Re: [RFC PATCH v3 1/3] rust: core abstractions for network PHY drivers

[Andrew Lunn <andrew@lunn.ch>]

> >> +/// Represents duplex mode.
> >> +pub enum DuplexMode {
> >> +    /// Full-duplex mode
> >> +    Half,
> >> +    /// Half-duplex mode
> >> +    Full,
> >> +    /// Unknown
> >> +    Unknown,
> >> +}
> > 
> > How are these enums going to be kept in sync with the C code?  This
> > doesn't seem like a good idea and will quickly cause very strange bugs
> > that will be impossible to debug :(
> 
> enum DeviceState is guaranteed to be kept in sync with enum phy_state
> in C. If the C code is changed without updating the Rust code,
> compiling the Rust code fails. This is because a rustified enum is
> generated from C's phy_state enum at compile time.
> 
> enum DuplexMode refers to C's defines in include/uapi/linux/ethtool.h:
> 
> #define DUPLEX_HALF             0x00
> #define DUPLEX_FULL             0x01
> #define DUPLEX_UNKNOWN          0xff
> 
> So we can't use the same trick. But I guess that these DUPLEX_* values
> are unlikely be changed.

I did suggest changing this into an enum. I've not tried it, but i
think it should just work.

      Andrew