From e56fa2471a6668261dd3b0428ebfb5babe851230 Mon Sep 17 00:00:00 2001
From: est31 <MTest31@outlook.com>
Date: Tue, 8 Aug 2017 11:24:30 +0200
Subject: [PATCH 01/15] Avoid calling the column!() macro in panic

---
 src/libcore/macros.rs            | 14 ++++++++++++--
 src/libstd/macros.rs             | 16 ++++++++++++++--
 src/libsyntax_ext/lib.rs         |  1 +
 src/test/run-pass/issue-43057.rs | 23 +++++++++++++++++++++++
 4 files changed, 50 insertions(+), 4 deletions(-)
 create mode 100644 src/test/run-pass/issue-43057.rs

diff --git a/src/libcore/macros.rs b/src/libcore/macros.rs
index ae74016ad7449..b09e6ea3328b8 100644
--- a/src/libcore/macros.rs
+++ b/src/libcore/macros.rs
@@ -8,6 +8,16 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[macro_export]
+// This stability attribute is totally useless.
+#[stable(feature = "rust1", since = "1.0.0")]
+#[cfg(stage0)]
+macro_rules! __rust_unstable_column {
+    () => {
+        column!()
+    }
+}
+
 /// Entry point of thread panic, for details, see std::macros
 #[macro_export]
 #[allow_internal_unstable]
@@ -18,7 +28,7 @@ macro_rules! panic {
     );
     ($msg:expr) => ({
         static _MSG_FILE_LINE_COL: (&'static str, &'static str, u32, u32) =
-            ($msg, file!(), line!(), column!());
+            ($msg, file!(), line!(), __rust_unstable_column!());
         $crate::panicking::panic(&_MSG_FILE_LINE_COL)
     });
     ($fmt:expr, $($arg:tt)*) => ({
@@ -27,7 +37,7 @@ macro_rules! panic {
         // insufficient, since the user may have
         // `#[forbid(dead_code)]` and which cannot be overridden.
         static _MSG_FILE_LINE_COL: (&'static str, u32, u32) =
-            (file!(), line!(), column!());
+            (file!(), line!(), __rust_unstable_column!());
         $crate::panicking::panic_fmt(format_args!($fmt, $($arg)*), &_MSG_FILE_LINE_COL)
     });
 }
diff --git a/src/libstd/macros.rs b/src/libstd/macros.rs
index 6ad22820a7d90..43c4ba48b1bcc 100644
--- a/src/libstd/macros.rs
+++ b/src/libstd/macros.rs
@@ -14,6 +14,16 @@
 //! library. Each macro is available for use when linking against the standard
 //! library.
 
+#[macro_export]
+// This stability attribute is totally useless.
+#[stable(feature = "rust1", since = "1.0.0")]
+#[cfg(stage0)]
+macro_rules! __rust_unstable_column {
+    () => {
+        column!()
+    }
+}
+
 /// The entry point for panic of Rust threads.
 ///
 /// This macro is used to inject panic into a Rust thread, causing the thread to
@@ -48,7 +58,8 @@ macro_rules! panic {
     ($msg:expr) => ({
         $crate::rt::begin_panic_new($msg, {
             // static requires less code at runtime, more constant data
-            static _FILE_LINE_COL: (&'static str, u32, u32) = (file!(), line!(), column!());
+            static _FILE_LINE_COL: (&'static str, u32, u32) = (file!(), line!(),
+                __rust_unstable_column!());
             &_FILE_LINE_COL
         })
     });
@@ -58,7 +69,8 @@ macro_rules! panic {
             // used inside a dead function. Just `#[allow(dead_code)]` is
             // insufficient, since the user may have
             // `#[forbid(dead_code)]` and which cannot be overridden.
-            static _FILE_LINE_COL: (&'static str, u32, u32) = (file!(), line!(), column!());
+            static _FILE_LINE_COL: (&'static str, u32, u32) = (file!(), line!(),
+                __rust_unstable_column!());
             &_FILE_LINE_COL
         })
     });
diff --git a/src/libsyntax_ext/lib.rs b/src/libsyntax_ext/lib.rs
index 8ba07c35b0543..558d2e90310fb 100644
--- a/src/libsyntax_ext/lib.rs
+++ b/src/libsyntax_ext/lib.rs
@@ -89,6 +89,7 @@ pub fn register_builtins(resolver: &mut syntax::ext::base::Resolver,
     use syntax::ext::source_util::*;
     register! {
         line: expand_line,
+        __rust_unstable_column: expand_column,
         column: expand_column,
         file: expand_file,
         stringify: expand_stringify,
diff --git a/src/test/run-pass/issue-43057.rs b/src/test/run-pass/issue-43057.rs
new file mode 100644
index 0000000000000..152ddfb193fc5
--- /dev/null
+++ b/src/test/run-pass/issue-43057.rs
@@ -0,0 +1,23 @@
+// Copyright 2017 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.
+
+#![allow(unused)]
+
+macro_rules! column {
+    ($i:ident) => {
+        $i
+    };
+}
+
+fn foo() -> ! {
+    panic!();
+}
+
+fn main() {}

From c51b709ae6ca2c009f3c59d2e3b677b6174cffe7 Mon Sep 17 00:00:00 2001
From: est31 <MTest31@outlook.com>
Date: Thu, 10 Aug 2017 01:42:36 +0200
Subject: [PATCH 02/15] Add a feature gate

@alexcrichton figured out a way how to do it :)
---
 src/libsyntax/ext/source_util.rs                   | 10 ++++++++++
 src/libsyntax_ext/lib.rs                           |  2 +-
 .../compile-fail/rust-unstable-column-gated.rs     | 14 ++++++++++++++
 3 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 src/test/compile-fail/rust-unstable-column-gated.rs

diff --git a/src/libsyntax/ext/source_util.rs b/src/libsyntax/ext/source_util.rs
index 3cdd3a4b2c31d..b293aa8de38b2 100644
--- a/src/libsyntax/ext/source_util.rs
+++ b/src/libsyntax/ext/source_util.rs
@@ -52,6 +52,16 @@ pub fn expand_column(cx: &mut ExtCtxt, sp: Span, tts: &[tokenstream::TokenTree])
     base::MacEager::expr(cx.expr_u32(topmost, loc.col.to_usize() as u32))
 }
 
+/* __rust_unstable_column!(): expands to the current column number */
+pub fn expand_column_gated(cx: &mut ExtCtxt, sp: Span, tts: &[tokenstream::TokenTree])
+                  -> Box<base::MacResult+'static> {
+    if sp.allows_unstable() {
+        expand_column(cx, sp, tts)
+    } else {
+        cx.span_fatal(sp, "the __rust_unstable_column macro is unstable");
+    }
+}
+
 /// file!(): expands to the current filename */
 /// The filemap (`loc.file`) contains a bunch more information we could spit
 /// out if we wanted.
diff --git a/src/libsyntax_ext/lib.rs b/src/libsyntax_ext/lib.rs
index 558d2e90310fb..5eab81dd28fc4 100644
--- a/src/libsyntax_ext/lib.rs
+++ b/src/libsyntax_ext/lib.rs
@@ -89,7 +89,7 @@ pub fn register_builtins(resolver: &mut syntax::ext::base::Resolver,
     use syntax::ext::source_util::*;
     register! {
         line: expand_line,
-        __rust_unstable_column: expand_column,
+        __rust_unstable_column: expand_column_gated,
         column: expand_column,
         file: expand_file,
         stringify: expand_stringify,
diff --git a/src/test/compile-fail/rust-unstable-column-gated.rs b/src/test/compile-fail/rust-unstable-column-gated.rs
new file mode 100644
index 0000000000000..abc92c86eec6a
--- /dev/null
+++ b/src/test/compile-fail/rust-unstable-column-gated.rs
@@ -0,0 +1,14 @@
+// Copyright 2017 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.
+
+fn main() {
+    println!("{}", __rust_unstable_column!());
+    //~^ERROR the __rust_unstable_column macro is unstable
+}

From 309ab478d31a699493fdb1593d9cb133705f51f0 Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Sat, 29 Jul 2017 21:40:37 +0300
Subject: [PATCH 03/15] save the subobligations as well

---
 src/librustc/traits/project.rs   | 18 +++++---
 src/test/run-pass/issue-43132.rs | 74 ++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 6 deletions(-)
 create mode 100644 src/test/run-pass/issue-43132.rs

diff --git a/src/librustc/traits/project.rs b/src/librustc/traits/project.rs
index b5284852747f9..9e095945624cf 100644
--- a/src/librustc/traits/project.rs
+++ b/src/librustc/traits/project.rs
@@ -462,13 +462,19 @@ fn opt_normalize_projection_type<'a, 'b, 'gcx, 'tcx>(
             selcx.infcx().report_overflow_error(&obligation, false);
         }
         Err(ProjectionCacheEntry::NormalizedTy(ty)) => {
-            // If we find the value in the cache, then the obligations
-            // have already been returned from the previous entry (and
-            // should therefore have been honored).
+            // If we find the value in the cache, then return it along
+            // with the obligations that went along with it. Note
+            // that, when using a fulfillment context, these
+            // obligations could in principle be ignored: they have
+            // already been registered when the cache entry was
+            // created (and hence the new ones will quickly be
+            // discarded as duplicated). But when doing trait
+            // evaluation this is not the case, and dropping the trait
+            // evaluations can causes ICEs (e.g. #43132).
             debug!("opt_normalize_projection_type: \
                     found normalized ty `{:?}`",
                    ty);
-            return Some(NormalizedTy { value: ty, obligations: vec![] });
+            return Some(ty);
         }
         Err(ProjectionCacheEntry::Error) => {
             debug!("opt_normalize_projection_type: \
@@ -1336,7 +1342,7 @@ enum ProjectionCacheEntry<'tcx> {
     InProgress,
     Ambiguous,
     Error,
-    NormalizedTy(Ty<'tcx>),
+    NormalizedTy(NormalizedTy<'tcx>),
 }
 
 // NB: intentionally not Clone
@@ -1389,7 +1395,7 @@ impl<'tcx> ProjectionCache<'tcx> {
         let fresh_key = if cacheable {
             debug!("ProjectionCacheEntry::complete: adding cache entry: key={:?}, value={:?}",
                    key, value);
-            self.map.insert(key, ProjectionCacheEntry::NormalizedTy(value.value))
+            self.map.insert(key, ProjectionCacheEntry::NormalizedTy(value.clone()))
         } else {
             debug!("ProjectionCacheEntry::complete: cannot cache: key={:?}, value={:?}",
                    key, value);
diff --git a/src/test/run-pass/issue-43132.rs b/src/test/run-pass/issue-43132.rs
new file mode 100644
index 0000000000000..64b3b092b8936
--- /dev/null
+++ b/src/test/run-pass/issue-43132.rs
@@ -0,0 +1,74 @@
+// Copyright 2017 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.
+
+#![allow(unused)]
+
+fn main() {
+}
+
+fn foo() {
+    let b = mk::<
+        Forward<(Box<Future<Error = u32>>,)>,
+    >();
+    b.map_err(|_| ()).join();
+}
+
+fn mk<T>() -> T {
+    loop {}
+}
+
+impl<I: Future<Error = E>, E> Future for (I,) {
+    type Error = E;
+}
+
+struct Forward<T: Future> {
+    _a: T,
+}
+
+impl<T: Future> Future for Forward<T>
+where
+    T::Error: From<u32>,
+{
+    type Error = T::Error;
+}
+
+trait Future {
+    type Error;
+
+    fn map_err<F, E>(self, _: F) -> (Self, F)
+    where
+        F: FnOnce(Self::Error) -> E,
+        Self: Sized,
+    {
+        loop {}
+    }
+
+    fn join(self) -> (MaybeDone<Self>, ())
+    where
+        Self: Sized,
+    {
+        loop {}
+    }
+}
+
+impl<S: ?Sized + Future> Future for Box<S> {
+    type Error = S::Error;
+}
+
+enum MaybeDone<A: Future> {
+    _Done(A::Error),
+}
+
+impl<U, A: Future, F> Future for (A, F)
+where
+    F: FnOnce(A::Error) -> U,
+{
+    type Error = U;
+}

From 086f9e497fae515f7149848c5ccf78dfb6fbecad Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Thu, 27 Jul 2017 14:53:44 -0700
Subject: [PATCH 04/15] std: Mark `Layout::repeat` as `#[inline]`

This fixes an optimization regression by allowing LLVM to see through more
functions.

Closes #43272
---
 src/liballoc/allocator.rs              |  1 +
 src/test/codegen/vec-optimizes-away.rs | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+)
 create mode 100644 src/test/codegen/vec-optimizes-away.rs

diff --git a/src/liballoc/allocator.rs b/src/liballoc/allocator.rs
index ca5388b470147..23a005cbaf788 100644
--- a/src/liballoc/allocator.rs
+++ b/src/liballoc/allocator.rs
@@ -207,6 +207,7 @@ impl Layout {
     /// of each element in the array.
     ///
     /// On arithmetic overflow, returns `None`.
+    #[inline]
     pub fn repeat(&self, n: usize) -> Option<(Self, usize)> {
         let padded_size = match self.size.checked_add(self.padding_needed_for(self.align)) {
             None => return None,
diff --git a/src/test/codegen/vec-optimizes-away.rs b/src/test/codegen/vec-optimizes-away.rs
new file mode 100644
index 0000000000000..261564ed51aed
--- /dev/null
+++ b/src/test/codegen/vec-optimizes-away.rs
@@ -0,0 +1,21 @@
+// Copyright 2017 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.
+//
+// no-system-llvm
+// compile-flags: -O
+#![crate_type="lib"]
+
+#[no_mangle]
+pub fn sum_me() -> i32 {
+    // CHECK-LABEL: @sum_me
+    // CHECK-NEXT: {{^.*:$}}
+    // CHECK-NEXT: ret i32 6
+    vec![1, 2, 3].iter().sum::<i32>()
+}

From 1206c808a63fa99d039657a61a1515c3a734e5b2 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Thu, 20 Jul 2017 15:38:59 -0700
Subject: [PATCH 05/15] std: Stabilize `char_escape_debug`

Stabilizes:

* `<char>::escape_debug`
* `std::char::EscapeDebug`

Closes #35068
---
 src/liballoc/lib.rs        |  1 -
 src/libcore/char.rs        | 10 +++++-----
 src/libcore/tests/lib.rs   |  1 -
 src/libstd/lib.rs          |  1 -
 src/libstd_unicode/char.rs |  5 +----
 src/libstd_unicode/lib.rs  |  1 -
 6 files changed, 6 insertions(+), 13 deletions(-)

diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index b419aeb5ab593..9dc3d5390c707 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -79,7 +79,6 @@
 
 #![cfg_attr(test, allow(deprecated))] // rand
 #![cfg_attr(test, feature(placement_in))]
-#![cfg_attr(not(test), feature(char_escape_debug))]
 #![cfg_attr(not(test), feature(core_float))]
 #![cfg_attr(not(test), feature(exact_size_is_empty))]
 #![cfg_attr(not(test), feature(slice_rotate))]
diff --git a/src/libcore/char.rs b/src/libcore/char.rs
index bb4cb0ac3b215..e8b81db07067c 100644
--- a/src/libcore/char.rs
+++ b/src/libcore/char.rs
@@ -379,7 +379,7 @@ pub trait CharExt {
     fn escape_unicode(self) -> EscapeUnicode;
     #[stable(feature = "core", since = "1.6.0")]
     fn escape_default(self) -> EscapeDefault;
-    #[unstable(feature = "char_escape_debug", issue = "35068")]
+    #[stable(feature = "char_escape_debug", since = "1.20.0")]
     fn escape_debug(self) -> EscapeDebug;
     #[stable(feature = "core", since = "1.6.0")]
     fn len_utf8(self) -> usize;
@@ -776,24 +776,24 @@ impl fmt::Display for EscapeDefault {
 ///
 /// [`escape_debug`]: ../../std/primitive.char.html#method.escape_debug
 /// [`char`]: ../../std/primitive.char.html
-#[unstable(feature = "char_escape_debug", issue = "35068")]
+#[stable(feature = "char_escape_debug", since = "1.20.0")]
 #[derive(Clone, Debug)]
 pub struct EscapeDebug(EscapeDefault);
 
-#[unstable(feature = "char_escape_debug", issue = "35068")]
+#[stable(feature = "char_escape_debug", since = "1.20.0")]
 impl Iterator for EscapeDebug {
     type Item = char;
     fn next(&mut self) -> Option<char> { self.0.next() }
     fn size_hint(&self) -> (usize, Option<usize>) { self.0.size_hint() }
 }
 
-#[unstable(feature = "char_escape_debug", issue = "35068")]
+#[stable(feature = "char_escape_debug", since = "1.20.0")]
 impl ExactSizeIterator for EscapeDebug { }
 
 #[unstable(feature = "fused", issue = "35602")]
 impl FusedIterator for EscapeDebug {}
 
-#[unstable(feature = "char_escape_debug", issue = "35068")]
+#[stable(feature = "char_escape_debug", since = "1.20.0")]
 impl fmt::Display for EscapeDebug {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         fmt::Display::fmt(&self.0, f)
diff --git a/src/libcore/tests/lib.rs b/src/libcore/tests/lib.rs
index 26e4c21dc8f4d..a85c347146b05 100644
--- a/src/libcore/tests/lib.rs
+++ b/src/libcore/tests/lib.rs
@@ -11,7 +11,6 @@
 #![deny(warnings)]
 
 #![feature(box_syntax)]
-#![feature(char_escape_debug)]
 #![feature(const_fn)]
 #![feature(core_float)]
 #![feature(core_private_bignum)]
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index a012f2f42c19c..8fe0ecfcf5397 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -249,7 +249,6 @@
 #![feature(cfg_target_has_atomic)]
 #![feature(cfg_target_thread_local)]
 #![feature(cfg_target_vendor)]
-#![feature(char_escape_debug)]
 #![feature(char_error_internals)]
 #![feature(char_internals)]
 #![feature(collections_range)]
diff --git a/src/libstd_unicode/char.rs b/src/libstd_unicode/char.rs
index d6836418b4b5c..5cf05bff8c5b1 100644
--- a/src/libstd_unicode/char.rs
+++ b/src/libstd_unicode/char.rs
@@ -326,7 +326,6 @@ impl char {
     /// As an iterator:
     ///
     /// ```
-    /// # #![feature(char_escape_debug)]
     /// for c in '\n'.escape_debug() {
     ///     print!("{}", c);
     /// }
@@ -336,7 +335,6 @@ impl char {
     /// Using `println!` directly:
     ///
     /// ```
-    /// # #![feature(char_escape_debug)]
     /// println!("{}", '\n'.escape_debug());
     /// ```
     ///
@@ -349,10 +347,9 @@ impl char {
     /// Using `to_string`:
     ///
     /// ```
-    /// # #![feature(char_escape_debug)]
     /// assert_eq!('\n'.escape_debug().to_string(), "\\n");
     /// ```
-    #[unstable(feature = "char_escape_debug", issue = "35068")]
+    #[stable(feature = "char_escape_debug", since = "1.20.0")]
     #[inline]
     pub fn escape_debug(self) -> EscapeDebug {
         C::escape_debug(self)
diff --git a/src/libstd_unicode/lib.rs b/src/libstd_unicode/lib.rs
index 98624800b4c6c..698210e83f3e3 100644
--- a/src/libstd_unicode/lib.rs
+++ b/src/libstd_unicode/lib.rs
@@ -32,7 +32,6 @@
 #![deny(warnings)]
 #![no_std]
 
-#![feature(char_escape_debug)]
 #![feature(core_char_ext)]
 #![feature(str_internals)]
 #![feature(core_intrinsics)]

From d85df50da0522c26ed7fd5c09254dc7afb4c7687 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Thu, 20 Jul 2017 15:40:23 -0700
Subject: [PATCH 06/15] std: Stabilize `option_entry` feature

Stabilized:

* `Option::get_or_insert`
* `Option::get_or_insert_with`

Closes #39288
---
 src/libcore/option.rs | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/src/libcore/option.rs b/src/libcore/option.rs
index e825acad4713e..ef41b6794105d 100644
--- a/src/libcore/option.rs
+++ b/src/libcore/option.rs
@@ -671,8 +671,6 @@ impl<T> Option<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(option_entry)]
-    ///
     /// let mut x = None;
     ///
     /// {
@@ -685,7 +683,7 @@ impl<T> Option<T> {
     /// assert_eq!(x, Some(7));
     /// ```
     #[inline]
-    #[unstable(feature = "option_entry", issue = "39288")]
+    #[stable(feature = "option_entry", since = "1.20.0")]
     pub fn get_or_insert(&mut self, v: T) -> &mut T {
         match *self {
             None => *self = Some(v),
@@ -706,8 +704,6 @@ impl<T> Option<T> {
     /// # Examples
     ///
     /// ```
-    /// #![feature(option_entry)]
-    ///
     /// let mut x = None;
     ///
     /// {
@@ -720,7 +716,7 @@ impl<T> Option<T> {
     /// assert_eq!(x, Some(7));
     /// ```
     #[inline]
-    #[unstable(feature = "option_entry", issue = "39288")]
+    #[stable(feature = "option_entry", since = "1.20.0")]
     pub fn get_or_insert_with<F: FnOnce() -> T>(&mut self, f: F) -> &mut T {
         match *self {
             None => *self = Some(f()),

From b20d248b08bef08c681fd2d7404970520c0d4fee Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Thu, 20 Jul 2017 15:42:14 -0700
Subject: [PATCH 07/15] std: Stabilize `str_checked_slicing` feature

Stabilized

* `<str>::get`
* `<str>::get_mut`
* `<str>::get_unchecked`
* `<str>::get_unchecked_mut`

Closes #39932
---
 src/liballoc/lib.rs       |  1 -
 src/liballoc/str.rs       | 12 ++++--------
 src/liballoc/tests/lib.rs |  1 -
 src/libcore/str/mod.rs    | 20 ++++++++++----------
 4 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index 9dc3d5390c707..605302ec71ee6 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -82,7 +82,6 @@
 #![cfg_attr(not(test), feature(core_float))]
 #![cfg_attr(not(test), feature(exact_size_is_empty))]
 #![cfg_attr(not(test), feature(slice_rotate))]
-#![cfg_attr(not(test), feature(str_checked_slicing))]
 #![cfg_attr(test, feature(rand, test))]
 #![cfg_attr(stage0, feature(allocator))]
 #![feature(allow_internal_unstable)]
diff --git a/src/liballoc/str.rs b/src/liballoc/str.rs
index f56288c30132c..e4953988c5c12 100644
--- a/src/liballoc/str.rs
+++ b/src/liballoc/str.rs
@@ -328,14 +328,13 @@ impl str {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(str_checked_slicing)]
     /// let v = "🗻∈🌏";
     /// assert_eq!(Some("🗻"), v.get(0..4));
     /// assert!(v.get(1..).is_none());
     /// assert!(v.get(..8).is_none());
     /// assert!(v.get(..42).is_none());
     /// ```
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     #[inline]
     pub fn get<I: SliceIndex<str>>(&self, i: I) -> Option<&I::Output> {
         core_str::StrExt::get(self, i)
@@ -351,14 +350,13 @@ impl str {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(str_checked_slicing)]
     /// let mut v = String::from("🗻∈🌏");
     /// assert_eq!(Some("🗻"), v.get_mut(0..4).map(|v| &*v));
     /// assert!(v.get_mut(1..).is_none());
     /// assert!(v.get_mut(..8).is_none());
     /// assert!(v.get_mut(..42).is_none());
     /// ```
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     #[inline]
     pub fn get_mut<I: SliceIndex<str>>(&mut self, i: I) -> Option<&mut I::Output> {
         core_str::StrExt::get_mut(self, i)
@@ -383,7 +381,6 @@ impl str {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(str_checked_slicing)]
     /// let v = "🗻∈🌏";
     /// unsafe {
     ///     assert_eq!("🗻", v.get_unchecked(0..4));
@@ -391,7 +388,7 @@ impl str {
     ///     assert_eq!("🌏", v.get_unchecked(7..11));
     /// }
     /// ```
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     #[inline]
     pub unsafe fn get_unchecked<I: SliceIndex<str>>(&self, i: I) -> &I::Output {
         core_str::StrExt::get_unchecked(self, i)
@@ -416,7 +413,6 @@ impl str {
     /// # Examples
     ///
     /// ```
-    /// # #![feature(str_checked_slicing)]
     /// let mut v = String::from("🗻∈🌏");
     /// unsafe {
     ///     assert_eq!("🗻", v.get_unchecked_mut(0..4));
@@ -424,7 +420,7 @@ impl str {
     ///     assert_eq!("🌏", v.get_unchecked_mut(7..11));
     /// }
     /// ```
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     #[inline]
     pub unsafe fn get_unchecked_mut<I: SliceIndex<str>>(&mut self, i: I) -> &mut I::Output {
         core_str::StrExt::get_unchecked_mut(self, i)
diff --git a/src/liballoc/tests/lib.rs b/src/liballoc/tests/lib.rs
index c6d70ee7575f8..75ff781113722 100644
--- a/src/liballoc/tests/lib.rs
+++ b/src/liballoc/tests/lib.rs
@@ -24,7 +24,6 @@
 #![feature(repr_align)]
 #![feature(slice_rotate)]
 #![feature(splice)]
-#![feature(str_checked_slicing)]
 #![feature(str_escape)]
 #![feature(test)]
 #![feature(unboxed_closures)]
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index 3862b4a2eb046..af95bc41731b6 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -1776,7 +1776,7 @@ mod traits {
         }
     }
 
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     impl SliceIndex<str> for ops::RangeFull {
         type Output = str;
         #[inline]
@@ -1805,7 +1805,7 @@ mod traits {
         }
     }
 
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     impl SliceIndex<str> for ops::Range<usize> {
         type Output = str;
         #[inline]
@@ -1859,7 +1859,7 @@ mod traits {
         }
     }
 
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     impl SliceIndex<str> for ops::RangeTo<usize> {
         type Output = str;
         #[inline]
@@ -1904,7 +1904,7 @@ mod traits {
         }
     }
 
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     impl SliceIndex<str> for ops::RangeFrom<usize> {
         type Output = str;
         #[inline]
@@ -1951,7 +1951,7 @@ mod traits {
         }
     }
 
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     impl SliceIndex<str> for ops::RangeInclusive<usize> {
         type Output = str;
         #[inline]
@@ -1994,7 +1994,7 @@ mod traits {
 
 
 
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     impl SliceIndex<str> for ops::RangeToInclusive<usize> {
         type Output = str;
         #[inline]
@@ -2094,13 +2094,13 @@ pub trait StrExt {
     #[rustc_deprecated(since = "1.6.0", reason = "use lines() instead now")]
     #[allow(deprecated)]
     fn lines_any(&self) -> LinesAny;
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     fn get<I: SliceIndex<str>>(&self, i: I) -> Option<&I::Output>;
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     fn get_mut<I: SliceIndex<str>>(&mut self, i: I) -> Option<&mut I::Output>;
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     unsafe fn get_unchecked<I: SliceIndex<str>>(&self, i: I) -> &I::Output;
-    #[unstable(feature = "str_checked_slicing", issue = "39932")]
+    #[stable(feature = "str_checked_slicing", since = "1.20.0")]
     unsafe fn get_unchecked_mut<I: SliceIndex<str>>(&mut self, i: I) -> &mut I::Output;
     #[stable(feature = "core", since = "1.6.0")]
     unsafe fn slice_unchecked(&self, begin: usize, end: usize) -> &str;

From 9ec2b5b1220bbccba9bb7f9b5f1daf574d6ac71b Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Thu, 20 Jul 2017 15:44:35 -0700
Subject: [PATCH 08/15] std: Stabilize CString/OsString/PathBuf extra methods

Stabilizes:

* `CString::as_c_str`
* `CString::into_boxed_c_str`
* `CStr::into_c_string`
* `OsString::into_boxed_os_str`
* `OsStr::into_os_string`
* `PathBuf::into_boxed_path`
* `PathBuf::into_path_buf`

Closes #40380
---
 src/libstd/ffi/c_str.rs  | 6 +++---
 src/libstd/ffi/os_str.rs | 4 ++--
 src/libstd/path.rs       | 4 ++--
 3 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/src/libstd/ffi/c_str.rs b/src/libstd/ffi/c_str.rs
index 5f0b11a616eb0..5dd7bb1c0c1d9 100644
--- a/src/libstd/ffi/c_str.rs
+++ b/src/libstd/ffi/c_str.rs
@@ -462,7 +462,7 @@ impl CString {
     /// assert_eq!(c_str, CStr::from_bytes_with_nul(b"foo\0").unwrap());
     /// ```
     #[inline]
-    #[unstable(feature = "as_c_str", issue = "40380")]
+    #[stable(feature = "as_c_str", since = "1.20.0")]
     pub fn as_c_str(&self) -> &CStr {
         &*self
     }
@@ -482,7 +482,7 @@ impl CString {
     /// let boxed = c_string.into_boxed_c_str();
     /// assert_eq!(&*boxed, CStr::from_bytes_with_nul(b"foo\0").unwrap());
     /// ```
-    #[unstable(feature = "into_boxed_c_str", issue = "40380")]
+    #[stable(feature = "into_boxed_c_str", since = "1.20.0")]
     pub fn into_boxed_c_str(self) -> Box<CStr> {
         unsafe { mem::transmute(self.into_inner()) }
     }
@@ -1009,7 +1009,7 @@ impl CStr {
     /// let boxed = c_string.into_boxed_c_str();
     /// assert_eq!(boxed.into_c_string(), CString::new("foo").unwrap());
     /// ```
-    #[unstable(feature = "into_boxed_c_str", issue = "40380")]
+    #[stable(feature = "into_boxed_c_str", since = "1.20.0")]
     pub fn into_c_string(self: Box<CStr>) -> CString {
         unsafe { mem::transmute(self) }
     }
diff --git a/src/libstd/ffi/os_str.rs b/src/libstd/ffi/os_str.rs
index 02a13ed7a5a03..6f147ea0eeccb 100644
--- a/src/libstd/ffi/os_str.rs
+++ b/src/libstd/ffi/os_str.rs
@@ -260,7 +260,7 @@ impl OsString {
     ///
     /// let b: Box<OsStr> = s.into_boxed_os_str();
     /// ```
-    #[unstable(feature = "into_boxed_os_str", issue = "40380")]
+    #[stable(feature = "into_boxed_os_str", since = "1.20.0")]
     pub fn into_boxed_os_str(self) -> Box<OsStr> {
         unsafe { mem::transmute(self.inner.into_box()) }
     }
@@ -511,7 +511,7 @@ impl OsStr {
     ///
     /// [`Box`]: ../boxed/struct.Box.html
     /// [`OsString`]: struct.OsString.html
-    #[unstable(feature = "into_boxed_os_str", issue = "40380")]
+    #[stable(feature = "into_boxed_os_str", since = "1.20.0")]
     pub fn into_os_string(self: Box<OsStr>) -> OsString {
         let inner: Box<Slice> = unsafe { mem::transmute(self) };
         OsString { inner: Buf::from_box(inner) }
diff --git a/src/libstd/path.rs b/src/libstd/path.rs
index 432605cf3b25b..a1a1825ffbf8e 100644
--- a/src/libstd/path.rs
+++ b/src/libstd/path.rs
@@ -1327,7 +1327,7 @@ impl PathBuf {
     ///
     /// [`Box`]: ../../std/boxed/struct.Box.html
     /// [`Path`]: struct.Path.html
-    #[unstable(feature = "into_boxed_path", issue = "40380")]
+    #[stable(feature = "into_boxed_path", since = "1.20.0")]
     pub fn into_boxed_path(self) -> Box<Path> {
         unsafe { mem::transmute(self.inner.into_boxed_os_str()) }
     }
@@ -2300,7 +2300,7 @@ impl Path {
     ///
     /// [`Box`]: ../../std/boxed/struct.Box.html
     /// [`PathBuf`]: struct.PathBuf.html
-    #[unstable(feature = "into_boxed_path", issue = "40380")]
+    #[stable(feature = "into_boxed_path", since = "1.20.0")]
     pub fn into_path_buf(self: Box<Path>) -> PathBuf {
         let inner: Box<OsStr> = unsafe { mem::transmute(self) };
         PathBuf { inner: OsString::from(inner) }

From 59ccb2f27768ac5af46f843f0e6476a60bbec0ab Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Thu, 20 Jul 2017 15:46:46 -0700
Subject: [PATCH 09/15] std: Stabilize `utf8_error_error_len` feature

Stabilizes:

* `Utf8Error::error_len`

Closes #40494
---
 src/liballoc/tests/lib.rs | 1 -
 src/libcore/str/mod.rs    | 2 +-
 2 files changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/liballoc/tests/lib.rs b/src/liballoc/tests/lib.rs
index 75ff781113722..27b23d14059f8 100644
--- a/src/liballoc/tests/lib.rs
+++ b/src/liballoc/tests/lib.rs
@@ -28,7 +28,6 @@
 #![feature(test)]
 #![feature(unboxed_closures)]
 #![feature(unicode)]
-#![feature(utf8_error_error_len)]
 
 extern crate alloc;
 extern crate test;
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index af95bc41731b6..10cf3bd29c6ba 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -207,7 +207,7 @@ impl Utf8Error {
     ///   that starts at the index given by `valid_up_to()`.
     ///   Decoding should resume after that sequence
     ///   (after inserting a U+FFFD REPLACEMENT CHARACTER) in case of lossy decoding.
-    #[unstable(feature = "utf8_error_error_len", reason ="new", issue = "40494")]
+    #[stable(feature = "utf8_error_error_len", since = "1.20.0")]
     pub fn error_len(&self) -> Option<usize> {
         self.error_len.map(|len| len as usize)
     }

From 7e22e241a857945537ac9d1678119b272c2eddb0 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Thu, 20 Jul 2017 15:48:15 -0700
Subject: [PATCH 10/15] std: Stabilize `manually_drop` feature

Stabilizes

* `core::mem::ManuallyDrop`
* `std::mem::ManuallyDrop`
* `ManuallyDrop::new`
* `ManuallyDrop::into_inner`
* `ManuallyDrop::drop`
* `Deref for ManuallyDrop`
* `DerefMut for ManuallyDrop`

Closes #40673
---
 src/liballoc/lib.rs                 |  1 -
 src/libcore/mem.rs                  | 17 +++++++----------
 src/librustc_data_structures/lib.rs |  1 -
 3 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index 605302ec71ee6..789c548238f53 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -101,7 +101,6 @@
 #![feature(i128_type)]
 #![feature(inclusive_range)]
 #![feature(lang_items)]
-#![feature(manually_drop)]
 #![feature(needs_allocator)]
 #![feature(nonzero)]
 #![feature(offset_to)]
diff --git a/src/libcore/mem.rs b/src/libcore/mem.rs
index 6c1e8e8960f75..d891796c1d359 100644
--- a/src/libcore/mem.rs
+++ b/src/libcore/mem.rs
@@ -795,7 +795,6 @@ pub fn discriminant<T>(v: &T) -> Discriminant<T> {
 /// the type:
 ///
 /// ```rust
-/// # #![feature(manually_drop)]
 /// use std::mem::ManuallyDrop;
 /// struct Peach;
 /// struct Banana;
@@ -821,7 +820,7 @@ pub fn discriminant<T>(v: &T) -> Discriminant<T> {
 ///     }
 /// }
 /// ```
-#[unstable(feature = "manually_drop", issue = "40673")]
+#[stable(feature = "manually_drop", since = "1.20.0")]
 #[allow(unions_with_drop_fields)]
 pub union ManuallyDrop<T>{ value: T }
 
@@ -831,11 +830,10 @@ impl<T> ManuallyDrop<T> {
     /// # Examples
     ///
     /// ```rust
-    /// # #![feature(manually_drop)]
     /// use std::mem::ManuallyDrop;
     /// ManuallyDrop::new(Box::new(()));
     /// ```
-    #[unstable(feature = "manually_drop", issue = "40673")]
+    #[stable(feature = "manually_drop", since = "1.20.0")]
     #[inline]
     pub fn new(value: T) -> ManuallyDrop<T> {
         ManuallyDrop { value: value }
@@ -846,12 +844,11 @@ impl<T> ManuallyDrop<T> {
     /// # Examples
     ///
     /// ```rust
-    /// # #![feature(manually_drop)]
     /// use std::mem::ManuallyDrop;
     /// let x = ManuallyDrop::new(Box::new(()));
     /// let _: Box<()> = ManuallyDrop::into_inner(x);
     /// ```
-    #[unstable(feature = "manually_drop", issue = "40673")]
+    #[stable(feature = "manually_drop", since = "1.20.0")]
     #[inline]
     pub fn into_inner(slot: ManuallyDrop<T>) -> T {
         unsafe {
@@ -866,14 +863,14 @@ impl<T> ManuallyDrop<T> {
     /// This function runs the destructor of the contained value and thus the wrapped value
     /// now represents uninitialized data. It is up to the user of this method to ensure the
     /// uninitialized data is not actually used.
-    #[unstable(feature = "manually_drop", issue = "40673")]
+    #[stable(feature = "manually_drop", since = "1.20.0")]
     #[inline]
     pub unsafe fn drop(slot: &mut ManuallyDrop<T>) {
         ptr::drop_in_place(&mut slot.value)
     }
 }
 
-#[unstable(feature = "manually_drop", issue = "40673")]
+#[stable(feature = "manually_drop", since = "1.20.0")]
 impl<T> ::ops::Deref for ManuallyDrop<T> {
     type Target = T;
     #[inline]
@@ -884,7 +881,7 @@ impl<T> ::ops::Deref for ManuallyDrop<T> {
     }
 }
 
-#[unstable(feature = "manually_drop", issue = "40673")]
+#[stable(feature = "manually_drop", since = "1.20.0")]
 impl<T> ::ops::DerefMut for ManuallyDrop<T> {
     #[inline]
     fn deref_mut(&mut self) -> &mut Self::Target {
@@ -894,7 +891,7 @@ impl<T> ::ops::DerefMut for ManuallyDrop<T> {
     }
 }
 
-#[unstable(feature = "manually_drop", issue = "40673")]
+#[stable(feature = "manually_drop", since = "1.20.0")]
 impl<T: ::fmt::Debug> ::fmt::Debug for ManuallyDrop<T> {
     fn fmt(&self, fmt: &mut ::fmt::Formatter) -> ::fmt::Result {
         unsafe {
diff --git a/src/librustc_data_structures/lib.rs b/src/librustc_data_structures/lib.rs
index 5d856597cad53..eb766e71bf297 100644
--- a/src/librustc_data_structures/lib.rs
+++ b/src/librustc_data_structures/lib.rs
@@ -34,7 +34,6 @@
 #![feature(conservative_impl_trait)]
 #![feature(discriminant_value)]
 #![feature(specialization)]
-#![feature(manually_drop)]
 
 #![cfg_attr(stage0, feature(associated_consts))]
 #![cfg_attr(stage0, feature(struct_field_attributes))]

From febb25540d6a9c86d34f564f02c8682273562e89 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Thu, 20 Jul 2017 15:50:33 -0700
Subject: [PATCH 11/15] Stabilize the `compile_error_macro` feature

Stabilizes:

* `compile_error!` as a macro defined by rustc

Closes #40872
---
 .../src/language-features/compile-error.md    | 20 -------------------
 src/libcore/macros.rs                         |  2 +-
 src/libstd/macros.rs                          |  2 +-
 src/libsyntax/ext/expand.rs                   |  1 -
 src/libsyntax/feature_gate.rs                 |  6 ++----
 src/libsyntax_ext/compile_error.rs            | 10 ----------
 src/test/compile-fail/compile_error_macro.rs  |  2 --
 .../feature-gate-compile_error.rs             | 13 ------------
 8 files changed, 4 insertions(+), 52 deletions(-)
 delete mode 100644 src/doc/unstable-book/src/language-features/compile-error.md
 delete mode 100644 src/test/compile-fail/feature-gate-compile_error.rs

diff --git a/src/doc/unstable-book/src/language-features/compile-error.md b/src/doc/unstable-book/src/language-features/compile-error.md
deleted file mode 100644
index 4de631e1fb307..0000000000000
--- a/src/doc/unstable-book/src/language-features/compile-error.md
+++ /dev/null
@@ -1,20 +0,0 @@
-# `compile_error`
-
-The tracking issue for this feature is: [#40872]
-
-[#40872]: https://github.com/rust-lang/rust/issues/40872
-
-------------------------
-
-The `compile_error` feature adds a macro which will generate a compilation
-error with the specified error message.
-
-## Examples
-
-```rust,compile_fail
-#![feature(compile_error)]
-
-fn main() {
-    compile_error!("The error message"); //ERROR The error message
-}
-```
diff --git a/src/libcore/macros.rs b/src/libcore/macros.rs
index b09e6ea3328b8..684b81a27f82e 100644
--- a/src/libcore/macros.rs
+++ b/src/libcore/macros.rs
@@ -584,7 +584,7 @@ mod builtin {
     /// For more information, see the [RFC].
     ///
     /// [RFC]: https://github.com/rust-lang/rfcs/blob/master/text/1695-add-error-macro.md
-    #[unstable(feature = "compile_error_macro", issue = "40872")]
+    #[stable(feature = "compile_error_macro", since = "1.20.0")]
     #[macro_export]
     #[cfg(dox)]
     macro_rules! compile_error { ($msg:expr) => ({ /* compiler built-in */ }) }
diff --git a/src/libstd/macros.rs b/src/libstd/macros.rs
index 43c4ba48b1bcc..1545c1f9ab152 100644
--- a/src/libstd/macros.rs
+++ b/src/libstd/macros.rs
@@ -261,7 +261,7 @@ pub mod builtin {
     /// For more information, see the [RFC].
     ///
     /// [RFC]: https://github.com/rust-lang/rfcs/blob/master/text/1695-add-error-macro.md
-    #[unstable(feature = "compile_error_macro", issue = "40872")]
+    #[stable(feature = "compile_error_macro", since = "1.20.0")]
     #[macro_export]
     macro_rules! compile_error { ($msg:expr) => ({ /* compiler built-in */ }) }
 
diff --git a/src/libsyntax/ext/expand.rs b/src/libsyntax/ext/expand.rs
index d2e51c9cb4868..352b0e5327f2a 100644
--- a/src/libsyntax/ext/expand.rs
+++ b/src/libsyntax/ext/expand.rs
@@ -1041,7 +1041,6 @@ impl<'feat> ExpansionConfig<'feat> {
         fn enable_allow_internal_unstable = allow_internal_unstable,
         fn enable_custom_derive = custom_derive,
         fn proc_macro_enabled = proc_macro,
-        fn enable_compile_error = compile_error,
     }
 }
 
diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
index 448f95c93a087..e8de8cf41c970 100644
--- a/src/libsyntax/feature_gate.rs
+++ b/src/libsyntax/feature_gate.rs
@@ -117,7 +117,6 @@ macro_rules! declare_features {
 
 declare_features! (
     (active, asm, "1.0.0", Some(29722)),
-    (active, compile_error, "1.20.0", Some(40872)),
     (active, concat_idents, "1.0.0", Some(29599)),
     (active, link_args, "1.0.0", Some(29596)),
     (active, log_syntax, "1.0.0", Some(29598)),
@@ -445,6 +444,8 @@ declare_features! (
     // Allows the definition of associated constants in `trait` or `impl`
     // blocks.
     (accepted, associated_consts, "1.20.0", Some(29646)),
+    // Usage of the `compile_error!` macro
+    (accepted, compile_error, "1.20.0", Some(40872)),
 );
 
 // If you change this, please modify src/doc/unstable-book as well. You must
@@ -1040,9 +1041,6 @@ pub const EXPLAIN_LOG_SYNTAX: &'static str =
 pub const EXPLAIN_CONCAT_IDENTS: &'static str =
     "`concat_idents` is not stable enough for use and is subject to change";
 
-pub const EXPLAIN_COMPILE_ERROR: &'static str =
-    "`compile_error` is not stable enough for use and is subject to change";
-
 pub const EXPLAIN_TRACE_MACROS: &'static str =
     "`trace_macros` is not stable enough for use and is subject to change";
 pub const EXPLAIN_ALLOW_INTERNAL_UNSTABLE: &'static str =
diff --git a/src/libsyntax_ext/compile_error.rs b/src/libsyntax_ext/compile_error.rs
index bb496716d8c46..7bc7afba63cb4 100644
--- a/src/libsyntax_ext/compile_error.rs
+++ b/src/libsyntax_ext/compile_error.rs
@@ -12,7 +12,6 @@
 
 use syntax::ext::base::*;
 use syntax::ext::base;
-use syntax::feature_gate;
 use syntax_pos::Span;
 use syntax::tokenstream;
 
@@ -20,15 +19,6 @@ pub fn expand_compile_error<'cx>(cx: &'cx mut ExtCtxt,
                               sp: Span,
                               tts: &[tokenstream::TokenTree])
                               -> Box<base::MacResult + 'cx> {
-    if !cx.ecfg.enable_compile_error() {
-        feature_gate::emit_feature_err(&cx.parse_sess,
-                                       "compile_error",
-                                       sp,
-                                       feature_gate::GateIssue::Language,
-                                       feature_gate::EXPLAIN_COMPILE_ERROR);
-        return DummyResult::expr(sp);
-    }
-
     let var = match get_single_str_from_tts(cx, sp, tts, "compile_error!") {
         None => return DummyResult::expr(sp),
         Some(v) => v,
diff --git a/src/test/compile-fail/compile_error_macro.rs b/src/test/compile-fail/compile_error_macro.rs
index 2a2c3fd809232..e9c5993098c3e 100644
--- a/src/test/compile-fail/compile_error_macro.rs
+++ b/src/test/compile-fail/compile_error_macro.rs
@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(compile_error)]
-
 fn main() {
     compile_error!("a very descriptive error message"); //~ ERROR: a very descriptive error message
 }
diff --git a/src/test/compile-fail/feature-gate-compile_error.rs b/src/test/compile-fail/feature-gate-compile_error.rs
deleted file mode 100644
index 545c6852961c7..0000000000000
--- a/src/test/compile-fail/feature-gate-compile_error.rs
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright 2017 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.
-
-fn main() {
-    compile_error!("test"); //~ ERROR: `compile_error` is not stable enough
-}

From a2b855652cbf2de0caa2fae6240730d2db4a18de Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Thu, 20 Jul 2017 15:52:12 -0700
Subject: [PATCH 12/15] std: Stabilize the `str_{mut,box}_extras` feature

Stabilizes

* `<&mut str>::as_bytes_mut`
* `<Box<str>>::into_boxed_bytes`
* `std::str::from_boxed_utf8_unchecked`
* `std::str::from_utf8_mut`
* `std::str::from_utf8_unchecked_mut`

Closes #41119
---
 src/liballoc/lib.rs      | 1 -
 src/liballoc/str.rs      | 6 +++---
 src/libcore/str/mod.rs   | 8 ++++----
 src/libstd/ffi/c_str.rs  | 6 ------
 src/libstd/ffi/os_str.rs | 2 --
 src/libstd/lib.rs        | 1 -
 6 files changed, 7 insertions(+), 17 deletions(-)

diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index 789c548238f53..7a5acb1856528 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -115,7 +115,6 @@
 #![feature(specialization)]
 #![feature(staged_api)]
 #![feature(str_internals)]
-#![feature(str_mut_extras)]
 #![feature(trusted_len)]
 #![feature(unboxed_closures)]
 #![feature(unicode)]
diff --git a/src/liballoc/str.rs b/src/liballoc/str.rs
index e4953988c5c12..4df13c509a835 100644
--- a/src/liballoc/str.rs
+++ b/src/liballoc/str.rs
@@ -290,7 +290,7 @@ impl str {
     }
 
     /// Converts a mutable string slice to a mutable byte slice.
-    #[unstable(feature = "str_mut_extras", issue = "41119")]
+    #[stable(feature = "str_mut_extras", since = "1.20.0")]
     #[inline(always)]
     pub unsafe fn as_bytes_mut(&mut self) -> &mut [u8] {
         core_str::StrExt::as_bytes_mut(self)
@@ -1725,7 +1725,7 @@ impl str {
     }
 
     /// Converts a `Box<str>` into a `Box<[u8]>` without copying or allocating.
-    #[unstable(feature = "str_box_extras", issue = "41119")]
+    #[stable(feature = "str_box_extras", since = "1.20.0")]
     pub fn into_boxed_bytes(self: Box<str>) -> Box<[u8]> {
         self.into()
     }
@@ -1992,7 +1992,7 @@ impl str {
 
 /// Converts a boxed slice of bytes to a boxed string slice without checking
 /// that the string contains valid UTF-8.
-#[unstable(feature = "str_box_extras", issue = "41119")]
+#[stable(feature = "str_box_extras", since = "1.20.0")]
 pub unsafe fn from_boxed_utf8_unchecked(v: Box<[u8]>) -> Box<str> {
     mem::transmute(v)
 }
diff --git a/src/libcore/str/mod.rs b/src/libcore/str/mod.rs
index 10cf3bd29c6ba..cc18222815c3b 100644
--- a/src/libcore/str/mod.rs
+++ b/src/libcore/str/mod.rs
@@ -301,7 +301,7 @@ pub fn from_utf8(v: &[u8]) -> Result<&str, Utf8Error> {
 }
 
 /// Converts a mutable slice of bytes to a mutable string slice.
-#[unstable(feature = "str_mut_extras", issue = "41119")]
+#[stable(feature = "str_mut_extras", since = "1.20.0")]
 pub fn from_utf8_mut(v: &mut [u8]) -> Result<&mut str, Utf8Error> {
     run_utf8_validation(v)?;
     Ok(unsafe { from_utf8_unchecked_mut(v) })
@@ -381,8 +381,8 @@ pub unsafe fn from_utf8_unchecked(v: &[u8]) -> &str {
 /// See the immutable version, [`from_utf8_unchecked()`][fromutf8], for more information.
 ///
 /// [fromutf8]: fn.from_utf8_unchecked.html
-#[inline(always)]
-#[unstable(feature = "str_mut_extras", issue = "41119")]
+#[inline]
+#[stable(feature = "str_mut_extras", since = "1.20.0")]
 pub unsafe fn from_utf8_unchecked_mut(v: &mut [u8]) -> &mut str {
     mem::transmute(v)
 }
@@ -2123,7 +2123,7 @@ pub trait StrExt {
     fn is_char_boundary(&self, index: usize) -> bool;
     #[stable(feature = "core", since = "1.6.0")]
     fn as_bytes(&self) -> &[u8];
-    #[unstable(feature = "str_mut_extras", issue = "41119")]
+    #[stable(feature = "str_mut_extras", since = "1.20.0")]
     unsafe fn as_bytes_mut(&mut self) -> &mut [u8];
     #[stable(feature = "core", since = "1.6.0")]
     fn find<'a, P: Pattern<'a>>(&'a self, pat: P) -> Option<usize>;
diff --git a/src/libstd/ffi/c_str.rs b/src/libstd/ffi/c_str.rs
index 5dd7bb1c0c1d9..db64d41011c6b 100644
--- a/src/libstd/ffi/c_str.rs
+++ b/src/libstd/ffi/c_str.rs
@@ -453,8 +453,6 @@ impl CString {
     /// # Examples
     ///
     /// ```
-    /// #![feature(as_c_str)]
-    ///
     /// use std::ffi::{CString, CStr};
     ///
     /// let c_string = CString::new(b"foo".to_vec()).unwrap();
@@ -474,8 +472,6 @@ impl CString {
     /// # Examples
     ///
     /// ```
-    /// #![feature(into_boxed_c_str)]
-    ///
     /// use std::ffi::{CString, CStr};
     ///
     /// let c_string = CString::new(b"foo".to_vec()).unwrap();
@@ -1001,8 +997,6 @@ impl CStr {
     /// # Examples
     ///
     /// ```
-    /// #![feature(into_boxed_c_str)]
-    ///
     /// use std::ffi::CString;
     ///
     /// let c_string = CString::new(b"foo".to_vec()).unwrap();
diff --git a/src/libstd/ffi/os_str.rs b/src/libstd/ffi/os_str.rs
index 6f147ea0eeccb..d62e3e905e3ca 100644
--- a/src/libstd/ffi/os_str.rs
+++ b/src/libstd/ffi/os_str.rs
@@ -252,8 +252,6 @@ impl OsString {
     /// # Examples
     ///
     /// ```
-    /// #![feature(into_boxed_os_str)]
-    ///
     /// use std::ffi::{OsString, OsStr};
     ///
     /// let s = OsString::from("hello");
diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs
index 8fe0ecfcf5397..82262f1551ac0 100644
--- a/src/libstd/lib.rs
+++ b/src/libstd/lib.rs
@@ -303,7 +303,6 @@
 #![feature(stmt_expr_attributes)]
 #![feature(str_char)]
 #![feature(str_internals)]
-#![feature(str_mut_extras)]
 #![feature(str_utf16)]
 #![feature(test, rustc_private)]
 #![feature(thread_local)]

From 808f8ea9379cf8412fdaef60fbf2fb4b24c3a659 Mon Sep 17 00:00:00 2001
From: est31 <MTest31@outlook.com>
Date: Tue, 18 Jul 2017 05:16:46 +0200
Subject: [PATCH 13/15] float_bits_conv made it into 1.20

---
 src/libstd/f32.rs | 4 ++--
 src/libstd/f64.rs | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/libstd/f32.rs b/src/libstd/f32.rs
index 9bacfee055385..0135cd0a588cf 100644
--- a/src/libstd/f32.rs
+++ b/src/libstd/f32.rs
@@ -1094,7 +1094,7 @@ impl f32 {
     /// assert_eq!((12.5f32).to_bits(), 0x41480000);
     ///
     /// ```
-    #[stable(feature = "float_bits_conv", since = "1.21.0")]
+    #[stable(feature = "float_bits_conv", since = "1.20.0")]
     #[inline]
     pub fn to_bits(self) -> u32 {
         unsafe { ::mem::transmute(self) }
@@ -1125,7 +1125,7 @@ impl f32 {
     /// let snan = 0x7F800001;
     /// assert_ne!(f32::from_bits(snan).to_bits(), snan);
     /// ```
-    #[stable(feature = "float_bits_conv", since = "1.21.0")]
+    #[stable(feature = "float_bits_conv", since = "1.20.0")]
     #[inline]
     pub fn from_bits(mut v: u32) -> Self {
         const EXP_MASK: u32   = 0x7F800000;
diff --git a/src/libstd/f64.rs b/src/libstd/f64.rs
index 5236048ade43f..d73d7cd2c7bd1 100644
--- a/src/libstd/f64.rs
+++ b/src/libstd/f64.rs
@@ -1009,7 +1009,7 @@ impl f64 {
     /// assert_eq!((12.5f64).to_bits(), 0x4029000000000000);
     ///
     /// ```
-    #[stable(feature = "float_bits_conv", since = "1.21.0")]
+    #[stable(feature = "float_bits_conv", since = "1.20.0")]
     #[inline]
     pub fn to_bits(self) -> u64 {
         unsafe { ::mem::transmute(self) }
@@ -1040,7 +1040,7 @@ impl f64 {
     /// let snan = 0x7FF0000000000001;
     /// assert_ne!(f64::from_bits(snan).to_bits(), snan);
     /// ```
-    #[stable(feature = "float_bits_conv", since = "1.21.0")]
+    #[stable(feature = "float_bits_conv", since = "1.20.0")]
     #[inline]
     pub fn from_bits(mut v: u64) -> Self {
         const EXP_MASK: u64   = 0x7FF0000000000000;

From 44a6d0ba3e9f24a51f15787602536fe2b391321e Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Sat, 12 Aug 2017 19:28:19 -0700
Subject: [PATCH 14/15] Update cargo submodule

---
 src/Cargo.lock  | 13 +++++++++++--
 src/tools/cargo |  2 +-
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/src/Cargo.lock b/src/Cargo.lock
index 33eae1ca982ed..bcec823403d0e 100644
--- a/src/Cargo.lock
+++ b/src/Cargo.lock
@@ -160,7 +160,7 @@ dependencies = [
  "curl 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "docopt 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "env_logger 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)",
- "error-chain 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "error-chain 0.11.0-rc.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "filetime 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "flate2 0.2.19 (registry+https://github.com/rust-lang/crates.io-index)",
  "fs2 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -290,7 +290,7 @@ name = "crates-io"
 version = "0.10.0"
 dependencies = [
  "curl 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
- "error-chain 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "error-chain 0.11.0-rc.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_derive 1.0.10 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -377,6 +377,14 @@ dependencies = [
  "backtrace 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "error-chain"
+version = "0.11.0-rc.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "backtrace 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "error_index_generator"
 version = "0.0.0"
@@ -1791,6 +1799,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum dtoa 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "80c8b71fd71146990a9742fc06dcbbde19161a267e0ad4e572c35162f4578c90"
 "checksum env_logger 0.4.3 (registry+https://github.com/rust-lang/crates.io-index)" = "3ddf21e73e016298f5cb37d6ef8e8da8e39f91f9ec8b0df44b7deb16a9f8cd5b"
 "checksum error-chain 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d9435d864e017c3c6afeac1654189b06cdb491cf2ff73dbf0d73b0f292f42ff8"
+"checksum error-chain 0.11.0-rc.2 (registry+https://github.com/rust-lang/crates.io-index)" = "38d3a55d9a7a456748f2a3912c0941a5d9a68006eb15b3c3c9836b8420dc102d"
 "checksum filetime 0.1.10 (registry+https://github.com/rust-lang/crates.io-index)" = "5363ab8e4139b8568a6237db5248646e5a8a2f89bd5ccb02092182b11fd3e922"
 "checksum flate2 0.2.19 (registry+https://github.com/rust-lang/crates.io-index)" = "36df0166e856739905cd3d7e0b210fe818592211a008862599845e012d8d304c"
 "checksum foreign-types 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3e4056b9bd47f8ac5ba12be771f77a0dae796d1bbaaf5fd0b9c2d38b69b8a29d"
diff --git a/src/tools/cargo b/src/tools/cargo
index 7e00b82d96d3b..5b4b8b2ae3f6a 160000
--- a/src/tools/cargo
+++ b/src/tools/cargo
@@ -1 +1 @@
-Subproject commit 7e00b82d96d3b78241e2b95acdecb28551813b15
+Subproject commit 5b4b8b2ae3f6a884099544ce66dbb41626110ece

From 5f554ed507d70b51a6a86df987ccced43206d806 Mon Sep 17 00:00:00 2001
From: Alex Crichton <alex@alexcrichton.com>
Date: Sat, 12 Aug 2017 19:28:43 -0700
Subject: [PATCH 15/15] Bump beta to .2

---
 src/bootstrap/channel.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/bootstrap/channel.rs b/src/bootstrap/channel.rs
index 1153acfa57d39..aae02761708f7 100644
--- a/src/bootstrap/channel.rs
+++ b/src/bootstrap/channel.rs
@@ -28,7 +28,7 @@ pub const CFG_RELEASE_NUM: &str = "1.20.0";
 // An optional number to put after the label, e.g. '.2' -> '-beta.2'
 // Be sure to make this starts with a dot to conform to semver pre-release
 // versions (section 9)
-pub const CFG_PRERELEASE_VERSION: &str = ".1";
+pub const CFG_PRERELEASE_VERSION: &str = ".2";
 
 pub struct GitInfo {
     inner: Option<Info>,