Auto merge of #61672 - Centril:rollup-jxo89ir, r=Centril

Rollup of 6 pull requests

Successful merges:

 - #61646 (Remove useless allocations in macro_rules follow logic.)
 - #61658 (remove useless ident() functions in const tests)
 - #61660 (Minimize use of `#![feature(custom_attribute)]`)
 - #61666 (Add test for trait ICE)
 - #61669 ( syntax: Remove `Deref` impl from `Token`)
 - #61670 (Update RLS)

Failed merges:

r? @ghost

45 files changed, 656 insertions, 284 deletions

diff --git a/src/test/ui/attr-eq-token-tree.rs b/src/test/ui/attr-eq-token-tree.rs
index 6aacb9d572a..c301492b9e2 100644
--- a/src/test/ui/attr-eq-token-tree.rs
+++ b/src/test/ui/attr-eq-token-tree.rs
@@ -1,4 +1,2 @@
-#![feature(custom_attribute)]
-
 #[my_attr = !] //~ ERROR unexpected token: `!`
 fn main() {}
diff --git a/src/test/ui/attr-eq-token-tree.stderr b/src/test/ui/attr-eq-token-tree.stderr
index 571779dfa1a..bb37c2e0cc4 100644
--- a/src/test/ui/attr-eq-token-tree.stderr
+++ b/src/test/ui/attr-eq-token-tree.stderr
@@ -1,5 +1,5 @@
 error: unexpected token: `!`
-  --> $DIR/attr-eq-token-tree.rs:3:13
+  --> $DIR/attr-eq-token-tree.rs:1:13
    |
 LL | #[my_attr = !]
    |             ^
diff --git a/src/test/ui/attributes/attr-before-view-item.rs b/src/test/ui/attributes/attr-before-view-item.rs
new file mode 100644
index 00000000000..fc040bd1a5d
--- /dev/null
+++ b/src/test/ui/attributes/attr-before-view-item.rs
@@ -0,0 +1,10 @@
+// compile-pass
+// pretty-expanded FIXME #23616
+
+#![feature(rustc_attrs)]
+#![feature(test)]
+
+#[rustc_dummy = "bar"]
+extern crate test;
+
+fn main() {}
diff --git a/src/test/ui/attributes/attr-before-view-item2.rs b/src/test/ui/attributes/attr-before-view-item2.rs
new file mode 100644
index 00000000000..c7fad3802e9
--- /dev/null
+++ b/src/test/ui/attributes/attr-before-view-item2.rs
@@ -0,0 +1,12 @@
+// compile-pass
+// pretty-expanded FIXME #23616
+
+#![feature(rustc_attrs)]
+#![feature(test)]
+
+mod m {
+    #[rustc_dummy = "bar"]
+    extern crate test;
+}
+
+fn main() {}
diff --git a/src/test/ui/attributes/attr-mix-new.rs b/src/test/ui/attributes/attr-mix-new.rs
new file mode 100644
index 00000000000..d9cb5510960
--- /dev/null
+++ b/src/test/ui/attributes/attr-mix-new.rs
@@ -0,0 +1,11 @@
+// compile-pass
+// pretty-expanded FIXME #23616
+
+#![feature(rustc_attrs)]
+
+#[rustc_dummy(bar)]
+mod foo {
+  #![feature(globs)]
+}
+
+fn main() {}
diff --git a/src/test/ui/attrs-with-no-formal-in-generics/attrs-with-no-formal-in-generics-1.rs b/src/test/ui/attributes/attrs-with-no-formal-in-generics-1.rs
index ca5fdd9da85..ca5fdd9da85 100644
--- a/src/test/ui/attrs-with-no-formal-in-generics/attrs-with-no-formal-in-generics-1.rs
+++ b/src/test/ui/attributes/attrs-with-no-formal-in-generics-1.rs
diff --git a/src/test/ui/attrs-with-no-formal-in-generics/attrs-with-no-formal-in-generics-1.stderr b/src/test/ui/attributes/attrs-with-no-formal-in-generics-1.stderr
index 55e7a987784..55e7a987784 100644
--- a/src/test/ui/attrs-with-no-formal-in-generics/attrs-with-no-formal-in-generics-1.stderr
+++ b/src/test/ui/attributes/attrs-with-no-formal-in-generics-1.stderr
diff --git a/src/test/ui/attrs-with-no-formal-in-generics/attrs-with-no-formal-in-generics-2.rs b/src/test/ui/attributes/attrs-with-no-formal-in-generics-2.rs
index c795612acf0..c795612acf0 100644
--- a/src/test/ui/attrs-with-no-formal-in-generics/attrs-with-no-formal-in-generics-2.rs
+++ b/src/test/ui/attributes/attrs-with-no-formal-in-generics-2.rs
diff --git a/src/test/ui/attrs-with-no-formal-in-generics/attrs-with-no-formal-in-generics-2.stderr b/src/test/ui/attributes/attrs-with-no-formal-in-generics-2.stderr
index acd0ae3678a..acd0ae3678a 100644
--- a/src/test/ui/attrs-with-no-formal-in-generics/attrs-with-no-formal-in-generics-2.stderr
+++ b/src/test/ui/attributes/attrs-with-no-formal-in-generics-2.stderr
diff --git a/src/test/ui/attrs-with-no-formal-in-generics/attrs-with-no-formal-in-generics-3.rs b/src/test/ui/attributes/attrs-with-no-formal-in-generics-3.rs
index 3cfc70b4185..3cfc70b4185 100644
--- a/src/test/ui/attrs-with-no-formal-in-generics/attrs-with-no-formal-in-generics-3.rs
+++ b/src/test/ui/attributes/attrs-with-no-formal-in-generics-3.rs
diff --git a/src/test/ui/attrs-with-no-formal-in-generics/attrs-with-no-formal-in-generics-3.stderr b/src/test/ui/attributes/attrs-with-no-formal-in-generics-3.stderr
index b9ca0097467..b9ca0097467 100644
--- a/src/test/ui/attrs-with-no-formal-in-generics/attrs-with-no-formal-in-generics-3.stderr
+++ b/src/test/ui/attributes/attrs-with-no-formal-in-generics-3.stderr
diff --git a/src/test/ui/attributes/class-attributes-1.rs b/src/test/ui/attributes/class-attributes-1.rs
new file mode 100644
index 00000000000..7808367f2c1
--- /dev/null
+++ b/src/test/ui/attributes/class-attributes-1.rs
@@ -0,0 +1,19 @@
+// compile-pass
+// pp-exact - Make sure we actually print the attributes
+
+#![feature(rustc_attrs)]
+
+struct Cat {
+    name: String,
+}
+
+impl Drop for Cat {
+    #[rustc_dummy]
+    fn drop(&mut self) { println!("{} landed on hir feet" , self . name); }
+}
+
+
+#[rustc_dummy]
+fn cat(name: String) -> Cat { Cat{name: name,} }
+
+fn main() { let _kitty = cat("Spotty".to_string()); }
diff --git a/src/test/ui/attributes/class-attributes-2.rs b/src/test/ui/attributes/class-attributes-2.rs
new file mode 100644
index 00000000000..348c70f35c3
--- /dev/null
+++ b/src/test/ui/attributes/class-attributes-2.rs
@@ -0,0 +1,31 @@
+// compile-pass
+
+#![feature(rustc_attrs)]
+
+struct Cat {
+    name: String,
+}
+
+impl Drop for Cat {
+    #[rustc_dummy]
+    /**
+       Actually, cats don't always land on their feet when you drop them.
+    */
+    fn drop(&mut self) {
+        println!("{} landed on hir feet", self.name);
+    }
+}
+
+#[rustc_dummy]
+/**
+Maybe it should technically be a kitten_maker.
+*/
+fn cat(name: String) -> Cat {
+    Cat {
+        name: name
+    }
+}
+
+fn main() {
+    let _kitty = cat("Spotty".to_string());
+}
diff --git a/src/test/ui/attributes/item-attributes.rs b/src/test/ui/attributes/item-attributes.rs
new file mode 100644
index 00000000000..72c9a35dc07
--- /dev/null
+++ b/src/test/ui/attributes/item-attributes.rs
@@ -0,0 +1,181 @@
+// These are attributes of the implicit crate. Really this just needs to parse
+// for completeness since .rs files linked from .rc files support this
+// notation to specify their module's attributes
+
+// compile-pass
+
+#![feature(rustc_attrs)]
+
+#![rustc_dummy = "val"]
+#![rustc_dummy = "val"]
+#![rustc_dummy]
+#![rustc_dummy(attr5)]
+
+#![crate_id="foobar#0.1"]
+
+// These are attributes of the following mod
+#[rustc_dummy = "val"]
+#[rustc_dummy = "val"]
+mod test_first_item_in_file_mod {}
+
+mod test_single_attr_outer {
+    #[rustc_dummy = "val"]
+    pub static X: isize = 10;
+
+    #[rustc_dummy = "val"]
+    pub fn f() { }
+
+    #[rustc_dummy = "val"]
+    pub mod mod1 {}
+
+    pub mod rustrt {
+        #[rustc_dummy = "val"]
+        extern {}
+    }
+}
+
+mod test_multi_attr_outer {
+    #[rustc_dummy = "val"]
+    #[rustc_dummy = "val"]
+    pub static X: isize = 10;
+
+    #[rustc_dummy = "val"]
+    #[rustc_dummy = "val"]
+    pub fn f() { }
+
+    #[rustc_dummy = "val"]
+    #[rustc_dummy = "val"]
+    pub mod mod1 {}
+
+    pub mod rustrt {
+        #[rustc_dummy = "val"]
+        #[rustc_dummy = "val"]
+        extern {}
+    }
+
+    #[rustc_dummy = "val"]
+    #[rustc_dummy = "val"]
+    struct T {x: isize}
+}
+
+mod test_stmt_single_attr_outer {
+    pub fn f() {
+        #[rustc_dummy = "val"]
+        static X: isize = 10;
+
+        #[rustc_dummy = "val"]
+        fn f() { }
+
+        #[rustc_dummy = "val"]
+        mod mod1 {
+        }
+
+        mod rustrt {
+            #[rustc_dummy = "val"]
+            extern {
+            }
+        }
+    }
+}
+
+mod test_stmt_multi_attr_outer {
+    pub fn f() {
+
+        #[rustc_dummy = "val"]
+        #[rustc_dummy = "val"]
+        static X: isize = 10;
+
+        #[rustc_dummy = "val"]
+        #[rustc_dummy = "val"]
+        fn f() { }
+
+        #[rustc_dummy = "val"]
+        #[rustc_dummy = "val"]
+        mod mod1 {
+        }
+
+        mod rustrt {
+            #[rustc_dummy = "val"]
+            #[rustc_dummy = "val"]
+            extern {
+            }
+        }
+    }
+}
+
+mod test_attr_inner {
+    pub mod m {
+        // This is an attribute of mod m
+        #![rustc_dummy = "val"]
+    }
+}
+
+mod test_attr_inner_then_outer {
+    pub mod m {
+        // This is an attribute of mod m
+        #![rustc_dummy = "val"]
+        // This is an attribute of fn f
+        #[rustc_dummy = "val"]
+        fn f() { }
+    }
+}
+
+mod test_attr_inner_then_outer_multi {
+    pub mod m {
+        // This is an attribute of mod m
+        #![rustc_dummy = "val"]
+        #![rustc_dummy = "val"]
+        // This is an attribute of fn f
+        #[rustc_dummy = "val"]
+        #[rustc_dummy = "val"]
+        fn f() { }
+    }
+}
+
+mod test_distinguish_syntax_ext {
+    pub fn f() {
+        format!("test{}", "s");
+        #[rustc_dummy = "val"]
+        fn g() { }
+    }
+}
+
+mod test_other_forms {
+    #[rustc_dummy]
+    #[rustc_dummy(word)]
+    #[rustc_dummy(attr(word))]
+    #[rustc_dummy(key1 = "val", key2 = "val", attr)]
+    pub fn f() { }
+}
+
+mod test_foreign_items {
+    pub mod rustrt {
+        extern {
+            #![rustc_dummy]
+
+            #[rustc_dummy]
+            fn rust_get_test_int() -> u32;
+        }
+    }
+}
+
+
+// FIXME(#623): - these aren't supported yet
+/*mod test_literals {
+    #![str = "s"]
+    #![char = 'c']
+    #![isize = 100]
+    #![usize = 100_usize]
+    #![mach_int = 100u32]
+    #![float = 1.0]
+    #![mach_float = 1.0f32]
+    #![nil = ()]
+    #![bool = true]
+    mod m {}
+}*/
+
+fn test_fn_inner() {
+    #![rustc_dummy]
+}
+
+fn main() {}
diff --git a/src/test/ui/attributes/method-attributes.rs b/src/test/ui/attributes/method-attributes.rs
new file mode 100644
index 00000000000..2d608acc71f
--- /dev/null
+++ b/src/test/ui/attributes/method-attributes.rs
@@ -0,0 +1,28 @@
+// compile-pass
+// pp-exact - Make sure we print all the attributes
+// pretty-expanded FIXME #23616
+
+#![feature(rustc_attrs)]
+
+#[rustc_dummy]
+trait Frobable {
+    #[rustc_dummy]
+    fn frob(&self);
+    #[rustc_dummy]
+    fn defrob(&self);
+}
+
+#[rustc_dummy]
+impl Frobable for isize {
+    #[rustc_dummy]
+    fn frob(&self) {
+        #![rustc_dummy]
+    }
+
+    #[rustc_dummy]
+    fn defrob(&self) {
+        #![rustc_dummy]
+    }
+}
+
+fn main() {}
diff --git a/src/test/ui/attributes/obsolete-attr.rs b/src/test/ui/attributes/obsolete-attr.rs
new file mode 100644
index 00000000000..89e2ad2669c
--- /dev/null
+++ b/src/test/ui/attributes/obsolete-attr.rs
@@ -0,0 +1,7 @@
+// Obsolete attributes fall back to feature gated custom attributes.
+
+#[ab_isize="stdcall"] extern {} //~ ERROR attribute `ab_isize` is currently unknown
+
+#[fixed_stack_segment] fn f() {} //~ ERROR attribute `fixed_stack_segment` is currently unknown
+
+fn main() {}
diff --git a/src/test/ui/attributes/obsolete-attr.stderr b/src/test/ui/attributes/obsolete-attr.stderr
new file mode 100644
index 00000000000..2ed7f87935f
--- /dev/null
+++ b/src/test/ui/attributes/obsolete-attr.stderr
@@ -0,0 +1,21 @@
+error[E0658]: The attribute `fixed_stack_segment` is currently unknown to the compiler and may have meaning added to it in the future
+  --> $DIR/obsolete-attr.rs:5:3
+   |
+LL | #[fixed_stack_segment] fn f() {}
+   |   ^^^^^^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
+error[E0658]: The attribute `ab_isize` is currently unknown to the compiler and may have meaning added to it in the future
+  --> $DIR/obsolete-attr.rs:3:3
+   |
+LL | #[ab_isize="stdcall"] extern {}
+   |   ^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/attributes/unknown-attr.rs b/src/test/ui/attributes/unknown-attr.rs
new file mode 100644
index 00000000000..e2a4f3226d5
--- /dev/null
+++ b/src/test/ui/attributes/unknown-attr.rs
@@ -0,0 +1,9 @@
+// Unknown attributes fall back to feature gated custom attributes.
+
+#![feature(custom_inner_attributes)]
+
+#![mutable_doc] //~ ERROR attribute `mutable_doc` is currently unknown
+
+#[dance] mod a {} //~ ERROR attribute `dance` is currently unknown
+
+#[dance] fn main() {} //~ ERROR attribute `dance` is currently unknown
diff --git a/src/test/ui/attributes/unknown-attr.stderr b/src/test/ui/attributes/unknown-attr.stderr
new file mode 100644
index 00000000000..d0ac58108fc
--- /dev/null
+++ b/src/test/ui/attributes/unknown-attr.stderr
@@ -0,0 +1,30 @@
+error[E0658]: The attribute `mutable_doc` is currently unknown to the compiler and may have meaning added to it in the future
+  --> $DIR/unknown-attr.rs:5:4
+   |
+LL | #![mutable_doc]
+   |    ^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
+error[E0658]: The attribute `dance` is currently unknown to the compiler and may have meaning added to it in the future
+  --> $DIR/unknown-attr.rs:7:3
+   |
+LL | #[dance] mod a {}
+   |   ^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
+error[E0658]: The attribute `dance` is currently unknown to the compiler and may have meaning added to it in the future
+  --> $DIR/unknown-attr.rs:9:3
+   |
+LL | #[dance] fn main() {}
+   |   ^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
+error: aborting due to 3 previous errors
+
+For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/attributes/variant-attributes.rs b/src/test/ui/attributes/variant-attributes.rs
new file mode 100644
index 00000000000..a910340f4a0
--- /dev/null
+++ b/src/test/ui/attributes/variant-attributes.rs
@@ -0,0 +1,37 @@
+// compile-pass
+// pp-exact - Make sure we actually print the attributes
+// pretty-expanded FIXME #23616
+
+#![allow(non_camel_case_types)]
+#![feature(rustc_attrs)]
+
+enum crew_of_enterprise_d {
+
+    #[rustc_dummy]
+    jean_luc_picard,
+
+    #[rustc_dummy]
+    william_t_riker,
+
+    #[rustc_dummy]
+    beverly_crusher,
+
+    #[rustc_dummy]
+    deanna_troi,
+
+    #[rustc_dummy]
+    data,
+
+    #[rustc_dummy]
+    worf,
+
+    #[rustc_dummy]
+    geordi_la_forge,
+}
+
+fn boldly_go(_crew_member: crew_of_enterprise_d, _where: String) { }
+
+fn main() {
+    boldly_go(crew_of_enterprise_d::worf,
+              "where no one has gone before".to_string());
+}
diff --git a/src/test/ui/custom-attribute-multisegment.rs b/src/test/ui/custom-attribute-multisegment.rs
index 95cefe53938..24349213902 100644
--- a/src/test/ui/custom-attribute-multisegment.rs
+++ b/src/test/ui/custom-attribute-multisegment.rs
@@ -1,7 +1,5 @@
 // Unresolved multi-segment attributes are not treated as custom.
 
-#![feature(custom_attribute)]
-
 mod existent {}
 
 #[existent::nonexistent] //~ ERROR failed to resolve: could not find `nonexistent` in `existent`
diff --git a/src/test/ui/custom-attribute-multisegment.stderr b/src/test/ui/custom-attribute-multisegment.stderr
index 9ba9c00e55b..57eca211ed1 100644
--- a/src/test/ui/custom-attribute-multisegment.stderr
+++ b/src/test/ui/custom-attribute-multisegment.stderr
@@ -1,5 +1,5 @@
 error[E0433]: failed to resolve: could not find `nonexistent` in `existent`
-  --> $DIR/custom-attribute-multisegment.rs:7:13
+  --> $DIR/custom-attribute-multisegment.rs:5:13
    |
 LL | #[existent::nonexistent]
    |             ^^^^^^^^^^^ could not find `nonexistent` in `existent`
diff --git a/src/test/ui/expanded-cfg.rs b/src/test/ui/expanded-cfg.rs
index fbae093f2ac..c98fd7ffea8 100644
--- a/src/test/ui/expanded-cfg.rs
+++ b/src/test/ui/expanded-cfg.rs
@@ -1,6 +1,6 @@
 // skip-codegen
 // compile-pass
-#![feature(custom_attribute)]
+
 macro_rules! mac {
     {} => {
         #[cfg(attr)]
diff --git a/src/test/ui/issues/issue-24434.rs b/src/test/ui/issues/issue-24434.rs
index 7b270ceb688..2424a1c92cd 100644
--- a/src/test/ui/issues/issue-24434.rs
+++ b/src/test/ui/issues/issue-24434.rs
@@ -1,8 +1,7 @@
 // compile-pass
-#![allow(unused_attributes)]
 // compile-flags:--cfg set1
 
-#![cfg_attr(set1, feature(custom_attribute))]
+#![cfg_attr(set1, feature(rustc_attrs))]
+#![rustc_dummy]
 
-#![foobar]
 fn main() {}
diff --git a/src/test/ui/lint/lint-obsolete-attr.rs b/src/test/ui/lint/lint-obsolete-attr.rs
deleted file mode 100644
index 149948b5a6d..00000000000
--- a/src/test/ui/lint/lint-obsolete-attr.rs
+++ /dev/null
@@ -1,12 +0,0 @@
-// When denying at the crate level, be sure to not get random warnings from the
-// injected intrinsics by the compiler.
-
-#![deny(unused_attributes)]
-#![allow(dead_code)]
-#![feature(custom_attribute)]
-
-#[ab_isize="stdcall"] extern {} //~ ERROR unused attribute
-
-#[fixed_stack_segment] fn f() {} //~ ERROR unused attribute
-
-fn main() {}
diff --git a/src/test/ui/lint/lint-obsolete-attr.stderr b/src/test/ui/lint/lint-obsolete-attr.stderr
deleted file mode 100644
index c06bd26df2b..00000000000
--- a/src/test/ui/lint/lint-obsolete-attr.stderr
+++ /dev/null
@@ -1,20 +0,0 @@
-error: unused attribute
-  --> $DIR/lint-obsolete-attr.rs:8:1
-   |
-LL | #[ab_isize="stdcall"] extern {}
-   | ^^^^^^^^^^^^^^^^^^^^^
-   |
-note: lint level defined here
-  --> $DIR/lint-obsolete-attr.rs:4:9
-   |
-LL | #![deny(unused_attributes)]
-   |         ^^^^^^^^^^^^^^^^^
-
-error: unused attribute
-  --> $DIR/lint-obsolete-attr.rs:10:1
-   |
-LL | #[fixed_stack_segment] fn f() {}
-   | ^^^^^^^^^^^^^^^^^^^^^^
-
-error: aborting due to 2 previous errors
-
diff --git a/src/test/ui/lint/lint-unknown-attr.rs b/src/test/ui/lint/lint-unknown-attr.rs
deleted file mode 100644
index 828b869c12e..00000000000
--- a/src/test/ui/lint/lint-unknown-attr.rs
+++ /dev/null
@@ -1,11 +0,0 @@
-// When denying at the crate level, be sure to not get random warnings from the
-// injected intrinsics by the compiler.
-
-#![feature(custom_attribute)]
-#![deny(unused_attributes)]
-
-#![mutable_doc] //~ ERROR unused attribute
-
-#[dance] mod a {} //~ ERROR unused attribute
-
-#[dance] fn main() {} //~ ERROR unused attribute
diff --git a/src/test/ui/lint/lint-unknown-attr.stderr b/src/test/ui/lint/lint-unknown-attr.stderr
deleted file mode 100644
index 9817760c224..00000000000
--- a/src/test/ui/lint/lint-unknown-attr.stderr
+++ /dev/null
@@ -1,26 +0,0 @@
-error: unused attribute
-  --> $DIR/lint-unknown-attr.rs:9:1
-   |
-LL | #[dance] mod a {}
-   | ^^^^^^^^
-   |
-note: lint level defined here
-  --> $DIR/lint-unknown-attr.rs:5:9
-   |
-LL | #![deny(unused_attributes)]
-   |         ^^^^^^^^^^^^^^^^^
-
-error: unused attribute
-  --> $DIR/lint-unknown-attr.rs:11:1
-   |
-LL | #[dance] fn main() {}
-   | ^^^^^^^^
-
-error: unused attribute
-  --> $DIR/lint-unknown-attr.rs:7:1
-   |
-LL | #![mutable_doc]
-   | ^^^^^^^^^^^^^^^
-
-error: aborting due to 3 previous errors
-
diff --git a/src/test/ui/macros/macro-inner-attributes.rs b/src/test/ui/macros/macro-inner-attributes.rs
index 268ddda1b3c..56a90231566 100644
--- a/src/test/ui/macros/macro-inner-attributes.rs
+++ b/src/test/ui/macros/macro-inner-attributes.rs
@@ -1,4 +1,4 @@
-#![feature(custom_attribute)]
+#![feature(rustc_attrs)]
 
 macro_rules! test { ($nm:ident,
                      #[$a:meta],
@@ -12,7 +12,7 @@ test!(b,
       #[cfg(not(qux))],
       pub fn bar() { });
 
-#[qux]
+#[rustc_dummy]
 fn main() {
     a::bar();
     //~^ ERROR failed to resolve: use of undeclared type or module `a`
diff --git a/src/test/ui/macros/macro-input-future-proofing.stderr b/src/test/ui/macros/macro-input-future-proofing.stderr
index a35f6283afb..542486927df 100644
--- a/src/test/ui/macros/macro-input-future-proofing.stderr
+++ b/src/test/ui/macros/macro-input-future-proofing.stderr
@@ -55,10 +55,10 @@ LL |     ($($a:ty, $b:ty)* -) => ();
    = note: allowed there are: `{`, `[`, `=>`, `,`, `>`, `=`, `:`, `;`, `|`, `as` or `where`
 
 error: `$ty:ty` is followed by `-`, which is not allowed for `ty` fragments
-  --> $DIR/macro-input-future-proofing.rs:18:7
+  --> $DIR/macro-input-future-proofing.rs:18:15
    |
 LL |     ($($ty:ty)-+) => ();
-   |       ^^^^^^^^ not allowed after `ty` fragments
+   |               ^ not allowed after `ty` fragments
    |
    = note: allowed there are: `{`, `[`, `=>`, `,`, `>`, `=`, `:`, `;`, `|`, `as` or `where`
 
diff --git a/src/test/ui/macros/macro-outer-attributes.rs b/src/test/ui/macros/macro-outer-attributes.rs
index aa70060425f..0752f7e3153 100644
--- a/src/test/ui/macros/macro-outer-attributes.rs
+++ b/src/test/ui/macros/macro-outer-attributes.rs
@@ -1,4 +1,4 @@
-#![feature(custom_attribute)]
+#![feature(rustc_attrs)]
 
 macro_rules! test { ($nm:ident,
                      #[$a:meta],
@@ -13,7 +13,7 @@ test!(b,
       pub fn bar() { });
 
 // test1!(#[bar])
-#[qux]
+#[rustc_dummy]
 fn main() {
     a::bar(); //~ ERROR cannot find function `bar` in module `a`
     b::bar();
diff --git a/src/test/ui/malformed/malformed-interpolated.rs b/src/test/ui/malformed/malformed-interpolated.rs
index 7c4ca3c017e..5101b5caeea 100644
--- a/src/test/ui/malformed/malformed-interpolated.rs
+++ b/src/test/ui/malformed/malformed-interpolated.rs
@@ -1,9 +1,9 @@
-#![feature(custom_attribute)]
+#![feature(rustc_attrs)]
 
 macro_rules! check {
     ($expr: expr) => (
-        #[my_attr = $expr] //~ ERROR unexpected token: `-0`
-                           //~| ERROR unexpected token: `0 + 0`
+        #[rustc_dummy = $expr] //~ ERROR unexpected token: `-0`
+                               //~| ERROR unexpected token: `0 + 0`
         use main as _;
     );
 }
diff --git a/src/test/ui/malformed/malformed-interpolated.stderr b/src/test/ui/malformed/malformed-interpolated.stderr
index e805416172b..bcd2ef545d8 100644
--- a/src/test/ui/malformed/malformed-interpolated.stderr
+++ b/src/test/ui/malformed/malformed-interpolated.stderr
@@ -7,19 +7,19 @@ LL | check!(0u8);
    = help: instead of using a suffixed literal (1u8, 1.0f32, etc.), use an unsuffixed version (1, 1.0, etc.).
 
 error: unexpected token: `-0`
-  --> $DIR/malformed-interpolated.rs:5:21
+  --> $DIR/malformed-interpolated.rs:5:25
    |
-LL |         #[my_attr = $expr]
-   |                     ^^^^^
+LL |         #[rustc_dummy = $expr]
+   |                         ^^^^^
 ...
 LL | check!(-0); // ERROR, see above
    | ----------- in this macro invocation
 
 error: unexpected token: `0 + 0`
-  --> $DIR/malformed-interpolated.rs:5:21
+  --> $DIR/malformed-interpolated.rs:5:25
    |
-LL |         #[my_attr = $expr]
-   |                     ^^^^^
+LL |         #[rustc_dummy = $expr]
+   |                         ^^^^^
 ...
 LL | check!(0 + 0); // ERROR, see above
    | -------------- in this macro invocation
diff --git a/src/test/ui/proc-macro/resolve-error.rs b/src/test/ui/proc-macro/resolve-error.rs
index 82607136f0b..1298c08df84 100644
--- a/src/test/ui/proc-macro/resolve-error.rs
+++ b/src/test/ui/proc-macro/resolve-error.rs
@@ -2,8 +2,6 @@
 // aux-build:derive-clona.rs
 // aux-build:test-macros.rs
 
-#![feature(custom_attribute)]
-
 #[macro_use]
 extern crate derive_foo;
 #[macro_use]
@@ -25,10 +23,12 @@ macro_rules! attr_proc_mac {
 //~^ ERROR cannot find
 struct Foo;
 
-#[attr_proc_macra] // OK, interpreted as a custom attribute
+// Interpreted as a feature gated custom attribute
+#[attr_proc_macra] //~ ERROR attribute `attr_proc_macra` is currently unknown
 struct Bar;
 
-#[FooWithLongNan]  // OK, interpreted as a custom attribute
+// Interpreted as a feature gated custom attribute
+#[FooWithLongNan] //~ ERROR attribute `FooWithLongNan` is currently unknown
 struct Asdf;
 
 #[derive(Dlone)]
diff --git a/src/test/ui/proc-macro/resolve-error.stderr b/src/test/ui/proc-macro/resolve-error.stderr
index 705ef6006a0..f9f116c15dc 100644
--- a/src/test/ui/proc-macro/resolve-error.stderr
+++ b/src/test/ui/proc-macro/resolve-error.stderr
@@ -1,5 +1,23 @@
+error[E0658]: The attribute `attr_proc_macra` is currently unknown to the compiler and may have meaning added to it in the future
+  --> $DIR/resolve-error.rs:27:3
+   |
+LL | #[attr_proc_macra]
+   |   ^^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
+error[E0658]: The attribute `FooWithLongNan` is currently unknown to the compiler and may have meaning added to it in the future
+  --> $DIR/resolve-error.rs:31:3
+   |
+LL | #[FooWithLongNan]
+   |   ^^^^^^^^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
 error: cannot find derive macro `FooWithLongNan` in this scope
-  --> $DIR/resolve-error.rs:24:10
+  --> $DIR/resolve-error.rs:22:10
    |
 LL | #[derive(FooWithLongNan)]
    |          ^^^^^^^^^^^^^^ help: try: `FooWithLongName`
@@ -46,5 +64,6 @@ error: cannot find macro `bang_proc_macrp!` in this scope
 LL |     bang_proc_macrp!();
    |     ^^^^^^^^^^^^^^^ help: you could try the macro: `bang_proc_macro`
 
-error: aborting due to 8 previous errors
+error: aborting due to 10 previous errors
 
+For more information about this error, try `rustc --explain E0658`.
diff --git a/src/test/ui/stmt_expr_attrs_no_feature.rs b/src/test/ui/stmt_expr_attrs_no_feature.rs
index 8952175e425..674a5ed18ce 100644
--- a/src/test/ui/stmt_expr_attrs_no_feature.rs
+++ b/src/test/ui/stmt_expr_attrs_no_feature.rs
@@ -1,4 +1,4 @@
-#![feature(custom_attribute)]
+#![feature(rustc_attrs)]
 
 macro_rules! stmt_mac {
     () => {
@@ -7,18 +7,19 @@ macro_rules! stmt_mac {
 }
 
 fn main() {
-    #[attr]
+    #[rustc_dummy]
     fn a() {}
 
-    #[attr] //~ ERROR attributes on expressions are experimental
+    // Bug: built-in attrs like `rustc_dummy` are not gated on blocks, but other attrs are.
+    #[rustfmt::skip] //~ ERROR attributes on expressions are experimental
     {
 
     }
 
-    #[attr]
+    #[rustc_dummy]
     5;
 
-    #[attr]
+    #[rustc_dummy]
     stmt_mac!();
 }
 
@@ -26,25 +27,25 @@ fn main() {
 
 #[cfg(unset)]
 fn c() {
-    #[attr]
+    #[rustc_dummy]
     5;
 }
 
 #[cfg(not(unset))]
 fn j() {
-    #[attr]
+    #[rustc_dummy]
     5;
 }
 
 #[cfg_attr(not(unset), cfg(unset))]
 fn d() {
-    #[attr]
+    #[rustc_dummy]
     8;
 }
 
 #[cfg_attr(not(unset), cfg(not(unset)))]
 fn i() {
-    #[attr]
+    #[rustc_dummy]
     8;
 }
 
@@ -53,30 +54,30 @@ fn i() {
 macro_rules! item_mac {
     ($e:ident) => {
         fn $e() {
-            #[attr]
+            #[rustc_dummy]
             42;
 
             #[cfg(unset)]
             fn f() {
-                #[attr]
+                #[rustc_dummy]
                 5;
             }
 
             #[cfg(not(unset))]
             fn k() {
-                #[attr]
+                #[rustc_dummy]
                 5;
             }
 
             #[cfg_attr(not(unset), cfg(unset))]
             fn g() {
-                #[attr]
+                #[rustc_dummy]
                 8;
             }
 
             #[cfg_attr(not(unset), cfg(not(unset)))]
             fn h() {
-                #[attr]
+                #[rustc_dummy]
                 8;
             }
 
@@ -90,51 +91,51 @@ item_mac!(e);
 
 extern {
     #[cfg(unset)]
-    fn x(a: [u8; #[attr] 5]);
-    fn y(a: [u8; #[attr] 5]); //~ ERROR attributes on expressions are experimental
+    fn x(a: [u8; #[rustc_dummy] 5]);
+    fn y(a: [u8; #[rustc_dummy] 5]); //~ ERROR attributes on expressions are experimental
 }
 
 struct Foo;
 impl Foo {
     #[cfg(unset)]
-    const X: u8 = #[attr] 5;
-    const Y: u8 = #[attr] 5; //~ ERROR attributes on expressions are experimental
+    const X: u8 = #[rustc_dummy] 5;
+    const Y: u8 = #[rustc_dummy] 5; //~ ERROR attributes on expressions are experimental
 }
 
 trait Bar {
     #[cfg(unset)]
-    const X: [u8; #[attr] 5];
-    const Y: [u8; #[attr] 5]; //~ ERROR attributes on expressions are experimental
+    const X: [u8; #[rustc_dummy] 5];
+    const Y: [u8; #[rustc_dummy] 5]; //~ ERROR attributes on expressions are experimental
 }
 
 struct Joyce {
     #[cfg(unset)]
-    field: [u8; #[attr] 5],
-    field2: [u8; #[attr] 5] //~ ERROR attributes on expressions are experimental
+    field: [u8; #[rustc_dummy] 5],
+    field2: [u8; #[rustc_dummy] 5] //~ ERROR attributes on expressions are experimental
 }
 
 struct Walky(
-    #[cfg(unset)] [u8; #[attr] 5],
-    [u8; #[attr] 5] //~ ERROR attributes on expressions are experimental
+    #[cfg(unset)] [u8; #[rustc_dummy] 5],
+    [u8; #[rustc_dummy] 5] //~ ERROR attributes on expressions are experimental
 );
 
 enum Mike {
     Happy(
-        #[cfg(unset)] [u8; #[attr] 5],
-        [u8; #[attr] 5] //~ ERROR attributes on expressions are experimental
+        #[cfg(unset)] [u8; #[rustc_dummy] 5],
+        [u8; #[rustc_dummy] 5] //~ ERROR attributes on expressions are experimental
     ),
     Angry {
         #[cfg(unset)]
-        field: [u8; #[attr] 5],
-        field2: [u8; #[attr] 5] //~ ERROR attributes on expressions are experimental
+        field: [u8; #[rustc_dummy] 5],
+        field2: [u8; #[rustc_dummy] 5] //~ ERROR attributes on expressions are experimental
     }
 }
 
 fn pat() {
     match 5 {
         #[cfg(unset)]
-        5 => #[attr] (),
-        6 => #[attr] (), //~ ERROR attributes on expressions are experimental
+        5 => #[rustc_dummy] (),
+        6 => #[rustc_dummy] (), //~ ERROR attributes on expressions are experimental
         _ => (),
     }
 }
diff --git a/src/test/ui/stmt_expr_attrs_no_feature.stderr b/src/test/ui/stmt_expr_attrs_no_feature.stderr
index 1b5e989af7b..01372cc164b 100644
--- a/src/test/ui/stmt_expr_attrs_no_feature.stderr
+++ b/src/test/ui/stmt_expr_attrs_no_feature.stderr
@@ -1,80 +1,80 @@
 error[E0658]: attributes on expressions are experimental
-  --> $DIR/stmt_expr_attrs_no_feature.rs:13:5
+  --> $DIR/stmt_expr_attrs_no_feature.rs:14:5
    |
-LL |     #[attr]
-   |     ^^^^^^^
+LL |     #[rustfmt::skip]
+   |     ^^^^^^^^^^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/15701
    = help: add #![feature(stmt_expr_attributes)] to the crate attributes to enable
 
 error[E0658]: attributes on expressions are experimental
-  --> $DIR/stmt_expr_attrs_no_feature.rs:94:18
+  --> $DIR/stmt_expr_attrs_no_feature.rs:95:18
    |
-LL |     fn y(a: [u8; #[attr] 5]);
-   |                  ^^^^^^^
+LL |     fn y(a: [u8; #[rustc_dummy] 5]);
+   |                  ^^^^^^^^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/15701
    = help: add #![feature(stmt_expr_attributes)] to the crate attributes to enable
 
 error[E0658]: attributes on expressions are experimental
-  --> $DIR/stmt_expr_attrs_no_feature.rs:101:19
+  --> $DIR/stmt_expr_attrs_no_feature.rs:102:19
    |
-LL |     const Y: u8 = #[attr] 5;
-   |                   ^^^^^^^
+LL |     const Y: u8 = #[rustc_dummy] 5;
+   |                   ^^^^^^^^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/15701
    = help: add #![feature(stmt_expr_attributes)] to the crate attributes to enable
 
 error[E0658]: attributes on expressions are experimental
-  --> $DIR/stmt_expr_attrs_no_feature.rs:107:19
+  --> $DIR/stmt_expr_attrs_no_feature.rs:108:19
    |
-LL |     const Y: [u8; #[attr] 5];
-   |                   ^^^^^^^
+LL |     const Y: [u8; #[rustc_dummy] 5];
+   |                   ^^^^^^^^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/15701
    = help: add #![feature(stmt_expr_attributes)] to the crate attributes to enable
 
 error[E0658]: attributes on expressions are experimental
-  --> $DIR/stmt_expr_attrs_no_feature.rs:113:18
+  --> $DIR/stmt_expr_attrs_no_feature.rs:114:18
    |
-LL |     field2: [u8; #[attr] 5]
-   |                  ^^^^^^^
+LL |     field2: [u8; #[rustc_dummy] 5]
+   |                  ^^^^^^^^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/15701
    = help: add #![feature(stmt_expr_attributes)] to the crate attributes to enable
 
 error[E0658]: attributes on expressions are experimental
-  --> $DIR/stmt_expr_attrs_no_feature.rs:118:10
+  --> $DIR/stmt_expr_attrs_no_feature.rs:119:10
    |
-LL |     [u8; #[attr] 5]
-   |          ^^^^^^^
+LL |     [u8; #[rustc_dummy] 5]
+   |          ^^^^^^^^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/15701
    = help: add #![feature(stmt_expr_attributes)] to the crate attributes to enable
 
 error[E0658]: attributes on expressions are experimental
-  --> $DIR/stmt_expr_attrs_no_feature.rs:124:14
+  --> $DIR/stmt_expr_attrs_no_feature.rs:125:14
    |
-LL |         [u8; #[attr] 5]
-   |              ^^^^^^^
+LL |         [u8; #[rustc_dummy] 5]
+   |              ^^^^^^^^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/15701
    = help: add #![feature(stmt_expr_attributes)] to the crate attributes to enable
 
 error[E0658]: attributes on expressions are experimental
-  --> $DIR/stmt_expr_attrs_no_feature.rs:129:22
+  --> $DIR/stmt_expr_attrs_no_feature.rs:130:22
    |
-LL |         field2: [u8; #[attr] 5]
-   |                      ^^^^^^^
+LL |         field2: [u8; #[rustc_dummy] 5]
+   |                      ^^^^^^^^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/15701
    = help: add #![feature(stmt_expr_attributes)] to the crate attributes to enable
 
 error[E0658]: attributes on expressions are experimental
-  --> $DIR/stmt_expr_attrs_no_feature.rs:137:14
+  --> $DIR/stmt_expr_attrs_no_feature.rs:138:14
    |
-LL |         6 => #[attr] (),
-   |              ^^^^^^^
+LL |         6 => #[rustc_dummy] (),
+   |              ^^^^^^^^^^^^^^
    |
    = note: for more information, see https://github.com/rust-lang/rust/issues/15701
    = help: add #![feature(stmt_expr_attributes)] to the crate attributes to enable
diff --git a/src/test/ui/suffixed-literal-meta.rs b/src/test/ui/suffixed-literal-meta.rs
index bd2d6623d91..a6531490c01 100644
--- a/src/test/ui/suffixed-literal-meta.rs
+++ b/src/test/ui/suffixed-literal-meta.rs
@@ -1,15 +1,15 @@
-#![feature(custom_attribute)]
+#![feature(rustc_attrs)]
 
-#[my_attr = 1usize] //~ ERROR: suffixed literals are not allowed in attributes
-#[my_attr = 1u8] //~ ERROR: suffixed literals are not allowed in attributes
-#[my_attr = 1u16] //~ ERROR: suffixed literals are not allowed in attributes
-#[my_attr = 1u32] //~ ERROR: suffixed literals are not allowed in attributes
-#[my_attr = 1u64] //~ ERROR: suffixed literals are not allowed in attributes
-#[my_attr = 1isize] //~ ERROR: suffixed literals are not allowed in attributes
-#[my_attr = 1i8] //~ ERROR: suffixed literals are not allowed in attributes
-#[my_attr = 1i16] //~ ERROR: suffixed literals are not allowed in attributes
-#[my_attr = 1i32] //~ ERROR: suffixed literals are not allowed in attributes
-#[my_attr = 1i64] //~ ERROR: suffixed literals are not allowed in attributes
-#[my_attr = 1.0f32] //~ ERROR: suffixed literals are not allowed in attributes
-#[my_attr = 1.0f64] //~ ERROR: suffixed literals are not allowed in attributes
-fn main() { }
+#[rustc_dummy = 1usize] //~ ERROR: suffixed literals are not allowed in attributes
+#[rustc_dummy = 1u8] //~ ERROR: suffixed literals are not allowed in attributes
+#[rustc_dummy = 1u16] //~ ERROR: suffixed literals are not allowed in attributes
+#[rustc_dummy = 1u32] //~ ERROR: suffixed literals are not allowed in attributes
+#[rustc_dummy = 1u64] //~ ERROR: suffixed literals are not allowed in attributes
+#[rustc_dummy = 1isize] //~ ERROR: suffixed literals are not allowed in attributes
+#[rustc_dummy = 1i8] //~ ERROR: suffixed literals are not allowed in attributes
+#[rustc_dummy = 1i16] //~ ERROR: suffixed literals are not allowed in attributes
+#[rustc_dummy = 1i32] //~ ERROR: suffixed literals are not allowed in attributes
+#[rustc_dummy = 1i64] //~ ERROR: suffixed literals are not allowed in attributes
+#[rustc_dummy = 1.0f32] //~ ERROR: suffixed literals are not allowed in attributes
+#[rustc_dummy = 1.0f64] //~ ERROR: suffixed literals are not allowed in attributes
+fn main() {}
diff --git a/src/test/ui/suffixed-literal-meta.stderr b/src/test/ui/suffixed-literal-meta.stderr
index 495404af3e8..83de173b1a7 100644
--- a/src/test/ui/suffixed-literal-meta.stderr
+++ b/src/test/ui/suffixed-literal-meta.stderr
@@ -1,96 +1,96 @@
 error: suffixed literals are not allowed in attributes
-  --> $DIR/suffixed-literal-meta.rs:3:13
+  --> $DIR/suffixed-literal-meta.rs:3:17
    |
-LL | #[my_attr = 1usize]
-   |             ^^^^^^
+LL | #[rustc_dummy = 1usize]
+   |                 ^^^^^^
    |
    = help: instead of using a suffixed literal (1u8, 1.0f32, etc.), use an unsuffixed version (1, 1.0, etc.).
 
 error: suffixed literals are not allowed in attributes
-  --> $DIR/suffixed-literal-meta.rs:4:13
+  --> $DIR/suffixed-literal-meta.rs:4:17
    |
-LL | #[my_attr = 1u8]
-   |             ^^^
+LL | #[rustc_dummy = 1u8]
+   |                 ^^^
    |
    = help: instead of using a suffixed literal (1u8, 1.0f32, etc.), use an unsuffixed version (1, 1.0, etc.).
 
 error: suffixed literals are not allowed in attributes
-  --> $DIR/suffixed-literal-meta.rs:5:13
+  --> $DIR/suffixed-literal-meta.rs:5:17
    |
-LL | #[my_attr = 1u16]
-   |             ^^^^
+LL | #[rustc_dummy = 1u16]
+   |                 ^^^^
    |
    = help: instead of using a suffixed literal (1u8, 1.0f32, etc.), use an unsuffixed version (1, 1.0, etc.).
 
 error: suffixed literals are not allowed in attributes
-  --> $DIR/suffixed-literal-meta.rs:6:13
+  --> $DIR/suffixed-literal-meta.rs:6:17
    |
-LL | #[my_attr = 1u32]
-   |             ^^^^
+LL | #[rustc_dummy = 1u32]
+   |                 ^^^^
    |
    = help: instead of using a suffixed literal (1u8, 1.0f32, etc.), use an unsuffixed version (1, 1.0, etc.).
 
 error: suffixed literals are not allowed in attributes
-  --> $DIR/suffixed-literal-meta.rs:7:13
+  --> $DIR/suffixed-literal-meta.rs:7:17
    |
-LL | #[my_attr = 1u64]
-   |             ^^^^
+LL | #[rustc_dummy = 1u64]
+   |                 ^^^^
    |
    = help: instead of using a suffixed literal (1u8, 1.0f32, etc.), use an unsuffixed version (1, 1.0, etc.).
 
 error: suffixed literals are not allowed in attributes
-  --> $DIR/suffixed-literal-meta.rs:8:13
+  --> $DIR/suffixed-literal-meta.rs:8:17
    |
-LL | #[my_attr = 1isize]
-   |             ^^^^^^
+LL | #[rustc_dummy = 1isize]
+   |                 ^^^^^^
    |
    = help: instead of using a suffixed literal (1u8, 1.0f32, etc.), use an unsuffixed version (1, 1.0, etc.).
 
 error: suffixed literals are not allowed in attributes
-  --> $DIR/suffixed-literal-meta.rs:9:13
+  --> $DIR/suffixed-literal-meta.rs:9:17
    |
-LL | #[my_attr = 1i8]
-   |             ^^^
+LL | #[rustc_dummy = 1i8]
+   |                 ^^^
    |
    = help: instead of using a suffixed literal (1u8, 1.0f32, etc.), use an unsuffixed version (1, 1.0, etc.).
 
 error: suffixed literals are not allowed in attributes
-  --> $DIR/suffixed-literal-meta.rs:10:13
+  --> $DIR/suffixed-literal-meta.rs:10:17
    |
-LL | #[my_attr = 1i16]
-   |             ^^^^
+LL | #[rustc_dummy = 1i16]
+   |                 ^^^^
    |
    = help: instead of using a suffixed literal (1u8, 1.0f32, etc.), use an unsuffixed version (1, 1.0, etc.).
 
 error: suffixed literals are not allowed in attributes
-  --> $DIR/suffixed-literal-meta.rs:11:13
+  --> $DIR/suffixed-literal-meta.rs:11:17
    |
-LL | #[my_attr = 1i32]
-   |             ^^^^
+LL | #[rustc_dummy = 1i32]
+   |                 ^^^^
    |
    = help: instead of using a suffixed literal (1u8, 1.0f32, etc.), use an unsuffixed version (1, 1.0, etc.).
 
 error: suffixed literals are not allowed in attributes
-  --> $DIR/suffixed-literal-meta.rs:12:13
+  --> $DIR/suffixed-literal-meta.rs:12:17
    |
-LL | #[my_attr = 1i64]
-   |             ^^^^
+LL | #[rustc_dummy = 1i64]
+   |                 ^^^^
    |
    = help: instead of using a suffixed literal (1u8, 1.0f32, etc.), use an unsuffixed version (1, 1.0, etc.).
 
 error: suffixed literals are not allowed in attributes
-  --> $DIR/suffixed-literal-meta.rs:13:13
+  --> $DIR/suffixed-literal-meta.rs:13:17
    |
-LL | #[my_attr = 1.0f32]
-   |             ^^^^^^
+LL | #[rustc_dummy = 1.0f32]
+   |                 ^^^^^^
    |
    = help: instead of using a suffixed literal (1u8, 1.0f32, etc.), use an unsuffixed version (1, 1.0, etc.).
 
 error: suffixed literals are not allowed in attributes
-  --> $DIR/suffixed-literal-meta.rs:14:13
+  --> $DIR/suffixed-literal-meta.rs:14:17
    |
-LL | #[my_attr = 1.0f64]
-   |             ^^^^^^
+LL | #[rustc_dummy = 1.0f64]
+   |                 ^^^^^^
    |
    = help: instead of using a suffixed literal (1u8, 1.0f32, etc.), use an unsuffixed version (1, 1.0, etc.).
 
diff --git a/src/test/ui/tool-attributes/tool-attributes-misplaced-1.rs b/src/test/ui/tool-attributes/tool-attributes-misplaced-1.rs
index 33cffcefd89..ce902b7e7d2 100644
--- a/src/test/ui/tool-attributes/tool-attributes-misplaced-1.rs
+++ b/src/test/ui/tool-attributes/tool-attributes-misplaced-1.rs
@@ -1,12 +1,11 @@
-#![feature(custom_attribute)]
-
 type A = rustfmt; //~ ERROR expected type, found tool module `rustfmt`
 type B = rustfmt::skip; //~ ERROR expected type, found tool attribute `rustfmt::skip`
 
 #[derive(rustfmt)] //~ ERROR cannot find derive macro `rustfmt` in this scope
 struct S;
 
-#[rustfmt] // OK, interpreted as a custom attribute
+// Interpreted as a feature gated custom attribute
+#[rustfmt] //~ ERROR attribute `rustfmt` is currently unknown
 fn check() {}
 
 #[rustfmt::skip] // OK
diff --git a/src/test/ui/tool-attributes/tool-attributes-misplaced-1.stderr b/src/test/ui/tool-attributes/tool-attributes-misplaced-1.stderr
index 1c799b41c5a..1df9821f244 100644
--- a/src/test/ui/tool-attributes/tool-attributes-misplaced-1.stderr
+++ b/src/test/ui/tool-attributes/tool-attributes-misplaced-1.stderr
@@ -1,39 +1,49 @@
+error[E0658]: The attribute `rustfmt` is currently unknown to the compiler and may have meaning added to it in the future
+  --> $DIR/tool-attributes-misplaced-1.rs:8:3
+   |
+LL | #[rustfmt]
+   |   ^^^^^^^
+   |
+   = note: for more information, see https://github.com/rust-lang/rust/issues/29642
+   = help: add #![feature(custom_attribute)] to the crate attributes to enable
+
 error: cannot find derive macro `rustfmt` in this scope
-  --> $DIR/tool-attributes-misplaced-1.rs:6:10
+  --> $DIR/tool-attributes-misplaced-1.rs:4:10
    |
 LL | #[derive(rustfmt)]
    |          ^^^^^^^
 
 error: cannot find macro `rustfmt!` in this scope
-  --> $DIR/tool-attributes-misplaced-1.rs:15:5
+  --> $DIR/tool-attributes-misplaced-1.rs:14:5
    |
 LL |     rustfmt!();
    |     ^^^^^^^
 
 error[E0573]: expected type, found tool module `rustfmt`
-  --> $DIR/tool-attributes-misplaced-1.rs:3:10
+  --> $DIR/tool-attributes-misplaced-1.rs:1:10
    |
 LL | type A = rustfmt;
    |          ^^^^^^^ not a type
 
 error[E0573]: expected type, found tool attribute `rustfmt::skip`
-  --> $DIR/tool-attributes-misplaced-1.rs:4:10
+  --> $DIR/tool-attributes-misplaced-1.rs:2:10
    |
 LL | type B = rustfmt::skip;
    |          ^^^^^^^^^^^^^ not a type
 
 error[E0423]: expected value, found tool module `rustfmt`
-  --> $DIR/tool-attributes-misplaced-1.rs:14:5
+  --> $DIR/tool-attributes-misplaced-1.rs:13:5
    |
 LL |     rustfmt;
    |     ^^^^^^^ not a value
 
 error[E0423]: expected value, found tool attribute `rustfmt::skip`
-  --> $DIR/tool-attributes-misplaced-1.rs:17:5
+  --> $DIR/tool-attributes-misplaced-1.rs:16:5
    |
 LL |     rustfmt::skip;
    |     ^^^^^^^^^^^^^ not a value
 
-error: aborting due to 6 previous errors
+error: aborting due to 7 previous errors
 
-For more information about this error, try `rustc --explain E0423`.
+Some errors have detailed explanations: E0423, E0658.
+For more information about an error, try `rustc --explain E0423`.
diff --git a/src/test/ui/traits/trait-with-dst.rs b/src/test/ui/traits/trait-with-dst.rs
new file mode 100644
index 00000000000..86d6585bc61
--- /dev/null
+++ b/src/test/ui/traits/trait-with-dst.rs
@@ -0,0 +1,22 @@
+// compile-pass
+// #55266
+
+struct VTable<DST: ?Sized> {
+    _to_dst_ptr: fn(*mut ()) -> *mut DST,
+}
+
+trait HasVTableFor<DST: ?Sized + 'static> {
+    const VTABLE: &'static VTable<DST>;
+}
+
+impl<T, DST: ?Sized + 'static> HasVTableFor<DST> for T {
+    const VTABLE: &'static VTable<DST> = &VTable {
+        _to_dst_ptr: |_: *mut ()| unsafe { std::mem::zeroed() },
+    };
+}
+
+pub fn push<DST: ?Sized + 'static, T>() {
+    <T as HasVTableFor<DST>>::VTABLE;
+}
+
+fn main() {}
diff --git a/src/test/ui/unrestricted-attribute-tokens.rs b/src/test/ui/unrestricted-attribute-tokens.rs
index 4798f7b396c..b07ab96bce1 100644
--- a/src/test/ui/unrestricted-attribute-tokens.rs
+++ b/src/test/ui/unrestricted-attribute-tokens.rs
@@ -1,8 +1,8 @@
 // compile-pass
 
-#![feature(custom_attribute)]
+#![feature(rustc_attrs)]
 
-#[my_attr(a b c d)]
-#[my_attr[a b c d]]
-#[my_attr{a b c d}]
+#[rustc_dummy(a b c d)]
+#[rustc_dummy[a b c d]]
+#[rustc_dummy{a b c d}]
 fn main() {}
diff --git a/src/test/ui/unused/unused-attr.rs b/src/test/ui/unused/unused-attr.rs
index 810732a9775..cb8ac0e6a05 100644
--- a/src/test/ui/unused/unused-attr.rs
+++ b/src/test/ui/unused/unused-attr.rs
@@ -1,49 +1,48 @@
 #![deny(unused_attributes)]
-#![allow(dead_code, unused_imports, unused_extern_crates)]
-#![feature(custom_attribute)]
+#![feature(rustc_attrs)]
 
-#![foo] //~ ERROR unused attribute
+#![rustc_dummy] //~ ERROR unused attribute
 
-#[foo] //~ ERROR unused attribute
+#[rustc_dummy] //~ ERROR unused attribute
 extern crate core;
 
-#[foo] //~ ERROR unused attribute
+#[rustc_dummy] //~ ERROR unused attribute
 use std::collections;
 
-#[foo] //~ ERROR unused attribute
+#[rustc_dummy] //~ ERROR unused attribute
 extern "C" {
-    #[foo] //~ ERROR unused attribute
+    #[rustc_dummy] //~ ERROR unused attribute
     fn foo();
 }
 
-#[foo] //~ ERROR unused attribute
+#[rustc_dummy] //~ ERROR unused attribute
 mod foo {
-    #[foo] //~ ERROR unused attribute
+    #[rustc_dummy] //~ ERROR unused attribute
     pub enum Foo {
-        #[foo] //~ ERROR unused attribute
+        #[rustc_dummy] //~ ERROR unused attribute
         Bar,
     }
 }
 
-#[foo] //~ ERROR unused attribute
+#[rustc_dummy] //~ ERROR unused attribute
 fn bar(f: foo::Foo) {
     match f {
-        #[foo] //~ ERROR unused attribute
+        #[rustc_dummy] //~ ERROR unused attribute
         foo::Foo::Bar => {}
     }
 }
 
-#[foo] //~ ERROR unused attribute
+#[rustc_dummy] //~ ERROR unused attribute
 struct Foo {
-    #[foo] //~ ERROR unused attribute
+    #[rustc_dummy] //~ ERROR unused attribute
     a: isize
 }
 
-#[foo] //~ ERROR unused attribute
+#[rustc_dummy] //~ ERROR unused attribute
 trait Baz {
-    #[foo] //~ ERROR unused attribute
+    #[rustc_dummy] //~ ERROR unused attribute
     fn blah(&self);
-    #[foo] //~ ERROR unused attribute
+    #[rustc_dummy] //~ ERROR unused attribute
     fn blah2(&self) {}
 }
 
diff --git a/src/test/ui/unused/unused-attr.stderr b/src/test/ui/unused/unused-attr.stderr
index 6f096d74144..956b870715e 100644
--- a/src/test/ui/unused/unused-attr.stderr
+++ b/src/test/ui/unused/unused-attr.stderr
@@ -1,8 +1,8 @@
 error: unused attribute
-  --> $DIR/unused-attr.rs:7:1
+  --> $DIR/unused-attr.rs:6:1
    |
-LL | #[foo]
-   | ^^^^^^
+LL | #[rustc_dummy]
+   | ^^^^^^^^^^^^^^
    |
 note: lint level defined here
   --> $DIR/unused-attr.rs:1:9
@@ -11,88 +11,88 @@ LL | #![deny(unused_attributes)]
    |         ^^^^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:10:1
+  --> $DIR/unused-attr.rs:9:1
    |
-LL | #[foo]
-   | ^^^^^^
+LL | #[rustc_dummy]
+   | ^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:15:5
+  --> $DIR/unused-attr.rs:14:5
    |
-LL |     #[foo]
-   |     ^^^^^^
+LL |     #[rustc_dummy]
+   |     ^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:13:1
+  --> $DIR/unused-attr.rs:12:1
    |
-LL | #[foo]
-   | ^^^^^^
+LL | #[rustc_dummy]
+   | ^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:23:9
+  --> $DIR/unused-attr.rs:22:9
    |
-LL |         #[foo]
-   |         ^^^^^^
+LL |         #[rustc_dummy]
+   |         ^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:21:5
+  --> $DIR/unused-attr.rs:20:5
    |
-LL |     #[foo]
-   |     ^^^^^^
+LL |     #[rustc_dummy]
+   |     ^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:19:1
+  --> $DIR/unused-attr.rs:18:1
    |
-LL | #[foo]
-   | ^^^^^^
+LL | #[rustc_dummy]
+   | ^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:31:9
+  --> $DIR/unused-attr.rs:30:9
    |
-LL |         #[foo]
-   |         ^^^^^^
+LL |         #[rustc_dummy]
+   |         ^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:28:1
+  --> $DIR/unused-attr.rs:27:1
    |
-LL | #[foo]
-   | ^^^^^^
+LL | #[rustc_dummy]
+   | ^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:38:5
+  --> $DIR/unused-attr.rs:37:5
    |
-LL |     #[foo]
-   |     ^^^^^^
+LL |     #[rustc_dummy]
+   |     ^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:36:1
+  --> $DIR/unused-attr.rs:35:1
    |
-LL | #[foo]
-   | ^^^^^^
+LL | #[rustc_dummy]
+   | ^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:44:5
+  --> $DIR/unused-attr.rs:43:5
    |
-LL |     #[foo]
-   |     ^^^^^^
+LL |     #[rustc_dummy]
+   |     ^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:46:5
+  --> $DIR/unused-attr.rs:45:5
    |
-LL |     #[foo]
-   |     ^^^^^^
+LL |     #[rustc_dummy]
+   |     ^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:42:1
+  --> $DIR/unused-attr.rs:41:1
    |
-LL | #[foo]
-   | ^^^^^^
+LL | #[rustc_dummy]
+   | ^^^^^^^^^^^^^^
 
 error: unused attribute
-  --> $DIR/unused-attr.rs:5:1
+  --> $DIR/unused-attr.rs:4:1
    |
-LL | #![foo]
-   | ^^^^^^^
+LL | #![rustc_dummy]
+   | ^^^^^^^^^^^^^^^
 
 error: aborting due to 15 previous errors