[Qemu-devel] [PATCH RFC 2/3] error: allow local errors to trigger abort

[Michael S. Tsirkin]

It's a common idiom:

    Error *local_err = NULL;
    ....
    foo(&local_err);
    ...
    if (local_err) {
        error_propagate(errp, local_err);
        return;
    }

Unfortunately it means that call to foo(&local_err) will
not abort even if errp is set to error_abort.

Instead, we get an abort at error_propagate which is too late.

To fix, add an API to check errp and set local_err to error_abort
if errp is error_abort.

Signed-off-by: Michael S. Tsirkin <address@hidden>
---
 include/qapi/error.h | 5 +++++
 util/error.c         | 5 +++++
 2 files changed, 10 insertions(+)

diff --git a/include/qapi/error.h b/include/qapi/error.h
index f44c451..8246a62 100644
--- a/include/qapi/error.h
+++ b/include/qapi/error.h
@@ -88,6 +88,11 @@ const char *error_get_pretty(Error *err);
 void error_report_err(Error *);
 
 /**
+ * Init a local error. It must be propagated to errp using error_propagate.
+ */
+Error *error_init_local(Error **errp);
+
+/**
  * Propagate an error to an indirect pointer to an error.  This function will
  * always transfer ownership of the error reference and handles the case where
  * dst_err is NULL correctly.  Errors after the first are discarded.
diff --git a/util/error.c b/util/error.c
index ccf29ea..7489967 100644
--- a/util/error.c
+++ b/util/error.c
@@ -28,6 +28,11 @@ static bool error_is_abort(Error **errp)
     return errp && *errp && (*errp)->err_class == ERROR_CLASS_MAX;
 }
 
+Error *error_init_local(Error **errp)
+{
+    return error_is_abort(errp) ? *errp : NULL;
+}
+
 void error_set(Error **errp, ErrorClass err_class, const char *fmt, ...)
 {
     Error *err;
-- 
MST