| /* |
| * ProGuard -- shrinking, optimization, obfuscation, and preverification |
| * of Java bytecode. |
| * |
| * Copyright (c) 2002-2017 Eric Lafortune @ GuardSquare |
| * |
| * 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.util.SimplifiedVisitor; |
| |
| import java.util.Arrays; |
| |
| /** |
| * This AttributeVisitor trims the line number table attributes that it visits. |
| * |
| * @author Eric Lafortune |
| */ |
| public class LineNumberTableAttributeTrimmer |
| extends SimplifiedVisitor |
| implements AttributeVisitor |
| { |
| // Implementations for AttributeVisitor. |
| |
| public void visitAnyAttribute(Clazz clazz, Attribute attribute) {} |
| |
| |
| public void visitLineNumberTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LineNumberTableAttribute lineNumberTableAttribute) |
| { |
| LineNumberInfo[] lineNumberTable = lineNumberTableAttribute.lineNumberTable; |
| int lineNumberTableLength = lineNumberTableAttribute.u2lineNumberTableLength; |
| |
| // Overwrite all empty line number entries. |
| int newIndex = 0; |
| for (int index = 0; index < lineNumberTableLength; index++) |
| { |
| LineNumberInfo lineNumberInfo = lineNumberTable[index]; |
| |
| int startPC = lineNumberInfo.u2startPC; |
| int lineNumber = lineNumberInfo.u2lineNumber; |
| |
| // The offset must lie inside the code. |
| // The offset must be smaller than the next one. |
| // The line number should be different from the previous one. |
| if (startPC < codeAttribute.u4codeLength && |
| |
| (index == lineNumberTableLength - 1 || |
| startPC < lineNumberTable[index + 1].u2startPC) && |
| |
| (index == 0 || |
| lineNumber != lineNumberTable[index - 1].u2lineNumber)) |
| { |
| lineNumberTable[newIndex++] = lineNumberInfo; |
| } |
| } |
| |
| // Clear the unused array entries. |
| Arrays.fill(lineNumberTable, newIndex, lineNumberTableAttribute.u2lineNumberTableLength, null); |
| |
| lineNumberTableAttribute.u2lineNumberTableLength = newIndex; |
| } |
| } |