01: /* Soot - a J*va Optimization Framework
02: * Copyright (C) 1997-1999 Raja Vallee-Rai
03: *
04: * This library is free software; you can redistribute it and/or
05: * modify it under the terms of the GNU Lesser General Public
06: * License as published by the Free Software Foundation; either
07: * version 2.1 of the License, or (at your option) any later version.
08: *
09: * This library is distributed in the hope that it will be useful,
10: * but WITHOUT ANY WARRANTY; without even the implied warranty of
11: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12: * Lesser General Public License for more details.
13: *
14: * You should have received a copy of the GNU Lesser General Public
15: * License along with this library; if not, write to the
16: * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17: * Boston, MA 02111-1307, USA.
18: */
19:
20: /*
21: * Modified by the Sable Research Group and others 1997-1999.
22: * See the 'credits' file distributed with Soot for the complete list of
23: * contributors. (Soot is distributed at http://www.sable.mcgill.ca/soot)
24: */
25:
26: package soot;
27:
28: import java.io.*;
29:
30: /** A box which can contain units.
31: *
32: * @see Unit
33: */
34: public interface UnitBox extends Serializable {
35: /** Sets this box to contain the given unit. Subject to canContainValue() checks. */
36: public void setUnit(Unit u);
37:
38: /** Returns the unit contained within this box. */
39: public Unit getUnit();
40:
41: /** Returns true if this box can contain the given Unit. */
42: public boolean canContainUnit(Unit u);
43:
44: /**
45: * Returns true if the UnitBox is holding a Unit that is the
46: * target of a branch (ie a Unit at the beginning of a CFG block).
47: * This is the default case.
48: *
49: * <p> Returns false if the UnitBox is holding a Unit that
50: * indicates the end of a CFG block and may require specialised
51: * processing for SSA.
52: **/
53: public boolean isBranchTarget();
54:
55: public void toString(UnitPrinter up);
56: }
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