diff options
| author | Kevin Wolf <kwolf@redhat.com> | 2013-09-19 11:56:36 +0200 |
|---|---|---|
| committer | Kevin Wolf <kwolf@redhat.com> | 2013-10-11 16:50:01 +0200 |
| commit | 622f557f5aaea1326c94ca4cddfa4eafeade3723 (patch) | |
| tree | ca74eac5379e1003c4634119001400b737adb472 /docs | |
| parent | 14d36307ffdf949df9c1dd7f435e138b36f63bb0 (diff) | |
qapi-types/visit.py: Inheritance for structs
This introduces a new 'base' key for struct definitions that refers to
another struct type. On the JSON level, the fields of the base type are
included directly into the same namespace as the fields of the defined
type, like with unions. On the C level, a pointer to a struct of the
base type is included.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'docs')
| -rw-r--r-- | docs/qapi-code-gen.txt | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/docs/qapi-code-gen.txt b/docs/qapi-code-gen.txt index 0ce045c0b3..91f44d01b9 100644 --- a/docs/qapi-code-gen.txt +++ b/docs/qapi-code-gen.txt @@ -53,6 +53,23 @@ The use of '*' as a prefix to the name means the member is optional. Optional members should always be added to the end of the dictionary to preserve backwards compatibility. + +A complex type definition can specify another complex type as its base. +In this case, the fields of the base type are included as top-level fields +of the new complex type's dictionary in the QMP wire format. An example +definition is: + + { 'type': 'BlockdevOptionsGenericFormat', 'data': { 'file': 'str' } } + { 'type': 'BlockdevOptionsGenericCOWFormat', + 'base': 'BlockdevOptionsGenericFormat', + 'data': { '*backing': 'str' } } + +An example BlockdevOptionsGenericCOWFormat object on the wire could use +both fields like this: + + { "file": "/some/place/my-image", + "backing": "/some/place/my-backing-file" } + === Enumeration types === An enumeration type is a dictionary containing a single key whose value is a |