2 use rustc_ast::tokenstream::TokenStream;
3 use rustc_expand::base::{self, DummyResult};
4 use rustc_span::symbol::Symbol;
6 use std::string::String;
9 cx: &mut base::ExtCtxt<'_>,
12 ) -> Box<dyn base::MacResult + 'static> {
13 let Some(es) = base::get_exprs_from_tts(cx, sp, tts) else {
14 return DummyResult::any(sp);
16 let mut accumulator = String::new();
17 let mut missing_literal = vec![];
18 let mut has_errors = false;
21 ast::ExprKind::Lit(ref lit) => match lit.kind {
22 ast::LitKind::Str(ref s, _) | ast::LitKind::Float(ref s, _) => {
23 accumulator.push_str(s.as_str());
25 ast::LitKind::Char(c) => {
30 ast::LitIntType::Unsigned(_)
31 | ast::LitIntType::Signed(_)
32 | ast::LitIntType::Unsuffixed,
34 accumulator.push_str(&i.to_string());
36 ast::LitKind::Bool(b) => {
37 accumulator.push_str(&b.to_string());
39 ast::LitKind::Byte(..) | ast::LitKind::ByteStr(..) => {
40 cx.span_err(e.span, "cannot concatenate a byte string literal");
42 ast::LitKind::Err(_) => {
46 ast::ExprKind::Err => {
50 missing_literal.push(e.span);
54 if !missing_literal.is_empty() {
55 let mut err = cx.struct_span_err(missing_literal, "expected a literal");
56 err.note("only literals (like `\"foo\"`, `42` and `3.14`) can be passed to `concat!()`");
58 return DummyResult::any(sp);
59 } else if has_errors {
60 return DummyResult::any(sp);
62 let sp = cx.with_def_site_ctxt(sp);
63 base::MacEager::expr(cx.expr_str(sp, Symbol::intern(&accumulator)))