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Fixed #6852 (false negative: logical conjunction 'x == 0')

This commit is contained in:
Daniel Marjamäki 2015-07-21 22:26:22 +02:00
parent f9d22f70db
commit f711520892
2 changed files with 40 additions and 5 deletions
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35
lib/checkcondition.cpp
View File

@ -621,19 +621,29 @@ static bool parseComparison(const Token *comp, bool *not1, std::string *op, std:
comp = comp->astOperand1();
}
if (!comp || !comp->isComparisonOp() || !comp->astOperand1() || !comp->astOperand2())
if (!comp)
return false;
if (comp->astOperand1()->isLiteral()) {
if (!comp->isComparisonOp() || !comp->astOperand1() || !comp->astOperand2()) {
*op = "!=";
*value = "0";
*expr = comp;
} else if (comp->astOperand1()->isLiteral()) {
if (comp->astOperand1()->isExpandedMacro())
return false;
*op = invertOperatorForOperandSwap(comp->str());
*value = comp->astOperand1()->str();
*expr = comp->astOperand2();
} else if (comp->astOperand2()->isLiteral()) {
if (comp->astOperand2()->isExpandedMacro())
return false;
*op = comp->str();
*value = comp->astOperand2()->str();
*expr = comp->astOperand1();
} else {
return false;
*op = "!=";
*value = "0";
*expr = comp;
}
// Only float and int values are currently handled
@ -643,6 +653,21 @@ static bool parseComparison(const Token *comp, bool *not1, std::string *op, std:
return true;
}
static std::string conditionString(bool not1, const Token *expr1, const std::string &op, const std::string &value1)
{
if (expr1->astParent()->isComparisonOp())
return std::string(not1 ? "!(" : "") +
(expr1->isName() ? expr1->str() : std::string("EXPR")) +
" " +
op +
" " +
value1 +
(not1 ? ")" : "");
return std::string(not1 ? "!" : "") +
(expr1->isName() ? expr1->str() : std::string("EXPR"));
}
void CheckCondition::checkIncorrectLogicOperator()
{
const bool printStyle = _settings->isEnabled("style");
@ -758,8 +783,8 @@ void CheckCondition::checkIncorrectLogicOperator()
secondTrue &= !(result1 && !result2);
}
const std::string cond1str = std::string(not1?"!(":"") + (expr1->isName() ? expr1->str() : "EXPR") + " " + op1 + " " + value1 + std::string(not1?")":"");
const std::string cond2str = std::string(not2?"!(":"") + (expr2->isName() ? expr2->str() : "EXPR") + " " + op2 + " " + value2 + std::string(not2?")":"");
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);

10
test/testcondition.cpp
View File

@ -574,6 +574,16 @@ private:
);
ASSERT_EQUALS("[test.cpp:2]: (warning) Logical disjunction always evaluates to true: x != 1 || x != 3.\n", errout.str());
check("void f(int x) {\n"
" if (x<0 && !x) {}\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x < 0 && !x.\n", errout.str());
check("void f(int x) {\n"
" if (x==0 && x) {}\n"
"}\n");
ASSERT_EQUALS("[test.cpp:2]: (warning) Logical conjunction always evaluates to false: x == 0 && x.\n", errout.str());
check("void f(int x) {\n" // ast..
" if (y == 1 && x == 1 && x == 7) { }\n"
"}\n");