Use `dart compile wasm` for wasm compilations (#143298)

* Flags to `dart compile wasm`

Some options are not relevant to a standalone user of `dart compile
wasm` (e.g. specyfing dart-sdk, platform file etc). => Those aren't
offered by the `dart compile wasm` tool directly. => We use the
`--extra-compiler-option=` instead which passes through arbitrary
options to the dart2wasm compiler. => We don't maintain compatibility of
those options, if we update them we'll ensure to also update flutter
tools

* Binaryen optimization passes

This change will mean we use the binaryen flags from Dart SDK which are
slightly different from the ones in flutter.

* Optimization configuration

This change will also start using the more standardized `-O` flag for
determining optimization levels. The meaning of those flags have been
mostly aligned with dart2js (with some differences remaining).

* Minimization

Using the new optimization flags, namely `-O4` for `--wasm-opt=full`,
will automatically enable the new `--minify` support. Minification is
Dart semantics preserving but changes the `<obj>.runtimeType.toString()`
to use minified names (just as in dart2js).

* Code size changes

  Overall this change will reduce wonderous code size by around 10%.

Issue https://github.com/dart-lang/sdk/issues/54675

packages/flutter_tools/lib/src/build_system/targets/web.dart

@@ -249,9 +249,8 @@ class Dart2WasmTarget extends Dart2WebTarget {
     }
     final BuildMode buildMode = BuildMode.fromCliName(buildModeEnvironment);
     final Artifacts artifacts = environment.artifacts;
-    final File outputWasmFile = environment.buildDir.childFile(
-      compilerConfig.runWasmOpt ? 'main.dart.unopt.wasm' : 'main.dart.wasm'
-    );
+    final File outputWasmFile =
+        environment.buildDir.childFile('main.dart.wasm');
     final File depFile = environment.buildDir.childFile('dart2wasm.d');
     final String dartSdkPath = artifacts.getArtifactPath(Artifact.engineDartSdkPath, platform: TargetPlatform.web_javascript);
     final String platformBinariesPath = artifacts.getHostArtifact(HostArtifact.webPlatformKernelFolder).path;
@@ -261,12 +260,16 @@ class Dart2WasmTarget extends Dart2WebTarget {
     );
 
     final List<String> compilationArgs = <String>[
-      artifacts.getArtifactPath(Artifact.engineDartAotRuntime, platform: TargetPlatform.web_javascript),
-      '--disable-dart-dev',
-      artifacts.getArtifactPath(Artifact.dart2wasmSnapshot, platform: TargetPlatform.web_javascript),
+      artifacts.getArtifactPath(Artifact.engineDartBinary, platform: TargetPlatform.web_javascript),
+      'compile',
+      'wasm',
       '--packages=.dart_tool/package_config.json',
-      '--dart-sdk=$dartSdkPath',
-      '--platform=$platformFilePath',
+      '--extra-compiler-option=--dart-sdk=$dartSdkPath',
+      '--extra-compiler-option=--platform=$platformFilePath',
+      if (compilerConfig.renderer == WebRendererMode.skwasm) ...<String>[
+        '--extra-compiler-option=--import-shared-memory',
+        '--extra-compiler-option=--shared-memory-max-pages=32768',
+        ],
       if (buildMode == BuildMode.profile)
         '-Ddart.vm.profile=true'
       else
@@ -274,16 +277,12 @@ class Dart2WasmTarget extends Dart2WebTarget {
       ...decodeCommaSeparated(environment.defines, kExtraFrontEndOptions),
       for (final String dartDefine in dartDefines)
         '-D$dartDefine',
-      ...compilerConfig.toCommandOptions(),
-      if (compilerConfig.renderer == WebRendererMode.skwasm)
-        ...<String>[
-          '--import-shared-memory',
-          '--shared-memory-max-pages=32768',
-        ],
-      '--depfile=${depFile.path}',
+      '--extra-compiler-option=--depfile=${depFile.path}',
 
-      environment.buildDir.childFile('main.dart').path, // dartfile
+      ...compilerConfig.toCommandOptions(),
+      '-o',
       outputWasmFile.path,
+      environment.buildDir.childFile('main.dart').path, // dartfile
     ];
 
     final ProcessUtils processUtils = ProcessUtils(
@@ -295,37 +294,6 @@ class Dart2WasmTarget extends Dart2WebTarget {
       throwOnError: true,
       compilationArgs,
     );
-    if (compilerConfig.runWasmOpt) {
-      final String wasmOptBinary = artifacts.getArtifactPath(
-        Artifact.wasmOptBinary,
-        platform: TargetPlatform.web_javascript
-      );
-      final File optimizedOutput = environment.buildDir.childFile('main.dart.wasm');
-      final List<String> optimizeArgs = <String>[
-        wasmOptBinary,
-        '--all-features',
-        '--closed-world',
-        '--traps-never-happen',
-        '-O3',
-        '--type-ssa',
-        '--gufa',
-        '-O3',
-        '--type-merging',
-        if (compilerConfig.wasmOpt == WasmOptLevel.debug)
-          '--debuginfo',
-        outputWasmFile.path,
-        '-o',
-        optimizedOutput.path,
-      ];
-      await processUtils.run(
-        throwOnError: true,
-        optimizeArgs,
-      );
-
-      // Rename the .mjs file not to have the `.unopt` bit
-      final File jsRuntimeFile = environment.buildDir.childFile('main.dart.unopt.mjs');
-      await jsRuntimeFile.rename(environment.buildDir.childFile('main.dart.mjs').path);
-    }
   }
 
   @override

packages/flutter_tools/lib/src/web/compiler_config.dart

@@ -148,12 +148,23 @@ class WasmCompilerConfig extends WebCompilerConfig {
   @override
   CompileTarget get compileTarget => CompileTarget.wasm;
 
-  bool get runWasmOpt =>
-      wasmOpt == WasmOptLevel.full || wasmOpt == WasmOptLevel.debug;
-
-  List<String> toCommandOptions() => <String>[
-        if (omitTypeChecks) '--omit-type-checks',
-      ];
+  List<String> toCommandOptions() {
+    // -O1: Optimizes
+    // -O2: Same as -O1 but also minifies (still semantics preserving)
+    // -O3: Same as -O2 but also omits implicit type checks.
+    // -O4: Same as -O3 but also omits explicit type checks.
+    //      (NOTE: This differs from dart2js -O4 semantics atm.)
+
+    // Ortogonal: The name section is always kept by default and we emit it only
+    // in [WasmOptLevel.full] mode (similar to `--strip` of static symbols in
+    // AOT mode).
+    final String level = !omitTypeChecks ? '-O2' : '-O4';
+    return switch (wasmOpt) {
+      WasmOptLevel.none => <String>['-O0'],
+      WasmOptLevel.debug => <String>[level, '--no-minify'],
+      WasmOptLevel.full => <String>[level, '--no-name-section'],
+    };
+  }
 
   @override
   Map<String, Object> get buildEventAnalyticsValues => <String, Object>{

packages/flutter_tools/test/general.shard/build_system/targets/web_test.dart

@@ -30,24 +30,12 @@ const List<String> _kDart2jsLinuxArgs = <String>[
 ];
 
 const List<String> _kDart2WasmLinuxArgs = <String> [
-  'Artifact.engineDartAotRuntime.TargetPlatform.web_javascript',
-  '--disable-dart-dev',
-  'Artifact.dart2wasmSnapshot.TargetPlatform.web_javascript',
+  'Artifact.engineDartBinary.TargetPlatform.web_javascript',
+  'compile',
+  'wasm',
   '--packages=.dart_tool/package_config.json',
-  '--dart-sdk=Artifact.engineDartSdkPath.TargetPlatform.web_javascript',
-  '--platform=HostArtifact.webPlatformKernelFolder/dart2wasm_platform.dill',
-];
-
-const List<String> _kWasmOptLinuxArgrs = <String> [
-  'Artifact.wasmOptBinary.TargetPlatform.web_javascript',
-  '--all-features',
-  '--closed-world',
-  '--traps-never-happen',
-  '-O3',
-  '--type-ssa',
-  '--gufa',
-  '-O3',
-  '--type-merging',
+  '--extra-compiler-option=--dart-sdk=Artifact.engineDartSdkPath.TargetPlatform.web_javascript',
+  '--extra-compiler-option=--platform=HostArtifact.webPlatformKernelFolder/dart2wasm_platform.dill',
 ];
 
 void main() {
@@ -920,7 +908,7 @@ void main() {
 
     final File depFile = environment.buildDir.childFile('dart2wasm.d');
 
-    final File outputJsFile = environment.buildDir.childFile('main.dart.unopt.mjs');
+    final File outputJsFile = environment.buildDir.childFile('main.dart.mjs');
     processManager.addCommand(FakeCommand(
       command: <String>[
         ..._kDart2WasmLinuxArgs,
@@ -929,32 +917,23 @@ void main() {
         '-DBAZ=qux',
         '-DFLUTTER_WEB_AUTO_DETECT=false',
         '-DFLUTTER_WEB_USE_SKIA=true',
-        '--depfile=${depFile.absolute.path}',
+        '--extra-compiler-option=--depfile=${depFile.absolute.path}',
+        '-O2',
+        '--no-name-section',
+        '-o',
+        environment.buildDir.childFile('main.dart.wasm').absolute.path,
         environment.buildDir.childFile('main.dart').absolute.path,
-        environment.buildDir.childFile('main.dart.unopt.wasm').absolute.path,
       ],
       onRun: (_) => outputJsFile..createSync()..writeAsStringSync('foo'))
     );
 
-    processManager.addCommand(FakeCommand(
-      command: <String>[
-        ..._kWasmOptLinuxArgrs,
-        environment.buildDir.childFile('main.dart.unopt.wasm').absolute.path,
-        '-o',
-        environment.buildDir.childFile('main.dart.wasm').absolute.path,
-      ])
-    );
-
     await Dart2WasmTarget(
       const WasmCompilerConfig(
         renderer: WebRendererMode.canvaskit
       )
     ).build(environment);
 
-    expect(outputJsFile.existsSync(), isFalse);
-    final File movedJsFile = environment.buildDir.childFile('main.dart.mjs');
-    expect(movedJsFile.existsSync(), isTrue);
-    expect(movedJsFile.readAsStringSync(), 'foo');
+    expect(outputJsFile.existsSync(), isTrue);
   }, overrides: <Type, Generator>{
     ProcessManager: () => processManager,
   }));
@@ -966,30 +945,23 @@ void main() {
 
     final File depFile = environment.buildDir.childFile('dart2wasm.d');
 
-    final File outputJsFile = environment.buildDir.childFile('main.dart.unopt.mjs');
+    final File outputJsFile = environment.buildDir.childFile('main.dart.mjs');
     processManager.addCommand(FakeCommand(
       command: <String>[
         ..._kDart2WasmLinuxArgs,
         '-Ddart.vm.product=true',
         '-DFLUTTER_WEB_AUTO_DETECT=false',
         '-DFLUTTER_WEB_USE_SKIA=true',
-        '--omit-type-checks',
-        '--depfile=${depFile.absolute.path}',
+        '--extra-compiler-option=--depfile=${depFile.absolute.path}',
+        '-O4',
+        '--no-name-section',
+        '-o',
+        environment.buildDir.childFile('main.dart.wasm').absolute.path,
         environment.buildDir.childFile('main.dart').absolute.path,
-        environment.buildDir.childFile('main.dart.unopt.wasm').absolute.path,
       ],
       onRun: (_) => outputJsFile..createSync()..writeAsStringSync('foo'))
     );
 
-    processManager.addCommand(FakeCommand(
-      command: <String>[
-        ..._kWasmOptLinuxArgrs,
-        environment.buildDir.childFile('main.dart.unopt.wasm').absolute.path,
-        '-o',
-        environment.buildDir.childFile('main.dart.wasm').absolute.path,
-      ])
-    );
-
     await Dart2WasmTarget(
       const WasmCompilerConfig(
         omitTypeChecks: true,
@@ -997,10 +969,7 @@ void main() {
       )
     ).build(environment);
 
-    expect(outputJsFile.existsSync(), isFalse);
-    final File movedJsFile = environment.buildDir.childFile('main.dart.mjs');
-    expect(movedJsFile.existsSync(), isTrue);
-    expect(movedJsFile.readAsStringSync(), 'foo');
+    expect(outputJsFile.existsSync(), isTrue);
   }, overrides: <Type, Generator>{
     ProcessManager: () => processManager,
   }));
@@ -1011,27 +980,21 @@ void main() {
 
     final File depFile = environment.buildDir.childFile('dart2wasm.d');
 
-    final File outputJsFile = environment.buildDir.childFile('main.dart.unopt.mjs');
+    final File outputJsFile = environment.buildDir.childFile('main.dart.mjs');
     processManager.addCommand(FakeCommand(
       command: <String>[
         ..._kDart2WasmLinuxArgs,
         '-Ddart.vm.product=true',
         '-DFLUTTER_WEB_AUTO_DETECT=false',
         '-DFLUTTER_WEB_USE_SKIA=true',
-        '--depfile=${depFile.absolute.path}',
+        '--extra-compiler-option=--depfile=${depFile.absolute.path}',
+        '-O2',
+        '--no-minify',
+        '-o',
+        environment.buildDir.childFile('main.dart.wasm').absolute.path,
         environment.buildDir.childFile('main.dart').absolute.path,
-        environment.buildDir.childFile('main.dart.unopt.wasm').absolute.path,
       ], onRun: (_) => outputJsFile..createSync()..writeAsStringSync('foo')));
 
-      processManager.addCommand(FakeCommand(
-        command: <String>[
-          ..._kWasmOptLinuxArgrs,
-          '--debuginfo',
-          environment.buildDir.childFile('main.dart.unopt.wasm').absolute.path,
-          '-o',
-          environment.buildDir.childFile('main.dart.wasm').absolute.path,
-        ]));
-
     await Dart2WasmTarget(
       const WasmCompilerConfig(
         wasmOpt: WasmOptLevel.debug,
@@ -1039,10 +1002,7 @@ void main() {
       )
     ).build(environment);
 
-    expect(outputJsFile.existsSync(), isFalse);
-    final File movedJsFile = environment.buildDir.childFile('main.dart.mjs');
-    expect(movedJsFile.existsSync(), isTrue);
-    expect(movedJsFile.readAsStringSync(), 'foo');
+    expect(outputJsFile.existsSync(), isTrue);
   }, overrides: <Type, Generator>{
     ProcessManager: () => processManager,
   }));
@@ -1060,9 +1020,11 @@ void main() {
         '-Ddart.vm.product=true',
         '-DFLUTTER_WEB_AUTO_DETECT=false',
         '-DFLUTTER_WEB_USE_SKIA=true',
-        '--depfile=${depFile.absolute.path}',
-        environment.buildDir.childFile('main.dart').absolute.path,
+        '--extra-compiler-option=--depfile=${depFile.absolute.path}',
+        '-O0',
+        '-o',
         environment.buildDir.childFile('main.dart.wasm').absolute.path,
+        environment.buildDir.childFile('main.dart').absolute.path,
       ], onRun: (_) => outputJsFile..createSync()..writeAsStringSync('foo')));
 
     await Dart2WasmTarget(
@@ -1080,31 +1042,26 @@ void main() {
     environment.defines[WasmCompilerConfig.kRunWasmOpt] = WasmOptLevel.defaultValue.name;
     final File depFile = environment.buildDir.childFile('dart2wasm.d');
 
-    final File outputJsFile = environment.buildDir.childFile('main.dart.unopt.mjs');
+    final File outputJsFile = environment.buildDir.childFile('main.dart.mjs');
     processManager.addCommand(FakeCommand(
       command: <String>[
         ..._kDart2WasmLinuxArgs,
+        '--extra-compiler-option=--import-shared-memory',
+        '--extra-compiler-option=--shared-memory-max-pages=32768',
         '-Ddart.vm.product=true',
         '-DFLUTTER_WEB_AUTO_DETECT=false',
         '-DFLUTTER_WEB_USE_SKIA=false',
         '-DFLUTTER_WEB_USE_SKWASM=true',
-        '--import-shared-memory',
-        '--shared-memory-max-pages=32768',
-        '--depfile=${depFile.absolute.path}',
+        '--extra-compiler-option=--depfile=${depFile.absolute.path}',
+        '-O2',
+        '--no-name-section',
+        '-o',
+        environment.buildDir.childFile('main.dart.wasm').absolute.path,
         environment.buildDir.childFile('main.dart').absolute.path,
-        environment.buildDir.childFile('main.dart.unopt.wasm').absolute.path,
       ],
       onRun: (_) => outputJsFile..createSync()..writeAsStringSync('foo'))
     );
 
-    processManager.addCommand(FakeCommand(
-      command: <String>[
-        ..._kWasmOptLinuxArgrs,
-        environment.buildDir.childFile('main.dart.unopt.wasm').absolute.path,
-        '-o',
-        environment.buildDir.childFile('main.dart.wasm').absolute.path,
-      ])
-    );
 
     await Dart2WasmTarget(
       const WasmCompilerConfig(