[RFC v5 089/126] I/O Channels: introduce ERRP_AUTO_PROPAGATE

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

If we want to add some info to errp (by error_prepend() or
error_append_hint()), we must use the ERRP_AUTO_PROPAGATE macro.
Otherwise, this info will not be added when errp == &fatal_err
(the program will exit prior to the error_append_hint() or
error_prepend() call).  Fix such cases.

If we want to check error after errp-function call, we need to
introduce local_err and than propagate it to errp. Instead, use
ERRP_AUTO_PROPAGATE macro, benefits are:
1. No need of explicit error_propagate call
2. No need of explicit local_err variable: use errp directly
3. ERRP_AUTO_PROPAGATE leaves errp as is if it's not NULL or
   &error_fatel, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

This commit (together with its neighbors) was generated by

for f in $(git grep -l errp \*.[ch]); do \
    spatch --sp-file scripts/coccinelle/auto-propagated-errp.cocci \
    --macro-file scripts/cocci-macro-file.h --in-place --no-show-diff $f; \
done;

then fix a bit of compilation problems: coccinelle for some reason
leaves several
f() {
    ...
    goto out;
    ...
    out:
}
patterns, with "out:" at function end.

then
./python/commit-per-subsystem.py MAINTAINERS "$(< auto-msg)"

(auto-msg was a file with this commit message)

Still, for backporting it may be more comfortable to use only the first
command and then do one huge commit.

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 io/dns-resolver.c | 7 +++----
 io/net-listener.c | 7 +++----
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/io/dns-resolver.c b/io/dns-resolver.c
index 6ebe2a5650..a45c5ca0c8 100644
--- a/io/dns-resolver.c
+++ b/io/dns-resolver.c
@@ -52,13 +52,13 @@ static int qio_dns_resolver_lookup_sync_inet(QIODNSResolver *resolver,
                                              SocketAddress ***addrs,
                                              Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     struct addrinfo ai, *res, *e;
     InetSocketAddress *iaddr = &addr->u.inet;
     char port[33];
     char uaddr[INET6_ADDRSTRLEN + 1];
     char uport[33];
     int rc;
-    Error *err = NULL;
     size_t i;
 
     *naddrs = 0;
@@ -69,11 +69,10 @@ static int qio_dns_resolver_lookup_sync_inet(QIODNSResolver *resolver,
     if (iaddr->has_numeric && iaddr->numeric) {
         ai.ai_flags |= AI_NUMERICHOST | AI_NUMERICSERV;
     }
-    ai.ai_family = inet_ai_family_from_address(iaddr, &err);
+    ai.ai_family = inet_ai_family_from_address(iaddr, errp);
     ai.ai_socktype = SOCK_STREAM;
 
-    if (err) {
-        error_propagate(errp, err);
+    if (*errp) {
         return -1;
     }
 
diff --git a/io/net-listener.c b/io/net-listener.c
index 5d8a226872..ba000e7ede 100644
--- a/io/net-listener.c
+++ b/io/net-listener.c
@@ -65,11 +65,11 @@ int qio_net_listener_open_sync(QIONetListener *listener,
                                int num,
                                Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     QIODNSResolver *resolver = qio_dns_resolver_get_instance();
     SocketAddress **resaddrs;
     size_t nresaddrs;
     size_t i;
-    Error *err = NULL;
     bool success = false;
 
     if (qio_dns_resolver_lookup_sync(resolver,
@@ -84,7 +84,7 @@ int qio_net_listener_open_sync(QIONetListener *listener,
         QIOChannelSocket *sioc = qio_channel_socket_new();
 
         if (qio_channel_socket_listen_sync(sioc, resaddrs[i], num,
-                                           err ? NULL : &err) == 0) {
+                                           *errp ? NULL : errp) == 0) {
             success = true;
 
             qio_net_listener_add(listener, sioc);
@@ -96,10 +96,9 @@ int qio_net_listener_open_sync(QIONetListener *listener,
     g_free(resaddrs);
 
     if (success) {
-        error_free(err);
+        error_free_errp(errp);
         return 0;
     } else {
-        error_propagate(errp, err);
         return -1;
     }
 }
-- 
2.21.0