unicorn/qemu/scripts
Eric Blake 6084be1882
qapi: Split visit_end_struct() into pieces
As mentioned in previous patches, we want to call visit_end_struct()
functions unconditionally, so that visitors can release resources
tied up since the matching visit_start_struct() without also having
to worry about error priority if more than one error occurs.

Even though error_propagate() can be safely used to ignore a second
error during cleanup caused by a first error, it is simpler if the
cleanup cannot set an error. So, split out the error checking
portion (basically, input visitors checking for unvisited keys) into
a new function visit_check_struct(), which can be safely skipped if
any earlier errors are encountered, and leave the cleanup portion
(which never fails, but must be called unconditionally if
visit_start_struct() succeeded) in visit_end_struct().

Generated code in qapi-visit.c has diffs resembling:

|@@ -59,10 +59,12 @@ void visit_type_ACPIOSTInfo(Visitor *v,
| goto out_obj;
| }
| visit_type_ACPIOSTInfo_members(v, obj, &err);
|- error_propagate(errp, err);
|- err = NULL;
|+ if (err) {
|+ goto out_obj;
|+ }
|+ visit_check_struct(v, &err);
| out_obj:
|- visit_end_struct(v, &err);
|+ visit_end_struct(v);
| out:

and in qapi-event.c:

@@ -47,7 +47,10 @@ void qapi_event_send_acpi_device_ost(ACP
| goto out;
| }
| visit_type_q_obj_ACPI_DEVICE_OST_arg_members(v, &param, &err);
|- visit_end_struct(v, err ? NULL : &err);
|+ if (!err) {
|+ visit_check_struct(v, &err);
|+ }
|+ visit_end_struct(v);
| if (err) {
| goto out;

Backports commit 15c2f669e3fb2bc97f7b42d1871f595c0ac24af8 from qemu
2018-02-23 19:13:47 -05:00
..
create_config more cleanup qemu/configure 2017-01-19 14:11:54 +08:00
make_device_config.sh fix file perms 2015-08-28 21:05:38 -07:00
ordereddict.py import 2015-08-21 15:04:50 +08:00
qapi-event.py qapi: Split visit_end_struct() into pieces 2018-02-23 19:13:47 -05:00
qapi-types.py qapi: Adjust layout of FooList types 2018-02-23 14:49:06 -05:00
qapi-visit.py qapi: Split visit_end_struct() into pieces 2018-02-23 19:13:47 -05:00
qapi.py qapi: Use anonymous bases in QMP flat unions 2018-02-21 22:55:12 -05:00