3 files changed, 78 insertions, 1 deletions
diff --git a/include/qapi/qmp/qdict.h b/include/qapi/qmp/qdict.h
index 363e431106..6588c7f0c8 100644
--- a/include/qapi/qmp/qdict.h
+++ b/include/qapi/qmp/qdict.h
@@ -53,13 +53,15 @@ void qdict_destroy_obj(QObject *obj);
 #define qdict_put(qdict, key, obj) \
         qdict_put_obj(qdict, key, QOBJECT(obj))
 
-/* Helpers for int, bool, and string */
+/* Helpers for int, bool, null, and string */
 #define qdict_put_int(qdict, key, value) \
         qdict_put(qdict, key, qnum_from_int(value))
 #define qdict_put_bool(qdict, key, value) \
         qdict_put(qdict, key, qbool_from_bool(value))
 #define qdict_put_str(qdict, key, value) \
         qdict_put(qdict, key, qstring_from_str(value))
+#define qdict_put_null(qdict, key) \
+        qdict_put(qdict, key, qnull())
 
 /* High level helpers */
 double qdict_get_double(const QDict *qdict, const char *key);
diff --git a/include/qapi/qmp/qlit.h b/include/qapi/qmp/qlit.h
new file mode 100644
index 0000000000..b18406bce9
--- /dev/null
+++ b/include/qapi/qmp/qlit.h
@@ -0,0 +1,54 @@
+/*
+ * Copyright IBM, Corp. 2009
+ * Copyright (c) 2013, 2015, 2017 Red Hat Inc.
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *  Markus Armbruster <armbru@redhat.com>
+ *  Marc-André Lureau <marcandre.lureau@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+#ifndef QLIT_H
+#define QLIT_H
+
+#include "qapi-types.h"
+#include "qobject.h"
+
+typedef struct QLitDictEntry QLitDictEntry;
+typedef struct QLitObject QLitObject;
+
+struct QLitObject {
+    int type;
+    union {
+        bool qbool;
+        int64_t qnum;
+        const char *qstr;
+        QLitDictEntry *qdict;
+        QLitObject *qlist;
+    } value;
+};
+
+struct QLitDictEntry {
+    const char *key;
+    QLitObject value;
+};
+
+#define QLIT_QNULL \
+    { .type = QTYPE_QNULL }
+#define QLIT_QBOOL(val) \
+    { .type = QTYPE_QBOOL, .value.qbool = (val) }
+#define QLIT_QNUM(val) \
+    { .type = QTYPE_QNUM, .value.qnum = (val) }
+#define QLIT_QSTR(val) \
+    { .type = QTYPE_QSTRING, .value.qstr = (val) }
+#define QLIT_QDICT(val) \
+    { .type = QTYPE_QDICT, .value.qdict = (val) }
+#define QLIT_QLIST(val) \
+    { .type = QTYPE_QLIST, .value.qlist = (val) }
+
+bool qlit_equal_qobject(const QLitObject *lhs, const QObject *rhs);
+
+#endif /* QLIT_H */
diff --git a/include/qapi/qmp/qnum.h b/include/qapi/qmp/qnum.h
index 09d745c490..d6b0791139 100644
--- a/include/qapi/qmp/qnum.h
+++ b/include/qapi/qmp/qnum.h
@@ -23,6 +23,27 @@ typedef enum {
     QNUM_DOUBLE
 } QNumKind;
 
+/*
+ * QNum encapsulates how our dialect of JSON fills in the blanks left
+ * by the JSON specification (RFC 7159) regarding numbers.
+ *
+ * Conceptually, we treat number as an abstract type with three
+ * concrete subtypes: floating-point, signed integer, unsigned
+ * integer.  QNum implements this as a discriminated union of double,
+ * int64_t, uint64_t.
+ *
+ * The JSON parser picks the subtype as follows.  If the number has a
+ * decimal point or an exponent, it is floating-point.  Else if it
+ * fits into int64_t, it's signed integer.  Else if it fits into
+ * uint64_t, it's unsigned integer.  Else it's floating-point.
+ *
+ * Any number can serve as double: qnum_get_double() converts under
+ * the hood.
+ *
+ * An integer can serve as signed / unsigned integer as long as it is
+ * in range: qnum_get_try_int() / qnum_get_try_uint() check range and
+ * convert under the hood.
+ */
 typedef struct QNum {
     QObject base;
     QNumKind kind;