Added some tests

src/test/compile-fail/generator/invalid-positions.rs

@@ -0,0 +1,23 @@
+// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![feature(generators)]
+
+const A: u8 = { yield 3u8; gen arg; 3u8};
+//~^ ERROR yield statement outside
+//~| ERROR gen arg expression outside
+
+static B: u8 = { yield 3u8; gen arg; 3u8};
+//~^ ERROR yield statement outside
+//~| ERROR gen arg expression outside
+
+fn main() { yield; gen arg; }
+//~^ ERROR yield statement outside
+//~| ERROR gen arg expression outside

src/test/compile-fail/generator/no-arguments-on-generators.rs

@@ -10,7 +10,8 @@
 
 #![feature(generators)]
 
-const A: u8 = { yield 3u8; 3u8}; //~ ERROR yield statement outside of function body
-static B: u8 = { yield 3u8; 3u8}; //~ ERROR yield statement outside of function body
-
-fn main() {}
+fn main() {
+    let gen = |start| { //~ ERROR generators cannot have explicit arguments
+        yield;
+    }; 
+}

src/test/run-pass/generator/implicit-argument-dead-when-suspended.rs

@@ -10,16 +10,24 @@
 
 #![feature(generators)]
 
-fn main() {
-    let mut a = Vec::<bool>::new();
+use std::cell::Cell;
 
-    let mut test = || {
-        let _: () = gen arg;
-        yield 3;
-        a.push(true);
-        2
+struct Flag<'a>(&'a Cell<bool>);
+
+impl<'a> Drop for Flag<'a> {
+    fn drop(&mut self) {
+        self.0.set(false)
+    }
+}
+
+fn main() {
+    let alive = Cell::new(true);
+
+    let gen = || {
+        yield;
     };
 
-    let a1 = test();
-    let a2 = test(); //~ ERROR use of moved value
+    gen.resume(Flag(&alive));
+
+    assert_eq!(alive.get(), false);
 }