diff --git a/configure b/configure
index 466d000..2dc3f31 100755
--- a/configure
+++ b/configure
@@ -1080,6 +1080,7 @@ done
 [ -d $outpath/src/tools ] || mkdir -p $outpath/src/tools
 cat > $outpath/src/tools/qconfig.cpp.new <<EOF
 /* Install paths from configure */
+#include "qglobal.h"
 
 static const char QT_INSTALL_PREFIX      [267] = "qt_nstpath=$QT_INSTALL_PREFIX";
 static const char QT_INSTALL_BINS        [267] = "qt_binpath=$QT_INSTALL_BINS";
diff --git a/mkspecs/linux-g++/qmake.conf b/mkspecs/linux-g++/qmake.conf
index 24c2ec7..64caaeb 100644
--- a/mkspecs/linux-g++/qmake.conf
+++ b/mkspecs/linux-g++/qmake.conf
@@ -16,7 +16,7 @@ QMAKE_YACCFLAGS		= -d
 QMAKE_YACCFLAGS_MANGLE  = -p $base -b $base
 QMAKE_YACC_HEADER       = $base.tab.h
 QMAKE_YACC_SOURCE       = $base.tab.c
-QMAKE_CFLAGS		= -pipe -g
+QMAKE_CFLAGS		= -pipe -g -fvisibility=hidden -fvisibility-inlines-hidden
 QMAKE_CFLAGS_DEPS	= -M
 QMAKE_CFLAGS_WARN_ON	= -Wall -W
 QMAKE_CFLAGS_WARN_OFF	= -w
diff --git a/src/kernel/qapplication_x11.cpp b/src/kernel/qapplication_x11.cpp
index 8eecdb4..4553fdf 100644
--- a/src/kernel/qapplication_x11.cpp
+++ b/src/kernel/qapplication_x11.cpp
@@ -337,7 +337,7 @@ static long qt_mode_switch_remove_mask = 0;
 
 // flags for extensions for special Languages, currently only for RTL languages
 static bool 	qt_use_rtl_extensions = FALSE;
-bool qt_hebrew_keyboard_hack = FALSE;
+Q_EXPORT bool qt_hebrew_keyboard_hack = FALSE;
 
 static Window	mouseActWindow	     = 0;	// window where mouse is
 static int	mouseButtonPressed   = 0;	// last mouse button pressed
@@ -3851,7 +3851,7 @@ void qt_leave_modal( QWidget *widget )
 }
 
 
-bool qt_try_modal( QWidget *widget, XEvent *event )
+Q_EXPORT bool qt_try_modal( QWidget *widget, XEvent *event )
 {
     if (qt_xdnd_dragging) {
 	// allow mouse events while DnD is active
diff --git a/src/kernel/qgplugin.h b/src/kernel/qgplugin.h
index 3fa4493..ba0914b 100644
--- a/src/kernel/qgplugin.h
+++ b/src/kernel/qgplugin.h
@@ -93,35 +93,19 @@
 	    return i->iface(); \
 	}
 
-#    ifdef Q_WS_WIN
-#	ifdef Q_CC_BOR
-#	    define Q_EXPORT_PLUGIN(PLUGIN) \
-	        Q_PLUGIN_VERIFICATION_DATA \
-		Q_EXTERN_C __declspec(dllexport) \
-                const char * __stdcall qt_ucm_query_verification_data() \
-                { return qt_ucm_verification_data; } \
-		Q_EXTERN_C __declspec(dllexport) QUnknownInterface* \
-                __stdcall ucm_instantiate() \
-		Q_PLUGIN_INSTANTIATE( PLUGIN )
-#	else
-#	    define Q_EXPORT_PLUGIN(PLUGIN) \
-	        Q_PLUGIN_VERIFICATION_DATA \
-		Q_EXTERN_C __declspec(dllexport) \
-                const char *qt_ucm_query_verification_data() \
-                { return qt_ucm_verification_data; } \
-		Q_EXTERN_C __declspec(dllexport) QUnknownInterface* ucm_instantiate() \
-		Q_PLUGIN_INSTANTIATE( PLUGIN )
-#	endif
-#    else
-#	define Q_EXPORT_PLUGIN(PLUGIN) \
+#if defined(Q_WS_WIN) && defined(Q_CC_BOR)
+#   define Q_STDCALL __stdcall
+#else
+#   define Q_STDCALL
+#endif
+
+#define Q_EXPORT_PLUGIN(PLUGIN) \
 	    Q_PLUGIN_VERIFICATION_DATA \
-	    Q_EXTERN_C \
-            const char *qt_ucm_query_verification_data() \
+	    Q_EXTERN_C Q_EXPORT \
+            const char * Q_STDCALL qt_ucm_query_verification_data() \
             { return qt_ucm_verification_data; } \
-	    Q_EXTERN_C QUnknownInterface* ucm_instantiate() \
+	    Q_EXTERN_C Q_EXPORT QUnknownInterface* Q_STDCALL ucm_instantiate() \
             Q_PLUGIN_INSTANTIATE( PLUGIN )
-#    endif
-
 #endif
 
 struct QUnknownInterface;
diff --git a/src/kernel/qtextengine_p.h b/src/kernel/qtextengine_p.h
index df7a79f..0bd5cd2 100644
--- a/src/kernel/qtextengine_p.h
+++ b/src/kernel/qtextengine_p.h
@@ -292,7 +292,7 @@ private:
 
 class QFontPrivate;
 
-class QTextEngine {
+class Q_EXPORT QTextEngine {
 public:
     QTextEngine( const QString &str, QFontPrivate *f );
     ~QTextEngine();
diff --git a/src/tools/qglobal.h b/src/tools/qglobal.h
index 135c289..0fbd4aa 100644
--- a/src/tools/qglobal.h
+++ b/src/tools/qglobal.h
@@ -885,6 +885,10 @@ class QDataStream;
 #    define Q_TEMPLATE_EXTERN
 #    undef  Q_DISABLE_COPY 	/* avoid unresolved externals */
 #  endif
+#elif defined(Q_CC_GNU) && __GNUC__ - 0 >= 4
+#    define Q_EXPORT __attribute__((visibility("default")))
+#    undef QT_MAKEDLL		/* ignore these for other platforms */
+#    undef QT_DLL
 #else
 #  undef QT_MAKEDLL		/* ignore these for other platforms */
 #  undef QT_DLL
diff --git a/tools/designer/shared/domtool.h b/tools/designer/shared/domtool.h
index 4fa561c..15e508d 100644
--- a/tools/designer/shared/domtool.h
+++ b/tools/designer/shared/domtool.h
@@ -40,7 +40,7 @@
 class QDomElement;
 class QDomDocument;
 
-class DomTool : public Qt
+class Q_EXPORT DomTool : public Qt
 {
 public:
     static QVariant readProperty( const QDomElement& e, const QString& name, const QVariant& defValue );
diff --git a/tools/designer/uilib/qwidgetfactory.cpp b/tools/designer/uilib/qwidgetfactory.cpp
index a1ff1c2..b7fc6e9 100644
--- a/tools/designer/uilib/qwidgetfactory.cpp
+++ b/tools/designer/uilib/qwidgetfactory.cpp
@@ -120,13 +120,13 @@ static QPluginManager<WidgetInterface> *widgetInterfaceManager = 0;
 static QMap<QString, bool> *availableWidgetMap = 0;
 static QStringList *availableWidgetList = 0;
 
-QMap<QWidget*, QString> *qwf_forms = 0;
+Q_EXPORT QMap<QWidget*, QString> *qwf_forms = 0;
 QString *qwf_language = 0;
-bool qwf_execute_code = TRUE;
+Q_EXPORT bool qwf_execute_code = TRUE;
 bool qwf_stays_on_top = FALSE;
 QString qwf_currFileName = "";
 QObject *qwf_form_object = 0;
-QString *qwf_plugin_dir = 0;
+Q_EXPORT QString *qwf_plugin_dir = 0;
 
 static void setupPluginDir()
 {
diff --git a/tools/designer/uilib/qwidgetfactory.h b/tools/designer/uilib/qwidgetfactory.h
index daf5db6..220ab27 100644
--- a/tools/designer/uilib/qwidgetfactory.h
+++ b/tools/designer/uilib/qwidgetfactory.h
@@ -55,7 +55,7 @@ class QWidget;
 class QWidgetFactoryPrivate;
 class UibStrTable;
 
-class QWidgetFactory
+class Q_EXPORT QWidgetFactory
 {
 public:
     QWidgetFactory();