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authorMichael Roth <mdroth@linux.vnet.ibm.com>2014-09-18 15:36:41 -0500
committerLuiz Capitulino <lcapitulino@redhat.com>2014-09-26 13:14:10 -0400
commit146db9f91979db89a123ea10d2b825d3670d2b36 (patch)
treea6b1d5ce3e635e4db14b9308f9bc7c7794e97635 /qapi/qapi-dealloc-visitor.c
parentcee2dedb85b97e4976c83bea84064c3921b8b7ac (diff)
qapi: dealloc visitor, implement visit_start_union
If the .data field of a QAPI Union is NULL, we don't need to free any of the union fields. Make use of the new visit_start_union interface to access this information and instruct the generated code to not visit these fields when this occurs. Cc: qemu-stable@nongnu.org Reported-by: Fam Zheng <famz@redhat.com> Suggested-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com> Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Diffstat (limited to 'qapi/qapi-dealloc-visitor.c')
-rw-r--r--qapi/qapi-dealloc-visitor.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/qapi/qapi-dealloc-visitor.c b/qapi/qapi-dealloc-visitor.c
index dc53545fa5..a14a1c7146 100644
--- a/qapi/qapi-dealloc-visitor.c
+++ b/qapi/qapi-dealloc-visitor.c
@@ -162,6 +162,31 @@ static void qapi_dealloc_type_enum(Visitor *v, int *obj, const char *strings[],
{
}
+/* If there's no data present, the dealloc visitor has nothing to free.
+ * Thus, indicate to visitor code that the subsequent union fields can
+ * be skipped. This is not an error condition, since the cleanup of the
+ * rest of an object can continue unhindered, so leave errp unset in
+ * these cases.
+ *
+ * NOTE: In cases where we're attempting to deallocate an object that
+ * may have missing fields, the field indicating the union type may
+ * be missing. In such a case, it's possible we don't have enough
+ * information to differentiate data_present == false from a case where
+ * data *is* present but happens to be a scalar with a value of 0.
+ * This is okay, since in the case of the dealloc visitor there's no
+ * work that needs to done in either situation.
+ *
+ * The current inability in QAPI code to more thoroughly verify a union
+ * type in such cases will likely need to be addressed if we wish to
+ * implement this interface for other types of visitors in the future,
+ * however.
+ */
+static bool qapi_dealloc_start_union(Visitor *v, bool data_present,
+ Error **errp)
+{
+ return data_present;
+}
+
Visitor *qapi_dealloc_get_visitor(QapiDeallocVisitor *v)
{
return &v->visitor;
@@ -191,6 +216,7 @@ QapiDeallocVisitor *qapi_dealloc_visitor_new(void)
v->visitor.type_str = qapi_dealloc_type_str;
v->visitor.type_number = qapi_dealloc_type_number;
v->visitor.type_size = qapi_dealloc_type_size;
+ v->visitor.start_union = qapi_dealloc_start_union;
QTAILQ_INIT(&v->stack);