--- configure.orig	2017-12-21 17:31:27 UTC
+++ configure
@@ -23308,7 +23308,7 @@ fi
 
 
 case "$host_os" in
-linux*)
+linux* | freebsd*)
     dri3_default=yes
     ;;
 *)
@@ -27028,9 +27028,19 @@ if test "x$enable_opencl" = xyes; then
         as_fn_error $? "cannot enable OpenCL without Gallium" "$LINENO" 5
     fi
 
+    if test "x$acv_mesa_CLANG" = xno; then
+
+    GCC_VERSION=`$CC -dumpversion`
+    if test $? -eq 0; then
+        GCC_VERSION_MAJOR=`echo $GCC_VERSION | cut -d. -f1`
+        GCC_VERSION_MINOR=`echo $GCC_VERSION | cut -d. -f2`
+    fi
+
     if test $GCC_VERSION_MAJOR -lt 4 -o $GCC_VERSION_MAJOR -eq 4 -a $GCC_VERSION_MINOR -lt 7; then
         as_fn_error $? "gcc >= 4.7 is required to build clover" "$LINENO" 5
     fi
+# end of clang test.
+    fi
 
     if test "x$have_libclc" = xno; then
         as_fn_error $? "pkg-config cannot find libclc.pc which is required to build clover.
@@ -27096,9 +27106,6 @@ rm -f core conftest.err conftest.$ac_obj
         CLANG_LIBDIR=${LLVM_LIBDIR}
     fi
     CLANG_RESOURCE_DIR=$CLANG_LIBDIR/clang/${LLVM_VERSION}
-    if test ! -f "$CLANG_RESOURCE_DIR/include/stddef.h"; then :
-  as_fn_error $? "Could not find clang internal header stddef.h in $CLANG_RESOURCE_DIR Use --with-clang-libdir to specify the correct path to the clang libraries." "$LINENO" 5
-fi
 fi
  if test "x$enable_opencl" = xyes; then
   HAVE_CLOVER_TRUE=