15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2012 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)package org.chromium.tools.findbugs.plugin; 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)import org.apache.bcel.classfile.Code; 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)import edu.umd.cs.findbugs.BugInstance; 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)import edu.umd.cs.findbugs.BugReporter; 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)import edu.umd.cs.findbugs.bcel.OpcodeStackDetector; 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)/** 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * This class detects the synchronized(this). 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * The pattern of byte code of synchronized(this) is 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * aload_0 # Load the 'this' pointer on top of stack 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * dup # Duplicate the 'this' pointer 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * astore_x # Store this for late use, it might be astore. 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) * monitorenter 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) */ 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)public class SynchronizedThisDetector extends OpcodeStackDetector { 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private final int PATTERN[] = {ALOAD_0, DUP, 0xff, 0xff, MONITORENTER}; 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private int mStep = 0; 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private BugReporter mBugReporter; 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public SynchronizedThisDetector(BugReporter bugReporter) { 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mBugReporter = bugReporter; 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) @Override 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public void visit(Code code) { 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mStep = 0; 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) super.visit(code); 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) @Override 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public void sawOpcode(int seen) { 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (PATTERN[mStep] == seen) { 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mStep++; 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) if (mStep == PATTERN.length) { 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mBugReporter.reportBug(new BugInstance(this, "CHROMIUM_SYNCHRONIZED_THIS", 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) NORMAL_PRIORITY) 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) .addClassAndMethod(this) 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) .addSourceLine(this)); 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mStep = 0; 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return; 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } else if (mStep == 2) { 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This could be astore_x 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) switch (seen) { 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) case ASTORE_0: 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) case ASTORE_1: 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) case ASTORE_2: 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) case ASTORE_3: 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mStep += 2; 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) break; 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) case ASTORE: 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mStep++; 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) break; 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) default: 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mStep = 0; 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) break; 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } else if (mStep == 3) { 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Could be any byte following the ASTORE. 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mStep++; 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } else { 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) mStep = 0; 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 74