clang-tools-extra/clang-tidy/android/CloexecCheck.h

   1 //===--- CloexecCheck.h - clang-tidy-----------------------------*- C++ -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 ///
   9 /// \file
  10 /// This file contains the declaration of the CloexecCheck class, which is the
  11 /// base class for all of the close-on-exec checks in Android module.
  12 ///
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_H
  16 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_H
  17
  18 #include "../ClangTidyCheck.h"
  19
  20 namespace clang::tidy::android {
  21
  22 /// The base class for all close-on-exec checks in Android module.
  23 /// To be specific, there are some functions that need the close-on-exec flag to
  24 /// prevent the file descriptor leakage on fork+exec and this class provides
  25 /// utilities to identify and fix these C functions.
  26 class CloexecCheck : public ClangTidyCheck {
  27 public:
  28   CloexecCheck(StringRef Name, ClangTidyContext *Context)
  29       : ClangTidyCheck(Name, Context) {}
  30
  31 protected:
  32   void
  33   registerMatchersImpl(ast_matchers::MatchFinder *Finder,
  34                        ast_matchers::internal::Matcher<FunctionDecl> Function);
  35
  36   /// Currently, we have three types of fixes.
  37   ///
  38   /// Type1 is to insert the necessary macro flag in the flag argument. For
  39   /// example, 'O_CLOEXEC' is required in function 'open()', so
  40   /// \code
  41   ///   open(file, O_RDONLY);
  42   /// \endcode
  43   /// should be
  44   /// \code
  45   ///   open(file, O_RDONLY | O_CLOEXE);
  46   /// \endcode
  47   ///
  48   /// \param [out] Result MatchResult from AST matcher.
  49   /// \param MacroFlag The macro name of the flag.
  50   /// \param ArgPos The 0-based position of the flag argument.
  51   void insertMacroFlag(const ast_matchers::MatchFinder::MatchResult &Result,
  52                        StringRef MacroFlag, int ArgPos);
  53
  54   /// Type2 is to replace the API to another function that has required the
  55   /// ability. For example:
  56   /// \code
  57   ///   creat(path, mode);
  58   /// \endcode
  59   /// should be
  60   /// \code
  61   ///   open(path, O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC, mode)
  62   /// \endcode
  63   ///
  64   /// \param [out] Result MatchResult from AST matcher.
  65   /// \param WarningMsg The warning message.
  66   /// \param FixMsg The fix message.
  67   void replaceFunc(const ast_matchers::MatchFinder::MatchResult &Result,
  68                    StringRef WarningMsg, StringRef FixMsg);
  69
  70   /// Type3 is also to add a flag to the corresponding argument, but this time,
  71   /// the flag is some string and each char represents a mode rather than a
  72   /// macro. For example, 'fopen' needs char 'e' in its mode argument string, so
  73   /// \code
  74   ///   fopen(in_file, "r");
  75   /// \endcode
  76   /// should be
  77   /// \code
  78   ///   fopen(in_file, "re");
  79   /// \endcode
  80   ///
  81   /// \param [out] Result MatchResult from AST matcher.
  82   /// \param Mode The required mode char.
  83   /// \param ArgPos The 0-based position of the flag argument.
  84   void insertStringFlag(const ast_matchers::MatchFinder::MatchResult &Result,
  85                         const char Mode, const int ArgPos);
  86
  87   /// Helper function to get the spelling of a particular argument.
  88   StringRef getSpellingArg(const ast_matchers::MatchFinder::MatchResult &Result,
  89                            int N) const;
  90
  91   /// Binding name of the FuncDecl of a function call.
  92   static const char *FuncDeclBindingStr;
  93
  94   /// Binding name of the function call expression.
  95   static const char *FuncBindingStr;
  96 };
  97
  98 } // namespace clang::tidy::android
  99
 100 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_ANDROID_CLOEXEC_H