diff --git a/include/llvm/Support/FileSystem.h b/include/llvm/Support/FileSystem.h
index 4f013f89e86..1fd0b7848f7 100644
--- a/include/llvm/Support/FileSystem.h
+++ b/include/llvm/Support/FileSystem.h
@@ -427,10 +427,13 @@ error_code symlink_status(const Twine &path, file_status &result);
 /// @param model Name to base unique path off of.
 /// @param result_fs Set to the opened file's file descriptor.
 /// @param result_path Set to the opened file's absolute path.
+/// @param makeAbsolute If true and @model is not an absolute path, a temp
+///        directory will be prepended.
 /// @results errc::success if result_{fd,path} have been successfully set,
 ///          otherwise a platform specific error_code.
 error_code unique_file(const Twine &model, int &result_fd,
-                             SmallVectorImpl<char> &result_path);
+                             SmallVectorImpl<char> &result_path,
+                             bool makeAbsolute = true);
 
 /// @brief Canonicalize path.
 ///
diff --git a/lib/Support/Unix/PathV2.inc b/lib/Support/Unix/PathV2.inc
index 03ff28367e4..efd04f65bbe 100644
--- a/lib/Support/Unix/PathV2.inc
+++ b/lib/Support/Unix/PathV2.inc
@@ -342,19 +342,22 @@ error_code status(const Twine &path, file_status &result) {
 }
 
 error_code unique_file(const Twine &model, int &result_fd,
-                             SmallVectorImpl<char> &result_path) {
+                             SmallVectorImpl<char> &result_path,
+                             bool makeAbsolute) {
   SmallString<128> Model;
   model.toVector(Model);
   // Null terminate.
   Model.c_str();
 
-  // Make model absolute by prepending a temp directory if it's not already.
-  bool absolute = path::is_absolute(Twine(Model));
-  if (!absolute) {
-    SmallString<128> TDir;
-    if (error_code ec = TempDir(TDir)) return ec;
-    path::append(TDir, Twine(Model));
-    Model.swap(TDir);
+  if (makeAbsolute) {
+    // Make model absolute by prepending a temp directory if it's not already.
+    bool absolute = path::is_absolute(Twine(Model));
+    if (!absolute) {
+      SmallString<128> TDir;
+      if (error_code ec = TempDir(TDir)) return ec;
+      path::append(TDir, Twine(Model));
+      Model.swap(TDir);
+    }
   }
 
   // Replace '%' with random chars. From here on, DO NOT modify model. It may be
diff --git a/lib/Support/Windows/PathV2.inc b/lib/Support/Windows/PathV2.inc
index af71b73cd69..e34d74a23ba 100644
--- a/lib/Support/Windows/PathV2.inc
+++ b/lib/Support/Windows/PathV2.inc
@@ -501,7 +501,8 @@ handle_status_error:
 }
 
 error_code unique_file(const Twine &model, int &result_fd,
-                             SmallVectorImpl<char> &result_path) {
+                             SmallVectorImpl<char> &result_path,
+                             bool makeAbsolute) {
   // Use result_path as temp storage.
   result_path.set_size(0);
   StringRef m = model.toStringRef(result_path);
@@ -509,17 +510,19 @@ error_code unique_file(const Twine &model, int &result_fd,
   SmallVector<wchar_t, 128> model_utf16;
   if (error_code ec = UTF8ToUTF16(m, model_utf16)) return ec;
 
-  // Make model absolute by prepending a temp directory if it's not already.
-  bool absolute = path::is_absolute(m);
-
-  if (!absolute) {
-    SmallVector<wchar_t, 64> temp_dir;
-    if (error_code ec = TempDir(temp_dir)) return ec;
-    // Handle c: by removing it.
-    if (model_utf16.size() > 2 && model_utf16[1] == L':') {
-      model_utf16.erase(model_utf16.begin(), model_utf16.begin() + 2);
+  if (makeAbsolute) {
+    // Make model absolute by prepending a temp directory if it's not already.
+    bool absolute = path::is_absolute(m);
+  
+    if (!absolute) {
+      SmallVector<wchar_t, 64> temp_dir;
+      if (error_code ec = TempDir(temp_dir)) return ec;
+      // Handle c: by removing it.
+      if (model_utf16.size() > 2 && model_utf16[1] == L':') {
+        model_utf16.erase(model_utf16.begin(), model_utf16.begin() + 2);
+      }
+      model_utf16.insert(model_utf16.begin(), temp_dir.begin(), temp_dir.end());
     }
-    model_utf16.insert(model_utf16.begin(), temp_dir.begin(), temp_dir.end());
   }
 
   // Replace '%' with random chars. From here on, DO NOT modify model. It may be