Re: PATCH: Add xmlRegisters= to qsupported query

["H.J. Lu" <hongjiu.lu@intel.com>]

On Mon, Mar 29, 2010 at 11:01:36AM -0700, H.J. Lu wrote:
> On Mon, Mar 29, 2010 at 09:19:10AM -0700, H.J. Lu wrote:
> > On Mon, Mar 29, 2010 at 07:55:49AM -0700, H.J. Lu wrote:
> > > On Sun, Mar 28, 2010 at 04:46:43PM -0700, H.J. Lu wrote:
> > > > On Sun, Mar 28, 2010 at 01:52:07PM -0700, H.J. Lu wrote:
> > > > > On Sun, Mar 28, 2010 at 01:48:07PM -0700, H.J. Lu wrote:
> > > > > > Hi,
> > > > > > 
> > > > > > This patch adds xmlRegisters= to qsupported query.  Any comments?
> > > > > > 
> > > > > > Thanks.
> > > > > > 
> > > > > > 
> > > > > 
> > > > > An updated patch.
> > > > > 
> > > > > 
> > > > 
> > > > Here is a new patch to simplify extending qsupported query and fix a
> > > > memory leak.  Any comments?
> > > > 
> > > 
> > > This patch updated documentation based on Eli's feedbacks. OK to
> > > install?
> > > 
> > > Thanks.
> > > 
> > 
> > We should check if libexpat is available. Any comments/suggestions?
> > 
> 
> Updated patch to pass "i386" instead of "x86" to
> register_remote_support_xml.  OK to install?
> 

Here is the updated patch.  OK to install?

Thanks.


H.J.
---
gdb/

2010-03-30  H.J. Lu  <hongjiu.lu@intel.com>

	* NEWS: Mention xmlRegisters= in qSupported packet.

	* i386-tdep.c: Include "remote.h".
	(_initialize_i386_tdep): Call register_remote_support_xml.

	* remote.c (remote_support_xml): New.
	(register_remote_support_xml): Likewise.
	(remote_query_supported_append): Likewise.
	(remote_query_supported): Support remote_support_xml.

	* remote.h (register_remote_support_xml): New.

gdb/doc/

2010-03-30  H.J. Lu  <hongjiu.lu@intel.com>

	* gdb.texinfo (General Query Packets): Add xmlRegisters.

diff --git a/gdb/NEWS b/gdb/NEWS
index f01b55e..0d27faa 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -3,6 +3,9 @@
 
 *** Changes since GDB 7.1
 
+* GDB now sends xmlRegisters= in qSupported packet to indicate that
+  it understands register description.
+
 * The --batch flag now disables pagination and queries.
 
 * X86 general purpose registers
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index ef51ed1..fab06a8 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -30633,6 +30633,12 @@ extensions to the remote protocol.  @value{GDBN} does not use such
 extensions unless the stub also reports that it supports them by
 including @samp{multiprocess+} in its @samp{qSupported} reply.
 @xref{multiprocess extensions}, for details.
+
+@item xmlRegisters
+This feature indicates that @value{GDBN} supports the XML target
+description.  If the stub sees @samp{xmlRegisters=} with target
+specific strings separated by a comma, it will report register
+description.
 @end table
 
 Stubs should ignore any unknown values for
diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c
index 83275ac..9b4c93e 100644
--- a/gdb/i386-tdep.c
+++ b/gdb/i386-tdep.c
@@ -44,6 +44,7 @@
 #include "value.h"
 #include "dis-asm.h"
 #include "disasm.h"
+#include "remote.h"
 
 #include "gdb_assert.h"
 #include "gdb_string.h"
@@ -6000,4 +6001,7 @@ is \"default\"."),
 
   /* Initialize the standard target descriptions.  */
   initialize_tdesc_i386 ();
+
+  /* Tell remote stub that we support XML target description.  */
+  register_remote_support_xml ("i386");
 }
diff --git a/gdb/remote.c b/gdb/remote.c
index dcae72c..03644d1 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -3467,6 +3467,53 @@ static struct protocol_feature remote_protocol_features[] = {
     PACKET_TracepointSource },
 };
 
+static char *remote_support_xml;
+
+/* Register string appended to "xmlRegisters=" in qSupported query.  */
+
+void
+register_remote_support_xml (const char *xml ATTRIBUTE_UNUSED)
+{
+#if defined(HAVE_LIBEXPAT)
+  if (remote_support_xml == NULL)
+    remote_support_xml = concat ("xmlRegisters=", xml, NULL);
+  else
+    {
+      char *copy = xstrdup (remote_support_xml + 13);
+      char *p = strtok (copy, ",");
+
+      do
+	{
+	  if (strcmp (p, xml) == 0)
+	    {
+	      /* already there */
+	      xfree (copy);
+	      return;
+	    }
+	}
+      while ((p = strtok (NULL, ",")) != NULL);
+      xfree (copy);
+
+      p = concat (remote_support_xml, ",", xml, NULL);
+      xfree (remote_support_xml);
+      remote_support_xml = p;
+    }
+#endif
+}
+
+static char *
+remote_query_supported_append (char *msg, const char *append)
+{
+  if (msg)
+    {
+      char *p = concat (msg, ";", append, NULL);
+      xfree (msg);
+      return p;
+    }
+  else
+    return xstrdup (append);
+}
+
 static void
 remote_query_supported (void)
 {
@@ -3485,24 +3532,27 @@ remote_query_supported (void)
   rs->buf[0] = 0;
   if (remote_protocol_packets[PACKET_qSupported].support != PACKET_DISABLE)
     {
+      char *q = NULL;
       const char *qsupported = gdbarch_qsupported (target_gdbarch);
+
+      if (rs->extended)
+	q = remote_query_supported_append (q, "multiprocess+");
+      
       if (qsupported)
+	q = remote_query_supported_append (q, qsupported);
+
+      if (remote_support_xml)
+	q = remote_query_supported_append (q, remote_support_xml);
+
+      if (q)
 	{
-	  char *q;
-	  if (rs->extended)
-	    q = concat ("qSupported:multiprocess+;", qsupported, NULL);
-	  else
-	    q = concat ("qSupported:", qsupported, NULL);
-	  putpkt (q);
+	  char *p = concat ("qSupported:", q, NULL);
 	  xfree (q);
+	  putpkt (p);
+	  xfree (p);
 	}
       else
-	{
-	  if (rs->extended)
-	    putpkt ("qSupported:multiprocess+");
-	  else
-	    putpkt ("qSupported");
-	}
+	putpkt ("qSupported");
 
       getpkt (&rs->buf, &rs->buf_size, 0);
 
diff --git a/gdb/remote.h b/gdb/remote.h
index a82d0d7..d480e26 100644
--- a/gdb/remote.h
+++ b/gdb/remote.h
@@ -66,6 +66,7 @@ extern void (*deprecated_target_wait_loop_hook) (void);
 
 void register_remote_g_packet_guess (struct gdbarch *gdbarch, int bytes,
 				     const struct target_desc *tdesc);
+void register_remote_support_xml (const char *);
 
 void remote_file_put (const char *local_file, const char *remote_file,
 		      int from_tty);