[Bf-committers] DNA structs with local scope

[Julian Eisel]

Hi all,

I wanted to discuss a thing about DNA that I really don't like: DNA
structs are always placed in headers that we allow to access globally
within the source code. Considering how programming techniques have
evolved, that's definitely a bad design for safe programming and no
good practice (no blaming here, DNA is from the 90's after all! ;) ).
So what I'd like to have is some way to declare structs that DNA can
parse but have a more limited scope.
One way to do this would be doing something similar to what we do for
DNA_DEPRECATED, where usage of struct members causes a compiler
warning if DNA_DEPRECATED_ALLOW wasn't defined in the file. However,
it would be a bit ugly to have such macros everywhere within structs
and it only works for GCC.
I tried a nicer way to do this in the workspaces branch, simply by
adding a local header (in this case workspace_dna.h) and doing a
relative include in makesdna.c. This seems to work just fine, and it's
not so ugly even. For reference, check the changes in workspace_dna.h
and makesdna.c: https://developer.blender.org/rBbdc209faa9fd172.
My question is if that's an acceptable solution or if somebody knows
an even better one. Well... or if we even prefer to have public access
for DNA structs everywhere ;)

Cheers,
- Julian -