2011-05-06 Sergio Durigan Junior <sergiodj@linux.vnet.ibm.com>

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

	Implement support for PowerPC BookE masked watchpoints.

gdb/
	* NEWS: Mention masked watchpoint support.  Create "Changed commands"
	section.
	* breakpoint.h (struct breakpoint_ops) <works_in_software_mode>: New
	method.  Initialize to NULL in all existing breakpoint_ops instances.
	(struct breakpoint) <hw_wp_mask>: New field.
	* breakpoint.c (is_masked_watchpoint): Add prototype.
	(update_watchpoint): Don't set b->val for masked watchpoints.  Call
	breakpoint's breakpoint_ops.works_in_software_mode if available.
	(watchpoints_triggered): Handle the case of a hardware masked
	watchpoint trigger.
	(watchpoint_check): Likewise.
	(works_in_software_mode_watchpoint): New function.
	(insert_masked_watchpoint, remove_masked_watchpoint)
	(resources_needed_masked_watchpoint)
	(works_in_software_mode_masked_watchpoint, print_it_masked_watchpoint)
	(print_one_detail_masked_watchpoint, print_mention_masked_watchpoint)
	(print_recreate_masked_watchpoint, is_masked_watchpoint): New
	functions.
	(masked_watchpoint_breakpoint_ops): New structure.
	(watch_command_1): Check for the existence of the `mask' parameter.
	Set b->ops according to the type of hardware watchpoint being created.
	* ppc-linux-nat.c (ppc_linux_insert_mask_watchpoint)
	(ppc_linux_remove_mask_watchpoint)
	(ppc_linux_masked_watch_num_registers): New functions.
	(_initialize_ppc_linux_nat): Initialize to_insert_mask_watchpoint,
	to_remove_mask_watchpoint and to_masked_watch_num_registers.
	* target.c (update_current_target): Mention to_insert_mask_watchpoint,
	to_remove_mask_watchpoint, and to_masked_watch_num_registers.
	(target_insert_mask_watchpoint, target_remove_mask_watchpoint)
	(target_masked_watch_num_registers): New functions.
	* target.h (struct target_ops) <to_insert_mask_watchpoint>,
	<to_remove_mask_watchpoint>, <to_masked_watch_num_registers>: New
	methods.
	(target_insert_mask_watchpoint, target_remove_mask_watchpoint)
	(target_masked_watch_num_registers): Add prototypes.

gdb/doc/
	* gdb.texinfo (Set Watchpoints): Document mask parameter.
	(PowerPC Embedded): Mention support of masked watchpoints.

2 files changed, 31 insertions, 4 deletions

diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index d7e610d..2eacb32 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,10 @@
+2011-05-06  Sergio Durigan Junior  <sergiodj@linux.vnet.ibm.com>
+	    Thiago Jung Bauermann  <bauerman@br.ibm.com>
+
+	Implement support for PowerPC BookE masked watchpoints.
+	* gdb.texinfo (Set Watchpoints): Document mask parameter.
+	(PowerPC Embedded): Mention support of masked watchpoints.
+
 2011-05-03  Joel Brobecker  <brobecker@adacore.com>
 
 	* gdb.texinfo (In Memoriam): Replace litteral uses of `GDB' with
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 0ac5672..3618b70 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -3725,7 +3725,7 @@ watchpoints, which do not slow down the running of your program.
 
 @table @code
 @kindex watch
-@item watch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]}
+@item watch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]} @r{[}mask @var{maskvalue}@r{]}
 Set a watchpoint for an expression.  @value{GDBN} will break when the
 expression @var{expr} is written into by the program and its value
 changes.  The simplest (and the most popular) use of this command is
@@ -3736,7 +3736,7 @@ to watch the value of a single variable:
 @end smallexample
 
 If the command includes a @code{@r{[}thread @var{threadnum}@r{]}}
-clause, @value{GDBN} breaks only when the thread identified by
+argument, @value{GDBN} breaks only when the thread identified by
 @var{threadnum} changes the value of @var{expr}.  If any other threads
 change the value of @var{expr}, @value{GDBN} will not break.  Note
 that watchpoints restricted to a single thread in this way only work
@@ -3751,13 +3751,30 @@ to determine the size of the watched memory.  If the expression's
 result does not have an address, then @value{GDBN} will print an
 error.
 
+The @code{@r{[}mask @var{maskvalue}@r{]}} argument allows creation
+of masked watchpoints, if the current architecture supports this
+feature (e.g., PowerPC Embedded architecture, see @ref{PowerPC
+Embedded}.)  A @dfn{masked watchpoint} specifies a mask in addition
+to an address to watch.  The mask specifies that some bits of an address
+(the bits which are reset in the mask) should be ignored when matching
+the address accessed by the inferior against the watchpoint address.
+Thus, a masked watchpoint watches many addresses simultaneously---those
+addresses whose unmasked bits are identical to the unmasked bits in the
+watchpoint address.  The @code{mask} argument implies @code{-location}.
+Examples:
+
+@smallexample
+(@value{GDBP}) watch foo mask 0xffff00ff
+(@value{GDBP}) watch *0xdeadbeef mask 0xffffff00
+@end smallexample
+
 @kindex rwatch
-@item rwatch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]}
+@item rwatch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]} @r{[}mask @var{maskvalue}@r{]}
 Set a watchpoint that will break when the value of @var{expr} is read
 by the program.
 
 @kindex awatch
-@item awatch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]}
+@item awatch @r{[}-l@r{|}-location@r{]} @var{expr} @r{[}thread @var{threadnum}@r{]} @r{[}mask @var{maskvalue}@r{]}
 Set a watchpoint that will break when @var{expr} is either read from
 or written into by the program.
 
@@ -18780,6 +18797,9 @@ region using one of the following commands (@pxref{Expressions}):
 (@value{GDBP}) watch @{char[@var{length}]@} @var{address}
 @end smallexample
 
+PowerPC embedded processors support masked watchpoints.  See the discussion
+about the @code{mask} argument in @ref{Set Watchpoints}.
+
 @cindex ranged breakpoint
 PowerPC embedded processors support hardware accelerated
 @dfn{ranged breakpoints}.  A ranged breakpoint stops execution of