qapi: Conjure up QAPIDoc.ArgSection for undocumented members

qapi2texi.py already conjures up ArgSections for undocumented
enumeration values, in texi_enum.  Drop that, and conjure them up for
all kinds of "arguments" (enumeration values, object and alternate
type members) in qapi.py instead.

Take care to keep generated documentation exactly the same for now.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <1489582656-31133-16-git-send-email-armbru@redhat.com>

scripts/qapi.py

@@ -224,9 +224,8 @@ def _append_freeform(self, line):
     def connect_member(self, member):
         if member.name not in self.args:
             # Undocumented TODO outlaw
-            pass
-        else:
-            self.args[member.name].connect(member)
+            self.args[member.name] = QAPIDoc.ArgSection(member.name)
+        self.args[member.name].connect(member)
 
 
 class QAPISchemaParser(object):

scripts/qapi2texi.py

@@ -123,7 +123,7 @@ def texi_format(doc):
     return "\n".join(lines)
 
 
-def texi_body(doc):
+def texi_body(doc, only_documented=False):
     """
     Format the body of a symbol documentation:
     - main body
@@ -131,17 +131,21 @@ def texi_body(doc):
     - followed by "Returns/Notes/Since/Example" sections
     """
     body = texi_format(str(doc.body)) + "\n"
-    if doc.args:
+
+    args = ''
+    for name, section in doc.args.iteritems():
+        if not section.content and not only_documented:
+            continue        # Undocumented TODO require doc and drop
+        desc = str(section)
+        opt = ''
+        if section.optional:
+            desc = re.sub(r'^ *#optional *\n?|\n? *#optional *$|#optional',
+                          '', desc)
+            opt = ' (optional)'
+        args += "@item @code{'%s'}%s\n%s\n" % (name, opt, texi_format(desc))
+    if args:
         body += "@table @asis\n"
-        for arg, section in doc.args.iteritems():
-            desc = str(section)
-            opt = ''
-            if section.optional:
-                desc = re.sub(r'^ *#optional *\n?|\n? *#optional *$|#optional',
-                              '', desc)
-                opt = ' (optional)'
-            body += "@item @code{'%s'}%s\n%s\n" % (arg, opt,
-                                                   texi_format(desc))
+        body += args
         body += "@end table\n"
 
     for section in doc.sections:
@@ -183,10 +187,7 @@ def texi_union(expr, doc):
 
 def texi_enum(expr, doc):
     """Format an enum to texi"""
-    for i in expr['data']:
-        if i not in doc.args:
-            doc.args[i] = qapi.QAPIDoc.ArgSection(i)
-    body = texi_body(doc)
+    body = texi_body(doc, True)
     return TYPE_FMT(type="Enum",
                     name=doc.symbol,
                     body=body)