 +}
 + 
  #endif // LLVM_ON_WIN32
-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, std::string(Filename) + ": Cannot close: ");
-+    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/SearchForAddressOfSpecialSymbol.cpp
 ===================================================================
 --- lib/Support/SearchForAddressOfSpecialSymbol.cpp	(revision 167609)

-  return DoSearch(symbolName);
-}
-}  // namespace llvm
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
+}

   // keep the internal refcount at +1.
-  if (!OpenedHandles->insert(handle).second)
-    dlclose(handle);
+  if (!OpenedHandles->insert(Handle).second)
+    CloseLibraryImpl(Handle, 0);
 
-  return DynamicLibrary(handle);
