1 files changed, 794 insertions, 12 deletions

diff --git a/deps/v8/src/rewriter.cc b/deps/v8/src/rewriter.cc
index 64d7b3684c..fd40cdc3fa 100644
--- a/deps/v8/src/rewriter.cc
+++ b/deps/v8/src/rewriter.cc
@@ -1,4 +1,4 @@
-// Copyright 2011 the V8 project authors. All rights reserved.
+// Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
@@ -36,6 +36,649 @@
 namespace v8 {
 namespace internal {
 
+class AstOptimizer: public AstVisitor {
+ public:
+  explicit AstOptimizer() : has_function_literal_(false) {}
+
+  void Optimize(ZoneList<Statement*>* statements);
+
+ private:
+  // Used for loop condition analysis.  Cleared before visiting a loop
+  // condition, set when a function literal is visited.
+  bool has_function_literal_;
+
+  // Helpers
+  void OptimizeArguments(ZoneList<Expression*>* arguments);
+
+  // Node visitors.
+#define DEF_VISIT(type) \
+  virtual void Visit##type(type* node);
+  AST_NODE_LIST(DEF_VISIT)
+#undef DEF_VISIT
+
+  DISALLOW_COPY_AND_ASSIGN(AstOptimizer);
+};
+
+
+void AstOptimizer::Optimize(ZoneList<Statement*>* statements) {
+  int len = statements->length();
+  for (int i = 0; i < len; i++) {
+    Visit(statements->at(i));
+  }
+}
+
+
+void AstOptimizer::OptimizeArguments(ZoneList<Expression*>* arguments) {
+  for (int i = 0; i < arguments->length(); i++) {
+    Visit(arguments->at(i));
+  }
+}
+
+
+void AstOptimizer::VisitBlock(Block* node) {
+  Optimize(node->statements());
+}
+
+
+void AstOptimizer::VisitExpressionStatement(ExpressionStatement* node) {
+  node->expression()->set_no_negative_zero(true);
+  Visit(node->expression());
+}
+
+
+void AstOptimizer::VisitIfStatement(IfStatement* node) {
+  node->condition()->set_no_negative_zero(true);
+  Visit(node->condition());
+  Visit(node->then_statement());
+  if (node->HasElseStatement()) {
+    Visit(node->else_statement());
+  }
+}
+
+
+void AstOptimizer::VisitDoWhileStatement(DoWhileStatement* node) {
+  node->cond()->set_no_negative_zero(true);
+  Visit(node->cond());
+  Visit(node->body());
+}
+
+
+void AstOptimizer::VisitWhileStatement(WhileStatement* node) {
+  has_function_literal_ = false;
+  node->cond()->set_no_negative_zero(true);
+  Visit(node->cond());
+  node->set_may_have_function_literal(has_function_literal_);
+  Visit(node->body());
+}
+
+
+void AstOptimizer::VisitForStatement(ForStatement* node) {
+  if (node->init() != NULL) {
+    Visit(node->init());
+  }
+  if (node->cond() != NULL) {
+    has_function_literal_ = false;
+    node->cond()->set_no_negative_zero(true);
+    Visit(node->cond());
+    node->set_may_have_function_literal(has_function_literal_);
+  }
+  Visit(node->body());
+  if (node->next() != NULL) {
+    Visit(node->next());
+  }
+}
+
+
+void AstOptimizer::VisitForInStatement(ForInStatement* node) {
+  Visit(node->each());
+  Visit(node->enumerable());
+  Visit(node->body());
+}
+
+
+void AstOptimizer::VisitTryCatchStatement(TryCatchStatement* node) {
+  Visit(node->try_block());
+  Visit(node->catch_var());
+  Visit(node->catch_block());
+}
+
+
+void AstOptimizer::VisitTryFinallyStatement(TryFinallyStatement* node) {
+  Visit(node->try_block());
+  Visit(node->finally_block());
+}
+
+
+void AstOptimizer::VisitSwitchStatement(SwitchStatement* node) {
+  node->tag()->set_no_negative_zero(true);
+  Visit(node->tag());
+  for (int i = 0; i < node->cases()->length(); i++) {
+    CaseClause* clause = node->cases()->at(i);
+    if (!clause->is_default()) {
+      Visit(clause->label());
+    }
+    Optimize(clause->statements());
+  }
+}
+
+
+void AstOptimizer::VisitContinueStatement(ContinueStatement* node) {
+  USE(node);
+}
+
+
+void AstOptimizer::VisitBreakStatement(BreakStatement* node) {
+  USE(node);
+}
+
+
+void AstOptimizer::VisitDeclaration(Declaration* node) {
+  // Will not be reached by the current optimizations.
+  USE(node);
+}
+
+
+void AstOptimizer::VisitEmptyStatement(EmptyStatement* node) {
+  USE(node);
+}
+
+
+void AstOptimizer::VisitReturnStatement(ReturnStatement* node) {
+  Visit(node->expression());
+}
+
+
+void AstOptimizer::VisitWithEnterStatement(WithEnterStatement* node) {
+  Visit(node->expression());
+}
+
+
+void AstOptimizer::VisitWithExitStatement(WithExitStatement* node) {
+  USE(node);
+}
+
+
+void AstOptimizer::VisitDebuggerStatement(DebuggerStatement* node) {
+  USE(node);
+}
+
+
+void AstOptimizer::VisitFunctionLiteral(FunctionLiteral* node) {
+  has_function_literal_ = true;
+}
+
+
+void AstOptimizer::VisitSharedFunctionInfoLiteral(
+    SharedFunctionInfoLiteral* node) {
+  USE(node);
+}
+
+
+void AstOptimizer::VisitConditional(Conditional* node) {
+  node->condition()->set_no_negative_zero(true);
+  Visit(node->condition());
+  Visit(node->then_expression());
+  Visit(node->else_expression());
+}
+
+
+void AstOptimizer::VisitVariableProxy(VariableProxy* node) {
+  Variable* var = node->AsVariable();
+  if (var != NULL) {
+    if (var->type()->IsKnown()) {
+      node->type()->CopyFrom(var->type());
+    } else if (node->type()->IsLikelySmi()) {
+      var->type()->SetAsLikelySmi();
+    }
+
+    if (FLAG_safe_int32_compiler) {
+      if (var->IsStackAllocated() &&
+          !var->is_arguments() &&
+          var->mode() != Variable::CONST) {
+        node->set_side_effect_free(true);
+      }
+    }
+  }
+}
+
+
+void AstOptimizer::VisitLiteral(Literal* node) {
+  Handle<Object> literal = node->handle();
+  if (literal->IsSmi()) {
+    node->type()->SetAsLikelySmi();
+    node->set_side_effect_free(true);
+  } else if (literal->IsHeapNumber()) {
+    if (node->to_int32()) {
+      // Any HeapNumber has an int32 value if it is the input to a bit op.
+      node->set_side_effect_free(true);
+    } else {
+      double double_value = HeapNumber::cast(*literal)->value();
+      int32_t int32_value = DoubleToInt32(double_value);
+      node->set_side_effect_free(double_value == int32_value);
+    }
+  }
+}
+
+
+void AstOptimizer::VisitRegExpLiteral(RegExpLiteral* node) {
+  USE(node);
+}
+
+
+void AstOptimizer::VisitArrayLiteral(ArrayLiteral* node) {
+  for (int i = 0; i < node->values()->length(); i++) {
+    Visit(node->values()->at(i));
+  }
+}
+
+void AstOptimizer::VisitObjectLiteral(ObjectLiteral* node) {
+  for (int i = 0; i < node->properties()->length(); i++) {
+    Visit(node->properties()->at(i)->key());
+    Visit(node->properties()->at(i)->value());
+  }
+}
+
+
+void AstOptimizer::VisitCatchExtensionObject(CatchExtensionObject* node) {
+  Visit(node->key());
+  Visit(node->value());
+}
+
+
+void AstOptimizer::VisitAssignment(Assignment* node) {
+  switch (node->op()) {
+    case Token::INIT_VAR:
+    case Token::INIT_CONST:
+    case Token::ASSIGN:
+      // No type can be infered from the general assignment.
+      break;
+    case Token::ASSIGN_BIT_OR:
+    case Token::ASSIGN_BIT_XOR:
+    case Token::ASSIGN_BIT_AND:
+    case Token::ASSIGN_SHL:
+    case Token::ASSIGN_SAR:
+    case Token::ASSIGN_SHR:
+      node->type()->SetAsLikelySmiIfUnknown();
+      node->target()->type()->SetAsLikelySmiIfUnknown();
+      node->value()->type()->SetAsLikelySmiIfUnknown();
+      node->value()->set_to_int32(true);
+      node->value()->set_no_negative_zero(true);
+      break;
+    case Token::ASSIGN_ADD:
+    case Token::ASSIGN_SUB:
+    case Token::ASSIGN_MUL:
+    case Token::ASSIGN_DIV:
+    case Token::ASSIGN_MOD:
+      if (node->type()->IsLikelySmi()) {
+        node->target()->type()->SetAsLikelySmiIfUnknown();
+        node->value()->type()->SetAsLikelySmiIfUnknown();
+      }
+      break;
+    default:
+      UNREACHABLE();
+      break;
+  }
+
+  Visit(node->target());
+  Visit(node->value());
+
+  switch (node->op()) {
+    case Token::INIT_VAR:
+    case Token::INIT_CONST:
+    case Token::ASSIGN:
+      // Pure assignment copies the type from the value.
+      node->type()->CopyFrom(node->value()->type());
+      break;
+    case Token::ASSIGN_BIT_OR:
+    case Token::ASSIGN_BIT_XOR:
+    case Token::ASSIGN_BIT_AND:
+    case Token::ASSIGN_SHL:
+    case Token::ASSIGN_SAR:
+    case Token::ASSIGN_SHR:
+      // Should have been setup above already.
+      break;
+    case Token::ASSIGN_ADD:
+    case Token::ASSIGN_SUB:
+    case Token::ASSIGN_MUL:
+    case Token::ASSIGN_DIV:
+    case Token::ASSIGN_MOD:
+      if (node->type()->IsUnknown()) {
+        if (node->target()->type()->IsLikelySmi() ||
+            node->value()->type()->IsLikelySmi()) {
+          node->type()->SetAsLikelySmi();
+        }
+      }
+      break;
+    default:
+      UNREACHABLE();
+      break;
+  }
+
+  // Since this is an assignment. We have to propagate this node's type to the
+  // variable.
+  VariableProxy* proxy = node->target()->AsVariableProxy();
+  if (proxy != NULL) {
+    Variable* var = proxy->AsVariable();
+    if (var != NULL) {
+      StaticType* var_type = var->type();
+      if (var_type->IsUnknown()) {
+        var_type->CopyFrom(node->type());
+      } else if (var_type->IsLikelySmi()) {
+        // We do not reset likely types to Unknown.
+      }
+    }
+  }
+}
+
+
+void AstOptimizer::VisitThrow(Throw* node) {
+  Visit(node->exception());
+}
+
+
+void AstOptimizer::VisitProperty(Property* node) {
+  node->key()->set_no_negative_zero(true);
+  Visit(node->obj());
+  Visit(node->key());
+}
+
+
+void AstOptimizer::VisitCall(Call* node) {
+  Visit(node->expression());
+  OptimizeArguments(node->arguments());
+}
+
+
+void AstOptimizer::VisitCallNew(CallNew* node) {
+  Visit(node->expression());
+  OptimizeArguments(node->arguments());
+}
+
+
+void AstOptimizer::VisitCallRuntime(CallRuntime* node) {
+  OptimizeArguments(node->arguments());
+}
+
+
+void AstOptimizer::VisitUnaryOperation(UnaryOperation* node) {
+  if (node->op() == Token::ADD || node->op() == Token::SUB) {
+    node->expression()->set_no_negative_zero(node->no_negative_zero());
+  } else {
+    node->expression()->set_no_negative_zero(true);
+  }
+  Visit(node->expression());
+  if (FLAG_safe_int32_compiler) {
+    switch (node->op()) {
+      case Token::BIT_NOT:
+        node->expression()->set_no_negative_zero(true);
+        node->expression()->set_to_int32(true);
+        // Fall through.
+      case Token::ADD:
+      case Token::SUB:
+        node->set_side_effect_free(node->expression()->side_effect_free());
+        break;
+      case Token::NOT:
+      case Token::DELETE:
+      case Token::TYPEOF:
+      case Token::VOID:
+        break;
+      default:
+        UNREACHABLE();
+        break;
+    }
+  } else if (node->op() == Token::BIT_NOT) {
+    node->expression()->set_to_int32(true);
+  }
+}
+
+
+void AstOptimizer::VisitIncrementOperation(IncrementOperation* node) {
+  UNREACHABLE();
+}
+
+
+void AstOptimizer::VisitCountOperation(CountOperation* node) {
+  // Count operations assume that they work on Smis.
+  node->expression()->set_no_negative_zero(node->is_prefix() ?
+                                           true :
+                                           node->no_negative_zero());
+  node->type()->SetAsLikelySmiIfUnknown();
+  node->expression()->type()->SetAsLikelySmiIfUnknown();
+  Visit(node->expression());
+}
+
+
+static bool CouldBeNegativeZero(AstNode* node) {
+  Literal* literal = node->AsLiteral();
+  if (literal != NULL) {
+    Handle<Object> handle = literal->handle();
+    if (handle->IsString() || handle->IsSmi()) {
+      return false;
+    } else if (handle->IsHeapNumber()) {
+      double double_value = HeapNumber::cast(*handle)->value();
+      if (double_value != 0) {
+        return false;
+      }
+    }
+  }
+  BinaryOperation* binary = node->AsBinaryOperation();
+  if (binary != NULL && Token::IsBitOp(binary->op())) {
+    return false;
+  }
+  return true;
+}
+
+
+static bool CouldBePositiveZero(AstNode* node) {
+  Literal* literal = node->AsLiteral();
+  if (literal != NULL) {
+    Handle<Object> handle = literal->handle();
+    if (handle->IsSmi()) {
+      if (Smi::cast(*handle) != Smi::FromInt(0)) {
+        return false;
+      }
+    } else if (handle->IsHeapNumber()) {
+      // Heap number literal can't be +0, because that's a Smi.
+      return false;
+    }
+  }
+  return true;
+}
+
+
+void AstOptimizer::VisitBinaryOperation(BinaryOperation* node) {
+  // Depending on the operation we can propagate this node's type down the
+  // AST nodes.
+  Token::Value op = node->op();
+  switch (op) {
+    case Token::COMMA:
+    case Token::OR:
+      node->left()->set_no_negative_zero(true);
+      node->right()->set_no_negative_zero(node->no_negative_zero());
+      break;
+    case Token::AND:
+      node->left()->set_no_negative_zero(node->no_negative_zero());
+      node->right()->set_no_negative_zero(node->no_negative_zero());
+      break;
+    case Token::BIT_OR:
+    case Token::BIT_XOR:
+    case Token::BIT_AND:
+    case Token::SHL:
+    case Token::SAR:
+    case Token::SHR:
+      node->type()->SetAsLikelySmiIfUnknown();
+      node->left()->type()->SetAsLikelySmiIfUnknown();
+      node->right()->type()->SetAsLikelySmiIfUnknown();
+      node->left()->set_to_int32(true);
+      node->right()->set_to_int32(true);
+      node->left()->set_no_negative_zero(true);
+      node->right()->set_no_negative_zero(true);
+      break;
+    case Token::MUL: {
+      VariableProxy* lvar_proxy = node->left()->AsVariableProxy();
+      VariableProxy* rvar_proxy = node->right()->AsVariableProxy();
+      if (lvar_proxy != NULL && rvar_proxy != NULL) {
+        Variable* lvar = lvar_proxy->AsVariable();
+        Variable* rvar = rvar_proxy->AsVariable();
+        if (lvar != NULL && rvar != NULL) {
+          if (lvar->mode() == Variable::VAR && rvar->mode() == Variable::VAR) {
+            Slot* lslot = lvar->AsSlot();
+            Slot* rslot = rvar->AsSlot();
+            if (lslot->type() == rslot->type() &&
+                (lslot->type() == Slot::PARAMETER ||
+                 lslot->type() == Slot::LOCAL) &&
+                lslot->index() == rslot->index()) {
+              // A number squared doesn't give negative zero.
+              node->set_no_negative_zero(true);
+            }
+          }
+        }
+      }
+    }
+    case Token::ADD:
+    case Token::SUB:
+    case Token::DIV:
+    case Token::MOD: {
+      if (node->type()->IsLikelySmi()) {
+        node->left()->type()->SetAsLikelySmiIfUnknown();
+        node->right()->type()->SetAsLikelySmiIfUnknown();
+      }
+      if (op == Token::ADD && (!CouldBeNegativeZero(node->left()) ||
+                               !CouldBeNegativeZero(node->right()))) {
+        node->left()->set_no_negative_zero(true);
+        node->right()->set_no_negative_zero(true);
+      } else if (op == Token::SUB && (!CouldBeNegativeZero(node->left()) ||
+                                      !CouldBePositiveZero(node->right()))) {
+        node->left()->set_no_negative_zero(true);
+        node->right()->set_no_negative_zero(true);
+      } else {
+        node->left()->set_no_negative_zero(node->no_negative_zero());
+        node->right()->set_no_negative_zero(node->no_negative_zero());
+      }
+      if (node->op() == Token::DIV) {
+        node->right()->set_no_negative_zero(false);
+      } else if (node->op() == Token::MOD) {
+        node->right()->set_no_negative_zero(true);
+      }
+      break;
+    }
+    default:
+      UNREACHABLE();
+      break;
+  }
+
+  Visit(node->left());
+  Visit(node->right());
+
+  // After visiting the operand nodes we have to check if this node's type
+  // can be updated. If it does, then we can push that information down
+  // towards the leaves again if the new information is an upgrade over the
+  // previous type of the operand nodes.
+  if (node->type()->IsUnknown()) {
+    if (node->left()->type()->IsLikelySmi() ||
+        node->right()->type()->IsLikelySmi()) {
+      node->type()->SetAsLikelySmi();
+    }
+    if (node->type()->IsLikelySmi()) {
+      // The type of this node changed to LIKELY_SMI. Propagate this knowledge
+      // down through the nodes.
+      if (node->left()->type()->IsUnknown()) {
+        node->left()->type()->SetAsLikelySmi();
+        Visit(node->left());
+      }
+      if (node->right()->type()->IsUnknown()) {
+        node->right()->type()->SetAsLikelySmi();
+        Visit(node->right());
+      }
+    }
+  }
+
+  if (FLAG_safe_int32_compiler) {
+    switch (node->op()) {
+      case Token::COMMA:
+      case Token::OR:
+      case Token::AND:
+        break;
+      case Token::BIT_OR:
+      case Token::BIT_XOR:
+      case Token::BIT_AND:
+      case Token::SHL:
+      case Token::SAR:
+      case Token::SHR:
+        // Add one to the number of bit operations in this expression.
+        node->set_num_bit_ops(1);
+        // Fall through.
+      case Token::ADD:
+      case Token::SUB:
+      case Token::MUL:
+      case Token::DIV:
+      case Token::MOD:
+        node->set_side_effect_free(node->left()->side_effect_free() &&
+                                   node->right()->side_effect_free());
+        node->set_num_bit_ops(node->num_bit_ops() +
+                                  node->left()->num_bit_ops() +
+                                  node->right()->num_bit_ops());
+        if (!node->no_negative_zero() && node->op() == Token::MUL) {
+          node->set_side_effect_free(false);
+        }
+        break;
+      default:
+        UNREACHABLE();
+        break;
+    }
+  }
+}
+
+
+void AstOptimizer::VisitCompareOperation(CompareOperation* node) {
+  if (node->type()->IsKnown()) {
+    // Propagate useful information down towards the leaves.
+    node->left()->type()->SetAsLikelySmiIfUnknown();
+    node->right()->type()->SetAsLikelySmiIfUnknown();
+  }
+
+  node->left()->set_no_negative_zero(true);
+  // Only [[HasInstance]] has the right argument passed unchanged to it.
+  node->right()->set_no_negative_zero(true);
+
+  Visit(node->left());
+  Visit(node->right());
+
+  // After visiting the operand nodes we have to check if this node's type
+  // can be updated. If it does, then we can push that information down
+  // towards the leaves again if the new information is an upgrade over the
+  // previous type of the operand nodes.
+  if (node->type()->IsUnknown()) {
+    if (node->left()->type()->IsLikelySmi() ||
+        node->right()->type()->IsLikelySmi()) {
+      node->type()->SetAsLikelySmi();
+    }
+    if (node->type()->IsLikelySmi()) {
+      // The type of this node changed to LIKELY_SMI. Propagate this knowledge
+      // down through the nodes.
+      if (node->left()->type()->IsUnknown()) {
+        node->left()->type()->SetAsLikelySmi();
+        Visit(node->left());
+      }
+      if (node->right()->type()->IsUnknown()) {
+        node->right()->type()->SetAsLikelySmi();
+        Visit(node->right());
+      }
+    }
+  }
+}
+
+
+void AstOptimizer::VisitCompareToNull(CompareToNull* node) {
+  Visit(node->expression());
+}
+
+
+void AstOptimizer::VisitThisFunction(ThisFunction* node) {
+  USE(node);
+}
+
+
 class Processor: public AstVisitor {
  public:
   explicit Processor(Variable* result)
@@ -197,18 +840,142 @@ void Processor::VisitBreakStatement(BreakStatement* node) {
 void Processor::VisitDeclaration(Declaration* node) {}
 void Processor::VisitEmptyStatement(EmptyStatement* node) {}
 void Processor::VisitReturnStatement(ReturnStatement* node) {}
-void Processor::VisitEnterWithContextStatement(
-    EnterWithContextStatement* node) {
-}
-void Processor::VisitExitContextStatement(ExitContextStatement* node) {}
+void Processor::VisitWithEnterStatement(WithEnterStatement* node) {}
+void Processor::VisitWithExitStatement(WithExitStatement* node) {}
 void Processor::VisitDebuggerStatement(DebuggerStatement* node) {}
 
 
 // Expressions are never visited yet.
-#define DEF_VISIT(type)                                         \
-  void Processor::Visit##type(type* expr) { UNREACHABLE(); }
-EXPRESSION_NODE_LIST(DEF_VISIT)
-#undef DEF_VISIT
+void Processor::VisitFunctionLiteral(FunctionLiteral* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitSharedFunctionInfoLiteral(
+    SharedFunctionInfoLiteral* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitConditional(Conditional* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitVariableProxy(VariableProxy* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitLiteral(Literal* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitRegExpLiteral(RegExpLiteral* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitArrayLiteral(ArrayLiteral* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitObjectLiteral(ObjectLiteral* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitCatchExtensionObject(CatchExtensionObject* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitAssignment(Assignment* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitThrow(Throw* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitProperty(Property* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitCall(Call* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitCallNew(CallNew* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitCallRuntime(CallRuntime* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitUnaryOperation(UnaryOperation* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitIncrementOperation(IncrementOperation* node) {
+  UNREACHABLE();
+}
+
+
+void Processor::VisitCountOperation(CountOperation* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitBinaryOperation(BinaryOperation* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitCompareOperation(CompareOperation* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitCompareToNull(CompareToNull* node) {
+  USE(node);
+  UNREACHABLE();
+}
+
+
+void Processor::VisitThisFunction(ThisFunction* node) {
+  USE(node);
+  UNREACHABLE();
+}
 
 
 // Assumes code has been parsed and scopes have been analyzed.  Mutates the
@@ -218,12 +985,11 @@ bool Rewriter::Rewrite(CompilationInfo* info) {
   ASSERT(function != NULL);
   Scope* scope = function->scope();
   ASSERT(scope != NULL);
-  if (!scope->is_global_scope() && !scope->is_eval_scope()) return true;
+  if (scope->is_function_scope()) return true;
 
   ZoneList<Statement*>* body = function->body();
   if (!body->is_empty()) {
-    Variable* result = scope->NewTemporary(
-        info->isolate()->factory()->result_symbol());
+    Variable* result = scope->NewTemporary(Factory::result_symbol());
     Processor processor(result);
     processor.Process(body);
     if (processor.HasStackOverflow()) return false;
@@ -238,4 +1004,20 @@ bool Rewriter::Rewrite(CompilationInfo* info) {
 }
 
 
+// Assumes code has been parsed and scopes have been analyzed.  Mutates the
+// AST, so the AST should not continue to be used in the case of failure.
+bool Rewriter::Analyze(CompilationInfo* info) {
+  FunctionLiteral* function = info->function();
+  ASSERT(function != NULL && function->scope() != NULL);
+
+  ZoneList<Statement*>* body = function->body();
+  if (FLAG_optimize_ast && !body->is_empty()) {
+    AstOptimizer optimizer;
+    optimizer.Optimize(body);
+    if (optimizer.HasStackOverflow()) return false;
+  }
+  return true;
+}
+
+
 } }  // namespace v8::internal