clang-tools-extra/clang-tidy/bugprone/SignalHandlerCheck.h

   1 //===--- SignalHandlerCheck.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 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SIGNALHANDLERCHECK_H
  10 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SIGNALHANDLERCHECK_H
  11
  12 #include "../ClangTidyCheck.h"
  13 #include "clang/Analysis/CallGraph.h"
  14 #include "llvm/ADT/DepthFirstIterator.h"
  15 #include "llvm/ADT/StringSet.h"
  16
  17 namespace clang::tidy::bugprone {
  18
  19 /// Checker for signal handler functions.
  20 ///
  21 /// For the user-facing documentation see:
  22 /// http://clang.llvm.org/extra/clang-tidy/checks/bugprone/signal-handler.html
  23 class SignalHandlerCheck : public ClangTidyCheck {
  24 public:
  25   enum class AsyncSafeFunctionSetKind { Minimal, POSIX };
  26
  27   SignalHandlerCheck(StringRef Name, ClangTidyContext *Context);
  28   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
  29   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override;
  30   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
  31   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
  32
  33 private:
  34   /// Check if a function is allowed as a signal handler.
  35   /// Should test the properties of the function, and check in the code body.
  36   /// Should not check function calls in the code (this part is done by the call
  37   /// graph scan).
  38   /// Bug reports are generated for the whole code body (no stop at the first
  39   /// found issue). For issues that are not in the code body, only one
  40   /// bug report is generated.
  41   /// \param FD The function to check. It may or may not have a definition.
  42   /// \param CallOrRef Location of the call to this function (in another
  43   /// function) or the reference to the function (if it is used as a registered
  44   /// signal handler). This is the location where diagnostics are to be placed.
  45   /// \param ChainReporter A function that adds bug report notes to display the
  46   /// chain of called functions from signal handler registration to the current
  47   /// function. This is called at every generated bug report.
  48   /// The bool parameter is used like \c SkipPathEnd in \c reportHandlerChain .
  49   /// \return Returns true if a diagnostic was emitted for this function.
  50   bool checkFunction(const FunctionDecl *FD, const Expr *CallOrRef,
  51                      std::function<void(bool)> ChainReporter);
  52   /// Similar as \c checkFunction but only check for C++14 rules.
  53   bool checkFunctionCPP14(const FunctionDecl *FD, const Expr *CallOrRef,
  54                           std::function<void(bool)> ChainReporter);
  55   /// Returns true if a standard library function is considered
  56   /// asynchronous-safe.
  57   bool isStandardFunctionAsyncSafe(const FunctionDecl *FD) const;
  58   /// Add diagnostic notes to show the call chain of functions from a signal
  59   /// handler to a function that is called (directly or indirectly) from it.
  60   /// Also add a note to the place where the signal handler is registered.
  61   /// @param Itr Position during a call graph depth-first iteration. It contains
  62   /// the "path" (call chain) from the signal handler to the actual found
  63   /// function call.
  64   /// @param HandlerRef Reference to the signal handler function where it is
  65   /// registered as signal handler.
  66   /// @param SkipPathEnd If true the last item of the call chain (farthest away
  67   /// from the \c signal call) is omitted from note generation.
  68   void reportHandlerChain(const llvm::df_iterator<clang::CallGraphNode *> &Itr,
  69                           const DeclRefExpr *HandlerRef, bool SkipPathEnd);
  70
  71   clang::CallGraph CG;
  72
  73   AsyncSafeFunctionSetKind AsyncSafeFunctionSet;
  74   llvm::StringSet<> ConformingFunctions;
  75 };
  76
  77 } // namespace clang::tidy::bugprone
  78
  79 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SIGNALHANDLERCHECK_H