[PATCH 6/9] agent capability of static tracepoint

[Yao Qi <yao at codesourcery dot com>]

This patch is to teach both GDB and GDBserver to check agent's capability on
static tracepoint, before performing any operations.

gdb:
2012-02-15  Yao Qi  <yao@codesourcery.com>

	* tracepoint.c (info_static_tracepoint_markers_command): Call
	agent_capability_check.

gdb/gdbserver:
2012-02-15  Yao Qi  <yao@codesourcery.com>

	* tracepoint.c (gdb_agent_capability): New global.
	(in_process_agent_loaded_ust): Renamed to
	`in_process_agent_supports_ust'.
	Update callers.
	(in_process_agent_supports_ust): Call agent_capability_check.
	(clear_installed_tracepoints): Assert that agent supports
	agent.
	(install_tracepoint): Call in_process_agent_supports_ust.
---
 gdb/gdbserver/tracepoint.c |   25 ++++++++++++++++++-------
 gdb/tracepoint.c           |    5 +++++
 2 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/gdb/gdbserver/tracepoint.c b/gdb/gdbserver/tracepoint.c
index 091af5a..0e1f9ed 100644
--- a/gdb/gdbserver/tracepoint.c
+++ b/gdb/gdbserver/tracepoint.c
@@ -239,10 +239,11 @@ in_process_agent_loaded (void)
 static int read_inferior_integer (CORE_ADDR symaddr, int *val);
 
 /* Returns true if both the in-process agent library and the static
-   tracepoints libraries are loaded in the inferior.  */
+   tracepoints libraries are loaded in the inferior, and agent has
+   capability on static tracepoints.  */
 
 static int
-in_process_agent_loaded_ust (void)
+in_process_agent_supports_ust (void)
 {
   int loaded = 0;
 
@@ -258,7 +259,10 @@ in_process_agent_loaded_ust (void)
       return 0;
     }
 
-  return loaded;
+  if (loaded)
+    return agent_capability_check (AGENT_CAPA_STATIC_TRACE);
+  else
+    return 0;
 }
 
 static void
@@ -310,7 +314,7 @@ maybe_write_ipa_ust_not_loaded (char *buffer)
       write_e_ipa_not_loaded (buffer);
       return 1;
     }
-  else if (!in_process_agent_loaded_ust ())
+  else if (!in_process_agent_supports_ust ())
     {
       write_e_ust_not_loaded (buffer);
       return 1;
@@ -2315,6 +2319,10 @@ clear_installed_tracepoints (void)
 	    ;
 	  else
 	    {
+	      /* Static tracepoints have been inserted, so agent should have
+		 been loaded and working.  */
+	      gdb_assert (in_process_agent_supports_ust ());
+
 	      unprobe_marker_at (tpoint->address);
 	      prev_stpoint = tpoint;
 	    }
@@ -2965,7 +2973,8 @@ install_tracepoint (struct tracepoint *tpoint, char *own_buf)
 	  write_e_ipa_not_loaded (own_buf);
 	  return;
 	}
-      if (tpoint->type == static_tracepoint && !in_process_agent_loaded_ust ())
+      if (tpoint->type == static_tracepoint
+	  && !in_process_agent_supports_ust ())
 	{
 	  trace_debug ("Requested a static tracepoint, but static "
 		       "tracepoints are not supported.");
@@ -2990,8 +2999,8 @@ install_tracepoint (struct tracepoint *tpoint, char *own_buf)
 	}
       else
 	{
-	  if (tp)
-	    tpoint->handle = (void *) -1;
+	  if (!in_process_agent_supports_ust ())
+	    warning ("Agent does not have capability for static tracepoint.");
 	  else
 	    {
 	      if (probe_marker_at (tpoint->address, own_buf) == 0)
@@ -7994,6 +8003,8 @@ gdb_agent_helper_thread (void *arg)
 #include <signal.h>
 #include <pthread.h>
 
+IP_AGENT_EXPORT int gdb_agent_capability = AGENT_CAPA_STATIC_TRACE;
+
 static void
 gdb_agent_init (void)
 {
diff --git a/gdb/tracepoint.c b/gdb/tracepoint.c
index c56a02c..c2801f9 100644
--- a/gdb/tracepoint.c
+++ b/gdb/tracepoint.c
@@ -4893,6 +4893,11 @@ info_static_tracepoint_markers_command (char *arg, int from_tty)
       warning (_("Agent is off.  Run `set agent on'."));
       return;
     }
+  if (!agent_capability_check (AGENT_CAPA_STATIC_TRACE))
+    {
+      warning (_("Agent is not capable of operating static tracepoints"));
+      return;
+    }
 
   old_chain
     = make_cleanup_ui_out_table_begin_end (uiout, 5, -1,
-- 
1.7.0.4