No option to disable derive(Debug)

[jethrogb]

Once #429 is fixed, it's once again possible to have types in your Rust structs that don't implement Debug. Therefore, deriving Debug is not possible for such types. bindgen 0.19 had a derive_debug option to turn off generating Debug.

[emilio]

This one is easy to support if there's a good use case for it, and this one seems like a decent one.

This is really easy to add. I'm digging in other problems now, but will do it.

[dimbleby]

Overlaps second bullet of #424

[andreeaflorescu]

It seems like derive debug is also added to packed structures. This generates the following warning on build:

warning: #[derive] can't be used on a #[repr(packed)] struct that does not derive Copy (error E0133)                                                                                                                                                                               
   --> virtio_gen/src/virtio_net.rs:684:10                                                                                                                                                                                                                                         
    |                                                                                                                                                                                                                                                                              
684 | #[derive(Debug, Default)]                                                                                                                                                                                                                                                    
    |          ^^^^^                                                                                                                                                                                                                                                               
    |                                                                                                                                                                                                                                                                              
    = note: #[warn(safe_packed_borrows)] on by default                                                                                                                                                                                                                             
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!                                                                                                                                              
    = note: for more information, see issue #46043 <https://github.com/rust-lang/rust/issues/46043>                                                                                                                                                                                                                                                                                 

The structure that is causing the previous error:

#[repr(C, packed)]
#[derive(Debug, Default)]
pub struct virtio_net_ctrl_mac {
    pub entries: __virtio32,
    pub macs: __IncompleteArrayField<[__u8; 6usize]>,
}

Our workaround right now is to manually remove the debug derive, but it would be nice to have an argument like --no-derive-debug=virtio_net_ctrl_mac.

[emilio]

Can you file a new issue for that? It's hard to keep track of comments in closed issues. IIUC what you want is an option to individually control #[derive(Debug)] per struct and such, right?

[andreeaflorescu]

Yap, that is exactly what I was thinking about. I'll open a new issue.