コード例 #1
0
void CheckLeakAutoVar::checkScope(const Token * const startToken,
                                  VarInfo *varInfo,
                                  std::set<unsigned int> notzero)
{
    std::map<unsigned int, int> &alloctype = varInfo->alloctype;
    std::map<unsigned int, std::string> &possibleUsage = varInfo->possibleUsage;
    const std::set<unsigned int> conditionalAlloc(varInfo->conditionalAlloc);

    // Parse all tokens
    const Token * const endToken = startToken->link();
    for (const Token *tok = startToken; tok && tok != endToken; tok = tok->next()) {
        // Deallocation and then dereferencing pointer..
        if (tok->varId() > 0) {
            const std::map<unsigned int, int>::iterator var = alloctype.find(tok->varId());
            if (var != alloctype.end()) {
                if (var->second == DEALLOC && !Token::Match(tok->previous(), "[;{},=] %var% =")) {
                    deallocUseError(tok, tok->str());
                } else if (Token::simpleMatch(tok->tokAt(-2), "= &")) {
                    varInfo->erase(tok->varId());
                } else if (tok->strAt(-1) == "=") {
                    varInfo->erase(tok->varId());
                }
            } else if (Token::Match(tok->previous(), "& %var% = %var% ;")) {
                varInfo->referenced.insert(tok->tokAt(2)->varId());
            }
        }

        if (tok->str() == "(" && tok->previous()->isName()) {
            functionCall(tok->previous(), varInfo, NOALLOC);
            tok = tok->link();
            continue;
        }

        // look for end of statement
        if (!Token::Match(tok, "[;{}]") || Token::Match(tok->next(), "[;{}]"))
            continue;
        tok = tok->next();
        if (!tok || tok == endToken)
            break;

        // parse statement

        // assignment..
        if (tok->varId() && Token::Match(tok, "%var% =")) {
            // taking address of another variable..
            if (Token::Match(tok->next(), "= %var% [+;]")) {
                if (tok->tokAt(2)->varId() != tok->varId()) {
                    // If variable points at allocated memory => error
                    leakIfAllocated(tok, *varInfo);

                    // no multivariable checking currently => bail out for rhs variables
                    for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) {
                        if (tok2->str() == ";") {
                            break;
                        }
                        if (tok2->varId()) {
                            varInfo->erase(tok2->varId());
                        }
                    }
                }
            }

            // is variable used in rhs?
            bool used_in_rhs = false;
            for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) {
                if (tok2->str() == ";") {
                    break;
                }
                if (tok->varId() == tok2->varId()) {
                    used_in_rhs = true;
                    break;
                }
            }
            // TODO: Better checking how the pointer is used in rhs?
            if (used_in_rhs)
                continue;

            // Variable has already been allocated => error
            if (conditionalAlloc.find(tok->varId()) == conditionalAlloc.end())
                leakIfAllocated(tok, *varInfo);
            varInfo->erase(tok->varId());

            // not a local variable nor argument?
            const Variable *var = tok->variable();
            if (var && !var->isArgument() && !var->isLocal()) {
                continue;
            }

            // Don't check reference variables
            if (var && var->isReference())
                continue;

            // allocation?
            if (Token::Match(tok->tokAt(2), "%type% (")) {
                int i = _settings->library.alloc(tok->tokAt(2));
                if (i > 0) {
                    alloctype[tok->varId()] = i;
                }
            }

            // Assigning non-zero value variable. It might be used to
            // track the execution for a later if condition.
            if (Token::Match(tok->tokAt(2), "%num% ;") && MathLib::toLongNumber(tok->strAt(2)) != 0)
                notzero.insert(tok->varId());
            else if (Token::Match(tok->tokAt(2), "- %type% ;") && tok->tokAt(3)->isUpperCaseName())
                notzero.insert(tok->varId());
            else
                notzero.erase(tok->varId());
        }

        // if/else
        else if (Token::simpleMatch(tok, "if (")) {
            // Parse function calls inside the condition
            for (const Token *innerTok = tok->tokAt(2); innerTok; innerTok = innerTok->next()) {
                if (innerTok->str() == ")")
                    break;
                if (innerTok->str() == "(" && innerTok->previous()->isName()) {
                    const int deallocId = _settings->library.dealloc(tok);
                    functionCall(innerTok->previous(), varInfo, deallocId);
                    innerTok = innerTok->link();
                }
            }

            const Token *tok2 = tok->linkAt(1);
            if (Token::simpleMatch(tok2, ") {")) {
                VarInfo varInfo1(*varInfo);  // VarInfo for if code
                VarInfo varInfo2(*varInfo);  // VarInfo for else code

                if (Token::Match(tok->next(), "( %var% )")) {
                    varInfo2.erase(tok->tokAt(2)->varId());
                    if (notzero.find(tok->tokAt(2)->varId()) != notzero.end())
                        varInfo2.clear();
                } else if (Token::Match(tok->next(), "( ! %var% )|&&")) {
                    varInfo1.erase(tok->tokAt(3)->varId());
                } else if (Token::Match(tok->next(), "( %var% ( ! %var% ) )|&&")) {
                    varInfo1.erase(tok->tokAt(5)->varId());
                } else if (Token::Match(tok->next(), "( %var% < 0 )|&&")) {
                    varInfo1.erase(tok->tokAt(2)->varId());
                } else if (Token::Match(tok->next(), "( 0 > %var% )|&&")) {
                    varInfo1.erase(tok->tokAt(4)->varId());
                } else if (Token::Match(tok->next(), "( %var% > 0 )|&&")) {
                    varInfo2.erase(tok->tokAt(2)->varId());
                } else if (Token::Match(tok->next(), "( 0 < %var% )|&&")) {
                    varInfo2.erase(tok->tokAt(4)->varId());
                }

                checkScope(tok2->next(), &varInfo1, notzero);
                tok2 = tok2->linkAt(1);
                if (Token::simpleMatch(tok2, "} else {")) {
                    checkScope(tok2->tokAt(2), &varInfo2, notzero);
                    tok = tok2->linkAt(2)->previous();
                } else {
                    tok = tok2->previous();
                }

                VarInfo old;
                old.swap(*varInfo);

                // Conditional allocation in varInfo1
                std::map<unsigned int, int>::const_iterator it;
                for (it = varInfo1.alloctype.begin(); it != varInfo1.alloctype.end(); ++it) {
                    if (varInfo2.alloctype.find(it->first) == varInfo2.alloctype.end() &&
                        old.alloctype.find(it->first) == old.alloctype.end()) {
                        varInfo->conditionalAlloc.insert(it->first);
                    }
                }

                // Conditional allocation in varInfo2
                for (it = varInfo2.alloctype.begin(); it != varInfo2.alloctype.end(); ++it) {
                    if (varInfo1.alloctype.find(it->first) == varInfo1.alloctype.end() &&
                        old.alloctype.find(it->first) == old.alloctype.end()) {
                        varInfo->conditionalAlloc.insert(it->first);
                    }
                }

                // Conditional allocation/deallocation
                for (it = varInfo1.alloctype.begin(); it != varInfo1.alloctype.end(); ++it) {
                    if (it->second == DEALLOC && conditionalAlloc.find(it->first) != conditionalAlloc.end()) {
                        varInfo->conditionalAlloc.erase(it->first);
                        varInfo2.erase(it->first);
                    }
                }
                for (it = varInfo2.alloctype.begin(); it != varInfo2.alloctype.end(); ++it) {
                    if (it->second == DEALLOC && conditionalAlloc.find(it->first) != conditionalAlloc.end()) {
                        varInfo->conditionalAlloc.erase(it->first);
                        varInfo1.erase(it->first);
                    }
                }

                alloctype.insert(varInfo1.alloctype.begin(), varInfo1.alloctype.end());
                alloctype.insert(varInfo2.alloctype.begin(), varInfo2.alloctype.end());

                possibleUsage.insert(varInfo1.possibleUsage.begin(), varInfo1.possibleUsage.end());
                possibleUsage.insert(varInfo2.possibleUsage.begin(), varInfo2.possibleUsage.end());
            }
        }

        // unknown control..
        else if (Token::Match(tok, "%type% (") && Token::simpleMatch(tok->linkAt(1), ") {")) {
            varInfo->clear();
            break;
        }

        // Function call..
        else if (Token::Match(tok, "%type% (") && tok->str() != "return") {
            const int dealloc = _settings->library.dealloc(tok);

            functionCall(tok, varInfo, dealloc);

            tok = tok->next()->link();

            // Handle scopes that might be noreturn
            if (dealloc == NOALLOC && Token::simpleMatch(tok, ") ; }")) {
                const std::string &functionName(tok->link()->previous()->str());
                bool unknown = false;
                if (_tokenizer->IsScopeNoReturn(tok->tokAt(2), &unknown)) {
                    if (!unknown)
                        varInfo->clear();
                    else if (_settings->library.leakignore.find(functionName) == _settings->library.leakignore.end() &&
                             _settings->library.use.find(functionName) == _settings->library.use.end())
                        varInfo->possibleUsageAll(functionName);
                }
            }

            continue;
        }

        // return
        else if (tok->str() == "return") {
            ret(tok, *varInfo);
            varInfo->clear();
        }

        // goto => weird execution path
        else if (tok->str() == "goto") {
            varInfo->clear();
        }

        // continue/break
        else if (Token::Match(tok, "continue|break ;")) {
            varInfo->clear();
        }

        // throw
        // TODO: if the execution leave the function then treat it as return
        else if (tok->str() == "throw") {
            varInfo->clear();
        }
    }
}
コード例 #2
0
ファイル: checkleakautovar.cpp プロジェクト: kimmov/cppcheck
void CheckLeakAutoVar::checkScope(const Token * const startToken,
                                  VarInfo *varInfo,
                                  std::set<unsigned int> notzero)
{
    std::map<unsigned int, std::string> &alloctype = varInfo->alloctype;
    std::map<unsigned int, std::string> &possibleUsage = varInfo->possibleUsage;
    const std::set<unsigned int> conditionalAlloc(varInfo->conditionalAlloc);

    // Allocation functions. key = function name, value = allocation type
    std::map<std::string, std::string> allocFunctions(cfgalloc);
    allocFunctions["malloc"] = "malloc";
    allocFunctions["strdup"] = "malloc";
    allocFunctions["fopen"] = "fopen";

    // Deallocation functions. key = function name, value = allocation type
    std::map<std::string, std::string> deallocFunctions(cfgdealloc);
    deallocFunctions["free"] = "malloc";
    deallocFunctions["fclose"] = "fopen";

    // Parse all tokens
    const Token * const endToken = startToken->link();
    for (const Token *tok = startToken; tok && tok != endToken; tok = tok->next()) {
        // Deallocation and then dereferencing pointer..
        if (tok->varId() > 0) {
            const std::map<unsigned int, std::string>::iterator var = alloctype.find(tok->varId());
            if (var != alloctype.end()) {
                if (var->second == "dealloc" && !Token::Match(tok->previous(), "[;{},=] %var% =")) {
                    deallocUseError(tok, tok->str());
                } else if (Token::simpleMatch(tok->tokAt(-2), "= &")) {
                    varInfo->erase(tok->varId());
                } else if (Token::simpleMatch(tok->previous(), "=")) {
                    varInfo->erase(tok->varId());
                }
            }
        }

        if (tok->str() == "(" && tok->previous()->isName()) {
            functionCall(tok->previous(), varInfo, "");
            tok = tok->link();
            continue;
        }

        // look for end of statement
        if (!Token::Match(tok, "[;{}]") || Token::Match(tok->next(), "[;{}]"))
            continue;
        tok = tok->next();
        if (tok == endToken)
            break;

        // parse statement

        // assignment..
        if (tok && tok->varId() && Token::Match(tok, "%var% =")) {
            // taking address of another variable..
            if (Token::Match(tok->next(), "= %var% [+;]")) {
                if (tok->tokAt(2)->varId() != tok->varId()) {
                    // If variable points at allocated memory => error
                    leakIfAllocated(tok, *varInfo);

                    // no multivariable checking currently => bail out for rhs variables
                    for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) {
                        if (tok2->str() == ";") {
                            break;
                        }
                        if (tok2->varId()) {
                            varInfo->erase(tok2->varId());
                        }
                    }
                }
            }

            // is variable used in rhs?
            bool used_in_rhs = false;
            for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) {
                if (tok2->str() == ";") {
                    break;
                }
                if (tok->varId() == tok2->varId()) {
                    used_in_rhs = true;
                    break;
                }
            }
            // TODO: Better checking how the pointer is used in rhs?
            if (used_in_rhs)
                continue;

            // Variable has already been allocated => error
            if (conditionalAlloc.find(tok->varId()) == conditionalAlloc.end())
                leakIfAllocated(tok, *varInfo);
            varInfo->erase(tok->varId());

            // not a local variable nor argument?
            const Variable *var = _tokenizer->getSymbolDatabase()->getVariableFromVarId(tok->varId());
            if (var && !var->isArgument() && !var->isLocal()) {
                continue;
            }

            // Don't check reference variables
            if (var && var->isReference())
                continue;

            // allocation?
            if (Token::Match(tok->tokAt(2), "%type% (")) {
                const std::map<std::string, std::string>::const_iterator it = allocFunctions.find(tok->strAt(2));
                if (it != allocFunctions.end()) {
                    alloctype[tok->varId()] = it->second;
                }
            }

            // Assigning non-zero value variable. It might be used to
            // track the execution for a later if condition.
            if (Token::Match(tok->tokAt(2), "%num% ;") && MathLib::toLongNumber(tok->strAt(2)) != 0)
                notzero.insert(tok->varId());
            else if (Token::Match(tok->tokAt(2), "- %type% ;") && tok->tokAt(3)->isUpperCaseName())
                notzero.insert(tok->varId());
            else
                notzero.erase(tok->varId());
        }

        // if/else
        else if (Token::simpleMatch(tok, "if (")) {
            // Parse function calls inside the condition
            for (const Token *innerTok = tok->tokAt(2); innerTok; innerTok = innerTok->next()) {
                if (innerTok->str() == ")")
                    break;
                if (innerTok->str() == "(" && innerTok->previous()->isName()) {
                    std::string dealloc;
                    {
                        const std::map<std::string, std::string>::iterator func = deallocFunctions.find(tok->str());
                        if (func != deallocFunctions.end()) {
                            dealloc = func->second;
                        }
                    }

                    functionCall(innerTok->previous(), varInfo, dealloc);
                    innerTok = innerTok->link();
                }
            }

            const Token *tok2 = tok->linkAt(1);
            if (Token::simpleMatch(tok2, ") {")) {
                VarInfo varInfo1(*varInfo);
                VarInfo varInfo2(*varInfo);

                if (Token::Match(tok->next(), "( %var% )")) {
                    varInfo2.erase(tok->tokAt(2)->varId());
                    if (notzero.find(tok->tokAt(2)->varId()) != notzero.end())
                        varInfo2.clear();
                } else if (Token::Match(tok->next(), "( ! %var% )|&&")) {
                    varInfo1.erase(tok->tokAt(3)->varId());
                } else if (Token::Match(tok->next(), "( %var% ( ! %var% ) )|&&")) {
                    varInfo1.erase(tok->tokAt(5)->varId());
                }

                checkScope(tok2->next(), &varInfo1, notzero);
                tok2 = tok2->linkAt(1);
                if (Token::simpleMatch(tok2, "} else {")) {
                    checkScope(tok2->tokAt(2), &varInfo2, notzero);
                    tok = tok2->linkAt(2)->previous();
                } else {
                    tok = tok2->previous();
                }

                VarInfo old;
                old.swap(*varInfo);

                // Conditional allocation in varInfo1
                std::map<unsigned int, std::string>::const_iterator it;
                for (it = varInfo1.alloctype.begin(); it != varInfo1.alloctype.end(); ++it) {
                    if (varInfo2.alloctype.find(it->first) == varInfo2.alloctype.end() &&
                        old.alloctype.find(it->first) == old.alloctype.end()) {
                        varInfo->conditionalAlloc.insert(it->first);
                    }
                }

                // Conditional allocation in varInfo2
                for (it = varInfo2.alloctype.begin(); it != varInfo2.alloctype.end(); ++it) {
                    if (varInfo1.alloctype.find(it->first) == varInfo1.alloctype.end() &&
                        old.alloctype.find(it->first) == old.alloctype.end()) {
                        varInfo->conditionalAlloc.insert(it->first);
                    }
                }

                // Conditional allocation/deallocation
                for (it = varInfo1.alloctype.begin(); it != varInfo1.alloctype.end(); ++it) {
                    if (it->second == "dealloc" && conditionalAlloc.find(it->first) != conditionalAlloc.end()) {
                        varInfo->conditionalAlloc.erase(it->first);
                        varInfo2.erase(it->first);
                    }
                }
                for (it = varInfo2.alloctype.begin(); it != varInfo2.alloctype.end(); ++it) {
                    if (it->second == "dealloc" && conditionalAlloc.find(it->first) != conditionalAlloc.end()) {
                        varInfo->conditionalAlloc.erase(it->first);
                        varInfo1.erase(it->first);
                    }
                }

                alloctype.insert(varInfo1.alloctype.begin(), varInfo1.alloctype.end());
                alloctype.insert(varInfo2.alloctype.begin(), varInfo2.alloctype.end());

                possibleUsage.insert(varInfo1.possibleUsage.begin(), varInfo1.possibleUsage.end());
                possibleUsage.insert(varInfo2.possibleUsage.begin(), varInfo2.possibleUsage.end());
            }
        }

        // unknown control..
        else if (Token::Match(tok, "%type% (") && Token::simpleMatch(tok->linkAt(1), ") {")) {
            varInfo->clear();
            break;
        }

        // Function call..
        else if (Token::Match(tok, "%type% (") && tok->str() != "return") {
            std::string dealloc;
            {
                const std::map<std::string, std::string>::iterator func = deallocFunctions.find(tok->str());
                if (func != deallocFunctions.end()) {
                    dealloc = func->second;
                }
            }

            functionCall(tok, varInfo, dealloc);

            tok = tok->next()->link();

            // Handle scopes that might be noreturn
            if (dealloc.empty() && Token::simpleMatch(tok, ") ; }")) {
                const std::string &functionName(tok->link()->previous()->str());
                bool unknown = false;
                if (cfgignore.find(functionName) == cfgignore.end() &&
                    cfguse.find(functionName) == cfguse.end() &&
                    _tokenizer->IsScopeNoReturn(tok->tokAt(2), &unknown)) {
                    if (unknown) {
                        //const std::string &functionName(tok->link()->previous()->str());
                        varInfo->possibleUsageAll(functionName);
                    } else {
                        varInfo->clear();
                    }
                }
            }

            continue;
        }

        // return
        else if (tok->str() == "return" || tok->str() == "throw") {
            ret(tok, *varInfo);
            varInfo->clear();
        }
    }
}
コード例 #3
0
void CheckLeakAutoVar::checkScope(const Token * const startToken,
                                  VarInfo *varInfo,
                                  std::set<unsigned int> notzero)
{
    std::map<unsigned int, VarInfo::AllocInfo> &alloctype = varInfo->alloctype;
    std::map<unsigned int, std::string> &possibleUsage = varInfo->possibleUsage;
    const std::set<unsigned int> conditionalAlloc(varInfo->conditionalAlloc);

    // Parse all tokens
    const Token * const endToken = startToken->link();
    for (const Token *tok = startToken; tok && tok != endToken; tok = tok->next()) {
        if (!tok->scope()->isExecutable()) {
            tok = tok->scope()->classEnd;
            if (!tok) // Ticket #6666 (crash upon invalid code)
                break;
        }

        // Deallocation and then dereferencing pointer..
        if (tok->varId() > 0) {
            const std::map<unsigned int, VarInfo::AllocInfo>::const_iterator var = alloctype.find(tok->varId());
            if (var != alloctype.end()) {
                if (var->second.status == VarInfo::DEALLOC && tok->strAt(-1) != "&" && (!Token::Match(tok, "%name% =") || tok->strAt(-1) == "*")) {
                    deallocUseError(tok, tok->str());
                } else if (Token::simpleMatch(tok->tokAt(-2), "= &")) {
                    varInfo->erase(tok->varId());
                } else if (tok->strAt(-1) == "=") {
                    varInfo->erase(tok->varId());
                }
            } else if (Token::Match(tok->previous(), "& %name% = %var% ;")) {
                varInfo->referenced.insert(tok->tokAt(2)->varId());
            }
        }

        if (tok->str() == "(" && tok->previous()->isName()) {
            VarInfo::AllocInfo allocation(0, VarInfo::NOALLOC);
            functionCall(tok->previous(), varInfo, allocation);
            tok = tok->link();
            continue;
        }

        // look for end of statement
        if (!Token::Match(tok, "[;{}]") || Token::Match(tok->next(), "[;{}]"))
            continue;

        tok = tok->next();
        if (!tok || tok == endToken)
            break;

        // parse statement, skip to last member
        while (Token::Match(tok, "%name% ::|. %name% !!("))
            tok = tok->tokAt(2);

        // assignment..
        if (Token::Match(tok, "%var% =")) {
            // taking address of another variable..
            if (Token::Match(tok->next(), "= %var% [+;]")) {
                if (tok->tokAt(2)->varId() != tok->varId()) {
                    // If variable points at allocated memory => error
                    leakIfAllocated(tok, *varInfo);

                    // no multivariable checking currently => bail out for rhs variables
                    for (const Token *tok2 = tok; tok2; tok2 = tok2->next()) {
                        if (tok2->str() == ";") {
                            break;
                        }
                        if (tok2->varId()) {
                            varInfo->erase(tok2->varId());
                        }
                    }
                }
            }

            // is variable used in rhs?
            bool used_in_rhs = false;
            for (const Token *tok2 = tok->tokAt(2); tok2; tok2 = tok2->next()) {
                if (tok2->str() == ";") {
                    break;
                }
                if (tok->varId() == tok2->varId()) {
                    used_in_rhs = true;
                    break;
                }
            }
            // TODO: Better checking how the pointer is used in rhs?
            if (used_in_rhs)
                continue;

            // Variable has already been allocated => error
            if (conditionalAlloc.find(tok->varId()) == conditionalAlloc.end())
                leakIfAllocated(tok, *varInfo);
            varInfo->erase(tok->varId());

            // not a local variable nor argument?
            const Variable *var = tok->variable();
            if (var && !var->isArgument() && (!var->isLocal() || var->isStatic()))
                continue;

            // Don't check reference variables
            if (var && var->isReference())
                continue;

            // non-pod variable
            if (_tokenizer->isCPP()) {
                if (!var)
                    continue;
                // Possibly automatically deallocated memory
                if (!var->typeStartToken()->isStandardType() && Token::Match(tok, "%var% = new"))
                    continue;
            }

            // allocation?
            if (tok->next()->astOperand2() && Token::Match(tok->next()->astOperand2()->previous(), "%type% (")) {
                int i = _settings->library.alloc(tok->next()->astOperand2()->previous());
                if (i > 0) {
                    alloctype[tok->varId()].type = i;
                    alloctype[tok->varId()].status = VarInfo::ALLOC;
                }
            } else if (_tokenizer->isCPP() && tok->strAt(2) == "new") {
                alloctype[tok->varId()].type = -1;
                alloctype[tok->varId()].status = VarInfo::ALLOC;
            }

            // Assigning non-zero value variable. It might be used to
            // track the execution for a later if condition.
            if (Token::Match(tok->tokAt(2), "%num% ;") && MathLib::toLongNumber(tok->strAt(2)) != 0)
                notzero.insert(tok->varId());
            else if (Token::Match(tok->tokAt(2), "- %type% ;") && tok->tokAt(3)->isUpperCaseName())
                notzero.insert(tok->varId());
            else
                notzero.erase(tok->varId());
        }

        // if/else
        else if (Token::simpleMatch(tok, "if (")) {
            // Parse function calls inside the condition
            for (const Token *innerTok = tok->tokAt(2); innerTok; innerTok = innerTok->next()) {
                if (innerTok->str() == ")")
                    break;
                if (innerTok->str() == "(" && innerTok->previous()->isName()) {
                    VarInfo::AllocInfo allocation(_settings->library.dealloc(tok), VarInfo::DEALLOC);
                    if (allocation.type == 0)
                        allocation.status = VarInfo::NOALLOC;
                    functionCall(innerTok->previous(), varInfo, allocation);
                    innerTok = innerTok->link();
                }
            }

            const Token *tok2 = tok->linkAt(1);
            if (Token::simpleMatch(tok2, ") {")) {
                VarInfo varInfo1(*varInfo);  // VarInfo for if code
                VarInfo varInfo2(*varInfo);  // VarInfo for else code

                // Recursively scan variable comparisons in condition
                std::stack<const Token *> tokens;
                tokens.push(tok->next()->astOperand2());
                while (!tokens.empty()) {
                    const Token *tok3 = tokens.top();
                    tokens.pop();
                    if (!tok3)
                        continue;
                    if (tok3->str() == "&&") {
                        tokens.push(tok3->astOperand1());
                        tokens.push(tok3->astOperand2());
                        continue;
                    }
                    if (tok3->str() == "(" && Token::Match(tok3->astOperand1(), "UNLIKELY|LIKELY")) {
                        tokens.push(tok3->astOperand2());
                        continue;
                    }

                    const Token *vartok = nullptr;
                    if (astIsVariableComparison(tok3, "!=", "0", &vartok)) {
                        varInfo2.erase(vartok->varId());
                        if (notzero.find(vartok->varId()) != notzero.end())
                            varInfo2.clear();
                    } else if (astIsVariableComparison(tok3, "==", "0", &vartok)) {
                        varInfo1.erase(vartok->varId());
                    } else if (astIsVariableComparison(tok3, "<", "0", &vartok)) {
                        varInfo1.erase(vartok->varId());
                    } else if (astIsVariableComparison(tok3, ">", "0", &vartok)) {
                        varInfo2.erase(vartok->varId());
                    } else if (astIsVariableComparison(tok3, "==", "-1", &vartok)) {
                        varInfo1.erase(vartok->varId());
                    }
                }

                checkScope(tok2->next(), &varInfo1, notzero);
                tok2 = tok2->linkAt(1);
                if (Token::simpleMatch(tok2, "} else {")) {
                    checkScope(tok2->tokAt(2), &varInfo2, notzero);
                    tok = tok2->linkAt(2)->previous();
                } else {
                    tok = tok2->previous();
                }

                VarInfo old;
                old.swap(*varInfo);

                // Conditional allocation in varInfo1
                std::map<unsigned int, VarInfo::AllocInfo>::const_iterator it;
                for (it = varInfo1.alloctype.begin(); it != varInfo1.alloctype.end(); ++it) {
                    if (varInfo2.alloctype.find(it->first) == varInfo2.alloctype.end() &&
                        old.alloctype.find(it->first) == old.alloctype.end()) {
                        varInfo->conditionalAlloc.insert(it->first);
                    }
                }

                // Conditional allocation in varInfo2
                for (it = varInfo2.alloctype.begin(); it != varInfo2.alloctype.end(); ++it) {
                    if (varInfo1.alloctype.find(it->first) == varInfo1.alloctype.end() &&
                        old.alloctype.find(it->first) == old.alloctype.end()) {
                        varInfo->conditionalAlloc.insert(it->first);
                    }
                }

                // Conditional allocation/deallocation
                for (it = varInfo1.alloctype.begin(); it != varInfo1.alloctype.end(); ++it) {
                    if (it->second.status == VarInfo::DEALLOC && conditionalAlloc.find(it->first) != conditionalAlloc.end()) {
                        varInfo->conditionalAlloc.erase(it->first);
                        varInfo2.erase(it->first);
                    }
                }
                for (it = varInfo2.alloctype.begin(); it != varInfo2.alloctype.end(); ++it) {
                    if (it->second.status == VarInfo::DEALLOC && conditionalAlloc.find(it->first) != conditionalAlloc.end()) {
                        varInfo->conditionalAlloc.erase(it->first);
                        varInfo1.erase(it->first);
                    }
                }

                alloctype.insert(varInfo1.alloctype.begin(), varInfo1.alloctype.end());
                alloctype.insert(varInfo2.alloctype.begin(), varInfo2.alloctype.end());

                possibleUsage.insert(varInfo1.possibleUsage.begin(), varInfo1.possibleUsage.end());
                possibleUsage.insert(varInfo2.possibleUsage.begin(), varInfo2.possibleUsage.end());
            }
        }

        // unknown control.. (TODO: handle loops)
        else if ((Token::Match(tok, "%type% (") && Token::simpleMatch(tok->linkAt(1), ") {")) || Token::simpleMatch(tok, "do {")) {
            varInfo->clear();
            break;
        }

        // return
        else if (tok->str() == "return") {
            ret(tok, *varInfo);
            varInfo->clear();
        }

        // throw
        else if (_tokenizer->isCPP() && tok->str() == "throw") {
            bool tryFound = false;
            const Scope* scope = tok->scope();
            while (scope && scope->isExecutable()) {
                if (scope->type == Scope::eTry)
                    tryFound = true;
                scope = scope->nestedIn;
            }
            // If the execution leaves the function then treat it as return
            if (!tryFound)
                ret(tok, *varInfo);
            varInfo->clear();
        }

        // Function call..
        else if (Token::Match(tok, "%type% (")) {
            VarInfo::AllocInfo allocation(_settings->library.dealloc(tok), VarInfo::DEALLOC);
            if (allocation.type == 0)
                allocation.status = VarInfo::NOALLOC;
            functionCall(tok, varInfo, allocation);

            tok = tok->next()->link();

            // Handle scopes that might be noreturn
            if (allocation.status == VarInfo::NOALLOC && Token::simpleMatch(tok, ") ; }")) {
                const std::string &functionName(tok->link()->previous()->str());
                bool unknown = false;
                if (_tokenizer->IsScopeNoReturn(tok->tokAt(2), &unknown)) {
                    if (!unknown)
                        varInfo->clear();
                    else if (_settings->library.leakignore.find(functionName) == _settings->library.leakignore.end() &&
                             _settings->library.use.find(functionName) == _settings->library.use.end())
                        varInfo->possibleUsageAll(functionName);
                }
            }

            continue;
        }

        // delete
        else if (_tokenizer->isCPP() && tok->str() == "delete") {
            if (tok->strAt(1) == "[")
                tok = tok->tokAt(3);
            else
                tok = tok->next();
            while (Token::Match(tok, "%name% ::|."))
                tok = tok->tokAt(2);
            if (tok->varId() && tok->strAt(1) != "[") {
                VarInfo::AllocInfo allocation(-1, VarInfo::DEALLOC);
                changeAllocStatus(varInfo, allocation, tok, tok);
            }
        }

        // goto => weird execution path
        else if (tok->str() == "goto") {
            varInfo->clear();
        }

        // continue/break
        else if (Token::Match(tok, "continue|break ;")) {
            varInfo->clear();
        }
    }
}