# Copyright 2018 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.

import("//build/dart/dart_library.gni")
import("//build/dart/toolchain.gni")

_compiler_label = "//topaz/runtime/dart:kernel_compiler($host_toolchain)"
_compiler_path = get_label_info(_compiler_label, "root_out_dir") +
                 "/dart-tools/kernel_compiler"

# Generates dill files for a Dart application
#
# Parameters
#
#  platform_deps (required)
#    Dependent targets that populate `platform_path` with the platform dill
#    files.
#
#  sources_required (optional)
#    Whether complete source files are required by the rule. If true, all
#    files under the source_dir must be included in sources.
#    Defaults to false.
#
#  platform_path (required)
#    Path to the build output directory containing the platform dill files.
#
#  platform_name (required)
#    The name of the platform, either "flutter_runner" or "dart_runner".
#
#  main_dart (required)
#    Path to Dart source file containing main().
#
#  package_name (optional)
#    The name of the dart package. If not provided it will be inferred from the
#    target name.
#
#  sources (optional)
#    A list of the application's Dart source files.
#
#  manifest (optional)
#    Path to an output manifest file containing the list of partial dill files.
#
#  product (optional)
#    Whether this is a product build. Defaults to false.
#
#  aot (optional)
#    Whether this is an AOT build. Defaults to false.
#
#  args (optional)
#    A list of additional arguments to the compiler.dart program in this
#    directory that generates the kernel files.
#
#  gen_bytecode (optional)
#    Whether the kernel compiler should generate bytecode. Defaults to false.
#
#  Forwarded to dart_library:
#    deps, disable_analysis, non_dart_deps, source_dir.
template("dart_kernel") {
  assert(defined(invoker.platform_deps), "dart_kernel() requires platform_deps")
  assert(defined(invoker.platform_path), "dart_kernel() requires platform_path")
  assert(defined(invoker.platform_name), "dart_kernel() requires platform_name")
  assert(defined(invoker.main_dart), "dart_kernel() requires main_dart")

  args = []
  if (defined(invoker.args)) {
    args += invoker.args
  }

  aot = false
  if (defined(invoker.aot) && invoker.aot) {
    aot = invoker.aot
  }
  product = false
  if (defined(invoker.product) && invoker.product) {
    product = invoker.product
  }

  dart_library_target_name = "${target_name}_dart_library"
  dart_library(dart_library_target_name) {
    forward_variables_from(invoker,
                           [
                             "deps",
                             "package_root",
                             "disable_analysis",
                             "non_dart_deps",
                             "source_dir",
                           ])

    if (defined(invoker.package_name)) {
      package_name = invoker.package_name
    } else {
      infer_package_name = true
    }
    if (defined(invoker.sources_required)) {
      sources_required = invoker.sources_required
    }

    sources = []
    if (defined(invoker.sources)) {
      sources += invoker.sources
    }
    extra_sources = [ invoker.main_dart ]
  }

  # TODO(tvolkert): Name this ${target_name}
  action("${target_name}_kernel") {
    pool = "//build/dart:dart_pool($dart_toolchain)"
    forward_variables_from(invoker,
                           [
                             "testonly",
                             "visibility",
                           ])

    kernel_path = "$target_gen_dir/${target_name}.dil"

    depfile = "${kernel_path}.d"
    deps = invoker.platform_deps + [
             ":$dart_library_target_name",
             _compiler_label,
           ]
    outputs = [
      kernel_path,
    ]
    if (defined(invoker.manifest)) {
      outputs += [
        # Explicit output when using --manifest.
        invoker.manifest,

        # Implicit output when using --manifest; see createManifest in compiler.dart.
        invoker.manifest + ".dilplist",
        invoker.manifest + ".frameworkversion",
      ]
    }

    dart_target_gen_dir =
        get_label_info(":bogus($dart_toolchain)", "target_gen_dir")
    rebased_packages_path =
        rebase_path("$dart_target_gen_dir/$dart_library_target_name.packages",
                    "//")

    multi_root_scheme = "fuchsia-source"

    script = _compiler_path
    args += [
             # TODO(https://github.com/dart-lang/sdk/issues/36639):
             # Remove when new constant eval supports dilp files.
             "--enable-experiment=no-constant-update-2018",

             "--target",
             invoker.platform_name,
             "--platform",
             rebase_path("${invoker.platform_path}/platform_strong.dill"),
             "--filesystem-scheme",
             multi_root_scheme,
             "--filesystem-root",
             rebase_path("//"),
             "--packages",
             "$multi_root_scheme:///$rebased_packages_path",
             "--depfile",
             rebase_path(depfile, root_build_dir),
             "--output",
             rebase_path(kernel_path, root_build_dir),
             "--no-link-platform",
           ]
    if (defined(invoker.manifest)) {
      args += [
        "--split-output-by-packages",
        "--manifest",
        rebase_path(invoker.manifest),
      ]
    }
    if (is_debug) {
      args += [ "--embed-sources" ]
    } else {
      args += [ "--no-embed-sources" ]
    }

    if (aot) {
      args += [
        "--aot",
        "--tfa",
      ]
    }

    if (product) {
      # Setting this flag in a non-product release build for AOT (a "profile"
      # build) causes the vm service isolate code to be tree-shaken from an app.
      # See the pragma on the entrypoint here:
      #
      # https://github.com/dart-lang/sdk/blob/master/runtime/bin/vmservice/vmservice_io.dart#L240
      #
      # Also, this define excludes debugging and profiling code from Flutter.
      args += [
        "-Ddart.vm.product=true",
      ]
    } else {
      if (!is_debug) {
        # The following define excludes debugging code from Flutter.
        args += [
          "-Ddart.vm.profile=true",
        ]
      }
    }

    if (defined(invoker.gen_bytecode) && invoker.gen_bytecode) {
      args += [ "--gen-bytecode", "--drop-ast" ]
    }

    rebased_main_dart = rebase_path(invoker.main_dart, "//")
    args += [ "$multi_root_scheme:///$rebased_main_dart" ]
  }
}