diff --git a/compiler-rt/lib/tsan/CMakeLists.txt b/compiler-rt/lib/tsan/CMakeLists.txt
--- a/compiler-rt/lib/tsan/CMakeLists.txt
+++ b/compiler-rt/lib/tsan/CMakeLists.txt
@@ -24,6 +24,12 @@
 append_list_if(COMPILER_RT_HAS_WGLOBAL_CONSTRUCTORS_FLAG -Wglobal-constructors
                TSAN_RTL_CFLAGS)
 
+set(TSAN_RTL_DYNAMIC_CFLAGS ${TSAN_RTL_CFLAGS})
+list(REMOVE_ITEM TSAN_RTL_DYNAMIC_CFLAGS -fPIE)
+
+append_list_if(COMPILER_RT_HAS_LIBDL dl TSAN_DYNAMIC_LINK_LIBS)
+append_list_if(COMPILER_RT_HAS_LIBPTHREAD pthread TSAN_DYNAMIC_LINK_LIBS)
+
 set(TSAN_SOURCES
   rtl/tsan_clock.cpp
   rtl/tsan_debugging.cpp
@@ -257,6 +263,20 @@
       PARENT_TARGET tsan)
     list(APPEND TSAN_RUNTIME_LIBRARIES clang_rt.tsan-${arch}
                                        clang_rt.tsan_cxx-${arch})
+    add_compiler_rt_runtime(clang_rt.tsan
+      SHARED
+      ARCHS ${arch}
+      SOURCES ${TSAN_SOURCES} ${TSAN_ASM_SOURCES}
+              $<TARGET_OBJECTS:RTInterception.${arch}>
+              $<TARGET_OBJECTS:RTSanitizerCommon.${arch}>
+              $<TARGET_OBJECTS:RTSanitizerCommonLibc.${arch}>
+              $<TARGET_OBJECTS:RTSanitizerCommonCoverage.${arch}>
+              $<TARGET_OBJECTS:RTSanitizerCommonSymbolizer.${arch}>
+              $<TARGET_OBJECTS:RTUbsan.${arch}>
+      ADDITIONAL_HEADERS ${TSAN_HEADERS}
+      CFLAGS ${TSAN_RTL_DYNAMIC_CFLAGS}
+      LINK_LIBS ${TSAN_DYNAMIC_LINK_LIBS}
+      PARENT_TARGET tsan)
     add_sanitizer_rt_symbols(clang_rt.tsan
       ARCHS ${arch}
       EXTRA rtl/tsan.syms.extra)
diff --git a/libcxx/utils/merge_archives.py b/libcxx/utils/merge_archives.py
--- a/libcxx/utils/merge_archives.py
+++ b/libcxx/utils/merge_archives.py
@@ -8,6 +8,7 @@
 #===----------------------------------------------------------------------===##
 
 from argparse import ArgumentParser
+from ctypes.util import find_library
 import distutils.spawn
 import tempfile
 import os