xcb: Use QT_CONFIG macro to check for xcb-xlib

... and remove the XCB_USE_XLIB define.

This patch also removes the unnecessary checks for xcb-xlib in:

- qxcbglxintegration.cpp as this files is build _only_ when
xcb-xlib is present. From gl_integrations.pro:

 qtConfig(xcb-xlib):qtConfig(opengl):!qtConfig(opengles2) {
    SUBDIRS += xcb_glx
 }

This also would have been the right place where to define
XCB_USE_XLIB, instead of unconditional line in xcb_glx.pro:

 DEFINES += XCB_USE_GLX XCB_USE_XLIB

- qxcbnativeinterface.cpp as this cpp file does not use any
Xlib APIs directly, there is no need to include Xlib.h.

Change-Id: I531b5f1e79606fcfd1c63810cf51b7d5e9dc58a7
Reviewed-by: Gatis Paeglis <gatis.paeglis@qt.io>

1 files changed, 2 insertions, 2 deletions

diff --git a/src/plugins/platforms/xcb/qxcbintegration.cpp b/src/plugins/platforms/xcb/qxcbintegration.cpp
index 8e3ee20329..e742e91f7d 100644
--- a/src/plugins/platforms/xcb/qxcbintegration.cpp
+++ b/src/plugins/platforms/xcb/qxcbintegration.cpp
@@ -63,7 +63,7 @@
 
 #include <QtGui/private/qguiapplication_p.h>
 
-#ifdef XCB_USE_XLIB
+#if QT_CONFIG(xcb_xlib)
 #include <X11/Xlib.h>
 #endif
 
@@ -123,7 +123,7 @@ QXcbIntegration::QXcbIntegration(const QStringList &parameters, int &argc, char
     qApp->setAttribute(Qt::AA_CompressHighFrequencyEvents, true);
 
     qRegisterMetaType<QXcbWindow*>();
-#ifdef XCB_USE_XLIB
+#if QT_CONFIG(xcb_xlib)
     XInitThreads();
 #endif
     m_nativeInterface.reset(new QXcbNativeInterface);