Index: libunwind/trunk/CMakeLists.txt
===================================================================
--- libunwind/trunk/CMakeLists.txt
+++ libunwind/trunk/CMakeLists.txt
@@ -107,6 +107,7 @@
 option(LIBUNWIND_ENABLE_STATIC "Build libunwind as a static library." ON)
 option(LIBUNWIND_ENABLE_CROSS_UNWINDING "Enable cross-platform unwinding support." OFF)
 option(LIBUNWIND_ENABLE_ARM_WMMX "Enable unwinding support for ARM WMMX registers." OFF)
+option(LIBUNWIND_ENABLE_THREADS "Build libunwind with threading support." ON)
 
 set(LIBUNWIND_TARGET_TRIPLE "" CACHE STRING "Target triple for cross compiling.")
 set(LIBUNWIND_GCC_TOOLCHAIN "" CACHE PATH "GCC toolchain for cross compiling.")
@@ -242,6 +243,11 @@
   list(APPEND LIBUNWIND_COMPILE_FLAGS -D_LIBUNWIND_IS_NATIVE_ONLY)
 endif()
 
+# Threading-support
+if (NOT LIBUNWIND_ENABLE_THREADS)
+  list(APPEND LIBUNWIND_COMPILE_FLAGS -D_LIBUNWIND_HAS_NO_THREADS)
+endif()
+
 # ARM WMMX register support
 if (LIBUNWIND_ENABLE_ARM_WMMX)
   # __ARM_WMMX is a compiler pre-define (as per the ACLE 2.0). Clang does not
Index: libunwind/trunk/src/CMakeLists.txt
===================================================================
--- libunwind/trunk/src/CMakeLists.txt
+++ libunwind/trunk/src/CMakeLists.txt
@@ -53,7 +53,9 @@
 set(libraries ${LIBUNWINDCXX_ABI_LIBRARIES})
 append_if(libraries LIBUNWIND_HAS_C_LIB c)
 append_if(libraries LIBUNWIND_HAS_DL_LIB dl)
-append_if(libraries LIBUNWIND_HAS_PTHREAD_LIB pthread)
+if (LIBUNWIND_ENABLE_THREADS)
+  append_if(libraries LIBUNWIND_HAS_PTHREAD_LIB pthread)
+endif()
 
 # Setup flags.
 append_if(LIBUNWIND_COMPILE_FLAGS LIBUNWIND_HAS_FPIC_FLAG -fPIC)
Index: libunwind/trunk/src/UnwindCursor.hpp
===================================================================
--- libunwind/trunk/src/UnwindCursor.hpp
+++ libunwind/trunk/src/UnwindCursor.hpp
@@ -16,7 +16,9 @@
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <pthread.h>
+#ifndef _LIBUNWIND_HAS_NO_THREADS
+  #include <pthread.h>
+#endif
 #include <unwind.h>
 
 #ifdef __APPLE__
@@ -60,7 +62,9 @@
 
   // These fields are all static to avoid needing an initializer.
   // There is only one instance of this class per process.
+#ifndef _LIBUNWIND_HAS_NO_THREADS
   static pthread_rwlock_t _lock;
+#endif
 #ifdef __APPLE__
   static void dyldUnloadHook(const struct mach_header *mh, intptr_t slide);
   static bool _registeredForDyldUnloads;
@@ -87,8 +91,10 @@
 template <typename A>
 typename DwarfFDECache<A>::entry DwarfFDECache<A>::_initialBuffer[64];
 
+#ifndef _LIBUNWIND_HAS_NO_THREADS
 template <typename A>
 pthread_rwlock_t DwarfFDECache<A>::_lock = PTHREAD_RWLOCK_INITIALIZER;
+#endif
 
 #ifdef __APPLE__
 template <typename A>
Index: libunwind/trunk/src/Unwind_AppleExtras.cpp
===================================================================
--- libunwind/trunk/src/Unwind_AppleExtras.cpp
+++ libunwind/trunk/src/Unwind_AppleExtras.cpp
@@ -185,21 +185,29 @@
 
 #if !defined(FOR_DYLD) && _LIBUNWIND_BUILD_SJLJ_APIS
 
-#include <System/pthread_machdep.h>
+#ifndef _LIBUNWIND_HAS_NO_THREADS
+  #include <System/pthread_machdep.h>
+#else
+  _Unwind_FunctionContext *fc_ = nullptr;
+#endif
 
 // Accessors to get get/set linked list of frames for sjlj based execeptions.
 _LIBUNWIND_HIDDEN
 struct _Unwind_FunctionContext *__Unwind_SjLj_GetTopOfFunctionStack() {
+#ifndef _LIBUNWIND_HAS_NO_THREADS
   return (struct _Unwind_FunctionContext *)
     _pthread_getspecific_direct(__PTK_LIBC_DYLD_Unwind_SjLj_Key);
+#else
+  return fc_;
+#endif
 }
 
 _LIBUNWIND_HIDDEN
 void __Unwind_SjLj_SetTopOfFunctionStack(struct _Unwind_FunctionContext *fc) {
+#ifndef _LIBUNWIND_HAS_NO_THREADS
   _pthread_setspecific_direct(__PTK_LIBC_DYLD_Unwind_SjLj_Key, fc);
+#else
+  fc_ = fc;
+#endif
 }
 #endif
-
-
-
-
Index: libunwind/trunk/src/config.h
===================================================================
--- libunwind/trunk/src/config.h
+++ libunwind/trunk/src/config.h
@@ -85,13 +85,20 @@
   } while (0)
 #define _LIBUNWIND_LOG(msg, ...) fprintf(stderr, "libunwind: " msg "\n", __VA_ARGS__)
 
+#if defined(_LIBUNWIND_HAS_NO_THREADS)
+  // only used with pthread calls, not needed for the single-threaded builds
+  #define _LIBUNWIND_LOG_NON_ZERO(x)
+#endif
+
 // Macros that define away in non-Debug builds
 #ifdef NDEBUG
   #define _LIBUNWIND_DEBUG_LOG(msg, ...)
   #define _LIBUNWIND_TRACE_API(msg, ...)
   #define _LIBUNWIND_TRACING_UNWINDING 0
   #define _LIBUNWIND_TRACE_UNWINDING(msg, ...)
-  #define _LIBUNWIND_LOG_NON_ZERO(x) x
+  #ifndef _LIBUNWIND_LOG_NON_ZERO
+    #define _LIBUNWIND_LOG_NON_ZERO(x) x
+  #endif
 #else
   #ifdef __cplusplus
     extern "C" {
@@ -102,12 +109,14 @@
     }
   #endif
   #define _LIBUNWIND_DEBUG_LOG(msg, ...)  _LIBUNWIND_LOG(msg, __VA_ARGS__)
-  #define _LIBUNWIND_LOG_NON_ZERO(x) \
-            do { \
-              int _err = x; \
-              if ( _err != 0 ) \
-                _LIBUNWIND_LOG("" #x "=%d in %s", _err, __FUNCTION__); \
-             } while (0)
+  #ifndef _LIBUNWIND_LOG_NON_ZERO
+    #define _LIBUNWIND_LOG_NON_ZERO(x) \
+              do { \
+                int _err = x; \
+                if ( _err != 0 ) \
+                  _LIBUNWIND_LOG("" #x "=%d in %s", _err, __FUNCTION__); \
+               } while (0)
+  #endif
   #define _LIBUNWIND_TRACE_API(msg, ...) \
             do { \
               if ( logAPIs() ) _LIBUNWIND_LOG(msg, __VA_ARGS__); \