2 use rustc_ast::tokenstream::TokenStream;
3 use rustc_expand::base::{self, DummyResult};
4 use rustc_session::errors::report_lit_error;
5 use rustc_span::symbol::Symbol;
7 use std::string::String;
10 cx: &mut base::ExtCtxt<'_>,
13 ) -> Box<dyn base::MacResult + 'static> {
14 let Some(es) = base::get_exprs_from_tts(cx, sp, tts) else {
15 return DummyResult::any(sp);
17 let mut accumulator = String::new();
18 let mut missing_literal = vec![];
19 let mut has_errors = false;
22 ast::ExprKind::Lit(token_lit) => match ast::LitKind::from_token_lit(token_lit) {
23 Ok(ast::LitKind::Str(ref s, _) | ast::LitKind::Float(ref s, _)) => {
24 accumulator.push_str(s.as_str());
26 Ok(ast::LitKind::Char(c)) => {
29 Ok(ast::LitKind::Int(i, _)) => {
30 accumulator.push_str(&i.to_string());
32 Ok(ast::LitKind::Bool(b)) => {
33 accumulator.push_str(&b.to_string());
35 Ok(ast::LitKind::Byte(..) | ast::LitKind::ByteStr(..)) => {
36 cx.span_err(e.span, "cannot concatenate a byte string literal");
39 Ok(ast::LitKind::Err) => {
43 report_lit_error(&cx.sess.parse_sess, err, token_lit, e.span);
47 ast::ExprKind::IncludedBytes(..) => {
48 cx.span_err(e.span, "cannot concatenate a byte string literal")
50 ast::ExprKind::Err => {
54 missing_literal.push(e.span);
58 if !missing_literal.is_empty() {
59 let mut err = cx.struct_span_err(missing_literal, "expected a literal");
60 err.note("only literals (like `\"foo\"`, `42` and `3.14`) can be passed to `concat!()`");
62 return DummyResult::any(sp);
63 } else if has_errors {
64 return DummyResult::any(sp);
66 let sp = cx.with_def_site_ctxt(sp);
67 base::MacEager::expr(cx.expr_str(sp, Symbol::intern(&accumulator)))