Add recovery for use of removed `box` syntax

4 files changed, 77 insertions, 10 deletions

diff --git a/tests/ui/parser/removed-syntax-box.fixed b/tests/ui/parser/removed-syntax-box.fixed
new file mode 100644
index 00000000000..09d1304b775
--- /dev/null
+++ b/tests/ui/parser/removed-syntax-box.fixed
@@ -0,0 +1,14 @@
+// run-rustfix
+
+fn main() {
+    #[allow(dead_code)]
+    struct T {
+        a: u8,
+        b: u8,
+    }
+    let _ = Box::new(()); //~ ERROR `box_syntax` has been removed
+    let _ = Box::new(1); //~ ERROR `box_syntax` has been removed
+    let _ = Box::new(T { a: 12, b: 18 }); //~ ERROR `box_syntax` has been removed
+    let _ = Box::new([5; 30]); //~ ERROR `box_syntax` has been removed
+    let _: Box<()> = Box::new(()); //~ ERROR `box_syntax` has been removed
+}
diff --git a/tests/ui/parser/removed-syntax-box.rs b/tests/ui/parser/removed-syntax-box.rs
index b0e8eb0410e..1f5061b02c7 100644
--- a/tests/ui/parser/removed-syntax-box.rs
+++ b/tests/ui/parser/removed-syntax-box.rs
@@ -1,10 +1,14 @@
+// run-rustfix
+
 fn main() {
+    #[allow(dead_code)]
     struct T {
         a: u8,
         b: u8,
     }
-    let _ = box () //~ ERROR expected expression, found reserved keyword `box`
-    let _ = box 1;
-    let _ = box T { a: 12, b: 18 };
-    let _ = box [5; 30];
+    let _ = box (); //~ ERROR `box_syntax` has been removed
+    let _ = box 1; //~ ERROR `box_syntax` has been removed
+    let _ = box T { a: 12, b: 18 }; //~ ERROR `box_syntax` has been removed
+    let _ = box [5; 30]; //~ ERROR `box_syntax` has been removed
+    let _: Box<()> = box (); //~ ERROR `box_syntax` has been removed
 }
diff --git a/tests/ui/parser/removed-syntax-box.stderr b/tests/ui/parser/removed-syntax-box.stderr
index 8c8d5b3c4cb..46b891587d5 100644
--- a/tests/ui/parser/removed-syntax-box.stderr
+++ b/tests/ui/parser/removed-syntax-box.stderr
@@ -1,8 +1,57 @@
-error: expected expression, found reserved keyword `box`
-  --> $DIR/removed-syntax-box.rs:6:13
+error: `box_syntax` has been removed
+  --> $DIR/removed-syntax-box.rs:9:13
    |
-LL |     let _ = box ()
-   |             ^^^ expected expression
+LL |     let _ = box ();
+   |             ^^^^^^
+   |
+help: use `Box::new()` instead
+   |
+LL |     let _ = Box::new(());
+   |             ~~~~~~~~~~~~
+
+error: `box_syntax` has been removed
+  --> $DIR/removed-syntax-box.rs:10:13
+   |
+LL |     let _ = box 1;
+   |             ^^^^^
+   |
+help: use `Box::new()` instead
+   |
+LL |     let _ = Box::new(1);
+   |             ~~~~~~~~~~~
+
+error: `box_syntax` has been removed
+  --> $DIR/removed-syntax-box.rs:11:13
+   |
+LL |     let _ = box T { a: 12, b: 18 };
+   |             ^^^^^^^^^^^^^^^^^^^^^^
+   |
+help: use `Box::new()` instead
+   |
+LL |     let _ = Box::new(T { a: 12, b: 18 });
+   |             ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+error: `box_syntax` has been removed
+  --> $DIR/removed-syntax-box.rs:12:13
+   |
+LL |     let _ = box [5; 30];
+   |             ^^^^^^^^^^^
+   |
+help: use `Box::new()` instead
+   |
+LL |     let _ = Box::new([5; 30]);
+   |             ~~~~~~~~~~~~~~~~~
+
+error: `box_syntax` has been removed
+  --> $DIR/removed-syntax-box.rs:13:22
+   |
+LL |     let _: Box<()> = box ();
+   |                      ^^^^^^
+   |
+help: use `Box::new()` instead
+   |
+LL |     let _: Box<()> = Box::new(());
+   |                      ~~~~~~~~~~~~
 
-error: aborting due to previous error
+error: aborting due to 5 previous errors
 
diff --git a/tests/ui/unpretty/box.stdout b/tests/ui/unpretty/box.stdout
index 1318a56e3be..0c6e012e698 100644
--- a/tests/ui/unpretty/box.stdout
+++ b/tests/ui/unpretty/box.stdout
@@ -10,5 +10,5 @@ extern crate std;
 fn main() {
         let _ =
             #[rustc_box]
-            Box::new (1);
+            Box::new(1);
     }