[PATCH 3/4] New agent command 'kill' and used by gdbserver

[Yao Qi <yao@codesourcery.com>]

When GDB or GDBserver terminated inferior, agent has no chance to
remove socket file, even in atexit hook.  This patch adds a call
to send command 'kill' to agent in function kill_inferior, in
order to tell agent that inferior will be killed, and then agent
can do cleanup.

Of course, new agent command 'kill' is added and documented.

When GDB or GDBserver sends 'kill' command to an older agent, in
which 'kill is not known, and it will be ignored.

gdb/gdbserver:

2012-06-09  Yao Qi  <yao@codesourcery.com>

	* server.h: Declare run_inferior_command.
	* target.c (kill_inferior): New.  Send command 'kill'.
	* target.h (kill_inferior): Removed macro.
	* tracepoint.c (run_inferior_command): Remove static.
	Handle command 'kill'.

gdb/doc:

2012-06-09  Yao Qi  <yao@codesourcery.com>

	* gdb.texinfo (IPA Protocol Commands): Document new command
	'kill'.
---
 gdb/doc/gdb.texinfo        |    4 ++++
 gdb/gdbserver/server.h     |    1 +
 gdb/gdbserver/target.c     |    8 ++++++++
 gdb/gdbserver/target.h     |    5 ++---
 gdb/gdbserver/tracepoint.c |   17 +++++++++++++++--
 5 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index ad227a4..09339e5 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -33585,6 +33585,10 @@ for an error
 
 @end table
 
+@item kill
+Kills in-process agent.  Usually, this command is sent when @value{GDBN}
+or GDBserver is about to kill inferiors.
+
 @item qTfSTM
 @xref{qTfSTM}.
 @item qTsSTM
diff --git a/gdb/gdbserver/server.h b/gdb/gdbserver/server.h
index 02dfa29..452e400 100644
--- a/gdb/gdbserver/server.h
+++ b/gdb/gdbserver/server.h
@@ -558,4 +558,5 @@ int emit_error;
 extern const char version[];
 extern const char host_name[];
 
+int run_inferior_command (char *cmd, int len);
 #endif /* SERVER_H */
diff --git a/gdb/gdbserver/target.c b/gdb/gdbserver/target.c
index 7539476..35aaecd 100644
--- a/gdb/gdbserver/target.c
+++ b/gdb/gdbserver/target.c
@@ -182,3 +182,11 @@ target_waitstatus_to_string (const struct target_waitstatus *ws)
 
   return buf;
 }
+
+int
+kill_inferior(int pid)
+{
+  run_inferior_command ("kill", strlen ("kill"));
+
+  return (*the_target->kill) (pid);
+}
diff --git a/gdb/gdbserver/target.h b/gdb/gdbserver/target.h
index 0cf5687..101c3c4 100644
--- a/gdb/gdbserver/target.h
+++ b/gdb/gdbserver/target.h
@@ -409,9 +409,6 @@ void set_target_ops (struct target_ops *);
 #define myattach(pid) \
   (*the_target->attach) (pid)
 
-#define kill_inferior(pid) \
-  (*the_target->kill) (pid)
-
 #define detach_inferior(pid) \
   (*the_target->detach) (pid)
 
@@ -555,4 +552,6 @@ const char *target_pid_to_str (ptid_t);
 
 const char *target_waitstatus_to_string (const struct target_waitstatus *);
 
+int kill_inferior (int);
+
 #endif /* TARGET_H */
diff --git a/gdb/gdbserver/tracepoint.c b/gdb/gdbserver/tracepoint.c
index 4e6c3ec..bb2df8f 100644
--- a/gdb/gdbserver/tracepoint.c
+++ b/gdb/gdbserver/tracepoint.c
@@ -412,7 +412,7 @@ static int flush_trace_buffer_handler (CORE_ADDR);
 static void download_trace_state_variables (void);
 static void upload_fast_traceframes (void);
 
-static int run_inferior_command (char *cmd, int len);
+int run_inferior_command (char *cmd, int len);
 
 static int
 read_inferior_integer (CORE_ADDR symaddr, int *val)
@@ -6662,7 +6662,7 @@ static struct ltt_available_probe gdb_ust_probe =
    thread by means of direct memory xfering, and a socket for
    synchronization.  */
 
-static int
+int
 run_inferior_command (char *cmd, int len)
 {
   int err = -1;
@@ -7053,6 +7053,17 @@ gdb_agent_helper_thread (void *arg)
 
 	  if (cmd_buf[0])
 	    {
+	      if (strncmp ("kill", cmd_buf, 4) == 0)
+		{
+		  ret = write (fd, buf, 1);
+		  close (fd);
+
+		  close (listen_fd);
+		  unlink (agent_socket_name);
+
+		  return NULL;
+		}
+	      else
 #ifdef HAVE_UST
 	      if (strcmp ("qTfSTM", cmd_buf) == 0)
 		{
@@ -7080,7 +7091,9 @@ gdb_agent_helper_thread (void *arg)
 		{
 		  cmd_qtstmat (cmd_buf);
 		}
+	      else
 #endif /* HAVE_UST */
+		{}
 	    }
 
 	  /* Fix compiler's warning: ignoring return value of 'write'.  */
-- 
1.7.0.4