| /* |
| * 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.optimize.peephole; |
| |
| import proguard.classfile.*; |
| import proguard.classfile.attribute.*; |
| import proguard.classfile.attribute.visitor.*; |
| import proguard.classfile.util.*; |
| import proguard.classfile.visitor.*; |
| |
| import java.util.*; |
| |
| /** |
| * This ClassVisitor disambiguates line numbers, in the classes that it |
| * visits. It shifts line numbers that originate from different classes |
| * (e.g. due to method inlining or class merging) to blocks that don't |
| * overlap with the main line numbers and with each other. The line numbers |
| * then uniquely identify the inlined and merged code in the classes. |
| * |
| * @author Eric Lafortune |
| */ |
| public class LineNumberLinearizer |
| extends SimplifiedVisitor |
| implements ClassVisitor, |
| MemberVisitor, |
| AttributeVisitor, |
| LineNumberInfoVisitor |
| { |
| private static final boolean DEBUG = false; |
| |
| public static final int SHIFT_ROUNDING = 1000; |
| private static final int SHIFT_ROUNDING_LIMIT = 50000; |
| |
| |
| private Stack enclosingLineNumbers = new Stack(); |
| private LineNumberInfo previousLineNumberInfo; |
| private int highestUsedLineNumber; |
| private int currentLineNumberShift; |
| |
| |
| // Implementations for ClassVisitor. |
| |
| public void visitProgramClass(ProgramClass programClass) |
| { |
| // Find the highest line number in the entire class. |
| LineNumberRangeFinder lineNumberRangeFinder = |
| new LineNumberRangeFinder(); |
| |
| programClass.methodsAccept(new AllAttributeVisitor(true, |
| new AllLineNumberInfoVisitor( |
| lineNumberRangeFinder))); |
| |
| // Are there any inlined line numbers? |
| if (lineNumberRangeFinder.hasSource()) |
| { |
| // Remember the minimum initial shift. |
| highestUsedLineNumber = lineNumberRangeFinder.getHighestLineNumber(); |
| |
| // Shift the inlined line numbers. |
| programClass.methodsAccept(this); |
| } |
| } |
| |
| |
| // Implementations for MemberVisitor. |
| |
| public void visitProgramMethod(ProgramClass programClass, ProgramMethod programMethod) |
| { |
| programMethod.attributesAccept(programClass, this); |
| } |
| |
| |
| // Implementations for AttributeVisitor. |
| |
| public void visitAnyAttribute(Clazz clazz, Attribute attribute) {} |
| |
| |
| public void visitCodeAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute) |
| { |
| codeAttribute.attributesAccept(clazz, method, this); |
| } |
| |
| |
| public void visitLineNumberTableAttribute(Clazz clazz, Method method, CodeAttribute codeAttribute, LineNumberTableAttribute lineNumberTableAttribute) |
| { |
| if (DEBUG) |
| { |
| System.out.println("LineNumberLinearizer ["+clazz.getName()+"."+method.getName(clazz)+method.getDescriptor(clazz)+"]:"); |
| } |
| |
| enclosingLineNumbers.clear(); |
| previousLineNumberInfo = null; |
| |
| // Process all line numbers. |
| lineNumberTableAttribute.lineNumbersAccept(clazz, method, codeAttribute, this); |
| } |
| |
| |
| // Implementations for LineNumberInfoVisitor. |
| |
| public void visitLineNumberInfo(Clazz clazz, Method method, CodeAttribute codeAttribute, LineNumberInfo lineNumberInfo) |
| { |
| String source = lineNumberInfo.getSource(); |
| |
| if (DEBUG) |
| { |
| System.out.print(" [" + lineNumberInfo.u2startPC + "] line " + lineNumberInfo.u2lineNumber + (source == null ? "" : " [" + source + "]")); |
| } |
| |
| // Is it an inlined line number? |
| if (source != null) |
| { |
| ExtendedLineNumberInfo extendedLineNumberInfo = |
| (ExtendedLineNumberInfo)lineNumberInfo; |
| |
| int lineNumber = extendedLineNumberInfo.u2lineNumber; |
| |
| // Are we entering or exiting a new inlined block? |
| if (previousLineNumberInfo == null || |
| previousLineNumberInfo.getSource() != source) |
| { |
| // Are we entering a new inlined block? |
| if (lineNumber != MethodInliner.INLINED_METHOD_END_LINE_NUMBER) |
| { |
| // Remember information about the inlined block. |
| enclosingLineNumbers.push(previousLineNumberInfo != null ? |
| new MyLineNumberBlock(currentLineNumberShift, |
| previousLineNumberInfo.u2lineNumber, |
| previousLineNumberInfo.getSource()) : |
| new MyLineNumberBlock(0, 0, null)); |
| |
| // Parse the end line number from the source string, |
| // so we know how large a block this will be. |
| int separatorIndex1 = source.indexOf(':'); |
| int separatorIndex2 = source.indexOf(':', separatorIndex1 + 1); |
| |
| int startLineNumber = Integer.parseInt(source.substring(separatorIndex1 + 1, separatorIndex2)); |
| int endLineNumber = Integer.parseInt(source.substring(separatorIndex2 + 1)); |
| |
| // Start shifting, if necessary, so the block ends up beyond |
| // the highest used line number. We're striving for rounded |
| // shifts, unless we've reached a given limit, to avoid |
| // running out of line numbers too quickly. |
| currentLineNumberShift = |
| highestUsedLineNumber > SHIFT_ROUNDING_LIMIT ? |
| highestUsedLineNumber - startLineNumber + 1 : |
| startLineNumber > highestUsedLineNumber ? 0 : |
| (highestUsedLineNumber - startLineNumber + SHIFT_ROUNDING) |
| / SHIFT_ROUNDING * SHIFT_ROUNDING; |
| |
| highestUsedLineNumber = endLineNumber + currentLineNumberShift; |
| |
| if (DEBUG) |
| { |
| System.out.print(" (enter with shift "+currentLineNumberShift+")"); |
| } |
| |
| // Apply the shift. |
| lineNumberInfo.u2lineNumber += currentLineNumberShift; |
| } |
| |
| // TODO: There appear to be cases where the stack is empty at this point, so we've added a check. |
| else if (enclosingLineNumbers.isEmpty()) |
| { |
| if (DEBUG) |
| { |
| System.err.println("Problem linearizing line numbers for optimized code ("+clazz.getName()+"."+method.getName(clazz)+")"); |
| } |
| } |
| |
| // Are we exiting an inlined block? |
| else |
| { |
| // Pop information about the enclosing line number. |
| MyLineNumberBlock lineNumberBlock = |
| (MyLineNumberBlock)enclosingLineNumbers.pop(); |
| |
| // Set this end of the block to the line at which it was |
| // inlined. |
| extendedLineNumberInfo.u2lineNumber = lineNumberBlock.enclosingLineNumber; |
| extendedLineNumberInfo.source = lineNumberBlock.enclosingSource; |
| |
| // Reset the shift to the shift of the block. |
| currentLineNumberShift = lineNumberBlock.lineNumberShift; |
| |
| if (DEBUG) |
| { |
| System.out.print(" (exit to shift "+currentLineNumberShift+")"); |
| } |
| } |
| } |
| else |
| { |
| if (DEBUG) |
| { |
| System.out.print(" (apply shift "+currentLineNumberShift+")"); |
| } |
| |
| // Apply the shift. |
| lineNumberInfo.u2lineNumber += currentLineNumberShift; |
| } |
| } |
| |
| previousLineNumberInfo = lineNumberInfo; |
| |
| if (DEBUG) |
| { |
| System.out.println(" -> line " + lineNumberInfo.u2lineNumber); |
| } |
| } |
| |
| |
| /** |
| * This class represents a block of line numbers that originates from the |
| * same inlined method. |
| */ |
| private static class MyLineNumberBlock |
| { |
| public final int lineNumberShift; |
| public final int enclosingLineNumber; |
| public final String enclosingSource; |
| |
| public MyLineNumberBlock(int lineNumberShift, |
| int enclosingLineNumber, |
| String enclosingSource) |
| { |
| this.lineNumberShift = lineNumberShift; |
| this.enclosingLineNumber = enclosingLineNumber; |
| this.enclosingSource = enclosingSource; |
| } |
| } |
| } |