gdb_server: add "not supported" Z-packet reply

GDB remote serial protocol specifies breakpoint/watchpoint packet
responses can be an empty string to indicate the specified breakpoint
type is not supported.  Add support for this response alongside existing
"OK", "E NN" replies.

Signed-off-by: Ian Thompson <ianst@cadence.com>
Change-Id: Iaf6280e4c936eb95a92bc80cc74d451ebb328dc3
Reviewed-on: https://review.openocd.org/c/openocd/+/7102
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

diff --git a/src/server/gdb_server.c b/src/server/gdb_server.c
index 2e6c7304dd3d450469083da8c712f5e4f00ae822..28833c9ce35f6f85361ea7ef5ec5b9bbb5b78e98 100644 (file)
--- a/src/server/gdb_server.c
+++ b/src/server/gdb_server.c
@@ -1770,7 +1770,10 @@ static int gdb_breakpoint_watchpoint_packet(struct connection *connection,
                case 1:
                        if (packet[0] == 'Z') {
                                retval = breakpoint_add(target, address, size, bp_type);
-                               if (retval != ERROR_OK) {
+                               if (retval == ERROR_NOT_IMPLEMENTED) {
+                                       /* Send empty reply to report that breakpoints of this type are not supported */
+                                       gdb_put_packet(connection, "", 0);
+                               } else if (retval != ERROR_OK) {
                                        retval = gdb_error(connection, retval);
                                        if (retval != ERROR_OK)
                                                return retval;
@@ -1787,7 +1790,10 @@ static int gdb_breakpoint_watchpoint_packet(struct connection *connection,
                {
                        if (packet[0] == 'Z') {
                                retval = watchpoint_add(target, address, size, wp_type, 0, 0xffffffffu);
-                               if (retval != ERROR_OK) {
+                               if (retval == ERROR_NOT_IMPLEMENTED) {
+                                       /* Send empty reply to report that watchpoints of this type are not supported */
+                                       gdb_put_packet(connection, "", 0);
+                               } else if (retval != ERROR_OK) {
                                        retval = gdb_error(connection, retval);
                                        if (retval != ERROR_OK)
                                                return retval;