> Rust has formally rejected the notion that any function can return twice. Even LLVM has no special knowledge of the name of "sigsetjmp" or "setjmp", only that some functions can return twice.
> Thus, when you call sigsetjmp or setjmp from Rust, Rust doesn't believe that you called a function that can return twice. The Rust compiler refuses to annotate it with the required LLVMIR annotation. Thus LLVM sees a call to sigsetjmp that it believes cannot return twice... it's just an ordinary function that someone named "sigsetjmp" because they have a sense of humor. What LLVM does next is between itself and whatever gods that compilers believe in, and we have no more voice in such a matter.
In this particular case, it's hardly the fault of a "C wrapper."
Sure looks like it is, indeed, a C problem. Which checks out with my experience, the only time I had a crate fail to build in all these years it was C underneath and of course C is just anything which happened to compile and seemed to work. As an ex-C programmer I guess I sympathise, none of the non-trivial C I wrote 10-20 years ago actually builds out of the box on today's systems that's just how C is, so why would Rust magically fix that.
My issue with it at the time had to do with... how to put it... simply build the extension, & carry on with my life. Version after version it would build alright, and then suddenly, boom, it doesn't work no more. Okay, I understand that perhaps ppc64el is not the most popular architecture, and some things aren't easily portable, but this otherwise mirrors my experience with Rust programs. It's always requiring the latest version of everything. The recommended installation path involves sudoing shell scripts over network, and I'm sure Rust people love it, salivating over new versions and features that come along, constantly staying up to date, but to the rest of us normal people dealing with Rust software is a chore.
Cmake is a huge quality-of-life improvement all things considering!
> Rust has formally rejected the notion that any function can return twice. Even LLVM has no special knowledge of the name of "sigsetjmp" or "setjmp", only that some functions can return twice.
> Thus, when you call sigsetjmp or setjmp from Rust, Rust doesn't believe that you called a function that can return twice. The Rust compiler refuses to annotate it with the required LLVMIR annotation. Thus LLVM sees a call to sigsetjmp that it believes cannot return twice... it's just an ordinary function that someone named "sigsetjmp" because they have a sense of humor. What LLVM does next is between itself and whatever gods that compilers believe in, and we have no more voice in such a matter.
In this particular case, it's hardly the fault of a "C wrapper."