@@ -942,7 +942,11 @@ class QAPISchemaObjectType(QAPISchemaType):
self.members = None
def check(self, schema):
- assert self.members is not False # not running in cycles
+ if self.members is False: # check for cycles
+ assert self._base_name
+ raise QAPIExprError(self.info,
+ "Object %s cyclically depends on %s"
+ % (self.name, self._base_name))
if self.members:
return
self.members = False # mark as being checked
@@ -248,6 +248,7 @@ qapi-schema += bad-ident.json
qapi-schema += bad-type-bool.json
qapi-schema += bad-type-dict.json
qapi-schema += bad-type-int.json
+qapi-schema += base-cycle.json
qapi-schema += command-int.json
qapi-schema += comments.json
qapi-schema += double-data.json
new file mode 100644
@@ -0,0 +1 @@
+tests/qapi-schema/base-cycle.json:2: Object Base1 cyclically depends on Base2
new file mode 100644
@@ -0,0 +1 @@
+1
new file mode 100644
@@ -0,0 +1,3 @@
+# we reject a loop in base classes
+{ 'struct': 'Base1', 'base': 'Base2', 'data': {} }
+{ 'struct': 'Base2', 'base': 'Base1', 'data': {} }
It should be fairly obvious that qapi base classes need to form an acyclic graph, since QMP cannot specify the same key more than once, while base classes are included as flat members alongside other members added by the child. But the old check_member_clash() parser function was not prepared to check for this, and entered an infinite recursion (at least until python gives up about too deep of nesting). Now that check_member_clash() has been recently removed, attempts at self-inheritance trigger an assertion failure introduced by commit ac88219a. The obvious fix is to turn the assertion into a conditional. This patch includes both the test and the fix, since the .err file output for unbounded recursion is platform-specific (no guarantees at what limit it will quit trying to recurse) and rather large for how little useful content it provides. Signed-off-by: Eric Blake <eblake@redhat.com> --- v7: improve commit message v6: rebase to earlier info changes --- scripts/qapi.py | 6 +++++- tests/Makefile | 1 + tests/qapi-schema/base-cycle.err | 1 + tests/qapi-schema/base-cycle.exit | 1 + tests/qapi-schema/base-cycle.json | 3 +++ tests/qapi-schema/base-cycle.out | 0 6 files changed, 11 insertions(+), 1 deletion(-) create mode 100644 tests/qapi-schema/base-cycle.err create mode 100644 tests/qapi-schema/base-cycle.exit create mode 100644 tests/qapi-schema/base-cycle.json create mode 100644 tests/qapi-schema/base-cycle.out diff --git a/tests/qapi-schema/base-cycle.out b/tests/qapi-schema/base-cycle.out new file mode 100644 index 0000000..e69de29