Refactorizations in checknullpointer.cpp:
- Removed CheckNullPointer::nullPointerAfterLoop(), improved CheckNullPointer::nullPointerByCheckAndDeRef() to cover tests - Enhanced CheckNullPointer::nullPointerByDeRefAndChec() to check also 'else if' and 'while'
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PKEuS
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25ecd3ed71
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31129aad40
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@ -271,7 +271,7 @@ bool CheckNullPointer::isPointerDeRef(const Token *tok, bool &unknown, const Sym
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return true;
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// read/write member variable
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if (!Token::simpleMatch(tok->tokAt(-2), "& (") && !Token::Match(tok->tokAt(-2), "sizeof|decltype (") && tok->strAt(-1) != "&" && tok->strAt(-1) != "&&" && Token::Match(tok->next(), ". %var%")) {
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if (!Token::simpleMatch(tok->tokAt(-2), "& (") && !Token::Match(tok->tokAt(-2), "sizeof|decltype (") && tok->strAt(-1) != "&" && Token::Match(tok->next(), ". %var%")) {
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if (tok->strAt(3) != "(")
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return true;
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unknown = true;
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@ -410,81 +410,6 @@ bool CheckNullPointer::CanFunctionAssignPointer(const Token *functiontoken, unsi
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void CheckNullPointer::nullPointerAfterLoop()
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{
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const SymbolDatabase* const symbolDatabase = _tokenizer->getSymbolDatabase();
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// Locate insufficient null-pointer handling after loop
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for (std::list<Scope>::const_iterator i = symbolDatabase->scopeList.begin(); i != symbolDatabase->scopeList.end(); ++i) {
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// only interested in while ( %var% )
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// TODO: Aren't there false negatives. Shouldn't other loops be handled such as:
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// - while ( ! %var% )
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const Token* const tok = i->classDef;
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if (i->type != Scope::eWhile || !Token::Match(tok, "while ( %var% )|&&"))
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continue;
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// Get variable id for the loop variable
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const Variable* var(symbolDatabase->getVariableFromVarId(tok->tokAt(2)->varId()));
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// Is variable a pointer?
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if (!var || !var->isPointer())
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continue;
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// Get variable name for the loop variable
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const std::string& varname(tok->strAt(2));
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// Locate the end of the while loop body..
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const Token *tok2 = tok->next()->link()->next()->link();
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// Is this checking inconclusive?
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bool inconclusive = false;
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if (!tok2)
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continue;
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// Check if the variable is dereferenced after the while loop
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while (NULL != (tok2 = tok2->next())) {
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// inner and outer scopes
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if (tok2->str() == "{" || tok2->str() == "}") {
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// Not inconclusive: bail out
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if (!_settings->inconclusive)
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break;
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inconclusive = true;
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if (tok2->str() == "}") {
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// "}" => leaving function? then break.
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const Token *tok3 = tok2->link()->previous();
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if (!tok3 || !Token::Match(tok3, "[);]"))
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break;
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if (tok3->str() == ")" && !Token::Match(tok3->link()->previous(), "if|for|while"))
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break;
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}
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}
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// Stop checking if "break" is found
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else if (tok2->str() == "break")
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break;
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// loop variable is found..
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else if (tok2->varId() == var->varId()) {
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// dummy variable.. is it unknown if pointer is dereferenced or not?
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bool unknown = _settings->inconclusive;
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// Is the loop variable dereferenced?
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if (CheckNullPointer::isPointerDeRef(tok2, unknown, symbolDatabase)) {
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nullPointerError(tok2, varname, tok, inconclusive);
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}
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else if (unknown && _settings->inconclusive) {
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nullPointerError(tok2, varname, tok, true);
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}
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break;
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}
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}
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}
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}
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void CheckNullPointer::nullPointerLinkedList()
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{
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const SymbolDatabase* const symbolDatabase = _tokenizer->getSymbolDatabase();
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@ -757,9 +682,13 @@ void CheckNullPointer::nullPointerByDeRefAndChec()
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for (std::list<Scope>::const_iterator i = symbolDatabase->scopeList.begin(); i != symbolDatabase->scopeList.end(); ++i) {
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// TODO: false negatives.
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// - logical operators
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// - while
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const Token* const tok = i->classDef;
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if (i->type == Scope::eIf && tok && !tok->isExpandedMacro() && Token::Match(tok, "if ( !| %var% )|%oror%|&&")) {
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const Token* tok = i->classDef;
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if ((i->type == Scope::eIf || i->type == Scope::eElseIf || i->type == Scope::eWhile) &&
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tok && Token::Match(tok, "else| %var% ( !| %var% )|%oror%|&&") && !tok->next()->isExpandedMacro()) {
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if (tok->str() == "else")
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tok = tok->next();
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const Token * vartok = tok->tokAt(2);
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if (vartok->str() == "!")
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vartok = vartok->next();
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@ -787,10 +716,10 @@ void CheckNullPointer::nullPointerByDeRefAndChec()
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tok2 = tok2->previous();
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if (Token::Match(tok2, "[?:]"))
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break;
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if (Token::Match(tok2, "[;{}] %varid% = %var%", varid))
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if (Token::Match(tok2->next(), "%varid% = %var%", varid))
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break;
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if (Token::Match(tok1->link()->previous(), "while ( %varid%", varid))
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if (Token::Match(tok2->next(), "while ( %varid%", varid))
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break;
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if (Token::Match(tok1->link(), "( ! %varid% %oror%", varid) ||
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@ -804,7 +733,7 @@ void CheckNullPointer::nullPointerByDeRefAndChec()
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continue;
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}
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if (Token::Match(tok2, "[;{}] %var% ( %varid% ,", varid)) {
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if (Token::Match(tok2->next(), "%var% ( %varid% ,", varid)) {
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std::list<const Token *> varlist;
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parseFunctionCall(*(tok2->next()), varlist, 0);
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if (!varlist.empty() && varlist.front() == tok2->tokAt(3)) {
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@ -814,7 +743,7 @@ void CheckNullPointer::nullPointerByDeRefAndChec()
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}
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// Passing pointer as parameter..
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if (Token::Match(tok2, "[;{}] %type% (")) {
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if (Token::Match(tok2->next(), "%type% (")) {
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if (CanFunctionAssignPointer(tok2->next(), varid)) {
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if (!_settings->inconclusive)
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break;
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@ -953,31 +882,28 @@ void CheckNullPointer::nullPointerByCheckAndDeRef()
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if (!var || !var->isPointer())
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continue;
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const Scope* declScope = &*i;
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while (declScope->nestedIn && var->scope() != declScope && declScope->type != Scope::eFunction)
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declScope = declScope->nestedIn;
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if (Token::Match(vartok->next(), "&& ( %varid% =", varid))
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continue;
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// Name and line of the pointer
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const std::string &pointerName = vartok->str();
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// if this is true then it is known that the pointer is null
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bool null = true;
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// Check the condition (eg. ( !x && x->i )
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if (checkConditionStart) {
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const Token * const conditionEnd = tok->link();
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for (const Token *tok2 = checkConditionStart; tok2 != conditionEnd; tok2 = tok2->next()) {
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// If we hit a || operator, abort
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if (tok2->str() == "||") {
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if (tok2->str() == "||")
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break;
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}
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// Pointer is used
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else if (Token::Match(tok2, "* %varid%", varid)) {
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nullPointerError(tok2->tokAt(2), pointerName, vartok, false);
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break;
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}
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// Pointer is used
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else if (Token::Match(tok2, "%varid% .", varid)) {
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nullPointerError(tok2, pointerName, vartok, false);
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bool unknown = _settings->inconclusive;
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if (tok2->varId() == varid && (isPointerDeRef(tok2, unknown, symbolDatabase) || unknown)) {
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nullPointerError(tok2, pointerName, vartok, unknown);
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break;
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}
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}
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@ -987,27 +913,28 @@ void CheckNullPointer::nullPointerByCheckAndDeRef()
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const Token *tok1 = i->classStart;
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if (Token::Match(tok, "( %var% )|&&")) {
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// pointer might be null
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null = false;
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// start token = first token after the if/while body
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tok1 = i->classEnd->next();
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if (!tok1)
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continue;
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}
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unsigned int indentlevel = 0;
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int indentlevel = 0;
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// Set to true if we would normally bail out the check.
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bool inconclusive = false;
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// Count { and } for tok2
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for (const Token *tok2 = tok1; tok2; tok2 = tok2->next()) {
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for (const Token *tok2 = tok1; tok2 != declScope->classEnd; tok2 = tok2->next()) {
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if (tok2->str() == "{")
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++indentlevel;
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else if (tok2->str() == "}") {
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if (indentlevel == 0)
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break;
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if (indentlevel == 0) {
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if (_settings->inconclusive)
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inconclusive = true;
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else
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break;
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}
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--indentlevel;
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// calling exit function?
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@ -1019,11 +946,12 @@ void CheckNullPointer::nullPointerByCheckAndDeRef()
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break;
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}
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if (null && indentlevel == 0) {
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if (indentlevel <= 0) {
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// skip all "else" blocks because they are not executed in this execution path
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while (Token::simpleMatch(tok2, "} else {"))
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while (Token::simpleMatch(tok2, "} else if ("))
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tok2 = tok2->linkAt(3)->linkAt(1);
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if (Token::simpleMatch(tok2, "} else {"))
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tok2 = tok2->linkAt(2);
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null = false;
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}
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}
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@ -1040,7 +968,7 @@ void CheckNullPointer::nullPointerByCheckAndDeRef()
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break;
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}
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if (Token::Match(tok2, "goto|continue|break|if|switch|for"))
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if (Token::Match(tok2, "goto|continue|break|switch|for"))
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break;
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// parameters to sizeof are not dereferenced
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@ -1053,7 +981,7 @@ void CheckNullPointer::nullPointerByCheckAndDeRef()
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}
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// function call, check if pointer is dereferenced
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if (Token::Match(tok2, "%var% (")) {
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if (Token::Match(tok2, "%var% (") && !Token::Match(tok2, "if|while")) {
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std::list<const Token *> vars;
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parseFunctionCall(*tok2, vars, 0);
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for (std::list<const Token *>::const_iterator it = vars.begin(); it != vars.end(); ++it) {
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@ -1107,7 +1035,6 @@ void CheckNullPointer::nullPointerByCheckAndDeRef()
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void CheckNullPointer::nullPointer()
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{
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nullPointerAfterLoop();
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nullPointerLinkedList();
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nullPointerStructByDeRefAndChec();
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nullPointerByDeRefAndChec();
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@ -120,12 +120,6 @@ private:
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"* null pointer dereferencing\n";
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}
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/**
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* @brief Does one part of the check for nullPointer().
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* Locate insufficient null-pointer handling after loop
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*/
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void nullPointerAfterLoop();
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/**
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* @brief Does one part of the check for nullPointer().
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* looping through items in a linked list in a inner loop..
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