| Message ID | 156871563702.196432.5964411202152101367.stgit@bahia.lan |
|---|---|
| State | New |
| Headers | show |
| Series | Fix usage of error_append_hint() | expand |
On Tue, 17 Sep 2019 12:20:37 +0200 Greg Kurz <groug@kaod.org> wrote: > error_setg() and error_propagate(), as well as their variants, cause > QEMU to terminate when called with &error_fatal or &error_abort. This > prevents to add hints since error_append_hint() isn't even called in > this case. > > It means that error_append_hint() should only be used with a local > error object, and then propagate this local error to the caller. > > Document this in <qapi/error.h> . > > Signed-off-by: Greg Kurz <groug@kaod.org> > --- > include/qapi/error.h | 11 ++++++++++- It's a bit awkward requiring a local object, but better safe than sorry. Reviewed-by: Cornelia Huck <cohuck@redhat.com>
On 9/17/19 5:20 AM, Greg Kurz wrote: > error_setg() and error_propagate(), as well as their variants, cause > QEMU to terminate when called with &error_fatal or &error_abort. This > prevents to add hints since error_append_hint() isn't even called in s/to add/adding/ > this case. > > It means that error_append_hint() should only be used with a local > error object, and then propagate this local error to the caller. > > Document this in <qapi/error.h> . > > Signed-off-by: Greg Kurz <groug@kaod.org> > --- > include/qapi/error.h | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > Reviewed-by: Eric Blake <eblake@redhat.com>
diff --git a/include/qapi/error.h b/include/qapi/error.h index 3f95141a01a8..28174329ba71 100644 --- a/include/qapi/error.h +++ b/include/qapi/error.h @@ -27,6 +27,13 @@ * error_setg(&err, "invalid quark\n" * "Valid quarks are up, down, strange, charm, top, bottom."); * + * Dot *not* pass the errp parameter from the caller + * error_setg(errp, "invalid quark"); + * error_append_hint(errp, "Valid quarks are up, down, strange, " + * "charm, top, bottom.\n"); + * because error_setg() terminates QEMU if @errp is &error_fatal or + * &error_abort, and the hints are not even added. + * * Report an error to the current monitor if we have one, else stderr: * error_report_err(err); * This frees the error object. @@ -252,7 +259,9 @@ void error_prepend(Error **errp, const char *fmt, ...) * error message. * @errp may be NULL, but not &error_fatal or &error_abort. * Trivially the case if you call it only after error_setg() or - * error_propagate(). + * error_propagate(). CAUTION: error_setg() and error_propagate() do + * not return when passed &error_fatal. Always use a local error object + * and propagate it to the caller. * May be called multiple times. The resulting hint should end with a * newline. */
error_setg() and error_propagate(), as well as their variants, cause QEMU to terminate when called with &error_fatal or &error_abort. This prevents to add hints since error_append_hint() isn't even called in this case. It means that error_append_hint() should only be used with a local error object, and then propagate this local error to the caller. Document this in <qapi/error.h> . Signed-off-by: Greg Kurz <groug@kaod.org> --- include/qapi/error.h | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)