[Qemu-devel] [PATCH v2 15/19] qapi-visit: Move error check into gen_visit_members_call()

[Eric Blake <eblake@redhat.com>]

When first introduced, neither branch of gen_visit_members_call()
would output a goto.  But now that the implicit struct visit
always ends with a goto, we should do the same for regular
struct visits, so that callers don't have to worry about whether
they are creating two identical goto's in a row.

Generated code gets slightly larger; if desired, we could patch
qapi.py:gen_visit_members() to have a mode where it skips the
final goto and leave it up to the callers when to use that mode,
but that adds more maintenance burden when the compiler should
be smart enough to not bloat the .o file just because the .c
file got larger.

Signed-off-by: Eric Blake <eblake@redhat.com>

---
v2: rebase onto s/fields/members/ change
---
 scripts/qapi-visit.py | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index e281d21..a17ecc1 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -48,6 +48,7 @@ def gen_visit_members_call(typ, direct_name, implicit_name=None):
     visit_type_%(c_type)s_members(v, %(c_name)s, &err);
 ''',
                      c_type=typ.c_name(), c_name=direct_name)
+        ret += gen_err_check()
     return ret


@@ -63,7 +64,6 @@ void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)

     if base:
         ret += gen_visit_members_call(base, '(%s *)obj' % base.c_name())
-        ret += gen_err_check()

     ret += gen_visit_members(members, prefix='obj->')

@@ -95,9 +95,9 @@ void visit_type_%(c_name)s_members(Visitor *v, %(c_name)s *obj, Error **errp)
     }
 ''')

-    # 'goto out' produced for base, by gen_visit_members() for each member,
-    # and if variants were present
-    if base or members or variants:
+    # 'goto out' produced for non-empty base, by gen_visit_members() for
+    # each member, and if variants were present
+    if (base and not base.is_empty()) or members or variants:
         ret += mcgen('''

 out:
-- 
2.5.0