Auto merge of #50629 - Mark-Simulacrum:stage-step, r=alexcrichton

Switch to bootstrapping from 1.27

It's possible the Float trait could be removed from core, but I couldn't tell whether it was intended to be removed or not. @SimonSapin may be able to comment more here; we can presumably also do that in a follow up PR as this one is already quite large.

6 files changed, 6 insertions, 76 deletions

diff --git a/src/liballoc/Cargo.toml b/src/liballoc/Cargo.toml
index 6383bd1e941..ada21e04b30 100644
--- a/src/liballoc/Cargo.toml
+++ b/src/liballoc/Cargo.toml
@@ -2,6 +2,8 @@
 authors = ["The Rust Project Developers"]
 name = "alloc"
 version = "0.0.0"
+autotests = false
+autobenches = false
 
 [lib]
 name = "alloc"
diff --git a/src/liballoc/alloc.rs b/src/liballoc/alloc.rs
index 09d16b26520..79607b06f94 100644
--- a/src/liballoc/alloc.rs
+++ b/src/liballoc/alloc.rs
@@ -22,28 +22,6 @@ use core::usize;
 #[doc(inline)]
 pub use core::alloc::*;
 
-#[cfg(stage0)]
-extern "Rust" {
-    #[allocator]
-    #[rustc_allocator_nounwind]
-    fn __rust_alloc(size: usize, align: usize, err: *mut u8) -> *mut u8;
-    #[cold]
-    #[rustc_allocator_nounwind]
-    fn __rust_oom(err: *const u8) -> !;
-    #[rustc_allocator_nounwind]
-    fn __rust_dealloc(ptr: *mut u8, size: usize, align: usize);
-    #[rustc_allocator_nounwind]
-    fn __rust_realloc(ptr: *mut u8,
-                      old_size: usize,
-                      old_align: usize,
-                      new_size: usize,
-                      new_align: usize,
-                      err: *mut u8) -> *mut u8;
-    #[rustc_allocator_nounwind]
-    fn __rust_alloc_zeroed(size: usize, align: usize, err: *mut u8) -> *mut u8;
-}
-
-#[cfg(not(stage0))]
 extern "Rust" {
     #[allocator]
     #[rustc_allocator_nounwind]
@@ -74,10 +52,7 @@ pub const Heap: Global = Global;
 unsafe impl GlobalAlloc for Global {
     #[inline]
     unsafe fn alloc(&self, layout: Layout) -> *mut Opaque {
-        #[cfg(not(stage0))]
         let ptr = __rust_alloc(layout.size(), layout.align());
-        #[cfg(stage0)]
-        let ptr = __rust_alloc(layout.size(), layout.align(), &mut 0);
         ptr as *mut Opaque
     }
 
@@ -88,20 +63,13 @@ unsafe impl GlobalAlloc for Global {
 
     #[inline]
     unsafe fn realloc(&self, ptr: *mut Opaque, layout: Layout, new_size: usize) -> *mut Opaque {
-        #[cfg(not(stage0))]
         let ptr = __rust_realloc(ptr as *mut u8, layout.size(), layout.align(), new_size);
-        #[cfg(stage0)]
-        let ptr = __rust_realloc(ptr as *mut u8, layout.size(), layout.align(),
-                                 new_size, layout.align(), &mut 0);
         ptr as *mut Opaque
     }
 
     #[inline]
     unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut Opaque {
-        #[cfg(not(stage0))]
         let ptr = __rust_alloc_zeroed(layout.size(), layout.align());
-        #[cfg(stage0)]
-        let ptr = __rust_alloc_zeroed(layout.size(), layout.align(), &mut 0);
         ptr as *mut Opaque
     }
 }
@@ -152,14 +120,7 @@ unsafe fn exchange_malloc(size: usize, align: usize) -> *mut u8 {
     }
 }
 
-#[cfg(stage0)]
-#[lang = "box_free"]
-#[inline]
-unsafe fn old_box_free<T: ?Sized>(ptr: *mut T) {
-    box_free(Unique::new_unchecked(ptr))
-}
-
-#[cfg_attr(not(any(test, stage0)), lang = "box_free")]
+#[cfg_attr(not(test), lang = "box_free")]
 #[inline]
 pub(crate) unsafe fn box_free<T: ?Sized>(ptr: Unique<T>) {
     let ptr = ptr.as_ptr();
@@ -172,12 +133,6 @@ pub(crate) unsafe fn box_free<T: ?Sized>(ptr: Unique<T>) {
     }
 }
 
-#[cfg(stage0)]
-pub fn oom() -> ! {
-    unsafe { ::core::intrinsics::abort() }
-}
-
-#[cfg(not(stage0))]
 pub fn oom() -> ! {
     extern {
         #[lang = "oom"]
diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index f7dd9d4f010..91de3ad0c39 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -75,7 +75,6 @@
 #![deny(missing_debug_implementations)]
 
 #![cfg_attr(test, allow(deprecated))] // rand
-#![cfg_attr(all(not(test), stage0), feature(float_internals))]
 #![cfg_attr(not(test), feature(exact_size_is_empty))]
 #![cfg_attr(not(test), feature(generator_trait))]
 #![cfg_attr(test, feature(rand, test))]
@@ -90,13 +89,10 @@
 #![feature(collections_range)]
 #![feature(const_fn)]
 #![feature(core_intrinsics)]
-#![cfg_attr(stage0, feature(core_slice_ext))]
-#![cfg_attr(stage0, feature(core_str_ext))]
 #![feature(custom_attribute)]
 #![feature(dropck_eyepatch)]
 #![feature(exact_size_is_empty)]
 #![feature(fmt_internals)]
-#![cfg_attr(stage0, feature(fn_must_use))]
 #![feature(from_ref)]
 #![feature(fundamental)]
 #![feature(lang_items)]
@@ -122,7 +118,6 @@
 #![feature(exact_chunks)]
 #![feature(pointer_methods)]
 #![feature(inclusive_range_methods)]
-#![cfg_attr(stage0, feature(generic_param_attrs))]
 #![feature(rustc_const_unstable)]
 #![feature(const_vec_new)]
 
@@ -157,15 +152,10 @@ pub mod alloc;
 #[unstable(feature = "allocator_api", issue = "32838")]
 #[rustc_deprecated(since = "1.27.0", reason = "module renamed to `alloc`")]
 /// Use the `alloc` module instead.
-#[cfg(not(stage0))]
 pub mod heap {
     pub use alloc::*;
 }
 
-#[unstable(feature = "allocator_api", issue = "32838")]
-#[rustc_deprecated(since = "1.27.0", reason = "module renamed to `alloc`")]
-#[cfg(stage0)]
-pub mod heap;
 
 // Primitive types using the heaps above
 
diff --git a/src/liballoc/slice.rs b/src/liballoc/slice.rs
index 6caf12aa7eb..4427ac004f9 100644
--- a/src/liballoc/slice.rs
+++ b/src/liballoc/slice.rs
@@ -101,7 +101,6 @@ use core::cmp::Ordering::{self, Less};
 use core::mem::size_of;
 use core::mem;
 use core::ptr;
-#[cfg(stage0)] use core::slice::SliceExt;
 use core::{u8, u16, u32};
 
 use borrow::{Borrow, BorrowMut, ToOwned};
@@ -171,13 +170,9 @@ mod hack {
     }
 }
 
-#[cfg_attr(stage0, lang = "slice")]
-#[cfg_attr(not(stage0), lang = "slice_alloc")]
+#[lang = "slice_alloc"]
 #[cfg(not(test))]
 impl<T> [T] {
-    #[cfg(stage0)]
-    slice_core_methods!();
-
     /// Sorts the slice.
     ///
     /// This sort is stable (i.e. does not reorder equal elements) and `O(n log n)` worst-case.
@@ -467,8 +462,7 @@ impl<T> [T] {
     }
 }
 
-#[cfg_attr(stage0, lang = "slice_u8")]
-#[cfg_attr(not(stage0), lang = "slice_u8_alloc")]
+#[lang = "slice_u8_alloc"]
 #[cfg(not(test))]
 impl [u8] {
     /// Returns a vector containing a copy of this slice where each byte
@@ -504,9 +498,6 @@ impl [u8] {
         me.make_ascii_lowercase();
         me
     }
-
-    #[cfg(stage0)]
-    slice_u8_core_methods!();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/src/liballoc/str.rs b/src/liballoc/str.rs
index 42efdea74b1..c10c0a69433 100644
--- a/src/liballoc/str.rs
+++ b/src/liballoc/str.rs
@@ -40,7 +40,6 @@
 
 use core::fmt;
 use core::str as core_str;
-#[cfg(stage0)] use core::str::StrExt;
 use core::str::pattern::Pattern;
 use core::str::pattern::{Searcher, ReverseSearcher, DoubleEndedSearcher};
 use core::mem;
@@ -158,13 +157,9 @@ impl ToOwned for str {
 }
 
 /// Methods for string slices.
-#[cfg_attr(stage0, lang = "str")]
-#[cfg_attr(not(stage0), lang = "str_alloc")]
+#[lang = "str_alloc"]
 #[cfg(not(test))]
 impl str {
-    #[cfg(stage0)]
-    str_core_methods!();
-
     /// Converts a `Box<str>` into a `Box<[u8]>` without copying or allocating.
     ///
     /// # Examples
diff --git a/src/liballoc/vec.rs b/src/liballoc/vec.rs
index d30f8cd0fca..bf89b377b7e 100644
--- a/src/liballoc/vec.rs
+++ b/src/liballoc/vec.rs
@@ -73,9 +73,6 @@ use core::intrinsics::{arith_offset, assume};
 use core::iter::{FromIterator, FusedIterator, TrustedLen};
 use core::marker::PhantomData;
 use core::mem;
-#[cfg(not(test))]
-#[cfg(stage0)]
-use core::num::Float;
 use core::ops::Bound::{Excluded, Included, Unbounded};
 use core::ops::{Index, IndexMut, RangeBounds};
 use core::ops;