configure.ac: SOCL needs a recent version of OpenCL which defines cl_device_partition_property, Check it is available before enabling SOCL.

configure.ac

@@ -1295,26 +1295,33 @@ AC_ARG_ENABLE([socl],
   [enable_socl="$enableval"],
   [enable_socl="maybe"])
 
-AC_MSG_CHECKING(for SOCL)
-
 if test "x$enable_socl" = "xyes" -o "x$enable_socl" = "xmaybe" ; then
     if test "$have_valid_opencl" = "no" ; then
 	STARPU_LOOK_FOR_OPENCL()
     fi
+    if test "$have_valid_opencl" = "yes" ; then
+	AC_CHECK_TYPE(cl_device_partition_property,
+	    [have_valid_socl=yes],
+	    [have_valid_socl=no], [#include <CL/cl.h>])
+    fi
 fi
 
 # in case SOCL was explicitely required, but is not available, this is an error
 if test "x$enable_socl" = "xyes" -a "$have_valid_opencl" = "no" ; then
     AC_MSG_ERROR([SOCL cannot be enabled without OpenCL])
 fi
+if test "x$enable_socl" = "xyes" -a "$have_valid_socl" = "no" ; then
+    AC_MSG_ERROR([SOCL needs a recent version of OpenCL])
+fi
 
 # now we enable SOCL if and only if a proper setup is available
 if test "x$enable_socl" = "xyes" -o "x$enable_socl" = "xmaybe" ; then
-   build_socl=$have_valid_opencl
+   build_socl=$have_valid_socl
 else
    build_socl=no
 fi
 
+AC_MSG_CHECKING(for SOCL)
 AC_MSG_RESULT($build_socl)
 AM_CONDITIONAL([BUILD_SOCL], [test "x$build_socl" = "xyes"])
 AM_CONDITIONAL([STARPU_USE_SOCL], [test "x$build_socl" = "xyes"])