dart2js-kernel: Implement Let and PropertySet.

The Accessor builders capture some subexpressions to help map kernel
Nodes to Ast Nodes.

R=asgerf@google.com

Review URL: https://codereview.chromium.org/2526123002 .

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

@@ -73,6 +73,7 @@ class Kernel {
 
   final Map<ir.Node, Element> nodeToElement = <ir.Node, Element>{};
   final Map<ir.Node, Node> nodeToAst = <ir.Node, Node>{};
+  final Map<ir.Node, Node> nodeToAstOperator = <ir.Node, Node>{};
 
   /// FIFO queue of work that needs to be completed before the returned AST
   /// nodes are correct.

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

@@ -1230,6 +1230,7 @@ class KernelVisitor extends Object
   @override
   ir.Expression visitCompoundIndexSet(SendSet node, Node receiver, Node index,
       AssignmentOperator operator, Node rhs, _) {
+    // TODO(sra): Find binary operator.
     return buildIndexAccessor(receiver, index).buildCompoundAssignment(
         kernel.irName(operator.selectorName, currentElement),
         visitForValue(rhs),
@@ -1289,7 +1290,8 @@ class KernelVisitor extends Object
         receiver == null ? new ir.ThisExpression() : visitForValue(receiver);
     ir.Expression compound = buildCompound(
         PropertyAccessor.make(receiverNode, nameToIrName(name), null, null),
-        rhs);
+        rhs,
+        node);
     if (compound is ir.VariableSet) {
       associateNode(compound.value, node);
     } else {
@@ -1720,19 +1722,32 @@ class KernelVisitor extends Object
     return buildLocalGet(element);
   }
 
-  ir.Expression buildCompound(Accessor accessor, CompoundRhs rhs) {
+  ir.Expression buildCompound(
+      Accessor accessor, CompoundRhs rhs, SendSet node) {
     ir.Name name = kernel.irName(rhs.operator.selectorName, currentElement);
+    ir.Expression result;
     switch (rhs.kind) {
       case CompoundKind.POSTFIX:
-        return accessor.buildPostfixIncrement(name, voidContext: isVoidContext);
+        result =
+            accessor.buildPostfixIncrement(name, voidContext: isVoidContext);
+        break;
 
       case CompoundKind.PREFIX:
-        return accessor.buildPrefixIncrement(name, voidContext: isVoidContext);
+        result =
+            accessor.buildPrefixIncrement(name, voidContext: isVoidContext);
+        break;
 
       case CompoundKind.ASSIGNMENT:
-        return accessor.buildCompoundAssignment(name, visitForValue(rhs.rhs),
+        result = accessor.buildCompoundAssignment(name, visitForValue(rhs.rhs),
             voidContext: isVoidContext);
+        break;
     }
+    assert(accessor.builtBinary != null);
+    kernel.nodeToAstOperator[accessor.builtBinary] = node;
+    if (accessor.builtGetter != null) {
+      kernel.nodeToAst[accessor.builtGetter] = node;
+    }
+    return result;
   }
 
   @override
@@ -1740,7 +1755,7 @@ class KernelVisitor extends Object
       SendSet node, LocalElement local, CompoundRhs rhs, _,
       {bool isSetterValid}) {
     ir.Expression compound =
-        buildCompound(new VariableAccessor(getLocal(local)), rhs);
+        buildCompound(new VariableAccessor(getLocal(local)), rhs, node);
     if (compound is ir.VariableSet) {
       associateNode(compound.value, node);
     } else {
@@ -2235,6 +2250,7 @@ class KernelVisitor extends Object
       AssignmentOperator operator,
       Node rhs,
       _) {
+    // TODO(sra): Find binary operator.
     return buildSuperIndexAccessor(index, getter, setter)
         .buildCompoundAssignment(
             kernel.irName(operator.selectorName, currentElement),
@@ -2286,7 +2302,7 @@ class KernelVisitor extends Object
     if (setterKind == CompoundSetter.INVALID) {
       setter = null;
     }
-    return buildCompound(buildSuperPropertyAccessor(getter, setter), rhs);
+    return buildCompound(buildSuperPropertyAccessor(getter, setter), rhs, node);
   }
 
   @override
@@ -2301,13 +2317,14 @@ class KernelVisitor extends Object
     if (setterKind == CompoundSetter.INVALID) {
       setter = null;
     }
-    return buildCompound(buildStaticAccessor(getter, setter), rhs);
+    return buildCompound(buildStaticAccessor(getter, setter), rhs, node);
   }
 
   @override
   ir.Expression handleTypeLiteralConstantCompounds(
       SendSet node, ConstantExpression constant, CompoundRhs rhs, _) {
-    return buildCompound(new ReadOnlyAccessor(buildTypeLiteral(constant)), rhs);
+    return buildCompound(
+        new ReadOnlyAccessor(buildTypeLiteral(constant)), rhs, node);
   }
 
   ir.TypeLiteral buildTypeVariable(TypeVariableElement element) {
@@ -2317,7 +2334,8 @@ class KernelVisitor extends Object
   @override
   ir.Expression handleTypeVariableTypeLiteralCompounds(
       SendSet node, TypeVariableElement element, CompoundRhs rhs, _) {
-    return buildCompound(new ReadOnlyAccessor(buildTypeVariable(element)), rhs);
+    return buildCompound(
+        new ReadOnlyAccessor(buildTypeVariable(element)), rhs, node);
   }
 
   @override

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

@@ -86,6 +86,9 @@ class KernelSsaBuilder extends ir.Visitor with GraphBuilder {
   LoopHandler<ir.Node> loopHandler;
   TypeBuilder typeBuilder;
 
+  final Map<ir.VariableDeclaration, HInstruction> letBindings =
+      <ir.VariableDeclaration, HInstruction>{};
+
   KernelSsaBuilder(
       this.targetElement,
       this.resolvedAst,
@@ -939,10 +942,31 @@ class KernelSsaBuilder extends ir.Visitor with GraphBuilder {
 
   @override
   void visitVariableGet(ir.VariableGet variableGet) {
+    ir.VariableDeclaration variable = variableGet.variable;
+    HInstruction letBinding = letBindings[variable];
+    if (letBinding != null) {
+      stack.add(letBinding);
+      return;
+    }
+
     Local local = astAdapter.getLocal(variableGet.variable);
     stack.add(localsHandler.readLocal(local));
   }
 
+  @override
+  void visitPropertySet(ir.PropertySet propertySet) {
+    propertySet.receiver.accept(this);
+    HInstruction receiver = pop();
+    propertySet.value.accept(this);
+    HInstruction value = pop();
+
+    _pushDynamicInvocation(propertySet, astAdapter.typeOfSet(propertySet),
+        <HInstruction>[receiver, value]);
+
+    pop();
+    stack.add(value);
+  }
+
   @override
   void visitVariableSet(ir.VariableSet variableSet) {
     variableSet.value.accept(this);
@@ -984,6 +1008,16 @@ class KernelSsaBuilder extends ir.Visitor with GraphBuilder {
             value, astAdapter.getDartType(variable.type)));
   }
 
+  @override
+  void visitLet(ir.Let let) {
+    ir.VariableDeclaration variable = let.variable;
+    variable.initializer.accept(this);
+    HInstruction initializedValue = pop();
+    // TODO(sra): Apply inferred type information.
+    letBindings[variable] = initializedValue;
+    let.body.accept(this);
+  }
+
   // TODO(het): Also extract type arguments
   /// Extracts the list of instructions for the expressions in the arguments.
   List<HInstruction> _visitArguments(ir.Arguments arguments) {

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

@@ -96,7 +96,8 @@ class KernelAstAdapter {
 
   ast.Node getNode(ir.Node node) {
     ast.Node result = _nodeToAst[node];
-    assert(result != null);
+    assert(invariant(CURRENT_ELEMENT_SPANNABLE, result != null,
+        message: "No node found for $node"));
     return result;
   }
 
@@ -144,6 +145,7 @@ class KernelAstAdapter {
 
   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);
     _compiler.reporter.internalError(getNode(node),
         "Can only get the selector for a property get or an invocation.");
@@ -174,7 +176,18 @@ class KernelAstAdapter {
     return new Selector.getter(name);
   }
 
+  Selector getSetterSelector(ir.PropertySet setter) {
+    ir.Name irName = setter.name;
+    Name name = new Name(
+        irName.name, irName.isPrivate ? getElement(irName.library) : null);
+    return new Selector.setter(name);
+  }
+
   TypeMask typeOfInvocation(ir.Expression send) {
+    ast.Node operatorNode = kernel.nodeToAstOperator[send];
+    if (operatorNode != null) {
+      return _resultOf(_target).typeOfOperator(operatorNode);
+    }
     return _resultOf(_target).typeOfSend(getNode(send));
   }
 
@@ -182,6 +195,10 @@ class KernelAstAdapter {
     return _resultOf(_target).typeOfSend(getNode(getter));
   }
 
+  TypeMask typeOfSet(ir.PropertySet setter) {
+    return _compiler.closedWorld.commonMasks.dynamicType;
+  }
+
   TypeMask typeOfSend(ir.Expression send) {
     assert(send is ir.InvocationExpression || send is ir.PropertyGet);
     return _resultOf(_target).typeOfSend(getNode(send));

pkg/kernel/lib/frontend/accessors.dart

@@ -9,6 +9,13 @@ library kernel.frontend.accessors;
 import '../ast.dart';
 
 abstract class Accessor {
+  // [builtBinary] and [builtGetter] capture the inner nodes. Used by
+  // dart2js+rasta for determining how subexpressions map to legacy dart2js Ast
+  // nodes. This will be removed once dart2js type analysis (aka inference) is
+  // reimplemented on kernel.
+  Expression builtBinary;
+  Expression builtGetter;
+
   Expression buildSimpleRead() {
     return _finish(_makeSimpleRead());
   }
@@ -37,7 +44,8 @@ abstract class Accessor {
   Expression buildCompoundAssignment(Name binaryOperator, Expression value,
       {bool voidContext: false, Procedure interfaceTarget}) {
     return _finish(_makeWrite(
-        makeBinary(_makeRead(), binaryOperator, interfaceTarget, value),
+        builtBinary =
+            makeBinary(_makeRead(), binaryOperator, interfaceTarget, value),
         voidContext));
   }
 
@@ -56,7 +64,7 @@ abstract class Accessor {
     var value = new VariableDeclaration.forValue(_makeRead());
     valueAccess() => new VariableGet(value);
     var dummy = new VariableDeclaration.forValue(_makeWrite(
-        makeBinary(
+        builtBinary = makeBinary(
             valueAccess(), binaryOperator, interfaceTarget, new IntLiteral(1)),
         true));
     return _finish(makeLet(value, makeLet(dummy, valueAccess())));
@@ -122,7 +130,7 @@ class PropertyAccessor extends Accessor {
     return new VariableGet(_receiverVariable);
   }
 
-  _makeRead() => new PropertyGet(receiverAccess(), name, getter);
+  _makeRead() => builtGetter = new PropertyGet(receiverAccess(), name, getter);
 
   _makeWrite(Expression value, bool voidContext) {
     return new PropertySet(receiverAccess(), name, value, setter);
@@ -139,7 +147,8 @@ class ThisPropertyAccessor extends Accessor {
 
   ThisPropertyAccessor(this.name, this.getter, this.setter);
 
-  _makeRead() => new PropertyGet(new ThisExpression(), name, getter);
+  _makeRead() =>
+      builtGetter = new PropertyGet(new ThisExpression(), name, getter);
 
   _makeWrite(Expression value, bool voidContext) {
     return new PropertySet(new ThisExpression(), name, value, setter);
@@ -158,7 +167,7 @@ class NullAwarePropertyAccessor extends Accessor {
 
   receiverAccess() => new VariableGet(receiver);
 
-  _makeRead() => new PropertyGet(receiverAccess(), name, getter);
+  _makeRead() => builtGetter = new PropertyGet(receiverAccess(), name, getter);
 
   _makeWrite(Expression value, bool voidContext) {
     return new PropertySet(receiverAccess(), name, value, setter);