Auto merge of #52344 - Mark-Simulacrum:rollup, r=Mark-Simulacrum

Rollup of 16 pull requests

Successful merges:

 - #51962 (Provide llvm-strip in llvm-tools component)
 - #52003 (Implement `Option::replace` in the core library)
 - #52156 (Update std::ascii::ASCIIExt deprecation notes)
 - #52242 (NLL: Suggest `ref mut` and `&mut self`)
 - #52244 (Don't display default generic parameters in diagnostics that compare types)
 - #52290 (Deny bare trait objects in src/librustc_save_analysis)
 - #52293 (Deny bare trait objects in librustc_typeck)
 - #52299 (Deny bare trait objects in src/libserialize)
 - #52300 (Deny bare trait objects in librustc_target and libtest)
 - #52302 (Deny bare trait objects in the rest of rust)
 - #52310 (Backport 1.27.1 release notes to master)
 - #52314 (Fix ICE when using a pointer cast as array size)
 - #52315 (Resolve FIXME(#27942))
 - #52316 (task: remove wrong comments about non-existent LocalWake trait)
 - #52322 (Update llvm-rebuild-trigger in light of LLVM 7 upgrade)
 - #52332 (dead-code lint: say "constructed", "called" for structs, functions)

Failed merges:

r? @ghost

Author: bors

Diff for: RELEASES.md

@@ -140,6 +140,29 @@ Compatibility Notes
 [`{Any + Send + Sync}::downcast_ref`]: https://doc.rust-lang.org/std/any/trait.Any.html#method.downcast_ref-2
 [`{Any + Send + Sync}::is`]: https://doc.rust-lang.org/std/any/trait.Any.html#method.is-2
 
+Version 1.27.1 (2018-07-10)
+===========================
+
+Security Notes
+--------------
+
+- rustdoc would execute plugins in the /tmp/rustdoc/plugins directory
+  when running, which enabled executing code as some other user on a
+  given machine. This release fixes that vulnerability; you can read
+  more about this on the [blog][rustdoc-sec]. The associated CVE is [CVE-2018-1000622].
+
+  Thank you to Red Hat for responsibily disclosing this vulnerability to us.
+
+Compatibility Notes
+-------------------
+
+- The borrow checker was fixed to avoid an additional potential unsoundness when using
+  match ergonomics: [#51415][51415], [#49534][49534].
+
+[51415]: https://github.com/rust-lang/rust/issues/51415
+[49534]: https://github.com/rust-lang/rust/issues/49534
+[rustdoc-sec]: https://blog.rust-lang.org/2018/07/06/security-advisory-for-rustdoc.html
+[CVE-2018-1000622]: https://cve.mitre.org/cgi-bin/cvename.cgi?name=%20CVE-2018-1000622
 
 Version 1.27.0 (2018-06-21)
 ==========================

Diff for: src/bootstrap/lib.rs

@@ -206,7 +206,8 @@ const LLVM_TOOLS: &[&str] = &[
     "llvm-objcopy", // used to transform ELFs into binary format which flashing tools consume
     "llvm-objdump", // used to disassemble programs
     "llvm-profdata", // used to inspect and merge files generated by profiles
-    "llvm-size", // prints the size of the linker sections of a program
+    "llvm-size", // used to prints the size of the linker sections of a program
+    "llvm-strip", // used to discard symbols from binary files to reduce their size
 ];
 
 /// A structure representing a Rust compiler.

Diff for: src/build_helper/lib.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![deny(bare_trait_objects)]
+
 use std::fs::File;
 use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};

Diff for: src/liballoc_jemalloc/lib.rs

@@ -10,6 +10,7 @@
 
 #![no_std]
 #![allow(unused_attributes)]
+#![deny(bare_trait_objects)]
 #![unstable(feature = "alloc_jemalloc",
             reason = "implementation detail of std, does not provide any public API",
             issue = "0")]

Diff for: src/liballoc_system/lib.rs

@@ -10,6 +10,7 @@
 
 #![no_std]
 #![allow(unused_attributes)]
+#![deny(bare_trait_objects)]
 #![unstable(feature = "alloc_system",
             reason = "this library is unlikely to be stabilized in its current \
                       form or name",

Diff for: src/libarena/lib.rs

@@ -30,6 +30,7 @@
 #![cfg_attr(test, feature(test))]
 
 #![allow(deprecated)]
+#![deny(bare_trait_objects)]
 
 extern crate alloc;
 extern crate rustc_data_structures;

Diff for: src/libcore/option.rs

@@ -845,6 +845,33 @@ impl<T> Option<T> {
     pub fn take(&mut self) -> Option<T> {
         mem::replace(self, None)
     }
+
+    /// Replaces the actual value in the option by the value given in parameter,
+    /// returning the old value if present,
+    /// leaving a [`Some`] in its place without deinitializing either one.
+    ///
+    /// [`Some`]: #variant.Some
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(option_replace)]
+    ///
+    /// let mut x = Some(2);
+    /// let old = x.replace(5);
+    /// assert_eq!(x, Some(5));
+    /// assert_eq!(old, Some(2));
+    ///
+    /// let mut x = None;
+    /// let old = x.replace(3);
+    /// assert_eq!(x, Some(3));
+    /// assert_eq!(old, None);
+    /// ```
+    #[inline]
+    #[unstable(feature = "option_replace", issue = "51998")]
+    pub fn replace(&mut self, value: T) -> Option<T> {
+        mem::replace(self, Some(value))
+    }
 }
 
 impl<'a, T: Clone> Option<&'a T> {

Diff for: src/libcore/task/wake.rs

@@ -113,8 +113,8 @@ impl LocalWaker {
     /// but you otherwise shouldn't call it directly.
     ///
     /// If you're working with the standard library then it's recommended to
-    /// use the `LocalWaker::from` function instead which works with the safe
-    /// `Rc` type and the safe `LocalWake` trait.
+    /// use the `local_waker_from_nonlocal` or `local_waker` to convert a `Waker`
+    /// into a `LocalWaker`.
     ///
     /// For this function to be used safely, it must be sound to call `inner.wake_local()`
     /// on the current thread.
@@ -197,9 +197,7 @@ impl Drop for LocalWaker {
 /// customization.
 ///
 /// When using `std`, a default implementation of the `UnsafeWake` trait is provided for
-/// `Arc<T>` where `T: Wake` and `Rc<T>` where `T: LocalWake`.
-///
-/// Although the methods on `UnsafeWake` take pointers rather than references,
+/// `Arc<T>` where `T: Wake`.
 pub unsafe trait UnsafeWake: Send + Sync {
     /// Creates a clone of this `UnsafeWake` and stores it behind a `Waker`.
     ///

Diff for: src/libcore/tests/lib.rs

@@ -44,6 +44,7 @@
 #![feature(reverse_bits)]
 #![feature(iterator_find_map)]
 #![feature(slice_internals)]
+#![feature(option_replace)]
 
 extern crate core;
 extern crate test;

Diff for: src/libcore/tests/option.rs

@@ -297,3 +297,18 @@ fn test_try() {
     }
     assert_eq!(try_option_err(), Err(NoneError));
 }
+
+#[test]
+fn test_replace() {
+    let mut x = Some(2);
+    let old = x.replace(5);
+
+    assert_eq!(x, Some(5));
+    assert_eq!(old, Some(2));
+
+    let mut x = None;
+    let old = x.replace(3);
+
+    assert_eq!(x, Some(3));
+    assert_eq!(old, None);
+}

Diff for: src/libfmt_macros/lib.rs

@@ -14,6 +14,8 @@
 //! Parsing does not happen at runtime: structures of `std::fmt::rt` are
 //! generated instead.
 
+#![deny(bare_trait_objects)]
+
 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
        html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
        html_root_url = "https://doc.rust-lang.org/nightly/",

Diff for: src/libgraphviz/lib.rs

@@ -283,6 +283,8 @@
 //!
 //! * [DOT language](http://www.graphviz.org/doc/info/lang.html)
 
+#![deny(bare_trait_objects)]
+
 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
        html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
        html_root_url = "https://doc.rust-lang.org/nightly/",

Diff for: src/libpanic_abort/lib.rs

@@ -21,6 +21,7 @@
        issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/")]
 #![panic_runtime]
 #![allow(unused_features)]
+#![deny(bare_trait_objects)]
 
 #![feature(core_intrinsics)]
 #![feature(libc)]

Diff for: src/libproc_macro/lib.rs

@@ -22,6 +22,7 @@
 //! See [the book](../book/first-edition/procedural-macros.html) for more.
 
 #![stable(feature = "proc_macro_lib", since = "1.15.0")]
+#![deny(bare_trait_objects)]
 #![deny(missing_docs)]
 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
        html_favicon_url = "https://doc.rust-lang.org/favicon.ico",

Diff for: src/libprofiler_builtins/lib.rs

@@ -15,4 +15,5 @@
             reason = "internal implementation detail of rustc right now",
             issue = "0")]
 #![allow(unused_features)]
+#![deny(bare_trait_objects)]
 #![feature(staged_api)]

Diff for: src/librustc/infer/error_reporting/mod.rs

@@ -60,13 +60,13 @@ use super::{InferCtxt, RegionVariableOrigin, SubregionOrigin, TypeTrace, ValuePa
 use super::region_constraints::GenericKind;
 use super::lexical_region_resolve::RegionResolutionError;
 
-use std::fmt;
+use std::{cmp, fmt};
 use hir;
 use hir::map as hir_map;
 use hir::def_id::DefId;
 use middle::region;
 use traits::{ObligationCause, ObligationCauseCode};
-use ty::{self, Region, Ty, TyCtxt, TypeFoldable, TypeVariants};
+use ty::{self, subst::Subst, Region, Ty, TyCtxt, TypeFoldable, TypeVariants};
 use ty::error::TypeError;
 use syntax::ast::DUMMY_NODE_ID;
 use syntax_pos::{Pos, Span};
@@ -193,32 +193,12 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
 
         let scope = region.free_region_binding_scope(self);
         let node = self.hir.as_local_node_id(scope).unwrap_or(DUMMY_NODE_ID);
-        let unknown;
         let tag = match self.hir.find(node) {
             Some(hir_map::NodeBlock(_)) | Some(hir_map::NodeExpr(_)) => "body",
             Some(hir_map::NodeItem(it)) => Self::item_scope_tag(&it),
             Some(hir_map::NodeTraitItem(it)) => Self::trait_item_scope_tag(&it),
             Some(hir_map::NodeImplItem(it)) => Self::impl_item_scope_tag(&it),
-
-            // this really should not happen, but it does:
-            // FIXME(#27942)
-            Some(_) => {
-                unknown = format!(
-                    "unexpected node ({}) for scope {:?}.  \
-                     Please report a bug.",
-                    self.hir.node_to_string(node),
-                    scope
-                );
-                &unknown
-            }
-            None => {
-                unknown = format!(
-                    "unknown node for scope {:?}.  \
-                     Please report a bug.",
-                    scope
-                );
-                &unknown
-            }
+            _ => unreachable!()
         };
         let (prefix, span) = match *region {
             ty::ReEarlyBound(ref br) => {
@@ -672,6 +652,43 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
         }
     }
 
+    /// For generic types with parameters with defaults, remove the parameters corresponding to
+    /// the defaults. This repeats a lot of the logic found in `PrintContext::parameterized`.
+    fn strip_generic_default_params(
+        &self,
+        def_id: DefId,
+        substs: &ty::subst::Substs<'tcx>
+    ) -> &'tcx ty::subst::Substs<'tcx> {
+        let generics = self.tcx.generics_of(def_id);
+        let mut num_supplied_defaults = 0;
+        let mut type_params = generics.params.iter().rev().filter_map(|param| match param.kind {
+            ty::GenericParamDefKind::Lifetime => None,
+            ty::GenericParamDefKind::Type { has_default, .. } => {
+                Some((param.def_id, has_default))
+            }
+        }).peekable();
+        let has_default = {
+            let has_default = type_params.peek().map(|(_, has_default)| has_default);
+            *has_default.unwrap_or(&false)
+        };
+        if has_default {
+            let types = substs.types().rev();
+            for ((def_id, has_default), actual) in type_params.zip(types) {
+                if !has_default {
+                    break;
+                }
+                if self.tcx.type_of(def_id).subst(self.tcx, substs) != actual {
+                    break;
+                }
+                num_supplied_defaults += 1;
+            }
+        }
+        let len = generics.params.len();
+        let mut generics = generics.clone();
+        generics.params.truncate(len - num_supplied_defaults);
+        substs.truncate_to(self.tcx, &generics)
+    }
+
     /// Compare two given types, eliding parts that are the same between them and highlighting
     /// relevant differences, and return two representation of those types for highlighted printing.
     fn cmp(&self, t1: Ty<'tcx>, t2: Ty<'tcx>) -> (DiagnosticStyledString, DiagnosticStyledString) {
@@ -713,6 +730,8 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
 
         match (&t1.sty, &t2.sty) {
             (&ty::TyAdt(def1, sub1), &ty::TyAdt(def2, sub2)) => {
+                let sub_no_defaults_1 = self.strip_generic_default_params(def1.did, sub1);
+                let sub_no_defaults_2 = self.strip_generic_default_params(def2.did, sub2);
                 let mut values = (DiagnosticStyledString::new(), DiagnosticStyledString::new());
                 let path1 = self.tcx.item_path_str(def1.did.clone());
                 let path2 = self.tcx.item_path_str(def2.did.clone());
@@ -728,8 +747,19 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                     values.0.push_normal(path1);
                     values.1.push_normal(path2);
 
+                    // Avoid printing out default generic parameters that are common to both
+                    // types.
+                    let len1 = sub_no_defaults_1.len();
+                    let len2 = sub_no_defaults_2.len();
+                    let common_len = cmp::min(len1, len2);
+                    let remainder1: Vec<_> = sub1.types().skip(common_len).collect();
+                    let remainder2: Vec<_> = sub2.types().skip(common_len).collect();
+                    let common_default_params =
+                        remainder1.iter().rev().zip(remainder2.iter().rev())
+                                               .filter(|(a, b)| a == b).count();
+                    let len = sub1.len() - common_default_params;
+
                     // Only draw `<...>` if there're lifetime/type arguments.
-                    let len = sub1.len();
                     if len > 0 {
                         values.0.push_normal("<");
                         values.1.push_normal("<");
@@ -774,7 +804,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                     //         ^ elided type as this type argument was the same in both sides
                     let type_arguments = sub1.types().zip(sub2.types());
                     let regions_len = sub1.regions().collect::<Vec<_>>().len();
-                    for (i, (ta1, ta2)) in type_arguments.enumerate() {
+                    for (i, (ta1, ta2)) in type_arguments.take(len).enumerate() {
                         let i = i + regions_len;
                         if ta1 == ta2 {
                             values.0.push_normal("_");
@@ -804,7 +834,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                         &mut values.0,
                         &mut values.1,
                         path1.clone(),
-                        sub1,
+                        sub_no_defaults_1,
                         path2.clone(),
                         &t2,
                     ).is_some()
@@ -816,8 +846,14 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                     //     Bar<Qux>
                     //     Foo<Bar<Qux>>
                     //         ------- this type argument is exactly the same as the other type
-                    if self.cmp_type_arg(&mut values.1, &mut values.0, path2, sub2, path1, &t1)
-                        .is_some()
+                    if self.cmp_type_arg(
+                        &mut values.1,
+                        &mut values.0,
+                        path2,
+                        sub_no_defaults_2,
+                        path1,
+                        &t1,
+                    ).is_some()
                     {
                         return values;
                     }

Diff for: src/librustc/middle/dead.rs

@@ -567,12 +567,17 @@ impl<'a, 'tcx> Visitor<'tcx> for DeadVisitor<'a, 'tcx> {
                 hir::ItemImpl(..) => self.tcx.sess.codemap().def_span(item.span),
                 _ => item.span,
             };
+            let participle = match item.node {
+                hir::ItemFn(..) => "called",
+                hir::ItemStruct(..) => "constructed",
+                _ => "used"
+            };
             self.warn_dead_code(
                 item.id,
                 span,
                 item.name,
                 item.node.descriptive_variant(),
-                "used",
+                participle,
             );
         } else {
             // Only continue if we didn't warn
@@ -622,7 +627,8 @@ impl<'a, 'tcx> Visitor<'tcx> for DeadVisitor<'a, 'tcx> {
             hir::ImplItemKind::Method(_, body_id) => {
                 if !self.symbol_is_live(impl_item.id, None) {
                     let span = self.tcx.sess.codemap().def_span(impl_item.span);
-                    self.warn_dead_code(impl_item.id, span, impl_item.ident.name, "method", "used");
+                    self.warn_dead_code(impl_item.id, span, impl_item.ident.name,
+                                        "method", "called");
                 }
                 self.visit_nested_body(body_id)
             }