Adds support for immovable generators. Move checking of invalid borrows across suspension points to borrowck. Fixes #44197, #45259 and #45093.

src/test/ui/generator/auto-trait-regions.rs

@@ -0,0 +1,58 @@
+// 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)]
+#![feature(optin_builtin_traits)]
+
+auto trait Foo {}
+
+struct No;
+
+impl !Foo for No {}
+
+struct A<'a, 'b>(&'a mut bool, &'b mut bool, No);
+
+impl<'a, 'b: 'a> Foo for A<'a, 'b> {}
+
+struct OnlyFooIfStaticRef(No);
+impl Foo for &'static OnlyFooIfStaticRef {}
+
+struct OnlyFooIfRef(No);
+impl<'a> Foo for &'a OnlyFooIfRef {}
+
+fn assert_foo<T: Foo>(f: T) {}
+
+fn main() {
+    // Make sure 'static is erased for generator interiors so we can't match it in trait selection
+    let x: &'static _ = &OnlyFooIfStaticRef(No);
+    let gen = || {
+        let x = x;
+        yield;
+        assert_foo(x);
+    };
+    assert_foo(gen); //~ ERROR the trait bound `No: Foo` is not satisfied
+
+    // Allow impls which matches any lifetime
+    let x = &OnlyFooIfRef(No);
+    let gen = || {
+        let x = x;
+        yield;
+        assert_foo(x);
+    };
+    assert_foo(gen); // ok
+
+    // Disallow impls which relates lifetimes in the generator interior
+    let gen = || {
+        let a = A(&mut true, &mut true, No);
+        yield;
+        assert_foo(a);
+    };
+    assert_foo(gen); //~ ERROR the requirement `for<'r, 's> 'r : 's` is not satisfied
+}

src/test/ui/generator/auto-trait-regions.stderr

@@ -0,0 +1,35 @@
+error[E0277]: the trait bound `No: Foo` is not satisfied in `[generator@$DIR/auto-trait-regions.rs:35:15: 39:6 x:&&'static OnlyFooIfStaticRef for<'r> {&'r OnlyFooIfStaticRef, ()}]`
+  --> $DIR/auto-trait-regions.rs:40:5
+   |
+40 |     assert_foo(gen); //~ ERROR the trait bound `No: Foo` is not satisfied
+   |     ^^^^^^^^^^ within `[generator@$DIR/auto-trait-regions.rs:35:15: 39:6 x:&&'static OnlyFooIfStaticRef for<'r> {&'r OnlyFooIfStaticRef, ()}]`, the trait `Foo` is not implemented for `No`
+   |
+   = help: the following implementations were found:
+             <No as Foo>
+   = note: required because it appears within the type `OnlyFooIfStaticRef`
+   = note: required because it appears within the type `&OnlyFooIfStaticRef`
+   = note: required because it appears within the type `for<'r> {&'r OnlyFooIfStaticRef, ()}`
+   = note: required because it appears within the type `[generator@$DIR/auto-trait-regions.rs:35:15: 39:6 x:&&'static OnlyFooIfStaticRef for<'r> {&'r OnlyFooIfStaticRef, ()}]`
+note: required by `assert_foo`
+  --> $DIR/auto-trait-regions.rs:30:1
+   |
+30 | fn assert_foo<T: Foo>(f: T) {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0279]: the requirement `for<'r, 's> 'r : 's` is not satisfied (`expected bound lifetime parameter, found concrete lifetime`)
+  --> $DIR/auto-trait-regions.rs:57:5
+   |
+57 |     assert_foo(gen); //~ ERROR the requirement `for<'r, 's> 'r : 's` is not satisfied
+   |     ^^^^^^^^^^
+   |
+   = note: required because of the requirements on the impl of `for<'r, 's> Foo` for `A<'_, '_>`
+   = note: required because it appears within the type `for<'r, 's> {A<'r, 's>, ()}`
+   = note: required because it appears within the type `[generator@$DIR/auto-trait-regions.rs:52:15: 56:6 for<'r, 's> {A<'r, 's>, ()}]`
+note: required by `assert_foo`
+  --> $DIR/auto-trait-regions.rs:30:1
+   |
+30 | fn assert_foo<T: Foo>(f: T) {}
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 2 previous errors
+

src/test/ui/generator/not-send-sync.stderr

@@ -13,15 +13,15 @@ note: required by `main::assert_send`
 17 |     fn assert_send<T: Send>(_: T) {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error[E0277]: the trait bound `std::cell::Cell<i32>: std::marker::Sync` is not satisfied in `[generator@$DIR/not-send-sync.rs:19:17: 23:6 (std::cell::Cell<i32>, ())]`
+error[E0277]: the trait bound `std::cell::Cell<i32>: std::marker::Sync` is not satisfied in `[generator@$DIR/not-send-sync.rs:19:17: 23:6 {std::cell::Cell<i32>, ()}]`
   --> $DIR/not-send-sync.rs:19:5
    |
 19 |     assert_sync(|| {
    |     ^^^^^^^^^^^ `std::cell::Cell<i32>` cannot be shared between threads safely
    |
-   = help: within `[generator@$DIR/not-send-sync.rs:19:17: 23:6 (std::cell::Cell<i32>, ())]`, the trait `std::marker::Sync` is not implemented for `std::cell::Cell<i32>`
-   = note: required because it appears within the type `(std::cell::Cell<i32>, ())`
-   = note: required because it appears within the type `[generator@$DIR/not-send-sync.rs:19:17: 23:6 (std::cell::Cell<i32>, ())]`
+   = help: within `[generator@$DIR/not-send-sync.rs:19:17: 23:6 {std::cell::Cell<i32>, ()}]`, the trait `std::marker::Sync` is not implemented for `std::cell::Cell<i32>`
+   = note: required because it appears within the type `{std::cell::Cell<i32>, ()}`
+   = note: required because it appears within the type `[generator@$DIR/not-send-sync.rs:19:17: 23:6 {std::cell::Cell<i32>, ()}]`
 note: required by `main::assert_sync`
   --> $DIR/not-send-sync.rs:16:5
    |