#endif
+#ifndef LACKS_UNISTD_H
+# include <unistd.h>
+#endif
+
/*
Define HAVE_MMAP to optionally make malloc() use mmap() to
allocate very large blocks. These will be returned to the
*/
#ifndef HAVE_MMAP
-#define HAVE_MMAP 1
+# ifdef _POSIX_MAPPED_FILES
+# define HAVE_MMAP 1
+# endif
#endif
/*
bsd/gnu getpagesize.h
*/
-#ifndef LACKS_UNISTD_H
-# include <unistd.h>
-#endif
-
#ifndef malloc_getpagesize
# ifdef _SC_PAGESIZE /* some SVR4 systems omit an underscore */
# ifndef _SC_PAGE_SIZE