Index: libunwind/trunk/CMakeLists.txt
===================================================================
--- libunwind/trunk/CMakeLists.txt
+++ libunwind/trunk/CMakeLists.txt
@@ -164,6 +164,13 @@
 set(LIBUNWIND_BINARY_DIR  ${CMAKE_CURRENT_BINARY_DIR})
 set(LIBUNWIND_LIBRARY_DIR ${CMAKE_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX})
 
+set(LIBUNWIND_INSTALL_PREFIX "" CACHE STRING
+    "Define libunwind destination prefix.")
+
+if (NOT LIBUNWIND_INSTALL_PREFIX MATCHES "^$|.*/")
+  message(FATAL_ERROR "LIBUNWIND_INSTALL_PREFIX has to end with \"/\".")
+endif()
+
 set(LIBUNWIND_C_FLAGS "")
 set(LIBUNWIND_CXX_FLAGS "")
 set(LIBUNWIND_COMPILE_FLAGS "")
Index: libunwind/trunk/src/CMakeLists.txt
===================================================================
--- libunwind/trunk/src/CMakeLists.txt
+++ libunwind/trunk/src/CMakeLists.txt
@@ -133,6 +133,6 @@
 add_custom_target(unwind DEPENDS ${LIBUNWIND_TARGETS})
 
 install(TARGETS ${LIBUNWIND_TARGETS}
-        LIBRARY DESTINATION lib${LLVM_LIBDIR_SUFFIX}
-        ARCHIVE DESTINATION lib${LLVM_LIBDIR_SUFFIX})
+  LIBRARY DESTINATION ${LIBUNWIND_INSTALL_PREFIX}lib${LLVM_LIBDIR_SUFFIX}
+  ARCHIVE DESTINATION ${LIBUNWIND_INSTALL_PREFIX}lib${LLVM_LIBDIR_SUFFIX})