Implement modular compilation

lib/src/compiler/element_helpers.dart

Index: lib/src/compiler/element_helpers.dart
diff --git a/lib/src/compiler/element_helpers.dart b/lib/src/compiler/element_helpers.dart
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+// Copyright (c) 2016, 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.
+
+/// Helpers for Analyzer's Element model and corelib model.
+
+import 'package:analyzer/dart/ast/ast.dart'
+    show Expression, MethodInvocation, SimpleIdentifier;
+import 'package:analyzer/dart/element/element.dart'
+    show Element, FunctionElement;
+import 'package:analyzer/dart/element/type.dart'
+    show DartType, InterfaceType, ParameterizedType;
+import 'package:analyzer/src/dart/element/type.dart' show DynamicTypeImpl;
+import 'package:analyzer/src/generated/constant.dart' show DartObject;
+
+class Tuple2<T0, T1> {
+  final T0 e0;
+  final T1 e1;
+  Tuple2(this.e0, this.e1);
+}
+
+/*=T*/ fillDynamicTypeArgs/*<T extends DartType>*/(/*=T*/ t) {
+  if (t is ParameterizedType) {
+    var dyn = new List.filled(t.typeArguments.length, DynamicTypeImpl.instance);
+    return t.substitute2(dyn, t.typeArguments);
+  }
+  return t;
+}
+
+/// Given an annotated [node] and a [test] function, returns the first matching
+/// constant valued annotation.
+///
+/// For example if we had the ClassDeclaration node for `FontElement`:
+///
+///    @js.JS('HTMLFontElement')
+///    @deprecated
+///    class FontElement { ... }
+///
+/// We could match `@deprecated` with a test function like:
+///
+///    (v) => v.type.name == 'Deprecated' && v.type.element.library.isDartCore
+///
+DartObject findAnnotation(Element element, bool test(DartObject value)) {
+  for (var metadata in element.metadata) {
+    var value = metadata.constantValue;
+    if (value != null && test(value)) return value;
+  }
+  return null;
+}
+
+/// Searches all supertype, in order of most derived members, to see if any
+/// [match] a condition. If so, returns the first match, otherwise returns null.
+InterfaceType findSupertype(InterfaceType type, bool match(InterfaceType t)) {
+  for (var m in type.mixins.reversed) {
+    if (match(m)) return m;
+  }
+  var s = type.superclass;
+  if (s == null) return null;
+
+  if (match(s)) return type;
+  return findSupertype(s, match);
+}
+
+//TODO(leafp): Is this really necessary?  In theory I think
+// the static type should always be filled in for resolved
+// ASTs.  This may be a vestigial workaround.
+DartType getStaticType(Expression e) =>
+    e.staticType ?? DynamicTypeImpl.instance;
+
+// TODO(leafp) Factor this out or use an existing library
+/// Similar to [SimpleIdentifier] inGetterContext, inSetterContext, and
+/// inDeclarationContext, this method returns true if [node] is used in an
+/// invocation context such as a MethodInvocation.
+bool inInvocationContext(SimpleIdentifier node) {
+  var parent = node.parent;
+  return parent is MethodInvocation && parent.methodName == node;
+}
+
+bool isInlineJS(Element e) =>
+    e is FunctionElement &&
+    e.name == 'JS' &&
+    e.library.isInSdk &&
+    e.library.source.uri.toString() == 'dart:_foreign_helper';
+
+/// Returns the value of the `name` field from the [match]ing annotation on
+/// [element], or `null` if we didn't find a valid match or it was not a string.
+///
+/// For example, consider this code:
+///
+///     class MyAnnotation {
+///       final String name;
+///       // ...
+///       const MyAnnotation(this.name/*, ... other params ... */);
+///     }
+///
+///     @MyAnnotation('FooBar')
+///     main() { ... }
+///
+/// If we match the annotation for the `@MyAnnotation('FooBar')` this will
+/// return the string 'FooBar'.
+String getAnnotationName(Element element, bool match(DartObject value)) =>
+    findAnnotation(element, match)?.getField('name')?.toStringValue();