qapi: Implement boxed event argument documentation

Generate a reference "Arguments: the members of ...", just like we do
for commands since commit c2dd311cb7 "qapi2texi: Implement boxed
argument documentation".

No change to generated QMP documentation; we don't yet use boxed
events outside tests/.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20191024110237.30963-7-armbru@redhat.com>

scripts/qapi/doc.py

@@ -266,9 +266,17 @@ class QAPISchemaGenDocVisitor(QAPISchemaVisitor):
 
     def visit_event(self, name, info, ifcond, arg_type, boxed):
         doc = self.cur_doc
+        if boxed:
+            body = texi_body(doc)
+            body += ('\n@b{Arguments:} the members of @code{%s}\n'
+                     % arg_type.name)
+            body += texi_features(doc)
+            body += texi_sections(doc, ifcond)
+        else:
+            body = texi_entity(doc, 'Arguments', ifcond)
         self._gen.add(MSG_FMT(type='Event',
                               name=doc.symbol,
-                              body=texi_entity(doc, 'Arguments', ifcond)))
+                              body=body))
 
     def symbol(self, doc, entity):
         if self._gen._body:

tests/qapi-schema/doc-good.json

@@ -160,7 +160,6 @@
 
 ##
 # @EVT-BOXED:
-# BUG: generated doc misses arguments
 ##
 { 'event': 'EVT-BOXED',  'boxed': true,
   'data': 'Object' }

tests/qapi-schema/doc-good.out

@@ -196,4 +196,4 @@ another feature
 <- out
 doc symbol=EVT-BOXED
     body=
-BUG: generated doc misses arguments
+

tests/qapi-schema/doc-good.texi

@@ -279,7 +279,9 @@ another feature
 
 @deftypefn Event {} EVT-BOXED
 
-BUG: generated doc misses arguments
+
+
+@b{Arguments:} the members of @code{Object}
 
 @end deftypefn