Auto merge of #56051 - pietroalbini:rollup, r=pietroalbini

Rollup of 25 pull requests

Successful merges:

 - #55562 (Add powerpc- and powerpc64-unknown-linux-musl targets)
 - #55564 (test/linkage-visibility: Ignore on musl targets)
 - #55827 (A few tweaks to iterations/collecting)
 - #55834 (Forward the ABI of the non-zero sized fields of an union if they have the same ABI)
 - #55857 (remove unused dependency)
 - #55862 (in which the E0618 "expected function" diagnostic gets a makeover)
 - #55867 (do not panic just because cargo failed)
 - #55894 (miri enum discriminant handling: Fix treatment of pointers, better error when it is undef)
 - #55916 (Make miri value visitor usfeful for mutation)
 - #55919 (core/tests/num: Simplify `test_int_from_str_overflow()` test code)
 - #55923 (reword #[test] attribute error on fn items)
 - #55935 (appveyor: Use VS2017 for all our images)
 - #55949 (ty: return impl Iterator from Predicate::walk_tys)
 - #55952 (Update to Clang 7 on CI.)
 - #55953 (#53488 Refactoring UpvarId)
 - #55962 (rustdoc: properly calculate spans for intra-doc link resolution errors)
 - #55963 (Stress test for MPSC)
 - #55968 (Clean up some non-mod-rs stuff.)
 - #55970 (Miri backtrace improvements)
 - #56007 (CTFE: dynamically make sure we do not call non-const-fn)
 - #56011 (Replace data.clone() by Arc::clone(&data) in mutex doc.)
 - #56012 (avoid shared ref in UnsafeCell::get)
 - #56016 (Add VecDeque::resize_with)
 - #56027 (docs: Add missing backtick in object_safety.rs docs)
 - #56043 (remove "approx env bounds" if we already know from trait)

Failed merges:

r? @ghost

Author: bors

.travis.yml

@@ -227,9 +227,9 @@ install:
             chmod +x /usr/local/bin/sccache &&
           travis_retry curl -fo /usr/local/bin/stamp https://s3-us-west-1.amazonaws.com/rust-lang-ci2/rust-ci-mirror/2017-03-17-stamp-x86_64-apple-darwin &&
             chmod +x /usr/local/bin/stamp &&
-          travis_retry curl -f http://releases.llvm.org/6.0.0/clang+llvm-6.0.0-x86_64-apple-darwin.tar.xz | tar xJf - &&
-            export CC=`pwd`/clang+llvm-6.0.0-x86_64-apple-darwin/bin/clang &&
-            export CXX=`pwd`/clang+llvm-6.0.0-x86_64-apple-darwin/bin/clang++ &&
+          travis_retry curl -f http://releases.llvm.org/7.0.0/clang+llvm-7.0.0-x86_64-apple-darwin.tar.xz | tar xJf - &&
+            export CC=`pwd`/clang+llvm-7.0.0-x86_64-apple-darwin/bin/clang &&
+            export CXX=`pwd`/clang+llvm-7.0.0-x86_64-apple-darwin/bin/clang++ &&
             export AR=ar
           ;;
     esac

appveyor.yml

@@ -1,5 +1,8 @@
 environment:
-  SCCACHE_DIGEST: f808afabb4a4eb1d7112bcb3fa6be03b61e93412890c88e177c667eb37f46353d7ec294e559b16f9f4b5e894f2185fe7670a0df15fd064889ecbd80f0c34166c
+  # This is required for at least an AArch64 compiler in one image, and is
+  # otherwise recommended by AppVeyor currently for seeing if it has any
+  # affect on our job times.
+  APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017 Preview
 
   # By default schannel checks revocation of certificates unlike some other SSL
   # backends, but we've historically had problems on CI where a revocation
@@ -88,7 +91,6 @@ environment:
     DIST_REQUIRE_ALL_TOOLS: 1
     DEPLOY: 1
     CI_JOB_NAME: dist-x86_64-msvc
-    APPVEYOR_BUILD_WORKER_IMAGE: Visual Studio 2017 Preview
   - RUST_CONFIGURE_ARGS: >
       --build=i686-pc-windows-msvc
       --target=i586-pc-windows-msvc

src/Cargo.lock

@@ -2191,7 +2191,6 @@ dependencies = [
  "graphviz 0.0.0",
  "log 0.4.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "parking_lot_core 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-rayon 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-rayon-core 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",

src/bootstrap/compile.rs

@@ -22,7 +22,7 @@ use std::fs::{self, File};
 use std::io::BufReader;
 use std::io::prelude::*;
 use std::path::{Path, PathBuf};
-use std::process::{Command, Stdio};
+use std::process::{Command, Stdio, exit};
 use std::str;
 
 use build_helper::{output, mtime, up_to_date};
@@ -1098,7 +1098,7 @@ pub fn run_cargo(builder: &Builder,
     });
 
     if !ok {
-        panic!("cargo must succeed");
+        exit(1);
     }
 
     // Ok now we need to actually find all the files listed in `toplevel`. We've

src/ci/docker/dist-i686-linux/Dockerfile

@@ -67,7 +67,7 @@ RUN ./build-gcc.sh
 COPY dist-x86_64-linux/build-python.sh /tmp/
 RUN ./build-python.sh
 
-# Now build LLVM+Clang 6, afterwards configuring further compilations to use the
+# Now build LLVM+Clang 7, afterwards configuring further compilations to use the
 # clang/clang++ compilers.
 COPY dist-x86_64-linux/build-clang.sh /tmp/
 RUN ./build-clang.sh

src/ci/docker/dist-x86_64-linux/Dockerfile

@@ -67,7 +67,7 @@ RUN ./build-gcc.sh
 COPY dist-x86_64-linux/build-python.sh /tmp/
 RUN ./build-python.sh
 
-# Now build LLVM+Clang 6, afterwards configuring further compilations to use the
+# Now build LLVM+Clang 7, afterwards configuring further compilations to use the
 # clang/clang++ compilers.
 COPY dist-x86_64-linux/build-clang.sh /tmp/
 RUN ./build-clang.sh

src/ci/docker/dist-x86_64-linux/build-clang.sh

@@ -13,7 +13,7 @@ set -ex
 
 source shared.sh
 
-LLVM=6.0.0
+LLVM=7.0.0
 
 mkdir clang
 cd clang

src/ci/docker/scripts/musl.sh

@@ -51,7 +51,7 @@ hide_output make clean
 
 cd ..
 
-LLVM=60
+LLVM=70
 
 # may have been downloaded in a previous run
 if [ ! -d libunwind-release_$LLVM ]; then

src/liballoc/collections/vec_deque.rs

@@ -19,7 +19,7 @@
 
 use core::cmp::Ordering;
 use core::fmt;
-use core::iter::{repeat, FromIterator, FusedIterator};
+use core::iter::{repeat, repeat_with, FromIterator, FusedIterator};
 use core::mem;
 use core::ops::Bound::{Excluded, Included, Unbounded};
 use core::ops::{Index, IndexMut, RangeBounds};
@@ -1920,6 +1920,44 @@ impl<T: Clone> VecDeque<T> {
             self.truncate(new_len);
         }
     }
+
+    /// Modifies the `VecDeque` in-place so that `len()` is equal to `new_len`,
+    /// either by removing excess elements from the back or by appending
+    /// elements generated by calling `generator` to the back.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(vec_resize_with)]
+    ///
+    /// use std::collections::VecDeque;
+    ///
+    /// let mut buf = VecDeque::new();
+    /// buf.push_back(5);
+    /// buf.push_back(10);
+    /// buf.push_back(15);
+    /// assert_eq!(buf, [5, 10, 15]);
+    ///
+    /// buf.resize_with(5, Default::default);
+    /// assert_eq!(buf, [5, 10, 15, 0, 0]);
+    ///
+    /// buf.resize_with(2, || unreachable!());
+    /// assert_eq!(buf, [5, 10]);
+    ///
+    /// let mut state = 100;
+    /// buf.resize_with(5, || { state += 1; state });
+    /// assert_eq!(buf, [5, 10, 101, 102, 103]);
+    /// ```
+    #[unstable(feature = "vec_resize_with", issue = "41758")]
+    pub fn resize_with(&mut self, new_len: usize, generator: impl FnMut()->T) {
+        let len = self.len();
+
+        if new_len > len {
+            self.extend(repeat_with(generator).take(new_len - len))
+        } else {
+            self.truncate(new_len);
+        }
+    }
 }
 
 /// Returns the index in the underlying buffer for a given logical element index.

src/libcore/cell.rs

@@ -1509,7 +1509,9 @@ impl<T: ?Sized> UnsafeCell<T> {
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
     pub const fn get(&self) -> *mut T {
-        &self.value as *const T as *mut T
+        // We can just cast the pointer from `UnsafeCell<T>` to `T` because of
+        // #[repr(transparent)]
+        self as *const UnsafeCell<T> as *const T as *mut T
     }
 }