Generative constructors in the new dart backend.

pkg/compiler/lib/src/tree_ir/optimization/statement_rewriter.dart

 // Copyright (c) 2014, 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 tree_ir.optimization;
 
 /**
  * Performs the following transformations on the tree:
  * - Assignment propagation
  * - If-to-conditional conversion
@@ skipping 73 matching lines @@
  * to their label are redirected.
  * For example, where 'jump' is either break or continue:
  *
  *   L0: {... break L0 ...}; jump L1
  *     ==>
  *   {... jump L1 ...}
  *
  * This may trigger a flattening of nested ifs in case the eliminated label
  * separated two ifs.
  */
-class StatementRewriter extends Visitor<Statement, Expression> implements Pass {
+class StatementRewriter extends Visitor<Statement, Expression> with PassMixin {
   // The binding environment.  The rightmost element of the list is the nearest
   // available enclosing binding.
   List<Assign> environment;
 
   /// Substitution map for labels. Any break to a label L should be substituted
   /// for a break to L' if L maps to L'.
   Map<Label, Jump> labelRedirects = <Label, Jump>{};
 
   /// Returns the redirect target of [label] or [label] itself if it should not
   /// be redirected.
   Jump redirect(Jump jump) {
     Jump newJump = labelRedirects[jump.target];
     return newJump != null ? newJump : jump;
   }
 
-  void rewrite(ExecutableDefinition definition) => definition.applyPass(this);
 
-  void rewriteFieldDefinition(FieldDefinition definition) {
-    if (!definition.hasInitializer) return;
+  rewriteExecutableDefinition(ExecutableDefinition definition) {
+    definition.body = rewriteInEmptyEnvironment(definition.body);
+  }
 
+  void rewriteConstructorDefinition(ConstructorDefinition definition) {
+    if (definition.isAbstract) return;
+    definition.initializers.forEach(visitExpression);
+    rewriteExecutableDefinition(definition);
+  }
+
+  Statement rewriteInEmptyEnvironment(Statement body) {
+    List<Assign> oldEnvironment = environment;
     environment = <Assign>[];
-    definition.body = visitStatement(definition.body);
 
+    Statement result = visitStatement(body);
     // TODO(kmillikin):  Allow definitions that are not propagated.  Here,
     // this means rebuilding the binding with a recursively unnamed definition,
     // or else introducing a variable definition and an assignment.
     assert(environment.isEmpty);
+    environment = oldEnvironment;
+    return result;
   }
 
-  void rewriteFunctionDefinition(FunctionDefinition definition) {
-    if (definition.isAbstract) return;
-
-    environment = <Assign>[];
-    definition.body = visitStatement(definition.body);
-
-    // TODO(kmillikin):  Allow definitions that are not propagated.  Here,
-    // this means rebuilding the binding with a recursively unnamed definition,
-    // or else introducing a variable definition and an assignment.
-    assert(environment.isEmpty);
+  Expression visitFieldInitializer(FieldInitializer node) {
+    node.body = rewriteInEmptyEnvironment(node.body);
+    return node;
   }
 
+  Expression visitSuperInitializer(SuperInitializer node) {
+    for (int i = node.arguments.length - 1; i >= 0; --i) {
+      node.arguments[i] = rewriteInEmptyEnvironment(node.arguments[i]);
+    }
+    return node;
+  }
 
   Expression visitExpression(Expression e) => e.processed ? e : e.accept(this);
 
   Expression visitVariable(Variable node) {
     // Propagate a variable's definition to its use site if:
     // 1.  It has a single use, to avoid code growth and potential duplication
     //     of side effects, AND
     // 2.  It was the most recent expression evaluated so that we do not
     //     reorder expressions with side effects.
     if (!environment.isEmpty &&
@@ skipping 411 matching lines @@
   }
 
   Expression makeCondition(Expression e, bool polarity) {
     return polarity ? e : new Not(e);
   }
 
   Statement getBranch(If node, bool polarity) {
     return polarity ? node.thenStatement : node.elseStatement;
   }
 }