Index: clang/CMakeLists.txt
===================================================================
--- clang/CMakeLists.txt
+++ clang/CMakeLists.txt
@@ -599,8 +599,8 @@
       if(NOT BOOTSTRAP_LLVM_ENABLE_LLD AND LLVM_BINUTILS_INCDIR)
         add_dependencies(clang-bootstrap-deps LLVMgold)
       endif()
-      set(LTO_AR -DCMAKE_AR=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ar)
-      set(LTO_RANLIB -DCMAKE_RANLIB=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ranlib)
+      set(${CLANG_STAGE}_AR -DCMAKE_AR=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ar)
+      set(${CLANG_STAGE}_RANLIB -DCMAKE_RANLIB=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ranlib)
     endif()
   endif()
 
@@ -666,6 +666,26 @@
     -DCMAKE_ASM_COMPILER=${LLVM_RUNTIME_OUTPUT_INTDIR}/${C_COMPILER}
     -DCMAKE_ASM_COMPILER_ID=Clang)
 
+  if(BOOTSTRAP_CMAKE_SYSTEM_NAME)
+    set(${CLANG_STAGE}_CONFIG -DLLVM_CONFIG_PATH=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-config)
+    set(${CLANG_STAGE}_TABLEGEN
+      -DLLVM_TABLEGEN=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-tblgen
+      -DCLANG_TABLEGEN=${LLVM_RUNTIME_OUTPUT_INTDIR}/clang-tblgen)
+    if(BOOTSTRAP_CMAKE_SYSTEM_NAME STREQUAL "Linux")
+      if(BOOTSTRAP_LLVM_ENABLE_LLD)
+        set(${CLANG_STAGE}_LINKER -DCMAKE_LINKER=${LLVM_RUNTIME_OUTPUT_INTDIR}/ld.lld)
+      endif()
+      if(NOT BOOTSTRAP_LLVM_ENABLE_LTO)
+        add_dependencies(clang-bootstrap-deps llvm-ar llvm-ranlib)
+        set(${CLANG_STAGE}_AR -DCMAKE_AR=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ar)
+        set(${CLANG_STAGE}_RANLIB -DCMAKE_RANLIB=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-ranlib)
+      endif()
+      add_dependencies(clang-bootstrap-deps llvm-objcopy llvm-strip)
+      set(${CLANG_STAGE}_OBJCOPY -DCMAKE_OBJCOPY=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-objcopy)
+      set(${CLANG_STAGE}_STRIP -DCMAKE_STRIP=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-strip)
+    endif()
+  endif()
+
   if(BOOTSTRAP_LLVM_BUILD_INSTRUMENTED)
     add_dependencies(clang-bootstrap-deps llvm-profdata)
     set(PGO_OPT -DLLVM_PROFDATA=${LLVM_RUNTIME_OUTPUT_INTDIR}/llvm-profdata)
@@ -734,7 +754,14 @@
                 ${PASSTHROUGH_VARIABLES}
                  -DCLANG_STAGE=${NEXT_CLANG_STAGE}
                 ${COMPILER_OPTIONS}
-                ${LTO_LIBRARY} ${LTO_AR} ${LTO_RANLIB} ${verbose} ${PGO_OPT}
+                ${${CLANG_STAGE}_CONFIG}
+                ${${CLANG_STAGE}_TABLEGEN}
+                ${LTO_LIBRARY} ${verbose} ${PGO_OPT}
+                ${${CLANG_STAGE}_LINKER}
+                ${${CLANG_STAGE}_AR}
+                ${${CLANG_STAGE}_RANLIB}
+                ${${CLANG_STAGE}_OBJCOPY}
+                ${${CLANG_STAGE}_STRIP}
     INSTALL_COMMAND ""
     STEP_TARGETS configure build
     USES_TERMINAL_CONFIGURE 1
Index: llvm/cmake/modules/LLVMExternalProjectUtils.cmake
===================================================================
--- llvm/cmake/modules/LLVMExternalProjectUtils.cmake
+++ llvm/cmake/modules/LLVMExternalProjectUtils.cmake
@@ -162,8 +162,35 @@
                       -DCMAKE_OBJDUMP=${CMAKE_OBJDUMP}
                       -DCMAKE_STRIP=${CMAKE_STRIP})
     set(llvm_config_path ${LLVM_CONFIG_PATH})
+
+    if(CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+      string(REGEX MATCH "[0-9]+\\.[0-9]+(\\.[0-9]+)?" CLANG_VERSION
+             ${PACKAGE_VERSION})
+      set(resource_dir "${LLVM_LIBRARY_DIR}/clang/${CLANG_VERSION}")
+      set(flag_types ASM C CXX MODULE_LINKER SHARED_LINKER EXE_LINKER)
+      foreach(type ${flag_types})
+        set(${type}_flag -DCMAKE_${type}_FLAGS=-resource-dir=${resource_dir})
+      endforeach()
+      string(REPLACE ";" "|" flag_string "${flag_types}")
+      foreach(arg ${ARG_CMAKE_ARGS})
+        if(arg MATCHES "^-DCMAKE_(${flag_string})_FLAGS")
+          foreach(type ${flag_types})
+            if(arg MATCHES "^-DCMAKE_${type}_FLAGS")
+              string(REGEX REPLACE "^-DCMAKE_${type}_FLAGS=(.*)$" "\\1" flag_value "${arg}")
+              set(${type}_flag "${${type}_flag} ${flag_value}")
+            endif()
+          endforeach()
+        else()
+          list(APPEND cmake_args ${arg})
+        endif()
+      endforeach()
+      foreach(type ${flag_types})
+        list(APPEND cmake_args ${${type}_flag})
+      endforeach()
+    endif()
   else()
     set(llvm_config_path "$<TARGET_FILE:llvm-config>")
+    set(cmake_args ${ARG_CMAKE_ARGS})
   endif()
 
   ExternalProject_Add(${name}
@@ -187,7 +214,7 @@
                -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
                -DCMAKE_MAKE_PROGRAM=${CMAKE_MAKE_PROGRAM}
                -DCMAKE_EXPORT_COMPILE_COMMANDS=1
-               ${ARG_CMAKE_ARGS}
+               ${cmake_args}
                ${PASSTHROUGH_VARIABLES}
     INSTALL_COMMAND ""
     STEP_TARGETS configure build