Accessing global static values from modules

help
#1

Following the rust book, I have migrated all the logic of my app into lib.rs, with the main.rs calling the lib.rs run, parsing a command line struct, like so.

main.rs

use std::process;
#[macro_use]
extern crate log;
use structopt::StructOpt;

#[derive(StructOpt, Debug)]
pub struct CliOpt {
    #[structopt(short = "c", long = "config-file", parse(from_os_str))]
    config_file_path: std::path::PathBuf,
}

lazy_static! {
    pub static ref CFG: CliOpt = CliOpt::from_args();
}

fn main() {
    if let Err(err) = mylib::run() {
        error!("{}", err);
        process::exit(1);
    }
}

How do I make this global static variable CFG declared in main.rs to be accessible in other parts of the program (like lib.rs) ?

I've tried a few things: Using crate::CFG only works if I place the lazy_static! block inside the lib.rs file. That creates a different set of problems (like how to define and run tests).

Alternately, I could pass CFG as a parameter to mylib::run() -- which also works, but I'd prefer to have CFG as a global to simplify access and simplify function signatures.

Any help would be appreciated. Any other design to share global configuration values would also be appreciated!

#2

The lib.rs file cannot access stuff in main.rs. You should think of main.rs as a separate crate from lib.rs, that has a dependency on lib.rs, and you can't have dependency cycles in Rust.