Convert unknown_features lint into an error

218 files changed, 247 insertions, 575 deletions

diff --git a/src/librustc/diagnostics.rs b/src/librustc/diagnostics.rs
index b78cfc9499f..a3c0688dcc8 100644
--- a/src/librustc/diagnostics.rs
+++ b/src/librustc/diagnostics.rs
@@ -1918,6 +1918,17 @@ fn foo<'a>(x: &'a i32, y: &i32) -> &'a i32 {
 ```
 "##,
 
+E0635: r##"
+The `#![feature]` attribute specified an unknown feature.
+
+Erroneous code example:
+
+```compile_fail,E0635
+#![feature(nonexistent_rust_feature)] // error: unknown feature
+```
+
+"##,
+
 E0636: r##"
 A `#![feature]` attribute was declared multiple times.
 
diff --git a/src/librustc/lint/builtin.rs b/src/librustc/lint/builtin.rs
index 6536ab6ea73..590b59568c4 100644
--- a/src/librustc/lint/builtin.rs
+++ b/src/librustc/lint/builtin.rs
@@ -106,12 +106,6 @@ declare_lint! {
 }
 
 declare_lint! {
-    pub UNKNOWN_FEATURES,
-    Deny,
-    "unknown features found in crate-level #[feature] directives"
-}
-
-declare_lint! {
     pub STABLE_FEATURES,
     Warn,
     "stable features found in #[feature] directive"
@@ -368,7 +362,6 @@ impl LintPass for HardwiredLints {
             UNUSED_MACROS,
             WARNINGS,
             UNUSED_FEATURES,
-            UNKNOWN_FEATURES,
             STABLE_FEATURES,
             UNKNOWN_CRATE_TYPES,
             TRIVIAL_CASTS,
diff --git a/src/librustc/middle/stability.rs b/src/librustc/middle/stability.rs
index bbf03801fdb..34b253ff9c6 100644
--- a/src/librustc/middle/stability.rs
+++ b/src/librustc/middle/stability.rs
@@ -840,6 +840,10 @@ pub fn check_unused_or_stable_features<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
     // FIXME(varkor): we don't properly handle lib features behind `cfg` attributes yet,
     // but it happens just to affect `libc`, so we're just going to hard-code it for now.
     remaining_lib_features.remove(&Symbol::intern("libc"));
+    // FIXME(varkor): we have a problem gathering features on macros right now, so we're
+    // going to hard-code some features here for now.
+    remaining_lib_features.remove(&Symbol::intern("await_macro"));
+    remaining_lib_features.remove(&Symbol::intern("unstable_macros"));
 
     for (feature, stable) in tcx.lib_features().iter() {
         if let Some(since) = stable {
@@ -852,10 +856,7 @@ pub fn check_unused_or_stable_features<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>) {
     }
 
     for (feature, span) in remaining_lib_features {
-        tcx.lint_node(lint::builtin::UNKNOWN_FEATURES,
-                      ast::CRATE_NODE_ID,
-                      span,
-                      &format!("unknown feature `{}`", feature));
+        struct_span_err!(tcx.sess, span, E0635, "unknown feature `{}`", feature).emit();
     }
 
     // FIXME(#44232): the `used_features` table no longer exists, so we
diff --git a/src/librustc_lint/lib.rs b/src/librustc_lint/lib.rs
index 396e5e869f3..75d16232a37 100644
--- a/src/librustc_lint/lib.rs
+++ b/src/librustc_lint/lib.rs
@@ -188,7 +188,6 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
                     UNUSED_DOC_COMMENTS,
                     UNUSED_EXTERN_CRATES,
                     UNUSED_FEATURES,
-                    UNKNOWN_FEATURES,
                     UNUSED_LABELS,
                     UNUSED_PARENS);
 
@@ -343,6 +342,7 @@ pub fn register_builtins(store: &mut lint::LintStore, sess: Option<&Session>) {
     store.register_renamed("bare_trait_object", "bare_trait_objects");
     store.register_renamed("unstable_name_collision", "unstable_name_collisions");
     store.register_renamed("unused_doc_comment", "unused_doc_comments");
+    store.register_removed("unknown_features", "replaced by an error");
     store.register_removed("unsigned_negation", "replaced by negate_unsigned feature gate");
     store.register_removed("negate_unsigned", "cast a signed value instead");
     store.register_removed("raw_pointer_derive", "using derive with raw pointers is ok");
diff --git a/src/libsyntax/diagnostic_list.rs b/src/libsyntax/diagnostic_list.rs
index 20be7f8361a..8534969c623 100644
--- a/src/libsyntax/diagnostic_list.rs
+++ b/src/libsyntax/diagnostic_list.rs
@@ -374,18 +374,6 @@ and likely to change in the future.
 
 "##,
 
-E0635: r##"
-The `#![feature]` attribute specified an unknown feature.
-
-Erroneous code example:
-
-```compile_fail,E0635
-#![feature(nonexistent_rust_feature)] // error: unknown feature
-```
-
-"##,
-
-
 }
 
 register_diagnostics! {
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index 9ca9909ffa6..4aafe8bba58 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -140,7 +140,6 @@ declare_features! (
     (active, linkage, "1.0.0", Some(29603), None),
     (active, quote, "1.0.0", Some(29601), None),
 
-
     // rustc internal
     (active, rustc_diagnostic_macros, "1.0.0", None, None),
     (active, rustc_const_unstable, "1.0.0", None, None),
diff --git a/src/test/compile-fail/lint-renamed-allow.rs b/src/test/compile-fail/lint-renamed-allow.rs
index ae010b64bfd..f6b94e89826 100644
--- a/src/test/compile-fail/lint-renamed-allow.rs
+++ b/src/test/compile-fail/lint-renamed-allow.rs
@@ -13,6 +13,6 @@
 
 #![allow(renamed_and_removed_lints)]
 
-#[deny(unknown_features)]
+#[deny(single_use_lifetime)]
 #[deny(unused)]
 fn main() { let unused = (); } //~ ERROR unused
diff --git a/src/test/compile-fail/lint-unknown-feature-default.rs b/src/test/compile-fail/lint-unknown-feature-default.rs
index 79ba3ea45e1..5a0568f05e6 100644
--- a/src/test/compile-fail/lint-unknown-feature-default.rs
+++ b/src/test/compile-fail/lint-unknown-feature-default.rs
@@ -10,8 +10,9 @@
 
 // Tests the default for the unused_features lint
 
+#![allow(stable_features)]
 // FIXME(#44232) we should warn that this isn't used.
-#![feature(this_is_not_a_feature)]
+#![feature(rust1)]
 
 #![feature(rustc_attrs)]
 
diff --git a/src/test/compile-fail/lint-unknown-feature.rs b/src/test/compile-fail/lint-unknown-feature.rs
index d230297aaba..81f99f99492 100644
--- a/src/test/compile-fail/lint-unknown-feature.rs
+++ b/src/test/compile-fail/lint-unknown-feature.rs
@@ -10,8 +10,9 @@
 
 #![warn(unused_features)]
 
+#![allow(stable_features)]
 // FIXME(#44232) we should warn that this isn't used.
-#![feature(this_is_not_a_feature)]
+#![feature(rust1)]
 
 #![feature(rustc_attrs)]
 
diff --git a/src/test/run-fail/args-panic.rs b/src/test/run-fail/args-panic.rs
index b8fb03faf08..3eca89fbed3 100644
--- a/src/test/run-fail/args-panic.rs
+++ b/src/test/run-fail/args-panic.rs
@@ -11,7 +11,6 @@
 
 // error-pattern:meep
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn f(_a: isize, _b: isize, _c: Box<isize>) {
diff --git a/src/test/run-fail/panic-macro-any.rs b/src/test/run-fail/panic-macro-any.rs
index 7ca45565d85..c8f851be556 100644
--- a/src/test/run-fail/panic-macro-any.rs
+++ b/src/test/run-fail/panic-macro-any.rs
@@ -10,7 +10,6 @@
 
 // error-pattern:panicked at 'Box<Any>'
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn main() {
diff --git a/src/test/run-pass-fulldeps/deriving-encodable-decodable-box.rs b/src/test/run-pass-fulldeps/deriving-encodable-decodable-box.rs
index 1573b080717..4c5b3259902 100644
--- a/src/test/run-pass-fulldeps/deriving-encodable-decodable-box.rs
+++ b/src/test/run-pass-fulldeps/deriving-encodable-decodable-box.rs
@@ -9,7 +9,6 @@
 // except according to those terms.
 
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 #![feature(rustc_private)]
 
diff --git a/src/test/run-pass-valgrind/coerce-match.rs b/src/test/run-pass-valgrind/coerce-match.rs
index 6bf5c4d596f..360e8c9cc4f 100644
--- a/src/test/run-pass-valgrind/coerce-match.rs
+++ b/src/test/run-pass-valgrind/coerce-match.rs
@@ -12,7 +12,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/alignment-gep-tup-like-1.rs b/src/test/run-pass/alignment-gep-tup-like-1.rs
index 72a79e188b3..c1f75d5ee74 100644
--- a/src/test/run-pass/alignment-gep-tup-like-1.rs
+++ b/src/test/run-pass/alignment-gep-tup-like-1.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct pair<A,B> {
diff --git a/src/test/run-pass/associated-types-doubleendediterator-object.rs b/src/test/run-pass/associated-types-doubleendediterator-object.rs
index 0a6135080bb..de83e4edd85 100644
--- a/src/test/run-pass/associated-types-doubleendediterator-object.rs
+++ b/src/test/run-pass/associated-types-doubleendediterator-object.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn pairwise_sub(mut t: Box<DoubleEndedIterator<Item=isize>>) -> isize {
diff --git a/src/test/run-pass/async-await.rs b/src/test/run-pass/async-await.rs
index 669d61fdb19..0ac37485d3d 100644
--- a/src/test/run-pass/async-await.rs
+++ b/src/test/run-pass/async-await.rs
@@ -10,9 +10,6 @@
 
 // edition:2018
 
-// FIXME(varkor): `await_macro` isn't visible.
-#![allow(unknown_features)]
-
 #![feature(arbitrary_self_types, async_await, await_macro, futures_api, pin)]
 
 use std::boxed::PinBox;
diff --git a/src/test/run-pass/attr-shebang.rs b/src/test/run-pass/attr-shebang.rs
index 95f3ea61dd8..73f10410828 100644
--- a/src/test/run-pass/attr-shebang.rs
+++ b/src/test/run-pass/attr-shebang.rs
@@ -1,4 +1,4 @@
-#![allow(unknown_features)]
-#![feature(bogus)]
+#![allow(stable_features)]
+#![feature(rust1)]
 pub fn main() { }
 // ignore-license
diff --git a/src/test/run-pass/autoderef-method-on-trait.rs b/src/test/run-pass/autoderef-method-on-trait.rs
index 5c5364de6a8..f6ff9a31fa1 100644
--- a/src/test/run-pass/autoderef-method-on-trait.rs
+++ b/src/test/run-pass/autoderef-method-on-trait.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait double {
diff --git a/src/test/run-pass/autoderef-method-priority.rs b/src/test/run-pass/autoderef-method-priority.rs
index c80a92a185a..234af92610a 100644
--- a/src/test/run-pass/autoderef-method-priority.rs
+++ b/src/test/run-pass/autoderef-method-priority.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait double {
diff --git a/src/test/run-pass/autoderef-method-twice-but-not-thrice.rs b/src/test/run-pass/autoderef-method-twice-but-not-thrice.rs
index 2a782cfa176..5890fe44166 100644
--- a/src/test/run-pass/autoderef-method-twice-but-not-thrice.rs
+++ b/src/test/run-pass/autoderef-method-twice-but-not-thrice.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait double {
diff --git a/src/test/run-pass/autoderef-method-twice.rs b/src/test/run-pass/autoderef-method-twice.rs
index a1bcf65ab75..2598ec17d2a 100644
--- a/src/test/run-pass/autoderef-method-twice.rs
+++ b/src/test/run-pass/autoderef-method-twice.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait double {
diff --git a/src/test/run-pass/autoderef-method.rs b/src/test/run-pass/autoderef-method.rs
index 326218674ae..7c83b9c982f 100644
--- a/src/test/run-pass/autoderef-method.rs
+++ b/src/test/run-pass/autoderef-method.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait double {
diff --git a/src/test/run-pass/autoref-intermediate-types-issue-3585.rs b/src/test/run-pass/autoref-intermediate-types-issue-3585.rs
index 05f12fd089a..4096d45d8df 100644
--- a/src/test/run-pass/autoref-intermediate-types-issue-3585.rs
+++ b/src/test/run-pass/autoref-intermediate-types-issue-3585.rs
@@ -8,9 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait Foo {
diff --git a/src/test/run-pass/auxiliary/cci_nested_lib.rs b/src/test/run-pass/auxiliary/cci_nested_lib.rs
index 8c1a283a72d..91de734ec3a 100644
--- a/src/test/run-pass/auxiliary/cci_nested_lib.rs
+++ b/src/test/run-pass/auxiliary/cci_nested_lib.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::cell::RefCell;
diff --git a/src/test/run-pass/auxiliary/issue-2380.rs b/src/test/run-pass/auxiliary/issue-2380.rs
index cfebc4abaaa..b3e0f061485 100644
--- a/src/test/run-pass/auxiliary/issue-2380.rs
+++ b/src/test/run-pass/auxiliary/issue-2380.rs
@@ -11,7 +11,6 @@
 #![crate_name="a"]
 #![crate_type = "lib"]
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub trait i<T>
diff --git a/src/test/run-pass/auxiliary/method_self_arg1.rs b/src/test/run-pass/auxiliary/method_self_arg1.rs
index 348b71faf0c..785a8b05664 100644
--- a/src/test/run-pass/auxiliary/method_self_arg1.rs
+++ b/src/test/run-pass/auxiliary/method_self_arg1.rs
@@ -10,7 +10,6 @@
 
 #![crate_type = "lib"]
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 static mut COUNT: u64 = 1;
diff --git a/src/test/run-pass/auxiliary/method_self_arg2.rs b/src/test/run-pass/auxiliary/method_self_arg2.rs
index b67ec1b9bfc..3761d58087e 100644
--- a/src/test/run-pass/auxiliary/method_self_arg2.rs
+++ b/src/test/run-pass/auxiliary/method_self_arg2.rs
@@ -10,7 +10,6 @@
 
 #![crate_type = "lib"]
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 static mut COUNT: u64 = 1;
diff --git a/src/test/run-pass/borrowck/borrowck-borrow-from-expr-block.rs b/src/test/run-pass/borrowck/borrowck-borrow-from-expr-block.rs
index 7fdc65a96e2..1d7230510df 100644
--- a/src/test/run-pass/borrowck/borrowck-borrow-from-expr-block.rs
+++ b/src/test/run-pass/borrowck/borrowck-borrow-from-expr-block.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn borrow<F>(x: &isize, f: F) where F: FnOnce(&isize) {
diff --git a/src/test/run-pass/borrowck/borrowck-field-sensitivity.rs b/src/test/run-pass/borrowck/borrowck-field-sensitivity.rs
index d97564a2914..a465c9cf811 100644
--- a/src/test/run-pass/borrowck/borrowck-field-sensitivity.rs
+++ b/src/test/run-pass/borrowck/borrowck-field-sensitivity.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct A { a: isize, b: Box<isize> }
diff --git a/src/test/run-pass/borrowck/borrowck-move-by-capture-ok.rs b/src/test/run-pass/borrowck/borrowck-move-by-capture-ok.rs
index 158594df8ca..c3645867117 100644
--- a/src/test/run-pass/borrowck/borrowck-move-by-capture-ok.rs
+++ b/src/test/run-pass/borrowck/borrowck-move-by-capture-ok.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/borrowck/borrowck-mut-uniq.rs b/src/test/run-pass/borrowck/borrowck-mut-uniq.rs
index f535c5fcfc9..ec868bc5c85 100644
--- a/src/test/run-pass/borrowck/borrowck-mut-uniq.rs
+++ b/src/test/run-pass/borrowck/borrowck-mut-uniq.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::mem::swap;
diff --git a/src/test/run-pass/borrowck/borrowck-use-mut-borrow.rs b/src/test/run-pass/borrowck/borrowck-use-mut-borrow.rs
index 7ad81b6be6e..8c94df6dbf4 100644
--- a/src/test/run-pass/borrowck/borrowck-use-mut-borrow.rs
+++ b/src/test/run-pass/borrowck/borrowck-use-mut-borrow.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct A { a: isize, b: Box<isize> }
diff --git a/src/test/run-pass/cancel-clean-via-immediate-rvalue-ref.rs b/src/test/run-pass/cancel-clean-via-immediate-rvalue-ref.rs
index d2eb5c33eae..ac309216250 100644
--- a/src/test/run-pass/cancel-clean-via-immediate-rvalue-ref.rs
+++ b/src/test/run-pass/cancel-clean-via-immediate-rvalue-ref.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn foo(x: &mut Box<u8>) {
diff --git a/src/test/run-pass/cci_borrow.rs b/src/test/run-pass/cci_borrow.rs
index cd8f783a2e5..1535ddfb4de 100644
--- a/src/test/run-pass/cci_borrow.rs
+++ b/src/test/run-pass/cci_borrow.rs
@@ -10,7 +10,6 @@
 
 // aux-build:cci_borrow_lib.rs
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 extern crate cci_borrow_lib;
diff --git a/src/test/run-pass/class-cast-to-trait-cross-crate-2.rs b/src/test/run-pass/class-cast-to-trait-cross-crate-2.rs
index da51ad761c7..04c4b2cb377 100644
--- a/src/test/run-pass/class-cast-to-trait-cross-crate-2.rs
+++ b/src/test/run-pass/class-cast-to-trait-cross-crate-2.rs
@@ -10,7 +10,6 @@
 
 // aux-build:cci_class_cast.rs
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 extern crate cci_class_cast;
diff --git a/src/test/run-pass/class-separate-impl.rs b/src/test/run-pass/class-separate-impl.rs
index 52853658c82..343d414758c 100644
--- a/src/test/run-pass/class-separate-impl.rs
+++ b/src/test/run-pass/class-separate-impl.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::fmt;
diff --git a/src/test/run-pass/cleanup-arm-conditional.rs b/src/test/run-pass/cleanup-arm-conditional.rs
index 58d7c1df19c..dd900c56b40 100644
--- a/src/test/run-pass/cleanup-arm-conditional.rs
+++ b/src/test/run-pass/cleanup-arm-conditional.rs
@@ -13,7 +13,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax, os)]
 
 use std::os;
diff --git a/src/test/run-pass/cleanup-rvalue-during-if-and-while.rs b/src/test/run-pass/cleanup-rvalue-during-if-and-while.rs
index d813a6d8102..b117f4abd95 100644
--- a/src/test/run-pass/cleanup-rvalue-during-if-and-while.rs
+++ b/src/test/run-pass/cleanup-rvalue-during-if-and-while.rs
@@ -8,12 +8,9 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
 // This test verifies that temporaries created for `while`'s and `if`
 // conditions are dropped after the condition is evaluated.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Temporary;
diff --git a/src/test/run-pass/cleanup-rvalue-temp-during-incomplete-alloc.rs b/src/test/run-pass/cleanup-rvalue-temp-during-incomplete-alloc.rs
index c401b529c30..ae455d916b6 100644
--- a/src/test/run-pass/cleanup-rvalue-temp-during-incomplete-alloc.rs
+++ b/src/test/run-pass/cleanup-rvalue-temp-during-incomplete-alloc.rs
@@ -26,7 +26,6 @@
 
 // ignore-emscripten no threads support
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::thread;
diff --git a/src/test/run-pass/clone-with-exterior.rs b/src/test/run-pass/clone-with-exterior.rs
index 48aa41cf1d1..6ac7acd2a6b 100644
--- a/src/test/run-pass/clone-with-exterior.rs
+++ b/src/test/run-pass/clone-with-exterior.rs
@@ -10,7 +10,6 @@
 
 // ignore-emscripten no threads support
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::thread;
diff --git a/src/test/run-pass/close-over-big-then-small-data.rs b/src/test/run-pass/close-over-big-then-small-data.rs
index 99fdc346026..ba700e4e326 100644
--- a/src/test/run-pass/close-over-big-then-small-data.rs
+++ b/src/test/run-pass/close-over-big-then-small-data.rs
@@ -12,7 +12,6 @@
 // storing closure data (as we used to do), the u64 would
 // overwrite the u16.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Pair<A,B> {
diff --git a/src/test/run-pass/coerce-expect-unsized.rs b/src/test/run-pass/coerce-expect-unsized.rs
index a074aea9caa..5a1953b563a 100644
--- a/src/test/run-pass/coerce-expect-unsized.rs
+++ b/src/test/run-pass/coerce-expect-unsized.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::cell::RefCell;
diff --git a/src/test/run-pass/crate-method-reexport-grrrrrrr.rs b/src/test/run-pass/crate-method-reexport-grrrrrrr.rs
index 028b3f43e2a..c0bc97b1f65 100644
--- a/src/test/run-pass/crate-method-reexport-grrrrrrr.rs
+++ b/src/test/run-pass/crate-method-reexport-grrrrrrr.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 // This is a regression test that the metadata for the
diff --git a/src/test/run-pass/deref-lval.rs b/src/test/run-pass/deref-lval.rs
index fc97b22a4a9..0e65e5b43b7 100644
--- a/src/test/run-pass/deref-lval.rs
+++ b/src/test/run-pass/deref-lval.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::cell::Cell;
diff --git a/src/test/run-pass/deref.rs b/src/test/run-pass/deref.rs
index 4722ddd64c8..0e6b3d87d34 100644
--- a/src/test/run-pass/deref.rs
+++ b/src/test/run-pass/deref.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/deriving-default-box.rs b/src/test/run-pass/deriving-default-box.rs
index c9e5b014da3..70ac284cd30 100644
--- a/src/test/run-pass/deriving-default-box.rs
+++ b/src/test/run-pass/deriving-default-box.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::default::Default;
diff --git a/src/test/run-pass/drop-on-empty-block-exit.rs b/src/test/run-pass/drop-on-empty-block-exit.rs
index 268de8ec55c..8dea648508d 100644
--- a/src/test/run-pass/drop-on-empty-block-exit.rs
+++ b/src/test/run-pass/drop-on-empty-block-exit.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 enum t { foo(Box<isize>), }
diff --git a/src/test/run-pass/drop-struct-as-object.rs b/src/test/run-pass/drop-struct-as-object.rs
index 33d5c72772c..17603e11ddd 100644
--- a/src/test/run-pass/drop-struct-as-object.rs
+++ b/src/test/run-pass/drop-struct-as-object.rs
@@ -11,8 +11,6 @@
 // Test that destructor on a struct runs successfully after the struct
 // is boxed and converted to an object.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 static mut value: usize = 0;
diff --git a/src/test/run-pass/drop-trait-enum.rs b/src/test/run-pass/drop-trait-enum.rs
index 912cb4c5e87..a6027615adb 100644
--- a/src/test/run-pass/drop-trait-enum.rs
+++ b/src/test/run-pass/drop-trait-enum.rs
@@ -10,7 +10,6 @@
 
 // ignore-emscripten no threads support
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::thread;
diff --git a/src/test/run-pass/dst-struct.rs b/src/test/run-pass/dst-struct.rs
index 56199c1aa61..40ca8472787 100644
--- a/src/test/run-pass/dst-struct.rs
+++ b/src/test/run-pass/dst-struct.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Fat<T: ?Sized> {
diff --git a/src/test/run-pass/dst-trait.rs b/src/test/run-pass/dst-trait.rs
index d8d7d9a28bf..a412306b966 100644
--- a/src/test/run-pass/dst-trait.rs
+++ b/src/test/run-pass/dst-trait.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Fat<T: ?Sized> {
diff --git a/src/test/run-pass/dst-tuple.rs b/src/test/run-pass/dst-tuple.rs
index 2f5b28495b8..7c2125d00f9 100644
--- a/src/test/run-pass/dst-tuple.rs
+++ b/src/test/run-pass/dst-tuple.rs
@@ -9,7 +9,6 @@
 // except according to those terms.
 
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 #![feature(unsized_tuple_coercion)]
 
diff --git a/src/test/run-pass/enum-nullable-simplifycfg-misopt.rs b/src/test/run-pass/enum-nullable-simplifycfg-misopt.rs
index c8a1047cfa8..b5db8d91320 100644
--- a/src/test/run-pass/enum-nullable-simplifycfg-misopt.rs
+++ b/src/test/run-pass/enum-nullable-simplifycfg-misopt.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 /*!
diff --git a/src/test/run-pass/explicit-self-generic.rs b/src/test/run-pass/explicit-self-generic.rs
index 1b50d3028b1..d2274ced556 100644
--- a/src/test/run-pass/explicit-self-generic.rs
+++ b/src/test/run-pass/explicit-self-generic.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 #[derive(Copy, Clone)]
diff --git a/src/test/run-pass/explicit-self-objects-uniq.rs b/src/test/run-pass/explicit-self-objects-uniq.rs
index 4021ae89e36..bb7e612a9f2 100644
--- a/src/test/run-pass/explicit-self-objects-uniq.rs
+++ b/src/test/run-pass/explicit-self-objects-uniq.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait Foo {
diff --git a/src/test/run-pass/explicit-self.rs b/src/test/run-pass/explicit-self.rs
index d2a0d60eb66..11711e6ab74 100644
--- a/src/test/run-pass/explicit-self.rs
+++ b/src/test/run-pass/explicit-self.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 static tau: f64 = 2.0*3.14159265358979323;
diff --git a/src/test/run-pass/expr-block-generic-unique1.rs b/src/test/run-pass/expr-block-generic-unique1.rs
index 1654c87c6a4..304f1c7a2ea 100644
--- a/src/test/run-pass/expr-block-generic-unique1.rs
+++ b/src/test/run-pass/expr-block-generic-unique1.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn test_generic<T, F>(expected: Box<T>, eq: F) where T: Clone, F: FnOnce(Box<T>, Box<T>) -> bool {
diff --git a/src/test/run-pass/expr-block-generic-unique2.rs b/src/test/run-pass/expr-block-generic-unique2.rs
index 5477a9227aa..af3f5547867 100644
--- a/src/test/run-pass/expr-block-generic-unique2.rs
+++ b/src/test/run-pass/expr-block-generic-unique2.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn test_generic<T, F>(expected: T, eq: F) where T: Clone, F: FnOnce(T, T) -> bool {
diff --git a/src/test/run-pass/expr-block-unique.rs b/src/test/run-pass/expr-block-unique.rs
index eb24d70de90..2426ee5966c 100644
--- a/src/test/run-pass/expr-block-unique.rs
+++ b/src/test/run-pass/expr-block-unique.rs
@@ -8,9 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() { let x: Box<_> = { box 100 }; assert_eq!(*x, 100); }
diff --git a/src/test/run-pass/expr-if-unique.rs b/src/test/run-pass/expr-if-unique.rs
index 12000fd54e7..a8547536603 100644
--- a/src/test/run-pass/expr-if-unique.rs
+++ b/src/test/run-pass/expr-if-unique.rs
@@ -8,12 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
-
 // Tests for if as expressions returning boxed types
 fn test_box() {
     let rs: Box<_> = if true { box 100 } else { box 101 };
diff --git a/src/test/run-pass/expr-match-generic-unique1.rs b/src/test/run-pass/expr-match-generic-unique1.rs
index 738fcecb2e0..3fce798c285 100644
--- a/src/test/run-pass/expr-match-generic-unique1.rs
+++ b/src/test/run-pass/expr-match-generic-unique1.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn test_generic<T: Clone, F>(expected: Box<T>, eq: F) where F: FnOnce(Box<T>, Box<T>) -> bool {
diff --git a/src/test/run-pass/expr-match-generic-unique2.rs b/src/test/run-pass/expr-match-generic-unique2.rs
index 88ea2415241..5500edcf239 100644
--- a/src/test/run-pass/expr-match-generic-unique2.rs
+++ b/src/test/run-pass/expr-match-generic-unique2.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn test_generic<T: Clone, F>(expected: T, eq: F) where F: FnOnce(T, T) -> bool {
diff --git a/src/test/run-pass/expr-match-unique.rs b/src/test/run-pass/expr-match-unique.rs
index e752c20a512..e66f09c63ea 100644
--- a/src/test/run-pass/expr-match-unique.rs
+++ b/src/test/run-pass/expr-match-unique.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 // Tests for match as expressions resulting in boxed types
diff --git a/src/test/run-pass/fsu-moves-and-copies.rs b/src/test/run-pass/fsu-moves-and-copies.rs
index e6ac8b52c51..efd7f66e93b 100644
--- a/src/test/run-pass/fsu-moves-and-copies.rs
+++ b/src/test/run-pass/fsu-moves-and-copies.rs
@@ -11,8 +11,6 @@
 // Issue 4691: Ensure that functional-struct-updates operates
 // correctly and moves rather than copy when appropriate.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax, core)]
 
 struct ncint { v: isize }
diff --git a/src/test/run-pass/func-arg-incomplete-pattern.rs b/src/test/run-pass/func-arg-incomplete-pattern.rs
index 6030da44e4a..7d9501879d0 100644
--- a/src/test/run-pass/func-arg-incomplete-pattern.rs
+++ b/src/test/run-pass/func-arg-incomplete-pattern.rs
@@ -11,8 +11,6 @@
 // Test that we do not leak when the arg pattern must drop part of the
 // argument (in this case, the `y` field).
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Foo {
diff --git a/src/test/run-pass/func-arg-ref-pattern.rs b/src/test/run-pass/func-arg-ref-pattern.rs
index ab565e7abca..5214f2d02f5 100644
--- a/src/test/run-pass/func-arg-ref-pattern.rs
+++ b/src/test/run-pass/func-arg-ref-pattern.rs
@@ -14,8 +14,6 @@
 // boxes. Make sure that we don't free the box as we match the
 // pattern.
 
-
-#![allow(unknown_features)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 
diff --git a/src/test/run-pass/generic-alias-unique.rs b/src/test/run-pass/generic-alias-unique.rs
index b8d7c2140be..c4fd3119615 100644
--- a/src/test/run-pass/generic-alias-unique.rs
+++ b/src/test/run-pass/generic-alias-unique.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn id<T:Send>(t: T) -> T { return t; }
diff --git a/src/test/run-pass/generic-exterior-unique.rs b/src/test/run-pass/generic-exterior-unique.rs
index 8dbe6de8388..64091d2926c 100644
--- a/src/test/run-pass/generic-exterior-unique.rs
+++ b/src/test/run-pass/generic-exterior-unique.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Recbox<T> {x: Box<T>}
diff --git a/src/test/run-pass/generic-fn-unique.rs b/src/test/run-pass/generic-fn-unique.rs
index 6599aa74124..3585cd2e079 100644
--- a/src/test/run-pass/generic-fn-unique.rs
+++ b/src/test/run-pass/generic-fn-unique.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn f<T>(x: Box<T>) -> Box<T> { return x; }
diff --git a/src/test/run-pass/generic-object.rs b/src/test/run-pass/generic-object.rs
index 0a59a925a5f..7e737fe00af 100644
--- a/src/test/run-pass/generic-object.rs
+++ b/src/test/run-pass/generic-object.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait Foo<T> {
diff --git a/src/test/run-pass/generic-recursive-tag.rs b/src/test/run-pass/generic-recursive-tag.rs
index 433bd7cd906..ca2bf0ac224 100644
--- a/src/test/run-pass/generic-recursive-tag.rs
+++ b/src/test/run-pass/generic-recursive-tag.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 enum list<T> { cons(Box<T>, Box<list<T>>), nil, }
diff --git a/src/test/run-pass/generic-tag.rs b/src/test/run-pass/generic-tag.rs
index 75fd9fcb7b6..a79465c8cd8 100644
--- a/src/test/run-pass/generic-tag.rs
+++ b/src/test/run-pass/generic-tag.rs
@@ -12,7 +12,6 @@
 
 #![allow(dead_assignment)]
 #![allow(unused_variables)]
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 enum option<T> { some(Box<T>), none, }
diff --git a/src/test/run-pass/generic-unique.rs b/src/test/run-pass/generic-unique.rs
index 21e9a9a80d0..1b1355ea336 100644
--- a/src/test/run-pass/generic-unique.rs
+++ b/src/test/run-pass/generic-unique.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Triple<T> { x: T, y: T, z: T }
diff --git a/src/test/run-pass/hashmap-memory.rs b/src/test/run-pass/hashmap-memory.rs
index f88ce83e37d..2e98e0fe5ca 100644
--- a/src/test/run-pass/hashmap-memory.rs
+++ b/src/test/run-pass/hashmap-memory.rs
@@ -10,8 +10,6 @@
 
 // ignore-emscripten No support for threads
 
-#![allow(unknown_features)]
-
 /**
    A somewhat reduced test case to expose some Valgrind issues.
 
diff --git a/src/test/run-pass/hrtb-precedence-of-plus.rs b/src/test/run-pass/hrtb-precedence-of-plus.rs
index 516278df178..511d3234857 100644
--- a/src/test/run-pass/hrtb-precedence-of-plus.rs
+++ b/src/test/run-pass/hrtb-precedence-of-plus.rs
@@ -10,8 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
-
 // Test that `Fn(isize) -> isize + 'static` parses as `(Fn(isize) -> isize) +
 // 'static` and not `Fn(isize) -> (isize + 'static)`. The latter would
 // cause a compilation error. Issue #18772.
diff --git a/src/test/run-pass/intrinsic-atomics.rs b/src/test/run-pass/intrinsic-atomics.rs
index a675528424e..4b11158e8c3 100644
--- a/src/test/run-pass/intrinsic-atomics.rs
+++ b/src/test/run-pass/intrinsic-atomics.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 #![feature(intrinsics)]
 
diff --git a/src/test/run-pass/issue-10682.rs b/src/test/run-pass/issue-10682.rs
index c049bdfe83c..67b73bdadbb 100644
--- a/src/test/run-pass/issue-10682.rs
+++ b/src/test/run-pass/issue-10682.rs
@@ -13,7 +13,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn work(_: Box<isize>) {}
diff --git a/src/test/run-pass/issue-10767.rs b/src/test/run-pass/issue-10767.rs
index b5ef6020b57..2184aa00fa4 100644
--- a/src/test/run-pass/issue-10767.rs
+++ b/src/test/run-pass/issue-10767.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/issue-10802.rs b/src/test/run-pass/issue-10802.rs
index 2256315a379..1e700d4e18b 100644
--- a/src/test/run-pass/issue-10802.rs
+++ b/src/test/run-pass/issue-10802.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct DroppableStruct;
diff --git a/src/test/run-pass/issue-11552.rs b/src/test/run-pass/issue-11552.rs
index 5193330a45a..aa980e48c5e 100644
--- a/src/test/run-pass/issue-11552.rs
+++ b/src/test/run-pass/issue-11552.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 
diff --git a/src/test/run-pass/issue-13323.rs b/src/test/run-pass/issue-13323.rs
index 68c6ce7a7b7..de72d7152f8 100644
--- a/src/test/run-pass/issue-13323.rs
+++ b/src/test/run-pass/issue-13323.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct StrWrap {
diff --git a/src/test/run-pass/issue-14399.rs b/src/test/run-pass/issue-14399.rs
index aa91f125e48..d5c67bea099 100644
--- a/src/test/run-pass/issue-14399.rs
+++ b/src/test/run-pass/issue-14399.rs
@@ -15,7 +15,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 #[derive(Clone)]
diff --git a/src/test/run-pass/issue-15571.rs b/src/test/run-pass/issue-15571.rs
index 3dc76f4a089..35915a62102 100644
--- a/src/test/run-pass/issue-15571.rs
+++ b/src/test/run-pass/issue-15571.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn match_on_local() {
diff --git a/src/test/run-pass/issue-15763.rs b/src/test/run-pass/issue-15763.rs
index 0baaaac2676..e1176d47063 100644
--- a/src/test/run-pass/issue-15763.rs
+++ b/src/test/run-pass/issue-15763.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 #[derive(PartialEq, Debug)]
diff --git a/src/test/run-pass/issue-16668.rs b/src/test/run-pass/issue-16668.rs
index 5613211b31d..7944e80a428 100644
--- a/src/test/run-pass/issue-16668.rs
+++ b/src/test/run-pass/issue-16668.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
-
 struct Parser<'a, I, O> {
     parse: Box<FnMut(I) -> Result<O, String> + 'a>
 }
diff --git a/src/test/run-pass/issue-16739.rs b/src/test/run-pass/issue-16739.rs
index ca2b9209eba..2bdedfebe3e 100644
--- a/src/test/run-pass/issue-16739.rs
+++ b/src/test/run-pass/issue-16739.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 #![feature(unboxed_closures, fn_traits)]
 
diff --git a/src/test/run-pass/issue-16774.rs b/src/test/run-pass/issue-16774.rs
index 9ec5910c2f6..1309d2ffab8 100644
--- a/src/test/run-pass/issue-16774.rs
+++ b/src/test/run-pass/issue-16774.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 #![feature(box_patterns)]
 
diff --git a/src/test/run-pass/issue-17322.rs b/src/test/run-pass/issue-17322.rs
index a9f5476d0f8..47dfe878c26 100644
--- a/src/test/run-pass/issue-17322.rs
+++ b/src/test/run-pass/issue-17322.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax, io)]
 
 use std::io::{self, Write};
diff --git a/src/test/run-pass/issue-2288.rs b/src/test/run-pass/issue-2288.rs
index 379715f5390..b8353ea4413 100644
--- a/src/test/run-pass/issue-2288.rs
+++ b/src/test/run-pass/issue-2288.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait clam<A> {
diff --git a/src/test/run-pass/issue-2633-2.rs b/src/test/run-pass/issue-2633-2.rs
index 7b5a055d334..b955947c410 100644
--- a/src/test/run-pass/issue-2633-2.rs
+++ b/src/test/run-pass/issue-2633-2.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 
diff --git a/src/test/run-pass/issue-2708.rs b/src/test/run-pass/issue-2708.rs
index d3916db3f75..cf565b9f901 100644
--- a/src/test/run-pass/issue-2708.rs
+++ b/src/test/run-pass/issue-2708.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Font {
diff --git a/src/test/run-pass/issue-2734.rs b/src/test/run-pass/issue-2734.rs
index 18cd9a87e6b..916e3dd689f 100644
--- a/src/test/run-pass/issue-2734.rs
+++ b/src/test/run-pass/issue-2734.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait hax {
diff --git a/src/test/run-pass/issue-2735.rs b/src/test/run-pass/issue-2735.rs
index cd6c6a59e2a..af8eef557f8 100644
--- a/src/test/run-pass/issue-2735.rs
+++ b/src/test/run-pass/issue-2735.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait hax {
diff --git a/src/test/run-pass/issue-2935.rs b/src/test/run-pass/issue-2935.rs
index 511344a792f..b2ea183e9f8 100644
--- a/src/test/run-pass/issue-2935.rs
+++ b/src/test/run-pass/issue-2935.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 //type t = { a: isize };
diff --git a/src/test/run-pass/issue-3121.rs b/src/test/run-pass/issue-3121.rs
index 6e9ee7fb15c..a0bdcf18ec5 100644
--- a/src/test/run-pass/issue-3121.rs
+++ b/src/test/run-pass/issue-3121.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 #[derive(Copy, Clone)]
diff --git a/src/test/run-pass/issue-3290.rs b/src/test/run-pass/issue-3290.rs
index b09820146f5..6c775e15fb5 100644
--- a/src/test/run-pass/issue-3290.rs
+++ b/src/test/run-pass/issue-3290.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/issue-3447.rs b/src/test/run-pass/issue-3447.rs
index 12c2155dd57..1558d94bae7 100644
--- a/src/test/run-pass/issue-3447.rs
+++ b/src/test/run-pass/issue-3447.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::cell::RefCell;
diff --git a/src/test/run-pass/issue-3794.rs b/src/test/run-pass/issue-3794.rs
index 3d5f38e38cc..badb833ee80 100644
--- a/src/test/run-pass/issue-3794.rs
+++ b/src/test/run-pass/issue-3794.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait T {
diff --git a/src/test/run-pass/issue-3878.rs b/src/test/run-pass/issue-3878.rs
index 5d094af2149..e0e11b4fd86 100644
--- a/src/test/run-pass/issue-3878.rs
+++ b/src/test/run-pass/issue-3878.rs
@@ -11,7 +11,6 @@
 // pretty-expanded FIXME #23616
 
 #![allow(path_statements)]
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/issue-4759.rs b/src/test/run-pass/issue-4759.rs
index a26d6b05d7e..7788a8f3ec2 100644
--- a/src/test/run-pass/issue-4759.rs
+++ b/src/test/run-pass/issue-4759.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct T { a: Box<isize> }
diff --git a/src/test/run-pass/issue-5192.rs b/src/test/run-pass/issue-5192.rs
index d8f7f25508d..0758ace42da 100644
--- a/src/test/run-pass/issue-5192.rs
+++ b/src/test/run-pass/issue-5192.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub trait EventLoop {
diff --git a/src/test/run-pass/issue-5666.rs b/src/test/run-pass/issue-5666.rs
index e28a929d527..eba83227f44 100644
--- a/src/test/run-pass/issue-5666.rs
+++ b/src/test/run-pass/issue-5666.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Dog {
diff --git a/src/test/run-pass/issue-5718.rs b/src/test/run-pass/issue-5718.rs
index 964809631d9..0bc9a07cb00 100644
--- a/src/test/run-pass/issue-5718.rs
+++ b/src/test/run-pass/issue-5718.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Element;
diff --git a/src/test/run-pass/issue-5884.rs b/src/test/run-pass/issue-5884.rs
index 2096bebd2b2..c3247876c7a 100644
--- a/src/test/run-pass/issue-5884.rs
+++ b/src/test/run-pass/issue-5884.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub struct Foo {
diff --git a/src/test/run-pass/issue-6318.rs b/src/test/run-pass/issue-6318.rs
index 12b71f519b1..69c7ec4cf1f 100644
--- a/src/test/run-pass/issue-6318.rs
+++ b/src/test/run-pass/issue-6318.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub enum Thing {
diff --git a/src/test/run-pass/issue-6557.rs b/src/test/run-pass/issue-6557.rs
index eba87f418e4..109383b343b 100644
--- a/src/test/run-pass/issue-6557.rs
+++ b/src/test/run-pass/issue-6557.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 
diff --git a/src/test/run-pass/issue-7673-cast-generically-implemented-trait.rs b/src/test/run-pass/issue-7673-cast-generically-implemented-trait.rs
index 43b5a997c19..f5acebf3a66 100644
--- a/src/test/run-pass/issue-7673-cast-generically-implemented-trait.rs
+++ b/src/test/run-pass/issue-7673-cast-generically-implemented-trait.rs
@@ -16,7 +16,6 @@
 
 */
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {}
diff --git a/src/test/run-pass/issue-9129.rs b/src/test/run-pass/issue-9129.rs
index a9f29fdb38c..485f10357b3 100644
--- a/src/test/run-pass/issue-9129.rs
+++ b/src/test/run-pass/issue-9129.rs
@@ -10,7 +10,6 @@
 
 // ignore-pretty unreported
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub trait bomb { fn boom(&self, _: Ident); }
diff --git a/src/test/run-pass/issue-9382.rs b/src/test/run-pass/issue-9382.rs
index fb7ffdcd515..7538e55fd95 100644
--- a/src/test/run-pass/issue-9382.rs
+++ b/src/test/run-pass/issue-9382.rs
@@ -11,7 +11,6 @@
 // except according to those terms.
 
 #![allow(unnecessary_allocation)]
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 // Tests for a previous bug that occurred due to an interaction
diff --git a/src/test/run-pass/kindck-owned-trait-contains-1.rs b/src/test/run-pass/kindck-owned-trait-contains-1.rs
index 9df72f4760a..9b56666fd46 100644
--- a/src/test/run-pass/kindck-owned-trait-contains-1.rs
+++ b/src/test/run-pass/kindck-owned-trait-contains-1.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait repeat<A> { fn get(&self) -> A; }
diff --git a/src/test/run-pass/last-use-is-capture.rs b/src/test/run-pass/last-use-is-capture.rs
index 35a17150787..cb2a2061406 100644
--- a/src/test/run-pass/last-use-is-capture.rs
+++ b/src/test/run-pass/last-use-is-capture.rs
@@ -10,7 +10,6 @@
 
 // Make sure #1399 stays fixed
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct A { a: Box<isize> }
diff --git a/src/test/run-pass/leak-unique-as-tydesc.rs b/src/test/run-pass/leak-unique-as-tydesc.rs
index 30838b3121a..d89888927e1 100644
--- a/src/test/run-pass/leak-unique-as-tydesc.rs
+++ b/src/test/run-pass/leak-unique-as-tydesc.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn leaky<T>(_t: T) { }
diff --git a/src/test/run-pass/let-assignability.rs b/src/test/run-pass/let-assignability.rs
index c53bc83ef6b..69b0eab99f7 100644
--- a/src/test/run-pass/let-assignability.rs
+++ b/src/test/run-pass/let-assignability.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn f() {
diff --git a/src/test/run-pass/list.rs b/src/test/run-pass/list.rs
index 8f0cbf96b60..37612415555 100644
--- a/src/test/run-pass/list.rs
+++ b/src/test/run-pass/list.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 enum list { cons(isize, Box<list>), nil, }
diff --git a/src/test/run-pass/macro-stability.rs b/src/test/run-pass/macro-stability.rs
index b23947cc2b5..9afcd51aa85 100644
--- a/src/test/run-pass/macro-stability.rs
+++ b/src/test/run-pass/macro-stability.rs
@@ -10,9 +10,6 @@
 
 // aux-build:unstable-macros.rs
 
-// FIXME(varkor): `unstable_macros` isn't visible.
-#![allow(unknown_features)]
-
 #![feature(unstable_macros)]
 
 #[macro_use] extern crate unstable_macros;
diff --git a/src/test/run-pass/match-implicit-copy-unique.rs b/src/test/run-pass/match-implicit-copy-unique.rs
index caf76b3ab2f..10de6eeabdd 100644
--- a/src/test/run-pass/match-implicit-copy-unique.rs
+++ b/src/test/run-pass/match-implicit-copy-unique.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Pair { a: Box<isize>, b: Box<isize> }
diff --git a/src/test/run-pass/match-unique-bind.rs b/src/test/run-pass/match-unique-bind.rs
index 78b02d709e2..ca864c05cfd 100644
--- a/src/test/run-pass/match-unique-bind.rs
+++ b/src/test/run-pass/match-unique-bind.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 
diff --git a/src/test/run-pass/match-value-binding-in-guard-3291.rs b/src/test/run-pass/match-value-binding-in-guard-3291.rs
index d4f4f3bb27e..ab56a8cfc93 100644
--- a/src/test/run-pass/match-value-binding-in-guard-3291.rs
+++ b/src/test/run-pass/match-value-binding-in-guard-3291.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn foo(x: Option<Box<isize>>, b: bool) -> isize {
diff --git a/src/test/run-pass/method-self-arg-aux1.rs b/src/test/run-pass/method-self-arg-aux1.rs
index e7615711b4c..2572baf68fd 100644
--- a/src/test/run-pass/method-self-arg-aux1.rs
+++ b/src/test/run-pass/method-self-arg-aux1.rs
@@ -10,8 +10,6 @@
 
 // Test method calls with self as an argument (cross-crate)
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 // aux-build:method_self_arg1.rs
diff --git a/src/test/run-pass/method-self-arg-aux2.rs b/src/test/run-pass/method-self-arg-aux2.rs
index 0a1efc96fcf..51de69ff01f 100644
--- a/src/test/run-pass/method-self-arg-aux2.rs
+++ b/src/test/run-pass/method-self-arg-aux2.rs
@@ -10,8 +10,6 @@
 
 // Test method calls with self as an argument (cross-crate)
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 // aux-build:method_self_arg2.rs
diff --git a/src/test/run-pass/method-self-arg-trait.rs b/src/test/run-pass/method-self-arg-trait.rs
index d93cf2b0983..34e849bd0d2 100644
--- a/src/test/run-pass/method-self-arg-trait.rs
+++ b/src/test/run-pass/method-self-arg-trait.rs
@@ -10,8 +10,6 @@
 
 // Test method calls with self as an argument
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 static mut COUNT: u64 = 1;
diff --git a/src/test/run-pass/method-self-arg.rs b/src/test/run-pass/method-self-arg.rs
index 4361c9b0563..b7fb2fa138d 100644
--- a/src/test/run-pass/method-self-arg.rs
+++ b/src/test/run-pass/method-self-arg.rs
@@ -10,8 +10,6 @@
 
 // Test method calls with self as an argument
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 static mut COUNT: usize = 1;
diff --git a/src/test/run-pass/method-two-trait-defer-resolution-2.rs b/src/test/run-pass/method-two-trait-defer-resolution-2.rs
index 82d747b6c27..f403f526039 100644
--- a/src/test/run-pass/method-two-trait-defer-resolution-2.rs
+++ b/src/test/run-pass/method-two-trait-defer-resolution-2.rs
@@ -19,8 +19,6 @@
 // codegen the call as `Foo::foo(&x)` and let the specific impl get
 // chosen later.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait Foo {
diff --git a/src/test/run-pass/move-1-unique.rs b/src/test/run-pass/move-1-unique.rs
index 34a3bdf8765..5c8dd41c646 100644
--- a/src/test/run-pass/move-1-unique.rs
+++ b/src/test/run-pass/move-1-unique.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 #[derive(Clone)]
diff --git a/src/test/run-pass/move-2-unique.rs b/src/test/run-pass/move-2-unique.rs
index 2babf19e164..0b67e54e234 100644
--- a/src/test/run-pass/move-2-unique.rs
+++ b/src/test/run-pass/move-2-unique.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct X { x: isize, y: isize, z: isize }
diff --git a/src/test/run-pass/move-2.rs b/src/test/run-pass/move-2.rs
index 926e28ed155..0fbc2de91e6 100644
--- a/src/test/run-pass/move-2.rs
+++ b/src/test/run-pass/move-2.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct X { x: isize, y: isize, z: isize }
diff --git a/src/test/run-pass/move-3-unique.rs b/src/test/run-pass/move-3-unique.rs
index 360593ffe48..36ad3a40b3f 100644
--- a/src/test/run-pass/move-3-unique.rs
+++ b/src/test/run-pass/move-3-unique.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 #[derive(Clone)]
diff --git a/src/test/run-pass/move-4-unique.rs b/src/test/run-pass/move-4-unique.rs
index 153da8e1339..266e34c98a4 100644
--- a/src/test/run-pass/move-4-unique.rs
+++ b/src/test/run-pass/move-4-unique.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Triple {a: isize, b: isize, c: isize}
diff --git a/src/test/run-pass/move-4.rs b/src/test/run-pass/move-4.rs
index 1346860d51d..481068869e3 100644
--- a/src/test/run-pass/move-4.rs
+++ b/src/test/run-pass/move-4.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Triple { a: isize, b: isize, c: isize }
diff --git a/src/test/run-pass/move-arg-2-unique.rs b/src/test/run-pass/move-arg-2-unique.rs
index 0ff5a66adc2..b6e225cc8b7 100644
--- a/src/test/run-pass/move-arg-2-unique.rs
+++ b/src/test/run-pass/move-arg-2-unique.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn test(foo: Box<Vec<isize>> ) { assert_eq!((*foo)[0], 10); }
diff --git a/src/test/run-pass/move-arg-2.rs b/src/test/run-pass/move-arg-2.rs
index 8de487bc363..78774854c9f 100644
--- a/src/test/run-pass/move-arg-2.rs
+++ b/src/test/run-pass/move-arg-2.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn test(foo: Box<Vec<isize>>) { assert_eq!((*foo)[0], 10); }
diff --git a/src/test/run-pass/mut-function-arguments.rs b/src/test/run-pass/mut-function-arguments.rs
index 010f656d531..bf4d4ea921a 100644
--- a/src/test/run-pass/mut-function-arguments.rs
+++ b/src/test/run-pass/mut-function-arguments.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn f(mut y: Box<isize>) {
diff --git a/src/test/run-pass/new-box.rs b/src/test/run-pass/new-box.rs
index 17f71c3de43..d6881ea90af 100644
--- a/src/test/run-pass/new-box.rs
+++ b/src/test/run-pass/new-box.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn f(x: Box<isize>) {
diff --git a/src/test/run-pass/nullable-pointer-iotareduction.rs b/src/test/run-pass/nullable-pointer-iotareduction.rs
index 7e8d082a286..d33102a38f9 100644
--- a/src/test/run-pass/nullable-pointer-iotareduction.rs
+++ b/src/test/run-pass/nullable-pointer-iotareduction.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 // Iota-reduction is a rule in the Calculus of (Co-)Inductive Constructions,
diff --git a/src/test/run-pass/object-one-type-two-traits.rs b/src/test/run-pass/object-one-type-two-traits.rs
index aa2dbf03bb2..284beccdb29 100644
--- a/src/test/run-pass/object-one-type-two-traits.rs
+++ b/src/test/run-pass/object-one-type-two-traits.rs
@@ -11,7 +11,6 @@
 // Testing creating two vtables with the same self type, but different
 // traits.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::any::Any;
diff --git a/src/test/run-pass/objects-owned-object-borrowed-method-headerless.rs b/src/test/run-pass/objects-owned-object-borrowed-method-headerless.rs
index 768f126e4ed..c27bc62ada8 100644
--- a/src/test/run-pass/objects-owned-object-borrowed-method-headerless.rs
+++ b/src/test/run-pass/objects-owned-object-borrowed-method-headerless.rs
@@ -12,8 +12,6 @@
 // closed over do not contain managed values, and thus the boxes do
 // not have headers.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 
diff --git a/src/test/run-pass/objects-owned-object-owned-method.rs b/src/test/run-pass/objects-owned-object-owned-method.rs
index 71ed995e76c..5d9658dc15d 100644
--- a/src/test/run-pass/objects-owned-object-owned-method.rs
+++ b/src/test/run-pass/objects-owned-object-owned-method.rs
@@ -12,8 +12,6 @@
 // closed over contain managed values. This implies that the boxes
 // will have headers that must be skipped over.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait FooTrait {
diff --git a/src/test/run-pass/output-slot-variants.rs b/src/test/run-pass/output-slot-variants.rs
index 4c3017c066e..2171b8c481d 100644
--- a/src/test/run-pass/output-slot-variants.rs
+++ b/src/test/run-pass/output-slot-variants.rs
@@ -12,7 +12,6 @@
 
 #![allow(dead_assignment)]
 #![allow(unused_variables)]
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct A { a: isize, b: isize }
diff --git a/src/test/run-pass/overloaded-autoderef.rs b/src/test/run-pass/overloaded-autoderef.rs
index d9ffbe51aa5..759e2aace61 100644
--- a/src/test/run-pass/overloaded-autoderef.rs
+++ b/src/test/run-pass/overloaded-autoderef.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax, core)]
 
 use std::cell::RefCell;
diff --git a/src/test/run-pass/overloaded-index-autoderef.rs b/src/test/run-pass/overloaded-index-autoderef.rs
index efa00514934..9988599d59d 100644
--- a/src/test/run-pass/overloaded-index-autoderef.rs
+++ b/src/test/run-pass/overloaded-index-autoderef.rs
@@ -10,8 +10,6 @@
 
 // Test overloaded indexing combined with autoderef.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax, core)]
 
 use std::ops::{Index, IndexMut};
diff --git a/src/test/run-pass/pure-sum.rs b/src/test/run-pass/pure-sum.rs
index c27b95e1f13..3313196a5ec 100644
--- a/src/test/run-pass/pure-sum.rs
+++ b/src/test/run-pass/pure-sum.rs
@@ -12,7 +12,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn sums_to(v: Vec<isize> , sum: isize) -> bool {
diff --git a/src/test/run-pass/rcvr-borrowed-to-region.rs b/src/test/run-pass/rcvr-borrowed-to-region.rs
index 6e9769ea2b9..bc869113fe9 100644
--- a/src/test/run-pass/rcvr-borrowed-to-region.rs
+++ b/src/test/run-pass/rcvr-borrowed-to-region.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait get {
diff --git a/src/test/run-pass/regions-borrow-at.rs b/src/test/run-pass/regions-borrow-at.rs
index 83a82041af9..abebb670e65 100644
--- a/src/test/run-pass/regions-borrow-at.rs
+++ b/src/test/run-pass/regions-borrow-at.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn foo(x: &usize) -> usize {
diff --git a/src/test/run-pass/regions-borrow-uniq.rs b/src/test/run-pass/regions-borrow-uniq.rs
index 2a08940dab6..48b09b33851 100644
--- a/src/test/run-pass/regions-borrow-uniq.rs
+++ b/src/test/run-pass/regions-borrow-uniq.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn foo(x: &usize) -> usize {
diff --git a/src/test/run-pass/regions-close-over-type-parameter-successfully.rs b/src/test/run-pass/regions-close-over-type-parameter-successfully.rs
index d048633519a..4a24e201b35 100644
--- a/src/test/run-pass/regions-close-over-type-parameter-successfully.rs
+++ b/src/test/run-pass/regions-close-over-type-parameter-successfully.rs
@@ -11,8 +11,6 @@
 // A test where we (successfully) close over a reference into
 // an object.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait SomeTrait { fn get(&self) -> isize; }
diff --git a/src/test/run-pass/regions-dependent-addr-of.rs b/src/test/run-pass/regions-dependent-addr-of.rs
index e9a3e16438f..c8b39bbe749 100644
--- a/src/test/run-pass/regions-dependent-addr-of.rs
+++ b/src/test/run-pass/regions-dependent-addr-of.rs
@@ -11,8 +11,6 @@
 // Test lifetimes are linked properly when we create dependent region pointers.
 // Issue #3148.
 
-
-#![allow(unknown_features)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 
diff --git a/src/test/run-pass/regions-early-bound-trait-param.rs b/src/test/run-pass/regions-early-bound-trait-param.rs
index 86fcfb9e6dd..75c209a0920 100644
--- a/src/test/run-pass/regions-early-bound-trait-param.rs
+++ b/src/test/run-pass/regions-early-bound-trait-param.rs
@@ -11,8 +11,6 @@
 // Tests that you can use an early-bound lifetime parameter as
 // on of the generic parameters in a trait.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait Trait<'a> {
diff --git a/src/test/run-pass/regions-escape-into-other-fn.rs b/src/test/run-pass/regions-escape-into-other-fn.rs
index 597333482fd..7cb719cccce 100644
--- a/src/test/run-pass/regions-escape-into-other-fn.rs
+++ b/src/test/run-pass/regions-escape-into-other-fn.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn foo(x: &usize) -> &usize { x }
diff --git a/src/test/run-pass/regions-fn-subtyping.rs b/src/test/run-pass/regions-fn-subtyping.rs
index c7a4accff85..f762b4f41ed 100644
--- a/src/test/run-pass/regions-fn-subtyping.rs
+++ b/src/test/run-pass/regions-fn-subtyping.rs
@@ -14,7 +14,6 @@
 
 #![allow(dead_assignment)]
 #![allow(unused_variables)]
-#![allow(unknown_features)]
 
 // Should pass region checking.
 fn ok(f: Box<FnMut(&usize)>) {
diff --git a/src/test/run-pass/regions-infer-borrow-scope-within-loop-ok.rs b/src/test/run-pass/regions-infer-borrow-scope-within-loop-ok.rs
index a89f6f4a7b5..a40ba8382fc 100644
--- a/src/test/run-pass/regions-infer-borrow-scope-within-loop-ok.rs
+++ b/src/test/run-pass/regions-infer-borrow-scope-within-loop-ok.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn borrow<T>(x: &T) -> &T {x}
diff --git a/src/test/run-pass/regions-infer-borrow-scope.rs b/src/test/run-pass/regions-infer-borrow-scope.rs
index 01f41637311..72208272df7 100644
--- a/src/test/run-pass/regions-infer-borrow-scope.rs
+++ b/src/test/run-pass/regions-infer-borrow-scope.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Point {x: isize, y: isize}
diff --git a/src/test/run-pass/regions-lifetime-nonfree-late-bound.rs b/src/test/run-pass/regions-lifetime-nonfree-late-bound.rs
index a2c07d27288..2a20cd2b773 100644
--- a/src/test/run-pass/regions-lifetime-nonfree-late-bound.rs
+++ b/src/test/run-pass/regions-lifetime-nonfree-late-bound.rs
@@ -24,7 +24,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/regions-relate-bound-regions-on-closures-to-inference-variables.rs b/src/test/run-pass/regions-relate-bound-regions-on-closures-to-inference-variables.rs
index 3162ef54f39..3322fc36fd3 100644
--- a/src/test/run-pass/regions-relate-bound-regions-on-closures-to-inference-variables.rs
+++ b/src/test/run-pass/regions-relate-bound-regions-on-closures-to-inference-variables.rs
@@ -17,8 +17,6 @@
 // changes were caught. However, those uses in the compiler could
 // easily get changed or refactored away in the future.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Ctxt<'tcx> {
diff --git a/src/test/run-pass/self-impl.rs b/src/test/run-pass/self-impl.rs
index 688b66a0a87..fcd233c361b 100644
--- a/src/test/run-pass/self-impl.rs
+++ b/src/test/run-pass/self-impl.rs
@@ -12,7 +12,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct Foo;
diff --git a/src/test/run-pass/self-in-mut-slot-default-method.rs b/src/test/run-pass/self-in-mut-slot-default-method.rs
index 877988e60a9..905a23f22a6 100644
--- a/src/test/run-pass/self-in-mut-slot-default-method.rs
+++ b/src/test/run-pass/self-in-mut-slot-default-method.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct X {
diff --git a/src/test/run-pass/self-re-assign.rs b/src/test/run-pass/self-re-assign.rs
index a523340784c..05295aa3309 100644
--- a/src/test/run-pass/self-re-assign.rs
+++ b/src/test/run-pass/self-re-assign.rs
@@ -11,8 +11,6 @@
 // Ensure assigning an owned or managed variable to itself works. In particular,
 // that we do not glue_drop before we glue_take (#3290).
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::rc::Rc;
diff --git a/src/test/run-pass/sendfn-spawn-with-fn-arg.rs b/src/test/run-pass/sendfn-spawn-with-fn-arg.rs
index fb5877b8a48..ecd0bfb1440 100644
--- a/src/test/run-pass/sendfn-spawn-with-fn-arg.rs
+++ b/src/test/run-pass/sendfn-spawn-with-fn-arg.rs
@@ -10,7 +10,6 @@
 
 // ignore-emscripten no threads support
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::thread;
diff --git a/src/test/run-pass/task-spawn-move-and-copy.rs b/src/test/run-pass/task-spawn-move-and-copy.rs
index cd6cb5a4b52..94b69a1c3e4 100644
--- a/src/test/run-pass/task-spawn-move-and-copy.rs
+++ b/src/test/run-pass/task-spawn-move-and-copy.rs
@@ -10,7 +10,6 @@
 
 // ignore-emscripten no threads support
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::thread;
diff --git a/src/test/run-pass/trait-bounds-in-arc.rs b/src/test/run-pass/trait-bounds-in-arc.rs
index 9623da3309a..7b57d66ef21 100644
--- a/src/test/run-pass/trait-bounds-in-arc.rs
+++ b/src/test/run-pass/trait-bounds-in-arc.rs
@@ -12,7 +12,7 @@
 // and shared between threads as long as all types fulfill Send.
 
 // ignore-emscripten no threads support
-#![allow(unknown_features)]
+
 #![feature(box_syntax)]
 
 use std::sync::Arc;
diff --git a/src/test/run-pass/trait-object-generics.rs b/src/test/run-pass/trait-object-generics.rs
index 61d32bd6ffc..4b14ac2f76f 100644
--- a/src/test/run-pass/trait-object-generics.rs
+++ b/src/test/run-pass/trait-object-generics.rs
@@ -10,8 +10,6 @@
 
 // test for #8664
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::marker;
diff --git a/src/test/run-pass/traits-conditional-dispatch.rs b/src/test/run-pass/traits-conditional-dispatch.rs
index 8d2faaf418b..53457d85e01 100644
--- a/src/test/run-pass/traits-conditional-dispatch.rs
+++ b/src/test/run-pass/traits-conditional-dispatch.rs
@@ -12,8 +12,6 @@
 // blanket impl for T:Copy coexists with an impl for Box<T>, because
 // Box does not impl Copy.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 trait Get {
diff --git a/src/test/run-pass/type-param-constraints.rs b/src/test/run-pass/type-param-constraints.rs
index 381f1b68257..1a3bdcca7a1 100644
--- a/src/test/run-pass/type-param-constraints.rs
+++ b/src/test/run-pass/type-param-constraints.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn p_foo<T>(_pinned: T) { }
diff --git a/src/test/run-pass/typeclasses-eq-example-static.rs b/src/test/run-pass/typeclasses-eq-example-static.rs
index 0ea7a1be432..d386f27d8c2 100644
--- a/src/test/run-pass/typeclasses-eq-example-static.rs
+++ b/src/test/run-pass/typeclasses-eq-example-static.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 // Example from lkuper's intern talk, August 2012 -- now with static
diff --git a/src/test/run-pass/typeclasses-eq-example.rs b/src/test/run-pass/typeclasses-eq-example.rs
index 69d22cf34f1..8e8fd9bf648 100644
--- a/src/test/run-pass/typeclasses-eq-example.rs
+++ b/src/test/run-pass/typeclasses-eq-example.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 // Example from lkuper's intern talk, August 2012.
diff --git a/src/test/run-pass/ufcs-explicit-self.rs b/src/test/run-pass/ufcs-explicit-self.rs
index bd09a311b70..b3cbd2c4eb3 100644
--- a/src/test/run-pass/ufcs-explicit-self.rs
+++ b/src/test/run-pass/ufcs-explicit-self.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 #[derive(Copy, Clone)]
diff --git a/src/test/run-pass/unboxed-closures-boxed.rs b/src/test/run-pass/unboxed-closures-boxed.rs
index 069f26841d2..72d5a1dc043 100644
--- a/src/test/run-pass/unboxed-closures-boxed.rs
+++ b/src/test/run-pass/unboxed-closures-boxed.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::ops::FnMut;
diff --git a/src/test/run-pass/unboxed-closures-call-sugar-object-autoderef.rs b/src/test/run-pass/unboxed-closures-call-sugar-object-autoderef.rs
index 789d2237c54..f4453f1bb8a 100644
--- a/src/test/run-pass/unboxed-closures-call-sugar-object-autoderef.rs
+++ b/src/test/run-pass/unboxed-closures-call-sugar-object-autoderef.rs
@@ -10,8 +10,6 @@
 
 // Test that the call operator autoderefs when calling to an object type.
 
-#![allow(unknown_features)]
-
 use std::ops::FnMut;
 
 fn make_adder(x: isize) -> Box<FnMut(isize)->isize + 'static> {
diff --git a/src/test/run-pass/unboxed-closures-call-sugar-object.rs b/src/test/run-pass/unboxed-closures-call-sugar-object.rs
index e7307715471..2fdb9e9b346 100644
--- a/src/test/run-pass/unboxed-closures-call-sugar-object.rs
+++ b/src/test/run-pass/unboxed-closures-call-sugar-object.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
-
 use std::ops::FnMut;
 
 fn make_adder(x: isize) -> Box<FnMut(isize)->isize + 'static> {
diff --git a/src/test/run-pass/uniq-self-in-mut-slot.rs b/src/test/run-pass/uniq-self-in-mut-slot.rs
index 7910380abee..a4f953ceaf5 100644
--- a/src/test/run-pass/uniq-self-in-mut-slot.rs
+++ b/src/test/run-pass/uniq-self-in-mut-slot.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct X {
diff --git a/src/test/run-pass/unique-assign-copy.rs b/src/test/run-pass/unique-assign-copy.rs
index 3323b3c046b..1e36f5287a7 100644
--- a/src/test/run-pass/unique-assign-copy.rs
+++ b/src/test/run-pass/unique-assign-copy.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-assign-drop.rs b/src/test/run-pass/unique-assign-drop.rs
index 37aa1f0a64b..1227c14ec02 100644
--- a/src/test/run-pass/unique-assign-drop.rs
+++ b/src/test/run-pass/unique-assign-drop.rs
@@ -10,7 +10,6 @@
 
 
 #![allow(dead_assignment)]
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-assign-generic.rs b/src/test/run-pass/unique-assign-generic.rs
index 249b734a691..1abc8203305 100644
--- a/src/test/run-pass/unique-assign-generic.rs
+++ b/src/test/run-pass/unique-assign-generic.rs
@@ -8,11 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
-
 fn f<T>(t: T) -> T {
     let t1 = t;
     t1
diff --git a/src/test/run-pass/unique-assign.rs b/src/test/run-pass/unique-assign.rs
index 8e97fdd4a6a..66b78d27c59 100644
--- a/src/test/run-pass/unique-assign.rs
+++ b/src/test/run-pass/unique-assign.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-autoderef-field.rs b/src/test/run-pass/unique-autoderef-field.rs
index a711dbb685f..4ad465abc48 100644
--- a/src/test/run-pass/unique-autoderef-field.rs
+++ b/src/test/run-pass/unique-autoderef-field.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct J { j: isize }
diff --git a/src/test/run-pass/unique-autoderef-index.rs b/src/test/run-pass/unique-autoderef-index.rs
index 1ef61008b3c..b0abcfab78e 100644
--- a/src/test/run-pass/unique-autoderef-index.rs
+++ b/src/test/run-pass/unique-autoderef-index.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-cmp.rs b/src/test/run-pass/unique-cmp.rs
index 1bd44ecb721..e949215396c 100644
--- a/src/test/run-pass/unique-cmp.rs
+++ b/src/test/run-pass/unique-cmp.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-containing-tag.rs b/src/test/run-pass/unique-containing-tag.rs
index ce5a2bed48d..94f523eb396 100644
--- a/src/test/run-pass/unique-containing-tag.rs
+++ b/src/test/run-pass/unique-containing-tag.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-create.rs b/src/test/run-pass/unique-create.rs
index 6d638bbf562..5ebabf0c29a 100644
--- a/src/test/run-pass/unique-create.rs
+++ b/src/test/run-pass/unique-create.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-decl-init-copy.rs b/src/test/run-pass/unique-decl-init-copy.rs
index 9d749803ffb..71197b9d02f 100644
--- a/src/test/run-pass/unique-decl-init-copy.rs
+++ b/src/test/run-pass/unique-decl-init-copy.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-decl-init.rs b/src/test/run-pass/unique-decl-init.rs
index a00de08998f..2501caddb46 100644
--- a/src/test/run-pass/unique-decl-init.rs
+++ b/src/test/run-pass/unique-decl-init.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-decl-move.rs b/src/test/run-pass/unique-decl-move.rs
index f4ff44ffff5..fc6421e2e08 100644
--- a/src/test/run-pass/unique-decl-move.rs
+++ b/src/test/run-pass/unique-decl-move.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-deref.rs b/src/test/run-pass/unique-deref.rs
index 70b2617797d..8c008683ef3 100644
--- a/src/test/run-pass/unique-deref.rs
+++ b/src/test/run-pass/unique-deref.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-destructure.rs b/src/test/run-pass/unique-destructure.rs
index b368cbee2f6..70b4af1886f 100644
--- a/src/test/run-pass/unique-destructure.rs
+++ b/src/test/run-pass/unique-destructure.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 
diff --git a/src/test/run-pass/unique-drop-complex.rs b/src/test/run-pass/unique-drop-complex.rs
index 1910d51bd0b..bcfb65769da 100644
--- a/src/test/run-pass/unique-drop-complex.rs
+++ b/src/test/run-pass/unique-drop-complex.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-fn-arg-move.rs b/src/test/run-pass/unique-fn-arg-move.rs
index d101cbd3129..45cc530659f 100644
--- a/src/test/run-pass/unique-fn-arg-move.rs
+++ b/src/test/run-pass/unique-fn-arg-move.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn f(i: Box<isize>) {
diff --git a/src/test/run-pass/unique-fn-arg-mut.rs b/src/test/run-pass/unique-fn-arg-mut.rs
index ebe89b275d4..77c4fa29558 100644
--- a/src/test/run-pass/unique-fn-arg-mut.rs
+++ b/src/test/run-pass/unique-fn-arg-mut.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn f(i: &mut Box<isize>) {
diff --git a/src/test/run-pass/unique-fn-arg.rs b/src/test/run-pass/unique-fn-arg.rs
index 97006d2a01a..20a0008ef56 100644
--- a/src/test/run-pass/unique-fn-arg.rs
+++ b/src/test/run-pass/unique-fn-arg.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn f(i: Box<isize>) {
diff --git a/src/test/run-pass/unique-fn-ret.rs b/src/test/run-pass/unique-fn-ret.rs
index d3be0cf01f1..7d88176828e 100644
--- a/src/test/run-pass/unique-fn-ret.rs
+++ b/src/test/run-pass/unique-fn-ret.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn f() -> Box<isize> {
diff --git a/src/test/run-pass/unique-in-tag.rs b/src/test/run-pass/unique-in-tag.rs
index 0762b37ff8b..517cdd02535 100644
--- a/src/test/run-pass/unique-in-tag.rs
+++ b/src/test/run-pass/unique-in-tag.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 fn test1() {
diff --git a/src/test/run-pass/unique-in-vec-copy.rs b/src/test/run-pass/unique-in-vec-copy.rs
index ece206caa02..a460aa6ec10 100644
--- a/src/test/run-pass/unique-in-vec-copy.rs
+++ b/src/test/run-pass/unique-in-vec-copy.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-in-vec.rs b/src/test/run-pass/unique-in-vec.rs
index bd965d41eea..a7edc9cc710 100644
--- a/src/test/run-pass/unique-in-vec.rs
+++ b/src/test/run-pass/unique-in-vec.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-init.rs b/src/test/run-pass/unique-init.rs
index bd7a6495260..768614b1e3c 100644
--- a/src/test/run-pass/unique-init.rs
+++ b/src/test/run-pass/unique-init.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-kinds.rs b/src/test/run-pass/unique-kinds.rs
index f45b3285da7..80364114bce 100644
--- a/src/test/run-pass/unique-kinds.rs
+++ b/src/test/run-pass/unique-kinds.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::cmp::PartialEq;
diff --git a/src/test/run-pass/unique-log.rs b/src/test/run-pass/unique-log.rs
index 148ca4757ae..0c17acb3d89 100644
--- a/src/test/run-pass/unique-log.rs
+++ b/src/test/run-pass/unique-log.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-move-drop.rs b/src/test/run-pass/unique-move-drop.rs
index c2813771b7c..ba865abc371 100644
--- a/src/test/run-pass/unique-move-drop.rs
+++ b/src/test/run-pass/unique-move-drop.rs
@@ -10,7 +10,6 @@
 
 
 #![allow(unused_variables)]
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-move-temp.rs b/src/test/run-pass/unique-move-temp.rs
index 4b937625201..8c1178b9a7e 100644
--- a/src/test/run-pass/unique-move-temp.rs
+++ b/src/test/run-pass/unique-move-temp.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-move.rs b/src/test/run-pass/unique-move.rs
index bed1d6e171a..e731ca818fe 100644
--- a/src/test/run-pass/unique-move.rs
+++ b/src/test/run-pass/unique-move.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-mutable.rs b/src/test/run-pass/unique-mutable.rs
index 8beec6a4198..48006010300 100644
--- a/src/test/run-pass/unique-mutable.rs
+++ b/src/test/run-pass/unique-mutable.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unique-object-move.rs b/src/test/run-pass/unique-object-move.rs
index 4d120e7caf3..d93df4e96f9 100644
--- a/src/test/run-pass/unique-object-move.rs
+++ b/src/test/run-pass/unique-object-move.rs
@@ -12,7 +12,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub trait EventLoop { fn foo(&self) {} }
diff --git a/src/test/run-pass/unique-pat-2.rs b/src/test/run-pass/unique-pat-2.rs
index c314b70e536..12e81a202e9 100644
--- a/src/test/run-pass/unique-pat-2.rs
+++ b/src/test/run-pass/unique-pat-2.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 
diff --git a/src/test/run-pass/unique-pat-3.rs b/src/test/run-pass/unique-pat-3.rs
index 648e9599a97..9f361d460e0 100644
--- a/src/test/run-pass/unique-pat-3.rs
+++ b/src/test/run-pass/unique-pat-3.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 enum bar { u(Box<isize>), w(isize), }
diff --git a/src/test/run-pass/unique-pat.rs b/src/test/run-pass/unique-pat.rs
index 1312ea924b5..8af160b1f56 100644
--- a/src/test/run-pass/unique-pat.rs
+++ b/src/test/run-pass/unique-pat.rs
@@ -9,7 +9,6 @@
 // except according to those terms.
 
 
-#![allow(unknown_features)]
 #![feature(box_patterns)]
 #![feature(box_syntax)]
 
diff --git a/src/test/run-pass/unique-rec.rs b/src/test/run-pass/unique-rec.rs
index 72975c27eea..aa3fc8f5bb5 100644
--- a/src/test/run-pass/unique-rec.rs
+++ b/src/test/run-pass/unique-rec.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 struct X { x: isize }
diff --git a/src/test/run-pass/unique-send-2.rs b/src/test/run-pass/unique-send-2.rs
index 2e864797db0..7a0e585e8b0 100644
--- a/src/test/run-pass/unique-send-2.rs
+++ b/src/test/run-pass/unique-send-2.rs
@@ -10,7 +10,6 @@
 
 // ignore-emscripten no threads support
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::sync::mpsc::{channel, Sender};
diff --git a/src/test/run-pass/unique-send.rs b/src/test/run-pass/unique-send.rs
index bc0f790b2b0..7644da08e4a 100644
--- a/src/test/run-pass/unique-send.rs
+++ b/src/test/run-pass/unique-send.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::sync::mpsc::channel;
diff --git a/src/test/run-pass/unique-swap.rs b/src/test/run-pass/unique-swap.rs
index cfa076f1a07..6e6fe4e420b 100644
--- a/src/test/run-pass/unique-swap.rs
+++ b/src/test/run-pass/unique-swap.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::mem::swap;
diff --git a/src/test/run-pass/unsized2.rs b/src/test/run-pass/unsized2.rs
index 50d8d3d27f2..90b99f98533 100644
--- a/src/test/run-pass/unsized2.rs
+++ b/src/test/run-pass/unsized2.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 // Test sized-ness checking in substitution.
diff --git a/src/test/run-pass/unused-move-capture.rs b/src/test/run-pass/unused-move-capture.rs
index b155620e519..e5a77d1cdbd 100644
--- a/src/test/run-pass/unused-move-capture.rs
+++ b/src/test/run-pass/unused-move-capture.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/unused-move.rs b/src/test/run-pass/unused-move.rs
index e4b9d14fb4b..9a0ea181d99 100644
--- a/src/test/run-pass/unused-move.rs
+++ b/src/test/run-pass/unused-move.rs
@@ -15,7 +15,6 @@
 // pretty-expanded FIXME #23616
 
 #![allow(path_statements)]
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main()
diff --git a/src/test/run-pass/unwind-unique.rs b/src/test/run-pass/unwind-unique.rs
index 320a11f64d8..321e8198817 100644
--- a/src/test/run-pass/unwind-unique.rs
+++ b/src/test/run-pass/unwind-unique.rs
@@ -10,7 +10,6 @@
 
 // ignore-emscripten no threads support
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 use std::thread;
diff --git a/src/test/run-pass/vec-dst.rs b/src/test/run-pass/vec-dst.rs
index aadbb922f67..cf4222b405e 100644
--- a/src/test/run-pass/vec-dst.rs
+++ b/src/test/run-pass/vec-dst.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() {
diff --git a/src/test/run-pass/vector-no-ann-2.rs b/src/test/run-pass/vector-no-ann-2.rs
index 10f71b3e12c..09e70cf03ca 100644
--- a/src/test/run-pass/vector-no-ann-2.rs
+++ b/src/test/run-pass/vector-no-ann-2.rs
@@ -10,7 +10,6 @@
 
 // pretty-expanded FIXME #23616
 
-#![allow(unknown_features)]
 #![feature(box_syntax)]
 
 pub fn main() { let _quux: Box<Vec<usize>> = box Vec::new(); }
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.rs b/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.rs
index db50b951443..dd235cb9c3a 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.rs
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.rs
@@ -43,6 +43,7 @@
 #![feature(rustc_attrs)] // For `rustc_error`; see note below.
 #![warn(unused_attributes, unknown_lints)]
 #![allow(dead_code)]
+#![allow(stable_features)]
 
 // UNGATED WHITE-LISTED BUILT-IN ATTRIBUTES
 
@@ -100,7 +101,7 @@
 // For #![crate_id], see issue #43142. (I cannot bear to enshrine current behavior in a test)
 
 // FIXME(#44232) we should warn that this isn't used.
-#![feature                    ( x0600)]
+#![feature                    ( rust1)]
 
 // For #![no_start], see issue #43144. (I cannot bear to enshrine current behavior in a test)
 
diff --git a/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.stderr b/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.stderr
index 2dbe9831014..fd38fb6f976 100644
--- a/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.stderr
+++ b/src/test/ui/feature-gate/issue-43106-gating-of-builtin-attrs.stderr
@@ -1,5 +1,5 @@
 warning: unknown lint: `x5400`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:49:33
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:50:33
    |
 LL | #![warn                        (x5400)] //~ WARN unknown lint: `x5400`
    |                                 ^^^^^
@@ -11,175 +11,175 @@ LL | #![warn(unused_attributes, unknown_lints)]
    |                            ^^^^^^^^^^^^^
 
 warning: unknown lint: `x5300`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:50:33
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:51:33
    |
 LL | #![allow                       (x5300)] //~ WARN unknown lint: `x5300`
    |                                 ^^^^^
 
 warning: unknown lint: `x5200`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:51:33
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:52:33
    |
 LL | #![forbid                      (x5200)] //~ WARN unknown lint: `x5200`
    |                                 ^^^^^
 
 warning: unknown lint: `x5100`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:52:33
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:53:33
    |
 LL | #![deny                        (x5100)] //~ WARN unknown lint: `x5100`
    |                                 ^^^^^
 
 warning: unknown lint: `x5400`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:114:8
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:115:8
    |
 LL | #[warn(x5400)]
    |        ^^^^^
 
 warning: unknown lint: `x5400`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:117:25
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:118:25
    |
 LL |     mod inner { #![warn(x5400)] }
    |                         ^^^^^
 
 warning: unknown lint: `x5400`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:120:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:121:12
    |
 LL |     #[warn(x5400)] fn f() { }
    |            ^^^^^
 
 warning: unknown lint: `x5400`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:123:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:124:12
    |
 LL |     #[warn(x5400)] struct S;
    |            ^^^^^
 
 warning: unknown lint: `x5400`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:126:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:127:12
    |
 LL |     #[warn(x5400)] type T = S;
    |            ^^^^^
 
 warning: unknown lint: `x5400`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:129:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:130:12
    |
 LL |     #[warn(x5400)] impl S { }
    |            ^^^^^
 
 warning: unknown lint: `x5300`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:133:9
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:134:9
    |
 LL | #[allow(x5300)]
    |         ^^^^^
 
 warning: unknown lint: `x5300`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:136:26
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:137:26
    |
 LL |     mod inner { #![allow(x5300)] }
    |                          ^^^^^
 
 warning: unknown lint: `x5300`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:139:13
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:140:13
    |
 LL |     #[allow(x5300)] fn f() { }
    |             ^^^^^
 
 warning: unknown lint: `x5300`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:142:13
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:143:13
    |
 LL |     #[allow(x5300)] struct S;
    |             ^^^^^
 
 warning: unknown lint: `x5300`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:145:13
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:146:13
    |
 LL |     #[allow(x5300)] type T = S;
    |             ^^^^^
 
 warning: unknown lint: `x5300`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:148:13
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:149:13
    |
 LL |     #[allow(x5300)] impl S { }
    |             ^^^^^
 
 warning: unknown lint: `x5200`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:152:10
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:153:10
    |
 LL | #[forbid(x5200)]
    |          ^^^^^
 
 warning: unknown lint: `x5200`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:155:27
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:156:27
    |
 LL |     mod inner { #![forbid(x5200)] }
    |                           ^^^^^
 
 warning: unknown lint: `x5200`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:158:14
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:159:14
    |
 LL |     #[forbid(x5200)] fn f() { }
    |              ^^^^^
 
 warning: unknown lint: `x5200`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:161:14
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:162:14
    |
 LL |     #[forbid(x5200)] struct S;
    |              ^^^^^
 
 warning: unknown lint: `x5200`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:164:14
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:165:14
    |
 LL |     #[forbid(x5200)] type T = S;
    |              ^^^^^
 
 warning: unknown lint: `x5200`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:167:14
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:168:14
    |
 LL |     #[forbid(x5200)] impl S { }
    |              ^^^^^
 
 warning: unknown lint: `x5100`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:171:8
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:172:8
    |
 LL | #[deny(x5100)]
    |        ^^^^^
 
 warning: unknown lint: `x5100`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:174:25
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:175:25
    |
 LL |     mod inner { #![deny(x5100)] }
    |                         ^^^^^
 
 warning: unknown lint: `x5100`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:177:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:178:12
    |
 LL |     #[deny(x5100)] fn f() { }
    |            ^^^^^
 
 warning: unknown lint: `x5100`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:180:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:181:12
    |
 LL |     #[deny(x5100)] struct S;
    |            ^^^^^
 
 warning: unknown lint: `x5100`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:183:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:184:12
    |
 LL |     #[deny(x5100)] type T = S;
    |            ^^^^^
 
 warning: unknown lint: `x5100`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:186:12
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:187:12
    |
 LL |     #[deny(x5100)] impl S { }
    |            ^^^^^
 
 warning: macro_escape is a deprecated synonym for macro_use
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:500:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:501:1
    |
 LL | #[macro_escape]
    | ^^^^^^^^^^^^^^^
 
 warning: macro_escape is a deprecated synonym for macro_use
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:503:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:504:17
    |
 LL |     mod inner { #![macro_escape] }
    |                 ^^^^^^^^^^^^^^^^
@@ -187,7 +187,7 @@ LL |     mod inner { #![macro_escape] }
    = help: consider an outer attribute, #[macro_use] mod ...
 
 warning: `repr` attribute isn't configurable with a literal
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:316:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:317:17
    |
 LL |     mod inner { #![repr="3900"] }
    |                 ^^^^^^^^^^^^^^^ needs a hint
@@ -197,7 +197,7 @@ LL |     mod inner { #![repr="3900"] }
    = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html>
 
 warning: `repr` attribute isn't configurable with a literal
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:320:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:321:5
    |
 LL |     #[repr = "3900"] fn f() { }
    |     ^^^^^^^^^^^^^^^^ needs a hint
@@ -206,7 +206,7 @@ LL |     #[repr = "3900"] fn f() { }
    = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html>
 
 warning: `repr` attribute isn't configurable with a literal
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:326:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:327:5
    |
 LL |     #[repr = "3900"] type T = S;
    |     ^^^^^^^^^^^^^^^^ needs a hint
@@ -215,7 +215,7 @@ LL |     #[repr = "3900"] type T = S;
    = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html>
 
 warning: `repr` attribute isn't configurable with a literal
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:330:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:331:5
    |
 LL |     #[repr = "3900"] impl S { }
    |     ^^^^^^^^^^^^^^^^ needs a hint
@@ -224,7 +224,7 @@ LL |     #[repr = "3900"] impl S { }
    = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html>
 
 warning: `repr` attribute isn't configurable with a literal
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:312:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:313:1
    |
 LL | #[repr = "3900"]
    | ^^^^^^^^^^^^^^^^ needs a hint
@@ -233,7 +233,7 @@ LL | #[repr = "3900"]
    = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html>
 
 warning: `repr` attribute isn't configurable with a literal
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:62:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:63:1
    |
 LL | #![repr                       = "3900"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ needs a hint
@@ -242,7 +242,7 @@ LL | #![repr                       = "3900"]
    = note: for more information, visit <https://doc.rust-lang.org/reference/type-layout.html>
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:194:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:195:5
    |
 LL |     #[macro_use] fn f() { }
    |     ^^^^^^^^^^^^
@@ -254,277 +254,277 @@ LL | #![warn(unused_attributes, unknown_lints)]
    |         ^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:197:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:198:5
    |
 LL |     #[macro_use] struct S;
    |     ^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:200:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:201:5
    |
 LL |     #[macro_use] type T = S;
    |     ^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:203:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:204:5
    |
 LL |     #[macro_use] impl S { }
    |     ^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:210:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:211:17
    |
 LL |     mod inner { #![macro_export="4800"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:213:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:214:5
    |
 LL |     #[macro_export = "4800"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:216:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:217:5
    |
 LL |     #[macro_export = "4800"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:219:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:220:5
    |
 LL |     #[macro_export = "4800"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:222:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:223:5
    |
 LL |     #[macro_export = "4800"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:207:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:208:1
    |
 LL | #[macro_export = "4800"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:229:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:230:17
    |
 LL |     mod inner { #![plugin_registrar="4700"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:234:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:235:5
    |
 LL |     #[plugin_registrar = "4700"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:237:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:238:5
    |
 LL |     #[plugin_registrar = "4700"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:240:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:241:5
    |
 LL |     #[plugin_registrar = "4700"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:226:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:227:1
    |
 LL | #[plugin_registrar = "4700"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:247:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:248:17
    |
 LL |     mod inner { #![main="4300"] }
    |                 ^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:252:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:253:5
    |
 LL |     #[main = "4400"] struct S;
    |     ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:255:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:256:5
    |
 LL |     #[main = "4400"] type T = S;
    |     ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:258:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:259:5
    |
 LL |     #[main = "4400"] impl S { }
    |     ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:244:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:245:1
    |
 LL | #[main = "4400"]
    | ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:265:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:266:17
    |
 LL |     mod inner { #![start="4300"] }
    |                 ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:270:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:271:5
    |
 LL |     #[start = "4300"] struct S;
    |     ^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:273:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:274:5
    |
 LL |     #[start = "4300"] type T = S;
    |     ^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:276:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:277:5
    |
 LL |     #[start = "4300"] impl S { }
    |     ^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:262:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:263:1
    |
 LL | #[start = "4300"]
    | ^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:316:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:317:17
    |
 LL |     mod inner { #![repr="3900"] }
    |                 ^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:320:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:321:5
    |
 LL |     #[repr = "3900"] fn f() { }
    |     ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:326:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:327:5
    |
 LL |     #[repr = "3900"] type T = S;
    |     ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:330:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:331:5
    |
 LL |     #[repr = "3900"] impl S { }
    |     ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:312:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:313:1
    |
 LL | #[repr = "3900"]
    | ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:339:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:340:5
    |
 LL |     #[path = "3800"] fn f() { }
    |     ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:342:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:343:5
    |
 LL |     #[path = "3800"]  struct S;
    |     ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:345:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:346:5
    |
 LL |     #[path = "3800"] type T = S;
    |     ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:348:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:349:5
    |
 LL |     #[path = "3800"] impl S { }
    |     ^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:355:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:356:17
    |
 LL |     mod inner { #![abi="3700"] }
    |                 ^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:358:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:359:5
    |
 LL |     #[abi = "3700"] fn f() { }
    |     ^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:361:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:362:5
    |
 LL |     #[abi = "3700"] struct S;
    |     ^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:364:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:365:5
    |
 LL |     #[abi = "3700"] type T = S;
    |     ^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:367:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:368:5
    |
 LL |     #[abi = "3700"] impl S { }
    |     ^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:352:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:353:1
    |
 LL | #[abi = "3700"]
    | ^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:374:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:375:17
    |
 LL |     mod inner { #![automatically_derived="3600"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:377:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:378:5
    |
 LL |     #[automatically_derived = "3600"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:380:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:381:5
    |
 LL |     #[automatically_derived = "3600"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:383:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:384:5
    |
 LL |     #[automatically_derived = "3600"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:386:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:387:5
    |
 LL |     #[automatically_derived = "3600"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:371:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:372:1
    |
 LL | #[automatically_derived = "3600"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: function is marked #[no_mangle], but not exported
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:394:27
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:395:27
    |
 LL |     #[no_mangle = "3500"] fn f() { }
    |                           -^^^^^^^^^
@@ -534,787 +534,787 @@ LL |     #[no_mangle = "3500"] fn f() { }
    = note: #[warn(private_no_mangle_fns)] on by default
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:407:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:408:17
    |
 LL |     mod inner { #![no_link="3400"] }
    |                 ^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:410:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:411:5
    |
 LL |     #[no_link = "3400"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:413:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:414:5
    |
 LL |     #[no_link = "3400"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:416:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:417:5
    |
 LL |     #[no_link = "3400"]type T = S;
    |     ^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:419:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:420:5
    |
 LL |     #[no_link = "3400"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:404:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:405:1
    |
 LL | #[no_link = "3400"]
    | ^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:426:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:427:17
    |
 LL |     mod inner { #![should_panic="3200"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:429:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:430:5
    |
 LL |     #[should_panic = "3200"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:432:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:433:5
    |
 LL |     #[should_panic = "3200"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:435:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:436:5
    |
 LL |     #[should_panic = "3200"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:438:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:439:5
    |
 LL |     #[should_panic = "3200"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:423:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:424:1
    |
 LL | #[should_panic = "3200"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:445:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:446:17
    |
 LL |     mod inner { #![ignore="3100"] }
    |                 ^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:448:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:449:5
    |
 LL |     #[ignore = "3100"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:451:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:452:5
    |
 LL |     #[ignore = "3100"] struct S;
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:454:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:455:5
    |
 LL |     #[ignore = "3100"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:457:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:458:5
    |
 LL |     #[ignore = "3100"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:442:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:443:1
    |
 LL | #[ignore = "3100"]
    | ^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:464:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:465:17
    |
 LL |     mod inner { #![no_implicit_prelude="3000"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:467:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:468:5
    |
 LL |     #[no_implicit_prelude = "3000"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:470:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:471:5
    |
 LL |     #[no_implicit_prelude = "3000"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:473:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:474:5
    |
 LL |     #[no_implicit_prelude = "3000"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:476:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:477:5
    |
 LL |     #[no_implicit_prelude = "3000"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:461:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:462:1
    |
 LL | #[no_implicit_prelude = "3000"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:483:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:484:17
    |
 LL |     mod inner { #![reexport_test_harness_main="2900"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:486:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:487:5
    |
 LL |     #[reexport_test_harness_main = "2900"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:489:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:490:5
    |
 LL |     #[reexport_test_harness_main = "2900"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:492:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:493:5
    |
 LL |     #[reexport_test_harness_main = "2900"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:495:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:496:5
    |
 LL |     #[reexport_test_harness_main = "2900"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:480:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:481:1
    |
 LL | #[reexport_test_harness_main = "2900"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:506:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:507:5
    |
 LL |     #[macro_escape] fn f() { }
    |     ^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:509:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:510:5
    |
 LL |     #[macro_escape] struct S;
    |     ^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:512:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:513:5
    |
 LL |     #[macro_escape] type T = S;
    |     ^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:515:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:516:5
    |
 LL |     #[macro_escape] impl S { }
    |     ^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:523:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:524:17
    |
 LL |     mod inner { #![no_std="2600"] }
    |                 ^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:523:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:524:17
    |
 LL |     mod inner { #![no_std="2600"] }
    |                 ^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:527:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:528:5
    |
 LL |     #[no_std = "2600"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:527:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:528:5
    |
 LL |     #[no_std = "2600"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:531:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:532:5
    |
 LL |     #[no_std = "2600"] struct S;
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:531:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:532:5
    |
 LL |     #[no_std = "2600"] struct S;
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:535:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:536:5
    |
 LL |     #[no_std = "2600"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:535:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:536:5
    |
 LL |     #[no_std = "2600"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:539:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:540:5
    |
 LL |     #[no_std = "2600"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:539:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:540:5
    |
 LL |     #[no_std = "2600"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:519:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:520:1
    |
 LL | #[no_std = "2600"]
    | ^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:519:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:520:1
    |
 LL | #[no_std = "2600"]
    | ^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:678:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:679:17
    |
 LL |     mod inner { #![crate_name="0900"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:678:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:679:17
    |
 LL |     mod inner { #![crate_name="0900"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:682:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:683:5
    |
 LL |     #[crate_name = "0900"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:682:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:683:5
    |
 LL |     #[crate_name = "0900"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:686:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:687:5
    |
 LL |     #[crate_name = "0900"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:686:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:687:5
    |
 LL |     #[crate_name = "0900"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:690:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:691:5
    |
 LL |     #[crate_name = "0900"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:690:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:691:5
    |
 LL |     #[crate_name = "0900"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:694:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:695:5
    |
 LL |     #[crate_name = "0900"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:694:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:695:5
    |
 LL |     #[crate_name = "0900"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:674:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:675:1
    |
 LL | #[crate_name = "0900"]
    | ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:674:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:675:1
    |
 LL | #[crate_name = "0900"]
    | ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:703:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:704:17
    |
 LL |     mod inner { #![crate_type="0800"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:703:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:704:17
    |
 LL |     mod inner { #![crate_type="0800"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:707:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:708:5
    |
 LL |     #[crate_type = "0800"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:707:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:708:5
    |
 LL |     #[crate_type = "0800"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:711:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:712:5
    |
 LL |     #[crate_type = "0800"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:711:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:712:5
    |
 LL |     #[crate_type = "0800"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:715:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:716:5
    |
 LL |     #[crate_type = "0800"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:715:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:716:5
    |
 LL |     #[crate_type = "0800"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:719:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:720:5
    |
 LL |     #[crate_type = "0800"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:719:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:720:5
    |
 LL |     #[crate_type = "0800"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:699:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:700:1
    |
 LL | #[crate_type = "0800"]
    | ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:699:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:700:1
    |
 LL | #[crate_type = "0800"]
    | ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:728:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:729:17
    |
 LL |     mod inner { #![feature(x0600)] }
    |                 ^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:728:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:729:17
    |
 LL |     mod inner { #![feature(x0600)] }
    |                 ^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:732:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:733:5
    |
 LL |     #[feature(x0600)] fn f() { }
    |     ^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:732:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:733:5
    |
 LL |     #[feature(x0600)] fn f() { }
    |     ^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:736:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:737:5
    |
 LL |     #[feature(x0600)] struct S;
    |     ^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:736:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:737:5
    |
 LL |     #[feature(x0600)] struct S;
    |     ^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:740:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:741:5
    |
 LL |     #[feature(x0600)] type T = S;
    |     ^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:740:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:741:5
    |
 LL |     #[feature(x0600)] type T = S;
    |     ^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:744:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:745:5
    |
 LL |     #[feature(x0600)] impl S { }
    |     ^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:744:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:745:5
    |
 LL |     #[feature(x0600)] impl S { }
    |     ^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:724:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:725:1
    |
 LL | #[feature(x0600)]
    | ^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:724:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:725:1
    |
 LL | #[feature(x0600)]
    | ^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:754:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:755:17
    |
 LL |     mod inner { #![no_main="0400"] }
    |                 ^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:754:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:755:17
    |
 LL |     mod inner { #![no_main="0400"] }
    |                 ^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:758:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:759:5
    |
 LL |     #[no_main = "0400"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:758:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:759:5
    |
 LL |     #[no_main = "0400"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:762:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:763:5
    |
 LL |     #[no_main = "0400"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:762:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:763:5
    |
 LL |     #[no_main = "0400"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:766:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:767:5
    |
 LL |     #[no_main = "0400"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:766:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:767:5
    |
 LL |     #[no_main = "0400"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:770:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:771:5
    |
 LL |     #[no_main = "0400"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:770:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:771:5
    |
 LL |     #[no_main = "0400"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:750:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:751:1
    |
 LL | #[no_main = "0400"]
    | ^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:750:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:751:1
    |
 LL | #[no_main = "0400"]
    | ^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:792:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:793:17
    |
 LL |     mod inner { #![recursion_limit="0200"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:792:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:793:17
    |
 LL |     mod inner { #![recursion_limit="0200"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:796:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:797:5
    |
 LL |     #[recursion_limit="0200"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:796:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:797:5
    |
 LL |     #[recursion_limit="0200"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:800:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:801:5
    |
 LL |     #[recursion_limit="0200"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:800:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:801:5
    |
 LL |     #[recursion_limit="0200"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:804:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:805:5
    |
 LL |     #[recursion_limit="0200"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:804:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:805:5
    |
 LL |     #[recursion_limit="0200"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:808:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:809:5
    |
 LL |     #[recursion_limit="0200"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:808:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:809:5
    |
 LL |     #[recursion_limit="0200"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:788:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:789:1
    |
 LL | #[recursion_limit="0200"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:788:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:789:1
    |
 LL | #[recursion_limit="0200"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:817:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:818:17
    |
 LL |     mod inner { #![type_length_limit="0100"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:817:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:818:17
    |
 LL |     mod inner { #![type_length_limit="0100"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:821:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:822:5
    |
 LL |     #[type_length_limit="0100"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:821:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:822:5
    |
 LL |     #[type_length_limit="0100"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:825:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:826:5
    |
 LL |     #[type_length_limit="0100"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:825:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:826:5
    |
 LL |     #[type_length_limit="0100"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:829:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:830:5
    |
 LL |     #[type_length_limit="0100"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:829:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:830:5
    |
 LL |     #[type_length_limit="0100"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:833:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:834:5
    |
 LL |     #[type_length_limit="0100"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:833:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:834:5
    |
 LL |     #[type_length_limit="0100"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:813:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:814:1
    |
 LL | #[type_length_limit="0100"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: #![foo]
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:813:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:814:1
    |
 LL | #[type_length_limit="0100"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:54:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:55:1
    |
 LL | #![macro_export               = "4800"] //~ WARN unused attribute
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:55:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:56:1
    |
 LL | #![plugin_registrar           = "4700"] //~ WARN unused attribute
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:58:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:59:1
    |
 LL | #![main                      = "x4400"] //~ WARN unused attribute
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:59:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:60:1
    |
 LL | #![start                     = "x4300"] //~ WARN unused attribute
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:62:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:63:1
    |
 LL | #![repr                       = "3900"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:65:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:66:1
    |
 LL | #![path                       = "3800"] //~ WARN unused attribute
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:66:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:67:1
    |
 LL | #![abi                        = "3700"] //~ WARN unused attribute
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:67:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:68:1
    |
 LL | #![automatically_derived      = "3600"] //~ WARN unused attribute
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:69:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:70:1
    |
 LL | #![no_link                    = "3400"] //~ WARN unused attribute
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:71:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:72:1
    |
 LL | #![should_panic               = "3200"] //~ WARN unused attribute
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:72:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:73:1
    |
 LL | #![ignore                     = "3100"] //~ WARN unused attribute
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: unused attribute
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:78:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:79:1
    |
 LL | #![proc_macro_derive          = "2500"] //~ WARN unused attribute
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: compilation successful
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:844:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:845:1
    |
 LL | / fn main() { //~ ERROR compilation successful
 LL | |     println!("Hello World");
diff --git a/src/test/ui/feature-gate/unknown-feature.rs b/src/test/ui/feature-gate/unknown-feature.rs
index 4101faf7dd0..da1b257f634 100644
--- a/src/test/ui/feature-gate/unknown-feature.rs
+++ b/src/test/ui/feature-gate/unknown-feature.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![deny(unknown_features)]
-
 #![feature(unknown_rust_feature)] //~ ERROR unknown feature
 
 fn main() {}
diff --git a/src/test/ui/feature-gate/unknown-feature.stderr b/src/test/ui/feature-gate/unknown-feature.stderr
index 392d918246f..f44aaeec032 100644
--- a/src/test/ui/feature-gate/unknown-feature.stderr
+++ b/src/test/ui/feature-gate/unknown-feature.stderr
@@ -1,14 +1,9 @@
-error: unknown feature `unknown_rust_feature`
-  --> $DIR/unknown-feature.rs:13:12
+error[E0635]: unknown feature `unknown_rust_feature`
+  --> $DIR/unknown-feature.rs:11:12
    |
 LL | #![feature(unknown_rust_feature)] //~ ERROR unknown feature
    |            ^^^^^^^^^^^^^^^^^^^^
-   |
-note: lint level defined here
-  --> $DIR/unknown-feature.rs:11:9
-   |
-LL | #![deny(unknown_features)]
-   |         ^^^^^^^^^^^^^^^^
 
 error: aborting due to previous error
 
+For more information about this error, try `rustc --explain E0635`.
diff --git a/src/test/ui/lint-output-format-2.rs b/src/test/ui/lint-output-format-2.rs
index 811b14063bb..e87ddde7413 100644
--- a/src/test/ui/lint-output-format-2.rs
+++ b/src/test/ui/lint-output-format-2.rs
@@ -10,9 +10,6 @@
 
 // aux-build:lint_output_format.rs
 
-// FIXME(#44232) we should warn that this isn't used.
-#![feature(foo)]
-
 #![feature(unstable_test_feature)]
 #![feature(rustc_attrs)]
 
diff --git a/src/test/ui/lint-output-format-2.stderr b/src/test/ui/lint-output-format-2.stderr
index d484061ef96..8c6247688e8 100644
--- a/src/test/ui/lint-output-format-2.stderr
+++ b/src/test/ui/lint-output-format-2.stderr
@@ -1,5 +1,5 @@
 warning: use of deprecated item 'lint_output_format::foo': text
-  --> $DIR/lint-output-format-2.rs:20:26
+  --> $DIR/lint-output-format-2.rs:17:26
    |
 LL | use lint_output_format::{foo, bar};
    |                          ^^^
@@ -7,13 +7,13 @@ LL | use lint_output_format::{foo, bar};
    = note: #[warn(deprecated)] on by default
 
 warning: use of deprecated item 'lint_output_format::foo': text
-  --> $DIR/lint-output-format-2.rs:25:14
+  --> $DIR/lint-output-format-2.rs:22:14
    |
 LL |     let _x = foo();
    |              ^^^
 
 error: compilation successful
-  --> $DIR/lint-output-format-2.rs:24:1
+  --> $DIR/lint-output-format-2.rs:21:1
    |
 LL | / fn main() { //~ ERROR: compilation successful
 LL | |     let _x = foo();