clazz, localVariableInfo.u2nameIndex); - markConstant(clazz, localVariableInfo.u2descriptorIndex); - } - - - // Implementations for LocalVariableTypeInfoVisitor. - - public void visitLocalVariableTypeInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTypeInfo localVariableTypeInfo) - { - markConstant(clazz, localVariableTypeInfo.u2nameIndex); - markConstant(clazz, localVariableTypeInfo.u2signatureIndex); - } - - - // Implementations for AnnotationVisitor. - - public void visitAnnotation(Clazz clazz, Annotation annotation) - { - markConstant(clazz, annotation.u2typeIndex); - - // Mark the constant pool entries referenced by the element values. - annotation.elementValuesAccept(clazz, this); - } - - - // Implementations for ElementValueVisitor. - - public void visitConstantElementValue(Clazz clazz, Annotation annotation, ConstantElementValue constantElementValue) - { - if (constantElementValue.u2elementNameIndex != 0) - { - markConstant(clazz, constantElementValue.u2elementNameIndex); - } - - markConstant(clazz, constantElementValue.u2constantValueIndex); - } - - - public void visitEnumConstantElementValue(Clazz clazz, Annotation annotation, EnumConstantElementValue enumConstantElementValue) - { - if (enumConstantElementValue.u2elementNameIndex != 0) - { - markConstant(clazz, enumConstantElementValue.u2elementNameIndex); - } - - markConstant(clazz, enumConstantElementValue.u2typeNameIndex); - markConstant(clazz, enumConstantElementValue.u2constantNameIndex); - } - - - public void visitClassElementValue(Clazz clazz, Annotation annotation, ClassElementValue classElementValue) - { - if (classElementValue.u2elementNameIndex != 0) - { - markConstant(clazz, classElementValue.u2elementNameIndex); - } - - markConstant(clazz, classElementValue.u2classInfoIndex); - } - - - public void visitAnnotationElementValue(Clazz clazz, Annotation annotation, AnnotationElementValue annotationElementValue) - { - if (annotationElementValue.u2elementNameIndex != 0) - { - markConstant(clazz, annotationElementValue.u2elementNameIndex); - } - - // Mark the constant pool entries referenced by the annotation. - annotationElementValue.annotationAccept(clazz, this); - } - - - public void visitArrayElementValue(Clazz clazz, Annotation annotation, ArrayElementValue arrayElementValue) - { - if (arrayElementValue.u2elementNameIndex != 0) - { - markConstant(clazz, arrayElementValue.u2elementNameIndex); - } - - // Mark the constant pool entries referenced by the element values. - arrayElementValue.elementValuesAccept(clazz, annotation, this); - } - - - // Implementations for InstructionVisitor. - - public void visitAnyInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, Instruction instruction) {} - - - public void visitConstantInstruction(Clazz clazz, Method method, CodeAttribute codeAttribute, int offset, ConstantInstruction constantInstruction) - { - markConstant(clazz, constantInstruction.constantIndex); - } - - - // Small utility methods. - - /** - * Marks the given constant pool entry of the given class. This includes - * visiting any referenced objects. - */ - private void markConstant(Clazz clazz, int index) - { - clazz.constantPoolEntryAccept(index, this); - } - - - /** - * Marks the given visitor accepter as being used. - */ - private void markAsUsed(Constant constant) - { - constant.setVisitorInfo(USED); - } - - - /** - * Returns whether the given visitor accepter has been marked as being used. - */ - private boolean isUsed(VisitorAccepter visitorAccepter) - { - return visitorAccepter.getVisitorInfo() == USED; - } - - - /** - * Removes all constants 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.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 = 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; - } -} |