#!/bin/bash
# Copyright 2019 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.

### set up a build directory (EXPERIMENTAL)

## usage: fx set PRODUCT.BOARD [--with GNLABEL1,GNLABEL2,...]
##               [--release] [--build-dir BUILDDIR]
##               [--args ARG] [--help-args [ARG]] [--variant VARIANT]
##               [--with-base GNLABEL1,GNLABEL2,...]
##
## where PRODUCT is an entry from `//products` or `//vendor/*/products` and
## BOARD is an entry from `//boards` or `//vendor/*/boards`. Use the
## `fx list-products` and `fx list-boards` commands to see a list of
## possible products and boards (respectively). See the README.md in those
## directories for a description of the various options.
##
## BUILDDIR is the directory where the build output goes.
## If it begins with `//` or `out/` then it's taken as relative to FUCHSIA_DIR.
## Otherwise it should be an absolute path or a path relative to the current
## working directory that winds up in `FUCHSIA_DIR/out`.
## It defaults to `out/default`.
##
## This command store the location of the build directory in the //.config file,
## which causes subsequent `fx` commands to use that build directory. Use
## `fx use` to switch build directories.
##
## Ensures Goma is ready (if Goma is enabled).
##
## This is a wrapper around running `gn gen --check BUILDDIR --args ...`.
## If GN fails with an error, `fx set` does not change anything.
##
## optional arguments:
##   --with GNLABEL        Labels of additional packages to include in the
##                         universe of available packages. These packages can
##                         be run ephemerally. Multiple labels can be provided
##                         delimited by commas or the --with argument can be
##                         provided multiple times.
##   --variant             Selects which runtime variant to use (e.g., asan) by
##                         passing a `select_variant=[VARIANT*,...]` argument
##                         to gn that collects all the --variant arguments in
##                         order. Variants are normal builds in most respects,
##                         but allow users to test different runtime settings
##                         for either the whole build or for a specific target.
##                         This can be specified by passing the variant name
##                         to this argument (e.g. `--variant asan`) for the
##                         former, or the variant name and the target name
##                         separated by a slash (e.g. `--variant asan/my_test`)
##                         for the latter.
##   --fuzz-with           Pass a sanitizer name, e.g. "--fuzz-with asan" to
##                         enable ALL supporting fuzzers.  Use --variant for
##                         individual fuzzers, e.g. "--variant asan-fuzzer/foo".
##   --args                Additional argument to pass to gn.  If the --args
##                         argument is given multiple times, all the specified
##                         arguments are passed to gn.
##                         N.B. Arguments must be expressed using GN's syntax.
##                         In particular this means that for strings they must
##                         be quoted with double-quotes, and the quoting must
##                         survive, for example, the shell. Thus when passing
##                         an argument that takes a string, pass it with
##                         something like --args=foo='"bar"'. E.g.,
##                         bash$ fx set core.x64 --args=foo='"bar"'
##                         More complicated arguments, e.g., lists, require
##                         their own special syntax. See GN documentation
##                         for the syntax of each kind of argument.
##   --netboot             Ensure that a network ramboot image is always built.
##   --help-args           Display GN arguments documentation.  If --help-args
##                         is followed by a GN build argument identifier, just
##                         that argument's documentation is displayed.
##                         If --help-args is used alone, all GN build arguments
##                         are displayed (lots of output).
##                         This option requires an existing build directory.
##   --goma|--no-goma      Whether to use the goma service during the build. Goma
##                         attempts to make builds faster using remote build
##                         servers. Defaults to detecting whether goma is installed
##                         on your machine.
##   --no-ensure-goma      Skip ensuring that goma is started when using goma.
##   --goma-dir            The directory where goma is installed. Defaults to
##                         ~/goma.
##   --ccache|--no-ccache  Whether to use ccache during the build. Ccache attempts
##                         to make builds faster by caching build artifacts.
##                         Defaults to detecting whether the CCACHE_DIR environment
##                         variable is set to a directory.
##   --ide                 Pass --ide=VALUE to gn when generating to create project
##                         files usable with that IDE. Useful values include "vs"
##                         for Visual Studio or "xcode" for Xcode.
##   --release             an alias for "--args=is_debug=false"
##   --with-base GNLABEL   Labels of additional packages to include in the
##                         base set of packages. These packages are included in
##                         the system image and can be updated only with an OTA.
##                         Multiple labels can be provided delimited by commas
##                         or the --with-base argument can be provided multiple
##                         times.
##
## Example:
##
##   $ fx set core.x64 --with //bundles:tests
##   -> build directory: out/default
##      board: //boards/x64.gni
##      product: //products/core.gni
##      universe: //bundles:tests (all test packages)

source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/lib/vars.sh || exit $?

set -e

function find_config {
  local config_type="$1"
  local config_name="$2"

  for directory in vendor/*/"${config_type}" "${config_type}"; do
    local guessed_config="${directory}/${config_name}.gni"
    if [[ -a "${guessed_config}" ]]; then
      echo "${guessed_config}"
      return
    fi
  done

  fx-error "Could not find a ${config_type} configuration matching \"${config_name}\""
  fx-error "Checked:"
  for directory in vendor/*/"${config_type}" "${config_type}"; do
    local guessed_config="${directory}/${config_name}.gni"
    fx-error "  ${guessed_config}"
  done
  exit 1
}

function explain-goal-argument {
  fx-error You must specify which product and which board you wish to build.
  fx-error Example:
  fx-error "  fx set core.x64"
  fx-error
  fx-error Run \"fx list-products\" to see the available products.
  fx-error Run \"fx list-boards\" to see the available boards.
  fx-error Run \"fx set --help\" to see full usage.
  return 0
}

function main {
  fx-standard-switches "$@"
  set -- "${FX_ARGV[@]}"

  if [[ $# -lt 1 ]]; then
      fx-error Missing an explicit PRODUCT.BOARD goal.
      explain-goal-argument
      return 1
  fi

  cd "${FUCHSIA_DIR}"

  local gn_args=""
  case "$1" in
    *.*)
      local product_name="${1%.*}"
      local board_name="${1##*.}"
      local product="$(find_config "products" "${product_name}")"
      local board="$(find_config "boards" "${board_name}")"
      gn_args+=" import(\"//${board}\") import(\"//${product}\")"
      ;;
    *)
      fx-error Unable to parse PRODUCT.BOARD goal \"$1\"
      explain-goal-argument
      return 1
      ;;
  esac
  shift

  local gn_args+=" allow_layer_guesswork=false"

  local gn_cmd='gen'
  local -a gn_switches=(--check)
  local gn_after_args=""
  local base=()
  local universe=()
  local zircon_args=(-v -g)
  local build_dir=
  local variant=
  local use_goma
  local goma_dir
  local ensure_goma=1
  local ccache
  while [[ $# -ne 0 ]]; do
    case "$1" in
      --with-base)
        if [[ $# -lt 2 ]]; then
          fx-command-help
          return 1
        fi
        IFS=, base+=("$2")
        shift
        ;;
      --with)
        if [[ $# -lt 2 ]]; then
          fx-command-help
          return 1
        fi
        IFS=, universe+=("$2")
        shift
        ;;
      --netboot)
        gn_after_args+=" enable_netboot=true"
        ;;
      --goma)
        use_goma=1
        ;;
      --no-goma)
        use_goma=0
        ;;
      --no-ensure-goma)
        ensure_goma=0
        ;;
      --goma-dir)
        if [[ $# -lt 2 ]]; then
          fx-command-help
          return 1
        fi
        goma_dir=$2
        if [[ ! -d "${goma_dir}" ]]; then
          fx-error "GOMA directory does not exist: ${goma_dir}"
          return 1
        fi
        shift
        ;;
      --build-dir)
        if [[ $# -lt 2 ]]; then
          fx-command-help
          return 1
        fi
        build_dir="$2"
        shift
        ;;
      --release)
        gn_args+=" is_debug=false"
        ;;
      --variant)
        if [[ $# -lt 2 ]]; then
          fx-command-help
          return 1
        fi
        variant+="\"$2\","
        shift
        ;;
      --fuzz-with)
        if [[ $# -lt 2 ]]; then
          fx-command-help
          return 1
        fi
        variant+="{variant=\"$2-fuzzer\" target_type=[\"fuzzed_executable\"]},"
        shift
        ;;
      --args)
        if [[ $# -lt 2 ]]; then
          fx-command-help
          return 1
        fi
        gn_args+=" $2"
        shift
        ;;
      --help-args)
        gn_cmd=args
        if [[ $# -ge 2 ]] && [[ "$2" != '--*' ]]; then
          gn_switches+=("--list=$2")
          shift
        else
          gn_switches+=(--list)
        fi
        ;;
      --ccache)
        ccache=1
        ;;
      --no-ccache)
        ccache=0
        ;;
      --ide)
        if [[ $# -lt 2 ]]; then
          fx-command-help
          return 1
        fi
        gn_switches+=("--ide=$2")
        shift
        ;;
      *)
        fx-error "Unknown argument \"$1\""
        fx-command-help
        return 1
        ;;
    esac
    shift
  done

  # Remove any trailing slash from build directory name.
  build_dir="${build_dir%/}"

  local config_build_dir
  case "$build_dir" in
    '')
      # Default is "//out/default".  Store it as relative.
      config_build_dir="out/default"
      build_dir="${FUCHSIA_DIR}/${config_build_dir}"
      ;;
    //*|out/*)
      # GN-style "source-relative" path or relative out/something.
      config_build_dir="${build_dir#//}"
      build_dir="${FUCHSIA_DIR}/${config_build_dir}"
      ;;
    *)
      fx-error "Invalid build directory: ${build_dir}"
      fx-error "Please specify a build directory as \"out/something\"."
      exit 1
      ;;
  esac

  # If a goma directory wasn't specified explicitly then default to "~/goma".
  if [[ -z "${goma_dir}" ]]; then
    goma_dir="$HOME/goma"
  fi

  # Automatically detect goma and ccache if not specified explicitly.
  if [[ -z "${use_goma}" ]] && [[ -z "${ccache}" ]]; then
    if [[ -d "${goma_dir}" ]]; then
      use_goma=1
    elif [[ -n "${CCACHE_DIR}" ]] && [[ -d "${CCACHE_DIR}" ]]; then
      ccache=1
    fi
  fi

  # Add goma or ccache settings as appropriate.
  if [[ "${use_goma}" -eq 1 ]]; then
    gn_args+=" use_goma=true goma_dir=\"${goma_dir}\""
    zircon_args+=(use_goma=true "goma_dir=\"${goma_dir}\"")
  elif [[ "${ccache}" -eq 1 ]]; then
    gn_args+=" use_ccache=true"
  fi

  gn_args+="
# See: fx args --list=base_package_labels
base_package_labels+=["

  for package in ${base[@]}; do
    gn_args+="\"${package}\","
  done
  gn_args+="]

# See: fx args --list=cache_package_labels
cache_package_labels+=[]

# See: fx args --list=universe_package_labels
universe_package_labels+=["

  for package in ${universe[@]}; do
    gn_args+="\"${package}\","
  done
  gn_args+="]"

  if [[ -n "${variant}" ]]; then
    gn_args+=" select_variant=[${variant}]"
  fi

  gn_args+="${gn_after_args}"

  # Zircon's `gn gen` phase has to be done before Fuchsia's `gn gen`.
  # The former produces the legacy-$cpu.json file consumed by the latter.
  "${FUCHSIA_DIR}/scripts/build-zircon.sh" "${zircon_args[@]}"
  "${FUCHSIA_DIR}/buildtools/gn" ${gn_cmd} "${build_dir}" \
                                  "${gn_switches[@]}" --args="${gn_args}" "$@"

  fx-config-write "${config_build_dir}"

  if [[ "${use_goma}" -eq 1 ]] && [[ "${ensure_goma}" -eq 1 ]]; then
    if ! [[ $("${goma_dir}/gomacc" port) =~ ^[0-9]+$ ]]; then
      "${goma_dir}/goma_ctl.py" ensure_start || return $?
    fi
  fi
}

main "$@"