readline: decouple readline from the monitor

Make the readline.c functionality reusable.  Instead of calling
monitor_printf() and monitor_flush() directly, invoke function pointers
provided by the user.

This way readline.c does not know about Monitor and other users will be
able to make use of readline.c.

Note that there is already an "opaque" argument to the ReadLineFunc
callback.  Consistently call it "readline_opaque" from now on to
distinguish from the ReadLinePrintfFunc/ReadLineFlushFunc "opaque"
argument.

I also dropped the printf macro trickery since it's now highly unlikely
that anyone modifying readline.c would call printf(3) directly.  We no
longer need this protection.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 32 insertions, 7 deletions

diff --git a/monitor.c b/monitor.c
index 845f608665..32d02640a0 100644
--- a/monitor.c
+++ b/monitor.c
@@ -217,8 +217,8 @@ static const mon_cmd_t qmp_cmds[];
 Monitor *cur_mon;
 Monitor *default_mon;
 
-static void monitor_command_cb(Monitor *mon, const char *cmdline,
-                               void *opaque);
+static void monitor_command_cb(void *opaque, const char *cmdline,
+                               void *readline_opaque);
 
 static inline int qmp_cmd_mode(const Monitor *mon)
 {
@@ -4338,9 +4338,10 @@ static void monitor_find_completion_by_table(Monitor *mon,
     }
 }
 
-static void monitor_find_completion(Monitor *mon,
+static void monitor_find_completion(void *opaque,
                                     const char *cmdline)
 {
+    Monitor *mon = opaque;
     char *args[MAX_ARGS];
     int nb_args, len;
 
@@ -4751,8 +4752,11 @@ static void monitor_read(void *opaque, const uint8_t *buf, int size)
     cur_mon = old_mon;
 }
 
-static void monitor_command_cb(Monitor *mon, const char *cmdline, void *opaque)
+static void monitor_command_cb(void *opaque, const char *cmdline,
+                               void *readline_opaque)
 {
+    Monitor *mon = opaque;
+
     monitor_suspend(mon);
     handle_user_command(mon, cmdline);
     monitor_resume(mon);
@@ -4881,6 +4885,22 @@ static void sortcmdlist(void)
  * End:
  */
 
+/* These functions just adapt the readline interface in a typesafe way.  We
+ * could cast function pointers but that discards compiler checks.
+ */
+static void monitor_readline_printf(void *opaque, const char *fmt, ...)
+{
+    va_list ap;
+    va_start(ap, fmt);
+    monitor_vprintf(opaque, fmt, ap);
+    va_end(ap);
+}
+
+static void monitor_readline_flush(void *opaque)
+{
+    monitor_flush(opaque);
+}
+
 void monitor_init(CharDriverState *chr, int flags)
 {
     static int is_first_init = 1;
@@ -4898,7 +4918,10 @@ void monitor_init(CharDriverState *chr, int flags)
     mon->chr = chr;
     mon->flags = flags;
     if (flags & MONITOR_USE_READLINE) {
-        mon->rs = readline_init(mon, monitor_find_completion);
+        mon->rs = readline_init(monitor_readline_printf,
+                                monitor_readline_flush,
+                                mon,
+                                monitor_find_completion);
         monitor_read_command(mon, 0);
     }
 
@@ -4920,9 +4943,11 @@ void monitor_init(CharDriverState *chr, int flags)
         default_mon = mon;
 }
 
-static void bdrv_password_cb(Monitor *mon, const char *password, void *opaque)
+static void bdrv_password_cb(void *opaque, const char *password,
+                             void *readline_opaque)
 {
-    BlockDriverState *bs = opaque;
+    Monitor *mon = opaque;
+    BlockDriverState *bs = readline_opaque;
     int ret = 0;
 
     if (bdrv_set_key(bs, password) != 0) {