Eric Blake <ebl...@redhat.com> writes:
> Add a test that proves (at least when run under valgrind) that
> we are correctly handling allocated memory even when a visit
> is aborted in the middle for whatever other reason.
>
> See commit f24582d "qapi: fix double free in
> qmp_output_visitor_cleanup()" for a fix that was lacking
> testsuite exposure prior to this patch.
>
> Signed-off-by: Eric Blake <ebl...@redhat.com>
> ---
> tests/test-qobject-output-visitor.c | 46
> ++++++++++++++++++++++++++++++++++++-
> 1 file changed, 45 insertions(+), 1 deletion(-)
>
> diff --git a/tests/test-qobject-output-visitor.c
> b/tests/test-qobject-output-visitor.c
> index 749c540..1e9a5d1 100644
> --- a/tests/test-qobject-output-visitor.c
> +++ b/tests/test-qobject-output-visitor.c
> @@ -1,7 +1,7 @@
> /*
> * QObject Output Visitor unit-tests.
> *
> - * Copyright (C) 2011-2016 Red Hat Inc.
> + * Copyright (C) 2011-2017 Red Hat Inc.
> *
> * Authors:
> * Luiz Capitulino <lcapitul...@redhat.com>
> @@ -251,6 +251,48 @@ static void
> test_visitor_out_struct_errors(TestOutputVisitorData *data,
> }
>
>
> +static void test_visitor_out_partial_visit(TestOutputVisitorData *data,
> + const void *unused)
> +{
> + /* Various checks that a mid-visit abort doesn't leak or double-free. */
> + const char *str = "hi";
> + Error *err = NULL;
> + UserDefAlternate uda = {
> + .type = QTYPE_QDICT,
> + .u.udfu = { .integer = 1,
> + .string = (char *) "bye",
> + .enum1 = -1 } /* intentionally bad */
> + };
> + UserDefAlternate *obj = &uda;
> +
> + /* Abort within a nested object with no data members */
> + visit_start_struct(data->ov, NULL, NULL, 0, &error_abort);
> + visit_start_struct(data->ov, "nested", NULL, 0, &error_abort);
> + visitor_reset(data);
> +
> + /* Abort in the middle of a list of strings */
> + visit_start_list(data->ov, "list", NULL, 0, &error_abort);
> + visit_type_str(data->ov, NULL, (char **)&str, &error_abort);
> + visit_type_str(data->ov, NULL, (char **)&str, &error_abort);
> + visitor_reset(data);
> +
> + /*
> + * Abort in the middle of an alternate. Alternates can't be
> + * virtually visited, so we get to inline the first half of
> + * visit_type_UserDefAlternate().
> + */
Not exactly inline. Perhaps:
/*
* Abort in the middle of an alternate. Since alternates don't
* support virtual visits, we perform a real one, similar to what
* visit_type_UserDefAlternate() would do.
*/
Hmm, what would visit_type_UserDefAlternate() do for @uda? Could we
simply call it here and be done?
I've explored supporting virtual alternate visits, but my solution isn't
quite ready, yet.
> + visit_start_alternate(data->ov, NULL, (GenericAlternate **)&obj,
> + sizeof(uda), &error_abort);
> + visit_start_struct(data->ov, NULL, NULL, 0, &error_abort);
> + visit_type_UserDefUnionBase_members(data->ov,
> + (UserDefUnionBase *)&uda.u.udfu,
> + &err);
> + /* error expected because of bad "enum1" discriminator value */
> + error_free_or_abort(&err);
> + visitor_reset(data);
> +}
> +
> +
> static void test_visitor_out_list(TestOutputVisitorData *data,
> const void *unused)
> {
> @@ -815,6 +857,8 @@ int main(int argc, char **argv)
> &out_visitor_data,
> test_visitor_out_struct_nested);
> output_visitor_test_add("/visitor/output/struct-errors",
> &out_visitor_data,
> test_visitor_out_struct_errors);
> + output_visitor_test_add("/visitor/output/partial-visit",
> + &out_visitor_data,
> test_visitor_out_partial_visit);
> output_visitor_test_add("/visitor/output/list",
> &out_visitor_data, test_visitor_out_list);
> output_visitor_test_add("/visitor/output/any",
