// force-host // no-prefer-dynamic // ignore-tidy-linelength #![feature(proc_macro_quote)] #![crate_type = "proc-macro"] extern crate proc_macro; use std::str::FromStr; use proc_macro::*; #[proc_macro] pub fn custom_quote(input: TokenStream) -> TokenStream { let mut tokens: Vec<_> = input.into_iter().collect(); assert_eq!(tokens.len(), 1, "Unexpected input: {:?}", tokens); match tokens.pop() { Some(TokenTree::Ident(ident)) => { assert_eq!(ident.to_string(), "my_ident"); let proc_macro_crate = TokenStream::from_str("::proc_macro").unwrap(); let quoted_span = proc_macro::quote_span(proc_macro_crate, ident.span()); let prefix = TokenStream::from_str(r#"let mut ident = proc_macro::Ident::new("my_ident", proc_macro::Span::call_site());"#).unwrap(); let set_span_method = TokenStream::from_str("ident.set_span").unwrap(); let set_span_arg = TokenStream::from(TokenTree::Group(Group::new(Delimiter::Parenthesis, quoted_span))); let suffix = TokenStream::from_str(";proc_macro::TokenStream::from(proc_macro::TokenTree::Ident(ident))").unwrap(); let full_stream: TokenStream = std::array::IntoIter::new([prefix, set_span_method, set_span_arg, suffix]).collect(); full_stream } _ => unreachable!() } }