[clang-tidy] Add a close-on-exec check on dup() in Android module.

Summary:
dup() is better to be replaced by fcntl() to avoid file descriptor leakage.

Differential Revision: https://reviews.llvm.org/D35364

llvm-svn: 310858
diff --git a/clang-tools-extra/clang-tidy/android/CloexecCheck.h b/clang-tools-extra/clang-tidy/android/CloexecCheck.h
index 9c1c1a96..a7a6106 100644
--- a/clang-tools-extra/clang-tidy/android/CloexecCheck.h
+++ b/clang-tools-extra/clang-tidy/android/CloexecCheck.h
@@ -86,6 +86,10 @@
   /// \param ArgPos The 0-based position of the flag argument.
   void insertStringFlag(const ast_matchers::MatchFinder::MatchResult &Result,
                         const char Mode, const int ArgPos);
+
+  /// Helper function to get the spelling of a particular argument.
+  StringRef getSpellingArg(const ast_matchers::MatchFinder::MatchResult &Result,
+                           int N) const;
 };
 
 } // namespace android