Use Extension Member data instead of desugar api.

Swap to finding the mapping of Procedure to ExtensionMemberDescriptor
data, instead of using the front_end desugar api for extension
member kind, name, and isStatic information.

Change-Id: I4bca55e8f1d3044def420060ddecc75600452a11
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/214305
Reviewed-by: Sigmund Cherem <sigmund@google.com>
Reviewed-by: Srujan Gaddam <srujzs@google.com>

pkg/_js_interop_checks/lib/src/transformations/js_util_optimizer.dart

@@ -2,7 +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.
 
-import 'package:front_end/src/api_unstable/dart2js.dart' as api;
 import 'package:kernel/ast.dart';
 import 'package:kernel/class_hierarchy.dart';
 import 'package:kernel/core_types.dart';
@@ -37,6 +36,7 @@ class JsUtilOptimizer extends Transformer {
 
   final CoreTypes _coreTypes;
   final StatefulStaticTypeContext _staticTypeContext;
+  Map<Reference, ExtensionMemberDescriptor>? _extensionMemberIndex;
 
   JsUtilOptimizer(this._coreTypes, ClassHierarchy hierarchy)
       : _jsTarget =
@@ -74,6 +74,7 @@ class JsUtilOptimizer extends Transformer {
     _staticTypeContext.enterLibrary(lib);
     lib.transformChildren(this);
     _staticTypeContext.leaveLibrary(lib);
+    _extensionMemberIndex = null;
     return lib;
   }
 
@@ -88,21 +89,24 @@ class JsUtilOptimizer extends Transformer {
   @override
   visitProcedure(Procedure node) {
     _staticTypeContext.enterMember(node);
-    if (node.isExternal && node.isExtensionMember && !_isDeclaredStatic(node)) {
+    var transformedBody;
-      var transformedBody;
+    if (node.isExternal && node.isExtensionMember) {
-      if (api.getExtensionMemberKind(node) == ProcedureKind.Getter) {
+      var index = _extensionMemberIndex ??=
-        transformedBody = _getExternalGetterBody(node);
+          _createExtensionMembersIndex(node.enclosingLibrary);
-      } else if (api.getExtensionMemberKind(node) == ProcedureKind.Setter) {
+      var nodeDescriptor = index[node.reference]!;
-        transformedBody = _getExternalSetterBody(node);
+      if (!nodeDescriptor.isStatic) {
-      } else if (api.getExtensionMemberKind(node) == ProcedureKind.Method) {
+        if (nodeDescriptor.kind == ExtensionMemberKind.Getter) {
-        transformedBody = _getExternalMethodBody(node);
+          transformedBody = _getExternalGetterBody(node);
-      }
+        } else if (nodeDescriptor.kind == ExtensionMemberKind.Setter) {
-      // TODO(rileyporter): Add transformation for static members and any
+          transformedBody = _getExternalSetterBody(node);
-      // operators we decide to support.
+        } else if (nodeDescriptor.kind == ExtensionMemberKind.Method) {
-      if (transformedBody != null) {
+          transformedBody = _getExternalMethodBody(node);
-        node.function.body = transformedBody;
+        }
-        node.isExternal = false;
       }
+    }
+    if (transformedBody != null) {
+      node.function.body = transformedBody;
+      node.isExternal = false;
     } else {
       node.transformChildren(this);
     }
@@ -110,6 +114,18 @@ class JsUtilOptimizer extends Transformer {
     return node;
   }
 
+  /// Returns and initializes `_extensionMemberIndex` to an index of the member
+  /// reference to the member `ExtensionMemberDescriptor`, for all extension
+  /// members in the given [library].
+  Map<Reference, ExtensionMemberDescriptor> _createExtensionMembersIndex(
+      Library library) {
+    _extensionMemberIndex = {};
+    library.extensions.forEach((extension) => extension.members.forEach(
+        (descriptor) =>
+            _extensionMemberIndex![descriptor.member] = descriptor));
+    return _extensionMemberIndex!;
+  }
+
   /// Returns a new function body for the given [node] external getter.
   ///
   /// The new function body will call the optimized version of
@@ -121,7 +137,7 @@ class JsUtilOptimizer extends Transformer {
         _getPropertyTarget,
         Arguments([
           VariableGet(function.positionalParameters.first),
-          StringLiteral(_getMemberName(node))
+          StringLiteral(_getExtensionMemberName(node))
         ]))
       ..fileOffset = node.fileOffset;
     return ReturnStatement(AsExpression(
@@ -139,7 +155,7 @@ class JsUtilOptimizer extends Transformer {
         _setPropertyTarget,
         Arguments([
           VariableGet(function.positionalParameters.first),
-          StringLiteral(_getMemberName(node)),
+          StringLiteral(_getExtensionMemberName(node)),
           VariableGet(function.positionalParameters.last)
         ]))
       ..fileOffset = node.fileOffset;
@@ -157,7 +173,7 @@ class JsUtilOptimizer extends Transformer {
         _callMethodTarget,
         Arguments([
           VariableGet(function.positionalParameters.first),
-          StringLiteral(_getMemberName(node)),
+          StringLiteral(_getExtensionMemberName(node)),
           ListLiteral(function.positionalParameters
               .sublist(1)
               .map((argument) => VariableGet(argument))
@@ -168,29 +184,17 @@ class JsUtilOptimizer extends Transformer {
         _lowerCallMethod(callMethodInvocation), function.returnType));
   }
 
-  /// Returns the member name, either from the `@JS` annotation if non-empty,
+  /// Returns the extension member name.
-  /// or parsed from CFE generated node name.
+  ///
-  String _getMemberName(Procedure node) {
+  /// Returns either the name from the `@JS` annotation if non-empty, or the
+  /// declared name of the extension member. Does not return the CFE generated
+  /// name for the top level member for this extension member.
+  String _getExtensionMemberName(Procedure node) {
     var jsAnnotationName = getJSName(node);
     if (jsAnnotationName.isNotEmpty) {
       return jsAnnotationName;
     }
-    // TODO(rileyporter): Switch to using the ExtensionMemberDescriptor data.
+    return _extensionMemberIndex![node.reference]!.name.text;
-    var nodeName = node.name.text;
-    if (nodeName.contains('#')) {
-      return nodeName.substring(nodeName.indexOf('#') + 1);
-    } else {
-      return nodeName.substring(nodeName.indexOf('|') + 1);
-    }
-  }
-
-  /// Returns whether the given extension [node] is declared as `static`.
-  ///
-  /// All extension members have `isStatic` true, but the members declared as
-  /// static will not have a synthesized `this` variable.
-  bool _isDeclaredStatic(Procedure node) {
-    return node.function.positionalParameters.isEmpty ||
-        node.function.positionalParameters.first.name != '#this';
   }
 
   /// Replaces js_util method calls with optimization when possible.

pkg/_js_interop_checks/pubspec.yaml

@@ -8,7 +8,5 @@ environment:
 dependencies:
   _fe_analyzer_shared:
     path: ../_fe_analyzer_shared
-  front_end:
-    path: ../front_end
   kernel:
     path: ../kernel

pkg/front_end/lib/src/api_unstable/dart2js.dart

@@ -241,23 +241,3 @@ Iterable<String> getSupportedLibraryNames(
 // TODO(sigmund): Delete this API once `member.isRedirectingFactory`
 // is implemented correctly for patch files (Issue #33495).
 bool isRedirectingFactory(ir.Procedure member) => member.isRedirectingFactory;
-
-/// Determines what `ProcedureKind` the given extension [member] is based on
-/// the member name.
-///
-/// Note: classifies operators as `ProcedureKind.Method`.
-ir.ProcedureKind getExtensionMemberKind(ir.Procedure member) {
-  assert(member.isExtensionMember);
-  String name = member.name.text;
-  int pipeIndex = name.indexOf('|');
-  int poundIndex = name.indexOf('#');
-  assert(pipeIndex >= 0);
-  if (poundIndex >= 0) {
-    String getOrSet = name.substring(pipeIndex + 1, poundIndex);
-    return getOrSet == 'get'
-        ? ir.ProcedureKind.Getter
-        : ir.ProcedureKind.Setter;
-  } else {
-    return member.kind;
-  }
-}

pkg/front_end/test/desugar_test.dart

@@ -28,7 +28,6 @@ Future<void> main() async {
     await testRedirectingFactoryDirect();
     await testRedirectingFactorySerialized();
     await testRedirectingFactoryPatchFile();
-    await testExtensionMemberKind();
   });
 }
 
@@ -80,97 +79,3 @@ class _B implements A {
   _B(int x);
 }
 ''';
-
-Future<void> testExtensionMemberKind() async {
-  var component = await compileUnit(['e.dart'], {'e.dart': extensionSource});
-  var library = component.libraries
-      .firstWhere((l) => l.importUri.path.endsWith('e.dart'));
-  var descriptors =
-      library.extensions.expand((extension) => extension.members).toList();
-
-  // Check generated getters and setters for fields.
-  var fieldGetter =
-      findExtensionField(descriptors, 'field', ir.ExtensionMemberKind.Getter);
-  Expect.equals(
-      api.getExtensionMemberKind(fieldGetter), ir.ProcedureKind.Getter);
-  var fieldSetter =
-      findExtensionField(descriptors, 'field', ir.ExtensionMemberKind.Setter);
-  Expect.equals(
-      api.getExtensionMemberKind(fieldSetter), ir.ProcedureKind.Setter);
-  var staticFieldGetter = findExtensionField(
-      descriptors, 'staticField', ir.ExtensionMemberKind.Getter);
-  Expect.equals(
-      api.getExtensionMemberKind(staticFieldGetter), ir.ProcedureKind.Getter);
-  var staticFieldSetter = findExtensionField(
-      descriptors, 'staticField', ir.ExtensionMemberKind.Setter);
-  Expect.equals(
-      api.getExtensionMemberKind(staticFieldSetter), ir.ProcedureKind.Setter);
-
-  // Check getters and setters.
-  var getter = findExtensionMember(descriptors, 'getter');
-  Expect.equals(api.getExtensionMemberKind(getter), ir.ProcedureKind.Getter);
-  var setter = findExtensionMember(descriptors, 'setter');
-  Expect.equals(api.getExtensionMemberKind(setter), ir.ProcedureKind.Setter);
-  var staticGetter = findExtensionMember(descriptors, 'staticGetter');
-  Expect.equals(
-      api.getExtensionMemberKind(staticGetter), ir.ProcedureKind.Getter);
-  var staticSetter = findExtensionMember(descriptors, 'staticSetter');
-  Expect.equals(
-      api.getExtensionMemberKind(staticSetter), ir.ProcedureKind.Setter);
-
-  // Check methods.
-  var method = findExtensionMember(descriptors, 'method');
-  Expect.equals(api.getExtensionMemberKind(method), ir.ProcedureKind.Method);
-  var methodTearoff = findExtensionTearoff(descriptors, 'get#method');
-  Expect.equals(
-      api.getExtensionMemberKind(methodTearoff), ir.ProcedureKind.Getter);
-  var staticMethod = findExtensionMember(descriptors, 'staticMethod');
-  Expect.equals(
-      api.getExtensionMemberKind(staticMethod), ir.ProcedureKind.Method);
-
-  // Check operators.
-  var operator = findExtensionMember(descriptors, '+');
-  Expect.equals(api.getExtensionMemberKind(operator), ir.ProcedureKind.Method);
-}
-
-ir.Member findExtensionMember(
-    List<ir.ExtensionMemberDescriptor> descriptors, String memberName) {
-  return descriptors
-      .firstWhere((d) => d.name.text == memberName)
-      .member
-      .asMember;
-}
-
-ir.Member findExtensionField(List<ir.ExtensionMemberDescriptor> descriptors,
-    String fieldName, ir.ExtensionMemberKind kind) {
-  return descriptors
-      .firstWhere((d) => d.name.text == fieldName && d.kind == kind)
-      .member
-      .asMember;
-}
-
-ir.Member findExtensionTearoff(
-    List<ir.ExtensionMemberDescriptor> descriptors, String memberName) {
-  return descriptors
-      .map((d) => d.member.asMember)
-      .firstWhere((m) => m.name.text.contains(memberName));
-}
-
-const extensionSource = '''
-class Foo {}
-
-extension Ext on Foo {
-  external int field;
-  external static int staticField;
-
-  external get getter;
-  external set setter(_);
-  external static get staticGetter;
-  external static set staticSetter(_);
-
-  external int method();
-  external static int staticMethod();
-
-  external operator +(_);
-}
-''';