1/*
2 * Copyright (C) 2006 Apple Computer, Inc.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Library General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * 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 * Library General Public License for more details.
13 *
14 * You should have received a copy of the GNU Library General Public License
15 * along with this library; see the file COPYING.LIB.  If not, write to
16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
17 * Boston, MA 02110-1301, USA.
18 *
19 */
20
21#ifndef StaticConstructors_h
22#define StaticConstructors_h
23
24// We need to avoid having static constructors. This is accomplished by defining
25// a static array of the appropriate size and alignment, and defining a const
26// reference that points to the buffer. During initialization, the object will
27// be constructed with placement new into the buffer. This works with MSVC, GCC,
28// and Clang without producing dynamic initialization code even at -O0. The only
29// downside is that all external translation units will have to emit one more
30// load, while a real global could be referenced directly by absolute or
31// relative addressing.
32
33// Use an array of pointers instead of an array of char in case there is some alignment issue.
34#define DEFINE_GLOBAL(type, name, ...) \
35    void* name##Storage[(sizeof(type) + sizeof(void *) - 1) / sizeof(void *)]; \
36    const type& name = *reinterpret_cast<type*>(&name##Storage);
37
38#endif // StaticConstructors_h
39