You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: elf.rs
    path of file: ./repos/core-os-riscv/kernel/src
    
    the code of the file until where you have to start completion: // Copyright (c) 2020 Alex Chi
//
// This software is released under the MIT License.
// https://opensource.org/licenses/MIT

//! ELF parsing

use crate::panic;
use crate::mem;
use crate::arch;
use crate::page;
use crate::process;
use crate::symbols::*;
use crate::{info, println};

#[repr(C)]
pub struct 
    
pub fn parse_elf(a: &[u8], pgtable: &mut page::Table) -> u64 {
    let a = a.as_ptr();
    /* TODO: Use something safer */
    // peek head of byte array to get ELF information
    let elfhdr = unsafe { &*(a as *const ELFHeader) };
    if elfhdr.magic != ELF_MAGIC {
        panic!("wrong magic number");
    }
    let mut proghdr = unsafe {
        let offset_u8 = a.offset(elfhdr.phoff as isize);
        offset_u8 as *const ProgramHeader
    };
    for _i in 0..elfhdr.phnum {
        let hdr: &ProgramHeader = unsafe {
            let hdr = &*proghdr;
            proghdr = proghdr.offset(1);
            hdr
        };
        if hdr.ptype != ELF_PROG_LOAD {
            continue;
        }
        if hdr.memsz < hdr.filesz {
            panic!("bad elf: memsz");
        }
        if hdr.vaddr + hdr.memsz < hdr.vaddr {
            panic!("bad elf: vaddr");
        }
        if hdr.vaddr as usize % PAGE_SIZE != 0 {
            println!("{:X}", hdr.vaddr);
            panic!("bad elf: vaddr align")
        }
        load_segment(
            pgtable,
            hdr.vaddr as usize,
            a,
            hdr.off as usize,
            hdr.filesz as usize,
        );
        /* println!(
            "map segment ELF 0x{:X}~0x{:X} -> MEM 0x{:X}",
            hdr.off,
            hdr.off + hdr.filesz,
            hdr.vaddr
        ); */
    }
    elfhdr.entry
}