Add tests

Author: aerooneqq

compiler/rustc_ast_lowering/src/delegation.rs

@@ -285,7 +285,7 @@ impl<'hir> LoweringContext<'_, 'hir> {
                 }
             }
 
-            // Def id is either None or is from non-local crate, fallback to the original routine.
+            // DefId is either None or is from non-local crate, fallback to the original routine.
             return self.def_id_or_guaranteed_err(def_id, node_id, span);
         }
     }

tests/ui/delegation/auxiliary/recursive-delegation-aux.rs

@@ -0,0 +1,9 @@
+#![feature(fn_delegation)]
+#![allow(incomplete_features)]
+
+fn foo() {
+
+}
+
+reuse foo as bar;
+pub reuse bar as goo;

tests/ui/delegation/recursive_delegation_errors.rs

@@ -0,0 +1,44 @@
+#![feature(fn_delegation)]
+#![allow(incomplete_features)]
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+
+mod first_mod {
+    reuse foo;
+    //~^ ERROR failed to resolve delegation callee
+}
+
+mod second_mod {
+    reuse foo as bar;
+    //~^ ERROR failed to resolve delegation callee
+    reuse bar as foo;
+    //~^ ERROR failed to resolve delegation callee
+
+}
+
+mod third_mod {
+    reuse foo as foo1;
+    //~^ ERROR failed to resolve delegation callee
+    reuse foo1 as foo2;
+    //~^ ERROR failed to resolve delegation callee
+    reuse foo2 as foo3;
+    //~^ ERROR failed to resolve delegation callee
+    reuse foo3 as foo4;
+    //~^ ERROR failed to resolve delegation callee
+    reuse foo4 as foo5;
+    //~^ ERROR failed to resolve delegation callee
+    reuse foo5 as foo;
+    //~^ ERROR failed to resolve delegation callee
+}
+
+mod fourth_mod {
+    trait Trait {
+        reuse Trait::foo as bar;
+        //~^ ERROR failed to resolve delegation callee
+        reuse Trait::bar as foo;
+        //~^ ERROR failed to resolve delegation callee
+    }
+}
+
+fn main() {}

tests/ui/delegation/recursive_delegation_errors.stderr

@@ -0,0 +1,68 @@
+error: failed to resolve delegation callee
+  --> $DIR/recursive_delegation_errors.rs:8:11
+   |
+LL |     reuse foo;
+   |           ^^^
+
+error: failed to resolve delegation callee
+  --> $DIR/recursive_delegation_errors.rs:13:11
+   |
+LL |     reuse foo as bar;
+   |           ^^^
+
+error: failed to resolve delegation callee
+  --> $DIR/recursive_delegation_errors.rs:15:11
+   |
+LL |     reuse bar as foo;
+   |           ^^^
+
+error: failed to resolve delegation callee
+  --> $DIR/recursive_delegation_errors.rs:21:11
+   |
+LL |     reuse foo as foo1;
+   |           ^^^
+
+error: failed to resolve delegation callee
+  --> $DIR/recursive_delegation_errors.rs:23:11
+   |
+LL |     reuse foo1 as foo2;
+   |           ^^^^
+
+error: failed to resolve delegation callee
+  --> $DIR/recursive_delegation_errors.rs:25:11
+   |
+LL |     reuse foo2 as foo3;
+   |           ^^^^
+
+error: failed to resolve delegation callee
+  --> $DIR/recursive_delegation_errors.rs:27:11
+   |
+LL |     reuse foo3 as foo4;
+   |           ^^^^
+
+error: failed to resolve delegation callee
+  --> $DIR/recursive_delegation_errors.rs:29:11
+   |
+LL |     reuse foo4 as foo5;
+   |           ^^^^
+
+error: failed to resolve delegation callee
+  --> $DIR/recursive_delegation_errors.rs:31:11
+   |
+LL |     reuse foo5 as foo;
+   |           ^^^^
+
+error: failed to resolve delegation callee
+  --> $DIR/recursive_delegation_errors.rs:37:22
+   |
+LL |         reuse Trait::foo as bar;
+   |                      ^^^
+
+error: failed to resolve delegation callee
+  --> $DIR/recursive_delegation_errors.rs:39:22
+   |
+LL |         reuse Trait::bar as foo;
+   |                      ^^^
+
+error: aborting due to 11 previous errors
+

tests/ui/delegation/recursive_delegation_pass.rs

@@ -0,0 +1,53 @@
+//@ run-pass
+//@ edition:2018
+//@ aux-crate:recursive_delegation_aux=recursive-delegation-aux.rs
+
+#![feature(fn_delegation)]
+#![allow(incomplete_features)]
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+extern crate recursive_delegation_aux;
+
+mod first_mod {
+    pub mod to_reuse {
+        pub fn foo(x: usize) -> usize {
+            x + 1
+        }
+    }
+
+    reuse to_reuse::foo;
+    reuse foo as bar;
+    reuse foo as bar1;
+    reuse bar as goo;
+    reuse goo as koo;
+    reuse koo as too;
+}
+
+mod second_mod {
+    trait T {
+        fn foo(&self);
+        reuse T::foo as bar;
+        reuse T::bar as goo;
+        reuse T::goo as poo;
+    }
+}
+
+mod third_mod {
+    reuse crate::first_mod::to_reuse::foo {
+        reuse foo as bar {
+            reuse bar as goo {
+                bar(123)
+            }
+
+            goo(123)
+        }(123)
+    }
+}
+
+mod fourth_mod {
+    reuse recursive_delegation_aux::goo as bar;
+    reuse bar as foo;
+}
+
+fn main() {}