error: Eliminate error_propagate() with Coccinelle, part 2

When all we do with an Error we receive into a local variable is
propagating to somewhere else, we can just as well receive it there
right away.  The previous commit did that with a Coccinelle script I
consider fairly trustworthy.  This commit uses the same script with
the matching of return taken out, i.e. we convert

    if (!foo(..., &err)) {
        ...
        error_propagate(errp, err);
        ...
    }

to

    if (!foo(..., errp)) {
        ...
        ...
    }

This is unsound: @err could still be read between afterwards.  I don't
know how to express "no read of @err without an intervening write" in
Coccinelle.  Instead, I manually double-checked for uses of @err.

Suboptimal line breaks tweaked manually.  qdev_realize() simplified
further to placate scripts/checkpatch.pl.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200707160613.848843-36-armbru@redhat.com>

1 files changed, 2 insertions, 5 deletions

diff --git a/block/blkdebug.c b/block/blkdebug.c
index 3c0a9d4..9c08d8a 100644
--- a/block/blkdebug.c
+++ b/block/blkdebug.c
@@ -359,7 +359,6 @@ static int blkdebug_parse_perm_list(uint64_t *dest, QDict *options,
     QObject *crumpled_subqdict = NULL;
     Visitor *v = NULL;
     BlockPermissionList *perm_list = NULL, *element;
-    Error *local_err = NULL;
 
     *dest = 0;
 
@@ -375,8 +374,7 @@ static int blkdebug_parse_perm_list(uint64_t *dest, QDict *options,
     }
 
     v = qobject_input_visitor_new(crumpled_subqdict);
-    if (!visit_type_BlockPermissionList(v, NULL, &perm_list, &local_err)) {
-        error_propagate(errp, local_err);
+    if (!visit_type_BlockPermissionList(v, NULL, &perm_list, errp)) {
         ret = -EINVAL;
         goto out;
     }
@@ -471,8 +469,7 @@ static int blkdebug_open(BlockDriverState *bs, QDict *options, int flags,
     uint64_t align;
 
     opts = qemu_opts_create(&runtime_opts, NULL, 0, &error_abort);
-    if (!qemu_opts_absorb_qdict(opts, options, &local_err)) {
-        error_propagate(errp, local_err);
+    if (!qemu_opts_absorb_qdict(opts, options, errp)) {
         ret = -EINVAL;
         goto out;
     }