Implementation of null-aware operators.

pkg/compiler/lib/src/resolution/semantic_visitor_mixins.dart

Index: pkg/compiler/lib/src/resolution/semantic_visitor_mixins.dart
diff --git a/pkg/compiler/lib/src/resolution/semantic_visitor_mixins.dart b/pkg/compiler/lib/src/resolution/semantic_visitor_mixins.dart
index 3e10c20c9ac6b216b6f716d731b779eb57d4a20a..69665d7547c8f514159056c053cef01854170132 100644
--- a/pkg/compiler/lib/src/resolution/semantic_visitor_mixins.dart
+++ b/pkg/compiler/lib/src/resolution/semantic_visitor_mixins.dart
@@ -86,6 +86,16 @@ abstract class PrefixBulkMixin<R, A>
     return bulkHandlePrefix(node, arg);
   }
 
+  R visitIfNotNullDynamicPropertyPrefix(
+      Send node,
+      Node receiver,
+      IncDecOperator operator,
+      Selector getterSelector,
+      Selector setterSelector,
+      A arg) {
+    return bulkHandlePrefix(node, arg);
+  }
+
   @override
   R visitIndexPrefix(
       Send node,
@@ -504,6 +514,16 @@ abstract class PostfixBulkMixin<R, A>
   }
 
   @override
+  R visitIfNotNullDynamicPropertyPostfix(
+      Send node,
+      Node receiver,
+      IncDecOperator operator,
+      Selector getterSelector,
+      Selector setterSelector,
+      A arg) {
+    return bulkHandlePostfix(node, arg);
+  }
+
   R visitIndexPostfix(
       Send node,
       Node receiver,
@@ -930,6 +950,18 @@ abstract class CompoundBulkMixin<R, A>
   }
 
   @override
+  R visitIfNotNullDynamicPropertyCompound(
+      Send node,
+      Node receiver,
+      AssignmentOperator operator,
+      Node rhs,
+      Selector getterSelector,
+      Selector setterSelector,
+      A arg) {
+    return bulkHandleCompound(node, arg);
+  }
+
+  @override
   R visitLocalVariableCompound(
       Send node,
       LocalVariableElement variable,
@@ -1337,6 +1369,16 @@ abstract class InvokeBulkMixin<R, A>
   }
 
   @override
+  R visitIfNotNullDynamicPropertyInvoke(
+      Send node,
+      Node receiver,
+      NodeList arguments,
+      Selector selector,
+      A arg) {
+    return bulkHandleInvoke(node, arg);
+  }
+
+  @override
   R visitDynamicTypeLiteralInvoke(
       Send node,
       ConstantExpression constant,
@@ -1635,6 +1677,15 @@ abstract class GetBulkMixin<R, A>
   }
 
   @override
+  R visitIfNotNullDynamicPropertyGet(
+      Send node,
+      Node receiver,
+      Selector selector,
+      A arg) {
+    return bulkHandleGet(node, arg);
+  }
+
+  @override
   R visitDynamicTypeLiteralGet(
       Send node,
       ConstantExpression constant,
@@ -1839,6 +1890,16 @@ abstract class SetBulkMixin<R, A>
   }
 
   @override
+  R visitIfNotNullDynamicPropertySet(
+      SendSet node,
+      Node receiver,
+      Selector selector,
+      Node rhs,
+      A arg) {
+    return bulkHandleSet(node, arg);
+  }
+
+  @override
   R visitLocalVariableSet(
       SendSet node,
       LocalVariableElement variable,
@@ -2382,6 +2443,15 @@ abstract class BaseBulkMixin<R, A>
   }
 
   @override
+  R visitIfNull(
+      Send node,
+      Node left,
+      Node right,
+      A arg) {
+    return bulkHandleNode(node, 'If-null (Lazy ?? `#`) unhandled.', arg);
+  }
+
+  @override
   R visitLogicalAnd(
       Send node,
       Node left,
@@ -3840,6 +3910,20 @@ class TraversalSendMixin<R, A> implements SemanticSendVisitor<R, A> {
   }
 
   @override
+  R visitIfNotNullDynamicPropertyCompound(
+      Send node,
+      Node receiver,
+      AssignmentOperator operator,
+      Node rhs,
+      Selector getterSelector,
+      Selector setterSelector,
+      A arg) {
+    apply(receiver, arg);
+    apply(rhs, arg);
+    return null;
+  }
+
+  @override
   R visitDynamicPropertyGet(
       Send node,
       Node receiver,
@@ -3850,6 +3934,16 @@ class TraversalSendMixin<R, A> implements SemanticSendVisitor<R, A> {
   }
 
   @override
+  R visitIfNotNullDynamicPropertyGet(
+      Send node,
+      Node receiver,
+      Selector selector,
+      A arg) {
+    apply(receiver, arg);
+    return null;
+  }
+
+  @override
   R visitDynamicPropertyInvoke(
       Send node,
       Node receiver,
@@ -3862,6 +3956,18 @@ class TraversalSendMixin<R, A> implements SemanticSendVisitor<R, A> {
   }
 
   @override
+  R visitIfNotNullDynamicPropertyInvoke(
+      Send node,
+      Node receiver,
+      NodeList arguments,
+      Selector selector,
+      A arg) {
+    apply(receiver, arg);
+    apply(arguments, arg);
+    return null;
+  }
+
+  @override
   R visitDynamicPropertyPostfix(
       Send node,
       Node receiver,
@@ -3874,6 +3980,18 @@ class TraversalSendMixin<R, A> implements SemanticSendVisitor<R, A> {
   }
 
   @override
+  R visitIfNotNullDynamicPropertyPostfix(
+      Send node,
+      Node receiver,
+      IncDecOperator operator,
+      Selector getterSelector,
+      Selector setterSelector,
+      A arg) {
+    apply(receiver, arg);
+    return null;
+  }
+
+  @override
   R visitDynamicPropertyPrefix(
       Send node,
       Node receiver,
@@ -3886,6 +4004,18 @@ class TraversalSendMixin<R, A> implements SemanticSendVisitor<R, A> {
   }
 
   @override
+  R visitIfNotNullDynamicPropertyPrefix(
+      Send node,
+      Node receiver,
+      IncDecOperator operator,
+      Selector getterSelector,
+      Selector setterSelector,
+      A arg) {
+    apply(receiver, arg);
+    return null;
+  }
+
+  @override
   R visitDynamicPropertySet(
       SendSet node,
       Node receiver,
@@ -3898,6 +4028,17 @@ class TraversalSendMixin<R, A> implements SemanticSendVisitor<R, A> {
   }
 
   @override
+  R visitIfNotNullDynamicPropertySet(
+      SendSet node,
+      Node receiver,
+      Selector selector,
+      Node rhs,
+      A arg) {
+    apply(rhs, arg);
+    return null;
+  }
+
+  @override
   R visitDynamicTypeLiteralCompound(
       Send node,
       ConstantExpression constant,
@@ -4090,6 +4231,17 @@ class TraversalSendMixin<R, A> implements SemanticSendVisitor<R, A> {
   }
 
   @override
+  R visitIfNull(
+      Send node,
+      Node left,
+      Node right,
+      A arg) {
+    apply(left, arg);
+    apply(right, arg);
+    return null;
+  }
+
+  @override
   R visitLogicalAnd(
       Send node,
       Node left,
@@ -7498,6 +7650,16 @@ abstract class BaseImplementationOfDynamicsMixin<R, A>
   }
 
   @override
+  R visitIfNotNullDynamicPropertyGet(
+      Send node,
+      Node receiver,
+      Selector selector,
+      A arg) {
+    // TODO(johnniwinther): should these redirect to handleDynamicX?
+    return handleDynamicGet(node, receiver, selector, arg);
+  }
+
+  @override
   R visitDynamicPropertyInvoke(
       Send node,
       Node receiver,
@@ -7508,6 +7670,16 @@ abstract class BaseImplementationOfDynamicsMixin<R, A>
   }
 
   @override
+  R visitIfNotNullDynamicPropertyInvoke(
+      Send node,
+      Node receiver,
+      NodeList arguments,
+      Selector selector,
+      A arg) {
+    return handleDynamicInvoke(node, receiver, arguments, selector, arg);
+  }
+
+  @override
   R visitDynamicPropertySet(
       SendSet node,
       Node receiver,
@@ -7518,6 +7690,16 @@ abstract class BaseImplementationOfDynamicsMixin<R, A>
   }
 
   @override
+  R visitIfNotNullDynamicPropertySet(
+      SendSet node,
+      Node receiver,
+      Selector selector,
+      Node rhs,
+      A arg) {
+    return handleDynamicSet(node, receiver, selector, rhs, arg);
+  }
+
+  @override
   R visitThisPropertyGet(
       Send node,
       Selector selector,
@@ -7592,6 +7774,19 @@ abstract class BaseImplementationOfDynamicCompoundsMixin<R, A>
   }
 
   @override
+  R visitIfNotNullDynamicPropertyCompound(
+      Send node,
+      Node receiver,
+      AssignmentOperator operator,
+      Node rhs,
+      Selector getterSelector,
+      Selector setterSelector,
+      A arg) {
+    return handleDynamicCompound(
+        node, receiver, operator, rhs, getterSelector, setterSelector, arg);
+  }
+
+  @override
   R visitDynamicPropertyPostfix(
       Send node,
       Node receiver,
@@ -7605,6 +7800,19 @@ abstract class BaseImplementationOfDynamicCompoundsMixin<R, A>
   }
 
   @override
+  R visitIfNotNullDynamicPropertyPostfix(
+      Send node,
+      Node receiver,
+      IncDecOperator operator,
+      Selector getterSelector,
+      Selector setterSelector,
+      A arg) {
+    return handleDynamicPostfixPrefix(
+        node, receiver, operator,
+        getterSelector, setterSelector, arg, isPrefix: false);
+  }
+
+  @override
   R visitDynamicPropertyPrefix(
       Send node,
       Node receiver,
@@ -7618,6 +7826,19 @@ abstract class BaseImplementationOfDynamicCompoundsMixin<R, A>
   }
 
   @override
+  R visitIfNotNullDynamicPropertyPrefix(
+      Send node,
+      Node receiver,
+      IncDecOperator operator,
+      Selector getterSelector,
+      Selector setterSelector,
+      A arg) {
+    return handleDynamicPostfixPrefix(
+        node, receiver, operator,
+        getterSelector, setterSelector, arg, isPrefix: true);
+  }
+
+  @override
   R visitThisPropertyCompound(
       Send node,
       AssignmentOperator operator,
@@ -7829,6 +8050,23 @@ abstract class BaseImplementationOfCompoundsMixin<R, A>
         arg);
   }
 
+  R visitIfNotNullDynamicPropertyCompound(
+      Send node,
+      Node receiver,
+      AssignmentOperator operator,
+      Node rhs,
+      Selector getterSelector,
+      Selector setterSelector,
+      A arg) {
+    return handleDynamicCompounds(
+        node,
+        receiver,
+        new AssignmentCompound(operator, rhs),
+        getterSelector,
+        setterSelector,
+        arg);
+  }
+
   @override
   R visitThisPropertyCompound(
       Send node,
@@ -8212,6 +8450,22 @@ abstract class BaseImplementationOfCompoundsMixin<R, A>
         arg);
   }
 
+  R visitIfNotNullDynamicPropertyPrefix(
+      Send node,
+      Node receiver,
+      IncDecOperator operator,
+      Selector getterSelector,
+      Selector setterSelector,
+      A arg) {
+    return handleDynamicCompounds(
+        node,
+        receiver,
+        new IncDecCompound(CompoundKind.PREFIX, operator),
+        getterSelector,
+        setterSelector,
+        arg);
+  }
+
   @override
   R visitParameterPrefix(
       Send node,
@@ -8517,6 +8771,23 @@ abstract class BaseImplementationOfCompoundsMixin<R, A>
   }
 
   @override
+  R visitIfNotNullDynamicPropertyPostfix(
+      Send node,
+      Node receiver,
+      IncDecOperator operator,
+      Selector getterSelector,
+      Selector setterSelector,
+      A arg) {
+    return handleDynamicCompounds(
+        node,
+        receiver,
+        new IncDecCompound(CompoundKind.POSTFIX, operator),
+        getterSelector,
+        setterSelector,
+        arg);
+  }
+
+  @override
   R visitParameterPostfix(
       Send node,
       ParameterElement parameter,