Monitor: Report more than one error in handlers

[qemu.git] / monitor.c

diff --git a/monitor.c b/monitor.c
index 6eb0e2cfa917c2f81b114e9aa9dc73abb6cd90a3..6a64e6e218c86f10ac722fdba864b546f2b9ebf8 100644 (file)
--- a/monitor.c
+++ b/monitor.c
@@ -120,7 +120,6 @@ struct mon_fd_t {
 
 typedef struct MonitorControl {
     QObject *id;
-    int print_enabled;
     JSONMessageParser parser;
     int command_mode;
 } MonitorControl;
@@ -138,11 +137,41 @@ struct Monitor {
     CPUState *mon_cpu;
     BlockDriverCompletionFunc *password_completion_cb;
     void *password_opaque;
+#ifdef CONFIG_DEBUG_MONITOR
+    int print_calls_nr;
+#endif
     QError *error;
     QLIST_HEAD(,mon_fd_t) fds;
     QLIST_ENTRY(Monitor) entry;
 };
 
+#ifdef CONFIG_DEBUG_MONITOR
+#define MON_DEBUG(fmt, ...) do {    \
+    fprintf(stderr, "Monitor: ");       \
+    fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
+
+static inline void mon_print_count_inc(Monitor *mon)
+{
+    mon->print_calls_nr++;
+}
+
+static inline void mon_print_count_init(Monitor *mon)
+{
+    mon->print_calls_nr = 0;
+}
+
+static inline int mon_print_count_get(const Monitor *mon)
+{
+    return mon->print_calls_nr;
+}
+
+#else /* !CONFIG_DEBUG_MONITOR */
+#define MON_DEBUG(fmt, ...) do { } while (0)
+static inline void mon_print_count_inc(Monitor *mon) { }
+static inline void mon_print_count_init(Monitor *mon) { }
+static inline int mon_print_count_get(const Monitor *mon) { return 0; }
+#endif /* CONFIG_DEBUG_MONITOR */
+
 static QLIST_HEAD(mon_list, Monitor) mon_list;
 
 static const mon_cmd_t mon_cmds[];
@@ -218,16 +247,19 @@ static void monitor_puts(Monitor *mon, const char *str)
 
 void monitor_vprintf(Monitor *mon, const char *fmt, va_list ap)
 {
+    char buf[4096];
+
     if (!mon)
         return;
 
-    if (mon->mc && !mon->mc->print_enabled) {
-        qemu_error_new(QERR_UNDEFINED_ERROR);
-    } else {
-        char buf[4096];
-        vsnprintf(buf, sizeof(buf), fmt, ap);
-        monitor_puts(mon, buf);
+    mon_print_count_inc(mon);
+
+    if (monitor_ctrl_mode(mon)) {
+        return;
     }
+
+    vsnprintf(buf, sizeof(buf), fmt, ap);
+    monitor_puts(mon, buf);
 }
 
 void monitor_printf(Monitor *mon, const char *fmt, ...)
@@ -298,9 +330,8 @@ static void monitor_json_emitter(Monitor *mon, const QObject *data)
     json = qobject_to_json(data);
     assert(json != NULL);
 
-    mon->mc->print_enabled = 1;
-    monitor_printf(mon, "%s\n", qstring_get_str(json));
-    mon->mc->print_enabled = 0;
+    qstring_append_chr(json, '\n');
+    monitor_puts(mon, qstring_get_str(json));
 
     QDECREF(json);
 }
@@ -3840,12 +3871,59 @@ static int is_async_return(const QObject *data)
     return 0;
 }
 
+static void handler_audit(Monitor *mon, const mon_cmd_t *cmd, int ret)
+{
+    if (ret && !monitor_has_error(mon)) {
+        /*
+         * If it returns failure, it must have passed on error.
+         *
+         * Action: Report an internal error to the client if in QMP.
+         */
+        if (monitor_ctrl_mode(mon)) {
+            qemu_error_new(QERR_UNDEFINED_ERROR);
+        }
+        MON_DEBUG("command '%s' returned failure but did not pass an error\n",
+                  cmd->name);
+    }
+
+#ifdef CONFIG_DEBUG_MONITOR
+    if (!ret && monitor_has_error(mon)) {
+        /*
+         * If it returns success, it must not have passed an error.
+         *
+         * Action: Report the passed error to the client.
+         */
+        MON_DEBUG("command '%s' returned success but passed an error\n",
+                  cmd->name);
+    }
+
+    if (mon_print_count_get(mon) > 0 && strcmp(cmd->name, "info") != 0) {
+        /*
+         * Handlers should not call Monitor print functions.
+         *
+         * Action: Ignore them in QMP.
+         *
+         * (XXX: we don't check any 'info' or 'query' command here
+         * because the user print function _is_ called by do_info(), hence
+         * we will trigger this check. This problem will go away when we
+         * make 'query' commands real and kill do_info())
+         */
+        MON_DEBUG("command '%s' called print functions %d time(s)\n",
+                  cmd->name, mon_print_count_get(mon));
+    }
+#endif
+}
+
 static void monitor_call_handler(Monitor *mon, const mon_cmd_t *cmd,
                                  const QDict *params)
 {
+    int ret;
     QObject *data = NULL;
 
-    cmd->mhandler.cmd_new(mon, params, &data);
+    mon_print_count_init(mon);
+
+    ret = cmd->mhandler.cmd_new(mon, params, &data);
+    handler_audit(mon, cmd, ret);
 
     if (is_async_return(data)) {
         /*
@@ -4682,7 +4760,8 @@ void qemu_error_internal(const char *file, int linenr, const char *func,
         if (!qemu_error_sink->mon->error) {
             qemu_error_sink->mon->error = qerror;
         } else {
-            /* XXX: warn the programmer */
+            MON_DEBUG("Additional error report at %s:%d\n", qerror->file,
+                      qerror->linenr);
             QDECREF(qerror);
         }
         break;