const std = @import("std");
const elf = std.elf;

extern var __rela_dyn_start: u8;
extern var __rela_dyn_end: u8;

pub fn relocateSelf(base_addr: usize) callconv(.c) void {
    const rela_size = (@intFromPtr(&__rela_dyn_end) - @intFromPtr(&__rela_dyn_start)) / @sizeOf(elf.Elf64_Rela);
    const relas = @as([*]elf.Elf64_Rela, @ptrCast(@alignCast(&__rela_dyn_start)))[0..rela_size];
    for (relas) |rela| {
        const offset = rela.r_offset;
        const addend = rela.r_addend;
        // const sym_index = rela.r_info >> 32;
        const type_ = rela.r_info & 0xffffffff;
        if (type_ == @intFromEnum(elf.R_X86_64.RELATIVE)) {
            const reloc_addr: *u64 = @ptrFromInt(offset + base_addr);
            reloc_addr.* = base_addr + @as(usize, @intCast(addend));
        }
    }
}