devshell/build

#!/bin/bash
# Copyright 2017 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

### build Fuchsia

## usage: fx build [ninja option,...] [target,...]

source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"/lib/vars.sh
fx-config-read

function main {
  local args=()
  local have_load=false
  local have_jobs=false
  while [[ $# -gt 0 ]]; do
    case "$1" in
    -l) have_load=true ;;
    -j) have_jobs=true ;;
    esac
    args+=("$1")
    shift
  done

  if ! $have_load; then
    if [[ "$(uname -s)" == "Darwin" ]]; then
      # Load level on Darwin is quite different from that of Linux, wherein a
      # load level of 1 per CPU is not necessarily a prohibitive load level. An
      # unscientific study of build side effects suggests that cpus*20 is a
      # reaosnable value to prevent catastrophic load (i.e. user can not kill
      # the build, can not lock the screen, etc).
      local cpus="$(fx-cpu-count)"
      args=("-l" $(($cpus * 20)) "${args[@]}")
    fi
  fi

  if ! $have_jobs; then
    local concurrency="$(fx-choose-build-concurrency)"
    # macOS in particular has a low default for number of open file descriptors
    # per process, which is prohibitive for higher job counts. Here we raise
    # the number of allowed file descriptors per process if it appears to be
    # low in order to avoid failures due to the limit. See `getrlimit(2)` for
    # more information.
    local min_limit=$((${concurrency} * 2))
    if [[ $(ulimit -n) -lt "${min_limit}" ]]; then
      ulimit -n "${min_limit}"
    fi
    args=("-j" "${concurrency}" "${args[@]}")
  fi


  # TERM is passed for the pretty ninja UI
  # PATH is passed as some tools are referenced via $PATH due to platform differences.
  # TMPDIR is passed for Goma on macOS. TMPDIR must be set, or unset, not
  # empty. Some Dart build tools have been observed writing into source paths
  # when TMPDIR="" - it is deliberately unquoted and using the ${+} expansion
  # expression).
  fx-try-locked env -i TERM="${TERM}" PATH="${PATH}" \
    ${NINJA_STATUS+"NINJA_STATUS=${NINJA_STATUS}"} \
    ${TMPDIR+"TMPDIR=$TMPDIR"} \
    "${FUCHSIA_DIR}/buildtools/ninja" -C "${FUCHSIA_BUILD_DIR}" "${args[@]}"
}

main "$@"