[PATCH v6 09/11] TPM: 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 == &error_fatal
(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 then 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_fatal, this means that we don't break error_abort
   (we'll abort on error_set, not on error_propagate)

This commit is generated by command

    sed -n '/^TPM$/,/^$/{s/^F: //p}' MAINTAINERS | \
    xargs git ls-files | grep '\.[hc]$' | \
    xargs spatch \
        --sp-file scripts/coccinelle/auto-propagated-errp.cocci \
        --macro-file scripts/cocci-macro-file.h \
        --in-place --no-show-diff --max-width 80

Reported-by: Kevin Wolf <kwolf@redhat.com>
Reported-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
---
 hw/tpm/tpm_util.c | 7 +++----
 tpm.c             | 7 +++----
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/hw/tpm/tpm_util.c b/hw/tpm/tpm_util.c
index 62b091f0c0..b0657bbbf2 100644
--- a/hw/tpm/tpm_util.c
+++ b/hw/tpm/tpm_util.c
@@ -47,8 +47,8 @@ static void get_tpm(Object *obj, Visitor *v, const char *name, void *opaque,
 static void set_tpm(Object *obj, Visitor *v, const char *name, void *opaque,
                     Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     DeviceState *dev = DEVICE(obj);
-    Error *local_err = NULL;
     Property *prop = opaque;
     TPMBackend *s, **be = qdev_get_prop_ptr(dev, prop);
     char *str;
@@ -58,9 +58,8 @@ static void set_tpm(Object *obj, Visitor *v, const char *name, void *opaque,
         return;
     }
 
-    visit_type_str(v, name, &str, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    visit_type_str(v, name, &str, errp);
+    if (*errp) {
         return;
     }
 
diff --git a/tpm.c b/tpm.c
index 9c9e20bbb7..359ebb7f68 100644
--- a/tpm.c
+++ b/tpm.c
@@ -81,11 +81,11 @@ TPMBackend *qemu_find_tpm_be(const char *id)
 
 static int tpm_init_tpmdev(void *dummy, QemuOpts *opts, Error **errp)
 {
+    ERRP_AUTO_PROPAGATE();
     const char *value;
     const char *id;
     const TPMBackendClass *be;
     TPMBackend *drv;
-    Error *local_err = NULL;
     int i;
 
     if (!QLIST_EMPTY(&tpm_backends)) {
@@ -116,9 +116,8 @@ static int tpm_init_tpmdev(void *dummy, QemuOpts *opts, Error **errp)
     }
 
     /* validate backend specific opts */
-    qemu_opts_validate(opts, be->opts, &local_err);
-    if (local_err) {
-        error_propagate(errp, local_err);
+    qemu_opts_validate(opts, be->opts, errp);
+    if (*errp) {
         return 1;
     }
 
-- 
2.21.0