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.

4 files changed, 3 insertions, 91 deletions

diff --git a/src/libstd/alloc.rs b/src/libstd/alloc.rs
index a8578404467..78d3d6d5e60 100644
--- a/src/libstd/alloc.rs
+++ b/src/libstd/alloc.rs
@@ -17,7 +17,6 @@
 #[doc(inline)] pub use alloc_system::System;
 #[doc(inline)] pub use core::alloc::*;
 
-#[cfg(not(stage0))]
 #[cfg(not(test))]
 #[doc(hidden)]
 #[lang = "oom"]
@@ -43,13 +42,6 @@ pub mod __default_lib_allocator {
         System.alloc(layout) as *mut u8
     }
 
-    #[cfg(stage0)]
-    #[no_mangle]
-    #[rustc_std_internal_symbol]
-    pub unsafe extern fn __rdl_oom() -> ! {
-        super::oom()
-    }
-
     #[no_mangle]
     #[rustc_std_internal_symbol]
     pub unsafe extern fn __rdl_dealloc(ptr: *mut u8,
@@ -74,57 +66,4 @@ pub mod __default_lib_allocator {
         let layout = Layout::from_size_align_unchecked(size, align);
         System.alloc_zeroed(layout) as *mut u8
     }
-
-    #[cfg(stage0)]
-    pub mod stage0 {
-        #[no_mangle]
-        #[rustc_std_internal_symbol]
-        pub unsafe extern fn __rdl_usable_size(_layout: *const u8,
-                                               _min: *mut usize,
-                                               _max: *mut usize) {
-            unimplemented!()
-        }
-
-        #[no_mangle]
-        #[rustc_std_internal_symbol]
-        pub unsafe extern fn __rdl_alloc_excess(_size: usize,
-                                                _align: usize,
-                                                _excess: *mut usize,
-                                                _err: *mut u8) -> *mut u8 {
-            unimplemented!()
-        }
-
-        #[no_mangle]
-        #[rustc_std_internal_symbol]
-        pub unsafe extern fn __rdl_realloc_excess(_ptr: *mut u8,
-                                                  _old_size: usize,
-                                                  _old_align: usize,
-                                                  _new_size: usize,
-                                                  _new_align: usize,
-                                                  _excess: *mut usize,
-                                                  _err: *mut u8) -> *mut u8 {
-            unimplemented!()
-        }
-
-        #[no_mangle]
-        #[rustc_std_internal_symbol]
-        pub unsafe extern fn __rdl_grow_in_place(_ptr: *mut u8,
-                                                 _old_size: usize,
-                                                 _old_align: usize,
-                                                 _new_size: usize,
-                                                 _new_align: usize) -> u8 {
-            unimplemented!()
-        }
-
-        #[no_mangle]
-        #[rustc_std_internal_symbol]
-        pub unsafe extern fn __rdl_shrink_in_place(_ptr: *mut u8,
-                                                   _old_size: usize,
-                                                   _old_align: usize,
-                                                   _new_size: usize,
-                                                   _new_align: usize) -> u8 {
-            unimplemented!()
-        }
-
-    }
 }
diff --git a/src/libstd/f32.rs b/src/libstd/f32.rs
index 7314d32b020..ae30321f46d 100644
--- a/src/libstd/f32.rs
+++ b/src/libstd/f32.rs
@@ -19,14 +19,8 @@
 #![allow(missing_docs)]
 
 #[cfg(not(test))]
-#[cfg(stage0)]
-use core::num::Float;
-#[cfg(not(test))]
 use intrinsics;
 #[cfg(not(test))]
-#[cfg(stage0)]
-use num::FpCategory;
-#[cfg(not(test))]
 use sys::cmath;
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -41,12 +35,8 @@ pub use core::f32::{MIN, MIN_POSITIVE, MAX};
 pub use core::f32::consts;
 
 #[cfg(not(test))]
-#[cfg_attr(stage0, lang = "f32")]
-#[cfg_attr(not(stage0), lang = "f32_runtime")]
+#[lang = "f32_runtime"]
 impl f32 {
-    #[cfg(stage0)]
-    f32_core_methods!();
-
     /// Returns the largest integer less than or equal to a number.
     ///
     /// # Examples
diff --git a/src/libstd/f64.rs b/src/libstd/f64.rs
index 75edba8979f..7950d434b77 100644
--- a/src/libstd/f64.rs
+++ b/src/libstd/f64.rs
@@ -19,14 +19,8 @@
 #![allow(missing_docs)]
 
 #[cfg(not(test))]
-#[cfg(stage0)]
-use core::num::Float;
-#[cfg(not(test))]
 use intrinsics;
 #[cfg(not(test))]
-#[cfg(stage0)]
-use num::FpCategory;
-#[cfg(not(test))]
 use sys::cmath;
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -41,12 +35,8 @@ pub use core::f64::{MIN, MIN_POSITIVE, MAX};
 pub use core::f64::consts;
 
 #[cfg(not(test))]
-#[cfg_attr(stage0, lang = "f64")]
-#[cfg_attr(not(stage0), lang = "f64_runtime")]
+#[lang = "f64_runtime"]
 impl f64 {
-    #[cfg(stage0)]
-    f64_core_methods!();
-
     /// Returns the largest integer less than or equal to a number.
     ///
     /// # Examples
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 9cdc6a21622..f7d06852f27 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -252,7 +252,6 @@
 #![feature(collections_range)]
 #![feature(compiler_builtins_lib)]
 #![feature(const_fn)]
-#![cfg_attr(stage0, feature(core_float))]
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
 #![feature(exact_size_is_empty)]
@@ -260,10 +259,8 @@
 #![feature(fs_read_write)]
 #![feature(fixed_size_array)]
 #![feature(float_from_str_radix)]
-#![cfg_attr(stage0, feature(float_internals))]
 #![feature(fn_traits)]
 #![feature(fnbox)]
-#![cfg_attr(stage0, feature(generic_param_attrs))]
 #![feature(hashmap_internals)]
 #![feature(heap_api)]
 #![feature(int_error_internals)]
@@ -319,6 +316,7 @@
 #![cfg_attr(test, feature(update_panic_count))]
 #![cfg_attr(windows, feature(used))]
 #![feature(doc_alias)]
+#![feature(float_internals)]
 
 #![default_lib_allocator]
 
@@ -364,11 +362,6 @@ extern crate libc;
 #[allow(unused_extern_crates)]
 extern crate unwind;
 
-// compiler-rt intrinsics
-#[doc(masked)]
-#[cfg(stage0)]
-extern crate compiler_builtins;
-
 // During testing, this crate is not actually the "real" std library, but rather
 // it links to the real std library, which was compiled from this same source
 // code. So any lang items std defines are conditionally excluded (or else they