[Qemu-devel] [RFC PATCH 05/11] qapi: Add visitor for implicit structs

[Kevin Wolf <kwolf@redhat.com>]

These can be used when an embedded struct is parsed and members not
belonging to the struct may be present in the input (parsing flat
namespect QMP union with discriminator)

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 include/qapi/visitor-impl.h |  4 ++++
 include/qapi/visitor.h      |  3 +++
 qapi/qapi-visit-core.c      | 16 ++++++++++++++++
 qapi/qmp-input-visitor.c    | 14 ++++++++++++++
 4 files changed, 37 insertions(+)

diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h
index 5159964..5c1297f 100644
--- a/include/qapi/visitor-impl.h
+++ b/include/qapi/visitor-impl.h
@@ -22,6 +22,10 @@ struct Visitor
                          const char *name, size_t size, Error **errp);
     void (*end_struct)(Visitor *v, Error **errp);
 
+    void (*start_implicit_struct)(Visitor *v, void **obj, size_t size,
+                                  Error **errp);
+    void (*end_implicit_struct)(Visitor *v, Error **errp);
+
     void (*start_list)(Visitor *v, const char *name, Error **errp);
     GenericList *(*next_list)(Visitor *v, GenericList **list, Error **errp);
     void (*end_list)(Visitor *v, Error **errp);
diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h
index 28c21d8..bd24f85 100644
--- a/include/qapi/visitor.h
+++ b/include/qapi/visitor.h
@@ -33,6 +33,9 @@ void visit_end_handle(Visitor *v, Error **errp);
 void visit_start_struct(Visitor *v, void **obj, const char *kind,
                         const char *name, size_t size, Error **errp);
 void visit_end_struct(Visitor *v, Error **errp);
+void visit_start_implicit_struct(Visitor *v, void **obj, size_t size,
+                                 Error **errp);
+void visit_end_implicit_struct(Visitor *v, Error **errp);
 void visit_start_list(Visitor *v, const char *name, Error **errp);
 GenericList *visit_next_list(Visitor *v, GenericList **list, Error **errp);
 void visit_end_list(Visitor *v, Error **errp);
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index 401ee6e..9b4d51b 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -45,6 +45,22 @@ void visit_end_struct(Visitor *v, Error **errp)
     v->end_struct(v, errp);
 }
 
+void visit_start_implicit_struct(Visitor *v, void **obj, size_t size,
+                                 Error **errp)
+{
+    if (!error_is_set(errp) && v->start_implicit_struct) {
+        v->start_implicit_struct(v, obj, size, errp);
+    }
+}
+
+void visit_end_implicit_struct(Visitor *v, Error **errp)
+{
+    assert(!error_is_set(errp));
+    if (v->end_implicit_struct) {
+        v->end_implicit_struct(v, errp);
+    }
+}
+
 void visit_start_list(Visitor *v, const char *name, Error **errp)
 {
     if (!error_is_set(errp)) {
diff --git a/qapi/qmp-input-visitor.c b/qapi/qmp-input-visitor.c
index 67fb127..59c5cac 100644
--- a/qapi/qmp-input-visitor.c
+++ b/qapi/qmp-input-visitor.c
@@ -144,6 +144,18 @@ static void qmp_input_end_struct(Visitor *v, Error **errp)
     qmp_input_pop(qiv, errp);
 }
 
+static void qmp_input_start_implicit_struct(Visitor *v, void **obj,
+                                            size_t size, Error **errp)
+{
+    if (obj) {
+        *obj = g_malloc0(size);
+    }
+}
+
+static void qmp_input_end_implicit_struct(Visitor *v, Error **errp)
+{
+}
+
 static void qmp_input_start_list(Visitor *v, const char *name, Error **errp)
 {
     QmpInputVisitor *qiv = to_qiv(v);
@@ -293,6 +305,8 @@ QmpInputVisitor *qmp_input_visitor_new(QObject *obj)
 
     v->visitor.start_struct = qmp_input_start_struct;
     v->visitor.end_struct = qmp_input_end_struct;
+    v->visitor.start_implicit_struct = qmp_input_start_implicit_struct;
+    v->visitor.end_implicit_struct = qmp_input_end_implicit_struct;
     v->visitor.start_list = qmp_input_start_list;
     v->visitor.next_list = qmp_input_next_list;
     v->visitor.end_list = qmp_input_end_list;
-- 
1.8.1.4