Enable ARM cross-compilation

closes #244

.travis.yml

@@ -20,6 +20,11 @@ matrix:
     - os: osx
       rust: stable
       env: TARGET=x86_64-apple-darwin
+    - os: linux
+      rust: stable
+      env:
+        - TARGET=arm-unknown-linux-gnueabihf
+        - CARGO_TARGET_ARM_UNKNOWN_LINUX_GNUEABIHF_LINKER=arm-linux-gnueabihf-gcc-4.8
 
     # Beta channel.
     - os: linux
@@ -82,13 +87,10 @@ matrix:
         - cargo install --debug --force rustfmt-nightly
       script: cargo fmt -- --check
 
-addons:
-  apt:
-    packages:
-      # needed for i686-unknown-linux-gnu target
-      - gcc-multilib
-      # needed to build deb packages
-      - fakeroot
+sudo: required
+
+before_install:
+  - ci/before_install.bash
 
 env:
   global:
@@ -103,9 +105,7 @@ install:
   - if [[ $TRAVIS_OS_NAME = linux && $HOST != $TARGET ]]; then rustup target add $TARGET; fi
 
 script:
-  # Incorporate TARGET env var to the build and test process
-  - cargo build --target $TARGET --verbose
-  - cargo test --target $TARGET --verbose
+  - ci/script.bash
 
 before_deploy:
   - bash ci/before_deploy.bash

ci/before_deploy.bash

@@ -11,18 +11,25 @@ pack() {
     local tempdir
     local out_dir
     local package_name
+    local gcc_prefix
 
     tempdir=$(mktemp -d 2>/dev/null || mktemp -d -t tmp)
     out_dir=$(pwd)
     package_name="$PROJECT_NAME-$TRAVIS_TAG-$TARGET"
 
+    if [[ $TARGET == "arm-unknown-linux-gnueabihf" ]]; then
+        gcc_prefix="arm-linux-gnueabihf-"
+    else
+        gcc_prefix=""
+    fi
+
     # create a "staging" directory
     mkdir "$tempdir/$package_name"
     mkdir "$tempdir/$package_name/autocomplete"
 
     # copying the main binary
     cp "target/$TARGET/release/$PROJECT_NAME" "$tempdir/$package_name/"
-    strip "$tempdir/$package_name/$PROJECT_NAME"
+    "${gcc_prefix}"strip "$tempdir/$package_name/$PROJECT_NAME"
 
     # manpage, readme and license
     cp "doc/$PROJECT_NAME.1" "$tempdir/$package_name"
@@ -57,8 +64,8 @@ make_deb() {
             architecture=i386
             ;;
         *)
-            echo "ERROR: unknown target" >&2
-            return 1
+            echo "make_deb: skipping target '${TARGET}'" >&2
+            return 0
             ;;
     esac
     version=${TRAVIS_TAG#v}

ci/before_install.bash

@@ -0,0 +1,26 @@
+#!/usr/bin/env bash
+
+set -ex
+
+if [ "$TRAVIS_OS_NAME" != linux ]; then
+    exit 0
+fi
+
+sudo apt-get update
+
+# needed to build deb packages
+sudo apt-get install -y fakeroot
+
+# needed for i686 linux gnu target
+if [[ $TARGET == i686-unknown-linux-gnu ]]; then
+    sudo apt-get install -y gcc-multilib
+fi
+
+# needed for cross-compiling for arm
+if [[ $TARGET == arm-unknown-linux-gnueabihf ]]; then
+    sudo apt-get install -y \
+        gcc-4.8-arm-linux-gnueabihf \
+        binutils-arm-linux-gnueabihf \
+        libc6-armhf-cross \
+        libc6-dev-armhf-cross
+fi

ci/script.bash

@@ -0,0 +1,11 @@
+#!/usr/bin/env bash
+
+set -ex
+
+# Incorporate TARGET env var to the build and test process
+cargo build --target "$TARGET" --verbose
+
+# We cannot run arm executables on linux
+if [[ $TARGET != arm-unknown-linux-gnueabihf ]]; then
+    cargo test --target "$TARGET" --verbose
+fi