2011-11-02 Stan Shebs <stan@codesourcery.com>

	String collection for tracepoints.
	* NEWS: Mention string collection.
	* common/ax.def (tracenz): New bytecode.
	* ax-gdb.h (trace_string_kludge): Declare.
	* ax-gdb.c: Include valprint.h and c-lang.h.
	(trace_string_kludge): New global.
	(gen_traced_pop): Add string case.
	(agent_command): Add string case.
	* tracepoint.h (decode_agent_options): Declare.
	* tracepoint.c: Include cli-utils.h.
	(decode_agent_options): New function.
	(validate_actionline): Call it.
	(encode_actions_1): Ditto.
	* target.h (struct target_ops): New method to_supports_string_tracing.
	(target_supports_string_tracing): New macro.
	* target.c (update_current_target): Add to_supports_string_tracing.
	* remote.c (struct remote_state): New field string_tracing.
	(remote_string_tracing_feature): New function.
	(remote_protocol_features): New feature tracenz.
	(remote_supports_string_tracing): New function.
	(init_remote_ops): Set to_supports_string_tracing.

	* tracepoint.c (agent_mem_read_string): New function.
	(eval_agent_expr): Call it for tracenz.
	* server.c (handle_query): Report support for tracenz.

	* gdb.texinfo (Tracepoint Action Lists): Document collect/s.
	(General Query Packets): Describe tracenz feature.
	* agentexpr.texi (Bytecode Descriptions): Describe tracenz.

	* gdb.trace/collection.c: Add code using strings.
	* gdb.trace/collection.exp: Add tests of string collection.

3 files changed, 31 insertions, 1 deletions

diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 1108974..f459be2 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,9 @@
+2011-11-02  Stan Shebs  <stan@codesourcery.com>
+
+	* gdb.texinfo (Tracepoint Action Lists): Document collect/s.
+	(General Query Packets): Describe tracenz feature.
+	* agentexpr.texi (Bytecode Descriptions): Describe tracenz.
+
 2011-10-28  Paul Koning  <paul_koning@dell.com>
 
 	* gdb.texinfo (gdb.types): Rename deepitems to deep_items.
diff --git a/gdb/doc/agentexpr.texi b/gdb/doc/agentexpr.texi
index f2d51b7..2104235 100644
--- a/gdb/doc/agentexpr.texi
+++ b/gdb/doc/agentexpr.texi
@@ -489,6 +489,11 @@ named @code{trace_quick16}, for consistency.
 Record the value of trace state variable number @var{n} in the trace
 buffer.  The handling of @var{n} is as described for @code{getv}.
 
+@item @code{tracenz} (0x2f)  @var{addr} @var{size} @result{}
+Record the bytes at @var{addr} in a trace buffer, for later retrieval
+by GDB.  Stop at either the first zero byte, or when @var{size} bytes
+have been recorded, whichever occurs first.
+
 @item @code{end} (0x27): @result{}
 Stop executing bytecode; the result should be the top element of the
 stack.  If the purpose of the expression was to compute an lvalue or a
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 0f37e6e..19236b3 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -10666,7 +10666,7 @@ end
 @end smallexample
 
 @kindex collect @r{(tracepoints)}
-@item collect @var{expr1}, @var{expr2}, @dots{}
+@item collect@r{[}/@var{mods}@r{]} @var{expr1}, @var{expr2}, @dots{}
 Collect values of the given expressions when the tracepoint is hit.
 This command accepts a comma-separated list of any valid expressions.
 In addition to global, static, or local variables, the following
@@ -10712,6 +10712,15 @@ You can give several consecutive @code{collect} commands, each one
 with a single argument, or one @code{collect} command with several
 arguments separated by commas; the effect is the same.
 
+The optional @var{mods} changes the usual handling of the arguments.
+@code{s} requests that pointers to chars be handled as strings, in
+particular collecting the contents of the memory being pointed at, up
+to the first zero.  The upper bound is by default the value of the
+@code{print elements} variable; if @code{s} is followed by a decimal
+number, that is the upper bound instead.  So for instance
+@samp{collect/s25 mystr} collects as many as 25 characters at
+@samp{mystr}.
+
 The command @code{info scope} (@pxref{Symbols, info scope}) is
 particularly useful for figuring out what data to collect.
 
@@ -34707,6 +34716,11 @@ These are the currently defined stub features and their properties:
 @tab @samp{-}
 @tab No
 
+@item @samp{tracenz}
+@tab No
+@tab @samp{-}
+@tab No
+
 @end multitable
 
 These are the currently defined stub features, in more detail:
@@ -34831,6 +34845,11 @@ The remote stub supports the @samp{QTEnable} (@pxref{QTEnable}) and
 @samp{QTDisable} (@pxref{QTDisable}) packets that allow tracepoints
 to be enabled and disabled while a trace experiment is running.
 
+@item tracenz
+@cindex string tracing, in remote protocol
+The remote stub supports the @samp{tracenz} bytecode for collecting strings.
+See @ref{Bytecode Descriptions} for details about the bytecode.
+
 @end table
 
 @item qSymbol::