Have "configure" fail if GPOPT/GPOS header files are not present (#20).

configure

@@ -8949,7 +8949,9 @@ fi
 ## Header files
 ##
 
-{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for ANSI C header files" >&5
+# Check for Greenplum Query Optimizer (orca) and supporting Greenplum OS header files.
+if test "$enable_orca" = yes ; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ANSI C header files" >&5
 $as_echo_n "checking for ANSI C header files... " >&6; }
 if ${ac_cv_header_stdc+:} false; then :
   $as_echo_n "(cached) " >&6
@@ -9078,6 +9080,39 @@ fi
 done
 
 
+for ac_header in gpopt/init.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "gpopt/init.h" "ac_cv_header_gpopt_init_h" "$ac_includes_default"
+if test "x$ac_cv_header_gpopt_init_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_GPOPT_INIT_H 1
+_ACEOF
+
+else
+  as_fn_error $? "gpopt/init.h GPOPT header file is required for Greenplum Query Optimizer (orca)" "$LINENO" 5
+fi
+
+done
+
+fi
+
+if test "$enable_orca" = yes ; then
+  for ac_header in gpos/assert.h
+do :
+  ac_fn_c_check_header_mongrel "$LINENO" "gpos/assert.h" "ac_cv_header_gpos_assert_h" "$ac_includes_default"
+if test "x$ac_cv_header_gpos_assert_h" = xyes; then :
+  cat >>confdefs.h <<_ACEOF
+#define HAVE_GPOS_ASSERT_H 1
+_ACEOF
+
+else
+  as_fn_error $? "gpos/assert.h GPOS header file is required for Greenplum Query Optimizer (orca)" "$LINENO" 5
+fi
+
+done
+
+fi
+
 for ac_header in crypt.h dld.h endian.h fp_class.h getopt.h ieeefp.h ifaddrs.h langinfo.h poll.h pwd.h sys/ioctl.h sys/ipc.h sys/poll.h sys/pstat.h sys/resource.h sys/select.h sys/sem.h sys/shm.h sys/socket.h sys/sockio.h sys/tas.h sys/time.h sys/un.h termios.h ucred.h utime.h wchar.h wctype.h kernel/OS.h kernel/image.h SupportDefs.h
 do :
   as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`

configure.in

@@ -1023,6 +1023,15 @@ fi
 ## Header files
 ##
 
+# Check for Greenplum Query Optimizer (orca) and supporting Greenplum OS header files.
+if test "$enable_orca" = yes ; then
+  AC_CHECK_HEADERS(gpopt/init.h, [], [AC_MSG_ERROR([gpopt/init.h GPOPT header file is required for Greenplum Query Optimizer (orca)])])
+fi
+
+if test "$enable_orca" = yes ; then
+  AC_CHECK_HEADERS(gpos/assert.h, [], [AC_MSG_ERROR([gpos/assert.h GPOS header file is required for Greenplum Query Optimizer (orca)])])
+fi
+
 dnl sys/socket.h is required by AC_FUNC_ACCEPT_ARGTYPES
 AC_CHECK_HEADERS([crypt.h dld.h endian.h fp_class.h getopt.h ieeefp.h ifaddrs.h langinfo.h poll.h pwd.h sys/ioctl.h sys/ipc.h sys/poll.h sys/pstat.h sys/resource.h sys/select.h sys/sem.h sys/shm.h sys/socket.h sys/sockio.h sys/tas.h sys/time.h sys/un.h termios.h ucred.h utime.h wchar.h wctype.h kernel/OS.h kernel/image.h SupportDefs.h])