fixes #31575, DDC kernel backend can now compile the SDK to JS

Also adds this to the build script, so we can eventually replace the existing SDK compile step with this new one.

Change-Id: Iba0720df5bbab302d2fdd0b5aeeb182de152cc98
Reviewed-on: https://dart-review.googlesource.com/32504
Commit-Queue: Jenny Messerly <jmesserly@google.com>
Reviewed-by: Vijay Menon <vsm@google.com>

pkg/dev_compiler/lib/src/kernel/compiler.dart

@@ -398,7 +398,7 @@ class ProgramCompiler
     if (bootstrap) _emitLibraryProcedures(library);
 
     library.classes.forEach(_emitClass);
-    _moduleItems.addAll(library.typedefs.map(_emitTypedef));
+    library.typedefs.forEach(_emitTypedef);
     if (bootstrap) {
       _moduleItems.add(_emitInternalSdkFields(library.fields));
     } else {
@@ -1884,7 +1884,7 @@ class ProgramCompiler
     var jsMethods = <JS.Method>[];
     if (field.isStatic) return jsMethods;
 
-    var name = getAnnotationName(field, isJSName) ?? field.name;
+    var name = getAnnotationName(field, isJSName) ?? field.name.name;
     // Generate getter
     var fn = new JS.Fun([], js.statement('{ return this.#; }', [name]));
     var method = new JS.Method(_declareMemberName(field), fn, isGetter: true);
@@ -2012,16 +2012,18 @@ class ProgramCompiler
     return js.statement('# = #;', [_emitTopLevelName(c), jsTypeName]);
   }
 
-  JS.Statement _emitTypedef(Typedef t) {
+  void _emitTypedef(Typedef t) {
     var body = _callHelper(
         'typedef(#, () => #)', [js.string(t.name, "'"), _emitType(t.type)]);
 
+    JS.Statement result;
     if (t.typeParameters.isNotEmpty) {
-      return _defineClassTypeArguments(
+      result = _defineClassTypeArguments(
           t, t.typeParameters, js.statement('const # = #;', [t.name, body]));
     } else {
-      return js.statement('# = #;', [_emitTopLevelName(t), body]);
+      result = js.statement('# = #;', [_emitTopLevelName(t), body]);
     }
+    _moduleItems.add(result);
   }
 
   /// Treat dart:_runtime fields as safe to eagerly evaluate.
@@ -2057,11 +2059,7 @@ class ProgramCompiler
     for (var field in fields) {
       var name = field.name.name;
       var access = _emitStaticMemberName(name);
-      accessors.add(new JS.Method(
-          access,
-          js.call('function() { return #; }',
-                  _visitInitializer(field.initializer, field.annotations))
-              as JS.Fun,
+      accessors.add(new JS.Method(access, _emitStaticFieldInitializer(field),
           isGetter: true));
 
       // TODO(jmesserly): currently uses a dummy setter to indicate writable.
@@ -2077,6 +2075,20 @@ class ProgramCompiler
     return _callHelperStatement('defineLazy(#, { # });', [objExpr, accessors]);
   }
 
+  JS.Fun _emitStaticFieldInitializer(Field field) {
+    var savedLetVariables = _letVariables;
+    _letVariables = [];
+
+    var body = [
+      new JS.Return(_visitInitializer(field.initializer, field.annotations))
+    ];
+    _initTempVars(body);
+
+    _letVariables = savedLetVariables;
+
+    return new JS.Fun([], new JS.Block(body));
+  }
+
   JS.PropertyAccess _emitTopLevelName(NamedNode n, {String suffix: ''}) {
     return _emitJSInterop(n) ?? _emitTopLevelNameNoInterop(n, suffix: suffix);
   }

pkg/dev_compiler/tool/kernel_sdk.dart

@@ -49,7 +49,7 @@ Future main(List<String> args) async {
 
   if (generateJS) {
     var jsModule = compileToJSModule(program, [], [], {});
-    var jsPath = path.join(path.basename(outputPath), 'dart_sdk.kernel.js');
+    var jsPath = path.join(path.dirname(outputPath), 'dart_sdk.kernel.js');
     new File(jsPath)
         .writeAsStringSync(jsProgramToCode(jsModule, ModuleFormat.es6).code);
   }

tests/language_2/language_2_dartdevc.status

@@ -190,7 +190,6 @@ call_non_method_field_test/01: MissingCompileTimeError
 call_non_method_field_test/02: MissingCompileTimeError
 call_with_no_such_method_test: CompileTimeError # Issue 31402 Error: A value of type '#lib1::F' can't be assigned to a variable of type 'dart.core::Function'.
 callable_test/none: CompileTimeError
-cascade_on_static_field_test: Crash
 check_member_static_test/01: MissingCompileTimeError
 check_member_static_test/02: MissingCompileTimeError
 class_cycle_test/02: MissingCompileTimeError
@@ -681,7 +680,6 @@ type_variable_bounds_test/05: MissingCompileTimeError
 type_variable_bounds_test/06: MissingCompileTimeError
 type_variable_bounds_test/08: MissingCompileTimeError
 type_variable_bounds_test/11: MissingCompileTimeError
-typedef_class_in_other_file_test: Crash
 void_block_return_test/00: MissingCompileTimeError
 void_type_callbacks_test/none: CompileTimeError
 wrong_number_type_arguments_test/01: MissingCompileTimeError

utils/dartdevc/BUILD.gn

@@ -353,7 +353,7 @@ compiled_action("dartdevc_test_pkg") {
   ]
 }
 
-# Compiles the DDC SDK's kernel summary.
+# Compiles the DDC SDK's kernel summary and JS code.
 compiled_action("dartdevc_sdk_kernel_summary") {
   tool = "../../runtime/bin:dart"
 
@@ -367,10 +367,12 @@ compiled_action("dartdevc_sdk_kernel_summary") {
 
   outputs = [
     "$target_gen_dir/ddc_sdk.dill",
+    "$target_gen_dir/dart_sdk.kernel.js"
   ]
 
   args = [
     rebase_path("../../pkg/dev_compiler/tool/kernel_sdk.dart"),
+    "--generate-javascript",
     rebase_path("$target_gen_dir/ddc_sdk.dill"),
   ]
 }