Odd compiler warning

[ccleve]

I just upgraded to v0.11.0 from 0.10.something. I now get this compiler warning:

warning: `extern` block uses type `NodeTag`, which is not FFI-safe
  --> src/cfuncs/bindings.rs:11:16
   |
11 |         index: Relation,
   |                ^^^^^^^^ not FFI-safe
   |
   = note: this enum is non-exhaustive
   = note: `#[warn(improper_ctypes)]` on by default

on this code:

extern "C" {
    pub fn rdb_read_page(
        index: Relation,
        blkno: u32,
        lock_type: ::std::os::raw::c_int,
        pg_buffer: *mut u32,
    ) -> *mut ::std::os::raw::c_char;
}

This points to a function I wrote in C to read/write pages in an index relation.

This warning is a bit odd, because NodeTag doesn't appear in the method signature and I don't know why Relation would not be ffi-safe.

I've been using this code successfully for quite a while now.

[workingjubilee]

That's... odd. What version of rustc are you using?

[ccleve]

rustc 1.72.1 (d5c2e9c34 2023-09-13) Just now, I did a `rustup update` to 1.73. Same error.

…

On Mon, Oct 16, 2023 at 8:11 PM Jubilee ***@***.***> wrote: That's... odd. What version of rustc are you using? — Reply to this email directly, view it on GitHub <#1340 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAITHKUPVRE6H4IBBLAUI2LX7XLMBAVCNFSM6AAAAAA6C7HFSCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTONRVGQ4TQOBUHA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[workingjubilee]

It looks like Rust examines the fields recursively and sometimes forgets to check locality.

[workingjubilee]

Just to clarify, that's pgrx_pg_sys::Relation which is a *mut pgrx_pg_sys::RelationData, right?

[workingjubilee]

Reported as rust-lang/rust#116831

[ccleve]

It says "use crate::pg_sys::Relation;" at the top of the file. Hover over it in CLion and it says: pgrx_pg_sys::include::pg16 pub type Relation = *mut RelationData

…

On Mon, Oct 16, 2023 at 10:14 PM Jubilee ***@***.***> wrote: Just to clarify, that's pgrx_pg_sys::Relation which is a *mut pgrx_pg_sys::RelationData, right? — Reply to this email directly, view it on GitHub <#1340 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAITHKXO5GLPVZRMYELDYXTX7XZXXAVCNFSM6AAAAAA6C7HFSCVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTONRVGU4TKMBTGA> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[ccleve]

The workaround, for now, is to put

#![allow(improper_ctypes)]

in lib.rs.