1/*
2 * Copyright (C) 2017 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#pragma once
27
28namespace WebCore {
29
30class LayoutDisallowedScope {
31public:
32 enum class Reason { PerformanceOptimization, ReentrancyAvoidance };
33
34#if ASSERT_DISABLED
35 LayoutDisallowedScope(Reason) { }
36 static bool isLayoutAllowed() { return true; }
37#else
38 LayoutDisallowedScope(Reason)
39 : m_previousAssertion(s_currentAssertion)
40 {
41 s_currentAssertion = this;
42 }
43
44 ~LayoutDisallowedScope()
45 {
46 s_currentAssertion = m_previousAssertion;
47 }
48
49 static bool isLayoutAllowed() { return !s_currentAssertion; }
50
51private:
52 LayoutDisallowedScope* m_previousAssertion;
53 static LayoutDisallowedScope* s_currentAssertion;
54#endif
55};
56
57}
58