If we define our own statement using YANG extension and supply that YANG to CONFD
what will happen ?
Basically nothing. Assuming that the extension is correctly defined, and used according to the definition, confdc will accept it - but since it has no way of knowing what the extension “means”, there is nothing for it to enter into the generated .fxs file. You can use a tool such as ‘pyang’ with a plugin that processes your extensions, and e.g. generates C files that can be compiled and linked with your application. Using the “generic” tailf extension meta-data may be an alternate solution to the problem you are trying to solve.