rustc: Implement the #[global_allocator] attribute

This PR is an implementation of [RFC 1974] which specifies a new method of
defining a global allocator for a program. This obsoletes the old
`#![allocator]` attribute and also removes support for it.

[RFC 1974]: https://github.com/rust-lang/rfcs/pull/197

The new `#[global_allocator]` attribute solves many issues encountered with the
`#![allocator]` attribute such as composition and restrictions on the crate
graph itself. The compiler now has much more control over the ABI of the
allocator and how it's implemented, allowing much more freedom in terms of how
this feature is implemented.

cc #27389

1 files changed, 0 insertions, 61 deletions

diff --git a/src/liballoc/oom.rs b/src/liballoc/oom.rs
deleted file mode 100644
index 3640156fec2..00000000000
--- a/src/liballoc/oom.rs
+++ /dev/null
@@ -1,61 +0,0 @@
-// Copyright 2014-2015 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
-// option. This file may not be copied, modified, or distributed
-// except according to those terms.
-
-#[cfg(target_has_atomic = "ptr")]
-pub use self::imp::set_oom_handler;
-use core::intrinsics;
-
-fn default_oom_handler() -> ! {
-    // The default handler can't do much more since we can't assume the presence
-    // of libc or any way of printing an error message.
-    unsafe { intrinsics::abort() }
-}
-
-/// Common out-of-memory routine
-#[cold]
-#[inline(never)]
-#[unstable(feature = "oom", reason = "not a scrutinized interface",
-           issue = "27700")]
-pub fn oom() -> ! {
-    self::imp::oom()
-}
-
-#[cfg(target_has_atomic = "ptr")]
-mod imp {
-    use core::mem;
-    use core::sync::atomic::{AtomicPtr, Ordering};
-
-    static OOM_HANDLER: AtomicPtr<()> = AtomicPtr::new(super::default_oom_handler as *mut ());
-
-    #[inline(always)]
-    pub fn oom() -> ! {
-        let value = OOM_HANDLER.load(Ordering::SeqCst);
-        let handler: fn() -> ! = unsafe { mem::transmute(value) };
-        handler();
-    }
-
-    /// Set a custom handler for out-of-memory conditions
-    ///
-    /// To avoid recursive OOM failures, it is critical that the OOM handler does
-    /// not allocate any memory itself.
-    #[unstable(feature = "oom", reason = "not a scrutinized interface",
-               issue = "27700")]
-    pub fn set_oom_handler(handler: fn() -> !) {
-        OOM_HANDLER.store(handler as *mut (), Ordering::SeqCst);
-    }
-}
-
-#[cfg(not(target_has_atomic = "ptr"))]
-mod imp {
-    #[inline(always)]
-    pub fn oom() -> ! {
-        super::default_oom_handler()
-    }
-}