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[v10,11/25] qapi: Track all failures between visit_start/stop

Message ID 1454075341-13658-12-git-send-email-eblake@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Eric Blake Jan. 29, 2016, 1:48 p.m. UTC
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>

---
v10: enhance commit message, move out_obj label and drop R-b
v9: enhance commit message
v8: no change
v7: place earlier in series
v6: based loosely on v5 7/46, but mostly a rewrite to get the last
generated code in the same form as all the others, so that the
later conversion to split visit_check_struct() will be easier
---
 scripts/qapi-visit.py | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)
diff mbox

Patch

diff --git a/scripts/qapi-visit.py b/scripts/qapi-visit.py
index b93690b..ec16e36 100644
--- a/scripts/qapi-visit.py
+++ b/scripts/qapi-visit.py
@@ -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);
 }
 ''',