Re: [Qemu-devel] [PATCH for-2.10 03/10] qapi: Introduce a first class 'null' type

[Markus Armbruster]

Markus Armbruster <address@hidden> writes:

> Eric Blake <address@hidden> writes:
>
>> On 07/18/2017 09:53 AM, Eric Blake wrote:
>>> On 07/18/2017 08:41 AM, Markus Armbruster wrote:
>>>> I expect the 'null' type to be useful mostly for members of alternate
>>>> types.
>>>>
>>>> Signed-off-by: Markus Armbruster <address@hidden>
>>>> ---
>>> 
>>
>>> Reviewed-by: Eric Blake <address@hidden>
>>
>> Actually, do we need to update any qapi docs to mention the new builtin
>> type?
>
> Yes, we do.  I'll give it a shot.

Incremental patch appended.  May I keep your R-by?


diff --git a/docs/devel/qapi-code-gen.txt b/docs/devel/qapi-code-gen.txt
index 52e3874..6d8e00c 100644
--- a/docs/devel/qapi-code-gen.txt
+++ b/docs/devel/qapi-code-gen.txt
@@ -283,6 +283,7 @@ The following types are predefined, and map to C as follows:
                        accepts size suffixes
   bool      bool       JSON true or false
   any       QObject *  any JSON value
+  null      QNull *    JSON null
   QType     QType      JSON string matching enum QType values
 
 
@@ -536,10 +537,11 @@ can only express a choice between types represented 
differently in
 JSON.  If a branch is typed as the 'bool' built-in, the alternate
 accepts true and false; if it is typed as any of the various numeric
 built-ins, it accepts a JSON number; if it is typed as a 'str'
-built-in or named enum type, it accepts a JSON string; and if it is
-typed as a complex type (struct or union), it accepts a JSON object.
-Two different complex types, for instance, aren't permitted, because
-both are represented as a JSON object.
+built-in or named enum type, it accepts a JSON string; if it is typed
+as the 'null' built-in, it accepts JSON null, and if it is typed as a
+complex type (struct or union), it accepts a JSON object.  Two
+different complex types, for instance, aren't permitted, because both
+are represented as a JSON object.
 
 The example alternate declaration above allows using both of the
 following example objects: