diff --git a/.travis_rust.yml b/.travis_rust.yml
@@ -0,0 +1,328 @@
+  
+language: shell
+  
+sudo: required
+  
+dist: trusty
+  
+services:
+  
+  - docker
+  
+addons:
+  
+  apt:
+  
+    packages:
+  
+      - gdb
+  
+
+  
+git:
+  
+  depth: 2
+  
+  submodules: false
+  
+
+  
+matrix:
+  
+  fast_finish: true
+  
+  include:
+  
+    # Images used in testing PR and try-build should be run first.
+  
+    - env: IMAGE=x86_64-gnu-llvm-6.0 RUST_BACKTRACE=1
+  
+      if: type = pull_request OR branch = auto
+  
+
+  
+    - env: IMAGE=dist-x86_64-linux DEPLOY=1
+  
+      if: branch = try OR branch = auto
+  
+
+  
+    # "alternate" deployments, these are "nightlies" but have LLVM assertions
+  
+    # turned on, they're deployed to a different location primarily for
+  
+    # additional testing.
+  
+    - env: IMAGE=dist-x86_64-linux DEPLOY_ALT=1 CI_JOB_NAME=dist-x86_64-linux-alt
+  
+      if: branch = try OR branch = auto
+  
+
+  
+    - env: >
+  
+        RUST_CHECK_TARGET=dist
+  
+        RUST_CONFIGURE_ARGS="--enable-extended --enable-profiler --enable-lldb --set rust.jemalloc"
+  
+        SRC=.
+  
+        DEPLOY_ALT=1
+  
+        RUSTC_RETRY_LINKER_ON_SEGFAULT=1
+  
+        MACOSX_DEPLOYMENT_TARGET=10.7
+  
+        NO_LLVM_ASSERTIONS=1
+  
+        NO_DEBUG_ASSERTIONS=1
+  
+        CI_JOB_NAME=dist-x86_64-apple-alt
+  
+      os: osx
+  
+      osx_image: xcode9.3-moar
+  
+      if: branch = auto
+  
+
+  
+    # macOS builders. These are placed near the beginning because they are very
+  
+    # slow to run.
+  
+
+  
+    # OSX builders running tests, these run the full test suite.
+  
+    # NO_DEBUG_ASSERTIONS=1 to make them go faster, but also do have some
+  
+    # runners that run `//ignore-debug` tests.
+  
+    #
+  
+    # Note that the compiler is compiled to target 10.8 here because the Xcode
+  
+    # version that we're using, 8.2, cannot compile LLVM for OSX 10.7.
+  
+    - env: >
+  
+        RUST_CHECK_TARGET=check
+  
+        RUST_CONFIGURE_ARGS="--build=x86_64-apple-darwin --enable-sanitizers --enable-profiler --set rust.jemalloc"
+  
+        SRC=.
+  
+        RUSTC_RETRY_LINKER_ON_SEGFAULT=1
+  
+        MACOSX_DEPLOYMENT_TARGET=10.8
+  
+        MACOSX_STD_DEPLOYMENT_TARGET=10.7
+  
+        NO_LLVM_ASSERTIONS=1
+  
+        NO_DEBUG_ASSERTIONS=1
+  
+        CI_JOB_NAME=x86_64-apple
+  
+      os: osx
+  
+      osx_image: xcode9.3-moar
+  
+      if: branch = auto
+  
+
+  
+    - env: >
+  
+        RUST_CHECK_TARGET=check
+  
+        RUST_CONFIGURE_ARGS="--build=i686-apple-darwin --set rust.jemalloc"
+  
+        SRC=.
+  
+        RUSTC_RETRY_LINKER_ON_SEGFAULT=1
+  
+        MACOSX_DEPLOYMENT_TARGET=10.8
+  
+        MACOSX_STD_DEPLOYMENT_TARGET=10.7
+  
+        NO_LLVM_ASSERTIONS=1
+  
+        NO_DEBUG_ASSERTIONS=1
+  
+        CI_JOB_NAME=i686-apple
+  
+      os: osx
+  
+      osx_image: xcode9.3-moar
+  
+      if: branch = auto
+  
+
+  
+    # OSX builders producing releases. These do not run the full test suite and
+  
+    # just produce a bunch of artifacts.
+  
+    #
+  
+    # Note that these are running in the `xcode7` image instead of the
+  
+    # `xcode8.2` image as above. That's because we want to build releases for
+  
+    # OSX 10.7 and `xcode7` is the latest Xcode able to compile LLVM for 10.7.
+  
+    - env: >
+  
+        RUST_CHECK_TARGET=dist
+  
+        RUST_CONFIGURE_ARGS="--build=i686-apple-darwin --enable-full-tools --enable-profiler --enable-lldb --set rust.jemalloc"
+  
+        SRC=.
+  
+        DEPLOY=1
+  
+        RUSTC_RETRY_LINKER_ON_SEGFAULT=1
+  
+        MACOSX_DEPLOYMENT_TARGET=10.7
+  
+        NO_LLVM_ASSERTIONS=1
+  
+        NO_DEBUG_ASSERTIONS=1
+  
+        DIST_REQUIRE_ALL_TOOLS=1
+  
+        CI_JOB_NAME=dist-i686-apple
+  
+      os: osx
+  
+      osx_image: xcode9.3-moar
+  
+      if: branch = auto
+  
+
+  
+    - env: >
+  
+        RUST_CHECK_TARGET=dist
+  
+        RUST_CONFIGURE_ARGS="--target=aarch64-apple-ios,armv7-apple-ios,armv7s-apple-ios,i386-apple-ios,x86_64-apple-ios --enable-full-tools --enable-sanitizers --enable-profiler --enable-lldb --set rust.jemalloc"
+  
+        SRC=.
+  
+        DEPLOY=1
+  
+        RUSTC_RETRY_LINKER_ON_SEGFAULT=1
+  
+        MACOSX_DEPLOYMENT_TARGET=10.7
+  
+        NO_LLVM_ASSERTIONS=1
+  
+        NO_DEBUG_ASSERTIONS=1
+  
+        DIST_REQUIRE_ALL_TOOLS=1
+  
+        CI_JOB_NAME=dist-x86_64-apple
+  
+      os: osx
+  
+      osx_image: xcode9.3-moar
+  
+      if: branch = auto
+  
+
+  
+    # Linux builders, remaining docker images
+  
+    - env: IMAGE=arm-android
+  
+      if: branch = auto
+  
+    - env: IMAGE=armhf-gnu
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-various-1 DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-various-2 DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-aarch64-linux DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-android DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-arm-linux DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-armhf-linux DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-armv7-linux DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-i586-gnu-i586-i686-musl DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-i686-freebsd DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-i686-linux DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-mips-linux DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-mips64-linux DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-mips64el-linux DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-mipsel-linux DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-powerpc-linux DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-powerpc64-linux DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-powerpc64le-linux DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-s390x-linux DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-x86_64-freebsd DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-x86_64-musl DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=dist-x86_64-netbsd DEPLOY=1
+  
+      if: branch = auto
+  
+    - env: IMAGE=asmjs
+  
+      if: branch = auto
+  
+    - env: IMAGE=i686-gnu
+  
+      if: branch = auto
+  
+    - env: IMAGE=i686-gnu-nopt
+  
+      if: branch = auto
+  
+    - env: IMAGE=wasm32-unknown
+  
+      if: branch = auto
+  
+    - env: IMAGE=x86_64-gnu
+  
+      if: branch = auto
+  
+    - env: IMAGE=x86_64-gnu-full-bootstrap
+  
+      if: branch = auto
+  
+    - env: IMAGE=x86_64-gnu-aux
+  
+      if: branch = auto
+  
+    - env: IMAGE=x86_64-gnu-tools
+  
+      if: branch = auto OR (type = pull_request AND commit_message =~ /(?i:^update.*\b(rls|rustfmt|clippy|miri|cargo)\b)/)
+  
+    - env: IMAGE=x86_64-gnu-debug
+  
+      if: branch = auto
+  
+    - env: IMAGE=x86_64-gnu-nopt
+  
+      if: branch = auto
+  
+    - env: IMAGE=x86_64-gnu-distcheck
+  
+      if: branch = auto
+  
+    - env: IMAGE=mingw-check
+  
+      if: type = pull_request OR branch = auto
+  
+
+  
+    - stage: publish toolstate
+  
+      if: branch = master AND type = push
+  
+      before_install: []
+  
+      install: []
+  
+      sudo: false
+  
+      script:
+  
+        MESSAGE_FILE=$(mktemp -t msg.XXXXXX);
+  
+        . src/ci/docker/x86_64-gnu-tools/repo.sh;
+  
+        commit_toolstate_change "$MESSAGE_FILE" "$TRAVIS_BUILD_DIR/src/tools/publish_toolstate.py" "$(git rev-parse HEAD)" "$(git log --format=%s -n1 HEAD)" "$MESSAGE_FILE" "$TOOLSTATE_REPO_ACCESS_TOKEN";
+  
+
+  
+before_install:
+  
+  # We'll use the AWS cli to download/upload cached docker layers as well as
+  
+  # push our deployments, so download that here.
+  
+  - pip install --user awscli; export PATH=$PATH:$HOME/.local/bin:$HOME/Library/Python/2.7/bin/
+  
+  - mkdir -p $HOME/rustsrc
+  
+  # FIXME(#46924): these two commands are required to enable IPv6,
+  
+  # they shouldn't exist, please revert once more official solutions appeared.
+  
+  # see https://github.com/travis-ci/travis-ci/issues/8891#issuecomment-353403729
+  
+  - if [ "$TRAVIS_OS_NAME" = linux ]; then
+  
+      echo '{"ipv6":true,"fixed-cidr-v6":"fd9a:8454:6789:13f7::/64"}' | sudo tee /etc/docker/daemon.json;
+  
+      sudo service docker restart;
+  
+    fi
+  
+
+  
+install:
+  
+  - case "$TRAVIS_OS_NAME" in
+  
+        linux)
+  
+          travis_retry curl -fo $HOME/stamp https://s3-us-west-1.amazonaws.com/rust-lang-ci2/rust-ci-mirror/2017-03-17-stamp-x86_64-unknown-linux-musl &&
+  
+            chmod +x $HOME/stamp &&
+  
+            export PATH=$PATH:$HOME
+  
+          ;;
+  
+        osx)
+  
+          if [[ "$RUST_CHECK_TARGET" == dist ]]; then
+  
+            travis_retry brew update &&
+  
+            travis_retry brew install xz &&
+  
+            travis_retry brew install swig;
+  
+          fi &&
+  
+          travis_retry curl -fo /usr/local/bin/sccache https://s3-us-west-1.amazonaws.com/rust-lang-ci2/rust-ci-mirror/2018-04-02-sccache-x86_64-apple-darwin &&
+  
+            chmod +x /usr/local/bin/sccache &&
+  
+          travis_retry curl -fo /usr/local/bin/stamp https://s3-us-west-1.amazonaws.com/rust-lang-ci2/rust-ci-mirror/2017-03-17-stamp-x86_64-apple-darwin &&
+  
+            chmod +x /usr/local/bin/stamp &&
+  
+          travis_retry curl -f http://releases.llvm.org/7.0.0/clang+llvm-7.0.0-x86_64-apple-darwin.tar.xz | tar xJf - &&
+  
+            export CC=`pwd`/clang+llvm-7.0.0-x86_64-apple-darwin/bin/clang &&
+  
+            export CXX=`pwd`/clang+llvm-7.0.0-x86_64-apple-darwin/bin/clang++ &&
+  
+            export AR=ar
+  
+          ;;
+  
+    esac
+  
+
+  
+before_script:
+  
+  - >
+  
+      echo "#### Disk usage before running script:";
+  
+      df -h;
+  
+      du . | sort -nr | head -n100
+  
+  - >
+  
+      RUN_SCRIPT="src/ci/init_repo.sh . $HOME/rustsrc";
+  
+      if [ "$TRAVIS_OS_NAME" = "osx" ]; then
+  
+          export RUN_SCRIPT="$RUN_SCRIPT && src/ci/run.sh";
+  
+      else
+  
+          export RUN_SCRIPT="$RUN_SCRIPT && src/ci/docker/run.sh $IMAGE";
+  
+          # Enable core dump on Linux.
+  
+          sudo sh -c 'echo "/checkout/obj/cores/core.%p.%E" > /proc/sys/kernel/core_pattern';
+  
+      fi
+  
+
+  
+# Log time information from this machine and an external machine for insight into possible
+  
+# clock drift. Timezones don't matter since relative deltas give all the necessary info.
+  
+script:
+  
+  - >
+  
+      date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
+  
+  - stamp sh -x -c "$RUN_SCRIPT"
+  
+  - >
+  
+      date && (curl -fs --head https://google.com | grep ^Date: | sed 's/Date: //g' || true)
+  
+
+  
+after_success:
+  
+  - >
+  
+      echo "#### Build successful; Disk usage after running script:";
+  
+      df -h;
+  
+      du . | sort -nr | head -n100
+  
+  - >
+  
+      if [ "$DEPLOY$DEPLOY_ALT" == "1" ]; then
+  
+        mkdir -p deploy/$TRAVIS_COMMIT;
+  
+        if [ "$TRAVIS_OS_NAME" == "osx" ]; then
+  
+            rm -rf build/dist/doc &&
+  
+            cp -r build/dist/* deploy/$TRAVIS_COMMIT;
+  
+        else
+  
+            rm -rf obj/build/dist/doc &&
+  
+            cp -r obj/build/dist/* deploy/$TRAVIS_COMMIT;
+  
+        fi;
+  
+        ls -la deploy/$TRAVIS_COMMIT;
+  
+        deploy_dir=rustc-builds;
+  
+        if [ "$DEPLOY_ALT" == "1" ]; then
+  
+            deploy_dir=rustc-builds-alt;
+  
+        fi;
+  
+        travis_retry aws s3 cp --no-progress --recursive --acl public-read ./deploy s3://rust-lang-ci2/$deploy_dir
+  
+      fi
+  
+
+  
+after_failure:
+  
+  - >
+  
+      echo "#### Build failed; Disk usage after running script:";
+  
+      df -h;
+  
+      du . | sort -nr | head -n100
+  
+
+  
+  # Random attempt at debugging currently. Just poking around in here to see if
+  
+  # anything shows up.
+  
+
+  
+  # Dump backtrace for macOS
+  
+  - ls -lat $HOME/Library/Logs/DiagnosticReports/
+  
+  - find $HOME/Library/Logs/DiagnosticReports
+  
+      -type f
+  
+      -name '*.crash'
+  
+      -not -name '*.stage2-*.crash'
+  
+      -not -name 'com.apple.CoreSimulator.CoreSimulatorService-*.crash'
+  
+      -exec printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" {} \;
+  
+      -exec head -750 {} \;
+  
+      -exec echo travis_fold":"end:crashlog \; || true
+  
+
+  
+  # Dump backtrace for Linux
+  
+  - ln -s . checkout &&
+  
+    for CORE in obj/cores/core.*; do
+  
+      EXE=$(echo $CORE | sed 's|obj/cores/core\.[0-9]*\.!checkout!\(.*\)|\1|;y|!|/|');
+  
+      if [ -f "$EXE" ]; then
+  
+        printf travis_fold":start:crashlog\n\033[31;1m%s\033[0m\n" "$CORE";
+  
+        gdb --batch -q -c "$CORE" "$EXE"
+  
+          -iex 'set auto-load off'
+  
+          -iex 'dir src/'
+  
+          -iex 'set sysroot .'
+  
+          -ex bt
+  
+          -ex q;
+  
+        echo travis_fold":"end:crashlog;
+  
+      fi;
+  
+    done || true
+  
+
+  
+  # see #50887
+  
+  - cat ./obj/build/x86_64-unknown-linux-gnu/native/asan/build/lib/asan/clang_rt.asan-dynamic-i386.vers || true
+  
+
+  
+  # attempt to debug anything killed by the oom killer on linux, just to see if
+  
+  # it happened
+  
+  - dmesg | grep -i kill
+  
+
+  
+notifications:
+  
+  email: false
diff --git a/Jenkinsfile b/Jenkinsfile
@@ -0,0 +1,14 @@
+  
+node('master') {
+  
+  stage('Checkout') {
+  
+    checkout scm
+  
+    sh 'git submodule update --init --recursive'
+  
+  }
+  
+
+  
+  stage('Build') {
+  
+      dir('build') {
+  
+        sh '../x.py build'
+  
+      }
+  
+  }
+  
+}
+  
+
+  
+
diff --git a/README.md b/README.md
@@ -1,247 +1,70 @@
-  
-# The Rust Programming Language
+  
+# Rust with AVR support
-  
-This is the main source code repository for [Rust]. It contains the compiler,
-  
-standard library, and documentation.
+  
+[![Gitter](https://img.shields.io/gitter/room/nwjs/nw.js.svg)](https://gitter.im/avr-rust)
-  
-[Rust]: https://www.rust-lang.org
+  
+This project adds support for the [AVR](https://en.wikipedia.org/wiki/Atmel_AVR)
+  
+microcontroller to Rust.
-  
-## Quick Start
-  
-[quick-start]: #quick-start
+  
+It uses the [AVR-LLVM backend](http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AVR/).
-  
-Read ["Installation"] from [The Book].
+  
+## Caveats
-  
-["Installation"]: https://doc.rust-lang.org/book/ch01-01-installation.html
-  
-[The Book]: https://doc.rust-lang.org/book/index.html
+  
+While the stock libcore may be compiled, certain code patterns may
+  
+still exercise code in LLVM that is broken or that produces
+  
+miscompiled code. Looking for existing issues or submitting a new
+  
+issue is appreciated!
-  
-## Building from Source
-  
-[building-from-source]: #building-from-source
+  
+## Building and installation
-  
-### Building on *nix
-  
-1. Make sure you have installed the dependencies:
+  
+This will compile Rust with AVR support. This will not create a
+  
+fully-fledged cross-compiler, however, as it does not compile any libraries
+  
+such as `libcore` or `liblibc`. To do this, the `--target=avr-unknown-unknown`
+  
+flag must be passed to `configure`, which is not fully supported yet due to bugs.
-  
-   * `g++` 4.7 or later or `clang++` 3.x or later
-  
-   * `python` 2.7 (but not 3.x)
-  
-   * GNU `make` 3.81 or later
-  
-   * `cmake` 3.4.3 or later
-  
-   * `curl`
-  
-   * `git`
+  
+First make sure you've installed all dependencies for building, as specified in
+  
+the main Rust repository [here](https://github.com/rust-lang/rust/#building-from-source).
+  
+Then use the following commands:
-  
-2. Clone the [source] with `git`:
+  
+``` bash
+  
+# Grab the avr-rust sources
+  
+git clone https://github.com/avr-rust/rust.git
-  
-   ```sh
-  
-   $ git clone https://github.com/rust-lang/rust.git
-  
-   $ cd rust
-  
-   ```
+  
+# Create a directory to place built files in
+  
+mkdir build && cd build
-  
-[source]: https://github.com/rust-lang/rust
+  
+# Generate Makefile using settings suitable for an experimental compiler
+  
+../rust/configure \
+  
+  --enable-debug \
+  
+  --disable-docs \
+  
+  --enable-llvm-assertions \
+  
+  --enable-debug-assertions \
+  
+  --enable-optimize \
+  
+  --enable-llvm-release-debuginfo \
+  
+  --experimental-targets=AVR \
+  
+  --prefix=/opt/avr-rust
-  
-3. Build and install:
+  
+# Build the compiler, optionally install it to /opt/avr-rust
+  
+make
+  
+make install
-  
-    ```sh
-  
-    $ git submodule update --init --recursive --progress
-  
-    $ ./x.py build && sudo ./x.py install
-  
-    ```
+  
+# Register the toolchain with rustup
+  
+rustup toolchain link avr-toolchain $(realpath $(find . -name 'stage1'))
-  
-    > ***Note:*** Install locations can be adjusted by copying the config file
-  
-    > from `./config.toml.example` to `./config.toml`, and
-  
-    > adjusting the `prefix` option under `[install]`. Various other options, such
-  
-    > as enabling debug information, are also supported, and are documented in
-  
-    > the config file.
-  
-
-  
-    When complete, `sudo ./x.py install` will place several programs into
-  
-    `/usr/local/bin`: `rustc`, the Rust compiler, and `rustdoc`, the
-  
-    API-documentation tool. This install does not include [Cargo],
-  
-    Rust's package manager, which you may also want to build.
-  
-
-  
-[Cargo]: https://github.com/rust-lang/cargo
-  
-
-  
-### Building on Windows
-  
-[building-on-windows]: #building-on-windows
-  
-
-  
-There are two prominent ABIs in use on Windows: the native (MSVC) ABI used by
-  
-Visual Studio, and the GNU ABI used by the GCC toolchain. Which version of Rust
-  
-you need depends largely on what C/C++ libraries you want to interoperate with:
-  
-for interop with software produced by Visual Studio use the MSVC build of Rust;
-  
-for interop with GNU software built using the MinGW/MSYS2 toolchain use the GNU
-  
-build.
-  
-
-  
-#### MinGW
-  
-[windows-mingw]: #windows-mingw
-  
-
-  
-[MSYS2][msys2] can be used to easily build Rust on Windows:
-  
-
-  
-[msys2]: https://msys2.github.io/
-  
-
-  
-1. Grab the latest [MSYS2 installer][msys2] and go through the installer.
-  
-
-  
-2. Run `mingw32_shell.bat` or `mingw64_shell.bat` from wherever you installed
-  
-   MSYS2 (i.e. `C:\msys64`), depending on whether you want 32-bit or 64-bit
-  
-   Rust. (As of the latest version of MSYS2 you have to run `msys2_shell.cmd
-  
-   -mingw32` or `msys2_shell.cmd -mingw64` from the command line instead)
-  
-
-  
-3. From this terminal, install the required tools:
-  
-
-  
-   ```sh
-  
-   # Update package mirrors (may be needed if you have a fresh install of MSYS2)
-  
-   $ pacman -Sy pacman-mirrors
-  
-
-  
-   # Install build tools needed for Rust. If you're building a 32-bit compiler,
-  
-   # then replace "x86_64" below with "i686". If you've already got git, python,
-  
-   # or CMake installed and in PATH you can remove them from this list. Note
-  
-   # that it is important that you do **not** use the 'python2' and 'cmake'
-  
-   # packages from the 'msys2' subsystem. The build has historically been known
-  
-   # to fail with these packages.
-  
-   $ pacman -S git \
-  
-               make \
-  
-               diffutils \
-  
-               tar \
-  
-               mingw-w64-x86_64-python2 \
-  
-               mingw-w64-x86_64-cmake \
-  
-               mingw-w64-x86_64-gcc
-  
-   ```
-  
-
-  
-4. Navigate to Rust's source code (or clone it), then build it:
-  
-
-  
-   ```sh
-  
-   $ ./x.py build && ./x.py install
-  
-   ```
-  
-
-  
-#### MSVC
-  
-[windows-msvc]: #windows-msvc
-  
-
-  
-MSVC builds of Rust additionally require an installation of Visual Studio 2013
-  
-(or later) so `rustc` can use its linker. Make sure to check the “C++ tools”
-  
-option.
-  
-
-  
-With these dependencies installed, you can build the compiler in a `cmd.exe`
-  
-shell with:
-  
-
-  
-```sh
-  
-> python x.py build
-  
-```
-  
-
-  
-Currently, building Rust only works with some known versions of Visual Studio. If
-  
-you have a more recent version installed the build system doesn't understand
-  
-then you may need to force rustbuild to use an older version. This can be done
-  
-by manually calling the appropriate vcvars file before running the bootstrap.
-  
-
-  
-```batch
-  
-> CALL "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64\vcvars64.bat"
-  
-> python x.py build
-  
-```
-  
-
-  
-#### Specifying an ABI
-  
-[specifying-an-abi]: #specifying-an-abi
-  
-
-  
-Each specific ABI can also be used from either environment (for example, using
-  
-the GNU ABI in PowerShell) by using an explicit build triple. The available
-  
-Windows build triples are:
-  
- GNU ABI (using GCC)
-  
-    - `i686-pc-windows-gnu`
-  
-    - `x86_64-pc-windows-gnu`
-  
- The MSVC ABI
-  
-    - `i686-pc-windows-msvc`
-  
-    - `x86_64-pc-windows-msvc`
-  
-
-  
-The build triple can be specified by either specifying `--build=<triple>` when
-  
-invoking `x.py` commands, or by copying the `config.toml` file (as described
-  
-in Building From Source), and modifying the `build` option under the `[build]`
-  
-section.
-  
-
-  
-### Configure and Make
-  
-[configure-and-make]: #configure-and-make
-  
-
-  
-While it's not the recommended build system, this project also provides a
-  
-configure script and makefile (the latter of which just invokes `x.py`).
-  
-
-  
-```sh
-  
-$ ./configure
-  
-$ make && sudo make install
-  
-```
-  
-
-  
-When using the configure script, the generated `config.mk` file may override the
-  
-`config.toml` file. To go back to the `config.toml` file, delete the generated
-  
-`config.mk` file.
-  
-
-  
-## Building Documentation
-  
-[building-documentation]: #building-documentation
-  
-
-  
-If you’d like to build the documentation, it’s almost the same:
-  
-
-  
-```sh
-  
-$ ./x.py doc
+  
+# Optionally enable the avr toolchain globally
+  
+rustup default avr-toolchain
 ```
-  
-The generated documentation will appear under `doc` in the `build` directory for
-  
-the ABI used. I.e., if the ABI was `x86_64-pc-windows-msvc`, the directory will be
-  
-`build\x86_64-pc-windows-msvc\doc`.
-  
-
-  
-## Notes
-  
-[notes]: #notes
-  
-
-  
-Since the Rust compiler is written in Rust, it must be built by a
-  
-precompiled "snapshot" version of itself (made in an earlier stage of
-  
-development). As such, source builds require a connection to the Internet, to
-  
-fetch snapshots, and an OS that can execute the available snapshot binaries.
-  
-
-  
-Snapshot binaries are currently built and tested on several platforms:
-  
-
-  
-| Platform / Architecture        | x86 | x86_64 |
-  
-|--------------------------------|-----|--------|
-  
-| Windows (7, 8, Server 2008 R2) | ✓   | ✓      |
-  
-| Linux (2.6.18 or later)        | ✓   | ✓      |
-  
-| OSX (10.7 Lion or later)       | ✓   | ✓      |
-  
-
-  
-You may find that other platforms work, but these are our officially
-  
-supported build environments that are most likely to work.
-  
-
-  
-Rust currently needs between 600MiB and 1.5GiB of RAM to build, depending on platform.
-  
-If it hits swap, it will take a very long time to build.
-  
-
-  
-There is more advice about hacking on Rust in [CONTRIBUTING.md].
-  
-
-  
-[CONTRIBUTING.md]: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md
-  
-
-  
-## Getting Help
-  
-[getting-help]: #getting-help
-  
-
-  
-The Rust community congregates in a few places:
-  
-
-  
-* [Stack Overflow] - Direct questions about using the language.
-  
-* [users.rust-lang.org] - General discussion and broader questions.
-  
-* [/r/rust] - News and general discussion.
-  
-
-  
-[Stack Overflow]: https://stackoverflow.com/questions/tagged/rust
-  
-[/r/rust]: https://reddit.com/r/rust
-  
-[users.rust-lang.org]: https://users.rust-lang.org/
-  
-
-  
-## Contributing
-  
-[contributing]: #contributing
-  
-
-  
-To contribute to Rust, please see [CONTRIBUTING](CONTRIBUTING.md).
-  
-
-  
-Rust has an [IRC] culture and most real-time collaboration happens in a
-  
-variety of channels on Mozilla's IRC network, irc.mozilla.org. The
-  
-most popular channel is [#rust], a venue for general discussion about
-  
-Rust. And a good place to ask for help would be [#rust-beginners].
-  
-
-  
-The [rustc guide] might be a good place to start if you want to find out how
-  
-various parts of the compiler work.
+  
+## Usage
-  
-Also, you may find the [rustdocs for the compiler itself][rustdocs] useful.
+  
+# With Xargo (recommended)
-  
-[IRC]: https://en.wikipedia.org/wiki/Internet_Relay_Chat
-  
-[#rust]: irc://irc.mozilla.org/rust
-  
-[#rust-beginners]: irc://irc.mozilla.org/rust-beginners
-  
-[rustc guide]: https://rust-lang.github.io/rustc-guide/about-this-guide.html
-  
-[rustdocs]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc/
+  
+Take a look at the example [blink](https://github.com/avr-rust/blink) program.
-  
-## License
-  
-[license]: #license
+  
+# Vanilla `rustc`
-  
-Rust is primarily distributed under the terms of both the MIT license
-  
-and the Apache License (Version 2.0), with portions covered by various
-  
-BSD-like licenses.
+  
+AVR support is enabled by passing the `--target avr-unknown-unknown` flag to `rustc`.
-  
-See [LICENSE-APACHE](LICENSE-APACHE), [LICENSE-MIT](LICENSE-MIT), and
-  
-[COPYRIGHT](COPYRIGHT) for details.
+  
+Note that the Rust `libcore` library (essentially required for every Rust program),
+  
+must be manually compiled for it to be used, as it will not be built for AVR during
+  
+compiler compilation (yet). Work is currently being done in order to allow `libcore`
+  
+to be automatically compiled for AVR.
diff --git a/RUST_README.md b/RUST_README.md
@@ -0,0 +1,247 @@
+  
+# The Rust Programming Language
+  
+
+  
+This is the main source code repository for [Rust]. It contains the compiler,
+  
+standard library, and documentation.
+  
+
+  
+[Rust]: https://www.rust-lang.org
+  
+
+  
+## Quick Start
+  
+[quick-start]: #quick-start
+  
+
+  
+Read ["Installation"] from [The Book].
+  
+
+  
+["Installation"]: https://doc.rust-lang.org/book/ch01-01-installation.html
+  
+[The Book]: https://doc.rust-lang.org/book/index.html
+  
+
+  
+## Building from Source
+  
+[building-from-source]: #building-from-source
+  
+
+  
+### Building on *nix
+  
+1. Make sure you have installed the dependencies:
+  
+
+  
+   * `g++` 4.7 or later or `clang++` 3.x or later
+  
+   * `python` 2.7 (but not 3.x)
+  
+   * GNU `make` 3.81 or later
+  
+   * `cmake` 3.4.3 or later
+  
+   * `curl`
+  
+   * `git`
+  
+
+  
+2. Clone the [source] with `git`:
+  
+
+  
+   ```sh
+  
+   $ git clone https://github.com/rust-lang/rust.git
+  
+   $ cd rust
+  
+   ```
+  
+
+  
+[source]: https://github.com/rust-lang/rust
+  
+
+  
+3. Build and install:
+  
+
+  
+    ```sh
+  
+    $ git submodule update --init --recursive --progress
+  
+    $ ./x.py build && sudo ./x.py install
+  
+    ```
+  
+
+  
+    > ***Note:*** Install locations can be adjusted by copying the config file
+  
+    > from `./config.toml.example` to `./config.toml`, and
+  
+    > adjusting the `prefix` option under `[install]`. Various other options, such
+  
+    > as enabling debug information, are also supported, and are documented in
+  
+    > the config file.
+  
+
+  
+    When complete, `sudo ./x.py install` will place several programs into
+  
+    `/usr/local/bin`: `rustc`, the Rust compiler, and `rustdoc`, the
+  
+    API-documentation tool. This install does not include [Cargo],
+  
+    Rust's package manager, which you may also want to build.
+  
+
+  
+[Cargo]: https://github.com/rust-lang/cargo
+  
+
+  
+### Building on Windows
+  
+[building-on-windows]: #building-on-windows
+  
+
+  
+There are two prominent ABIs in use on Windows: the native (MSVC) ABI used by
+  
+Visual Studio, and the GNU ABI used by the GCC toolchain. Which version of Rust
+  
+you need depends largely on what C/C++ libraries you want to interoperate with:
+  
+for interop with software produced by Visual Studio use the MSVC build of Rust;
+  
+for interop with GNU software built using the MinGW/MSYS2 toolchain use the GNU
+  
+build.
+  
+
+  
+#### MinGW
+  
+[windows-mingw]: #windows-mingw
+  
+
+  
+[MSYS2][msys2] can be used to easily build Rust on Windows:
+  
+
+  
+[msys2]: https://msys2.github.io/
+  
+
+  
+1. Grab the latest [MSYS2 installer][msys2] and go through the installer.
+  
+
+  
+2. Run `mingw32_shell.bat` or `mingw64_shell.bat` from wherever you installed
+  
+   MSYS2 (i.e. `C:\msys64`), depending on whether you want 32-bit or 64-bit
+  
+   Rust. (As of the latest version of MSYS2 you have to run `msys2_shell.cmd
+  
+   -mingw32` or `msys2_shell.cmd -mingw64` from the command line instead)
+  
+
+  
+3. From this terminal, install the required tools:
+  
+
+  
+   ```sh
+  
+   # Update package mirrors (may be needed if you have a fresh install of MSYS2)
+  
+   $ pacman -Sy pacman-mirrors
+  
+
+  
+   # Install build tools needed for Rust. If you're building a 32-bit compiler,
+  
+   # then replace "x86_64" below with "i686". If you've already got git, python,
+  
+   # or CMake installed and in PATH you can remove them from this list. Note
+  
+   # that it is important that you do **not** use the 'python2' and 'cmake'
+  
+   # packages from the 'msys2' subsystem. The build has historically been known
+  
+   # to fail with these packages.
+  
+   $ pacman -S git \
+  
+               make \
+  
+               diffutils \
+  
+               tar \
+  
+               mingw-w64-x86_64-python2 \
+  
+               mingw-w64-x86_64-cmake \
+  
+               mingw-w64-x86_64-gcc
+  
+   ```
+  
+
+  
+4. Navigate to Rust's source code (or clone it), then build it:
+  
+
+  
+   ```sh
+  
+   $ ./x.py build && ./x.py install
+  
+   ```
+  
+
+  
+#### MSVC
+  
+[windows-msvc]: #windows-msvc
+  
+
+  
+MSVC builds of Rust additionally require an installation of Visual Studio 2013
+  
+(or later) so `rustc` can use its linker. Make sure to check the “C++ tools”
+  
+option.
+  
+
+  
+With these dependencies installed, you can build the compiler in a `cmd.exe`
+  
+shell with:
+  
+
+  
+```sh
+  
+> python x.py build
+  
+```
+  
+
+  
+Currently, building Rust only works with some known versions of Visual Studio. If
+  
+you have a more recent version installed the build system doesn't understand
+  
+then you may need to force rustbuild to use an older version. This can be done
+  
+by manually calling the appropriate vcvars file before running the bootstrap.
+  
+
+  
+```batch
+  
+> CALL "C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\amd64\vcvars64.bat"
+  
+> python x.py build
+  
+```
+  
+
+  
+#### Specifying an ABI
+  
+[specifying-an-abi]: #specifying-an-abi
+  
+
+  
+Each specific ABI can also be used from either environment (for example, using
+  
+the GNU ABI in PowerShell) by using an explicit build triple. The available
+  
+Windows build triples are:
+  
+- GNU ABI (using GCC)
+  
+    - `i686-pc-windows-gnu`
+  
+    - `x86_64-pc-windows-gnu`
+  
+- The MSVC ABI
+  
+    - `i686-pc-windows-msvc`
+  
+    - `x86_64-pc-windows-msvc`
+  
+
+  
+The build triple can be specified by either specifying `--build=<triple>` when
+  
+invoking `x.py` commands, or by copying the `config.toml` file (as described
+  
+in Building From Source), and modifying the `build` option under the `[build]`
+  
+section.
+  
+
+  
+### Configure and Make
+  
+[configure-and-make]: #configure-and-make
+  
+
+  
+While it's not the recommended build system, this project also provides a
+  
+configure script and makefile (the latter of which just invokes `x.py`).
+  
+
+  
+```sh
+  
+$ ./configure
+  
+$ make && sudo make install
+  
+```
+  
+
+  
+When using the configure script, the generated `config.mk` file may override the
+  
+`config.toml` file. To go back to the `config.toml` file, delete the generated
+  
+`config.mk` file.
+  
+
+  
+## Building Documentation
+  
+[building-documentation]: #building-documentation
+  
+
+  
+If you’d like to build the documentation, it’s almost the same:
+  
+
+  
+```sh
+  
+$ ./x.py doc
+  
+```
+  
+
+  
+The generated documentation will appear under `doc` in the `build` directory for
+  
+the ABI used. I.e., if the ABI was `x86_64-pc-windows-msvc`, the directory will be
+  
+`build\x86_64-pc-windows-msvc\doc`.
+  
+
+  
+## Notes
+  
+[notes]: #notes
+  
+
+  
+Since the Rust compiler is written in Rust, it must be built by a
+  
+precompiled "snapshot" version of itself (made in an earlier stage of
+  
+development). As such, source builds require a connection to the Internet, to
+  
+fetch snapshots, and an OS that can execute the available snapshot binaries.
+  
+
+  
+Snapshot binaries are currently built and tested on several platforms:
+  
+
+  
+| Platform / Architecture        | x86 | x86_64 |
+  
+|--------------------------------|-----|--------|
+  
+| Windows (7, 8, Server 2008 R2) | ✓   | ✓      |
+  
+| Linux (2.6.18 or later)        | ✓   | ✓      |
+  
+| OSX (10.7 Lion or later)       | ✓   | ✓      |
+  
+
+  
+You may find that other platforms work, but these are our officially
+  
+supported build environments that are most likely to work.
+  
+
+  
+Rust currently needs between 600MiB and 1.5GiB of RAM to build, depending on platform.
+  
+If it hits swap, it will take a very long time to build.
+  
+
+  
+There is more advice about hacking on Rust in [CONTRIBUTING.md].
+  
+
+  
+[CONTRIBUTING.md]: https://github.com/rust-lang/rust/blob/master/CONTRIBUTING.md
+  
+
+  
+## Getting Help
+  
+[getting-help]: #getting-help
+  
+
+  
+The Rust community congregates in a few places:
+  
+
+  
+* [Stack Overflow] - Direct questions about using the language.
+  
+* [users.rust-lang.org] - General discussion and broader questions.
+  
+* [/r/rust] - News and general discussion.
+  
+
+  
+[Stack Overflow]: https://stackoverflow.com/questions/tagged/rust
+  
+[/r/rust]: https://reddit.com/r/rust
+  
+[users.rust-lang.org]: https://users.rust-lang.org/
+  
+
+  
+## Contributing
+  
+[contributing]: #contributing
+  
+
+  
+To contribute to Rust, please see [CONTRIBUTING](CONTRIBUTING.md).
+  
+
+  
+Rust has an [IRC] culture and most real-time collaboration happens in a
+  
+variety of channels on Mozilla's IRC network, irc.mozilla.org. The
+  
+most popular channel is [#rust], a venue for general discussion about
+  
+Rust. And a good place to ask for help would be [#rust-beginners].
+  
+
+  
+The [rustc guide] might be a good place to start if you want to find out how
+  
+various parts of the compiler work.
+  
+
+  
+Also, you may find the [rustdocs for the compiler itself][rustdocs] useful.
+  
+
+  
+[IRC]: https://en.wikipedia.org/wiki/Internet_Relay_Chat
+  
+[#rust]: irc://irc.mozilla.org/rust
+  
+[#rust-beginners]: irc://irc.mozilla.org/rust-beginners
+  
+[rustc guide]: https://rust-lang.github.io/rustc-guide/about-this-guide.html
+  
+[rustdocs]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc/
+  
+
+  
+## License
+  
+[license]: #license
+  
+
+  
+Rust is primarily distributed under the terms of both the MIT license
+  
+and the Apache License (Version 2.0), with portions covered by various
+  
+BSD-like licenses.
+  
+
+  
+See [LICENSE-APACHE](LICENSE-APACHE), [LICENSE-MIT](LICENSE-MIT), and
+  
+[COPYRIGHT](COPYRIGHT) for details.
diff --git a/config.toml.example b/config.toml.example
@@ -68,7 +68,7 @@
 # not built by default and the experimental Rust compilation targets that depend
 # on them will not work unless the user opts in to building them. By default the
 # `WebAssembly` and `RISCV` targets are enabled when compiling LLVM from scratch.
-  
-#experimental-targets = "WebAssembly;RISCV"
+  
+#experimental-targets = "AVR;WebAssembly;RISCV"
 # Cap the number of parallel linker invocations when compiling LLVM.
 # This can be useful when building LLVM with debug info, which significantly

diff --git a/src/bootstrap/config.rs b/src/bootstrap/config.rs
@@ -519,7 +519,7 @@ impl Config {
            set(&mut config.llvm_link_shared, llvm.link_shared);
            config.llvm_targets = llvm.targets.clone();
            config.llvm_experimental_targets = llvm.experimental_targets.clone()
-  
-                .unwrap_or_else(|| "WebAssembly;RISCV".to_string());
+  
+                .unwrap_or_else(|| "AVR;WebAssembly;RISCV".to_string());
            config.llvm_link_jobs = llvm.link_jobs;
            config.llvm_version_suffix = llvm.version_suffix.clone();
            config.llvm_clang_cl = llvm.clang_cl.clone();

diff --git a/src/librustc/ich/impls_syntax.rs b/src/librustc/ich/impls_syntax.rs
@@ -116,6 +116,8 @@ impl_stable_hash_for!(enum ::rustc_target::spec::abi::Abi {
    Msp430Interrupt,
    X86Interrupt,
    AmdGpuKernel,
+  
+    AvrInterrupt,
+  
+    AvrNonBlockingInterrupt,
    Rust,
    C,
    System,

diff --git a/src/librustc/session/config.rs b/src/librustc/session/config.rs
@@ -1397,6 +1397,7 @@ pub fn default_lib_output() -> CrateType {
 pub fn default_configuration(sess: &Session) -> ast::CrateConfig {
    let end = &sess.target.target.target_endian;
    let arch = &sess.target.target.arch;
+  
+    let cpu = &sess.target.target.options.cpu;
    let wordsz = &sess.target.target.target_pointer_width;
    let os = &sess.target.target.target_os;
    let env = &sess.target.target.target_env;
@@ -1426,6 +1427,10 @@ pub fn default_configuration(sess: &Session) -> ast::CrateConfig {
        Symbol::intern("target_vendor"),
        Some(Symbol::intern(vendor)),
    ));
+  
+    if sess.target.target.options.is_specific_cpu() {
+  
+        ret.insert((Symbol::intern("target_cpu"), Some(Symbol::intern(cpu))));
+  
+    }
+  
+
    if sess.target.target.options.has_elf_tls {
        ret.insert((Symbol::intern("target_thread_local"), None));
    }

diff --git a/src/librustc_codegen_llvm/abi.rs b/src/librustc_codegen_llvm/abi.rs
@@ -425,6 +425,8 @@ impl<'tcx> FnTypeExt<'tcx> for FnType<'tcx, Ty<'tcx>> {
            Msp430Interrupt => Conv::Msp430Intr,
            X86Interrupt => Conv::X86Intr,
            AmdGpuKernel => Conv::AmdGpuKernel,
+  
+            AvrInterrupt => Conv::AvrInterrupt,
+  
+            AvrNonBlockingInterrupt => Conv::AvrNonBlockingInterrupt,
            // These API constants ought to be more specific...
            Cdecl => Conv::C,
@@ -714,6 +716,8 @@ impl<'tcx> FnTypeExt<'tcx> for FnType<'tcx, Ty<'tcx>> {
        match self.conv {
            Conv::C => llvm::CCallConv,
            Conv::AmdGpuKernel => llvm::AmdGpuKernel,
+  
+            Conv::AvrInterrupt => llvm::AvrInterrupt,
+  
+            Conv::AvrNonBlockingInterrupt => llvm::AvrNonBlockingInterrupt,
            Conv::ArmAapcs => llvm::ArmAapcsCallConv,
            Conv::Msp430Intr => llvm::Msp430Intr,
            Conv::PtxKernel => llvm::PtxKernel,

diff --git a/src/librustc_codegen_llvm/llvm/ffi.rs b/src/librustc_codegen_llvm/llvm/ffi.rs
@@ -55,6 +55,8 @@ pub enum CallConv {
    X86_64_Win64 = 79,
    X86_VectorCall = 80,
    X86_Intr = 83,
+  
+    AvrNonBlockingInterrupt = 84,
+  
+    AvrInterrupt = 85,
    AmdGpuKernel = 91,
 }

diff --git a/src/librustc_llvm/build.rs b/src/librustc_llvm/build.rs
@@ -81,7 +81,7 @@ fn main() {
    let is_crossed = target != host;
    let mut optional_components =
-  
-        vec!["x86", "arm", "aarch64", "amdgpu", "mips", "powerpc",
+  
+        vec!["x86", "arm", "aarch64", "amdgpu", "avr", "mips", "powerpc",
             "systemz", "jsbackend", "webassembly", "msp430", "sparc", "nvptx"];
    let mut version_cmd = Command::new(&llvm_config);

diff --git a/src/librustc_llvm/lib.rs b/src/librustc_llvm/lib.rs
@@ -52,6 +52,12 @@ pub fn initialize_available_targets() {
                 LLVMInitializeARMTargetMC,
                 LLVMInitializeARMAsmPrinter,
                 LLVMInitializeARMAsmParser);
+  
+    init_target!(llvm_component = "avr",
+  
+                 LLVMInitializeAVRTargetInfo,
+  
+                 LLVMInitializeAVRTarget,
+  
+                 LLVMInitializeAVRTargetMC,
+  
+                 LLVMInitializeAVRAsmPrinter,
+  
+                 LLVMInitializeAVRAsmParser);
    init_target!(llvm_component = "aarch64",
                 LLVMInitializeAArch64TargetInfo,
                 LLVMInitializeAArch64Target,

diff --git a/src/librustc_target/abi/call/avr.rs b/src/librustc_target/abi/call/avr.rs
@@ -0,0 +1,43 @@
+  
+// Copyright 2012-2013 The Rust Project Developers. See the COPYRIGHT
+  
+// file at the top-level directory of this distribution and at
+  
+// http://rust-lang.org/COPYRIGHT.
+  
+//
+  
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+  
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+  
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+  
+// option. This file may not be copied, modified, or distributed
+  
+// except according to those terms.
+  
+
+  
+#![allow(non_upper_case_globals)]
+  
+
+  
+use abi::call::{FnType, ArgType};
+  
+
+  
+fn classify_ret_ty<Ty>(ret: &mut ArgType<Ty>) {
+  
+    if ret.layout.is_aggregate()  {
+  
+        ret.make_indirect();
+  
+    } else {
+  
+        ret.extend_integer_width_to(8); // Is 8 correct?
+  
+    }
+  
+}
+  
+
+  
+fn classify_arg_ty<Ty>(arg: &mut ArgType<Ty>) {
+  
+    if arg.layout.is_aggregate() {
+  
+        arg.make_indirect();
+  
+    } else {
+  
+        arg.extend_integer_width_to(8);
+  
+    }
+  
+}
+  
+
+  
+pub fn compute_abi_info<Ty>(fty: &mut FnType<Ty>) {
+  
+    if !fty.ret.is_ignore() {
+  
+        classify_ret_ty(&mut fty.ret);
+  
+    }
+  
+
+  
+    for arg in &mut fty.args {
+  
+        if arg.is_ignore() {
+  
+            continue;
+  
+        }
+  
+
+  
+        classify_arg_ty(arg);
+  
+    }
+  
+}
diff --git a/src/librustc_target/abi/call/mod.rs b/src/librustc_target/abi/call/mod.rs
@@ -16,6 +16,7 @@ mod aarch64;
 mod amdgpu;
 mod arm;
 mod asmjs;
+  
+mod avr;
 mod hexagon;
 mod mips;
 mod mips64;
@@ -462,6 +463,8 @@ pub enum Conv {
    X86_64Win64,
    AmdGpuKernel,
+  
+    AvrInterrupt,
+  
+    AvrNonBlockingInterrupt,
 }
 /// Metadata describing how the arguments to a native function
@@ -519,6 +522,7 @@ impl<'a, Ty> FnType<'a, Ty> {
                    wasm32::compute_abi_info(self)
                }
            }
+  
+            "avr" => avr::compute_abi_info(self),
            "msp430" => msp430::compute_abi_info(self),
            "sparc" => sparc::compute_abi_info(cx, self),
            "sparc64" => sparc64::compute_abi_info(cx, self),

diff --git a/src/librustc_target/spec/abi.rs b/src/librustc_target/spec/abi.rs
@@ -28,6 +28,8 @@ pub enum Abi {
    Msp430Interrupt,
    X86Interrupt,
    AmdGpuKernel,
+  
+    AvrInterrupt,
+  
+    AvrNonBlockingInterrupt,
    // Multiplatform / generic ABIs
    Rust,
@@ -65,6 +67,9 @@ const AbiDatas: &[AbiData] = &[
    AbiData {abi: Abi::Msp430Interrupt, name: "msp430-interrupt", generic: false },
    AbiData {abi: Abi::X86Interrupt, name: "x86-interrupt", generic: false },
    AbiData {abi: Abi::AmdGpuKernel, name: "amdgpu-kernel", generic: false },
+  
+    AbiData {abi: Abi::AvrInterrupt, name: "avr-interrupt", generic: false },
+  
+    AbiData {abi: Abi::AvrNonBlockingInterrupt, name: "avr-non-blocking-interrupt",
+  
+             generic: false },
    // Cross-platform ABIs
    AbiData {abi: Abi::Rust, name: "Rust", generic: true },

diff --git a/src/librustc_target/spec/avr_unknown_unknown.rs b/src/librustc_target/spec/avr_unknown_unknown.rs
@@ -0,0 +1,27 @@
+  
+// Copyright 2015 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 spec::{LinkerFlavor, Target, TargetResult};
+  
+
+  
+pub fn target() -> TargetResult {
+  
+    Ok(Target {
+  
+        llvm_target: "avr-unknown-unknown".to_string(),
+  
+        target_endian: "little".to_string(),
+  
+        target_pointer_width: "16".to_string(),
+  
+        data_layout: "e-P1-p:16:8-i8:8-i16:8-i32:8-i64:8-f32:8-f64:8-n8-a:8".to_string(),
+  
+        arch: "avr".to_string(),
+  
+        linker_flavor: LinkerFlavor::Gcc,
+  
+        target_os: "unknown".to_string(),
+  
+        target_env: "".to_string(),
+  
+        target_vendor: "unknown".to_string(),
+  
+        target_c_int_width: 16.to_string(),
+  
+        options: super::none_base::opts(),
+  
+    })
+  
+}
diff --git a/src/librustc_target/spec/mod.rs b/src/librustc_target/spec/mod.rs
@@ -65,6 +65,7 @@ mod haiku_base;
 mod hermit_base;
 mod linux_base;
 mod linux_musl_base;
+  
+mod none_base;
 mod openbsd_base;
 mod netbsd_base;
 mod solaris_base;
@@ -364,6 +365,8 @@ supported_targets! {
    ("aarch64-fuchsia", aarch64_fuchsia),
    ("x86_64-fuchsia", x86_64_fuchsia),
+  
+    ("avr-unknown-unknown", avr_unknown_unknown),
+  
+
    ("x86_64-unknown-l4re-uclibc", x86_64_unknown_l4re_uclibc),
    ("x86_64-unknown-redox", x86_64_unknown_redox),
@@ -444,7 +447,7 @@ pub struct Target {
    /// Vendor name to use for conditional compilation.
    pub target_vendor: String,
    /// Architecture to use for ABI considerations. Valid options: "x86",
-  
-    /// "x86_64", "arm", "aarch64", "mips", "powerpc", and "powerpc64".
+  
+    /// "x86_64", "arm", "aarch64", "avr", "mips", "powerpc", and "powerpc64".
    pub arch: String,
    /// [Data layout](http://llvm.org/docs/LangRef.html#data-layout) to pass to LLVM.
    pub data_layout: String,
@@ -785,6 +788,12 @@ impl Default for TargetOptions {
    }
 }
+  
+impl TargetOptions {
+  
+    pub fn is_specific_cpu(&self) -> bool {
+  
+        self.cpu != "generic"
+  
+    }
+  
+}
+  
+
 impl Target {
    /// Given a function ABI, turn it into the correct ABI for this target.
    pub fn adjust_abi(&self, abi: Abi) -> Abi {

diff --git a/src/librustc_target/spec/none_base.rs b/src/librustc_target/spec/none_base.rs
@@ -0,0 +1,37 @@
+  
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+  
+// file at the top-level directory of this distribution and at
+  
+// http://rust-lang.org/COPYRIGHT.
+  
+//
+  
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+  
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+  
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+  
+// option. This file may not be copied, modified, or distributed
+  
+// except according to those terms.
+  
+
+  
+use std::default::Default;
+  
+use spec::{LinkerFlavor, LinkArgs, TargetOptions};
+  
+
+  
+pub fn opts() -> TargetOptions {
+  
+    let mut args = LinkArgs::new();
+  
+
+  
+    args.insert(LinkerFlavor::Gcc, vec![
+  
+        // We want to be able to strip as much executable code as possible
+  
+        // from the linker command line, and this flag indicates to the
+  
+        // linker that it can avoid linking in dynamic libraries that don't
+  
+        // actually satisfy any symbols up to that point (as with many other
+  
+        // resolutions the linker does). This option only applies to all
+  
+        // following libraries so we're sure to pass it as one of the first
+  
+        // arguments.
+  
+        "-Wl,--as-needed".to_string(),
+  
+    ]);
+  
+
+  
+    TargetOptions {
+  
+        dynamic_linking: false,
+  
+        executables: true,
+  
+        linker_is_gnu: true,
+  
+        has_rpath: false,
+  
+        pre_link_args: args,
+  
+        position_independent_executables: true,
+  
+        .. Default::default()
+  
+    }
+  
+}
diff --git a/src/libstd/env.rs b/src/libstd/env.rs
@@ -821,6 +821,7 @@ pub mod consts {
    /// - x86_64
    /// - arm
    /// - aarch64
+  
+    /// - avr
    /// - mips
    /// - mips64
    /// - powerpc
@@ -933,6 +934,11 @@ mod arch {
    pub const ARCH: &str = "aarch64";
 }
+  
+#[cfg(target_arch = "avr")]
+  
+mod arch {
+  
+    pub const ARCH: &'static str = "avr";
+  
+}
+  
+
 #[cfg(target_arch = "mips")]
 mod arch {
    pub const ARCH: &str = "mips";

diff --git a/src/libsyntax/feature_gate.rs b/src/libsyntax/feature_gate.rs
@@ -331,6 +331,9 @@ declare_features! (
    // Allows `extern "x86-interrupt" fn()`.
    (active, abi_x86_interrupt, "1.17.0", Some(40180), None),
+  
+    // `extern "avr-interrupt" fn()`
+  
+    (active, abi_avr_interrupt, "1.18.0", Some(000), None),
+  
+
    // Allows the `try {...}` expression.
    (active, try_blocks, "1.29.0", Some(31436), None),
@@ -1475,6 +1478,11 @@ impl<'a> PostExpansionVisitor<'a> {
            Abi::X86Interrupt => {
                gate_feature_post!(&self, abi_x86_interrupt, span,
                                   "x86-interrupt ABI is experimental and subject to change");
+  
+            }
+  
+            Abi::AvrInterrupt | Abi::AvrNonBlockingInterrupt => {
+  
+                gate_feature_post!(&self, abi_avr_interrupt, span,
+  
+                                   "avr-interrupt and avr-non-blocking-interrupt ABIs are \
+  
+                                   experimental and subject to change");
            },
            Abi::AmdGpuKernel => {
                gate_feature_post!(&self, abi_amdgpu_kernel, span,

diff --git a/src/llvm b/src/llvm
diff --git a/src/rustllvm/PassWrapper.cpp b/src/rustllvm/PassWrapper.cpp
@@ -127,6 +127,12 @@ void LLVMRustPassManagerBuilderPopulateThinLTOPassManager(
 #define SUBTARGET_AARCH64
 #endif
+  
+#ifdef LLVM_COMPONENT_AVR
+  
+#define SUBTARGET_AVR SUBTARGET(AVR)
+  
+#else
+  
+#define SUBTARGET_AVR
+  
+#endif
+  
+
 #ifdef LLVM_COMPONENT_MIPS
 #define SUBTARGET_MIPS SUBTARGET(Mips)
 #else
@@ -173,6 +179,7 @@ void LLVMRustPassManagerBuilderPopulateThinLTOPassManager(
  SUBTARGET_X86                                                                \
  SUBTARGET_ARM                                                                \
  SUBTARGET_AARCH64                                                            \
+  
+  SUBTARGET_AVR                                                                \
  SUBTARGET_MIPS                                                               \
  SUBTARGET_PPC                                                                \
  SUBTARGET_SYSTEMZ                                                            \

diff --git a/src/test/run-pass/cfg-target-cpu.rs b/src/test/run-pass/cfg-target-cpu.rs
@@ -0,0 +1,18 @@
+  
+// 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.
+  
+
+  
+pub fn main() {
+  
+    if cfg!(target_cpu = "cortex-a8") {
+  
+        println!("Running on Cortex A8!");
+  
+    } else {
+  
+        println!("Running on an arbitrary cpu");
+  
+    }
+  
+}
+  
+
diff --git a/src/test/ui/feature-gates/feature-gate-abi-avr-interrupt.rs b/src/test/ui/feature-gates/feature-gate-abi-avr-interrupt.rs
@@ -0,0 +1,19 @@
+  
+// Copyright 2018 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.
+  
+
+  
+// Test that the AVR interrupt ABI cannot be used when avr_interrupt
+  
+// feature gate is not used.
+  
+
+  
+extern "avr-interrupt" fn foo() {}
+  
+//~^ ERROR avr-interrupt and avr-non-blocking-interrupt ABIs are experimental and subject to change
+  
+
+  
+fn main() {
+  
+    foo();
+  
+}
diff --git a/src/test/ui/feature-gates/feature-gate-abi-avr-interrupt.stderr b/src/test/ui/feature-gates/feature-gate-abi-avr-interrupt.stderr
@@ -0,0 +1,11 @@
+  
+error[E0658]: avr-interrupt and avr-non-blocking-interrupt ABIs are experimental and subject to change
+  
+  --> $DIR/feature-gate-abi-avr-interrupt.rs:14:1
+  
+   |
+  
+LL | extern "avr-interrupt" fn foo() {}
+  
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+  
+   |
+  
+   = help: add #![feature(abi_avr_interrupt)] to the crate attributes to enable
+  
+
+  
+error: aborting due to previous error
+  
+
+  
+For more information about this error, try `rustc --explain E0658`.
diff --git a/src/tools/compiletest/src/util.rs b/src/tools/compiletest/src/util.rs
@@ -31,6 +31,7 @@ const OS_TABLE: &'static [(&'static str, &'static str)] = &[
    ("linux", "linux"),
    ("mingw32", "windows"),
    ("netbsd", "netbsd"),
+  
+    ("none", "none"),
    ("openbsd", "openbsd"),
    ("redox", "redox"),
    ("solaris", "solaris"),
@@ -48,6 +49,7 @@ const ARCH_TABLE: &'static [(&'static str, &'static str)] = &[
    ("armv7", "arm"),
    ("armv7s", "arm"),
    ("asmjs", "asmjs"),
+  
+    ("avr", "avr"),
    ("hexagon", "hexagon"),
    ("i386", "x86"),
    ("i586", "x86"),
+30 −0		docs/AVRTarget.rst
+14 −0		include/llvm/CodeGen/SelectionDAGNodes.h
+23 −0		lib/CodeGen/SelectionDAG/ScheduleDAGRRList.cpp
+5 −5		lib/Target/AVR/AVRExpandPseudoInsts.cpp
+56 −20		lib/Target/AVR/AVRISelLowering.cpp
+7 −1		lib/Target/AVR/AVRISelLowering.h
+10 −2		lib/Target/AVR/AVRSubtarget.cpp
+4 −1		lib/Target/AVR/AVRSubtarget.h
+2 −1		lib/Transforms/IPO/ArgumentPromotion.cpp
+2 −2		lib/Transforms/IPO/DeadArgumentElimination.cpp
+1 −0		lib/Transforms/IPO/ExtractGV.cpp
+2 −1		lib/Transforms/IPO/FunctionImport.cpp
+15 −7		lib/Transforms/IPO/LowerTypeTests.cpp
+4 −4		lib/Transforms/IPO/MergeFunctions.cpp
+2 −1		lib/Transforms/IPO/ThinLTOBitcodeWriter.cpp
+4 −1		lib/Transforms/IPO/WholeProgramDevirt.cpp
+13 −0		test/CodeGen/AVR/PR37143.ll
+22 −22		test/CodeGen/AVR/atomics/load16.ll
+74 −0		test/CodeGen/AVR/avr-rust-issue-123.ll
+114 −0		test/CodeGen/AVR/calling-conv/c/return.ll
+2 −0		test/CodeGen/AVR/hardware-mul.ll
+6 −6		test/CodeGen/AVR/load.ll
+2 −2		test/CodeGen/AVR/pseudo/LDWRdPtr-same-src-dst.mir
+2 −2		test/CodeGen/AVR/pseudo/LDWRdPtr.mir
+1 −1		test/CodeGen/AVR/smul-with-overflow.ll
+28 −0		test/CodeGen/AVR/software-mul.ll
+1 −1		test/CodeGen/AVR/umul-with-overflow.ll
+24 −0		test/Transforms/ArgumentPromotion/nonzero-address-spaces.ll
+20 −0		test/Transforms/DeadArgElim/nonzero-address-spaces.ll
+30 −0		test/Transforms/MergeFunc/nonzero-address-spaces.ll