Auto merge of #42609 - brson:beta-next, r=alexcrichton

Beta next - #42521 - #42512 - #42482 - #42481 - #42480 r? @nikomatsakis remember to untag 'beta-nominated' on linked issues

Author: bors

src/Cargo.lock

@@ -28,7 +28,7 @@ pub const CFG_RELEASE_NUM: &'static str = "1.19.0";
 // 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: &'static str = ".1";
+pub const CFG_PRERELEASE_VERSION: &'static str = ".2";
 
 pub struct GitInfo {
  inner: Option<Info>,

src/bootstrap/channel.rs

@@ -1200,6 +1200,13 @@ impl<'a, 'gcx, 'tcx> RegionVarBindings<'a, 'gcx, 'tcx> {
  for verify in self.verifys.borrow().iter() {
  debug!("collect_errors: verify={:?}", verify);
  let sub = normalize(self.tcx, var_data, verify.region);
+
+ // This was an inference variable which didn't get
+ // constrained, therefore it can be assume to hold.
+ if let ty::ReEmpty = *sub {
+ continue;
+ }
+
  if verify.bound.is_met(region_rels, var_data, sub) {
  continue;
  }

src/librustc/infer/region_inference/mod.rs

@@ -446,9 +446,13 @@ impl<'a, 'gcx, 'tcx> ConfirmContext<'a, 'gcx, 'tcx> {
  // overloaded lvalue ops, and will be fixed by them in order to get
  // the correct region.
  let mut source = self.node_ty(expr.id);
- if let Some(adjustments) = self.tables.borrow_mut().adjustments.get_mut(&expr.id) {
+ // Do not mutate adjustments in place, but rather take them,
+ // and replace them after mutating them, to avoid having the
+ // tables borrowed during (`deref_mut`) method resolution.
+ let previous_adjustments = self.tables.borrow_mut().adjustments.remove(&expr.id);
+ if let Some(mut adjustments) = previous_adjustments {
  let pref = LvaluePreference::PreferMutLvalue;
- for adjustment in adjustments {
+ for adjustment in &mut adjustments {
  if let Adjust::Deref(Some(ref mut deref)) = adjustment.kind {
  if let Some(ok) = self.try_overloaded_deref(expr.span, source, pref) {
  let method = self.register_infer_ok_obligations(ok);
@@ -462,6 +466,7 @@ impl<'a, 'gcx, 'tcx> ConfirmContext<'a, 'gcx, 'tcx> {
  }
  source = adjustment.target;
  }
+ self.tables.borrow_mut().adjustments.insert(expr.id, adjustments);
  }
 
  match expr.node {

src/librustc_typeck/check/method/confirm.rs

@@ -11,8 +11,9 @@
 use io;
 use libc::{self, c_int};
 use mem;
-use sys::{cvt, cvt_r};
+use sync::atomic::{AtomicBool, ATOMIC_BOOL_INIT, Ordering};
 use sys::fd::FileDesc;
+use sys::{cvt, cvt_r};
 
 ////////////////////////////////////////////////////////////////////////////////
 // Anonymous pipes
@@ -21,6 +22,9 @@ use sys::fd::FileDesc;
 pub struct AnonPipe(FileDesc);
 
 pub fn anon_pipe() -> io::Result<(AnonPipe, AnonPipe)> {
+ weak! { fn pipe2(*mut c_int, c_int) -> c_int }
+ static INVALID: AtomicBool = ATOMIC_BOOL_INIT;
+
  let mut fds = [0; 2];
 
  // Unfortunately the only known way right now to create atomically set the
@@ -31,13 +35,26 @@ pub fn anon_pipe() -> io::Result<(AnonPipe, AnonPipe)> {
  target_os = "freebsd",
  target_os = "linux",
  target_os = "netbsd",
- target_os = "openbsd"))
+ target_os = "openbsd")) &&
+ !INVALID.load(Ordering::SeqCst)
  {
- weak! { fn pipe2(*mut c_int, c_int) -> c_int }
+
  if let Some(pipe) = pipe2.get() {
- cvt(unsafe { pipe(fds.as_mut_ptr(), libc::O_CLOEXEC) })?;
- return Ok((AnonPipe(FileDesc::new(fds[0])),
- AnonPipe(FileDesc::new(fds[1]))));
+ // Note that despite calling a glibc function here we may still
+ // get ENOSYS. Glibc has `pipe2` since 2.9 and doesn't try to
+ // emulate on older kernels, so if you happen to be running on
+ // an older kernel you may see `pipe2` as a symbol but still not
+ // see the syscall.
+ match cvt(unsafe { pipe(fds.as_mut_ptr(), libc::O_CLOEXEC) }) {
+ Ok(_) => {
+ return Ok((AnonPipe(FileDesc::new(fds[0])),
+ AnonPipe(FileDesc::new(fds[1]))));
+ }
+ Err(ref e) if e.raw_os_error() == Some(libc::ENOSYS) => {
+ INVALID.store(true, Ordering::SeqCst);
+ }
+ Err(e) => return Err(e),
+ }
  }
  }
  cvt(unsafe { libc::pipe(fds.as_mut_ptr()) })?;

src/libstd/sys/unix/pipe.rs

@@ -0,0 +1,41 @@
+// 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.
+
+use std::ops::{Deref, DerefMut};
+
+struct CheckedDeref<T, F> {
+ value: T,
+ check: F
+}
+
+impl<F: Fn(&T) -> bool, T> Deref for CheckedDeref<T, F> {
+ type Target = T;
+ fn deref(&self) -> &T {
+ assert!((self.check)(&self.value));
+ &self.value
+ }
+}
+
+impl<F: Fn(&T) -> bool, T> DerefMut for CheckedDeref<T, F> {
+ fn deref_mut(&mut self) -> &mut T {
+ assert!((self.check)(&self.value));
+ &mut self.value
+ }
+}
+
+
+fn main() {
+ let mut v = CheckedDeref {
+ value: vec![0],
+ check: |v: &Vec<_>| !v.is_empty()
+ };
+ v.push(1);
+ assert_eq!(*v, vec![0, 1]);
+}

src/test/run-pass/issue-42463.rs

@@ -0,0 +1,32 @@
+// 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.
+
+struct Foo<T>(T);
+
+struct IntoIter<T>(T);
+
+impl<'a, T: 'a> Iterator for IntoIter<T> {
+ type Item = ();
+
+ fn next(&mut self) -> Option<()> {
+ None
+ }
+}
+
+impl<T> IntoIterator for Foo<T> {
+ type Item = ();
+ type IntoIter = IntoIter<T>;
+
+ fn into_iter(self) -> IntoIter<T> {
+ IntoIter(self.0)
+ }
+}
+
+fn main() {}