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Diffstat (limited to 'src/proguard/shrink/LocalVariableTypeUsageMarker.java')
| -rw-r--r-- | src/proguard/shrink/LocalVariableTypeUsageMarker.java | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/src/proguard/shrink/LocalVariableTypeUsageMarker.java b/src/proguard/shrink/LocalVariableTypeUsageMarker.java new file mode 100644 index 0000000..573d8f6 --- /dev/null +++ b/src/proguard/shrink/LocalVariableTypeUsageMarker.java @@ -0,0 +1,178 @@ +/* + * ProGuard -- shrinking, optimization, obfuscation, and preverification + * of Java bytecode. + * + * Copyright (c) 2002-2013 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.shrink; + +import proguard.classfile.*; +import proguard.classfile.attribute.*; +import proguard.classfile.attribute.visitor.*; +import proguard.classfile.constant.Constant; +import proguard.classfile.constant.visitor.ConstantVisitor; +import proguard.classfile.util.SimplifiedVisitor; +import proguard.classfile.visitor.ClassVisitor; + +/** + * This AttributeVisitor recursively marks all information that points to used + * classes, in the LocalVariableTable and LocalVariableTypeTable attributes that + * it visits. + * + * @see UsageMarker + * + * @author Eric Lafortune + */ +public class LocalVariableTypeUsageMarker +extends SimplifiedVisitor +implements AttributeVisitor, + LocalVariableInfoVisitor, + LocalVariableTypeInfoVisitor, + ClassVisitor, + ConstantVisitor +{ + private final UsageMarker usageMarker; + + // Fields acting as a return parameters for several methods. + private boolean tableUsed; + private boolean variableInfoUsed; + + + /** + * Creates a new LocalVariableTypeUsageMarker. + * @param usageMarker the usage marker that is used to mark the classes + * and class members. + */ + public LocalVariableTypeUsageMarker(UsageMarker usageMarker) + { + this.usageMarker = usageMarker; + } + + + // Implementations for AttributeVisitor. + + public void visitAnyAttribute(Clazz clazz, Attribute attribute) {} + + + public void visitLocalVariableTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTableAttribute localVariableTableAttribute) + { + // Check and mark the individual entries. + tableUsed = false; + localVariableTableAttribute.localVariablesAccept(clazz, method, codeAttribute, this); + + // Mark the table if any of the entries is marked. + if (tableUsed) + { + usageMarker.markAsUsed(localVariableTableAttribute); + + markConstant(clazz, localVariableTableAttribute.u2attributeNameIndex); + } + } + + + public void visitLocalVariableTypeTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTypeTableAttribute localVariableTypeTableAttribute) + { + // Check and mark the individual entries. + tableUsed = false; + localVariableTypeTableAttribute.localVariablesAccept(clazz, method, codeAttribute, this); + + // Mark the table if any of the entries is marked. + if (tableUsed) + { + usageMarker.markAsUsed(localVariableTypeTableAttribute); + + markConstant(clazz, localVariableTypeTableAttribute.u2attributeNameIndex); + } + } + + + // Implementations for LocalVariableInfoVisitor. + + public void visitLocalVariableInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableInfo localVariableInfo) + { + // Only keep the local variable info if all of its classes are used. + variableInfoUsed = true; + localVariableInfo.referencedClassAccept(this); + + if (variableInfoUsed) + { + // We got a positive used flag, so the local variable info is useful. + usageMarker.markAsUsed(localVariableInfo); + + markConstant(clazz, localVariableInfo.u2nameIndex); + markConstant(clazz, localVariableInfo.u2descriptorIndex); + + tableUsed = true; + } + } + + + // Implementations for LocalVariableTypeInfoVisitor. + + public void visitLocalVariableTypeInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTypeInfo localVariableTypeInfo) + { + // Only keep the local variable info if all of its classes are used. + variableInfoUsed = true; + localVariableTypeInfo.referencedClassesAccept(this); + + if (variableInfoUsed) + { + // We got a positive used flag, so the local variable info is useful. + usageMarker.markAsUsed(localVariableTypeInfo); + + markConstant(clazz, localVariableTypeInfo.u2nameIndex); + markConstant(clazz, localVariableTypeInfo.u2signatureIndex); + + tableUsed = true; + } + } + + + // Implementations for ClassVisitor. + + public void visitLibraryClass(LibraryClass libraryClass) {} + + + public void visitProgramClass(ProgramClass programClass) + { + // Don't keep the local variable info if one of its classes is not used. + if (!usageMarker.isUsed(programClass)) + { + variableInfoUsed = false; + } + } + + + // Implementations for ConstantVisitor. + + public void visitAnyConstant(Clazz clazz, Constant constant) + { + usageMarker.markAsUsed(constant); + } + + + // Small utility methods. + + /** + * Marks the given constant pool entry of the given class. + */ + private void markConstant(Clazz clazz, int index) + { + clazz.constantPoolEntryAccept(index, this); + } +} |