clang-tidy/bugprone/SignalHandlerCheck.h

0001 //===--- SignalHandlerCheck.h - clang-tidy ----------------------*- C++ -*-===//
0002 //
0003 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
0004 // See https://llvm.org/LICENSE.txt for license information.
0005 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
0006 //
0007 //===----------------------------------------------------------------------===//
0008
0009 #ifndef LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SIGNALHANDLERCHECK_H
0010 #define LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SIGNALHANDLERCHECK_H
0011
0012 #include "../ClangTidyCheck.h"
0013 #include "clang/Analysis/CallGraph.h"
0014 #include "llvm/ADT/DepthFirstIterator.h"
0015 #include "llvm/ADT/StringSet.h"
0016
0017 namespace clang::tidy::bugprone {
0018
0019 /// Checker for signal handler functions.
0020 ///
0021 /// For the user-facing documentation see:
0022 /// http://clang.llvm.org/extra/clang-tidy/checks/bugprone/signal-handler.html
0023 class SignalHandlerCheck : public ClangTidyCheck {
0024 public:
0025   enum class AsyncSafeFunctionSetKind { Minimal, POSIX };
0026
0027   SignalHandlerCheck(StringRef Name, ClangTidyContext *Context);
0028   void storeOptions(ClangTidyOptions::OptionMap &Opts) override;
0029   bool isLanguageVersionSupported(const LangOptions &LangOpts) const override;
0030   void registerMatchers(ast_matchers::MatchFinder *Finder) override;
0031   void check(const ast_matchers::MatchFinder::MatchResult &Result) override;
0032
0033 private:
0034   /// Check if a function is allowed as a signal handler.
0035   /// Should test the properties of the function, and check in the code body.
0036   /// Should not check function calls in the code (this part is done by the call
0037   /// graph scan).
0038   /// Bug reports are generated for the whole code body (no stop at the first
0039   /// found issue). For issues that are not in the code body, only one
0040   /// bug report is generated.
0041   /// \param FD The function to check. It may or may not have a definition.
0042   /// \param CallOrRef Location of the call to this function (in another
0043   /// function) or the reference to the function (if it is used as a registered
0044   /// signal handler). This is the location where diagnostics are to be placed.
0045   /// \param ChainReporter A function that adds bug report notes to display the
0046   /// chain of called functions from signal handler registration to the current
0047   /// function. This is called at every generated bug report.
0048   /// The bool parameter is used like \c SkipPathEnd in \c reportHandlerChain .
0049   /// \return Returns true if a diagnostic was emitted for this function.
0050   bool checkFunction(const FunctionDecl *FD, const Expr *CallOrRef,
0051                      std::function<void(bool)> ChainReporter);
0052   /// Similar as \c checkFunction but only check for C++14 rules.
0053   bool checkFunctionCPP14(const FunctionDecl *FD, const Expr *CallOrRef,
0054                           std::function<void(bool)> ChainReporter);
0055   /// Returns true if a standard library function is considered
0056   /// asynchronous-safe.
0057   bool isStandardFunctionAsyncSafe(const FunctionDecl *FD) const;
0058   /// Add diagnostic notes to show the call chain of functions from a signal
0059   /// handler to a function that is called (directly or indirectly) from it.
0060   /// Also add a note to the place where the signal handler is registered.
0061   /// @param Itr Position during a call graph depth-first iteration. It contains
0062   /// the "path" (call chain) from the signal handler to the actual found
0063   /// function call.
0064   /// @param HandlerRef Reference to the signal handler function where it is
0065   /// registered as signal handler.
0066   /// @param SkipPathEnd If true the last item of the call chain (farthest away
0067   /// from the \c signal call) is omitted from note generation.
0068   void reportHandlerChain(const llvm::df_iterator<clang::CallGraphNode *> &Itr,
0069                           const DeclRefExpr *HandlerRef, bool SkipPathEnd);
0070
0071   clang::CallGraph CG;
0072
0073   AsyncSafeFunctionSetKind AsyncSafeFunctionSet;
0074   llvm::StringSet<> ConformingFunctions;
0075 };
0076
0077 } // namespace clang::tidy::bugprone
0078
0079 #endif // LLVM_CLANG_TOOLS_EXTRA_CLANG_TIDY_BUGPRONE_SIGNALHANDLERCHECK_H