cppcheck/lib/checknullpointer.h

168 lines
5.5 KiB
C++

/*
* Cppcheck - A tool for static C/C++ code analysis
* Copyright (C) 2007-2010 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 "check.h"
#include "settings.h"
class Token;
/// @addtogroup Checks
/// @{
/** @brief check for null pointer dereferencing */
class CheckNullPointer : public Check
{
public:
/** @brief This constructor is used when registering the CheckNullPointer */
CheckNullPointer() : Check()
{ }
/** @brief This constructor is used when running checks. */
CheckNullPointer(const Tokenizer *tokenizer, const Settings *settings, ErrorLogger *errorLogger)
: Check(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();
checkNullPointer.executionPaths();
}
/**
* @brief parse a function call and extract information about variable usage
* @param tok first token
* @param var variables that the function read / write.
* @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,
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 Does one part of the check for nullPointer().
* Checking if pointer is NULL and then dereferencing it..
*/
void nullPointerByCheckAndDeRef();
/** @brief dereferencing null constant (after Tokenizer::simplifyKnownVariables) */
void nullConstantDereference();
/** @brief new type of check: check execution paths */
void executionPaths();
void nullPointerError(const Token *tok); // variable name unknown / doesn't exist
void nullPointerError(const Token *tok, const std::string &varname);
void nullPointerError(const Token *tok, const std::string &varname, const unsigned int line);
/** Get error messages. Used by --errorlist */
void getErrorMessages(ErrorLogger *errorLogger, const Settings *settings)
{
CheckNullPointer c(0, settings, errorLogger);
c.nullPointerError(0, "pointer");
}
/** Name of check */
std::string name() const
{
return "Null pointer";
}
/** class info in WIKI format. Used by --doc */
std::string classInfo() const
{
return "Null pointers\n"
"* null pointer dereferencing\n";
}
private:
/**
* Check if a variable is a pointer
* @param varid variable id for variable
*/
bool isPointer(const unsigned int varid);
/**
* @brief Does one part of the check for nullPointer().
* Locate insufficient null-pointer handling after loop
*/
void nullPointerAfterLoop();
/**
* @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 struct pointer and then checking if it's NULL..
*/
void nullPointerStructByDeRefAndChec();
/**
* @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();
};
/// @}
//---------------------------------------------------------------------------
#endif