Compute sourceElement for closures

pkg/compiler/lib/src/ssa/builder_kernel.dart

 // 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.
 
 import 'package:kernel/ast.dart' as ir;
 
 import '../closure.dart';
 import '../common.dart';
 import '../common/codegen.dart' show CodegenRegistry, CodegenWorkItem;
 import '../common/names.dart';
@@ skipping 479 matching lines @@
     HInstruction errorMessage =
         graph.addConstantString(new DartString.literal(message), closedWorld);
     HInstruction trap = new HForeignCode(js.js.parseForeignJS("#.#"),
         commonMasks.dynamicType, <HInstruction>[nullValue, errorMessage]);
     trap.sideEffects
       ..setAllSideEffects()
       ..setDependsOnSomething();
     push(trap);
   }
 
-  /// Returns the current source element.
+  /// Returns the current source element. This is used by the type builder.
   ///
   /// The returned element is a declaration element.
   // TODO(efortuna): Update this when we implement inlining.
+  // TODO(sra): Re-implement type builder using Kernel types and the
+  // `target` for context.
   @override
-  Element get sourceElement => astAdapter.getElement(target);
+  Element get sourceElement => _sourceElementForTarget(target);
+
+  Element _sourceElementForTarget(ir.Node target) {
+    // For closure-converted (i.e. local functions) the source element is the
+    // 'call' method of the class that represents the closure.
+    if (target is ir.FunctionExpression) {
+      LocalFunctionElement element = astAdapter.getElement(target);
+      ClosureClassMap classMap = compiler.closureToClassMapper
+          .getClosureToClassMapping(element.resolvedAst);
+      return classMap.callElement;
+    }
+    if (target is ir.FunctionDeclaration) {
+      LocalFunctionElement element = astAdapter.getElement(target);
+      ClosureClassMap classMap = compiler.closureToClassMapper
+          .getClosureToClassMapping(element.resolvedAst);
+      return classMap.callElement;
+    }
+    Element element = astAdapter.getElement(target);
+    return element;
+  }
 
   @override
   void visitBlock(ir.Block block) {
     assert(!isAborted());
     for (ir.Statement statement in block.statements) {
       statement.accept(this);
       if (!isReachable) {
         // The block has been aborted by a return or a throw.
         if (stack.isNotEmpty) {
           compiler.reporter.internalError(
@@ skipping 1985 matching lines @@
     kernelBuilder.open(exitBlock);
     enterBlock.setBlockFlow(
         new HTryBlockInformation(
             kernelBuilder.wrapStatementGraph(bodyGraph),
             exception,
             kernelBuilder.wrapStatementGraph(catchGraph),
             kernelBuilder.wrapStatementGraph(finallyGraph)),
         exitBlock);
   }
 }