Mark a bad example more clearly. Fix the error_propagate_prepend()
example. Add a missing declaration and a second error pileup example.
Signed-off-by: Markus Armbruster <arm...@redhat.com>
Reviewed-by: Eric Blake <ebl...@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsement...@virtuozzo.com>
Reviewed-by: Greg Kurz <gr...@kaod.org>
---
include/qapi/error.h | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/include/qapi/error.h b/include/qapi/error.h
index ad5b6e896d..e8960eaad5 100644
--- a/include/qapi/error.h
+++ b/include/qapi/error.h
@@ -24,7 +24,7 @@
* "charm, top, bottom.\n");
*
* Do *not* contract this to
- * error_setg(&err, "invalid quark\n"
+ * error_setg(&err, "invalid quark\n" // WRONG!
* "Valid quarks are up, down, strange, charm, top, bottom.");
*
* Report an error to the current monitor if we have one, else stderr:
@@ -52,7 +52,8 @@
* where Error **errp is a parameter, by convention the last one.
*
* Pass an existing error to the caller with the message modified:
- * error_propagate_prepend(errp, err);
+ * error_propagate_prepend(errp, err,
+ * "Could not frobnicate '%s': ", name);
*
* Avoid
* error_propagate(errp, err);
@@ -108,12 +109,23 @@
* }
*
* Do *not* "optimize" this to
+ * Error *err = NULL;
* foo(arg, &err);
* bar(arg, &err); // WRONG!
* if (err) {
* handle the error...
* }
* because this may pass a non-null err to bar().
+ *
+ * Likewise, do *not*
+ * Error *err = NULL;
+ * if (cond1) {
+ * error_setg(&err, ...);
+ * }
+ * if (cond2) {
+ * error_setg(&err, ...); // WRONG!
+ * }
+ * because this may pass a non-null err to error_setg().
*/
#ifndef ERROR_H
--
2.26.2
