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Diffstat (limited to 'src/proguard/obfuscate/ParameterNameMarker.java')
-rw-r--r-- | src/proguard/obfuscate/ParameterNameMarker.java | 128 |
1 files changed, 128 insertions, 0 deletions
diff --git a/src/proguard/obfuscate/ParameterNameMarker.java b/src/proguard/obfuscate/ParameterNameMarker.java new file mode 100644 index 0000000..22af125 --- /dev/null +++ b/src/proguard/obfuscate/ParameterNameMarker.java @@ -0,0 +1,128 @@ +/* + * 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.obfuscate; + +import proguard.classfile.*; +import proguard.classfile.attribute.*; +import proguard.classfile.attribute.visitor.AttributeVisitor; +import proguard.classfile.util.*; + +/** + * This AttributeVisitor trims and marks all local variable (type) table + * attributes that it visits. It keeps parameter names and types and removes + * the ordinary local variable names and types. + * + * @author Eric Lafortune + */ +public class ParameterNameMarker +extends SimplifiedVisitor +implements AttributeVisitor +{ + private final AttributeVisitor attributeUsageMarker; + + + /** + * Constructs a new ParameterNameMarker. + * @param attributeUsageMarker the marker that will be used to mark + * attributes containing local variable info. + */ + public ParameterNameMarker(AttributeVisitor attributeUsageMarker) + { + this.attributeUsageMarker = attributeUsageMarker; + } + + + // Implementations for AttributeVisitor. + + public void visitAnyAttribute(Clazz clazz, Attribute attribute) {} + + + public void visitLocalVariableTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTableAttribute localVariableTableAttribute) + { + if (!AttributeUsageMarker.isUsed(localVariableTableAttribute) && + hasParameters(clazz, method)) + { + // Shift the entries that start at offset 0 to the front. + int newIndex = 0; + + for (int index = 0; index < localVariableTableAttribute.u2localVariableTableLength; index++) + { + LocalVariableInfo localVariableInfo = + localVariableTableAttribute.localVariableTable[index]; + + if (localVariableInfo.u2startPC == 0) + { + localVariableTableAttribute.localVariableTable[newIndex++] = + localVariableInfo; + } + } + + // Trim the table. + localVariableTableAttribute.u2localVariableTableLength = newIndex; + + // Mark the table if there are any entries. + if (newIndex > 0) + { + attributeUsageMarker.visitLocalVariableTableAttribute(clazz, method, codeAttribute, localVariableTableAttribute); + } + } + } + + + public void visitLocalVariableTypeTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LocalVariableTypeTableAttribute localVariableTypeTableAttribute) + { + if (!AttributeUsageMarker.isUsed(localVariableTypeTableAttribute) && + hasParameters(clazz, method)) + { + // Shift the entries that start at offset 0 to the front. + int newIndex = 0; + + for (int index = 0; index < localVariableTypeTableAttribute.u2localVariableTypeTableLength; index++) + { + LocalVariableTypeInfo localVariableTypeInfo = + localVariableTypeTableAttribute.localVariableTypeTable[index]; + + if (localVariableTypeInfo.u2startPC == 0) + { + localVariableTypeTableAttribute.localVariableTypeTable[newIndex++] = + localVariableTypeInfo; + } + } + + // Trim the table. + localVariableTypeTableAttribute.u2localVariableTypeTableLength = newIndex; + + // Mark the table if there are any entries. + if (newIndex > 0) + { + attributeUsageMarker.visitLocalVariableTypeTableAttribute(clazz, method, codeAttribute, localVariableTypeTableAttribute); + } + } + } + + + // Small utility methods. + + private boolean hasParameters(Clazz clazz, Method method) + { + return method.getDescriptor(clazz).charAt(1) != ClassConstants.INTERNAL_METHOD_ARGUMENTS_CLOSE; + } +}
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