On Tue, 17 Sep 2019 12:22:18 +0200
Greg Kurz <gr...@kaod.org> wrote:
> Passing errp from the argument list to error_append_hint()
> isn't recommended because it may cause unwanted behaviours
> when errp is equal to &error_fatal or &error_abort.
>
> First, error_append_hint() aborts QEMU when passed either of
> those.
>
> Second, consider the following:
>
> void foo(Error **errp)
> {
> error_setg(errp, "foo");
> error_append_hint(errp, "Try bar\n");
> }
>
> error_setg() causes QEMU to exit or abort, and hints aren't
> added.
>
> Signed-off-by: Greg Kurz <gr...@kaod.org>
> ---
> scripts/checkpatch.pl | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index aa9a354a0e7e..17ce026282a6 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -2902,6 +2902,10 @@ sub process {
> }
> }
>
Maybe add a comment here?
# using errp is common practice, so that check should hopefully be enough
> + if ($line =~ /error_append_hint\(errp/) {
> + WARN("suspicious errp passed to error_append_hint()\n" .
Add "(use a local error object)"?
> + $herecurr);
> + }
> # check for non-portable libc calls that have portable alternatives in QEMU
> if ($line =~ /\bffs\(/) {
> ERROR("use ctz32() instead of ffs()\n" . $herecurr);
>
