1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 package openjdk.jcov.filter.simplemethods;
  26 
  27 import org.objectweb.asm.tree.ClassNode;
  28 import org.objectweb.asm.tree.MethodNode;
  29 
  30 import java.util.function.BiPredicate;
  31 
  32 import static org.objectweb.asm.Opcodes.PUTFIELD;
  33 import static org.objectweb.asm.Opcodes.PUTSTATIC;
  34 import static org.objectweb.asm.Opcodes.RETURN;
  35 
  36 /**
  37  * Identifies simple setters. A simple setter is a method obtaining a value with a "simple" code and
  38  * assigning a field with it.
  39  * @see Utils#isSimpleInstruction(int)
  40  */
  41 public class Setters implements BiPredicate<ClassNode, MethodNode> {
  42     @Override
  43     public boolean test(ClassNode clazz, MethodNode m) {
  44         int index = 0;
  45         int opCode = -1;
  46         //skip all instructions allowed to get values
  47         for(; index < m.instructions.size(); index++) {
  48             opCode = m.instructions.get(index).getOpcode();
  49             if(opCode >=0) {
  50                 if (!Utils.isSimpleInstruction(opCode)) {
  51                     break;
  52                 }
  53             }
  54         }
  55         //that should be an instruction setting a field
  56         if(opCode != PUTFIELD && opCode != PUTSTATIC) {
  57             return false;
  58         }
  59         //find next
  60         for(index++; index < m.instructions.size(); index++) {
  61             opCode = m.instructions.get(index).getOpcode();
  62             if(opCode >=0) {
  63                 if (!Utils.isSimpleInstruction(opCode)) {
  64                     break;
  65                 }
  66             }
  67         }
  68         //and that should be a return
  69         return opCode == RETURN;
  70     }
  71 }