rust/tests/ui/macros/cross-crate-pat-span.rs

//@ edition:2021
//@ check-pass
//@ aux-build: foreign-crate-macro-pat.rs
//
// Tests that the edition of the foreign crate is used
// when determining the behavior of the `:pat` matcher.

extern crate foreign_crate_macro_pat;

fn main() {
    let _b = foreign_crate_macro_pat::custom_matches!(b'3', b'0' ..= b'9');
}
Use correct edition when parsing `:pat` matchers As described in issue #85708, we currently do not properly decode `SyntaxContext::root()` and `ExpnId::root()` from foreign crates. As a result, when we decode a span from a foreign crate with `SyntaxContext::root()`, we end up up considering it to have the edition of the current crate, instead of the foreign crate where it was originally created. A full fix for this issue will be a fairly significant undertaking. Fortunately, it's possible to implement a partial fix, which gives us the correct edition-dependent behavior for `:pat` matchers when the macro is loaded from another crate. Since we have the edition of the macro's defining crate available, we can 'recover' from seeing a `SyntaxContext::root()` and use the edition of the macro's defining crate. Any solution to issue #85708 must reproduce the behavior of this targeted fix - properly preserving a foreign `SyntaxContext::root()` means (among other things) preserving its edition, which by definition is the edition of the foreign crate itself. Therefore, this fix moves us closer to the correct overall solution, and does not expose any new incorrect behavior to macros. 2021-05-26 03:58:42 +00:00			`//@ edition:2021`
			`//@ check-pass`
			`//@ aux-build: foreign-crate-macro-pat.rs`
			`//`
			`// Tests that the edition of the foreign crate is used`
			// when determining the behavior of the `:pat` matcher.

			`extern crate foreign_crate_macro_pat;`

			`fn main() {`
			`let _b = foreign_crate_macro_pat::custom_matches!(b'3', b'0' ..= b'9');`
			`}`