check for null pointer dereferencing More...

#include <checknullpointer.h>

Inheritance diagram for CheckNullPointer:

Public Member Functions
	CheckNullPointer ()
	This constructor is used when registering the CheckNullPointer. More...

bool	isPointerDeRef (const Token *tok, bool &unknown) const
	Is there a pointer dereference? Everything that should result in a nullpointer dereference error message will result in a true return value. More...

Public Member Functions inherited from Check
	Check (const std::string &aname)
	This constructor is used when registering the CheckClass. More...

virtual	~Check ()

	Check (const Check &)=delete

Check &	operator= (const Check &)=delete

const std::string &	name () const
	class name, used to generate documentation More...

Static Public Member Functions
static bool	isPointerDeRef (const Token *tok, bool &unknown, const Settings &settings)

Static Public Member Functions inherited from Check
static std::list< Check * > &	instances ()
	List of registered check classes. More...

static void	writeToErrorList (const ErrorMessage &errmsg)
	Write given error to stdout in xml format. More...

Private Member Functions
	CheckNullPointer (const Tokenizer tokenizer, const Settings settings, ErrorLogger *errorLogger)
	This constructor is used when running checks. More...

void	runChecks (const Tokenizer &tokenizer, ErrorLogger *errorLogger) override
	Run checks against the normal token list. More...

void	nullPointer ()
	possible null pointer dereference More...

void	nullConstantDereference ()
	dereferencing null constant (after Tokenizer::simplifyKnownVariables) More...

void	nullPointerError (const Token *tok)

void	nullPointerError (const Token tok, const std::string &varname, const ValueFlow::Value value, bool inconclusive)

Check::FileInfo *	getFileInfo (const Tokenizer &tokenizer, const Settings &settings) const override
	Parse current TU and extract file info. More...

Check::FileInfo *	loadFileInfoFromXml (const tinyxml2::XMLElement *xmlElement) const override

bool	analyseWholeProgram (const CTU::FileInfo ctu, const std::list< Check::FileInfo > &fileInfo, const Settings &settings, ErrorLogger &errorLogger) override
	Analyse all file infos for all TU. More...

void	getErrorMessages (ErrorLogger errorLogger, const Settings settings) const override
	Get error messages. More...

std::string	classInfo () const override
	class info in WIKI format. More...

void	nullPointerByDeRefAndChec ()
	Does one part of the check for nullPointer(). More...

void	arithmetic ()
	undefined null pointer arithmetic More...

void	pointerArithmeticError (const Token tok, const ValueFlow::Value value, bool inconclusive)

void	redundantConditionWarning (const Token tok, const ValueFlow::Value value, const Token *condition, bool inconclusive)

Static Private Member Functions
static void	parseFunctionCall (const Token &tok, std::list< const Token * > &var, const Library &library)
	parse a function call and extract information about variable usage More...

static std::string	myName ()
	Name of check. More...

Friends
class	TestNullPointer

Additional Inherited Members
Protected Member Functions inherited from Check
	Check (std::string aname, const Tokenizer tokenizer, const Settings settings, ErrorLogger *errorLogger)
	This constructor is used when running checks. More...

void	reportError (const Token *tok, const Severity severity, const std::string &id, const std::string &msg)
	report an error More...

void	reportError (const Token *tok, const Severity severity, const std::string &id, const std::string &msg, const CWE &cwe, Certainty certainty)
	report an error More...

void	reportError (const std::list< const Token * > &callstack, Severity severity, const std::string &id, const std::string &msg)
	report an error More...

void	reportError (const std::list< const Token * > &callstack, Severity severity, const std::string &id, const std::string &msg, const CWE &cwe, Certainty certainty)
	report an error More...

void	reportError (const ErrorPath &errorPath, Severity severity, const char id[], const std::string &msg, const CWE &cwe, Certainty certainty)

void	logChecker (const char id[])
	log checker More...

ErrorPath	getErrorPath (const Token errtok, const ValueFlow::Value value, std::string bug) const

bool	wrongData (const Token tok, const char str)
	Use WRONG_DATA in checkers when you check for wrong data. More...

Static Protected Member Functions inherited from Check
static std::string	getMessageId (const ValueFlow::Value &value, const char id[])

Protected Attributes inherited from Check
const Tokenizer *const	mTokenizer {}

const Settings *const	mSettings {}

ErrorLogger *const	mErrorLogger {}

Detailed Description

check for null pointer dereferencing

Definition at line 52 of file checknullpointer.h.

Constructor & Destructor Documentation

◆ CheckNullPointer() [1/2]

CheckNullPointer::CheckNullPointer ( )

inline

This constructor is used when registering the CheckNullPointer.

Definition at line 57 of file checknullpointer.h.

◆ CheckNullPointer() [2/2]

CheckNullPointer::CheckNullPointer	(	const Tokenizer *	tokenizer,
		const Settings *	settings,
		ErrorLogger *	errorLogger
	)

inlineprivate

This constructor is used when running checks.

Definition at line 84 of file checknullpointer.h.

Member Function Documentation

◆ analyseWholeProgram()

bool CheckNullPointer::analyseWholeProgram	(	const CTU::FileInfo *	ctu,
		const std::list< Check::FileInfo * > &	fileInfo,
		const Settings &	settings,
		ErrorLogger &	errorLogger
	)

overrideprivatevirtual

Analyse all file infos for all TU.

Reimplemented from Check.

Definition at line 603 of file checknullpointer.cpp.

References CWE_NULL_POINTER_DEREFERENCE, emptyString, error, CTU::FileInfo::getCallsMap(), CTU::FileInfo::getErrorPath(), SimpleEnableGroup< T >::isEnabled(), Check::logChecker(), CTU::FileInfo::UnsafeUsage::myArgumentName, normal, CTU::FileInfo::null, ErrorLogger::reportErr(), Settings::severity, and warning.

◆ arithmetic()

void CheckNullPointer::arithmetic ( )

private

undefined null pointer arithmetic

Definition at line 466 of file checknullpointer.cpp.

References Token::astOperand1(), Token::astOperand2(), Scope::bodyEnd, Scope::bodyStart, Settings::certainty, ValueFlow::Value::condition, SymbolDatabase::functionScopes, Tokenizer::getSymbolDatabase(), Token::getValue(), inconclusive, ValueFlow::Value::intvalue, SimpleEnableGroup< T >::isEnabled(), ValueFlow::Value::isInconclusive(), ValueType::isIntegral(), Check::logChecker(), Token::Match(), Check::mSettings, Check::mTokenizer, Token::next(), pointerArithmeticError(), redundantConditionWarning(), Settings::severity, Token::valueType(), and warning.

Referenced by pointerArithmeticError(), redundantConditionWarning(), and runChecks().

◆ classInfo()

std::string CheckNullPointer::classInfo ( ) const

inlineoverrideprivatevirtual

class info in WIKI format.

Used by –doc

Implements Check.

Definition at line 130 of file checknullpointer.h.

◆ getErrorMessages()

void CheckNullPointer::getErrorMessages	(	ErrorLogger *	errorLogger,
		const Settings *	settings
	)		const

inlineoverrideprivatevirtual

Get error messages.

Used by –errorlist

Implements Check.

Definition at line 117 of file checknullpointer.h.

References nullPointerError(), pointerArithmeticError(), and redundantConditionWarning().

◆ getFileInfo()

Check::FileInfo * CheckNullPointer::getFileInfo	(	const Tokenizer &	tokenizer,
		const Settings &	settings
	)		const

overrideprivatevirtual

Parse current TU and extract file info.

Reimplemented from Check.

Definition at line 581 of file checknullpointer.cpp.

References CTU::getUnsafeUsage(), and isUnsafeUsage().

◆ isPointerDeRef() [1/2]

bool CheckNullPointer::isPointerDeRef	(	const Token *	tok,
		bool &	unknown
	)		const

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.

Parameters

tok	token for the pointer
unknown	it is not known if there is a pointer dereference (could be reported as a debug message)

Returns: true => there is a dereference

Definition at line 147 of file checknullpointer.cpp.

References Check::mSettings.

Referenced by CheckStl::checkDereferenceInvalidIterator2(), CheckLeakAutoVar::checkTokenInsideExpression(), isPointerDeRef(), isUnsafeUsage(), nullPointerByDeRefAndChec(), and CheckUninitVar::valueFlowUninit().

◆ isPointerDeRef() [2/2]

bool CheckNullPointer::isPointerDeRef	(	const Token *	tok,
		bool &	unknown,
		const Settings &	settings
	)

static

◆ loadFileInfoFromXml()

Check::FileInfo * CheckNullPointer::loadFileInfoFromXml ( const tinyxml2::XMLElement * xmlElement ) const

overrideprivatevirtual

Reimplemented from Check.

Definition at line 592 of file checknullpointer.cpp.

References CTU::loadUnsafeUsageListFromXml().

◆ myName()

static std::string CheckNullPointer::myName ( )

inlinestaticprivate

Name of check.

Definition at line 125 of file checknullpointer.h.

◆ nullConstantDereference()

void CheckNullPointer::nullConstantDereference ( )

private

dereferencing null constant (after Tokenizer::simplifyKnownVariables)

Dereferencing null constant (simplified token list)

Definition at line 333 of file checknullpointer.cpp.

References Scope::bodyEnd, Scope::bodyStart, Scope::function, SymbolDatabase::functionScopes, getArguments(), Tokenizer::getSymbolDatabase(), Function::hasBody(), Token::hasKnownIntValue(), Variable::isArray(), Function::isConstructor(), Library::isnullargbad(), Token::isOp(), Variable::isPointer(), Variable::isStlStringType(), Variable::isStlType(), isUnevaluated(), Settings::library, Token::link(), Check::logChecker(), Token::Match(), Check::mSettings, Check::mTokenizer, Token::next(), nullPointerError(), Token::originalName(), parseFunctionCall(), Token::previous(), Token::simpleMatch(), Token::str(), Token::strAt(), Token::tokAt(), Function::token, Token::values(), Token::variable(), and Token::varId().

Referenced by runChecks().

◆ nullPointer()

void CheckNullPointer::nullPointer ( )

private

possible null pointer dereference

Definition at line 319 of file checknullpointer.cpp.

References Check::logChecker(), and nullPointerByDeRefAndChec().

Referenced by runChecks().

◆ nullPointerByDeRefAndChec()

void CheckNullPointer::nullPointerByDeRefAndChec ( )

private

Does one part of the check for nullPointer().

Dereferencing a pointer and then checking if it's NULL..

Definition at line 282 of file checknullpointer.cpp.

References Settings::certainty, inconclusive, SimpleEnableGroup< T >::isEnabled(), ValueFlow::Value::isInconclusive(), isNullablePointer(), isPointerDeRef(), isUnevaluated(), Token::Match(), Check::mSettings, Check::mTokenizer, Token::next(), nullPointerError(), and Tokenizer::tokens().

Referenced by nullPointer().

◆ nullPointerError() [1/2]

void CheckNullPointer::nullPointerError ( const Token * tok )

inlineprivate

Definition at line 101 of file checknullpointer.h.

References emptyString, and ValueFlow::Value::setKnown().

Referenced by getErrorMessages(), nullConstantDereference(), and nullPointerByDeRefAndChec().

◆ nullPointerError() [2/2]

void CheckNullPointer::nullPointerError	(	const Token *	tok,
		const std::string &	varname,
		const ValueFlow::Value *	value,
		bool	inconclusive
	)

private

Definition at line 427 of file checknullpointer.cpp.

References ValueFlow::Value::condition, CWE_NULL_POINTER_DEREFERENCE, ValueFlow::Value::defaultArg, ValueFlow::eitherTheConditionIsRedundant(), error, Check::getErrorPath(), inconclusive, Settings::isEnabled(), ValueFlow::Value::isInconclusive(), ValueFlow::Value::isKnown(), Settings::isPremiumEnabled(), Check::mSettings, normal, Check::reportError(), and warning.

◆ parseFunctionCall()

void CheckNullPointer::parseFunctionCall	(	const Token &	tok,
		std::list< const Token * > &	var,
		const Library &	library
	)

staticprivate

parse a function call and extract information about variable usage

Parameters

tok	first token
var	variables that the function read / write.
library	–library files data

Definition at line 65 of file checknullpointer.cpp.

References checkNullpointerFunctionCallPlausibility(), Token::eString, Library::formatstr_argno(), Library::formatstr_function(), Library::formatstr_scan(), Token::function(), getArguments(), Variable::isArrayOrPointer(), Library::isnullargbad(), Variable::isStlStringType(), Token::Match(), and Token::tokAt().

Referenced by isPointerDeRef(), and nullConstantDereference().

◆ pointerArithmeticError()

void CheckNullPointer::pointerArithmeticError	(	const Token *	tok,
		const ValueFlow::Value *	value,
		bool	inconclusive
	)

private

Definition at line 513 of file checknullpointer.cpp.

References arithmetic(), arithmeticTypeString(), CWE_INCORRECT_CALCULATION, error, Check::getErrorPath(), inconclusive, normal, Check::reportError(), and Token::str().

Referenced by arithmetic(), and getErrorMessages().

◆ redundantConditionWarning()

void CheckNullPointer::redundantConditionWarning	(	const Token *	tok,
		const ValueFlow::Value *	value,
		const Token *	condition,
		bool	inconclusive
	)

private

Definition at line 532 of file checknullpointer.cpp.

References arithmetic(), arithmeticTypeString(), CWE_INCORRECT_CALCULATION, ValueFlow::eitherTheConditionIsRedundant(), Check::getErrorPath(), inconclusive, normal, Check::reportError(), Token::str(), and warning.

Referenced by arithmetic(), and getErrorMessages().

◆ runChecks()

void CheckNullPointer::runChecks	(	const Tokenizer &	tokenizer,
		ErrorLogger *	errorLogger
	)

inlineoverrideprivatevirtual

Run checks against the normal token list.

Implements Check.

Definition at line 88 of file checknullpointer.h.

References arithmetic(), Tokenizer::getSettings(), nullConstantDereference(), and nullPointer().

Friends And Related Function Documentation

◆ TestNullPointer

friend class TestNullPointer

friend

Definition at line 53 of file checknullpointer.h.

The documentation for this class was generated from the following files:

Public Member Functions

Static Public Member Functions

Private Member Functions

Static Private Member Functions

Friends

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ CheckNullPointer() [1/2]

◆ CheckNullPointer() [2/2]

Member Function Documentation

◆ analyseWholeProgram()

◆ arithmetic()

◆ classInfo()

◆ getErrorMessages()

◆ getFileInfo()

◆ isPointerDeRef() [1/2]

◆ isPointerDeRef() [2/2]

◆ loadFileInfoFromXml()

◆ myName()

◆ nullConstantDereference()

◆ nullPointer()

◆ nullPointerByDeRefAndChec()

◆ nullPointerError() [1/2]

◆ nullPointerError() [2/2]

◆ parseFunctionCall()

◆ pointerArithmeticError()

◆ redundantConditionWarning()

◆ runChecks()

Friends And Related Function Documentation

◆ TestNullPointer