We commonly use the error API like this:
err = NULL;
foo(..., &err);
if (err) {
goto out;
}
bar(..., &err);
Every error source is checked separately. The second function is only
called when the first one succeeds. Both functions are free to pass
their argument to error_set(). Because error_set() asserts no error
has been set, this effectively means they must not be called with an
error set.
The qapi-generated code uses the error API differently:
// *errp was initialized to NULL somewhere up the call chain
frob(..., errp);
gnat(..., errp);
Errors accumulate in *errp: first error wins, subsequent errors get
dropped. To make this work, the second function does nothing when
called with an error set. Requires non-null errp, or else the second
function can't see the first one fail.
This usage has also bled into visitor tests, and two device model
object property getters rtc_get_date() and balloon_stats_get_all().
With the "accumulate" technique, you need fewer error checks in
callers, and buy that with an error check in every callee. Can be
nice.
However, mixing the two techniques is confusing. You can't use the
"accumulate" technique with functions designed for the "check
separately" technique. You can use the "check separately" technique
with functions designed for the "accumulate" technique, but then
error_set() can't catch you setting an error more than once.
Standardize on the "check separately" technique for now, because it's
overwhelmingly prevalent.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
When visit_start_struct() fails, visit_end_struct() must not be
called. Three out of four visit_type_TestStruct() call it anyway. As
far as I can tell, visit_start_struct() doesn't actually fail there.
Fix them anyway.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
This will be used by "info qtree". For numbers it prints both the
decimal and hex values. For sizes it rounds to the nearest power
of 2^10. For strings, it puts quotes around the string and separates
NULL and empty string.
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
The macro g_assert_not_reached is a better self documenting replacement
for assert(0) or assert(false).
Signed-off-by: Stefan Weil <sw@weilnetz.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
We never actually stored the stringified double values into the strings
before we did the comparisons. This left number/double values completely
uncovered in test-visitor-serialization tests.
Fixing this exposed a bug in our handling of large whole number values
in QEMU's JSON parser which is now fixed.
Simplify the code while we're at it by dropping the
calc_float_string_storage() craziness in favor of GStrings.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Amos Kong <akong@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
qmp_output_get_qobject() increments the qobject's reference count. Since
we currently pass this straight into qobject_to_json() so we can feed
the data into a QMP input visitor, we never actually free the underlying
qobject when qmp_output_visitor_cleanup() is called. This causes leaks
on all of the QMP serialization tests.
Fix this by holding a pointer to the qobject and decref'ing it before
returning from qmp_deserialize().
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
This patch fixes some of the memory leaks in test-visitor-serialization but not all of them.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Currently we test our visitors individually, and seperately for input
vs. output. This is useful for validating internal representations
against the native C types and vice-versa, and other visitor-specific
testing, but it doesn't cover the potential use-case of using visitor
pairs for serialization/deserialization very well, and makes it
hard to easily extend the coverage for different C types / boundary
conditions.
To cover that we add a set of unit tests that takes a number of native C
values, passes them into an output visitor, extracts the values with an
input visitor, then compares the result to the original.
Plugging in new visitors to the test harness only requires a user to
implement the SerializeOps interface and add it to a list.
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Andreas Färber <afaerber@suse.de>
Markus Armbruster