#!/usr/bin/env bash

set -ue

function usage() {
  cat <<EOM
$(basename ${0}) [-h|--help] --libcxx-root <LIBCXX-ROOT> --libcxxabi-root <LIBCXXABI-ROOT> --std <STD> --arch <ARCHITECTURE> --deployment-target <TARGET> --sdk-version <SDK-VERSION> [--lit-args <ARGS...>]

This script is used to continually test the back-deployment use case of libc++ and libc++abi on MacOS.

  --libcxx-root       Full path to the root of the libc++ repository to test.
  --libcxxabi-root    Full path to the root of the libc++abi repository to test.
  --std               Version of the C++ Standard to run the tests under (c++03, c++11, etc..).
  --arch              Architecture to build the tests for (32, 64).
  --deployment-target The deployment target to run the tests for. This should be a version number of MacOS (e.g. 10.12). All MacOS versions until and including 10.7 are supported.
  --sdk-version       The version of the SDK to test with. This should be a version number of MacOS (e.g. 10.12). We'll link against the libc++ dylib in that SDK, but we'll run against the one on the given deployment target.
  [--lit-args]        Additional arguments to pass to lit (optional). If there are multiple arguments, quote them to pass them as a single argument to this script.
  [--no-cleanup]      Do not cleanup the temporary directory that was used for testing at the end. This can be useful to debug failures. Make sure to clean up manually after.
  [-h, --help]        Print this help.
EOM
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    --libcxx-root)
    LIBCXX_ROOT="${2}"
    if [[ ! -d "${LIBCXX_ROOT}" ]]; then
      echo "--libcxx-root '${LIBCXX_ROOT}' is not a valid directory"
      usage
      exit 1
    fi
    shift; shift
    ;;
    --libcxxabi-root)
    LIBCXXABI_ROOT="${2}"
    if [[ ! -d "${LIBCXXABI_ROOT}" ]]; then
      echo "--libcxxabi-root '${LIBCXXABI_ROOT}' is not a valid directory"
      usage
      exit 1
    fi
    shift; shift
    ;;
    --std)
    STD="${2}"
    shift; shift
    ;;
    --arch)
    ARCH="${2}"
    shift; shift
    ;;
    --deployment-target)
    DEPLOYMENT_TARGET="${2}"
    shift; shift
    ;;
    --sdk-version)
    MACOS_SDK_VERSION="${2}"
    shift; shift
    ;;
    --lit-args)
    ADDITIONAL_LIT_ARGS="${2}"
    shift; shift
    ;;
    --no-cleanup)
    NO_CLEANUP=""
    shift
    ;;
    -h|--help)
    usage
    exit 0
    ;;
    *)
    echo "${1} is not a supported argument"
    usage
    exit 1
    ;;
  esac
done

if [[ -z ${LIBCXX_ROOT+x} ]]; then echo "--libcxx-root is a required parameter"; usage; exit 1; fi
if [[ -z ${LIBCXXABI_ROOT+x} ]]; then echo "--libcxxabi-root is a required parameter"; usage; exit 1; fi
if [[ -z ${STD+x} ]]; then echo "--std is a required parameter"; usage; exit 1; fi
if [[ -z ${ARCH+x} ]]; then echo "--arch is a required parameter"; usage; exit 1; fi
if [[ -z ${DEPLOYMENT_TARGET+x} ]]; then echo "--deployment-target is a required parameter"; usage; exit 1; fi
if [[ -z ${MACOS_SDK_VERSION+x} ]]; then echo "--sdk-version is a required parameter"; usage; exit 1; fi
if [[ -z ${ADDITIONAL_LIT_ARGS+x} ]]; then ADDITIONAL_LIT_ARGS=""; fi


TEMP_DIR="$(mktemp -d)"
echo "Created temporary directory ${TEMP_DIR}"
function cleanup {
  if [[ -z ${NO_CLEANUP+x} ]]; then
    echo "Removing temporary directory ${TEMP_DIR}"
    rm -rf "${TEMP_DIR}"
  else
    echo "Temporary directory is at '${TEMP_DIR}', make sure to clean it up yourself"
  fi
}
trap cleanup EXIT


LLVM_ROOT="${TEMP_DIR}/llvm"
LIBCXX_BUILD_DIR="${TEMP_DIR}/libcxx-build"
LIBCXX_INSTALL_DIR="${TEMP_DIR}/libcxx-install"
LIBCXXABI_BUILD_DIR="${TEMP_DIR}/libcxxabi-build"
LIBCXXABI_INSTALL_DIR="${TEMP_DIR}/libcxxabi-install"

PREVIOUS_DYLIBS_URL="http://lab.llvm.org:8080/roots/libcxx-roots.tar.gz"
LLVM_TARBALL_URL="https://github.com/llvm-mirror/llvm/archive/master.tar.gz"
export CC="$(xcrun --find clang)"
export CXX="$(xcrun --find clang++)"


echo "@@@ Downloading LLVM tarball of master (only used for CMake configuration) @@@"
mkdir "${LLVM_ROOT}"
curl -L "${LLVM_TARBALL_URL}" | tar -xz --strip-components=1 -C "${LLVM_ROOT}"
echo "@@@@@@"


echo "@@@ Configuring architecture-related stuff @@@"
if [[ "${ARCH}" == "64" ]]; then CMAKE_ARCH_STRING="x86_64"; else CMAKE_ARCH_STRING="i386"; fi
if [[ "${ARCH}" == "64" ]]; then LIT_ARCH_STRING="";         else LIT_ARCH_STRING="--param=enable_32bit=true"; fi
echo "@@@@@@"


echo "@@@ Configuring CMake for libc++ @@@"
mkdir -p "${LIBCXX_BUILD_DIR}"
(cd "${LIBCXX_BUILD_DIR}" &&
  xcrun cmake "${LIBCXX_ROOT}" -GNinja \
    -DLLVM_PATH="${LLVM_ROOT}" \
    -DCMAKE_INSTALL_PREFIX="${LIBCXX_INSTALL_DIR}" \
    -DCMAKE_OSX_ARCHITECTURES="${CMAKE_ARCH_STRING}"
)
echo "@@@@@@"


echo "@@@ Configuring CMake for libc++abi @@@"
mkdir -p "${LIBCXXABI_BUILD_DIR}"
(cd "${LIBCXXABI_BUILD_DIR}" &&
  xcrun cmake "${LIBCXXABI_ROOT}" -GNinja \
    -DLIBCXXABI_LIBCXX_PATH="${LIBCXX_ROOT}" \
    -DLLVM_PATH="${LLVM_ROOT}" \
    -DCMAKE_INSTALL_PREFIX="${LIBCXXABI_INSTALL_DIR}" \
    -DCMAKE_OSX_ARCHITECTURES="${CMAKE_ARCH_STRING}"
)
echo "@@@@@@"


echo "@@@ Installing the latest libc++ headers @@@"
ninja -C "${LIBCXX_BUILD_DIR}" install-cxx-headers
echo "@@@@@@"


echo "@@@ Downloading dylibs for older deployment targets @@@"
# TODO: The tarball should contain libc++abi.dylib too, we shouldn't be relying on the system's
# TODO: We should also link against the libc++abi.dylib that was shipped in the SDK
PREVIOUS_DYLIBS_DIR="${TEMP_DIR}/libcxx-dylibs"
mkdir "${PREVIOUS_DYLIBS_DIR}"
curl "${PREVIOUS_DYLIBS_URL}" | tar -xz --strip-components=1 -C "${PREVIOUS_DYLIBS_DIR}"
LIBCXX_ON_DEPLOYMENT_TARGET="${PREVIOUS_DYLIBS_DIR}/macOS/${DEPLOYMENT_TARGET}/libc++.dylib"
LIBCXXABI_ON_DEPLOYMENT_TARGET="/usr/lib/libc++abi.dylib"
LIBCXX_IN_SDK="${PREVIOUS_DYLIBS_DIR}/macOS/${MACOS_SDK_VERSION}/libc++.dylib"
echo "@@@@@@"


# TODO: We need to also run the tests for libc++abi.
# TODO: Make sure lit will actually run against the libc++abi we specified
echo "@@@ Running tests for libc++ @@@"
"${LIBCXX_BUILD_DIR}/bin/llvm-lit" -sv "${LIBCXX_ROOT}/test" \
                                   --param=enable_experimental=false \
                                   --param=enable_filesystem=false \
                                   ${LIT_ARCH_STRING} \
                                   --param=cxx_under_test="${CXX}" \
                                   --param=cxx_headers="${LIBCXX_INSTALL_DIR}/include/c++/v1" \
                                   --param=std="${STD}" \
                                   --param=platform="macosx${DEPLOYMENT_TARGET}" \
                                   --param=cxx_runtime_root="$(dirname "${LIBCXX_ON_DEPLOYMENT_TARGET}")" \
                                   --param=abi_library_path="$(dirname "${LIBCXXABI_ON_DEPLOYMENT_TARGET}")" \
                                   --param=use_system_cxx_lib="$(dirname "${LIBCXX_IN_SDK}")" \
                                   ${ADDITIONAL_LIT_ARGS}
echo "@@@@@@"