[PATCH v2 19/47] gdb, gdbserver, ze: add library notification to U stop reply

[Tankut Baris Aktemur <tankut.baris.aktemur@intel.com>]

From: Markus Metzger <markus.t.metzger@intel.com>

If libraries have changed, add a ";library" notification to a 'U' stop
reply packet and handle it at the GDB side.

Reviewed-By: Eli Zaretskii <eliz@gnu.org>
---
 gdb/doc/gdb.texinfo       |  5 +++++
 gdb/remote.c              | 11 +++++++++--
 gdbserver/remote-utils.cc | 22 +++++++++++++++++++---
 3 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 1cf31d022843b41dfdc4014125438d5455dc0bb8..365f74a5817ae82f729f5491dd3fde8ed24dbc2c 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -43909,10 +43909,15 @@ or @samp{s} action is expected to be continued.  @xref{File-I/O Remote
 Protocol Extension}, for more details.
 
 @item U @var{thread-id}
+@itemx U @var{thread-id};library
 The program is currently unavailable.  The remote target tried to stop
 it but it would not respond.  The thread designator @var{thread-id}
 has the format and interpretation described in @ref{thread-id syntax}.
 
+If @samp{;library} is appended, the loaded libraries have changed.
+@value{GDBN} should use @samp{qXfer:libraries:read} to fetch a new
+list of loaded libraries.
+
 This packet should not be sent by default; older @value{GDBN} versions
 did not support it.  @value{GDBN} requests it, by supplying an
 appropriate @samp{qSupported} feature (@pxref{qSupported}).  The
diff --git a/gdb/remote.c b/gdb/remote.c
index e277370ab4f1783d781c9b3a9edd4f459397839e..d55ca04fc6fce91fc01fac049959a55bd0af85f4 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -8369,8 +8369,15 @@ Packet: '%s'\n"),
       event->ptid = minus_one_ptid;
       break;
     case 'U':
-      event->ws.set_unavailable ();
-      event->ptid = read_ptid (&buf[1], NULL);
+      {
+	const char *opt = nullptr;
+
+	event->ws.set_unavailable ();
+	event->ptid = read_ptid (&buf[1], &opt);
+
+	if (strcmp (opt, ";library") == 0)
+	  event->ws.set_loaded ();
+      }
       break;
     }
 }
diff --git a/gdbserver/remote-utils.cc b/gdbserver/remote-utils.cc
index bbf72146ee8d301a9540211ef636dc0f6c223ef6..153701ceb1ecaa60702d17c62528997154887676 100644
--- a/gdbserver/remote-utils.cc
+++ b/gdbserver/remote-utils.cc
@@ -1285,9 +1285,25 @@ prepare_resume_reply (char *buf, ptid_t ptid, const target_waitstatus &status)
       sprintf (buf, "N");
       break;
     case TARGET_WAITKIND_UNAVAILABLE:
-      sprintf (buf, "U");
-      buf += strlen (buf);
-      buf = write_ptid (buf, ptid);
+      {
+	sprintf (buf, "U");
+	buf += strlen (buf);
+	buf = write_ptid (buf, ptid);
+
+	process_info *proc = find_process_pid (ptid.pid ());
+	gdb_assert (proc != nullptr);
+	if (proc->dlls_changed)
+	  {
+	    strcpy (buf, ";library");
+	    buf += strlen (buf);
+	    proc->dlls_changed = false;
+	  }
+
+	/* In non-stop, don't change the general thread behind
+	   GDB's back.  */
+	if (!non_stop)
+	  cs.general_thread = ptid;
+      }
       break;
     default:
       error ("unhandled waitkind");

-- 
2.34.1

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