diff options
author | Thiago Macieira <thiago.macieira@intel.com> | 2015-06-02 11:15:05 -0700 |
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committer | Thiago Macieira <thiago.macieira@intel.com> | 2015-09-13 18:54:21 +0000 |
commit | 6de8c0aa09d4bb31ae927f7a98be47f5773acd70 (patch) | |
tree | 05e033f972fbc87a5fc54365d9e725726ae7aab2 /src/corelib/global/qversiontagging.cpp | |
parent | 72ba0079c3967bdfa26acdce78ce6cb98b30c27b (diff) |
Add a qt_version_tag symbol to QtCore that uses ELF versions
This symbol will exist with different ELF versions, allowing us to know
which version of Qt a given library or application was linked
against. When this symbol gets used, automatic packaging tools will
extract the dependency. The trick here is that the application uses
qt_version_tag without knowing which version is current, but the linker
resolves it to the current version and records that.
For example, if this were used with Qt 5.5, RPM's find-requires on an
application using QtCore would print:
libQt5Core.so.5()(64bit)
libQt5Core.so.5(Qt_5.5)(64bit)
libQt5Core.so.5(Qt_5)(64bit)
Whereas find-provides on QtCore would print:
libQt5Core.so.5()(64bit)
libQt5Core.so.5(libQt5Core.so.5)(64bit)
libQt5Core.so.5(Qt_5.0)(64bit)
libQt5Core.so.5(Qt_5.1)(64bit)
libQt5Core.so.5(Qt_5.2)(64bit)
libQt5Core.so.5(Qt_5.3)(64bit)
libQt5Core.so.5(Qt_5.4)(64bit)
libQt5Core.so.5(Qt_5.5)(64bit)
libQt5Core.so.5(Qt_5)(64bit)
Therefore, automatic dependency resolution would have the information it
needs to conclude that the application requires Qt >= 5.5.
Change-Id: I049a653beeb5454c9539ffff13e3fec9aeb50197
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Diffstat (limited to 'src/corelib/global/qversiontagging.cpp')
-rw-r--r-- | src/corelib/global/qversiontagging.cpp | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/src/corelib/global/qversiontagging.cpp b/src/corelib/global/qversiontagging.cpp new file mode 100644 index 0000000000..e3d9efa16b --- /dev/null +++ b/src/corelib/global/qversiontagging.cpp @@ -0,0 +1,62 @@ +/**************************************************************************** +** +** Copyright (C) 2015 Intel Corporation. +** Contact: http://www.qt.io/licensing/ +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL21$ +** Commercial License Usage +** Licensees holding valid commercial Qt licenses may use this file in +** accordance with the commercial license agreement provided with the +** Software or, alternatively, in accordance with the terms contained in +** a written agreement between you and The Qt Company. For licensing terms +** and conditions see http://www.qt.io/terms-conditions. For further +** information use the contact form at http://www.qt.io/contact-us. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 or version 3 as published by the Free +** Software Foundation and appearing in the file LICENSE.LGPLv21 and +** LICENSE.LGPLv3 included in the packaging of this file. Please review the +** following information to ensure the GNU Lesser General Public License +** requirements will be met: https://www.gnu.org/licenses/lgpl.html and +** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** As a special exception, The Qt Company gives you certain additional +** rights. These rights are described in The Qt Company LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qglobal.h" + +#if defined(Q_CC_GNU) && defined(Q_OS_LINUX) && defined(Q_PROCESSOR_X86) && !defined(QT_STATIC) +# define SYM QT_MANGLE_NAMESPACE(qt_version_tag) +# define SSYM QT_STRINGIFY(SYM) + +asm( +// ASM macro that makes one ELF versioned symbol qt_version_tag{sep}Qt_{major}.{minor} +// that is an alias to qt_version_tag_{major}_{minor}. +// The {sep} parameter must be @ for all old versions and @@ for the current version. +".macro make_one_tag major minor sep\n" +".globl " SSYM "_\\major\\()_\\minor\n" // make the symbol global +SSYM "_\\major\\()_\\minor:\n" // declare it +" .symver " SSYM "_\\major\\()_\\minor, " SSYM "\\sep\\()Qt_\\major\\().\\minor\n" +".endm\n" + +".altmacro\n" +".bss\n" +".set qt_version_major, " QT_STRINGIFY(QT_VERSION) " >> 16\n" // set qt_version_major +".set qt_version_minor, 0\n" // set qt_version_minor to 0 (it will grow to the current) +".rept (" QT_STRINGIFY(QT_VERSION) " >> 8) & 0xff\n" // repeat minor version times (0 to N-1) +" make_one_tag %qt_version_major, %qt_version_minor, @\n" +" .set qt_version_minor, (qt_version_minor + 1)\n" +".endr\n" +" make_one_tag %qt_version_major, %qt_version_minor, @@\n" // call the macro for the current version +" .space 1\n" // variable is 1 byte, value 0 +); + +#endif |