Merge remote-tracking branch 'remotes/armbru/tags/pull-qapi-2018-08-28' into staging

QAPI patches for 2018-08-28

# gpg: Signature made Tue 28 Aug 2018 17:23:32 BST
# gpg:                using RSA key 3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg:                 aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867  4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-qapi-2018-08-28:
  qapi: Add comments to aid debugging generated introspection
  qapi: Minor introspect.py cleanups
  qapi: Update docs for generator changes since commit 9ee86b85267
  qapi: Emit a blank line before dummy declaration
  qapi: Drop qapi_event_send_FOO()'s Error ** argument
  qapi: Fix build_params() for empty parameter list

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 5 insertions, 6 deletions

diff --git a/scripts/qapi/common.py b/scripts/qapi/common.py
index 02c5c6767a..7b62a4c7b0 100644
--- a/scripts/qapi/common.py
+++ b/scripts/qapi/common.py
@@ -2070,16 +2070,14 @@ extern const QEnumLookup %(c_name)s_lookup;
     return ret
 
 
-def build_params(arg_type, boxed, extra):
-    if not arg_type:
-        assert not boxed
-        return extra
+def build_params(arg_type, boxed, extra=None):
     ret = ''
     sep = ''
     if boxed:
+        assert arg_type
         ret += '%s arg' % arg_type.c_param_type()
         sep = ', '
-    else:
+    elif arg_type:
         assert not arg_type.variants
         for memb in arg_type.members:
             ret += sep
@@ -2090,7 +2088,7 @@ def build_params(arg_type, boxed, extra):
                               c_name(memb.name))
     if extra:
         ret += sep + extra
-    return ret
+    return ret if ret else 'void'
 
 
 #
@@ -2220,6 +2218,7 @@ class QAPIGenC(QAPIGenCCode):
 
     def _bottom(self, fname):
         return mcgen('''
+
 /* Dummy declaration to prevent empty .o file */
 char dummy_%(name)s;
 ''',