Re: Mainline loongarch64 defconfig+Rust build error

[Xi Ruoyao <xry111@xry111.site>]

On Tue, 2025-12-09 at 11:56 +0100, Miguel Ojeda wrote:
> Hi all,
> 
> I am seeing in mainline loongarch64 defconfig+Rust the following build
> error [1].
> 
> Cheers,
> Miguel
> 
> [1]
> 
>  error[E0425]: cannot find value `compat_ptr_ioctl` in crate `bindings`
>      --> drivers/android/binder/rust_binder_main.rs:317:38
>       |
> 317   |         compat_ioctl: Some(bindings::compat_ptr_ioctl),
>       |                                      ^^^^^^^^^^^^^^^^ help: a
> function with a similar name exists: `compat_sys_ioctl`
>       |
>      ::: /__w/quick/quick/linux/rust/bindings/bindings_generated.rs:78264:5
>       |
> 78264 |     pub fn compat_sys_ioctl(fd: ffi::c_uint, cmd: ffi::c_uint,
> arg: compat_ulong_t) -> ffi::c_long;
>       |     ----------------------------------------------------------------------------------------------
> similarly named function `compat_sys_ioctl` defined here

I highly doubt if this is really a LoongArch-only issue.  We have:

#ifdef CONFIG_COMPAT
extern long compat_ptr_ioctl(struct file *file, unsigned int cmd, 
                    unsigned long arg);
#else
#define compat_ptr_ioctl NULL
#endif

AFAIK bindgen does not translate C preprocessor macro definitions, so
when !CONFIG_COMPAT we won't have the Rust binding for it.

And as LA32 is not upstreamed it's pointless to support COMPAT for
LoongArch, yet.

-- 
Xi Ruoyao <xry111@xry111.site>