/* * Cppcheck - A tool for static C/C++ code analysis * Copyright (C) 2007-2014 Daniel Marjamäki and Cppcheck team. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ //--------------------------------------------------------------------------- #ifndef checknullpointerH #define checknullpointerH //--------------------------------------------------------------------------- #include "config.h" #include "check.h" /// @addtogroup Checks /// @{ /** @brief check for null pointer dereferencing */ class CPPCHECKLIB CheckNullPointer : public Check { public: /** @brief This constructor is used when registering the CheckNullPointer */ CheckNullPointer() : Check(myName()) { } /** @brief This constructor is used when running checks. */ CheckNullPointer(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) : Check(myName(), tokenizer, settings, errorLogger) { } /** @brief Run checks against the normal token list */ void runChecks(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) { CheckNullPointer checkNullPointer(tokenizer, settings, errorLogger); checkNullPointer.nullPointer(); } /** @brief Run checks against the simplified token list */ void runSimplifiedChecks(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger) { CheckNullPointer checkNullPointer(tokenizer, settings, errorLogger); checkNullPointer.nullConstantDereference(); } /** * @brief parse a function call and extract information about variable usage * @param tok first token * @param var variables that the function read / write. * @param library --library files data * @param value 0 => invalid with null pointers as parameter. * non-zero => invalid with uninitialized data. */ static void parseFunctionCall(const Token &tok, std::list<const Token *> &var, const Library *library, unsigned char value); /** * Is there a pointer dereference? Everything that should result in * a nullpointer dereference error message will result in a true * return value. If it's unknown if the pointer is dereferenced false * is returned. * @param tok token for the pointer * @param unknown it is not known if there is a pointer dereference (could be reported as a debug message) * @return true => there is a dereference */ static bool isPointerDeRef(const Token *tok, bool &unknown); /** @brief possible null pointer dereference */ void nullPointer(); /** @brief dereferencing null constant (after Tokenizer::simplifyKnownVariables) */ void nullConstantDereference(); void nullPointerError(const Token *tok); // variable name unknown / doesn't exist void nullPointerError(const Token *tok, const std::string &varname, bool inconclusive=false); void nullPointerError(const Token *tok, const std::string &varname, const Token* nullcheck, bool inconclusive = false); void nullPointerDefaultArgError(const Token *tok, const std::string &varname); private: /** Get error messages. Used by --errorlist */ void getErrorMessages(ErrorLogger *errorLogger, const Settings *settings) const { CheckNullPointer c(0, settings, errorLogger); c.nullPointerError(0, "pointer"); } /** Name of check */ static std::string myName() { return "Null pointer"; } /** class info in WIKI format. Used by --doc */ std::string classInfo() const { return "Null pointers\n" "* null pointer dereferencing\n"; } /** * @brief Does one part of the check for nullPointer(). * looping through items in a linked list in a inner loop.. */ void nullPointerLinkedList(); /** * @brief Does one part of the check for nullPointer(). * Dereferencing a pointer and then checking if it's NULL.. */ void nullPointerByDeRefAndChec(); /** * @brief Does one part of the check for nullPointer(). * -# initialize pointer to 0 * -# conditionally assign pointer * -# dereference pointer */ void nullPointerConditionalAssignment(); /** * @brief Does one part of the check for nullPointer(). * -# default argument that sets a pointer to 0 * -# dereference pointer */ void nullPointerDefaultArgument(); /** * @brief Removes any variable that may be assigned from pointerArgs. */ static void removeAssignedVarFromSet(const Token* tok, std::set<unsigned int>& pointerArgs); /** * @brief Investigate if function call can make pointer null. If * the pointer is passed by value it can't be made a null pointer. */ static bool CanFunctionAssignPointer(const Token *functiontoken, unsigned int varid, bool& unknown); }; /// @} //--------------------------------------------------------------------------- #endif // checknullpointerH