[PATCH v4 08/12] gdbstub: Introduce gdb_handle_query_supported_user()

[Ilya Leoshkevich <iii@linux.ibm.com>]

The upcoming follow-fork-mode child support requires advertising the
fork-events feature, which is user-specific. Introduce a user-specific
hook for this.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 gdbstub/gdbstub.c   | 12 +++++++++---
 gdbstub/internals.h |  1 +
 gdbstub/user.c      |  4 ++++
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/gdbstub/gdbstub.c b/gdbstub/gdbstub.c
index 7e73e916bdc..898a108b7f1 100644
--- a/gdbstub/gdbstub.c
+++ b/gdbstub/gdbstub.c
@@ -1622,9 +1622,15 @@ static void handle_query_supported(GArray *params, void *user_ctx)
     g_string_append(gdbserver_state.str_buf, ";qXfer:exec-file:read+");
 #endif
 
-    if (params->len &&
-        strstr(get_param(params, 0)->data, "multiprocess+")) {
-        gdbserver_state.multiprocess = true;
+    if (params->len) {
+        const char *gdb_supported = get_param(params, 0)->data;
+
+        if (strstr(gdb_supported, "multiprocess+")) {
+            gdbserver_state.multiprocess = true;
+        }
+#if defined(CONFIG_USER_ONLY)
+        gdb_handle_query_supported_user(gdb_supported);
+#endif
     }
 
     g_string_append(gdbserver_state.str_buf, ";vContSupported+;multiprocess+");
diff --git a/gdbstub/internals.h b/gdbstub/internals.h
index 56b7c13b750..e6063835b1f 100644
--- a/gdbstub/internals.h
+++ b/gdbstub/internals.h
@@ -196,6 +196,7 @@ void gdb_handle_v_file_pread(GArray *params, void *user_ctx); /* user */
 void gdb_handle_v_file_readlink(GArray *params, void *user_ctx); /* user */
 void gdb_handle_query_xfer_exec_file(GArray *params, void *user_ctx); /* user */
 void gdb_handle_set_catch_syscalls(GArray *params, void *user_ctx); /* user */
+void gdb_handle_query_supported_user(const char *gdb_supported); /* user */
 
 void gdb_handle_query_attached(GArray *params, void *user_ctx); /* both */
 
diff --git a/gdbstub/user.c b/gdbstub/user.c
index 866a25f9c06..c9e8b83d720 100644
--- a/gdbstub/user.c
+++ b/gdbstub/user.c
@@ -382,6 +382,10 @@ void gdbserver_fork_end(CPUState *cpu, pid_t pid)
     disable_gdbstub(cpu);
 }
 
+void gdb_handle_query_supported_user(const char *gdb_supported)
+{
+}
+
 /*
  * Execution state helpers
  */
-- 
2.43.2