1 /**************************************************************************** 2 ** 3 ** Copyright (C) 2016 Intel Corporation. 4 ** Contact: https://www.qt.io/licensing/ 5 ** 6 ** This file is part of the QtCore module of the Qt Toolkit. 7 ** 8 ** $QT_BEGIN_LICENSE:LGPL$ 9 ** Commercial License Usage 10 ** Licensees holding valid commercial Qt licenses may use this file in 11 ** accordance with the commercial license agreement provided with the 12 ** Software or, alternatively, in accordance with the terms contained in 13 ** a written agreement between you and The Qt Company. For licensing terms 14 ** and conditions see https://www.qt.io/terms-conditions. For further 15 ** information use the contact form at https://www.qt.io/contact-us. 16 ** 17 ** GNU Lesser General Public License Usage 18 ** Alternatively, this file may be used under the terms of the GNU Lesser 19 ** General Public License version 3 as published by the Free Software 20 ** Foundation and appearing in the file LICENSE.LGPL3 included in the 21 ** packaging of this file. Please review the following information to 22 ** ensure the GNU Lesser General Public License version 3 requirements 23 ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html. 24 ** 25 ** GNU General Public License Usage 26 ** Alternatively, this file may be used under the terms of the GNU 27 ** General Public License version 2.0 or (at your option) the GNU General 28 ** Public license version 3 or any later version approved by the KDE Free 29 ** Qt Foundation. The licenses are as published by the Free Software 30 ** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3 31 ** included in the packaging of this file. Please review the following 32 ** information to ensure the GNU General Public License requirements will 33 ** be met: https://www.gnu.org/licenses/gpl-2.0.html and 34 ** https://www.gnu.org/licenses/gpl-3.0.html. 35 ** 36 ** $QT_END_LICENSE$ 37 ** 38 ****************************************************************************/ 39 40 // qglobal.h includes this header, so keep it outside of our include guards 41 #include <QtCore/qglobal.h> 42 43 #if !defined(QVERSIONTAGGING_H) 44 #define QVERSIONTAGGING_H 45 46 QT_BEGIN_NAMESPACE 47 48 /* 49 * Ugly hack warning and explanation: 50 * 51 * This file causes all ELF modules, be they libraries or applications, to use the 52 * qt_version_tag symbol that is present in QtCore. Such symbol is versioned, 53 * so the linker will automatically pull the current Qt version and add it to 54 * the ELF header of the library/application. The assembly produces one section 55 * called ".qtversion" containing two 32-bit values. The first is a 56 * relocation to the qt_version_tag symbol (which is what causes the ELF 57 * version to get used). The second value is the current Qt version at the time 58 * of compilation. 59 * 60 * There will only be one copy of the section in the output library or application. 61 */ 62 63 #if defined(QT_BUILD_CORE_LIB) || defined(QT_BOOTSTRAPPED) || defined(QT_NO_VERSION_TAGGING) || defined(QT_STATIC) 64 // don't make tags in QtCore, bootstrapped systems or if the user asked not to 65 #elif defined(Q_CC_GNU) && !defined(Q_OS_ANDROID) 66 # if defined(Q_PROCESSOR_X86) && (defined(Q_OS_LINUX) || defined(Q_OS_FREEBSD_KERNEL)) 67 # if defined(Q_PROCESSOR_X86_64) && QT_POINTER_SIZE == 8 // x86-64 64-bit 68 # define QT_VERSION_TAG_RELOC(sym) ".quad " QT_STRINGIFY(QT_MANGLE_NAMESPACE(sym)) "@GOT\n" 69 # else // x86 or x86-64 32-bit (x32) 70 # define QT_VERSION_TAG_RELOC(sym) ".long " QT_STRINGIFY(QT_MANGLE_NAMESPACE(sym)) "@GOT\n" 71 # endif 72 # define QT_VERSION_TAG(sym) \ 73 asm ( \ 74 ".section .qtversion, \"aG\", @progbits, " QT_STRINGIFY(QT_MANGLE_NAMESPACE(sym)) ", comdat\n" \ 75 ".align 8\n" \ 76 QT_VERSION_TAG_RELOC(sym) \ 77 ".long " QT_STRINGIFY(QT_VERSION) "\n" \ 78 ".align 8\n" \ 79 ".previous" \ 80 ) 81 # endif 82 #endif 83 84 #if defined(QT_VERSION_TAG) 85 QT_VERSION_TAG(qt_version_tag); 86 #endif 87 88 QT_END_NAMESPACE 89 90 #endif // QVERSIONTAGGING_H 91