Apply borrowck to fns that appear in const declarations.

Fixes #22382.

Author: nikomatsakis

src/librustc_borrowck/borrowck/mod.rs

@@ -105,10 +105,10 @@ fn borrowck_item(this: &mut BorrowckCtxt, item: &ast::Item) {
         ast::ItemConst(_, ref ex) => {
             gather_loans::gather_loans_in_static_initializer(this, &**ex);
         }
-        _ => {
-            visit::walk_item(this, item);
-        }
+        _ => { }
     }
+
+    visit::walk_item(this, item);
 }
 
 /// Collection of conclusions determined via borrow checker analyses.

src/test/compile-fail/borrowck-fn-in-const-a.rs

@@ -0,0 +1,22 @@
+// Copyright 2014 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.
+
+// Check that we check fns appearing in constant declarations.
+// Issue #22382.
+
+const MOVE: fn(&String) -> String = {
+    fn broken(x: &String) -> String {
+        return *x //~ ERROR cannot move
+    }
+    broken
+};
+
+fn main() {
+}

src/test/compile-fail/borrowck-fn-in-const-b.rs

@@ -0,0 +1,24 @@
+// Copyright 2014 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.
+
+// Check that we check fns appearing in constant declarations.
+// Issue #22382.
+
+// How about mutating an immutable vector?
+const MUTATE: fn(&Vec<String>) = {
+    fn broken(x: &Vec<String>) {
+        x.push(format!("this is broken"));
+        //~^ ERROR cannot borrow
+    }
+    broken
+};
+
+fn main() {
+}

src/test/compile-fail/borrowck-fn-in-const-c.rs

@@ -0,0 +1,33 @@
+// Copyright 2014 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.
+
+// Check that we check fns appearing in constant declarations.
+// Issue #22382.
+
+// Returning local references?
+struct DropString {
+    inner: String
+}
+impl Drop for DropString {
+    fn drop(&mut self) {
+        self.inner.clear();
+        self.inner.push_str("dropped");
+    }
+}
+const LOCAL_REF: fn() -> &'static str = {
+    fn broken() -> &'static str {
+        let local = DropString { inner: format!("Some local string") };
+        return &local.inner; //~ ERROR does not live long enough
+    }
+    broken
+};
+
+fn main() {
+}