pub const FormValue = union(enum) {
    addr: u64,
    addrx: usize,
    block: []const u8,
    udata: u64,
    data16: *const [16]u8,
    sdata: i64,
    exprloc: []const u8,
    flag: bool,
    sec_offset: u64,
    ref: u64,
    ref_addr: u64,
    string: [:0]const u8,
    strp: u64,
    strx: usize,
    line_strp: u64,
    loclistx: u64,
    rnglistx: u64,

    fn getString(fv: FormValue, di: Dwarf) ![:0]const u8 {
        switch (fv) {
            .string => |s| return s,
            .strp => |off| return di.getString(off),
            .line_strp => |off| return di.getLineString(off),
            else => return bad(),
        }
    }

    fn getUInt(fv: FormValue, comptime U: type) !U {
        return switch (fv) {
            inline .udata,
            .sdata,
            .sec_offset,
            => |c| cast(U, c) orelse bad(),
            else => bad(),
        };
    }
}