Esempio n. 1
0
void CheckCondition::checkIncorrectLogicOperator()
{
    bool style = _settings->isEnabled("style");
    bool warning = _settings->isEnabled("warning");
    if (!style && !warning)
        return;

    const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
    const std::size_t functions = symbolDatabase->functionScopes.size();
    for (std::size_t ii = 0; ii < functions; ++ii) {
        const Scope * scope = symbolDatabase->functionScopes[ii];

        for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
            // Opposite comparisons
            if (Token::Match(tok, "%oror%|&&") &&
                tok->astOperand1() &&
                tok->astOperand2() &&
                (tok->astOperand1()->isName() || tok->astOperand2()->isName()) &&
                isOppositeCond(tok->astOperand1(), tok->astOperand2(), _settings->library.functionpure)) {

                const bool alwaysTrue(tok->str() == "||");
                incorrectLogicOperatorError(tok, tok->expressionString(), alwaysTrue);
            }

            else if (Token::Match(tok, "&&|%oror%")) {
                // Comparison #1 (LHS)
                const Token *comp1 = tok->astOperand1();
                if (comp1 && comp1->str() == tok->str())
                    comp1 = comp1->astOperand2();

                // Comparison #2 (RHS)
                const Token *comp2 = tok->astOperand2();

                if (!comp1 || !comp1->isComparisonOp() || !comp1->astOperand1() || !comp1->astOperand2())
                    continue;
                if (!comp2 || !comp2->isComparisonOp() || !comp2->astOperand1() || !comp2->astOperand2())
                    continue;

                std::string op1, value1;
                const Token *expr1;
                if (comp1->astOperand1()->isLiteral()) {
                    op1 = invertOperatorForOperandSwap(comp1->str());
                    value1 = comp1->astOperand1()->str();
                    expr1 = comp1->astOperand2();
                } else if (comp1->astOperand2()->isLiteral()) {
                    op1 = comp1->str();
                    value1 = comp1->astOperand2()->str();
                    expr1 = comp1->astOperand1();
                } else {
                    continue;
                }

                std::string op2, value2;
                const Token *expr2;
                if (comp2->astOperand1()->isLiteral()) {
                    op2 = invertOperatorForOperandSwap(comp2->str());
                    value2 = comp2->astOperand1()->str();
                    expr2 = comp2->astOperand2();
                } else if (comp2->astOperand2()->isLiteral()) {
                    op2 = comp2->str();
                    value2 = comp2->astOperand2()->str();
                    expr2 = comp2->astOperand1();
                } else {
                    continue;
                }

                // Only float and int values are currently handled
                if (!MathLib::isInt(value1) && !MathLib::isFloat(value1))
                    continue;
                if (!MathLib::isInt(value2) && !MathLib::isFloat(value2))
                    continue;

                if (isSameExpression(comp1, comp2, _settings->library.functionpure))
                    continue; // same expressions => only report that there are same expressions
                if (!isSameExpression(expr1, expr2, _settings->library.functionpure))
                    continue;

                const bool isfloat = astIsFloat(expr1, true) || MathLib::isFloat(value1) || astIsFloat(expr2, true) || MathLib::isFloat(value2);

                // don't check floating point equality comparisons. that is bad
                // and deserves different warnings.
                if (isfloat && (op1 == "==" || op1 == "!=" || op2 == "==" || op2 == "!="))
                    continue;

                // evaluate if expression is always true/false
                bool alwaysTrue = true, alwaysFalse = true;
                bool firstTrue = true, secondTrue = true;
                for (int test = 1; test <= 5; ++test) {
                    // test:
                    // 1 => testvalue is less than both value1 and value2
                    // 2 => testvalue is value1
                    // 3 => testvalue is between value1 and value2
                    // 4 => testvalue value2
                    // 5 => testvalue is larger than both value1 and value2
                    bool result1, result2;
                    if (isfloat) {
                        const double d1 = MathLib::toDoubleNumber(value1);
                        const double d2 = MathLib::toDoubleNumber(value2);
                        const double testvalue = getvalue<double>(test, d1, d2);
                        result1 = checkFloatRelation(op1, testvalue, d1);
                        result2 = checkFloatRelation(op2, testvalue, d2);
                    } else {
                        const MathLib::bigint i1 = MathLib::toLongNumber(value1);
                        const MathLib::bigint i2 = MathLib::toLongNumber(value2);
                        const MathLib::bigint testvalue = getvalue<MathLib::bigint>(test, i1, i2);
                        result1 = checkIntRelation(op1, testvalue, i1);
                        result2 = checkIntRelation(op2, testvalue, i2);
                    }
                    if (tok->str() == "&&") {
                        alwaysTrue &= (result1 && result2);
                        alwaysFalse &= !(result1 && result2);
                    } else {
                        alwaysTrue &= (result1 || result2);
                        alwaysFalse &= !(result1 || result2);
                    }
                    firstTrue &= !(!result1 && result2);
                    secondTrue &= !(result1 && !result2);
                }

                const std::string cond1str = (expr1->isName() ? expr1->str() : "EXPR") + " " + op1 + " " + value1;
                const std::string cond2str = (expr2->isName() ? expr2->str() : "EXPR") + " " + op2 + " " + value2;
                if (warning && (alwaysTrue || alwaysFalse)) {
                    const std::string text = cond1str + " " + tok->str() + " " + cond2str;
                    incorrectLogicOperatorError(tok, text, alwaysTrue);
                } else if (style && secondTrue) {
                    const std::string text = "If " + cond1str + ", the comparison " + cond2str +
                                             " is always " + (secondTrue ? "true" : "false") + ".";
                    redundantConditionError(tok, text);
                } else if (style && firstTrue) {
                    //const std::string text = "The comparison " + cond1str + " is always " +
                    //                         (firstTrue ? "true" : "false") + " when " +
                    //                         cond2str + ".";
                    const std::string text = "If " + cond2str + ", the comparison " + cond1str +
                                             " is always " + (firstTrue ? "true" : "false") + ".";
                    redundantConditionError(tok, text);
                }
            }
        }
    }
}
Esempio n. 2
0
void CheckCondition::checkIncorrectLogicOperator()
{
    const bool printStyle = _settings->isEnabled("style");
    const bool printWarning = _settings->isEnabled("warning");
    if (!printWarning && !printStyle)
        return;

    const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
    const std::size_t functions = symbolDatabase->functionScopes.size();
    for (std::size_t ii = 0; ii < functions; ++ii) {
        const Scope * scope = symbolDatabase->functionScopes[ii];

        for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
            if (!Token::Match(tok, "%oror%|&&") || !tok->astOperand1() || !tok->astOperand2())
                continue;

            // Opposite comparisons around || or && => always true or always false
            if ((tok->astOperand1()->isName() || tok->astOperand2()->isName()) &&
                isOppositeCond(true, tok->astOperand1(), tok->astOperand2(), _settings->library.functionpure)) {

                const bool alwaysTrue(tok->str() == "||");
                incorrectLogicOperatorError(tok, tok->expressionString(), alwaysTrue);
                continue;
            }


            // 'A && (!A || B)' is equivalent with 'A || B'
            if (printStyle && (tok->str() == "||") && tok->astOperand1() && tok->astOperand2() && tok->astOperand2()->str() == "&&") {
                const Token* tok2 = tok->astOperand2()->astOperand1();
                if (isOppositeCond(true, tok->astOperand1(), tok2, _settings->library.functionpure)) {
                    redundantConditionError(tok, tok2->expressionString() + ". 'A && (!A || B)' is equivalent to 'A || B'");
                    continue;
                }
            }

            // Comparison #1 (LHS)
            const Token *comp1 = tok->astOperand1();
            if (comp1 && comp1->str() == tok->str())
                comp1 = comp1->astOperand2();

            // Comparison #2 (RHS)
            const Token *comp2 = tok->astOperand2();

            // Parse LHS
            bool not1;
            std::string op1, value1;
            const Token *expr1;
            if (!parseComparison(comp1, &not1, &op1, &value1, &expr1))
                continue;

            // Parse RHS
            bool not2;
            std::string op2, value2;
            const Token *expr2;
            if (!parseComparison(comp2, &not2, &op2, &value2, &expr2))
                continue;

            if (isSameExpression(_tokenizer, comp1, comp2, _settings->library.functionpure))
                continue; // same expressions => only report that there are same expressions
            if (!isSameExpression(_tokenizer, expr1, expr2, _settings->library.functionpure))
                continue;

            const bool isfloat = astIsFloat(expr1, true) || MathLib::isFloat(value1) || astIsFloat(expr2, true) || MathLib::isFloat(value2);

            // don't check floating point equality comparisons. that is bad
            // and deserves different warnings.
            if (isfloat && (op1 == "==" || op1 == "!=" || op2 == "==" || op2 == "!="))
                continue;

            const double d1 = (isfloat) ? MathLib::toDoubleNumber(value1) : 0;
            const double d2 = (isfloat) ? MathLib::toDoubleNumber(value2) : 0;
            const MathLib::bigint i1 = (isfloat) ? 0 : MathLib::toLongNumber(value1);
            const MathLib::bigint i2 = (isfloat) ? 0 : MathLib::toLongNumber(value2);
            const bool useUnsignedInt = (std::numeric_limits<MathLib::bigint>::max()==i1)||(std::numeric_limits<MathLib::bigint>::max()==i2);
            const MathLib::biguint u1 = (useUnsignedInt) ? MathLib::toLongNumber(value1) : 0;
            const MathLib::biguint u2 = (useUnsignedInt) ? MathLib::toLongNumber(value2) : 0;
            // evaluate if expression is always true/false
            bool alwaysTrue = true, alwaysFalse = true;
            bool firstTrue = true, secondTrue = true;
            for (int test = 1; test <= 5; ++test) {
                // test:
                // 1 => testvalue is less than both value1 and value2
                // 2 => testvalue is value1
                // 3 => testvalue is between value1 and value2
                // 4 => testvalue value2
                // 5 => testvalue is larger than both value1 and value2
                bool result1, result2;
                if (isfloat) {
                    const double testvalue = getvalue<double>(test, d1, d2);
                    result1 = checkFloatRelation(op1, testvalue, d1);
                    result2 = checkFloatRelation(op2, testvalue, d2);
                } else if (useUnsignedInt) {
                    const MathLib::biguint testvalue = getvalue<MathLib::biguint>(test, u1, u2);
                    result1 = checkIntRelation(op1, testvalue, u1);
                    result2 = checkIntRelation(op2, testvalue, u2);
                } else {
                    const MathLib::bigint testvalue = getvalue<MathLib::bigint>(test, i1, i2);
                    result1 = checkIntRelation(op1, testvalue, i1);
                    result2 = checkIntRelation(op2, testvalue, i2);
                }
                if (not1)
                    result1 = !result1;
                if (not2)
                    result2 = !result2;
                if (tok->str() == "&&") {
                    alwaysTrue &= (result1 && result2);
                    alwaysFalse &= !(result1 && result2);
                } else {
                    alwaysTrue &= (result1 || result2);
                    alwaysFalse &= !(result1 || result2);
                }
                firstTrue &= !(!result1 && result2);
                secondTrue &= !(result1 && !result2);
            }

            const std::string cond1str = conditionString(not1, expr1, op1, value1);
            const std::string cond2str = conditionString(not2, expr2, op2, value2);
            if (printWarning && (alwaysTrue || alwaysFalse)) {
                const std::string text = cond1str + " " + tok->str() + " " + cond2str;
                incorrectLogicOperatorError(tok, text, alwaysTrue);
            } else if (printStyle && secondTrue) {
                const std::string text = "If " + cond1str + ", the comparison " + cond2str +
                                         " is always " + (secondTrue ? "true" : "false") + ".";
                redundantConditionError(tok, text);
            } else if (printStyle && firstTrue) {
                //const std::string text = "The comparison " + cond1str + " is always " +
                //                         (firstTrue ? "true" : "false") + " when " +
                //                         cond2str + ".";
                const std::string text = "If " + cond2str + ", the comparison " + cond1str +
                                         " is always " + (firstTrue ? "true" : "false") + ".";
                redundantConditionError(tok, text);
            }
        }
    }
}
Esempio n. 3
0
void CheckCondition::checkIncorrectLogicOperator()
{
    const bool printStyle = _settings->isEnabled(Settings::STYLE);
    const bool printWarning = _settings->isEnabled(Settings::WARNING);
    if (!printWarning && !printStyle)
        return;
    const bool printInconclusive = _settings->inconclusive;

    const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
    const std::size_t functions = symbolDatabase->functionScopes.size();
    for (std::size_t ii = 0; ii < functions; ++ii) {
        const Scope * scope = symbolDatabase->functionScopes[ii];

        for (const Token* tok = scope->classStart->next(); tok != scope->classEnd; tok = tok->next()) {
            if (!Token::Match(tok, "%oror%|&&") || !tok->astOperand1() || !tok->astOperand2())
                continue;

            // Opposite comparisons around || or && => always true or always false
            if ((tok->astOperand1()->isName() || tok->astOperand2()->isName()) &&
                isOppositeCond(true, _tokenizer->isCPP(), tok->astOperand1(), tok->astOperand2(), _settings->library, true)) {

                const bool alwaysTrue(tok->str() == "||");
                incorrectLogicOperatorError(tok, tok->expressionString(), alwaysTrue, false);
                continue;
            }


            // 'A && (!A || B)' is equivalent to 'A && B'
            // 'A || (!A && B)' is equivalent to 'A || B'
            if (printStyle &&
                ((tok->str() == "||" && tok->astOperand2()->str() == "&&") ||
                 (tok->str() == "&&" && tok->astOperand2()->str() == "||"))) {
                const Token* tok2 = tok->astOperand2()->astOperand1();
                if (isOppositeCond(true, _tokenizer->isCPP(), tok->astOperand1(), tok2, _settings->library, true)) {
                    std::string expr1(tok->astOperand1()->expressionString());
                    std::string expr2(tok->astOperand2()->astOperand1()->expressionString());
                    std::string expr3(tok->astOperand2()->astOperand2()->expressionString());
                    // make copy for later because the original string might get overwritten
                    const std::string expr1VerboseMsg = expr1;
                    const std::string expr2VerboseMsg = expr2;
                    const std::string expr3VerboseMsg = expr3;

                    if (expr1.length() + expr2.length() + expr3.length() > 50U) {
                        if (expr1[0] == '!' && expr2[0] != '!') {
                            expr1 = "!A";
                            expr2 = "A";
                        } else {
                            expr1 = "A";
                            expr2 = "!A";
                        }

                        expr3 = "B";
                    }

                    const std::string cond1 = expr1 + " " + tok->str() + " (" + expr2 + " " + tok->astOperand2()->str() + " " + expr3 + ")";
                    const std::string cond2 = expr1 + " " + tok->str() + " " + expr3;

                    const std::string cond1VerboseMsg = expr1VerboseMsg + " " + tok->str() + " " + expr2VerboseMsg + " " + tok->astOperand2()->str() + " " + expr3VerboseMsg;
                    const std::string cond2VerboseMsg = expr1VerboseMsg + " " + tok->str() + " " + expr3VerboseMsg;
                    // for the --verbose message, transform the actual condition and print it
                    const std::string msg = tok2->expressionString() + ". '" + cond1 + "' is equivalent to '" + cond2 + "'\n"
                                            "The condition '" + cond1VerboseMsg + "' is equivalent to '" + cond2VerboseMsg + "'.";
                    redundantConditionError(tok, msg, false);
                    continue;
                }
            }

            // Comparison #1 (LHS)
            const Token *comp1 = tok->astOperand1();
            if (comp1 && comp1->str() == tok->str())
                comp1 = comp1->astOperand2();

            // Comparison #2 (RHS)
            const Token *comp2 = tok->astOperand2();

            bool inconclusive = false;

            // Parse LHS
            bool not1;
            std::string op1, value1;
            const Token *expr1;
            if (!parseComparison(comp1, &not1, &op1, &value1, &expr1, &inconclusive))
                continue;

            // Parse RHS
            bool not2;
            std::string op2, value2;
            const Token *expr2;
            if (!parseComparison(comp2, &not2, &op2, &value2, &expr2, &inconclusive))
                continue;

            if (inconclusive && !printInconclusive)
                continue;

            if (isSameExpression(_tokenizer->isCPP(), true, comp1, comp2, _settings->library, true))
                continue; // same expressions => only report that there are same expressions
            if (!isSameExpression(_tokenizer->isCPP(), true, expr1, expr2, _settings->library, true))
                continue;

            const bool isfloat = astIsFloat(expr1, true) || MathLib::isFloat(value1) || astIsFloat(expr2, true) || MathLib::isFloat(value2);

            // don't check floating point equality comparisons. that is bad
            // and deserves different warnings.
            if (isfloat && (op1 == "==" || op1 == "!=" || op2 == "==" || op2 == "!="))
                continue;

            const double d1 = (isfloat) ? MathLib::toDoubleNumber(value1) : 0;
            const double d2 = (isfloat) ? MathLib::toDoubleNumber(value2) : 0;
            const MathLib::bigint i1 = (isfloat) ? 0 : MathLib::toLongNumber(value1);
            const MathLib::bigint i2 = (isfloat) ? 0 : MathLib::toLongNumber(value2);
            const bool useUnsignedInt = (std::numeric_limits<MathLib::bigint>::max()==i1)||(std::numeric_limits<MathLib::bigint>::max()==i2);
            const MathLib::biguint u1 = (useUnsignedInt) ? MathLib::toLongNumber(value1) : 0;
            const MathLib::biguint u2 = (useUnsignedInt) ? MathLib::toLongNumber(value2) : 0;
            // evaluate if expression is always true/false
            bool alwaysTrue = true, alwaysFalse = true;
            bool firstTrue = true, secondTrue = true;
            for (int test = 1; test <= 5; ++test) {
                // test:
                // 1 => testvalue is less than both value1 and value2
                // 2 => testvalue is value1
                // 3 => testvalue is between value1 and value2
                // 4 => testvalue value2
                // 5 => testvalue is larger than both value1 and value2
                bool result1, result2;
                if (isfloat) {
                    const double testvalue = getvalue<double>(test, d1, d2);
                    result1 = checkFloatRelation(op1, testvalue, d1);
                    result2 = checkFloatRelation(op2, testvalue, d2);
                } else if (useUnsignedInt) {
                    const MathLib::biguint testvalue = getvalue<MathLib::biguint>(test, u1, u2);
                    result1 = checkIntRelation(op1, testvalue, u1);
                    result2 = checkIntRelation(op2, testvalue, u2);
                } else {
                    const MathLib::bigint testvalue = getvalue<MathLib::bigint>(test, i1, i2);
                    result1 = checkIntRelation(op1, testvalue, i1);
                    result2 = checkIntRelation(op2, testvalue, i2);
                }
                if (not1)
                    result1 = !result1;
                if (not2)
                    result2 = !result2;
                if (tok->str() == "&&") {
                    alwaysTrue &= (result1 && result2);
                    alwaysFalse &= !(result1 && result2);
                } else {
                    alwaysTrue &= (result1 || result2);
                    alwaysFalse &= !(result1 || result2);
                }
                firstTrue &= !(!result1 && result2);
                secondTrue &= !(result1 && !result2);
            }

            const std::string cond1str = conditionString(not1, expr1, op1, value1);
            const std::string cond2str = conditionString(not2, expr2, op2, value2);
            if (printWarning && (alwaysTrue || alwaysFalse)) {
                const std::string text = cond1str + " " + tok->str() + " " + cond2str;
                incorrectLogicOperatorError(tok, text, alwaysTrue, inconclusive);
            } else if (printStyle && secondTrue) {
                const std::string text = "If '" + cond1str + "', the comparison '" + cond2str +
                                         "' is always " + (secondTrue ? "true" : "false") + ".";
                redundantConditionError(tok, text, inconclusive);
            } else if (printStyle && firstTrue) {
                //const std::string text = "The comparison " + cond1str + " is always " +
                //                         (firstTrue ? "true" : "false") + " when " +
                //                         cond2str + ".";
                const std::string text = "If '" + cond2str + "', the comparison '" + cond1str +
                                         "' is always " + (firstTrue ? "true" : "false") + ".";
                redundantConditionError(tok, text, inconclusive);
            }
        }
    }
}