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[Qemu-devel] [PATCH] error: Document how to accumulate multiple errors
From: |
Markus Armbruster |
Subject: |
[Qemu-devel] [PATCH] error: Document how to accumulate multiple errors |
Date: |
Tue, 17 Nov 2015 17:05:49 +0100 |
Suggested-by: Eric Blake <address@hidden>
Signed-off-by: Markus Armbruster <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
---
include/qapi/error.h | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/include/qapi/error.h b/include/qapi/error.h
index 4d42cdc..b2362a5 100644
--- a/include/qapi/error.h
+++ b/include/qapi/error.h
@@ -76,6 +76,23 @@
* But when all you do with the error is pass it on, please use
* foo(arg, errp);
* for readability.
+ *
+ * Receive and accumulate multiple errors (first one wins):
+ * Error *err = NULL, *local_err = NULL;
+ * foo(arg, &err);
+ * bar(arg, &local_err);
+ * error_propagate(&err, local_err);
+ * if (err) {
+ * handle the error...
+ * }
+ *
+ * Do *not* "optimize" this to
+ * foo(arg, &err);
+ * bar(arg, &err); // WRONG!
+ * if (err) {
+ * handle the error...
+ * }
+ * because this may pass a non-null err to bar().
*/
#ifndef ERROR_H
--
2.4.3
- [Qemu-devel] [PATCH] error: Document how to accumulate multiple errors,
Markus Armbruster <=