Add dart2wasm targets to benchmark builder (#806)

This updates benchmark builder with two dart2wasm targets:

- wasm: Default optimized build.
- wasm-omit-checks: Optimized build with `--omit-checks`.

README is updated with instructions to build and run new targets.

Author: osa1

benchmarks/README.md

@@ -13,6 +13,28 @@
     - AOT: `./out/from_binary.exe`
     - JS: `d8 $DART_SDK/lib/_internal/js_runtime/lib/preambles/d8.js out/from_binary.js`
 
+- **Wasm:**
+
+  - Get the Dart SDK source code following instructions [here][1], and build
+    `dart2wasm_platform` target with `tools/build.py -m release
+    dart2wasm_platform`.
+
+  - Make sure `$DART_SDK` environment variable set to the path of [Dart SDK's
+    "sdk" directory][1].
+
+  - Compile benchmarks with `./tool/compile_benchmarks.dart --target=<target>`
+    where `<target>` is one of:
+
+    - `wasm`: Default optimized build
+    - `wasm-omit-checks`: Optimized build with `--omit-checks`
+
+  - Run with: `$DART_SDK/bin/run_dart2wasm_d8 out/from_binary.wasm`, or use
+    `.omit-checks.wasm` extension for the `wasm-omit-checks` target:
+    `from_binary.omit-checks.wasm`.
+
+[1]: https://github.com/dart-lang/sdk/wiki/Building
+[2]: https://github.com/dart-lang/sdk/tree/main/sdk
+
 ## Development
 
 `protoc_version` file specifies the version of protoc Golem will use when

benchmarks/lib/readfile.dart

@@ -2,4 +2,6 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-export 'readfile_vm.dart' if (dart.library.js) 'readfile_d8.dart' show readfile;
+export 'readfile_vm.dart'
+    if (dart.library.js) 'readfile_js.dart'
+    if (dart.library.wasm) 'readfile_wasm.dart' show readfile;

benchmarks/lib/readfile_d8.dart benchmarks/lib/readfile_js.dart

@@ -0,0 +1,17 @@
+// Copyright (c) 2023, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:js_interop';
+import 'dart:typed_data';
+
+/// Read the file at the given [path].
+///
+/// This relies on the `readbuffer` function provided by d8.
+@JS()
+external ByteBuffer readbuffer(String path);
+
+/// Read the file at the given [path].
+Uint8List readfile(String path) {
+  return Uint8List.view(readbuffer(path));
+}

benchmarks/lib/readfile_wasm.dart

@@ -1,4 +1,5 @@
 #!/usr/bin/env dart
+// ignore_for_file: only_throw_errors
 
 import 'dart:io' show Directory, Platform, Process, ProcessResult, exit;
 
@@ -42,9 +43,17 @@ Future<void> main(List<String> args) async {
         targets.add(jsProductionTarget);
         break;
 
+      case 'wasm':
+        targets.add(wasmTarget);
+        break;
+
+      case 'wasm-omit-checks':
+        targets.add(wasmOmitChecksTarget);
+        break;
+
       default:
-        print(
-            'Unsupported target: $targetStr. Supported targets: aot, exe, jit, js, js-production');
+        print('Unsupported target: $targetStr. Supported targets: aot, exe, '
+            'jit, js, js-production, wasm, wasm-omit-checks');
         exit(1);
     }
   }
@@ -135,6 +144,9 @@ const exeTarget = Target('exe', exeProcessArgs);
 const jitTarget = Target('jit', jitProcessArgs);
 const jsTarget = Target('js', jsProcessArgs);
 const jsProductionTarget = Target('js-production', jsProductionProcessArgs);
+const wasmTarget = Target('wasm', wasmProcessArgs);
+const wasmOmitChecksTarget =
+    Target('wasm-omit-checks', wasmOmitChecksProcessArgs);
 
 List<String> aotProcessArgs(String sourceFile) {
   final baseName = path.basename(sourceFile);
@@ -185,3 +197,32 @@ List<String> jsProductionProcessArgs(String sourceFile) {
     'out/$baseNameNoExt.production.js'
   ];
 }
+
+List<String> wasmProcessArgs(String sourceFile) {
+  final sdkPath = Platform.environment['DART_SDK'];
+  if (sdkPath == null) {
+    throw '\$DART_SDK environment variable is not set';
+  }
+  final baseName = path.basename(sourceFile);
+  final baseNameNoExt = path.withoutExtension(baseName);
+  return [
+    '$sdkPath/../pkg/dart2wasm/tool/compile_benchmark',
+    sourceFile,
+    'out/$baseNameNoExt.wasm',
+  ];
+}
+
+List<String> wasmOmitChecksProcessArgs(String sourceFile) {
+  final sdkPath = Platform.environment['DART_SDK'];
+  if (sdkPath == null) {
+    throw '\$DART_SDK environment variable is not set';
+  }
+  final baseName = path.basename(sourceFile);
+  final baseNameNoExt = path.withoutExtension(baseName);
+  return [
+    '$sdkPath/../pkg/dart2wasm/tool/compile_benchmark',
+    sourceFile,
+    'out/$baseNameNoExt.omit-checks.wasm',
+    '--omit-checks',
+  ];
+}