CheckNullPointer: Removed some of the old checking that doesn't use ValueFlow
This commit is contained in:
Daniel Marjamäki
parent
311059f603
commit
5721e1d745
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@ -753,233 +753,55 @@ void CheckNullPointer::nullPointerByDeRefAndChec()
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{
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const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
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if (_settings->valueFlow) {
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for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
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if (!tok->isName() || tok->values.empty())
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continue;
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for (const Token *tok = _tokenizer->tokens(); tok; tok = tok->next()) {
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if (!tok->isName() || tok->values.empty())
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continue;
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const Variable *var = tok->variable();
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if (!var || !var->isPointer() || tok == var->nameToken())
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continue;
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const Variable *var = tok->variable();
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if (!var || !var->isPointer() || tok == var->nameToken())
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continue;
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// Can pointer be NULL?
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const ValueFlow::Value *value = 0;
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for (std::list<ValueFlow::Value>::const_iterator it = tok->values.begin(); it != tok->values.end(); ++it) {
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if (it->intvalue == 0) {
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value = &(*it);
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break;
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}
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}
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if (!value)
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continue;
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// Is pointer used as function parameter?
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if (Token::Match(tok->previous(), "[(,] %var% [,)]")) {
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const Token *ftok = tok->previous();
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while (ftok && ftok->str() != "(") {
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if (ftok->str() == ")")
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ftok = ftok->link();
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ftok = ftok->previous();
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}
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if (!ftok || !ftok->previous())
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continue;
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std::list<const Token *> varlist;
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parseFunctionCall(*ftok->previous(), varlist, &_settings->library, 0);
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if (std::find(varlist.begin(), varlist.end(), tok) != varlist.end()) {
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if (value->condition == NULL)
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nullPointerError(tok);
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else if (_settings->isEnabled("warning"))
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nullPointerError(tok, tok->str(), value->condition, value->inconclusive);
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}
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continue;
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}
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// Pointer dereference.
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bool unknown = false;
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if (!isPointerDeRef(tok,unknown))
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continue;
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if (value->condition == NULL)
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nullPointerError(tok);
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else if (_settings->isEnabled("warning"))
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nullPointerError(tok, tok->str(), value->condition, value->inconclusive);
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}
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return;
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}
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// Dereferencing a pointer and then checking if it's NULL..
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// This check will first scan for the check. And then scan backwards
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// from the check, searching for dereferencing.
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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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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->tokAt(tok->str()=="else"?1:0)->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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const Variable *var = vartok->variable();
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// Check that variable is a pointer..
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if (!var || !var->isPointer())
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continue;
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// Variable id for pointer
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const unsigned int varid(vartok->varId());
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// bailout for while scope if pointer is assigned inside the loop
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if (i->type == Scope::eWhile) {
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bool assign = false;
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for (const Token *tok2 = i->classStart; tok2 && tok2 != i->classEnd; tok2 = tok2->next()) {
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if (Token::Match(tok2, "%varid% =", varid)) {
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assign = true;
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break;
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}
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}
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if (assign)
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continue;
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}
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// Name of pointer
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const std::string& varname(vartok->str());
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const Token * const decltok = var->nameToken();
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bool inconclusive = false;
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for (const Token *tok1 = tok->previous(); tok1 && tok1 != decltok; tok1 = tok1->previous()) {
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if (tok1->str() == ")" && Token::Match(tok1->link()->previous(), "%var% (")) {
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const Token *tok2 = tok1->link();
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while (tok2 && !Token::Match(tok2, "[;{}?:]"))
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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->next(), "%varid% = %var%", varid))
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break;
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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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Token::Match(tok1->link(), "( %varid% &&", varid)) {
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tok1 = tok1->link();
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continue;
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}
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if (Token::simpleMatch(tok1->link()->previous(), "sizeof (")) {
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tok1 = tok1->link()->previous();
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continue;
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}
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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, &_settings->library, 0);
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if (!varlist.empty() && varlist.front() == tok2->tokAt(3)) {
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nullPointerError(tok2->tokAt(3), varname, tok, inconclusive);
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break;
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}
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}
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// Passing pointer as parameter..
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if (Token::Match(tok2->next(), "%type% (")) {
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bool unknown = false;
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if (CanFunctionAssignPointer(tok2->next(), varid, unknown)) {
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if (!_settings->inconclusive || !unknown)
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break;
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inconclusive = true;
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}
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}
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// calling unknown function => it might initialize the pointer
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if (!(var->isLocal() || var->isArgument()))
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break;
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}
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if (tok1->str() == "break")
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break;
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if (tok1->varId() == varid) {
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// Don't write warning if the dereferencing is
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// guarded by ?: or &&
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const Token *tok2 = tok1->previous();
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if (tok2 && (tok2->isArithmeticalOp() || Token::Match(tok2, "[(,]"))) {
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while (tok2 && !Token::Match(tok2, "[;{}?:]")) {
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if (tok2->str() == ")") {
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tok2 = tok2->link();
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if (Token::Match(tok2, "( %varid% =", varid)) {
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tok2 = tok2->next();
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break;
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}
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}
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// guarded by && or ||
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if (Token::Match(tok2, "%varid% &&|%oror%",varid))
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break;
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tok2 = tok2->previous();
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}
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}
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if (!tok2 || Token::Match(tok2, "[?:]") || tok2->varId() == varid)
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continue;
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// unknown : this is set by isPointerDeRef if it is
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// uncertain
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bool unknown = _settings->inconclusive;
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// reassign : is the pointer reassigned like this:
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// tok = tok->next();
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bool reassign = false;
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if (Token::Match(tok1->previous(), "= %varid% .", varid)) {
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const Token *back = tok1->tokAt(-2);
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while (back) {
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if (back->varId() == varid) {
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reassign = true;
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break;
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}
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if (Token::Match(back, "[{};,(]")) {
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break;
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}
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back = back->previous();
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}
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} else if (Token::Match(tok1->tokAt(-4), "%varid% = ( * %varid%", varid)) {
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reassign = true;
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} else if (Token::Match(tok1->tokAt(-3), "%varid% = * %varid%", varid)) {
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reassign = true;
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}
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if (reassign) {
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break;
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} else if (Token::simpleMatch(tok1->tokAt(-2), "* )") &&
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Token::Match(tok1->linkAt(-1)->tokAt(-2), "%varid% = (", tok1->varId())) {
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break;
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} else if (Token::simpleMatch(tok1->tokAt(-3), "* ) (") &&
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Token::Match(tok1->linkAt(-2)->tokAt(-2), "%varid% = (", tok1->varId())) {
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break;
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} else if (Token::Match(tok1->previous(), "&&|%oror%")) {
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break;
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} else if (Token::Match(tok1->tokAt(-2), "&&|%oror% !")) {
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break;
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} else if (CheckNullPointer::isPointerDeRef(tok1, unknown)) {
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nullPointerError(tok1, varname, tok, inconclusive);
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break;
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} else if (tok1->strAt(-1) == "&") {
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break;
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} else if (tok1->strAt(1) == "=") {
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break;
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}
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}
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else if (tok1->str() == "{" ||
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tok1->str() == "}")
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break;
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// label..
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else if (Token::Match(tok1, "%type% :"))
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break;
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// Can pointer be NULL?
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const ValueFlow::Value *value = 0;
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for (std::list<ValueFlow::Value>::const_iterator it = tok->values.begin(); it != tok->values.end(); ++it) {
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if (it->intvalue == 0) {
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value = &(*it);
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break;
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}
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}
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if (!value)
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continue;
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// Is pointer used as function parameter?
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if (Token::Match(tok->previous(), "[(,] %var% [,)]")) {
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const Token *ftok = tok->previous();
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while (ftok && ftok->str() != "(") {
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if (ftok->str() == ")")
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ftok = ftok->link();
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ftok = ftok->previous();
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}
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if (!ftok || !ftok->previous())
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continue;
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std::list<const Token *> varlist;
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parseFunctionCall(*ftok->previous(), varlist, &_settings->library, 0);
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if (std::find(varlist.begin(), varlist.end(), tok) != varlist.end()) {
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if (value->condition == NULL)
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nullPointerError(tok);
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else if (_settings->isEnabled("warning"))
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nullPointerError(tok, tok->str(), value->condition, value->inconclusive);
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}
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continue;
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}
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// Pointer dereference.
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bool unknown = false;
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if (!isPointerDeRef(tok,unknown))
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continue;
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if (value->condition == NULL)
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nullPointerError(tok);
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else if (_settings->isEnabled("warning"))
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nullPointerError(tok, tok->str(), value->condition, value->inconclusive);
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}
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}
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