+extern agent_expr_up gen_trace_for_expr (CORE_ADDR, struct expression *,
+ int);
+
+extern agent_expr_up gen_trace_for_var (CORE_ADDR, struct gdbarch *,
+ struct symbol *, int);
+
+extern agent_expr_up gen_trace_for_return_address (CORE_ADDR,
+ struct gdbarch *,
+ int);
+
+extern agent_expr_up gen_eval_for_expr (CORE_ADDR, struct expression *);