333388fd3c
There was an incomplete version of the check in parsing and a second version in AST validation. This meant that some, but not all, invalid uses were allowed inside macros/disabled cfgs. It also means that later passes have a hard time knowing when the let expression is in a valid location, sometimes causing ICEs. - Add a field to ExprKind::Let in AST/HIR to mark whether it's in a valid location. - Suppress later errors and MIR construction for invalid let expressions.
61 lines
1.6 KiB
Rust
61 lines
1.6 KiB
Rust
// gate-test-let_chains
|
||
|
||
// Here we test feature gating for ´let_chains`.
|
||
// See `disallowed-positions.rs` for the grammar
|
||
// defining the language for gated allowed positions.
|
||
|
||
#![allow(irrefutable_let_patterns)]
|
||
|
||
use std::ops::Range;
|
||
|
||
fn _if() {
|
||
if let 0 = 1 {} // Stable!
|
||
|
||
if true && let 0 = 1 {}
|
||
//~^ ERROR `let` expressions in this position are unstable [E0658]
|
||
|
||
if let 0 = 1 && true {}
|
||
//~^ ERROR `let` expressions in this position are unstable [E0658]
|
||
|
||
if let Range { start: _, end: _ } = (true..true) && false {}
|
||
//~^ ERROR `let` expressions in this position are unstable [E0658]
|
||
|
||
if let 1 = 1 && let true = { true } && false {
|
||
//~^ ERROR `let` expressions in this position are unstable [E0658]
|
||
//~| ERROR `let` expressions in this position are unstable [E0658]
|
||
}
|
||
}
|
||
|
||
fn _while() {
|
||
while let 0 = 1 {} // Stable!
|
||
|
||
while true && let 0 = 1 {}
|
||
//~^ ERROR `let` expressions in this position are unstable [E0658]
|
||
|
||
while let 0 = 1 && true {}
|
||
//~^ ERROR `let` expressions in this position are unstable [E0658]
|
||
|
||
while let Range { start: _, end: _ } = (true..true) && false {}
|
||
//~^ ERROR `let` expressions in this position are unstable [E0658]
|
||
}
|
||
|
||
fn _macros() {
|
||
macro_rules! noop_expr { ($e:expr) => {}; }
|
||
|
||
noop_expr!((let 0 = 1));
|
||
//~^ ERROR expected expression, found `let` statement
|
||
|
||
macro_rules! use_expr {
|
||
($e:expr) => {
|
||
if $e {}
|
||
while $e {}
|
||
}
|
||
}
|
||
#[cfg(FALSE)] (let 0 = 1);
|
||
//~^ ERROR expected expression, found `let` statement
|
||
use_expr!(let 0 = 1);
|
||
//~^ ERROR no rules expected the token `let`
|
||
}
|
||
|
||
fn main() {}
|