Extract reusable parts of KernelAstAdapter in a mixin.

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

Index: pkg/compiler/lib/src/kernel/element_adapter.dart
diff --git a/pkg/compiler/lib/src/kernel/element_adapter.dart b/pkg/compiler/lib/src/kernel/element_adapter.dart
index 5d9f69dc51fb983c31f1a356f6d7add69d9eb84a..15d7e0e96e4d8de0194e17b23f5bc7550190bd2d 100644
--- a/pkg/compiler/lib/src/kernel/element_adapter.dart
+++ b/pkg/compiler/lib/src/kernel/element_adapter.dart
@@ -4,15 +4,22 @@
 
 import 'package:kernel/ast.dart' as ir;
 
+import '../common.dart';
+import '../common/names.dart';
+import '../core_types.dart';
 import '../elements/elements.dart';
 import '../elements/entities.dart';
 import '../elements/types.dart';
+import '../js_backend/backend_helpers.dart';
 import '../native/native.dart' as native;
 import '../universe/call_structure.dart';
 import '../universe/selector.dart';
 
 /// Interface that translates between Kernel IR nodes and entities.
 abstract class KernelElementAdapter {
+  /// Access to the commonly used elements and types.
+  CommonElements get commonElements;
+
   /// Returns the [DartType] corresponding to [type].
   DartType getDartType(ir.DartType type);
 
@@ -52,7 +59,7 @@ abstract class KernelElementAdapter {
 
   /// Returns the [Local] corresponding to the [node]. The node must be either
   /// a [ir.FunctionDeclaration] or [ir.FunctionExpression].
-  Local getLocalFunction(ir.Node node);
+  Local getLocalFunction(ir.TreeNode node);
 
   /// Returns the [LibraryEntity] corresponding to the library [node].
   LibraryEntity getLibrary(ir.Library node);
@@ -104,3 +111,266 @@ enum ForeignKind {
   JS_INTERCEPTOR_CONSTANT,
   NONE,
 }
+
+abstract class KernelElementAdapterMixin implements KernelElementAdapter {
+  DiagnosticReporter get reporter;
+  CommonElements get commonElements;
+
+  LibraryEntity lookupLibrary(Uri uri);
+  ClassEntity lookupClass(LibraryEntity library, String name);
+  InterfaceType getRawType(ClassEntity cls);
+  InterfaceType getThisType(ClassEntity cls);
+
+  @override
+  Name getName(ir.Name name) {
+    return new Name(
+        name.name, name.isPrivate ? getLibrary(name.library) : null);
+  }
+
+  @override
+  CallStructure getCallStructure(ir.Arguments arguments) {
+    int argumentCount = arguments.positional.length + arguments.named.length;
+    List<String> namedArguments = arguments.named.map((e) => e.name).toList();
+    return new CallStructure(argumentCount, namedArguments);
+  }
+
+  @override
+  Selector getSelector(ir.Expression node) {
+    if (node is ir.PropertyGet) return getGetterSelector(node);
+    if (node is ir.PropertySet) return getSetterSelector(node);
+    if (node is ir.InvocationExpression) return getInvocationSelector(node);
+    throw new SpannableAssertionFailure(CURRENT_ELEMENT_SPANNABLE,
+        "Can only get the selector for a property get or an invocation: ${node}");

[Johnni Winther, 2017/01/30 14:40:00]

Fixed in later CL (dartfmt doesn't handle this)

+  }
+
+  Selector getInvocationSelector(ir.InvocationExpression invocation) {
+    Name name = getName(invocation.name);
+    SelectorKind kind;
+    if (Elements.isOperatorName(invocation.name.name)) {
+      if (name == Names.INDEX_NAME || name == Names.INDEX_SET_NAME) {
+        kind = SelectorKind.INDEX;
+      } else {
+        kind = SelectorKind.OPERATOR;
+      }
+    } else {
+      kind = SelectorKind.CALL;
+    }
+
+    CallStructure callStructure = getCallStructure(invocation.arguments);
+    return new Selector(kind, name, callStructure);
+  }
+
+  Selector getGetterSelector(ir.PropertyGet getter) {
+    ir.Name irName = getter.name;
+    Name name = new Name(
+        irName.name, irName.isPrivate ? getLibrary(irName.library) : null);
+    return new Selector.getter(name);
+  }
+
+  Selector getSetterSelector(ir.PropertySet setter) {
+    ir.Name irName = setter.name;
+    Name name = new Name(
+        irName.name, irName.isPrivate ? getLibrary(irName.library) : null);
+    return new Selector.setter(name);
+  }
+
+  /// Returns `true` is [node] has a `@Native(...)` annotation.
+  // TODO(johnniwinther): Cache this for later use.
+  bool isNativeClass(ir.Class node) {
+    for (ir.Expression annotation in node.annotations) {
+      if (annotation is ir.ConstructorInvocation) {
+        FunctionEntity target = getConstructor(annotation.target);
+        if (target.enclosingClass == commonElements.nativeAnnotationClass) {
+          return true;
+        }
+      }
+    }
+    return false;
+  }
+
+  /// Compute the kind of foreign helper function called by [node], if any.
+  ForeignKind getForeignKind(ir.StaticInvocation node) {
+    if (isForeignLibrary(node.target.enclosingLibrary)) {
+      switch (node.target.name.name) {
+        case BackendHelpers.JS:
+          return ForeignKind.JS;
+        case BackendHelpers.JS_BUILTIN:
+          return ForeignKind.JS_BUILTIN;
+        case BackendHelpers.JS_EMBEDDED_GLOBAL:
+          return ForeignKind.JS_EMBEDDED_GLOBAL;
+        case BackendHelpers.JS_INTERCEPTOR_CONSTANT:
+          return ForeignKind.JS_INTERCEPTOR_CONSTANT;
+      }
+    }
+    return ForeignKind.NONE;
+  }
+
+  /// Return `true` if [node] is the `dart:_foreign_helper` library.
+  bool isForeignLibrary(ir.Library node) {
+    return node.importUri == BackendHelpers.DART_FOREIGN_HELPER;
+  }
+
+  /// Looks up [typeName] for use in the spec-string of a `JS` called.
+  // TODO(johnniwinther): Use this in [native.NativeBehavior] instead of calling
+  // the `ForeignResolver`.
+  // TODO(johnniwinther): Cache the result to avoid redundant lookups?
+  native.TypeLookup typeLookup({bool resolveAsRaw: true}) {
+    return (String typeName) {
+      DartType findIn(Uri uri) {
+        LibraryEntity library = lookupLibrary(uri);
+        if (library != null) {
+          ClassEntity cls = lookupClass(library, typeName);
+          if (cls != null) {
+            // TODO(johnniwinther): Align semantics.
+            return resolveAsRaw ? getRawType(cls) : getThisType(cls);
+          }
+        }
+        return null;
+      }
+
+      DartType type = findIn(Uris.dart_core);
+      type ??= findIn(BackendHelpers.DART_JS_HELPER);
+      type ??= findIn(BackendHelpers.DART_INTERCEPTORS);
+      type ??= findIn(BackendHelpers.DART_ISOLATE_HELPER);
+      type ??= findIn(Uris.dart_collection);
+      type ??= findIn(Uris.dart_html);
+      type ??= findIn(Uris.dart_svg);
+      type ??= findIn(Uris.dart_web_audio);
+      type ??= findIn(Uris.dart_web_gl);
+      return type;
+    };
+  }
+
+  String _getStringArgument(ir.StaticInvocation node, int index) {
+    return node.arguments.positional[index].accept(new Stringifier());
+  }
+
+  /// Computes the [native.NativeBehavior] for a call to the [JS] function.
+  // TODO(johnniwinther): Cache this for later use.
+  native.NativeBehavior getNativeBehaviorForJsCall(ir.StaticInvocation node) {
+    if (node.arguments.positional.length < 2 ||
+        node.arguments.named.isNotEmpty) {
+      reporter.reportErrorMessage(
+          CURRENT_ELEMENT_SPANNABLE, MessageKind.WRONG_ARGUMENT_FOR_JS);
+      return new native.NativeBehavior();
+    }
+    String specString = _getStringArgument(node, 0);
+    if (specString == null) {
+      reporter.reportErrorMessage(
+          CURRENT_ELEMENT_SPANNABLE, MessageKind.WRONG_ARGUMENT_FOR_JS_FIRST);
+      return new native.NativeBehavior();
+    }
+
+    String codeString = _getStringArgument(node, 1);
+    if (codeString == null) {
+      reporter.reportErrorMessage(
+          CURRENT_ELEMENT_SPANNABLE, MessageKind.WRONG_ARGUMENT_FOR_JS_SECOND);
+      return new native.NativeBehavior();
+    }
+
+    return native.NativeBehavior.ofJsCall(
+        specString,
+        codeString,
+        typeLookup(resolveAsRaw: true),
+        CURRENT_ELEMENT_SPANNABLE,
+        reporter,
+        commonElements);
+  }
+
+  /// Computes the [native.NativeBehavior] for a call to the [JS_BUILTIN]
+  /// function.
+  // TODO(johnniwinther): Cache this for later use.
+  native.NativeBehavior getNativeBehaviorForJsBuiltinCall(
+      ir.StaticInvocation node) {
+    if (node.arguments.positional.length < 1) {
+      reporter.internalError(
+          CURRENT_ELEMENT_SPANNABLE, "JS builtin expression has no type.");
+      return new native.NativeBehavior();
+    }
+    if (node.arguments.positional.length < 2) {
+      reporter.internalError(
+          CURRENT_ELEMENT_SPANNABLE, "JS builtin is missing name.");
+      return new native.NativeBehavior();
+    }
+    String specString = _getStringArgument(node, 0);
+    if (specString == null) {
+      reporter.internalError(
+          CURRENT_ELEMENT_SPANNABLE, "Unexpected first argument.");
+      return new native.NativeBehavior();
+    }
+    return native.NativeBehavior.ofJsBuiltinCall(
+        specString,
+        typeLookup(resolveAsRaw: true),
+        CURRENT_ELEMENT_SPANNABLE,
+        reporter,
+        commonElements);
+  }
+
+  /// Computes the [native.NativeBehavior] for a call to the
+  /// [JS_EMBEDDED_GLOBAL] function.
+  // TODO(johnniwinther): Cache this for later use.
+  native.NativeBehavior getNativeBehaviorForJsEmbeddedGlobalCall(
+      ir.StaticInvocation node) {
+    if (node.arguments.positional.length < 1) {
+      reporter.internalError(CURRENT_ELEMENT_SPANNABLE,
+          "JS embedded global expression has no type.");
+      return new native.NativeBehavior();
+    }
+    if (node.arguments.positional.length < 2) {
+      reporter.internalError(
+          CURRENT_ELEMENT_SPANNABLE, "JS embedded global is missing name.");
+      return new native.NativeBehavior();
+    }
+    if (node.arguments.positional.length > 2 ||
+        node.arguments.named.isNotEmpty) {
+      reporter.internalError(CURRENT_ELEMENT_SPANNABLE,
+          "JS embedded global has more than 2 arguments.");
+      return new native.NativeBehavior();
+    }
+    String specString = _getStringArgument(node, 0);
+    if (specString == null) {
+      reporter.internalError(
+          CURRENT_ELEMENT_SPANNABLE, "Unexpected first argument.");
+      return new native.NativeBehavior();
+    }
+    return native.NativeBehavior.ofJsEmbeddedGlobalCall(
+        specString,
+        typeLookup(resolveAsRaw: true),
+        CURRENT_ELEMENT_SPANNABLE,
+        reporter,
+        commonElements);
+  }
+
+  /// Computes the [InterfaceType] referenced by a call to the
+  /// [JS_INTERCEPTOR_CONSTANT] function, if any.
+  InterfaceType getInterfaceTypeForJsInterceptorCall(ir.StaticInvocation node) {
+    if (node.arguments.positional.length != 1 ||
+        node.arguments.named.isNotEmpty) {
+      reporter.reportErrorMessage(CURRENT_ELEMENT_SPANNABLE,
+          MessageKind.WRONG_ARGUMENT_FOR_JS_INTERCEPTOR_CONSTANT);
+    }
+    ir.Node argument = node.arguments.positional.first;
+    if (argument is ir.TypeLiteral && argument.type is ir.InterfaceType) {
+      return getInterfaceType(argument.type);
+    }
+    return null;
+  }
+}
+
+/// Visitor that converts string literals and concatenations of string literals
+/// into the string value.
+class Stringifier extends ir.ExpressionVisitor<String> {
+  @override
+  String visitStringLiteral(ir.StringLiteral node) => node.value;
+
+  @override
+  String visitStringConcatenation(ir.StringConcatenation node) {
+    StringBuffer sb = new StringBuffer();
+    for (ir.Expression expression in node.expressions) {
+      String value = expression.accept(this);
+      if (value == null) return null;
+      sb.write(value);
+    }
+    return sb.toString();
+  }
+}