diff --git a/src/bootstrap/channel.rs b/src/bootstrap/channel.rs
index b17ee098ff62a..ec4bf9a04fa94 100644
--- a/src/bootstrap/channel.rs
+++ b/src/bootstrap/channel.rs
@@ -13,7 +13,7 @@ use build_helper::output;
 use crate::Build;
 
 // The version number
-pub const CFG_RELEASE_NUM: &str = "1.41.0";
+pub const CFG_RELEASE_NUM: &str = "1.42.0";
 
 pub struct GitInfo {
     inner: Option<Info>,
diff --git a/src/liballoc/collections/linked_list.rs b/src/liballoc/collections/linked_list.rs
index 4a74a479e71bb..5a6d4ee2aea93 100644
--- a/src/liballoc/collections/linked_list.rs
+++ b/src/liballoc/collections/linked_list.rs
@@ -275,10 +275,7 @@ impl<T> LinkedList<T> {
     /// let list: LinkedList<u32> = LinkedList::new();
     /// ```
     #[inline]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_linked_list_new", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_linked_list_new", since = "1.32.0")]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub const fn new() -> Self {
         LinkedList {
diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index d828e374a7b22..0137275bc1589 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -116,8 +116,6 @@
 #![feature(unsize)]
 #![feature(unsized_locals)]
 #![feature(allocator_internals)]
-#![cfg_attr(bootstrap, feature(on_unimplemented))]
-#![cfg_attr(bootstrap, feature(rustc_const_unstable))]
 #![feature(slice_partition_dedup)]
 #![feature(maybe_uninit_extra, maybe_uninit_slice)]
 #![feature(alloc_layout_extra)]
diff --git a/src/liballoc/string.rs b/src/liballoc/string.rs
index bf9bbba47535d..f880f5915a36a 100644
--- a/src/liballoc/string.rs
+++ b/src/liballoc/string.rs
@@ -367,10 +367,7 @@ impl String {
     /// let s = String::new();
     /// ```
     #[inline]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_string_new", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_string_new", since = "1.32.0")]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub const fn new() -> String {
         String { vec: Vec::new() }
diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs
index 2ad4e22884ea7..19c95e2079313 100644
--- a/src/liballoc/vec.rs
+++ b/src/liballoc/vec.rs
@@ -315,10 +315,7 @@ impl<T> Vec<T> {
     /// let mut vec: Vec<i32> = Vec::new();
     /// ```
     #[inline]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_vec_new", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_vec_new", since = "1.32.0")]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub const fn new() -> Vec<T> {
         Vec {
diff --git a/src/libcore/alloc.rs b/src/libcore/alloc.rs
index 71517ffb0065e..cb476acfb3a9e 100644
--- a/src/libcore/alloc.rs
+++ b/src/libcore/alloc.rs
@@ -100,7 +100,7 @@ impl Layout {
     /// This function is unsafe as it does not verify the preconditions from
     /// [`Layout::from_size_align`](#method.from_size_align).
     #[stable(feature = "alloc_layout", since = "1.28.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "alloc_layout", since = "1.28.0"))]
+    #[rustc_const_stable(feature = "alloc_layout", since = "1.28.0")]
     #[inline]
     pub const unsafe fn from_size_align_unchecked(size: usize, align: usize) -> Self {
         Layout { size_: size, align_: NonZeroUsize::new_unchecked(align) }
diff --git a/src/libcore/any.rs b/src/libcore/any.rs
index 7935c9b1b392d..882c4a53faf2a 100644
--- a/src/libcore/any.rs
+++ b/src/libcore/any.rs
@@ -423,14 +423,9 @@ impl TypeId {
     /// assert_eq!(is_string(&"cookie monster".to_string()), true);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(bootstrap, rustc_const_unstable(feature="const_type_id"))]
-    #[cfg_attr(not(bootstrap), rustc_const_unstable(feature="const_type_id", issue = "41875"))]
+    #[rustc_const_unstable(feature="const_type_id", issue = "41875")]
     pub const fn of<T: ?Sized + 'static>() -> TypeId {
         TypeId {
-            #[cfg(bootstrap)]
-            // SAFETY: going away soon
-            t: unsafe { intrinsics::type_id::<T>() },
-            #[cfg(not(bootstrap))]
             t: intrinsics::type_id::<T>(),
         }
     }
@@ -462,8 +457,7 @@ impl TypeId {
 /// );
 /// ```
 #[stable(feature = "type_name", since = "1.38.0")]
-#[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_type_name"))]
-#[cfg_attr(not(bootstrap), rustc_const_unstable(feature = "const_type_name", issue = "63084"))]
+#[rustc_const_unstable(feature = "const_type_name", issue = "63084")]
 pub const fn type_name<T: ?Sized>() -> &'static str {
     intrinsics::type_name::<T>()
 }
@@ -501,8 +495,7 @@ pub const fn type_name<T: ?Sized>() -> &'static str {
 /// println!("{}", type_name_of_val(&y));
 /// ```
 #[unstable(feature = "type_name_of_val", issue = "66359")]
-#[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_type_name"))]
-#[cfg_attr(not(bootstrap), rustc_const_unstable(feature = "const_type_name", issue = "63084"))]
+#[rustc_const_unstable(feature = "const_type_name", issue = "63084")]
 pub const fn type_name_of_val<T: ?Sized>(val: &T) -> &'static str {
     let _ = val;
     type_name::<T>()
diff --git a/src/libcore/cell.rs b/src/libcore/cell.rs
index e4b4cd31c63af..099e5307f64c8 100644
--- a/src/libcore/cell.rs
+++ b/src/libcore/cell.rs
@@ -324,7 +324,7 @@ impl<T> Cell<T> {
     /// let c = Cell::new(5);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_cell_new", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_cell_new", since = "1.32.0")]
     #[inline]
     pub const fn new(value: T) -> Cell<T> {
         Cell {
@@ -470,7 +470,7 @@ impl<T: ?Sized> Cell<T> {
     /// ```
     #[inline]
     #[stable(feature = "cell_as_ptr", since = "1.12.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_cell_as_ptr", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_cell_as_ptr", since = "1.32.0")]
     pub const fn as_ptr(&self) -> *mut T {
         self.value.get()
     }
@@ -651,7 +651,7 @@ impl<T> RefCell<T> {
     /// let c = RefCell::new(5);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_refcell_new", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_refcell_new", since = "1.32.0")]
     #[inline]
     pub const fn new(value: T) -> RefCell<T> {
         RefCell {
@@ -1504,10 +1504,7 @@ impl<T> UnsafeCell<T> {
     /// let uc = UnsafeCell::new(5);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_unsafe_cell_new", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_unsafe_cell_new", since = "1.32.0")]
     #[inline]
     pub const fn new(value: T) -> UnsafeCell<T> {
         UnsafeCell { value }
@@ -1550,10 +1547,7 @@ impl<T: ?Sized> UnsafeCell<T> {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_unsafecell_get", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_unsafecell_get", since = "1.32.0")]
     pub const fn get(&self) -> *mut T {
         // We can just cast the pointer from `UnsafeCell<T>` to `T` because of
         // #[repr(transparent)]. This exploits libstd's special status, there is
diff --git a/src/libcore/char/methods.rs b/src/libcore/char/methods.rs
index 5cfb9583a86d1..bb6d6db57d214 100644
--- a/src/libcore/char/methods.rs
+++ b/src/libcore/char/methods.rs
@@ -911,10 +911,7 @@ impl char {
     /// assert!(!non_ascii.is_ascii());
     /// ```
     #[stable(feature = "ascii_methods_on_intrinsics", since = "1.23.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_ascii_methods_on_intrinsics", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_ascii_methods_on_intrinsics", since = "1.32.0")]
     #[inline]
     pub const fn is_ascii(&self) -> bool {
         *self as u32 <= 0x7F
diff --git a/src/libcore/convert/mod.rs b/src/libcore/convert/mod.rs
index e5599f1dd373b..959fd63df51c2 100644
--- a/src/libcore/convert/mod.rs
+++ b/src/libcore/convert/mod.rs
@@ -101,7 +101,7 @@ pub use num::FloatToInt;
 /// assert_eq!(vec![1, 3], filtered);
 /// ```
 #[stable(feature = "convert_id", since = "1.33.0")]
-#[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_identity", since = "1.33.0"))]
+#[rustc_const_stable(feature = "const_identity", since = "1.33.0")]
 #[inline]
 pub const fn identity<T>(x: T) -> T {
     x
diff --git a/src/libcore/convert/num.rs b/src/libcore/convert/num.rs
index 6f5ee756f58f6..596da6f786bbd 100644
--- a/src/libcore/convert/num.rs
+++ b/src/libcore/convert/num.rs
@@ -13,7 +13,6 @@ mod private {
 /// Typically doesn’t need to be used directly.
 #[unstable(feature = "convert_float_to_int", issue = "67057")]
 pub trait FloatToInt<Int>: private::Sealed + Sized {
-    #[cfg(not(bootstrap))]
     #[unstable(feature = "float_approx_unchecked_to", issue = "67058")]
     #[doc(hidden)]
     unsafe fn approx_unchecked(self) -> Int;
@@ -26,7 +25,6 @@ macro_rules! impl_float_to_int {
         $(
             #[unstable(feature = "convert_float_to_int", issue = "67057")]
             impl FloatToInt<$Int> for $Float {
-                #[cfg(not(bootstrap))]
                 #[doc(hidden)]
                 #[inline]
                 unsafe fn approx_unchecked(self) -> $Int {
diff --git a/src/libcore/intrinsics.rs b/src/libcore/intrinsics.rs
index 1f72b7ab0902d..b02acce2d00bb 100644
--- a/src/libcore/intrinsics.rs
+++ b/src/libcore/intrinsics.rs
@@ -939,11 +939,7 @@ extern "rust-intrinsic" {
     /// }
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_transmute"))]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_unstable(feature = "const_transmute", issue = "53605"),
-    )]
+    #[rustc_const_unstable(feature = "const_transmute", issue = "53605")]
     pub fn transmute<T, U>(e: T) -> U;
 
     /// Returns `true` if the actual type given as `T` requires drop
@@ -1150,7 +1146,6 @@ extern "rust-intrinsic" {
 
     /// Convert with LLVM’s fptoui/fptosi, which may return undef for values out of range
     /// https://github.com/rust-lang/rust/issues/10184
-    #[cfg(not(bootstrap))]
     pub fn float_to_int_approx_unchecked<Float, Int>(value: Float) -> Int;
 
 
@@ -1361,7 +1356,6 @@ extern "rust-intrinsic" {
     /// Compiles to a NOP during non-Miri codegen.
     ///
     /// Perma-unstable: do not use
-    #[cfg(not(bootstrap))]
     pub fn miri_start_panic(data: *mut (dyn crate::any::Any + crate::marker::Send)) -> ();
 }
 
diff --git a/src/libcore/iter/adapters/mod.rs b/src/libcore/iter/adapters/mod.rs
index 39d571006e66a..019a3290f01e1 100644
--- a/src/libcore/iter/adapters/mod.rs
+++ b/src/libcore/iter/adapters/mod.rs
@@ -517,14 +517,6 @@ impl<I> Iterator for StepBy<I> where I: Iterator {
         // overflow handling
         loop {
             let mul = n.checked_mul(step);
-            #[cfg(bootstrap)]
-            {
-                // SAFETY: going away soon
-                if unsafe { intrinsics::likely(mul.is_some()) } {
-                    return self.iter.nth(mul.unwrap() - 1);
-                }
-            }
-            #[cfg(not(bootstrap))]
             {
                 if intrinsics::likely(mul.is_some()) {
                     return self.iter.nth(mul.unwrap() - 1);
diff --git a/src/libcore/iter/sources.rs b/src/libcore/iter/sources.rs
index 127b778e62e68..a65d47cc2c1f0 100644
--- a/src/libcore/iter/sources.rs
+++ b/src/libcore/iter/sources.rs
@@ -281,7 +281,7 @@ impl<T> Default for Empty<T> {
 /// assert_eq!(None, nope.next());
 /// ```
 #[stable(feature = "iter_empty", since = "1.2.0")]
-#[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_iter_empty", since = "1.32.0"))]
+#[rustc_const_stable(feature = "const_iter_empty", since = "1.32.0")]
 pub const fn empty<T>() -> Empty<T> {
     Empty(marker::PhantomData)
 }
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 7fe4f7e41a8d9..a2ab85e64baa1 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -74,8 +74,8 @@
 #![feature(const_fn)]
 #![feature(const_fn_union)]
 #![feature(const_generics)]
-#![cfg_attr(not(bootstrap), feature(const_ptr_offset_from))]
-#![cfg_attr(not(bootstrap), feature(const_type_name))]
+#![feature(const_ptr_offset_from)]
+#![feature(const_type_name)]
 #![feature(custom_inner_attributes)]
 #![feature(decl_macro)]
 #![feature(doc_cfg)]
@@ -91,18 +91,16 @@
 #![feature(nll)]
 #![feature(exhaustive_patterns)]
 #![feature(no_core)]
-#![cfg_attr(bootstrap, feature(on_unimplemented))]
 #![feature(optin_builtin_traits)]
 #![feature(prelude_import)]
 #![feature(repr_simd, platform_intrinsics)]
 #![feature(rustc_attrs)]
-#![cfg_attr(bootstrap, feature(rustc_const_unstable))]
 #![feature(simd_ffi)]
 #![feature(specialization)]
 #![feature(staged_api)]
 #![feature(std_internals)]
 #![feature(stmt_expr_attributes)]
-#![cfg_attr(not(bootstrap), feature(track_caller))]
+#![feature(track_caller)]
 #![feature(transparent_unions)]
 #![feature(unboxed_closures)]
 #![feature(unsized_locals)]
diff --git a/src/libcore/mem/manually_drop.rs b/src/libcore/mem/manually_drop.rs
index 6463668a03e3d..af4635f89f61e 100644
--- a/src/libcore/mem/manually_drop.rs
+++ b/src/libcore/mem/manually_drop.rs
@@ -63,10 +63,7 @@ impl<T> ManuallyDrop<T> {
     /// ManuallyDrop::new(Box::new(()));
     /// ```
     #[stable(feature = "manually_drop", since = "1.20.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_manually_drop", since = "1.36.0"),
-    )]
+    #[rustc_const_stable(feature = "const_manually_drop", since = "1.36.0")]
     #[inline(always)]
     pub const fn new(value: T) -> ManuallyDrop<T> {
         ManuallyDrop { value }
@@ -84,10 +81,7 @@ impl<T> ManuallyDrop<T> {
     /// let _: Box<()> = ManuallyDrop::into_inner(x); // This drops the `Box`.
     /// ```
     #[stable(feature = "manually_drop", since = "1.20.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_manually_drop", since = "1.36.0"),
-    )]
+    #[rustc_const_stable(feature = "const_manually_drop", since = "1.36.0")]
     #[inline(always)]
     pub const fn into_inner(slot: ManuallyDrop<T>) -> T {
         slot.value
diff --git a/src/libcore/mem/maybe_uninit.rs b/src/libcore/mem/maybe_uninit.rs
index 670a194e2d6cc..7f80f61aaf96d 100644
--- a/src/libcore/mem/maybe_uninit.rs
+++ b/src/libcore/mem/maybe_uninit.rs
@@ -250,10 +250,7 @@ impl<T> MaybeUninit<T> {
     ///
     /// [`assume_init`]: #method.assume_init
     #[stable(feature = "maybe_uninit", since = "1.36.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_maybe_uninit", since = "1.36.0"),
-    )]
+    #[rustc_const_stable(feature = "const_maybe_uninit", since = "1.36.0")]
     #[inline(always)]
     pub const fn new(val: T) -> MaybeUninit<T> {
         MaybeUninit { value: ManuallyDrop::new(val) }
@@ -268,12 +265,9 @@ impl<T> MaybeUninit<T> {
     ///
     /// [type]: union.MaybeUninit.html
     #[stable(feature = "maybe_uninit", since = "1.36.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_maybe_uninit", since = "1.36.0"),
-    )]
+    #[rustc_const_stable(feature = "const_maybe_uninit", since = "1.36.0")]
     #[inline(always)]
-    #[cfg_attr(all(not(bootstrap)), rustc_diagnostic_item = "maybe_uninit_uninit")]
+    #[rustc_diagnostic_item = "maybe_uninit_uninit"]
     pub const fn uninit() -> MaybeUninit<T> {
         MaybeUninit { uninit: () }
     }
@@ -357,7 +351,7 @@ impl<T> MaybeUninit<T> {
     /// ```
     #[stable(feature = "maybe_uninit", since = "1.36.0")]
     #[inline]
-    #[cfg_attr(all(not(bootstrap)), rustc_diagnostic_item = "maybe_uninit_zeroed")]
+    #[rustc_diagnostic_item = "maybe_uninit_zeroed"]
     pub fn zeroed() -> MaybeUninit<T> {
         let mut u = MaybeUninit::<T>::uninit();
         unsafe {
@@ -498,7 +492,7 @@ impl<T> MaybeUninit<T> {
     /// ```
     #[stable(feature = "maybe_uninit", since = "1.36.0")]
     #[inline(always)]
-    #[cfg_attr(all(not(bootstrap)), rustc_diagnostic_item = "assume_init")]
+    #[rustc_diagnostic_item = "assume_init"]
     pub unsafe fn assume_init(self) -> T {
         intrinsics::panic_if_uninhabited::<T>();
         ManuallyDrop::into_inner(self.value)
diff --git a/src/libcore/mem/mod.rs b/src/libcore/mem/mod.rs
index 00b32ad0b73f0..4e8ba8131f7a6 100644
--- a/src/libcore/mem/mod.rs
+++ b/src/libcore/mem/mod.rs
@@ -271,7 +271,7 @@ pub fn forget_unsized<T: ?Sized>(t: T) {
 #[inline(always)]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_promotable]
-#[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_size_of", since = "1.32.0"))]
+#[rustc_const_stable(feature = "const_size_of", since = "1.32.0")]
 pub const fn size_of<T>() -> usize {
     intrinsics::size_of::<T>()
 }
@@ -299,10 +299,6 @@ pub const fn size_of<T>() -> usize {
 #[inline]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub fn size_of_val<T: ?Sized>(val: &T) -> usize {
-    #[cfg(bootstrap)]
-    // SAFETY: going away soon
-    unsafe { intrinsics::size_of_val(val) }
-    #[cfg(not(bootstrap))]
     intrinsics::size_of_val(val)
 }
 
@@ -347,10 +343,6 @@ pub fn min_align_of<T>() -> usize {
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_deprecated(reason = "use `align_of_val` instead", since = "1.2.0")]
 pub fn min_align_of_val<T: ?Sized>(val: &T) -> usize {
-    #[cfg(bootstrap)]
-    // SAFETY: going away soon
-    unsafe { intrinsics::min_align_of_val(val) }
-    #[cfg(not(bootstrap))]
     intrinsics::min_align_of_val(val)
 }
 
@@ -372,7 +364,7 @@ pub fn min_align_of_val<T: ?Sized>(val: &T) -> usize {
 #[inline(always)]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_promotable]
-#[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_align_of", since = "1.32.0"))]
+#[rustc_const_stable(feature = "const_align_of", since = "1.32.0")]
 pub const fn align_of<T>() -> usize {
     intrinsics::min_align_of::<T>()
 }
@@ -455,7 +447,7 @@ pub fn align_of_val<T: ?Sized>(val: &T) -> usize {
 /// ```
 #[inline]
 #[stable(feature = "needs_drop", since = "1.21.0")]
-#[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_needs_drop", since = "1.36.0"))]
+#[rustc_const_stable(feature = "const_needs_drop", since = "1.36.0")]
 pub const fn needs_drop<T>() -> bool {
     intrinsics::needs_drop::<T>()
 }
@@ -501,7 +493,7 @@ pub const fn needs_drop<T>() -> bool {
 #[stable(feature = "rust1", since = "1.0.0")]
 #[allow(deprecated_in_future)]
 #[allow(deprecated)]
-#[cfg_attr(all(not(bootstrap)), rustc_diagnostic_item = "mem_zeroed")]
+#[rustc_diagnostic_item = "mem_zeroed"]
 pub unsafe fn zeroed<T>() -> T {
     intrinsics::panic_if_uninhabited::<T>();
     intrinsics::init()
@@ -534,7 +526,7 @@ pub unsafe fn zeroed<T>() -> T {
 #[stable(feature = "rust1", since = "1.0.0")]
 #[allow(deprecated_in_future)]
 #[allow(deprecated)]
-#[cfg_attr(all(not(bootstrap)), rustc_diagnostic_item = "mem_uninitialized")]
+#[rustc_diagnostic_item = "mem_uninitialized"]
 pub unsafe fn uninitialized<T>() -> T {
     intrinsics::panic_if_uninhabited::<T>();
     intrinsics::uninit()
@@ -874,11 +866,5 @@ impl<T> fmt::Debug for Discriminant<T> {
 /// ```
 #[stable(feature = "discriminant_value", since = "1.21.0")]
 pub fn discriminant<T>(v: &T) -> Discriminant<T> {
-    #[cfg(bootstrap)]
-    // SAFETY: going away soon
-    unsafe {
-        Discriminant(intrinsics::discriminant_value(v), PhantomData)
-    }
-    #[cfg(not(bootstrap))]
     Discriminant(intrinsics::discriminant_value(v), PhantomData)
 }
diff --git a/src/libcore/num/f32.rs b/src/libcore/num/f32.rs
index ac06f95e244b6..9e379e638103e 100644
--- a/src/libcore/num/f32.rs
+++ b/src/libcore/num/f32.rs
@@ -7,7 +7,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-#[cfg(not(bootstrap))]
 use crate::convert::FloatToInt;
 #[cfg(not(test))]
 use crate::intrinsics;
@@ -423,7 +422,6 @@ impl f32 {
     /// * Not be `NaN`
     /// * Not be infinite
     /// * Be representable in the return type `Int`, after truncating off its fractional part
-    #[cfg(not(bootstrap))]
     #[unstable(feature = "float_approx_unchecked_to", issue = "67058")]
     #[inline]
     pub unsafe fn approx_unchecked_to<Int>(self) -> Int where Self: FloatToInt<Int> {
diff --git a/src/libcore/num/f64.rs b/src/libcore/num/f64.rs
index 5446ce3e3b3e9..540c6a529d7c8 100644
--- a/src/libcore/num/f64.rs
+++ b/src/libcore/num/f64.rs
@@ -7,7 +7,6 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-#[cfg(not(bootstrap))]
 use crate::convert::FloatToInt;
 #[cfg(not(test))]
 use crate::intrinsics;
@@ -436,7 +435,6 @@ impl f64 {
     /// * Not be `NaN`
     /// * Not be infinite
     /// * Be representable in the return type `Int`, after truncating off its fractional part
-    #[cfg(not(bootstrap))]
     #[unstable(feature = "float_approx_unchecked_to", issue = "67058")]
     #[inline]
     pub unsafe fn approx_unchecked_to<Int>(self) -> Int
diff --git a/src/libcore/num/mod.rs b/src/libcore/num/mod.rs
index d091a8d86ea49..6c864f74b1f14 100644
--- a/src/libcore/num/mod.rs
+++ b/src/libcore/num/mod.rs
@@ -61,10 +61,7 @@ assert_eq!(size_of::<Option<core::num::", stringify!($Ty), ">>(), size_of::<", s
                 ///
                 /// The value must not be zero.
                 #[$stability]
-                #[cfg_attr(
-                    not(bootstrap),
-                    rustc_const_stable(feature = "nonzero", since = "1.34.0"),
-                )]
+                #[rustc_const_stable(feature = "nonzero", since = "1.34.0")]
                 #[inline]
                 pub const unsafe fn new_unchecked(n: $Int) -> Self {
                     Self(n)
@@ -85,10 +82,7 @@ assert_eq!(size_of::<Option<core::num::", stringify!($Ty), ">>(), size_of::<", s
                 /// Returns the value as a primitive type.
                 #[$stability]
                 #[inline]
-                #[cfg_attr(
-                    not(bootstrap),
-                    rustc_const_stable(feature = "nonzero", since = "1.34.0"),
-                )]
+                #[rustc_const_stable(feature = "nonzero", since = "1.34.0")]
                 pub const fn get(self) -> $Int {
                     self.0
                 }
@@ -264,10 +258,7 @@ $EndFeature, "
             #[stable(feature = "rust1", since = "1.0.0")]
             #[inline(always)]
             #[rustc_promotable]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_min_value", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_min_value", since = "1.32.0")]
             pub const fn min_value() -> Self {
                 !0 ^ ((!0 as $UnsignedT) >> 1) as Self
             }
@@ -287,10 +278,7 @@ $EndFeature, "
             #[stable(feature = "rust1", since = "1.0.0")]
             #[inline(always)]
             #[rustc_promotable]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_max_value", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
             pub const fn max_value() -> Self {
                 !Self::min_value()
             }
@@ -340,10 +328,7 @@ $EndFeature, "
 ```
 "),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[inline]
             pub const fn count_ones(self) -> u32 { (self as $UnsignedT).count_ones() }
         }
@@ -359,10 +344,7 @@ Basic usage:
 ", $Feature, "assert_eq!(", stringify!($SelfT), "::max_value().count_zeros(), 1);", $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[inline]
             pub const fn count_zeros(self) -> u32 {
                 (!self).count_ones()
@@ -383,10 +365,7 @@ assert_eq!(n.leading_zeros(), 0);",
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[inline]
             pub const fn leading_zeros(self) -> u32 {
                 (self as $UnsignedT).leading_zeros()
@@ -407,10 +386,7 @@ assert_eq!(n.trailing_zeros(), 2);",
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[inline]
             pub const fn trailing_zeros(self) -> u32 {
                 (self as $UnsignedT).trailing_zeros()
@@ -434,10 +410,7 @@ let m = ", $rot_result, ";
 assert_eq!(n.rotate_left(", $rot, "), m);
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -464,10 +437,7 @@ let m = ", $rot_op, ";
 assert_eq!(n.rotate_right(", $rot, "), m);
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -491,10 +461,7 @@ let m = n.swap_bytes();
 assert_eq!(m, ", $swapped, ");
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[inline]
             pub const fn swap_bytes(self) -> Self {
                 (self as $UnsignedT).swap_bytes() as Self
@@ -515,10 +482,7 @@ let m = n.reverse_bits();
 assert_eq!(m, ", $reversed, ");
 ```"),
             #[stable(feature = "reverse_bits", since = "1.37.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[inline]
             #[must_use]
             pub const fn reverse_bits(self) -> Self {
@@ -546,10 +510,7 @@ if cfg!(target_endian = \"big\") {
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_conversions", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
             #[inline]
             pub const fn from_be(x: Self) -> Self {
                 #[cfg(target_endian = "big")]
@@ -583,10 +544,7 @@ if cfg!(target_endian = \"little\") {
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_conversions", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
             #[inline]
             pub const fn from_le(x: Self) -> Self {
                 #[cfg(target_endian = "little")]
@@ -620,10 +578,7 @@ if cfg!(target_endian = \"big\") {
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_conversions", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
             #[inline]
             pub const fn to_be(self) -> Self { // or not to be?
                 #[cfg(target_endian = "big")]
@@ -657,10 +612,7 @@ if cfg!(target_endian = \"little\") {
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_conversions", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_conversions", since = "1.32.0")]
             #[inline]
             pub const fn to_le(self) -> Self {
                 #[cfg(target_endian = "little")]
@@ -1013,11 +965,7 @@ $EndFeature, "
 ```"),
 
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_saturating_int_methods"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_saturating_int_methods", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_saturating_int_methods", issue = "53718")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -1043,11 +991,7 @@ assert_eq!(", stringify!($SelfT), "::max_value().saturating_sub(-1), ", stringif
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_saturating_int_methods"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_saturating_int_methods", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_saturating_int_methods", issue = "53718")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -1187,10 +1131,7 @@ assert_eq!(", stringify!($SelfT), "::max_value().wrapping_add(2), ", stringify!(
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -1214,10 +1155,7 @@ stringify!($SelfT), "::max_value());",
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -1240,10 +1178,7 @@ assert_eq!(11i8.wrapping_mul(12), -124);",
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -1388,10 +1323,7 @@ assert_eq!(", stringify!($SelfT), "::min_value().wrapping_neg(), ", stringify!($
 $EndFeature, "
 ```"),
             #[stable(feature = "num_wrapping", since = "1.2.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[inline]
             pub const fn wrapping_neg(self) -> Self {
                 self.overflowing_neg().0
@@ -1417,10 +1349,7 @@ assert_eq!((-1", stringify!($SelfT), ").wrapping_shl(128), -1);",
 $EndFeature, "
 ```"),
             #[stable(feature = "num_wrapping", since = "1.2.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -1452,10 +1381,7 @@ assert_eq!((-128i16).wrapping_shr(64), -128);",
 $EndFeature, "
 ```"),
             #[stable(feature = "num_wrapping", since = "1.2.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -1489,10 +1415,7 @@ assert_eq!((-128i8).wrapping_abs() as u8, 128);",
 $EndFeature, "
 ```"),
             #[stable(feature = "no_panic_abs", since = "1.13.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[inline]
             pub const fn wrapping_abs(self) -> Self {
                 // sign is -1 (all ones) for negative numbers, 0 otherwise.
@@ -1567,10 +1490,7 @@ assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (", stringify!($Sel
 "::MIN, true));", $EndFeature, "
 ```"),
             #[stable(feature = "wrapping", since = "1.7.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -1598,10 +1518,7 @@ assert_eq!(", stringify!($SelfT), "::MIN.overflowing_sub(1), (", stringify!($Sel
 "::MAX, true));", $EndFeature, "
 ```"),
             #[stable(feature = "wrapping", since = "1.7.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -1627,10 +1544,7 @@ assert_eq!(1_000_000_000i32.overflowing_mul(10), (1410065408, true));",
 $EndFeature, "
 ```"),
             #[stable(feature = "wrapping", since = "1.7.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -1798,10 +1712,7 @@ assert_eq!(", stringify!($SelfT), "::MIN.overflowing_neg(), (", stringify!($Self
 ```"),
             #[inline]
             #[stable(feature = "wrapping", since = "1.7.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             pub const fn overflowing_neg(self) -> (Self, bool) {
                 ((!self).wrapping_add(1), self == Self::min_value())
             }
@@ -1824,10 +1735,7 @@ assert_eq!(0x1i32.overflowing_shl(36), (0x10, true));",
 $EndFeature, "
 ```"),
             #[stable(feature = "wrapping", since = "1.7.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -1853,10 +1761,7 @@ assert_eq!(0x10i32.overflowing_shr(36), (0x1, true));",
 $EndFeature, "
 ```"),
             #[stable(feature = "wrapping", since = "1.7.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -1885,10 +1790,7 @@ assert_eq!((", stringify!($SelfT), "::min_value()).overflowing_abs(), (", string
 $EndFeature, "
 ```"),
             #[stable(feature = "no_panic_abs", since = "1.13.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[inline]
             pub const fn overflowing_abs(self) -> (Self, bool) {
                 (self.wrapping_abs(), self == Self::min_value())
@@ -2093,10 +1995,7 @@ assert_eq!((-10", stringify!($SelfT), ").abs(), 10);",
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[inline]
             #[rustc_inherit_overflow_checks]
             pub const fn abs(self) -> Self {
@@ -2139,11 +2038,7 @@ assert_eq!((-10", stringify!($SelfT), ").signum(), -1);",
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_int_sign"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_int_sign", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_int_sign", issue = "53718")]
             #[inline]
             pub const fn signum(self) -> Self {
                 (self > 0) as Self - (self < 0) as Self
@@ -2164,10 +2059,7 @@ assert!(!(-10", stringify!($SelfT), ").is_positive());",
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[inline]
             pub const fn is_positive(self) -> bool { self > 0 }
         }
@@ -2186,10 +2078,7 @@ assert!(!10", stringify!($SelfT), ".is_negative());",
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_int_methods", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_int_methods", since = "1.32.0")]
             #[inline]
             pub const fn is_negative(self) -> bool { self < 0 }
         }
@@ -2207,11 +2096,7 @@ let bytes = ", $swap_op, stringify!($SelfT), ".to_be_bytes();
 assert_eq!(bytes, ", $be_bytes, ");
 ```"),
             #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_int_conversion"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_int_conversion", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_int_conversion", issue = "53718")]
             #[inline]
             pub const fn to_be_bytes(self) -> [u8; mem::size_of::<Self>()] {
                 self.to_be().to_ne_bytes()
@@ -2231,11 +2116,7 @@ let bytes = ", $swap_op, stringify!($SelfT), ".to_le_bytes();
 assert_eq!(bytes, ", $le_bytes, ");
 ```"),
             #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_int_conversion"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_int_conversion", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_int_conversion", issue = "53718")]
             #[inline]
             pub const fn to_le_bytes(self) -> [u8; mem::size_of::<Self>()] {
                 self.to_le().to_ne_bytes()
@@ -2270,11 +2151,7 @@ assert_eq!(
 );
 ```"),
             #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_int_conversion"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_int_conversion", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_int_conversion", issue = "53718")]
             #[inline]
             pub const fn to_ne_bytes(self) -> [u8; mem::size_of::<Self>()] {
                 // SAFETY: integers are plain old datatypes so we can always transmute them to
@@ -2308,11 +2185,7 @@ fn read_be_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT),
 }
 ```"),
             #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_int_conversion"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_int_conversion", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_int_conversion", issue = "53718")]
             #[inline]
             pub const fn from_be_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
                 Self::from_be(Self::from_ne_bytes(bytes))
@@ -2345,11 +2218,7 @@ fn read_le_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT),
 }
 ```"),
             #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_int_conversion"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_int_conversion", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_int_conversion", issue = "53718")]
             #[inline]
             pub const fn from_le_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
                 Self::from_le(Self::from_ne_bytes(bytes))
@@ -2392,11 +2261,7 @@ fn read_ne_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT),
 }
 ```"),
             #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_int_conversion"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_int_conversion", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_int_conversion", issue = "53718")]
             #[inline]
             pub const fn from_ne_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
                 // SAFETY: integers are plain old datatypes so we can always transmute to them
@@ -2490,10 +2355,7 @@ Basic usage:
             #[stable(feature = "rust1", since = "1.0.0")]
             #[rustc_promotable]
             #[inline(always)]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_min_value", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_min_value", since = "1.32.0")]
             pub const fn min_value() -> Self { 0 }
         }
 
@@ -2511,10 +2373,7 @@ stringify!($MaxV), ");", $EndFeature, "
             #[stable(feature = "rust1", since = "1.0.0")]
             #[rustc_promotable]
             #[inline(always)]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_max_value", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_max_value", since = "1.32.0")]
             pub const fn max_value() -> Self { !0 }
         }
 
@@ -2561,10 +2420,7 @@ Basic usage:
 assert_eq!(n.count_ones(), 3);", $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
             #[inline]
             pub const fn count_ones(self) -> u32 {
                 intrinsics::ctpop(self as $ActualT) as u32
@@ -2582,10 +2438,7 @@ Basic usage:
 ", $Feature, "assert_eq!(", stringify!($SelfT), "::max_value().count_zeros(), 0);", $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
             #[inline]
             pub const fn count_zeros(self) -> u32 {
                 (!self).count_ones()
@@ -2605,10 +2458,7 @@ Basic usage:
 assert_eq!(n.leading_zeros(), 2);", $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
             #[inline]
             pub const fn leading_zeros(self) -> u32 {
                 intrinsics::ctlz(self as $ActualT) as u32
@@ -2629,10 +2479,7 @@ Basic usage:
 assert_eq!(n.trailing_zeros(), 3);", $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
             #[inline]
             pub const fn trailing_zeros(self) -> u32 {
                 intrinsics::cttz(self) as u32
@@ -2656,10 +2503,7 @@ let m = ", $rot_result, ";
 assert_eq!(n.rotate_left(", $rot, "), m);
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -2686,10 +2530,7 @@ let m = ", $rot_op, ";
 assert_eq!(n.rotate_right(", $rot, "), m);
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -2713,10 +2554,7 @@ let m = n.swap_bytes();
 assert_eq!(m, ", $swapped, ");
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
             #[inline]
             pub const fn swap_bytes(self) -> Self {
                 intrinsics::bswap(self as $ActualT) as Self
@@ -2737,10 +2575,7 @@ let m = n.reverse_bits();
 assert_eq!(m, ", $reversed, ");
 ```"),
             #[stable(feature = "reverse_bits", since = "1.37.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
             #[inline]
             #[must_use]
             pub const fn reverse_bits(self) -> Self {
@@ -2768,10 +2603,7 @@ if cfg!(target_endian = \"big\") {
 }", $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
             #[inline]
             pub const fn from_be(x: Self) -> Self {
                 #[cfg(target_endian = "big")]
@@ -2805,10 +2637,7 @@ if cfg!(target_endian = \"little\") {
 }", $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
             #[inline]
             pub const fn from_le(x: Self) -> Self {
                 #[cfg(target_endian = "little")]
@@ -2842,10 +2671,7 @@ if cfg!(target_endian = \"big\") {
 }", $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
             #[inline]
             pub const fn to_be(self) -> Self { // or not to be?
                 #[cfg(target_endian = "big")]
@@ -2879,10 +2705,7 @@ if cfg!(target_endian = \"little\") {
 }", $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_math", since = "1.32.0")]
             #[inline]
             pub const fn to_le(self) -> Self {
                 #[cfg(target_endian = "little")]
@@ -3188,11 +3011,7 @@ assert_eq!(200u8.saturating_add(127), 255);", $EndFeature, "
             #[stable(feature = "rust1", since = "1.0.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_saturating_int_methods"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_saturating_int_methods", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_saturating_int_methods", issue = "53718")]
             #[inline]
             pub const fn saturating_add(self, rhs: Self) -> Self {
                 intrinsics::saturating_add(self, rhs)
@@ -3214,11 +3033,7 @@ assert_eq!(13", stringify!($SelfT), ".saturating_sub(127), 0);", $EndFeature, "
             #[stable(feature = "rust1", since = "1.0.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_saturating_int_methods"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_saturating_int_methods", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_saturating_int_methods", issue = "53718")]
             #[inline]
             pub const fn saturating_sub(self, rhs: Self) -> Self {
                 intrinsics::saturating_sub(self, rhs)
@@ -3290,10 +3105,7 @@ assert_eq!(200", stringify!($SelfT), ".wrapping_add(", stringify!($SelfT), "::ma
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -3316,10 +3128,7 @@ assert_eq!(100", stringify!($SelfT), ".wrapping_sub(", stringify!($SelfT), "::ma
 $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -3343,10 +3152,7 @@ $EndFeature, "
         /// assert_eq!(25u8.wrapping_mul(12), 44);
         /// ```
         #[stable(feature = "rust1", since = "1.0.0")]
-        #[cfg_attr(
-            not(bootstrap),
-            rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0"),
-        )]
+        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
         #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
         #[inline]
@@ -3476,10 +3282,7 @@ assert_eq!(100", stringify!($SelfT), ".wrapping_rem_euclid(10), 0);
         /// assert_eq!((-128i8).wrapping_neg(), -128);
         /// ```
         #[stable(feature = "num_wrapping", since = "1.2.0")]
-        #[cfg_attr(
-            not(bootstrap),
-            rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0"),
-        )]
+        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
         #[inline]
         pub const fn wrapping_neg(self) -> Self {
             self.overflowing_neg().0
@@ -3506,10 +3309,7 @@ Basic usage:
 assert_eq!(1", stringify!($SelfT), ".wrapping_shl(128), 1);", $EndFeature, "
 ```"),
             #[stable(feature = "num_wrapping", since = "1.2.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -3543,10 +3343,7 @@ Basic usage:
 assert_eq!(128", stringify!($SelfT), ".wrapping_shr(128), 128);", $EndFeature, "
 ```"),
             #[stable(feature = "num_wrapping", since = "1.2.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -3616,10 +3413,7 @@ assert_eq!(5", stringify!($SelfT), ".overflowing_add(2), (7, false));
 assert_eq!(", stringify!($SelfT), "::MAX.overflowing_add(1), (0, true));", $EndFeature, "
 ```"),
             #[stable(feature = "wrapping", since = "1.7.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -3648,10 +3442,7 @@ assert_eq!(0", stringify!($SelfT), ".overflowing_sub(1), (", stringify!($SelfT),
 $EndFeature, "
 ```"),
             #[stable(feature = "wrapping", since = "1.7.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -3679,10 +3470,7 @@ $EndFeature, "
         /// assert_eq!(1_000_000_000u32.overflowing_mul(10), (1410065408, true));
         /// ```
         #[stable(feature = "wrapping", since = "1.7.0")]
-        #[cfg_attr(
-            not(bootstrap),
-            rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0"),
-        )]
+        #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
         #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
         #[inline]
@@ -3828,10 +3616,7 @@ assert_eq!(2", stringify!($SelfT), ".overflowing_neg(), (-2i32 as ", stringify!(
 ```"),
             #[inline]
             #[stable(feature = "wrapping", since = "1.7.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
             pub const fn overflowing_neg(self) -> (Self, bool) {
                 ((!self).wrapping_add(1), self != 0)
             }
@@ -3855,10 +3640,7 @@ Basic usage
 assert_eq!(0x1", stringify!($SelfT), ".overflowing_shl(132), (0x10, true));", $EndFeature, "
 ```"),
             #[stable(feature = "wrapping", since = "1.7.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -3885,10 +3667,7 @@ Basic usage
 assert_eq!(0x10", stringify!($SelfT), ".overflowing_shr(132), (0x1, true));", $EndFeature, "
 ```"),
             #[stable(feature = "wrapping", since = "1.7.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_wrapping_math", since = "1.32.0")]
             #[must_use = "this returns the result of the operation, \
                           without modifying the original"]
             #[inline]
@@ -4054,10 +3833,7 @@ Basic usage:
 assert!(!10", stringify!($SelfT), ".is_power_of_two());", $EndFeature, "
 ```"),
             #[stable(feature = "rust1", since = "1.0.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_is_power_of_two", since = "1.32.0"),
-            )]
+            #[rustc_const_stable(feature = "const_is_power_of_two", since = "1.32.0")]
             #[inline]
             pub const fn is_power_of_two(self) -> bool {
                 self.count_ones() == 1
@@ -4169,11 +3945,7 @@ let bytes = ", $swap_op, stringify!($SelfT), ".to_be_bytes();
 assert_eq!(bytes, ", $be_bytes, ");
 ```"),
             #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_int_conversion"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_int_conversion", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_int_conversion", issue = "53718")]
             #[inline]
             pub const fn to_be_bytes(self) -> [u8; mem::size_of::<Self>()] {
                 self.to_be().to_ne_bytes()
@@ -4193,11 +3965,7 @@ let bytes = ", $swap_op, stringify!($SelfT), ".to_le_bytes();
 assert_eq!(bytes, ", $le_bytes, ");
 ```"),
             #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_int_conversion"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_int_conversion", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_int_conversion", issue = "53718")]
             #[inline]
             pub const fn to_le_bytes(self) -> [u8; mem::size_of::<Self>()] {
                 self.to_le().to_ne_bytes()
@@ -4232,11 +4000,7 @@ assert_eq!(
 );
 ```"),
             #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_int_conversion"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_int_conversion", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_int_conversion", issue = "53718")]
             #[inline]
             pub const fn to_ne_bytes(self) -> [u8; mem::size_of::<Self>()] {
                 // SAFETY: integers are plain old datatypes so we can always transmute them to
@@ -4270,11 +4034,7 @@ fn read_be_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT),
 }
 ```"),
             #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_int_conversion"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_int_conversion", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_int_conversion", issue = "53718")]
             #[inline]
             pub const fn from_be_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
                 Self::from_be(Self::from_ne_bytes(bytes))
@@ -4307,11 +4067,7 @@ fn read_le_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT),
 }
 ```"),
             #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_int_conversion"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_int_conversion", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_int_conversion", issue = "53718")]
             #[inline]
             pub const fn from_le_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
                 Self::from_le(Self::from_ne_bytes(bytes))
@@ -4354,11 +4110,7 @@ fn read_ne_", stringify!($SelfT), "(input: &mut &[u8]) -> ", stringify!($SelfT),
 }
 ```"),
             #[stable(feature = "int_to_from_bytes", since = "1.32.0")]
-            #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_int_conversion"))]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_unstable(feature = "const_int_conversion", issue = "53718"),
-            )]
+            #[rustc_const_unstable(feature = "const_int_conversion", issue = "53718")]
             #[inline]
             pub const fn from_ne_bytes(bytes: [u8; mem::size_of::<Self>()]) -> Self {
                 // SAFETY: integers are plain old datatypes so we can always transmute to them
diff --git a/src/libcore/num/wrapping.rs b/src/libcore/num/wrapping.rs
index 46398dd2f82ed..82fa6acfbd62a 100644
--- a/src/libcore/num/wrapping.rs
+++ b/src/libcore/num/wrapping.rs
@@ -530,10 +530,7 @@ assert_eq!(n.trailing_zeros(), 3);
             /// assert_eq!(m, Wrapping(-22016));
             /// ```
             #[stable(feature = "reverse_bits", since = "1.37.0")]
-            #[cfg_attr(
-                not(bootstrap),
-                rustc_const_stable(feature = "const_reverse_bits", since = "1.37.0"),
-            )]
+            #[rustc_const_stable(feature = "const_reverse_bits", since = "1.37.0")]
             #[inline]
             #[must_use]
             pub const fn reverse_bits(self) -> Self {
diff --git a/src/libcore/ops/range.rs b/src/libcore/ops/range.rs
index 54ce2917a368a..be6d8edb99f59 100644
--- a/src/libcore/ops/range.rs
+++ b/src/libcore/ops/range.rs
@@ -398,7 +398,7 @@ impl<Idx> RangeInclusive<Idx> {
     #[stable(feature = "inclusive_range_methods", since = "1.27.0")]
     #[inline]
     #[rustc_promotable]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_range_new", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_range_new", since = "1.32.0")]
     pub const fn new(start: Idx, end: Idx) -> Self {
         Self { start, end, is_empty: None }
     }
@@ -422,10 +422,7 @@ impl<Idx> RangeInclusive<Idx> {
     /// assert_eq!((3..=5).start(), &3);
     /// ```
     #[stable(feature = "inclusive_range_methods", since = "1.27.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_inclusive_range_methods", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_inclusive_range_methods", since = "1.32.0")]
     #[inline]
     pub const fn start(&self) -> &Idx {
         &self.start
@@ -450,10 +447,7 @@ impl<Idx> RangeInclusive<Idx> {
     /// assert_eq!((3..=5).end(), &5);
     /// ```
     #[stable(feature = "inclusive_range_methods", since = "1.27.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_inclusive_range_methods", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_inclusive_range_methods", since = "1.32.0")]
     #[inline]
     pub const fn end(&self) -> &Idx {
         &self.end
diff --git a/src/libcore/ops/try.rs b/src/libcore/ops/try.rs
index 22ba97b91df12..996a01d413cbc 100644
--- a/src/libcore/ops/try.rs
+++ b/src/libcore/ops/try.rs
@@ -5,26 +5,23 @@
 /// extracting those success or failure values from an existing instance and
 /// creating a new instance from a success or failure value.
 #[unstable(feature = "try_trait", issue = "42327")]
-#[cfg_attr(
-    not(bootstrap),
-    rustc_on_unimplemented(
-        on(
-            all(
-                any(from_method = "from_error", from_method = "from_ok"),
-                from_desugaring = "QuestionMark"
-            ),
-            message = "the `?` operator can only be used in {ItemContext} \
-                       that returns `Result` or `Option` \
-                       (or another type that implements `{Try}`)",
-            label = "cannot use the `?` operator in {ItemContext} that returns `{Self}`",
-            enclosing_scope = "this function should return `Result` or `Option` to accept `?`"
+#[rustc_on_unimplemented(
+    on(
+        all(
+            any(from_method = "from_error", from_method = "from_ok"),
+            from_desugaring = "QuestionMark"
         ),
-        on(
-            all(from_method = "into_result", from_desugaring = "QuestionMark"),
-            message = "the `?` operator can only be applied to values \
-                       that implement `{Try}`",
-            label = "the `?` operator cannot be applied to type `{Self}`"
-        )
+        message = "the `?` operator can only be used in {ItemContext} \
+                    that returns `Result` or `Option` \
+                    (or another type that implements `{Try}`)",
+        label = "cannot use the `?` operator in {ItemContext} that returns `{Self}`",
+        enclosing_scope = "this function should return `Result` or `Option` to accept `?`"
+    ),
+    on(
+        all(from_method = "into_result", from_desugaring = "QuestionMark"),
+        message = "the `?` operator can only be applied to values \
+                    that implement `{Try}`",
+        label = "the `?` operator cannot be applied to type `{Self}`"
     )
 )]
 #[doc(alias = "?")]
diff --git a/src/libcore/panic.rs b/src/libcore/panic.rs
index 48bb504a73c34..c9a1c4b004949 100644
--- a/src/libcore/panic.rs
+++ b/src/libcore/panic.rs
@@ -222,7 +222,6 @@ impl<'a> Location<'a> {
     /// assert_ne!(this_location.line(), another_location.line());
     /// assert_ne!(this_location.column(), another_location.column());
     /// ```
-    #[cfg(not(bootstrap))]
     #[unstable(feature = "track_caller",
                reason = "uses #[track_caller] which is not yet stable",
                issue = "47809")]
diff --git a/src/libcore/ptr/mod.rs b/src/libcore/ptr/mod.rs
index 33c23233fd1c2..776165e7bd70c 100644
--- a/src/libcore/ptr/mod.rs
+++ b/src/libcore/ptr/mod.rs
@@ -198,7 +198,7 @@ unsafe fn real_drop_in_place<T: ?Sized>(to_drop: &mut T) {
 #[inline(always)]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_promotable]
-#[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_ptr_null", since = "1.32.0"))]
+#[rustc_const_stable(feature = "const_ptr_null", since = "1.32.0")]
 pub const fn null<T>() -> *const T {
     0 as *const T
 }
@@ -216,7 +216,7 @@ pub const fn null<T>() -> *const T {
 #[inline(always)]
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_promotable]
-#[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_ptr_null", since = "1.32.0"))]
+#[rustc_const_stable(feature = "const_ptr_null", since = "1.32.0")]
 pub const fn null_mut<T>() -> *mut T {
     0 as *mut T
 }
@@ -1062,7 +1062,7 @@ impl<T: ?Sized> *const T {
 
     /// Casts to a pointer of another type.
     #[stable(feature = "ptr_cast", since = "1.38.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_ptr_cast", since = "1.38.0"))]
+    #[rustc_const_stable(feature = "const_ptr_cast", since = "1.38.0")]
     #[inline]
     pub const fn cast<U>(self) -> *const U {
         self as _
@@ -1310,11 +1310,7 @@ impl<T: ?Sized> *const T {
     /// }
     /// ```
     #[unstable(feature = "ptr_offset_from", issue = "41079")]
-    #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_ptr_offset_from"))]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_unstable(feature = "const_ptr_offset_from", issue = "41079"),
-    )]
+    #[rustc_const_unstable(feature = "const_ptr_offset_from", issue = "41079")]
     #[inline]
     pub const unsafe fn offset_from(self, origin: *const T) -> isize
     where
@@ -1770,7 +1766,7 @@ impl<T: ?Sized> *mut T {
 
     /// Casts to a pointer of another type.
     #[stable(feature = "ptr_cast", since = "1.38.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_ptr_cast", since = "1.38.0"))]
+    #[rustc_const_stable(feature = "const_ptr_cast", since = "1.38.0")]
     #[inline]
     pub const fn cast<U>(self) -> *mut U {
         self as _
@@ -2057,11 +2053,7 @@ impl<T: ?Sized> *mut T {
     /// }
     /// ```
     #[unstable(feature = "ptr_offset_from", issue = "41079")]
-    #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_ptr_offset_from"))]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_unstable(feature = "const_ptr_offset_from", issue = "41079"),
-    )]
+    #[rustc_const_unstable(feature = "const_ptr_offset_from", issue = "41079")]
     #[inline]
     pub const unsafe fn offset_from(self, origin: *const T) -> isize
     where
diff --git a/src/libcore/ptr/non_null.rs b/src/libcore/ptr/non_null.rs
index d1d97d7b332fa..6946fd2413eb3 100644
--- a/src/libcore/ptr/non_null.rs
+++ b/src/libcore/ptr/non_null.rs
@@ -66,10 +66,7 @@ impl<T: Sized> NonNull<T> {
     /// sentinel value. Types that lazily allocate must track initialization by
     /// some other means.
     #[stable(feature = "nonnull", since = "1.25.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_nonnull_dangling", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_nonnull_dangling", since = "1.32.0")]
     #[inline]
     pub const fn dangling() -> Self {
         unsafe {
@@ -86,10 +83,7 @@ impl<T: ?Sized> NonNull<T> {
     ///
     /// `ptr` must be non-null.
     #[stable(feature = "nonnull", since = "1.25.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_nonnull_new_unchecked", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_nonnull_new_unchecked", since = "1.32.0")]
     #[inline]
     pub const unsafe fn new_unchecked(ptr: *mut T) -> Self {
         NonNull { pointer: ptr as _ }
@@ -104,10 +98,7 @@ impl<T: ?Sized> NonNull<T> {
 
     /// Acquires the underlying `*mut` pointer.
     #[stable(feature = "nonnull", since = "1.25.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_nonnull_as_ptr", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_nonnull_as_ptr", since = "1.32.0")]
     #[inline]
     pub const fn as_ptr(self) -> *mut T {
         self.pointer as *mut T
@@ -137,10 +128,7 @@ impl<T: ?Sized> NonNull<T> {
 
     /// Casts to a pointer of another type.
     #[stable(feature = "nonnull_cast", since = "1.27.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_nonnull_cast", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_nonnull_cast", since = "1.32.0")]
     #[inline]
     pub const fn cast<U>(self) -> NonNull<U> {
         unsafe { NonNull::new_unchecked(self.as_ptr() as *mut U) }
diff --git a/src/libcore/slice/mod.rs b/src/libcore/slice/mod.rs
index a8e500d256fdc..05baa1899b3e0 100644
--- a/src/libcore/slice/mod.rs
+++ b/src/libcore/slice/mod.rs
@@ -62,7 +62,7 @@ impl<T> [T] {
     /// assert_eq!(a.len(), 3);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_slice_len", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_slice_len", since = "1.32.0")]
     #[inline]
     // SAFETY: const sound because we transmute out the length field as a usize (which it must be)
     #[allow(unused_attributes)]
@@ -82,10 +82,7 @@ impl<T> [T] {
     /// assert!(!a.is_empty());
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_slice_is_empty", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_slice_is_empty", since = "1.32.0")]
     #[inline]
     pub const fn is_empty(&self) -> bool {
         self.len() == 0
@@ -381,10 +378,7 @@ impl<T> [T] {
     ///
     /// [`as_mut_ptr`]: #method.as_mut_ptr
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_slice_as_ptr", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_slice_as_ptr", since = "1.32.0")]
     #[inline]
     pub const fn as_ptr(&self) -> *const T {
         self as *const [T] as *const T
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index 763714e536edc..3da992dca30ee 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -2090,7 +2090,7 @@ impl str {
     /// assert_eq!("ƒoo".chars().count(), 3);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_str_len", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_str_len", since = "1.32.0")]
     #[inline]
     pub const fn len(&self) -> usize {
         self.as_bytes().len()
@@ -2111,10 +2111,7 @@ impl str {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(
-        not(bootstrap),
-        rustc_const_stable(feature = "const_str_is_empty", since = "1.32.0"),
-    )]
+    #[rustc_const_stable(feature = "const_str_is_empty", since = "1.32.0")]
     pub const fn is_empty(&self) -> bool {
         self.len() == 0
     }
@@ -2171,7 +2168,7 @@ impl str {
     /// assert_eq!(b"bors", bytes);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "str_as_bytes", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "str_as_bytes", since = "1.32.0")]
     #[inline(always)]
     // SAFETY: const sound because we transmute two types with the same layout
     #[allow(unused_attributes)]
@@ -2245,7 +2242,7 @@ impl str {
     /// let ptr = s.as_ptr();
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "rustc_str_as_ptr", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "rustc_str_as_ptr", since = "1.32.0")]
     #[inline]
     pub const fn as_ptr(&self) -> *const u8 {
         self as *const str as *const u8
diff --git a/src/libcore/sync/atomic.rs b/src/libcore/sync/atomic.rs
index d5b0bc420382f..1f09895597a87 100644
--- a/src/libcore/sync/atomic.rs
+++ b/src/libcore/sync/atomic.rs
@@ -331,7 +331,7 @@ impl AtomicBool {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_atomic_new", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_atomic_new", since = "1.32.0")]
     pub const fn new(v: bool) -> AtomicBool {
         AtomicBool { v: UnsafeCell::new(v as u8) }
     }
@@ -856,7 +856,7 @@ impl<T> AtomicPtr<T> {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_atomic_new", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_atomic_new", since = "1.32.0")]
     pub const fn new(p: *mut T) -> AtomicPtr<T> {
         AtomicPtr { p: UnsafeCell::new(p) }
     }
@@ -1261,7 +1261,7 @@ let atomic_forty_two = ", stringify!($atomic_type), "::new(42);
 ```"),
                 #[inline]
                 #[$stable]
-                #[cfg_attr(not(bootstrap), $const_stable)]
+                #[$const_stable]
                 pub const fn new(v: $int_type) -> Self {
                     Self {v: UnsafeCell::new(v)}
                 }
diff --git a/src/libcore/task/wake.rs b/src/libcore/task/wake.rs
index c1e45f189b7a6..b070b665b4d09 100644
--- a/src/libcore/task/wake.rs
+++ b/src/libcore/task/wake.rs
@@ -39,7 +39,7 @@ impl RawWaker {
     /// function in the `vtable` of the underlying `RawWaker` will be called.
     #[rustc_promotable]
     #[stable(feature = "futures_api", since = "1.36.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "futures_api", since = "1.36.0"))]
+    #[rustc_const_stable(feature = "futures_api", since = "1.36.0")]
     pub const fn new(data: *const (), vtable: &'static RawWakerVTable) -> RawWaker {
         RawWaker { data, vtable }
     }
@@ -152,7 +152,7 @@ impl RawWakerVTable {
     // FIXME: remove whenever we have a stable way to accept fn pointers from const fn
     // (see https://github.com/rust-rfcs/const-eval/issues/19#issuecomment-472799062)
     #[rustc_allow_const_fn_ptr]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "futures_api", since = "1.36.0"))]
+    #[rustc_const_stable(feature = "futures_api", since = "1.36.0")]
     pub const fn new(
         clone: unsafe fn(*const ()) -> RawWaker,
         wake: unsafe fn(*const ()),
diff --git a/src/libcore/time.rs b/src/libcore/time.rs
index 7d04cfb5da518..c1d405239f96f 100644
--- a/src/libcore/time.rs
+++ b/src/libcore/time.rs
@@ -130,7 +130,7 @@ impl Duration {
     /// ```
     #[stable(feature = "duration", since = "1.3.0")]
     #[inline]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "duration_consts", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
     pub fn new(secs: u64, nanos: u32) -> Duration {
         let secs =
             secs.checked_add((nanos / NANOS_PER_SEC) as u64).expect("overflow in Duration::new");
@@ -153,7 +153,7 @@ impl Duration {
     #[stable(feature = "duration", since = "1.3.0")]
     #[inline]
     #[rustc_promotable]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "duration_consts", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
     pub const fn from_secs(secs: u64) -> Duration {
         Duration { secs, nanos: 0 }
     }
@@ -173,7 +173,7 @@ impl Duration {
     #[stable(feature = "duration", since = "1.3.0")]
     #[inline]
     #[rustc_promotable]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "duration_consts", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
     pub const fn from_millis(millis: u64) -> Duration {
         Duration {
             secs: millis / MILLIS_PER_SEC,
@@ -196,7 +196,7 @@ impl Duration {
     #[stable(feature = "duration_from_micros", since = "1.27.0")]
     #[inline]
     #[rustc_promotable]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "duration_consts", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
     pub const fn from_micros(micros: u64) -> Duration {
         Duration {
             secs: micros / MICROS_PER_SEC,
@@ -219,7 +219,7 @@ impl Duration {
     #[stable(feature = "duration_extras", since = "1.27.0")]
     #[inline]
     #[rustc_promotable]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "duration_consts", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "duration_consts", since = "1.32.0")]
     pub const fn from_nanos(nanos: u64) -> Duration {
         Duration {
             secs: nanos / (NANOS_PER_SEC as u64),
@@ -256,7 +256,7 @@ impl Duration {
     ///
     /// [`subsec_nanos`]: #method.subsec_nanos
     #[stable(feature = "duration", since = "1.3.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "duration", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "duration", since = "1.32.0")]
     #[inline]
     pub const fn as_secs(&self) -> u64 {
         self.secs
@@ -278,7 +278,7 @@ impl Duration {
     /// assert_eq!(duration.subsec_millis(), 432);
     /// ```
     #[stable(feature = "duration_extras", since = "1.27.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "duration_extras", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
     #[inline]
     pub const fn subsec_millis(&self) -> u32 {
         self.nanos / NANOS_PER_MILLI
@@ -300,7 +300,7 @@ impl Duration {
     /// assert_eq!(duration.subsec_micros(), 234_567);
     /// ```
     #[stable(feature = "duration_extras", since = "1.27.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "duration_extras", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "duration_extras", since = "1.32.0")]
     #[inline]
     pub const fn subsec_micros(&self) -> u32 {
         self.nanos / NANOS_PER_MICRO
@@ -322,7 +322,7 @@ impl Duration {
     /// assert_eq!(duration.subsec_nanos(), 10_000_000);
     /// ```
     #[stable(feature = "duration", since = "1.3.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "duration", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "duration", since = "1.32.0")]
     #[inline]
     pub const fn subsec_nanos(&self) -> u32 {
         self.nanos
@@ -339,7 +339,7 @@ impl Duration {
     /// assert_eq!(duration.as_millis(), 5730);
     /// ```
     #[stable(feature = "duration_as_u128", since = "1.33.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "duration_as_u128", since = "1.33.0"))]
+    #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
     #[inline]
     pub const fn as_millis(&self) -> u128 {
         self.secs as u128 * MILLIS_PER_SEC as u128 + (self.nanos / NANOS_PER_MILLI) as u128
@@ -356,7 +356,7 @@ impl Duration {
     /// assert_eq!(duration.as_micros(), 5730023);
     /// ```
     #[stable(feature = "duration_as_u128", since = "1.33.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "duration_as_u128", since = "1.33.0"))]
+    #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
     #[inline]
     pub const fn as_micros(&self) -> u128 {
         self.secs as u128 * MICROS_PER_SEC as u128 + (self.nanos / NANOS_PER_MICRO) as u128
@@ -373,7 +373,7 @@ impl Duration {
     /// assert_eq!(duration.as_nanos(), 5730023852);
     /// ```
     #[stable(feature = "duration_as_u128", since = "1.33.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "duration_as_u128", since = "1.33.0"))]
+    #[rustc_const_stable(feature = "duration_as_u128", since = "1.33.0")]
     #[inline]
     pub const fn as_nanos(&self) -> u128 {
         self.secs as u128 * NANOS_PER_SEC as u128 + self.nanos as u128
diff --git a/src/librustc/ty/codec.rs b/src/librustc/ty/codec.rs
index b3ef3217ec6a0..10c6a349ec801 100644
--- a/src/librustc/ty/codec.rs
+++ b/src/librustc/ty/codec.rs
@@ -76,9 +76,6 @@ pub fn encode_with_shorthand<E, T, M>(encoder: &mut E,
 
     // The shorthand encoding uses the same usize as the
     // discriminant, with an offset so they can't conflict.
-    #[cfg(bootstrap)]
-    let discriminant = unsafe { intrinsics::discriminant_value(variant) };
-    #[cfg(not(bootstrap))]
     let discriminant = intrinsics::discriminant_value(variant);
     assert!(discriminant < SHORTHAND_OFFSET as u64);
     let shorthand = start + SHORTHAND_OFFSET;
diff --git a/src/libstd/ffi/c_str.rs b/src/libstd/ffi/c_str.rs
index 14ca0423d8bc4..05008958ed2f0 100644
--- a/src/libstd/ffi/c_str.rs
+++ b/src/libstd/ffi/c_str.rs
@@ -1065,8 +1065,7 @@ impl CStr {
     /// ```
     #[inline]
     #[stable(feature = "cstr_from_bytes", since = "1.10.0")]
-    #[cfg_attr(bootstrap, rustc_const_unstable(feature = "const_cstr_unchecked"))]
-    #[cfg_attr(not(bootstrap), rustc_const_unstable(feature = "const_cstr_unchecked", issue = "0"))]
+    #[rustc_const_unstable(feature = "const_cstr_unchecked", issue = "0")]
     pub const unsafe fn from_bytes_with_nul_unchecked(bytes: &[u8]) -> &CStr {
         &*(bytes as *const [u8] as *const CStr)
     }
@@ -1120,7 +1119,7 @@ impl CStr {
     /// [`CString`]: struct.CString.html
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_str_as_ptr", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_str_as_ptr", since = "1.32.0")]
     pub const fn as_ptr(&self) -> *const c_char {
         self.inner.as_ptr()
     }
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index de33a2cb21461..340313b06dd40 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -283,7 +283,6 @@
 #![feature(needs_panic_runtime)]
 #![feature(never_type)]
 #![feature(nll)]
-#![cfg_attr(bootstrap, feature(on_unimplemented))]
 #![feature(optin_builtin_traits)]
 #![feature(panic_info_message)]
 #![feature(panic_internals)]
@@ -293,7 +292,6 @@
 #![feature(raw)]
 #![feature(renamed_spin_loop)]
 #![feature(rustc_attrs)]
-#![cfg_attr(bootstrap, feature(rustc_const_unstable))]
 #![feature(rustc_private)]
 #![feature(shrink_to)]
 #![feature(slice_concat_ext)]
diff --git a/src/libstd/net/ip.rs b/src/libstd/net/ip.rs
index 7d69f8f4b8d2f..9e24d707f77b5 100644
--- a/src/libstd/net/ip.rs
+++ b/src/libstd/net/ip.rs
@@ -319,7 +319,7 @@ impl Ipv4Addr {
     /// let addr = Ipv4Addr::new(127, 0, 0, 1);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_ipv4", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_ipv4", since = "1.32.0")]
     pub const fn new(a: u8, b: u8, c: u8, d: u8) -> Ipv4Addr {
         // FIXME: should just be u32::from_be_bytes([a, b, c, d]),
         // once that method is no longer rustc_const_unstable
@@ -407,7 +407,7 @@ impl Ipv4Addr {
     /// assert_eq!(Ipv4Addr::new(45, 22, 13, 197).is_unspecified(), false);
     /// ```
     #[stable(feature = "ip_shared", since = "1.12.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_ipv4", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_ipv4", since = "1.32.0")]
     pub const fn is_unspecified(&self) -> bool {
         self.inner.s_addr == 0
     }
@@ -1017,7 +1017,7 @@ impl Ipv6Addr {
     /// let addr = Ipv6Addr::new(0, 0, 0, 0, 0, 0xffff, 0xc00a, 0x2ff);
     /// ```
     #[stable(feature = "rust1", since = "1.0.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_ipv6", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_ipv6", since = "1.32.0")]
     pub const fn new(a: u16, b: u16, c: u16, d: u16, e: u16, f: u16,
                      g: u16, h: u16) -> Ipv6Addr {
         Ipv6Addr {
@@ -1483,7 +1483,7 @@ impl Ipv6Addr {
     ///            [255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]);
     /// ```
     #[stable(feature = "ipv6_to_octets", since = "1.12.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_ipv6", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_ipv6", since = "1.32.0")]
     pub const fn octets(&self) -> [u8; 16] {
         self.inner.s6_addr
     }
diff --git a/src/libstd/sync/once.rs b/src/libstd/sync/once.rs
index d8df09071cd69..61c4d0c2dbfba 100644
--- a/src/libstd/sync/once.rs
+++ b/src/libstd/sync/once.rs
@@ -188,7 +188,7 @@ struct WaiterQueue<'a> {
 impl Once {
     /// Creates a new `Once` value.
     #[stable(feature = "once_new", since = "1.2.0")]
-    #[cfg_attr(not(bootstrap), rustc_const_stable(feature = "const_once_new", since = "1.32.0"))]
+    #[rustc_const_stable(feature = "const_once_new", since = "1.32.0")]
     pub const fn new() -> Once {
         Once { state_and_queue: AtomicUsize::new(INCOMPLETE), _marker: marker::PhantomData }
     }
diff --git a/src/libsyntax_expand/expand.rs b/src/libsyntax_expand/expand.rs
index 9bfedb3b6174e..dc3d5789d1b55 100644
--- a/src/libsyntax_expand/expand.rs
+++ b/src/libsyntax_expand/expand.rs
@@ -85,7 +85,6 @@ macro_rules! ast_fragments {
                     $($(AstFragment::$Kind(ast) => ast.extend(placeholders.iter().flat_map(|id| {
                         // We are repeating through arguments with `many`, to do that we have to
                         // mention some macro variable from those arguments even if it's not used.
-                        #[cfg_attr(bootstrap, allow(unused_macros))]
                         macro _repeating($flat_map_ast_elt) {}
                         placeholder(AstFragmentKind::$Kind, *id, None).$make_ast()
                     })),)?)*
diff --git a/src/stage0.txt b/src/stage0.txt
index 3c84890158381..999218efa297d 100644
--- a/src/stage0.txt
+++ b/src/stage0.txt
@@ -12,7 +12,7 @@
 # source tarball for a stable release you'll likely see `1.x.0` for rustc and
 # `0.x.0` for Cargo where they were released on `date`.
 
-date: 2019-11-06
+date: 2019-12-18
 rustc: beta
 cargo: beta
 
diff --git a/src/tools/compiletest/src/main.rs b/src/tools/compiletest/src/main.rs
index 15f8abd75d59a..32965bbb292da 100644
--- a/src/tools/compiletest/src/main.rs
+++ b/src/tools/compiletest/src/main.rs
@@ -569,6 +569,7 @@ pub fn test_opts(config: &Config) -> test::TestOpts {
         list: false,
         options: test::Options::new(),
         time_options: None,
+        force_run_in_process: false,
     }
 }