[RFC v5 074/126] Graphics: introduce ERRP_AUTO_PROPAGATE

[Vladimir Sementsov-Ogievskiy]

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 <address@hidden>
Reported-by: Greg Kurz <address@hidden>
Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
---
 ui/input-barrier.c |  7 +++----
 ui/input.c         | 14 ++++++--------
 ui/vnc.c           | 19 ++++++++-----------
 3 files changed, 17 insertions(+), 23 deletions(-)

diff --git a/ui/input-barrier.c b/ui/input-barrier.c
index a2c961f285..cce1cf35c3 100644
--- a/ui/input-barrier.c
+++ b/ui/input-barrier.c
@@ -492,8 +492,8 @@ static gboolean input_barrier_event(QIOChannel *ioc 
G_GNUC_UNUSED,
 
 static void input_barrier_complete(UserCreatable *uc, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     InputBarrier *ib = INPUT_BARRIER(uc);
-    Error *local_err = NULL;
 
     if (!ib->name) {
         error_setg(errp, QERR_MISSING_PARAMETER, "name");
@@ -509,9 +509,8 @@ static void input_barrier_complete(UserCreatable *uc, Error 
**errp)
     ib->sioc = qio_channel_socket_new();
     qio_channel_set_name(QIO_CHANNEL(ib->sioc), "barrier-client");
 
-    qio_channel_socket_connect_sync(ib->sioc, &ib->saddr, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    qio_channel_socket_connect_sync(ib->sioc, &ib->saddr, errp);
+    if (*errp) {
         return;
     }
 
diff --git a/ui/input.c b/ui/input.c
index 4791b089c7..bea1745a33 100644
--- a/ui/input.c
+++ b/ui/input.c
@@ -87,12 +87,11 @@ void qemu_input_handler_bind(QemuInputHandlerState *s,
                              const char *device_id, int head,
                              Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     QemuConsole *con;
-    Error *err = NULL;
 
-    con = qemu_console_lookup_by_device_name(device_id, head, &err);
-    if (err) {
-        error_propagate(errp, err);
+    con = qemu_console_lookup_by_device_name(device_id, head, errp);
+    if (*errp) {
         return;
     }
 
@@ -128,18 +127,17 @@ void qmp_input_send_event(bool has_device, const char 
*device,
                           bool has_head, int64_t head,
                           InputEventList *events, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     InputEventList *e;
     QemuConsole *con;
-    Error *err = NULL;
 
     con = NULL;
     if (has_device) {
         if (!has_head) {
             head = 0;
         }
-        con = qemu_console_lookup_by_device_name(device, head, &err);
-        if (err) {
-            error_propagate(errp, err);
+        con = qemu_console_lookup_by_device_name(device, head, errp);
+        if (*errp) {
             return;
         }
     }
diff --git a/ui/vnc.c b/ui/vnc.c
index 4100d6e404..0354d30168 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -3795,6 +3795,7 @@ static int vnc_display_listen(VncDisplay *vd,
 
 void vnc_display_open(const char *id, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     VncDisplay *vd = vnc_display_find(id);
     QemuOpts *opts = qemu_opts_find(&qemu_vnc_opts, id);
     SocketAddress **saddr = NULL, **wsaddr = NULL;
@@ -4008,11 +4009,9 @@ void vnc_display_open(const char *id, Error **errp)
     device_id = qemu_opt_get(opts, "display");
     if (device_id) {
         int head = qemu_opt_get_number(opts, "head", 0);
-        Error *err = NULL;
 
-        con = qemu_console_lookup_by_device_name(device_id, head, &err);
-        if (err) {
-            error_propagate(errp, err);
+        con = qemu_console_lookup_by_device_name(device_id, head, errp);
+        if (*errp) {
             goto fail;
         }
     } else {
@@ -4106,18 +4105,16 @@ QemuOpts *vnc_parse(const char *str, Error **errp)
 
 int vnc_init_func(void *opaque, QemuOpts *opts, Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_AUTO_PROPAGATE();
     char *id = (char *)qemu_opts_id(opts);
 
     assert(id);
-    vnc_display_init(id, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    vnc_display_init(id, errp);
+    if (*errp) {
         return -1;
     }
-    vnc_display_open(id, &local_err);
-    if (local_err != NULL) {
-        error_propagate(errp, local_err);
+    vnc_display_open(id, errp);
+    if (*errp) {
         return -1;
     }
     return 0;
-- 
2.21.0