qapi: Test failure in middle of array parse

Our generated list visitors have the same problem as has been
mentioned elsewhere (see commit 2f52e20): they allocate data
even on failure. An upcoming patch will correct things to
provide saner guarantees, but first we need to expose the
behavior in the testsuite to ensure we aren't introducing any
memory usage bugs.

There are more test cases throughout the test-qmp-input-* tests
that already deal with partial allocation; a later commit will
clean up all visit_type_FOO(), without marking all of the tests
with FIXME at this time.

Signed-off-by: Eric Blake <[email protected]>
Message-Id: <1446791754[email protected]>
Signed-off-by: Markus Armbruster <[email protected]>

diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index f40c3c792f90cbecb5f22644c429759eb1cf99a7..3ef5c16a662c688e29c069f1ea33cf2f1cb10532 100644 (file)
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -138,6 +138,10 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error
 
 
 def gen_visit_list(name, element_type):
+    # FIXME: if *obj is NULL on entry, and the first visit_next_list()
+    # assigns to *obj, while a later one fails, we should clean up *obj
+    # rather than leaving it non-NULL. As currently written, the caller must
+    # call qapi_free_FOOList() to avoid a memory leak of the partial FOOList.
     return mcgen('''
 
 void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error **errp)

diff --git a/tests/test-qmp-input-visitor.c b/tests/test-qmp-input-visitor.c
index ef5284daa24cc45213bfd8431f990f8aea0d58a5..aa02eec765b14ca4e6c2589350f333596bedd07c 100644 (file)
--- a/tests/test-qmp-input-visitor.c
+++ b/tests/test-qmp-input-visitor.c
@@ -698,8 +698,10 @@ static void test_visitor_in_errors(TestInputVisitorData *data,
     TestStruct *p = NULL;
     Error *err = NULL;
     Visitor *v;
+    strList *q = NULL;
 
-    v = visitor_input_test_init(data, "{ 'integer': false, 'boolean': 'foo', 'string': -42 }");
+    v = visitor_input_test_init(data, "{ 'integer': false, 'boolean': 'foo', "
+                                "'string': -42 }");
 
     visit_type_TestStruct(v, &p, NULL, &err);
     error_free_or_abort(&err);
@@ -709,6 +711,12 @@ static void test_visitor_in_errors(TestInputVisitorData *data,
 
     g_free(p->string);
     g_free(p);
+
+    v = visitor_input_test_init(data, "[ '1', '2', false, '3' ]");
+    visit_type_strList(v, &q, NULL, &err);
+    error_free_or_abort(&err);
+    assert(q);
+    qapi_free_strList(q);
 }
 
 int main(int argc, char **argv)