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.

2 files changed, 33 insertions, 4 deletions

diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index d5f89b2..a64db4c 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,10 @@
+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.texinfo (PowerPC Embedded): Document ranged watchpoints and
+	the "set powerpc exact-watchpoints" flag.
+
 2011-01-07  Tom Tromey  <tromey@redhat.com>
 
 	* gdb.texinfo (Python API): Add descriptions to @menu items.
@@ -8,7 +15,7 @@
 
 2010-01-06  Paul Pluzhnikov  <ppluzhnikov@google.com>
 
-       * gdb.texinfo (Debugging Output): Document "set debug jit".
+	* gdb.texinfo (Debugging Output): Document "set debug jit".
 
 2011-01-06  Tom Tromey  <tromey@redhat.com>
 
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 7f8c785..8e42913 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -18721,9 +18721,25 @@ implement in hardware simple hardware watchpoint conditions of the form:
   if  @var{ADDRESS|VARIABLE} == @var{CONSTANT EXPRESSION}
 @end smallexample
 
-The DVC register will be automatically used whenever @value{GDBN} detects
-such pattern in a condition expression.  This feature is available in native
-@value{GDBN} running on a Linux kernel version 2.6.34 or newer.
+The DVC register will be automatically used when @value{GDBN} detects
+such pattern in a condition expression, and the created watchpoint uses one
+debug register (either the @code{exact-watchpoints} option is on and the
+variable is scalar, or the variable has a length of one byte).  This feature
+is available in native @value{GDBN} running on a Linux kernel version 2.6.34
+or newer.
+
+When running on PowerPC embedded processors, @value{GDBN} automatically uses
+ranged hardware watchpoints, unless the @code{exact-watchpoints} option is on,
+in which case watchpoints using only one debug register are created when
+watching variables of scalar types.
+
+You can create an artificial array to watch an arbitrary memory
+region using one of the following commands (@pxref{Expressions}):
+
+@smallexample
+(@value{GDBP}) watch *((char *) @var{address})@@@var{length}
+(@value{GDBP}) watch @{char[@var{length}]@} @var{address}
+@end smallexample
 
 @value{GDBN} provides the following PowerPC-specific commands:
 
@@ -18744,6 +18760,12 @@ arguments and return values.  The valid options are @samp{auto};
 registers.  By default, @value{GDBN} selects the calling convention
 based on the selected architecture and the provided executable file.
 
+@item set powerpc exact-watchpoints
+@itemx show powerpc exact-watchpoints
+Allow @value{GDBN} to use only one debug register when watching a variable
+of scalar type, thus assuming that the variable is accessed through the
+address of its first byte.
+
 @kindex target dink32
 @item target dink32 @var{dev}
 DINK32 ROM monitor.