build.sh

#!/bin/bash

set -e
set -o pipefail
set -x

CPU_COUNT="$(grep -c processor /proc/cpuinfo)"
BUILD_DIR=/build


function install_musl() {
    echo "** Installing musl"
    cd "${BUILD_DIR}"

    if [ -d "/usr/local/musl" ]; then
        return
    fi

    curl -L "http://www.musl-libc.org/releases/musl-${MUSL_VERSION}.tar.gz" | tar zxf -
    cd "musl-${MUSL_VERSION}"
    ./configure
    make -j"${CPU_COUNT}"
    make install
}

function build_llvm_components() {
    cd "${BUILD_DIR}"

    if [ -f "/usr/local/musl/lib/libunwind.a" ]; then
        return
    fi

    echo "** Fetching sources"
    curl "http://releases.llvm.org/${LLVM_VERSION}/llvm-${LLVM_VERSION}.src.tar.xz" | tar xJf -
    curl "http://releases.llvm.org/${LLVM_VERSION}/libunwind-${LLVM_VERSION}.src.tar.xz" | tar xJf -

    mv "llvm-${LLVM_VERSION}.src" llvm
    mv "libunwind-${LLVM_VERSION}.src" libunwind

    echo "** Building libunwind"

    cd "${BUILD_DIR}/libunwind"
    ln -s "${BUILD_DIR}/libcxxabi/include/__cxxabi_config.h" ./include/__cxxabi_config.h
    mkdir build && cd build
    cmake -DLLVM_PATH="${BUILD_DIR}/llvm" -DLIBUNWIND_ENABLE_SHARED=OFF ..
    make

    echo "** Copying to output"

    cp ./lib/libunwind.a /usr/local/musl/lib/
}

function build_rust() {
    echo "** Building rust"

    cd "${BUILD_DIR}"
    if [ ! -d "${BUILD_DIR}/rust" ]; then
        curl "https://static.rust-lang.org/dist/rustc-${RUST_VERSION}-src.tar.gz" | tar xzf -
        mv "rustc-${RUST_VERSION}-src" rust

        cd rust

        ./configure \
            --disable-docs \
            --target=x86_64-unknown-linux-musl \
            --musl-root=/usr/local/musl/
    else
        cd rust
    fi

    # These environment variables are set from the Dockerfile and control what
    # we build and whether we install the compiler.
    make -j"${CPU_COUNT}" "${RUST_BUILD_TARGET}"
    if [ "x${RUST_BUILD_INSTALL}" == "xtrue" ]; then
        make install
    fi

    # FIXME: temporary fix, make install does not install musl libraries properly
    mkdir -p /usr/local/lib/rustlib/x86_64-unknown-linux-musl/lib
    cp /build/rust/build/x86_64-unknown-linux-gnu/stage2-std/x86_64-unknown-linux-musl/release/deps/* /usr/local/lib/rustlib/x86_64-unknown-linux-musl/lib
    cp /usr/local/musl/lib/* /usr/local/lib/rustlib/x86_64-unknown-linux-musl/lib
}

function install_cargo() {
    echo "** Installing Cargo"

    if [ -f "/usr/local/bin/cargo" ]; then
        return
    fi

    cd "${BUILD_DIR}"
    curl -L "https://static.rust-lang.org/cargo-dist/cargo-nightly-x86_64-unknown-linux-gnu.tar.gz" | tar zxf -
    USER=root ./cargo-nightly-x86_64-unknown-linux-gnu/install.sh
}

function cleanup() {
    if [ "x${RUST_BUILD_CLEAN}" == "xtrue" ]; then
        rm -rf "${BUILD_DIR}"
        apt-get clean
        rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*
    fi
}

function main() {
    mkdir -p "${BUILD_DIR}" && cd "${BUILD_DIR}"

    install_musl
    build_llvm_components
    build_rust
    install_cargo
    cleanup

    echo "** Done"
}

main