Implement TARGET_OBJECT_STACK_MEMORY.

	* NEWS: Add note on new "set stack-cache" option.
	* corefile.c (read_stack): New function.
	* dcache.c (dcache_struct): New member ptid.
	(dcache_enable_p): Mark as obsolete.
	(show_dcache_enabled_p): Flag option as deprecated.
	(dcache_invalidate): Update ptid.
	(dcache_invalidate_line): New function.
	(dcache_read_line): No longer check cacheable attribute, stack
	accesses get cached despite attribute.
	(dcache_init): Set ptid.
	(dcache_xfer_memory): Flush cache if from different ptid than before.
	Update cache after write.
	(dcache_update): New function.
	(dcache_info): Report ptid.
	(_initialize_dcache): Update text for `remotecache' to indicate it
	is obsolete.
	* dcache.h (dcache_update): Declare.
	* dwarf2loc.c (dwarf2_evaluate_loc_desc): Mark values on stack with
	set_value_stack.
	* frame-unwind.c (frame_unwind_got_memory): Ditto.
	* gdbcore.h (read_stack): Declare.
	* memattr.c (mem_enable_command): Call target_dcache_invalidate
	instead of dcache_invalidate.
	(mem_disable_command, mem_delete_command): Ditto.
	* target.c (stack_cache_enabled_p_1): New static global.
	(stack_cache_enabled_p): New static global.
	(set_stack_cache_enabled_p): New function.
	(show_stack_cache_enabled_p): New function.
	(target_dcache): Make static.
	(target_dcache_invalidate): New function.
	(target_load, target_resume): Call target_dcache_invalidate
	instead of dcache_invalidate.
	(memory_xfer_partial): New arg object, all callers updated.
	Check for existing inferior before calling dcache routines.
	When writing non-TARGET_OBJECT_STACK_MEMORY, notify dcache.
	(target_xfer_partial): Call memory_xfer_partial for
	TARGET_OBJECT_STACK_MEMORY.
	(target_read_stack): New function.
	(initialize_targets): Install new option `stack-cache'.
	* target.h: Remove #include of dcache.h.
	(enum target_object): New value TARGET_OBJECT_STACK_MEMORY.
	(target_dcache): Delete.
	(target_dcache_invalidate): Declare.
	(target_read_stack): Declare.
	* top.c (prepare_execute_command): New function.
	(execute_command): Call prepare_execute_command
	instead of free_all_values.
	* top.h (prepare_execute_command): Declare.
	* valops.c (get_value_at): New function.
	(value_at): Guts moved to get_value_at.
	(value_at_lazy): Similarly.
	(value_fetch_lazy): Call read_stack for stack values.
	* value.c (struct value): New member `stack'.
	(value_stack, set_value_stack): New functions.
	* value.h (value_stack, set_value_stack): Declare.
	* mi/mi-main.c (mi_cmd_execute): Call prepare_execute_command
	instead of free_all_values.

	doc/
	* gdb.texinfo (Caching Data of Remote Targets): Update text.
	Mark `set/show remotecache' options as obsolete.
	Document new `set/show stack-cache' option.
	Update text for `info dcache'.

2 files changed, 36 insertions, 13 deletions

diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 3423ee2..8831e0a 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,11 @@
+2009-08-31  Jacob Potter  <jdpotter@google.com>
+	    Doug Evans  <dje@google.com>
+
+	* gdb.texinfo (Caching Data of Remote Targets): Update text.
+	Mark `set/show remotecache' options as obsolete.
+	Document new `set/show stack-cache' option.
+	Update text for `info dcache'.
+
 2009-08-27  Doug Evans  <dje@google.com>
 
 	* gdb.texinfo (Symbols): Delete `set print symbol-loading'.
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index cc66d12..0e9fd44 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -8421,32 +8421,47 @@ character.
 @section Caching Data of Remote Targets
 @cindex caching data of remote targets
 
-@value{GDBN} can cache data exchanged between the debugger and a
+@value{GDBN} caches data exchanged between the debugger and a
 remote target (@pxref{Remote Debugging}).  Such caching generally improves
 performance, because it reduces the overhead of the remote protocol by
-bundling memory reads and writes into large chunks.  Unfortunately,
-@value{GDBN} does not currently know anything about volatile
-registers, and thus data caching will produce incorrect results when
-volatile registers are in use.
+bundling memory reads and writes into large chunks.  Unfortunately, simply
+caching everything would lead to incorrect results, since @value{GDBN} 
+does not necessarily know anything about volatile values, memory-mapped I/O
+addresses, etc.  Therefore, by default, @value{GDBN} only caches data
+known to be on the stack.  Other regions of memory can be explicitly marked
+cacheable; see @pxref{Memory Region Attributes}.
 
 @table @code
 @kindex set remotecache
 @item set remotecache on
 @itemx set remotecache off
-Set caching state for remote targets.  When @code{ON}, use data
-caching.  By default, this option is @code{OFF}.
+This option no longer does anything; it exists for compatibility
+with old scripts.
 
 @kindex show remotecache
 @item show remotecache
-Show the current state of data caching for remote targets.
+Show the current state of the obsolete remotecache flag.
+
+@kindex set stack-cache
+@item set stack-cache on
+@itemx set stack-cache off
+Enable or disable caching of stack accesses.  When @code{ON}, use
+caching.  By default, this option is @code{ON}.
+
+@kindex show stack-cache
+@item show stack-cache
+Show the current state of data caching for memory accesses.
 
 @kindex info dcache
-@item info dcache
+@item info dcache @r{[}line@r{]}
 Print the information about the data cache performance.  The
-information displayed includes: the dcache width and depth; and for
-each cache line, how many times it was referenced, and its data and
-state (invalid, dirty, valid).  This command is useful for debugging
-the data cache operation.
+information displayed includes the dcache width and depth, and for
+each cache line, its number, address, and how many times it was
+referenced.  This command is useful for debugging the data cache
+operation.
+
+If a line number is specified, the contents of that line will be
+printed in hex.
 @end table
 
 @node Searching Memory