Ensure we're looking at the correct resolved AST when initializing fields in constructors.

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

Index: pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
diff --git a/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart b/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
index 7d78673c424e946a5c76fb730cf3324c48f49f16..d124af0a4fe87e4c223e812c47abfce4f59798b4 100644
--- a/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
+++ b/pkg/compiler/lib/src/ssa/kernel_ast_adapter.dart
@@ -5,6 +5,8 @@
 import 'package:js_runtime/shared/embedded_names.dart';
 import 'package:kernel/ast.dart' as ir;
 
+import 'dart:collection' show Queue;
+
 import '../common.dart';
 import '../common/names.dart';
 import '../compiler.dart';
@@ -36,7 +38,6 @@ import 'types.dart';
 class KernelAstAdapter {
   final Kernel kernel;
   final JavaScriptBackend _backend;
-  final ResolvedAst _resolvedAst;
   final Map<ir.Node, ast.Node> _nodeToAst;
   final Map<ir.Node, Element> _nodeToElement;
   final Map<ir.VariableDeclaration, SyntheticLocal> _syntheticLocals =
@@ -44,6 +45,12 @@ class KernelAstAdapter {
   final Map<ir.LabeledStatement, KernelJumpTarget> _jumpTargets =
       <ir.LabeledStatement, KernelJumpTarget>{};
   DartTypeConverter _typeConverter;
+  ResolvedAst _resolvedAst;
+
+  /// Sometimes for resolution the resolved AST element needs to change (for
+  /// example, if we're inlining, or if we're in a constructor, but then also
+  /// constructing the field values). We keep track of this with a stack.

[Siggi Cherem (dart-lang), 2017/01/05 23:23:31]

constructing => initializing

[Emily Fortuna, 2017/01/06 00:19:25]

oops yes

+  Queue<ResolvedAst> _resolvedAstStack;

[Siggi Cherem (dart-lang), 2017/01/05 23:23:31]

side comment: We have a tendency in dart2js to use Link<> (from
lib/src/util/link.dart) instead of Queue<> or List<>. That might have been
historical, and in this specific use case I'm guessing it doesn't matter, so I'm
OK keeping it as it is. I'll double check to see if there are any reasons to
continue using Link in this case.

[Emily Fortuna, 2017/01/06 00:19:25]

Acknowledged.

 
   KernelAstAdapter(this.kernel, this._backend, this._resolvedAst,
       this._nodeToAst, this._nodeToElement) {
@@ -67,6 +74,20 @@ class KernelAstAdapter {
       _nodeToElement[kernel.typeParameters[typeVariable]] = typeVariable;
     }
     _typeConverter = new DartTypeConverter(this);
+    _resolvedAstStack = new Queue<ResolvedAst>();
+  }
+
+  /// Push the existing resolved AST on the stack and shift the current resolved
+  /// AST to the AST that this kernel node points to.
+  void pushResolvedAst(ir.Node node) {
+    _resolvedAstStack.addLast(_resolvedAst);
+    _resolvedAst = getElement(node).resolvedAst;
+  }
+
+  /// Pop the resolved AST stack to reset it to the previous resolved AST node.
+  void popResolvedAstStack() {
+    assert(_resolvedAstStack.isNotEmpty);
+    _resolvedAst = _resolvedAstStack.removeLast();
   }
 
   Compiler get _compiler => _backend.compiler;