diff --git a/src/bootstrap/bin/rustc.rs b/src/bootstrap/bin/rustc.rs
index 54b689fb062a5..9c01de8aa8251 100644
--- a/src/bootstrap/bin/rustc.rs
+++ b/src/bootstrap/bin/rustc.rs
@@ -45,18 +45,6 @@ fn main() {
         }
     }
 
-    // Drop `--error-format json` because despite our desire for json messages
-    // from Cargo we don't want any from rustc itself.
-    if let Some(n) = args.iter().position(|n| n == "--error-format") {
-        args.remove(n);
-        args.remove(n);
-    }
-
-    if let Some(s) = env::var_os("RUSTC_ERROR_FORMAT") {
-        args.push("--error-format".into());
-        args.push(s);
-    }
-
     // Detect whether or not we're a build script depending on whether --target
     // is passed (a bit janky...)
     let target = args.windows(2)
@@ -110,7 +98,11 @@ fn main() {
 
     // Non-zero stages must all be treated uniformly to avoid problems when attempting to uplift
     // compiler libraries and such from stage 1 to 2.
-    if stage == "0" {
+    //
+    // FIXME: the fact that core here is excluded is due to core_arch from our stdarch submodule
+    // being broken on the beta compiler with bootstrap passed, so this is a temporary workaround
+    // (we've just snapped, so there are no cfg(bootstrap) related annotations in core).
+    if stage == "0" && crate_name != Some("core") {
         cmd.arg("--cfg").arg("bootstrap");
     }
 
@@ -132,10 +124,7 @@ fn main() {
         cmd.arg("-Dwarnings");
         cmd.arg("-Drust_2018_idioms");
         cmd.arg("-Dunused_lifetimes");
-        // cfg(not(bootstrap)): Remove this during the next stage 0 compiler update.
-        // `-Drustc::internal` is a new feature and `rustc_version` mis-reports the `stage`.
-        let cfg_not_bootstrap = stage != "0" && crate_name != Some("rustc_version");
-        if cfg_not_bootstrap && use_internal_lints(crate_name) {
+        if use_internal_lints(crate_name) {
             cmd.arg("-Zunstable-options");
             cmd.arg("-Drustc::internal");
         }
diff --git a/src/bootstrap/builder.rs b/src/bootstrap/builder.rs
index e54c9360baece..8dad5f2ef4632 100644
--- a/src/bootstrap/builder.rs
+++ b/src/bootstrap/builder.rs
@@ -145,7 +145,7 @@ impl StepDescription {
             only_hosts: S::ONLY_HOSTS,
             should_run: S::should_run,
             make_run: S::make_run,
-            name: unsafe { ::std::intrinsics::type_name::<S>() },
+            name: std::any::type_name::<S>(),
         }
     }
 
@@ -980,9 +980,6 @@ impl<'a> Builder<'a> {
         if let Some(target_linker) = self.linker(target) {
             cargo.env("RUSTC_TARGET_LINKER", target_linker);
         }
-        if let Some(ref error_format) = self.config.rustc_error_format {
-            cargo.env("RUSTC_ERROR_FORMAT", error_format);
-        }
         if !(["build", "check", "clippy", "fix", "rustc"].contains(&cmd)) && want_rustdoc {
             cargo.env("RUSTDOC_LIBDIR", self.rustc_libdir(compiler));
         }
diff --git a/src/bootstrap/channel.rs b/src/bootstrap/channel.rs
index 8e8d8f5e787a7..caa4843da4d36 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 = "1.38.0";
+pub const CFG_RELEASE_NUM: &str = "1.39.0";
 
 pub struct GitInfo {
     inner: Option<Info>,
diff --git a/src/bootstrap/compile.rs b/src/bootstrap/compile.rs
index 4cd793adaf574..4b4b072cc1c96 100644
--- a/src/bootstrap/compile.rs
+++ b/src/bootstrap/compile.rs
@@ -1116,10 +1116,6 @@ pub fn run_cargo(builder: &Builder<'_>,
                 },
                 ..
             } => (filenames, crate_types),
-            CargoMessage::CompilerMessage { message } => {
-                eprintln!("{}", message.rendered);
-                return;
-            }
             _ => return,
         };
         for filename in filenames {
@@ -1256,8 +1252,12 @@ pub fn stream_cargo(
     }
     // Instruct Cargo to give us json messages on stdout, critically leaving
     // stderr as piped so we can get those pretty colors.
-    cargo.arg("--message-format").arg("json")
-         .stdout(Stdio::piped());
+    let mut message_format = String::from("json-render-diagnostics");
+    if let Some(s) = &builder.config.rustc_error_format  {
+        message_format.push_str(",json-diagnostic-");
+        message_format.push_str(s);
+    }
+    cargo.arg("--message-format").arg(message_format).stdout(Stdio::piped());
 
     for arg in tail_args {
         cargo.arg(arg);
@@ -1310,12 +1310,4 @@ pub enum CargoMessage<'a> {
     BuildScriptExecuted {
         package_id: Cow<'a, str>,
     },
-    CompilerMessage {
-        message: ClippyMessage<'a>
-    }
-}
-
-#[derive(Deserialize)]
-pub struct ClippyMessage<'a> {
-    rendered: Cow<'a, str>,
 }
diff --git a/src/liballoc/collections/btree/node.rs b/src/liballoc/collections/btree/node.rs
index e067096f0c780..0b5a271dbea95 100644
--- a/src/liballoc/collections/btree/node.rs
+++ b/src/liballoc/collections/btree/node.rs
@@ -106,8 +106,8 @@ impl<K, V> LeafNode<K, V> {
         LeafNode {
             // As a general policy, we leave fields uninitialized if they can be, as this should
             // be both slightly faster and easier to track in Valgrind.
-            keys: uninit_array![_; CAPACITY],
-            vals: uninit_array![_; CAPACITY],
+            keys: [MaybeUninit::UNINIT; CAPACITY],
+            vals: [MaybeUninit::UNINIT; CAPACITY],
             parent: ptr::null(),
             parent_idx: MaybeUninit::uninit(),
             len: 0
@@ -159,7 +159,7 @@ impl<K, V> InternalNode<K, V> {
     unsafe fn new() -> Self {
         InternalNode {
             data: LeafNode::new(),
-            edges: uninit_array![_; 2*B],
+            edges: [MaybeUninit::UNINIT; 2*B]
         }
     }
 }
diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index a1936b36ac6bf..7421beddd9574 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -69,7 +69,7 @@
 #![warn(missing_debug_implementations)]
 #![deny(intra_doc_link_resolution_failure)] // rustdoc is run without -D warnings
 #![allow(explicit_outlives_requirements)]
-#![cfg_attr(not(bootstrap), allow(incomplete_features))]
+#![allow(incomplete_features)]
 
 #![cfg_attr(not(test), feature(generator_trait))]
 #![cfg_attr(test, feature(test))]
@@ -84,7 +84,7 @@
 #![feature(coerce_unsized)]
 #![feature(const_generic_impls_guard)]
 #![feature(const_generics)]
-#![cfg_attr(not(bootstrap), feature(const_in_array_repeat_expressions))]
+#![feature(const_in_array_repeat_expressions)]
 #![feature(dispatch_from_dyn)]
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
@@ -118,7 +118,7 @@
 #![feature(rustc_const_unstable)]
 #![feature(const_vec_new)]
 #![feature(slice_partition_dedup)]
-#![feature(maybe_uninit_extra, maybe_uninit_slice, maybe_uninit_array)]
+#![feature(maybe_uninit_extra, maybe_uninit_slice)]
 #![feature(alloc_layout_extra)]
 #![feature(try_trait)]
 #![feature(mem_take)]
diff --git a/src/libcore/any.rs b/src/libcore/any.rs
index 078091a9b5475..e8a0a88f12a7e 100644
--- a/src/libcore/any.rs
+++ b/src/libcore/any.rs
@@ -470,10 +470,5 @@ impl TypeId {
 #[stable(feature = "type_name", since = "1.38.0")]
 #[rustc_const_unstable(feature = "const_type_name")]
 pub const fn type_name<T: ?Sized>() -> &'static str {
-    #[cfg(bootstrap)]
-    unsafe {
-        intrinsics::type_name::<T>()
-    }
-    #[cfg(not(bootstrap))]
     intrinsics::type_name::<T>()
 }
diff --git a/src/libcore/char/methods.rs b/src/libcore/char/methods.rs
index aa834db2b9b3e..e91bf53c5b418 100644
--- a/src/libcore/char/methods.rs
+++ b/src/libcore/char/methods.rs
@@ -553,12 +553,7 @@ impl char {
     /// `XID_Start` is a Unicode Derived Property specified in
     /// [UAX #31](http://unicode.org/reports/tr31/#NFKC_Modifications),
     /// mostly similar to `ID_Start` but modified for closure under `NFKx`.
-    #[cfg_attr(bootstrap,
-               unstable(feature = "rustc_private",
-                        reason = "mainly needed for compiler internals",
-                        issue = "27812"))]
-    #[cfg_attr(not(bootstrap),
-               unstable(feature = "unicode_internals", issue = "0"))]
+    #[unstable(feature = "unicode_internals", issue = "0")]
     pub fn is_xid_start(self) -> bool {
         derived_property::XID_Start(self)
     }
@@ -569,12 +564,7 @@ impl char {
     /// `XID_Continue` is a Unicode Derived Property specified in
     /// [UAX #31](http://unicode.org/reports/tr31/#NFKC_Modifications),
     /// mostly similar to `ID_Continue` but modified for closure under NFKx.
-    #[cfg_attr(bootstrap,
-               unstable(feature = "rustc_private",
-                        reason = "mainly needed for compiler internals",
-                        issue = "27812"))]
-    #[cfg_attr(not(bootstrap),
-               unstable(feature = "unicode_internals", issue = "0"))]
+    #[unstable(feature = "unicode_internals", issue = "0")]
     #[inline]
     pub fn is_xid_continue(self) -> bool {
         derived_property::XID_Continue(self)
diff --git a/src/libcore/clone.rs b/src/libcore/clone.rs
index 0c99356390bda..ec22a7ccfe4c3 100644
--- a/src/libcore/clone.rs
+++ b/src/libcore/clone.rs
@@ -134,7 +134,6 @@ pub trait Clone : Sized {
 }
 
 /// Derive macro generating an impl of the trait `Clone`.
-#[cfg(not(bootstrap))]
 #[rustc_builtin_macro]
 #[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
diff --git a/src/libcore/cmp.rs b/src/libcore/cmp.rs
index 38a52d97da212..b802216036b93 100644
--- a/src/libcore/cmp.rs
+++ b/src/libcore/cmp.rs
@@ -201,7 +201,6 @@ pub trait PartialEq<Rhs: ?Sized = Self> {
 }
 
 /// Derive macro generating an impl of the trait `PartialEq`.
-#[cfg(not(bootstrap))]
 #[rustc_builtin_macro]
 #[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
@@ -265,7 +264,6 @@ pub trait Eq: PartialEq<Self> {
 }
 
 /// Derive macro generating an impl of the trait `Eq`.
-#[cfg(not(bootstrap))]
 #[rustc_builtin_macro]
 #[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
@@ -617,7 +615,6 @@ pub trait Ord: Eq + PartialOrd<Self> {
 }
 
 /// Derive macro generating an impl of the trait `Ord`.
-#[cfg(not(bootstrap))]
 #[rustc_builtin_macro]
 #[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
@@ -867,7 +864,6 @@ pub trait PartialOrd<Rhs: ?Sized = Self>: PartialEq<Rhs> {
 }
 
 /// Derive macro generating an impl of the trait `PartialOrd`.
-#[cfg(not(bootstrap))]
 #[rustc_builtin_macro]
 #[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
diff --git a/src/libcore/default.rs b/src/libcore/default.rs
index 8d95e9de15849..9b1616ccce448 100644
--- a/src/libcore/default.rs
+++ b/src/libcore/default.rs
@@ -116,7 +116,6 @@ pub trait Default: Sized {
 }
 
 /// Derive macro generating an impl of the trait `Default`.
-#[cfg(not(bootstrap))]
 #[rustc_builtin_macro]
 #[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
diff --git a/src/libcore/fmt/mod.rs b/src/libcore/fmt/mod.rs
index 0ea01d4b84a2c..d5fae9e740136 100644
--- a/src/libcore/fmt/mod.rs
+++ b/src/libcore/fmt/mod.rs
@@ -546,7 +546,6 @@ pub trait Debug {
 }
 
 // Separate module to reexport the macro `Debug` from prelude without the trait `Debug`.
-#[cfg(not(bootstrap))]
 pub(crate) mod macros {
     /// Derive macro generating an impl of the trait `Debug`.
     #[rustc_builtin_macro]
@@ -555,7 +554,6 @@ pub(crate) mod macros {
     #[allow_internal_unstable(core_intrinsics)]
     pub macro Debug($item:item) { /* compiler built-in */ }
 }
-#[cfg(not(bootstrap))]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[doc(inline)]
 pub use macros::Debug;
diff --git a/src/libcore/hash/mod.rs b/src/libcore/hash/mod.rs
index 685540ba6fc26..b397119112390 100644
--- a/src/libcore/hash/mod.rs
+++ b/src/libcore/hash/mod.rs
@@ -199,7 +199,6 @@ pub trait Hash {
 }
 
 // Separate module to reexport the macro `Hash` from prelude without the trait `Hash`.
-#[cfg(not(bootstrap))]
 pub(crate) mod macros {
     /// Derive macro generating an impl of the trait `Hash`.
     #[rustc_builtin_macro]
@@ -208,7 +207,6 @@ pub(crate) mod macros {
     #[allow_internal_unstable(core_intrinsics)]
     pub macro Hash($item:item) { /* compiler built-in */ }
 }
-#[cfg(not(bootstrap))]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[doc(inline)]
 pub use macros::Hash;
diff --git a/src/libcore/lib.rs b/src/libcore/lib.rs
index 678ff7687921b..c168d5c8a2eac 100644
--- a/src/libcore/lib.rs
+++ b/src/libcore/lib.rs
@@ -63,7 +63,7 @@
 #![warn(missing_debug_implementations)]
 #![deny(intra_doc_link_resolution_failure)] // rustdoc is run without -D warnings
 #![allow(explicit_outlives_requirements)]
-#![cfg_attr(not(bootstrap), allow(incomplete_features))]
+#![allow(incomplete_features)]
 
 #![feature(allow_internal_unstable)]
 #![feature(arbitrary_self_types)]
@@ -129,7 +129,7 @@
 #![feature(structural_match)]
 #![feature(abi_unadjusted)]
 #![feature(adx_target_feature)]
-#![feature(maybe_uninit_slice, maybe_uninit_array)]
+#![feature(maybe_uninit_slice)]
 #![feature(external_doc)]
 #![feature(mem_take)]
 #![feature(associated_type_bounds)]
diff --git a/src/libcore/macros.rs b/src/libcore/macros.rs
index f9dc53874acb1..bbed95167161d 100644
--- a/src/libcore/macros.rs
+++ b/src/libcore/macros.rs
@@ -635,46 +635,11 @@ macro_rules! todo {
     ($($arg:tt)+) => (panic!("not yet implemented: {}", format_args!($($arg)+)));
 }
 
-/// Creates an array of [`MaybeUninit`].
-///
-/// This macro constructs an uninitialized array of the type `[MaybeUninit<K>; N]`.
-/// It exists solely because bootstrap does not yet support const array-init expressions.
-///
-/// [`MaybeUninit`]: mem/union.MaybeUninit.html
-// FIXME: Remove both versions of this macro once bootstrap is 1.38.
-#[macro_export]
-#[unstable(feature = "maybe_uninit_array", issue = "53491")]
-#[cfg(bootstrap)]
-macro_rules! uninit_array {
-    // This `assume_init` is safe because an array of `MaybeUninit` does not
-    // require initialization.
-    ($t:ty; $size:expr) => (unsafe {
-        MaybeUninit::<[MaybeUninit<$t>; $size]>::uninit().assume_init()
-    });
-}
-
-/// Creates an array of [`MaybeUninit`].
-///
-/// This macro constructs an uninitialized array of the type `[MaybeUninit<K>; N]`.
-/// It exists solely because bootstrap does not yet support const array-init expressions.
-///
-/// [`MaybeUninit`]: mem/union.MaybeUninit.html
-// FIXME: Just inline this version of the macro once bootstrap is 1.38.
-#[macro_export]
-#[unstable(feature = "maybe_uninit_array", issue = "53491")]
-#[cfg(not(bootstrap))]
-macro_rules! uninit_array {
-    ($t:ty; $size:expr) => (
-        [MaybeUninit::<$t>::UNINIT; $size]
-    );
-}
-
 /// Definitions of built-in macros.
 ///
 /// Most of the macro properties (stability, visibility, etc.) are taken from the source code here,
 /// with exception of expansion functions transforming macro inputs into outputs,
 /// those functions are provided by the compiler.
-#[cfg(not(bootstrap))]
 pub(crate) mod builtin {
 
     /// Causes compilation to fail with the given error message when encountered.
diff --git a/src/libcore/marker.rs b/src/libcore/marker.rs
index 78a273611650c..3befd421b0125 100644
--- a/src/libcore/marker.rs
+++ b/src/libcore/marker.rs
@@ -289,7 +289,6 @@ pub trait Copy : Clone {
 }
 
 /// Derive macro generating an impl of the trait `Copy`.
-#[cfg(not(bootstrap))]
 #[rustc_builtin_macro]
 #[rustc_macro_transparency = "semitransparent"]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
diff --git a/src/libcore/mem/maybe_uninit.rs b/src/libcore/mem/maybe_uninit.rs
index 1bbea02e0c7c9..49711607262df 100644
--- a/src/libcore/mem/maybe_uninit.rs
+++ b/src/libcore/mem/maybe_uninit.rs
@@ -213,7 +213,7 @@ use crate::mem::ManuallyDrop;
 #[allow(missing_debug_implementations)]
 #[stable(feature = "maybe_uninit", since = "1.36.0")]
 // Lang item so we can wrap other types in it. This is useful for generators.
-#[cfg_attr(not(bootstrap), lang = "maybe_uninit")]
+#[lang = "maybe_uninit"]
 #[derive(Copy)]
 #[repr(transparent)]
 pub union MaybeUninit<T> {
diff --git a/src/libcore/mem/mod.rs b/src/libcore/mem/mod.rs
index 2534400b8334f..87ec05a243d36 100644
--- a/src/libcore/mem/mod.rs
+++ b/src/libcore/mem/mod.rs
@@ -453,7 +453,7 @@ pub const fn needs_drop<T>() -> bool {
 /// ```
 #[inline]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[cfg_attr(bootstrap, allow(deprecated_in_future))]
+#[allow(deprecated_in_future)]
 #[allow(deprecated)]
 pub unsafe fn zeroed<T>() -> T {
     intrinsics::panic_if_uninhabited::<T>();
@@ -481,7 +481,7 @@ pub unsafe fn zeroed<T>() -> T {
 #[inline]
 #[rustc_deprecated(since = "1.39.0", reason = "use `mem::MaybeUninit` instead")]
 #[stable(feature = "rust1", since = "1.0.0")]
-#[cfg_attr(bootstrap, allow(deprecated_in_future))]
+#[allow(deprecated_in_future)]
 #[allow(deprecated)]
 pub unsafe fn uninitialized<T>() -> T {
     intrinsics::panic_if_uninhabited::<T>();
diff --git a/src/libcore/prelude/v1.rs b/src/libcore/prelude/v1.rs
index 84cf85f339c99..762403790403d 100644
--- a/src/libcore/prelude/v1.rs
+++ b/src/libcore/prelude/v1.rs
@@ -46,16 +46,13 @@ pub use crate::option::Option::{self, Some, None};
 pub use crate::result::Result::{self, Ok, Err};
 
 // Re-exported built-in macros
-#[cfg(not(bootstrap))]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[doc(no_inline)]
 pub use crate::fmt::macros::Debug;
-#[cfg(not(bootstrap))]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[doc(no_inline)]
 pub use crate::hash::macros::Hash;
 
-#[cfg(not(bootstrap))]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[doc(no_inline)]
 pub use crate::{
@@ -83,7 +80,6 @@ pub use crate::{
     trace_macros,
 };
 
-#[cfg(not(bootstrap))]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[allow(deprecated)]
 #[doc(no_inline)]
diff --git a/src/librustc/lint/context.rs b/src/librustc/lint/context.rs
index de812410e8bd8..3584a12829018 100644
--- a/src/librustc/lint/context.rs
+++ b/src/librustc/lint/context.rs
@@ -1355,7 +1355,7 @@ struct LateLintPassObjects<'a> {
     lints: &'a mut [LateLintPassObject],
 }
 
-#[cfg_attr(not(bootstrap), allow(rustc::lint_pass_impl_without_macro))]
+#[allow(rustc::lint_pass_impl_without_macro)]
 impl LintPass for LateLintPassObjects<'_> {
     fn name(&self) -> &'static str {
         panic!()
@@ -1525,7 +1525,7 @@ struct EarlyLintPassObjects<'a> {
     lints: &'a mut [EarlyLintPassObject],
 }
 
-#[cfg_attr(not(bootstrap), allow(rustc::lint_pass_impl_without_macro))]
+#[allow(rustc::lint_pass_impl_without_macro)]
 impl LintPass for EarlyLintPassObjects<'_> {
     fn name(&self) -> &'static str {
         panic!()
diff --git a/src/librustc/lint/internal.rs b/src/librustc/lint/internal.rs
index 0b514f5927d30..dea1cc6601b04 100644
--- a/src/librustc/lint/internal.rs
+++ b/src/librustc/lint/internal.rs
@@ -23,7 +23,7 @@ pub struct DefaultHashTypes {
 
 impl DefaultHashTypes {
     // we are allowed to use `HashMap` and `HashSet` as identifiers for implementing the lint itself
-    #[cfg_attr(not(bootstrap), allow(rustc::default_hash_types))]
+    #[allow(rustc::default_hash_types)]
     pub fn new() -> Self {
         let mut map = FxHashMap::default();
         map.insert(sym::HashMap, sym::FxHashMap);
diff --git a/src/librustc/ty/codec.rs b/src/librustc/ty/codec.rs
index e3c6eca02d554..1ddc6780aca89 100644
--- a/src/librustc/ty/codec.rs
+++ b/src/librustc/ty/codec.rs
@@ -27,7 +27,7 @@ pub trait EncodableWithShorthand: Clone + Eq + Hash {
     fn variant(&self) -> &Self::Variant;
 }
 
-#[cfg_attr(not(bootstrap), allow(rustc::usage_of_ty_tykind))]
+#[allow(rustc::usage_of_ty_tykind)]
 impl<'tcx> EncodableWithShorthand for Ty<'tcx> {
     type Variant = ty::TyKind<'tcx>;
     fn variant(&self) -> &Self::Variant {
@@ -160,7 +160,7 @@ where
     Ok(decoder.map_encoded_cnum_to_current(cnum))
 }
 
-#[cfg_attr(not(bootstrap), allow(rustc::usage_of_ty_tykind))]
+#[allow(rustc::usage_of_ty_tykind)]
 #[inline]
 pub fn decode_ty<D>(decoder: &mut D) -> Result<Ty<'tcx>, D::Error>
 where
diff --git a/src/librustc/ty/context.rs b/src/librustc/ty/context.rs
index ef74d9e5b2899..d504ba4dfe086 100644
--- a/src/librustc/ty/context.rs
+++ b/src/librustc/ty/context.rs
@@ -130,7 +130,7 @@ impl<'tcx> CtxtInterners<'tcx> {
     }
 
     /// Intern a type
-    #[cfg_attr(not(bootstrap), allow(rustc::usage_of_ty_tykind))]
+    #[allow(rustc::usage_of_ty_tykind)]
     #[inline(never)]
     fn intern_ty(&self,
         st: TyKind<'tcx>
@@ -2076,7 +2076,7 @@ impl<'tcx> Hash for Interned<'tcx, TyS<'tcx>> {
     }
 }
 
-#[cfg_attr(not(bootstrap), allow(rustc::usage_of_ty_tykind))]
+#[allow(rustc::usage_of_ty_tykind)]
 impl<'tcx> Borrow<TyKind<'tcx>> for Interned<'tcx, TyS<'tcx>> {
     fn borrow<'a>(&'a self) -> &'a TyKind<'tcx> {
         &self.0.sty
@@ -2291,7 +2291,7 @@ impl<'tcx> TyCtxt<'tcx> {
         self.mk_fn_ptr(converted_sig)
     }
 
-    #[cfg_attr(not(bootstrap), allow(rustc::usage_of_ty_tykind))]
+    #[allow(rustc::usage_of_ty_tykind)]
     #[inline]
     pub fn mk_ty(&self, st: TyKind<'tcx>) -> Ty<'tcx> {
         self.interners.intern_ty(st)
diff --git a/src/librustc/ty/flags.rs b/src/librustc/ty/flags.rs
index 411b18e043a20..9119505acd174 100644
--- a/src/librustc/ty/flags.rs
+++ b/src/librustc/ty/flags.rs
@@ -18,7 +18,7 @@ impl FlagComputation {
         }
     }
 
-    #[cfg_attr(not(bootstrap), allow(rustc::usage_of_ty_tykind))]
+    #[allow(rustc::usage_of_ty_tykind)]
     pub fn for_sty(st: &ty::TyKind<'_>) -> FlagComputation {
         let mut result = FlagComputation::new();
         result.add_sty(st);
@@ -62,7 +62,7 @@ impl FlagComputation {
         } // otherwise, this binder captures nothing
     }
 
-    #[cfg_attr(not(bootstrap), allow(rustc::usage_of_ty_tykind))]
+    #[allow(rustc::usage_of_ty_tykind)]
     fn add_sty(&mut self, st: &ty::TyKind<'_>) {
         match st {
             &ty::Bool |
diff --git a/src/librustc/ty/mod.rs b/src/librustc/ty/mod.rs
index 9d563e290de96..a8ff36a394657 100644
--- a/src/librustc/ty/mod.rs
+++ b/src/librustc/ty/mod.rs
@@ -483,7 +483,7 @@ bitflags! {
     }
 }
 
-#[cfg_attr(not(bootstrap), allow(rustc::usage_of_ty_tykind))]
+#[allow(rustc::usage_of_ty_tykind)]
 pub struct TyS<'tcx> {
     pub sty: TyKind<'tcx>,
     pub flags: TypeFlags,
diff --git a/src/librustc/ty/sty.rs b/src/librustc/ty/sty.rs
index 129ea9b5b674a..42e367b851825 100644
--- a/src/librustc/ty/sty.rs
+++ b/src/librustc/ty/sty.rs
@@ -1,6 +1,6 @@
 //! This module contains `TyKind` and its major components.
 
-#![cfg_attr(not(bootstrap), allow(rustc::usage_of_ty_tykind))]
+#![allow(rustc::usage_of_ty_tykind)]
 
 use crate::hir;
 use crate::hir::def_id::DefId;
diff --git a/src/librustc_data_structures/lib.rs b/src/librustc_data_structures/lib.rs
index 9f103437d368e..f7593501959c7 100644
--- a/src/librustc_data_structures/lib.rs
+++ b/src/librustc_data_structures/lib.rs
@@ -27,7 +27,7 @@
 
 #![cfg_attr(unix, feature(libc))]
 
-#![cfg_attr(not(bootstrap), allow(rustc::default_hash_types))]
+#![allow(rustc::default_hash_types)]
 
 #[macro_use]
 extern crate log;
diff --git a/src/librustc_macros/src/lib.rs b/src/librustc_macros/src/lib.rs
index 85e2247ebd7e3..3d3a020ef0c8e 100644
--- a/src/librustc_macros/src/lib.rs
+++ b/src/librustc_macros/src/lib.rs
@@ -1,5 +1,5 @@
 #![feature(proc_macro_hygiene)]
-#![cfg_attr(not(bootstrap), allow(rustc::default_hash_types))]
+#![allow(rustc::default_hash_types)]
 
 #![recursion_limit="128"]
 
diff --git a/src/librustc_target/abi/mod.rs b/src/librustc_target/abi/mod.rs
index dd7ae742a63c6..dafa866117681 100644
--- a/src/librustc_target/abi/mod.rs
+++ b/src/librustc_target/abi/mod.rs
@@ -114,26 +114,20 @@ impl TargetDataLayout {
                 [p] if p.starts_with("P") => {
                     dl.instruction_address_space = parse_address_space(&p[1..], "P")?
                 }
-                // FIXME: Ping cfg(bootstrap) -- Use `ref a @ ..` with new bootstrap compiler.
-                ["a", ..] => {
-                    let a = &spec_parts[1..]; // FIXME inline into pattern.
+                ["a", ref a @ ..] => {
                     dl.aggregate_align = align(a, "a")?
                 }
-                ["f32", ..] => {
-                    let a = &spec_parts[1..]; // FIXME inline into pattern.
+                ["f32", ref a @ ..] => {
                     dl.f32_align = align(a, "f32")?
                 }
-                ["f64", ..] => {
-                    let a = &spec_parts[1..]; // FIXME inline into pattern.
+                ["f64", ref a @ ..] => {
                     dl.f64_align = align(a, "f64")?
                 }
-                [p @ "p", s, ..] | [p @ "p0", s, ..] => {
-                    let a = &spec_parts[2..]; // FIXME inline into pattern.
+                [p @ "p", s, ref a @ ..] | [p @ "p0", s, ref a @ ..] => {
                     dl.pointer_size = size(s, p)?;
                     dl.pointer_align = align(a, p)?;
                 }
-                [s, ..] if s.starts_with("i") => {
-                    let a = &spec_parts[1..]; // FIXME inline into pattern.
+                [s, ref a @ ..] if s.starts_with("i") => {
                     let bits = match s[1..].parse::<u64>() {
                         Ok(bits) => bits,
                         Err(_) => {
@@ -157,8 +151,7 @@ impl TargetDataLayout {
                         dl.i128_align = a;
                     }
                 }
-                [s, ..] if s.starts_with("v") => {
-                    let a = &spec_parts[1..]; // FIXME inline into pattern.
+                [s, ref a @ ..] if s.starts_with("v") => {
                     let v_size = size(&s[1..], "v")?;
                     let a = align(a, s)?;
                     if let Some(v) = dl.vector_align.iter_mut().find(|v| v.0 == v_size) {
diff --git a/src/librustc_typeck/check/mod.rs b/src/librustc_typeck/check/mod.rs
index 14fc0d6347e4b..52659b6902d31 100644
--- a/src/librustc_typeck/check/mod.rs
+++ b/src/librustc_typeck/check/mod.rs
@@ -1916,9 +1916,7 @@ fn bad_variant_count<'tcx>(tcx: TyCtxt<'tcx>, adt: &'tcx ty::AdtDef, sp: Span, d
     );
     let mut err = struct_span_err!(tcx.sess, sp, E0731, "transparent enum {}", msg);
     err.span_label(sp, &msg);
-    if let &[.., ref end] = &variant_spans[..] {
-        // FIXME: Ping cfg(bootstrap) -- Use `ref start @ ..` with new bootstrap compiler.
-        let start = &variant_spans[..variant_spans.len() - 1];
+    if let &[ref start @ .., ref end] = &variant_spans[..] {
         for variant_span in start {
             err.span_label(*variant_span, "");
         }
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index ba80d1b70049a..1f48315d3f8db 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -228,7 +228,7 @@
 // std is implemented with unstable features, many of which are internal
 // compiler details that will never be stable
 // NB: the following list is sorted to minimize merge conflicts.
-#![cfg_attr(not(bootstrap), feature(__rust_unstable_column))]
+#![feature(__rust_unstable_column)]
 #![feature(alloc_error_handler)]
 #![feature(alloc_layout_extra)]
 #![feature(allocator_api)]
@@ -513,7 +513,7 @@ pub use std_detect::detect;
 
 // Re-export macros defined in libcore.
 #[stable(feature = "rust1", since = "1.0.0")]
-#[allow(deprecated_in_future)]
+#[allow(deprecated, deprecated_in_future)]
 pub use core::{
     // Stable
     assert_eq,
@@ -531,7 +531,6 @@ pub use core::{
 };
 
 // Re-export built-in macros defined through libcore.
-#[cfg(not(bootstrap))]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 pub use core::{
     // Stable
diff --git a/src/libstd/os/raw/mod.rs b/src/libstd/os/raw/mod.rs
index 0761c50f4b229..611a1709c8d91 100644
--- a/src/libstd/os/raw/mod.rs
+++ b/src/libstd/os/raw/mod.rs
@@ -8,8 +8,7 @@
 
 #![stable(feature = "raw_os", since = "1.1.0")]
 
-#[cfg_attr(bootstrap, doc(include = "os/raw/char.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "char.md"))]
+#[doc(include = "char.md")]
 #[cfg(any(all(target_os = "linux", any(target_arch = "aarch64",
                                        target_arch = "arm",
                                        target_arch = "hexagon",
@@ -33,8 +32,7 @@
                                          target_arch = "powerpc")),
           all(target_os = "fuchsia", target_arch = "aarch64")))]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_char = u8;
-#[cfg_attr(bootstrap, doc(include = "os/raw/char.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "char.md"))]
+#[doc(include = "char.md")]
 #[cfg(not(any(all(target_os = "linux", any(target_arch = "aarch64",
                                            target_arch = "arm",
                                            target_arch = "hexagon",
@@ -58,51 +56,37 @@
                                              target_arch = "powerpc")),
               all(target_os = "fuchsia", target_arch = "aarch64"))))]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_char = i8;
-#[cfg_attr(bootstrap, doc(include = "os/raw/schar.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "schar.md"))]
+#[doc(include = "schar.md")]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_schar = i8;
-#[cfg_attr(bootstrap, doc(include = "os/raw/uchar.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "uchar.md"))]
+#[doc(include = "uchar.md")]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_uchar = u8;
-#[cfg_attr(bootstrap, doc(include = "os/raw/short.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "short.md"))]
+#[doc(include = "short.md")]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_short = i16;
-#[cfg_attr(bootstrap, doc(include = "os/raw/ushort.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "ushort.md"))]
+#[doc(include = "ushort.md")]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_ushort = u16;
-#[cfg_attr(bootstrap, doc(include = "os/raw/int.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "int.md"))]
+#[doc(include = "int.md")]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_int = i32;
-#[cfg_attr(bootstrap, doc(include = "os/raw/uint.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "uint.md"))]
+#[doc(include = "uint.md")]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_uint = u32;
-#[cfg_attr(bootstrap, doc(include = "os/raw/long.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "long.md"))]
+#[doc(include = "long.md")]
 #[cfg(any(target_pointer_width = "32", windows))]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_long = i32;
-#[cfg_attr(bootstrap, doc(include = "os/raw/ulong.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "ulong.md"))]
+#[doc(include = "ulong.md")]
 #[cfg(any(target_pointer_width = "32", windows))]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_ulong = u32;
-#[cfg_attr(bootstrap, doc(include = "os/raw/long.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "long.md"))]
+#[doc(include = "long.md")]
 #[cfg(all(target_pointer_width = "64", not(windows)))]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_long = i64;
-#[cfg_attr(bootstrap, doc(include = "os/raw/ulong.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "ulong.md"))]
+#[doc(include = "ulong.md")]
 #[cfg(all(target_pointer_width = "64", not(windows)))]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_ulong = u64;
-#[cfg_attr(bootstrap, doc(include = "os/raw/longlong.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "longlong.md"))]
+#[doc(include = "longlong.md")]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_longlong = i64;
-#[cfg_attr(bootstrap, doc(include = "os/raw/ulonglong.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "ulonglong.md"))]
+#[doc(include = "ulonglong.md")]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_ulonglong = u64;
-#[cfg_attr(bootstrap, doc(include = "os/raw/float.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "float.md"))]
+#[doc(include = "float.md")]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_float = f32;
-#[cfg_attr(bootstrap, doc(include = "os/raw/double.md"))]
-#[cfg_attr(not(bootstrap), doc(include = "double.md"))]
+#[doc(include = "double.md")]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_double = f64;
 
 #[stable(feature = "raw_os", since = "1.1.0")]
diff --git a/src/libstd/prelude/v1.rs b/src/libstd/prelude/v1.rs
index 1c61f21f7df4e..752c6202ee489 100644
--- a/src/libstd/prelude/v1.rs
+++ b/src/libstd/prelude/v1.rs
@@ -7,10 +7,6 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 
 // Re-exported core operators
-#[cfg(bootstrap)]
-#[stable(feature = "rust1", since = "1.0.0")]
-#[doc(no_inline)]
-pub use crate::marker::Copy;
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)]
 pub use crate::marker::{Send, Sized, Sync, Unpin};
@@ -24,21 +20,9 @@ pub use crate::ops::{Drop, Fn, FnMut, FnOnce};
 pub use crate::mem::drop;
 
 // Re-exported types and traits
-#[cfg(bootstrap)]
-#[stable(feature = "rust1", since = "1.0.0")]
-#[doc(no_inline)]
-pub use crate::clone::Clone;
-#[cfg(bootstrap)]
-#[stable(feature = "rust1", since = "1.0.0")]
-#[doc(no_inline)]
-pub use crate::cmp::{PartialEq, PartialOrd, Eq, Ord};
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)]
 pub use crate::convert::{AsRef, AsMut, Into, From};
-#[cfg(bootstrap)]
-#[stable(feature = "rust1", since = "1.0.0")]
-#[doc(no_inline)]
-pub use crate::default::Default;
 #[stable(feature = "rust1", since = "1.0.0")]
 #[doc(no_inline)]
 pub use crate::iter::{Iterator, Extend, IntoIterator};
@@ -53,7 +37,6 @@ pub use crate::option::Option::{self, Some, None};
 pub use crate::result::Result::{self, Ok, Err};
 
 // Re-exported built-in macros
-#[cfg(not(bootstrap))]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[doc(no_inline)]
 pub use core::prelude::v1::{
@@ -83,7 +66,6 @@ pub use core::prelude::v1::{
 
 // FIXME: Attribute and derive macros are not documented because for them rustdoc generates
 // dead links which fail link checker testing.
-#[cfg(not(bootstrap))]
 #[stable(feature = "builtin_macro_prelude", since = "1.38.0")]
 #[allow(deprecated)]
 #[doc(hidden)]
diff --git a/src/libstd/sync/mod.rs b/src/libstd/sync/mod.rs
index e29faf18d83e5..fd6e46fd61dc5 100644
--- a/src/libstd/sync/mod.rs
+++ b/src/libstd/sync/mod.rs
@@ -163,7 +163,6 @@ pub use self::condvar::{Condvar, WaitTimeoutResult};
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use self::mutex::{Mutex, MutexGuard};
 #[stable(feature = "rust1", since = "1.0.0")]
-#[cfg_attr(bootstrap, allow(deprecated_in_future))]
 #[allow(deprecated)]
 pub use self::once::{Once, OnceState, ONCE_INIT};
 #[stable(feature = "rust1", since = "1.0.0")]
diff --git a/src/libstd/sys/cloudabi/mod.rs b/src/libstd/sys/cloudabi/mod.rs
index 6e147612eb4b7..518aef4ed5e81 100644
--- a/src/libstd/sys/cloudabi/mod.rs
+++ b/src/libstd/sys/cloudabi/mod.rs
@@ -1,4 +1,4 @@
-#![allow(deprecated_in_future)] // mem::uninitialized; becomes `deprecated` when nightly is 1.39
+#![allow(deprecated)] // mem::uninitialized
 
 use crate::io::ErrorKind;
 use crate::mem;
diff --git a/src/libunwind/build.rs b/src/libunwind/build.rs
index da31a49ddf21f..c1b0dbc0881d3 100644
--- a/src/libunwind/build.rs
+++ b/src/libunwind/build.rs
@@ -4,13 +4,11 @@ fn main() {
     println!("cargo:rerun-if-changed=build.rs");
     let target = env::var("TARGET").expect("TARGET was not set");
 
-    // FIXME: the not(bootstrap) part is needed because of the issue addressed by #62286,
-    // and could be removed once that change is in beta.
-    if cfg!(all(not(bootstrap), feature = "llvm-libunwind")) &&
+    if cfg!(feature = "llvm-libunwind") &&
         (target.contains("linux") ||
          target.contains("fuchsia")) {
         // Build the unwinding from libunwind C/C++ source code.
-        #[cfg(all(not(bootstrap), feature = "llvm-libunwind"))]
+        #[cfg(feature = "llvm-libunwind")]
         llvm_libunwind::compile();
     } else if target.contains("linux") {
         if target.contains("musl") {
@@ -46,7 +44,7 @@ fn main() {
     }
 }
 
-#[cfg(all(not(bootstrap), feature = "llvm-libunwind"))]
+#[cfg(feature = "llvm-libunwind")]
 mod llvm_libunwind {
     use std::env;
     use std::path::Path;
diff --git a/src/libunwind/libunwind.rs b/src/libunwind/libunwind.rs
index aacbfc547d472..7c9eaa51fd94e 100644
--- a/src/libunwind/libunwind.rs
+++ b/src/libunwind/libunwind.rs
@@ -70,7 +70,7 @@ pub enum _Unwind_Context {}
 
 pub type _Unwind_Exception_Cleanup_Fn = extern "C" fn(unwind_code: _Unwind_Reason_Code,
                                                       exception: *mut _Unwind_Exception);
-#[cfg_attr(all(not(bootstrap), feature = "llvm-libunwind",
+#[cfg_attr(all(feature = "llvm-libunwind",
                any(target_os = "fuchsia", target_os = "linux")),
            link(name = "unwind", kind = "static"))]
 extern "C" {
@@ -97,7 +97,7 @@ if #[cfg(all(any(target_os = "ios", target_os = "netbsd", not(target_arch = "arm
     }
     pub use _Unwind_Action::*;
 
-    #[cfg_attr(all(not(bootstrap), feature = "llvm-libunwind",
+    #[cfg_attr(all(feature = "llvm-libunwind",
                    any(target_os = "fuchsia", target_os = "linux")),
                link(name = "unwind", kind = "static"))]
     extern "C" {
@@ -153,7 +153,7 @@ if #[cfg(all(any(target_os = "ios", target_os = "netbsd", not(target_arch = "arm
     pub const UNWIND_POINTER_REG: c_int = 12;
     pub const UNWIND_IP_REG: c_int = 15;
 
-    #[cfg_attr(all(not(bootstrap), feature = "llvm-libunwind",
+    #[cfg_attr(all(feature = "llvm-libunwind",
                    any(target_os = "fuchsia", target_os = "linux")),
                link(name = "unwind", kind = "static"))]
     extern "C" {
@@ -218,7 +218,7 @@ if #[cfg(all(any(target_os = "ios", target_os = "netbsd", not(target_arch = "arm
 cfg_if::cfg_if! {
 if #[cfg(not(all(target_os = "ios", target_arch = "arm")))] {
     // Not 32-bit iOS
-    #[cfg_attr(all(not(bootstrap), feature = "llvm-libunwind",
+    #[cfg_attr(all(feature = "llvm-libunwind",
                    any(target_os = "fuchsia", target_os = "linux")),
                link(name = "unwind", kind = "static"))]
     extern "C" {
@@ -230,7 +230,7 @@ if #[cfg(not(all(target_os = "ios", target_arch = "arm")))] {
     }
 } else {
     // 32-bit iOS uses SjLj and does not provide _Unwind_Backtrace()
-    #[cfg_attr(all(not(bootstrap), feature = "llvm-libunwind",
+    #[cfg_attr(all(feature = "llvm-libunwind",
                    any(target_os = "fuchsia", target_os = "linux")),
                link(name = "unwind", kind = "static"))]
     extern "C" {
diff --git a/src/stage0.txt b/src/stage0.txt
index 14d65bef8f6dd..1a9e64a1862c9 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: 2019-07-04
+date: 2019-08-13
 rustc: beta
 cargo: beta
 
@@ -25,7 +25,7 @@ cargo: beta
 #
 # This means that there's a small window of time (a few days) where artifacts
 # are downloaded from dev-static.rust-lang.org instead of static.rust-lang.org.
-# In order to ease this transition we have an extra key which is in the 
+# In order to ease this transition we have an extra key which is in the
 # configuration file below. When uncommented this will instruct the bootstrap.py
 # script to download from dev-static.rust-lang.org.
 #
diff --git a/src/test/ui/lint/lint-qualification.rs b/src/test/ui/lint/lint-qualification.rs
index 1b24191a111c2..0cace0ca0355a 100644
--- a/src/test/ui/lint/lint-qualification.rs
+++ b/src/test/ui/lint/lint-qualification.rs
@@ -1,5 +1,5 @@
 #![deny(unused_qualifications)]
-#[allow(deprecated)]
+#![allow(deprecated)]
 
 mod foo {
     pub fn bar() {}