How can I continue navigating into expressions inside a statement?

[shepmaster]

Here's a piece of code rudely extracted from my playing-around:

syn::ItemKind::Fn(_, _, _, _, _, block) => {
    for stmt in block.stmts {
        match stmt {
            syn::Stmt::Expr(i) => {
                // i.node; // `node` is private
                println!("e {:?}", i); // but I can see the interesting block under here
            }
            _ => unimplemented!(),
        }
    }
    // Descend
}

I am trying to parse this code:

pub fn unsafe_block_inside() {
    unsafe {}
}

---

My goal is to be able to answer a "simple" true/false question: does a crate use unsafe code? If you have pointers for a better way I should be doing that, I'd much appreciate it!

Thanks for making such a useful library! ❤️

[dtolnay]

Those definitely should have been public. I fixed it in 12dcd62 and released it as 0.10.2. You're on the right track!

I also went through and checked that every other AST struct has public fields.

[dtolnay]

One thing that would be helpful here is #44, some syn equivalent to libsyntax's visit module. Then implementing something like "does a crate use unsafe code" is a matter of writing a single Visitor with just a few methods implemented (visit_expr to check for an unsafe block, visit_item to check for an unsafe fn, maybe a couple more). Sounds like you'll be doing most of that work anyway to recursively walk through the entire tree of expressions. I would be delighted if you have the extra time to factor that into a syn visitor crate, even if it isn't fully complete and I can follow up from there to add the rest of the syntax when I have time.

[shepmaster]

Thanks for the quick fix! I'll skim over visit and see how close I am. One thing is that I don't care at all about visitation order, so I can be very slapdash about which nodes I visit.