01: /*
02: * Bytecode Analysis Framework
03: * Copyright (C) 2003,2004 University of Maryland
04: *
05: * This library is free software; you can redistribute it and/or
06: * modify it under the terms of the GNU Lesser General Public
07: * License as published by the Free Software Foundation; either
08: * version 2.1 of the License, or (at your option) any later version.
09: *
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
48: public MatchResult match(InstructionHandle handle,
49: ConstantPoolGen cpg, ValueNumberFrame before,
50: ValueNumberFrame after, BindingSet bindingSet)
51: throws DataflowAnalysisException {
52:
53: if (handle.getInstruction().getOpcode() == opcode)
54: return new MatchResult(this , bindingSet);
55: else
56: return null;
57:
58: }
59:
60: @Override
61: public boolean acceptBranch(Edge edge, InstructionHandle source) {
62: return true;
63: }
64:
65: @Override
66: public int minOccur() {
67: return 1;
68: }
69:
70: @Override
71: public int maxOccur() {
72: return 1;
73: }
74: }
75:
76: // vim:ts=4
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