Add visitor methods specific to ??= to SemanticSendVisitor.

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

 // Copyright (c) 2012, 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.
 
 part of ssa;
 
 class SsaFunctionCompiler implements FunctionCompiler {
   final SsaCodeGeneratorTask generator;
   final SsaBuilderTask builder;
   final SsaOptimizerTask optimizer;
@@ skipping 972 matching lines @@
     }
     super.close();
   }
 }
 
 /**
  * This class builds SSA nodes for functions represented in AST.
  */
 class SsaBuilder extends ast.Visitor
     with BaseImplementationOfCompoundsMixin,
+         BaseImplementationOfSetIfNullsMixin,
          SendResolverMixin,
          SemanticSendResolvedMixin,
          NewBulkMixin,
          ErrorBulkMixin
     implements SemanticSendVisitor {
   final Compiler compiler;
   final JavaScriptBackend backend;
   final ConstantSystem constantSystem;
   final CodegenWorkItem work;
   final RuntimeTypes rti;
@@ skipping 5718 matching lines @@
       ast.SendSet node,
       Element getter,
       CompoundGetter getterKind,
       Element setter,
       CompoundSetter setterKind,
       CompoundRhs rhs,
       _) {
     handleCompoundSendSet(node);
   }
 
+  @override
+  handleDynamicSetIfNulls(
+      ast.Send node,
+      ast.Node receiver,
+      Name name,
+      ast.Node rhs,
+      arg) {
+    handleCompoundSendSet(node);
+  }
+
+  @override
+  handleLocalSetIfNulls(
+      ast.SendSet node,
+      LocalElement local,
+      ast.Node rhs,
+      arg,
+      {bool isSetterValid}) {
+    handleCompoundSendSet(node);
+  }
+
+  @override
+  handleStaticSetIfNulls(
+      ast.SendSet node,
+      Element getter,
+      CompoundGetter getterKind,
+      Element setter,
+      CompoundSetter setterKind,
+      ast.Node rhs,
+      arg) {
+    handleCompoundSendSet(node);
+  }
+
+  @override
+  handleSuperSetIfNulls(
+      ast.SendSet node,
+      Element getter,
+      CompoundGetter getterKind,
+      Element setter,
+      CompoundSetter setterKind,
+      ast.Node rhs,
+      arg) {
+    handleSuperSendSet(node);
+  }
+
+  @override
+  handleTypeLiteralConstantSetIfNulls(
+      ast.SendSet node,
+      ConstantExpression constant,
+      ast.Node rhs,
+      arg) {
+    // The type variable is never `null`.
+    generateConstantTypeLiteral(node);
+  }
+
+  @override
+  visitTypeVariableTypeLiteralSetIfNull(
+      ast.Send node,
+      TypeVariableElement element,
+      ast.Node rhs,
+      arg) {
+    // The type variable is never `null`.
+    generateTypeVariableLiteral(node, element.type);
+  }
+
   void visitLiteralInt(ast.LiteralInt node) {
     stack.add(graph.addConstantInt(node.value, compiler));
   }
 
   void visitLiteralDouble(ast.LiteralDouble node) {
     stack.add(graph.addConstantDouble(node.value, compiler));
   }
 
   void visitLiteralBool(ast.LiteralBool node) {
     stack.add(graph.addConstantBool(node.value, compiler));
@@ skipping 1443 matching lines @@
       localsHandler.updateLocal(returnLocal, value);
     }
   }
 
   @override
   void handleTypeLiteralConstantCompounds(
       ast.SendSet node,
       ConstantExpression constant,
       CompoundRhs rhs,
       _) {
-    if (rhs.operator.kind == BinaryOperatorKind.IF_NULL) {
-      handleCompoundSendSet(node);
-    } else {
-      handleTypeLiteralCompound(node);
-    }
+    handleTypeLiteralCompound(node);
   }
 
   @override
   void handleTypeVariableTypeLiteralCompounds(
       ast.SendSet node,
       TypeVariableElement typeVariable,
       CompoundRhs rhs,
       _) {
     handleTypeLiteralCompound(node);
   }
@@ skipping 656 matching lines @@
     if (unaliased is TypedefType) throw 'unable to unalias $type';
     unaliased.accept(this, builder);
   }
 
   void visitDynamicType(DynamicType type, SsaBuilder builder) {
     JavaScriptBackend backend = builder.compiler.backend;
     ClassElement cls = backend.findHelper('DynamicRuntimeType');
     builder.push(new HDynamicType(type, new TypeMask.exact(cls, classWorld)));
   }
 }