diff --git a/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp b/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp
index 21b581fa6df2e1e..5a43c70a5ebc372 100644
--- a/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp
+++ b/clang-tools-extra/clang-doc/tool/ClangDocMain.cpp
@@ -81,6 +81,12 @@ static llvm::cl::list<std::string> UserStylesheets(
     llvm::cl::desc("CSS stylesheets to extend the default styles."),
     llvm::cl::cat(ClangDocCategory));
 
+static llvm::cl::opt<std::string> UserAssetPath(
+    "asset",
+    llvm::cl::desc("User supplied asset path to "
+                   "override the default css and js files for html output"),
+    llvm::cl::cat(ClangDocCategory));
+
 static llvm::cl::opt<std::string> SourceRoot("source-root", llvm::cl::desc(R"(
 Directory where processed files are stored.
 Links to definition locations will only be
@@ -127,16 +133,86 @@ std::string getFormatString() {
 // GetMainExecutable (since some platforms don't support taking the
 // address of main, and some platforms can't implement GetMainExecutable
 // without being given the address of a function in the main executable).
-std::string GetExecutablePath(const char *Argv0, void *MainAddr) {
+std::string getExecutablePath(const char *Argv0, void *MainAddr) {
   return llvm::sys::fs::getMainExecutable(Argv0, MainAddr);
 }
 
+llvm::Error getAssetFiles(clang::doc::ClangDocContext &CDCtx) {
+  using DirIt = llvm::sys::fs::directory_iterator;
+  std::error_code FileErr;
+  llvm::SmallString<128> FilePath(UserAssetPath);
+  for (DirIt DirStart = DirIt(UserAssetPath, FileErr),
+                   DirEnd;
+       !FileErr && DirStart != DirEnd; DirStart.increment(FileErr)) {
+    FilePath = DirStart->path();
+    if (llvm::sys::fs::is_regular_file(FilePath)) {
+      if (llvm::sys::path::extension(FilePath) == ".css")
+        CDCtx.UserStylesheets.insert(CDCtx.UserStylesheets.begin(),
+                                     std::string(FilePath));
+      else if (llvm::sys::path::extension(FilePath) == ".js")
+        CDCtx.FilesToCopy.emplace_back(FilePath.str());
+    }
+  }
+  if (FileErr)
+    return llvm::createFileError(FilePath, FileErr);
+  return llvm::Error::success();
+}
+
+llvm::Error getDefaultAssetFiles(const char *Argv0,
+                                 clang::doc::ClangDocContext &CDCtx) {
+  void *MainAddr = (void *)(intptr_t)getExecutablePath;
+  std::string ClangDocPath = getExecutablePath(Argv0, MainAddr);
+  llvm::SmallString<128> NativeClangDocPath;
+  llvm::sys::path::native(ClangDocPath, NativeClangDocPath);
+
+  llvm::SmallString<128> AssetsPath;
+  AssetsPath = llvm::sys::path::parent_path(NativeClangDocPath);
+  llvm::sys::path::append(AssetsPath, "..", "share", "clang");
+  llvm::SmallString<128> DefaultStylesheet;
+  llvm::sys::path::native(AssetsPath, DefaultStylesheet);
+  llvm::sys::path::append(DefaultStylesheet,
+                          "clang-doc-default-stylesheet.css");
+  llvm::SmallString<128> IndexJS;
+  llvm::sys::path::native(AssetsPath, IndexJS);
+  llvm::sys::path::append(IndexJS, "index.js");
+
+  llvm::outs() << "Using default asset: " << AssetsPath << "\n";
+
+  if (!llvm::sys::fs::is_regular_file(IndexJS))
+    return llvm::createStringError(llvm::inconvertibleErrorCode(),
+                                   "default index.js file missing at " +
+                                       IndexJS + "\n");
+
+  if (!llvm::sys::fs::is_regular_file(DefaultStylesheet))
+    return llvm::createStringError(
+        llvm::inconvertibleErrorCode(),
+        "default clang-doc-default-stylesheet.css file missing at " +
+            DefaultStylesheet + "\n");
+
+  CDCtx.UserStylesheets.insert(CDCtx.UserStylesheets.begin(),
+                               std::string(DefaultStylesheet));
+  CDCtx.FilesToCopy.emplace_back(IndexJS.str());
+
+  return llvm::Error::success();
+}
+
+llvm::Error getHtmlAssetFiles(const char *Argv0,
+                              clang::doc::ClangDocContext &CDCtx) {
+  if (!UserAssetPath.empty() &&
+      !llvm::sys::fs::is_directory(std::string(UserAssetPath)))
+    llvm::outs() << "Asset path supply is not a directory: " << UserAssetPath
+                 << " falling back to default\n";
+  if (llvm::sys::fs::is_directory(std::string(UserAssetPath)))
+    return getAssetFiles(CDCtx);
+  return getDefaultAssetFiles(Argv0, CDCtx);
+}
+
 int main(int argc, const char **argv) {
   llvm::sys::PrintStackTraceOnErrorSignal(argv[0]);
   std::error_code OK;
 
   const char *Overview =
-    R"(Generates documentation from source code and comments.
+      R"(Generates documentation from source code and comments.
 
 Example usage for files without flags (default):
 
@@ -182,23 +258,9 @@ Example usage for a project using a compile commands database:
       {"index.js", "index_json.js"}};
 
   if (Format == "html") {
-    void *MainAddr = (void *)(intptr_t)GetExecutablePath;
-    std::string ClangDocPath = GetExecutablePath(argv[0], MainAddr);
-    llvm::SmallString<128> NativeClangDocPath;
-    llvm::sys::path::native(ClangDocPath, NativeClangDocPath);
-    llvm::SmallString<128> AssetsPath;
-    AssetsPath = llvm::sys::path::parent_path(NativeClangDocPath);
-    llvm::sys::path::append(AssetsPath, "..", "share", "clang");
-    llvm::SmallString<128> DefaultStylesheet;
-    llvm::sys::path::native(AssetsPath, DefaultStylesheet);
-    llvm::sys::path::append(DefaultStylesheet,
-                            "clang-doc-default-stylesheet.css");
-    llvm::SmallString<128> IndexJS;
-    llvm::sys::path::native(AssetsPath, IndexJS);
-    llvm::sys::path::append(IndexJS, "index.js");
-    CDCtx.UserStylesheets.insert(CDCtx.UserStylesheets.begin(),
-                                 std::string(DefaultStylesheet));
-    CDCtx.FilesToCopy.emplace_back(IndexJS.str());
+    if (auto Err = getHtmlAssetFiles(argv[0], CDCtx)) {
+      llvm::outs() << "warning: " <<  toString(std::move(Err)) << "\n";
+    }
   }
 
   // Mapping phase
@@ -299,8 +361,7 @@ Example usage for a project using a compile commands database:
   llvm::outs() << "Generating assets for docs...\n";
   Err = G->get()->createResources(CDCtx);
   if (Err) {
-    llvm::errs() << toString(std::move(Err)) << "\n";
-    return 1;
+    llvm::outs() << "warning: " << toString(std::move(Err)) << "\n";
   }
 
   return 0;
diff --git a/clang-tools-extra/test/clang-doc/single-source-html.cpp b/clang-tools-extra/test/clang-doc/single-source-html.cpp
new file mode 100644
index 000000000000000..32f232b9c45a048
--- /dev/null
+++ b/clang-tools-extra/test/clang-doc/single-source-html.cpp
@@ -0,0 +1,2 @@
+// RUN: clang-doc --format=html --executor=standalone %s -output=%t/docs | FileCheck %s
+// CHECK: Using default asset: {{.*}}{{[\/]}}share{{[\/]}}clang
\ No newline at end of file