[RFC v5 105/126] Bootdevice: 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>
---
 bootdevice.c | 31 +++++++++++++------------------
 1 file changed, 13 insertions(+), 18 deletions(-)

diff --git a/bootdevice.c b/bootdevice.c
index 1d225202f9..ca69cbeb05 100644
--- a/bootdevice.c
+++ b/bootdevice.c
@@ -53,7 +53,7 @@ void qemu_register_boot_set(QEMUBootSetHandler *func, void 
*opaque)
 
 void qemu_boot_set(const char *boot_order, Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_AUTO_PROPAGATE();
 
     if (!boot_set_handler) {
         error_setg(errp, "no function defined to set boot device list for"
@@ -61,9 +61,8 @@ void qemu_boot_set(const char *boot_order, Error **errp)
         return;
     }
 
-    validate_bootdevices(boot_order, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    validate_bootdevices(boot_order, errp);
+    if (*errp) {
         return;
     }
 
@@ -286,26 +285,23 @@ static void device_get_bootindex(Object *obj, Visitor *v, 
const char *name,
 static void device_set_bootindex(Object *obj, Visitor *v, const char *name,
                                  void *opaque, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     BootIndexProperty *prop = opaque;
     int32_t boot_index;
-    Error *local_err = NULL;
 
-    visit_type_int32(v, name, &boot_index, &local_err);
-    if (local_err) {
-        goto out;
+    visit_type_int32(v, name, &boot_index, errp);
+    if (*errp) {
+        return;
     }
     /* check whether bootindex is present in fw_boot_order list  */
-    check_boot_index(boot_index, &local_err);
-    if (local_err) {
-        goto out;
+    check_boot_index(boot_index, errp);
+    if (*errp) {
+        return;
     }
     /* change bootindex to a new one */
     *prop->bootindex = boot_index;
 
     add_boot_device_path(*prop->bootindex, prop->dev, prop->suffix);
-
-out:
-    error_propagate(errp, local_err);
 }
 
 static void property_release_bootindex(Object *obj, const char *name,
@@ -322,7 +318,7 @@ void device_add_bootindex_property(Object *obj, int32_t 
*bootindex,
                                    const char *name, const char *suffix,
                                    DeviceState *dev, Error **errp)
 {
-    Error *local_err = NULL;
+    ERRP_AUTO_PROPAGATE();
     BootIndexProperty *prop = g_malloc0(sizeof(*prop));
 
     prop->bootindex = bootindex;
@@ -333,10 +329,9 @@ void device_add_bootindex_property(Object *obj, int32_t 
*bootindex,
                         device_get_bootindex,
                         device_set_bootindex,
                         property_release_bootindex,
-                        prop, &local_err);
+                        prop, errp);
 
-    if (local_err) {
-        error_propagate(errp, local_err);
+    if (*errp) {
         g_free(prop);
         return;
     }
-- 
2.21.0