diff --git a/openmp/CMakeLists.txt b/openmp/CMakeLists.txt
--- a/openmp/CMakeLists.txt
+++ b/openmp/CMakeLists.txt
@@ -59,19 +59,11 @@
 # Currently libomptarget cannot be compiled on Windows or MacOS X.
 # Since the device plugins are only supported on Linux anyway,
 # there is no point in trying to compile libomptarget on other OSes.
-if (APPLE OR WIN32 OR NOT OPENMP_HAVE_STD_CPP14_FLAG)
+if (APPLE OR WIN32 OR NOT OPENMP_HAVE_STD_CPP14_FLAG OR
+    OPENMP_STANDALONE_BUILD)
   set(ENABLE_LIBOMPTARGET OFF)
 endif()
 
-# Attempt to locate LLVM source, required by libomptarget
-if (NOT LIBOMPTARGET_LLVM_INCLUDE_DIRS)
-  if (LLVM_MAIN_INCLUDE_DIR)
-    list(APPEND LIBOMPTARGET_LLVM_INCLUDE_DIRS ${LLVM_MAIN_INCLUDE_DIR})
-  elseif (EXISTS ${CMAKE_CURRENT_SOURCE_DIR}/../llvm/include)
-    list(APPEND LIBOMPTARGET_LLVM_INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}/../llvm/include)
-  endif()
-endif()
-
 if (NOT LIBOMPTARGET_LLVM_INCLUDE_DIRS)
   message(STATUS "Missing definition for LIBOMPTARGET_LLVM_INCLUDE_DIRS, disabling libomptarget")
   set(ENABLE_LIBOMPTARGET OFF)
@@ -93,6 +85,8 @@
     message(FATAL_ERROR "libomptarget cannot be built on Windows and MacOS X!")
   elseif (NOT OPENMP_HAVE_STD_CPP14_FLAG)
     message(FATAL_ERROR "Host compiler must support C++14 to build libomptarget!")
+  elseif (OPENMP_STANDALONE_BUILD)
+    message(FATAL_ERROR "libomptarget cannot be built out of LLVM tree!")
   endif()
 
   add_subdirectory(libomptarget)
diff --git a/openmp/libomptarget/cmake/Modules/LibomptargetGetDependencies.cmake b/openmp/libomptarget/cmake/Modules/LibomptargetGetDependencies.cmake
--- a/openmp/libomptarget/cmake/Modules/LibomptargetGetDependencies.cmake
+++ b/openmp/libomptarget/cmake/Modules/LibomptargetGetDependencies.cmake
@@ -250,27 +250,4 @@
   endif()
 endif()
 
-if (OPENMP_STANDALONE_BUILD)
-  # This duplicates code from llvm/cmake/config-ix.cmake
-  if( WIN32 AND NOT CYGWIN )
-    # We consider Cygwin as another Unix
-    set(PURE_WINDOWS 1)
-  endif()
-
-  # library checks
-  if( NOT PURE_WINDOWS )
-    check_library_exists(pthread pthread_create "" HAVE_LIBPTHREAD)
-  endif()
-
-  if(HAVE_LIBPTHREAD)
-    # 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(OPENMP_PTHREAD_LIB ${CMAKE_THREAD_LIBS_INIT})
-  endif()
-else()
-  set(OPENMP_PTHREAD_LIB ${LLVM_PTHREAD_LIB})
-endif()
+set(OPENMP_PTHREAD_LIB ${LLVM_PTHREAD_LIB})
diff --git a/openmp/libomptarget/src/CMakeLists.txt b/openmp/libomptarget/src/CMakeLists.txt
--- a/openmp/libomptarget/src/CMakeLists.txt
+++ b/openmp/libomptarget/src/CMakeLists.txt
@@ -24,23 +24,19 @@
 
 include_directories(${LIBOMPTARGET_LLVM_INCLUDE_DIRS})
 
-# Build libomptarget library with libdl dependency. Add LLVMSupport
-# dependency if building in-tree with profiling enabled.
-if(OPENMP_STANDALONE_BUILD OR (NOT OPENMP_ENABLE_LIBOMPTARGET_PROFILING))
-  add_library(omptarget SHARED ${LIBOMPTARGET_SRC_FILES})
-  target_link_libraries(omptarget
-    ${CMAKE_DL_LIBS}
-    "-Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/exports")
-else()
-  set(LLVM_LINK_COMPONENTS
-    Support
-    )
-  add_llvm_library(omptarget SHARED ${LIBOMPTARGET_SRC_FILES}
-      LINK_LIBS ${CMAKE_DL_LIBS}
-      "-Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/exports"
-      )
+# Build libomptarget library with libdl dependency.
+add_library(omptarget SHARED ${LIBOMPTARGET_SRC_FILES})
+if (OPENMP_ENABLE_LIBOMPTARGET_PROFILING)
+  # Add LLVMSupport dependency if profiling is enabled.
+  # Linking with LLVM component libraries also requires
+  # aligning the compile flags.
+  llvm_update_compile_flags(omptarget)
   target_compile_definitions(omptarget PUBLIC OMPTARGET_PROFILE_ENABLED)
+  target_link_libraries(omptarget PRIVATE LLVMSupport)
 endif()
+target_link_libraries(omptarget PRIVATE
+  ${CMAKE_DL_LIBS}
+  "-Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/exports")
 
 # libomptarget needs to be set separately because add_llvm_library doesn't
 # conform with location configuration of its parent scope.