Add new configure parameter for Xcb-Xlib

This adds a new configuration parameter, xcb-xlib, which allows
overriding the configure test for that existing configuration option.

The use of xcb-xlib in the xcb platform plugin becomes the preferred path
for non-OpenGL ES 2 builds, while the EGL codepath is used otherwise.
This has the advantage that EGL can be used with Desktop OpenGL if Qt is
configured with -no-xcb-xlib.

Change-Id: I5018e31fe0399b94f020c671eff9414d00431c44
Reviewed-by: Jørgen Lind <jorgen.lind@digia.com>

2 files changed, 25 insertions, 11 deletions

diff --git a/configure b/configure
index 72c13ab75d..a20fdaa0bc 100755
--- a/configure
+++ b/configure
@@ -647,6 +647,7 @@ CFG_XINPUT=runtime
 CFG_XKB=auto
 CFG_XKBCOMMON=auto
 CFG_XCB=auto
+CFG_XCB_XLIB=auto
 CFG_XCB_GLX=no
 CFG_EGLFS=auto
 CFG_DIRECTFB=auto
@@ -1690,6 +1691,13 @@ while [ "$#" -gt 0 ]; do
             UNKNOWN_OPT=yes
         fi
         ;;
+    xcb-xlib)
+        if [ "$VAL" = "yes" ] || [ "$VAL" = "no" ]; then
+            CFG_XCB_XLIB="$VAL"
+        else
+            UNKNOWN_OPT=yes
+        fi
+        ;;
     wayland)
         CFG_OBSOLETE_WAYLAND=yes
         ;;
@@ -2335,6 +2343,9 @@ Third Party Libraries:
     -no-xinput2 ........ Do not compile XInput2 support.
  *  -xinput2 ........... Compile XInput2 support.
 
+    -no-xcb-xlib........ Do not compile Xcb-Xlib support.
+ *  -xcb-xlib........... Compile Xcb-Xlib support.
+
     -no-glib ........... Do not compile Glib support.
  +  -glib .............. Compile Glib support.
 
@@ -5128,8 +5139,10 @@ if [ "$CFG_XCB" != "no" ]; then
             exit 1
         fi
 
-        if compileTest qpa/xcb-xlib "xcb-xlib" $QMAKE_CFLAGS_XCB $QMAKE_LIBS_XCB; then
-            QT_CONFIG="$QT_CONFIG xcb-xlib"
+        if [ "$CFG_XCB_XLIB" != "no" ]; then
+            if compileTest qpa/xcb-xlib "xcb-xlib" $QMAKE_CFLAGS_XCB $QMAKE_LIBS_XCB; then
+                QT_CONFIG="$QT_CONFIG xcb-xlib"
+            fi
         fi
 
         if [ "$CFG_SM" != "no" ] && [ -n "$PKG_CONFIG" ]; then
@@ -6694,6 +6707,7 @@ report_support "    LinuxFB .............." "$CFG_LINUXFB"
 report_support "    XCB .................." "$CFG_XCB" system "system library" qt "bundled copy"
 if [ "$CFG_XCB" != "no" ]; then
     report_support "      MIT-SHM ............" "$CFG_MITSHM"
+    report_support "      Xcb-Xlib ..........." "$CFG_XCB_XLIB"
     report_support "      Xcursor ............" "$CFG_XCURSOR" runtime "loaded at runtime"
     report_support "      Xfixes ............." "$CFG_XFIXES" runtime "loaded at runtime"
     report_support "      Xi ................." "$CFG_XINPUT" runtime "loaded at runtime"
diff --git a/src/plugins/platforms/xcb/xcb-plugin.pro b/src/plugins/platforms/xcb/xcb-plugin.pro
index 4f69ca8aab..8968d020c4 100644
--- a/src/plugins/platforms/xcb/xcb-plugin.pro
+++ b/src/plugins/platforms/xcb/xcb-plugin.pro
@@ -81,15 +81,7 @@ contains(QT_CONFIG, xcb-sm) {
 }
 
 contains(QT_CONFIG, opengl) {
-    contains(QT_CONFIG, opengles2) {
-        DEFINES += XCB_USE_EGL
-        CONFIG += egl
-        HEADERS += qxcbeglsurface.h
-
-        # EGL on MeeGo 1.2 Harmattan needs this macro to map EGLNativeDisplayType
-        # and other types to the correct X11 types
-        DEFINES += SUPPORT_X11
-    } else:contains(QT_CONFIG, xcb-xlib) {
+    contains(QT_CONFIG, xcb-xlib):!contains(QT_CONFIG, opengles2) {
         DEFINES += XCB_USE_GLX
         HEADERS += qglxintegration.h
         SOURCES += qglxintegration.cpp
@@ -98,6 +90,14 @@ contains(QT_CONFIG, opengl) {
             DEFINES += XCB_HAS_XCB_GLX
             LIBS += -lxcb-glx
         }
+    } else:contains(QT_CONFIG, egl) {
+        DEFINES += XCB_USE_EGL
+        CONFIG += egl
+        HEADERS += qxcbeglsurface.h
+
+        # EGL on MeeGo 1.2 Harmattan needs this macro to map EGLNativeDisplayType
+        # and other types to the correct X11 types
+        DEFINES += SUPPORT_X11
     }
 }