Gate literal box expressions in addition to types

Closes #10920

Author: alexcrichton

src/librustc/front/feature_gate.rs

@@ -77,6 +77,14 @@ impl Context {
         }
     }
 
+    fn gate_box(&self, span: Span) {
+        self.gate_feature("managed_boxes", span,
+                          "The managed box syntax is being replaced by the \
+                           `std::gc::Gc` and `std::rc::Rc` types. Equivalent \
+                           functionality to managed trait objects will be \
+                           implemented but is currently missing.");
+    }
+
     fn has_feature(&self, feature: &str) -> bool {
         self.features.iter().any(|n| n.as_slice() == feature)
     }
@@ -172,17 +180,24 @@ impl Visitor<()> for Context {
                                    experimental and likely to be removed");
 
             },
-            ast::ty_box(_) => {
-                self.gate_feature("managed_boxes", t.span,
-                                  "The managed box syntax is being replaced by the `std::gc::Gc` \
-                                  and `std::rc::Rc` types. Equivalent functionality to managed \
-                                  trait objects will be implemented but is currently missing.");
-            }
+            ast::ty_box(_) => { self.gate_box(t.span); }
             _ => {}
         }
 
         visit::walk_ty(self, t, ());
     }
+
+    fn visit_expr(&mut self, e: @ast::Expr, _: ()) {
+        match e.node {
+            ast::ExprUnary(_, ast::UnBox(..), _) |
+            ast::ExprVstore(_, ast::ExprVstoreBox) |
+            ast::ExprVstore(_, ast::ExprVstoreMutBox) => {
+                self.gate_box(e.span);
+            }
+            _ => {}
+        }
+        visit::walk_expr(self, e, ());
+    }
 }
 
 pub fn check_crate(sess: Session, crate: &ast::Crate) {

src/test/compile-fail/auto-ref-slice-plus-ref.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[feature(managed_boxes)];
+
 fn main() {
 
     // Testing that method lookup does not automatically borrow

src/test/compile-fail/borrowck-loan-rcvr-overloaded-op.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[feature(managed_boxes)];
+
 struct Point {
     x: int,
     y: int,

src/test/compile-fail/borrowck-loan-rcvr.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[feature(managed_boxes)];
+
 struct point { x: int, y: int }
 
 trait methods {

src/test/compile-fail/borrowck-mut-boxed-vec.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[feature(managed_boxes)];
+
 fn main() {
     let v = @mut [ 1, 2, 3 ];
     for _x in v.iter() {

src/test/compile-fail/issue-3763.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[feature(managed_boxes)];
+
 mod my_mod {
     pub struct MyStruct {
         priv priv_field: int

src/test/compile-fail/moves-based-on-type-exprs.rs

@@ -1,6 +1,8 @@
 // Tests that references to move-by-default values trigger moves when
 // they occur as part of various kinds of expressions.
 
+#[feature(managed_boxes)];
+
 struct Foo<A> { f: A }
 fn guard(_s: ~str) -> bool {fail!()}
 fn touch<A>(_a: &A) {}

src/test/compile-fail/non-exhaustive-match.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[feature(managed_boxes)];
+
 enum t { a, b, }
 
 fn main() {

src/test/compile-fail/occurs-check.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[feature(managed_boxes)];
+
 fn main() {
     let f; //~ ERROR cyclic type of infinite size
     f = @f;

src/test/compile-fail/static-region-bound.rs

@@ -1,3 +1,5 @@
+#[feature(managed_boxes)];
+
 fn f<T:'static>(_: T) {}
 
 fn main() {

src/test/compile-fail/unique-unique-kind.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[feature(managed_boxes)];
+
 fn f<T:Send>(_i: T) {
 }
 

src/test/run-fail/borrowck-wg-autoderef-and-autoborrowvec-combined-fail-issue-6272.rs

@@ -8,6 +8,8 @@
 //
 // for a detailed explanation of what is going on here.
 
+#[feature(managed_boxes)];
+
 fn main() {
     let a = @mut [3i];
     let b = @mut [a];

src/test/run-fail/borrowck-wg-fail-2.rs

@@ -3,6 +3,8 @@
 // Test that write guards trigger when there is a write to a field
 // of a frozen structure.
 
+#[feature(managed_boxes)];
+
 struct S {
     x: int
 }

src/test/run-fail/borrowck-wg-fail-3.rs

@@ -3,6 +3,8 @@
 // Test that write guards trigger when there is a write to a directly
 // frozen @mut box.
 
+#[feature(managed_boxes)];
+
 fn main() {
     let x = @mut 3;
     let _y: &mut int = x;

src/test/run-fail/borrowck-wg-one-mut-one-imm-slice-method.rs

@@ -3,6 +3,8 @@
 // Test that write guards trigger when there is a coercion to
 // a slice on the receiver of a method.
 
+#[feature(managed_boxes)];
+
 trait MyMutSlice {
     fn my_mut_slice(self) -> Self;
 }

src/test/run-fail/borrowck-wg-one-mut-one-imm-slices.rs

@@ -2,6 +2,8 @@
 
 // Test that write guards trigger when arguments are coerced to slices.
 
+#[feature(managed_boxes)];
+
 fn add(x:&mut [int], y:&[int])
 {
     x[0] = x[0] + y[0];

src/test/run-fail/borrowck-wg-one-mut-one-imm.rs

@@ -3,6 +3,8 @@
 // Test that write guards trigger when we are indexing into
 // an @mut vector.
 
+#[feature(managed_boxes)];
+
 fn add(x:&mut int, y:&int)
 {
     *x = *x + *y;

src/test/run-fail/borrowck-wg-two-array-indices.rs

@@ -3,6 +3,8 @@
 // Test that arguments trigger when there are *two mutable* borrows
 // of indices.
 
+#[feature(managed_boxes)];
+
 fn add(x:&mut int, y:&mut int)
 {
     *x = *x + *y;

src/test/run-fail/unwind-assert.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn main() {
     let _a = @0;
     assert!(false);

src/test/run-fail/unwind-box-res.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 use std::cast;
 
 fn failfn() {

src/test/run-fail/unwind-box-str.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn failfn() {
     fail!();
 }

src/test/run-fail/unwind-box-unique-unique.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn failfn() {
     fail!();
 }

src/test/run-fail/unwind-box-unique.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn failfn() {
     fail!();
 }

src/test/run-fail/unwind-box-vec.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn failfn() {
     fail!();
 }

src/test/run-fail/unwind-box.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn failfn() {
     fail!();
 }

src/test/run-fail/unwind-fail.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn main() {
     @0;
     fail!();

src/test/run-fail/unwind-iter.rs

@@ -10,6 +10,7 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
 #[allow(unreachable_code)];
 #[allow(unused_variable)];
 

src/test/run-fail/unwind-iter2.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn x(it: |int|) {
     let _a = @0;
     it(1);

src/test/run-fail/unwind-match.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[feature(managed_boxes)];
+
 // Issue #945
 // error-pattern:non-exhaustive match failure
 fn test_box() {

src/test/run-fail/unwind-misc-1.rs

@@ -11,6 +11,8 @@
 // exec-env:RUST_NEWRT=1
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn main() {
     let _count = @mut 0u;
     let mut map = std::hashmap::HashMap::new();

src/test/run-fail/unwind-nested.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn main() {
     let _a = @0;
     {

src/test/run-fail/unwind-partial-box.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn f() -> ~[int] { fail!(); }
 
 // Voodoo. In unwind-alt we had to do this to trigger the bug. Might

src/test/run-fail/unwind-partial-unique.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn f() -> ~[int] { fail!(); }
 
 // Voodoo. In unwind-alt we had to do this to trigger the bug. Might

src/test/run-fail/unwind-partial-vec.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn f() -> ~[int] { fail!(); }
 
 // Voodoo. In unwind-alt we had to do this to trigger the bug. Might

src/test/run-fail/unwind-stacked.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn f() {
     let _a = @0;
     fail!();

src/test/run-fail/unwind-uninitialized.rs

@@ -10,6 +10,8 @@
 
 // error-pattern:fail
 
+#[feature(managed_boxes)];
+
 fn f() {
     fail!();
 }

src/test/run-pass/auto-ref-slice-plus-ref.rs

@@ -11,6 +11,8 @@
 // Testing that method lookup automatically both borrows vectors to slices
 // and also references them to create the &self pointer
 
+#[feature(managed_boxes)];
+
 trait MyIter {
     fn test_imm(&self);
 }

src/test/run-pass/autoderef-method-twice.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[feature(managed_boxes)];
+
 trait double {
     fn double(@self) -> uint;
 }

src/test/run-pass/autoderef-method.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[feature(managed_boxes)];
+
 trait double {
     fn double(@self) -> uint;
 }

src/test/run-pass/borrowck-borrow-from-at-vec.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[feature(managed_boxes)];
+
 fn sum_slice(x: &[int]) -> int {
     let mut sum = 0;
     for i in x.iter() { sum += *i; }