Streamline the CPS IR Visitor interface.

pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart

Index: pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart
diff --git a/pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart b/pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart
index 1fcb5a732889f1a964485fdda261b1df811d129f..448210697508567eaf96f77b1d8a58222fafbb2d 100644
--- a/pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart
+++ b/pkg/compiler/lib/src/cps_ir/cps_ir_tracer.dart
@@ -31,34 +31,51 @@ class IRTracer extends TracerUtil implements cps_ir.Visitor {
   // 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) {
@@ -71,7 +88,7 @@ class IRTracer extends TracerUtil implements cps_ir.Visitor {
     return count;
   }
 
-  printNode(Block block) {
+  printBlock(Block block) {
     tag("block", () {
       printProperty("name", block.name);
       printProperty("from_bci", -1);
@@ -320,16 +337,6 @@ class IRTracer extends TracerUtil implements cps_ir.Visitor {
     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) {}
 }
 
 /**
@@ -385,7 +392,7 @@ class Block {
   }
 }
 
-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>();
@@ -403,36 +410,34 @@ class BlockCollector extends cps_ir.Visitor {
     return block;
   }
 
-  visitRunnableBody(cps_ir.RunnableBody node) {
-    current_block = new Block(names.name(node), [], node.body);
-    entries.add(current_block);
-    visit(node.body);
-  }
+  visit(cps_ir.Node node) => node.accept(this);
 
-  visitFieldInitializer(cps_ir.FieldInitializer node) {
-    visit(node.body);
+  visitFieldDefinition(cps_ir.FieldDefinition node) {
+    if (node.hasInitializer) {
+      visit(node.body);
+    }
   }
 
-  visitSuperInitializer(cps_ir.SuperInitializer node) {
-    node.arguments.forEach(visit);
+  visitFunctionDefinition(cps_ir.FunctionDefinition node) {
+    visit(node.body);
   }
 
-  visitExecutableDefinition(cps_ir.ExecutableDefinition node) {
+  visitConstructorDefinition(cps_ir.ConstructorDefinition node) {
     visit(node.body);
   }
 
-  visitFieldDefinition(cps_ir.FieldDefinition node) {
-    if (node.hasInitializer) {
-      visitExecutableDefinition(node);
-    }
+  visitRunnableBody(cps_ir.RunnableBody node) {
+    current_block = new Block(names.name(node), [], node.body);
+    entries.add(current_block);
+    visit(node.body);
   }
 
-  visitFunctionDefinition(cps_ir.FunctionDefinition node) {
-    visitExecutableDefinition(node);
+  visitFieldInitializer(cps_ir.FieldInitializer node) {
+    visit(node.body);
   }
 
-  visitConstructorDefinition(cps_ir.ConstructorDefinition node) {
-    visitExecutableDefinition(node);
+  visitSuperInitializer(cps_ir.SuperInitializer node) {
+    node.arguments.forEach(visit);
   }
 
   visitLetPrim(cps_ir.LetPrim exp) {
@@ -460,6 +465,10 @@ class BlockCollector extends cps_ir.Visitor {
     }
   }
 
+  visitInvokeContinuation(cps_ir.InvokeContinuation exp) {
+    addEdgeToContinuation(exp.continuation);
+  }
+
   visitInvokeStatic(cps_ir.InvokeStatic exp) {
     addEdgeToContinuation(exp.continuation);
   }
@@ -468,15 +477,15 @@ class BlockCollector extends cps_ir.Visitor {
     addEdgeToContinuation(exp.continuation);
   }
 
-  visitInvokeConstructor(cps_ir.InvokeConstructor exp) {
+  visitInvokeMethodDirectly(cps_ir.InvokeMethodDirectly exp) {
     addEdgeToContinuation(exp.continuation);
   }
 
-  visitConcatenateStrings(cps_ir.ConcatenateStrings exp) {
+  visitInvokeConstructor(cps_ir.InvokeConstructor exp) {
     addEdgeToContinuation(exp.continuation);
   }
 
-  visitInvokeContinuation(cps_ir.InvokeContinuation exp) {
+  visitConcatenateStrings(cps_ir.ConcatenateStrings exp) {
     addEdgeToContinuation(exp.continuation);
   }
 
@@ -503,10 +512,66 @@ class BlockCollector extends cps_ir.Visitor {
     }
   }
 
+  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);
+  }
 }