[PATCH v3 04/13] qapi/introspect.py: guard against ifcond/comment misuse

[John Snow <jsnow@redhat.com>]

_tree_to_qlit is called recursively on dict values alone; at such a
point in generating output it is too late to apply an ifcond. Similarly,
comments do not necessarily have a "tidy" place they can be printed in
such a circumstance.

Forbid this usage.

Signed-off-by: John Snow <jsnow@redhat.com>
---
 scripts/qapi/introspect.py | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/scripts/qapi/introspect.py b/scripts/qapi/introspect.py
index 4749f65ea3c..ccdf4f1c0d0 100644
--- a/scripts/qapi/introspect.py
+++ b/scripts/qapi/introspect.py
@@ -43,6 +43,12 @@ def indent(level):
         ifobj, extra = obj
         ifcond = extra.get('if')
         comment = extra.get('comment')
+
+        # NB: _tree_to_qlit is called recursively on the values of a key:value
+        # pair; those values can't be decorated with comments or conditionals.
+        msg = "dict values cannot have attached comments or if-conditionals."
+        assert not suppress_first_indent, msg
+
         ret = ''
         if comment:
             ret += indent(level) + '/* %s */\n' % comment
-- 
2.26.2