From a8d4a2e4d7e1a0207699de47142c9bdbf2cc8675 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Mon, 4 May 2015 09:05:07 -0600 Subject: qapi: Forbid base without discriminator in unions None of the existing QMP or QGA interfaces uses a union with a base type but no discriminator; it is easier to avoid this in the generator to save room for other future extensions more likely to be useful. An earlier commit added a union-base-no-discriminator test to ensure that we eventually give a decent error message; likewise, removing UserDefUnion outright is okay, because we moved all the tests we wish to keep into the tests of the simple union UserDefNativeListUnion in the previous commit. Now is the time to actually forbid simple union with base, and remove the last vestiges from the testsuite. Signed-off-by: Eric Blake Reviewed-by: Markus Armbruster Signed-off-by: Markus Armbruster --- scripts/qapi.py | 20 ++++++++++---------- 1 file changed, 10 insertions(+), 10 deletions(-) (limited to 'scripts/qapi.py') diff --git a/scripts/qapi.py b/scripts/qapi.py index 3ce8c3321b..438468e3aa 100644 --- a/scripts/qapi.py +++ b/scripts/qapi.py @@ -259,22 +259,22 @@ def check_union(expr, expr_info): discriminator = expr.get('discriminator') members = expr['data'] - # If the object has a member 'base', its value must name a complex type. - if base: + # If the object has a member 'base', its value must name a complex type, + # and there must be a discriminator. + if base is not None: + if discriminator is None: + raise QAPIExprError(expr_info, + "Union '%s' requires a discriminator to go " + "along with base" %name) base_fields = find_base_fields(base) if not base_fields: raise QAPIExprError(expr_info, "Base '%s' is not a valid type" % base) - # If the union object has no member 'discriminator', it's an - # ordinary union. - if not discriminator: - enum_define = None - - # Else if the value of member 'discriminator' is {}, it's an - # anonymous union. - elif discriminator == {}: + # If the union object has no member 'discriminator', it's a + # simple union. If 'discriminator' is {}, it is an anonymous union. + if not discriminator or discriminator == {}: enum_define = None # Else, it's a flat union. -- cgit v1.2.3