diff --git a/lld/test/CMakeLists.txt b/lld/test/CMakeLists.txt
--- a/lld/test/CMakeLists.txt
+++ b/lld/test/CMakeLists.txt
@@ -14,7 +14,18 @@
   ${CMAKE_CURRENT_BINARY_DIR}/lit.site.cfg.py
   MAIN_CONFIG
   ${CMAKE_CURRENT_SOURCE_DIR}/lit.cfg.py
-)
+  PATHS
+  "LLVM_SOURCE_DIR"
+  "LLVM_BINARY_DIR"
+  "LLVM_TOOLS_DIR"
+  "LLVM_LIBS_DIR"
+  "SHLIBDIR"
+  "LLVM_LIT_TOOLS_DIR"
+  "LLD_BINARY_DIR"
+  "CURRENT_LIBS_DIR"
+  "CURRENT_TOOLS_DIR"
+  "LLD_SOURCE_DIR"
+  )
 configure_lit_site_cfg(
   ${CMAKE_CURRENT_SOURCE_DIR}/Unit/lit.site.cfg.py.in
   ${CMAKE_CURRENT_BINARY_DIR}/Unit/lit.site.cfg.py
diff --git a/lld/test/lit.site.cfg.py.in b/lld/test/lit.site.cfg.py.in
--- a/lld/test/lit.site.cfg.py.in
+++ b/lld/test/lit.site.cfg.py.in
@@ -3,18 +3,18 @@
 import lit.util
 
 config.have_dia_sdk = lit.util.pythonize_bool("@LLVM_ENABLE_DIA_SDK@")
-config.llvm_src_root = "@LLVM_SOURCE_DIR@"
-config.llvm_obj_root = "@LLVM_BINARY_DIR@"
-config.llvm_tools_dir = lit_config.substitute("@LLVM_TOOLS_DIR@")
-config.llvm_libs_dir = lit_config.substitute("@LLVM_LIBS_DIR@")
-config.llvm_shlib_dir = "@SHLIBDIR@"
+config.llvm_src_root = path(r"@LLVM_SOURCE_DIR@")
+config.llvm_obj_root = path(r"@LLVM_BINARY_DIR@")
+config.llvm_tools_dir = lit_config.substitute(path(r"@LLVM_TOOLS_DIR@"))
+config.llvm_libs_dir = lit_config.substitute(path(r"@LLVM_LIBS_DIR@"))
+config.llvm_shlib_dir = path(r"@SHLIBDIR@")
 config.llvm_shlib_ext = "@SHLIBEXT@"
-config.lit_tools_dir = "@LLVM_LIT_TOOLS_DIR@"
+config.lit_tools_dir = path(r"@LLVM_LIT_TOOLS_DIR@")
 config.enable_backtrace = @ENABLE_BACKTRACES@
 config.errc_messages = "@LLVM_LIT_ERRC_MESSAGES@"
-config.lld_obj_root = "@LLD_BINARY_DIR@"
-config.lld_libs_dir = lit_config.substitute("@CURRENT_LIBS_DIR@")
-config.lld_tools_dir = lit_config.substitute("@CURRENT_TOOLS_DIR@")
+config.lld_obj_root = path(r"@LLD_BINARY_DIR@")
+config.lld_libs_dir = lit_config.substitute(path(r"@CURRENT_LIBS_DIR@"))
+config.lld_tools_dir = lit_config.substitute(path(r"@CURRENT_TOOLS_DIR@"))
 config.host_triple = "@LLVM_HOST_TRIPLE@"
 config.target_triple = "@LLVM_TARGET_TRIPLE@"
 config.python_executable = "@Python3_EXECUTABLE@"
@@ -31,4 +31,5 @@
 lit.llvm.initialize(lit_config, config)
 
 # Let the main config do the real work.
-lit_config.load_config(config, "@LLD_SOURCE_DIR@/test/lit.cfg.py")
+lit_config.load_config(
+    config, os.path.join(path(r"@LLD_SOURCE_DIR@"), "test/lit.cfg.py"))
diff --git a/llvm/utils/gn/secondary/lld/test/BUILD.gn b/llvm/utils/gn/secondary/lld/test/BUILD.gn
--- a/llvm/utils/gn/secondary/lld/test/BUILD.gn
+++ b/llvm/utils/gn/secondary/lld/test/BUILD.gn
@@ -11,13 +11,20 @@
   write_cmake_config(target_name) {
     input = invoker.input
     output = invoker.output
+    dir = get_path_info(output, "dir")
     values = [
       "LIT_SITE_CFG_IN_HEADER=" +
           "## Autogenerated from $input, do not edit\n\n" + lit_path_function,
       "LLD_BINARY_DIR=" +
-          rebase_path(get_label_info("//lld", "target_out_dir")),
-      "LLD_SOURCE_DIR=" + rebase_path("//lld"),
+          rebase_path(get_label_info("//lld", "target_out_dir"), dir),
+      "LLD_SOURCE_DIR=" + rebase_path("//lld", dir),
     ]
+    if (host_os == "win") {
+      # See comment for Windows solink in llvm/utils/gn/build/toolchain/BUILD.gn
+      values += [ "SHLIBDIR=" + rebase_path("$root_out_dir/bin", dir) ]
+    } else {
+      values += [ "SHLIBDIR=" + rebase_path("$root_out_dir/lib", dir) ]
+    }
     values += invoker.extra_values
   }
 }
@@ -30,15 +37,15 @@
 
   extra_values = [
     "CURRENT_LIBS_DIR=",  # FIXME: for shared builds only (?)
-    "CURRENT_TOOLS_DIR=" + rebase_path("$root_out_dir/bin"),
+    "CURRENT_TOOLS_DIR=" + rebase_path("$root_out_dir/bin", dir),
     "ENABLE_BACKTRACES=1",
     "LLVM_BINARY_DIR=" +
-        rebase_path(get_label_info("//llvm", "target_out_dir")),
+        rebase_path(get_label_info("//llvm", "target_out_dir"), dir),
     "LLVM_HOST_TRIPLE=$llvm_current_triple",
     "LLVM_LIBS_DIR=",  # needed only for shared builds
     "LLVM_LIT_TOOLS_DIR=",  # Intentionally empty, matches cmake build.
-    "LLVM_SOURCE_DIR=" + rebase_path("//llvm"),
-    "LLVM_TOOLS_DIR=" + rebase_path("$root_out_dir/bin"),
+    "LLVM_SOURCE_DIR=" + rebase_path("//llvm", dir),
+    "LLVM_TOOLS_DIR=" + rebase_path("$root_out_dir/bin", dir),
     "Python3_EXECUTABLE=$python_path",
     "LLVM_TARGET_TRIPLE=$llvm_target_triple",
 
@@ -53,15 +60,11 @@
       "LLVM_LIT_ERRC_MESSAGES=no such file or directory;is a directory;" +
           "invalid argument;permission denied",
       "LLVM_ENABLE_PLUGINS=0",
-
-      # See comment for Windows solink in llvm/utils/gn/build/toolchain/BUILD.gn
-      "SHLIBDIR=" + rebase_path("$root_out_dir/bin", dir),
     ]
   } else {
     extra_values += [
       "LLVM_LIT_ERRC_MESSAGES=",
       "LLVM_ENABLE_PLUGINS=1",
-      "SHLIBDIR=" + rebase_path("$root_out_dir/lib", dir),
     ]
   }
 
@@ -104,13 +107,6 @@
   input = "//lld/test/Unit/lit.site.cfg.py.in"
   output = lld_lit_unit_site_cfg_file
   extra_values = [ "LLVM_BUILD_MODE=." ]
-  dir = get_path_info(output, "dir")
-  if (host_os == "win") {
-    # See comment for Windows solink in llvm/utils/gn/build/toolchain/BUILD.gn
-    extra_values += [ "SHLIBDIR=" + rebase_path("$root_out_dir/bin", dir) ]
-  } else {
-    extra_values += [ "SHLIBDIR=" + rebase_path("$root_out_dir/lib", dir) ]
-  }
 }
 
 # This target should contain all dependencies of check-lld.