Build Web SDK in wasm build tree (#36520)

Author: eyebrowsoffire

BUILD.gn

@@ -12,6 +12,8 @@ import("//third_party/dart/build/dart/copy_tree.gni")
 
 # Whether to build the dartdevc sdk, libraries, and source files
 # required for the flutter web sdk.
+# TODO(jacksongardner): remove this poorly named argument once the recipes stop
+# using it.
 declare_args() {
   full_dart_sdk = false
 }
@@ -44,30 +46,6 @@ config("export_dynamic_symbols") {
   }
 }
 
-if (flutter_prebuilt_dart_sdk) {
-  copy_trees("_copy_trees") {
-    sources = [
-      {
-        target = "copy_dart_sdk"
-        visibility = [ ":dart_sdk" ]
-        source = prebuilt_dart_sdk
-        dest = "$root_out_dir/dart-sdk"
-        ignore_patterns = "{}"
-      },
-    ]
-  }
-}
-
-group("dart_sdk") {
-  if (build_engine_artifacts) {
-    if (flutter_prebuilt_dart_sdk) {
-      public_deps = [ ":copy_dart_sdk" ]
-    } else {
-      public_deps = [ "//third_party/dart:create_sdk" ]
-    }
-  }
-}
-
 group("flutter") {
   testonly = true
 
@@ -96,7 +74,7 @@ group("flutter") {
 
     if (build_engine_artifacts) {
       public_deps += [
-        ":dart_sdk",
+        "//flutter/dart_sdk",
         "//flutter/flutter_frontend_server:frontend_server",
 
         # This must be listed explicitly for desktop cross-builds since

build/archives/BUILD.gn

@@ -220,13 +220,6 @@ if (build_engine_artifacts && !flutter_prebuilt_dart_sdk) {
   }
 }
 
-# Archives Flutter Web SDK
-if (!is_fuchsia) {
-  group("flutter_web_sdk") {
-    deps = [ "//flutter/web_sdk:flutter_web_sdk_archive" ]
-  }
-}
-
 # Archives Flutter Windows Artifacts
 if (host_os == "win") {
   zip_bundle("windows_flutter") {

ci/builders/linux_host_engine.json

@@ -64,7 +64,7 @@
                     "flutter/build/archives:embedder",
                     "flutter/build/archives:flutter_patched_sdk",
                     "flutter/build/archives:dart_sdk_archive",
-                    "flutter/build/archives:flutter_web_sdk",
+                    "flutter/web_sdk",
                     "flutter/tools/font-subset",
                     "flutter/shell/platform/linux:flutter_gtk"
                 ]
@@ -151,8 +151,7 @@
                 "targets": [
                     "flutter:unittests",
                     "flutter/build/archives:flutter_patched_sdk",
-                    "flutter/shell/platform/linux:flutter_gtk",
-                    "flutter/build/archives:flutter_web_sdk"
+                    "flutter/shell/platform/linux:flutter_gtk"
                 ]
             },
             "tests": [

common/config.gni

@@ -22,6 +22,8 @@ declare_args() {
 
   # Whether to use a prebuilt Dart SDK instead of building one.
   flutter_prebuilt_dart_sdk = false
+
+  build_flutter_web_sdk = false
 }
 
 # feature_defines_list ---------------------------------------------------------
@@ -114,7 +116,7 @@ if (flutter_prebuilt_dart_sdk) {
   # There is no prebuilt Dart SDK targeting Fuchsia, but we also don't need
   # one, so even when the build is targeting Fuchsia, use the prebuilt
   # Dart SDK for the host.
-  if (current_toolchain == host_toolchain || is_fuchsia) {
+  if (current_toolchain == host_toolchain || is_fuchsia || is_wasm) {
     prebuilt_dart_sdk = host_prebuilt_dart_sdk
     prebuilt_dart_sdk_config = _host_prebuilt_dart_sdk_config
   } else {

dart_sdk/BUILD.gn

@@ -0,0 +1,24 @@
+import("//flutter/common/config.gni")
+import("//third_party/dart/build/dart/copy_tree.gni")
+
+if (flutter_prebuilt_dart_sdk) {
+  copy_trees("_copy_trees") {
+    sources = [
+      {
+        target = "copy_dart_sdk"
+        visibility = [ ":dart_sdk" ]
+        source = prebuilt_dart_sdk
+        dest = "$root_out_dir/dart-sdk"
+        ignore_patterns = "{}"
+      },
+    ]
+  }
+}
+
+group("dart_sdk") {
+  if (flutter_prebuilt_dart_sdk) {
+    public_deps = [ ":copy_dart_sdk" ]
+  } else {
+    public_deps = [ "//third_party/dart:create_sdk" ]
+  }
+}

lib/web_ui/dev/build.dart

@@ -3,7 +3,7 @@
 // found in the LICENSE file.
 
 import 'dart:async';
-import 'dart:io' show Directory, Platform;
+import 'dart:io' show Directory;
 
 import 'package:args/command_runner.dart';
 import 'package:path/path.dart' as path;
@@ -25,6 +25,7 @@ class BuildCommand extends Command<bool> with ArgUtils<bool> {
       'build-canvaskit',
       help: 'Build CanvasKit locally instead of getting it from CIPD. Disabled '
           'by default.',
+      defaultsTo: true
     );
   }
 
@@ -42,15 +43,9 @@ class BuildCommand extends Command<bool> with ArgUtils<bool> {
   FutureOr<bool> run() async {
     final FilePath libPath = FilePath.fromWebUi('lib');
     final List<PipelineStep> steps = <PipelineStep>[
-      GnPipelineStep(),
-      NinjaPipelineStep(target: environment.engineBuildDir),
+      GnPipelineStep(buildCanvasKit: buildCanvasKit),
+      NinjaPipelineStep(target: environment.wasmReleaseOutDir),
     ];
-    if (buildCanvasKit) {
-      steps.addAll(<PipelineStep>[
-        GnPipelineStep(target: 'canvaskit'),
-        NinjaPipelineStep(target: environment.wasmReleaseOutDir),
-      ]);
-    }
     final Pipeline buildPipeline = Pipeline(steps: steps);
     await buildPipeline.run();
 
@@ -73,39 +68,24 @@ class BuildCommand extends Command<bool> with ArgUtils<bool> {
 /// Not safe to interrupt as it may leave the `out/` directory in a corrupted
 /// state. GN is pretty quick though, so it's OK to not support interruption.
 class GnPipelineStep extends ProcessStep {
-  GnPipelineStep({this.target = 'engine'})
-      : assert(target == 'engine' || target == 'canvaskit');
+  GnPipelineStep({required this.buildCanvasKit});
+
+  final bool buildCanvasKit;
 
   @override
   String get description => 'gn';
 
   @override
   bool get isSafeToInterrupt => false;
 
-  /// The target to build with gn.
-  ///
-  /// Acceptable values: engine, canvaskit
-  final String target;
-
   @override
   Future<ProcessManager> createProcess() {
-    print('Running gn for $target...');
-    final List<String> gnArgs = <String>[];
-    if (target == 'engine') {
-      gnArgs.addAll(<String>[
-        '--unopt',
-        if (Platform.isMacOS) '--xcode-symlinks',
-        '--full-dart-sdk',
-        if (environment.isMacosArm) '--mac-cpu=arm64',
-      ]);
-    } else if (target == 'canvaskit') {
-      gnArgs.addAll(<String>[
-        '--wasm',
-        '--runtime-mode=release',
-      ]);
-    } else {
-      throw StateError('Target was not engine or canvaskit: $target');
-    }
+    print('Running gn...');
+    final List<String> gnArgs = <String>[
+      '--web',
+      '--runtime-mode=release',
+      if (buildCanvasKit) '--build-canvaskit',
+    ];
     return startProcess(
       path.join(environment.flutterDirectory.path, 'tools', 'gn'),
       gnArgs,

lib/web_ui/dev/environment.dart

@@ -20,21 +20,17 @@ Environment? _environment;
 class Environment {
   factory Environment() {
     final bool isMacosArm = ffi.Abi.current() == ffi.Abi.macosArm64;
+    final io.File dartExecutable = io.File(io.Platform.resolvedExecutable);
     final io.File self = io.File.fromUri(io.Platform.script);
+
     final io.Directory engineSrcDir = self.parent.parent.parent.parent.parent;
     final io.Directory engineToolsDir =
         io.Directory(pathlib.join(engineSrcDir.path, 'flutter', 'tools'));
     final io.Directory outDir =
         io.Directory(pathlib.join(engineSrcDir.path, 'out'));
-    final io.Directory engineBuildDir =
-        io.Directory(pathlib.join(
-          outDir.path,
-          isMacosArm ? 'host_debug_unopt_arm64' : 'host_debug_unopt'
-        ));
     final io.Directory wasmReleaseOutDir =
         io.Directory(pathlib.join(outDir.path, 'wasm_release'));
-    final io.Directory dartSdkDir =
-        io.Directory(pathlib.join(engineBuildDir.path, 'dart-sdk'));
+    final io.Directory dartSdkDir = dartExecutable.parent.parent;
     final io.Directory webUiRootDir = io.Directory(
         pathlib.join(engineSrcDir.path, 'flutter', 'lib', 'web_ui'));
 
@@ -55,7 +51,6 @@ class Environment {
       engineSrcDir: engineSrcDir,
       engineToolsDir: engineToolsDir,
       outDir: outDir,
-      engineBuildDir: engineBuildDir,
       wasmReleaseOutDir: wasmReleaseOutDir,
       dartSdkDir: dartSdkDir,
     );
@@ -68,7 +63,6 @@ class Environment {
     required this.engineSrcDir,
     required this.engineToolsDir,
     required this.outDir,
-    required this.engineBuildDir,
     required this.wasmReleaseOutDir,
     required this.dartSdkDir,
   });
@@ -93,9 +87,6 @@ class Environment {
   /// This is where you'll find the ninja output, such as the Dart SDK.
   final io.Directory outDir;
 
-  /// The output directory for the host_debug_unopt build.
-  final io.Directory engineBuildDir;
-
   /// The output directory for the wasm_release build.
   ///
   /// We build CanvasKit in release mode to reduce code size.

tools/gn

@@ -21,6 +21,8 @@ SRC_ROOT = os.path.dirname(
 def get_out_dir(args):
   if args.target_os is not None:
     target_dir = [args.target_os]
+  elif args.web:
+    target_dir = ['wasm']
   else:
     target_dir = ['host']
 
@@ -251,10 +253,15 @@ def to_gn_args(args):
 
   # If building for WASM, set the GN args using 'to_gn_wasm_args' as most
   # of the Flutter SDK specific arguments are unused.
-  if args.target_os == 'wasm':
+  if args.target_os == 'wasm' or args.web:
     to_gn_wasm_args(args, gn_args)
     return gn_args
 
+  gn_args['build_flutter_web_sdk'] = args.build_web_sdk
+  gn_args['full_dart_sdk'] = args.full_dart_sdk
+  if args.build_web_sdk or args.full_dart_sdk:
+    gn_args['build_canvaskit'] = args.build_canvaskit
+
   if args.enable_unittests:
     gn_args['enable_unittests'] = args.enable_unittests
 
@@ -359,7 +366,6 @@ def to_gn_args(args):
   gn_args['embedder_for_target'] = args.embedder_for_target
   gn_args['dart_lib_export_symbols'] = False
   gn_args['flutter_runtime_mode'] = runtime_mode
-  gn_args['full_dart_sdk'] = args.full_dart_sdk
   gn_args['dart_version_git_info'] = not args.no_dart_version_git_info
 
   gn_args['dart_lib_export_symbols'] = False
@@ -627,6 +633,12 @@ def to_gn_wasm_args(args, gn_args):
   gn_args['skia_canvaskit_enable_webgpu'] = False
   is_profile_build = args.runtime_mode == 'profile' or args.runtime_mode == 'debug'
   gn_args['skia_canvaskit_profile_build'] = is_profile_build
+  gn_args['flutter_prebuilt_dart_sdk'] = True
+
+  # TODO(jacksongardner): Make this based off of the input argument rather
+  # than forced to true, once the recipes are updated.
+  gn_args['build_canvaskit'] = True
+  gn_args['build_flutter_web_sdk'] = True
 
 
 def parse_args(args):
@@ -702,6 +714,7 @@ def parse_args(args):
   parser.add_argument(
       '--wasm', dest='target_os', action='store_const', const='wasm'
   )
+  parser.add_argument('--web', action='store_true', default=False)
   parser.add_argument(
       '--windows', dest='target_os', action='store_const', const='win'
   )
@@ -825,6 +838,27 @@ def parse_args(args):
       '--no-full-dart-sdk', dest='full_dart_sdk', action='store_false'
   )
 
+  parser.add_argument(
+      '--build-web-sdk',
+      default=False,
+      action='store_true',
+      help='build the flutter web sdk'
+  )
+  parser.add_argument(
+      '--no-build-web-sdk', dest='build_web_sdk', action='store_false'
+  )
+
+  parser.add_argument(
+      '--build-canvaskit',
+      default=False,
+      action='store_true',
+      help='build canvaskit from source'
+  )
+
+  parser.add_argument(
+      '--no-build-canvaskit', dest='build_canvaskit', action='store_false'
+  )
+
   parser.add_argument(
       '--ide',
       default='',
@@ -968,16 +1002,17 @@ def main(argv):
       '--export-compile-commands',
   ]
 
-  if args.ide != '':
-    command.append('--ide=%s' % args.ide)
-  elif sys.platform == 'darwin':
-    # On the Mac, generate an Xcode project by default.
-    command.append('--ide=xcode')
-    command.append('--xcode-project=flutter_engine')
-    command.append('--xcode-build-system=new')
-  elif sys.platform.startswith('win'):
-    # On Windows, generate a Visual Studio project.
-    command.append('--ide=vs')
+  if args.target_os != 'wasm':
+    if args.ide != '':
+      command.append('--ide=%s' % args.ide)
+    elif sys.platform == 'darwin':
+      # On the Mac, generate an Xcode project by default.
+      command.append('--ide=xcode')
+      command.append('--xcode-project=flutter_engine')
+      command.append('--xcode-build-system=new')
+    elif sys.platform.startswith('win'):
+      # On Windows, generate a Visual Studio project.
+      command.append('--ide=vs')
 
   command.append('--export-compile-commands=default')
 

wasm/BUILD.gn

@@ -6,7 +6,11 @@
 # //flutter/BUILD.gn pulls in Flutter SDK dependencies which will crash
 # when the target CPU is WASM.
 
+import("//flutter/common/config.gni")
+
 # This is the default target when building when the target CPU is WASM.
 group("wasm") {
-  deps = [ "//third_party/skia/modules/canvaskit" ]
+  if (build_flutter_web_sdk) {
+    deps = [ "//flutter/web_sdk" ]
+  }
 }