Merge remote-tracking branch 'remotes/ericb/tags/pull-qapi-2018-03-12-v4' into staging

qapi patches for 2018-03-12, 2.12 softfreeze

- Marc-André Lureau: 0/4 qapi: generate a literal qobject for introspection
- Max Reitz: 0/7 block: Handle null backing link
- Daniel P. Berrange: chardev: tcp: postpone TLS work until machine done
- Peter Xu: 00/23 QMP: out-of-band (OOB) execution support
- Vladimir Sementsov-Ogievskiy: 0/2 block latency histogram
- Eric Blake: qapi: Pass '-u' when doing non-silent diff

# gpg: Signature made Mon 19 Mar 2018 19:59:04 GMT
# gpg:                using RSA key A7A16B4A2527436A
# gpg: Good signature from "Eric Blake <eblake@redhat.com>"
# gpg:                 aka "Eric Blake (Free Software Programmer) <ebb9@byu.net>"
# gpg:                 aka "[jpeg image of size 6874]"
# Primary key fingerprint: 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

* remotes/ericb/tags/pull-qapi-2018-03-12-v4: (38 commits)
  qapi: Pass '-u' when doing non-silent diff
  qapi: add block latency histogram interface
  block/accounting: introduce latency histogram
  tests: qmp-test: add oob test
  tests: qmp-test: verify command batching
  qmp: add command "x-oob-test"
  monitor: enable IO thread for (qmp & !mux) typed
  qmp: isolate responses into io thread
  qmp: support out-of-band (oob) execution
  qapi: introduce new cmd option "allow-oob"
  monitor: send event when command queue full
  qmp: add new event "command-dropped"
  monitor: separate QMP parser and dispatcher
  monitor: let suspend/resume work even with QMPs
  monitor: let suspend_cnt be thread safe
  monitor: introduce monitor_qmp_respond()
  qmp: introduce QMPCapability
  monitor: allow using IO thread for parsing
  monitor: let mon_list be tail queue
  monitor: unify global init
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 29 insertions, 0 deletions

diff --git a/include/qapi/qmp/qobject.h b/include/qapi/qmp/qobject.h
index 012439a2e3..e022707578 100644
--- a/include/qapi/qmp/qobject.h
+++ b/include/qapi/qmp/qobject.h
@@ -50,6 +50,21 @@ struct QObject {
 #define QDECREF(obj)              \
     qobject_decref(obj ? QOBJECT(obj) : NULL)
 
+/* Required for qobject_to() */
+#define QTYPE_CAST_TO_QNull     QTYPE_QNULL
+#define QTYPE_CAST_TO_QNum      QTYPE_QNUM
+#define QTYPE_CAST_TO_QString   QTYPE_QSTRING
+#define QTYPE_CAST_TO_QDict     QTYPE_QDICT
+#define QTYPE_CAST_TO_QList     QTYPE_QLIST
+#define QTYPE_CAST_TO_QBool     QTYPE_QBOOL
+
+QEMU_BUILD_BUG_MSG(QTYPE__MAX != 7,
+                   "The QTYPE_CAST_TO_* list needs to be extended");
+
+#define qobject_to(type, obj) ({ \
+    QObject *_tmp = qobject_check_type(obj, glue(QTYPE_CAST_TO_, type)); \
+    _tmp ? container_of(_tmp, type, base) : (type *)NULL; })
+
 /* Initialize an object to default values */
 static inline void qobject_init(QObject *obj, QType type)
 {
@@ -102,4 +117,18 @@ static inline QType qobject_type(const QObject *obj)
     return obj->type;
 }
 
+/**
+ * qobject_check_type(): Helper function for the qobject_to() macro.
+ * Return @obj, but only if @obj is not NULL and @type is equal to
+ * @obj's type.  Return NULL otherwise.
+ */
+static inline QObject *qobject_check_type(const QObject *obj, QType type)
+{
+    if (obj && qobject_type(obj) == type) {
+        return (QObject *)obj;
+    } else {
+        return NULL;
+    }
+}
+
 #endif /* QOBJECT_H */