Streamline the CPS IR Visitor interface.

pkg/compiler/lib/src/cps_ir/cps_ir_tracer.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.
 
 library dart2js.ir_tracer;
 
 import 'dart:async' show EventSink;
 
 import 'cps_ir_nodes.dart' as cps_ir hide Function;
 import '../tracer.dart';
@@ skipping 13 matching lines @@
   void traceGraph(String name, cps_ir.ExecutableDefinition graph) {
     tag("cfg", () {
       printProperty("name", name);
       visit(graph);
     });
   }
 
   // Temporary field used during tree walk
   Names names;
 
-  visitExecutableDefinition(cps_ir.ExecutableDefinition node) {
+  printDefinition(cps_ir.ExecutableDefinition node) {
     names = new Names();
     BlockCollector builder = new BlockCollector(names);
     builder.visit(node);
 
     for (Block block in builder.entries) {
-      printNode(block);
+      printBlock(block);
     }
     for (Block block in builder.cont2block.values) {
-      printNode(block);
+      printBlock(block);
     }
     names = null;
   }
 
   visitFieldDefinition(cps_ir.FieldDefinition node) {
     if (node.hasInitializer) {
-      visitExecutableDefinition(node);
+      printDefinition(node);
     }
   }
 
   visitFunctionDefinition(cps_ir.FunctionDefinition node) {
     if (node.isAbstract) return;
-    visitExecutableDefinition(node);
+    printDefinition(node);
   }
 
   visitConstructorDefinition(cps_ir.ConstructorDefinition node) {
     if (node.isAbstract) return;
-    visitExecutableDefinition(node);
+    printDefinition(node);
+  }
+
+  // Bodies and initializers are not visited.  They contain continuations which
+  // are found by a BlockCollector, then those continuations are processed by
+  // this visitor.
+  unexpectedNode(cps_ir.Node node) {
+    throw 'The IR tracer reached an unexpected IR instruction: $node';
+  }
+
+  visitRunnableBody(cps_ir.RunnableBody node) {
+    unexpectedNode(node);
+  }
+  visitFieldInitializer(cps_ir.FieldInitializer node) {
+    unexpectedNode(node);
+  }
+  visitSuperInitializer(cps_ir.SuperInitializer node) {
+    unexpectedNode(node);
   }
 
   int countUses(cps_ir.Definition definition) {
     int count = 0;
     cps_ir.Reference ref = definition.firstRef;
     while (ref != null) {
       ++count;
       ref = ref.next;
     }
     return count;
   }
 
-  printNode(Block block) {
+  printBlock(Block block) {
     tag("block", () {
       printProperty("name", block.name);
       printProperty("from_bci", -1);
       printProperty("to_bci", -1);
       printProperty("predecessors", block.pred.map((n) => n.name));
       printProperty("successors", block.succ.map((n) => n.name));
       printEmptyProperty("xhandlers");
       printEmptyProperty("flags");
       tag("states", () {
         tag("locals", () {
@@ skipping 228 matching lines @@
   }
 
   visitCreateFunction(cps_ir.CreateFunction node) {
     return "CreateFunction ${node.definition.element.name}";
   }
 
   visitGetMutableVariable(cps_ir.GetMutableVariable node) {
     String variable = names.name(node.variable.definition);
     return '${node.runtimeType} $variable';
   }
-
-  visitRunnableBody(cps_ir.RunnableBody node) {}
-  visitFieldInitializer(cps_ir.FieldInitializer node) {}
-  visitSuperInitializer(cps_ir.SuperInitializer node) {}
-  visitCondition(cps_ir.Condition c) {}
-  visitExpression(cps_ir.Expression e) {}
-  visitPrimitive(cps_ir.Primitive p) {}
-  visitDefinition(cps_ir.Definition d) {}
-  visitInitializer(cps_ir.Initializer i) {}
-  visitNode(cps_ir.Node n) {}
 }
 
 /**
  * Invents (and remembers) names for Continuations, Parameters, etc.
  * The names must match the conventions used by IR Hydra, e.g.
  * Continuations and Functions must have names of form B### since they
  * are visualized as basic blocks.
  */
 class Names {
   final Map<Object, String> names = {};
@@ skipping 35 matching lines @@
   final List<Block> pred = <Block>[];
 
   Block(this.name, this.parameters, this.body);
 
   void addEdgeTo(Block successor) {
     succ.add(successor);
     successor.pred.add(this);
   }
 }
 
-class BlockCollector extends cps_ir.Visitor {
+class BlockCollector implements cps_ir.Visitor {
   final Map<cps_ir.Continuation, Block> cont2block =
       <cps_ir.Continuation, Block>{};
   final Set<Block> entries = new Set<Block>();
   Block current_block;
 
   Names names;
   BlockCollector(this.names);
 
   Block getBlock(cps_ir.Continuation c) {
     Block block = cont2block[c];
     if (block == null) {
       block = new Block(names.name(c), c.parameters, c.body);
       cont2block[c] = block;
     }
     return block;
   }
 
+  visit(cps_ir.Node node) => node.accept(this);
+
+  visitFieldDefinition(cps_ir.FieldDefinition node) {
+    if (node.hasInitializer) {
+      visit(node.body);
+    }
+  }
+
+  visitFunctionDefinition(cps_ir.FunctionDefinition node) {
+    visit(node.body);
+  }
+
+  visitConstructorDefinition(cps_ir.ConstructorDefinition node) {
+    visit(node.body);
+  }
+
   visitRunnableBody(cps_ir.RunnableBody node) {
     current_block = new Block(names.name(node), [], node.body);
     entries.add(current_block);
     visit(node.body);
   }
 
   visitFieldInitializer(cps_ir.FieldInitializer node) {
     visit(node.body);
   }
 
   visitSuperInitializer(cps_ir.SuperInitializer node) {
     node.arguments.forEach(visit);
   }
 
-  visitExecutableDefinition(cps_ir.ExecutableDefinition node) {
-    visit(node.body);
-  }
-
-  visitFieldDefinition(cps_ir.FieldDefinition node) {
-    if (node.hasInitializer) {
-      visitExecutableDefinition(node);
-    }
-  }
-
-  visitFunctionDefinition(cps_ir.FunctionDefinition node) {
-    visitExecutableDefinition(node);
-  }
-
-  visitConstructorDefinition(cps_ir.ConstructorDefinition node) {
-    visitExecutableDefinition(node);
-  }
-
   visitLetPrim(cps_ir.LetPrim exp) {
     visit(exp.body);
   }
 
   visitLetCont(cps_ir.LetCont exp) {
     exp.continuations.forEach(visit);
     visit(exp.body);
   }
 
   visitLetHandler(cps_ir.LetHandler exp) {
     visit(exp.handler);
     visit(exp.body);
   }
 
   visitLetMutable(cps_ir.LetMutable exp) {
     visit(exp.body);
   }
 
   void addEdgeToContinuation(cps_ir.Reference continuation) {
     cps_ir.Definition target = continuation.definition;
     if (target is cps_ir.Continuation && !target.isReturnContinuation) {
       current_block.addEdgeTo(getBlock(target));
     }
   }
 
+  visitInvokeContinuation(cps_ir.InvokeContinuation exp) {
+    addEdgeToContinuation(exp.continuation);
+  }
+
   visitInvokeStatic(cps_ir.InvokeStatic exp) {
     addEdgeToContinuation(exp.continuation);
   }
 
   visitInvokeMethod(cps_ir.InvokeMethod exp) {
     addEdgeToContinuation(exp.continuation);
   }
 
+  visitInvokeMethodDirectly(cps_ir.InvokeMethodDirectly exp) {
+    addEdgeToContinuation(exp.continuation);
+  }
+
   visitInvokeConstructor(cps_ir.InvokeConstructor exp) {
     addEdgeToContinuation(exp.continuation);
   }
 
   visitConcatenateStrings(cps_ir.ConcatenateStrings exp) {
     addEdgeToContinuation(exp.continuation);
   }
 
-  visitInvokeContinuation(cps_ir.InvokeContinuation exp) {
-    addEdgeToContinuation(exp.continuation);
-  }
-
   visitSetMutableVariable(cps_ir.SetMutableVariable exp) {
     visit(exp.body);
   }
 
   visitSetField(cps_ir.SetField exp) {
     visit(exp.body);
   }
 
   visitDeclareFunction(cps_ir.DeclareFunction exp) {
     visit(exp.body);
   }
 
   visitBranch(cps_ir.Branch exp) {
     cps_ir.Continuation trueTarget = exp.trueContinuation.definition;
     if (!trueTarget.isReturnContinuation) {
       current_block.addEdgeTo(getBlock(trueTarget));
     }
     cps_ir.Continuation falseTarget = exp.falseContinuation.definition;
     if (!falseTarget.isReturnContinuation) {
       current_block.addEdgeTo(getBlock(falseTarget));
     }
   }
 
+  visitTypeOperator(cps_ir.TypeOperator exp) {
+    addEdgeToContinuation(exp.continuation);
+  }
+
   visitContinuation(cps_ir.Continuation c) {
     var old_node = current_block;
     current_block = getBlock(c);
     visit(c.body);
     current_block = old_node;
   }
+
+  // Primitives and conditions are not visited when searching for blocks.
+  unexpectedNode(cps_ir.Node node) {
+    throw "The IR tracer's block collector reached an unexpected IR "
+        "instruction: $node";
+  }
+
+  visitLiteralList(cps_ir.LiteralList node) {
+    unexpectedNode(node);
+  }
+  visitLiteralMap(cps_ir.LiteralMap node) {
+    unexpectedNode(node);
+  }
+  visitConstant(cps_ir.Constant node) {
+    unexpectedNode(node);
+  }
+  visitThis(cps_ir.This node) {
+    unexpectedNode(node);
+  }
+  visitReifyTypeVar(cps_ir.ReifyTypeVar node) {
+    unexpectedNode(node);
+  }
+  visitCreateFunction(cps_ir.CreateFunction node) {
+    unexpectedNode(node);
+  }
+  visitGetMutableVariable(cps_ir.GetMutableVariable node) {
+    unexpectedNode(node);
+  }
+  visitParameter(cps_ir.Parameter node) {
+    unexpectedNode(node);
+  }
+  visitMutableVariable(cps_ir.MutableVariable node) {
+    unexpectedNode(node);
+  }
+  visitGetField(cps_ir.GetField node) {
+    unexpectedNode(node);
+  }
+  visitCreateBox(cps_ir.CreateBox node) {
+    unexpectedNode(node);
+  }
+  visitCreateInstance(cps_ir.CreateInstance node) {
+    unexpectedNode(node);
+  }
+  visitIsTrue(cps_ir.IsTrue node) {
+    unexpectedNode(node);
+  }
+  visitIdentical(cps_ir.Identical node) {
+    unexpectedNode(node);
+  }
+  visitInterceptor(cps_ir.Interceptor node) {
+    unexpectedNode(node);
+  }
 }