Merge remote-tracking branch 'upstream/master'

.gitignore

@@ -103,3 +103,6 @@ version.texi
 .cargo
 !src/vendor/**
 /src/target/
+
+no_llvm_build
+

CONTRIBUTING.md

@@ -461,6 +461,7 @@ For people new to Rust, and just starting to contribute, or even for
 more seasoned developers, some useful places to look for information
 are:
 
+* [Rust Forge][rustforge] contains additional documentation, including write-ups of how to achieve common tasks
 * The [Rust Internals forum][rif], a place to ask questions and
   discuss Rust's internals
 * The [generated documentation for rust's compiler][gdfrustc]
@@ -476,6 +477,7 @@ are:
 [gsearchdocs]: https://www.google.com/search?q=site:doc.rust-lang.org+your+query+here
 [rif]: http://internals.rust-lang.org
 [rr]: https://doc.rust-lang.org/book/README.html
+[rustforge]: https://forge.rust-lang.org/
 [tlgba]: http://tomlee.co/2014/04/a-more-detailed-tour-of-the-rust-compiler/
 [ro]: http://www.rustaceans.org/
 [rctd]: ./src/test/COMPILER_TESTS.md

src/Cargo.toml

@@ -38,6 +38,8 @@ members = [
   "tools/rls/test_data/infer_custom_bin",
   "tools/rls/test_data/infer_lib",
   "tools/rls/test_data/omit_init_build",
+  "tools/rls/test_data/unicødë",
+  "tools/rls/test_data/workspace_symbol",
 ]
 
 # Curiously, compiletest will segfault if compiled with opt-level=3 on 64-bit
@@ -60,10 +62,5 @@ debug-assertions = false
 [patch."https://github.com/rust-lang/cargo"]
 cargo = { path = "tools/cargo" }
 
-# Override rustfmt dependencies both on the repo and the crate (the RLS
-# sometimes uses either).
-# FIXME should only need the crates.io patch, long term.
-[patch."https://github.com/rust-lang-nursery/rustfmt"]
-rustfmt-nightly = { path = "tools/rustfmt" }
 [patch.crates-io]
 rustfmt-nightly = { path = "tools/rustfmt" }

src/bootstrap/Cargo.toml

@@ -34,7 +34,7 @@ cmake = "0.1.23"
 filetime = "0.1"
 num_cpus = "1.0"
 getopts = "0.2"
-gcc = "0.3.54"
+cc = "1.0"
 libc = "0.2"
 serde = "1.0.8"
 serde_derive = "1.0.8"

src/bootstrap/bin/sccache-plus-cl.rs

@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern crate gcc;
+extern crate cc;
 
 use std::env;
 use std::process::{self, Command};
@@ -18,7 +18,7 @@ fn main() {
     // Locate the actual compiler that we're invoking
     env::remove_var("CC");
     env::remove_var("CXX");
-    let mut cfg = gcc::Build::new();
+    let mut cfg = cc::Build::new();
     cfg.cargo_metadata(false)
        .out_dir("/")
        .target(&target)

src/bootstrap/bootstrap.py

@@ -682,7 +682,7 @@ def bootstrap():
     try:
         with open(args.config or 'config.toml') as config:
             build.config_toml = config.read()
-    except OSError:
+    except (OSError, IOError):
         pass
 
     if '\nverbose = 2' in build.config_toml:

src/bootstrap/builder.rs

@@ -306,7 +306,7 @@ impl<'a> Builder<'a> {
             Subcommand::Bench { ref paths, .. } => (Kind::Bench, &paths[..]),
             Subcommand::Dist { ref paths } => (Kind::Dist, &paths[..]),
             Subcommand::Install { ref paths } => (Kind::Install, &paths[..]),
-            Subcommand::Clean => panic!(),
+            Subcommand::Clean { .. } => panic!(),
         };
 
         let builder = Builder {
@@ -531,7 +531,10 @@ impl<'a> Builder<'a> {
         // For other crates, however, we know that we've already got a standard
         // library up and running, so we can use the normal compiler to compile
         // build scripts in that situation.
-        if mode == Mode::Libstd {
+        //
+        // If LLVM support is disabled we need to use the snapshot compiler to compile
+        // build scripts, as the new compiler doesnt support executables.
+        if mode == Mode::Libstd || !self.build.config.llvm_enabled {
             cargo.env("RUSTC_SNAPSHOT", &self.initial_rustc)
                  .env("RUSTC_SNAPSHOT_LIBDIR", self.rustc_snapshot_libdir());
         } else {

src/bootstrap/cc_detect.rs

@@ -23,7 +23,7 @@
 //! 6. "cc"
 //!
 //! Some of this logic is implemented here, but much of it is farmed out to the
-//! `gcc` crate itself, so we end up having the same fallbacks as there.
+//! `cc` crate itself, so we end up having the same fallbacks as there.
 //! Similar logic is then used to find a C++ compiler, just some s/cc/c++/ is
 //! used.
 //!
@@ -35,7 +35,7 @@ use std::process::Command;
 use std::iter;
 
 use build_helper::{cc2ar, output};
-use gcc;
+use cc;
 
 use Build;
 use config::Target;
@@ -45,7 +45,7 @@ pub fn find(build: &mut Build) {
     // For all targets we're going to need a C compiler for building some shims
     // and such as well as for being a linker for Rust code.
     for target in build.targets.iter().chain(&build.hosts).cloned().chain(iter::once(build.build)) {
-        let mut cfg = gcc::Build::new();
+        let mut cfg = cc::Build::new();
         cfg.cargo_metadata(false).opt_level(0).warnings(false).debug(false)
            .target(&target).host(&build.build);
 
@@ -67,7 +67,7 @@ pub fn find(build: &mut Build) {
 
     // For all host triples we need to find a C++ compiler as well
     for host in build.hosts.iter().cloned().chain(iter::once(build.build)) {
-        let mut cfg = gcc::Build::new();
+        let mut cfg = cc::Build::new();
         cfg.cargo_metadata(false).opt_level(0).warnings(false).debug(false).cpp(true)
            .target(&host).host(&build.build);
         let config = build.config.target_config.get(&host);
@@ -82,7 +82,7 @@ pub fn find(build: &mut Build) {
     }
 }
 
-fn set_compiler(cfg: &mut gcc::Build,
+fn set_compiler(cfg: &mut cc::Build,
                 gnu_compiler: &str,
                 target: Interned<String>,
                 config: Option<&Target>,

src/bootstrap/check.rs

@@ -254,7 +254,11 @@ impl Step for Rls {
 
         builder.add_rustc_lib_path(compiler, &mut cargo);
 
-        try_run(build, &mut cargo);
+        try_run_expecting(
+            build,
+            &mut cargo,
+            builder.build.config.toolstate.rls.passes(ToolState::Testing),
+        );
     }
 }
 
@@ -295,7 +299,11 @@ impl Step for Rustfmt {
 
         builder.add_rustc_lib_path(compiler, &mut cargo);
 
-        try_run(build, &mut cargo);
+        try_run_expecting(
+            build,
+            &mut cargo,
+            builder.build.config.toolstate.rustfmt.passes(ToolState::Testing),
+        );
     }
 }
 

src/bootstrap/clean.rs

@@ -13,7 +13,7 @@
 //! Responsible for cleaning out a build directory of all old and stale
 //! artifacts to prepare for a fresh build. Currently doesn't remove the
 //! `build/cache` directory (download cache) or the `build/$target/llvm`
-//! directory as we want that cached between builds.
+//! directory unless the --all flag is present.
 
 use std::fs;
 use std::io::{self, ErrorKind};
@@ -21,24 +21,29 @@ use std::path::Path;
 
 use Build;
 
-pub fn clean(build: &Build) {
+pub fn clean(build: &Build, all: bool) {
     rm_rf("tmp".as_ref());
-    rm_rf(&build.out.join("tmp"));
-    rm_rf(&build.out.join("dist"));
 
-    for host in &build.hosts {
-        let entries = match build.out.join(host).read_dir() {
-            Ok(iter) => iter,
-            Err(_) => continue,
-        };
+    if all {
+        rm_rf(&build.out);
+    } else {
+        rm_rf(&build.out.join("tmp"));
+        rm_rf(&build.out.join("dist"));
 
-        for entry in entries {
-            let entry = t!(entry);
-            if entry.file_name().to_str() == Some("llvm") {
-                continue
+        for host in &build.hosts {
+            let entries = match build.out.join(host).read_dir() {
+                Ok(iter) => iter,
+                Err(_) => continue,
+            };
+
+            for entry in entries {
+                let entry = t!(entry);
+                if entry.file_name().to_str() == Some("llvm") {
+                    continue
+                }
+                let path = t!(entry.path().canonicalize());
+                rm_rf(&path);
             }
-            let path = t!(entry.path().canonicalize());
-            rm_rf(&path);
         }
     }
 }

src/bootstrap/configure.py

@@ -109,6 +109,8 @@ v("musl-root-armhf", "target.arm-unknown-linux-musleabihf.musl-root",
   "arm-unknown-linux-musleabihf install directory")
 v("musl-root-armv7", "target.armv7-unknown-linux-musleabihf.musl-root",
   "armv7-unknown-linux-musleabihf install directory")
+v("musl-root-aarch64", "target.aarch64-unknown-linux-musl.musl-root",
+  "aarch64-unknown-linux-musl install directory")
 v("qemu-armhf-rootfs", "target.arm-unknown-linux-gnueabihf.qemu-rootfs",
   "rootfs in qemu testing, you probably don't want to use this")
 v("qemu-aarch64-rootfs", "target.aarch64-unknown-linux-gnu.qemu-rootfs",

src/bootstrap/dist.rs

@@ -1098,13 +1098,8 @@ impl Step for Rls {
            .arg("--output-dir").arg(&distdir(build))
            .arg("--non-installed-overlay").arg(&overlay)
            .arg(format!("--package-name={}-{}", name, target))
-           .arg("--legacy-manifest-dirs=rustlib,cargo");
-
-        if build.config.channel == "nightly" {
-            cmd.arg("--component-name=rls");
-        } else {
-            cmd.arg("--component-name=rls-preview");
-        }
+           .arg("--legacy-manifest-dirs=rustlib,cargo")
+           .arg("--component-name=rls-preview");
 
         build.run(&mut cmd);
         distdir(build).join(format!("{}-{}.tar.gz", name, target))
@@ -1333,12 +1328,8 @@ impl Step for Extended {
             cp_r(&work.join(&format!("{}-{}", pkgname(build, "rust-std"), target))
                         .join(format!("rust-std-{}", target)),
                     &exe.join("rust-std"));
-            let rls_path = if build.config.channel == "nightly" {
-                work.join(&format!("{}-{}", pkgname(build, "rls"), target)).join("rls")
-            } else {
-                work.join(&format!("{}-{}", pkgname(build, "rls"), target)).join("rls-preview")
-            };
-            cp_r(&rls_path, &exe.join("rls"));
+            cp_r(&work.join(&format!("{}-{}", pkgname(build, "rls"), target)).join("rls-preview"),
+                 &exe.join("rls"));
             cp_r(&work.join(&format!("{}-{}", pkgname(build, "rust-analysis"), target))
                         .join(format!("rust-analysis-{}", target)),
                     &exe.join("rust-analysis"));

src/bootstrap/flags.rs

@@ -60,7 +60,9 @@ pub enum Subcommand {
         paths: Vec<PathBuf>,
         test_args: Vec<String>,
     },
-    Clean,
+    Clean {
+        all: bool,
+    },
     Dist {
         paths: Vec<PathBuf>,
     },
@@ -147,6 +149,7 @@ To learn more about a subcommand, run `./x.py <subcommand> -h`");
                 opts.optmulti("", "test-args", "extra arguments", "ARGS");
             },
             "bench" => { opts.optmulti("", "test-args", "extra arguments", "ARGS"); },
+            "clean" => { opts.optflag("", "all", "clean all build artifacts"); },
             _ => { },
         };
 
@@ -250,7 +253,7 @@ Arguments:
             }
         });
 
-        // All subcommands can have an optional "Available paths" section
+        // All subcommands except `clean` can have an optional "Available paths" section
         if matches.opt_present("verbose") {
             let config = Config::parse(&["build".to_string()]);
             let mut build = Build::new(config);
@@ -258,9 +261,10 @@ Arguments:
 
             let maybe_rules_help = Builder::get_help(&build, subcommand.as_str());
             extra_help.push_str(maybe_rules_help.unwrap_or_default().as_str());
-        } else {
-            extra_help.push_str(format!("Run `./x.py {} -h -v` to see a list of available paths.",
-                     subcommand).as_str());
+        } else if subcommand.as_str() != "clean" {
+            extra_help.push_str(format!(
+                "Run `./x.py {} -h -v` to see a list of available paths.",
+                subcommand).as_str());
         }
 
         // User passed in -h/--help?
@@ -290,10 +294,13 @@ Arguments:
             }
             "clean" => {
                 if paths.len() > 0 {
-                    println!("\nclean takes no arguments\n");
+                    println!("\nclean does not take a path argument\n");
                     usage(1, &opts, &subcommand_help, &extra_help);
                 }
-                Subcommand::Clean
+
+                Subcommand::Clean {
+                    all: matches.opt_present("all"),
+                }
             }
             "dist" => {
                 Subcommand::Dist {

src/bootstrap/lib.rs

@@ -126,7 +126,7 @@ extern crate lazy_static;
 extern crate serde_json;
 extern crate cmake;
 extern crate filetime;
-extern crate gcc;
+extern crate cc;
 extern crate getopts;
 extern crate num_cpus;
 extern crate toml;
@@ -148,7 +148,7 @@ use build_helper::{run_silent, run_suppressed, try_run_silent, try_run_suppresse
 
 use util::{exe, libdir, OutputFolder, CiEnv};
 
-mod cc;
+mod cc_detect;
 mod channel;
 mod check;
 mod clean;
@@ -241,9 +241,9 @@ pub struct Build {
 
     // Runtime state filled in later on
     // target -> (cc, ar)
-    cc: HashMap<Interned<String>, (gcc::Tool, Option<PathBuf>)>,
+    cc: HashMap<Interned<String>, (cc::Tool, Option<PathBuf>)>,
     // host -> (cc, ar)
-    cxx: HashMap<Interned<String>, gcc::Tool>,
+    cxx: HashMap<Interned<String>, cc::Tool>,
     crates: HashMap<Interned<String>, Crate>,
     is_sudo: bool,
     ci_env: CiEnv,
@@ -345,12 +345,12 @@ impl Build {
             job::setup(self);
         }
 
-        if let Subcommand::Clean = self.config.cmd {
-            return clean::clean(self);
+        if let Subcommand::Clean { all } = self.config.cmd {
+            return clean::clean(self, all);
         }
 
         self.verbose("finding compilers");
-        cc::find(self);
+        cc_detect::find(self);
         self.verbose("running sanity check");
         sanity::check(self);
         // If local-rust is the same major.minor as the current version, then force a local-rebuild
@@ -619,7 +619,7 @@ impl Build {
     /// specified.
     fn cflags(&self, target: Interned<String>) -> Vec<String> {
         // Filter out -O and /O (the optimization flags) that we picked up from
-        // gcc-rs because the build scripts will determine that for themselves.
+        // cc-rs because the build scripts will determine that for themselves.
         let mut base = self.cc[&target].0.args().iter()
                            .map(|s| s.to_string_lossy().into_owned())
                            .filter(|s| !s.starts_with("-O") && !s.starts_with("/O"))

src/bootstrap/native.rs

@@ -27,7 +27,7 @@ use std::process::Command;
 
 use build_helper::output;
 use cmake;
-use gcc;
+use cc;
 
 use Build;
 use util;
@@ -289,7 +289,7 @@ impl Step for TestHelpers {
         let _folder = build.fold_output(|| "build_test_helpers");
         println!("Building test helpers");
         t!(fs::create_dir_all(&dst));
-        let mut cfg = gcc::Build::new();
+        let mut cfg = cc::Build::new();
 
         // We may have found various cross-compilers a little differently due to our
         // extra configuration, so inform gcc of these compilers. Note, though, that
@@ -367,7 +367,7 @@ impl Step for Openssl {
             if !ok {
                 panic!("failed to download openssl source")
             }
-            let mut shasum = if target.contains("apple") {
+            let mut shasum = if target.contains("apple") || build.build.contains("netbsd") {
                 let mut cmd = Command::new("shasum");
                 cmd.arg("-a").arg("256");
                 cmd
@@ -387,7 +387,7 @@ impl Step for Openssl {
         let dst = build.openssl_install_dir(target).unwrap();
         drop(fs::remove_dir_all(&obj));
         drop(fs::remove_dir_all(&dst));
-        build.run(Command::new("tar").arg("xf").arg(&tarball).current_dir(&out));
+        build.run(Command::new("tar").arg("zxf").arg(&tarball).current_dir(&out));
 
         let mut configure = Command::new("perl");
         configure.arg(obj.join("Configure"));
@@ -399,6 +399,7 @@ impl Step for Openssl {
         let os = match &*target {
             "aarch64-linux-android" => "linux-aarch64",
             "aarch64-unknown-linux-gnu" => "linux-aarch64",
+            "aarch64-unknown-linux-musl" => "linux-aarch64",
             "arm-linux-androideabi" => "android",
             "arm-unknown-linux-gnueabi" => "linux-armv4",
             "arm-unknown-linux-gnueabihf" => "linux-armv4",

src/bootstrap/sanity.rs

@@ -221,8 +221,9 @@ $ pacman -R cmake && pacman -S mingw-w64-x86_64-cmake
     let run = |cmd: &mut Command| {
         cmd.output().map(|output| {
             String::from_utf8_lossy(&output.stdout)
-                   .lines().next().unwrap()
-                   .to_string()
+                   .lines().next().unwrap_or_else(|| {
+                       panic!("{:?} failed {:?}", cmd, output)
+                   }).to_string()
         })
     };
     build.lldb_version = run(Command::new("lldb").arg("--version")).ok();

src/bootstrap/tool.rs

@@ -126,6 +126,10 @@ pub fn prepare_tool_cargo(
         cargo.env("LIBZ_SYS_STATIC", "1");
     }
 
+    // if tools are using lzma we want to force the build script to build its
+    // own copy
+    cargo.env("LZMA_API_STATIC", "1");
+
     cargo.env("CFG_RELEASE_CHANNEL", &build.config.channel);
     cargo.env("CFG_VERSION", build.rust_version());
 
@@ -304,6 +308,11 @@ impl Step for Rustdoc {
                                            target,
                                            "build",
                                            "src/tools/rustdoc");
+
+        // Most tools don't get debuginfo, but rustdoc should.
+        cargo.env("RUSTC_DEBUGINFO", builder.config.rust_debuginfo.to_string())
+             .env("RUSTC_DEBUGINFO_LINES", builder.config.rust_debuginfo_lines.to_string());
+
         build.run(&mut cargo);
         // Cargo adds a number of paths to the dylib search path on windows, which results in
         // the wrong rustdoc being executed. To avoid the conflicting rustdocs, we name the "tool"
@@ -449,7 +458,7 @@ impl Step for Rls {
             tool: "rls",
             mode: Mode::Librustc,
             path: "src/tools/rls",
-            expectation: BuildExpectation::None,
+            expectation: builder.build.config.toolstate.rls.passes(ToolState::Compiling),
         })
     }
 }
@@ -484,7 +493,7 @@ impl Step for Rustfmt {
             tool: "rustfmt",
             mode: Mode::Librustc,
             path: "src/tools/rustfmt",
-            expectation: BuildExpectation::None,
+            expectation: builder.build.config.toolstate.rustfmt.passes(ToolState::Compiling),
         })
     }
 }

src/bootstrap/toolstate.rs

@@ -46,4 +46,6 @@ impl Default for ToolState {
 pub struct ToolStates {
     pub miri: ToolState,
     pub clippy: ToolState,
+    pub rls: ToolState,
+    pub rustfmt: ToolState,
 }

src/ci/docker/cross/Dockerfile

@@ -14,6 +14,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
   zlib1g-dev \
   g++-arm-linux-gnueabi \
   g++-arm-linux-gnueabihf \
+  g++-aarch64-linux-gnu \
   gcc-sparc64-linux-gnu \
   libc6-dev-sparc64-cross \
   bzip2 \
@@ -46,6 +47,7 @@ ENV TARGETS=$TARGETS,mipsel-unknown-linux-musl
 ENV TARGETS=$TARGETS,arm-unknown-linux-musleabi
 ENV TARGETS=$TARGETS,arm-unknown-linux-musleabihf
 ENV TARGETS=$TARGETS,armv7-unknown-linux-musleabihf
+ENV TARGETS=$TARGETS,aarch64-unknown-linux-musl
 ENV TARGETS=$TARGETS,sparc64-unknown-linux-gnu
 ENV TARGETS=$TARGETS,x86_64-unknown-redox
 
@@ -62,7 +64,8 @@ ENV RUST_CONFIGURE_ARGS \
       --target=$TARGETS \
       --musl-root-arm=/usr/local/arm-linux-musleabi \
       --musl-root-armhf=/usr/local/arm-linux-musleabihf \
-      --musl-root-armv7=/usr/local/armv7-linux-musleabihf
+      --musl-root-armv7=/usr/local/armv7-linux-musleabihf \
+      --musl-root-aarch64=/usr/local/aarch64-linux-musl
 ENV SCRIPT python2.7 ../x.py dist --target $TARGETS
 
 # sccache

src/ci/docker/cross/build-arm-musl.sh

@@ -65,11 +65,24 @@ CFLAGS="-march=armv7-a" \
 hide_output make -j$(nproc)
 hide_output make install
 cd ..
+rm -rf musl-$MUSL
+
+tar xf musl-$MUSL.tar.gz
+cd musl-$MUSL
+CC=aarch64-linux-gnu-gcc \
+CFLAGS="" \
+    hide_output ./configure \
+        --prefix=/usr/local/aarch64-linux-musl \
+        --enable-wrapper=gcc
+hide_output make -j$(nproc)
+hide_output make install
+cd ..
 rm -rf musl-$MUSL*
 
 ln -nsf ../arm-linux-musleabi/bin/musl-gcc /usr/local/bin/arm-linux-musleabi-gcc
 ln -nsf ../arm-linux-musleabihf/bin/musl-gcc /usr/local/bin/arm-linux-musleabihf-gcc
 ln -nsf ../armv7-linux-musleabihf/bin/musl-gcc /usr/local/bin/armv7-linux-musleabihf-gcc
+ln -nsf ../aarch64-linux-musl/bin/musl-gcc /usr/local/bin/aarch64-unknown-linux-musl-gcc
 
 curl -L https://github.com/llvm-mirror/llvm/archive/release_39.tar.gz | tar xzf -
 curl -L https://github.com/llvm-mirror/libunwind/archive/release_39.tar.gz | tar xzf -
@@ -116,5 +129,19 @@ cp lib/libunwind.a /usr/local/armv7-linux-musleabihf/lib
 cd ..
 rm -rf libunwind-build
 
+mkdir libunwind-build
+cd libunwind-build
+cmake ../libunwind-release_39 \
+          -DLLVM_PATH=/tmp/llvm-release_39 \
+          -DLIBUNWIND_ENABLE_SHARED=0 \
+          -DCMAKE_C_COMPILER=aarch64-linux-gnu-gcc \
+          -DCMAKE_CXX_COMPILER=aarch64-linux-gnu-g++ \
+          -DCMAKE_C_FLAGS="" \
+          -DCMAKE_CXX_FLAGS=""
+make -j$(nproc)
+cp lib/libunwind.a /usr/local/aarch64-linux-musl/lib
+cd ..
+rm -rf libunwind-build
+
 rm -rf libunwind-release_39
 rm -rf llvm-release_39

src/ci/docker/disabled/aarch64-gnu/Dockerfile

@@ -31,7 +31,7 @@ WORKDIR /build
 # The `config` config file was a previously generated config file for
 # the kernel. This file was generated by running `make defconfig`
 # followed by `make menuconfig` and then enabling the IPv6 protocol page.
-COPY disabled/aarch64-gnu/config /build/.config
+COPY aarch64-gnu/config /build/.config
 RUN curl https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.4.42.tar.xz | \
       tar xJf - && \
       cd /build/linux-4.4.42 && \

src/ci/docker/disabled/wasm32-exp/Dockerfile

@@ -17,7 +17,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
 
 # emscripten
 COPY scripts/emscripten-wasm.sh /scripts/
-COPY disabled/wasm32-exp/node.sh /usr/local/bin/node
+COPY wasm32-exp/node.sh /usr/local/bin/node
 RUN bash /scripts/emscripten-wasm.sh
 
 # cache

src/ci/docker/dist-fuchsia/Dockerfile

@@ -1,27 +1,26 @@
 FROM ubuntu:16.04
 
-RUN apt-get update && apt-get install -y --no-install-recommends \
+RUN apt-get update && apt-get build-dep -y clang llvm && apt-get install -y \
+  build-essential \
+  bzip2 \
+  ca-certificates \
+  cmake \
+  curl \
+  file \
   g++ \
+  gdb \
+  git \
+  libedit-dev \
   make \
   ninja-build \
-  file \
-  curl \
-  ca-certificates \
+  nodejs \
   python2.7-dev \
-  git \
   sudo \
-  bzip2 \
   xz-utils \
-  swig \
-  libedit-dev \
-  libncurses5-dev \
-  patch
-
-RUN curl -L https://cmake.org/files/v3.8/cmake-3.8.0-rc1-Linux-x86_64.tar.gz | \
-      tar xzf - -C /usr/local --strip-components=1
+  unzip
 
 WORKDIR /tmp
-COPY dist-fuchsia/shared.sh dist-fuchsia/build-toolchain.sh dist-fuchsia/compiler-rt-dso-handle.patch /tmp/
+COPY dist-fuchsia/shared.sh dist-fuchsia/build-toolchain.sh /tmp/
 RUN /tmp/build-toolchain.sh
 
 COPY scripts/sccache.sh /scripts/
@@ -39,4 +38,4 @@ ENV TARGETS=x86_64-unknown-fuchsia
 ENV TARGETS=$TARGETS,aarch64-unknown-fuchsia
 
 ENV RUST_CONFIGURE_ARGS --target=$TARGETS --enable-extended
-ENV SCRIPT python2.7 ../x.py dist --target $TARGETS
+ENV SCRIPT python2.7 ../x.py dist --target $TARGETS

src/ci/docker/dist-fuchsia/build-toolchain.sh

@@ -14,105 +14,44 @@
 set -ex
 source shared.sh
 
+ZIRCON=e9a26dbc70d631029f8ee9763103910b7e3a2fe1
+
+mkdir -p zircon
+pushd zircon > /dev/null
+
 # Download sources
-SRCS=(
-  "https://fuchsia.googlesource.com/magenta magenta d17073dc8de344ead3b65e8cc6a12280dec38c84"
-  "https://llvm.googlesource.com/llvm llvm 3f58a16d8eec385e2b3ebdfbb84ff9d3bf27e025"
-  "https://llvm.googlesource.com/clang llvm/tools/clang 727ea63e6e82677f6e10e05e08bc7d6bdbae3111"
-  "https://llvm.googlesource.com/lld llvm/tools/lld a31286c1366e5e89b8872803fded13805a1a084b"
-  "https://llvm.googlesource.com/lldb llvm/tools/lldb 0b2384abec4cb99ad66687712e07dee4dd9d187e"
-  "https://llvm.googlesource.com/compiler-rt llvm/runtimes/compiler-rt 9093a35c599fe41278606a20b51095ea8bd5a081"
-  "https://llvm.googlesource.com/libcxx llvm/runtimes/libcxx 607e0c71ec4f7fd377ad3f6c47b08dbe89f66eaa"
-  "https://llvm.googlesource.com/libcxxabi llvm/runtimes/libcxxabi 0a3a1a8a5ca5ef69e0f6b7d5b9d13e63e6fd2c19"
-  "https://llvm.googlesource.com/libunwind llvm/runtimes/libunwind e128003563d99d9ee62247c4cee40f07d21c03e3"
-)
+git init
+git remote add origin https://fuchsia.googlesource.com/zircon
+git fetch --depth=1 origin $ZIRCON
+git reset --hard FETCH_HEAD
 
-fetch() {
-  mkdir -p $2
-  pushd $2 > /dev/null
-  git init
-  git remote add origin $1
-  git fetch --depth=1 origin $3
-  git reset --hard FETCH_HEAD
-  popd > /dev/null
-}
+# Download toolchain
+./scripts/download-toolchain
+chmod -R a+rx prebuilt/downloads/clang+llvm-x86_64-linux
+cp -a prebuilt/downloads/clang+llvm-x86_64-linux/. /usr/local
 
-for i in "${SRCS[@]}"; do
-  fetch $i
-done
-
-# Remove this once https://reviews.llvm.org/D28791 is resolved
-cd llvm/runtimes/compiler-rt
-patch -Np1 < /tmp/compiler-rt-dso-handle.patch
-cd ../../..
-
-# Build toolchain
-cd llvm
-mkdir build
-cd build
-hide_output cmake -GNinja \
-  -DFUCHSIA_SYSROOT=${PWD}/../../magenta/third_party/ulib/musl \
-  -DLLVM_ENABLE_LTO=OFF \
-  -DCLANG_BOOTSTRAP_PASSTHROUGH=LLVM_ENABLE_LTO \
-  -C ../tools/clang/cmake/caches/Fuchsia.cmake \
-  ..
-hide_output ninja stage2-distribution
-hide_output ninja stage2-install-distribution
-cd ../..
-
-# Build sysroot
-rm -rf llvm/runtimes/compiler-rt
-./magenta/scripts/download-toolchain
-
-build_sysroot() {
+build() {
   local arch="$1"
 
   case "${arch}" in
-    x86_64) tgt="magenta-pc-x86-64" ;;
-    aarch64) tgt="magenta-qemu-arm64" ;;
+    x86_64) tgt="zircon-pc-x86-64" ;;
+    aarch64) tgt="zircon-qemu-arm64" ;;
   esac
 
-  hide_output make -C magenta -j$(getconf _NPROCESSORS_ONLN) $tgt
+  hide_output make -j$(getconf _NPROCESSORS_ONLN) $tgt
   dst=/usr/local/${arch}-unknown-fuchsia
   mkdir -p $dst
-  cp -r magenta/build-${tgt}/sysroot/include $dst/
-  cp -r magenta/build-${tgt}/sysroot/lib $dst/
-
-  cd llvm
-  mkdir build-runtimes-${arch}
-  cd build-runtimes-${arch}
-  hide_output cmake -GNinja \
-    -DCMAKE_C_COMPILER=clang \
-    -DCMAKE_CXX_COMPILER=clang++ \
-    -DCMAKE_AR=/usr/local/bin/llvm-ar \
-    -DCMAKE_RANLIB=/usr/local/bin/llvm-ranlib \
-    -DCMAKE_INSTALL_PREFIX= \
-    -DLLVM_MAIN_SRC_DIR=${PWD}/.. \
-    -DLLVM_BINARY_DIR=${PWD}/../build \
-    -DLLVM_ENABLE_WERROR=OFF \
-    -DCMAKE_BUILD_TYPE=Release \
-    -DLLVM_INCLUDE_TESTS=ON \
-    -DCMAKE_SYSTEM_NAME=Fuchsia \
-    -DCMAKE_C_COMPILER_TARGET=${arch}-fuchsia \
-    -DCMAKE_CXX_COMPILER_TARGET=${arch}-fuchsia \
-    -DUNIX=1 \
-    -DLIBCXX_HAS_MUSL_LIBC=ON \
-    -DLIBCXXABI_USE_LLVM_UNWINDER=ON \
-    -DCMAKE_SYSROOT=${dst} \
-    -DCMAKE_C_COMPILER_FORCED=TRUE \
-    -DCMAKE_CXX_COMPILER_FORCED=TRUE \
-    -DLLVM_ENABLE_LIBCXX=ON \
-    -DCMAKE_EXE_LINKER_FLAGS="-nodefaultlibs -lc" \
-    -DCMAKE_SHARED_LINKER_FLAGS="$(clang --target=${arch}-fuchsia -print-libgcc-file-name)" \
-    ../runtimes
-  hide_output env DESTDIR="${dst}" ninja install
-  cd ../..
+  cp -a build-${tgt}/sysroot/include $dst/
+  cp -a build-${tgt}/sysroot/lib $dst/
 }
 
-build_sysroot "x86_64"
-build_sysroot "aarch64"
+# Build sysroot
+for arch in x86_64 aarch64; do
+  build ${arch}
+done
 
-rm -rf magenta llvm
+popd > /dev/null
+rm -rf zircon
 
 for arch in x86_64 aarch64; do
   for tool in clang clang++; do

src/ci/docker/dist-fuchsia/compiler-rt-dso-handle.patch

@@ -1,41 +0,0 @@
-diff --git a/lib/builtins/CMakeLists.txt b/lib/builtins/CMakeLists.txt
-index fc4384af2..b442264c0 100644
---- a/lib/builtins/CMakeLists.txt
-+++ b/lib/builtins/CMakeLists.txt
-@@ -194,6 +194,12 @@ if(APPLE)
-     atomic_thread_fence.c)
- endif()
- 
-+if(FUCHSIA)
-+  set(GENERIC_SOURCES
-+    ${GENERIC_SOURCES}
-+    dso_handle.c)
-+endif()
-+
- if(NOT WIN32 OR MINGW)
-   set(GENERIC_SOURCES
-       ${GENERIC_SOURCES}
-diff --git a/lib/builtins/dso_handle.c b/lib/builtins/dso_handle.c
-new file mode 100644
-index 000000000..7766cd0aa
---- /dev/null
-+++ b/lib/builtins/dso_handle.c
-@@ -0,0 +1,18 @@
-+/* ===-- dso_handle.c - Provide __dso_handle -------------------------------===
-+ *
-+ *               The LLVM Compiler Infrastructure
-+ *
-+ * This file is dual licensed under the MIT and the University of Illinois Open
-+ * Source Licenses. See LICENSE.TXT for details.
-+ *
-+ * ===----------------------------------------------------------------------===
-+ */
-+
-+/* __dso_handle symbol is mandated by C++ ABI with a value which is an address
-+ * in one of the object's segments, and as such this symbol has to be included
-+ * statically and cannot be a part of a shared library. Traditionally, it has
-+ * been defined in crtbegin.o but there's no principled reason for it to be
-+ * there. We defined this symbol in the builtin library which is built as a
-+ * static library and always included in the final link.
-+ */
-+__attribute__((visibility("hidden"))) void *const __dso_handle;

src/ci/docker/run.sh

@@ -36,12 +36,14 @@ elif [ -f "$docker_dir/disabled/$image/Dockerfile" ]; then
         echo Cannot run disabled images on travis!
         exit 1
     fi
-    retry docker \
+    # retry messes with the pipe from tar to docker. Not needed on non-travis
+    # Transform changes the context of disabled Dockerfiles to match the enabled ones
+    tar --transform 's#^./disabled/#./#' -C $docker_dir -c . | docker \
       build \
       --rm \
       -t rust-ci \
-      -f "$docker_dir/disabled/$image/Dockerfile" \
-      "$docker_dir"
+      -f "$image/Dockerfile" \
+      -
 else
     echo Invalid image: $image
     exit 1

src/doc/unstable-book/src/language-features/inclusive-range-syntax.md

@@ -7,13 +7,13 @@ The tracking issue for this feature is: [#28237]
 ------------------------
 
 To get a range that goes from 0 to 10 and includes the value 10, you
-can write `0...10`:
+can write `0..=10`:
 
 ```rust
 #![feature(inclusive_range_syntax)]
 
 fn main() {
-    for i in 0...10 {
+    for i in 0..=10 {
         println!("{}", i);
     }
 }

src/liballoc/arc.rs

@@ -72,13 +72,13 @@ const MAX_REFCOUNT: usize = (isize::MAX) as usize;
 /// first: after all, isn't the point of `Arc<T>` thread safety? The key is
 /// this: `Arc<T>` makes it thread safe to have multiple ownership of the same
 /// data, but it  doesn't add thread safety to its data. Consider
-/// `Arc<RefCell<T>>`. `RefCell<T>` isn't [`Sync`], and if `Arc<T>` was always
-/// [`Send`], `Arc<RefCell<T>>` would be as well. But then we'd have a problem:
-/// `RefCell<T>` is not thread safe; it keeps track of the borrowing count using
+/// `Arc<`[`RefCell<T>`]`>`. [`RefCell<T>`] isn't [`Sync`], and if `Arc<T>` was always
+/// [`Send`], `Arc<`[`RefCell<T>`]`>` would be as well. But then we'd have a problem:
+/// [`RefCell<T>`] is not thread safe; it keeps track of the borrowing count using
 /// non-atomic operations.
 ///
 /// In the end, this means that you may need to pair `Arc<T>` with some sort of
-/// `std::sync` type, usually `Mutex<T>`.
+/// [`std::sync`] type, usually [`Mutex<T>`][mutex].
 ///
 /// ## Breaking cycles with `Weak`
 ///
@@ -106,7 +106,7 @@ const MAX_REFCOUNT: usize = (isize::MAX) as usize;
 /// // a and b both point to the same memory location as foo.
 /// ```
 ///
-/// The `Arc::clone(&from)` syntax is the most idiomatic because it conveys more explicitly
+/// The [`Arc::clone(&from)`] syntax is the most idiomatic because it conveys more explicitly
 /// the meaning of the code. In the example above, this syntax makes it easier to see that
 /// this code is creating a new reference rather than copying the whole content of foo.
 ///
@@ -141,6 +141,9 @@ const MAX_REFCOUNT: usize = (isize::MAX) as usize;
 /// [upgrade]: struct.Weak.html#method.upgrade
 /// [`None`]: ../../std/option/enum.Option.html#variant.None
 /// [assoc]: ../../book/first-edition/method-syntax.html#associated-functions
+/// [`RefCell<T>`]: ../../std/cell/struct.RefCell.html
+/// [`std::sync`]: ../../std/sync/index.html
+/// [`Arc::clone(&from)`]: #method.clone
 ///
 /// # Examples
 ///

src/liballoc/lib.rs

@@ -98,6 +98,7 @@
 #![feature(generic_param_attrs)]
 #![feature(i128_type)]
 #![feature(inclusive_range)]
+#![feature(iter_rfold)]
 #![feature(lang_items)]
 #![feature(needs_allocator)]
 #![feature(nonzero)]

src/liballoc/tests/btree/map.rs

@@ -182,7 +182,7 @@ fn test_range_small() {
 fn test_range_inclusive() {
     let size = 500;
 
-    let map: BTreeMap<_, _> = (0...size).map(|i| (i, i)).collect();
+    let map: BTreeMap<_, _> = (0..=size).map(|i| (i, i)).collect();
 
     fn check<'a, L, R>(lhs: L, rhs: R)
         where L: IntoIterator<Item=(&'a i32, &'a i32)>,
@@ -193,18 +193,18 @@ fn test_range_inclusive() {
         assert_eq!(lhs, rhs);
     }
 
-    check(map.range(size + 1...size + 1), vec![]);
-    check(map.range(size...size), vec![(&size, &size)]);
-    check(map.range(size...size + 1), vec![(&size, &size)]);
-    check(map.range(0...0), vec![(&0, &0)]);
-    check(map.range(0...size - 1), map.range(..size));
-    check(map.range(-1...-1), vec![]);
-    check(map.range(-1...size), map.range(..));
-    check(map.range(...size), map.range(..));
-    check(map.range(...200), map.range(..201));
-    check(map.range(5...8), vec![(&5, &5), (&6, &6), (&7, &7), (&8, &8)]);
-    check(map.range(-1...0), vec![(&0, &0)]);
-    check(map.range(-1...2), vec![(&0, &0), (&1, &1), (&2, &2)]);
+    check(map.range(size + 1..=size + 1), vec![]);
+    check(map.range(size..=size), vec![(&size, &size)]);
+    check(map.range(size..=size + 1), vec![(&size, &size)]);
+    check(map.range(0..=0), vec![(&0, &0)]);
+    check(map.range(0..=size - 1), map.range(..size));
+    check(map.range(-1..=-1), vec![]);
+    check(map.range(-1..=size), map.range(..));
+    check(map.range(..=size), map.range(..));
+    check(map.range(..=200), map.range(..201));
+    check(map.range(5..=8), vec![(&5, &5), (&6, &6), (&7, &7), (&8, &8)]);
+    check(map.range(-1..=0), vec![(&0, &0)]);
+    check(map.range(-1..=2), vec![(&0, &0), (&1, &1), (&2, &2)]);
 }
 
 #[test]
@@ -212,7 +212,7 @@ fn test_range_inclusive_max_value() {
     let max = ::std::usize::MAX;
     let map: BTreeMap<_, _> = vec![(max, 0)].into_iter().collect();
 
-    assert_eq!(map.range(max...max).collect::<Vec<_>>(), &[(&max, &0)]);
+    assert_eq!(map.range(max..=max).collect::<Vec<_>>(), &[(&max, &0)]);
 }
 
 #[test]

src/liballoc/tests/str.rs

@@ -361,13 +361,13 @@ fn test_slice_fail() {
 #[test]
 #[should_panic]
 fn test_str_slice_rangetoinclusive_max_panics() {
-    &"hello"[...usize::max_value()];
+    &"hello"[..=usize::max_value()];
 }
 
 #[test]
 #[should_panic]
 fn test_str_slice_rangeinclusive_max_panics() {
-    &"hello"[1...usize::max_value()];
+    &"hello"[1..=usize::max_value()];
 }
 
 #[test]
@@ -375,7 +375,7 @@ fn test_str_slice_rangeinclusive_max_panics() {
 fn test_str_slicemut_rangetoinclusive_max_panics() {
     let mut s = "hello".to_owned();
     let s: &mut str = &mut s;
-    &mut s[...usize::max_value()];
+    &mut s[..=usize::max_value()];
 }
 
 #[test]
@@ -383,7 +383,7 @@ fn test_str_slicemut_rangetoinclusive_max_panics() {
 fn test_str_slicemut_rangeinclusive_max_panics() {
     let mut s = "hello".to_owned();
     let s: &mut str = &mut s;
-    &mut s[1...usize::max_value()];
+    &mut s[1..=usize::max_value()];
 }
 
 #[test]
@@ -391,13 +391,13 @@ fn test_str_get_maxinclusive() {
     let mut s = "hello".to_owned();
     {
         let s: &str = &s;
-        assert_eq!(s.get(...usize::max_value()), None);
-        assert_eq!(s.get(1...usize::max_value()), None);
+        assert_eq!(s.get(..=usize::max_value()), None);
+        assert_eq!(s.get(1..=usize::max_value()), None);
     }
     {
         let s: &mut str = &mut s;
-        assert_eq!(s.get(...usize::max_value()), None);
-        assert_eq!(s.get(1...usize::max_value()), None);
+        assert_eq!(s.get(..=usize::max_value()), None);
+        assert_eq!(s.get(1..=usize::max_value()), None);
     }
 }
 

src/liballoc/tests/string.rs

@@ -456,9 +456,9 @@ fn test_splice_char_boundary() {
 #[test]
 fn test_splice_inclusive_range() {
     let mut v = String::from("12345");
-    v.splice(2...3, "789");
+    v.splice(2..=3, "789");
     assert_eq!(v, "127895");
-    v.splice(1...2, "A");
+    v.splice(1..=2, "A");
     assert_eq!(v, "1A895");
 }
 
@@ -473,7 +473,7 @@ fn test_splice_out_of_bounds() {
 #[should_panic]
 fn test_splice_inclusive_out_of_bounds() {
     let mut s = String::from("12345");
-    s.splice(5...5, "789");
+    s.splice(5..=5, "789");
 }
 
 #[test]

src/liballoc/tests/vec.rs

@@ -537,27 +537,27 @@ fn test_drain_range() {
 #[test]
 fn test_drain_inclusive_range() {
     let mut v = vec!['a', 'b', 'c', 'd', 'e'];
-    for _ in v.drain(1...3) {
+    for _ in v.drain(1..=3) {
     }
     assert_eq!(v, &['a', 'e']);
 
-    let mut v: Vec<_> = (0...5).map(|x| x.to_string()).collect();
-    for _ in v.drain(1...5) {
+    let mut v: Vec<_> = (0..=5).map(|x| x.to_string()).collect();
+    for _ in v.drain(1..=5) {
     }
     assert_eq!(v, &["0".to_string()]);
 
-    let mut v: Vec<String> = (0...5).map(|x| x.to_string()).collect();
-    for _ in v.drain(0...5) {
+    let mut v: Vec<String> = (0..=5).map(|x| x.to_string()).collect();
+    for _ in v.drain(0..=5) {
     }
     assert_eq!(v, Vec::<String>::new());
 
-    let mut v: Vec<_> = (0...5).map(|x| x.to_string()).collect();
-    for _ in v.drain(0...3) {
+    let mut v: Vec<_> = (0..=5).map(|x| x.to_string()).collect();
+    for _ in v.drain(0..=3) {
     }
     assert_eq!(v, &["4".to_string(), "5".to_string()]);
 
-    let mut v: Vec<_> = (0...1).map(|x| x.to_string()).collect();
-    for _ in v.drain(...0) {
+    let mut v: Vec<_> = (0..=1).map(|x| x.to_string()).collect();
+    for _ in v.drain(..=0) {
     }
     assert_eq!(v, &["1".to_string()]);
 }
@@ -572,7 +572,7 @@ fn test_drain_max_vec_size() {
 
     let mut v = Vec::<()>::with_capacity(usize::max_value());
     unsafe { v.set_len(usize::max_value()); }
-    for _ in v.drain(usize::max_value() - 1...usize::max_value() - 1) {
+    for _ in v.drain(usize::max_value() - 1..=usize::max_value() - 1) {
     }
     assert_eq!(v.len(), usize::max_value() - 1);
 }
@@ -581,7 +581,7 @@ fn test_drain_max_vec_size() {
 #[should_panic]
 fn test_drain_inclusive_out_of_bounds() {
     let mut v = vec![1, 2, 3, 4, 5];
-    v.drain(5...5);
+    v.drain(5..=5);
 }
 
 #[test]
@@ -598,10 +598,10 @@ fn test_splice() {
 fn test_splice_inclusive_range() {
     let mut v = vec![1, 2, 3, 4, 5];
     let a = [10, 11, 12];
-    let t1: Vec<_> = v.splice(2...3, a.iter().cloned()).collect();
+    let t1: Vec<_> = v.splice(2..=3, a.iter().cloned()).collect();
     assert_eq!(v, &[1, 2, 10, 11, 12, 5]);
     assert_eq!(t1, &[3, 4]);
-    let t2: Vec<_> = v.splice(1...2, Some(20)).collect();
+    let t2: Vec<_> = v.splice(1..=2, Some(20)).collect();
     assert_eq!(v, &[1, 20, 11, 12, 5]);
     assert_eq!(t2, &[2, 10]);
 }
@@ -619,7 +619,7 @@ fn test_splice_out_of_bounds() {
 fn test_splice_inclusive_out_of_bounds() {
     let mut v = vec![1, 2, 3, 4, 5];
     let a = [10, 11, 12];
-    v.splice(5...5, a.iter().cloned());
+    v.splice(5..=5, a.iter().cloned());
 }
 
 #[test]

src/liballoc/vec.rs

@@ -1950,7 +1950,7 @@ impl<T> Vec<T> {
     /// assert_eq!(u, &[1, 2]);
     /// ```
     #[inline]
-    #[stable(feature = "vec_splice", since = "1.22.0")]
+    #[stable(feature = "vec_splice", since = "1.21.0")]
     pub fn splice<R, I>(&mut self, range: R, replace_with: I) -> Splice<I::IntoIter>
         where R: RangeArgument<usize>, I: IntoIterator<Item=T>
     {
@@ -2553,13 +2553,13 @@ impl<'a, T> InPlace<T> for PlaceBack<'a, T> {
 /// [`splice()`]: struct.Vec.html#method.splice
 /// [`Vec`]: struct.Vec.html
 #[derive(Debug)]
-#[stable(feature = "vec_splice", since = "1.22.0")]
+#[stable(feature = "vec_splice", since = "1.21.0")]
 pub struct Splice<'a, I: Iterator + 'a> {
     drain: Drain<'a, I::Item>,
     replace_with: I,
 }
 
-#[stable(feature = "vec_splice", since = "1.22.0")]
+#[stable(feature = "vec_splice", since = "1.21.0")]
 impl<'a, I: Iterator> Iterator for Splice<'a, I> {
     type Item = I::Item;
 
@@ -2572,18 +2572,18 @@ impl<'a, I: Iterator> Iterator for Splice<'a, I> {
     }
 }
 
-#[stable(feature = "vec_splice", since = "1.22.0")]
+#[stable(feature = "vec_splice", since = "1.21.0")]
 impl<'a, I: Iterator> DoubleEndedIterator for Splice<'a, I> {
     fn next_back(&mut self) -> Option<Self::Item> {
         self.drain.next_back()
     }
 }
 
-#[stable(feature = "vec_splice", since = "1.22.0")]
+#[stable(feature = "vec_splice", since = "1.21.0")]
 impl<'a, I: Iterator> ExactSizeIterator for Splice<'a, I> {}
 
 
-#[stable(feature = "vec_splice", since = "1.22.0")]
+#[stable(feature = "vec_splice", since = "1.21.0")]
 impl<'a, I: Iterator> Drop for Splice<'a, I> {
     fn drop(&mut self) {
         // exhaust drain first

src/liballoc/vec_deque.rs

@@ -558,7 +558,7 @@ impl<T> VecDeque<T> {
             .and_then(|needed_cap| needed_cap.checked_next_power_of_two())
             .expect("capacity overflow");
 
-        if new_cap > self.capacity() {
+        if new_cap > old_cap {
             self.buf.reserve_exact(used_cap, new_cap - used_cap);
             unsafe {
                 self.handle_cap_increase(old_cap);
@@ -1973,6 +1973,14 @@ impl<'a, T> DoubleEndedIterator for Iter<'a, T> {
         self.head = wrap_index(self.head.wrapping_sub(1), self.ring.len());
         unsafe { Some(self.ring.get_unchecked(self.head)) }
     }
+
+    fn rfold<Acc, F>(self, mut accum: Acc, mut f: F) -> Acc
+        where F: FnMut(Acc, Self::Item) -> Acc
+    {
+        let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
+        accum = back.iter().rfold(accum, &mut f);
+        front.iter().rfold(accum, &mut f)
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -2058,6 +2066,14 @@ impl<'a, T> DoubleEndedIterator for IterMut<'a, T> {
             Some(&mut *(elem as *mut _))
         }
     }
+
+    fn rfold<Acc, F>(self, mut accum: Acc, mut f: F) -> Acc
+        where F: FnMut(Acc, Self::Item) -> Acc
+    {
+        let (front, back) = RingSlices::ring_slices(self.ring, self.head, self.tail);
+        accum = back.iter_mut().rfold(accum, &mut f);
+        front.iter_mut().rfold(accum, &mut f)
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]

src/liballoc_jemalloc/Cargo.toml

@@ -19,7 +19,7 @@ libc = { path = "../rustc/libc_shim" }
 
 [build-dependencies]
 build_helper = { path = "../build_helper" }
-gcc = "0.3.50"
+cc = "1.0"
 
 [features]
 debug = []

src/liballoc_jemalloc/build.rs

@@ -11,7 +11,7 @@
 #![deny(warnings)]
 
 extern crate build_helper;
-extern crate gcc;
+extern crate cc;
 
 use std::env;
 use std::path::PathBuf;
@@ -63,7 +63,7 @@ fn main() {
         _ => return,
     };
 
-    let compiler = gcc::Build::new().get_compiler();
+    let compiler = cc::Build::new().get_compiler();
     // only msvc returns None for ar so unwrap is okay
     let ar = build_helper::cc2ar(compiler.path(), &target).unwrap();
     let cflags = compiler.args()
@@ -150,7 +150,7 @@ fn main() {
     // sure the symbols are available.
     if target.contains("androideabi") {
         println!("cargo:rerun-if-changed=pthread_atfork_dummy.c");
-        gcc::Build::new()
+        cc::Build::new()
             .flag("-fvisibility=hidden")
             .file("pthread_atfork_dummy.c")
             .compile("libpthread_atfork_dummy.a");

src/libcore/benches/iter.rs

@@ -147,40 +147,131 @@ fn bench_for_each_chain_ref_fold(b: &mut Bencher) {
     });
 }
 
-#[bench]
-fn bench_flat_map_sum(b: &mut Bencher) {
-    b.iter(|| -> i64 {
-        (0i64..1000).flat_map(|x| x..x+1000)
-            .map(black_box)
-            .sum()
-    });
+
+/// Helper to benchmark `sum` for iterators taken by value which
+/// can optimize `fold`, and by reference which cannot.
+macro_rules! bench_sums {
+    ($bench_sum:ident, $bench_ref_sum:ident, $iter:expr) => {
+        #[bench]
+        fn $bench_sum(b: &mut Bencher) {
+            b.iter(|| -> i64 {
+                $iter.map(black_box).sum()
+            });
+        }
+
+        #[bench]
+        fn $bench_ref_sum(b: &mut Bencher) {
+            b.iter(|| -> i64 {
+                $iter.map(black_box).by_ref().sum()
+            });
+        }
+    }
 }
 
-#[bench]
-fn bench_flat_map_ref_sum(b: &mut Bencher) {
-    b.iter(|| -> i64 {
-        (0i64..1000).flat_map(|x| x..x+1000)
-            .map(black_box)
-            .by_ref()
-            .sum()
-    });
+bench_sums! {
+    bench_flat_map_sum,
+    bench_flat_map_ref_sum,
+    (0i64..1000).flat_map(|x| x..x+1000)
 }
 
-#[bench]
-fn bench_flat_map_chain_sum(b: &mut Bencher) {
-    b.iter(|| -> i64 {
-        (0i64..1000000).flat_map(|x| once(x).chain(once(x)))
-            .map(black_box)
-            .sum()
-    });
+bench_sums! {
+    bench_flat_map_chain_sum,
+    bench_flat_map_chain_ref_sum,
+    (0i64..1000000).flat_map(|x| once(x).chain(once(x)))
 }
 
-#[bench]
-fn bench_flat_map_chain_ref_sum(b: &mut Bencher) {
-    b.iter(|| -> i64 {
-        (0i64..1000000).flat_map(|x| once(x).chain(once(x)))
-            .map(black_box)
-            .by_ref()
-            .sum()
-    });
+bench_sums! {
+    bench_enumerate_sum,
+    bench_enumerate_ref_sum,
+    (0i64..1000000).enumerate().map(|(i, x)| x * i as i64)
+}
+
+bench_sums! {
+    bench_enumerate_chain_sum,
+    bench_enumerate_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).enumerate().map(|(i, x)| x * i as i64)
+}
+
+bench_sums! {
+    bench_filter_sum,
+    bench_filter_ref_sum,
+    (0i64..1000000).filter(|x| x % 2 == 0)
+}
+
+bench_sums! {
+    bench_filter_chain_sum,
+    bench_filter_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).filter(|x| x % 2 == 0)
+}
+
+bench_sums! {
+    bench_filter_map_sum,
+    bench_filter_map_ref_sum,
+    (0i64..1000000).filter_map(|x| x.checked_mul(x))
+}
+
+bench_sums! {
+    bench_filter_map_chain_sum,
+    bench_filter_map_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).filter_map(|x| x.checked_mul(x))
+}
+
+bench_sums! {
+    bench_fuse_sum,
+    bench_fuse_ref_sum,
+    (0i64..1000000).fuse()
+}
+
+bench_sums! {
+    bench_fuse_chain_sum,
+    bench_fuse_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).fuse()
+}
+
+bench_sums! {
+    bench_inspect_sum,
+    bench_inspect_ref_sum,
+    (0i64..1000000).inspect(|_| {})
+}
+
+bench_sums! {
+    bench_inspect_chain_sum,
+    bench_inspect_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).inspect(|_| {})
+}
+
+bench_sums! {
+    bench_peekable_sum,
+    bench_peekable_ref_sum,
+    (0i64..1000000).peekable()
+}
+
+bench_sums! {
+    bench_peekable_chain_sum,
+    bench_peekable_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).peekable()
+}
+
+bench_sums! {
+    bench_skip_sum,
+    bench_skip_ref_sum,
+    (0i64..1000000).skip(1000)
+}
+
+bench_sums! {
+    bench_skip_chain_sum,
+    bench_skip_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).skip(1000)
+}
+
+bench_sums! {
+    bench_skip_while_sum,
+    bench_skip_while_ref_sum,
+    (0i64..1000000).skip_while(|&x| x < 1000)
+}
+
+bench_sums! {
+    bench_skip_while_chain_sum,
+    bench_skip_while_chain_ref_sum,
+    (0i64..1000000).chain(0..1000000).skip_while(|&x| x < 1000)
 }

src/libcore/cmp.rs

@@ -456,7 +456,7 @@ pub trait Ord: Eq + PartialOrd<Self> {
     /// assert_eq!(2, 1.max(2));
     /// assert_eq!(2, 2.max(2));
     /// ```
-    #[stable(feature = "ord_max_min", since = "1.22.0")]
+    #[stable(feature = "ord_max_min", since = "1.21.0")]
     fn max(self, other: Self) -> Self
     where Self: Sized {
         if other >= self { other } else { self }
@@ -472,7 +472,7 @@ pub trait Ord: Eq + PartialOrd<Self> {
     /// assert_eq!(1, 1.min(2));
     /// assert_eq!(2, 2.min(2));
     /// ```
-    #[stable(feature = "ord_max_min", since = "1.22.0")]
+    #[stable(feature = "ord_max_min", since = "1.21.0")]
     fn min(self, other: Self) -> Self
     where Self: Sized {
         if self <= other { self } else { other }

src/libcore/convert.rs

@@ -48,8 +48,25 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use str::FromStr;
+use fmt;
 
+/// A type used as the error type for implementations of fallible conversion
+/// traits in cases where conversions cannot actually fail.
+///
+/// Because `Infallible` has no variants, a value of this type can never exist.
+/// It is used only to satisfy trait signatures that expect an error type, and
+/// signals to both the compiler and the user that the error case is impossible.
+#[unstable(feature = "try_from", issue = "33417")]
+#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
+pub enum Infallible {}
+
+#[unstable(feature = "try_from", issue = "33417")]
+impl fmt::Display for Infallible {
+    fn fmt(&self, _: &mut fmt::Formatter) -> fmt::Result {
+        match *self {
+        }
+    }
+}
 /// A cheap reference-to-reference conversion. Used to convert a value to a
 /// reference value within generic code.
 ///
@@ -417,6 +434,17 @@ impl<T, U> TryInto<U> for T where U: TryFrom<T>
     }
 }
 
+// Infallible conversions are semantically equivalent to fallible conversions
+// with an uninhabited error type.
+#[unstable(feature = "try_from", issue = "33417")]
+impl<T, U> TryFrom<U> for T where T: From<U> {
+    type Error = Infallible;
+
+    fn try_from(value: U) -> Result<Self, Self::Error> {
+        Ok(T::from(value))
+    }
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // CONCRETE IMPLS
 ////////////////////////////////////////////////////////////////////////////////
@@ -442,14 +470,3 @@ impl AsRef<str> for str {
         self
     }
 }
-
-// FromStr implies TryFrom<&str>
-#[unstable(feature = "try_from", issue = "33417")]
-impl<'a, T> TryFrom<&'a str> for T where T: FromStr
-{
-    type Error = <T as FromStr>::Err;
-
-    fn try_from(s: &'a str) -> Result<T, Self::Error> {
-        FromStr::from_str(s)
-    }
-}

src/libcore/fmt/mod.rs

@@ -488,13 +488,14 @@ impl<'a> Display for Arguments<'a> {
 /// The origin is: Point { x: 0, y: 0 }
 /// ```
 ///
-/// There are a number of `debug_*` methods on `Formatter` to help you with manual
+/// There are a number of `debug_*` methods on [`Formatter`] to help you with manual
 /// implementations, such as [`debug_struct`][debug_struct].
 ///
 /// `Debug` implementations using either `derive` or the debug builder API
-/// on `Formatter` support pretty printing using the alternate flag: `{:#?}`.
+/// on [`Formatter`] support pretty printing using the alternate flag: `{:#?}`.
 ///
 /// [debug_struct]: ../../std/fmt/struct.Formatter.html#method.debug_struct
+/// [`Formatter`]: ../../std/fmt/struct.Formatter.html
 ///
 /// Pretty printing with `#?`:
 ///
@@ -1321,8 +1322,11 @@ impl<'a> Formatter<'a> {
         self.flags & (1 << FlagV1::SignAwareZeroPad as u32) != 0
     }
 
-    /// Creates a `DebugStruct` builder designed to assist with creation of
-    /// `fmt::Debug` implementations for structs.
+    /// Creates a [`DebugStruct`] builder designed to assist with creation of
+    /// [`fmt::Debug`] implementations for structs.
+    ///
+    /// [`DebugStruct`]: ../../std/fmt/struct.DebugStruct.html
+    /// [`fmt::Debug`]: ../../std/fmt/trait.Debug.html
     ///
     /// # Examples
     ///
@@ -1700,8 +1704,18 @@ impl<T: ?Sized + Debug> Debug for RefCell<T> {
                     .finish()
             }
             Err(_) => {
+                // The RefCell is mutably borrowed so we can't look at its value
+                // here. Show a placeholder instead.
+                struct BorrowedPlaceholder;
+
+                impl Debug for BorrowedPlaceholder {
+                    fn fmt(&self, f: &mut Formatter) -> Result {
+                        f.write_str("<borrowed>")
+                    }
+                }
+
                 f.debug_struct("RefCell")
-                    .field("value", &"<borrowed>")
+                    .field("value", &BorrowedPlaceholder)
                     .finish()
             }
         }

src/libcore/internal_macros.rs

@@ -68,3 +68,22 @@ macro_rules! forward_ref_binop {
         }
     }
 }
+
+// implements "T op= &U", based on "T op= U"
+// where U is expected to be `Copy`able
+macro_rules! forward_ref_op_assign {
+    (impl $imp:ident, $method:ident for $t:ty, $u:ty) => {
+        forward_ref_op_assign!(impl $imp, $method for $t, $u,
+                #[stable(feature = "op_assign_builtins_by_ref", since = "1.22.0")]);
+    };
+    (impl $imp:ident, $method:ident for $t:ty, $u:ty, #[$attr:meta]) => {
+        #[$attr]
+        impl<'a> $imp<&'a $u> for $t {
+            #[inline]
+            fn $method(&mut self, other: &'a $u) {
+                $imp::$method(self, *other);
+            }
+        }
+    }
+}
+

src/libcore/iter/iterator.rs

@@ -518,7 +518,7 @@ pub trait Iterator {
     ///       .for_each(|(i, x)| println!("{}:{}", i, x));
     /// ```
     #[inline]
-    #[stable(feature = "iterator_for_each", since = "1.22.0")]
+    #[stable(feature = "iterator_for_each", since = "1.21.0")]
     fn for_each<F>(self, mut f: F) where
         Self: Sized, F: FnMut(Self::Item),
     {
@@ -1337,7 +1337,7 @@ pub trait Iterator {
         (left, right)
     }
 
-    /// An iterator adaptor that applies a function, producing a single, final value.
+    /// An iterator method that applies a function, producing a single, final value.
     ///
     /// `fold()` takes two arguments: an initial value, and a closure with two
     /// arguments: an 'accumulator', and an element. The closure returns the value that

src/libcore/iter/mod.rs

@@ -359,6 +359,12 @@ impl<I> Iterator for Rev<I> where I: DoubleEndedIterator {
     #[inline]
     fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
 
+    fn fold<Acc, F>(self, init: Acc, f: F) -> Acc
+        where F: FnMut(Acc, Self::Item) -> Acc,
+    {
+        self.iter.rfold(init, f)
+    }
+
     #[inline]
     fn find<P>(&mut self, predicate: P) -> Option<Self::Item>
         where P: FnMut(&Self::Item) -> bool
@@ -379,6 +385,12 @@ impl<I> DoubleEndedIterator for Rev<I> where I: DoubleEndedIterator {
     #[inline]
     fn next_back(&mut self) -> Option<<I as Iterator>::Item> { self.iter.next() }
 
+    fn rfold<Acc, F>(self, init: Acc, f: F) -> Acc
+        where F: FnMut(Acc, Self::Item) -> Acc,
+    {
+        self.iter.fold(init, f)
+    }
+
     fn rfind<P>(&mut self, predicate: P) -> Option<Self::Item>
         where P: FnMut(&Self::Item) -> bool
     {
@@ -449,6 +461,12 @@ impl<'a, I, T: 'a> DoubleEndedIterator for Cloned<I>
     fn next_back(&mut self) -> Option<T> {
         self.it.next_back().cloned()
     }
+
+    fn rfold<Acc, F>(self, init: Acc, mut f: F) -> Acc
+        where F: FnMut(Acc, Self::Item) -> Acc,
+    {
+        self.it.rfold(init, move |acc, elt| f(acc, elt.clone()))
+    }
 }
 
 #[stable(feature = "iter_cloned", since = "1.1.0")]
@@ -470,7 +488,7 @@ impl<'a, I, T: 'a> FusedIterator for Cloned<I>
 {}
 
 #[doc(hidden)]
-unsafe impl<'a, I, T: 'a> TrustedRandomAccess for Cloned<I>
+default unsafe impl<'a, I, T: 'a> TrustedRandomAccess for Cloned<I>
     where I: TrustedRandomAccess<Item=&'a T>, T: Clone
 {
     unsafe fn get_unchecked(&mut self, i: usize) -> Self::Item {
@@ -481,6 +499,18 @@ unsafe impl<'a, I, T: 'a> TrustedRandomAccess for Cloned<I>
     fn may_have_side_effect() -> bool { true }
 }
 
+#[doc(hidden)]
+unsafe impl<'a, I, T: 'a> TrustedRandomAccess for Cloned<I>
+    where I: TrustedRandomAccess<Item=&'a T>, T: Copy
+{
+    unsafe fn get_unchecked(&mut self, i: usize) -> Self::Item {
+        *self.it.get_unchecked(i)
+    }
+
+    #[inline]
+    fn may_have_side_effect() -> bool { false }
+}
+
 #[unstable(feature = "trusted_len", issue = "37572")]
 unsafe impl<'a, I, T: 'a> TrustedLen for Cloned<I>
     where I: TrustedLen<Item=&'a T>,
@@ -528,7 +558,7 @@ impl<I> Iterator for Cycle<I> where I: Clone + Iterator {
 #[unstable(feature = "fused", issue = "35602")]
 impl<I> FusedIterator for Cycle<I> where I: Clone + Iterator {}
 
-/// An adapter for stepping iterators by a custom amount.
+/// An iterator for stepping iterators by a custom amount.
 ///
 /// This `struct` is created by the [`step_by`] method on [`Iterator`]. See
 /// its documentation for more.
@@ -761,6 +791,26 @@ impl<A, B> DoubleEndedIterator for Chain<A, B> where
             ChainState::Back => self.b.next_back(),
         }
     }
+
+    fn rfold<Acc, F>(self, init: Acc, mut f: F) -> Acc
+        where F: FnMut(Acc, Self::Item) -> Acc,
+    {
+        let mut accum = init;
+        match self.state {
+            ChainState::Both | ChainState::Back => {
+                accum = self.b.rfold(accum, &mut f);
+            }
+            _ => { }
+        }
+        match self.state {
+            ChainState::Both | ChainState::Front => {
+                accum = self.a.rfold(accum, &mut f);
+            }
+            _ => { }
+        }
+        accum
+    }
+
 }
 
 // Note: *both* must be fused to handle double-ended iterators.
@@ -1094,6 +1144,13 @@ impl<B, I: DoubleEndedIterator, F> DoubleEndedIterator for Map<I, F> where
     fn next_back(&mut self) -> Option<B> {
         self.iter.next_back().map(&mut self.f)
     }
+
+    fn rfold<Acc, G>(self, init: Acc, mut g: G) -> Acc
+        where G: FnMut(Acc, Self::Item) -> Acc,
+    {
+        let mut f = self.f;
+        self.iter.rfold(init, move |acc, elt| g(acc, f(elt)))
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1193,6 +1250,18 @@ impl<I: Iterator, P> Iterator for Filter<I, P> where P: FnMut(&I::Item) -> bool
         }
         count
     }
+
+    #[inline]
+    fn fold<Acc, Fold>(self, init: Acc, mut fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        let mut predicate = self.predicate;
+        self.iter.fold(init, move |acc, item| if predicate(&item) {
+            fold(acc, item)
+        } else {
+            acc
+        })
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1208,6 +1277,18 @@ impl<I: DoubleEndedIterator, P> DoubleEndedIterator for Filter<I, P>
         }
         None
     }
+
+    #[inline]
+    fn rfold<Acc, Fold>(self, init: Acc, mut fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        let mut predicate = self.predicate;
+        self.iter.rfold(init, move |acc, item| if predicate(&item) {
+            fold(acc, item)
+        } else {
+            acc
+        })
+    }
 }
 
 #[unstable(feature = "fused", issue = "35602")]
@@ -1259,6 +1340,17 @@ impl<B, I: Iterator, F> Iterator for FilterMap<I, F>
         let (_, upper) = self.iter.size_hint();
         (0, upper) // can't know a lower bound, due to the predicate
     }
+
+    #[inline]
+    fn fold<Acc, Fold>(self, init: Acc, mut fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        let mut f = self.f;
+        self.iter.fold(init, move |acc, item| match f(item) {
+            Some(x) => fold(acc, x),
+            None => acc,
+        })
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1274,6 +1366,17 @@ impl<B, I: DoubleEndedIterator, F> DoubleEndedIterator for FilterMap<I, F>
         }
         None
     }
+
+    #[inline]
+    fn rfold<Acc, Fold>(self, init: Acc, mut fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        let mut f = self.f;
+        self.iter.rfold(init, move |acc, item| match f(item) {
+            Some(x) => fold(acc, x),
+            None => acc,
+        })
+    }
 }
 
 #[unstable(feature = "fused", issue = "35602")]
@@ -1338,6 +1441,19 @@ impl<I> Iterator for Enumerate<I> where I: Iterator {
     fn count(self) -> usize {
         self.iter.count()
     }
+
+    #[inline]
+    #[rustc_inherit_overflow_checks]
+    fn fold<Acc, Fold>(self, init: Acc, mut fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        let mut count = self.count;
+        self.iter.fold(init, move |acc, item| {
+            let acc = fold(acc, (count, item));
+            count += 1;
+            acc
+        })
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1353,6 +1469,19 @@ impl<I> DoubleEndedIterator for Enumerate<I> where
             (self.count + len, a)
         })
     }
+
+    #[inline]
+    fn rfold<Acc, Fold>(self, init: Acc, mut fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        // Can safely add and subtract the count, as `ExactSizeIterator` promises
+        // that the number of elements fits into a `usize`.
+        let mut count = self.count + self.iter.len();
+        self.iter.rfold(init, move |acc, item| {
+            count -= 1;
+            fold(acc, (count, item))
+        })
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1464,6 +1593,18 @@ impl<I: Iterator> Iterator for Peekable<I> {
         let hi = hi.and_then(|x| x.checked_add(peek_len));
         (lo, hi)
     }
+
+    #[inline]
+    fn fold<Acc, Fold>(self, init: Acc, mut fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        let acc = match self.peeked {
+            Some(None) => return init,
+            Some(Some(v)) => fold(init, v),
+            None => init,
+        };
+        self.iter.fold(acc, fold)
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1572,6 +1713,19 @@ impl<I: Iterator, P> Iterator for SkipWhile<I, P>
         let (_, upper) = self.iter.size_hint();
         (0, upper) // can't know a lower bound, due to the predicate
     }
+
+    #[inline]
+    fn fold<Acc, Fold>(mut self, mut init: Acc, mut fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        if !self.flag {
+            match self.next() {
+                Some(v) => init = fold(init, v),
+                None => return init,
+            }
+        }
+        self.iter.fold(init, fold)
+    }
 }
 
 #[unstable(feature = "fused", issue = "35602")]
@@ -1712,6 +1866,19 @@ impl<I> Iterator for Skip<I> where I: Iterator {
 
         (lower, upper)
     }
+
+    #[inline]
+    fn fold<Acc, Fold>(mut self, init: Acc, fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        if self.n > 0 {
+            // nth(n) skips n+1
+            if self.iter.nth(self.n - 1).is_none() {
+                return init;
+            }
+        }
+        self.iter.fold(init, fold)
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -1934,6 +2101,16 @@ impl<I: DoubleEndedIterator, U, F> DoubleEndedIterator for FlatMap<I, U, F> wher
             }
         }
     }
+
+    #[inline]
+    fn rfold<Acc, Fold>(self, init: Acc, mut fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        self.frontiter.into_iter()
+            .chain(self.iter.map(self.f).map(U::into_iter))
+            .chain(self.backiter)
+            .rfold(init, |acc, iter| iter.rfold(acc, &mut fold))
+    }
 }
 
 #[unstable(feature = "fused", issue = "35602")]
@@ -2011,6 +2188,17 @@ impl<I> Iterator for Fuse<I> where I: Iterator {
             self.iter.size_hint()
         }
     }
+
+    #[inline]
+    default fn fold<Acc, Fold>(self, init: Acc, fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        if self.done {
+            init
+        } else {
+            self.iter.fold(init, fold)
+        }
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -2025,6 +2213,17 @@ impl<I> DoubleEndedIterator for Fuse<I> where I: DoubleEndedIterator {
             next
         }
     }
+
+    #[inline]
+    default fn rfold<Acc, Fold>(self, init: Acc, fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        if self.done {
+            init
+        } else {
+            self.iter.rfold(init, fold)
+        }
+    }
 }
 
 unsafe impl<I> TrustedRandomAccess for Fuse<I>
@@ -2065,6 +2264,13 @@ impl<I> Iterator for Fuse<I> where I: FusedIterator {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
+
+    #[inline]
+    fn fold<Acc, Fold>(self, init: Acc, fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        self.iter.fold(init, fold)
+    }
 }
 
 #[unstable(feature = "fused", reason = "recently added", issue = "35602")]
@@ -2075,6 +2281,13 @@ impl<I> DoubleEndedIterator for Fuse<I>
     fn next_back(&mut self) -> Option<<I as Iterator>::Item> {
         self.iter.next_back()
     }
+
+    #[inline]
+    fn rfold<Acc, Fold>(self, init: Acc, fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        self.iter.rfold(init, fold)
+    }
 }
 
 
@@ -2139,6 +2352,14 @@ impl<I: Iterator, F> Iterator for Inspect<I, F> where F: FnMut(&I::Item) {
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.iter.size_hint()
     }
+
+    #[inline]
+    fn fold<Acc, Fold>(self, init: Acc, mut fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        let mut f = self.f;
+        self.iter.fold(init, move |acc, item| { f(&item); fold(acc, item) })
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -2150,6 +2371,14 @@ impl<I: DoubleEndedIterator, F> DoubleEndedIterator for Inspect<I, F>
         let next = self.iter.next_back();
         self.do_inspect(next)
     }
+
+    #[inline]
+    fn rfold<Acc, Fold>(self, init: Acc, mut fold: Fold) -> Acc
+        where Fold: FnMut(Acc, Self::Item) -> Acc,
+    {
+        let mut f = self.f;
+        self.iter.rfold(init, move |acc, item| { f(&item); fold(acc, item) })
+    }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]

src/libcore/iter/range.rs

@@ -89,6 +89,7 @@ macro_rules! step_impl_unsigned {
             }
 
             #[inline]
+            #[allow(unreachable_patterns)]
             fn add_usize(&self, n: usize) -> Option<Self> {
                 match <$t>::try_from(n) {
                     Ok(n_as_t) => self.checked_add(n_as_t),
@@ -120,6 +121,7 @@ macro_rules! step_impl_signed {
             }
 
             #[inline]
+            #[allow(unreachable_patterns)]
             fn add_usize(&self, n: usize) -> Option<Self> {
                 match <$unsigned>::try_from(n) {
                     Ok(n_as_unsigned) => {

src/libcore/iter/traits.rs

@@ -415,6 +415,70 @@ pub trait DoubleEndedIterator: Iterator {
     #[stable(feature = "rust1", since = "1.0.0")]
     fn next_back(&mut self) -> Option<Self::Item>;
 
+    /// An iterator method that reduces the iterator's elements to a single,
+    /// final value, starting from the back.
+    ///
+    /// This is the reverse version of [`fold()`]: it takes elements starting from
+    /// the back of the iterator.
+    ///
+    /// `rfold()` takes two arguments: an initial value, and a closure with two
+    /// arguments: an 'accumulator', and an element. The closure returns the value that
+    /// the accumulator should have for the next iteration.
+    ///
+    /// The initial value is the value the accumulator will have on the first
+    /// call.
+    ///
+    /// After applying this closure to every element of the iterator, `rfold()`
+    /// returns the accumulator.
+    ///
+    /// This operation is sometimes called 'reduce' or 'inject'.
+    ///
+    /// Folding is useful whenever you have a collection of something, and want
+    /// to produce a single value from it.
+    ///
+    /// [`fold()`]: trait.Iterator.html#method.fold
+    ///
+    /// # Examples
+    ///
+    /// Basic usage:
+    ///
+    /// ```
+    /// #![feature(iter_rfold)]
+    /// let a = [1, 2, 3];
+    ///
+    /// // the sum of all of the elements of a
+    /// let sum = a.iter()
+    ///            .rfold(0, |acc, &x| acc + x);
+    ///
+    /// assert_eq!(sum, 6);
+    /// ```
+    ///
+    /// This example builds a string, starting with an initial value
+    /// and continuing with each element from the back until the front:
+    ///
+    /// ```
+    /// #![feature(iter_rfold)]
+    /// let numbers = [1, 2, 3, 4, 5];
+    ///
+    /// let zero = "0".to_string();
+    ///
+    /// let result = numbers.iter().rfold(zero, |acc, &x| {
+    ///     format!("({} + {})", x, acc)
+    /// });
+    ///
+    /// assert_eq!(result, "(1 + (2 + (3 + (4 + (5 + 0)))))");
+    /// ```
+    #[inline]
+    #[unstable(feature = "iter_rfold", issue = "44705")]
+    fn rfold<B, F>(mut self, mut accum: B, mut f: F) -> B where
+        Self: Sized, F: FnMut(B, Self::Item) -> B,
+    {
+        while let Some(x) = self.next_back() {
+            accum = f(accum, x);
+        }
+        accum
+    }
+
     /// Searches for an element of an iterator from the right that satisfies a predicate.
     ///
     /// `rfind()` takes a closure that returns `true` or `false`. It applies

src/libcore/marker.rs

@@ -122,7 +122,7 @@ pub trait Sized {
 /// [RFC982]: https://github.com/rust-lang/rfcs/blob/master/text/0982-dst-coercion.md
 /// [nomicon-coerce]: ../../nomicon/coercions.html
 #[unstable(feature = "unsize", issue = "27732")]
-#[lang="unsize"]
+#[lang = "unsize"]
 pub trait Unsize<T: ?Sized> {
     // Empty.
 }

src/libcore/mem.rs

@@ -177,15 +177,59 @@ pub fn forget<T>(t: T) {
 
 /// Returns the size of a type in bytes.
 ///
-/// More specifically, this is the offset in bytes between successive
-/// items of the same type, including alignment padding.
+/// More specifically, this is the offset in bytes between successive elements
+/// in an array with that item type including alignment padding. Thus, for any
+/// type `T` and length `n`, `[T; n]` has a size of `n * size_of::<T>()`.
+///
+/// In general, the size of a type is not stable across compilations, but
+/// specific types such as primitives are.
+///
+/// The following table gives the size for primitives.
+///
+/// Type | size_of::\<Type>()
+/// ---- | ---------------
+/// () | 0
+/// u8 | 1
+/// u16 | 2
+/// u32 | 4
+/// u64 | 8
+/// i8 | 1
+/// i16 | 2
+/// i32 | 4
+/// i64 | 8
+/// f32 | 4
+/// f64 | 8
+/// char | 4
+///
+/// Furthermore, `usize` and `isize` have the same size.
+///
+/// The types `*const T`, `&T`, `Box<T>`, `Option<&T>`, and `Option<Box<T>>` all have
+/// the same size. If `T` is Sized, all of those types have the same size as `usize`.
+///
+/// The mutability of a pointer does not change its size. As such, `&T` and `&mut T`
+/// have the same size. Likewise for `*const T` and `*mut T`.
 ///
 /// # Examples
 ///
 /// ```
 /// use std::mem;
 ///
+/// // Some primitives
 /// assert_eq!(4, mem::size_of::<i32>());
+/// assert_eq!(8, mem::size_of::<f64>());
+/// assert_eq!(0, mem::size_of::<()>());
+///
+/// // Some arrays
+/// assert_eq!(8, mem::size_of::<[i32; 2]>());
+/// assert_eq!(12, mem::size_of::<[i32; 3]>());
+/// assert_eq!(0, mem::size_of::<[i32; 0]>());
+///
+///
+/// // Pointer size equality
+/// assert_eq!(mem::size_of::<&i32>(), mem::size_of::<*const i32>());
+/// assert_eq!(mem::size_of::<&i32>(), mem::size_of::<Box<i32>>());
+/// assert_eq!(mem::size_of::<&i32>(), mem::size_of::<Option<&i32>>());
+/// assert_eq!(mem::size_of::<Box<i32>>(), mem::size_of::<Option<Box<i32>>>());
 /// ```
 #[inline]
 #[stable(feature = "rust1", since = "1.0.0")]
@@ -358,7 +402,7 @@ pub fn align_of_val<T: ?Sized>(val: &T) -> usize {
 /// }
 /// ```
 #[inline]
-#[stable(feature = "needs_drop", since = "1.22.0")]
+#[stable(feature = "needs_drop", since = "1.21.0")]
 pub fn needs_drop<T>() -> bool {
     unsafe { intrinsics::needs_drop::<T>() }
 }

src/libcore/num/mod.rs

@@ -12,7 +12,7 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
-use convert::TryFrom;
+use convert::{Infallible, TryFrom};
 use fmt;
 use intrinsics;
 use str::FromStr;
@@ -2507,16 +2507,24 @@ impl fmt::Display for TryFromIntError {
     }
 }
 
+#[unstable(feature = "try_from", issue = "33417")]
+impl From<Infallible> for TryFromIntError {
+    fn from(infallible: Infallible) -> TryFromIntError {
+        match infallible {
+        }
+    }
+}
+
 // no possible bounds violation
 macro_rules! try_from_unbounded {
     ($source:ty, $($target:ty),*) => {$(
         #[unstable(feature = "try_from", issue = "33417")]
         impl TryFrom<$source> for $target {
-            type Error = TryFromIntError;
+            type Error = Infallible;
 
             #[inline]
-            fn try_from(u: $source) -> Result<$target, TryFromIntError> {
-                Ok(u as $target)
+            fn try_from(value: $source) -> Result<Self, Self::Error> {
+                Ok(value as $target)
             }
         }
     )*}
@@ -2588,31 +2596,17 @@ macro_rules! rev {
 }
 
 /// intra-sign conversions
-try_from_unbounded!(u8, u8, u16, u32, u64, u128);
-try_from_unbounded!(u16, u16, u32, u64, u128);
-try_from_unbounded!(u32, u32, u64, u128);
-try_from_unbounded!(u64, u64, u128);
-try_from_unbounded!(u128, u128);
 try_from_upper_bounded!(u16, u8);
 try_from_upper_bounded!(u32, u16, u8);
 try_from_upper_bounded!(u64, u32, u16, u8);
 try_from_upper_bounded!(u128, u64, u32, u16, u8);
 
-try_from_unbounded!(i8, i8, i16, i32, i64, i128);
-try_from_unbounded!(i16, i16, i32, i64, i128);
-try_from_unbounded!(i32, i32, i64, i128);
-try_from_unbounded!(i64, i64, i128);
-try_from_unbounded!(i128, i128);
 try_from_both_bounded!(i16, i8);
 try_from_both_bounded!(i32, i16, i8);
 try_from_both_bounded!(i64, i32, i16, i8);
 try_from_both_bounded!(i128, i64, i32, i16, i8);
 
 // unsigned-to-signed
-try_from_unbounded!(u8, i16, i32, i64, i128);
-try_from_unbounded!(u16, i32, i64, i128);
-try_from_unbounded!(u32, i64, i128);
-try_from_unbounded!(u64, i128);
 try_from_upper_bounded!(u8, i8);
 try_from_upper_bounded!(u16, i8, i16);
 try_from_upper_bounded!(u32, i8, i16, i32);
@@ -2631,15 +2625,13 @@ try_from_both_bounded!(i64, u32, u16, u8);
 try_from_both_bounded!(i128, u64, u32, u16, u8);
 
 // usize/isize
-try_from_unbounded!(usize, usize);
 try_from_upper_bounded!(usize, isize);
 try_from_lower_bounded!(isize, usize);
-try_from_unbounded!(isize, isize);
 
 #[cfg(target_pointer_width = "16")]
 mod ptr_try_from_impls {
     use super::TryFromIntError;
-    use convert::TryFrom;
+    use convert::{Infallible, TryFrom};
 
     try_from_upper_bounded!(usize, u8);
     try_from_unbounded!(usize, u16, u32, u64, u128);
@@ -2651,21 +2643,21 @@ mod ptr_try_from_impls {
     try_from_both_bounded!(isize, i8);
     try_from_unbounded!(isize, i16, i32, i64, i128);
 
-    rev!(try_from_unbounded, usize, u8, u16);
+    rev!(try_from_unbounded, usize, u16);
     rev!(try_from_upper_bounded, usize, u32, u64, u128);
     rev!(try_from_lower_bounded, usize, i8, i16);
     rev!(try_from_both_bounded, usize, i32, i64, i128);
 
     rev!(try_from_unbounded, isize, u8);
     rev!(try_from_upper_bounded, isize, u16, u32, u64, u128);
-    rev!(try_from_unbounded, isize, i8, i16);
+    rev!(try_from_unbounded, isize, i16);
     rev!(try_from_both_bounded, isize, i32, i64, i128);
 }
 
 #[cfg(target_pointer_width = "32")]
 mod ptr_try_from_impls {
     use super::TryFromIntError;
-    use convert::TryFrom;
+    use convert::{Infallible, TryFrom};
 
     try_from_upper_bounded!(usize, u8, u16);
     try_from_unbounded!(usize, u32, u64, u128);
@@ -2677,21 +2669,21 @@ mod ptr_try_from_impls {
     try_from_both_bounded!(isize, i8, i16);
     try_from_unbounded!(isize, i32, i64, i128);
 
-    rev!(try_from_unbounded, usize, u8, u16, u32);
+    rev!(try_from_unbounded, usize, u16, u32);
     rev!(try_from_upper_bounded, usize, u64, u128);
     rev!(try_from_lower_bounded, usize, i8, i16, i32);
     rev!(try_from_both_bounded, usize, i64, i128);
 
     rev!(try_from_unbounded, isize, u8, u16);
     rev!(try_from_upper_bounded, isize, u32, u64, u128);
-    rev!(try_from_unbounded, isize, i8, i16, i32);
+    rev!(try_from_unbounded, isize, i16, i32);
     rev!(try_from_both_bounded, isize, i64, i128);
 }
 
 #[cfg(target_pointer_width = "64")]
 mod ptr_try_from_impls {
     use super::TryFromIntError;
-    use convert::TryFrom;
+    use convert::{Infallible, TryFrom};
 
     try_from_upper_bounded!(usize, u8, u16, u32);
     try_from_unbounded!(usize, u64, u128);
@@ -2703,14 +2695,14 @@ mod ptr_try_from_impls {
     try_from_both_bounded!(isize, i8, i16, i32);
     try_from_unbounded!(isize, i64, i128);
 
-    rev!(try_from_unbounded, usize, u8, u16, u32, u64);
+    rev!(try_from_unbounded, usize, u16, u32, u64);
     rev!(try_from_upper_bounded, usize, u128);
     rev!(try_from_lower_bounded, usize, i8, i16, i32, i64);
     rev!(try_from_both_bounded, usize, i128);
 
     rev!(try_from_unbounded, isize, u8, u16, u32);
     rev!(try_from_upper_bounded, isize, u64, u128);
-    rev!(try_from_unbounded, isize, i8, i16, i32, i64);
+    rev!(try_from_unbounded, isize, i16, i32, i64);
     rev!(try_from_both_bounded, isize, i128);
 }
 

src/libcore/num/wrapping.rs

@@ -36,6 +36,7 @@ macro_rules! sh_impl_signed {
                 *self = *self << other;
             }
         }
+        forward_ref_op_assign! { impl ShlAssign, shl_assign for Wrapping<$t>, $f }
 
         #[stable(feature = "rust1", since = "1.0.0")]
         impl Shr<$f> for Wrapping<$t> {
@@ -58,6 +59,7 @@ macro_rules! sh_impl_signed {
                 *self = *self >> other;
             }
         }
+        forward_ref_op_assign! { impl ShrAssign, shr_assign for Wrapping<$t>, $f }
     )
 }
 
@@ -80,6 +82,7 @@ macro_rules! sh_impl_unsigned {
                 *self = *self << other;
             }
         }
+        forward_ref_op_assign! { impl ShlAssign, shl_assign for Wrapping<$t>, $f }
 
         #[stable(feature = "rust1", since = "1.0.0")]
         impl Shr<$f> for Wrapping<$t> {
@@ -98,6 +101,7 @@ macro_rules! sh_impl_unsigned {
                 *self = *self >> other;
             }
         }
+        forward_ref_op_assign! { impl ShrAssign, shr_assign for Wrapping<$t>, $f }
     )
 }
 
@@ -142,6 +146,7 @@ macro_rules! wrapping_impl {
                 *self = *self + other;
             }
         }
+        forward_ref_op_assign! { impl AddAssign, add_assign for Wrapping<$t>, Wrapping<$t> }
 
         #[stable(feature = "rust1", since = "1.0.0")]
         impl Sub for Wrapping<$t> {
@@ -162,6 +167,7 @@ macro_rules! wrapping_impl {
                 *self = *self - other;
             }
         }
+        forward_ref_op_assign! { impl SubAssign, sub_assign for Wrapping<$t>, Wrapping<$t> }
 
         #[stable(feature = "rust1", since = "1.0.0")]
         impl Mul for Wrapping<$t> {
@@ -182,6 +188,7 @@ macro_rules! wrapping_impl {
                 *self = *self * other;
             }
         }
+        forward_ref_op_assign! { impl MulAssign, mul_assign for Wrapping<$t>, Wrapping<$t> }
 
         #[stable(feature = "wrapping_div", since = "1.3.0")]
         impl Div for Wrapping<$t> {
@@ -202,6 +209,7 @@ macro_rules! wrapping_impl {
                 *self = *self / other;
             }
         }
+        forward_ref_op_assign! { impl DivAssign, div_assign for Wrapping<$t>, Wrapping<$t> }
 
         #[stable(feature = "wrapping_impls", since = "1.7.0")]
         impl Rem for Wrapping<$t> {
@@ -222,6 +230,7 @@ macro_rules! wrapping_impl {
                 *self = *self % other;
             }
         }
+        forward_ref_op_assign! { impl RemAssign, rem_assign for Wrapping<$t>, Wrapping<$t> }
 
         #[stable(feature = "rust1", since = "1.0.0")]
         impl Not for Wrapping<$t> {
@@ -254,6 +263,7 @@ macro_rules! wrapping_impl {
                 *self = *self ^ other;
             }
         }
+        forward_ref_op_assign! { impl BitXorAssign, bitxor_assign for Wrapping<$t>, Wrapping<$t> }
 
         #[stable(feature = "rust1", since = "1.0.0")]
         impl BitOr for Wrapping<$t> {
@@ -274,6 +284,7 @@ macro_rules! wrapping_impl {
                 *self = *self | other;
             }
         }
+        forward_ref_op_assign! { impl BitOrAssign, bitor_assign for Wrapping<$t>, Wrapping<$t> }
 
         #[stable(feature = "rust1", since = "1.0.0")]
         impl BitAnd for Wrapping<$t> {
@@ -294,6 +305,7 @@ macro_rules! wrapping_impl {
                 *self = *self & other;
             }
         }
+        forward_ref_op_assign! { impl BitAndAssign, bitand_assign for Wrapping<$t>, Wrapping<$t> }
 
         #[stable(feature = "wrapping_neg", since = "1.10.0")]
         impl Neg for Wrapping<$t> {

src/libcore/ops/arith.rs

@@ -662,6 +662,8 @@ macro_rules! add_assign_impl {
             #[rustc_inherit_overflow_checks]
             fn add_assign(&mut self, other: $t) { *self += other }
         }
+
+        forward_ref_op_assign! { impl AddAssign, add_assign for $t, $t }
     )+)
 }
 
@@ -713,6 +715,8 @@ macro_rules! sub_assign_impl {
             #[rustc_inherit_overflow_checks]
             fn sub_assign(&mut self, other: $t) { *self -= other }
         }
+
+        forward_ref_op_assign! { impl SubAssign, sub_assign for $t, $t }
     )+)
 }
 
@@ -755,6 +759,8 @@ macro_rules! mul_assign_impl {
             #[rustc_inherit_overflow_checks]
             fn mul_assign(&mut self, other: $t) { *self *= other }
         }
+
+        forward_ref_op_assign! { impl MulAssign, mul_assign for $t, $t }
     )+)
 }
 
@@ -796,6 +802,8 @@ macro_rules! div_assign_impl {
             #[inline]
             fn div_assign(&mut self, other: $t) { *self /= other }
         }
+
+        forward_ref_op_assign! { impl DivAssign, div_assign for $t, $t }
     )+)
 }
 
@@ -841,6 +849,8 @@ macro_rules! rem_assign_impl {
             #[inline]
             fn rem_assign(&mut self, other: $t) { *self %= other }
         }
+
+        forward_ref_op_assign! { impl RemAssign, rem_assign for $t, $t }
     )+)
 }
 

src/libcore/ops/bit.rs

@@ -593,6 +593,8 @@ macro_rules! bitand_assign_impl {
             #[inline]
             fn bitand_assign(&mut self, other: $t) { *self &= other }
         }
+
+        forward_ref_op_assign! { impl BitAndAssign, bitand_assign for $t, $t }
     )+)
 }
 
@@ -638,6 +640,8 @@ macro_rules! bitor_assign_impl {
             #[inline]
             fn bitor_assign(&mut self, other: $t) { *self |= other }
         }
+
+        forward_ref_op_assign! { impl BitOrAssign, bitor_assign for $t, $t }
     )+)
 }
 
@@ -683,6 +687,8 @@ macro_rules! bitxor_assign_impl {
             #[inline]
             fn bitxor_assign(&mut self, other: $t) { *self ^= other }
         }
+
+        forward_ref_op_assign! { impl BitXorAssign, bitxor_assign for $t, $t }
     )+)
 }
 
@@ -729,6 +735,8 @@ macro_rules! shl_assign_impl {
                 *self <<= other
             }
         }
+
+        forward_ref_op_assign! { impl ShlAssign, shl_assign for $t, $f }
     )
 }
 
@@ -793,6 +801,8 @@ macro_rules! shr_assign_impl {
                 *self >>= other
             }
         }
+
+        forward_ref_op_assign! { impl ShrAssign, shr_assign for $t, $f }
     )
 }
 

src/libcore/ops/range.rs

@@ -241,9 +241,9 @@ impl<Idx: PartialOrd<Idx>> RangeTo<Idx> {
     }
 }
 
-/// An range bounded inclusively below and above (`start...end`).
+/// An range bounded inclusively below and above (`start..=end`).
 ///
-/// The `RangeInclusive` `start...end` contains all values with `x >= start`
+/// The `RangeInclusive` `start..=end` contains all values with `x >= start`
 /// and `x <= end`.
 ///
 /// # Examples
@@ -251,12 +251,12 @@ impl<Idx: PartialOrd<Idx>> RangeTo<Idx> {
 /// ```
 /// #![feature(inclusive_range,inclusive_range_syntax)]
 ///
-/// assert_eq!((3...5), std::ops::RangeInclusive { start: 3, end: 5 });
-/// assert_eq!(3 + 4 + 5, (3...5).sum());
+/// assert_eq!((3..=5), std::ops::RangeInclusive { start: 3, end: 5 });
+/// assert_eq!(3 + 4 + 5, (3..=5).sum());
 ///
 /// let arr = [0, 1, 2, 3];
-/// assert_eq!(arr[ ...2], [0,1,2  ]);
-/// assert_eq!(arr[1...2], [  1,2  ]);  // RangeInclusive
+/// assert_eq!(arr[ ..=2], [0,1,2  ]);
+/// assert_eq!(arr[1..=2], [  1,2  ]);  // RangeInclusive
 /// ```
 #[derive(Clone, PartialEq, Eq, Hash)]  // not Copy -- see #27186
 #[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
@@ -276,7 +276,7 @@ pub struct RangeInclusive<Idx> {
 #[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
 impl<Idx: fmt::Debug> fmt::Debug for RangeInclusive<Idx> {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        write!(fmt, "{:?}...{:?}", self.start, self.end)
+        write!(fmt, "{:?}..={:?}", self.start, self.end)
     }
 }
 
@@ -289,32 +289,32 @@ impl<Idx: PartialOrd<Idx>> RangeInclusive<Idx> {
     /// ```
     /// #![feature(range_contains,inclusive_range_syntax)]
     ///
-    /// assert!(!(3...5).contains(2));
-    /// assert!( (3...5).contains(3));
-    /// assert!( (3...5).contains(4));
-    /// assert!( (3...5).contains(5));
-    /// assert!(!(3...5).contains(6));
+    /// assert!(!(3..=5).contains(2));
+    /// assert!( (3..=5).contains(3));
+    /// assert!( (3..=5).contains(4));
+    /// assert!( (3..=5).contains(5));
+    /// assert!(!(3..=5).contains(6));
     ///
-    /// assert!( (3...3).contains(3));
-    /// assert!(!(3...2).contains(3));
+    /// assert!( (3..=3).contains(3));
+    /// assert!(!(3..=2).contains(3));
     /// ```
     pub fn contains(&self, item: Idx) -> bool {
         self.start <= item && item <= self.end
     }
 }
 
-/// A range only bounded inclusively above (`...end`).
+/// A range only bounded inclusively above (`..=end`).
 ///
-/// The `RangeToInclusive` `...end` contains all values with `x <= end`.
+/// The `RangeToInclusive` `..=end` contains all values with `x <= end`.
 /// It cannot serve as an [`Iterator`] because it doesn't have a starting point.
 ///
 /// # Examples
 ///
-/// The `...end` syntax is a `RangeToInclusive`:
+/// The `..=end` syntax is a `RangeToInclusive`:
 ///
 /// ```
 /// #![feature(inclusive_range,inclusive_range_syntax)]
-/// assert_eq!((...5), std::ops::RangeToInclusive{ end: 5 });
+/// assert_eq!((..=5), std::ops::RangeToInclusive{ end: 5 });
 /// ```
 ///
 /// It does not have an [`IntoIterator`] implementation, so you can't use it in a
@@ -325,7 +325,7 @@ impl<Idx: PartialOrd<Idx>> RangeInclusive<Idx> {
 ///
 /// // error[E0277]: the trait bound `std::ops::RangeToInclusive<{integer}>:
 /// // std::iter::Iterator` is not satisfied
-/// for i in ...5 {
+/// for i in ..=5 {
 ///     // ...
 /// }
 /// ```
@@ -337,8 +337,8 @@ impl<Idx: PartialOrd<Idx>> RangeInclusive<Idx> {
 /// #![feature(inclusive_range_syntax)]
 ///
 /// let arr = [0, 1, 2, 3];
-/// assert_eq!(arr[ ...2], [0,1,2  ]);  // RangeToInclusive
-/// assert_eq!(arr[1...2], [  1,2  ]);
+/// assert_eq!(arr[ ..=2], [0,1,2  ]);  // RangeToInclusive
+/// assert_eq!(arr[1..=2], [  1,2  ]);
 /// ```
 ///
 /// [`IntoIterator`]: ../iter/trait.Iterator.html
@@ -357,7 +357,7 @@ pub struct RangeToInclusive<Idx> {
 #[unstable(feature = "inclusive_range", reason = "recently added, follows RFC", issue = "28237")]
 impl<Idx: fmt::Debug> fmt::Debug for RangeToInclusive<Idx> {
     fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        write!(fmt, "...{:?}", self.end)
+        write!(fmt, "..={:?}", self.end)
     }
 }
 
@@ -370,9 +370,9 @@ impl<Idx: PartialOrd<Idx>> RangeToInclusive<Idx> {
     /// ```
     /// #![feature(range_contains,inclusive_range_syntax)]
     ///
-    /// assert!( (...5).contains(-1_000_000_000));
-    /// assert!( (...5).contains(5));
-    /// assert!(!(...5).contains(6));
+    /// assert!( (..=5).contains(-1_000_000_000));
+    /// assert!( (..=5).contains(5));
+    /// assert!(!(..=5).contains(6));
     /// ```
     pub fn contains(&self, item: Idx) -> bool {
         (item <= self.end)

src/libcore/ops/unsize.rs

@@ -42,7 +42,7 @@ use marker::Unsize;
 /// [unsize]: ../marker/trait.Unsize.html
 /// [nomicon-coerce]: ../../nomicon/coercions.html
 #[unstable(feature = "coerce_unsized", issue = "27732")]
-#[lang="coerce_unsized"]
+#[lang = "coerce_unsized"]
 pub trait CoerceUnsized<T> {
     // Empty.
 }

src/libcore/option.rs

@@ -146,7 +146,7 @@
 #![stable(feature = "rust1", since = "1.0.0")]
 
 use iter::{FromIterator, FusedIterator, TrustedLen};
-use mem;
+use {mem, ops};
 
 // Note that this is not a lang item per se, but it has a hidden dependency on
 // `Iterator`, which is one. The compiler assumes that the `next` method of
@@ -1123,3 +1123,29 @@ impl<A, V: FromIterator<A>> FromIterator<Option<A>> for Option<V> {
         }
     }
 }
+
+/// The error type that results from applying the try operator (`?`) to a `None` value. If you wish
+/// to allow `x?` (where `x` is an `Option<T>`) to be converted into your error type, you can
+/// implement `impl From<NoneError>` for `YourErrorType`. In that case, `x?` within a function that
+/// returns `Result<_, YourErrorType>` will translate a `None` value into an `Err` result.
+#[unstable(feature = "try_trait", issue = "42327")]
+#[derive(Clone, Copy, PartialEq, PartialOrd, Eq, Ord, Debug, Hash)]
+pub struct NoneError;
+
+#[unstable(feature = "try_trait", issue = "42327")]
+impl<T> ops::Try for Option<T> {
+    type Ok = T;
+    type Error = NoneError;
+
+    fn into_result(self) -> Result<T, NoneError> {
+        self.ok_or(NoneError)
+    }
+
+    fn from_ok(v: T) -> Self {
+        Some(v)
+    }
+
+    fn from_error(_: NoneError) -> Self {
+        None
+    }
+}

src/libcore/ptr.rs

@@ -56,7 +56,7 @@ pub use intrinsics::write_bytes;
 /// This has all the same safety problems as `ptr::read` with respect to
 /// invalid pointers, types, and double drops.
 #[stable(feature = "drop_in_place", since = "1.8.0")]
-#[lang="drop_in_place"]
+#[lang = "drop_in_place"]
 #[allow(unconditional_recursion)]
 pub unsafe fn drop_in_place<T: ?Sized>(to_drop: *mut T) {
     // Code here does not matter - this is replaced by the

src/libcore/slice/mod.rs

@@ -16,6 +16,9 @@
 
 #![stable(feature = "rust1", since = "1.0.0")]
 
+// FIXME: after next stage0, change RangeInclusive { ... } back to ..=
+use ops::RangeInclusive;
+
 // How this module is organized.
 //
 // The library infrastructure for slices is fairly messy. There's
@@ -1044,32 +1047,32 @@ impl<T> SliceIndex<[T]> for ops::RangeToInclusive<usize> {
 
     #[inline]
     fn get(self, slice: &[T]) -> Option<&[T]> {
-        (0...self.end).get(slice)
+        (RangeInclusive { start: 0, end: self.end }).get(slice)
     }
 
     #[inline]
     fn get_mut(self, slice: &mut [T]) -> Option<&mut [T]> {
-        (0...self.end).get_mut(slice)
+        (RangeInclusive { start: 0, end: self.end }).get_mut(slice)
     }
 
     #[inline]
     unsafe fn get_unchecked(self, slice: &[T]) -> &[T] {
-        (0...self.end).get_unchecked(slice)
+        (RangeInclusive { start: 0, end: self.end }).get_unchecked(slice)
     }
 
     #[inline]
     unsafe fn get_unchecked_mut(self, slice: &mut [T]) -> &mut [T] {
-        (0...self.end).get_unchecked_mut(slice)
+        (RangeInclusive { start: 0, end: self.end }).get_unchecked_mut(slice)
     }
 
     #[inline]
     fn index(self, slice: &[T]) -> &[T] {
-        (0...self.end).index(slice)
+        (RangeInclusive { start: 0, end: self.end }).index(slice)
     }
 
     #[inline]
     fn index_mut(self, slice: &mut [T]) -> &mut [T] {
-        (0...self.end).index_mut(slice)
+        (RangeInclusive { start: 0, end: self.end }).index_mut(slice)
     }
 }
 

src/libcore/str/mod.rs

@@ -18,9 +18,9 @@ use self::pattern::Pattern;
 use self::pattern::{Searcher, ReverseSearcher, DoubleEndedSearcher};
 
 use char;
-use convert::TryFrom;
 use fmt;
-use iter::{Map, Cloned, FusedIterator};
+use iter::{Map, Cloned, FusedIterator, TrustedLen};
+use iter_private::TrustedRandomAccess;
 use slice::{self, SliceIndex};
 use mem;
 
@@ -818,6 +818,17 @@ impl<'a> ExactSizeIterator for Bytes<'a> {
 #[unstable(feature = "fused", issue = "35602")]
 impl<'a> FusedIterator for Bytes<'a> {}
 
+#[unstable(feature = "trusted_len", issue = "37572")]
+unsafe impl<'a> TrustedLen for Bytes<'a> {}
+
+#[doc(hidden)]
+unsafe impl<'a> TrustedRandomAccess for Bytes<'a> {
+    unsafe fn get_unchecked(&mut self, i: usize) -> u8 {
+        self.0.get_unchecked(i)
+    }
+    fn may_have_side_effect() -> bool { false }
+}
+
 /// This macro generates a Clone impl for string pattern API
 /// wrapper types of the form X<'a, P>
 macro_rules! derive_pattern_clone {
@@ -1399,9 +1410,6 @@ Section: Comparing strings
 */
 
 /// Bytewise slice equality
-/// NOTE: This function is (ab)used in rustc::middle::trans::_match
-/// to compare &[u8] byte slices that are not necessarily valid UTF-8.
-#[lang = "str_eq"]
 #[inline]
 fn eq_slice(a: &str, b: &str) -> bool {
     a.as_bytes() == b.as_bytes()
@@ -2189,7 +2197,7 @@ pub trait StrExt {
     #[stable(feature = "core", since = "1.6.0")]
     fn is_empty(&self) -> bool;
     #[stable(feature = "core", since = "1.6.0")]
-    fn parse<'a, T: TryFrom<&'a str>>(&'a self) -> Result<T, T::Error>;
+    fn parse<T: FromStr>(&self) -> Result<T, T::Err>;
 }
 
 // truncate `&str` to length at most equal to `max`
@@ -2509,9 +2517,7 @@ impl StrExt for str {
     fn is_empty(&self) -> bool { self.len() == 0 }
 
     #[inline]
-    fn parse<'a, T>(&'a self) -> Result<T, T::Error> where T: TryFrom<&'a str> {
-        T::try_from(self)
-    }
+    fn parse<T: FromStr>(&self) -> Result<T, T::Err> { FromStr::from_str(self) }
 }
 
 #[stable(feature = "rust1", since = "1.0.0")]

src/libcore/sync/atomic.rs

@@ -926,10 +926,24 @@ macro_rules! atomic_int {
      $stable_cxchg:meta,
      $stable_debug:meta,
      $stable_access:meta,
+     $s_int_type:expr, $int_ref:expr,
      $int_type:ident $atomic_type:ident $atomic_init:ident) => {
         /// An integer type which can be safely shared between threads.
         ///
-        /// This type has the same in-memory representation as the underlying integer type.
+        /// This type has the same in-memory representation as the underlying
+        /// integer type, [`
+        #[doc = $s_int_type]
+        /// `](
+        #[doc = $int_ref]
+        /// ). For more about the differences between atomic types and
+        /// non-atomic types, please see the [module-level documentation].
+        ///
+        /// Please note that examples are shared between atomic variants of
+        /// primitive integer types, so it's normal that they are all
+        /// demonstrating [`AtomicIsize`].
+        ///
+        /// [module-level documentation]: index.html
+        /// [`AtomicIsize`]: struct.AtomicIsize.html
         #[$stable]
         pub struct $atomic_type {
             v: UnsafeCell<$int_type>,
@@ -1339,6 +1353,7 @@ atomic_int! {
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
+    "i8", "../../../std/primitive.i8.html",
     i8 AtomicI8 ATOMIC_I8_INIT
 }
 #[cfg(target_has_atomic = "8")]
@@ -1348,6 +1363,7 @@ atomic_int! {
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
+    "u8", "../../../std/primitive.u8.html",
     u8 AtomicU8 ATOMIC_U8_INIT
 }
 #[cfg(target_has_atomic = "16")]
@@ -1357,6 +1373,7 @@ atomic_int! {
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
+    "i16", "../../../std/primitive.i16.html",
     i16 AtomicI16 ATOMIC_I16_INIT
 }
 #[cfg(target_has_atomic = "16")]
@@ -1366,6 +1383,7 @@ atomic_int! {
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
+    "u16", "../../../std/primitive.u16.html",
     u16 AtomicU16 ATOMIC_U16_INIT
 }
 #[cfg(target_has_atomic = "32")]
@@ -1375,6 +1393,7 @@ atomic_int! {
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
+    "i32", "../../../std/primitive.i32.html",
     i32 AtomicI32 ATOMIC_I32_INIT
 }
 #[cfg(target_has_atomic = "32")]
@@ -1384,6 +1403,7 @@ atomic_int! {
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
+    "u32", "../../../std/primitive.u32.html",
     u32 AtomicU32 ATOMIC_U32_INIT
 }
 #[cfg(target_has_atomic = "64")]
@@ -1393,6 +1413,7 @@ atomic_int! {
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
+    "i64", "../../../std/primitive.i64.html",
     i64 AtomicI64 ATOMIC_I64_INIT
 }
 #[cfg(target_has_atomic = "64")]
@@ -1402,6 +1423,7 @@ atomic_int! {
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
     unstable(feature = "integer_atomics", issue = "32976"),
+    "u64", "../../../std/primitive.u64.html",
     u64 AtomicU64 ATOMIC_U64_INIT
 }
 #[cfg(target_has_atomic = "ptr")]
@@ -1411,6 +1433,7 @@ atomic_int!{
     stable(feature = "extended_compare_and_swap", since = "1.10.0"),
     stable(feature = "atomic_debug", since = "1.3.0"),
     stable(feature = "atomic_access", since = "1.15.0"),
+    "isize", "../../../std/primitive.isize.html",
     isize AtomicIsize ATOMIC_ISIZE_INIT
 }
 #[cfg(target_has_atomic = "ptr")]
@@ -1420,6 +1443,7 @@ atomic_int!{
     stable(feature = "extended_compare_and_swap", since = "1.10.0"),
     stable(feature = "atomic_debug", since = "1.3.0"),
     stable(feature = "atomic_access", since = "1.15.0"),
+    "usize", "../../../std/primitive.usize.html",
     usize AtomicUsize ATOMIC_USIZE_INIT
 }
 
@@ -1752,7 +1776,7 @@ pub fn fence(order: Ordering) {
 /// [`Relaxed`]: enum.Ordering.html#variant.Relaxed
 /// [memory barriers]: https://www.kernel.org/doc/Documentation/memory-barriers.txt
 #[inline]
-#[stable(feature = "compiler_fences", since = "1.22.0")]
+#[stable(feature = "compiler_fences", since = "1.21.0")]
 pub fn compiler_fence(order: Ordering) {
     unsafe {
         match order {

src/libcore/tests/char.rs

@@ -32,7 +32,6 @@ fn test_convert() {
 #[test]
 fn test_from_str() {
     assert_eq!(char::from_str("a").unwrap(), 'a');
-    assert_eq!(char::try_from("a").unwrap(), 'a');
     assert_eq!(char::from_str("\0").unwrap(), '\0');
     assert_eq!(char::from_str("\u{D7FF}").unwrap(), '\u{d7FF}');
     assert!(char::from_str("").is_err());

src/libcore/tests/iter.rs

@@ -248,6 +248,25 @@ fn test_filter_map() {
     assert_eq!(it.collect::<Vec<usize>>(), [0*0, 2*2, 4*4, 6*6, 8*8]);
 }
 
+#[test]
+fn test_filter_map_fold() {
+    let xs = [0, 1, 2, 3, 4, 5, 6, 7, 8];
+    let ys = [0*0, 2*2, 4*4, 6*6, 8*8];
+    let it = xs.iter().filter_map(|&x| if x % 2 == 0 { Some(x*x) } else { None });
+    let i = it.fold(0, |i, x| {
+        assert_eq!(x, ys[i]);
+        i + 1
+    });
+    assert_eq!(i, ys.len());
+
+    let it = xs.iter().filter_map(|&x| if x % 2 == 0 { Some(x*x) } else { None });
+    let i = it.rfold(ys.len(), |i, x| {
+        assert_eq!(x, ys[i - 1]);
+        i - 1
+    });
+    assert_eq!(i, 0);
+}
+
 #[test]
 fn test_iterator_enumerate() {
     let xs = [0, 1, 2, 3, 4, 5];
@@ -282,7 +301,31 @@ fn test_iterator_enumerate_nth() {
 #[test]
 fn test_iterator_enumerate_count() {
     let xs = [0, 1, 2, 3, 4, 5];
-    assert_eq!(xs.iter().count(), 6);
+    assert_eq!(xs.iter().enumerate().count(), 6);
+}
+
+#[test]
+fn test_iterator_enumerate_fold() {
+    let xs = [0, 1, 2, 3, 4, 5];
+    let mut it = xs.iter().enumerate();
+    // steal a couple to get an interesting offset
+    assert_eq!(it.next(), Some((0, &0)));
+    assert_eq!(it.next(), Some((1, &1)));
+    let i = it.fold(2, |i, (j, &x)| {
+        assert_eq!(i, j);
+        assert_eq!(x, xs[j]);
+        i + 1
+    });
+    assert_eq!(i, xs.len());
+
+    let mut it = xs.iter().enumerate();
+    assert_eq!(it.next(), Some((0, &0)));
+    let i = it.rfold(xs.len() - 1, |i, (j, &x)| {
+        assert_eq!(i, j);
+        assert_eq!(x, xs[j]);
+        i - 1
+    });
+    assert_eq!(i, 0);
 }
 
 #[test]
@@ -291,6 +334,25 @@ fn test_iterator_filter_count() {
     assert_eq!(xs.iter().filter(|&&x| x % 2 == 0).count(), 5);
 }
 
+#[test]
+fn test_iterator_filter_fold() {
+    let xs = [0, 1, 2, 3, 4, 5, 6, 7, 8];
+    let ys = [0, 2, 4, 6, 8];
+    let it = xs.iter().filter(|&&x| x % 2 == 0);
+    let i = it.fold(0, |i, &x| {
+        assert_eq!(x, ys[i]);
+        i + 1
+    });
+    assert_eq!(i, ys.len());
+
+    let it = xs.iter().filter(|&&x| x % 2 == 0);
+    let i = it.rfold(ys.len(), |i, &x| {
+        assert_eq!(x, ys[i - 1]);
+        i - 1
+    });
+    assert_eq!(i, 0);
+}
+
 #[test]
 fn test_iterator_peekable() {
     let xs = vec![0, 1, 2, 3, 4, 5];
@@ -381,6 +443,18 @@ fn test_iterator_peekable_last() {
     assert_eq!(it.last(), None);
 }
 
+#[test]
+fn test_iterator_peekable_fold() {
+    let xs = [0, 1, 2, 3, 4, 5];
+    let mut it = xs.iter().peekable();
+    assert_eq!(it.peek(), Some(&&0));
+    let i = it.fold(0, |i, &x| {
+        assert_eq!(x, xs[i]);
+        i + 1
+    });
+    assert_eq!(i, xs.len());
+}
+
 /// This is an iterator that follows the Iterator contract,
 /// but it is not fused. After having returned None once, it will start
 /// producing elements if .next() is called again.
@@ -470,6 +544,26 @@ fn test_iterator_skip_while() {
     assert_eq!(i, ys.len());
 }
 
+#[test]
+fn test_iterator_skip_while_fold() {
+    let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19];
+    let ys = [15, 16, 17, 19];
+    let it = xs.iter().skip_while(|&x| *x < 15);
+    let i = it.fold(0, |i, &x| {
+        assert_eq!(x, ys[i]);
+        i + 1
+    });
+    assert_eq!(i, ys.len());
+
+    let mut it = xs.iter().skip_while(|&x| *x < 15);
+    assert_eq!(it.next(), Some(&ys[0])); // process skips before folding
+    let i = it.fold(1, |i, &x| {
+        assert_eq!(x, ys[i]);
+        i + 1
+    });
+    assert_eq!(i, ys.len());
+}
+
 #[test]
 fn test_iterator_skip() {
     let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30];
@@ -566,6 +660,26 @@ fn test_iterator_skip_last() {
     assert_eq!(it.last(), Some(&30));
 }
 
+#[test]
+fn test_iterator_skip_fold() {
+    let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19, 20, 30];
+    let ys = [13, 15, 16, 17, 19, 20, 30];
+    let it = xs.iter().skip(5);
+    let i = it.fold(0, |i, &x| {
+        assert_eq!(x, ys[i]);
+        i + 1
+    });
+    assert_eq!(i, ys.len());
+
+    let mut it = xs.iter().skip(5);
+    assert_eq!(it.next(), Some(&ys[0])); // process skips before folding
+    let i = it.fold(1, |i, &x| {
+        assert_eq!(x, ys[i]);
+        i + 1
+    });
+    assert_eq!(i, ys.len());
+}
+
 #[test]
 fn test_iterator_take() {
     let xs = [0, 1, 2, 3, 5, 13, 15, 16, 17, 19];
@@ -661,13 +775,22 @@ fn test_iterator_flat_map_fold() {
     let xs = [0, 3, 6];
     let ys = [1, 2, 3, 4, 5, 6, 7];
     let mut it = xs.iter().flat_map(|&x| x..x+3);
-    it.next();
-    it.next_back();
+    assert_eq!(it.next(), Some(0));
+    assert_eq!(it.next_back(), Some(8));
     let i = it.fold(0, |i, x| {
         assert_eq!(x, ys[i]);
         i + 1
     });
     assert_eq!(i, ys.len());
+
+    let mut it = xs.iter().flat_map(|&x| x..x+3);
+    assert_eq!(it.next(), Some(0));
+    assert_eq!(it.next_back(), Some(8));
+    let i = it.rfold(ys.len(), |i, x| {
+        assert_eq!(x, ys[i - 1]);
+        i - 1
+    });
+    assert_eq!(i, 0);
 }
 
 #[test]
@@ -684,6 +807,32 @@ fn test_inspect() {
     assert_eq!(&xs[..], &ys[..]);
 }
 
+#[test]
+fn test_inspect_fold() {
+    let xs = [1, 2, 3, 4];
+    let mut n = 0;
+    {
+        let it = xs.iter().inspect(|_| n += 1);
+        let i = it.fold(0, |i, &x| {
+            assert_eq!(x, xs[i]);
+            i + 1
+        });
+        assert_eq!(i, xs.len());
+    }
+    assert_eq!(n, xs.len());
+
+    let mut n = 0;
+    {
+        let it = xs.iter().inspect(|_| n += 1);
+        let i = it.rfold(xs.len(), |i, &x| {
+            assert_eq!(x, xs[i - 1]);
+            i - 1
+        });
+        assert_eq!(i, 0);
+    }
+    assert_eq!(n, xs.len());
+}
+
 #[test]
 fn test_cycle() {
     let cycle_len = 3;
@@ -1094,21 +1243,21 @@ fn test_range() {
 
 #[test]
 fn test_range_inclusive_exhaustion() {
-    let mut r = 10...10;
+    let mut r = 10..=10;
     assert_eq!(r.next(), Some(10));
-    assert_eq!(r, 1...0);
+    assert_eq!(r, 1..=0);
 
-    let mut r = 10...10;
+    let mut r = 10..=10;
     assert_eq!(r.next_back(), Some(10));
-    assert_eq!(r, 1...0);
+    assert_eq!(r, 1..=0);
 
-    let mut r = 10...12;
+    let mut r = 10..=12;
     assert_eq!(r.nth(2), Some(12));
-    assert_eq!(r, 1...0);
+    assert_eq!(r, 1..=0);
 
-    let mut r = 10...12;
+    let mut r = 10..=12;
     assert_eq!(r.nth(5), None);
-    assert_eq!(r, 1...0);
+    assert_eq!(r, 1..=0);
 
 }
 
@@ -1145,20 +1294,20 @@ fn test_range_from_nth() {
 
 #[test]
 fn test_range_inclusive_nth() {
-    assert_eq!((10...15).nth(0), Some(10));
-    assert_eq!((10...15).nth(1), Some(11));
-    assert_eq!((10...15).nth(5), Some(15));
-    assert_eq!((10...15).nth(6), None);
+    assert_eq!((10..=15).nth(0), Some(10));
+    assert_eq!((10..=15).nth(1), Some(11));
+    assert_eq!((10..=15).nth(5), Some(15));
+    assert_eq!((10..=15).nth(6), None);
 
-    let mut r = 10_u8...20;
+    let mut r = 10_u8..=20;
     assert_eq!(r.nth(2), Some(12));
-    assert_eq!(r, 13...20);
+    assert_eq!(r, 13..=20);
     assert_eq!(r.nth(2), Some(15));
-    assert_eq!(r, 16...20);
+    assert_eq!(r, 16..=20);
     assert_eq!(r.is_empty(), false);
     assert_eq!(r.nth(10), None);
     assert_eq!(r.is_empty(), true);
-    assert_eq!(r, 1...0);  // We may not want to document/promise this detail
+    assert_eq!(r, 1..=0);  // We may not want to document/promise this detail
 }
 
 #[test]
@@ -1241,6 +1390,31 @@ fn test_fuse_count() {
     // Can't check len now because count consumes.
 }
 
+#[test]
+fn test_fuse_fold() {
+    let xs = [0, 1, 2];
+    let it = xs.iter(); // `FusedIterator`
+    let i = it.fuse().fold(0, |i, &x| {
+        assert_eq!(x, xs[i]);
+        i + 1
+    });
+    assert_eq!(i, xs.len());
+
+    let it = xs.iter(); // `FusedIterator`
+    let i = it.fuse().rfold(xs.len(), |i, &x| {
+        assert_eq!(x, xs[i - 1]);
+        i - 1
+    });
+    assert_eq!(i, 0);
+
+    let it = xs.iter().scan((), |_, &x| Some(x)); // `!FusedIterator`
+    let i = it.fuse().fold(0, |i, x| {
+        assert_eq!(x, xs[i]);
+        i + 1
+    });
+    assert_eq!(i, xs.len());
+}
+
 #[test]
 fn test_once() {
     let mut it = once(42);

src/libcore/tests/lib.rs

@@ -25,6 +25,7 @@
 #![feature(inclusive_range)]
 #![feature(inclusive_range_syntax)]
 #![feature(iter_rfind)]
+#![feature(iter_rfold)]
 #![feature(nonzero)]
 #![feature(rand)]
 #![feature(raw)]
@@ -38,6 +39,7 @@
 #![feature(test)]
 #![feature(trusted_len)]
 #![feature(try_from)]
+#![feature(try_trait)]
 #![feature(unique)]
 
 #![feature(const_atomic_bool_new)]

src/libcore/tests/num/mod.rs

@@ -8,10 +8,11 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use core::convert::TryFrom;
+use core::convert::{TryFrom, TryInto};
 use core::cmp::PartialEq;
 use core::fmt::Debug;
 use core::marker::Copy;
+use core::num::TryFromIntError;
 use core::ops::{Add, Sub, Mul, Div, Rem};
 use core::option::Option;
 use core::option::Option::{Some, None};
@@ -134,6 +135,13 @@ fn test_empty() {
     assert_eq!("".parse::<u8>().ok(), None);
 }
 
+#[test]
+fn test_infallible_try_from_int_error() {
+    let func = |x: i8| -> Result<i32, TryFromIntError> { Ok(x.try_into()?) };
+
+    assert!(func(0).is_ok());
+}
+
 macro_rules! test_impl_from {
     ($fn_name: ident, $Small: ty, $Large: ty) => {
         #[test]

src/libcore/tests/option.rs

@@ -270,3 +270,30 @@ fn test_cloned() {
     assert_eq!(opt_ref_ref.clone().cloned(), Some(&val));
     assert_eq!(opt_ref_ref.cloned().cloned(), Some(1));
 }
+
+#[test]
+fn test_try() {
+    fn try_option_some() -> Option<u8> {
+        let val = Some(1)?;
+        Some(val)
+    }
+    assert_eq!(try_option_some(), Some(1));
+
+    fn try_option_none() -> Option<u8> {
+        let val = None?;
+        Some(val)
+    }
+    assert_eq!(try_option_none(), None);
+
+    fn try_option_ok() -> Result<u8, NoneError> {
+        let val = Some(1)?;
+        Ok(val)
+    }
+    assert_eq!(try_option_ok(), Ok(1));
+
+    fn try_option_err() -> Result<u8, NoneError> {
+        let val = None?;
+        Ok(val)
+    }
+    assert_eq!(try_option_err(), Err(NoneError));
+}

src/libcore/tests/result.rs

@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+use core::option::*;
+
 fn op1() -> Result<isize, &'static str> { Ok(666) }
 fn op2() -> Result<isize, &'static str> { Err("sadface") }
 
@@ -202,3 +204,30 @@ pub fn test_unwrap_or_default() {
     assert_eq!(op1().unwrap_or_default(), 666);
     assert_eq!(op2().unwrap_or_default(), 0);
 }
+
+#[test]
+fn test_try() {
+    fn try_result_some() -> Option<u8> {
+        let val = Ok(1)?;
+        Some(val)
+    }
+    assert_eq!(try_result_some(), Some(1));
+
+    fn try_result_none() -> Option<u8> {
+        let val = Err(NoneError)?;
+        Some(val)
+    }
+    assert_eq!(try_result_none(), None);
+
+    fn try_result_ok() -> Result<u8, u8> {
+        let val = Ok(1)?;
+        Ok(val)
+    }
+    assert_eq!(try_result_ok(), Ok(1));
+
+    fn try_result_err() -> Result<u8, u8> {
+        let val = Err(1)?;
+        Ok(val)
+    }
+    assert_eq!(try_result_err(), Err(1));
+}

src/liblibc

@@ -1 +1 @@
-Subproject commit 95848f9622deccc9cbadcd5d3a4faef01a90ead4
+Subproject commit 44e4018e1a37716286ec98cb5b7dd7d33ecaf940

src/libproc_macro/lib.rs

@@ -509,6 +509,7 @@ impl TokenTree {
             Dot => op!('.'),
             DotDot => joint!('.', Dot),
             DotDotDot => joint!('.', DotDot),
+            DotDotEq => joint!('.', DotEq),
             Comma => op!(','),
             Semi => op!(';'),
             Colon => op!(':'),
@@ -531,6 +532,7 @@ impl TokenTree {
                 })
             }
 
+            DotEq => unreachable!(),
             OpenDelim(..) | CloseDelim(..) => unreachable!(),
             Whitespace | Comment | Shebang(..) | Eof => unreachable!(),
         };

src/libproc_macro/quote.rs

@@ -202,8 +202,8 @@ impl Quote for Token {
 
         gen_match! {
             Eq, Lt, Le, EqEq, Ne, Ge, Gt, AndAnd, OrOr, Not, Tilde, At, Dot, DotDot, DotDotDot,
-            Comma, Semi, Colon, ModSep, RArrow, LArrow, FatArrow, Pound, Dollar, Question,
-            Underscore;
+            DotDotEq, Comma, Semi, Colon, ModSep, RArrow, LArrow, FatArrow, Pound, Dollar,
+            Question, Underscore;
 
             Token::OpenDelim(delim) => quote!(rt::token::OpenDelim((quote delim))),
             Token::CloseDelim(delim) => quote!(rt::token::CloseDelim((quote delim))),

src/libprofiler_builtins/Cargo.toml

@@ -15,4 +15,4 @@ doc = false
 core = { path = "../libcore" }
 
 [build-dependencies]
-gcc = "0.3.50"
+cc = "1.0"

src/libprofiler_builtins/build.rs

@@ -12,14 +12,14 @@
 //!
 //! See the build.rs for libcompiler_builtins crate for details.
 
-extern crate gcc;
+extern crate cc;
 
 use std::env;
 use std::path::Path;
 
 fn main() {
     let target = env::var("TARGET").expect("TARGET was not set");
-    let cfg = &mut gcc::Build::new();
+    let cfg = &mut cc::Build::new();
 
     let mut profile_sources = vec!["GCDAProfiling.c",
                                    "InstrProfiling.c",

src/librustc/README.md

@@ -37,7 +37,7 @@ incremental improves that may change.)
 
 The dependency structure of these crates is roughly a diamond:
 
-````
+```
                   rustc_driver
                 /      |       \
               /        |         \

src/librustc/dep_graph/dep_node.rs

@@ -60,7 +60,7 @@
 //! user of the `DepNode` API of having to know how to compute the expected
 //! fingerprint for a given set of node parameters.
 
-use hir::def_id::{CrateNum, DefId, DefIndex};
+use hir::def_id::{CrateNum, DefId, DefIndex, CRATE_DEF_INDEX};
 use hir::map::DefPathHash;
 use hir::{HirId, ItemLocalId};
 
@@ -80,14 +80,28 @@ macro_rules! erase {
     ($x:tt) => ({})
 }
 
-macro_rules! anon_attr_to_bool {
-    (anon) => (true)
+macro_rules! is_anon_attr {
+    (anon) => (true);
+    ($attr:ident) => (false);
+}
+
+macro_rules! is_input_attr {
+    (input) => (true);
+    ($attr:ident) => (false);
+}
+
+macro_rules! contains_anon_attr {
+    ($($attr:ident),*) => ({$(is_anon_attr!($attr) | )* false});
+}
+
+macro_rules! contains_input_attr {
+    ($($attr:ident),*) => ({$(is_input_attr!($attr) | )* false});
 }
 
 macro_rules! define_dep_nodes {
     (<$tcx:tt>
     $(
-        [$($anon:ident)*]
+        [$($attr:ident),* ]
         $variant:ident $(( $($tuple_arg:tt),* ))*
                        $({ $($struct_arg_name:ident : $struct_arg_ty:ty),* })*
       ,)*
@@ -105,7 +119,9 @@ macro_rules! define_dep_nodes {
                 match *self {
                     $(
                         DepKind :: $variant => {
-                            $(return !anon_attr_to_bool!($anon);)*
+                            if contains_anon_attr!($($attr),*) {
+                                return false;
+                            }
 
                             // tuple args
                             $({
@@ -126,15 +142,20 @@ macro_rules! define_dep_nodes {
                 }
             }
 
-            #[allow(unreachable_code)]
             #[inline]
-            pub fn is_anon<$tcx>(&self) -> bool {
+            pub fn is_anon(&self) -> bool {
                 match *self {
                     $(
-                        DepKind :: $variant => {
-                            $(return anon_attr_to_bool!($anon);)*
-                            false
-                        }
+                        DepKind :: $variant => { contains_anon_attr!($($attr),*) }
+                    )*
+                }
+            }
+
+            #[inline]
+            pub fn is_input(&self) -> bool {
+                match *self {
+                    $(
+                        DepKind :: $variant => { contains_input_attr!($($attr),*) }
                     )*
                 }
             }
@@ -366,6 +387,17 @@ impl DefId {
     }
 }
 
+impl DepKind {
+    #[inline]
+    pub fn fingerprint_needed_for_crate_hash(self) -> bool {
+        match self {
+            DepKind::HirBody |
+            DepKind::Krate => true,
+            _ => false,
+        }
+    }
+}
+
 define_dep_nodes!( <'tcx>
     // Represents the `Krate` as a whole (the `hir::Krate` value) (as
     // distinct from the krate module). This is basically a hash of
@@ -378,18 +410,17 @@ define_dep_nodes!( <'tcx>
     // suitable wrapper, you can use `tcx.dep_graph.ignore()` to gain
     // access to the krate, but you must remember to add suitable
     // edges yourself for the individual items that you read.
-    [] Krate,
-
-    // Represents the HIR node with the given node-id
-    [] Hir(DefId),
+    [input] Krate,
 
     // Represents the body of a function or method. The def-id is that of the
     // function/method.
-    [] HirBody(DefId),
+    [input] HirBody(DefId),
 
-    // Represents the metadata for a given HIR node, typically found
-    // in an extern crate.
-    [] MetaData(DefId),
+    // Represents the HIR node with the given node-id
+    [input] Hir(DefId),
+
+    // Represents metadata from an extern crate.
+    [input] CrateMetadata(CrateNum),
 
     // Represents some artifact that we save to disk. Note that these
     // do not have a def-id as part of their identifier.
@@ -414,6 +445,7 @@ define_dep_nodes!( <'tcx>
     [] BorrowCheckKrate,
     [] BorrowCheck(DefId),
     [] MirBorrowCheck(DefId),
+    [] UnsafetyViolations(DefId),
 
     [] RvalueCheck(DefId),
     [] Reachability,
@@ -529,7 +561,7 @@ define_dep_nodes!( <'tcx>
     [] ExternCrate(DefId),
     [] LintLevels,
     [] Specializes { impl1: DefId, impl2: DefId },
-    [] InScopeTraits(DefIndex),
+    [input] InScopeTraits(DefIndex),
     [] ModuleExports(DefId),
     [] IsSanitizerRuntime(CrateNum),
     [] IsProfilerRuntime(CrateNum),
@@ -647,6 +679,22 @@ impl<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> DepNodeParams<'a, 'gcx, 'tcx> for (DefIndex,
     }
 }
 
+impl<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> DepNodeParams<'a, 'gcx, 'tcx> for (CrateNum,) {
+    const CAN_RECONSTRUCT_QUERY_KEY: bool = true;
+
+    fn to_fingerprint(&self, tcx: TyCtxt) -> Fingerprint {
+        let def_id = DefId {
+            krate: self.0,
+            index: CRATE_DEF_INDEX,
+        };
+        tcx.def_path_hash(def_id).0
+    }
+
+    fn to_debug_str(&self, tcx: TyCtxt<'a, 'gcx, 'tcx>) -> String {
+        tcx.crate_name(self.0).as_str().to_string()
+    }
+}
+
 impl<'a, 'gcx: 'tcx + 'a, 'tcx: 'a> DepNodeParams<'a, 'gcx, 'tcx> for (DefId, DefId) {
     const CAN_RECONSTRUCT_QUERY_KEY: bool = false;
 

src/librustc/dep_graph/edges.rs

@@ -17,7 +17,7 @@ use std::mem;
 use super::{DepGraphQuery, DepKind, DepNode};
 use super::debug::EdgeFilter;
 
-pub struct DepGraphEdges {
+pub(super) struct DepGraphEdges {
     nodes: Vec<DepNode>,
     indices: FxHashMap<DepNode, DepNodeIndex>,
     edges: FxHashSet<(DepNodeIndex, DepNodeIndex)>,
@@ -31,8 +31,8 @@ pub struct DepGraphEdges {
 }
 
 #[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
-pub struct DepNodeIndex {
-    index: u32
+pub(super) struct DepNodeIndex {
+    index: u32,
 }
 
 impl DepNodeIndex {
@@ -123,6 +123,7 @@ impl DepGraphEdges {
             reads
         } = popped_node {
             debug_assert_eq!(node, key);
+            debug_assert!(!node.kind.is_input() || reads.is_empty());
 
             let target_id = self.get_or_create_node(node);
 

src/librustc/dep_graph/graph.rs

@@ -8,11 +8,13 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use rustc_data_structures::fx::FxHashMap;
 use rustc_data_structures::stable_hasher::{HashStable, StableHasher,
                                            StableHashingContextProvider};
+use rustc_data_structures::fx::{FxHashMap, FxHashSet};
+use rustc_data_structures::indexed_vec::{Idx, IndexVec};
 use session::config::OutputType;
 use std::cell::{Ref, RefCell};
+use std::hash::Hash;
 use std::rc::Rc;
 use util::common::{ProfileQueriesMsg, profq_msg};
 
@@ -22,17 +24,56 @@ use super::dep_node::{DepNode, DepKind, WorkProductId};
 use super::query::DepGraphQuery;
 use super::raii;
 use super::safe::DepGraphSafe;
-use super::edges::{DepGraphEdges, DepNodeIndex};
+use super::edges::{self, DepGraphEdges};
+use super::serialized::{SerializedDepGraph, SerializedDepNodeIndex};
+use super::prev::PreviousDepGraph;
 
 #[derive(Clone)]
 pub struct DepGraph {
-    data: Option<Rc<DepGraphData>>
+    data: Option<Rc<DepGraphData>>,
+
+    // At the moment we are using DepNode as key here. In the future it might
+    // be possible to use an IndexVec<DepNodeIndex, _> here. At the moment there
+    // are a few problems with that:
+    // - Some fingerprints are needed even if incr. comp. is disabled -- yet
+    //   we need to have a dep-graph to generate DepNodeIndices.
+    // - The architecture is still in flux and it's not clear what how to best
+    //   implement things.
+    fingerprints: Rc<RefCell<FxHashMap<DepNode, Fingerprint>>>
+}
+
+/// As a temporary measure, while transitioning to the new DepGraph
+/// implementation, we maintain the old and the new dep-graph encoding in
+/// parallel, so a DepNodeIndex actually contains two indices, one for each
+/// version.
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub struct DepNodeIndex {
+    legacy: edges::DepNodeIndex,
+    new: DepNodeIndexNew,
+}
+
+impl DepNodeIndex {
+    pub const INVALID: DepNodeIndex = DepNodeIndex {
+        legacy: edges::DepNodeIndex::INVALID,
+        new: DepNodeIndexNew::INVALID,
+    };
 }
 
 struct DepGraphData {
-    /// The actual graph data.
+    /// The old, initial encoding of the dependency graph. This will soon go
+    /// away.
     edges: RefCell<DepGraphEdges>,
 
+    /// The new encoding of the dependency graph, optimized for red/green
+    /// tracking. The `current` field is the dependency graph of only the
+    /// current compilation session: We don't merge the previous dep-graph into
+    /// current one anymore.
+    current: RefCell<CurrentDepGraph>,
+
+    /// The dep-graph from the previous compilation session. It contains all
+    /// nodes and edges as well as all fingerprints of nodes that have them.
+    previous: PreviousDepGraph,
+
     /// When we load, there may be `.o` files, cached mir, or other such
     /// things available to us. If we find that they are not dirty, we
     /// load the path to the file storing those work-products here into
@@ -46,18 +87,25 @@ struct DepGraphData {
 }
 
 impl DepGraph {
-    pub fn new(enabled: bool) -> DepGraph {
+
+    pub fn new(prev_graph: PreviousDepGraph) -> DepGraph {
         DepGraph {
-            data: if enabled {
-                Some(Rc::new(DepGraphData {
-                    previous_work_products: RefCell::new(FxHashMap()),
-                    work_products: RefCell::new(FxHashMap()),
-                    edges: RefCell::new(DepGraphEdges::new()),
-                    dep_node_debug: RefCell::new(FxHashMap()),
-                }))
-            } else {
-                None
-            }
+            data: Some(Rc::new(DepGraphData {
+                previous_work_products: RefCell::new(FxHashMap()),
+                work_products: RefCell::new(FxHashMap()),
+                edges: RefCell::new(DepGraphEdges::new()),
+                dep_node_debug: RefCell::new(FxHashMap()),
+                current: RefCell::new(CurrentDepGraph::new()),
+                previous: prev_graph,
+            })),
+            fingerprints: Rc::new(RefCell::new(FxHashMap())),
+        }
+    }
+
+    pub fn new_disabled() -> DepGraph {
+        DepGraph {
+            data: None,
+            fingerprints: Rc::new(RefCell::new(FxHashMap())),
         }
     }
 
@@ -72,7 +120,8 @@ impl DepGraph {
     }
 
     pub fn in_ignore<'graph>(&'graph self) -> Option<raii::IgnoreTask<'graph>> {
-        self.data.as_ref().map(|data| raii::IgnoreTask::new(&data.edges))
+        self.data.as_ref().map(|data| raii::IgnoreTask::new(&data.edges,
+                                                            &data.current))
     }
 
     pub fn with_ignore<OP,R>(&self, op: OP) -> R
@@ -120,6 +169,7 @@ impl DepGraph {
     {
         if let Some(ref data) = self.data {
             data.edges.borrow_mut().push_task(key);
+            data.current.borrow_mut().push_task(key);
             if cfg!(debug_assertions) {
                 profq_msg(ProfileQueriesMsg::TaskBegin(key.clone()))
             };
@@ -135,15 +185,36 @@ impl DepGraph {
             if cfg!(debug_assertions) {
                 profq_msg(ProfileQueriesMsg::TaskEnd)
             };
-            let dep_node_index = data.edges.borrow_mut().pop_task(key);
+
+            let dep_node_index_legacy = data.edges.borrow_mut().pop_task(key);
+            let dep_node_index_new = data.current.borrow_mut().pop_task(key);
 
             let mut stable_hasher = StableHasher::new();
             result.hash_stable(&mut hcx, &mut stable_hasher);
-            let _: Fingerprint = stable_hasher.finish();
 
-            (result, dep_node_index)
+            assert!(self.fingerprints
+                        .borrow_mut()
+                        .insert(key, stable_hasher.finish())
+                        .is_none());
+
+            (result, DepNodeIndex {
+                legacy: dep_node_index_legacy,
+                new: dep_node_index_new,
+            })
         } else {
-            (task(cx, arg), DepNodeIndex::INVALID)
+            if key.kind.fingerprint_needed_for_crate_hash() {
+                let mut hcx = cx.create_stable_hashing_context();
+                let result = task(cx, arg);
+                let mut stable_hasher = StableHasher::new();
+                result.hash_stable(&mut hcx, &mut stable_hasher);
+                assert!(self.fingerprints
+                            .borrow_mut()
+                            .insert(key, stable_hasher.finish())
+                            .is_none());
+                (result, DepNodeIndex::INVALID)
+            } else {
+                (task(cx, arg), DepNodeIndex::INVALID)
+            }
         }
     }
 
@@ -154,9 +225,14 @@ impl DepGraph {
     {
         if let Some(ref data) = self.data {
             data.edges.borrow_mut().push_anon_task();
+            data.current.borrow_mut().push_anon_task();
             let result = op();
-            let dep_node = data.edges.borrow_mut().pop_anon_task(dep_kind);
-            (result, dep_node)
+            let dep_node_index_legacy = data.edges.borrow_mut().pop_anon_task(dep_kind);
+            let dep_node_index_new = data.current.borrow_mut().pop_anon_task(dep_kind);
+            (result, DepNodeIndex {
+                legacy: dep_node_index_legacy,
+                new: dep_node_index_new,
+            })
         } else {
             (op(), DepNodeIndex::INVALID)
         }
@@ -166,13 +242,21 @@ impl DepGraph {
     pub fn read(&self, v: DepNode) {
         if let Some(ref data) = self.data {
             data.edges.borrow_mut().read(v);
+
+            let mut current = data.current.borrow_mut();
+            if let Some(&dep_node_index_new) = current.node_to_node_index.get(&v) {
+                current.read_index(dep_node_index_new);
+            } else {
+                bug!("DepKind {:?} should be pre-allocated but isn't.", v.kind)
+            }
         }
     }
 
     #[inline]
     pub fn read_index(&self, v: DepNodeIndex) {
         if let Some(ref data) = self.data {
-            data.edges.borrow_mut().read_index(v);
+            data.edges.borrow_mut().read_index(v.legacy);
+            data.current.borrow_mut().read_index(v.new);
         }
     }
 
@@ -187,12 +271,12 @@ impl DepGraph {
         self.data.as_ref().unwrap().edges.borrow_mut().add_node(node);
     }
 
-    pub fn alloc_input_node(&self, node: DepNode) -> DepNodeIndex {
-        if let Some(ref data) = self.data {
-            data.edges.borrow_mut().add_node(node)
-        } else {
-            DepNodeIndex::INVALID
-        }
+    pub fn fingerprint_of(&self, dep_node: &DepNode) -> Fingerprint {
+        self.fingerprints.borrow()[dep_node]
+    }
+
+    pub fn prev_fingerprint_of(&self, dep_node: &DepNode) -> Fingerprint {
+        self.data.as_ref().unwrap().previous.fingerprint_of(dep_node)
     }
 
     /// Indicates that a previous work product exists for `v`. This is
@@ -261,6 +345,44 @@ impl DepGraph {
     pub(super) fn dep_node_debug_str(&self, dep_node: DepNode) -> Option<String> {
         self.data.as_ref().and_then(|t| t.dep_node_debug.borrow().get(&dep_node).cloned())
     }
+
+    pub fn serialize(&self) -> SerializedDepGraph {
+        let fingerprints = self.fingerprints.borrow();
+        let current_dep_graph = self.data.as_ref().unwrap().current.borrow();
+
+        let nodes: IndexVec<_, _> = current_dep_graph.nodes.iter().map(|dep_node| {
+            let fingerprint = fingerprints.get(dep_node)
+                                          .cloned()
+                                          .unwrap_or(Fingerprint::zero());
+            (*dep_node, fingerprint)
+        }).collect();
+
+        let total_edge_count: usize = current_dep_graph.edges.iter()
+                                                             .map(|v| v.len())
+                                                             .sum();
+
+        let mut edge_list_indices = IndexVec::with_capacity(nodes.len());
+        let mut edge_list_data = Vec::with_capacity(total_edge_count);
+
+        for (current_dep_node_index, edges) in current_dep_graph.edges.iter_enumerated() {
+            let start = edge_list_data.len() as u32;
+            // This should really just be a memcpy :/
+            edge_list_data.extend(edges.iter().map(|i| SerializedDepNodeIndex(i.index)));
+            let end = edge_list_data.len() as u32;
+
+            debug_assert_eq!(current_dep_node_index.index(), edge_list_indices.len());
+            edge_list_indices.push((start, end));
+        }
+
+        debug_assert!(edge_list_data.len() <= ::std::u32::MAX as usize);
+        debug_assert_eq!(edge_list_data.len(), total_edge_count);
+
+        SerializedDepGraph {
+            nodes,
+            edge_list_indices,
+            edge_list_data,
+        }
+    }
 }
 
 /// A "work product" is an intermediate result that we save into the
@@ -305,3 +427,174 @@ pub struct WorkProduct {
     /// Saved files associated with this CGU
     pub saved_files: Vec<(OutputType, String)>,
 }
+
+pub(super) struct CurrentDepGraph {
+    nodes: IndexVec<DepNodeIndexNew, DepNode>,
+    edges: IndexVec<DepNodeIndexNew, Vec<DepNodeIndexNew>>,
+    node_to_node_index: FxHashMap<DepNode, DepNodeIndexNew>,
+
+    task_stack: Vec<OpenTask>,
+}
+
+impl CurrentDepGraph {
+    fn new() -> CurrentDepGraph {
+        CurrentDepGraph {
+            nodes: IndexVec::new(),
+            edges: IndexVec::new(),
+            node_to_node_index: FxHashMap(),
+            task_stack: Vec::new(),
+        }
+    }
+
+    pub(super) fn push_ignore(&mut self) {
+        self.task_stack.push(OpenTask::Ignore);
+    }
+
+    pub(super) fn pop_ignore(&mut self) {
+        let popped_node = self.task_stack.pop().unwrap();
+        debug_assert_eq!(popped_node, OpenTask::Ignore);
+    }
+
+    pub(super) fn push_task(&mut self, key: DepNode) {
+        self.task_stack.push(OpenTask::Regular {
+            node: key,
+            reads: Vec::new(),
+            read_set: FxHashSet(),
+        });
+    }
+
+    pub(super) fn pop_task(&mut self, key: DepNode) -> DepNodeIndexNew {
+        let popped_node = self.task_stack.pop().unwrap();
+
+        if let OpenTask::Regular {
+            node,
+            read_set: _,
+            reads
+        } = popped_node {
+            debug_assert_eq!(node, key);
+            self.alloc_node(node, reads)
+        } else {
+            bug!("pop_task() - Expected regular task to be popped")
+        }
+    }
+
+    fn push_anon_task(&mut self) {
+        self.task_stack.push(OpenTask::Anon {
+            reads: Vec::new(),
+            read_set: FxHashSet(),
+        });
+    }
+
+    fn pop_anon_task(&mut self, kind: DepKind) -> DepNodeIndexNew {
+        let popped_node = self.task_stack.pop().unwrap();
+
+        if let OpenTask::Anon {
+            read_set: _,
+            reads
+        } = popped_node {
+            let mut fingerprint = Fingerprint::zero();
+            let mut hasher = StableHasher::new();
+
+            for &read in reads.iter() {
+                let read_dep_node = self.nodes[read];
+
+                ::std::mem::discriminant(&read_dep_node.kind).hash(&mut hasher);
+
+                // Fingerprint::combine() is faster than sending Fingerprint
+                // through the StableHasher (at least as long as StableHasher
+                // is so slow).
+                fingerprint = fingerprint.combine(read_dep_node.hash);
+            }
+
+            fingerprint = fingerprint.combine(hasher.finish());
+
+            let target_dep_node = DepNode {
+                kind,
+                hash: fingerprint,
+            };
+
+            if let Some(&index) = self.node_to_node_index.get(&target_dep_node) {
+                return index;
+            }
+
+            self.alloc_node(target_dep_node, reads)
+        } else {
+            bug!("pop_anon_task() - Expected anonymous task to be popped")
+        }
+    }
+
+    fn read_index(&mut self, source: DepNodeIndexNew) {
+        match self.task_stack.last_mut() {
+            Some(&mut OpenTask::Regular {
+                ref mut reads,
+                ref mut read_set,
+                node: _,
+            }) => {
+                if read_set.insert(source) {
+                    reads.push(source);
+                }
+            }
+            Some(&mut OpenTask::Anon {
+                ref mut reads,
+                ref mut read_set,
+            }) => {
+                if read_set.insert(source) {
+                    reads.push(source);
+                }
+            }
+            Some(&mut OpenTask::Ignore) | None => {
+                // ignore
+            }
+        }
+    }
+
+    fn alloc_node(&mut self,
+                  dep_node: DepNode,
+                  edges: Vec<DepNodeIndexNew>)
+                  -> DepNodeIndexNew {
+        debug_assert_eq!(self.edges.len(), self.nodes.len());
+        debug_assert_eq!(self.node_to_node_index.len(), self.nodes.len());
+        debug_assert!(!self.node_to_node_index.contains_key(&dep_node));
+        let dep_node_index = DepNodeIndexNew::new(self.nodes.len());
+        self.nodes.push(dep_node);
+        self.node_to_node_index.insert(dep_node, dep_node_index);
+        self.edges.push(edges);
+        dep_node_index
+    }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, Hash)]
+pub(super) struct DepNodeIndexNew {
+    index: u32,
+}
+
+impl Idx for DepNodeIndexNew {
+    fn new(v: usize) -> DepNodeIndexNew {
+        assert!((v & 0xFFFF_FFFF) == v);
+        DepNodeIndexNew { index: v as u32 }
+    }
+
+    fn index(self) -> usize {
+        self.index as usize
+    }
+}
+
+impl DepNodeIndexNew {
+    const INVALID: DepNodeIndexNew = DepNodeIndexNew {
+        index: ::std::u32::MAX,
+    };
+}
+
+#[derive(Clone, Debug, PartialEq)]
+enum OpenTask {
+    Regular {
+        node: DepNode,
+        reads: Vec<DepNodeIndexNew>,
+        read_set: FxHashSet<DepNodeIndexNew>,
+    },
+    Anon {
+        reads: Vec<DepNodeIndexNew>,
+        read_set: FxHashSet<DepNodeIndexNew>,
+    },
+    Ignore,
+}

src/librustc/dep_graph/mod.rs

@@ -13,19 +13,17 @@ mod dep_node;
 mod dep_tracking_map;
 mod edges;
 mod graph;
+mod prev;
 mod query;
 mod raii;
 mod safe;
+mod serialized;
 
 pub use self::dep_tracking_map::{DepTrackingMap, DepTrackingMapConfig};
-pub use self::dep_node::DepNode;
-pub use self::dep_node::WorkProductId;
-pub use self::graph::DepGraph;
-pub use self::graph::WorkProduct;
-pub use self::edges::DepNodeIndex;
+pub use self::dep_node::{DepNode, DepKind, DepConstructor, WorkProductId};
+pub use self::graph::{DepGraph, WorkProduct, DepNodeIndex};
+pub use self::prev::PreviousDepGraph;
 pub use self::query::DepGraphQuery;
 pub use self::safe::AssertDepGraphSafe;
 pub use self::safe::DepGraphSafe;
-pub use self::raii::DepTask;
-
-pub use self::dep_node::{DepKind, DepConstructor};
+pub use self::serialized::SerializedDepGraph;

src/librustc/dep_graph/prev.rs

@@ -0,0 +1,46 @@
+// 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 ich::Fingerprint;
+use rustc_data_structures::fx::FxHashMap;
+use super::dep_node::DepNode;
+use super::serialized::{SerializedDepGraph, SerializedDepNodeIndex};
+
+#[derive(Debug, RustcEncodable, RustcDecodable)]
+pub struct PreviousDepGraph {
+    data: SerializedDepGraph,
+    index: FxHashMap<DepNode, SerializedDepNodeIndex>,
+}
+
+impl PreviousDepGraph {
+    pub fn new(data: SerializedDepGraph) -> PreviousDepGraph {
+        let index: FxHashMap<_, _> = data.nodes
+            .iter_enumerated()
+            .map(|(idx, &(dep_node, _))| (dep_node, idx))
+            .collect();
+        PreviousDepGraph { data, index }
+    }
+
+    pub fn with_edges_from<F>(&self, dep_node: &DepNode, mut f: F)
+    where
+        F: FnMut(&(DepNode, Fingerprint)),
+    {
+        let node_index = self.index[dep_node];
+        self.data
+            .edge_targets_from(node_index)
+            .into_iter()
+            .for_each(|&index| f(&self.data.nodes[index]));
+    }
+
+    pub fn fingerprint_of(&self, dep_node: &DepNode) -> Fingerprint {
+        let node_index = self.index[dep_node];
+        self.data.nodes[node_index].1
+    }
+}

src/librustc/dep_graph/raii.rs

@@ -8,50 +8,33 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use super::DepNode;
 use super::edges::DepGraphEdges;
+use super::graph::CurrentDepGraph;
 
 use std::cell::RefCell;
 
-pub struct DepTask<'graph> {
-    graph: &'graph RefCell<DepGraphEdges>,
-    key: DepNode,
-}
-
-impl<'graph> DepTask<'graph> {
-    pub fn new(graph: &'graph RefCell<DepGraphEdges>,
-               key: DepNode)
-               -> DepTask<'graph> {
-        graph.borrow_mut().push_task(key);
-        DepTask {
-            graph,
-            key,
-        }
-    }
-}
-
-impl<'graph> Drop for DepTask<'graph> {
-    fn drop(&mut self) {
-        self.graph.borrow_mut().pop_task(self.key);
-    }
-}
-
 pub struct IgnoreTask<'graph> {
-    graph: &'graph RefCell<DepGraphEdges>,
+    legacy_graph: &'graph RefCell<DepGraphEdges>,
+    new_graph: &'graph RefCell<CurrentDepGraph>,
 }
 
 impl<'graph> IgnoreTask<'graph> {
-    pub fn new(graph: &'graph RefCell<DepGraphEdges>) -> IgnoreTask<'graph> {
-        graph.borrow_mut().push_ignore();
+    pub(super) fn new(legacy_graph: &'graph RefCell<DepGraphEdges>,
+                      new_graph: &'graph RefCell<CurrentDepGraph>)
+                      -> IgnoreTask<'graph> {
+        legacy_graph.borrow_mut().push_ignore();
+        new_graph.borrow_mut().push_ignore();
         IgnoreTask {
-            graph
+            legacy_graph,
+            new_graph,
         }
     }
 }
 
 impl<'graph> Drop for IgnoreTask<'graph> {
     fn drop(&mut self) {
-        self.graph.borrow_mut().pop_ignore();
+        self.legacy_graph.borrow_mut().pop_ignore();
+        self.new_graph.borrow_mut().pop_ignore();
     }
 }
 

src/librustc/dep_graph/serialized.rs

@@ -0,0 +1,63 @@
+// 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.
+
+//! The data that we will serialize and deserialize.
+
+use dep_graph::DepNode;
+use ich::Fingerprint;
+use rustc_data_structures::indexed_vec::{IndexVec, Idx};
+
+/// The index of a DepNode in the SerializedDepGraph::nodes array.
+#[derive(Copy, Clone, Hash, Eq, PartialEq, Ord, PartialOrd, Debug,
+         RustcEncodable, RustcDecodable)]
+pub struct SerializedDepNodeIndex(pub u32);
+
+impl Idx for SerializedDepNodeIndex {
+    #[inline]
+    fn new(idx: usize) -> Self {
+        assert!(idx <= ::std::u32::MAX as usize);
+        SerializedDepNodeIndex(idx as u32)
+    }
+
+    #[inline]
+    fn index(self) -> usize {
+        self.0 as usize
+    }
+}
+
+/// Data for use when recompiling the **current crate**.
+#[derive(Debug, RustcEncodable, RustcDecodable)]
+pub struct SerializedDepGraph {
+    /// The set of all DepNodes in the graph
+    pub nodes: IndexVec<SerializedDepNodeIndex, (DepNode, Fingerprint)>,
+    /// For each DepNode, stores the list of edges originating from that
+    /// DepNode. Encoded as a [start, end) pair indexing into edge_list_data,
+    /// which holds the actual DepNodeIndices of the target nodes.
+    pub edge_list_indices: IndexVec<SerializedDepNodeIndex, (u32, u32)>,
+    /// A flattened list of all edge targets in the graph. Edge sources are
+    /// implicit in edge_list_indices.
+    pub edge_list_data: Vec<SerializedDepNodeIndex>,
+}
+
+impl SerializedDepGraph {
+
+    pub fn new() -> SerializedDepGraph {
+        SerializedDepGraph {
+            nodes: IndexVec::new(),
+            edge_list_indices: IndexVec::new(),
+            edge_list_data: Vec::new(),
+        }
+    }
+
+    pub fn edge_targets_from(&self, source: SerializedDepNodeIndex) -> &[SerializedDepNodeIndex] {
+        let targets = self.edge_list_indices[source];
+        &self.edge_list_data[targets.0 as usize..targets.1 as usize]
+    }
+}

src/librustc/diagnostics.rs

@@ -479,40 +479,6 @@ fn main() {
 ```
 "##,
 
-E0133: r##"
-Unsafe code was used outside of an unsafe function or block.
-
-Erroneous code example:
-
-```compile_fail,E0133
-unsafe fn f() { return; } // This is the unsafe code
-
-fn main() {
-    f(); // error: call to unsafe function requires unsafe function or block
-}
-```
-
-Using unsafe functionality is potentially dangerous and disallowed by safety
-checks. Examples:
-
-* Dereferencing raw pointers
-* Calling functions via FFI
-* Calling functions marked unsafe
-
-These safety checks can be relaxed for a section of the code by wrapping the
-unsafe instructions with an `unsafe` block. For instance:
-
-```
-unsafe fn f() { return; }
-
-fn main() {
-    unsafe { f(); } // ok!
-}
-```
-
-See also https://doc.rust-lang.org/book/first-edition/unsafe.html
-"##,
-
 // This shouldn't really ever trigger since the repeated value error comes first
 E0136: r##"
 A binary can only have one entry point, and by default that entry point is the
@@ -1139,11 +1105,13 @@ already specify all requirements that will be used for every type parameter.
 "##,
 
 E0281: r##"
+#### Note: this error code is no longer emitted by the compiler.
+
 You tried to supply a type which doesn't implement some trait in a location
 which expected that trait. This error typically occurs when working with
 `Fn`-based types. Erroneous code example:
 
-```compile_fail,E0281
+```compile-fail
 fn foo<F: Fn(usize)>(x: F) { }
 
 fn main() {
@@ -1383,74 +1351,6 @@ struct Foo<T: 'static> {
 ```
 "##,
 
-E0312: r##"
-A lifetime of reference outlives lifetime of borrowed content.
-
-Erroneous code example:
-
-```compile_fail,E0312
-fn make_child<'tree, 'human>(
-  x: &'human i32,
-  y: &'tree i32
-) -> &'human i32 {
-    if x > y
-       { x }
-    else
-       { y }
-       // error: lifetime of reference outlives lifetime of borrowed content
-}
-```
-
-The function declares that it returns a reference with the `'human`
-lifetime, but it may return data with the `'tree` lifetime. As neither
-lifetime is declared longer than the other, this results in an
-error. Sometimes, this error is because the function *body* is
-incorrect -- that is, maybe you did not *mean* to return data from
-`y`. In that case, you should fix the function body.
-
-Often, however, the body is correct. In that case, the function
-signature needs to be altered to match the body, so that the caller
-understands that data from either `x` or `y` may be returned. The
-simplest way to do this is to give both function parameters the *same*
-named lifetime:
-
-```
-fn make_child<'human>(
-  x: &'human i32,
-  y: &'human i32
-) -> &'human i32 {
-    if x > y
-       { x }
-    else
-       { y } // ok!
-}
-```
-
-However, in some cases, you may prefer to explicitly declare that one lifetime
-outlives another using a `where` clause:
-
-```
-fn make_child<'tree, 'human>(
-  x: &'human i32,
-  y: &'tree i32
-) -> &'human i32
-where
-  'tree: 'human
-{
-    if x > y
-       { x }
-    else
-       { y } // ok!
-}
-```
-
-Here, the where clause `'tree: 'human` can be read as "the lifetime
-'tree outlives the lifetime 'human" -- meaning, references with the
-`'tree` lifetime live *at least as long as* references with the
-`'human` lifetime. Therefore, it is safe to return data with lifetime
-`'tree` when data with the lifetime `'human` is needed.
-"##,
-
 E0317: r##"
 This error occurs when an `if` expression without an `else` block is used in a
 context where a type other than `()` is expected, for example a `let`
@@ -2060,6 +1960,7 @@ register_diagnostics! {
 //  E0304, // expected signed integer constant
 //  E0305, // expected constant
     E0311, // thing may not live long enough
+    E0312, // lifetime of reference outlives lifetime of borrowed content
     E0313, // lifetime of borrowed pointer outlives lifetime of captured variable
     E0314, // closure outlives stack frame
     E0315, // cannot invoke closure outside of its lifetime
@@ -2086,4 +1987,6 @@ register_diagnostics! {
     E0566, // conflicting representation hints
     E0623, // lifetime mismatch where both parameters are anonymous regions
     E0628, // generators cannot have explicit arguments
+    E0631, // type mismatch in closure arguments
+    E0637, // "'_" is not a valid lifetime bound
 }

src/librustc/hir/def_id.rs

@@ -97,6 +97,17 @@ impl serialize::UseSpecializedDecodable for CrateNum {
            RustcDecodable, Hash, Copy)]
 pub struct DefIndex(u32);
 
+impl Idx for DefIndex {
+    fn new(value: usize) -> Self {
+        assert!(value < (u32::MAX) as usize);
+        DefIndex(value as u32)
+    }
+
+    fn index(self) -> usize {
+        self.0 as usize
+    }
+}
+
 impl fmt::Debug for DefIndex {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         write!(f,

src/librustc/hir/intravisit.rs

@@ -422,7 +422,12 @@ pub fn walk_local<'v, V: Visitor<'v>>(visitor: &mut V, local: &'v Local) {
 
 pub fn walk_lifetime<'v, V: Visitor<'v>>(visitor: &mut V, lifetime: &'v Lifetime) {
     visitor.visit_id(lifetime.id);
-    visitor.visit_name(lifetime.span, lifetime.name);
+    match lifetime.name {
+        LifetimeName::Name(name) => {
+            visitor.visit_name(lifetime.span, name);
+        }
+        LifetimeName::Static | LifetimeName::Implicit | LifetimeName::Underscore => {}
+    }
 }
 
 pub fn walk_lifetime_def<'v, V: Visitor<'v>>(visitor: &mut V, lifetime_def: &'v LifetimeDef) {
@@ -622,7 +627,9 @@ pub fn walk_path_segment<'v, V: Visitor<'v>>(visitor: &mut V,
                                              path_span: Span,
                                              segment: &'v PathSegment) {
     visitor.visit_name(path_span, segment.name);
-    visitor.visit_path_parameters(path_span, &segment.parameters);
+    if let Some(ref parameters) = segment.parameters {
+        visitor.visit_path_parameters(path_span, parameters);
+    }
 }
 
 pub fn walk_path_parameters<'v, V: Visitor<'v>>(visitor: &mut V,

src/librustc/hir/lowering.rs

@@ -65,7 +65,7 @@ use syntax::codemap::{self, respan, Spanned, CompilerDesugaringKind};
 use syntax::std_inject;
 use syntax::symbol::{Symbol, keywords};
 use syntax::tokenstream::{TokenStream, TokenTree, Delimited};
-use syntax::parse::token::{Token, DelimToken};
+use syntax::parse::token::Token;
 use syntax::util::small_vector::SmallVector;
 use syntax::visit::{self, Visitor};
 use syntax_pos::Span;
@@ -606,10 +606,12 @@ impl<'a> LoweringContext<'a> {
     }
 
     fn lower_token_stream(&mut self, tokens: TokenStream) -> TokenStream {
-        tokens.into_trees().map(|tree| self.lower_token_tree(tree)).collect()
+        tokens.into_trees()
+            .flat_map(|tree| self.lower_token_tree(tree).into_trees())
+            .collect()
     }
 
-    fn lower_token_tree(&mut self, tree: TokenTree) -> TokenTree {
+    fn lower_token_tree(&mut self, tree: TokenTree) -> TokenStream {
         match tree {
             TokenTree::Token(span, token) => {
                 self.lower_token(token, span)
@@ -618,23 +620,19 @@ impl<'a> LoweringContext<'a> {
                 TokenTree::Delimited(span, Delimited {
                     delim: delimited.delim,
                     tts: self.lower_token_stream(delimited.tts.into()).into(),
-                })
+                }).into()
             }
         }
     }
 
-    fn lower_token(&mut self, token: Token, span: Span) -> TokenTree {
+    fn lower_token(&mut self, token: Token, span: Span) -> TokenStream {
         match token {
             Token::Interpolated(_) => {}
-            other => return TokenTree::Token(span, other),
+            other => return TokenTree::Token(span, other).into(),
         }
 
         let tts = token.interpolated_to_tokenstream(&self.sess.parse_sess, span);
-        let tts = self.lower_token_stream(tts);
-        TokenTree::Delimited(span, Delimited {
-            delim: DelimToken::NoDelim,
-            tts: tts.into(),
-        })
+        self.lower_token_stream(tts)
     }
 
     fn lower_arm(&mut self, arm: &Arm) -> hir::Arm {
@@ -685,17 +683,16 @@ impl<'a> LoweringContext<'a> {
                 return self.lower_ty(ty);
             }
             TyKind::Path(ref qself, ref path) => {
-                let id = self.lower_node_id(t.id).node_id;
+                let id = self.lower_node_id(t.id);
                 let qpath = self.lower_qpath(t.id, qself, path, ParamMode::Explicit);
                 return self.ty_path(id, t.span, qpath);
             }
             TyKind::ImplicitSelf => {
                 hir::TyPath(hir::QPath::Resolved(None, P(hir::Path {
                     def: self.expect_full_def(t.id),
-                    segments: hir_vec![hir::PathSegment {
-                        name: keywords::SelfType.name(),
-                        parameters: hir::PathParameters::none()
-                    }],
+                    segments: hir_vec![
+                        hir::PathSegment::from_name(keywords::SelfType.name())
+                    ],
                     span: t.span,
                 })))
             }
@@ -734,10 +731,12 @@ impl<'a> LoweringContext<'a> {
             TyKind::Mac(_) => panic!("TyMac should have been expanded by now."),
         };
 
+        let LoweredNodeId { node_id, hir_id } = self.lower_node_id(t.id);
         P(hir::Ty {
-            id: self.lower_node_id(t.id).node_id,
+            id: node_id,
             node: kind,
             span: t.span,
+            hir_id,
         })
     }
 
@@ -863,7 +862,7 @@ impl<'a> LoweringContext<'a> {
             // Otherwise, the base path is an implicit `Self` type path,
             // e.g. `Vec` in `Vec::new` or `<I as Iterator>::Item` in
             // `<I as Iterator>::Item::default`.
-            let new_id = self.next_id().node_id;
+            let new_id = self.next_id();
             self.ty_path(new_id, p.span, hir::QPath::Resolved(qself, path))
         };
 
@@ -888,7 +887,7 @@ impl<'a> LoweringContext<'a> {
             }
 
             // Wrap the associated extension in another type node.
-            let new_id = self.next_id().node_id;
+            let new_id = self.next_id();
             ty = self.ty_path(new_id, p.span, qpath);
         }
 
@@ -914,12 +913,8 @@ impl<'a> LoweringContext<'a> {
             segments: segments.map(|segment| {
                 self.lower_path_segment(p.span, segment, param_mode, 0,
                                         ParenthesizedGenericArgs::Err)
-            }).chain(name.map(|name| {
-                hir::PathSegment {
-                    name,
-                    parameters: hir::PathParameters::none()
-                }
-            })).collect(),
+            }).chain(name.map(|name| hir::PathSegment::from_name(name)))
+              .collect(),
             span: p.span,
         }
     }
@@ -940,7 +935,7 @@ impl<'a> LoweringContext<'a> {
                           expected_lifetimes: usize,
                           parenthesized_generic_args: ParenthesizedGenericArgs)
                           -> hir::PathSegment {
-        let mut parameters = if let Some(ref parameters) = segment.parameters {
+        let (mut parameters, infer_types) = if let Some(ref parameters) = segment.parameters {
             let msg = "parenthesized parameters may only be used with a trait";
             match **parameters {
                 PathParameters::AngleBracketed(ref data) => {
@@ -951,12 +946,12 @@ impl<'a> LoweringContext<'a> {
                     ParenthesizedGenericArgs::Warn => {
                         self.sess.buffer_lint(PARENTHESIZED_PARAMS_IN_TYPES_AND_MODULES,
                                               CRATE_NODE_ID, data.span, msg.into());
-                        hir::PathParameters::none()
+                        (hir::PathParameters::none(), true)
                     }
                     ParenthesizedGenericArgs::Err => {
                         struct_span_err!(self.sess, data.span, E0214, "{}", msg)
                             .span_label(data.span, "only traits may use parentheses").emit();
-                        hir::PathParameters::none()
+                        (hir::PathParameters::none(), true)
                     }
                 }
             }
@@ -970,39 +965,39 @@ impl<'a> LoweringContext<'a> {
             }).collect();
         }
 
-        hir::PathSegment {
-            name: self.lower_ident(segment.identifier),
+        hir::PathSegment::new(
+            self.lower_ident(segment.identifier),
             parameters,
-        }
+            infer_types
+        )
     }
 
     fn lower_angle_bracketed_parameter_data(&mut self,
                                             data: &AngleBracketedParameterData,
                                             param_mode: ParamMode)
-                                            -> hir::PathParameters {
+                                            -> (hir::PathParameters, bool) {
         let &AngleBracketedParameterData { ref lifetimes, ref types, ref bindings, .. } = data;
-        hir::PathParameters {
+        (hir::PathParameters {
             lifetimes: self.lower_lifetimes(lifetimes),
             types: types.iter().map(|ty| self.lower_ty(ty)).collect(),
-            infer_types: types.is_empty() && param_mode == ParamMode::Optional,
             bindings: bindings.iter().map(|b| self.lower_ty_binding(b)).collect(),
             parenthesized: false,
-        }
+        }, types.is_empty() && param_mode == ParamMode::Optional)
     }
 
     fn lower_parenthesized_parameter_data(&mut self,
                                           data: &ParenthesizedParameterData)
-                                          -> hir::PathParameters {
+                                          -> (hir::PathParameters, bool) {
         let &ParenthesizedParameterData { ref inputs, ref output, span } = data;
         let inputs = inputs.iter().map(|ty| self.lower_ty(ty)).collect();
         let mk_tup = |this: &mut Self, tys, span| {
-            P(hir::Ty { node: hir::TyTup(tys), id: this.next_id().node_id, span })
+            let LoweredNodeId { node_id, hir_id } = this.next_id();
+            P(hir::Ty { node: hir::TyTup(tys), id: node_id, hir_id, span })
         };
 
-        hir::PathParameters {
+        (hir::PathParameters {
             lifetimes: hir::HirVec::new(),
             types: hir_vec![mk_tup(self, inputs, span)],
-            infer_types: false,
             bindings: hir_vec![hir::TypeBinding {
                 id: self.next_id().node_id,
                 name: Symbol::intern(FN_OUTPUT_NAME),
@@ -1011,7 +1006,7 @@ impl<'a> LoweringContext<'a> {
                 span: output.as_ref().map_or(span, |ty| ty.span),
             }],
             parenthesized: true,
-        }
+        }, false)
     }
 
     fn lower_local(&mut self, l: &Local) -> P<hir::Local> {
@@ -1108,6 +1103,10 @@ impl<'a> LoweringContext<'a> {
             default: tp.default.as_ref().map(|x| self.lower_ty(x)),
             span: tp.span,
             pure_wrt_drop: tp.attrs.iter().any(|attr| attr.check_name("may_dangle")),
+            synthetic: tp.attrs.iter()
+                               .filter(|attr| attr.check_name("rustc_synthetic"))
+                               .map(|_| hir::SyntheticTyParamKind::ImplTrait)
+                               .nth(0),
         }
     }
 
@@ -1121,7 +1120,11 @@ impl<'a> LoweringContext<'a> {
     fn lower_lifetime(&mut self, l: &Lifetime) -> hir::Lifetime {
         hir::Lifetime {
             id: self.lower_node_id(l.id).node_id,
-            name: self.lower_ident(l.ident),
+            name: match self.lower_ident(l.ident) {
+                x if x == "'_" => hir::LifetimeName::Underscore,
+                x if x == "'static" => hir::LifetimeName::Static,
+                name => hir::LifetimeName::Name(name),
+            },
             span: l.span,
         }
     }
@@ -1865,7 +1868,7 @@ impl<'a> LoweringContext<'a> {
 
     fn lower_range_end(&mut self, e: &RangeEnd) -> hir::RangeEnd {
         match *e {
-            RangeEnd::Included => hir::RangeEnd::Included,
+            RangeEnd::Included(_) => hir::RangeEnd::Included,
             RangeEnd::Excluded => hir::RangeEnd::Excluded,
         }
     }
@@ -2972,7 +2975,7 @@ impl<'a> LoweringContext<'a> {
         self.expr_block(block, attrs)
     }
 
-    fn ty_path(&mut self, id: NodeId, span: Span, qpath: hir::QPath) -> P<hir::Ty> {
+    fn ty_path(&mut self, id: LoweredNodeId, span: Span, qpath: hir::QPath) -> P<hir::Ty> {
         let mut id = id;
         let node = match qpath {
             hir::QPath::Resolved(None, path) => {
@@ -2982,14 +2985,14 @@ impl<'a> LoweringContext<'a> {
                         bound_lifetimes: hir_vec![],
                         trait_ref: hir::TraitRef {
                             path: path.and_then(|path| path),
-                            ref_id: id,
+                            ref_id: id.node_id,
                         },
                         span,
                     };
 
                     // The original ID is taken by the `PolyTraitRef`,
                     // so the `Ty` itself needs a different one.
-                    id = self.next_id().node_id;
+                    id = self.next_id();
 
                     hir::TyTraitObject(hir_vec![principal], self.elided_lifetime(span))
                 } else {
@@ -2998,14 +3001,14 @@ impl<'a> LoweringContext<'a> {
             }
             _ => hir::TyPath(qpath)
         };
-        P(hir::Ty { id, node, span })
+        P(hir::Ty { id: id.node_id, hir_id: id.hir_id, node, span })
     }
 
     fn elided_lifetime(&mut self, span: Span) -> hir::Lifetime {
         hir::Lifetime {
             id: self.next_id().node_id,
             span,
-            name: keywords::Invalid.name()
+            name: hir::LifetimeName::Implicit,
         }
     }
 }

src/librustc/hir/map/collector.rs

@@ -16,6 +16,9 @@ use std::iter::repeat;
 use syntax::ast::{NodeId, CRATE_NODE_ID};
 use syntax_pos::Span;
 
+use ich::StableHashingContext;
+use rustc_data_structures::stable_hasher::{HashStable, StableHasher, StableHasherResult};
+
 /// A Visitor that walks over the HIR and collects Nodes into a HIR map
 pub(super) struct NodeCollector<'a, 'hir> {
     /// The crate
@@ -25,37 +28,113 @@ pub(super) struct NodeCollector<'a, 'hir> {
     /// The parent of this node
     parent_node: NodeId,
 
+    // These fields keep track of the currently relevant DepNodes during
+    // the visitor's traversal.
     current_dep_node_owner: DefIndex,
-    current_dep_node_index: DepNodeIndex,
+    current_signature_dep_index: DepNodeIndex,
+    current_full_dep_index: DepNodeIndex,
+    currently_in_body: bool,
 
     dep_graph: &'a DepGraph,
     definitions: &'a definitions::Definitions,
+
+    hcx: StableHashingContext<'a>,
+
+    // We are collecting DepNode::HirBody hashes here so we can compute the
+    // crate hash from then later on.
+    hir_body_nodes: Vec<DefPathHash>,
 }
 
 impl<'a, 'hir> NodeCollector<'a, 'hir> {
     pub(super) fn root(krate: &'hir Crate,
-                dep_graph: &'a DepGraph,
-                definitions: &'a definitions::Definitions)
+                       dep_graph: &'a DepGraph,
+                       definitions: &'a definitions::Definitions,
+                       hcx: StableHashingContext<'a>)
                 -> NodeCollector<'a, 'hir> {
         let root_mod_def_path_hash = definitions.def_path_hash(CRATE_DEF_INDEX);
-        let root_mod_dep_node = root_mod_def_path_hash.to_dep_node(DepKind::Hir);
-        let root_mod_dep_node_index = dep_graph.alloc_input_node(root_mod_dep_node);
+
+        // Allocate DepNodes for the root module
+        let (root_mod_sig_dep_index, root_mod_full_dep_index);
+        {
+            let Crate {
+                ref module,
+                // Crate attributes are not copied over to the root `Mod`, so hash
+                // them explicitly here.
+                ref attrs,
+                span,
+
+                // These fields are handled separately:
+                exported_macros: _,
+                items: _,
+                trait_items: _,
+                impl_items: _,
+                bodies: _,
+                trait_impls: _,
+                trait_default_impl: _,
+                body_ids: _,
+            } = *krate;
+
+            root_mod_sig_dep_index = dep_graph.with_task(
+                root_mod_def_path_hash.to_dep_node(DepKind::Hir),
+                &hcx,
+                HirItemLike { item_like: (module, attrs, span), hash_bodies: false },
+                identity_fn
+            ).1;
+            root_mod_full_dep_index = dep_graph.with_task(
+                root_mod_def_path_hash.to_dep_node(DepKind::HirBody),
+                &hcx,
+                HirItemLike { item_like: (module, attrs, span), hash_bodies: true },
+                identity_fn
+            ).1;
+        }
+
+        {
+            dep_graph.with_task(
+                DepNode::new_no_params(DepKind::AllLocalTraitImpls),
+                &hcx,
+                &krate.trait_impls,
+                identity_fn
+            );
+        }
+
+        let hir_body_nodes = vec![root_mod_def_path_hash];
 
         let mut collector = NodeCollector {
             krate,
             map: vec![],
             parent_node: CRATE_NODE_ID,
-            current_dep_node_index: root_mod_dep_node_index,
+            current_signature_dep_index: root_mod_sig_dep_index,
+            current_full_dep_index: root_mod_full_dep_index,
             current_dep_node_owner: CRATE_DEF_INDEX,
+            currently_in_body: false,
             dep_graph,
             definitions,
+            hcx,
+            hir_body_nodes,
         };
-        collector.insert_entry(CRATE_NODE_ID, RootCrate(root_mod_dep_node_index));
+        collector.insert_entry(CRATE_NODE_ID, RootCrate(root_mod_sig_dep_index));
 
         collector
     }
 
-    pub(super) fn into_map(self) -> Vec<MapEntry<'hir>> {
+    pub(super) fn finalize_and_compute_crate_hash(self,
+                                                  crate_disambiguator: &str)
+                                                  -> Vec<MapEntry<'hir>> {
+        let mut node_hashes: Vec<_> = self
+            .hir_body_nodes
+            .iter()
+            .map(|&def_path_hash| {
+                let dep_node = def_path_hash.to_dep_node(DepKind::HirBody);
+                (def_path_hash, self.dep_graph.fingerprint_of(&dep_node))
+            })
+            .collect();
+
+        node_hashes.sort_unstable_by(|&(ref d1, _), &(ref d2, _)| d1.cmp(d2));
+
+        self.dep_graph.with_task(DepNode::new_no_params(DepKind::Krate),
+                                 &self.hcx,
+                                 (node_hashes, crate_disambiguator),
+                                 identity_fn);
         self.map
     }
 
@@ -70,7 +149,11 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
 
     fn insert(&mut self, id: NodeId, node: Node<'hir>) {
         let parent = self.parent_node;
-        let dep_node_index = self.current_dep_node_index;
+        let dep_node_index = if self.currently_in_body {
+            self.current_full_dep_index
+        } else {
+            self.current_signature_dep_index
+        };
 
         let entry = match node {
             NodeItem(n) => EntryItem(parent, dep_node_index, n),
@@ -91,6 +174,7 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
             NodeTyParam(n) => EntryTyParam(parent, dep_node_index, n),
             NodeVisibility(n) => EntryVisibility(parent, dep_node_index, n),
             NodeLocal(n) => EntryLocal(parent, dep_node_index, n),
+            NodeMacroDef(n) => EntryMacroDef(dep_node_index, n),
         };
 
         // Make sure that the DepNode of some node coincides with the HirId
@@ -127,22 +211,41 @@ impl<'a, 'hir> NodeCollector<'a, 'hir> {
         self.parent_node = parent_node;
     }
 
-    fn with_dep_node_owner<F: FnOnce(&mut Self)>(&mut self,
+    fn with_dep_node_owner<T: HashStable<StableHashingContext<'a>>,
+                           F: FnOnce(&mut Self)>(&mut self,
                                                  dep_node_owner: DefIndex,
+                                                 item_like: &T,
                                                  f: F) {
         let prev_owner = self.current_dep_node_owner;
-        let prev_index = self.current_dep_node_index;
+        let prev_signature_dep_index = self.current_signature_dep_index;
+        let prev_full_dep_index = self.current_signature_dep_index;
+        let prev_in_body = self.currently_in_body;
+
+        let def_path_hash = self.definitions.def_path_hash(dep_node_owner);
+
+        self.current_signature_dep_index = self.dep_graph.with_task(
+            def_path_hash.to_dep_node(DepKind::Hir),
+            &self.hcx,
+            HirItemLike { item_like, hash_bodies: false },
+            identity_fn
+        ).1;
+
+        self.current_full_dep_index = self.dep_graph.with_task(
+            def_path_hash.to_dep_node(DepKind::HirBody),
+            &self.hcx,
+            HirItemLike { item_like, hash_bodies: true },
+            identity_fn
+        ).1;
+
+        self.hir_body_nodes.push(def_path_hash);
 
-        // When we enter a new owner (item, impl item, or trait item), we always
-        // start out again with DepKind::Hir.
-        let new_dep_node = self.definitions
-                               .def_path_hash(dep_node_owner)
-                               .to_dep_node(DepKind::Hir);
-        self.current_dep_node_index = self.dep_graph.alloc_input_node(new_dep_node);
         self.current_dep_node_owner = dep_node_owner;
+        self.currently_in_body = false;
         f(self);
-        self.current_dep_node_index = prev_index;
+        self.currently_in_body = prev_in_body;
         self.current_dep_node_owner = prev_owner;
+        self.current_full_dep_index = prev_full_dep_index;
+        self.current_signature_dep_index = prev_signature_dep_index;
     }
 }
 
@@ -169,24 +272,17 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     }
 
     fn visit_nested_body(&mut self, id: BodyId) {
-        // When we enter a body, we switch to DepKind::HirBody.
-        // Note that current_dep_node_index might already be DepKind::HirBody,
-        // e.g. when entering the body of a closure that is already part of a
-        // surrounding body. That's expected and not a problem.
-        let prev_index = self.current_dep_node_index;
-        let new_dep_node = self.definitions
-                               .def_path_hash(self.current_dep_node_owner)
-                               .to_dep_node(DepKind::HirBody);
-        self.current_dep_node_index = self.dep_graph.alloc_input_node(new_dep_node);
+        let prev_in_body = self.currently_in_body;
+        self.currently_in_body = true;
         self.visit_body(self.krate.body(id));
-        self.current_dep_node_index = prev_index;
+        self.currently_in_body = prev_in_body;
     }
 
     fn visit_item(&mut self, i: &'hir Item) {
         debug!("visit_item: {:?}", i);
         debug_assert_eq!(i.hir_id.owner,
                          self.definitions.opt_def_index(i.id).unwrap());
-        self.with_dep_node_owner(i.hir_id.owner, |this| {
+        self.with_dep_node_owner(i.hir_id.owner, i, |this| {
             this.insert(i.id, NodeItem(i));
             this.with_parent(i.id, |this| {
                 match i.node {
@@ -222,7 +318,7 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     fn visit_trait_item(&mut self, ti: &'hir TraitItem) {
         debug_assert_eq!(ti.hir_id.owner,
                          self.definitions.opt_def_index(ti.id).unwrap());
-        self.with_dep_node_owner(ti.hir_id.owner, |this| {
+        self.with_dep_node_owner(ti.hir_id.owner, ti, |this| {
             this.insert(ti.id, NodeTraitItem(ti));
 
             this.with_parent(ti.id, |this| {
@@ -234,7 +330,7 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     fn visit_impl_item(&mut self, ii: &'hir ImplItem) {
         debug_assert_eq!(ii.hir_id.owner,
                          self.definitions.opt_def_index(ii.id).unwrap());
-        self.with_dep_node_owner(ii.hir_id.owner, |this| {
+        self.with_dep_node_owner(ii.hir_id.owner, ii, |this| {
             this.insert(ii.id, NodeImplItem(ii));
 
             this.with_parent(ii.id, |this| {
@@ -328,7 +424,11 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
     }
 
     fn visit_macro_def(&mut self, macro_def: &'hir MacroDef) {
-        self.insert_entry(macro_def.id, NotPresent);
+        let def_index = self.definitions.opt_def_index(macro_def.id).unwrap();
+
+        self.with_dep_node_owner(def_index, macro_def, |this| {
+            this.insert(macro_def.id, NodeMacroDef(macro_def));
+        });
     }
 
     fn visit_variant(&mut self, v: &'hir Variant, g: &'hir Generics, item_id: NodeId) {
@@ -375,3 +475,28 @@ impl<'a, 'hir> Visitor<'hir> for NodeCollector<'a, 'hir> {
         self.visit_nested_impl_item(id);
     }
 }
+
+// We use this with DepGraph::with_task(). Since we are handling only input
+// values here, the "task" computing them just passes them through.
+fn identity_fn<T>(_: &StableHashingContext, item_like: T) -> T {
+    item_like
+}
+
+// This is a wrapper structure that allows determining if span values within
+// the wrapped item should be hashed or not.
+struct HirItemLike<T> {
+    item_like: T,
+    hash_bodies: bool,
+}
+
+impl<'hir, T> HashStable<StableHashingContext<'hir>> for HirItemLike<T>
+    where T: HashStable<StableHashingContext<'hir>>
+{
+    fn hash_stable<W: StableHasherResult>(&self,
+                                          hcx: &mut StableHashingContext<'hir>,
+                                          hasher: &mut StableHasher<W>) {
+        hcx.while_hashing_hir_bodies(self.hash_bodies, |hcx| {
+            self.item_like.hash_stable(hcx, hasher);
+        });
+    }
+}

src/librustc/hir/map/mod.rs

@@ -57,6 +57,7 @@ pub enum Node<'hir> {
     NodePat(&'hir Pat),
     NodeBlock(&'hir Block),
     NodeLocal(&'hir Local),
+    NodeMacroDef(&'hir MacroDef),
 
     /// NodeStructCtor represents a tuple struct.
     NodeStructCtor(&'hir VariantData),
@@ -93,6 +94,8 @@ enum MapEntry<'hir> {
     EntryVisibility(NodeId, DepNodeIndex, &'hir Visibility),
     EntryLocal(NodeId, DepNodeIndex, &'hir Local),
 
+    EntryMacroDef(DepNodeIndex, &'hir MacroDef),
+
     /// Roots for node trees. The DepNodeIndex is the dependency node of the
     /// crate's root module.
     RootCrate(DepNodeIndex),
@@ -127,6 +130,7 @@ impl<'hir> MapEntry<'hir> {
             EntryLocal(id, _, _) => id,
 
             NotPresent |
+            EntryMacroDef(..) |
             RootCrate(_) => return None,
         })
     }
@@ -151,6 +155,7 @@ impl<'hir> MapEntry<'hir> {
             EntryTyParam(_, _, n) => NodeTyParam(n),
             EntryVisibility(_, _, n) => NodeVisibility(n),
             EntryLocal(_, _, n) => NodeLocal(n),
+            EntryMacroDef(_, n) => NodeMacroDef(n),
 
             NotPresent |
             RootCrate(_) => return None
@@ -285,20 +290,12 @@ impl<'hir> Map<'hir> {
             EntryVisibility(_, dep_node_index, _) |
             EntryExpr(_, dep_node_index, _) |
             EntryLocal(_, dep_node_index, _) |
+            EntryMacroDef(dep_node_index, _) |
             RootCrate(dep_node_index) => {
                 self.dep_graph.read_index(dep_node_index);
             }
             NotPresent => {
-                // Some nodes, notably macro definitions, are not
-                // present in the map for whatever reason, but
-                // they *do* have def-ids. So if we encounter an
-                // empty hole, check for that case.
-                if let Some(def_index) = self.definitions.opt_def_index(id) {
-                    let def_path_hash = self.definitions.def_path_hash(def_index);
-                    self.dep_graph.read(def_path_hash.to_dep_node(DepKind::Hir));
-                } else {
-                    bug!("called HirMap::read() with invalid NodeId")
-                }
+                bug!("called HirMap::read() with invalid NodeId")
             }
         }
     }
@@ -805,7 +802,7 @@ impl<'hir> Map<'hir> {
             NodeTraitItem(ti) => ti.name,
             NodeVariant(v) => v.node.name,
             NodeField(f) => f.name,
-            NodeLifetime(lt) => lt.name,
+            NodeLifetime(lt) => lt.name.name(),
             NodeTyParam(tp) => tp.name,
             NodeBinding(&Pat { node: PatKind::Binding(_,_,l,_), .. }) => l.node,
             NodeStructCtor(_) => self.name(self.get_parent(id)),
@@ -875,20 +872,11 @@ impl<'hir> Map<'hir> {
             Some(EntryVisibility(_, _, &Visibility::Restricted { ref path, .. })) => path.span,
             Some(EntryVisibility(_, _, v)) => bug!("unexpected Visibility {:?}", v),
             Some(EntryLocal(_, _, local)) => local.span,
+            Some(EntryMacroDef(_, macro_def)) => macro_def.span,
 
             Some(RootCrate(_)) => self.forest.krate.span,
             Some(NotPresent) | None => {
-                // Some nodes, notably macro definitions, are not
-                // present in the map for whatever reason, but
-                // they *do* have def-ids. So if we encounter an
-                // empty hole, check for that case.
-                if let Some(def_index) = self.definitions.opt_def_index(id) {
-                    let def_path_hash = self.definitions.def_path_hash(def_index);
-                    self.dep_graph.read(def_path_hash.to_dep_node(DepKind::Hir));
-                    DUMMY_SP
-                } else {
-                    bug!("hir::map::Map::span: id not in map: {:?}", id)
-                }
+                bug!("hir::map::Map::span: id not in map: {:?}", id)
             }
         }
     }
@@ -1012,15 +1000,22 @@ impl Named for StructField { fn name(&self) -> Name { self.name } }
 impl Named for TraitItem { fn name(&self) -> Name { self.name } }
 impl Named for ImplItem { fn name(&self) -> Name { self.name } }
 
-pub fn map_crate<'hir>(forest: &'hir mut Forest,
+pub fn map_crate<'hir>(sess: &::session::Session,
+                       cstore: &::middle::cstore::CrateStore,
+                       forest: &'hir mut Forest,
                        definitions: &'hir Definitions)
                        -> Map<'hir> {
     let map = {
+        let hcx = ::ich::StableHashingContext::new(sess, &forest.krate, definitions, cstore);
+
         let mut collector = NodeCollector::root(&forest.krate,
                                                 &forest.dep_graph,
-                                                &definitions);
+                                                &definitions,
+                                                hcx);
         intravisit::walk_crate(&mut collector, &forest.krate);
-        collector.into_map()
+
+        let crate_disambiguator = sess.local_crate_disambiguator().as_str();
+        collector.finalize_and_compute_crate_hash(&crate_disambiguator)
     };
 
     if log_enabled!(::log::LogLevel::Debug) {
@@ -1103,6 +1098,7 @@ impl<'a> print::State<'a> {
             // printing.
             NodeStructCtor(_)  => bug!("cannot print isolated StructCtor"),
             NodeLocal(a)       => self.print_local_decl(&a),
+            NodeMacroDef(_)    => bug!("cannot print MacroDef"),
         }
     }
 }
@@ -1219,6 +1215,9 @@ fn node_id_to_string(map: &Map, id: NodeId, include_id: bool) -> String {
         Some(NodeVisibility(ref vis)) => {
             format!("visibility {:?}{}", vis, id_str)
         }
+        Some(NodeMacroDef(_)) => {
+            format!("macro {}{}",  path_str(), id_str)
+        }
         None => {
             format!("unknown node{}", id_str)
         }

src/librustc/hir/mod.rs

@@ -145,7 +145,27 @@ pub struct Lifetime {
     /// HIR lowering inserts these placeholders in type paths that
     /// refer to type definitions needing lifetime parameters,
     /// `&T` and `&mut T`, and trait objects without `... + 'a`.
-    pub name: Name,
+    pub name: LifetimeName,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Copy)]
+pub enum LifetimeName {
+    Implicit,
+    Underscore,
+    Static,
+    Name(Name),
+}
+
+impl LifetimeName {
+    pub fn name(&self) -> Name {
+        use self::LifetimeName::*;
+        match *self {
+            Implicit => keywords::Invalid.name(),
+            Underscore => Symbol::intern("'_"),
+            Static => keywords::StaticLifetime.name(),
+            Name(name) => name,
+        }
+    }
 }
 
 impl fmt::Debug for Lifetime {
@@ -159,11 +179,15 @@ impl fmt::Debug for Lifetime {
 
 impl Lifetime {
     pub fn is_elided(&self) -> bool {
-        self.name == keywords::Invalid.name()
+        use self::LifetimeName::*;
+        match self.name {
+            Implicit | Underscore => true,
+            Static | Name(_) => false,
+        }
     }
 
     pub fn is_static(&self) -> bool {
-        self.name == "'static"
+        self.name == LifetimeName::Static
     }
 }
 
@@ -212,7 +236,13 @@ pub struct PathSegment {
     /// this is more than just simple syntactic sugar; the use of
     /// parens affects the region binding rules, so we preserve the
     /// distinction.
-    pub parameters: PathParameters,
+    pub parameters: Option<P<PathParameters>>,
+
+    /// Whether to infer remaining type parameters, if any.
+    /// This only applies to expression and pattern paths, and
+    /// out of those only the segments with no type parameters
+    /// to begin with, e.g. `Vec::new` is `<Vec<..>>::new::<..>`.
+    pub infer_types: bool,
 }
 
 impl PathSegment {
@@ -220,9 +250,35 @@ impl PathSegment {
     pub fn from_name(name: Name) -> PathSegment {
         PathSegment {
             name,
-            parameters: PathParameters::none()
+            infer_types: true,
+            parameters: None
         }
     }
+
+    pub fn new(name: Name, parameters: PathParameters, infer_types: bool) -> Self {
+        PathSegment {
+            name,
+            infer_types,
+            parameters: if parameters.is_empty() {
+                None
+            } else {
+                Some(P(parameters))
+            }
+        }
+    }
+
+    // FIXME: hack required because you can't create a static
+    // PathParameters, so you can't just return a &PathParameters.
+    pub fn with_parameters<F, R>(&self, f: F) -> R
+        where F: FnOnce(&PathParameters) -> R
+    {
+        let dummy = PathParameters::none();
+        f(if let Some(ref params) = self.parameters {
+            &params
+        } else {
+            &dummy
+        })
+    }
 }
 
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
@@ -231,11 +287,6 @@ pub struct PathParameters {
     pub lifetimes: HirVec<Lifetime>,
     /// The type parameters for this path segment, if present.
     pub types: HirVec<P<Ty>>,
-    /// Whether to infer remaining type parameters, if any.
-    /// This only applies to expression and pattern paths, and
-    /// out of those only the segments with no type parameters
-    /// to begin with, e.g. `Vec::new` is `<Vec<..>>::new::<..>`.
-    pub infer_types: bool,
     /// Bindings (equality constraints) on associated types, if present.
     /// E.g., `Foo<A=Bar>`.
     pub bindings: HirVec<TypeBinding>,
@@ -250,12 +301,16 @@ impl PathParameters {
         Self {
             lifetimes: HirVec::new(),
             types: HirVec::new(),
-            infer_types: true,
             bindings: HirVec::new(),
             parenthesized: false,
         }
     }
 
+    pub fn is_empty(&self) -> bool {
+        self.lifetimes.is_empty() && self.types.is_empty() &&
+            self.bindings.is_empty() && !self.parenthesized
+    }
+
     pub fn inputs(&self) -> &[P<Ty>] {
         if self.parenthesized {
             if let Some(ref ty) = self.types.get(0) {
@@ -296,6 +351,7 @@ pub struct TyParam {
     pub default: Option<P<Ty>>,
     pub span: Span,
     pub pure_wrt_drop: bool,
+    pub synthetic: Option<SyntheticTyParamKind>,
 }
 
 /// Represents lifetimes and type parameters attached to a declaration
@@ -364,6 +420,13 @@ impl Generics {
     }
 }
 
+/// Synthetic Type Parameters are converted to an other form during lowering, this allows
+/// to track the original form they had. Usefull for error messages.
+#[derive(Copy, Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
+pub enum SyntheticTyParamKind {
+    ImplTrait
+}
+
 /// A `where` clause in a definition
 #[derive(Clone, PartialEq, Eq, RustcEncodable, RustcDecodable, Hash, Debug)]
 pub struct WhereClause {
@@ -1330,6 +1393,7 @@ pub struct Ty {
     pub id: NodeId,
     pub node: Ty_,
     pub span: Span,
+    pub hir_id: HirId,
 }
 
 impl fmt::Debug for Ty {

src/librustc/hir/print.rs

@@ -1213,11 +1213,17 @@ impl<'a> State<'a> {
         self.print_expr_maybe_paren(&args[0], parser::PREC_POSTFIX)?;
         self.s.word(".")?;
         self.print_name(segment.name)?;
-        if !segment.parameters.lifetimes.is_empty() ||
-                !segment.parameters.types.is_empty() ||
-                !segment.parameters.bindings.is_empty() {
-            self.print_path_parameters(&segment.parameters, true)?;
-        }
+
+        segment.with_parameters(|parameters| {
+            if !parameters.lifetimes.is_empty() ||
+                !parameters.types.is_empty() ||
+                !parameters.bindings.is_empty()
+            {
+                self.print_path_parameters(&parameters, segment.infer_types, true)
+            } else {
+                Ok(())
+            }
+        })?;
         self.print_call_post(base_args)
     }
 
@@ -1564,8 +1570,12 @@ impl<'a> State<'a> {
             }
             if segment.name != keywords::CrateRoot.name() &&
                segment.name != keywords::DollarCrate.name() {
-                self.print_name(segment.name)?;
-                self.print_path_parameters(&segment.parameters, colons_before_params)?;
+               self.print_name(segment.name)?;
+               segment.with_parameters(|parameters| {
+                   self.print_path_parameters(parameters,
+                                              segment.infer_types,
+                                              colons_before_params)
+               })?;
             }
         }
 
@@ -1593,7 +1603,11 @@ impl<'a> State<'a> {
                     if segment.name != keywords::CrateRoot.name() &&
                        segment.name != keywords::DollarCrate.name() {
                         self.print_name(segment.name)?;
-                        self.print_path_parameters(&segment.parameters, colons_before_params)?;
+                        segment.with_parameters(|parameters| {
+                            self.print_path_parameters(parameters,
+                                                       segment.infer_types,
+                                                       colons_before_params)
+                        })?;
                     }
                 }
 
@@ -1601,7 +1615,11 @@ impl<'a> State<'a> {
                 self.s.word("::")?;
                 let item_segment = path.segments.last().unwrap();
                 self.print_name(item_segment.name)?;
-                self.print_path_parameters(&item_segment.parameters, colons_before_params)
+                item_segment.with_parameters(|parameters| {
+                    self.print_path_parameters(parameters,
+                                               item_segment.infer_types,
+                                               colons_before_params)
+                })
             }
             hir::QPath::TypeRelative(ref qself, ref item_segment) => {
                 self.s.word("<")?;
@@ -1609,13 +1627,18 @@ impl<'a> State<'a> {
                 self.s.word(">")?;
                 self.s.word("::")?;
                 self.print_name(item_segment.name)?;
-                self.print_path_parameters(&item_segment.parameters, colons_before_params)
+                item_segment.with_parameters(|parameters| {
+                    self.print_path_parameters(parameters,
+                                               item_segment.infer_types,
+                                               colons_before_params)
+                })
             }
         }
     }
 
     fn print_path_parameters(&mut self,
                              parameters: &hir::PathParameters,
+                             infer_types: bool,
                              colons_before_params: bool)
                              -> io::Result<()> {
         if parameters.parenthesized {
@@ -1652,7 +1675,7 @@ impl<'a> State<'a> {
 
             // FIXME(eddyb) This would leak into error messages, e.g.:
             // "non-exhaustive patterns: `Some::<..>(_)` not covered".
-            if parameters.infer_types && false {
+            if infer_types && false {
                 start_or_comma(self)?;
                 self.s.word("..")?;
             }
@@ -1975,7 +1998,7 @@ impl<'a> State<'a> {
     }
 
     pub fn print_lifetime(&mut self, lifetime: &hir::Lifetime) -> io::Result<()> {
-        self.print_name(lifetime.name)
+        self.print_name(lifetime.name.name())
     }
 
     pub fn print_lifetime_def(&mut self, lifetime: &hir::LifetimeDef) -> io::Result<()> {

src/librustc/ich/caching_codemap_view.rs

@@ -22,6 +22,7 @@ struct CacheEntry {
     file_index: usize,
 }
 
+#[derive(Clone)]
 pub struct CachingCodemapView<'cm> {
     codemap: &'cm CodeMap,
     line_cache: [CacheEntry; 3],

src/librustc/ich/hcx.rs

@@ -43,6 +43,7 @@ thread_local!(static IGNORED_ATTR_NAMES: RefCell<FxHashSet<Symbol>> =
 /// enough information to transform DefIds and HirIds into stable DefPaths (i.e.
 /// a reference to the TyCtxt) and it holds a few caches for speeding up various
 /// things (e.g. each DefId/DefPath is only hashed once).
+#[derive(Clone)]
 pub struct StableHashingContext<'gcx> {
     sess: &'gcx Session,
     definitions: &'gcx Definitions,
@@ -168,6 +169,11 @@ impl<'gcx> StableHashingContext<'gcx> {
         self.definitions.def_path_hash(def_index)
     }
 
+    #[inline]
+    pub fn node_to_hir_id(&self, node_id: ast::NodeId) -> hir::HirId {
+        self.definitions.node_to_hir_id(node_id)
+    }
+
     #[inline]
     pub fn hash_spans(&self) -> bool {
         self.hash_spans
@@ -259,6 +265,18 @@ impl<'a, 'gcx, 'lcx> StableHashingContextProvider for TyCtxt<'a, 'gcx, 'lcx> {
     }
 }
 
+
+impl<'gcx> StableHashingContextProvider for StableHashingContext<'gcx> {
+    type ContextType = StableHashingContext<'gcx>;
+    fn create_stable_hashing_context(&self) -> Self::ContextType {
+        self.clone()
+    }
+}
+
+impl<'gcx> ::dep_graph::DepGraphSafe for StableHashingContext<'gcx> {
+}
+
+
 impl<'gcx> HashStable<StableHashingContext<'gcx>> for hir::BodyId {
     fn hash_stable<W: StableHasherResult>(&self,
                                           hcx: &mut StableHashingContext<'gcx>,

src/librustc/ich/impls_hir.rs

@@ -123,6 +123,13 @@ impl<'gcx> HashStable<StableHashingContext<'gcx>> for hir::ImplItemId {
     }
 }
 
+impl_stable_hash_for!(enum hir::LifetimeName {
+    Implicit,
+    Underscore,
+    Static,
+    Name(name)
+});
+
 impl_stable_hash_for!(struct hir::Lifetime {
     id,
     span,
@@ -143,13 +150,13 @@ impl_stable_hash_for!(struct hir::Path {
 
 impl_stable_hash_for!(struct hir::PathSegment {
     name,
+    infer_types,
     parameters
 });
 
 impl_stable_hash_for!(struct hir::PathParameters {
     lifetimes,
     types,
-    infer_types,
     bindings,
     parenthesized
 });
@@ -170,7 +177,8 @@ impl_stable_hash_for!(struct hir::TyParam {
     bounds,
     default,
     span,
-    pure_wrt_drop
+    pure_wrt_drop,
+    synthetic
 });
 
 impl_stable_hash_for!(struct hir::Generics {
@@ -180,6 +188,10 @@ impl_stable_hash_for!(struct hir::Generics {
     span
 });
 
+impl_stable_hash_for!(enum hir::SyntheticTyParamKind {
+    ImplTrait
+});
+
 impl_stable_hash_for!(struct hir::WhereClause {
     id,
     predicates
@@ -238,6 +250,7 @@ impl<'gcx> HashStable<StableHashingContext<'gcx>> for hir::Ty {
         hcx.while_hashing_hir_bodies(true, |hcx| {
             let hir::Ty {
                 id: _,
+                hir_id: _,
                 ref node,
                 ref span,
             } = *self;
@@ -691,7 +704,7 @@ impl<'gcx> HashStable<StableHashingContext<'gcx>> for hir::TraitItem {
                                           hcx: &mut StableHashingContext<'gcx>,
                                           hasher: &mut StableHasher<W>) {
         let hir::TraitItem {
-            id,
+            id: _,
             hir_id: _,
             name,
             ref attrs,
@@ -700,7 +713,6 @@ impl<'gcx> HashStable<StableHashingContext<'gcx>> for hir::TraitItem {
         } = *self;
 
         hcx.hash_hir_item_like(attrs, |hcx| {
-            id.hash_stable(hcx, hasher);
             name.hash_stable(hcx, hasher);
             attrs.hash_stable(hcx, hasher);
             node.hash_stable(hcx, hasher);
@@ -725,7 +737,7 @@ impl<'gcx> HashStable<StableHashingContext<'gcx>> for hir::ImplItem {
                                           hcx: &mut StableHashingContext<'gcx>,
                                           hasher: &mut StableHasher<W>) {
         let hir::ImplItem {
-            id,
+            id: _,
             hir_id: _,
             name,
             ref vis,
@@ -736,7 +748,6 @@ impl<'gcx> HashStable<StableHashingContext<'gcx>> for hir::ImplItem {
         } = *self;
 
         hcx.hash_hir_item_like(attrs, |hcx| {
-            id.hash_stable(hcx, hasher);
             name.hash_stable(hcx, hasher);
             vis.hash_stable(hcx, hasher);
             defaultness.hash_stable(hcx, hasher);
@@ -1160,6 +1171,25 @@ for hir::TraitCandidate {
     }
 }
 
+impl<'gcx> ToStableHashKey<StableHashingContext<'gcx>> for hir::TraitCandidate {
+    type KeyType = (DefPathHash, Option<(DefPathHash, hir::ItemLocalId)>);
+
+    fn to_stable_hash_key(&self,
+                          hcx: &StableHashingContext<'gcx>)
+                          -> Self::KeyType {
+        let hir::TraitCandidate {
+            def_id,
+            import_id,
+        } = *self;
+
+        let import_id = import_id.map(|node_id| hcx.node_to_hir_id(node_id))
+                                 .map(|hir_id| (hcx.local_def_path_hash(hir_id.owner),
+                                                hir_id.local_id));
+        (hcx.def_path_hash(def_id), import_id)
+    }
+}
+
+
 impl_stable_hash_for!(struct hir::Freevar {
     def,
     span

src/librustc/ich/impls_mir.rs

@@ -28,10 +28,12 @@ impl_stable_hash_for!(struct mir::LocalDecl<'tcx> {
     name,
     source_info,
     internal,
+    lexical_scope,
     is_user_variable
 });
 impl_stable_hash_for!(struct mir::UpvarDecl { debug_name, by_ref });
 impl_stable_hash_for!(struct mir::BasicBlockData<'tcx> { statements, terminator, is_cleanup });
+impl_stable_hash_for!(struct mir::UnsafetyViolation { source_info, description, lint_node_id });
 
 impl<'gcx> HashStable<StableHashingContext<'gcx>>
 for mir::Terminator<'gcx> {
@@ -75,6 +77,22 @@ for mir::Terminator<'gcx> {
     }
 }
 
+impl<'gcx, T> HashStable<StableHashingContext<'gcx>> for mir::ClearOnDecode<T>
+    where T: HashStable<StableHashingContext<'gcx>>
+{
+    #[inline]
+    fn hash_stable<W: StableHasherResult>(&self,
+                                          hcx: &mut StableHashingContext<'gcx>,
+                                          hasher: &mut StableHasher<W>) {
+        mem::discriminant(self).hash_stable(hcx, hasher);
+        match *self {
+            mir::ClearOnDecode::Clear => {}
+            mir::ClearOnDecode::Set(ref value) => {
+                value.hash_stable(hcx, hasher);
+            }
+        }
+    }
+}
 
 impl<'gcx> HashStable<StableHashingContext<'gcx>> for mir::Local {
     #[inline]
@@ -347,6 +365,26 @@ for mir::ProjectionElem<'gcx, V, T>
 }
 
 impl_stable_hash_for!(struct mir::VisibilityScopeData { span, parent_scope });
+impl_stable_hash_for!(struct mir::VisibilityScopeInfo {
+    lint_root, safety
+});
+
+impl<'gcx> HashStable<StableHashingContext<'gcx>> for mir::Safety {
+    fn hash_stable<W: StableHasherResult>(&self,
+                                          hcx: &mut StableHashingContext<'gcx>,
+                                          hasher: &mut StableHasher<W>) {
+        mem::discriminant(self).hash_stable(hcx, hasher);
+
+        match *self {
+            mir::Safety::Safe |
+            mir::Safety::BuiltinUnsafe |
+            mir::Safety::FnUnsafe => {}
+            mir::Safety::ExplicitUnsafe(node_id) => {
+                node_id.hash_stable(hcx, hasher);
+            }
+        }
+    }
+}
 
 impl<'gcx> HashStable<StableHashingContext<'gcx>> for mir::Operand<'gcx> {
     fn hash_stable<W: StableHasherResult>(&self,

src/librustc/ich/impls_syntax.rs

@@ -272,6 +272,8 @@ fn hash_token<'gcx, W: StableHasherResult>(token: &token::Token,
         token::Token::Dot |
         token::Token::DotDot |
         token::Token::DotDotDot |
+        token::Token::DotDotEq |
+        token::Token::DotEq |
         token::Token::Comma |
         token::Token::Semi |
         token::Token::Colon |

src/librustc/ich/impls_ty.rs

@@ -463,7 +463,8 @@ impl_stable_hash_for!(struct ty::TypeParameterDef {
     index,
     has_default,
     object_lifetime_default,
-    pure_wrt_drop
+    pure_wrt_drop,
+    synthetic
 });
 
 impl<'gcx, T> HashStable<StableHashingContext<'gcx>>
@@ -514,13 +515,8 @@ impl_stable_hash_for!(enum ty::cast::CastKind {
     FnPtrAddrCast
 });
 
-impl_stable_hash_for!(enum ::middle::region::Scope {
-    Node(local_id),
-    Destruction(local_id),
-    CallSite(local_id),
-    Arguments(local_id),
-    Remainder(block_remainder)
-});
+impl_stable_hash_for!(struct ::middle::region::FirstStatementIndex { idx });
+impl_stable_hash_for!(struct ::middle::region::Scope { id, code });
 
 impl<'gcx> ToStableHashKey<StableHashingContext<'gcx>> for region::Scope {
     type KeyType = region::Scope;

src/librustc/infer/error_reporting/different_lifetimes.rs

@@ -18,6 +18,7 @@ use infer::region_inference::RegionResolutionError;
 use hir::map as hir_map;
 use middle::resolve_lifetime as rl;
 use hir::intravisit::{self, Visitor, NestedVisitorMap};
+use infer::error_reporting::util::AnonymousArgInfo;
 
 impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     // This method prints the error message for lifetime errors when both the concerned regions
@@ -57,6 +58,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
         let ty_sup = or_false!(self.find_anon_type(sup, &bregion_sup));
 
         let ty_sub = or_false!(self.find_anon_type(sub, &bregion_sub));
+
         debug!("try_report_anon_anon_conflict: found_arg1={:?} sup={:?} br1={:?}",
                ty_sub,
                sup,
@@ -66,56 +68,70 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                sub,
                bregion_sub);
 
-        let (main_label, label1, label2) = if let (Some(sup_arg), Some(sub_arg)) =
-            (self.find_arg_with_region(sup, sup), self.find_arg_with_region(sub, sub)) {
+        let (ty_sup, ty_fndecl_sup) = ty_sup;
+        let (ty_sub, ty_fndecl_sub) = ty_sub;
 
-            let (anon_arg_sup, is_first_sup, anon_arg_sub, is_first_sub) =
-                (sup_arg.arg, sup_arg.is_first, sub_arg.arg, sub_arg.is_first);
-            if self.is_self_anon(is_first_sup, scope_def_id_sup) ||
-               self.is_self_anon(is_first_sub, scope_def_id_sub) {
-                return false;
-            }
+        let AnonymousArgInfo { arg: anon_arg_sup, .. } =
+            or_false!(self.find_arg_with_region(sup, sup));
+        let AnonymousArgInfo { arg: anon_arg_sub, .. } =
+            or_false!(self.find_arg_with_region(sub, sub));
 
-            if self.is_return_type_anon(scope_def_id_sup, bregion_sup) ||
-               self.is_return_type_anon(scope_def_id_sub, bregion_sub) {
-                return false;
-            }
+        let sup_is_ret_type =
+            self.is_return_type_anon(scope_def_id_sup, bregion_sup, ty_fndecl_sup);
+        let sub_is_ret_type =
+            self.is_return_type_anon(scope_def_id_sub, bregion_sub, ty_fndecl_sub);
 
-            if anon_arg_sup == anon_arg_sub {
-                (format!("this type was declared with multiple lifetimes..."),
-                 format!(" with one lifetime"),
-                 format!(" into the other"))
-            } else {
-                let span_label_var1 = if let Some(simple_name) = anon_arg_sup.pat.simple_name() {
-                    format!(" from `{}`", simple_name)
-                } else {
-                    format!("")
-                };
-
-                let span_label_var2 = if let Some(simple_name) = anon_arg_sub.pat.simple_name() {
-                    format!(" into `{}`", simple_name)
-                } else {
-                    format!("")
-                };
-
-                let span_label =
-                    format!("these two types are declared with different lifetimes...",);
-
-                (span_label, span_label_var1, span_label_var2)
-            }
+        let span_label_var1 = if let Some(simple_name) = anon_arg_sup.pat.simple_name() {
+            format!(" from `{}`", simple_name)
         } else {
-            debug!("no arg with anon region found");
-            debug!("try_report_anon_anon_conflict: is_suitable(sub) = {:?}",
-                   self.is_suitable_region(sub));
-            debug!("try_report_anon_anon_conflict: is_suitable(sup) = {:?}",
-                   self.is_suitable_region(sup));
-            return false;
+            format!("")
         };
 
+        let span_label_var2 = if let Some(simple_name) = anon_arg_sub.pat.simple_name() {
+            format!(" into `{}`", simple_name)
+        } else {
+            format!("")
+        };
+
+
+        let (span_1, span_2, main_label, span_label) = match (sup_is_ret_type, sub_is_ret_type) {
+            (None, None) => {
+                let (main_label_1, span_label_1) = if ty_sup == ty_sub {
+
+                    (format!("this type is declared with multiple lifetimes..."),
+                     format!("...but data{} flows{} here",
+                             format!(" with one lifetime"),
+                             format!(" into the other")))
+                } else {
+                    (format!("these two types are declared with different lifetimes..."),
+                     format!("...but data{} flows{} here",
+                             span_label_var1,
+                             span_label_var2))
+                };
+                (ty_sup.span, ty_sub.span, main_label_1, span_label_1)
+            }
+
+            (Some(ret_span), _) => {
+                (ty_sub.span,
+                 ret_span,
+                 format!("this parameter and the return type are declared \
+                          with different lifetimes...",),
+                 format!("...but data{} is returned here", span_label_var1))
+            }
+            (_, Some(ret_span)) => {
+                (ty_sup.span,
+                 ret_span,
+                 format!("this parameter and the return type are declared \
+                          with different lifetimes...",),
+                 format!("...but data{} is returned here", span_label_var1))
+            }
+        };
+
+
         struct_span_err!(self.tcx.sess, span, E0623, "lifetime mismatch")
-            .span_label(ty_sup.span, main_label)
-            .span_label(ty_sub.span, format!(""))
-            .span_label(span, format!("...but data{} flows{} here", label1, label2))
+            .span_label(span_1, main_label)
+            .span_label(span_2, format!(""))
+            .span_label(span, span_label)
             .emit();
         return true;
     }
@@ -135,28 +151,32 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     /// ```
     /// The function returns the nested type corresponding to the anonymous region
     /// for e.g. `&u8` and Vec<`&u8`.
-    pub fn find_anon_type(&self, region: Region<'tcx>, br: &ty::BoundRegion) -> Option<&hir::Ty> {
+    pub fn find_anon_type(&self,
+                          region: Region<'tcx>,
+                          br: &ty::BoundRegion)
+                          -> Option<(&hir::Ty, &hir::FnDecl)> {
         if let Some(anon_reg) = self.is_suitable_region(region) {
             let def_id = anon_reg.def_id;
             if let Some(node_id) = self.tcx.hir.as_local_node_id(def_id) {
-                let inputs: &[_] = match self.tcx.hir.get(node_id) {
+                let fndecl = match self.tcx.hir.get(node_id) {
                     hir_map::NodeItem(&hir::Item { node: hir::ItemFn(ref fndecl, ..), .. }) => {
-                        &fndecl.inputs
+                        &fndecl
                     }
                     hir_map::NodeTraitItem(&hir::TraitItem {
-                                               node: hir::TraitItemKind::Method(ref fndecl, ..), ..
-                                           }) => &fndecl.decl.inputs,
+                                               node: hir::TraitItemKind::Method(ref m, ..), ..
+                                           }) |
                     hir_map::NodeImplItem(&hir::ImplItem {
-                                              node: hir::ImplItemKind::Method(ref fndecl, ..), ..
-                                          }) => &fndecl.decl.inputs,
-
-                    _ => &[],
+                                              node: hir::ImplItemKind::Method(ref m, ..), ..
+                                          }) => &m.decl,
+                    _ => return None,
                 };
 
-                return inputs
+                return fndecl
+                           .inputs
                            .iter()
-                           .filter_map(|arg| self.find_component_for_bound_region(&**arg, br))
-                           .next();
+                           .filter_map(|arg| self.find_component_for_bound_region(arg, br))
+                           .next()
+                           .map(|ty| (ty, &**fndecl));
             }
         }
         None

src/librustc/infer/error_reporting/mod.rs

@@ -72,6 +72,8 @@ use syntax::ast::DUMMY_NODE_ID;
 use syntax_pos::{Pos, Span};
 use errors::{DiagnosticBuilder, DiagnosticStyledString};
 
+use rustc_data_structures::indexed_vec::Idx;
+
 mod note;
 
 mod need_type_info;
@@ -152,21 +154,21 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
                         return;
                     }
                 };
-                let scope_decorated_tag = match scope {
-                    region::Scope::Node(_) => tag,
-                    region::Scope::CallSite(_) => {
+                let scope_decorated_tag = match scope.data() {
+                    region::ScopeData::Node(_) => tag,
+                    region::ScopeData::CallSite(_) => {
                         "scope of call-site for function"
                     }
-                    region::Scope::Arguments(_) => {
+                    region::ScopeData::Arguments(_) => {
                         "scope of function body"
                     }
-                    region::Scope::Destruction(_) => {
+                    region::ScopeData::Destruction(_) => {
                         new_string = format!("destruction scope surrounding {}", tag);
                         &new_string[..]
                     }
-                    region::Scope::Remainder(r) => {
+                    region::ScopeData::Remainder(r) => {
                         new_string = format!("block suffix following statement {}",
-                                             r.first_statement_index);
+                                             r.first_statement_index.index());
                         &new_string[..]
                     }
                 };
@@ -333,11 +335,20 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
             GenericBoundFailure(..) => true,
         };
 
-        if errors.iter().all(|e| is_bound_failure(e)) {
+
+        let mut errors = if errors.iter().all(|e| is_bound_failure(e)) {
             errors.clone()
         } else {
             errors.iter().filter(|&e| !is_bound_failure(e)).cloned().collect()
-        }
+        };
+
+        // sort the errors by span, for better error message stability.
+        errors.sort_by_key(|u| match *u {
+            ConcreteFailure(ref sro, _, _) => sro.span(),
+            GenericBoundFailure(ref sro, _, _) => sro.span(),
+            SubSupConflict(ref rvo, _, _, _, _) => rvo.span(),
+        });
+        errors
     }
 
     /// Adds a note if the types come from similarly named crates
@@ -774,10 +785,44 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                                     bound_kind: GenericKind<'tcx>,
                                     sub: Region<'tcx>)
     {
-        // FIXME: it would be better to report the first error message
-        // with the span of the parameter itself, rather than the span
-        // where the error was detected. But that span is not readily
-        // accessible.
+        // Attempt to obtain the span of the parameter so we can
+        // suggest adding an explicit lifetime bound to it.
+        let type_param_span = match (self.in_progress_tables, bound_kind) {
+            (Some(ref table), GenericKind::Param(ref param)) => {
+                let table = table.borrow();
+                table.local_id_root.and_then(|did| {
+                    let generics = self.tcx.generics_of(did);
+                    // Account for the case where `did` corresponds to `Self`, which doesn't have
+                    // the expected type argument.
+                    if generics.types.len() > 0 {
+                        let type_param = generics.type_param(param);
+                        let hir = &self.tcx.hir;
+                        hir.as_local_node_id(type_param.def_id).map(|id| {
+                            // Get the `hir::TyParam` to verify wether it already has any bounds.
+                            // We do this to avoid suggesting code that ends up as `T: 'a'b`,
+                            // instead we suggest `T: 'a + 'b` in that case.
+                            let has_lifetimes = if let hir_map::NodeTyParam(ref p) = hir.get(id) {
+                                p.bounds.len() > 0
+                            } else {
+                                false
+                            };
+                            let sp = hir.span(id);
+                            // `sp` only covers `T`, change it so that it covers
+                            // `T:` when appropriate
+                            let sp = if has_lifetimes {
+                                sp.to(sp.next_point().next_point())
+                            } else {
+                                sp
+                            };
+                            (sp, has_lifetimes)
+                        })
+                    } else {
+                        None
+                    }
+                })
+            }
+            _ => None,
+        };
 
         let labeled_user_string = match bound_kind {
             GenericKind::Param(ref p) =>
@@ -799,6 +844,26 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
             return;
         }
 
+        fn binding_suggestion<'tcx, S: fmt::Display>(err: &mut DiagnosticBuilder<'tcx>,
+                                                     type_param_span: Option<(Span, bool)>,
+                                                     bound_kind: GenericKind<'tcx>,
+                                                     sub: S) {
+            let consider = &format!("consider adding an explicit lifetime bound `{}: {}`...",
+                                    bound_kind,
+                                    sub);
+            if let Some((sp, has_lifetimes)) = type_param_span {
+                let tail = if has_lifetimes {
+                    " + "
+                } else {
+                    ""
+                };
+                let suggestion = format!("{}: {}{}", bound_kind, sub, tail);
+                err.span_suggestion_short(sp, consider, suggestion);
+            } else {
+                err.help(consider);
+            }
+        }
+
         let mut err = match *sub {
             ty::ReEarlyBound(_) |
             ty::ReFree(ty::FreeRegion {bound_region: ty::BrNamed(..), ..}) => {
@@ -808,9 +873,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                                                E0309,
                                                "{} may not live long enough",
                                                labeled_user_string);
-                err.help(&format!("consider adding an explicit lifetime bound `{}: {}`...",
-                         bound_kind,
-                         sub));
+                binding_suggestion(&mut err, type_param_span, bound_kind, sub);
                 err
             }
 
@@ -821,9 +884,7 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                                                E0310,
                                                "{} may not live long enough",
                                                labeled_user_string);
-                err.help(&format!("consider adding an explicit lifetime \
-                                   bound `{}: 'static`...",
-                                  bound_kind));
+                binding_suggestion(&mut err, type_param_span, bound_kind, "'static");
                 err
             }
 

src/librustc/infer/error_reporting/named_anon_conflict.rs

@@ -35,15 +35,17 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
         // only introduced anonymous regions in parameters) as well as a
         // version new_ty of its type where the anonymous region is replaced
         // with the named one.//scope_def_id
-        let (named, anon_arg_info, region_info) =
+        let (named, anon, anon_arg_info, region_info) =
             if self.is_named_region(sub) && self.is_suitable_region(sup).is_some() &&
                self.find_arg_with_region(sup, sub).is_some() {
                 (sub,
+                 sup,
                  self.find_arg_with_region(sup, sub).unwrap(),
                  self.is_suitable_region(sup).unwrap())
             } else if self.is_named_region(sup) && self.is_suitable_region(sub).is_some() &&
                       self.find_arg_with_region(sub, sup).is_some() {
                 (sup,
+                 sub,
                  self.find_arg_with_region(sub, sup).unwrap(),
                  self.is_suitable_region(sub).unwrap())
             } else {
@@ -76,33 +78,29 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
             return false;
         }
 
-        if self.is_return_type_anon(scope_def_id, br) {
-            debug!("try_report_named_anon_conflict: is_return_type_anon({:?}, {:?}) = true",
-                   scope_def_id,
-                   br);
-            return false;
-        } else if self.is_self_anon(is_first, scope_def_id) {
-            debug!("try_report_named_anon_conflict: is_self_anon({:?}, {:?}) = true",
-                   is_first,
-                   scope_def_id);
-            return false;
-        } else {
-            let (error_var, span_label_var) = if let Some(simple_name) = arg.pat.simple_name() {
-                (format!("the type of `{}`", simple_name), format!("the type of `{}`", simple_name))
-            } else {
-                ("parameter type".to_owned(), "type".to_owned())
-            };
-
-            struct_span_err!(self.tcx.sess,
-                             span,
-                             E0621,
-                             "explicit lifetime required in {}",
-                             error_var)
-                    .span_label(arg.pat.span,
-                                format!("consider changing {} to `{}`", span_label_var, new_ty))
-                    .span_label(span, format!("lifetime `{}` required", named))
-                    .emit();
-            return true;
+        if let Some((_, fndecl)) = self.find_anon_type(anon, &br) {
+            if self.is_return_type_anon(scope_def_id, br, fndecl).is_some() ||
+               self.is_self_anon(is_first, scope_def_id) {
+                return false;
+            }
         }
+
+        let (error_var, span_label_var) = if let Some(simple_name) = arg.pat.simple_name() {
+            (format!("the type of `{}`", simple_name), format!("the type of `{}`", simple_name))
+        } else {
+            ("parameter type".to_owned(), "type".to_owned())
+        };
+
+        struct_span_err!(self.tcx.sess,
+                         span,
+                         E0621,
+                         "explicit lifetime required in {}",
+                         error_var)
+                .span_label(arg.pat.span,
+                            format!("consider changing {} to `{}`", span_label_var, new_ty))
+                .span_label(span, format!("lifetime `{}` required", named))
+                .emit();
+        return true;
+
     }
 }

src/librustc/infer/error_reporting/util.rs

@@ -15,6 +15,7 @@ use infer::InferCtxt;
 use ty::{self, Region, Ty};
 use hir::def_id::DefId;
 use hir::map as hir_map;
+use syntax_pos::Span;
 
 macro_rules! or_false {
      ($v:expr) => {
@@ -163,7 +164,11 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
     // Here, we check for the case where the anonymous region
     // is in the return type.
     // FIXME(#42703) - Need to handle certain cases here.
-    pub fn is_return_type_anon(&self, scope_def_id: DefId, br: ty::BoundRegion) -> bool {
+    pub fn is_return_type_anon(&self,
+                               scope_def_id: DefId,
+                               br: ty::BoundRegion,
+                               decl: &hir::FnDecl)
+                               -> Option<Span> {
         let ret_ty = self.tcx.type_of(scope_def_id);
         match ret_ty.sty {
             ty::TyFnDef(_, _) => {
@@ -171,12 +176,12 @@ impl<'a, 'gcx, 'tcx> InferCtxt<'a, 'gcx, 'tcx> {
                 let late_bound_regions = self.tcx
                     .collect_referenced_late_bound_regions(&sig.output());
                 if late_bound_regions.iter().any(|r| *r == br) {
-                    return true;
+                    return Some(decl.output.span());
                 }
             }
             _ => {}
         }
-        false
+        None
     }
     // Here we check for the case where anonymous region
     // corresponds to self and if yes, we display E0312.

src/librustc/lib.rs

@@ -111,7 +111,6 @@ pub mod middle {
     pub mod dataflow;
     pub mod dead;
     pub mod dependency_format;
-    pub mod effect;
     pub mod entry;
     pub mod exported_symbols;
     pub mod free_region;

src/librustc/lint/builtin.rs

@@ -30,7 +30,7 @@ declare_lint! {
 
 declare_lint! {
     pub UNUSED_EXTERN_CRATES,
-    Warn,
+    Allow,
     "extern crates that are never used"
 }
 

src/librustc/lint/levels.rs

@@ -384,6 +384,11 @@ impl LintLevelMap {
             self.sets.get_lint_level(lint, *idx, None)
         })
     }
+
+    /// Returns if this `id` has lint level information.
+    pub fn lint_level_set(&self, id: HirId) -> Option<u32> {
+        self.id_to_set.get(&id).cloned()
+    }
 }
 
 impl<'gcx> HashStable<StableHashingContext<'gcx>> for LintLevelMap {