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#![allow(dead_code)]
#![allow(unused_macros)]
extern crate proc_macro;
#[cfg(feature = "debug")]
macro_rules! proc_dbg {
($x:expr) => {
dbg!($x)
};
}
#[cfg(not(feature = "debug"))]
macro_rules! proc_dbg {
($x:expr) => {};
}
struct Tokens {
expr: syn::Expr,
}
impl syn::parse::Parse for Tokens {
fn parse(input: syn::parse::ParseStream) -> syn::Result<Self> {
Ok(Tokens {
expr: input.parse()?,
})
}
}
#[proc_macro]
#[cfg(not(test))]
pub fn main(stream: proc_macro::TokenStream) -> proc_macro::TokenStream {
let Tokens { expr } = syn::parse_macro_input!(stream as Tokens);
proc_dbg!(&expr);
const ARG_PANIC_TEXT: &str =
"expected ident lexical path (or a literal string version) to 'uumain()' as argument";
let mut expr = match expr {
syn::Expr::Lit(expr_lit) => match expr_lit.lit {
syn::Lit::Str(ref lit_str) => lit_str.parse::<syn::ExprPath>().unwrap(),
_ => panic!(ARG_PANIC_TEXT),
},
syn::Expr::Path(expr_path) => expr_path,
_ => panic!(ARG_PANIC_TEXT),
};
proc_dbg!(&expr);
if expr.path.segments.len() < 2 {
expr = syn::parse_quote!( #expr::uumain );
};
proc_dbg!(&expr);
let f = quote::quote! { #expr(uucore::args().collect()) };
proc_dbg!(&f);
let result = quote::quote! {
fn main() {
use std::io::Write;
uucore::panic::mute_sigpipe_panic();
let code = #f;
std::io::stdout().flush().expect("could not flush stdout");
std::process::exit(code);
}
};
proc_macro::TokenStream::from(result)
}