This patch teaches GDB the concept of hardware accelerated watchpoint
conditions, and enables the target to say when a condition can be
accelerated or not.

In the case of BookE processors, the condition will be accelerated
when the user types "watch A if A == B", where A and B are either
address (e.g. "*0x12345678") or variables.
-- 
[]'s
Thiago Jung Bauermann
IBM Linux Technology Center


2009-12-23  Sergio Durigan Junior  <sergiodj@linux.vnet.ibm.com>
	    Thiago Jung Bauermann  <bauerman@br.ibm.com>

	* breakpoint.c (update_watchpoint): Disabled watchpoints before
	checking the used count.  Handled the case when the hardware supports
	the acceleration of the watchpoint's condition evaluation.
	(insert_bp_location): Calling the correct insertion method according
	to the type of the hardware watchpoint.
	(remove_breakpoint_1): Calling the correct deletion method according
	to the type of the hardware watchpoint.
	(set_raw_breakpoint_without_location): Setting the flag to zero.
	(watch_command_1): Handling the creation of hardware-accelerated
	condition watchpoint.
	(update_breakpoint_locations):  Handling the case of a hardware
	watchpoint with a condition begin hardware-accelerated.
	(exp_is_address_p): New function.
	(exp_is_var_p): Ditto.
	(cond_is_address_equal_literal_p): Ditto.
	(cond_is_var_equal_literal_p): Ditto.
	(get_var_address): Ditto.
	(default_watch_address_if_var_equal_literal_p): Ditto.
	(default_watch_var_if_address_equal_literal_p): Ditto.
	(default_watch_var_if_var_equal_literal_p): Ditto.
	(default_watch_address_if_address_equal_literal_p): Ditto.
	* breakpoint.h (struct bp_target_info) <length>: New field.
	(struct bp_location) <cond_hw_accel>, <cond_hw_addr>: New
	fields.
	(enum hw_point_flag): New.
	(struct breakpoint) <hw_point_flag>: New field.
	(default_watch_address_if_address_equal_literal_p): Declare.
	(default_watch_var_if_var_equal_literal_p): Ditto.
	(default_watch_address_if_var_equal_literal_p): Ditto.
	(default_watch_var_if_address_equal_literal_p): Ditto.
	* ppc-linux-nat.c (ppc_linux_can_use_special_hw_point_p): New function.
	(ppc_linux_insert_cond_accel_watchpoint): Ditto.
	(ppc_linux_remove_cond_accel_watchpoint): Ditto.
	(ppc_linux_get_watchpoint_cond_accel_addr): Ditto.
	(ppc_linux_can_use_watchpoint_cond_accel_p): Ditto.
	(_initialize_ppc_linux_nat): Initialize to_can_use_special_hw_point_p,
	to_get_watchpoint_cond_accel_addr, co_can_use_watchpoint_cond_accel_p
	to_insert_cond_accel_watchpoint and to_remove_cond_accel_watchpoint.
	* target.c (update_current_target): Add to_can_use_special_hw_point_p,
	to_get_watchpoint_cond_accel_addr, co_can_use_watchpoint_cond_accel_p
	to_insert_cond_accel_watchpoint and to_remove_cond_accel_watchpoint.
	* target.h: Add opaque declarations for bp_location, breakpoint and
	hw_point_flag.
	(struct target_ops <to_can_use_special_hw_point_p>,
	<to_can_use_watchpoint_cond_accel_p>, 
	<to_insert_cond_accel_watchpoint>,
	<to_remove_cond_accel_watchpoint>,
	<to_get_watchpoint_cond_accel_addr>): New callbacks.
	(target_region_ok_for_hw_watchpoint): Surround with ifndef.
	(target_can_use_special_hw_point_p): New define.
	(target_can_use_watchpoint_cond_accel_p): Ditto.
	(target_get_watchpoint_cond_accel_addr): Ditto.
	(target_insert_cond_accel_watchpoint): Ditto.
	(target_remove_cond_accel_watchpoint): Ditto.