diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs index b051928ff9d3c..2c4fa8e15edf2 100644 --- a/src/libsyntax/parse/parser.rs +++ b/src/libsyntax/parse/parser.rs @@ -302,11 +302,20 @@ impl<'a> Parser<'a> { if i + 1 < tts.len() { self.tts.push((tts, i + 1)); } - if let TokenTree::Token(sp, tok) = tt { - TokenAndSpan { tok: tok, sp: sp } - } else { - self.tts.push((tt, 0)); - continue + // FIXME(jseyfried): remove after fixing #39390 in #39419. + if self.quote_depth > 0 { + if let TokenTree::Sequence(sp, _) = tt { + self.span_err(sp, "attempted to repeat an expression containing no \ + syntax variables matched as repeating at this depth"); + } + } + match tt { + TokenTree::Token(sp, tok) => TokenAndSpan { tok: tok, sp: sp }, + _ if tt.len() > 0 => { + self.tts.push((tt, 0)); + continue + } + _ => continue, } } else { TokenAndSpan { tok: token::Eof, sp: self.span } diff --git a/src/test/compile-fail/issue-39709.rs b/src/test/compile-fail/issue-39709.rs new file mode 100644 index 0000000000000..0f66fe8439336 --- /dev/null +++ b/src/test/compile-fail/issue-39709.rs @@ -0,0 +1,15 @@ +// Copyright 2017 The Rust Project Developers. See the COPYRIGHT +// file at the top-level directory of this distribution and at +// http://rust-lang.org/COPYRIGHT. +// +// Licensed under the Apache License, Version 2.0 or the MIT license +// , at your +// option. This file may not be copied, modified, or distributed +// except according to those terms. + +fn main() { + println!("{}", { macro_rules! x { ($()*) => {} } 33 }); + //~^ ERROR no syntax variables matched as repeating at this depth +} +