mir-borrowck: Remove parens in the lvalue description of a deref

Author: zilbuz

src/librustc_mir/borrow_check.rs

@@ -1601,9 +1601,8 @@ impl<'cx, 'gcx, 'tcx> MirBorrowckCtxt<'cx, 'gcx, 'tcx> {
                         if autoderef {
                             self.append_lvalue_to_string(&proj.base, buf, Some(autoderef));
                         } else {
-                            buf.push_str(&"(*");
+                            buf.push_str(&"*");
                             self.append_lvalue_to_string(&proj.base, buf, Some(autoderef));
-                            buf.push_str(&")");
                         }
                     },
                     ProjectionElem::Downcast(..) => {

src/test/compile-fail/borrowck/borrowck-closures-mut-and-imm.rs

@@ -70,7 +70,7 @@ fn f() {
     let c1 = || get(&*x);
     *x = 5; //[ast]~ ERROR cannot assign
             //[mir]~^ ERROR cannot assign to `*x` because it is borrowed (Ast)
-            //[mir]~| ERROR cannot assign to `(*x)` because it is borrowed (Mir)
+            //[mir]~| ERROR cannot assign to `*x` because it is borrowed (Mir)
 }
 
 fn g() {
@@ -82,7 +82,7 @@ fn g() {
     let c1 = || get(&*x.f);
     *x.f = 5; //[ast]~ ERROR cannot assign to `*x.f`
               //[mir]~^ ERROR cannot assign to `*x.f` because it is borrowed (Ast)
-              //[mir]~| ERROR cannot assign to `(*x.f)` because it is borrowed (Mir)
+              //[mir]~| ERROR cannot assign to `*x.f` because it is borrowed (Mir)
 }
 
 fn h() {

src/test/compile-fail/borrowck/borrowck-describe-lvalue.rs

@@ -252,7 +252,7 @@ fn main() {
         fn bump<'a>(mut block: &mut Block<'a>) {
             let x = &mut block;
             let p: &'a u8 = &*block.current;
-            //[mir]~^ ERROR cannot borrow `(*block.current)` as immutable because it is also borrowed as mutable (Mir)
+            //[mir]~^ ERROR cannot borrow `*block.current` as immutable because it is also borrowed as mutable (Mir)
             // No errors in AST because of issue rust#38899
         }
     }
@@ -266,7 +266,7 @@ fn main() {
         unsafe fn bump2(mut block: *mut Block2) {
             let x = &mut block;
             let p : *const u8 = &*(*block).current;
-            //[mir]~^ ERROR cannot borrow `(*block.current)` as immutable because it is also borrowed as mutable (Mir)
+            //[mir]~^ ERROR cannot borrow `*block.current` as immutable because it is also borrowed as mutable (Mir)
             // No errors in AST because of issue rust#38899
         }
     }
@@ -279,7 +279,7 @@ fn main() {
         //[ast]~^ ERROR cannot use `v[..].y` because it was mutably borrowed
         //[mir]~^^ ERROR cannot use `v[..].y` because it was mutably borrowed (Ast)
         //[mir]~| ERROR cannot use `v[..].y` because it was mutably borrowed (Mir)
-        //[mir]~| ERROR cannot use `(*v)` because it was mutably borrowed (Mir)
+        //[mir]~| ERROR cannot use `*v` because it was mutably borrowed (Mir)
     }
     // Field of constant index
     {
@@ -300,7 +300,7 @@ fn main() {
             let y = &mut x;
             &mut x; //[ast]~ ERROR cannot borrow `**x` as mutable more than once at a time
                     //[mir]~^ ERROR cannot borrow `**x` as mutable more than once at a time (Ast)
-                    //[mir]~| ERROR cannot borrow `(*x)` as mutable more than once at a time (Mir)
+                    //[mir]~| ERROR cannot borrow `*x` as mutable more than once at a time (Mir)
             *y = 1;
         };
     }
@@ -312,7 +312,7 @@ fn main() {
                 let y = &mut x;
                 &mut x; //[ast]~ ERROR cannot borrow `**x` as mutable more than once at a time
                         //[mir]~^ ERROR cannot borrow `**x` as mutable more than once at a time (Ast)
-                        //[mir]~| ERROR cannot borrow `(*x)` as mutable more than once at a time (Mir)
+                        //[mir]~| ERROR cannot borrow `*x` as mutable more than once at a time (Mir)
                 *y = 1;
                 }
            };

src/test/compile-fail/coerce-overloaded-autoderef.rs

@@ -22,7 +22,7 @@ fn double_mut_borrow<T>(x: &mut Box<T>) {
     let z = borrow_mut(x);
     //[ast]~^ ERROR cannot borrow `*x` as mutable more than once at a time
     //[mir]~^^ ERROR cannot borrow `*x` as mutable more than once at a time (Ast)
-    //[mir]~| ERROR cannot borrow `(*x)` as mutable more than once at a time (Mir)
+    //[mir]~| ERROR cannot borrow `*x` as mutable more than once at a time (Mir)
 }
 
 fn double_imm_borrow(x: &mut Box<i32>) {
@@ -31,21 +31,21 @@ fn double_imm_borrow(x: &mut Box<i32>) {
     **x += 1;
     //[ast]~^ ERROR cannot assign to `**x` because it is borrowed
     //[mir]~^^ ERROR cannot assign to `**x` because it is borrowed (Ast)
-    //[mir]~| ERROR cannot assign to `(*(*x))` because it is borrowed (Mir)
+    //[mir]~| ERROR cannot assign to `**x` because it is borrowed (Mir)
 }
 
 fn double_mut_borrow2<T>(x: &mut Box<T>) {
     borrow_mut2(x, x);
     //[ast]~^ ERROR cannot borrow `*x` as mutable more than once at a time
     //[mir]~^^ ERROR cannot borrow `*x` as mutable more than once at a time (Ast)
-    //[mir]~| ERROR cannot borrow `(*x)` as mutable more than once at a time (Mir)
+    //[mir]~| ERROR cannot borrow `*x` as mutable more than once at a time (Mir)
 }
 
 fn double_borrow2<T>(x: &mut Box<T>) {
     borrow2(x, x);
     //[ast]~^ ERROR cannot borrow `*x` as immutable because it is also borrowed as mutable
     //[mir]~^^ ERROR cannot borrow `*x` as immutable because it is also borrowed as mutable (Ast)
-    //[mir]~| ERROR cannot borrow `(*x)` as immutable because it is also borrowed as mutable (Mir)
+    //[mir]~| ERROR cannot borrow `*x` as immutable because it is also borrowed as mutable (Mir)
 }
 
 pub fn main() {}

src/test/compile-fail/mut-pattern-internal-mutability.rs

@@ -27,5 +27,5 @@ fn main() {
     let &mut ref x = foo;
     *foo += 1; //[ast]~ ERROR cannot assign to `*foo` because it is borrowed
                //[mir]~^ ERROR cannot assign to `*foo` because it is borrowed (Ast)
-               //[mir]~| ERROR cannot assign to `(*foo)` because it is borrowed (Mir)
+               //[mir]~| ERROR cannot assign to `*foo` because it is borrowed (Mir)
 }

src/test/ui/nll/get_default.stderr

@@ -34,7 +34,7 @@ error[E0502]: cannot borrow `*map` as mutable because it is also borrowed as imm
 51 | }
    | - immutable borrow ends here
 
-error[E0502]: cannot borrow `(*map)` as mutable because it is also borrowed as immutable (Mir)
+error[E0502]: cannot borrow `*map` as mutable because it is also borrowed as immutable (Mir)
   --> $DIR/get_default.rs:43:17
    |
 41 |         match map.get() {