Rollup merge of #149151 - mu001999-contrib:test/use-path-kw, r=petrochenkov

Add test for importing path-segment keyword

Adding new test to make a snapshot of current compiler's behavior. See #146972 (comment)

r? `@petrochenkov`

Author: GuillaumeGomez

tests/ui/use/use-path-segment-kw.rs

@@ -0,0 +1,250 @@
+//@ edition: 2021
+
+macro_rules! macro_dollar_crate {
+    () => {
+        use $crate::*;
+        use $crate::{};
+
+        type A1 = $crate; //~ ERROR expected type, found module `$crate`
+        use $crate; //~ ERROR `$crate` may not be imported
+        pub use $crate as _dollar_crate; //~ ERROR `$crate` may not be imported
+
+        type A2 = ::$crate; //~ ERROR failed to resolve: global paths cannot start with `$crate`
+        use ::$crate; //~ ERROR unresolved import `$crate`
+        use ::$crate as _dollar_crate2; //~ ERROR unresolved import `$crate`
+        use ::{$crate}; //~ ERROR unresolved import `$crate`
+        use ::{$crate as _nested_dollar_crate2}; //~ ERROR unresolved import `$crate`
+
+        type A3 = foobar::$crate; //~ ERROR failed to resolve: `$crate` in paths can only be used in start position
+        use foobar::$crate; //~ ERROR unresolved import `foobar::$crate`
+        use foobar::$crate as _dollar_crate3; //~ ERROR unresolved import `foobar::$crate`
+        use foobar::{$crate}; //~ ERROR unresolved import `foobar::$crate`
+        use foobar::{$crate as _nested_dollar_crate3}; //~ ERROR unresolved import `foobar::$crate`
+
+        type A4 = crate::$crate; //~ ERROR failed to resolve: `$crate` in paths can only be used in start position
+        use crate::$crate; //~ ERROR unresolved import `crate::$crate`
+        use crate::$crate as _dollar_crate4; //~ ERROR unresolved import `crate::$crate`
+        use crate::{$crate}; //~ ERROR unresolved import `crate::$crate`
+        use crate::{$crate as _nested_dollar_crate4}; //~ ERROR unresolved import `crate::$crate`
+
+        type A5 = super::$crate; //~ ERROR failed to resolve: `$crate` in paths can only be used in start position
+        use super::$crate; //~ ERROR unresolved import `super::$crate`
+        use super::$crate as _dollar_crate5; //~ ERROR unresolved import `super::$crate`
+        use super::{$crate}; //~ ERROR unresolved import `super::$crate`
+        use super::{$crate as _nested_dollar_crate5}; //~ ERROR unresolved import `super::$crate`
+
+        type A6 = self::$crate; //~ ERROR failed to resolve: `$crate` in paths can only be used in start position
+        use self::$crate;
+        use self::$crate as _dollar_crate6;
+        use self::{$crate};
+        use self::{$crate as _nested_dollar_crate6};
+
+        type A7 = $crate::$crate; //~ ERROR failed to resolve: `$crate` in paths can only be used in start position
+        use $crate::$crate; //~ ERROR unresolved import `$crate::$crate`
+        use $crate::$crate as _dollar_crate7; //~ ERROR unresolved import `$crate::$crate`
+        use $crate::{$crate}; //~ ERROR unresolved import `$crate::$crate`
+        use $crate::{$crate as _nested_dollar_crate7}; //~ ERROR unresolved import `$crate::$crate`
+
+        type A8 = $crate::crate; //~ ERROR failed to resolve: `crate` in paths can only be used in start position
+        use $crate::crate; //~ ERROR unresolved import `$crate::crate`
+        //~^ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        use $crate::crate as _m_crate8; //~ ERROR unresolved import `$crate::crate`
+        use $crate::{crate}; //~ ERROR unresolved import `$crate::crate`
+        //~^ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        use $crate::{crate as _m_nested_crate8}; //~ ERROR unresolved import `$crate::crate`
+
+        type A9 = $crate::super; //~ ERROR failed to resolve: `super` in paths can only be used in start position
+        use $crate::super; //~ ERROR unresolved import `$crate::super`
+        use $crate::super as _m_super8; //~ ERROR unresolved import `$crate::super`
+        use $crate::{super}; //~ ERROR unresolved import `$crate::super`
+        use $crate::{super as _m_nested_super8}; //~ ERROR unresolved import `$crate::super`
+
+        type A10 = $crate::self; //~ ERROR failed to resolve: `self` in paths can only be used in start position
+        use $crate::self; //~ ERROR `$crate` may not be imported
+        //~^ ERROR `self` imports are only allowed within a { } list
+        //~^^ ERROR the name `<!dummy!>` is defined multiple times
+        pub use $crate::self as _m_self8; //~ ERROR `self` imports are only allowed within a { } list
+        //~^ ERROR `$crate` may not be imported
+        use $crate::{self};
+        //~^ ERROR the name `$crate` is defined multiple times
+        pub use $crate::{self as _m_nested_self8}; // Good
+    }
+}
+
+fn outer() {}
+
+mod foo {
+    pub mod bar {
+        pub mod foobar {
+            pub mod qux {
+                pub use super::inner;
+            }
+
+            pub mod baz {
+                pub use super::inner;
+            }
+
+            pub fn inner() {}
+        }
+
+        // --- $crate ---
+        macro_dollar_crate!();
+
+        // --- crate ---
+        use crate::*;
+        use crate::{};
+
+        type B1 = crate; //~ ERROR expected type, found module `crate`
+        use crate; //~ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        pub use crate as _crate; // Good
+
+        type B2 = ::crate; //~ ERROR failed to resolve: global paths cannot start with `crate`
+        use ::crate; //~ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        //~^ ERROR unresolved import `crate`
+        use ::crate as _crate2; //~ ERROR unresolved import `crate`
+        use ::{crate}; //~ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        //~^ ERROR unresolved import `crate`
+        use ::{crate as _nested_crate2}; //~ ERROR unresolved import `crate`
+
+        type B3 = foobar::crate; //~ ERROR failed to resolve: `crate` in paths can only be used in start position
+        use foobar::crate; //~ ERROR unresolved import `foobar::crate`
+        //~^ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        use foobar::crate as _crate3; //~ ERROR unresolved import `foobar::crate`
+        use foobar::{crate}; //~ ERROR unresolved import `foobar::crate`
+        //~^ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        use foobar::{crate as _nested_crate3}; //~ ERROR unresolved import `foobar::crate`
+
+        type B4 = crate::crate; //~ ERROR failed to resolve: `crate` in paths can only be used in start position
+        use crate::crate; //~ ERROR unresolved import `crate::crate`
+        //~^ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        use crate::crate as _crate4; //~ ERROR unresolved import `crate::crate`
+        use crate::{crate}; //~ ERROR unresolved import `crate::crate`
+        //~^ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        use crate::{crate as _nested_crate4}; //~ ERROR unresolved import `crate::crate`
+
+        type B5 = super::crate; //~ ERROR failed to resolve: `crate` in paths can only be used in start position
+        use super::crate; //~ ERROR unresolved import `super::crate`
+        //~^ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        use super::crate as _crate5; //~ ERROR unresolved import `super::crate`
+        use super::{crate}; //~ ERROR unresolved import `super::crate`
+        //~^ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        use super::{crate as _nested_crate5}; //~ ERROR unresolved import `super::crate`
+
+        type B6 = self::crate; //~ ERROR failed to resolve: `crate` in paths can only be used in start position
+        use self::crate; //~ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        //~^ ERROR the name `crate` is defined multiple times
+        use self::crate as _crate6;
+        use self::{crate}; //~ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        //~^ ERROR the name `crate` is defined multiple times
+        use self::{crate as _nested_crate6};
+
+        // --- super ---
+        use super::*;
+        use super::{}; //~ ERROR unresolved import `super`
+
+        type C1 = super; //~ ERROR expected type, found module `super`
+        use super; //~ ERROR unresolved import `super`
+        pub use super as _super; //~ ERROR unresolved import `super`
+
+        type C2 = ::super; //~ ERROR failed to resolve: global paths cannot start with `super`
+        use ::super; //~ ERROR unresolved import `super`
+        use ::super as _super2; //~ ERROR unresolved import `super`
+        use ::{super}; //~ ERROR unresolved import `super`
+        use ::{super as _nested_super2}; //~ ERROR unresolved import `super`
+
+        type C3 = foobar::super; //~ ERROR failed to resolve: `super` in paths can only be used in start position
+        use foobar::super; //~ ERROR unresolved import `foobar::super`
+        use foobar::super as _super3; //~ ERROR unresolved import `foobar::super`
+        use foobar::{super}; //~ ERROR unresolved import `foobar::super`
+        use foobar::{super as _nested_super3}; //~ ERROR unresolved import `foobar::super`
+
+        type C4 = crate::super; //~ ERROR failed to resolve: `super` in paths can only be used in start position
+        use crate::super; //~ ERROR unresolved import `crate::super`
+        use crate::super as _super4; //~ ERROR unresolved import `crate::super`
+        use crate::{super}; //~ ERROR unresolved import `crate::super`
+        use crate::{super as _nested_super4}; //~ ERROR unresolved import `crate::super`
+
+        type C5 = super::super; //~ ERROR expected type, found module `super::super`
+        use super::super; //~ ERROR unresolved import `super::super`
+        pub use super::super as _super5; //~ ERROR unresolved import `super::super`
+        use super::{super}; //~ ERROR unresolved import `super::super`
+        pub use super::{super as _nested_super5}; //~ ERROR unresolved import `super::super`
+
+        type C6 = self::super; //~ ERROR expected type, found module `self::super`
+        use self::super;
+        use self::super as _super6;
+        use self::{super};
+        use self::{super as _nested_super6};
+
+        // --- self ---
+        // use self::*; // Suppress other errors
+        use self::{}; //~ ERROR unresolved import `self`
+
+        type D1 = self; //~ ERROR expected type, found module `self`
+        use self; //~ ERROR `self` imports are only allowed within a { } list
+        pub use self as _self; //~ ERROR `self` imports are only allowed within a { } list
+
+        type D2 = ::self; //~ ERROR failed to resolve: global paths cannot start with `self`
+        use ::self; //~ ERROR `self` imports are only allowed within a { } list
+        //~^ ERROR unresolved import `{{root}}`
+        use ::self as _self2; //~ ERROR `self` imports are only allowed within a { } list
+        //~^ ERROR unresolved import `{{root}}`
+        use ::{self}; //~ ERROR `self` import can only appear in an import list with a non-empty prefix
+        use ::{self as _nested_self2}; //~ ERROR `self` import can only appear in an import list with a non-empty prefix
+
+        type D3 = foobar::self; //~ ERROR failed to resolve: `self` in paths can only be used in start position
+        pub use foobar::qux::self; //~ ERROR `self` imports are only allowed within a { } list
+        pub use foobar::self as _self3; //~ ERROR `self` imports are only allowed within a { } list
+        pub use foobar::baz::{self}; // Good
+        pub use foobar::{self as _nested_self3}; // Good
+
+        type D4 = crate::self; //~ ERROR failed to resolve: `self` in paths can only be used in start position
+        use crate::self; //~ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        //~^ ERROR `self` imports are only allowed within a { } list
+        //~^^ ERROR the name `crate` is defined multiple times
+        pub use crate::self as _self4; //~ ERROR `self` imports are only allowed within a { } list
+        use crate::{self}; //~ ERROR crate root imports need to be explicitly named: `use crate as name;`
+        //~^ ERROR the name `crate` is defined multiple times
+        pub use crate::{self as _nested_self4}; // Good
+
+        type D5 = super::self; //~ ERROR failed to resolve: `self` in paths can only be used in start position
+        use super::self; //~ ERROR unresolved import `super`
+        //~^ ERROR `self` imports are only allowed within a { } list
+        pub use super::self as _self5; //~ ERROR `self` imports are only allowed within a { } list
+        //~^ ERROR unresolved import `super`
+        use super::{self}; //~ ERROR unresolved import `super`
+        pub use super::{self as _nested_self5}; //~ ERROR unresolved import `super`
+
+        type D6 = self::self; //~ ERROR failed to resolve: `self` in paths can only be used in start position
+        use self::self; //~ ERROR `self` imports are only allowed within a { } list
+        pub use self::self as _self6; //~ ERROR `self` imports are only allowed within a { } list
+        use self::{self}; //~ ERROR unresolved import `self`
+        pub use self::{self as _nested_self6}; //~ ERROR unresolved import `self`
+    }
+}
+
+fn main() {
+    foo::bar::_dollar_crate::outer();
+    foo::bar::_m_self8::outer();
+    foo::bar::_dollar_crate::foo::bar::foobar::inner();
+    foo::bar::_m_self8::foo::bar::foobar::inner();
+
+    foo::bar::_crate::outer();
+    foo::bar::_crate::foo::bar::foobar::inner();
+
+    foo::bar::_super::bar::foobar::inner();
+    foo::bar::_super5::outer();
+    foo::bar::_nested_super5::outer();
+
+    foo::bar::_self::foobar::inner();
+    foo::bar::qux::inner(); // Works after recovery
+    foo::bar::baz::inner();
+    foo::bar::_self3::inner(); // Works after recovery
+    foo::bar::_nested_self3::inner();
+    foo::bar::_self4::outer(); // Works after recovery
+    foo::bar::_nested_self4::outer();
+    foo::bar::_self5::bar::foobar::inner(); // Works after recovery
+    foo::bar::_nested_self5::bar::foobar::inner();
+    foo::bar::_self6::foobar::inner(); // Works after recovery
+    foo::bar::_nested_self6::foobar::inner();
+}