Defining a protocol of message types with lists of IEs bears a lot of
repetitive, copy-paste-error-prone writing out of data structures.
Add a third layer to libosmo-gtlv, which allows helpful code generation.
By non-repetitive data structures that briefly describe the protocol's
messages and IEs, generate possibly repetitive IE list arrays and
decoded-struct definitions automatically, avoiding grunt work errors.
I tried C macros for this at first, but it became too convoluted.
Generating C code that can be read and grepped makes things easier.
A usage example is found in tests/libosmo-gtlv/test_gtlv_gen/.
Related: SYS#5599
Change-Id: Ifb3ea54d2797ce060b95834aa117725ec2d6c4cf
Neels Hofmeyr
Neels Hofmeyr