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Java > Open Source Codes > edu > umd > cs > findbugs > ba > bcp > Opcode


1 /*
2  * Bytecode Analysis Framework
3  * Copyright (C) 2003,2004 University of Maryland
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this library; if not, write to the Free Software
17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */

19
20 package edu.umd.cs.findbugs.ba.bcp;
21
22 import org.apache.bcel.generic.ConstantPoolGen;
23 import org.apache.bcel.generic.InstructionHandle;
24
25 import edu.umd.cs.findbugs.ba.DataflowAnalysisException;
26 import edu.umd.cs.findbugs.ba.Edge;
27 import edu.umd.cs.findbugs.ba.vna.ValueNumberFrame;
28
29 /**
30  * PatternElement to match instructions with a particular opcode.
31  *
32  * @author David Hovemeyer
33  * @see PatternElement
34  */

35 public class Opcode extends PatternElement {
36     private int opcode;
37
38     /**
39      * Constructor.
40      *
41      * @param opcode the opcode to match
42      */

43     public Opcode(int opcode) {
44         this.opcode = opcode;
45     }
46
47     @Override JavaDoc
48          public MatchResult match(InstructionHandle handle, ConstantPoolGen cpg,
49                              ValueNumberFrame before, ValueNumberFrame after, BindingSet bindingSet) throws DataflowAnalysisException {
50
51         if (handle.getInstruction().getOpcode() == opcode)
52             return new MatchResult(this, bindingSet);
53         else
54             return null;
55
56     }
57
58     @Override JavaDoc
59          public boolean acceptBranch(Edge edge, InstructionHandle source) {
60         return true;
61     }
62
63     @Override JavaDoc
64          public int minOccur() {
65         return 1;
66     }
67
68     @Override JavaDoc
69          public int maxOccur() {
70         return 1;
71     }
72 }
73
74 // vim:ts=4
75
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