Make X11 fully optional

Make X11 Backend (in addition to XWayland) optional and small bug fix on XWayland includes.

backend/backend.c

@@ -94,6 +94,7 @@ struct wlr_backend *wlr_backend_autocreate(struct wl_display *display) {
 		}
 	}
 
+#ifdef WLR_HAS_X11_BACKEND
 	const char *x11_display = getenv("DISPLAY");
 	if (x11_display) {
 		struct wlr_backend *x11_backend =
@@ -101,6 +102,7 @@ struct wlr_backend *wlr_backend_autocreate(struct wl_display *display) {
 		wlr_multi_backend_add(backend, x11_backend);
 		return backend;
 	}
+#endif
 
 	// Attempt DRM+libinput
 	struct wlr_session *session = wlr_session_create(display);

backend/meson.build

@@ -24,7 +24,6 @@ backend_files = files(
 	'wayland/output.c',
 	'wayland/registry.c',
 	'wayland/wl_seat.c',
-	'x11/backend.c',
 )
 
 backend_deps = [
@@ -50,6 +49,10 @@ if conf_data.get('WLR_HAS_SYSTEMD', false)
 	backend_deps += systemd
 endif
 
+if conf_data.get('WLR_HAS_X11_BACKEND', false)
+	backend_files += files('x11/backend.c')
+endif
+
 if conf_data.get('WLR_HAS_ELOGIND', false)
 	backend_files += files('session/logind.c')
 	backend_deps += elogind

meson.build

@@ -58,14 +58,6 @@ libinput       = dependency('libinput', version: '>=1.7.0')
 xkbcommon      = dependency('xkbcommon')
 udev           = dependency('libudev')
 pixman         = dependency('pixman-1')
-xcb            = dependency('xcb')
-xcb_composite  = dependency('xcb-composite')
-xcb_xfixes     = dependency('xcb-xfixes')
-xcb_image      = dependency('xcb-image')
-xcb_render     = dependency('xcb-render')
-xcb_icccm      = dependency('xcb-icccm', required: false)
-xcb_errors     = dependency('xcb-errors', required: get_option('enable_xcb_errors') == 'true')
-x11_xcb        = dependency('x11-xcb')
 libcap         = dependency('libcap', required: get_option('enable_libcap') == 'true')
 systemd        = dependency('libsystemd', required: get_option('enable_systemd') == 'true')
 elogind        = dependency('libelogind', required: get_option('enable_elogind') == 'true')
@@ -75,14 +67,6 @@ exclude_headers = []
 wlr_parts = []
 wlr_deps = []
 
-if xcb_icccm.found()
-	conf_data.set('WLR_HAS_XCB_ICCCM', true)
-endif
-
-if xcb_errors.found() and get_option('enable_xcb_errors') != 'false'
-	conf_data.set('WLR_HAS_XCB_ERRORS', true)
-endif
-
 if libcap.found() and get_option('enable_libcap') != 'false'
 	conf_data.set('WLR_HAS_LIBCAP', true)
 	wlr_deps += libcap
@@ -97,6 +81,38 @@ if elogind.found() and get_option('enable_elogind') != 'false'
 	conf_data.set('WLR_HAS_ELOGIND', true)
 endif
 
+if get_option('enable_x11_backend') or get_option('enable_xwayland')
+        xcb            = dependency('xcb')
+        xcb_composite  = dependency('xcb-composite')
+        xcb_xfixes     = dependency('xcb-xfixes')
+        xcb_image      = dependency('xcb-image')
+        xcb_render     = dependency('xcb-render')
+        x11_xcb        = dependency('x11-xcb')
+
+        xcb_icccm      = dependency('xcb-icccm', required: false)
+        xcb_errors     = dependency('xcb-errors', required: get_option('enable_xcb_errors') == 'true')
+
+        if xcb_icccm.found()
+                conf_data.set('WLR_HAS_XCB_ICCCM', true)
+        endif
+
+        if xcb_errors.found() and get_option('enable_xcb_errors') != 'false'
+                conf_data.set('WLR_HAS_XCB_ERRORS', true)
+        endif
+
+        wlr_deps += [
+                xcb,
+                xcb_composite,
+                x11_xcb,
+        ]
+else
+        add_project_arguments('-DMESA_EGL_NO_X11_HEADERS', language: 'c')
+endif
+
+if get_option('enable_x11_backend')
+        conf_data.set('WLR_HAS_X11_BACKEND', true)
+endif
+
 if get_option('enable_xwayland')
 	subdir('xwayland')
 	wlr_parts += [lib_wlr_xwayland]
@@ -138,9 +154,6 @@ wlr_deps += [
 	xkbcommon,
 	udev,
 	pixman,
-	xcb,
-	xcb_composite,
-	x11_xcb,
 	math,
 ]
 
@@ -172,6 +185,7 @@ summary = [
 	'     systemd: @0@'.format(conf_data.get('WLR_HAS_SYSTEMD', false)),
 	'     elogind: @0@'.format(conf_data.get('WLR_HAS_ELOGIND', false)),
 	'    xwayland: @0@'.format(conf_data.get('WLR_HAS_XWAYLAND', false)),
+	' x11_backend: @0@'.format(conf_data.get('WLR_HAS_X11BACKEND', false)),
 	'   xcb-icccm: @0@'.format(conf_data.get('WLR_HAS_XCB_ICCCM', false)),
 	'  xcb-errors: @0@'.format(conf_data.get('WLR_HAS_XCB_ERRORS', false)),
 	'----------------',

meson_options.txt

@@ -3,3 +3,4 @@ option('enable_systemd', type: 'combo', choices: ['auto', 'true', 'false'], valu
 option('enable_elogind', type: 'combo', choices: ['auto', 'true', 'false'], value: 'auto', description: 'Enable support for logind')
 option('enable_xcb_errors', type: 'combo', choices: ['auto', 'true', 'false'], value: 'auto', description: 'Use xcb-errors util library')
 option('enable_xwayland', type: 'boolean', value: true, description: 'Enable support X11 applications')
+option('enable_x11_backend', type: 'boolean', value: false, description: 'Enable X11 backend')

rootston/input.c

@@ -5,7 +5,9 @@
 #include <wlr/types/wlr_cursor.h>
 #include <wlr/util/log.h>
 #include <wlr/xcursor.h>
-#include <wlr/xwayland.h>
+#ifdef WLR_HAS_XWAYLAND
+#    include <wlr/xwayland.h>
+#endif
 #include "rootston/config.h"
 #include "rootston/input.h"
 #include "rootston/keyboard.h"