bool isOppositeCond(bool isNot, bool cpp, const Token * const cond1, const Token * const cond2, const std::set<std::string> &constFunctions, bool isStrict)
{
if (!cond1 || !cond2)
return false;
//handle if(NULL == pstReply) { if(pstReply){ a=3;}}
if (Token::Match(cond1, "== 0|nullptr") && !Token::Match(cond2, "==|!="))
{
return isSameExpression(cpp, cond1->astOperand1(), cond2, constFunctions);
}
if (Token::Match(cond1->tokAt(-1), "0|nullptr ==") && !Token::Match(cond2, "==|!="))
{
return isSameExpression(cpp, cond1->astOperand2(), cond2, constFunctions);
}
if (cond1->str() == "!") {
if (cond2->str() == "!=") {
if (cond2->astOperand1() && cond2->astOperand1()->str() == "0")
return isSameExpression(cpp, cond1->astOperand1(), cond2->astOperand2(), constFunctions);
if (cond2->astOperand2() && cond2->astOperand2()->str() == "0")
return isSameExpression(cpp, cond1->astOperand1(), cond2->astOperand1(), constFunctions);
}
return isSameExpression(cpp, cond1->astOperand1(), cond2, constFunctions);
}
if (cond2->str() == "!")
return isOppositeCond(isNot, cpp, cond2, cond1, constFunctions);
if (!cond1->isComparisonOp() || !cond2->isComparisonOp())
return false;
const std::string &comp1 = cond1->str();
// condition found .. get comparator
std::string comp2;
if (isSameExpression(cpp, cond1->astOperand1(), cond2->astOperand1(), constFunctions) &&
isSameExpression(cpp, cond1->astOperand2(), cond2->astOperand2(), constFunctions)) {
comp2 = cond2->str();
}
else if (isSameExpression(cpp, cond1->astOperand1(), cond2->astOperand2(), constFunctions) &&
isSameExpression(cpp, cond1->astOperand2(), cond2->astOperand1(), constFunctions)) {
comp2 = cond2->str();
if (comp2[0] == '>')
comp2[0] = '<';
else if (comp2[0] == '<')
comp2[0] = '>';
}
// is condition opposite?
return ((comp1 == "==" && comp2 == "!=") ||
(comp1 == "!=" && comp2 == "==") ||
(comp1 == "<" && comp2 == ">=") ||
(comp1 == "<=" && comp2 == ">") ||
(comp1 == ">" && comp2 == "<=") ||
(comp1 == ">=" && comp2 == "<") ||
(!isNot && ((comp1 == "<" && comp2 == ">") ||
(comp1 == ">" && comp2 == "<"))) ||
(!isStrict && ((comp1 == "<=" && comp2 == ">=") || (comp1 == ">=" && comp2 == "<="))));
}
bool isOppositeExpression(bool cpp, const Token * const tok1, const Token * const tok2, const Library& library, bool pure, bool followVar, ErrorPath* errors)
{
if (!tok1 || !tok2)
return false;
if (isOppositeCond(true, cpp, tok1, tok2, library, pure, followVar, errors))
return true;
if (tok1->isUnaryOp("-"))
return isSameExpression(cpp, true, tok1->astOperand1(), tok2, library, pure, followVar, errors);
if (tok2->isUnaryOp("-"))
return isSameExpression(cpp, true, tok2->astOperand1(), tok1, library, pure, followVar, errors);
return false;
}
void CheckCondition::checkInvalidTestForOverflow()
{
if (!_settings->isEnabled("warning"))
return;
const SymbolDatabase *symbolDatabase = _tokenizer->getSymbolDatabase();
const std::size_t functions = symbolDatabase->functionScopes.size();
for (std::size_t i = 0; i < functions; ++i) {
const Scope * scope = symbolDatabase->functionScopes[i];
for (const Token* tok = scope->classStart; tok != scope->classEnd; tok = tok->next()) {
if (!tok->isComparisonOp() || !tok->astOperand1() || !tok->astOperand2())
continue;
const Token *calcToken, *exprToken;
bool result;
if (Token::Match(tok, "<|>=") && tok->astOperand1()->str() == "+") {
calcToken = tok->astOperand1();
exprToken = tok->astOperand2();
result = (tok->str() == ">=");
} else if (Token::Match(tok, ">|<=") && tok->astOperand2()->str() == "+") {
calcToken = tok->astOperand2();
exprToken = tok->astOperand1();
result = (tok->str() == "<=");
} else
continue;
// Only warn for signed integer overflows and pointer overflows.
if (!(calcToken->valueType() && (calcToken->valueType()->pointer || calcToken->valueType()->sign == ValueType::Sign::SIGNED)))
continue;
if (!(exprToken->valueType() && (exprToken->valueType()->pointer || exprToken->valueType()->sign == ValueType::Sign::SIGNED)))
continue;
const Token *termToken;
if (isSameExpression(_tokenizer->isCPP(), true, exprToken, calcToken->astOperand1(), _settings->library.functionpure))
termToken = calcToken->astOperand2();
else if (isSameExpression(_tokenizer->isCPP(), true, exprToken, calcToken->astOperand2(), _settings->library.functionpure))
termToken = calcToken->astOperand1();
else
continue;
if (!termToken)
continue;
// Only warn when termToken is always positive
if (termToken->valueType() && termToken->valueType()->sign == ValueType::Sign::UNSIGNED)
invalidTestForOverflow(tok, result);
else if (termToken->isNumber() && MathLib::isPositive(termToken->str()))
invalidTestForOverflow(tok, result);
}
}
}
bool CheckCondition::isOverlappingCond(const Token * const cond1, const Token * const cond2, bool pure) const
{
if (!cond1 || !cond2)
return false;
// same expressions
if (isSameExpression(_tokenizer->isCPP(), true, cond1, cond2, _settings->library, pure))
return true;
// bitwise overlap for example 'x&7' and 'x==1'
if (cond1->str() == "&" && cond1->astOperand1() && cond2->astOperand2()) {
const Token *expr1 = cond1->astOperand1();
const Token *num1 = cond1->astOperand2();
if (!num1) // unary operator&
return false;
if (!num1->isNumber())
std::swap(expr1,num1);
if (!num1->isNumber() || MathLib::isNegative(num1->str()))
return false;
if (!Token::Match(cond2, "&|==") || !cond2->astOperand1() || !cond2->astOperand2())
return false;
const Token *expr2 = cond2->astOperand1();
const Token *num2 = cond2->astOperand2();
if (!num2->isNumber())
std::swap(expr2,num2);
if (!num2->isNumber() || MathLib::isNegative(num2->str()))
return false;
if (!isSameExpression(_tokenizer->isCPP(), true, expr1, expr2, _settings->library, pure))
return false;
const MathLib::bigint value1 = MathLib::toLongNumber(num1->str());
const MathLib::bigint value2 = MathLib::toLongNumber(num2->str());
if (cond2->str() == "&")
return ((value1 & value2) == value2);
return ((value1 & value2) > 0);
}
return false;
}
static bool isOverlappingCond(const Token * const cond1, const Token * const cond2, const std::set<std::string> &constFunctions)
{
if (!cond1 || !cond2)
return false;
// same expressions
if (isSameExpression(cond1,cond2,constFunctions))
return true;
// bitwise overlap for example 'x&7' and 'x==1'
if (cond1->str() == "&" && cond1->astOperand1() && cond2->astOperand2()) {
const Token *expr1 = cond1->astOperand1();
const Token *num1 = cond1->astOperand2();
if (!num1) // unary operator&
return false;
if (!num1->isNumber())
std::swap(expr1,num1);
if (!num1->isNumber() || MathLib::isNegative(num1->str()))
return false;
if (!Token::Match(cond2, "&|==") || !cond2->astOperand1() || !cond2->astOperand2())
return false;
const Token *expr2 = cond2->astOperand1();
const Token *num2 = cond2->astOperand2();
if (!num2->isNumber())
std::swap(expr2,num2);
if (!num2->isNumber() || MathLib::isNegative(num2->str()))
return false;
if (!isSameExpression(expr1,expr2,constFunctions))
return false;
const MathLib::bigint value1 = MathLib::toLongNumber(num1->str());
const MathLib::bigint value2 = MathLib::toLongNumber(num2->str());
return ((value1 & value2) > 0);
}
return false;
}
bool CheckCondition::isOppositeCond(bool isNot, const Token * const cond1, const Token * const cond2, const std::set<std::string> &constFunctions) const
{
if (!cond1 || !cond2)
return false;
if (cond1->str() == "!") {
if (cond2->str() == "!=") {
if (cond2->astOperand1()->str() == "0")
return isSameExpression(_tokenizer, cond1->astOperand1(), cond2->astOperand2(), constFunctions);
if (cond2->astOperand2()->str() == "0")
return isSameExpression(_tokenizer, cond1->astOperand1(), cond2->astOperand1(), constFunctions);
}
return isSameExpression(_tokenizer, cond1->astOperand1(), cond2, constFunctions);
}
if (cond2->str() == "!")
return isOppositeCond(isNot, cond2, cond1, constFunctions);
if (!cond1->isComparisonOp() || !cond2->isComparisonOp())
return false;
const std::string &comp1 = cond1->str();
// condition found .. get comparator
std::string comp2;
if (isSameExpression(_tokenizer, cond1->astOperand1(), cond2->astOperand1(), constFunctions) &&
isSameExpression(_tokenizer, cond1->astOperand2(), cond2->astOperand2(), constFunctions)) {
comp2 = cond2->str();
} else if (isSameExpression(_tokenizer, cond1->astOperand1(), cond2->astOperand2(), constFunctions) &&
isSameExpression(_tokenizer, cond1->astOperand2(), cond2->astOperand1(), constFunctions)) {
comp2 = cond2->str();
if (comp2[0] == '>')
comp2[0] = '<';
else if (comp2[0] == '<')
comp2[0] = '>';
}
// is condition opposite?
return ((comp1 == "==" && comp2 == "!=") ||
(comp1 == "!=" && comp2 == "==") ||
(comp1 == "<" && comp2 == ">=") ||
(comp1 == "<=" && comp2 == ">") ||
(comp1 == ">" && comp2 == "<=") ||
(comp1 == ">=" && comp2 == "<") ||
(!isNot && ((comp1 == "<" && comp2 == ">") ||
(comp1 == ">" && comp2 == "<"))));
}
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, ¬1, &op1, &value1, &expr1))
continue;
// Parse RHS
bool not2;
std::string op2, value2;
const Token *expr2;
if (!parseComparison(comp2, ¬2, &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);
}
}
}
}
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);
}
}
}
}
}
bool isOppositeCond(bool isNot, bool cpp, const Token * const cond1, const Token * const cond2, const Library& library, bool pure, bool followVar, ErrorPath* errors)
{
if (!cond1 || !cond2)
return false;
if (cond1->str() == "!") {
if (cond2->str() == "!=") {
if (cond2->astOperand1() && cond2->astOperand1()->str() == "0")
return isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand2(), library, pure, followVar, errors);
if (cond2->astOperand2() && cond2->astOperand2()->str() == "0")
return isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure, followVar, errors);
}
return isSameExpression(cpp, true, cond1->astOperand1(), cond2, library, pure, followVar, errors);
}
if (cond2->str() == "!")
return isOppositeCond(isNot, cpp, cond2, cond1, library, pure, followVar, errors);
if (!isNot) {
if (cond1->str() == "==" && cond2->str() == "==") {
if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure, followVar, errors))
return isDifferentKnownValues(cond1->astOperand2(), cond2->astOperand2());
if (isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand2(), library, pure, followVar, errors))
return isDifferentKnownValues(cond1->astOperand1(), cond2->astOperand1());
}
// TODO: Handle reverse conditions
if (Library::isContainerYield(cond1, Library::Container::EMPTY, "empty") &&
Library::isContainerYield(cond2->astOperand1(), Library::Container::SIZE, "size") &&
cond1->astOperand1()->astOperand1()->varId() == cond2->astOperand1()->astOperand1()->astOperand1()->varId()) {
return !isZeroBoundCond(cond2);
}
if (Library::isContainerYield(cond2, Library::Container::EMPTY, "empty") &&
Library::isContainerYield(cond1->astOperand1(), Library::Container::SIZE, "size") &&
cond2->astOperand1()->astOperand1()->varId() == cond1->astOperand1()->astOperand1()->astOperand1()->varId()) {
return !isZeroBoundCond(cond1);
}
}
if (!cond1->isComparisonOp() || !cond2->isComparisonOp())
return false;
const std::string &comp1 = cond1->str();
// condition found .. get comparator
std::string comp2;
if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand1(), library, pure, followVar, errors) &&
isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand2(), library, pure, followVar, errors)) {
comp2 = cond2->str();
} else if (isSameExpression(cpp, true, cond1->astOperand1(), cond2->astOperand2(), library, pure, followVar, errors) &&
isSameExpression(cpp, true, cond1->astOperand2(), cond2->astOperand1(), library, pure, followVar, errors)) {
comp2 = cond2->str();
if (comp2[0] == '>')
comp2[0] = '<';
else if (comp2[0] == '<')
comp2[0] = '>';
}
if (!isNot && comp2.empty()) {
const Token *expr1 = nullptr, *value1 = nullptr, *expr2 = nullptr, *value2 = nullptr;
std::string op1 = cond1->str(), op2 = cond2->str();
if (cond1->astOperand2()->hasKnownIntValue()) {
expr1 = cond1->astOperand1();
value1 = cond1->astOperand2();
} else if (cond1->astOperand1()->hasKnownIntValue()) {
expr1 = cond1->astOperand2();
value1 = cond1->astOperand1();
if (op1[0] == '>')
op1[0] = '<';
else if (op1[0] == '<')
op1[0] = '>';
}
if (cond2->astOperand2()->hasKnownIntValue()) {
expr2 = cond2->astOperand1();
value2 = cond2->astOperand2();
} else if (cond2->astOperand1()->hasKnownIntValue()) {
expr2 = cond2->astOperand2();
value2 = cond2->astOperand1();
if (op2[0] == '>')
op2[0] = '<';
else if (op2[0] == '<')
op2[0] = '>';
}
if (!expr1 || !value1 || !expr2 || !value2) {
return false;
}
if (!isSameExpression(cpp, true, expr1, expr2, library, pure, followVar, errors))
return false;
const ValueFlow::Value &rhsValue1 = value1->values().front();
const ValueFlow::Value &rhsValue2 = value2->values().front();
if (op1 == "<" || op1 == "<=")
return (op2 == "==" || op2 == ">" || op2 == ">=") && (rhsValue1.intvalue < rhsValue2.intvalue);
else if (op1 == ">=" || op1 == ">")
return (op2 == "==" || op2 == "<" || op2 == "<=") && (rhsValue1.intvalue > rhsValue2.intvalue);
return false;
}
// is condition opposite?
return ((comp1 == "==" && comp2 == "!=") ||
(comp1 == "!=" && comp2 == "==") ||
(comp1 == "<" && comp2 == ">=") ||
(comp1 == "<=" && comp2 == ">") ||
(comp1 == ">" && comp2 == "<=") ||
(comp1 == ">=" && comp2 == "<") ||
(!isNot && ((comp1 == "<" && comp2 == ">") ||
(comp1 == ">" && comp2 == "<") ||
(comp1 == "==" && (comp2 == "!=" || comp2 == ">" || comp2 == "<")) ||
((comp1 == "!=" || comp1 == ">" || comp1 == "<") && comp2 == "==")
)));
}
bool isSameExpression(bool cpp, bool macro, const Token *tok1, const Token *tok2, const Library& library, bool pure, bool followVar, ErrorPath* errors)
{
if (tok1 == nullptr && tok2 == nullptr)
return true;
if (tok1 == nullptr || tok2 == nullptr)
return false;
if (cpp) {
if (tok1->str() == "." && tok1->astOperand1() && tok1->astOperand1()->str() == "this")
tok1 = tok1->astOperand2();
if (tok2->str() == "." && tok2->astOperand1() && tok2->astOperand1()->str() == "this")
tok2 = tok2->astOperand2();
}
// Skip double not
if (Token::simpleMatch(tok1, "!") && Token::simpleMatch(tok1->astOperand1(), "!") && !Token::simpleMatch(tok1->astParent(), "=")) {
return isSameExpression(cpp, macro, tok1->astOperand1()->astOperand1(), tok2, library, pure, followVar, errors);
}
if (Token::simpleMatch(tok2, "!") && Token::simpleMatch(tok2->astOperand1(), "!") && !Token::simpleMatch(tok2->astParent(), "=")) {
return isSameExpression(cpp, macro, tok1, tok2->astOperand1()->astOperand1(), library, pure, followVar, errors);
}
// Follow variable
if (followVar && tok1->str() != tok2->str() && (Token::Match(tok1, "%var%") || Token::Match(tok2, "%var%"))) {
const Token * varTok1 = followVariableExpression(tok1, cpp, tok2);
if (varTok1->str() == tok2->str()) {
followVariableExpressionError(tok1, varTok1, errors);
return isSameExpression(cpp, macro, varTok1, tok2, library, true, errors);
}
const Token * varTok2 = followVariableExpression(tok2, cpp, tok1);
if (tok1->str() == varTok2->str()) {
followVariableExpressionError(tok2, varTok2, errors);
return isSameExpression(cpp, macro, tok1, varTok2, library, true, errors);
}
if (varTok1->str() == varTok2->str()) {
followVariableExpressionError(tok1, varTok1, errors);
followVariableExpressionError(tok2, varTok2, errors);
return isSameExpression(cpp, macro, varTok1, varTok2, library, true, errors);
}
}
if (tok1->varId() != tok2->varId() || tok1->str() != tok2->str() || tok1->originalName() != tok2->originalName()) {
if ((Token::Match(tok1,"<|>") && Token::Match(tok2,"<|>")) ||
(Token::Match(tok1,"<=|>=") && Token::Match(tok2,"<=|>="))) {
return isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand2(), library, pure, followVar, errors) &&
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand1(), library, pure, followVar, errors);
}
return false;
}
if (macro && (tok1->isExpandedMacro() || tok2->isExpandedMacro() || tok1->isTemplateArg() || tok2->isTemplateArg()))
return false;
if (tok1->isComplex() != tok2->isComplex())
return false;
if (tok1->isLong() != tok2->isLong())
return false;
if (tok1->isUnsigned() != tok2->isUnsigned())
return false;
if (tok1->isSigned() != tok2->isSigned())
return false;
if (pure && tok1->isName() && tok1->next()->str() == "(" && tok1->str() != "sizeof") {
if (!tok1->function()) {
if (!Token::Match(tok1->previous(), ".|::") && !library.isFunctionConst(tok1) && !tok1->isAttributeConst() && !tok1->isAttributePure())
return false;
if (Token::simpleMatch(tok1->previous(), ".")) {
const Token *lhs = tok1->previous();
while (Token::Match(lhs, "(|.|["))
lhs = lhs->astOperand1();
const bool lhsIsConst = (lhs->variable() && lhs->variable()->isConst()) ||
(lhs->valueType() && lhs->valueType()->constness > 0) ||
(Token::Match(lhs, "%var% . %name% (") && library.isFunctionConst(lhs->tokAt(2)));
if (!lhsIsConst)
return false;
}
} else {
if (tok1->function() && !tok1->function()->isConst() && !tok1->function()->isAttributeConst() && !tok1->function()->isAttributePure())
return false;
}
}
// templates/casts
if ((Token::Match(tok1, "%name% <") && tok1->next()->link()) ||
(Token::Match(tok2, "%name% <") && tok2->next()->link())) {
// non-const template function that is not a dynamic_cast => return false
if (pure && Token::simpleMatch(tok1->next()->link(), "> (") &&
!(tok1->function() && tok1->function()->isConst()) &&
tok1->str() != "dynamic_cast")
return false;
// some template/cast stuff.. check that the template arguments are same
const Token *t1 = tok1->next();
const Token *t2 = tok2->next();
const Token *end1 = t1->link();
const Token *end2 = t2->link();
while (t1 && t2 && t1 != end1 && t2 != end2) {
if (t1->str() != t2->str())
return false;
t1 = t1->next();
t2 = t2->next();
}
if (t1 != end1 || t2 != end2)
return false;
}
if (tok1->tokType() == Token::eIncDecOp || tok1->isAssignmentOp())
return false;
// bailout when we see ({..})
if (tok1->str() == "{")
return false;
// cast => assert that the casts are equal
if (tok1->str() == "(" && tok1->previous() &&
!tok1->previous()->isName() &&
!(tok1->previous()->str() == ">" && tok1->previous()->link())) {
const Token *t1 = tok1->next();
const Token *t2 = tok2->next();
while (t1 && t2 &&
t1->str() == t2->str() &&
t1->isLong() == t2->isLong() &&
t1->isUnsigned() == t2->isUnsigned() &&
t1->isSigned() == t2->isSigned() &&
(t1->isName() || t1->str() == "*")) {
t1 = t1->next();
t2 = t2->next();
}
if (!t1 || !t2 || t1->str() != ")" || t2->str() != ")")
return false;
}
bool noncommutativeEquals =
isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand1(), library, pure, followVar, errors);
noncommutativeEquals = noncommutativeEquals &&
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand2(), library, pure, followVar, errors);
if (noncommutativeEquals)
return true;
// in c++, a+b might be different to b+a, depending on the type of a and b
if (cpp && tok1->str() == "+" && tok1->isBinaryOp()) {
const ValueType* vt1 = tok1->astOperand1()->valueType();
const ValueType* vt2 = tok1->astOperand2()->valueType();
if (!(vt1 && (vt1->type >= ValueType::VOID || vt1->pointer) && vt2 && (vt2->type >= ValueType::VOID || vt2->pointer)))
return false;
}
const bool commutative = tok1->isBinaryOp() && Token::Match(tok1, "%or%|%oror%|+|*|&|&&|^|==|!=");
bool commutativeEquals = commutative &&
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand1(), library, pure, followVar, errors);
commutativeEquals = commutativeEquals &&
isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand2(), library, pure, followVar, errors);
return commutativeEquals;
}
bool isSameExpression(bool cpp, bool macro, const Token *tok1, const Token *tok2, const std::set<std::string> &constFunctions)
{
if (tok1 == nullptr && tok2 == nullptr)
return true;
if (tok1 == nullptr || tok2 == nullptr)
return false;
if (cpp) {
if (tok1->str() == "." && tok1->astOperand1() && tok1->astOperand1()->str() == "this")
tok1 = tok1->astOperand2();
if (tok2->str() == "." && tok2->astOperand1() && tok2->astOperand1()->str() == "this")
tok2 = tok2->astOperand2();
}
if (tok1->varId() != tok2->varId() || tok1->str() != tok2->str() || tok1->originalName() != tok2->originalName()) {
if ((Token::Match(tok1,"<|>") && Token::Match(tok2,"<|>")) ||
(Token::Match(tok1,"<=|>=") && Token::Match(tok2,"<=|>="))) {
return isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand2(), constFunctions) &&
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand1(), constFunctions);
}
return false;
}
if (macro && (tok1->isExpandedMacro() || tok2->isExpandedMacro()))
return false;
if (tok1->isName() && tok1->next()->str() == "(" && tok1->str() != "sizeof") {
if (!tok1->function() && !Token::Match(tok1->previous(), ".|::") && constFunctions.find(tok1->str()) == constFunctions.end() && !tok1->isAttributeConst() && !tok1->isAttributePure())
return false;
else if (tok1->function() && !tok1->function()->isConst() && !tok1->function()->isAttributeConst() && !tok1->function()->isAttributePure())
return false;
}
// templates/casts
if ((Token::Match(tok1, "%name% <") && tok1->next()->link()) ||
(Token::Match(tok2, "%name% <") && tok2->next()->link())) {
// non-const template function that is not a dynamic_cast => return false
if (Token::simpleMatch(tok1->next()->link(), "> (") &&
!(tok1->function() && tok1->function()->isConst()) &&
tok1->str() != "dynamic_cast")
return false;
// some template/cast stuff.. check that the template arguments are same
const Token *t1 = tok1->next();
const Token *t2 = tok2->next();
const Token *end1 = t1->link();
const Token *end2 = t2->link();
while (t1 && t2 && t1 != end1 && t2 != end2) {
if (t1->str() != t2->str())
return false;
t1 = t1->next();
t2 = t2->next();
}
if (t1 != end1 || t2 != end2)
return false;
}
if (tok1->tokType() == Token::eIncDecOp || tok1->isAssignmentOp())
return false;
// bailout when we see ({..})
if (tok1->str() == "{")
return false;
if (tok1->str() == "(" && tok1->previous() && !tok1->previous()->isName()) { // cast => assert that the casts are equal
const Token *t1 = tok1->next();
const Token *t2 = tok2->next();
while (t1 && t2 && t1->str() == t2->str() && (t1->isName() || t1->str() == "*")) {
t1 = t1->next();
t2 = t2->next();
}
if (!t1 || !t2 || t1->str() != ")" || t2->str() != ")")
return false;
}
bool noncommuative_equals =
isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand1(), constFunctions);
noncommuative_equals = noncommuative_equals &&
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand2(), constFunctions);
if (noncommuative_equals)
return true;
const bool commutative = tok1->astOperand1() && tok1->astOperand2() && Token::Match(tok1, "%or%|%oror%|+|*|&|&&|^|==|!=");
bool commuative_equals = commutative &&
isSameExpression(cpp, macro, tok1->astOperand2(), tok2->astOperand1(), constFunctions);
commuative_equals = commuative_equals &&
isSameExpression(cpp, macro, tok1->astOperand1(), tok2->astOperand2(), constFunctions);
// in c++, "a"+b might be different to b+"a"
if (cpp && commuative_equals && tok1->str() == "+" &&
(tok1->astOperand1()->tokType() == Token::eString || tok1->astOperand2()->tokType() == Token::eString)) {
const Token * const other = tok1->astOperand1()->tokType() != Token::eString ? tok1->astOperand1() : tok1->astOperand2();
return other && astIsIntegral(other,false);
}
return commuative_equals;
}
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, ¬1, &op1, &value1, &expr1, &inconclusive))
continue;
// Parse RHS
bool not2;
std::string op2, value2;
const Token *expr2;
if (!parseComparison(comp2, ¬2, &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);
}
}
}
}
bool isSameCond(bool cpp, const Token * const cond1, const Token * const cond2, const std::set<std::string> &constFunctions)
{
if (!cond1 || !cond2)
return false;
if (isSameExpression(cpp, cond1, cond2, constFunctions))
return true;
const Token* tok1(nullptr);
const Token* tok2(nullptr);
if (cond1->str() == "!" && cond2->str() == "==")
{
tok1 = cond1->astOperand1();
tok2 = cond2;
}
else if (cond2->str() == "!=")
{
tok1 = cond1;
tok2 = cond2;
}
else if (cond2->str() == "!" && cond1->str() == "==")
{
tok1 = cond2->astOperand1();
tok2 = cond1;
}
else if (cond1->str() == "!=")
{
tok1 = cond2;
tok2 = cond1;
}
if (tok1 && tok2) {
if (tok2->astOperand1() && tok2->astOperand1()->str() == "0")
return isSameExpression(cpp, tok1, tok2->astOperand2(), constFunctions);
if (tok2->astOperand2() && tok2->astOperand2()->str() == "0")
return isSameExpression(cpp, tok1, tok2->astOperand1(), constFunctions);
return false;
}
if (!cond1->isComparisonOp() || !cond2->isComparisonOp())
return false;
const std::string &comp1 = cond1->str();
// condition found .. get comparator
std::string comp2;
if (isSameExpression(cpp, cond1->astOperand1(), cond2->astOperand1(), constFunctions) &&
isSameExpression(cpp, cond1->astOperand2(), cond2->astOperand2(), constFunctions))
{
comp2 = cond2->str();
}
else if (isSameExpression(cpp, cond1->astOperand1(), cond2->astOperand2(), constFunctions) &&
isSameExpression(cpp, cond1->astOperand2(), cond2->astOperand1(), constFunctions))
{
comp2 = cond2->str();
if (comp2[0] == '>')
comp2[0] = '<';
else if (comp2[0] == '<')
comp2[0] = '>';
}
return (comp1 == comp2);
}
