[connicpu]

Honestly, longjmp is just extremely problematic for any code that isn't pure C. Even just adding C++ into the mix can easily make longjmp something that can't be used without invoking UB.

"If replacing std::longjmp with throw and setjmp with catch would invoke a non-trivial destructor for any automatic object, the behavior of such std::longjmp is undefined."[1]

[1]: https://en.cppreference.com/w/cpp/utility/program/longjmp

[jeff-davis]

setjmp/longjmp exist in a lot of real world C code, so there is a lot of value in allowing rust to deal with longjmp in a defined way at least in some narrow cases.

And I don't think it's impossible -- it probably requires some special wrappers (perhaps bindgen could generate them?) that would call setjmp before entering the C code. setjmp has its own set of problems, but I don't believe those are impossible to solve, either.