Reapply 0c78abd0900d

pkg/compiler/lib/src/ssa/kernel_ast_adapter.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:js_runtime/shared/embedded_names.dart';
 import 'package:kernel/ast.dart' as ir;
 
 import '../common.dart';
 import '../common/names.dart';
 import '../compiler.dart';
@@ skipping 18 matching lines @@
 import '../world.dart';
 import 'locals_handler.dart';
 import 'types.dart';
 
 /// A helper class that abstracts all accesses of the AST from Kernel nodes.
 ///
 /// The goal is to remove all need for the AST from the Kernel SSA builder.
 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 =
       <ir.VariableDeclaration, SyntheticLocal>{};
   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.
+  final List<ResolvedAst> _resolvedAstStack = <ResolvedAst>[];
 
   KernelAstAdapter(this.kernel, this._backend, this._resolvedAst,
       this._nodeToAst, this._nodeToElement) {
     // TODO(het): Maybe just use all of the kernel maps directly?
     for (FieldElement fieldElement in kernel.fields.keys) {
       _nodeToElement[kernel.fields[fieldElement]] = fieldElement;
     }
     for (FunctionElement functionElement in kernel.functions.keys) {
       _nodeToElement[kernel.functions[functionElement]] = functionElement;
     }
     for (ClassElement classElement in kernel.classes.keys) {
       _nodeToElement[kernel.classes[classElement]] = classElement;
     }
     for (LibraryElement libraryElement in kernel.libraries.keys) {
       _nodeToElement[kernel.libraries[libraryElement]] = libraryElement;
     }
     for (LocalFunctionElement localFunction in kernel.localFunctions.keys) {
       _nodeToElement[kernel.localFunctions[localFunction]] = localFunction;
     }
     for (TypeVariableElement typeVariable in kernel.typeParameters.keys) {
       _nodeToElement[kernel.typeParameters[typeVariable]] = typeVariable;
     }
     _typeConverter = new DartTypeConverter(this);
   }
 
+  /// 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.add(_resolvedAst);
+    _resolvedAst = (getElement(node) as AstElement).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;
   TreeElements get elements => _resolvedAst.elements;
   DiagnosticReporter get reporter => _compiler.reporter;
   Element get _target => _resolvedAst.element;
 
   GlobalTypeInferenceResults get _globalInferenceResults =>
       _compiler.globalInference.results;
 
   GlobalTypeInferenceElementResult _resultOf(Element e) =>
       _globalInferenceResults.resultOf(e);
@@ skipping 860 matching lines @@
 
   @override
   String get name => null;
 
   @override
   int get nestingLevel => 1;
 
   @override
   ast.Node get statement => null;
 }