qapi: Track all failures between visit_start/stop

Inside the generated code between visit_start_struct() and
visit_end_struct(), we were blindly setting the error into
the caller's errp parameter.  But a future patch to split
visit_end_struct() will require that we take action based
on whether an error has occurred, which requires us to track
all actions through a local err.  Rewrite the visits to be
more in line with the other generated calls.

Generated code changes look like:

|     visit_start_struct(v, (void **)obj, "Abort", name, sizeof(Abort), &err);
|-    if (!err) {
|-        if (*obj) {
|-            visit_type_Abort_fields(v, obj, errp);
|-        }
|-        visit_end_struct(v, &err);
|+    if (err) {
|+        goto out;
|     }
|+    if (!*obj) {
|+        goto out_obj;
|+    }
|+    visit_type_Abort_fields(v, obj, &err);
|+    error_propagate(errp, err);
|+    err = NULL;
|+out_obj:
|+    visit_end_struct(v, &err);
|+out:
|     error_propagate(errp, err);
| }

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1454075341-13658-12-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
This commit is contained in:
Eric Blake 2016-01-29 06:48:47 -07:00 committed by Markus Armbruster
parent a16e3e5c58
commit 92b09babc1

View File

@ -2,7 +2,7 @@
# QAPI visitor generator
#
# Copyright IBM, Corp. 2011
# Copyright (C) 2014-2015 Red Hat, Inc.
# Copyright (C) 2014-2016 Red Hat, Inc.
#
# Authors:
# Anthony Liguori <aliguori@us.ibm.com>
@ -123,12 +123,18 @@ void visit_type_%(c_name)s(Visitor *v, %(c_name)s **obj, const char *name, Error
Error *err = NULL;
visit_start_struct(v, (void **)obj, "%(name)s", name, sizeof(%(c_name)s), &err);
if (!err) {
if (*obj) {
visit_type_%(c_name)s_fields(v, obj, errp);
}
visit_end_struct(v, &err);
if (err) {
goto out;
}
if (!*obj) {
goto out_obj;
}
visit_type_%(c_name)s_fields(v, obj, &err);
error_propagate(errp, err);
err = NULL;
out_obj:
visit_end_struct(v, &err);
out:
error_propagate(errp, err);
}
''',