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diff --git a/lib/Parse/AstGuard.h b/lib/Parse/AstGuard.h
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+++ b/lib/Parse/AstGuard.h
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+//===--- AstGuard.h - Parser Ownership Tracking Utilities -------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+//  This file defines RAII objects for managing ExprTy* and StmtTy*.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_PARSE_ASTGUARD_H
+#define LLVM_CLANG_PARSE_ASTGUARD_H
+
+#include "clang/Parse/Action.h"
+#include "llvm/ADT/SmallVector.h"
+
+namespace clang
+{
+  /// RAII guard for freeing StmtTys and ExprTys on early exit in the parser.
+  /// Instantiated for statements and expressions (Action::DeleteStmt and
+  /// Action::DeleteExpr).
+  template <void (Action::*Destroyer)(void*)>
+  class ASTGuard {
+    Action &Actions;
+    void *Node;
+
+    void destroy() {
+      if (Node)
+        (Actions.*Destroyer)(Node);
+    }
+
+    ASTGuard(const ASTGuard&); // DO NOT IMPLEMENT
+    // Reference member prevents copy assignment.
+
+  public:
+    explicit ASTGuard(Action &actions) : Actions(actions), Node(0) {}
+    ASTGuard(Action &actions, void *node)
+      : Actions(actions), Node(node) {}
+    template <unsigned N>
+    ASTGuard(Action &actions, const Action::ActionResult<N> &res)
+      : Actions(actions), Node(res.Val) {}
+    ~ASTGuard() { destroy(); }
+
+    void reset(void *element) {
+      destroy();
+      Node = element;
+    }
+    template <unsigned N>
+    void reset(const Action::ActionResult<N> &res) {
+      reset(res.Val);
+    }
+    void *take() {
+      void *Temp = Node;
+      Node = 0;
+      return Temp;
+    }
+    void *get() const { return Node; }
+  };
+
+  typedef ASTGuard<&Action::DeleteStmt> StmtGuard;
+  typedef ASTGuard<&Action::DeleteExpr> ExprGuard;
+
+  /// RAII SmallVector wrapper that holds Action::ExprTy* and similar,
+  /// automatically freeing them on destruction unless it's been disowned.
+  /// Instantiated for statements and expressions (Action::DeleteStmt and
+  /// Action::DeleteExpr).
+  template <void (Action::*Destroyer)(void*), unsigned N>
+  class ASTVector : public llvm::SmallVector<void*, N> {
+  private:
+    Action &Actions;
+    bool Owns;
+
+    void destroy() {
+      if (Owns) {
+        while (!this->empty()) {
+          (Actions.*Destroyer)(this->back());
+          this->pop_back();
+        }
+      }
+    }
+
+    ASTVector(const ASTVector&); // DO NOT IMPLEMENT
+    // Reference member prevents copy assignment.
+
+  public:
+    ASTVector(Action &actions) : Actions(actions), Owns(true) {}
+
+    ~ASTVector() { destroy(); }
+
+    void **take() {
+      Owns = false;
+      return &(*this)[0];
+    }
+  };
+
+  /// A SmallVector of statements, with stack size 32 (as that is the only one
+  /// used.)
+  typedef ASTVector<&Action::DeleteStmt, 32> StmtVector;
+  /// A SmallVector of expressions, with stack size 12 (the maximum used.)
+  typedef ASTVector<&Action::DeleteExpr, 12> ExprVector;
+}
+
+#endif