-void syscallerror(const char *what) NONRETURNING;
-void *xmalloc(size_t s);
-void *xrealloc(void *p, size_t s);
-void makeroom(char **buffer, int *size, int needed);
+int makeroom(char **buffer, int *size, int needed);
+/* makeroom returns -1 if needed was far too large; otherwise returns 0. */