--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/clang-tools-extra/clang-tidy/utils/LexerUtils.h	Thu Feb 13 15:10:13 2020 +0900
@@ -0,0 +1,112 @@
+//===--- LexerUtils.h - 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_UTILS_LEXER_UTILS_H
+#define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_UTILS_LEXER_UTILS_H
+
+#include "clang/AST/ASTContext.h"
+#include "clang/Basic/TokenKinds.h"
+#include "clang/Lex/Lexer.h"
+
+namespace clang {
+namespace tidy {
+namespace utils {
+namespace lexer {
+
+/// Returns previous token or ``tok::unknown`` if not found.
+Token getPreviousToken(SourceLocation Location, const SourceManager &SM,
+                       const LangOptions &LangOpts, bool SkipComments = true);
+
+SourceLocation findPreviousTokenStart(SourceLocation Start,
+                                      const SourceManager &SM,
+                                      const LangOptions &LangOpts);
+
+SourceLocation findPreviousTokenKind(SourceLocation Start,
+                                     const SourceManager &SM,
+                                     const LangOptions &LangOpts,
+                                     tok::TokenKind TK);
+
+SourceLocation findNextTerminator(SourceLocation Start, const SourceManager &SM,
+                                  const LangOptions &LangOpts);
+
+template <typename TokenKind, typename... TokenKinds>
+SourceLocation findPreviousAnyTokenKind(SourceLocation Start,
+                                        const SourceManager &SM,
+                                        const LangOptions &LangOpts,
+                                        TokenKind TK, TokenKinds... TKs) {
+  if (Start.isInvalid() || Start.isMacroID())
+    return SourceLocation();
+  while (true) {
+    SourceLocation L = findPreviousTokenStart(Start, SM, LangOpts);
+    if (L.isInvalid() || L.isMacroID())
+      return SourceLocation();
+
+    Token T;
+    // Returning 'true' is used to signal failure to retrieve the token.
+    if (Lexer::getRawToken(L, T, SM, LangOpts, /*IgnoreWhiteSpace=*/true))
+      return SourceLocation();
+
+    if (T.isOneOf(TK, TKs...))
+      return T.getLocation();
+
+    Start = L;
+  }
+}
+
+template <typename TokenKind, typename... TokenKinds>
+SourceLocation findNextAnyTokenKind(SourceLocation Start,
+                                    const SourceManager &SM,
+                                    const LangOptions &LangOpts, TokenKind TK,
+                                    TokenKinds... TKs) {
+  while (true) {
+    Optional<Token> CurrentToken = Lexer::findNextToken(Start, SM, LangOpts);
+
+    if (!CurrentToken)
+      return SourceLocation();
+
+    Token PotentialMatch = *CurrentToken;
+    if (PotentialMatch.isOneOf(TK, TKs...))
+      return PotentialMatch.getLocation();
+
+    // If we reach the end of the file, and eof is not the target token, we stop
+    // the loop, otherwise we will get infinite loop (findNextToken will return
+    // eof on eof).
+    if (PotentialMatch.is(tok::eof))
+      return SourceLocation();
+    Start = PotentialMatch.getLastLoc();
+  }
+}
+
+// Finds next token that's not a comment.
+Optional<Token> findNextTokenSkippingComments(SourceLocation Start,
+                                              const SourceManager &SM,
+                                              const LangOptions &LangOpts);
+
+/// Re-lex the provide \p Range and return \c false if either a macro spans
+/// multiple tokens, a pre-processor directive or failure to retrieve the
+/// next token is found, otherwise \c true.
+bool rangeContainsExpansionsOrDirectives(SourceRange Range,
+                                         const SourceManager &SM,
+                                         const LangOptions &LangOpts);
+
+/// Assuming that ``Range`` spans a CVR-qualified type, returns the
+/// token in ``Range`` that is responsible for the qualification. ``Range``
+/// must be valid with respect to ``SM``.  Returns ``None`` if no qualifying
+/// tokens are found.
+/// \note: doesn't support member function qualifiers.
+llvm::Optional<Token> getQualifyingToken(tok::TokenKind TK,
+                                         CharSourceRange Range,
+                                         const ASTContext &Context,
+                                         const SourceManager &SM);
+
+} // namespace lexer
+} // namespace utils
+} // namespace tidy
+} // namespace clang
+
+#endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_UTILS_LEXER_UTILS_H