+# Check for dlopen support and enable plugins if possible.
+enable_plugins=yes
+ac_fn_c_check_header_compile "$LINENO" "dlfcn.h" "ac_cv_header_dlfcn_h" "$ac_includes_default
+"
+if test "x$ac_cv_header_dlfcn_h" = x""yes; then :
+
+else
+ enable_plugins=no
+fi
+
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for library containing dlopen" >&5
+$as_echo_n "checking for library containing dlopen... " >&6; }
+if test "${ac_cv_search_dlopen+set}" = set; then :
+ $as_echo_n "(cached) " >&6
+else
+ ac_func_search_save_LIBS=$LIBS
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+/* Override any GCC internal prototype to avoid an error.
+ Use char because int might match the return type of a GCC
+ builtin and then its argument prototype would still apply. */
+#ifdef __cplusplus
+extern "C"
+#endif
+char dlopen ();
+int
+main ()
+{
+return dlopen ();
+ ;
+ return 0;
+}
+_ACEOF
+for ac_lib in '' dl; do
+ if test -z "$ac_lib"; then
+ ac_res="none required"
+ else
+ ac_res=-l$ac_lib
+ LIBS="-l$ac_lib $ac_func_search_save_LIBS"
+ fi
+ if ac_fn_c_try_link "$LINENO"; then :
+ ac_cv_search_dlopen=$ac_res
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext
+ if test "${ac_cv_search_dlopen+set}" = set; then :
+ break
+fi
+done
+if test "${ac_cv_search_dlopen+set}" = set; then :
+
+else
+ ac_cv_search_dlopen=no
+fi
+rm conftest.$ac_ext
+LIBS=$ac_func_search_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_search_dlopen" >&5
+$as_echo "$ac_cv_search_dlopen" >&6; }
+ac_res=$ac_cv_search_dlopen
+if test "$ac_res" != no; then :
+ test "$ac_res" = "none required" || LIBS="$ac_res $LIBS"
+
+else
+ enable_plugins=no
+fi
+
+for ac_func in dlopen dlsym dlclose
+do :
+ as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
+ac_fn_c_check_func "$LINENO" "$ac_func" "$as_ac_var"
+eval as_val=\$$as_ac_var
+ if test "x$as_val" = x""yes; then :
+ cat >>confdefs.h <<_ACEOF
+#define `$as_echo "HAVE_$ac_func" | $as_tr_cpp` 1
+_ACEOF
+
+else
+ enable_plugins=no
+fi
+done
+
+# We also support plugins on Windows (MinGW).
+if test x$enable_plugins = xno ; then
+ for ac_header in Windows.h
+do :
+ ac_fn_c_check_header_compile "$LINENO" "Windows.h" "ac_cv_header_Windows_h" "$ac_includes_default
+"
+if test "x$ac_cv_header_Windows_h" = x""yes; then :
+ cat >>confdefs.h <<_ACEOF
+#define HAVE_WINDOWS_H 1
+_ACEOF
+ enable_plugins=yes
+fi
+
+done
+
+fi
+ if test x$enable_plugins = xyes; then
+ ENABLE_PLUGINS_TRUE=
+ ENABLE_PLUGINS_FALSE='#'
+else
+ ENABLE_PLUGINS_TRUE='#'
+ ENABLE_PLUGINS_FALSE=
+fi
+
+