From 00ca59a478cb95ca5cfa5bdfaba81d72beae491d Mon Sep 17 00:00:00 2001
From: Jackson Gardner <jacksongardner@google.com>
Date: Thu, 8 Dec 2022 00:59:23 +0000
Subject: [PATCH] [dart2wasm] Support --multi-root and --multi-root-scheme
 flags.

Change-Id: I111748742677073bb3cf4c1655b69cb21d42f546
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/274089
Reviewed-by: Joshua Litt <joshualitt@google.com>
Commit-Queue: Jackson Gardner <jacksongardner@google.com>
---
 pkg/dart2wasm/bin/dart2wasm.dart        |  8 ++++++--
 pkg/dart2wasm/lib/compile.dart          | 11 +++++++++++
 pkg/dart2wasm/lib/compiler_options.dart |  2 ++
 pkg/dart2wasm/lib/option.dart           | 13 +++++++++++++
 pkg/dart2wasm/pubspec.yaml              |  1 +
 5 files changed, 33 insertions(+), 2 deletions(-)

diff --git a/pkg/dart2wasm/bin/dart2wasm.dart b/pkg/dart2wasm/bin/dart2wasm.dart
index bc0b106693c..3c4dd94a7ae 100644
--- a/pkg/dart2wasm/bin/dart2wasm.dart
+++ b/pkg/dart2wasm/bin/dart2wasm.dart
@@ -50,8 +50,12 @@ final List<Option> options = [
   StringMultiOption(
       "define", (o, values) => o.environment = processEnvironment(values),
       abbr: "D"),
-  StringMultiOption("enable-experiment",
-      (o, values) => o.feExperimentalFlags = processFeExperimentalFlags(values))
+  StringMultiOption(
+      "enable-experiment",
+      (o, values) =>
+          o.feExperimentalFlags = processFeExperimentalFlags(values)),
+  StringOption("multi-root-scheme", (o, value) => o.multiRootScheme = value),
+  UriMultiOption("multi-root", (o, values) => o.multiRoots = values),
 ];
 
 Map<fe.ExperimentalFlag, bool> processFeExperimentalFlags(
diff --git a/pkg/dart2wasm/lib/compile.dart b/pkg/dart2wasm/lib/compile.dart
index 145b6e74bb1..47c2ca7befe 100644
--- a/pkg/dart2wasm/lib/compile.dart
+++ b/pkg/dart2wasm/lib/compile.dart
@@ -4,6 +4,11 @@
 
 import 'dart:typed_data';
 
+import 'package:build_integration/file_system/multi_root.dart'
+    show MultiRootFileSystem;
+
+import 'package:front_end/src/api_prototype/standard_file_system.dart'
+    show StandardFileSystem;
 import 'package:front_end/src/api_unstable/vm.dart'
     show
         CompilerOptions,
@@ -52,6 +57,12 @@ Future<Uint8List?> compileToModule(compiler.CompilerOptions options,
     ..verbose = false
     ..onDiagnostic = diagnosticMessageHandler
     ..nnbdMode = NnbdMode.Strong;
+  if (options.multiRootScheme != null) {
+    compilerOptions.fileSystem = new MultiRootFileSystem(
+        options.multiRootScheme!,
+        options.multiRoots.isEmpty ? [Uri.base] : options.multiRoots,
+        StandardFileSystem.instance);
+  }
 
   if (options.platformPath != null) {
     compilerOptions.sdkSummary = options.platformPath;
diff --git a/pkg/dart2wasm/lib/compiler_options.dart b/pkg/dart2wasm/lib/compiler_options.dart
index 015cf8cc14d..6929bf43046 100644
--- a/pkg/dart2wasm/lib/compiler_options.dart
+++ b/pkg/dart2wasm/lib/compiler_options.dart
@@ -18,6 +18,8 @@ class CompilerOptions {
   String outputFile;
   Map<String, String> environment = const {};
   Map<fe.ExperimentalFlag, bool> feExperimentalFlags = const {};
+  String? multiRootScheme;
+  List<Uri> multiRoots = const [];
 
   factory CompilerOptions.defaultOptions() =>
       CompilerOptions(mainUri: Uri(), outputFile: '');
diff --git a/pkg/dart2wasm/lib/option.dart b/pkg/dart2wasm/lib/option.dart
index b8e20dc7d34..7802d0b6457 100644
--- a/pkg/dart2wasm/lib/option.dart
+++ b/pkg/dart2wasm/lib/option.dart
@@ -51,6 +51,12 @@ class IntOption extends ValueOption<int> {
             defaultsTo: defaultsTo);
 }
 
+class StringOption extends ValueOption<String> {
+  StringOption(String name, void applyToOptions(CompilerOptions o, String v),
+      {String? defaultsTo})
+      : super(name, applyToOptions, (v) => v, defaultsTo: defaultsTo);
+}
+
 class UriOption extends ValueOption<Uri> {
   UriOption(String name, void applyToOptions(CompilerOptions o, Uri v),
       {String? defaultsTo})
@@ -86,3 +92,10 @@ class StringMultiOption extends MultiValueOption<String> {
       : super(name, applyToOptions, (v) => v,
             abbr: abbr, defaultsTo: defaultsTo);
 }
+
+class UriMultiOption extends MultiValueOption<Uri> {
+  UriMultiOption(name, void applyToOptions(CompilerOptions o, List<Uri> v),
+      {Iterable<String>? defaultsTo})
+      : super(name, applyToOptions, (v) => Uri.file(Directory(v).absolute.path),
+            defaultsTo: defaultsTo);
+}
diff --git a/pkg/dart2wasm/pubspec.yaml b/pkg/dart2wasm/pubspec.yaml
index 6162b48fd16..108cc6e8f79 100644
--- a/pkg/dart2wasm/pubspec.yaml
+++ b/pkg/dart2wasm/pubspec.yaml
@@ -9,6 +9,7 @@ dependencies:
   _fe_analyzer_shared: any
   _js_interop_checks: any
   args: any
+  build_integration: any
   front_end: any
   kernel: any
   vm: any