Overhaul tree IR visitor and rename IR classes.

pkg/compiler/lib/src/tree_ir/tree_ir_integrity.dart

 library tree_ir.integrity;
 
 import 'tree_ir_nodes.dart';
 
 /// Performs integrity checks on the tree_ir.
 ///
 /// Should only be run for debugging purposes, not in production.
 ///
 /// - Reference counts on must match the actual number of references.
 /// - Labels must be in scope when referenced.
 /// - Breaks must target a [LabeledStatement].
 /// - Continues must target a [Loop].
 /// - Variables must only be used after their first assignment
 ///   (checked on a best-effort basis).
 /// - Variables with a declaration must only be referenced in scope.
 /// - Variables must not have more than one declaration.
 ///
 class CheckTreeIntegrity extends RecursiveVisitor {
-  ExecutableDefinition topLevelNode;
+  RootNode topLevelNode;
 
   Map<Variable, int> varReads = <Variable, int>{};
   Map<Variable, int> varWrites = <Variable, int>{};
   Map<Label, int> labelUses = <Label, int>{};
   Map<Label, JumpTarget> label2declaration = <Label, JumpTarget>{};
 
   /// Variables that are currently in scope.
   Set<Variable> scope = new Set<Variable>();
 
   /// Variables for which we have seen a declaration.
@@ skipping 48 matching lines @@
     }
   }
 
   visitTry(Try node) {
     visitStatement(node.tryBody);
     node.catchParameters.forEach(declare);
     visitStatement(node.catchBody);
     node.catchParameters.forEach(undeclare);
   }
 
-  visitFunctionDefinition(FunctionDefinition node) {
-    node.parameters.forEach(declare);
-    if (node.body != null) visitStatement(node.body);
-    node.parameters.forEach(undeclare);
-  }
-
-  visitConstructorDefinition(ConstructorDefinition node) {
-    node.parameters.forEach(declare);
-    if (node.initializers != null) node.initializers.forEach(visitInitializer);
-    if (node.body != null) visitStatement(node.body);
-    node.parameters.forEach(undeclare);
-  }
-
   visitFunctionDeclaration(FunctionDeclaration node) {
     declare(node.variable);
-    visitFunctionDefinition(node.definition);
+    checkBody(node.definition);
     visitStatement(node.next);
     undeclare(node.variable);
     if (varWrites[node.variable] > 1) {
       error('Assignment to function declaration ${node.variable}');
     }
   }
 
   visitJumpTargetBody(JumpTarget target) {
     Label label = target.label;
     if (label2declaration.containsKey(label)) {
@@ skipping 38 matching lines @@
   visitContinue(Continue node) {
     if (!label2declaration.containsKey(node.target)) {
       error('Continue to label that is not in scope');
     }
     if (label2declaration[node.target] is! Loop) {
       error('Continue to non-loop statement ${label2declaration[node.target]}');
     }
     labelUses[node.target]++;
   }
 
+  visitInnerFunction(FunctionDefinition node) {
+    checkBody(node);
+  }
+
+  void checkBody(RootNode node) {
+    node.parameters.forEach(declare);
+    node.forEachBody(visitStatement);
+    node.parameters.forEach(undeclare);
+  }
+
   dynamic error(String message) {
     throw 'Tree IR integrity violation in ${topLevelNode.element}:\n$message';
   }
 
-  void check(ExecutableDefinition node) {
+  void check(RootNode node) {
     topLevelNode = node;
-    visitExecutableDefinition(node);
+    checkBody(node);
 
     // Verify reference counters for all variables.
     List<Variable> seenVariables = new List<Variable>();
     seenVariables.addAll(varReads.keys);
     seenVariables.addAll(varWrites.keys);
     for (Variable variable in seenVariables) {
       int reads = varReads.putIfAbsent(variable, () => 0);
       int writes = varWrites.putIfAbsent(variable, () => 0);
       if (reads != variable.readCount || writes != variable.writeCount) {
         error('Invalid reference count for $variable:\n'
               '- Variable has $reads reads and $writes writes\n'
               '- Reference count is ${variable.readCount} reads and '
               '${variable.writeCount} writes');
       }
     }
   }
 
 }