Re-land "Cache the locations of NOLINTBEGIN/END blocks" with fix for build bot
diff --git a/clang-tools-extra/clang-tidy/NoLintDirectiveHandler.h b/clang-tools-extra/clang-tidy/NoLintDirectiveHandler.h
new file mode 100644
index 0000000..db9fd59
--- /dev/null
+++ b/clang-tools-extra/clang-tidy/NoLintDirectiveHandler.h
@@ -0,0 +1,51 @@
+//===-- clang-tools-extra/clang-tidy/NoLintDirectiveHandler.h ----*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_NOLINTDIRECTIVEHANDLER_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_NOLINTDIRECTIVEHANDLER_H
+
+#include "clang/Basic/Diagnostic.h"
+#include "llvm/ADT/StringRef.h"
+#include <memory>
+
+namespace clang {
+namespace tooling {
+struct Diagnostic;
+} // namespace tooling
+} // namespace clang
+
+namespace llvm {
+template <typename T> class SmallVectorImpl;
+} // namespace llvm
+
+namespace clang {
+namespace tidy {
+
+/// This class is used to locate NOLINT comments in the file being analyzed, to
+/// decide whether a diagnostic should be suppressed.
+/// This class keeps a cache of every NOLINT comment found so that files do not
+/// have to be repeatedly parsed each time a new diagnostic is raised.
+class NoLintDirectiveHandler {
+public:
+ NoLintDirectiveHandler();
+ ~NoLintDirectiveHandler();
+
+ bool shouldSuppress(DiagnosticsEngine::Level DiagLevel,
+ const Diagnostic &Diag, llvm::StringRef DiagName,
+ llvm::SmallVectorImpl<tooling::Diagnostic> &NoLintErrors,
+ bool AllowIO, bool EnableNoLintBlocks);
+
+private:
+ class Impl;
+ std::unique_ptr<Impl> PImpl;
+};
+
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_NOLINTDIRECTIVEHANDLER_H
