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: */package com.tc.asm.tree.analysis;
30:
31: import java.util.ArrayList;
32: import java.util.List;
33:
34: import com.tc.asm.tree.JumpInsnNode;
35: import com.tc.asm.tree.LabelNode;
36:
37: /**
38: * A method subroutine (corresponds to a JSR instruction).
39: *
40: * @author Eric Bruneton
41: */
42: class Subroutine {
43:
44: LabelNode start;
45:
46: boolean[] access;
47:
48: List callers;
49:
50: private Subroutine() {
51: }
52:
53: public Subroutine(final LabelNode start, final int maxLocals,
54: final JumpInsnNode caller) {
55: this .start = start;
56: this .access = new boolean[maxLocals];
57: this .callers = new ArrayList();
58: callers.add(caller);
59: }
60:
61: public Subroutine copy() {
62: Subroutine result = new Subroutine();
63: result.start = start;
64: result.access = new boolean[access.length];
65: System.arraycopy(access, 0, result.access, 0, access.length);
66: result.callers = new ArrayList(callers);
67: return result;
68: }
69:
70: public boolean merge(final Subroutine subroutine)
71: throws AnalyzerException {
72: boolean changes = false;
73: for (int i = 0; i < access.length; ++i) {
74: if (subroutine.access[i] && !access[i]) {
75: access[i] = true;
76: changes = true;
77: }
78: }
79: if (subroutine.start == start) {
80: for (int i = 0; i < subroutine.callers.size(); ++i) {
81: Object caller = subroutine.callers.get(i);
82: if (!callers.contains(caller)) {
83: callers.add(caller);
84: changes = true;
85: }
86: }
87: }
88: return changes;
89: }
90: }
|