Add checks for more empty attributes.

compiler/rustc_passes/src/check_attr.rs

@@ -173,8 +173,17 @@ impl CheckAttrVisitor<'tcx> {
             }
 
             // Warn on useless empty attributes.
-            if matches!(attr.name_or_empty(), sym::macro_use)
+            if matches!(
-                && attr.meta_item_list().map_or(false, |list| list.is_empty())
+                attr.name_or_empty(),
+                sym::macro_use
+                    | sym::allow
+                    | sym::warn
+                    | sym::deny
+                    | sym::forbid
+                    | sym::feature
+                    | sym::repr
+                    | sym::target_feature
+            ) && attr.meta_item_list().map_or(false, |list| list.is_empty())
             {
                 self.tcx.struct_span_lint_hir(UNUSED_ATTRIBUTES, hir_id, attr.span, |lint| {
                     lint.build("unused attribute")

src/test/ui/empty/empty-attributes.rs

@@ -0,0 +1,14 @@
+#![deny(unused_attributes)]
+#![allow()] //~ ERROR unused attribute
+#![warn()] //~ ERROR unused attribute
+#![deny()] //~ ERROR unused attribute
+#![forbid()] //~ ERROR unused attribute
+#![feature()] //~ ERROR unused attribute
+
+#[repr()] //~ ERROR unused attribute
+pub struct S;
+
+#[target_feature()] //~ ERROR unused attribute
+pub unsafe fn foo() {}
+
+fn main() {}

src/test/ui/empty/empty-attributes.stderr

@@ -0,0 +1,63 @@
+error: unused attribute
+  --> $DIR/empty-attributes.rs:8:1
+   |
+LL | #[repr()]
+   | ^^^^^^^^^ help: remove this attribute
+   |
+note: the lint level is defined here
+  --> $DIR/empty-attributes.rs:1:9
+   |
+LL | #![deny(unused_attributes)]
+   |         ^^^^^^^^^^^^^^^^^
+   = note: attribute `repr` with an empty list has no effect
+
+error: unused attribute
+  --> $DIR/empty-attributes.rs:11:1
+   |
+LL | #[target_feature()]
+   | ^^^^^^^^^^^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `target_feature` with an empty list has no effect
+
+error: unused attribute
+  --> $DIR/empty-attributes.rs:2:1
+   |
+LL | #![allow()]
+   | ^^^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `allow` with an empty list has no effect
+
+error: unused attribute
+  --> $DIR/empty-attributes.rs:3:1
+   |
+LL | #![warn()]
+   | ^^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `warn` with an empty list has no effect
+
+error: unused attribute
+  --> $DIR/empty-attributes.rs:4:1
+   |
+LL | #![deny()]
+   | ^^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `deny` with an empty list has no effect
+
+error: unused attribute
+  --> $DIR/empty-attributes.rs:5:1
+   |
+LL | #![forbid()]
+   | ^^^^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `forbid` with an empty list has no effect
+
+error: unused attribute
+  --> $DIR/empty-attributes.rs:6:1
+   |
+LL | #![feature()]
+   | ^^^^^^^^^^^^^ help: remove this attribute
+   |
+   = note: attribute `feature` with an empty list has no effect
+
+error: aborting due to 7 previous errors
+

src/test/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.rs

@@ -134,4 +134,27 @@ mod start {
     //~^ ERROR: `start` attribute can only be used on functions
 }
 
+#[repr(C)]
+//~^ ERROR: attribute should be applied to a struct, enum, or union
+mod repr {
+//~^ NOTE not a struct, enum, or union
+    mod inner { #![repr(C)] }
+    //~^ ERROR: attribute should be applied to a struct, enum, or union
+    //~| NOTE not a struct, enum, or union
+
+    #[repr(C)] fn f() { }
+    //~^ ERROR: attribute should be applied to a struct, enum, or union
+    //~| NOTE not a struct, enum, or union
+
+    struct S;
+
+    #[repr(C)] type T = S;
+    //~^ ERROR: attribute should be applied to a struct, enum, or union
+    //~| NOTE not a struct, enum, or union
+
+    #[repr(C)] impl S { }
+    //~^ ERROR: attribute should be applied to a struct, enum, or union
+    //~| NOTE not a struct, enum, or union
+}
+
 fn main() {}

src/test/ui/feature-gates/issue-43106-gating-of-builtin-attrs-error.stderr

@@ -91,6 +91,21 @@ LL | |     }
 LL | | }
    | |_- not a free function, impl method or static
 
+error[E0517]: attribute should be applied to a struct, enum, or union
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:137:8
+   |
+LL |   #[repr(C)]
+   |          ^
+LL |
+LL | / mod repr {
+LL | |
+LL | |     mod inner { #![repr(C)] }
+LL | |
+...  |
+LL | |
+LL | | }
+   | |_- not a struct, enum, or union
+
 error: attribute should be applied to an `extern crate` item
   --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:25:1
    |
@@ -235,7 +250,31 @@ error: attribute should be applied to a free function, impl method or static
 LL |         #[export_name = "2200"] fn bar() {}
    |         ^^^^^^^^^^^^^^^^^^^^^^^ ----------- not a free function, impl method or static
 
-error: aborting due to 34 previous errors
+error[E0517]: attribute should be applied to a struct, enum, or union
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:141:25
+   |
+LL |     mod inner { #![repr(C)] }
+   |     --------------------^---- not a struct, enum, or union
 
-Some errors have detailed explanations: E0518, E0658.
+error[E0517]: attribute should be applied to a struct, enum, or union
-For more information about an error, try `rustc --explain E0518`.
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:145:12
+   |
+LL |     #[repr(C)] fn f() { }
+   |            ^   ---------- not a struct, enum, or union
+
+error[E0517]: attribute should be applied to a struct, enum, or union
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:151:12
+   |
+LL |     #[repr(C)] type T = S;
+   |            ^   ----------- not a struct, enum, or union
+
+error[E0517]: attribute should be applied to a struct, enum, or union
+  --> $DIR/issue-43106-gating-of-builtin-attrs-error.rs:155:12
+   |
+LL |     #[repr(C)] impl S { }
+   |            ^   ---------- not a struct, enum, or union
+
+error: aborting due to 39 previous errors
+
+Some errors have detailed explanations: E0517, E0518, E0658.
+For more information about an error, try `rustc --explain E0517`.

src/test/ui/feature-gates/issue-43106-gating-of-builtin-attrs.rs

@@ -245,19 +245,6 @@ mod bench {
     impl S { }
 }
 
-#[repr()]
-mod repr {
-    mod inner { #![repr()] }
-
-    #[repr()] fn f() { }
-
-    struct S;
-
-    #[repr()] type T = S;
-
-    #[repr()] impl S { }
-}
-
 #[path = "3800"]
 mod path {
     mod inner { #![path="3800"] }

src/test/ui/feature-gates/issue-43106-gating-of-builtin-attrs.stderr

@@ -173,7 +173,7 @@ LL |     #[deny(x5100)] impl S { }
    |            ^^^^^
 
 warning: `#[macro_escape]` is a deprecated synonym for `#[macro_use]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:412:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:399:17
    |
 LL |     mod inner { #![macro_escape] }
    |                 ^^^^^^^^^^^^^^^^
@@ -181,7 +181,7 @@ LL |     mod inner { #![macro_escape] }
    = help: try an outer attribute: `#[macro_use]`
 
 warning: `#[macro_escape]` is a deprecated synonym for `#[macro_use]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:409:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:396:1
    |
 LL | #[macro_escape]
    | ^^^^^^^^^^^^^^^
@@ -213,13 +213,13 @@ LL | #![warn(unused_attributes, unknown_lints)]
    |         ^^^^^^^^^^^^^^^^^
 
 warning: `#[automatically_derived]` only has an effect on items
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:278:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:265:1
    |
 LL | #[automatically_derived]
    | ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:296:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:283:1
    |
 LL |   #[no_mangle]
    |   ^^^^^^^^^^^^
@@ -236,31 +236,31 @@ LL | | }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: `#[should_panic]` only has an effect on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:336:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:323:1
    |
 LL | #[should_panic]
    | ^^^^^^^^^^^^^^^
 
 warning: `#[ignore]` only has an effect on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:354:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:341:1
    |
 LL | #[ignore]
    | ^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:389:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:376:1
    |
 LL | #[reexport_test_harness_main = "2900"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:429:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:416:1
    |
 LL | #[no_std]
    | ^^^^^^^^^
 
 warning: attribute should be applied to a function
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:465:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:452:1
    |
 LL |   #[cold]
    |   ^^^^^^^
@@ -277,7 +277,7 @@ LL | | }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a foreign function or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:494:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:481:1
    |
 LL |   #[link_name = "1900"]
    |   ^^^^^^^^^^^^^^^^^^^^^
@@ -294,7 +294,7 @@ LL | | }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a function or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:533:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:520:1
    |
 LL |   #[link_section = "1800"]
    |   ^^^^^^^^^^^^^^^^^^^^^^^^
@@ -311,37 +311,37 @@ LL | | }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:624:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:611:1
    |
 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:643:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:630:1
    |
 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:662:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:649:1
    |
 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:682:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:669:1
    |
 LL | #[no_main]
    | ^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:714:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:701:1
    |
 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:733:1
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:720:1
    |
 LL | #[type_length_limit="0100"]
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -443,55 +443,55 @@ LL |     #[macro_export] impl S { }
    |     ^^^^^^^^^^^^^^^
 
 warning: `#[path]` only has an effect on modules
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:265:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:252:5
    |
 LL |     #[path = "3800"] fn f() { }
    |     ^^^^^^^^^^^^^^^^
 
 warning: `#[path]` only has an effect on modules
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:268:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:255:5
    |
 LL |     #[path = "3800"]  struct S;
    |     ^^^^^^^^^^^^^^^^
 
 warning: `#[path]` only has an effect on modules
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:271:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:258:5
    |
 LL |     #[path = "3800"] type T = S;
    |     ^^^^^^^^^^^^^^^^
 
 warning: `#[path]` only has an effect on modules
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:274:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:261:5
    |
 LL |     #[path = "3800"] impl S { }
    |     ^^^^^^^^^^^^^^^^
 
 warning: `#[automatically_derived]` only has an effect on items
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:281:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:268:17
    |
 LL |     mod inner { #![automatically_derived] }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[automatically_derived]` only has an effect on items
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:284:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:271:5
    |
 LL |     #[automatically_derived] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[automatically_derived]` only has an effect on items
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:287:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:274:5
    |
 LL |     #[automatically_derived] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[automatically_derived]` only has an effect on items
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:290:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:277:5
    |
 LL |     #[automatically_derived] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:301:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:288:17
    |
 LL |     mod inner { #![no_mangle] }
    |     ------------^^^^^^^^^^^^^-- not a free function, impl method or static
@@ -499,7 +499,7 @@ LL |     mod inner { #![no_mangle] }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:308:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:295:5
    |
 LL |     #[no_mangle] struct S;
    |     ^^^^^^^^^^^^ --------- not a free function, impl method or static
@@ -507,7 +507,7 @@ LL |     #[no_mangle] struct S;
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:313:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:300:5
    |
 LL |     #[no_mangle] type T = S;
    |     ^^^^^^^^^^^^ ----------- not a free function, impl method or static
@@ -515,7 +515,7 @@ LL |     #[no_mangle] type T = S;
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:318:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:305:5
    |
 LL |     #[no_mangle] impl S { }
    |     ^^^^^^^^^^^^ ---------- not a free function, impl method or static
@@ -523,7 +523,7 @@ LL |     #[no_mangle] impl S { }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:324:9
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:311:9
    |
 LL |         #[no_mangle] fn foo();
    |         ^^^^^^^^^^^^ --------- not a free function, impl method or static
@@ -531,7 +531,7 @@ LL |         #[no_mangle] fn foo();
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a free function, impl method or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:329:9
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:316:9
    |
 LL |         #[no_mangle] fn bar() {}
    |         ^^^^^^^^^^^^ ----------- not a free function, impl method or static
@@ -539,163 +539,163 @@ LL |         #[no_mangle] fn bar() {}
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: `#[should_panic]` only has an effect on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:339:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:326:17
    |
 LL |     mod inner { #![should_panic] }
    |                 ^^^^^^^^^^^^^^^^
 
 warning: `#[should_panic]` only has an effect on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:344:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:331:5
    |
 LL |     #[should_panic] struct S;
    |     ^^^^^^^^^^^^^^^
 
 warning: `#[should_panic]` only has an effect on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:347:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:334:5
    |
 LL |     #[should_panic] type T = S;
    |     ^^^^^^^^^^^^^^^
 
 warning: `#[should_panic]` only has an effect on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:350:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:337:5
    |
 LL |     #[should_panic] impl S { }
    |     ^^^^^^^^^^^^^^^
 
 warning: `#[ignore]` only has an effect on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:357:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:344:17
    |
 LL |     mod inner { #![ignore] }
    |                 ^^^^^^^^^^
 
 warning: `#[ignore]` only has an effect on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:362:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:349:5
    |
 LL |     #[ignore] struct S;
    |     ^^^^^^^^^
 
 warning: `#[ignore]` only has an effect on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:365:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:352:5
    |
 LL |     #[ignore] type T = S;
    |     ^^^^^^^^^
 
 warning: `#[ignore]` only has an effect on functions
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:368:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:355:5
    |
 LL |     #[ignore] impl S { }
    |     ^^^^^^^^^
 
 warning: `#[no_implicit_prelude]` only has an effect on modules
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:376:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:363:5
    |
 LL |     #[no_implicit_prelude] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[no_implicit_prelude]` only has an effect on modules
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:379:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:366:5
    |
 LL |     #[no_implicit_prelude] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[no_implicit_prelude]` only has an effect on modules
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:382:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:369:5
    |
 LL |     #[no_implicit_prelude] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[no_implicit_prelude]` only has an effect on modules
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:385:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:372:5
    |
 LL |     #[no_implicit_prelude] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:392:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:379:17
    |
 LL |     mod inner { #![reexport_test_harness_main="2900"] }
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:395:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:382:5
    |
 LL |     #[reexport_test_harness_main = "2900"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:398:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:385:5
    |
 LL |     #[reexport_test_harness_main = "2900"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:401:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:388:5
    |
 LL |     #[reexport_test_harness_main = "2900"] 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:404:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:391:5
    |
 LL |     #[reexport_test_harness_main = "2900"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: `#[macro_escape]` only has an effect on `extern crate` and modules
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:416:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:403:5
    |
 LL |     #[macro_escape] fn f() { }
    |     ^^^^^^^^^^^^^^^
 
 warning: `#[macro_escape]` only has an effect on `extern crate` and modules
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:419:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:406:5
    |
 LL |     #[macro_escape] struct S;
    |     ^^^^^^^^^^^^^^^
 
 warning: `#[macro_escape]` only has an effect on `extern crate` and modules
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:422:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:409:5
    |
 LL |     #[macro_escape] type T = S;
    |     ^^^^^^^^^^^^^^^
 
 warning: `#[macro_escape]` only has an effect on `extern crate` and modules
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:425:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:412:5
    |
 LL |     #[macro_escape] impl S { }
    |     ^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:432:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:419:17
    |
 LL |     mod inner { #![no_std] }
    |                 ^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:435:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:422:5
    |
 LL |     #[no_std] fn f() { }
    |     ^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:438:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:425:5
    |
 LL |     #[no_std] struct S;
    |     ^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:441:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:428:5
    |
 LL |     #[no_std] 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:444:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:431:5
    |
 LL |     #[no_std] impl S { }
    |     ^^^^^^^^^
 
 warning: attribute should be applied to a function
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:471:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:458:17
    |
 LL |     mod inner { #![cold] }
    |     ------------^^^^^^^^-- not a function
@@ -703,7 +703,7 @@ LL |     mod inner { #![cold] }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a function
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:478:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:465:5
    |
 LL |     #[cold] struct S;
    |     ^^^^^^^ --------- not a function
@@ -711,7 +711,7 @@ LL |     #[cold] struct S;
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a function
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:483:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:470:5
    |
 LL |     #[cold] type T = S;
    |     ^^^^^^^ ----------- not a function
@@ -719,7 +719,7 @@ LL |     #[cold] type T = S;
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a function
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:488:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:475:5
    |
 LL |     #[cold] impl S { }
    |     ^^^^^^^ ---------- not a function
@@ -727,7 +727,7 @@ LL |     #[cold] impl S { }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a foreign function or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:500:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:487:5
    |
 LL |     #[link_name = "1900"]
    |     ^^^^^^^^^^^^^^^^^^^^^
@@ -737,13 +737,13 @@ LL |     extern "C" { }
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 help: try `#[link(name = "1900")]` instead
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:500:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:487:5
    |
 LL |     #[link_name = "1900"]
    |     ^^^^^^^^^^^^^^^^^^^^^
 
 warning: attribute should be applied to a foreign function or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:507:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:494:17
    |
 LL |     mod inner { #![link_name="1900"] }
    |     ------------^^^^^^^^^^^^^^^^^^^^-- not a foreign function or static
@@ -751,7 +751,7 @@ LL |     mod inner { #![link_name="1900"] }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a foreign function or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:512:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:499:5
    |
 LL |     #[link_name = "1900"] fn f() { }
    |     ^^^^^^^^^^^^^^^^^^^^^ ---------- not a foreign function or static
@@ -759,7 +759,7 @@ LL |     #[link_name = "1900"] fn f() { }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a foreign function or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:517:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:504:5
    |
 LL |     #[link_name = "1900"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^ --------- not a foreign function or static
@@ -767,7 +767,7 @@ LL |     #[link_name = "1900"] struct S;
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a foreign function or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:522:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:509:5
    |
 LL |     #[link_name = "1900"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^ ----------- not a foreign function or static
@@ -775,7 +775,7 @@ LL |     #[link_name = "1900"] type T = S;
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a foreign function or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:527:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:514:5
    |
 LL |     #[link_name = "1900"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^ ---------- not a foreign function or static
@@ -783,7 +783,7 @@ LL |     #[link_name = "1900"] impl S { }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a function or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:539:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:526:17
    |
 LL |     mod inner { #![link_section="1800"] }
    |     ------------^^^^^^^^^^^^^^^^^^^^^^^-- not a function or static
@@ -791,7 +791,7 @@ LL |     mod inner { #![link_section="1800"] }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a function or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:546:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:533:5
    |
 LL |     #[link_section = "1800"] struct S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^ --------- not a function or static
@@ -799,7 +799,7 @@ LL |     #[link_section = "1800"] struct S;
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a function or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:551:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:538:5
    |
 LL |     #[link_section = "1800"] type T = S;
    |     ^^^^^^^^^^^^^^^^^^^^^^^^ ----------- not a function or static
@@ -807,7 +807,7 @@ LL |     #[link_section = "1800"] type T = S;
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: attribute should be applied to a function or static
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:556:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:543:5
    |
 LL |     #[link_section = "1800"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^ ---------- not a function or static
@@ -815,181 +815,181 @@ LL |     #[link_section = "1800"] impl S { }
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:627:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:614:17
    |
 LL |     mod inner { #![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:630:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:617:5
    |
 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:633:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:620:5
    |
 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:636:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:623:5
    |
 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:639:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:626:5
    |
 LL |     #[crate_name = "0900"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:646:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:633:17
    |
 LL |     mod inner { #![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:649:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:636:5
    |
 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:652:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:639:5
    |
 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:655:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:642:5
    |
 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:658:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:645:5
    |
 LL |     #[crate_type = "0800"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:665:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:652:17
    |
 LL |     mod inner { #![feature(x0600)] }
    |                 ^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:668:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:655:5
    |
 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:671:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:658:5
    |
 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:674:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:661:5
    |
 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:677:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:664:5
    |
 LL |     #[feature(x0600)] impl S { }
    |     ^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:685:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:672:17
    |
 LL |     mod inner { #![no_main] }
    |                 ^^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:688:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:675:5
    |
 LL |     #[no_main] fn f() { }
    |     ^^^^^^^^^^
 
 warning: crate-level attribute should be an inner attribute: add an exclamation mark: `#![foo]`
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:691:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:678:5
    |
 LL |     #[no_main] struct 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:681:5
    |
 LL |     #[no_main] 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:697:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:684:5
    |
 LL |     #[no_main] impl S { }
    |     ^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:717:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:704:17
    |
 LL |     mod inner { #![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:720:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:707:5
    |
 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:723:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:710:5
    |
 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:726:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:713:5
    |
 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:729:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:716:5
    |
 LL |     #[recursion_limit="0200"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 warning: crate-level attribute should be in the root module
-  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:736:17
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:723:17
    |
 LL |     mod inner { #![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:739:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:726:5
    |
 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:742:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:729:5
    |
 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:745:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:732:5
    |
 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:748:5
+  --> $DIR/issue-43106-gating-of-builtin-attrs.rs:735:5
    |
 LL |     #[type_length_limit="0100"] impl S { }
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^