From 4b5766488fd3549dc47a75331cf4db62f477536c Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Wed, 17 Oct 2018 10:26:25 +0200 Subject: error: Fix use of error_prepend() with &error_fatal, &error_abort MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From include/qapi/error.h: * Pass an existing error to the caller with the message modified: * error_propagate(errp, err); * error_prepend(errp, "Could not frobnicate '%s': ", name); Fei Li pointed out that doing error_propagate() first doesn't work well when @errp is &error_fatal or &error_abort: the error_prepend() is never reached. Since I doubt fixing the documentation will stop people from getting it wrong, introduce error_propagate_prepend(), in the hope that it lures people away from using its constituents in the wrong order. Update the instructions in error.h accordingly. Convert existing error_prepend() next to error_propagate to error_propagate_prepend(). If any of these get reached with &error_fatal or &error_abort, the error messages improve. I didn't check whether that's the case anywhere. Cc: Fei Li Signed-off-by: Markus Armbruster Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Eric Blake Message-Id: <20181017082702.5581-2-armbru@redhat.com> --- util/error.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'util/error.c') diff --git a/util/error.c b/util/error.c index 3efdd69162..b5ccbd8eac 100644 --- a/util/error.c +++ b/util/error.c @@ -292,3 +292,16 @@ void error_propagate(Error **dst_errp, Error *local_err) error_free(local_err); } } + +void error_propagate_prepend(Error **dst_errp, Error *err, + const char *fmt, ...) +{ + va_list ap; + + if (dst_errp && !*dst_errp) { + va_start(ap, fmt); + error_vprepend(&err, fmt, ap); + va_end(ap); + } /* else error is being ignored, don't bother with prepending */ + error_propagate(dst_errp, err); +} -- cgit 1.4.1