Add an option gl-accel to disable GL acceleration:
* When enabled, configure try best to enable GL acceleration and fail when
  missing host dependency(libSDL and libGL), which is the default.
* When disabled, end user choose to turn off GL capability, thus remove the
  host dependence in building.

Upstream-Status: Inappropriate [other] - depends on GL patch

Signed-off-by: Zhai Edwin <edwin.zhai@intel.com>

Index: qemu-0.15.1/Makefile.target
===================================================================
--- qemu-0.15.1.orig/Makefile.target	2012-05-29 11:20:04.000000000 +0800
+++ qemu-0.15.1/Makefile.target	2012-05-29 11:20:04.000000000 +0800
@@ -80,13 +80,16 @@
 endif
 libobj-$(CONFIG_NEED_MMU) += mmu.o
 ifndef CONFIG_LINUX_USER
+ifdef CONFIG_GL_ACCEL
 libobj-$(TARGET_I386) += helper_opengl.o opengl_exec.o
 libobj-$(TARGET_X86_64) += helper_opengl.o opengl_exec.o
 else
-ifdef CONFIG_SDL
 libobj-$(TARGET_I386) += dummygl.o
 libobj-$(TARGET_X86_64) += dummygl.o
-endif
+endif #CONFIG_GL_ACCEL
+else
+libobj-$(TARGET_I386) += dummygl.o
+libobj-$(TARGET_X86_64) += dummygl.o
 endif #CONFIG_LINUX_USER
 libobj-$(TARGET_ARM) += dummygl.o
 libobj-$(TARGET_MIPS) += dummygl.o
@@ -262,8 +265,10 @@
 obj-i386-$(CONFIG_SPICE) += qxl.o qxl-logger.o qxl-render.o
 
 ifeq ($(TARGET_BASE_ARCH), i386)
+ifdef CONFIG_GL_ACCEL
 QEMU_CFLAGS += -DTARGET_OPENGL_OK
 endif
+endif
 
 # shared objects
 obj-ppc-y = ppc.o
@@ -409,8 +414,6 @@
 
 monitor.o: hmp-commands.h qmp-commands.h
 
-LIBS += -lGL -lGLU
-
 $(obj-y) $(obj-$(TARGET_BASE_ARCH)-y): $(GENERATED_HEADERS)
 
 obj-y += $(addprefix ../, $(common-obj-y))
Index: qemu-0.15.1/configure
===================================================================
--- qemu-0.15.1.orig/configure	2012-05-29 11:20:03.000000000 +0800
+++ qemu-0.15.1/configure	2012-05-29 11:20:04.000000000 +0800
@@ -2021,6 +2021,39 @@
   fi
 fi
 
+#####################################################
+# GL acceleration probe depending on gl, glu and sdl
+if test "$gl_accel" != "no" ; then
+  if test "$sdl" = "no" ; then
+    gl_accel=no
+    echo "libSDL and header no found to build opengl acceleration for qemu-native.
+    Ubuntu package names are: libsdl1.2-dev.
+    Fedora package names are: SDL-devel."
+    exit 1;
+  fi
+
+  gl_accel_libs="-lGL -lGLU"
+  cat > $TMPC << EOF
+#include <X11/Xlib.h>
+#include <GL/gl.h>
+#include <GL/glx.h>
+#include <GL/glu.h>
+int main(void) { GL_VERSION; return 0; }
+EOF
+  if compile_prog "" "-lGL -lGLU" ; then
+    gl_accel=yes
+    libs_softmmu="$gl_accel_libs $libs_softmmu"
+  else
+    feature_not_found "gl_accel"
+    gl_accel=no
+    gl_accel_libs=
+    echo "libGL.so and libGLU.so not found to build opengl acceleration for qemu-native.
+    Ubuntu package names are: libgl1-mesa-dev, libglu1-mesa-dev and libsdl1.2-dev.
+    Fedora package names are: mesa-libGL mesa-libGLU SDL-devel."
+    exit 1;
+  fi
+fi
+
 #
 # Check for xxxat() functions when we are building linux-user
 # emulator.  This is done because older glibc versions don't
@@ -2722,6 +2755,7 @@
 echo "nss used          $smartcard_nss"
 echo "usb net redir     $usb_redir"
 echo "OpenGL support    $opengl"
+echo "GL acceleration support    $gl_accel"
 echo "build guest agent $guest_agent"
 
 if test $sdl_too_old = "yes"; then
@@ -3025,6 +3059,10 @@
   echo "CONFIG_OPENGL=y" >> $config_host_mak
 fi
 
+if test "$gl_accel" = "yes" ; then
+  echo "CONFIG_GL_ACCEL=y" >> $config_host_mak
+fi
+
 # XXX: suppress that
 if [ "$bsd" = "yes" ] ; then
   echo "CONFIG_BSD=y" >> $config_host_mak
Index: qemu-0.15.1/qemu-char.c
===================================================================
--- qemu-0.15.1.orig/qemu-char.c	2012-05-29 11:20:03.000000000 +0800
+++ qemu-0.15.1/qemu-char.c	2012-05-29 11:20:04.000000000 +0800
@@ -2387,7 +2387,6 @@
     return d->outbuf_size;
 }
 
-#define TARGET_OPENGL_OK
 #if defined(TARGET_OPENGL_OK)
 static uint8_t buffer[32];
 static int buffer_len;
@@ -2447,7 +2446,7 @@
     return chr;
 }
 #else
-#define qemu_chr_open_opengl() 0
+#define qemu_chr_open_opengl NULL
 #endif
 
 QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)