diff --git a/src/doc/unstable-book/src/language-features/param-attrs.md b/src/doc/unstable-book/src/language-features/param-attrs.md
deleted file mode 100644
index 4b83c204ba105..0000000000000
--- a/src/doc/unstable-book/src/language-features/param-attrs.md
+++ /dev/null
@@ -1,27 +0,0 @@
-# `param_attrs`
-
-The tracking issue for this feature is: [#60406]
-
-[#60406]: https://github.com/rust-lang/rust/issues/60406
-
-Allow attributes in formal function parameter position so external tools and compiler internals can
-take advantage of the additional information that the parameters provide.
-
-Enables finer conditional compilation with `#[cfg(..)]` and linting control of variables. Moreover,
-opens the path to richer DSLs created by users.
-
-------------------------
-
-Example:
-
-```rust
-#![feature(param_attrs)]
-
-fn len(
-  #[cfg(windows)] slice: &[u16],
-  #[cfg(not(windows))] slice: &[u8],
-) -> usize
-{
-  slice.len()
-}
-```
diff --git a/src/libsyntax/feature_gate/accepted.rs b/src/libsyntax/feature_gate/accepted.rs
index eff9f90a8619e..5538daf388e2f 100644
--- a/src/libsyntax/feature_gate/accepted.rs
+++ b/src/libsyntax/feature_gate/accepted.rs
@@ -243,6 +243,8 @@ declare_features! (
     (accepted, async_await, "1.39.0", Some(50547), None),
     /// Allows mixing bind-by-move in patterns and references to those identifiers in guards.
     (accepted, bind_by_move_pattern_guards, "1.39.0", Some(15287), None),
+    /// Allows attributes in formal function parameters.
+    (accepted, param_attrs, "1.39.0", Some(60406), None),
 
     // -------------------------------------------------------------------------
     // feature-group-end: accepted features
diff --git a/src/libsyntax/feature_gate/active.rs b/src/libsyntax/feature_gate/active.rs
index dd78777b56986..38c16dbac6ab7 100644
--- a/src/libsyntax/feature_gate/active.rs
+++ b/src/libsyntax/feature_gate/active.rs
@@ -489,9 +489,6 @@ declare_features! (
     /// Allows the user of associated type bounds.
     (active, associated_type_bounds, "1.34.0", Some(52662), None),
 
-    /// Attributes on formal function params.
-    (active, param_attrs, "1.36.0", Some(60406), None),
-
     /// Allows calling constructor functions in `const fn`.
     (active, const_constructor, "1.37.0", Some(61456), None),
 
diff --git a/src/libsyntax/feature_gate/check.rs b/src/libsyntax/feature_gate/check.rs
index 5711b269ff092..6b76a6a60c3d6 100644
--- a/src/libsyntax/feature_gate/check.rs
+++ b/src/libsyntax/feature_gate/check.rs
@@ -892,7 +892,6 @@ pub fn check_crate(krate: &ast::Crate,
         }
     }
 
-    gate_all!(param_attrs, "attributes on function parameters are unstable");
     gate_all!(let_chains, "`let` expressions in this position are experimental");
     gate_all!(async_closure, "async closures are unstable");
     gate_all!(yields, generators, "yield syntax is experimental");
diff --git a/src/libsyntax/parse/attr.rs b/src/libsyntax/parse/attr.rs
index 9aa1ec0b14fe9..bba70973631fe 100644
--- a/src/libsyntax/parse/attr.rs
+++ b/src/libsyntax/parse/attr.rs
@@ -19,13 +19,6 @@ const DEFAULT_UNEXPECTED_INNER_ATTR_ERR_MSG: &str = "an inner attribute is not \
                                                      permitted in this context";
 
 impl<'a> Parser<'a> {
-    crate fn parse_param_attributes(&mut self) -> PResult<'a, Vec<ast::Attribute>> {
-        let attrs = self.parse_outer_attributes()?;
-        self.sess.gated_spans.param_attrs.borrow_mut()
-            .extend(attrs.iter().map(|a| a.span));
-        Ok(attrs)
-    }
-
     /// Parses attributes that appear before an item.
     crate fn parse_outer_attributes(&mut self) -> PResult<'a, Vec<ast::Attribute>> {
         let mut attrs: Vec<ast::Attribute> = Vec::new();
diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index bc1bc00ac8405..6a8a64f369d99 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -42,8 +42,6 @@ pub type PResult<'a, T> = Result<T, DiagnosticBuilder<'a>>;
 /// used and should be feature gated accordingly in `check_crate`.
 #[derive(Default)]
 pub struct GatedSpans {
-    /// Spans collected for gating `param_attrs`, e.g. `fn foo(#[attr] x: u8) {}`.
-    pub param_attrs: Lock<Vec<Span>>,
     /// Spans collected for gating `let_chains`, e.g. `if a && let b = c {}`.
     pub let_chains: Lock<Vec<Span>>,
     /// Spans collected for gating `async_closure`, e.g. `async || ..`.
diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index fcebfa2996233..b2b6504919e96 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -979,7 +979,7 @@ impl<'a> Parser<'a> {
         is_name_required: impl Fn(&token::Token) -> bool,
     ) -> PResult<'a, Param> {
         let lo = self.token.span;
-        let attrs = self.parse_param_attributes()?;
+        let attrs = self.parse_outer_attributes()?;
         if let Some(mut param) = self.parse_self_param()? {
             param.attrs = attrs.into();
             return self.recover_bad_self_param(param, is_trait_item);
@@ -1362,7 +1362,7 @@ impl<'a> Parser<'a> {
     /// Returns the parsed optional self parameter with attributes and whether a self
     /// shortcut was used.
     fn parse_self_parameter_with_attrs(&mut self) -> PResult<'a, Option<Param>> {
-        let attrs = self.parse_param_attributes()?;
+        let attrs = self.parse_outer_attributes()?;
         let param_opt = self.parse_self_param()?;
         Ok(param_opt.map(|mut param| {
             param.attrs = attrs.into();
diff --git a/src/libsyntax/parse/parser/expr.rs b/src/libsyntax/parse/parser/expr.rs
index 31b28443abbc3..b383498b7b64d 100644
--- a/src/libsyntax/parse/parser/expr.rs
+++ b/src/libsyntax/parse/parser/expr.rs
@@ -1176,7 +1176,7 @@ impl<'a> Parser<'a> {
     /// Parses a parameter in a closure header (e.g., `|arg, arg|`).
     fn parse_fn_block_param(&mut self) -> PResult<'a, Param> {
         let lo = self.token.span;
-        let attrs = self.parse_param_attributes()?;
+        let attrs = self.parse_outer_attributes()?;
         let pat = self.parse_pat(PARAM_EXPECTED)?;
         let t = if self.eat(&token::Colon) {
             self.parse_ty()?
diff --git a/src/test/ui/lint/lint-unused-mut-variables.rs b/src/test/ui/lint/lint-unused-mut-variables.rs
index f140546b04819..1af44ecf362bf 100644
--- a/src/test/ui/lint/lint-unused-mut-variables.rs
+++ b/src/test/ui/lint/lint-unused-mut-variables.rs
@@ -3,7 +3,7 @@
 // Exercise the unused_mut attribute in some positive and negative cases
 
 #![deny(unused_mut)]
-#![feature(async_closure, param_attrs)]
+#![feature(async_closure)]
 
 async fn baz_async(
     mut a: i32,
diff --git a/src/test/ui/lint/lint-unused-variables.rs b/src/test/ui/lint/lint-unused-variables.rs
index 06b818636f956..1a6b5183f0fae 100644
--- a/src/test/ui/lint/lint-unused-variables.rs
+++ b/src/test/ui/lint/lint-unused-variables.rs
@@ -1,7 +1,7 @@
 // compile-flags: --cfg something
 // edition:2018
 
-#![feature(async_closure, param_attrs)]
+#![feature(async_closure)]
 #![deny(unused_variables)]
 
 async fn foo_async(
diff --git a/src/test/ui/parser/fn-arg-doc-comment.rs b/src/test/ui/parser/fn-arg-doc-comment.rs
index 4a4f959e21353..995eb62d0bb59 100644
--- a/src/test/ui/parser/fn-arg-doc-comment.rs
+++ b/src/test/ui/parser/fn-arg-doc-comment.rs
@@ -2,14 +2,10 @@ pub fn f(
     /// Comment
     //~^ ERROR documentation comments cannot be applied to function parameters
     //~| NOTE doc comments are not allowed here
-    //~| ERROR attributes on function parameters are unstable
-    //~| NOTE https://github.com/rust-lang/rust/issues/60406
     id: u8,
     /// Other
     //~^ ERROR documentation comments cannot be applied to function parameters
     //~| NOTE doc comments are not allowed here
-    //~| ERROR attributes on function parameters are unstable
-    //~| NOTE https://github.com/rust-lang/rust/issues/60406
     a: u8,
 ) {}
 
diff --git a/src/test/ui/parser/fn-arg-doc-comment.stderr b/src/test/ui/parser/fn-arg-doc-comment.stderr
index d8884de1fe84d..669785af45f93 100644
--- a/src/test/ui/parser/fn-arg-doc-comment.stderr
+++ b/src/test/ui/parser/fn-arg-doc-comment.stderr
@@ -1,5 +1,5 @@
 error: attributes cannot be applied to a function parameter's type
-  --> $DIR/fn-arg-doc-comment.rs:16:12
+  --> $DIR/fn-arg-doc-comment.rs:12:12
    |
 LL | fn bar(id: #[allow(dead_code)] i32) {}
    |            ^^^^^^^^^^^^^^^^^^^ attributes are not allowed here
@@ -11,31 +11,13 @@ LL |     /// Comment
    |     ^^^^^^^^^^^ doc comments are not allowed here
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/fn-arg-doc-comment.rs:8:5
+  --> $DIR/fn-arg-doc-comment.rs:6:5
    |
 LL |     /// Other
    |     ^^^^^^^^^ doc comments are not allowed here
 
-error[E0658]: attributes on function parameters are unstable
-  --> $DIR/fn-arg-doc-comment.rs:2:5
-   |
-LL |     /// Comment
-   |     ^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/60406
-   = help: add `#![feature(param_attrs)]` to the crate attributes to enable
-
-error[E0658]: attributes on function parameters are unstable
-  --> $DIR/fn-arg-doc-comment.rs:8:5
-   |
-LL |     /// Other
-   |     ^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/60406
-   = help: add `#![feature(param_attrs)]` to the crate attributes to enable
-
 error[E0308]: mismatched types
-  --> $DIR/fn-arg-doc-comment.rs:22:7
+  --> $DIR/fn-arg-doc-comment.rs:18:7
    |
 LL |     f("", "");
    |       ^^ expected u8, found reference
@@ -44,7 +26,7 @@ LL |     f("", "");
               found type `&'static str`
 
 error[E0308]: mismatched types
-  --> $DIR/fn-arg-doc-comment.rs:22:11
+  --> $DIR/fn-arg-doc-comment.rs:18:11
    |
 LL |     f("", "");
    |           ^^ expected u8, found reference
@@ -53,7 +35,7 @@ LL |     f("", "");
               found type `&'static str`
 
 error[E0308]: mismatched types
-  --> $DIR/fn-arg-doc-comment.rs:29:9
+  --> $DIR/fn-arg-doc-comment.rs:25:9
    |
 LL |     bar("");
    |         ^^ expected i32, found reference
@@ -61,7 +43,6 @@ LL |     bar("");
    = note: expected type `i32`
               found type `&'static str`
 
-error: aborting due to 8 previous errors
+error: aborting due to 6 previous errors
 
-Some errors have detailed explanations: E0308, E0658.
-For more information about an error, try `rustc --explain E0308`.
+For more information about this error, try `rustc --explain E0308`.
diff --git a/src/test/ui/rfc-2565-param-attrs/param-attrs-2018.rs b/src/test/ui/rfc-2565-param-attrs/param-attrs-2018.rs
index d71711336b06e..a6f693bd5b5f4 100644
--- a/src/test/ui/rfc-2565-param-attrs/param-attrs-2018.rs
+++ b/src/test/ui/rfc-2565-param-attrs/param-attrs-2018.rs
@@ -1,7 +1,5 @@
 // edition:2018
 
-#![feature(param_attrs)]
-
 trait Trait2015 { fn foo(#[allow(C)] i32); }
 //~^ ERROR expected one of `:`, `@`, or `|`, found `)`
 
diff --git a/src/test/ui/rfc-2565-param-attrs/param-attrs-2018.stderr b/src/test/ui/rfc-2565-param-attrs/param-attrs-2018.stderr
index 26b414e426805..9860e9805b2ed 100644
--- a/src/test/ui/rfc-2565-param-attrs/param-attrs-2018.stderr
+++ b/src/test/ui/rfc-2565-param-attrs/param-attrs-2018.stderr
@@ -1,5 +1,5 @@
 error: expected one of `:`, `@`, or `|`, found `)`
-  --> $DIR/param-attrs-2018.rs:5:41
+  --> $DIR/param-attrs-2018.rs:3:41
    |
 LL | trait Trait2015 { fn foo(#[allow(C)] i32); }
    |                                         ^ expected one of `:`, `@`, or `|` here
diff --git a/src/test/ui/rfc-2565-param-attrs/param-attrs-allowed.rs b/src/test/ui/rfc-2565-param-attrs/param-attrs-allowed.rs
index 5eeda66173ded..1217f89cb3168 100644
--- a/src/test/ui/rfc-2565-param-attrs/param-attrs-allowed.rs
+++ b/src/test/ui/rfc-2565-param-attrs/param-attrs-allowed.rs
@@ -2,7 +2,6 @@
 // compile-flags: --cfg something
 
 #![deny(unused_mut)]
-#![feature(param_attrs)]
 
 extern "C" {
     fn ffi(
diff --git a/src/test/ui/rfc-2565-param-attrs/param-attrs-builtin-attrs.rs b/src/test/ui/rfc-2565-param-attrs/param-attrs-builtin-attrs.rs
index a8fe5d6c1f60e..c4684a3fa82b0 100644
--- a/src/test/ui/rfc-2565-param-attrs/param-attrs-builtin-attrs.rs
+++ b/src/test/ui/rfc-2565-param-attrs/param-attrs-builtin-attrs.rs
@@ -1,5 +1,3 @@
-#![feature(param_attrs)]
-
 extern "C" {
     fn ffi(
         /// Foo
diff --git a/src/test/ui/rfc-2565-param-attrs/param-attrs-builtin-attrs.stderr b/src/test/ui/rfc-2565-param-attrs/param-attrs-builtin-attrs.stderr
index 8ab3fc39a0ccb..0fc6ca2f7f37a 100644
--- a/src/test/ui/rfc-2565-param-attrs/param-attrs-builtin-attrs.stderr
+++ b/src/test/ui/rfc-2565-param-attrs/param-attrs-builtin-attrs.stderr
@@ -1,311 +1,311 @@
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/param-attrs-builtin-attrs.rs:7:9
+  --> $DIR/param-attrs-builtin-attrs.rs:5:9
    |
 LL |         #[test] a: i32,
    |         ^^^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/param-attrs-builtin-attrs.rs:23:5
+  --> $DIR/param-attrs-builtin-attrs.rs:21:5
    |
 LL |     #[test] a: u32,
    |     ^^^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/param-attrs-builtin-attrs.rs:38:5
+  --> $DIR/param-attrs-builtin-attrs.rs:36:5
    |
 LL |     #[test] a: u32,
    |     ^^^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/param-attrs-builtin-attrs.rs:58:9
+  --> $DIR/param-attrs-builtin-attrs.rs:56:9
    |
 LL |         #[test] a: i32,
    |         ^^^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/param-attrs-builtin-attrs.rs:79:9
+  --> $DIR/param-attrs-builtin-attrs.rs:77:9
    |
 LL |         #[test] a: i32,
    |         ^^^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/param-attrs-builtin-attrs.rs:98:9
+  --> $DIR/param-attrs-builtin-attrs.rs:96:9
    |
 LL |         #[test] a: i32,
    |         ^^^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/param-attrs-builtin-attrs.rs:117:9
+  --> $DIR/param-attrs-builtin-attrs.rs:115:9
    |
 LL |         #[test] a: i32,
    |         ^^^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/param-attrs-builtin-attrs.rs:134:9
+  --> $DIR/param-attrs-builtin-attrs.rs:132:9
    |
 LL |         #[test] a: u32,
    |         ^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:5:9
+  --> $DIR/param-attrs-builtin-attrs.rs:3:9
    |
 LL |         /// Foo
    |         ^^^^^^^ doc comments are not allowed here
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:9:9
+  --> $DIR/param-attrs-builtin-attrs.rs:7:9
    |
 LL |         /// Bar
    |         ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:11:9
+  --> $DIR/param-attrs-builtin-attrs.rs:9:9
    |
 LL |         #[must_use]
    |         ^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:13:9
+  --> $DIR/param-attrs-builtin-attrs.rs:11:9
    |
 LL |         /// Baz
    |         ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:15:9
+  --> $DIR/param-attrs-builtin-attrs.rs:13:9
    |
 LL |         #[no_mangle] b: i32,
    |         ^^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:21:5
+  --> $DIR/param-attrs-builtin-attrs.rs:19:5
    |
 LL |     /// Foo
    |     ^^^^^^^ doc comments are not allowed here
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:25:5
+  --> $DIR/param-attrs-builtin-attrs.rs:23:5
    |
 LL |     /// Bar
    |     ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:27:5
+  --> $DIR/param-attrs-builtin-attrs.rs:25:5
    |
 LL |     #[must_use]
    |     ^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:29:5
+  --> $DIR/param-attrs-builtin-attrs.rs:27:5
    |
 LL |     /// Baz
    |     ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:31:5
+  --> $DIR/param-attrs-builtin-attrs.rs:29:5
    |
 LL |     #[no_mangle] b: i32,
    |     ^^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:36:5
+  --> $DIR/param-attrs-builtin-attrs.rs:34:5
    |
 LL |     /// Foo
    |     ^^^^^^^ doc comments are not allowed here
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:40:5
+  --> $DIR/param-attrs-builtin-attrs.rs:38:5
    |
 LL |     /// Bar
    |     ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:42:5
+  --> $DIR/param-attrs-builtin-attrs.rs:40:5
    |
 LL |     #[must_use]
    |     ^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:44:5
+  --> $DIR/param-attrs-builtin-attrs.rs:42:5
    |
 LL |     /// Baz
    |     ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:46:5
+  --> $DIR/param-attrs-builtin-attrs.rs:44:5
    |
 LL |     #[no_mangle] b: i32,
    |     ^^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:53:9
+  --> $DIR/param-attrs-builtin-attrs.rs:51:9
    |
 LL |         /// Foo
    |         ^^^^^^^ doc comments are not allowed here
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:56:9
+  --> $DIR/param-attrs-builtin-attrs.rs:54:9
    |
 LL |         /// Bar
    |         ^^^^^^^ doc comments are not allowed here
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:60:9
+  --> $DIR/param-attrs-builtin-attrs.rs:58:9
    |
 LL |         /// Baz
    |         ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:62:9
+  --> $DIR/param-attrs-builtin-attrs.rs:60:9
    |
 LL |         #[must_use]
    |         ^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:64:9
+  --> $DIR/param-attrs-builtin-attrs.rs:62:9
    |
 LL |         /// Qux
    |         ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:66:9
+  --> $DIR/param-attrs-builtin-attrs.rs:64:9
    |
 LL |         #[no_mangle] b: i32,
    |         ^^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:74:9
+  --> $DIR/param-attrs-builtin-attrs.rs:72:9
    |
 LL |         /// Foo
    |         ^^^^^^^ doc comments are not allowed here
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:77:9
+  --> $DIR/param-attrs-builtin-attrs.rs:75:9
    |
 LL |         /// Bar
    |         ^^^^^^^ doc comments are not allowed here
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:81:9
+  --> $DIR/param-attrs-builtin-attrs.rs:79:9
    |
 LL |         /// Baz
    |         ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:83:9
+  --> $DIR/param-attrs-builtin-attrs.rs:81:9
    |
 LL |         #[must_use]
    |         ^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:85:9
+  --> $DIR/param-attrs-builtin-attrs.rs:83:9
    |
 LL |         /// Qux
    |         ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:87:9
+  --> $DIR/param-attrs-builtin-attrs.rs:85:9
    |
 LL |         #[no_mangle] b: i32,
    |         ^^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:93:9
+  --> $DIR/param-attrs-builtin-attrs.rs:91:9
    |
 LL |         /// Foo
    |         ^^^^^^^ doc comments are not allowed here
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:96:9
+  --> $DIR/param-attrs-builtin-attrs.rs:94:9
    |
 LL |         /// Bar
    |         ^^^^^^^ doc comments are not allowed here
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:100:9
+  --> $DIR/param-attrs-builtin-attrs.rs:98:9
    |
 LL |         /// Baz
    |         ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:102:9
+  --> $DIR/param-attrs-builtin-attrs.rs:100:9
    |
 LL |         #[must_use]
    |         ^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:104:9
+  --> $DIR/param-attrs-builtin-attrs.rs:102:9
    |
 LL |         /// Qux
    |         ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:106:9
+  --> $DIR/param-attrs-builtin-attrs.rs:104:9
    |
 LL |         #[no_mangle] b: i32,
    |         ^^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:112:9
+  --> $DIR/param-attrs-builtin-attrs.rs:110:9
    |
 LL |         /// Foo
    |         ^^^^^^^ doc comments are not allowed here
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:115:9
+  --> $DIR/param-attrs-builtin-attrs.rs:113:9
    |
 LL |         /// Bar
    |         ^^^^^^^ doc comments are not allowed here
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:119:9
+  --> $DIR/param-attrs-builtin-attrs.rs:117:9
    |
 LL |         /// Baz
    |         ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:121:9
+  --> $DIR/param-attrs-builtin-attrs.rs:119:9
    |
 LL |         #[must_use]
    |         ^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:123:9
+  --> $DIR/param-attrs-builtin-attrs.rs:121:9
    |
 LL |         /// Qux
    |         ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:125:9
+  --> $DIR/param-attrs-builtin-attrs.rs:123:9
    |
 LL |         #[no_mangle] b: i32,
    |         ^^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:132:9
+  --> $DIR/param-attrs-builtin-attrs.rs:130:9
    |
 LL |         /// Foo
    |         ^^^^^^^ doc comments are not allowed here
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:136:9
+  --> $DIR/param-attrs-builtin-attrs.rs:134:9
    |
 LL |         /// Bar
    |         ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:138:9
+  --> $DIR/param-attrs-builtin-attrs.rs:136:9
    |
 LL |         #[must_use]
    |         ^^^^^^^^^^^
 
 error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:140:9
+  --> $DIR/param-attrs-builtin-attrs.rs:138:9
    |
 LL |         /// Baz
    |         ^^^^^^^ doc comments are not allowed here
 
 error: allow, cfg, cfg_attr, deny, forbid, and warn are the only allowed built-in attributes in function parameters
-  --> $DIR/param-attrs-builtin-attrs.rs:142:9
+  --> $DIR/param-attrs-builtin-attrs.rs:140:9
    |
 LL |         #[no_mangle] b: i32
    |         ^^^^^^^^^^^^
diff --git a/src/test/ui/rfc-2565-param-attrs/param-attrs-cfg.rs b/src/test/ui/rfc-2565-param-attrs/param-attrs-cfg.rs
index 5ad6e23cf2a63..d44ff14e99247 100644
--- a/src/test/ui/rfc-2565-param-attrs/param-attrs-cfg.rs
+++ b/src/test/ui/rfc-2565-param-attrs/param-attrs-cfg.rs
@@ -1,7 +1,7 @@
 // compile-flags: --cfg something
 // edition:2018
 
-#![feature(async_closure, param_attrs)]
+#![feature(async_closure)]
 #![deny(unused_variables)]
 
 extern "C" {
diff --git a/src/test/ui/rfc-2565-param-attrs/param-attrs-feature-gate.rs b/src/test/ui/rfc-2565-param-attrs/param-attrs-feature-gate.rs
deleted file mode 100644
index a7f4855915b24..0000000000000
--- a/src/test/ui/rfc-2565-param-attrs/param-attrs-feature-gate.rs
+++ /dev/null
@@ -1,16 +0,0 @@
-// gate-test-param_attrs
-
-#![deny(unused_variables)]
-
-fn foo(
-    /// Foo
-    //~^ ERROR documentation comments cannot be applied to function parameters
-    //~| NOTE doc comments are not allowed here
-    //~| ERROR attributes on function parameters are unstable
-    //~| NOTE https://github.com/rust-lang/rust/issues/60406
-    #[allow(unused_variables)] a: u8
-    //~^ ERROR attributes on function parameters are unstable
-    //~| NOTE https://github.com/rust-lang/rust/issues/60406
-) {}
-
-fn main() {}
diff --git a/src/test/ui/rfc-2565-param-attrs/param-attrs-feature-gate.stderr b/src/test/ui/rfc-2565-param-attrs/param-attrs-feature-gate.stderr
deleted file mode 100644
index 0bb9d05dca0ac..0000000000000
--- a/src/test/ui/rfc-2565-param-attrs/param-attrs-feature-gate.stderr
+++ /dev/null
@@ -1,27 +0,0 @@
-error: documentation comments cannot be applied to function parameters
-  --> $DIR/param-attrs-feature-gate.rs:6:5
-   |
-LL |     /// Foo
-   |     ^^^^^^^ doc comments are not allowed here
-
-error[E0658]: attributes on function parameters are unstable
-  --> $DIR/param-attrs-feature-gate.rs:6:5
-   |
-LL |     /// Foo
-   |     ^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/60406
-   = help: add `#![feature(param_attrs)]` to the crate attributes to enable
-
-error[E0658]: attributes on function parameters are unstable
-  --> $DIR/param-attrs-feature-gate.rs:11:5
-   |
-LL |     #[allow(unused_variables)] a: u8
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-   = note: for more information, see https://github.com/rust-lang/rust/issues/60406
-   = help: add `#![feature(param_attrs)]` 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/rfc-2565-param-attrs/param-attrs-pretty.rs b/src/test/ui/rfc-2565-param-attrs/param-attrs-pretty.rs
index 1a7e948174506..fb86020d992e9 100644
--- a/src/test/ui/rfc-2565-param-attrs/param-attrs-pretty.rs
+++ b/src/test/ui/rfc-2565-param-attrs/param-attrs-pretty.rs
@@ -2,7 +2,6 @@
 
 // check-pass
 
-#![feature(param_attrs)]
 #![feature(c_variadic)]
 
 extern crate param_attrs;
diff --git a/src/test/ui/rfc-2565-param-attrs/proc-macro-cannot-be-used.rs b/src/test/ui/rfc-2565-param-attrs/proc-macro-cannot-be-used.rs
index 7f00308925442..9f4e2710dc420 100644
--- a/src/test/ui/rfc-2565-param-attrs/proc-macro-cannot-be-used.rs
+++ b/src/test/ui/rfc-2565-param-attrs/proc-macro-cannot-be-used.rs
@@ -1,6 +1,5 @@
 // aux-build:ident-mac.rs
 
-#![feature(param_attrs)]
 #![feature(c_variadic)]
 
 extern crate ident_mac;
diff --git a/src/test/ui/rfc-2565-param-attrs/proc-macro-cannot-be-used.stderr b/src/test/ui/rfc-2565-param-attrs/proc-macro-cannot-be-used.stderr
index 3b72e8ab4bdf9..b4946fa74943f 100644
--- a/src/test/ui/rfc-2565-param-attrs/proc-macro-cannot-be-used.stderr
+++ b/src/test/ui/rfc-2565-param-attrs/proc-macro-cannot-be-used.stderr
@@ -1,149 +1,149 @@
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:11:21
+  --> $DIR/proc-macro-cannot-be-used.rs:10:21
    |
 LL | extern "C" { fn ffi(#[id] arg1: i32, #[id] ...); }
    |                     ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:11:38
+  --> $DIR/proc-macro-cannot-be-used.rs:10:38
    |
 LL | extern "C" { fn ffi(#[id] arg1: i32, #[id] ...); }
    |                                      ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:15:38
+  --> $DIR/proc-macro-cannot-be-used.rs:14:38
    |
 LL | unsafe extern "C" fn cvar(arg1: i32, #[id] mut args: ...) {}
    |                                      ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:18:28
+  --> $DIR/proc-macro-cannot-be-used.rs:17:28
    |
 LL | type Alias = extern "C" fn(#[id] u8, #[id] ...);
    |                            ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:18:38
+  --> $DIR/proc-macro-cannot-be-used.rs:17:38
    |
 LL | type Alias = extern "C" fn(#[id] u8, #[id] ...);
    |                                      ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:22:9
+  --> $DIR/proc-macro-cannot-be-used.rs:21:9
    |
 LL | fn free(#[id] arg1: u8) {
    |         ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:24:16
+  --> $DIR/proc-macro-cannot-be-used.rs:23:16
    |
 LL |     let lam = |#[id] W(x), #[id] y| ();
    |                ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:24:28
+  --> $DIR/proc-macro-cannot-be-used.rs:23:28
    |
 LL |     let lam = |#[id] W(x), #[id] y| ();
    |                            ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:30:18
+  --> $DIR/proc-macro-cannot-be-used.rs:29:18
    |
 LL |     fn inherent1(#[id] self, #[id] arg1: u8) {}
    |                  ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:30:30
+  --> $DIR/proc-macro-cannot-be-used.rs:29:30
    |
 LL |     fn inherent1(#[id] self, #[id] arg1: u8) {}
    |                              ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:33:18
+  --> $DIR/proc-macro-cannot-be-used.rs:32:18
    |
 LL |     fn inherent2(#[id] &self, #[id] arg1: u8) {}
    |                  ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:33:31
+  --> $DIR/proc-macro-cannot-be-used.rs:32:31
    |
 LL |     fn inherent2(#[id] &self, #[id] arg1: u8) {}
    |                               ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:36:22
+  --> $DIR/proc-macro-cannot-be-used.rs:35:22
    |
 LL |     fn inherent3<'a>(#[id] &'a mut self, #[id] arg1: u8) {}
    |                      ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:36:42
+  --> $DIR/proc-macro-cannot-be-used.rs:35:42
    |
 LL |     fn inherent3<'a>(#[id] &'a mut self, #[id] arg1: u8) {}
    |                                          ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:39:22
+  --> $DIR/proc-macro-cannot-be-used.rs:38:22
    |
 LL |     fn inherent4<'a>(#[id] self: Box<Self>, #[id] arg1: u8) {}
    |                      ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:39:45
+  --> $DIR/proc-macro-cannot-be-used.rs:38:45
    |
 LL |     fn inherent4<'a>(#[id] self: Box<Self>, #[id] arg1: u8) {}
    |                                             ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:45:15
+  --> $DIR/proc-macro-cannot-be-used.rs:44:15
    |
 LL |     fn trait1(#[id] self, #[id] arg1: u8);
    |               ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:45:27
+  --> $DIR/proc-macro-cannot-be-used.rs:44:27
    |
 LL |     fn trait1(#[id] self, #[id] arg1: u8);
    |                           ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:48:15
+  --> $DIR/proc-macro-cannot-be-used.rs:47:15
    |
 LL |     fn trait2(#[id] &self, #[id] arg1: u8);
    |               ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:48:28
+  --> $DIR/proc-macro-cannot-be-used.rs:47:28
    |
 LL |     fn trait2(#[id] &self, #[id] arg1: u8);
    |                            ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:51:19
+  --> $DIR/proc-macro-cannot-be-used.rs:50:19
    |
 LL |     fn trait3<'a>(#[id] &'a mut self, #[id] arg1: u8);
    |                   ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:51:39
+  --> $DIR/proc-macro-cannot-be-used.rs:50:39
    |
 LL |     fn trait3<'a>(#[id] &'a mut self, #[id] arg1: u8);
    |                                       ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:54:19
+  --> $DIR/proc-macro-cannot-be-used.rs:53:19
    |
 LL |     fn trait4<'a>(#[id] self: Box<Self>, #[id] arg1: u8, #[id] Vec<u8>);
    |                   ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:54:42
+  --> $DIR/proc-macro-cannot-be-used.rs:53:42
    |
 LL |     fn trait4<'a>(#[id] self: Box<Self>, #[id] arg1: u8, #[id] Vec<u8>);
    |                                          ^^^^^
 
 error: expected an inert attribute, found an attribute macro
-  --> $DIR/proc-macro-cannot-be-used.rs:54:58
+  --> $DIR/proc-macro-cannot-be-used.rs:53:58
    |
 LL |     fn trait4<'a>(#[id] self: Box<Self>, #[id] arg1: u8, #[id] Vec<u8>);
    |                                                          ^^^^^