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
