Derive Debug is not generated for structs with large array fields (len() > 32) (need to add new rustc target)

[DmitrySamoylov]

Hi! If my struct contains large arrays, then Debug is not being generated. However if I add Debug manually, it compiles and runs just fine.

Input C/C++ Header

typedef struct {
    char f[33];
} A;

Bindgen Invocation

$ bindgen input.h

Actual Results

/* automatically generated by rust-bindgen 0.56.0 */

#[repr(C)]
#[derive(Copy, Clone)]
pub struct A {
    pub f: [::std::os::raw::c_char; 33usize],
}

...

Expected Results

#[repr(C)]
#[derive(Debug, Copy, Clone)]
pub struct A {
    pub f: [::std::os::raw::c_char; 33usize],
}

[jplatte]

Arrays with more than 32 elements only implement Debug since 1.47.

[jplatte]

The latest --rust-target supported being 1.47 apart from nightly, I guess this won't be supported even with --rust-target nightly.

[emilio]

If Rust supports this now we should add a new rustc version to the code and restrict the limitations to older versions of rust.

[jplatte]

I've already done the first part, I'll try to get to the latter soon or post a WIP PR with some notes if I don't find the time to finish it (or somebody else is eager to work on this 🙂).