Rollup merge of rust-lang#55801 - pnkfelix:update-box-insensitivity-t…

…est-for-nll, r=davidtwco

NLL: Update box insensitivity test

This is just keeping one of our tests honest with respect to NLL, in two ways:

 1. Adds uses of borrows that would otherwise be too short to observe the error that we would have expected to see...
 2. ... I say "would have expected" because all of the errors in this file are part of the reversion of rust-lang/rfcs#130 that is attached to NLL (you can see more discussion of this here rust-lang#43234 (comment) )

src/test/ui/borrowck/borrowck-box-insensitivity.stderr → src/test/ui/borrowck/borrowck-box-insensitivity.ast.stderr

@@ -3,8 +3,8 @@ error[E0382]: use of moved value: `a`
    |
 LL |     let _x = a.x;
    |         -- value moved here
-LL |     //~^ value moved here
-LL |     let _y = a.y; //~ ERROR use of moved
+LL |     //[ast]~^ value moved here
+LL |     let _y = a.y; //[ast]~ ERROR use of moved
    |         ^^ value used here after move
    |
    = note: move occurs because `a.x` has type `std::boxed::Box<isize>`, which does not implement the `Copy` trait
@@ -14,8 +14,8 @@ error[E0382]: use of moved value: `a`
    |
 LL |     let _x = a.x;
    |         -- value moved here
-LL |     //~^ value moved here
-LL |     let _y = a.y; //~ ERROR use of moved
+LL |     //[ast]~^ value moved here
+LL |     let _y = a.y; //[ast]~ ERROR use of moved
    |         ^^ value used here after move
    |
    = note: move occurs because `a.x` has type `std::boxed::Box<isize>`, which does not implement the `Copy` trait
@@ -25,8 +25,8 @@ error[E0382]: use of moved value: `a`
    |
 LL |     let _x = a.x;
    |         -- value moved here
-LL |     //~^ value moved here
-LL |     let _y = &a.y; //~ ERROR use of moved
+LL |     //[ast]~^ value moved here
+LL |     let _y = &a.y; //[ast]~ ERROR use of moved
    |               ^^^ value used here after move
    |
    = note: move occurs because `a.x` has type `std::boxed::Box<isize>`, which does not implement the `Copy` trait
@@ -44,7 +44,7 @@ error[E0503]: cannot use `a.y` because it was mutably borrowed
    |
 LL |     let _x = &mut a.x;
    |                   --- borrow of `a.x` occurs here
-LL |     let _y = a.y; //~ ERROR cannot use
+LL |     let _y = a.y; //[ast]~ ERROR cannot use
    |         ^^ use of borrowed `a.x`
 
 error[E0505]: cannot move out of `a.y` because it is borrowed
@@ -60,9 +60,9 @@ error[E0502]: cannot borrow `a` (via `a.y`) as immutable because `a` is also bor
    |
 LL |     let _x = &mut a.x;
    |                   --- mutable borrow occurs here (via `a.x`)
-LL |     let _y = &a.y; //~ ERROR cannot borrow
+LL |     let _y = &a.y; //[ast]~ ERROR cannot borrow
    |               ^^^ immutable borrow occurs here (via `a.y`)
-LL |     //~^ immutable borrow occurs here (via `a.y`)
+...
 LL | }
    | - mutable borrow ends here
 
@@ -71,9 +71,9 @@ error[E0502]: cannot borrow `a` (via `a.y`) as mutable because `a` is also borro
    |
 LL |     let _x = &a.x;
    |               --- immutable borrow occurs here (via `a.x`)
-LL |     let _y = &mut a.y; //~ ERROR cannot borrow
+LL |     let _y = &mut a.y; //[ast]~ ERROR cannot borrow
    |                   ^^^ mutable borrow occurs here (via `a.y`)
-LL |     //~^ mutable borrow occurs here (via `a.y`)
+...
 LL | }
    | - immutable borrow ends here
 
@@ -82,8 +82,8 @@ error[E0382]: use of collaterally moved value: `a.y`
    |
 LL |     let _x = a.x.x;
    |         -- value moved here
-LL |     //~^ value moved here
-LL |     let _y = a.y; //~ ERROR use of collaterally moved
+LL |     //[ast]~^ value moved here
+LL |     let _y = a.y; //[ast]~ ERROR use of collaterally moved
    |         ^^ value used here after move
    |
    = note: move occurs because `a.x.x` has type `std::boxed::Box<isize>`, which does not implement the `Copy` trait
@@ -93,8 +93,8 @@ error[E0382]: use of collaterally moved value: `a.y`
    |
 LL |     let _x = a.x.x;
    |         -- value moved here
-LL |     //~^ value moved here
-LL |     let _y = a.y; //~ ERROR use of collaterally moved
+LL |     //[ast]~^ value moved here
+LL |     let _y = a.y; //[ast]~ ERROR use of collaterally moved
    |         ^^ value used here after move
    |
    = note: move occurs because `a.x.x` has type `std::boxed::Box<isize>`, which does not implement the `Copy` trait
@@ -104,8 +104,8 @@ error[E0382]: use of collaterally moved value: `a.y`
    |
 LL |     let _x = a.x.x;
    |         -- value moved here
-LL |     //~^ value moved here
-LL |     let _y = &a.y; //~ ERROR use of collaterally moved
+LL |     //[ast]~^ value moved here
+LL |     let _y = &a.y; //[ast]~ ERROR use of collaterally moved
    |               ^^^ value used here after move
    |
    = note: move occurs because `a.x.x` has type `std::boxed::Box<isize>`, which does not implement the `Copy` trait
@@ -115,7 +115,7 @@ error[E0505]: cannot move out of `a.y` because it is borrowed
    |
 LL |     let _x = &a.x.x;
    |               ----- borrow of `a.x.x` occurs here
-LL |     //~^ borrow of `a.x.x` occurs here
+LL |     //[ast]~^ borrow of `a.x.x` occurs here
 LL |     let _y = a.y;
    |         ^^ move out of `a.y` occurs here
 
@@ -124,7 +124,7 @@ error[E0503]: cannot use `a.y` because it was mutably borrowed
    |
 LL |     let _x = &mut a.x.x;
    |                   ----- borrow of `a.x.x` occurs here
-LL |     let _y = a.y; //~ ERROR cannot use
+LL |     let _y = a.y; //[ast]~ ERROR cannot use
    |         ^^ use of borrowed `a.x.x`
 
 error[E0505]: cannot move out of `a.y` because it is borrowed
@@ -140,10 +140,10 @@ error[E0502]: cannot borrow `a.y` as immutable because `a.x.x` is also borrowed
    |
 LL |     let _x = &mut a.x.x;
    |                   ----- mutable borrow occurs here
-LL |     //~^ mutable borrow occurs here
-LL |     let _y = &a.y; //~ ERROR cannot borrow
+LL |     //[ast]~^ mutable borrow occurs here
+LL |     let _y = &a.y; //[ast]~ ERROR cannot borrow
    |               ^^^ immutable borrow occurs here
-LL |     //~^ immutable borrow occurs here
+...
 LL | }
    | - mutable borrow ends here
 
@@ -152,10 +152,10 @@ error[E0502]: cannot borrow `a.y` as mutable because `a.x.x` is also borrowed as
    |
 LL |     let _x = &a.x.x;
    |               ----- immutable borrow occurs here
-LL |     //~^ immutable borrow occurs here
-LL |     let _y = &mut a.y; //~ ERROR cannot borrow
+LL |     //[ast]~^ immutable borrow occurs here
+LL |     let _y = &mut a.y; //[ast]~ ERROR cannot borrow
    |                   ^^^ mutable borrow occurs here
-LL |     //~^ mutable borrow occurs here
+...
 LL | }
    | - immutable borrow ends here
 

src/test/ui/borrowck/borrowck-box-insensitivity.mir.stderr

@@ -0,0 +1,14 @@
+error: compilation successful
+  --> $DIR/borrowck-box-insensitivity.rs:160:1
+   |
+LL | / fn main() { //[mir]~ ERROR compilation successful
+LL | |     copy_after_move();
+LL | |     move_after_move();
+LL | |     borrow_after_move();
+...  |
+LL | |     mut_borrow_after_borrow_nested();
+LL | | }
+   | |_^
+
+error: aborting due to previous error
+

src/test/ui/borrowck/borrowck-box-insensitivity.rs

@@ -1,13 +1,13 @@
-// 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.
+// This test is an artifact of the old policy that `Box<T>` should not
+// be treated specially by the AST-borrowck.
 //
-// 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.
+// NLL goes back to treating `Box<T>` specially (namely, knowing that
+// it uniquely owns the data it holds). See rust-lang/rfcs#130.
 
+// revisions: ast mir
+//[ast] compile-flags: -Z borrowck=ast
+//[mir] compile-flags: -Z borrowck=mir
+// ignore-compare-mode-nll
 #![feature(box_syntax, rustc_attrs)]
 
 struct A {
@@ -33,131 +33,131 @@ struct D {
 fn copy_after_move() {
     let a: Box<_> = box A { x: box 0, y: 1 };
     let _x = a.x;
-    //~^ value moved here
-    let _y = a.y; //~ ERROR use of moved
-    //~^ move occurs because `a.x` has type `std::boxed::Box<isize>`
-    //~| value used here after move
+    //[ast]~^ value moved here
+    let _y = a.y; //[ast]~ ERROR use of moved
+    //[ast]~^ move occurs because `a.x` has type `std::boxed::Box<isize>`
+    //[ast]~| value used here after move
 }
 
 fn move_after_move() {
     let a: Box<_> = box B { x: box 0, y: box 1 };
     let _x = a.x;
-    //~^ value moved here
-    let _y = a.y; //~ ERROR use of moved
-    //~^ move occurs because `a.x` has type `std::boxed::Box<isize>`
-    //~| value used here after move
+    //[ast]~^ value moved here
+    let _y = a.y; //[ast]~ ERROR use of moved
+    //[ast]~^ move occurs because `a.x` has type `std::boxed::Box<isize>`
+    //[ast]~| value used here after move
 }
 
 fn borrow_after_move() {
     let a: Box<_> = box A { x: box 0, y: 1 };
     let _x = a.x;
-    //~^ value moved here
-    let _y = &a.y; //~ ERROR use of moved
-    //~^ move occurs because `a.x` has type `std::boxed::Box<isize>`
-    //~| value used here after move
+    //[ast]~^ value moved here
+    let _y = &a.y; //[ast]~ ERROR use of moved
+    //[ast]~^ move occurs because `a.x` has type `std::boxed::Box<isize>`
+    //[ast]~| value used here after move
 }
 
 fn move_after_borrow() {
     let a: Box<_> = box B { x: box 0, y: box 1 };
     let _x = &a.x;
     let _y = a.y;
-    //~^ ERROR cannot move
-    //~| move out of
+    //[ast]~^ ERROR cannot move
+    //[ast]~| move out of
+    use_imm(_x);
 }
-
 fn copy_after_mut_borrow() {
     let mut a: Box<_> = box A { x: box 0, y: 1 };
     let _x = &mut a.x;
-    let _y = a.y; //~ ERROR cannot use
+    let _y = a.y; //[ast]~ ERROR cannot use
+    use_mut(_x);
 }
-
 fn move_after_mut_borrow() {
     let mut a: Box<_> = box B { x: box 0, y: box 1 };
     let _x = &mut a.x;
     let _y = a.y;
-    //~^ ERROR cannot move
-    //~| move out of
+    //[ast]~^ ERROR cannot move
+    //[ast]~| move out of
+    use_mut(_x);
 }
-
 fn borrow_after_mut_borrow() {
     let mut a: Box<_> = box A { x: box 0, y: 1 };
     let _x = &mut a.x;
-    let _y = &a.y; //~ ERROR cannot borrow
-    //~^ immutable borrow occurs here (via `a.y`)
+    let _y = &a.y; //[ast]~ ERROR cannot borrow
+    //[ast]~^ immutable borrow occurs here (via `a.y`)
+    use_mut(_x);
 }
-
 fn mut_borrow_after_borrow() {
     let mut a: Box<_> = box A { x: box 0, y: 1 };
     let _x = &a.x;
-    let _y = &mut a.y; //~ ERROR cannot borrow
-    //~^ mutable borrow occurs here (via `a.y`)
+    let _y = &mut a.y; //[ast]~ ERROR cannot borrow
+    //[ast]~^ mutable borrow occurs here (via `a.y`)
+    use_imm(_x);
 }
-
 fn copy_after_move_nested() {
     let a: Box<_> = box C { x: box A { x: box 0, y: 1 }, y: 2 };
     let _x = a.x.x;
-    //~^ value moved here
-    let _y = a.y; //~ ERROR use of collaterally moved
-    //~| value used here after move
+    //[ast]~^ value moved here
+    let _y = a.y; //[ast]~ ERROR use of collaterally moved
+    //[ast]~| value used here after move
 }
 
 fn move_after_move_nested() {
     let a: Box<_> = box D { x: box A { x: box 0, y: 1 }, y: box 2 };
     let _x = a.x.x;
-    //~^ value moved here
-    let _y = a.y; //~ ERROR use of collaterally moved
-    //~| value used here after move
+    //[ast]~^ value moved here
+    let _y = a.y; //[ast]~ ERROR use of collaterally moved
+    //[ast]~| value used here after move
 }
 
 fn borrow_after_move_nested() {
     let a: Box<_> = box C { x: box A { x: box 0, y: 1 }, y: 2 };
     let _x = a.x.x;
-    //~^ value moved here
-    let _y = &a.y; //~ ERROR use of collaterally moved
-    //~| value used here after move
+    //[ast]~^ value moved here
+    let _y = &a.y; //[ast]~ ERROR use of collaterally moved
+    //[ast]~| value used here after move
 }
 
 fn move_after_borrow_nested() {
     let a: Box<_> = box D { x: box A { x: box 0, y: 1 }, y: box 2 };
     let _x = &a.x.x;
-    //~^ borrow of `a.x.x` occurs here
+    //[ast]~^ borrow of `a.x.x` occurs here
     let _y = a.y;
-    //~^ ERROR cannot move
-    //~| move out of
+    //[ast]~^ ERROR cannot move
+    //[ast]~| move out of
+    use_imm(_x);
 }
-
 fn copy_after_mut_borrow_nested() {
     let mut a: Box<_> = box C { x: box A { x: box 0, y: 1 }, y: 2 };
     let _x = &mut a.x.x;
-    let _y = a.y; //~ ERROR cannot use
+    let _y = a.y; //[ast]~ ERROR cannot use
+    use_mut(_x);
 }
-
 fn move_after_mut_borrow_nested() {
     let mut a: Box<_> = box D { x: box A { x: box 0, y: 1 }, y: box 2 };
     let _x = &mut a.x.x;
     let _y = a.y;
-    //~^ ERROR cannot move
-    //~| move out of
+    //[ast]~^ ERROR cannot move
+    //[ast]~| move out of
+    use_mut(_x);
 }
-
 fn borrow_after_mut_borrow_nested() {
     let mut a: Box<_> = box C { x: box A { x: box 0, y: 1 }, y: 2 };
     let _x = &mut a.x.x;
-    //~^ mutable borrow occurs here
-    let _y = &a.y; //~ ERROR cannot borrow
-    //~^ immutable borrow occurs here
+    //[ast]~^ mutable borrow occurs here
+    let _y = &a.y; //[ast]~ ERROR cannot borrow
+    //[ast]~^ immutable borrow occurs here
+    use_mut(_x);
 }
-
 fn mut_borrow_after_borrow_nested() {
     let mut a: Box<_> = box C { x: box A { x: box 0, y: 1 }, y: 2 };
     let _x = &a.x.x;
-    //~^ immutable borrow occurs here
-    let _y = &mut a.y; //~ ERROR cannot borrow
-    //~^ mutable borrow occurs here
+    //[ast]~^ immutable borrow occurs here
+    let _y = &mut a.y; //[ast]~ ERROR cannot borrow
+    //[ast]~^ mutable borrow occurs here
+    use_imm(_x);
 }
-
 #[rustc_error]
-fn main() {
+fn main() { //[mir]~ ERROR compilation successful
     copy_after_move();
     move_after_move();
     borrow_after_move();
@@ -180,3 +180,6 @@ fn main() {
     borrow_after_mut_borrow_nested();
     mut_borrow_after_borrow_nested();
 }
+
+fn use_mut<T>(_: &mut T) { }
+fn use_imm<T>(_: &T) { }