How to link my rust version of calloc and free to rust mbedtlsld in no_std enviroment correcly?

[yaoxin1995]

Sorry @zugzwang , I can't reopen the old issue. So I create a new one.

Old issue How to link rust-mbedtls to a no_std project

I got a compilation error when I tried to link my rust calloc and free to mbedtls.

@DrTobe I have a follow up question of how to link the rust version 'calloc' and 'free' in no_std environment.

I implemented my own version of 'calloc' and 'free' as follows, and put the code in a random place of my project:

const ALIGNMENT: usize = 16;

#[no_mangle]
pub extern "C" fn calloc(number_of_elements: core::ffi::c_ulong, element_size: core::ffi::c_ulong) -> *mut core::ffi::c_void {


    // TODO: CHECK number_of_elements or element_size is null
    // 0 as *mut c_void;
    //core::mem::transmute(0) as *mut c_void
    if number_of_elements == 0 || element_size == 0 {
        return core::ptr::null_mut() as *mut core::ffi::c_void;
    }

    let total_size = number_of_elements * element_size;
    let layout = Layout::from_size_align(total_size as usize, ALIGNMENT).unwrap();

    let ptr;
    unsafe {
        ptr = alloc(layout);
    }

    let pointer_addr = ptr.addr();

    {
        let mut allocator_tracker = ALLCATOR_RECODER.write();
        allocator_tracker.memory_layout_records.insert(pointer_addr, layout.clone());
    }

    ptr as *mut core::ffi::c_void
}

#[no_mangle]
pub extern "C" fn free(ptr: *mut core::ffi::c_void) {
    if ptr.is_null() { return }

    let ptr = ptr as *mut u8;

    let ptr_addr = ptr.addr();

    let layout;
    {
        let allocator_tracker = ALLCATOR_RECODER.write();
        layout = match allocator_tracker.memory_layout_records.get(&ptr_addr) {
            Some(e) => e.clone(),
            None => return,
        };
    }

    unsafe{
        dealloc(ptr, layout);
    }
}

But for some reason, I got the compilation error ld: failed to convert GOTPCREL relocation; relink with --no-relax.

Do you have any idea how to link my own version of calloc and free to mbedtls?