From f669ea0d54302de31456d57286aa0e4ca1443e98 Mon Sep 17 00:00:00 2001
From: Lada Trimasova <ltrimas@synopsys.com>
Date: Wed, 3 Feb 2016 22:33:02 +0300
Subject: [PATCH] Link with -ldl option only when it is supported
-ldl option was used unconditionally while libdl is not supported
when libc is static.
Add build test to configure which checks if libdl is supported.
QMAKE_LIBS_DYNLOAD in "src/corelib/plugin/plugin.pri" is now used only
if libdl is available.
qt_linux_find_symbol_sys from qlibrary_unix is now used only if
QT_NO_DYNAMIC_LIBRARY is not defined.
Initially reported by Buildroot autobuilder here:
http://autobuild.buildroot.net/results/a85/a85a1839a45fb6102e53131ecc8f6dadf92bcdc2
Change-Id: I0397472456efdc4f3ab5f24d01253bee8048a9d1
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
---
config.tests/unix/libdl/libdl.cpp | 39 ++++++++++++++++++++++++++++
config.tests/unix/libdl/libdl.pro | 3 +++
configure | 6 +++++
src/corelib/plugin/plugin.pri | 2 +-
src/corelib/plugin/qlibrary_unix.cpp | 2 +-
5 files changed, 50 insertions(+), 2 deletions(-)
create mode 100644 config.tests/unix/libdl/libdl.cpp
create mode 100644 config.tests/unix/libdl/libdl.pro
diff --git a/config.tests/unix/libdl/libdl.cpp b/config.tests/unix/libdl/libdl.cpp
new file mode 100644
index 00000000000..28a82330f2d
--- /dev/null
+++ b/config.tests/unix/libdl/libdl.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);
+}
diff --git a/config.tests/unix/libdl/libdl.pro b/config.tests/unix/libdl/libdl.pro
new file mode 100644
index 00000000000..00d4c47c6c9
--- /dev/null
+++ b/config.tests/unix/libdl/libdl.pro
@@ -0,0 +1,3 @@
+SOURCES = libdl.cpp
+CONFIG -= qt dylib
+LIBS += -ldl
diff --git a/configure b/configure
index 0c579b3e747..1473a62c5b0 100755
--- a/configure
+++ b/configure
@@ -4734,6 +4734,12 @@ if [ "$CFG_LIBPNG" = "auto" ]; then
fi
fi
+# detect dl
+if ! compileTest unix/libdl "libdl"; then
+ QMakeVar add DEFINES QT_NO_DYNAMIC_LIBRARY
+ QMAKE_CONFIG="$QMAKE_CONFIG no-libdl"
+fi
+
if [ "$CFG_EGLFS" = "yes" ]; then
if [ "$CFG_EGL" = "no" ]; then
echo "The EGLFS plugin requires EGL support and cannot be built"
diff --git a/src/corelib/plugin/plugin.pri b/src/corelib/plugin/plugin.pri
index 8b64f934676..473480eb559 100644
--- a/src/corelib/plugin/plugin.pri
+++ b/src/corelib/plugin/plugin.pri
@@ -35,4 +35,4 @@ integrity {
SOURCES += plugin/qlibrary_unix.cpp
}
-LIBS_PRIVATE += $$QMAKE_LIBS_DYNLOAD
+!no-libdl: LIBS_PRIVATE += $$QMAKE_LIBS_DYNLOAD
diff --git a/src/corelib/plugin/qlibrary_unix.cpp b/src/corelib/plugin/qlibrary_unix.cpp
index cd158a9e49e..13bc1296050 100644
--- a/src/corelib/plugin/qlibrary_unix.cpp
+++ b/src/corelib/plugin/qlibrary_unix.cpp
@@ -286,7 +286,7 @@ bool QLibraryPrivate::unload_sys()
return true;
}
-#ifdef Q_OS_LINUX
+#if defined(Q_OS_LINUX) && !defined(QT_NO_DYNAMIC_LIBRARY)
Q_CORE_EXPORT QFunctionPointer qt_linux_find_symbol_sys(const char *symbol)
{
return QFunctionPointer(dlsym(RTLD_DEFAULT, symbol));
--
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