Multidimensional array binding has incorrect mutability.

[jbangelo]

Input C/C++ Header

void foo(const int array[][5]);

Bindgen Invocation

Using bindgen execute version 0.54.1

$ bindgen array_func.h

Actual Results

extern "C" {
    pub fn foo(array: *mut [::std::os::raw::c_int; 5usize]);
}

Expected Results

extern "C" {
    pub fn foo(array: *const [::std::os::raw::c_int; 5usize]);
}

The pointer in the bindings should not be mutable. In the C function the const applies to all dimensions of the array, and there's no way to legally modify any part of the array. A single dimension array works as expected, so it seems to be just an issue with multidimensional arrays.

[jbangelo]

I'd be happy to help resolve this issue, assuming it is indeed a real problem. Pointers/suggestions on where or how to fix this would be appreciated (sorry about the pun 😄).

[emilio]

Hmm, I'd look at similar issues like #1727 and such. e09602b is the fix for that, maybe we're missing a similar check in the code that parses arrays. Though I'd first double-check that that is what the C compiler is doing.

Thanks for filing this!