Index: cmake/config-ix.cmake
===================================================================
--- cmake/config-ix.cmake
+++ cmake/config-ix.cmake
@@ -110,7 +110,13 @@
 endif()
 
 if(HAVE_LIBPTHREAD)
-  set(PTHREAD_LIB pthread)
+  # We want to find pthreads library and at the moment we do want to
+  # have it reported as '-l<lib>' instead of '-pthread'.
+  # TODO: switch to -pthread once the rest of the build system can deal with it.
+  set(CMAKE_THREAD_PREFER_PTHREAD TRUE)
+  set(THREADS_HAVE_PTHREAD_ARG Off)
+  find_package(Threads REQUIRED)
+  set(PTHREAD_LIB ${CMAKE_THREAD_LIBS_INIT})
 endif()
 
 # Don't look for these libraries on Windows. Also don't look for them if we're
Index: cmake/modules/AddLLVM.cmake
===================================================================
--- cmake/modules/AddLLVM.cmake
+++ cmake/modules/AddLLVM.cmake
@@ -670,6 +670,12 @@
   if(NOT ARG_IGNORE_EXTERNALIZE_DEBUGINFO)
     llvm_externalize_debuginfo(${name})
   endif()
+  if (PTHREAD_LIB)
+    # libpthreads overrides some standard library symbols, so main
+    # executable must be linked with it in order to provide consistent
+    # API for all shared libaries loaded by this executable.
+    target_link_libraries(${name} ${PTHREAD_LIB})
+  endif()
 endmacro(add_llvm_executable name)
 
 function(export_executable_symbols target)
@@ -953,7 +959,10 @@
   add_llvm_executable(${test_name} IGNORE_EXTERNALIZE_DEBUGINFO ${ARGN})
   set(outdir ${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_CFG_INTDIR})
   set_output_directory(${test_name} BINARY_DIR ${outdir} LIBRARY_DIR ${outdir})
-  target_link_libraries(${test_name} gtest_main gtest)
+  # libpthreads overrides some standard library symbols, so main
+  # executable must be linked with it in order to provide consistent
+  # API for all shared libaries loaded by this executable.
+  target_link_libraries(${test_name} gtest_main gtest ${PTHREAD_LIB})
 
   add_dependencies(${test_suite} ${test_name})
   get_target_property(test_suite_folder ${test_suite} FOLDER)
Index: tools/llvm-config/CMakeLists.txt
===================================================================
--- tools/llvm-config/CMakeLists.txt
+++ tools/llvm-config/CMakeLists.txt
@@ -14,7 +14,13 @@
   if(MSVC)
     set(SYSTEM_LIBS ${SYSTEM_LIBS} "${l}.lib")
   else()
-    set(SYSTEM_LIBS ${SYSTEM_LIBS} "-l${l}")
+    if (l MATCHES "^-")
+      # If it's an option, pass it without changes.
+      set(SYSTEM_LIBS ${SYSTEM_LIBS} "${l}")
+    else()
+      # Otherwise assume it's a library name we need to link with.
+      set(SYSTEM_LIBS ${SYSTEM_LIBS} "-l${l}")
+    endif()
   endif()
 endforeach()
 string(REPLACE ";" " " SYSTEM_LIBS "${SYSTEM_LIBS}")