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by kokonoko 1268 days ago
Creating a separate gcc plugin for this seems unnecessary if I am not misunderstanding something. Just ensure the invariant function is called at every method, in debug builds maybe. You could of course change the object properties without using a method but then you have bigger problems.
1 comments

> Just ensure the invariant function is called at every method

You make this sound way easier than I would expect it to be in the general case.

They're suggesting you write the output of the codegen shown in the image here:

https://gavinray97.github.io/static/images/ghidra-check-inva...

Yeah you totally could, and before writing this plugin it's what I was doing, haha. As there is a human involved, it is very error prone though, and boy is it tedious!

You add something like:

  DCHECK(myInvariants());
to your method bodies. Sure, it makes it possible to forget, but it's not that hard to use.
A big part of DbC is that contracts are part of the public interface, not the implementation. This becomes especially important once you mesh them with Simula-style OOP, as derived classes need a way for overridden methods to widen or narrow the inherited contract.