--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang-tools-extra/clang-tidy/ClangTidyProfiling.cpp	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,92 @@
+//===--- ClangTidyProfiling.cpp - clang-tidy --------------------*- 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 "ClangTidyProfiling.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Path.h"
+#include "llvm/Support/YAMLTraits.h"
+#include "llvm/Support/raw_ostream.h"
+#include <system_error>
+#include <utility>
+
+#define DEBUG_TYPE "clang-tidy-profiling"
+
+namespace clang {
+namespace tidy {
+
+ClangTidyProfiling::StorageParams::StorageParams(llvm::StringRef ProfilePrefix,
+                                                 llvm::StringRef SourceFile)
+    : Timestamp(std::chrono::system_clock::now()), SourceFilename(SourceFile) {
+  llvm::SmallString<32> TimestampStr;
+  llvm::raw_svector_ostream OS(TimestampStr);
+  llvm::format_provider<decltype(Timestamp)>::format(Timestamp, OS,
+                                                     "%Y%m%d%H%M%S%N");
+
+  llvm::SmallString<256> FinalPrefix(ProfilePrefix);
+  llvm::sys::path::append(FinalPrefix, TimestampStr);
+
+  // So the full output name is: /ProfilePrefix/timestamp-inputfilename.json
+  StoreFilename = llvm::Twine(FinalPrefix + "-" +
+                              llvm::sys::path::filename(SourceFile) + ".json")
+                      .str();
+}
+
+void ClangTidyProfiling::printUserFriendlyTable(llvm::raw_ostream &OS) {
+  TG->print(OS);
+  OS.flush();
+}
+
+void ClangTidyProfiling::printAsJSON(llvm::raw_ostream &OS) {
+  OS << "{\n";
+  OS << "\"file\": \"" << Storage->SourceFilename << "\",\n";
+  OS << "\"timestamp\": \"" << Storage->Timestamp << "\",\n";
+  OS << "\"profile\": {\n";
+  TG->printJSONValues(OS, "");
+  OS << "\n}\n";
+  OS << "}\n";
+  OS.flush();
+}
+
+void ClangTidyProfiling::storeProfileData() {
+  assert(Storage.hasValue() && "We should have a filename.");
+
+  llvm::SmallString<256> OutputDirectory(Storage->StoreFilename);
+  llvm::sys::path::remove_filename(OutputDirectory);
+  if (std::error_code EC = llvm::sys::fs::create_directories(OutputDirectory)) {
+    llvm::errs() << "Unable to create output directory '" << OutputDirectory
+                 << "': " << EC.message() << "\n";
+    return;
+  }
+
+  std::error_code EC;
+  llvm::raw_fd_ostream OS(Storage->StoreFilename, EC, llvm::sys::fs::OF_None);
+  if (EC) {
+    llvm::errs() << "Error opening output file '" << Storage->StoreFilename
+                 << "': " << EC.message() << "\n";
+    return;
+  }
+
+  printAsJSON(OS);
+}
+
+ClangTidyProfiling::ClangTidyProfiling(llvm::Optional<StorageParams> Storage)
+    : Storage(std::move(Storage)) {}
+
+ClangTidyProfiling::~ClangTidyProfiling() {
+  TG.emplace("clang-tidy", "clang-tidy checks profiling", Records);
+
+  if (!Storage.hasValue())
+    printUserFriendlyTable(llvm::errs());
+  else
+    storeProfileData();
+}
+
+} // namespace tidy
+} // namespace clang