build/dart/internal/flutter_snapshot.gni

# Copyright 2013 The Flutter 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/compiled_action.gni")
import("//flutter/build/dart/internal/flutter_frontend_server.gni")
import("//flutter/common/config.gni")

# Creates a dart kernel (dill) file suitable for use with gen_snapshot, as well
# as the app-jit, aot-elf, or aot-assembly snapshot for targeting Flutter on
# Android or iOS.
#
# Invoker must supply dart_main. Invoker may optionally supply package_config,
# which otherwise defaults to the repo-wide pacakge_config, and optionally
# supply aot as a boolean and product as a boolean.
#
# On Android, the invoker may provide output_aot_lib as a string to override
# the default filename for the aot-elf snapshot.
template("flutter_snapshot") {
  assert(!is_fuchsia)
  assert(defined(invoker.main_dart), "main_dart is a required parameter.")

  kernel_target = "_${target_name}_kernel"
  snapshot_target = "_${target_name}_snapshot"
  is_aot =
      flutter_runtime_mode == "profile" || flutter_runtime_mode == "release"

  kernel_output = "$target_gen_dir/kernel_blob.bin"

  extra_frontend_server_args = []
  if (is_aot) {
    extra_frontend_server_args += [
      "--aot",
      "--tfa",
    ]
  } else {
    # --no-link-platform is only valid when --aot isn't specified
    extra_frontend_server_args += [ "--no-link-platform" ]
  }

  if (defined(invoker.product) && invoker.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/main/sdk/lib/_internal/vm/bin/vmservice_io.dart#L240
    #
    # Also, this define excludes debugging and profiling code from Flutter.
    extra_frontend_server_args += [ "-Ddart.vm.product=true" ]
  } else {
    if (flutter_runtime_mode == "profile") {
      # The following define excludes debugging code from Flutter.
      extra_frontend_server_args += [ "-Ddart.vm.profile=true" ]
    }
  }

  if (defined(invoker.package_config)) {
    flutter_frontend_server(kernel_target) {
      main_dart = invoker.main_dart
      package_config = invoker.package_config
      kernel_output = kernel_output
      extra_args = extra_frontend_server_args
    }
  } else {
    flutter_frontend_server(kernel_target) {
      main_dart = invoker.main_dart
      kernel_output = kernel_output
      extra_args = extra_frontend_server_args
    }
  }

  compiled_action(snapshot_target) {
    if (target_cpu == "x86" && host_os == "linux") {
      # By default Dart will create a 32-bit gen_snapshot host binary if the target
      # platform is 32-bit.  Override this to create a 64-bit gen_snapshot for x86
      # targets because some host platforms may not support 32-bit binaries.
      tool = "$dart_src/runtime/bin:gen_snapshot_host_targeting_host"
      toolchain = "//build/toolchain/$host_os:clang_x64"
    } else {
      tool = "$dart_src/runtime/bin:gen_snapshot"
    }

    inputs = [ kernel_output ]
    deps = [ ":$kernel_target" ]
    outputs = []

    args = []

    if (is_debug && flutter_runtime_mode != "profile" &&
        flutter_runtime_mode != "release" &&
        flutter_runtime_mode != "jit_release") {
      args += [ "--enable_asserts" ]
    }

    if (is_aot) {
      args += [ "--deterministic" ]
      if (is_ios) {
        snapshot_assembly = "$target_gen_dir/ios/snapshot_assembly.S"
        outputs += [ snapshot_assembly ]
        args += [
          "--snapshot_kind=app-aot-assembly",
          "--assembly=" + rebase_path(snapshot_assembly),
        ]
      } else if (is_android) {
        if (defined(invoker.output_aot_lib)) {
          output_aot_lib = invoker.output_aot_lib
        } else {
          output_aot_lib = "libapp.so"
        }
        libapp = "$target_gen_dir/android/libs/$android_app_abi/$output_aot_lib"
        outputs += [ libapp ]
        args += [
          "--snapshot_kind=app-aot-elf",
          "--elf=" + rebase_path(libapp),
        ]
      } else {
        assert(false)
      }
    } else {
      deps += [ "//flutter/lib/snapshot:generate_snapshot_bin" ]
      vm_snapshot_data =
          "$root_gen_dir/flutter/lib/snapshot/vm_isolate_snapshot.bin"
      snapshot_data = "$root_gen_dir/flutter/lib/snapshot/isolate_snapshot.bin"
      isolate_snapshot_data = "$target_gen_dir/isolate_snapshot_data"
      isolate_snapshot_instructions = "$target_gen_dir/isolate_snapshot_instr"

      inputs += [
        vm_snapshot_data,
        snapshot_data,
      ]

      outputs += [
        isolate_snapshot_data,
        isolate_snapshot_instructions,
      ]
      args += [
        "--snapshot_kind=app-jit",
        "--load_vm_snapshot_data=" + rebase_path(vm_snapshot_data),
        "--load_isolate_snapshot_data=" + rebase_path(snapshot_data),
        "--isolate_snapshot_data=" + rebase_path(isolate_snapshot_data),
        "--isolate_snapshot_instructions=" +
            rebase_path(isolate_snapshot_instructions),
      ]
    }

    args += [ rebase_path(kernel_output) ]
  }

  group(target_name) {
    public_deps = [
      ":$kernel_target",
      ":$snapshot_target",
    ]
  }
}