Fix dynamic librariy support detection for platforms without libdl

Some platforms (e.g. FreeBSD) do not have libdl, but dlopen and related
functions are part of libc. So first check for dlopen in libc, and only
if that fails, look for it in libdl.

Task-number: QTBUG-52951
Change-Id: I65a8ed18fce157da32f4e1ffeba30d7513385a8f
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 39 insertions, 0 deletions

diff --git a/config.tests/unix/dlopen/dlopen.cpp b/config.tests/unix/dlopen/dlopen.cpp
new file mode 100644
index 0000000000..28a82330f2
--- /dev/null
+++ b/config.tests/unix/dlopen/dlopen.cpp
@@ -0,0 +1,39 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the config.tests 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 <dlfcn.h>
+
+int main(int, char **)
+{
+    dlopen(0, 0);
+}