      /// This functions permanently adds the symbol \p symbolName with the
      /// value \p symbolValue.  These symbols are searched before any
      /// libraries.
+Index: lib/Support/Unix/DynamicLibrary.inc
+===================================================================
+--- lib/Support/Unix/DynamicLibrary.inc	(revision 0)
++++ lib/Support/Unix/DynamicLibrary.inc	(revision 0)
+@@ -0,0 +1,118 @@
++//===--- Unix/DynamicLibrary.cpp - Unix DL Implementation -------*- C++ -*-===//
++//
++//                     The LLVM Compiler Infrastructure
++//
++// This file is distributed under the University of Illinois Open Source
++// License. See LICENSE.TXT for details.
++//
++//===----------------------------------------------------------------------===//
++//
++// This file provides the dlsym specific implementation of DynamicLibrary.
++//
++//===----------------------------------------------------------------------===//
++
++#include <dlfcn.h>
++
++static void MakeDlErrMsg(std::string *ErrMsg) {
++  if (ErrMsg) {
++    *ErrMsg = dlerror();
++  } else {
++    // Flush error state whether or not ErrMsg is provided.
++    dlerror();
++  }
++}
++
++void *OpenLibraryImpl(const char *Filename, std::string *ErrMsg) {
++  void *Handle = dlopen(Filename, RTLD_LAZY|RTLD_GLOBAL);
++  if (Handle == 0) {
++    MakeDlErrMsg(ErrMsg);
++    return NULL;
++  }
++
++#ifdef __CYGWIN__
++  // Cygwin searches symbols only in the main
++  // with the handle of dlopen(NULL, RTLD_GLOBAL).
++  if (Filename == NULL)
++    Handle = RTLD_DEFAULT;
++#endif
++  return Handle;
++}
++
++bool CloseLibraryImpl(void *DlHandle, std::string *ErrMsg) {
++  if (dlclose(DlHandle)) {
++    MakeDlErrMsg(ErrMsg);
++    return false;
++  }
++  return true;
++}
++
++void *GetAddressOfSymbolImpl(void *DlHandle, const char *SymbolName,
++                             bool /*Global*/) {
++  return dlsym(DlHandle, SymbolName);
++}
++
++#include <string.h>
++
++// Must declare the symbols in the global namespace.
++void PopulateSpecialSymbolsImpl(StringMap<void *>& SymMap) {
++// This macro returns the address of a well-known, explicit symbol
++#define EXPLICIT_SYMBOL(SYM) \
++    SymMap[#SYM] = &SYM
++
++// On linux we have a weird situation. The stderr/out/in symbols are both
++// macros and global variables because of standards requirements. So, we
++// boldly use the EXPLICIT_SYMBOL macro without checking for a #define first.
++#if defined(__linux__) and !defined(__ANDROID__)
++  {
++    EXPLICIT_SYMBOL(stderr);
++    EXPLICIT_SYMBOL(stdout);
++    EXPLICIT_SYMBOL(stdin);
++  }
++#else
++  // For everything else, we want to check to make sure the symbol isn't defined
++  // as a macro before using EXPLICIT_SYMBOL.
++  {
++#ifndef stdin
++    EXPLICIT_SYMBOL(stdin);
++#endif
++#ifndef stdout
++    EXPLICIT_SYMBOL(stdout);
++#endif
++#ifndef stderr
++    EXPLICIT_SYMBOL(stderr);
++#endif
++  }
++#endif
++#undef EXPLICIT_SYMBOL
++
++#define EXPLICIT_SYMBOL(SYM) \
++   extern "C" void *SYM; symMap[#SYM] = &SYM
++
++  // If this is darwin, it has some funky issues, try to solve them here.  Some
++  // important symbols are marked 'private external' which doesn't allow
++  // SearchForAddressOfSymbol to find them.  As such, we special case them here,
++  // there is only a small handful of them.
++
++#ifdef __APPLE__
++  {
++    // __eprintf is sometimes used for assert() handling on x86.
++    //
++    // FIXME: Currently disabled when using Clang, as we don't always have our
++    // runtime support libraries available.
++#ifndef __clang__
++#ifdef __i386__
++    EXPLICIT_SYMBOL(__eprintf);
++#endif
++#endif
++  }
++#endif
++
++#ifdef __CYGWIN__
++  {
++    EXPLICIT_SYMBOL(_alloca);
++    EXPLICIT_SYMBOL(__main);
++  }
++#endif
++
++#undef EXPLICIT_SYMBOL
++}
 Index: lib/Support/DynamicLibrary.cpp
 ===================================================================
 --- lib/Support/DynamicLibrary.cpp	(revision 167609)

-  return DoSearch(symbolName);
-}
-}  // namespace llvm
Index: lib/Support/CMakeLists.txt
===================================================================
--- lib/Support/CMakeLists.txt	(revision 167609)
+++ lib/Support/CMakeLists.txt	(working copy)
@@ -80,6 +80,7 @@ add_llvm_library(LLVMSupport
   Threading.cpp
   TimeValue.cpp
   Valgrind.cpp
+  Unix/DynamicLibrary.inc
   Unix/Host.inc
   Unix/Memory.inc
   Unix/Mutex.inc
Index: lib/Support/Windows/DynamicLibrary.inc
===================================================================
--- lib/Support/Windows/DynamicLibrary.inc	(revision 167609)
+++ lib/Support/Windows/DynamicLibrary.inc	(working copy)
@@ -31,16 +31,8 @@
  #pragma comment(lib, "dbghelp.lib")
 #endif
 
-namespace llvm {
-using namespace sys;
+using namespace llvm;
 
-//===----------------------------------------------------------------------===//
-//=== WARNING: Implementation here must contain only Win32 specific code
-//===          and must not be UNIX code.
-//===----------------------------------------------------------------------===//
-
-static DenseSet<HMODULE> *OpenedHandles;
-
 extern "C" {
 
   static BOOL CALLBACK ELM_Callback(WIN32_ELMCB_PCSTR ModuleName,
@@ -63,49 +55,61 @@ extern "C" {
 #endif
         stricmp(ModuleName, "msvcrt20") != 0 &&
         stricmp(ModuleName, "msvcrt40") != 0) {
-      OpenedHandles->insert((HMODULE)ModuleBase);
+       OpenedHandles->insert((HMODULE)ModuleBase);
     }
     return TRUE;
   }
-}
+} // extern "C"
 
-DynamicLibrary DynamicLibrary::getPermanentLibrary(const char *filename,
-                                                   std::string *errMsg) {
-  SmartScopedLock<true> lock(getMutex());
-
-  if (!filename) {
+void *OpenLibraryImpl(const char *Filename, std::string *ErrMsg) {
+  if (!Filename) {
     // When no file is specified, enumerate all DLLs and EXEs in the process.
     if (OpenedHandles == 0)
-      OpenedHandles = new DenseSet<HMODULE>();
+      OpenedHandles = new DenseSet<void *>();
 
     EnumerateLoadedModules(GetCurrentProcess(), ELM_Callback, 0);
     // Dummy library that represents "search all handles".
     // This is mostly to ensure that the return value still shows up as "valid".
-    return DynamicLibrary(&OpenedHandles);
+    return &OpenedHandles;
   }
   
-  HMODULE a_handle = LoadLibrary(filename);
+  HMODULE a_handle = LoadLibrary(Filename);
 
   if (a_handle == 0) {
-    MakeErrMsg(errMsg, std::string(filename) + ": Can't open : ");
-    return DynamicLibrary();
+    MakeErrMsg(ErrMsg, std::string(Filename) + ": Can't open : ");
+    return NULL;
   }
 
-  if (OpenedHandles == 0)
-    OpenedHandles = new DenseSet<HMODULE>();
+  return (void *)a_handle;
+}
 
-  // If we've already loaded this library, FreeLibrary() the handle in order to
-  // keep the internal refcount at +1.
-  if (!OpenedHandles->insert(a_handle).second)
-    FreeLibrary(a_handle);
+bool CloseLibraryImpl(void *DlHandle, std::string *ErrMsg) {
+  if (!FreeLibrary((HMODULE)DlHandle)) {
+    MakeErrMsg(ErrMsg, "Cannot free DLL: ");
+    return false;
+  }
+  return true;
+}
 
-  return DynamicLibrary(a_handle);
+void *GetAddressOfSymbolImpl(void *DlHandle, const char *SymbolName,
+                             bool Global) {
+  if (DlHandle == &OpenedHandles) {
+    // Dummy library that represents "search all handles".
+    if (Global) {
+      // All libraries are already being searched, do not recurse.
+      return 0;
+    } else {
+      // Perform a global symbol search through all libraries.
+      DynamicLibrary::SearchForLibrarySymbol(SymbolName);
+    }
+  }
+  return (void *)(intptr_t) GetProcAddress((HMODULE)DlHandle, SymbolName);
 }
 
 // Stack probing routines are in the support library (e.g. libgcc), but we don't
 // have dynamic linking on windows. Provide a hook.
 #define EXPLICIT_SYMBOL(SYM)                    \
-  extern "C" { extern void *SYM; }
+  extern "C" void *SYM;
 #define EXPLICIT_SYMBOL2(SYMFROM, SYMTO) EXPLICIT_SYMBOL(SYMTO)
 
 #include "explicit_symbols.inc"
@@ -113,51 +117,13 @@ extern "C" {
 #undef EXPLICIT_SYMBOL
 #undef EXPLICIT_SYMBOL2
 
-void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
-  SmartScopedLock<true> Lock(getMutex());
+void PopulateSpecialSymbolsImpl(StringMap<void *>& SymMap) {
+#define EXPLICIT_SYMBOL(SYM)                    \
+  SymMap[#SYM] = &SYM;
+#define EXPLICIT_SYMBOL2(SYMFROM, SYMTO) EXPLICIT_SYMBOL(SYMTO)
 
-  // First check symbols added via AddSymbol().
-  if (ExplicitSymbols) {
-    StringMap<void *>::iterator i = ExplicitSymbols->find(symbolName);
+#include "explicit_symbols.inc"
 
-    if (i != ExplicitSymbols->end())
-      return i->second;
-  }
-
-  // Now search the libraries.
-  if (OpenedHandles) {
-    for (DenseSet<HMODULE>::iterator I = OpenedHandles->begin(),
-         E = OpenedHandles->end(); I != E; ++I) {
-      FARPROC ptr = GetProcAddress((HMODULE)*I, symbolName);
-      if (ptr) {
-        return (void *)(intptr_t)ptr;
-      }
-    }
-  }
-
-  #define EXPLICIT_SYMBOL(SYM)                    \
-    if (!strcmp(symbolName, #SYM)) return (void*)&SYM;
-  #define EXPLICIT_SYMBOL2(SYMFROM, SYMTO)        \
-    if (!strcmp(symbolName, #SYMFROM)) return (void*)&SYMTO;
-
-  {
-    #include "explicit_symbols.inc"
-  }
-
-  #undef EXPLICIT_SYMBOL
-  #undef EXPLICIT_SYMBOL2
-
-  return 0;
+#undef EXPLICIT_SYMBOL
+#undef EXPLICIT_SYMBOL2
 }
-
-
-void *DynamicLibrary::getAddressOfSymbol(const char *symbolName) {
-  if (!isValid())
-    return NULL;
-  if (Data == &OpenedHandles)
-    return SearchForAddressOfSymbol(symbolName);
-  return (void *)(intptr_t)GetProcAddress((HMODULE)Data, symbolName);
-}
-
-
-}

+}
+ 
 #endif // LLVM_ON_WIN32
Index: lib/Support/Windows/DynamicLibrary.inc
===================================================================
--- lib/Support/Windows/DynamicLibrary.inc	(revision 167609)
+++ lib/Support/Windows/DynamicLibrary.inc	(working copy)
@@ -31,16 +31,8 @@
  #pragma comment(lib, "dbghelp.lib")
 #endif
 
-namespace llvm {
-using namespace sys;
+using namespace llvm;
 
-//===----------------------------------------------------------------------===//
-//=== WARNING: Implementation here must contain only Win32 specific code
-//===          and must not be UNIX code.
-//===----------------------------------------------------------------------===//
-
-static DenseSet<HMODULE> *OpenedHandles;
-
 extern "C" {
 
   static BOOL CALLBACK ELM_Callback(WIN32_ELMCB_PCSTR ModuleName,
@@ -63,49 +55,61 @@ extern "C" {
 #endif
         stricmp(ModuleName, "msvcrt20") != 0 &&
         stricmp(ModuleName, "msvcrt40") != 0) {
-      OpenedHandles->insert((HMODULE)ModuleBase);
+       OpenedHandles->insert((HMODULE)ModuleBase);
     }
     return TRUE;
   }
-}
+} // extern "C"
 
-DynamicLibrary DynamicLibrary::getPermanentLibrary(const char *filename,
-                                                   std::string *errMsg) {
-  SmartScopedLock<true> lock(getMutex());
-
-  if (!filename) {
+void *OpenLibraryImpl(const char *Filename, std::string *ErrMsg) {
+  if (!Filename) {
     // When no file is specified, enumerate all DLLs and EXEs in the process.
     if (OpenedHandles == 0)
-      OpenedHandles = new DenseSet<HMODULE>();
+      OpenedHandles = new DenseSet<void *>();
 
     EnumerateLoadedModules(GetCurrentProcess(), ELM_Callback, 0);
     // Dummy library that represents "search all handles".
     // This is mostly to ensure that the return value still shows up as "valid".
-    return DynamicLibrary(&OpenedHandles);
+    return &OpenedHandles;
   }
   
-  HMODULE a_handle = LoadLibrary(filename);
+  HMODULE a_handle = LoadLibrary(Filename);
 
   if (a_handle == 0) {
-    MakeErrMsg(errMsg, std::string(filename) + ": Can't open : ");
-    return DynamicLibrary();
+    MakeErrMsg(ErrMsg, std::string(Filename) + ": Can't open : ");
+    return NULL;
   }
 
-  if (OpenedHandles == 0)
-    OpenedHandles = new DenseSet<HMODULE>();
+  return (void *)a_handle;
+}
 
-  // If we've already loaded this library, FreeLibrary() the handle in order to
-  // keep the internal refcount at +1.
-  if (!OpenedHandles->insert(a_handle).second)
-    FreeLibrary(a_handle);
+bool CloseLibraryImpl(void *DlHandle, std::string *ErrMsg) {
+  if (!FreeLibrary((HMODULE)DlHandle)) {
+    MakeErrMsg(ErrMsg, "Cannot free DLL: ");
+    return false;
+  }
+  return true;
+}
 
-  return DynamicLibrary(a_handle);
+void *GetAddressOfSymbolImpl(void *DlHandle, const char *SymbolName,
+                             bool Global) {
+  if (DlHandle == &OpenedHandles) {
+    // Dummy library that represents "search all handles".
+    if (Global) {
+      // All libraries are already being searched, do not recurse.
+      return 0;
+    } else {
+      // Perform a global symbol search through all libraries.
+      DynamicLibrary::SearchForLibrarySymbol(SymbolName);
+    }
+  }
+  return (void *)(intptr_t) GetProcAddress((HMODULE)DlHandle, SymbolName);
 }
 
 // Stack probing routines are in the support library (e.g. libgcc), but we don't
 // have dynamic linking on windows. Provide a hook.
 #define EXPLICIT_SYMBOL(SYM)                    \
-  extern "C" { extern void *SYM; }
+  extern "C" void *SYM;
 #define EXPLICIT_SYMBOL2(SYMFROM, SYMTO) EXPLICIT_SYMBOL(SYMTO)
 
 #include "explicit_symbols.inc"
@@ -113,51 +117,13 @@ extern "C" {
 #undef EXPLICIT_SYMBOL
 #undef EXPLICIT_SYMBOL2
 
-void* DynamicLibrary::SearchForAddressOfSymbol(const char* symbolName) {
-  SmartScopedLock<true> Lock(getMutex());
+void PopulateSpecialSymbolsImpl(StringMap<void *>& SymMap) {
+#define EXPLICIT_SYMBOL(SYM)                    \
+  SymMap[#SYM] = &SYM;
+#define EXPLICIT_SYMBOL2(SYMFROM, SYMTO) EXPLICIT_SYMBOL(SYMTO)
 
-  // First check symbols added via AddSymbol().
-  if (ExplicitSymbols) {
-    StringMap<void *>::iterator i = ExplicitSymbols->find(symbolName);
+#include "explicit_symbols.inc"
 
-    if (i != ExplicitSymbols->end())
-      return i->second;
-  }
-
-  // Now search the libraries.
-  if (OpenedHandles) {
-    for (DenseSet<HMODULE>::iterator I = OpenedHandles->begin(),
-         E = OpenedHandles->end(); I != E; ++I) {
-      FARPROC ptr = GetProcAddress((HMODULE)*I, symbolName);
-      if (ptr) {
-        return (void *)(intptr_t)ptr;
-      }
-    }
-  }
-
-  #define EXPLICIT_SYMBOL(SYM)                    \
-    if (!strcmp(symbolName, #SYM)) return (void*)&SYM;
-  #define EXPLICIT_SYMBOL2(SYMFROM, SYMTO)        \
-    if (!strcmp(symbolName, #SYMFROM)) return (void*)&SYMTO;
-
-  {
-    #include "explicit_symbols.inc"
-  }
-
-  #undef EXPLICIT_SYMBOL
-  #undef EXPLICIT_SYMBOL2
-
-  return 0;
+#undef EXPLICIT_SYMBOL
+#undef EXPLICIT_SYMBOL2
 }
-
-
-void *DynamicLibrary::getAddressOfSymbol(const char *symbolName) {
-  if (!isValid())
-    return NULL;
-  if (Data == &OpenedHandles)
-    return SearchForAddressOfSymbol(symbolName);
-  return (void *)(intptr_t)GetProcAddress((HMODULE)Data, symbolName);
-}
-
-
-}
Index: lib/Support/CMakeLists.txt
===================================================================
--- lib/Support/CMakeLists.txt	(revision 167609)
+++ lib/Support/CMakeLists.txt	(working copy)
@@ -80,6 +80,7 @@ add_llvm_library(LLVMSupport
   Threading.cpp
   TimeValue.cpp
   Valgrind.cpp
+  Unix/DynamicLibrary.inc
   Unix/Host.inc
   Unix/Memory.inc
   Unix/Mutex.inc
Index: lib/Support/SearchForAddressOfSpecialSymbol.cpp
===================================================================
--- lib/Support/SearchForAddressOfSpecialSymbol.cpp	(revision 167609)
