qPacketInfo support for the branch (pending for mainline)

1 files changed, 168 insertions, 85 deletions

diff --git a/gdb/remote.c b/gdb/remote.c
index 0862f851fa2..897901266a8 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -189,8 +189,21 @@ static void show_packet_config_cmd (struct packet_config *config);
 
 static void update_packet_config (struct packet_config *config);
 
+static void set_remote_protocol_packet_cmd (char *args, int from_tty,
+					    struct cmd_list_element *c);
+
+static void show_remote_protocol_packet_cmd (struct ui_file *file,
+					     int from_tty,
+					     struct cmd_list_element *c,
+					     const char *value);
+
 void _initialize_remote (void);
 
+/* For "set remote" and "show remote".  */
+
+static struct cmd_list_element *remote_set_cmdlist;
+static struct cmd_list_element *remote_show_cmdlist;
+
 /* Description of the remote protocol.  Strictly speaking, when the
    target is open()ed, remote.c should create a per-target description
    of the remote protocol using that target's architecture.
@@ -229,6 +242,10 @@ struct remote_state
   /* This is the maximum size (in chars) of a non read/write packet.
      It is also used as a cap on the size of read/write packets.  */
   long remote_packet_size;
+
+  /* This flag is set if we negotiated packet size explicitly (and
+     can bypass various heuristics).  */
+  int explicit_packet_size;
 };
 
 
@@ -457,10 +474,13 @@ get_memory_packet_size (struct memory_packet_config *config)
       if (config->size > 0
 	  && what_they_get > config->size)
 	what_they_get = config->size;
-      /* Limit it to the size of the targets ``g'' response.  */
-      if ((rs->actual_register_packet_size) > 0
-	  && what_they_get > (rs->actual_register_packet_size))
-	what_they_get = (rs->actual_register_packet_size);
+
+      /* Limit it to the size of the targets ``g'' response unless we have
+	 permission from the stub to use a larger packet size.  */
+      if (!rs->explicit_packet_size
+	  && rs->actual_register_packet_size > 0
+	  && what_they_get > rs->actual_register_packet_size)
+	what_they_get = rs->actual_register_packet_size;
     }
   if (what_they_get > MAX_REMOTE_PACKET_SIZE)
     what_they_get = MAX_REMOTE_PACKET_SIZE;
@@ -596,6 +616,7 @@ struct packet_config
     char *title;
     enum auto_boolean detect;
     enum packet_support support;
+    int must_be_reported;
   };
 
 /* Analyze a packet's return value and update the packet config
@@ -659,11 +680,8 @@ static void
 add_packet_config_cmd (struct packet_config *config,
 		       char *name,
 		       char *title,
-		       cmd_sfunc_ftype *set_func,
-		       show_value_ftype *show_func,
-		       struct cmd_list_element **set_remote_list,
-		       struct cmd_list_element **show_remote_list,
-		       int legacy)
+		       int legacy,
+		       int must_be_reported)
 {
   char *set_doc;
   char *show_doc;
@@ -673,6 +691,7 @@ add_packet_config_cmd (struct packet_config *config,
   config->title = title;
   config->detect = AUTO_BOOLEAN_AUTO;
   config->support = PACKET_SUPPORT_UNKNOWN;
+  config->must_be_reported = must_be_reported;
   set_doc = xstrprintf ("Set use of remote protocol `%s' (%s) packet",
 			name, title);
   show_doc = xstrprintf ("Show current use of remote protocol `%s' (%s) packet",
@@ -681,17 +700,18 @@ add_packet_config_cmd (struct packet_config *config,
   cmd_name = xstrprintf ("%s-packet", title);
   add_setshow_auto_boolean_cmd (cmd_name, class_obscure,
 				&config->detect, set_doc, show_doc, NULL, /* help_doc */
-				set_func, show_func,
-				set_remote_list, show_remote_list);
+				set_remote_protocol_packet_cmd,
+				show_remote_protocol_packet_cmd,
+				&remote_set_cmdlist, &remote_show_cmdlist);
   /* set/show remote NAME-packet {auto,on,off} -- legacy.  */
   if (legacy)
     {
       char *legacy_name;
       legacy_name = xstrprintf ("%s-packet", name);
       add_alias_cmd (legacy_name, cmd_name, class_obscure, 0,
-		     set_remote_list);
+		     &remote_set_cmdlist);
       add_alias_cmd (legacy_name, cmd_name, class_obscure, 0,
-		     show_remote_list);
+		     &remote_show_cmdlist);
     }
 }
 
@@ -762,6 +782,7 @@ packet_ok (const char *buf, struct packet_config *config)
 enum {
   PACKET_vCont = 0,
   PACKET_X,
+  PACKET_qOffsets,
   PACKET_qSymbol,
   PACKET_P,
   PACKET_p,
@@ -1827,14 +1848,20 @@ get_offsets (void)
   CORE_ADDR text_addr, data_addr, bss_addr;
   struct section_offsets *offs;
 
+  if (remote_protocol_packets[PACKET_qOffsets].support == PACKET_DISABLE)
+    return;
+
   putpkt ("qOffsets");
   getpkt (buf, rs->remote_packet_size, 0);
 
-  if (buf[0] == '\000')
-    return;			/* Return silently.  Stub doesn't support
-				   this command.  */
-  if (buf[0] == 'E')
+  switch (packet_ok (buf, &remote_protocol_packets[PACKET_qOffsets]))
     {
+    case PACKET_OK:
+      break;
+    case PACKET_UNKNOWN:
+      return;			/* Return silently.  Stub doesn't support
+				   this command.  */
+    case PACKET_ERROR:
       warning (_("Remote failure reply: %s"), buf);
       return;
     }
@@ -2034,6 +2061,108 @@ Some events may be lost, rendering further debugging impossible."));
 }
 
 static void
+remote_query_packet_info (void)
+{
+  struct remote_state *rs = get_remote_state ();
+  char *reply, *next;
+  int i;
+
+  reply = alloca (rs->remote_packet_size);
+
+  putpkt ("qPacketInfo");
+  getpkt (reply, rs->remote_packet_size, 0);
+
+  next = reply;
+  while (*next)
+    {
+      enum packet_support is_supported;
+      char *p, *end, *name_end;
+
+      p = next;
+      end = strchr (p, ';');
+      if (end == NULL)
+	{
+	  end = p + strlen (p);
+	  next = end;
+	}
+      else
+	{
+	  if (end == p)
+	    {
+	      warning (_("empty item in \"qPacketInfo\" response"));
+	      continue;
+	    }
+
+	  *end = '\0';
+	  next = end + 1;
+	}
+
+      name_end = strchr (p, '=');
+      if (name_end)
+	{
+	  /* This is a name=value entry.  */
+	  char *value;
+
+	  value = name_end + 1;
+	  *name_end = '\0';
+
+	  if (strcmp (p, "PacketSize") == 0)
+	    {
+	      int packet_size;
+	      char *value_end;
+
+	      packet_size = strtol (value, &value_end, 16);
+	      if (*value != '\0' && *value_end == '\0')
+		{
+		  /* MERGE WARNING: This needs the infinite length
+		     incoming packet support, which in turn needs us
+		     to adjust rs->buf_size here.  */
+		  if (packet_size >= MAX_REMOTE_PACKET_SIZE)
+		    {
+		      warning (_("limiting remote suggested packet size (%d bytes) to %d"),
+			       packet_size, MAX_REMOTE_PACKET_SIZE);
+		      packet_size = MAX_REMOTE_PACKET_SIZE;
+		    }
+		  rs->remote_packet_size = packet_size;
+		  rs->explicit_packet_size = 1;
+
+		  continue;
+		}
+	    }
+
+	  /* Should we even warn about this?  For testing, at least, yes.  */
+	  warning (_("unrecognized item \"%s=%s\" in \"qPacketInfo\" response"),
+		   p, value);
+	  continue;
+	}
+
+      if (end[-1] != '+' && end[-1] != '-')
+	{
+	  warning (_("unrecognized item \"%s\" in \"qPacketInfo\" response"), p);
+	  continue;
+	}
+
+      is_supported = (end[-1] == '+') ? PACKET_ENABLE : PACKET_DISABLE;
+      end[-1] = '\0';
+
+      for (i = 0; i < PACKET_MAX; i++)
+	if (strcmp (remote_protocol_packets[i].name, p) == 0)
+	  {
+	    if (remote_protocol_packets[i].support == PACKET_SUPPORT_UNKNOWN)
+	      remote_protocol_packets[i].support = is_supported;
+	    break;
+	  }
+    }
+
+  /* Default some unmentioned packets to unsupported.  */
+  for (i = 0; i < PACKET_MAX; i++)
+    if (remote_protocol_packets[i].must_be_reported
+	&& remote_protocol_packets[i].support == PACKET_SUPPORT_UNKNOWN)
+      remote_protocol_packets[i].support = PACKET_DISABLE;
+}
+
+
+static void
 remote_open_1 (char *name, int from_tty, struct target_ops *target,
 	       int extended_p, int async_p)
 {
@@ -2095,6 +2224,11 @@ remote_open_1 (char *name, int from_tty, struct target_ops *target,
   use_threadinfo_query = 1;
   use_threadextra_query = 1;
 
+  /* The first packet we send to the target is the optional "supported
+     packets" request.  If the target can answer this, it will tell us
+     which later probes to skip.  */
+  remote_query_packet_info ();
+
   /* Without this, some commands which require an active target (such
      as kill) won't work.  This variable serves (at least) double duty
      as both the pid of the target process (if it has such), and as a
@@ -3138,7 +3272,7 @@ fetch_registers_using_g (void)
     error (_("remote 'g' packet reply is too large: %s"), buf);
   if (buf_len % 2 != 0)
     error (_("Remote 'g' packet reply is of odd length: %s"), buf);
-  if (REGISTER_BYTES_OK_P () && !REGISTER_BYTES_OK (i))
+  if (REGISTER_BYTES_OK_P () && !REGISTER_BYTES_OK (buf_len / 2))
     error (_("Remote 'g' packet reply is too short: %s"), buf);
 
   /* Save the size of the packet sent to us by the target.  It is used
@@ -5485,9 +5619,6 @@ Specify the serial device it is connected to (e.g. /dev/ttya).",
   extended_async_remote_ops.to_mourn_inferior = extended_remote_mourn;
 }
 
-static struct cmd_list_element *remote_set_cmdlist;
-static struct cmd_list_element *remote_show_cmdlist;
-
 static void
 set_remote_cmd (char *args, int from_tty)
 {
@@ -5665,95 +5796,47 @@ Show the maximum size of the address (in bits) in a memory packet."), NULL,
 			   &setlist, &showlist);
 
   add_packet_config_cmd (&remote_protocol_packets[PACKET_X],
-			 "X", "binary-download",
-			 set_remote_protocol_packet_cmd,
-			 show_remote_protocol_packet_cmd,
-			 &remote_set_cmdlist, &remote_show_cmdlist,
-			 1);
+			 "X", "binary-download", 1, 0);
 
   add_packet_config_cmd (&remote_protocol_packets[PACKET_vCont],
-			 "vCont", "verbose-resume",
-			 set_remote_protocol_packet_cmd,
-			 show_remote_protocol_packet_cmd,
-			 &remote_set_cmdlist, &remote_show_cmdlist,
-			 0);
+			 "vCont", "verbose-resume", 0, 0);
+
+  add_packet_config_cmd (&remote_protocol_packets[PACKET_qOffsets],
+			 "qOffsets", "load-offsets", 0, 0);
 
   add_packet_config_cmd (&remote_protocol_packets[PACKET_qSymbol],
-			 "qSymbol", "symbol-lookup",
-			 set_remote_protocol_packet_cmd,
-			 show_remote_protocol_packet_cmd,
-			 &remote_set_cmdlist, &remote_show_cmdlist,
-			 0);
+			 "qSymbol", "symbol-lookup", 0, 0);
 
   add_packet_config_cmd (&remote_protocol_packets[PACKET_P],
-			 "P", "set-register",
-			 set_remote_protocol_packet_cmd,
-			 show_remote_protocol_packet_cmd,
-			 &remote_set_cmdlist, &remote_show_cmdlist,
-			 1);
+			 "P", "set-register", 1, 0);
 
   add_packet_config_cmd (&remote_protocol_packets[PACKET_p],
-			 "p", "fetch-register",
-			 set_remote_protocol_packet_cmd,
-			 show_remote_protocol_packet_cmd,
-			 &remote_set_cmdlist, &remote_show_cmdlist,
-			 1);
+			 "p", "fetch-register", 1, 0);
 
   add_packet_config_cmd (&remote_protocol_packets[PACKET_Z0],
-			 "Z0", "software-breakpoint",
-			 set_remote_protocol_packet_cmd,
-			 show_remote_protocol_packet_cmd,
-			 &remote_set_cmdlist, &remote_show_cmdlist,
-			 0);
+			 "Z0", "software-breakpoint", 0, 0);
 
   add_packet_config_cmd (&remote_protocol_packets[PACKET_Z1],
-			 "Z1", "hardware-breakpoint",
-			 set_remote_protocol_packet_cmd,
-			 show_remote_protocol_packet_cmd,
-			 &remote_set_cmdlist, &remote_show_cmdlist,
-			 0);
+			 "Z1", "hardware-breakpoint", 0, 0);
 
   add_packet_config_cmd (&remote_protocol_packets[PACKET_Z2],
-			 "Z2", "write-watchpoint",
-			 set_remote_protocol_packet_cmd,
-			 show_remote_protocol_packet_cmd,
-			 &remote_set_cmdlist, &remote_show_cmdlist,
-			 0);
+			 "Z2", "write-watchpoint", 0, 0);
 
   add_packet_config_cmd (&remote_protocol_packets[PACKET_Z3],
-			 "Z3", "read-watchpoint",
-			 set_remote_protocol_packet_cmd,
-			 show_remote_protocol_packet_cmd,
-			 &remote_set_cmdlist, &remote_show_cmdlist,
-			 0);
+			 "Z3", "read-watchpoint", 0, 0);
 
   add_packet_config_cmd (&remote_protocol_packets[PACKET_Z4],
-			 "Z4", "access-watchpoint",
-			 set_remote_protocol_packet_cmd,
-			 show_remote_protocol_packet_cmd,
-			 &remote_set_cmdlist, &remote_show_cmdlist,
-			 0);
+			 "Z4", "access-watchpoint",  0, 0);
 
   add_packet_config_cmd (&remote_protocol_packets[PACKET_qPart_auxv],
-			 "qPart_auxv", "read-aux-vector",
-			 set_remote_protocol_packet_cmd,
-			 show_remote_protocol_packet_cmd,
-			 &remote_set_cmdlist, &remote_show_cmdlist,
-			 0);
+			 "qPart:auxv", "read-aux-vector", 0, 0);
 
   add_packet_config_cmd (&remote_protocol_packets[PACKET_qPart_features],
-			 "qPart_features", "target-features",
-			 set_remote_protocol_packet_cmd,
-			 show_remote_protocol_packet_cmd,
-			 &remote_set_cmdlist, &remote_show_cmdlist,
-			 0);
+			 "qPart:features", "target-features", 0, 1);
 
   add_packet_config_cmd (&remote_protocol_packets[PACKET_qGetTLSAddr],
 			 "qGetTLSAddr", "get-thread-local-storage-address",
-			 set_remote_protocol_packet_cmd,
-			 show_remote_protocol_packet_cmd,
-			 &remote_set_cmdlist, &remote_show_cmdlist,
-			 0);
+			 0, 0);
 
   /* Keep the old ``set remote Z-packet ...'' working.  Each individual
      Z sub-packet has its own set and show commands, but users may