[v3,1/3] gdb, gdbserver, zpoint: report z_point support

diff --git a/gdb/NEWS b/gdb/NEWS
index 96aba256dbb..6e9f679dd56 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -75,6 +75,10 @@  QThreadOptions in qSupported
   QThreadOptions packet, and the qSupported response can contain the
   set of thread options the remote stub supports.
 
+qSupported
+  Gdbserver now reports which types of breakpoints and watchpoints
+  are supported when exchanging features using Z<type>+, Z<type>-.
+
 *** Changes in GDB 14
 
 * GDB now supports the AArch64 Scalable Matrix Extension 2 (SME2), which
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index e4c00143fd1..ccc513df0cc 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -44631,6 +44631,31 @@  These are the currently defined stub features and their properties:
 @tab @samp{-}
 @tab No
 
+@item @samp{Z0}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{Z1}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{Z2}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{Z3}
+@tab No
+@tab @samp{-}
+@tab No
+
+@item @samp{Z4}
+@tab No
+@tab @samp{-}
+@tab No
+
 @end multitable
 
 These are the currently defined stub features, in more detail:
@@ -44858,6 +44883,13 @@  The remote stub supports and implements the required memory tagging
 functionality and understands the @samp{qMemTags} (@pxref{qMemTags}) and
 @samp{QMemTags} (@pxref{QMemTags}) packets.
 
+@item Z@var{type}
+The remote stub reports which types of breakpoints and watchpoints are
+supported.  This is done using flags, @samp{Z@var{type}+} for supported
+and @samp{Z@var{type}-} for unsupported, where @var{type} is one of
+@samp{0}, @samp{1}, @samp{2}, @samp{3}, @samp{4}
+(@pxref{insert breakpoint or watchpoint packet}).
+
 For AArch64 GNU/Linux systems, this feature also requires access to the
 @file{/proc/@var{pid}/smaps} file so memory mapping page flags can be inspected.
 This is done via the @samp{vFile} requests.
diff --git a/gdb/remote.c b/gdb/remote.c
index ce5addade6f..7aa380a5989 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -808,6 +808,10 @@  class remote_target : public process_stratum_target
   int insert_watchpoint (CORE_ADDR, int, enum target_hw_bp_type,
 			 struct expression *) override;
 
+  /* Returns true if GDB Z breakpoint type TYPE is supported,
+     false otherwise.  */
+  bool supports_z_point_type (int type);
+
   int remove_watchpoint (CORE_ADDR, int, enum target_hw_bp_type,
 			 struct expression *) override;
 
@@ -5717,6 +5721,11 @@  static const struct protocol_feature remote_protocol_features[] = {
   { "no-resumed", PACKET_DISABLE, remote_supported_packet, PACKET_no_resumed },
   { "memory-tagging", PACKET_DISABLE, remote_supported_packet,
     PACKET_memory_tagging_feature },
+  { "Z0", PACKET_SUPPORT_UNKNOWN, remote_supported_packet, PACKET_Z0 },
+  { "Z1", PACKET_SUPPORT_UNKNOWN, remote_supported_packet, PACKET_Z1 },
+  { "Z2", PACKET_SUPPORT_UNKNOWN, remote_supported_packet, PACKET_Z2 },
+  { "Z3", PACKET_SUPPORT_UNKNOWN, remote_supported_packet, PACKET_Z3 },
+  { "Z4", PACKET_SUPPORT_UNKNOWN, remote_supported_packet, PACKET_Z4 },
 };
 
 static char *remote_support_xml;
@@ -10991,6 +11000,13 @@  watchpoint_to_Z_packet (int type)
     }
 }
 
+bool
+remote_target::supports_z_point_type (int type)
+{
+  Z_packet_type packet = watchpoint_to_Z_packet (type);
+  return (m_features.packet_support (PACKET_Z0 + packet) != PACKET_DISABLE);
+}
+
 int
 remote_target::insert_watchpoint (CORE_ADDR addr, int len,
 				  enum target_hw_bp_type type, struct expression *cond)
diff --git a/gdbserver/mem-break.cc b/gdbserver/mem-break.cc
index 3bee8bc8990..7c3a1d1d47e 100644
--- a/gdbserver/mem-break.cc
+++ b/gdbserver/mem-break.cc
@@ -998,7 +998,7 @@  find_gdb_breakpoint (char z_type, CORE_ADDR addr, int kind)
   return NULL;
 }
 
-static int
+int
 z_type_supported (char z_type)
 {
   return (z_type >= '0' && z_type <= '4'
diff --git a/gdbserver/mem-break.h b/gdbserver/mem-break.h
index 9bf7aa84932..b27f0a23ac2 100644
--- a/gdbserver/mem-break.h
+++ b/gdbserver/mem-break.h
@@ -276,4 +276,8 @@  int remove_memory_breakpoint (struct raw_breakpoint *bp);
 void clone_all_breakpoints (struct thread_info *child_thread,
 			    const struct thread_info *parent_thread);
 
+
+/* Returns true if Z_TYPE is supported by the target.  */
+
+int z_type_supported (char z_type);
 #endif /* GDBSERVER_MEM_BREAK_H */
diff --git a/gdbserver/server.cc b/gdbserver/server.cc
index a8e23561dcb..e727973ad45 100644
--- a/gdbserver/server.cc
+++ b/gdbserver/server.cc
@@ -2613,6 +2613,13 @@  handle_query (char *own_buf, int packet_len, int *new_packet_len_p)
       if (target_supports_memory_tagging ())
 	strcat (own_buf, ";memory-tagging+");
 
+      /* Z points support.  */
+      strcat (own_buf, z_type_supported ('0') ? ";Z0+" : ";Z0-");
+      strcat (own_buf, z_type_supported ('1') ? ";Z1+" : ";Z1-");
+      strcat (own_buf, z_type_supported ('2') ? ";Z2+" : ";Z2-");
+      strcat (own_buf, z_type_supported ('3') ? ";Z3+" : ";Z3-");
+      strcat (own_buf, z_type_supported ('4') ? ";Z4+" : ";Z4-");
+
       /* Reinitialize components as needed for the new connection.  */
       hostio_handle_new_gdb_connection ();
       target_handle_new_gdb_connection ();