Disallow forbidden usage of non-ascii identifiers.

src/test/ui/rfc-2457/auxiliary/mod_file_nonascii_with_path_allowed-aux.rs

@@ -0,0 +1 @@
+pub trait Foo {}

src/test/ui/rfc-2457/mod_file_nonascii_forbidden.rs

@@ -0,0 +1,6 @@
+#![feature(non_ascii_idents)]
+
+mod řųśť; //~ trying to load file for
+//~^ file not found for
+
+fn main() {}

src/test/ui/rfc-2457/mod_file_nonascii_forbidden.stderr

@@ -0,0 +1,20 @@
+error[E0583]: file not found for module `řųśť`
+  --> $DIR/mod_file_nonascii_forbidden.rs:3:1
+   |
+LL | mod řųśť;
+   | ^^^^^^^^^
+   |
+   = help: to create the module `řųśť`, create file "$DIR/řųśť.rs"
+
+error[E0754]: trying to load file for module `řųśť` with non ascii identifer name
+  --> $DIR/mod_file_nonascii_forbidden.rs:3:5
+   |
+LL | mod řųśť;
+   |     ^^^^
+   |
+   = help: consider using `#[path]` attribute to specify filesystem path
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0583, E0754.
+For more information about an error, try `rustc --explain E0583`.

src/test/ui/rfc-2457/mod_file_nonascii_with_path_allowed.rs

@@ -0,0 +1,7 @@
+// check-pass
+#![feature(non_ascii_idents)]
+
+#[path="auxiliary/mod_file_nonascii_with_path_allowed-aux.rs"]
+mod řųśť;
+
+fn main() {}

src/test/ui/rfc-2457/mod_inline_nonascii_allowed.rs

@@ -0,0 +1,8 @@
+// check-pass
+#![feature(non_ascii_idents)]
+
+mod řųśť {
+    const IS_GREAT: bool = true;
+}
+
+fn main() {}

src/test/ui/rfc-2457/no_mangle_nonascii_forbidden.rs

@@ -0,0 +1,6 @@
+#![feature(non_ascii_idents)]
+
+#[no_mangle]
+pub fn řųśť() {}  //~ `#[no_mangle]` requires ASCII identifier
+
+fn main() {}

src/test/ui/rfc-2457/no_mangle_nonascii_forbidden.stderr

@@ -0,0 +1,9 @@
+error[E0754]: `#[no_mangle]` requires ASCII identifier
+  --> $DIR/no_mangle_nonascii_forbidden.rs:4:1
+   |
+LL | pub fn řųśť() {}
+   | ^^^^^^^^^^^^^
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0754`.