Auto merge of #27261 - arielb1:drop-sanity-check, r=pnkfelix

This fixes multiple bugs, and as several of these are soundness issue, is a [breaking-change].

r? @pnkfelix

Author: bors

src/librustc_typeck/check/dropck.rs

@@ -174,7 +174,7 @@ pub fn regionck_ensure_component_tys_wf<'a, 'tcx>(fcx: &FnCtxt<'a, 'tcx>,
 // INTERNALS
 
 pub struct Rcx<'a, 'tcx: 'a> {
-    fcx: &'a FnCtxt<'a, 'tcx>,
+    pub fcx: &'a FnCtxt<'a, 'tcx>,
 
     region_bound_pairs: Vec<(ty::Region, GenericKind<'tcx>)>,
 

src/librustc_typeck/check/regionck.rs

@@ -0,0 +1,47 @@
+// Copyright 2015 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 dropck does the right thing with misc. Ty variants
+
+use std::fmt;
+struct NoisyDrop<T: fmt::Debug>(T);
+impl<T: fmt::Debug> Drop for NoisyDrop<T> {
+    fn drop(&mut self) {
+        let _ = vec!["0wned"];
+        println!("dropping {:?}", self.0)
+    }
+}
+
+trait Associator {
+    type As;
+}
+impl<T: fmt::Debug> Associator for T {
+    type As = NoisyDrop<T>;
+}
+struct Wrap<A: Associator>(<A as Associator>::As);
+
+fn projection() {
+    let (_w, bomb);
+    bomb = vec![""];
+    _w = Wrap::<&[&str]>(NoisyDrop(&bomb));
+    //~^ ERROR `bomb` does not live long enough
+}
+
+fn closure() {
+    let (_w,v);
+    v = vec![""];
+    _w = {
+        let u = NoisyDrop(&v);
+        //~^ ERROR `v` does not live long enough
+        move || u.0.len()
+    };
+}
+
+fn main() { closure(); projection() }

src/test/compile-fail/dropck_misc_variants.rs

@@ -0,0 +1,29 @@
+// Copyright 2015 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.
+
+pub struct Registry<'a> {
+    listener: &'a mut (),
+}
+
+pub struct Listener<'a> {
+    pub announce: Option<Box<FnMut(&mut Registry) + 'a>>,
+    pub remove: Option<Box<FnMut(&mut Registry) + 'a>>,
+}
+
+impl<'a> Drop for Registry<'a> {
+    fn drop(&mut self) {}
+}
+
+fn main() {
+    let mut registry_listener = Listener {
+        announce: None,
+        remove: None,
+    };
+}

src/test/run-pass/issue-24086.rs

@@ -0,0 +1,15 @@
+// Copyright 2015 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.
+
+struct Parser<'a>(Box<FnMut(Parser) + 'a>);
+
+fn main() {
+    let _x = Parser(Box::new(|_|{}));
+}

src/test/run-pass/issue-26641.rs

@@ -0,0 +1,33 @@
+// Copyright 2015 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.
+
+use std::fmt;
+struct NoisyDrop<T: fmt::Debug>(T);
+impl<T: fmt::Debug> Drop for NoisyDrop<T> {
+    fn drop(&mut self) {}
+}
+
+struct Bar<T: fmt::Debug>([*const NoisyDrop<T>; 2]);
+
+fn fine() {
+    let (u,b);
+    u = vec![43];
+    b = Bar([&NoisyDrop(&u), &NoisyDrop(&u)]);
+}
+
+struct Bar2<T: fmt::Debug>(*const NoisyDrop<T>, *const NoisyDrop<T>);
+
+fn lolwut() {
+    let (u,v);
+    u = vec![43];
+    v = Bar2(&NoisyDrop(&u), &NoisyDrop(&u));
+}
+
+fn main() { fine(); lolwut() }