rust/tests/ui/rfcs/rfc-2497-if-let-chains/avoid-invalid-mir.rs

// Regression test for #104172

const N: usize = {
    struct U;
    !let y = 42;
    //~^ ERROR expected expression, found `let` statement
    3
};

struct S {
    x: [(); N]
}

fn main() {}
Don't create drop scopes after item statements These scopes would not exist in MIR and can cause ICEs with invalid uses of let expressions. 2023-09-06 12:52:34 +00:00			`// Regression test for #104172`

			`const N: usize = {`
			`struct U;`
			`!let y = 42;`
			//~^ ERROR expected expression, found `let` statement
			`3`
			`};`

			`struct S {`
			`x: [(); N]`
			`}`

Move let expression checking to parsing 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. 2023-09-08 10:14:36 +00:00			`fn main() {}`