pants_venv

#!/usr/bin/env bash
# Copyright 2014 Pants project contributors (see CONTRIBUTORS.md).
# Licensed under the Apache License, Version 2.0 (see LICENSE).

REPO_ROOT=$(cd "$(dirname "${BASH_SOURCE[0]}")" && cd .. && pwd -P)

# shellcheck source=build-support/common.sh
source "${REPO_ROOT}/build-support/common.sh"

REQUIREMENTS=(
  "${REPO_ROOT}/3rdparty/python/requirements.txt"
)

platform=$(uname -mps)

function venv_dir() {
  # Include the entire version string in order to differentiate e.g. PyPy from CPython.
  # Fingerprinting uname and python output avoids shebang length limits and any odd chars.
  venv_fingerprint=$( (
    echo "${platform}"
    ${PY} --version
  ) | fingerprint_data)

  # NB: We house these outside the working copy to avoid needing to gitignore them, but also to
  # dodge https://github.com/hashicorp/vagrant/issues/12057.
  echo "${HOME}/.cache/pants/pants_dev_deps/${venv_fingerprint}.venv"
}

function activate_venv() {
  # Because the venv/bin/activate script's location is dynamic and not located in a fixed
  # place, Shellcheck will not be able to find it so we tell Shellcheck to ignore the file.
  # shellcheck source=/dev/null
  source "$(venv_dir)/bin/activate"
}

function create_venv() {
  rm -rf "$(venv_dir)"
  "${PY}" -m venv "$(venv_dir)" && "$(venv_dir)/bin/pip" install wheel
}

function ensure_gcc() {
  if ! GCC_VERSION="$(gcc -v 2>&1)"; then
    die "$(
      cat << MESSAGE
ERROR: unable to execute 'gcc'. Please verify that your compiler is installed, in your
       \$PATH and functional.

Hint: on macOS, you may need to accept the XCode EULA: 'sudo xcodebuild -license accept'.
MESSAGE
    )"
  fi
  # Prevent bootstrapping failure due to unrecognized flag:
  # https://github.com/pantsbuild/pants/issues/78
  if [[ "$GCC_VERSION" == *503.0.38* ]]; then
    # Required for clang version 503.0.38
    export ARCHFLAGS=-Wno-error=unused-command-line-argument-hard-error-in-future
  fi
}

function activate_pants_venv() {
  # Allow for multiple calls to `activate_pants_venv`.
  if [[ -n "${VENV_ACTIVATED_FOR_PANTS:-}" ]]; then
    return
  else
    export VENV_ACTIVATED_FOR_PANTS="true"
  fi

  fingerprint=""
  for req in "${REQUIREMENTS[@]}"; do
    fingerprint="${fingerprint}$(fingerprint_data < "${req}")"
  done
  fingerprint=$(echo "${fingerprint}" | fingerprint_data)

  BOOTSTRAPPED_FILE="$(venv_dir)/BOOTSTRAPPED.${fingerprint}"

  if ! [ -f "${BOOTSTRAPPED_FILE}" ]; then
    log "Bootstrapping pants_deps with requirements:"
    # Use -f ${REPO_ROOT}/third_party if patching in local dependencies like so:
    #
    #   pip_extra=(-f "${REPO_ROOT}/third_party")
    #
    pip_extra=()

    for req in "${REQUIREMENTS[@]}"; do
      log "  ${req}"
    done

    create_venv || die "Failed to create venv."
    activate_venv || die "Failed to activate venv."

    # Needed for compilation of native python distributions.
    ensure_gcc

    for req in "${REQUIREMENTS[@]}"; do
      # NB: For the pip_extra reference, see:
      #   https://stackoverflow.com/questions/7577052/bash-empty-array-expansion-with-set-u
      pip install "${pip_extra[@]+"${pip_extra[@]}"}" -r "${req}" ||
        die "Failed to install requirements from ${req}."
    done
    touch "${BOOTSTRAPPED_FILE}"
  else
    activate_venv || die "Failed to activate venv."
  fi
}