Obviously the problem is with using objects in the message which are invalid. The compiler may or may not work as you expect and that’s your problem, not the compilers.

You can try to defend yourself by stating the call is done by some framework but that just means the problem is still not in the language, it’s in the framework.

First, the compiler and framework come from the same vendor, so it's perfectly fine to blame them. Unless you consider things like compilers and frameworks to be independent subjects capable of being blamed.

Second, whether the behavior is defined or undefined, the compiler has no business touching arguments that the code didn't tell it to touch. If it does so, it isn't fit for purpose and can be criticised as being unfit for purpose.

And the C standard is very clear and adamant that being in compliance with the standard is not, and in many ways cannot be, equivalent to being fit for purpose.

Last not least, I think we are probably not going to agree as to whether dereferencing unused arguments is a valid response to the presence of undefined behavior. See

https://blog.metaobject.com/2018/07/a-one-word-change-to-c-s...