[clang-tools-extra] [llvm] [clang-doc] Adds a mustache backend (PR #133161)

[Paul Kirth via llvm-commits]

================
@@ -0,0 +1,75 @@
+//===-- FileHelpersClangDoc.cpp - File Helpers -------------------*- C++-*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+#include "FileHelpersClangDoc.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"
+
+namespace clang {
+namespace doc {
+
+llvm::Error
+copyFile(llvm::StringRef FilePath, llvm::StringRef OutDirectory) {
+  llvm::SmallString<128> PathWrite;
+  llvm::sys::path::native(OutDirectory, PathWrite);
+  llvm::sys::path::append(PathWrite, llvm::sys::path::filename(FilePath));
+  llvm::SmallString<128> PathRead;
+  llvm::sys::path::native(FilePath, PathRead);
+  std::error_code OK;
+  std::error_code FileErr = llvm::sys::fs::copy_file(PathRead, PathWrite);
+  if (FileErr != OK) {
+    return llvm::createStringError(llvm::inconvertibleErrorCode(),
+                                   "error creating file " +
+                                       llvm::sys::path::filename(FilePath) +
+                                       ": " + FileErr.message() + "\n");
+  }
+  return llvm::Error::success();
+}
+
+
+llvm::SmallString<128> computeRelativePath(llvm::StringRef Destination,
+                                                  llvm::StringRef Origin) {
----------------
ilovepi wrote:

Maybe we should drop this in favor of `std::filesystem::relative()`?

https://github.com/llvm/llvm-project/pull/133161