Code shared from the Rust Playground

playground.rs

// lib.rs
use proc_macro::TokenStream;
use quote::quote;
use syn::{parse_macro_input, ItemFn};

#[proc_macro_attribute]
pub fn rust_decorator(_attr: TokenStream, input: TokenStream) -> TokenStream {
    let func = parse_macro_input!(input as ItemFn);
    let fn_name = &func.sig.ident;

    quote!{
        println!("aaaa");
        #fn_name();
    };
    TokenStream::from(quote!(#func))
}



// bin.rs
#[rust_decorator]
fn task(){
    println!("Task is running!!!");
}

pub fn main() {
    task();
}