Nested ifs for celix_status_t

[Pepijn Noltes]

Hi All,

I'm currently busy with the device_access code and not really happy
with how many nested if statements are needed when using error
handling (celix_status_t).
See the following snipper for an example:

char *bsn = NULL;
MODULE module = NULL;
BUNDLE bundle = NULL;
SERVICE_REGISTRATION registration = NULL;
SERVICE_REGISTRY registry = NULL;
substatus = serviceReference_getBundle(ref, &bundle);
if (substatus == CELIX_SUCCESS) {
        substatus = bundle_getCurrentModule(bundle, &module);
        if (substatus == CELIX_SUCCESS) {
                substatus = module_getSymbolicName(module, &bsn);
                if (substatus == CELIX_SUCCESS) {
                        substatus = 
serviceReference_getServiceRegistration(ref, &registration);
                        if (substatus == CELIX_SUCCESS) {
                                substatus = 
serviceRegistration_getRegistry(registration, &registry);
                                if (substatus == CELIX_SUCCESS) {
                                        ...

In my opinion this makes the code very unclear and I am thinking about
adding the following macro to address this problem:
#define DO_IF_SUCCESS(status, call_func) ((status) == CELIX_SUCCESS) ?
(call_func) : (status)

The previous snippet could then be rewritten to:
char *bsn = NULL;
MODULE module = NULL;
BUNDLE bundle = NULL;
SERVICE_REGISTRATION registration = NULL;
SERVICE_REGISTRY registry = NULL;
substatus = serviceReference_getBundle(ref, &bundle);
substatus = DO_IF_SUCCESS(substatus, bundle_getCurrentModule(bundle, &module));
substatus = DO_IF_SUCCESS(substatus, module_getSymbolicName(module, &bsn));
substatus = DO_IF_SUCCESS(substatus,
serviceReference_getServiceRegistration(ref, &registration));
substatus = DO_IF_SUCCESS(substatus,
serviceRegistration_getRegistry(registration, &registry));
if (substatus == CELIX_SUCCESS) {
        ...


I would like to hear some opinions about this solution and if it is
something which can be added to celix_errno.h ?

Greetings,
Pepijn