---

yaml
---
r: 54159
b: refs/heads/dist-snap
c: 113fbfc
h: refs/heads/master
i:
  54157: 4c9a03b
  54155: 45dd069
  54151: 4456694
  54143: 9aa2c6b
v: v3

Author: brson

[refs]

@@ -7,7 +7,7 @@ refs/tags/release-0.1: 1f5c5126e96c79d22cb7862f75304136e204f105
 refs/heads/ndm: f3868061cd7988080c30d6d5bf352a5a5fe2460b
 refs/heads/try2: 147ecfdd8221e4a4d4e090486829a06da1e0ca3c
 refs/heads/incoming: 44d4d6de762f3f9aae1fedcf454c66b79b3ad58d
-refs/heads/dist-snap: d96bbb907edf803dc2917b3e69d387f5b6657100
+refs/heads/dist-snap: 113fbfc795951a10f6c0b08563944bfb6a965956
 refs/tags/release-0.2: c870d2dffb391e14efb05aa27898f1f6333a9596
 refs/tags/release-0.3: b5f0d0f648d9a6153664837026ba1be43d3e2503
 refs/heads/try3: 9387340aab40a73e8424c48fd42f0c521a4875c0

branches/dist-snap/src/libcore/core.rc

@@ -10,27 +10,39 @@
 
 /*!
 
-The Rust core library
+# The Rust core library
 
 The Rust core library provides runtime features required by the language,
 including the task scheduler and memory allocators, as well as library
 support for Rust built-in types, platform abstractions, and other commonly
 used features.
 
 `core` includes modules corresponding to each of the integer types, each of
-the floating point types, the `bool` type, tuples, characters, strings,
-vectors (`vec`), managed boxes (`managed`), owned boxes (`owned`), and unsafe
-and borrowed pointers (`ptr`).  Additionally, `core` provides task management
-and creation (`task`), communication primitives (`comm` and `pipes`), platform
-abstractions (`os` and `path`), basic I/O abstractions (`io`), common traits
-(`cmp`, `num`, `to_str`), and complete bindings to the C standard library
-(`libc`).
+the floating point types, the `bool` type, tuples, characters, strings
+(`str`), vectors (`vec`), managed boxes (`managed`), owned boxes (`owned`),
+and unsafe and borrowed pointers (`ptr`).  Additionally, `core` provides
+pervasive types (`option` and `result`), task creation and communication
+primitives (`task`, `comm`), platform abstractions (`os` and `path`), basic
+I/O abstractions (`io`), common traits (`kinds`, `ops`, `cmp`, `num`,
+`to_str`), and complete bindings to the C standard library (`libc`).
 
-`core` is linked to all crates by default and its contents imported.
-Implicitly, all crates behave as if they included the following prologue:
+# Core injection and the Rust prelude
+
+`core` is imported at the topmost level of every crate by default, as
+if the first line of each crate was
 
     extern mod core;
-    use core::*;
+
+This means that the contents of core can be accessed from from any context
+with the `core::` path prefix, as in `use core::vec`, `use core::task::spawn`,
+etc.
+
+Additionally, `core` contains a `prelude` module that reexports many of the
+most common core modules, types and traits. The contents of the prelude are
+imported inte every *module* by default.  Implicitly, all modules behave as if
+they contained the following prologue:
+
+    use core::prelude::*;
 
 */
 

branches/dist-snap/src/libcore/prelude.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// This file is imported into every module by default.
+//! The Rust prelude. Imported into every module by default.
 
 /* Reexported core operators */
 

branches/dist-snap/src/libcore/unstable/lang.rs

@@ -99,12 +99,8 @@ pub unsafe fn borrow_as_imm(a: *u8) {
 #[lang="return_to_mut"]
 #[inline(always)]
 pub unsafe fn return_to_mut(a: *u8) {
-    // Sometimes the box is null, if it is conditionally frozen.
-    // See e.g. #4904.
-    if !a.is_null() {
-        let a: *mut BoxRepr = transmute(a);
-        (*a).header.ref_count &= !FROZEN_BIT;
-    }
+    let a: *mut BoxRepr = transmute(a);
+    (*a).header.ref_count &= !FROZEN_BIT;
 }
 
 #[lang="check_not_borrowed"]

branches/dist-snap/src/librustc/middle/typeck/check/regionck.rs

@@ -615,7 +615,7 @@ pub mod guarantor {
         // expressions, both of which always yield a region variable, so
         // mk_subr should never fail.
         let rptr_ty = rcx.resolve_node_type(id);
-        if !ty::type_is_error(rptr_ty) && !ty::type_is_bot(rptr_ty) {
+        if !ty::type_is_error(rptr_ty) {
             let tcx = rcx.fcx.ccx.tcx;
             debug!("rptr_ty=%s", ty_to_str(tcx, rptr_ty));
             let r = ty::ty_region(tcx, span, rptr_ty);