qapi: Eliminate accidental global frontend state

The frontend can't be run more than once due to its global state.
A future commit will want to do that.

The only global frontend state remaining is accidental:
QAPISchemaParser.__init__()'s parameter previously_included=[].
Python evaluates the default once, at definition time.  Any
modifications to it are visible in subsequent calls.  Well-known
Python trap.  Change the default to None and replace it by the real
default in the function body.  Use the opportunity to convert
previously_included to a set.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20191018074345.24034-4-armbru@redhat.com>
This commit is contained in:
Markus Armbruster 2019-10-18 09:43:41 +02:00
parent 2a7bbedd77
commit 0002b557b5

View File

@ -391,8 +391,9 @@ class QAPIDoc(object):
class QAPISchemaParser(object):
def __init__(self, fname, previously_included=[], incl_info=None):
previously_included.append(os.path.abspath(fname))
def __init__(self, fname, previously_included=None, incl_info=None):
previously_included = previously_included or set()
previously_included.add(os.path.abspath(fname))
try:
if sys.version_info[0] >= 3: