01: /*
02: * ASM: a very small and fast Java bytecode manipulation framework
03: * Copyright (c) 2000-2005 INRIA, France Telecom
04: * All rights reserved.
05: *
06: * Redistribution and use in source and binary forms, with or without
07: * modification, are permitted provided that the following conditions
08: * are met:
09: * 1. Redistributions of source code must retain the above copyright
10: * notice, this list of conditions and the following disclaimer.
11: * 2. Redistributions in binary form must reproduce the above copyright
12: * notice, this list of conditions and the following disclaimer in the
13: * documentation and/or other materials provided with the distribution.
14: * 3. Neither the name of the copyright holders nor the names of its
15: * contributors may be used to endorse or promote products derived from
16: * this software without specific prior written permission.
17: *
18: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19: * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21: * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
22: * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
28: * THE POSSIBILITY OF SUCH DAMAGE.
29: */
30: package org.objectweb.asm.tree.analysis;
31:
32: import java.util.ArrayList;
33: import java.util.List;
34:
35: import org.objectweb.asm.tree.JumpInsnNode;
36: import org.objectweb.asm.tree.LabelNode;
37:
38: /**
39: * A method subroutine (corresponds to a JSR instruction).
40: *
41: * @author Eric Bruneton
42: */
43: @SuppressWarnings("unchecked")
44: class Subroutine {
45:
46: LabelNode start;
47:
48: boolean[] access;
49:
50: List callers;
51:
52: private Subroutine() {
53: }
54:
55: public Subroutine(final LabelNode start, final int maxLocals,
56: final JumpInsnNode caller) {
57: this .start = start;
58: this .access = new boolean[maxLocals];
59: this .callers = new ArrayList();
60: callers.add(caller);
61: }
62:
63: public Subroutine copy() {
64: Subroutine result = new Subroutine();
65: result.start = start;
66: result.access = new boolean[access.length];
67: System.arraycopy(access, 0, result.access, 0, access.length);
68: result.callers = new ArrayList(callers);
69: return result;
70: }
71:
72: public boolean merge(final Subroutine subroutine,
73: final boolean checkOverlap) throws AnalyzerException {
74: if (checkOverlap && subroutine.start != start) {
75: throw new AnalyzerException("Overlapping sub routines");
76: }
77: boolean changes = false;
78: for (int i = 0; i < access.length; ++i) {
79: if (subroutine.access[i] && !access[i]) {
80: access[i] = true;
81: changes = true;
82: }
83: }
84: for (int i = 0; i < subroutine.callers.size(); ++i) {
85: Object caller = subroutine.callers.get(i);
86: if (!callers.contains(caller)) {
87: callers.add(caller);
88: changes = true;
89: }
90: }
91: return changes;
92: }
93: }
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