diff --git a/include/Support/ThreadSupport.h b/include/Support/ThreadSupport.h.in
similarity index 90%
rename from include/Support/ThreadSupport.h
rename to include/Support/ThreadSupport.h.in
index 9689307f87a..470010219fc 100644
--- a/include/Support/ThreadSupport.h
+++ b/include/Support/ThreadSupport.h.in
@@ -17,9 +17,7 @@
 #ifndef SUPPORT_THREADSUPPORT_H
 #define SUPPORT_THREADSUPPORT_H
 
-// FIXME: Eventually don't #include config.h here
-#include "Config/config.h"
-#if defined(HAVE_PTHREAD_MUTEX_LOCK) && HAVE_PTHREAD_MUTEX_LOCK
+#if @HAVE_PTHREAD_MUTEX_LOCK@
 #include "Support/ThreadSupport-PThreads.h"
 #else
 #include "Support/ThreadSupport-NoSupport.h"
diff --git a/include/llvm/Support/MutexGuard.h b/include/llvm/Support/MutexGuard.h
new file mode 100644
index 00000000000..470010219fc
--- /dev/null
+++ b/include/llvm/Support/MutexGuard.h
@@ -0,0 +1,40 @@
+//===-- Support/ThreadSupport.h - Generic threading support -----*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file defines platform-agnostic interfaces that can be used to write
+// multi-threaded programs.  Autoconf is used to chose the correct
+// implementation of these interfaces, or default to a non-thread-capable system
+// if no matching system support is available.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUPPORT_THREADSUPPORT_H
+#define SUPPORT_THREADSUPPORT_H
+
+#if @HAVE_PTHREAD_MUTEX_LOCK@
+#include "Support/ThreadSupport-PThreads.h"
+#else
+#include "Support/ThreadSupport-NoSupport.h"
+#endif // If no system support is available
+
+namespace llvm {
+  /// MutexLocker - Instances of this class acquire a given Lock when
+  /// constructed and hold that lock until destruction.
+  ///
+  class MutexLocker {
+    Mutex &M;
+    MutexLocker(const MutexLocker &);    // DO NOT IMPLEMENT
+    void operator=(const MutexLocker &); // DO NOT IMPLEMENT
+  public:
+    MutexLocker(Mutex &m) : M(m) { M.acquire(); }
+    ~MutexLocker() { M.release(); }
+  };
+}
+
+#endif // SUPPORT_THREADSUPPORT_H
diff --git a/include/llvm/Support/ThreadSupport.h.in b/include/llvm/Support/ThreadSupport.h.in
new file mode 100644
index 00000000000..470010219fc
--- /dev/null
+++ b/include/llvm/Support/ThreadSupport.h.in
@@ -0,0 +1,40 @@
+//===-- Support/ThreadSupport.h - Generic threading support -----*- C++ -*-===//
+// 
+//                     The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+// 
+//===----------------------------------------------------------------------===//
+//
+// This file defines platform-agnostic interfaces that can be used to write
+// multi-threaded programs.  Autoconf is used to chose the correct
+// implementation of these interfaces, or default to a non-thread-capable system
+// if no matching system support is available.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SUPPORT_THREADSUPPORT_H
+#define SUPPORT_THREADSUPPORT_H
+
+#if @HAVE_PTHREAD_MUTEX_LOCK@
+#include "Support/ThreadSupport-PThreads.h"
+#else
+#include "Support/ThreadSupport-NoSupport.h"
+#endif // If no system support is available
+
+namespace llvm {
+  /// MutexLocker - Instances of this class acquire a given Lock when
+  /// constructed and hold that lock until destruction.
+  ///
+  class MutexLocker {
+    Mutex &M;
+    MutexLocker(const MutexLocker &);    // DO NOT IMPLEMENT
+    void operator=(const MutexLocker &); // DO NOT IMPLEMENT
+  public:
+    MutexLocker(Mutex &m) : M(m) { M.acquire(); }
+    ~MutexLocker() { M.release(); }
+  };
+}
+
+#endif // SUPPORT_THREADSUPPORT_H