pipe-loader: wrap pipe_loader_sw_probe_xlib within HAVE_PIPE_LOADER_XLIB

The above function implies using the the xlib winsys, which
has additional library dependencies that should not be forced.

Make the software xlib pipe loader optional thus avoid all
the dependency hell. A user that wishes to use the particular
pipe-loader would need to set the following within configure.ac.

 enable_gallium_xlib_loader=yes

v2:
 - Wrap sw/xlib/xlib_sw_winsys.h to handle compilation on systems
lacking X11 headers. Spotted by Christian Prochaska.

Tested-by: Tom Stellard <thomas.stellard@amd.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=75356
Signed-off-by: Emil Velikov <emil.l.velikov@gmail.com>

configure.ac

@@ -1887,6 +1887,12 @@ AM_CONDITIONAL(NEED_GALLIUM_LLVMPIPE_DRIVER, test "x$HAVE_GALLIUM_I915" = xyes -
 if test "x$enable_gallium_loader" = xyes; then
     GALLIUM_WINSYS_DIRS="$GALLIUM_WINSYS_DIRS sw/null"
 
+    if test "x$enable_gallium_xlib_loader" = xyes; then
+        GALLIUM_WINSYS_DIRS="$GALLIUM_WINSYS_DIRS sw/xlib"
+        NEED_WINSYS_XLIB="yes"
+        GALLIUM_PIPE_LOADER_DEFINES="$GALLIUM_PIPE_LOADER_DEFINES -DHAVE_PIPE_LOADER_XLIB"
+    fi
+
     if test "x$enable_gallium_drm_loader" = xyes; then
         GALLIUM_PIPE_LOADER_DEFINES="$GALLIUM_PIPE_LOADER_DEFINES -DHAVE_PIPE_LOADER_DRM"
         PKG_CHECK_MODULES([GALLIUM_PIPE_LOADER_XCB], [xcb xcb-dri2],
@@ -1905,6 +1911,7 @@ if test "x$enable_gallium_loader" = xyes; then
     AC_SUBST([GALLIUM_PIPE_LOADER_CLIENT_DEFINES])
     AC_SUBST([GALLIUM_PIPE_LOADER_CLIENT_LIBS])
 fi
+AM_CONDITIONAL(NEED_PIPE_LOADER_XLIB, test "x$enable_gallium_xlib_loader" = xyes)
 
 AM_CONDITIONAL(HAVE_I915_DRI, test x$HAVE_I915_DRI = xyes)
 AM_CONDITIONAL(HAVE_I965_DRI, test x$HAVE_I965_DRI = xyes)

src/gallium/auxiliary/pipe-loader/Makefile.am

@@ -8,10 +8,6 @@ AM_CPPFLAGS = $(DEFINES) \
 	-I$(top_srcdir)/src/gallium/auxiliary \
 	-I$(top_srcdir)/src/gallium/winsys
 
-if NEED_WINSYS_XLIB
-AM_CPPFLAGS += -DHAVE_WINSYS_XLIB
-endif
-
 noinst_LTLIBRARIES =
 
 if HAVE_LOADER_GALLIUM

src/gallium/auxiliary/pipe-loader/pipe_loader.h

@@ -35,7 +35,7 @@
 
 #include "pipe/p_compiler.h"
 
-#ifdef HAVE_WINSYS_XLIB
+#ifdef HAVE_PIPE_LOADER_XLIB
 #include <X11/Xlib.h>
 #endif
 
@@ -105,7 +105,7 @@ pipe_loader_create_screen(struct pipe_loader_device *dev,
 void
 pipe_loader_release(struct pipe_loader_device **devs, int ndev);
 
-#ifdef HAVE_WINSYS_XLIB
+#ifdef HAVE_PIPE_LOADER_XLIB
 
 /**
  * Initialize Xlib for an associated display.

src/gallium/auxiliary/pipe-loader/pipe_loader_sw.c

@@ -31,7 +31,10 @@
 #include "util/u_dl.h"
 #include "sw/dri/dri_sw_winsys.h"
 #include "sw/null/null_sw_winsys.h"
+#ifdef HAVE_PIPE_LOADER_XLIB
+/* Explicitly wrap the header to ease build without X11 headers */
 #include "sw/xlib/xlib_sw_winsys.h"
+#endif
 #include "target-helpers/inline_sw_helper.h"
 #include "state_tracker/drisw_api.h"
 
@@ -49,7 +52,7 @@ static struct sw_winsys *(*backends[])() = {
    null_sw_create
 };
 
-#ifdef HAVE_WINSYS_XLIB
+#ifdef HAVE_PIPE_LOADER_XLIB
 bool
 pipe_loader_sw_probe_xlib(struct pipe_loader_device **devs, Display *display)
 {

src/gallium/targets/gbm/Makefile.am

@@ -50,6 +50,13 @@ gbm_gallium_drm_la_LIBADD = \
 	$(LIBDRM_LIBS) \
 	-lm
 
+if NEED_PIPE_LOADER_XLIB
+gbm_gallium_drm_la_LIBADD += \
+	$(top_builddir)/src/gallium/winsys/sw/xlib/libws_xlib.la \
+	-lX11 -lXext -lXfixes \
+	$(LIBDRM_LIBS)
+endif
+
 gbm_gallium_drm_la_LDFLAGS = -no-undefined -avoid-version -module
 
 # FIXME: this shouldn't be needed

src/gallium/targets/opencl/Makefile.am

@@ -28,6 +28,13 @@ lib@OPENCL_LIBNAME@_la_LIBADD = \
 	-lclangBasic \
 	$(LLVM_LIBS)
 
+if NEED_PIPE_LOADER_XLIB
+lib@OPENCL_LIBNAME@_la_LIBADD += \
+	$(top_builddir)/src/gallium/winsys/sw/xlib/libws_xlib.la \
+	-lX11 -lXext -lXfixes \
+	$(LIBDRM_LIBS)
+endif
+
 lib@OPENCL_LIBNAME@_la_SOURCES =
 
 # Force usage of a C++ linker

src/gallium/targets/xa/Makefile.am

@@ -48,6 +48,13 @@ libxatracker_la_LIBADD = \
 	$(LIBUDEV_LIBS) \
 	$(LIBDRM_LIBS)
 
+if NEED_PIPE_LOADER_XLIB
+libxatracker_la_LIBADD += \
+	$(top_builddir)/src/gallium/winsys/sw/xlib/libws_xlib.la \
+	-lX11 -lXext -lXfixes \
+	$(LIBDRM_LIBS)
+endif
+
 libxatracker_la_LDFLAGS = \
 	-no-undefined \
 	-version-number $(XA_MAJOR):$(XA_MINOR):$(XA_TINY)

src/gallium/tests/trivial/Makefile.am

@@ -20,6 +20,13 @@ LDADD = $(GALLIUM_PIPE_LOADER_CLIENT_LIBS) \
 	$(PTHREAD_LIBS) \
 	-lm
 
+if NEED_PIPE_LOADER_XLIB
+LDADD += \
+	$(top_builddir)/src/gallium/winsys/sw/xlib/libws_xlib.la \
+	-lX11 -lXext -lXfixes \
+	$(LIBDRM_LIBS)
+endif
+
 noinst_PROGRAMS = compute tri quad-tex
 
 compute_SOURCES = compute.c