rust/src/test/compile-fail/issue-43250.rs
Ariel Ben-Yehuda a2adb7db68 ast_validation: forbid "nonstandard" literal patterns
Since #42886, macros can create "nonstandard" PatKind::Lit patterns,
that contain path expressions instead of the usual literal expr. These
can cause trouble, including ICEs.

We *could* map these nonstandard patterns to PatKind::Path patterns
during HIR lowering, but that would be much effort for little gain, and
I think is too risky for beta. So let's just forbid them during AST
validation.

Fixes #43250.
2017-08-13 18:35:44 +03:00

24 lines
752 B
Rust

// 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 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
fn main() {
let mut y;
const C: u32 = 0;
macro_rules! m {
($a:expr) => {
let $a = 0;
}
}
m!(y);
//~^ ERROR arbitrary expressions aren't allowed in patterns
m!(C);
//~^ ERROR arbitrary expressions aren't allowed in patterns
}