gistfile1.c

/* Helper for finding a slot number. */
static INTVAL try_get_slot(PARROT_INTERP, CStructREPRData *repr_data, PMC *class_key, STRING *name, PMC **attrptr) {
    INTVAL slot = -1;
    if (repr_data->name_to_index_mapping) {
        CStructNameMap *cur_map_entry = repr_data->name_to_index_mapping;
        while (cur_map_entry->class_key != NULL) {
            if (cur_map_entry->class_key == class_key) {
                PMC *slot_pmc = VTABLE_get_pmc_keyed_str(interp, cur_map_entry->name_map, name);
                if (!PMC_IS_NULL(slot_pmc)) {
                    slot = VTABLE_get_integer(interp, slot_pmc);
                    if(attrptr)
                        *attrptr = slot_pmc;
                }
                break;
            }
            cur_map_entry++;
        }
    }
    return slot;
}

/* Gets the current value for an attribute. */                                                                       
static PMC * get_attribute_boxed(PARROT_INTERP, STable *st, void *data, PMC *class_handle, STRING *name, INTVAL hint) {
    CStructREPRData *repr_data = (CStructREPRData *)st->REPR_data;                                                   
    CStructBody     *body      = (CStructBody *)data;
    STRING          *type_str  = Parrot_str_new_constant(interp, "type");                                            
    INTVAL           slot;
    PMC             *attr;                                                                                           
    
    /* Look up slot, then offset and compute address. */                                                             
    slot = hint >= 0 ? hint :
        try_get_slot(interp, repr_data, class_handle, name, &attr);                                                  
    if (slot >= 0) {
        INTVAL placement = repr_data->attribute_locations[slot] & CSTRUCT_ATTR_MASK;                                 
        INTVAL real_slot = repr_data->attribute_locations[slot] >> CSTRUCT_ATTR_SHIFT;                               
        
        if(placement == CSTRUCT_ATTR_IN_STRUCT)                                                                      
            Parrot_ex_throw_from_c_args(interp, NULL, EXCEPTION_INVALID_OPERATION,                                   
                    "CStruct Can't perform boxed get on flattened attributes yet");                                  
        else {      
            PMC *obj = body->child_objs[real_slot];                                                                  
            if(!obj) 
                obj = accessor_call(interp, attr, type_str);                                                         
            return obj;
        }   
    }   
    
    /* Otherwise, complain that the attribute doesn't exist. */                                                      
    no_such_attribute(interp, "get", class_handle, name);
}