2011-01-11 Sergio Durigan Junior <sergiodj@linux.vnet.ibm.com>

	    Thiago Jung Bauermann  <bauerman@br.ibm.com>

	Implement support for PowerPC BookE ranged watchpoints.

gdb/
	* breakpoint.h
	(struct breakpoint_ops) <resources_needed>: New method.
	Initialize to NULL in all existing breakpoint_ops instances.
	(struct breakpoint) <exact>: New field.
	(target_exact_watchpoints): Declare external global.
	* breakpoint.c (target_exact_watchpoints): New global flag.
	(update_watchpoint): Set b->type to bp_hardware_watchpoint and
	b->enable_state to bp_enabled before calling
	hw_watchpoint_used_count.
	(hw_watchpoint_used_count): Iterate over all bp_locations in a
	watchpoint.  Call breakpoint's breakpoint_ops.resources_needed
	if available.
	(insert_watchpoint, remove_watchpoint): Use fixed length of 1 byte
	if the watchpoint is exact.
	(resources_needed_watchpoint): New function.
	(watchpoint_breakpoint_ops): Add resources_needed_watchpoint.
	(watch_command_1): Set b->exact if the user asked for an exact
	watchpoint and one can be set.
	(can_use_hardware_watchpoint): Add exact_watchpoints argument.
	Pass fixed length of 1 to target_region_ok_for_hw_watchpoint if
	the user asks for an exact watchpoint and one can be set.  Return
	number of needed debug registers to watch the expression.
	* gdbtypes.c (is_scalar_type): New function, based on
	valprint.c:scalar_type_p.
	(is_scalar_type_recursive): New function.
	* gdbtypes.h (is_scalar_type_recursive): Declare.
	* ppc-linux-nat.c (ppc_linux_region_ok_for_hw_watchpoint): Always
	handle regions when ranged watchpoints are available.
	(create_watchpoint_request): New function.
	(ppc_linux_insert_watchpoint, ppc_linux_remove_watchpoint): Use
	create_watchpoint_request.
	* rs6000-tdep.c (show_powerpc_exact_watchpoints): New function.
	(_initialize_rs6000_tdep): Add `exact-watchpoints' boolean to the
	`set powerpc' and `show powerpc' commands.
	* target.h (struct target_ops) <to_region_ok_for_hw_watchpoint>:
	Mention documentation comment in the target macro.
	(target_region_ok_for_hw_watchpoint): Document return value.

gdb/doc/
	* gdb.texinfo (PowerPC Embedded): Document ranged watchpoints and
	the "set powerpc exact-watchpoints" flag.

1 files changed, 16 insertions, 1 deletions

diff --git a/gdb/breakpoint.h b/gdb/breakpoint.h
index cd9b6b8..69598a7 100644
--- a/gdb/breakpoint.h
+++ b/gdb/breakpoint.h
@@ -385,6 +385,11 @@ struct breakpoint_ops
      breakpoint was hit.  */
   int (*breakpoint_hit) (struct breakpoint *);
 
+  /* Tell how many hardware resources (debug registers) are needed
+     for this breakpoint.  If this function is not provided, then
+     the breakpoint or watchpoint needs one debug register.  */
+  int (*resources_needed) (const struct bp_location *);
+
   /* The normal print routine for this breakpoint, called when we
      hit it.  */
   enum print_stop_action (*print_it) (struct breakpoint *);
@@ -425,6 +430,13 @@ DEF_VEC_P(bp_location_p);
    detail to the breakpoints module.  */
 struct counted_command_line;
 
+/* Some targets (e.g., embedded PowerPC) need two debug registers to set
+   a watchpoint over a memory region.  If this flag is true, GDB will use
+   only one register per watchpoint, thus assuming that all acesses that
+   modify a memory location happen at its starting address. */
+
+extern int target_exact_watchpoints;
+
 /* Note that the ->silent field is not currently used by any commands
    (though the code is in there if it was to be, and set_raw_breakpoint
    does set it to 0).  I implemented it because I thought it would be
@@ -595,7 +607,10 @@ struct breakpoint
        can sometimes be NULL for enabled GDBs as not all breakpoint
        types are tracked by the Python scripting API.  */
     struct breakpoint_object *py_bp_object;
-};
+
+    /* Whether this watchpoint is exact (see target_exact_watchpoints).  */
+    int exact;
+  };
 
 typedef struct breakpoint *breakpoint_p;
 DEF_VEC_P(breakpoint_p);