+debug_malloc=no
+AC_ARG_ENABLE(malloc_logging,
+ AS_HELP_STRING([--enable-malloc-logging],
+ [Include free space in logging messages (requires malloc.h).]),
+ [debug_malloc=$enableval], [])
+
+AC_MSG_CHECKING([whether to enable malloc free space logging]);
+AC_MSG_RESULT($debug_malloc)
+if test $debug_malloc = yes; then
+ AC_DEFINE([_DEBUG_FREE_SPACE_],[1], [Include malloc free space in logging])
+fi
+
+